WorldWideScience
 
 
1

Radiation detection device and a radiation detection method  

International Nuclear Information System (INIS)

A radiation detection device is described including at least one scintillator in the path of radiation emissions from a distributed radiation source; a plurality of photodetectors for viewing each scintillator; a signal processing means, a storage means, and a data processing means that are interconnected with one another and connected to said photodetectors; and display means connected to the data processing means to locate a plurality of radiation sources in said distributed radiation source and to provide an image of the distributed radiation sources. The storage means includes radiation emission response data and location data from a plurality of known locations for use by the data processing means to derive a more accurate image by comparison of radiation responses from known locations with radiation responses from unknown locations. (auth)

1975-01-01

2

Method of radiation detection in devices with microchannel plates  

International Nuclear Information System (INIS)

Pulsed laser ultraviolet radiation detection is considered as an illustration of the opportunity of coordinate data reception directly from plates as a memory matrix in radiation detectors on the base of microchannel plates. A TV channel comprising an electron-optical vidicon system, TV transmission chamber and TV monitor has been used for data readout and display

1986-01-01

3

Review and analysis of detection methods and detection of laser radiation in infrared  

Energy Technology Data Exchange (ETDEWEB)

Discusses measuring methods and detectors of energy and power of carbon dioxide lasers and weak laser radiation. Pyroelectric, photomagnetoelectric, HgCdTe detectors, photoresistors and photodiodes are reviewed. Basic parameters of seven photon detectors and six pyroelectric detectors are presented. Application of infrared detectors in investigations into coal and its combustion products is considered, in particular for measurements of the power absorbed or reflected from coal samples (ash content measurement), molecular spectroscopy and detection of weak infrared radiation. 17 refs.

Sikora, T.; Strzelec, M. (Osrodek Badawczo-Rozwojowy Elektrotechiki i Automatyki Gornictwa EMAG (Poland))

1991-05-01

4

Method for detecting radiation dose utilizing thermoluminescent material  

Energy Technology Data Exchange (ETDEWEB)

The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Miller, Steven D. (Richland, WA); McDonald, Joseph C. (Pasco, WA); Eichner, Fred N. (Kennewick, WA); Durham, James S. (Richland, WA)

1992-01-01

5

Method for detecting radiation dose utilizing thermoluminescent material  

Energy Technology Data Exchange (ETDEWEB)

The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material to a cryogenic temperature. The thermoluminescent material is then optically stimulated by exposure to ultraviolet light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Miller, Steven D. (Richland, WA); McDonald, Joseph C. (Pasco, WA); Eichner, Fred N. (Kennewick, WA); Tomeraasen, Paul L. (Richland, WA)

1991-01-01

6

Gravitational radiation detection by the spectral hole-burning method  

International Nuclear Information System (INIS)

A new method of measurement of body slight vibration excited by gravitational wave using supernarrow holes in absorption spectrum of a whisker is suggested. According to this method body vibrations are transferred to the crystal and are recorded when transparency of the crystal changes at the hole frequency. Evaluations show that the method suggested permits to record gravitational radiation of cosmic sources using sample bodies with the mass of ? 1 kg

1988-01-01

7

Main Achievements 2003-2004 - Interdisciplinary Research - Radiation detection methods for health, earth and environmental sciences  

International Nuclear Information System (INIS)

The IFJ research programme in this area is aimed at developing quantitative methods to monitor various environmental hazards, such as natural (including extra-terrestrial) and anthropogenic nuclear radiation, greenhouse gases emission etc. Its second task is to design and manufacture dedicated detectors of ionising radiation for radiation protection and for medical applications, and to detect environmental radiation and pollution. One of the strongest areas of project development is directed towards Earth sciences

2005-01-01

8

A Testing Method on Detection Threshold for Channel Vehicle Radiation Monitoring System to ? Radionuclide Activity  

International Nuclear Information System (INIS)

A testing method on detection threshold for channel vehicle radiation monitoring system to ? radionuclide activity was discussed. The detection threshold to certain radionuelide indicates the minimum detectable activity, which characterizes the detection ability of system as well as is the foundation for system alarm setting. The detection threshold can be obtained by calculating the statistical fluctuation of the background of detector and the measuring results to activity response of reference point, for a certain reference point, detection threshold is related to the statistical fluctuation of the background and ?-energy spectrum. (authors)

2009-07-01

9

FISH as a method for detection of radiation Induced genetic damage  

International Nuclear Information System (INIS)

Fluorescence in situ hybridisation (FISH) has been considered as a suitable method for the rapid and easy detection of chromosome aberrations. In contrast to the standard conventional staining procedure, this technique enables the specification of stable chromosomal re-arrangements, which could be transmitted from common ancestral to next cell generations. FISH chromosome-specific painting probes have been effectively applied for the detection of chromosomal damage after exposure to radiation. (authors)

2006-12-01

10

Novel detection methods for radiation-induced electron-hole pairs.  

Energy Technology Data Exchange (ETDEWEB)

Most common ionizing radiation detectors typically rely on one of two general methods: collection of charge generated by the radiation, or collection of light produced by recombination of excited species. Substantial efforts have been made to improve the performance of materials used in these types of detectors, e.g. to raise the operating temperature, to improve the energy resolution, timing or tracking ability. However, regardless of the material used, all these detectors are limited in performance by statistical variation in the collection efficiency, for charge or photons. We examine three alternative schemes for detecting ionizing radiation that do not rely on traditional direct collection of the carriers or photons produced by the radiation. The first method detects refractive index changes in a resonator structure. The second looks at alternative means to sense the chemical changes caused by radiation on a scintillator-type material. The final method examines the possibilities of sensing the perturbation caused by radiation on the transmission of a RF transmission line structure. Aspects of the feasibility of each approach are examined and recommendations made for further work.

Nordquist, Christopher Daniel; Cich, Michael Joseph; Vawter, Gregory Allen; Derzon, Mark Steven; Martinez, Marino John

2010-09-01

11

Method for Creating and Detecting Hydrogen Sorption Sites Using Gamma Radiation  

CERN Multimedia

Using gamma radiation and volumetric analysis of desorbed gas, hydrogen gas bonding sites have been created and detected in select materials. Desorption of hydrogen was followed over a benign temperature-pressure range. The extent of active site formation depends on radiation dosage; quenching of sites occurs over prolonged heating at low pressures. An estimate of the hydrogen bonding energy can be made on the basis of a partial temperature profile of the gas released at one atmosphere pressure. It appears that the bonding energy can be adjusted by mixing candidate materials. A guide for further investigation and application of the method is outlined.

Muga, Barbara G

2010-01-01

12

FISH as A method for detection of radiation Induced genetic damage  

International Nuclear Information System (INIS)

Fluorescence in situ hybridization (FISH) has been considered as a suitable method for rapid and easy detection of chromosome aberrations. In contrast to the standard conventional staining procedure, this technique enables the detection and specification of stable chromosomal re-arrangements, which are compatible with cellular division and thus, they could be transmitted from common ancestral to next cell generations. FISH chromosome - specific painting probes have been effectively applied for the detection of chromosomal damage after exposure to radiation. During last years, several specific fluorescent labeled probes were performed that allowed precise detection of centromeres, sub-telomeres or other regions (sequences) in genome. Our paper deals with describing of different types of FISH probes and their possibilities for application in radiobiology. (authors)

2006-05-01

13

Detection by EPR method of radiation treatment in dried fruits containing crystalline sugar  

International Nuclear Information System (INIS)

The results of EPR (electron paramagnetic resonance) measurements are presented on the detection ability and stability of radiation induced sugar-born radicals in the samples of dried (dehydrated) fruits available in the market and related to doses of 0.5, 1 and 3 kGy, respectively. The experiments have been conducted during 12 months of storage. Measurements were done with an EPR - 10 MINI spectrometer in X band (frequency of microwaves 9.5 GHz), St. Petersburg Instruments Ltd. The aim of the work was to prove the reliability of acceptability of the method in routine control of irradiated food. (author)

2006-01-01

14

Detecting gravitational radiation from neutron stars using a six-parameter adaptive MCMC method  

CERN Multimedia

We present a Markov chain Monte Carlo technique for detecting gravitational radiation from a neutron star in laser interferometer data. The algorithm can estimate up to six unknown parameters of the target, including the rotation frequency and frequency derivative, using reparametrization, delayed rejection and simulated annealing. We highlight how a simple extension of the method, distributed over multiple computer processors, will allow for a search over a narrow frequency band. The ultimate goal of this research is to search for sources at a known locations, but uncertain spin parameters, such as may be found in SN1987A.

Umstätter, R; Dupuis, R J; Veitch, J; Woan, G; Christensen, N; Umst\\"atter, Richard; Meyer, Renate; Veitch, John; Woan, Graham; Christensen, Nelson

2004-01-01

15

Sentinel node detection of patients with breast cancer by radionuclide method. Consideration of radiation safety  

International Nuclear Information System (INIS)

Sentinel node was detected by 99mTc labeled nanocolloid in five patients with breast cancer. Surgery of breast cancer was done at 16 hours after the administration of 74 BMq of 99mTc labeled nanocolloid. Sentinel node was searched by scintigraphy prior to surgery and by gamma-probe during surgery. Radioactivity of injected site, sentinel nodes, blood contaminated gauze, and other garbage was measured by GM detector. Radiation to medical staffs was monitored by a pocket radiation detector and film batches. Sentinel nodes were successfully detected both by scintigraphy and gamma-detector. More than 70% of radioactivity remained in the administered site at 16 hours. Small amount of radioactivity was detectable in the sentinel node. Almost no radioactivity was detectable in blood contaminated gauze and other garbage. Radiation dose to the main surgeon was 4 to 6 ?Sv per surgery by a pocket radiation detector. Radiation dose to the assistant surgeon was 2 ?Sv per surgery. Radiation dose by labeling or injection was 0 to 1 ?Sv per procedure. No detectable radiation was measured by film batches. It is concluded that the detection of sentinel node by 99mTc labeled nanocolloid is a safe procedure from the point of radiation safety consideration. (author)

2001-01-01

16

Effects of ionizing radiation on biological molecules-mechanisms of damage and emerging methods of detection.  

Science.gov (United States)

Abstract Significance: The detrimental effects of ionizing radiation (IR) involve a highly orchestrated series of events that are amplified by endogenous signaling and culminating in oxidative damage to DNA, lipids, proteins, and many metabolites. Despite the global impact of IR, the molecular mechanisms underlying tissue damage reveal that many biomolecules are chemoselectively modified by IR. Recent Advances: The development of high-throughput "omics" technologies for mapping DNA and protein modifications have revolutionized the study of IR effects on biological systems. Studies in cells, tissues, and biological fluids are used to identify molecular features or biomarkers of IR exposure and response and the molecular mechanisms that regulate their expression or synthesis. Critical Issues: In this review, chemical mechanisms are described for IR-induced modifications of biomolecules along with methods for their detection. Included with the detection methods are crucial experimental considerations and caveats for their use. Additional factors critical to the cellular response to radiation, including alterations in protein expression, metabolomics, and epigenetic factors, are also discussed. Future Directions: Throughout the review, the synergy of combined "omics" technologies such as genomics and epigenomics, proteomics, and metabolomics is highlighted. These are anticipated to lead to new hypotheses to understand IR effects on biological systems and improve IR-based therapies. Antioxid. Redox Signal. 21: 260-292. PMID:24382094

Reisz, Julie A; Bansal, Nidhi; Qian, Jiang; Zhao, Weiling; Furdui, Cristina M

2014-07-10

17

Level Crossing Analysis of Cosmic Microwave Background Radiation: A method for detecting cosmic strings  

CERN Multimedia

In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, $G\\mu$, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with $G\\mu\\gtrsim 4\\times 10^{-9}$ in the simulated map without instrumental noise and the resolution $R=1'$ could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to $G\\mu\\gtrsim 5.8\\times 10^{-9}$.

Movahed, M Sadegh

2010-01-01

18

Detection of radiation-induced lung injury by 99mTc-DTPA aerosol inhalation method  

International Nuclear Information System (INIS)

We prospectively monitored pulmonary 99mTc-diethylene triamine penta acetate (DTPA) clearance in patients who received chest radiation therapy in order to determine whether this method allows us to predict the development of radiation pneumonitis. The rate constant of pulmonary 99mTc-DTPA clearance (k; %/min) was used to assess pulmonary epithelial damage. Fifteen nonsmoking patients who underwent radiation therapy were studied. The subjects included 4 patients who had already developed radiation pneumonitis at the time of study, and 11 in whom we prospectively observed 99mTc-DTPA clearance serially during the course of chest radiation therapy. In the 4 patients with pre-existing radiation pneumonitis, the mean k value obtained from the area with infiltration on the chest X-ray was significantly greater than that from the opposite lung (p99mTc-DTPA clearance may be useful for predicting the development of radiation pneumonitis. (author)

1993-02-01

19

Semiconductor radiation detection systems  

CERN Multimedia

Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

2010-01-01

20

Apparatus and method for examining a blood vessel of interest using radiation detected outside the body  

International Nuclear Information System (INIS)

A gamma camera is described in detail for use in examining the blood circulation in vessels adjacent to the heart. The radiation source (e.g. 68Ga) emits positrons whose annihilation is localised and produces two 0.115 MeV gamma rays in exactly opposite directions. By detecting both gamma rays in coincidence in position sensitive multi-wire proportional chambers, lines may be drawn between detected pairs and the intersection of of all such pairs will define the position of the positron emitting source. The radiation source may be tracked in three dimensions by suitably arranging the detectors around the patient's chest. The position of the radiation source can be recorded as a function of time and hence provide information about the velocity of blood flow through each coronary artery. This information may help determine the extent, severity and location of stenotic lesions of the coronary arteries. (U.K.)

1980-01-01

 
 
 
 
21

Gravitational radiation detection  

International Nuclear Information System (INIS)

Resonant gravitational wave detectors and related data analysis are studied. Different forms (strain amplitude) of the equation of motion for a medium responding to a gravitational wave are discussed in relation to the detection of such waves. Utilizing ''Bayesian techniques'' an optimal method for data analysis is developed. Noise and filter theory is reviewed. It is seen that the ''Bayesian techniques'' integrates filter theory and data analysis, providing both filter properties and optimal methods for integrating the data. (In particular the method leads to a nonthreshold type of analysis, and ''looks for'' correlation between two detectors without the use of time delay). Expression for optimal sensitivity (and filters) of detector systems are given, including the limit of perfect sensors and electronics. The signal to noise ratio in terms of the spectral power of the gravitational radiation is derived. Long baseline interferometry is discussed. A computer program simulating a pair of Weber type detectors is developed to study different approaches to data analysis

1976-01-01

22

Radiometry and the detection of optical radiation  

International Nuclear Information System (INIS)

This book presents a unified treatment of radiometry and detection, at a graduate level. It discusses some of the basic aspects of radiation transfer through optical systems, and infrared radiation detection by optical methods. Materials which are covered in the book include the elements of a course in radiochemistry and detection which has been taught at the Institute of Optics of the University of Rochester for many years. Topics are: Electromagnetic radiation, Theory o blackbody radiation, Radiation detectors, Photoemissive detectors, Photoconducive detectors, Photovoltaic detectors, Fluctuations of the radiation field. Topics are: Electromagnetic radiation, Theory of blackbody radiation, Radiation detectors, Photoemissive detectors, Photoconducive detectors, Photovoltaic detectors, Fluctuations of the radiation field

1983-01-01

23

Radiometry and the detection of optical radiation  

Energy Technology Data Exchange (ETDEWEB)

This book presents a unified treatment of radiometry and detection, at a graduate level. It discusses some of the basic aspects of radiation transfer through optical systems, and infrared radiation detection by optical methods. Materials which are covered in the book include the elements of a course in radiochemistry and detection which has been taught at the Institute of Optics of the University of Rochester for many years. Topics are: Electromagnetic radiation, Theory o blackbody radiation, Radiation detectors, Photoemissive detectors, Photoconducive detectors, Photovoltaic detectors, Fluctuations of the radiation field. Topics are: Electromagnetic radiation, Theory of blackbody radiation, Radiation detectors, Photoemissive detectors, Photoconducive detectors, Photovoltaic detectors, Fluctuations of the radiation field.

Boyd, R.W.

1983-01-01

24

Radiation detection system  

Energy Technology Data Exchange (ETDEWEB)

A radiation detection system including a radiation-to-light converter and fiber optic wave guides to transmit the light to a remote location for processing. The system utilizes fluors particularly developed for use with optical fibers emitting at wavelengths greater than about 500 nm and having decay times less than about 10 ns.

Franks, Larry A. (Santa Barbara, CA); Lutz, Stephen S. (Santa Barbara, CA); Lyons, Peter B. (Los Alamos, NM)

1981-01-01

25

Scintillator assembly for alpha radiation detection and an associated method of making  

International Nuclear Information System (INIS)

A scintillator assembly for use in conjunction with a photomultiplier or the like in the detection of alpha radiation utilizes a substrate or transparent yttrium aluminum garnet and a relatively thin film of cerium-doped yttrium aluminum garnet coated upon the substrate. The film material is applied to the substrate in a sputtering process, and the applied film and substrate are annealed to effect crystallization of the film upon the substrate. The resultant assembly provides relatively high energy resolution during use in a detection instrument and is sufficiently rugged for use in field environments. 4 figs

1992-08-12

26

Infrared radiation detecting systems  

Energy Technology Data Exchange (ETDEWEB)

An infrared radiation detecting system comprises a detector element forming part of a detector incorporating a cold shield and an optical system for imaging infrared radiation from a field of view onto a real image surface spaced from the detector element and relaying the image I from the surface to the detector element is provided with a graticule having markings which are reflective to infrared radiation emitted by the detector. Graticule is located at the image surface so that the graticule markings are imaged onto the detector element in superimposition with the infrared radiation from the field of view.

Berry, P.J.; Mclean, G.H.; Neil, I.A.

1983-05-10

27

Radiation detection device  

International Nuclear Information System (INIS)

A radiation detection device is provided which comprises a box-like housing having a radiation permeable window located in one side. A scintillator is mounted in the housing; the scintillator comprising a first tube of radiation permeable material encasing a central core of scintillation material such as sodium iodide surrounded by a light reflective material, and a means for converting light signals into electric signals are connected with the scintillator. A rotating collimator surrounds the scintillator including a second tube of radiation permeable material, a plurality of channel forming members comprised of a radiation impermeable material formed in groups around the second tube, a plurality of groups being located axially along the second tube, wherein each group of channel forming members define a plurality of radial channels capable of being directed toward the radiation permeable window during rotation

1985-01-01

28

Development of techniques using DNA analysis method for detection/analysis of radiation-induced mutation. Development of an useful probe/primer and improvement of detection efficacy  

International Nuclear Information System (INIS)

Previously, it was demonstrated that detection of centromere became easy and reliable through fluorescent staining by FISH method using a probe of the sequence preserved in ?-satelite DNA. Since it was, however, found inappropriate to detect dicentrics based on the relative amount of DNA probe on each chromosome. A prove which allows homogeneous detection of ?-satelite DNA for each chromosome was constructed. A presumed sequence specific to kinetochore, CENP-B box was amplified by PCR method and the product DNA was used as a probe. However, the variation in amounts of probe DNA among chromosomes was decreased by only about 20%. Then, a program for image processing of the results obtained from FISH using ?-satelite DNA was constructed to use as a marker for centromere. When compared with detection of abnormal chromosomes stained by the conventional method, calculation efficacy for only detection of centromere was improved by the use of this program. Calculation to discriminate the normal or not was still complicated and the detection efficacy was little improved. Chromosomal abnormalities in lymphocytes were used to detect the effects of radiation. In this method, it is needed to shift the phase of cells into metaphase. The mutation induced by radiation might be often repaired during shifting. To exclude this possibility, DNA extraction was conducted at a low temperature and immediately after exposure to 137Cs, and a rapid genome detection method was established using the genome DNA. As the model genomes, the following three were used: 1) long chain repeated sequences widely dispersed over chromosome, 2) cluster genes, 3) single copy genes. The effects of radiation were detectable at 1-2 Gy for the long repeated sequences and at 7 Gy for the cluster genes, respectively, whereas no significant effects were observed at any Gy tested for the single copy genes. Amplification was marked in the cells exposed at 1-10 Gy (peak at 4 Gy), suggesting that these regions had very highly ordered structures. (M.N.)

1999-02-01

29

Electrets for ? radiation detection  

International Nuclear Information System (INIS)

The use of electrets for ? radiation detection is described. Such a detector showed a linear decrease of charge with increasing absorbed dose over a certain range of charge of the electret. Different radiation field geometries and wall materials for the outer jacket were tested, in order to obtain the highest sensitivity and energy independence of the electret response. This was obtained with perpendicular geometry (electret axis perpendicular to the radiation field) and open detector (without outer jacket); the lowest absorbed dose measurable was 2,5 ?Gy for 90Sr-90Y and 204Tl sources. Depending on the ? dose range, other conditions must be chosen

1984-01-01

30

Method for the detection and localisation of radiation and an arrangement for the application of this method  

International Nuclear Information System (INIS)

Procedure for the detection and localisation of neutral radiation, particularly soft gamma or X-radiation, whereby photoelectrons will be formed, so that the incident radiation influences gas atoms which are contained in a gas vessel; with the assistance of an electric field the electrons in the field space may be deflected by a movement depending on the electric field, the strength of which is sufficient for secondary photons to promote (by excitation of the gas atoms) the excited state of these atoms, and the place at which the secondary photons may be determined, characterised in that simultaneously a selected value of the energy of the secondary photons may be found. (G.C.)

1980-01-01

31

Scintillator assembly for alpha radiation detection and method of making the assembly  

International Nuclear Information System (INIS)

A scintillator assembly for use in the detection of alpha radiation includes a body of optically-transparent epoxy and an amount of phosphor particles embedded within the body adjacent one surface thereof. When making the body, the phosphor particles are mixed with the epoxy when in an uncured condition and permitted to settle to the bottom surface of a mold within which the epoxy/phosphor mixture is contained. When the mixture subsequently cures to form a hardened body, the one surface of the body which cured against the bottom surface of the mold is coated with a thin layer of opaque material for preventing ambient light form entering the body through the one surface. The layer of opaque material is thereafter coated with a layer of protective material to provide the assembly with a damage-resistant entrance window. 6 figs

1991-01-16

32

Arrangement for radiation detection  

International Nuclear Information System (INIS)

Radiation detection arrangement provided with scintillation element wherein a scintillation path is developed in a wave length trajectory between short wave visible and ultra-violet irradiation and with a detector for the recording of this scintillation irradiation. Characterised in that the surface particles on the underside of the unit wherein the scintillation beam impinges are provided with a covering layer which is strongly reflective to the irradiation beam concerned. (G.C.)

1978-01-01

33

Photostimulated luminescence of corrugated fiberboard as an additional screening method for detecting radiated foods  

International Nuclear Information System (INIS)

In this study, PSL of non-irradiated and irradiated corrugated fiberboards (CFs) was investigated to evaluate the possibility that CFs can be used as alternative specimens for the screening detection method of food irradiation. The irradiation at a dose of only 0.15 kGy increased PSL signals of the CF over 1 order of magnitude. The PSL signals increased with increasing in gamma irradiation dose and became almost saturated at a dose of 5 kGy. The core of CFs showed PSL signals sufficient for distinguishing irradiated from non-irradiated at least 6 months after irradiation even though the CF was exposed to light and the environmental temperature increased to 50 °C. These results suggest that the PSL property of the core of CFs is useful for detecting irradiation. However, the large variation of PSL signals among CFs made it difficult to set a well-defined “positive” threshold limit to distinguish irradiated from non-irradiated completely. All of the non-irradiated CFs showed PSL signals above 103 counts, which is much higher than that detected for foods. It is apparent that the threshold limit of EN 13751 is not applicable to detecting irradiated CFs. More detailed collaborative research with large number of samples is needed to establish new threshold limits involving “intermediate” classification. - Highlights: ? Corrugated fiberboards (CF) as a packaging material were gamma-irradiated. ? The photostimulated luminescence (PSL) signals of irradiated CF were measured. ? The PSL signals were sufficient for detecting irradiation. ? The signals were well retained for 6 months after irradiation upon exposure to light. ? The environmental temperature at 50 °C had little effects on the signal retention.

2012-07-01

34

Radiation detection system for embarkations  

International Nuclear Information System (INIS)

A nuclear radiation detection system is developed in order to use in frigate for continuous monitoring of ambient (water and air) radiation levels. The detection assembly consists of plastic scintillation detector and ionization chamber. (author)

1999-09-03

35

Development of techniques using DNA analysis method for detection/analysis of radiation-induced mutation. Development of an useful probe/primer and improvement of detection efficacy  

Energy Technology Data Exchange (ETDEWEB)

Previously, it was demonstrated that detection of centromere became easy and reliable through fluorescent staining by FISH method using a probe of the sequence preserved in {alpha}-satelite DNA. Since it was, however, found inappropriate to detect dicentrics based on the relative amount of DNA probe on each chromosome. A prove which allows homogeneous detection of {alpha}-satelite DNA for each chromosome was constructed. A presumed sequence specific to kinetochore, CENP-B box was amplified by PCR method and the product DNA was used as a probe. However, the variation in amounts of probe DNA among chromosomes was decreased by only about 20%. Then, a program for image processing of the results obtained from FISH using {alpha}-satelite DNA was constructed to use as a marker for centromere. When compared with detection of abnormal chromosomes stained by the conventional method, calculation efficacy for only detection of centromere was improved by the use of this program. Calculation to discriminate the normal or not was still complicated and the detection efficacy was little improved. Chromosomal abnormalities in lymphocytes were used to detect the effects of radiation. In this method, it is needed to shift the phase of cells into metaphase. The mutation induced by radiation might be often repaired during shifting. To exclude this possibility, DNA extraction was conducted at a low temperature and immediately after exposure to {sup 137}Cs, and a rapid genome detection method was established using the genome DNA. As the model genomes, the following three were used: (1) long chain repeated sequences widely dispersed over chromosome, (2) cluster genes, (3) single copy genes. The effects of radiation were detectable at 1-2 Gy for the long repeated sequences and at 7 Gy for the cluster genes, respectively, whereas no significant effects were observed at any Gy tested for the single copy genes. Amplification was marked in the cells exposed at 1-10 Gy (peak at 4 Gy), suggesting that these regions had very highly ordered structures. (M.N.)

Maekawa, Hideaki; Tsuchida, Kozo; Hashido, Kazuo; Takada, Naoko; Kameoka, Yosuke; Hirata, Makoto [National Inst. of Infectious Diseases, Tokyo (Japan)

1999-02-01

36

Remote detection device and detection method therefor  

International Nuclear Information System (INIS)

The present invention provides a non-destructive detection device for collectively, efficiently and effectively conducting maintenance and detection for confirming the integrity of a nuclear reactor by way of a shielding member for shielding radiation rays generated from an objective portion to be detected. Namely, devices for direct visual detection using an under water TV camera as a sensor, an eddy current detection using a coil as a sensor and each magnetic powder flow detection are integrated and applied collectively. Specifically, the visual detection by using the TV camera and the eddy current flaw detection are adopted together. The flaw detection with magnetic powder is applied as a means for confirming the results of the two kinds of detections by other method. With such procedures, detection techniques using respective specific theories are combined thereby enabling to enhance the accuracy for the evaluation of the detection. (I.S.)

1995-10-24

37

Data derandomizer and method of operation for radiation imaging detection systems  

International Nuclear Information System (INIS)

A nuclear imaging system includes an analog signal processor which features analog data derandomization for minimizing data loss due to pulse pile-up. A scintillation detector provides a sequence of analog data pulses to the signal processor, the data pulses characterizing the energy level and situs of respective radiation events striking the detector. The signal processor includes sets of novel peak detectors and of sample and hold circuits which are serially connected and are operated to derandomize or space the sequence of analog data pulses so that the system can process pulses corresponding to photopeak events occurring only 1.5 microseconds apart. The analog data pulses are stored in analog pulse form in the peak detectors and are selectively transferred into the sample and hold circuitry from which they are transferred to the display mechanism. The signal processor is multiplexed with several data input channels for accommodating dual isotope operation. A control unit is provided which controls the data processing cycle according to a predetermined processing time, or according to signals from external system apparatus. The control unit provides automatic resetting for assurance that the signal processor does not become locked into an inoperative, nondata processing state. The novel peak detectors are controlled by the control unit and feature input biasing for increased detection sensitivity, proportional dumping for discharging the stored peak value at a rate proportional to the value of the stored peak, and selective input data gating so that only the peak containing portion of the input signal is input into the detector. 28 claims, 10 figures

1977-01-01

38

Radiation detection system  

International Nuclear Information System (INIS)

A circuit is disclosed that detects radiation transients and provides a clamping signal in response to each transient. The clamping signal is present from the time the transient rises above a given threshold level and for a known duration thereafter. The system includes radiation sensors, a blocking oscillator that generates a pulse in response to each sensor signal, and an output pulse duration control circuit. The oscillator pulses are fed simultaneously to the output pulse duration control circuit and to an OR gate, the output of which comprises the system output. The output pulse duration is controlled by the time required to magnetize a magnetic core to saturation in first one direction and then the other

1976-01-01

39

Radiation protection, measurements and methods  

International Nuclear Information System (INIS)

The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP)

1982-10-19

40

Detection and identification of radiation induced hydrocarbons in meets with the use of gas chromatography as one of methods for the detection of irradiated food  

International Nuclear Information System (INIS)

Results of the determination of the content of radiation induced hydrocarbons in meat samples (chicken, pork, beef) as well as proportion between the concentration of individual hydrocarbons in relation to the content of fatty acids in a given product are presented. The measurements have been done with the use of a Perkin Elmer model 8700 gas chromatograph equipped with a FID detector. The present study is a preliminary work on the implementation of a routine method for the detection of irradiation in foods that contain fats. (author)

2000-01-01

 
 
 
 
41

Measuring element for detection and dose measurement of gamma radiation and neutrons and manufacturing method for the measuring element  

International Nuclear Information System (INIS)

The measuring element consists of a bubble-free glass composed on the basis of metaphosphate material. The detection of the ?-radiation takes place through the photoluminescence of the element, and detection of the neutrons by means of resulting ? particles producing Cerenkov radiation in the radioluminescence material, that can be measured. For this purpose in addition to Ag the glass contains As as a second excitable element. (DG)

1979-01-01

42

Radiation Detection Computational Benchmark Scenarios  

Energy Technology Data Exchange (ETDEWEB)

Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for compilation. This is a report describing the details of the selected Benchmarks and results from various transport codes.

Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

2013-09-24

43

A method and apparatus for converting a liquid scintillation counter for beta detection into a gamma radiation counter  

International Nuclear Information System (INIS)

Description is given of a flask for measuring the gamma radiation of samples in a scintillation counter intended for beta radiation detection. That flask is provided with a scintillator made of a mineral crystal of generally cylindrical shape, comprising a sample-receiving central chamber, the volume of which is from about 4 to 15 cubic centimeters. Sais scintillator is sealingly enclosed in a protective container with a light transparent cylindrical outer face. The flask height is less than 7cm and its diameter less than 3cm. This can be applied to converting liquid scintillation counters for beta radiation into gamma radiation counters

1974-02-01

44

Evaluation methods for detecting changes in beam output and energy in radiation beams from high-energy linear accelerators  

Directory of Open Access Journals (Sweden)

Full Text Available There is need for simple methods for checking consistency of beam outputs and energy in linear accelerators used for radiotherapy. A method was designed by the department using perspex phantom with which the dosimetric data of two medical linear accelerators (Clinac 600 CD, Clinac 2300 CD were evaluated over a period of 30 months. The efficacy of methods followed was checked. Routine beam consistency checks were designed for photon beams with 15 cm/ 5 cm depth ionizations in perspex phantom and variable depth combinations for electron beams. Calculated ionization ratios were compared with measured values to show their significance. The dose/MU for all radiation beams was maintained within 2% accuracy over the period of 30 months. Clinac 600 CD machine showed decreasing trend of cGy/MU, while Clinac 2300 CD showed increasing trend of cGy/MU over a period, which needed tuning of monitor chamber two times each. Tuning of output to achieve standard value was carried out once, for all electron energies when the output dose/MU exceeded 3%. During one week (June 2005, there were slight changes in electron energy detected using the ratio method, which did not recur anytime afterwards. The methods designed are adequate to find the consistency in the beam output and energies in the radiotherapy linacs.

Ravichandran R

2007-01-01

45

Detection methods for irradiated food  

International Nuclear Information System (INIS)

The plenary lecture gives a brief historical review of the development of methods for the detection of food irradiation and defines the demands on such methods. The methods described in detail are as follows: 1) Physical methods: As examples of luminescence methods, thermoluminescence and chermoluminescence are mentioned; ESR spectroscopy is discussed in detail by means of individual examples (crustaceans, frutis and vegetables, spieces and herbs, nuts). 2) Chemical methods: Examples given for these are methods that make use of alterations in lipids through radiation (formation of long-chain hydrocarbons, formation of 2-alkyl butanones), respectively radiation-induced alterations in the DNA. 3) Microbiological methods. An extensive bibliography is appended. (VHE)

1993-09-05

46

Apparatus and method for examining a blood vessel of interest using radiation detected outside the body  

International Nuclear Information System (INIS)

Stenotic atherosclerotic lesions of the coronary arteries are detected by injecting a number of particulate signal sources such as positron-emitting particles (e.g. gallium 68) into the blood of a subject to determine the velocity of blood flow through the coronary vessels. The particles are tracked in three dimensions whenever they appear in the region of the heart by means of high-resolution high-speed gamma detectors that surround the chest. These recordings of particle position as a function of time are analyzed, and the velocity of blood as it flows through the coronary artery is measured by timing the transit of the particle. From the accumulated data of multiple particle transits through the coronary circulation, a three-dimensional representation of the lumen of the coronary arterial system is constructed

1982-01-01

47

Assessment of pulse height selection methods for several spectrum shapes in radiation detection  

Energy Technology Data Exchange (ETDEWEB)

The minimum pulse height selection method developed more than forty years ago to process the information provided by detectors with an energy spectrum responding to a Landau distribution is extended in this work to consider other information processing criteria such as the maximum pulse height and the pulse height closest to the mode. The latter is a selection method whereby the mode is calculated for a distribution and then, a pulse closest to it is selected from a given set and stored. We analyze the combined resolution of a set of identical sampling detectors in terms of the number of detectors and the shape of the characteristic pulse height distribution from a single detector. To make this treatment as general as possible, five analytical forms are tested as symmetric and asymmetric pulse height distributions, applying to each of them the three selection methods mentioned above. We also compare these results with the average of the pulse heights in each case. For these evaluations, analytical calculations and Monte Carlo simulations were carried out. It was thus possible to select the most appropriate selection method based on the shape parameters of a distribution.

Mainardi, Raul T. E-mail: mainardi@famaf.unc.edu.ar; Plivelic, Tomas S. E-mail: tomas@lnls.br; Derosa, Pedro A. E-mail: derosa@engr.sc.edu

2003-03-01

48

Assessment of pulse height selection methods for several spectrum shapes in radiation detection  

International Nuclear Information System (INIS)

The minimum pulse height selection method developed more than forty years ago to process the information provided by detectors with an energy spectrum responding to a Landau distribution is extended in this work to consider other information processing criteria such as the maximum pulse height and the pulse height closest to the mode. The latter is a selection method whereby the mode is calculated for a distribution and then, a pulse closest to it is selected from a given set and stored. We analyze the combined resolution of a set of identical sampling detectors in terms of the number of detectors and the shape of the characteristic pulse height distribution from a single detector. To make this treatment as general as possible, five analytical forms are tested as symmetric and asymmetric pulse height distributions, applying to each of them the three selection methods mentioned above. We also compare these results with the average of the pulse heights in each case. For these evaluations, analytical calculations and Monte Carlo simulations were carried out. It was thus possible to select the most appropriate selection method based on the shape parameters of a distribution

2003-03-01

49

Measurement and detection of radiation  

CERN Multimedia

This is an update of the standard textbook for the field of radiation measurement. It includes illustrative examples and new problems. The research and applications of nuclear instrumentation have grown substantially since publication of the previous editions. With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines, including nuclear nonproliferation, homeland security, and nuclear medicine. Continuing in the tradition of its bestselling predecessors, "Measurement and Detection of Radiation, Third Edition" illustrates the fundamentals of nuclear interactions and radiation detection with a multitude of examples and problems. It offers a clearly written, accessible introduction to nuclear instrumentation concepts. The following are new to the third edition: a new chapter on the latest applications of radiation detection, covering nuclear medicine, dosimetry, health physics, no...

Tsoulfanidis, Nicholas

2011-01-01

50

Electronics for radiation detection  

CERN Document Server

Addresses the developments in the design of semiconductor detectors and integrated circuits, in the context of medical imaging using ionizing radiation. This book explains how circuits for radiation are built, focusing on practical information about how they are being used, rather than mathematical details.

2011-01-01

51

Methods for routine control of irradiated food: Optimization of a method for detection of radiation-induced hydrocarbons and its application to various foods  

Science.gov (United States)

By comparison of two methods for the isolation of radiation-induced hydrocarbons, high vacuum "cold finger" distillation and Florisil column chromatography, it could be shown that the sensitivity of both was similar whereas the latter seemed to be more practical for routine application. In optimizing studies, the influence of the degree of Florisil activation and the influence of the irradiation temperature on hydrocarbon yields as well as the resolution of hydrocarbons on polar and non-polar gas chromatographic capillary columns have been examined. From the successful application of the method to different fat containing foodstuffs, it is concluded that the Florisils column chromatography is well suited as clean-up procedure for the gas chromatographic/mass spectrometric (GC/MS) detection of irradiated products by routine food control analyses.

Spiegelberg, A.; Schulzki, G.; Helle, N.; Bögl, K. W.; Schreiber, G. A.

1994-05-01

52

Methods for routine control of irradiated food: optimization of a method for detection of radiation-induced hydrocarbons and its application to various foods  

International Nuclear Information System (INIS)

By comparison of two methods for the isolation of radiation-induced hydrocarbons, high vacuum ''cold finger'' distillation and Florisil column chromatography, it could be shown that the sensitivity of both was similar whereas the latter seemed to be more practical for routine application. In optimizing studies, the influence of the degree of Florisil activation and the influence of the irradiation temperature on hydrocarbon yields as the resolution of hydrocarbons on polar and non-polar gas chromatographic capillary columns have been examined. From the successful application of the method to different fat containing foodstuffs, it is concluded that the Florisil column chromatography is well suited as clean-up procedure for the gas chromatographic/mass spectrometric (GC/MS) detection of irradiated products by routine food control analyses. (author)

1994-05-01

53

Methods for routine control of irradiated food: optimization of a method for detection of radiation-induced hydrocarbons and its application to various foods  

Energy Technology Data Exchange (ETDEWEB)

By comparison of two methods for the isolation of radiation-induced hydrocarbons, high vacuum ``cold finger`` distillation and Florisil column chromatography, it could be shown that the sensitivity of both was similar whereas the latter seemed to be more practical for routine application. In optimizing studies, the influence of the degree of Florisil activation and the influence of the irradiation temperature on hydrocarbon yields as the resolution of hydrocarbons on polar and non-polar gas chromatographic capillary columns have been examined. From the successful application of the method to different fat containing foodstuffs, it is concluded that the Florisil column chromatography is well suited as clean-up procedure for the gas chromatographic/mass spectrometric (GC/MS) detection of irradiated products by routine food control analyses. (author).

Spiegelberg, A.; Schulzki, G.; Helle, N.; Boegl, K.W.; Schrieber, G.A. [Federal Health Office, Berlin (Germany). Institute for Social Medicine and Epidemiology

1994-05-01

54

Etching method employing radiation  

International Nuclear Information System (INIS)

This invention provides a method for etching a silicon oxide, carbide, nitride, or oxynitride surface using an electron or ion beam in the presence of a xenon or krypton fluoride. No additional steps are required after exposure to radiation

1982-01-01

55

Radiation detection tube having spurious radiation shield  

International Nuclear Information System (INIS)

A radiation detection tube is described having a glass envelope surrounding an anode and cathode in a gaseous mixture. The improvement described here consists of a conductive band on the exterior of the glass envelope in the region of the anode and cathode and an electrical conductor coupling the conductive band to the anode

1986-01-01

56

Detection of nuclear radiations  

International Nuclear Information System (INIS)

A summary of the lectures about the ordinary detectors of nuclear radiations explained by the author in the courses of Nuclear Engineering held at the J.E.N. up to the date of publication is given. Those lectures are considered to be a necessary introduction to Nuclear Instrumentation and Applied Electronics to Nuclear Engineering so it has been intended to underline those characteristics of radiation detectors that must be taken in consideration in choosing or designing the electronic equipment associated to them in order to take advantage of each detector possibilities. (Author)

1967-01-01

57

Radiation detection and measurement  

International Nuclear Information System (INIS)

The fundamental mechanism for the operation of a radiation detector is dissipation of the energy of a charged particle in a suitable medium. Useful energy dissipation is principally by two processes: ionisation and scintillation. The electrostatics of pulse formation for the ionisation chamber is discussed in detail

1982-10-01

58

Detection of gravitational radiation  

International Nuclear Information System (INIS)

In this report the main contributions presented at the named symposium are collected. These concern astrophysical sources of gravitational radiation, ultracryogenic gravitational wave experiments, read out and data analysis of gravitational wave antennas, cryogenic aspects of large mass cooling to mK temperatures, and metallurgical and engineering aspects of large Cu structure manufacturing. (HSI)

1994-05-24

59

Device for nuclear radiation detection  

International Nuclear Information System (INIS)

The invention concerns a device for the detection of nuclear radiation on the field of reactor engineering, nuclear medicine and radiation protection. It has a remote indication for the nuclear radiation with a low level fault liability and small size. The nuclear radiation is converted into light quanta by means of a replaceable scintillation plate and discharged by means of a glass-fibre conductor. The invention can be applied to monitoring systems in reactor buildings, storage rooms for radioactive isotopes and rooms with a large smoke development

1984-06-20

60

Electronic detection systems and methods  

Energy Technology Data Exchange (ETDEWEB)

Electronic detection systems and methods are provided for detecting the unauthorized passage of a person or object past a checkpoint defined, for example, by a doorway to a room or building, an entrance or exit gate for a piece of property, a post or pole supporting the detection equipment or hidden detection means. The detection system includes one or more alarms which operate either in the vicinity of the unauthorized object or person detected and/or remote therefrom such as a central monitor station for monitoring a plurality of checkpoint locations. An alarm deactivating device is employed which may be carried by a person or object and which either generates a code or deactivating signal and broadcasts same to a receiver located at the checkpoint or predeterminately affect or alters a radiation field generated in the vicinity of the checkpoint which code, signal or field change is detected and employed to deactivate and alarm or other circuit.

Lemelson, J.H.

1984-09-11

 
 
 
 
61

Measurement and detection of radiation.  

Canada Institute for Scientific and Technical Information (Canada)

"The research and applications of nuclear instrumentation have grown substantially since publication of the previous editions. With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines, including nuclear nonproliferation, homeland security, and nuclear medicine. Continuing in the tradition of its bestselling predecessors, measurement and detection of radiation, third edition illustrates the fundamentals of nuclear interactions and radiation detection with a multitude of examples and problems. It offers a clearly written, accessible introduction to nuclear instrumentation concepts. New to the third edition. A new chapter on the latest applications of radiation detection, covering nuclear medicine, dosimetry, health physics, nonproliferation, and homeland security. Updates to all chapters and subtopics within chapters, as needed. Many new references and a completely updated bibliography. This third edition of a classic textbook continues to serve new students entering the nuclear science and engineering fields. It enables them to select the proper detector, analyze the results of counting experiments, and perform radiation measurements that follow proper health physics procedures. A solutions manual is available with qualifying course adoption"--Provided by publisher.

62

Radiation Detection for Homeland Security Applications  

Science.gov (United States)

In the past twenty years or so, there have been significant changes in the strategy and applications for homeland security. Recently there have been significant at deterring and interdicting terrorists and associated organizations. This is a shift in the normal paradigm of deterrence and surveillance of a nation and the `conventional' methods of warfare to the `unconventional' means that terrorist organizations resort to. With that shift comes the responsibility to monitor international borders for weapons of mass destruction, including radiological weapons. As a result, countries around the world are deploying radiation detection instrumentation to interdict the illegal shipment of radioactive material crossing international borders. These efforts include deployments at land, rail, air, and sea ports of entry in the US and in European and Asian countries. Radioactive signatures of concern include radiation dispersal devices (RDD), nuclear warheads, and special nuclear material (SNM). Radiation portal monitors (RPMs) are used as the main screening tool for vehicles and cargo at borders, supplemented by handheld detectors, personal radiation detectors, and x-ray imaging systems. This talk will present an overview of radiation detection equipment with emphasis on radiation portal monitors. In the US, the deployment of radiation detection equipment is being coordinated by the Domestic Nuclear Detection Office within the Department of Homeland Security, and a brief summary of the program will be covered. Challenges with current generation systems will be discussed as well as areas of investigation and opportunities for improvements. The next generation of radiation portal monitors is being produced under the Advanced Spectroscopic Portal program and will be available for deployment in the near future. Additional technologies, from commercially available to experimental, that provide additional information for radiation screening, such as density imaging equipment, will be reviewed. Opportunities for further research and development to improve the current equipment and methodologies for radiation detection for the important task of homeland security will be the final topic to be discussed.

Ely, James

2008-05-01

63

Radiation detection system  

Science.gov (United States)

A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

Riedel, Richard A. (Knoxville, TN); Wintenberg, Alan L. (Knoxville, TN); Clonts, Lloyd G. (Knoxville, TN); Cooper, Ronald G. (Oak Ridge, TN)

2012-02-14

64

Development of detection {center_dot} analytical techniques applied with new DNA analytical methods for radiation mutation. Improvement of detection efficiency, development of effective probe and primer and detection techniques  

Energy Technology Data Exchange (ETDEWEB)

Evaluation of the degree of gene defects in a special region was made using culture cell lines and long PCR method was found usable. A genome size in a length around 30 kb or more was detectable and an insertion of about 5 kb was also detectable. Based on these results, several model genes; (1) long repeated sequences dispersed in a genome, (2) gene group consisting a large cluster and (3) single gene were chosen to detect by PCR amplification. In this fiscal year, the sequence which constructs chromosome end was isolated as a marker sequence and the effects of radiation on the sequence were investigated. Its amplification hardly occurred at 0.5 Gy and started at a range, 1-10 Gy. The peak effects were observed at {approx}4 Gy. These results suggest that these sequences have high-ordered conformations till radiation exposure produces a cleavage in the sequence, so that its amplification by PCR method would not occur without any structural change. (M.N.)

Maekawa, Hideaki; Tsuchida, Kozo; Hashido, Kazuo; Takada, Naoko; Kameoka, Yosuke; Hirata, Makoto [National Inst. of Infectious Diseases, Tokyo (Japan)

1998-02-01

65

A method for detection of hydroxyl radicals in the vicinity of biomolecules using radiation-induced fluorescence of coumarin  

International Nuclear Information System (INIS)

A novel method is described to quantitate radiation-induced hydroxyl radicals in the vicinity of biomolecules in aqueous solutions. Coumarin-3-carboxylic acid (CCA) is a non-fluorescent molecule that, upon interaction with radiation in aqueous solution, produces fluorescent products. CCA was derivatized to its succinimidyl ester (SECCA) and coupled to free primary amines of albumin, avidin, histone-H1, polylysine, and an oligonucleotide. When SECCA-biomolecule conjugates were irradiated, the relationship between induced fluorescence and dose was linear in the dose range examined (0.01-10 Gy). The data indicate that the induction of fluorescence on SECCA-biomolecule conjugates records specifically the presence of the hydroxyl radical in the immediate vicinity of the irradiated biomolecule. The method is rapid and sensitive, uses standard instrumentation, and the sample remains available for further studies. (Author)

1993-04-01

66

A method for detection of hydroxyl radicals in the vicinity of biomolecules using radiation-induced fluorescence of coumarin  

Energy Technology Data Exchange (ETDEWEB)

A novel method is described to quantitate radiation-induced hydroxyl radicals in the vicinity of biomolecules in aqueous solutions. Coumarin-3-carboxylic acid (CCA) is a non-fluorescent molecule that, upon interaction with radiation in aqueous solution, produces fluorescent products. CCA was derivatized to its succinimidyl ester (SECCA) and coupled to free primary amines of albumin, avidin, histone-H1, polylysine, and an oligonucleotide. When SECCA-biomolecule conjugates were irradiated, the relationship between induced fluorescence and dose was linear in the dose range examined (0.01-10 Gy). The data indicate that the induction of fluorescence on SECCA-biomolecule conjugates records specifically the presence of the hydroxyl radical in the immediate vicinity of the irradiated biomolecule. The method is rapid and sensitive, uses standard instrumentation, and the sample remains available for further studies. (Author).

Makrigiorgos, G.M.; Baranowska-Kortylewicz, J.; Bump, E.; Sahu, S.K.; Berman, R.M.; Kassis, A.I. (Harvard Medical School, Boston, MA (United States))

1993-04-01

67

Multigrid contact detection method  

Science.gov (United States)

Contact detection is a general problem of many physical simulations. This work presents a O(N) multigrid method for general contact detection problems (MGCD). The multigrid idea is integrated with contact detection problems. Both the time complexity and memory consumption of the MGCD are O(N) . Unlike other methods, whose efficiencies are influenced strongly by the object size distribution, the performance of MGCD is insensitive to the object size distribution. We compare the MGCD with the no binary search (NBS) method and the multilevel boxing method in three dimensions for both time complexity and memory consumption. For objects with similar size, the MGCD is as good as the NBS method, both of which outperform the multilevel boxing method regarding memory consumption. For objects with diverse size, the MGCD outperform both the NBS method and the multilevel boxing method. We use the MGCD to solve the contact detection problem for a granular simulation system based on the discrete element method. From this granular simulation, we get the density property of monosize packing and binary packing with size ratio equal to 10. The packing density for monosize particles is 0.636. For binary packing with size ratio equal to 10, when the number of small particles is 300 times as the number of big particles, the maximal packing density 0.824 is achieved.

He, Kejing; Dong, Shoubin; Zhou, Zhaoyao

2007-03-01

68

Optical fiber-applied radiation detection system  

International Nuclear Information System (INIS)

A technique to measure radiation by using plastic scintillation fibers doped radiation fluorescent (scintillator) to plastic optical fiber for a radiation sensor, was developed. The technique contains some superiority such as high flexibility due to using fibers, relatively easy large area due to detecting portion of whole of fibers, and no electromagnetic noise effect due to optical radiation detection and signal transmission. Measurable to wide range of and continuous radiation distribution along optical fiber cable at a testing portion using scintillation fiber and flight time method, the optical fiber-applied radiation sensing system can effectively monitor space radiation dose or apparatus operation condition monitoring. And, a portable type scintillation optical fiber body surface pollution monitor can measure pollution concentration of radioactive materials attached onto body surface by arranging scintillation fiber processed to a plate with small size and flexibility around a man to be tested. Here were described on outline and fundamental properties of various application products using these plastic scintillation fiber. (G.K.)

2001-05-01

69

Radiation detector and light transmitting device for radiation detecting  

International Nuclear Information System (INIS)

Existent radiation detectors and measuring methods require electric processing and special read-out devices, which make signal processing systems complicate. Then, there is disposed a radiation sensitive light emission wavelength converter comprising a scintilator layer emitting fluorescence and fluorescent plastic optical fibers for absorbing fluorescent light and excitating, collecting and optically transmitting fluorescent light of different wavelengths, and the detected light emitted from the convertor is transmitted to a remote places by way of optical fibers having a microlense as required. When radiation rays are irradiated, the scintilator emits fluorescent light and the light is outputted by way of the fluorescent plastic optical fibers. Since the light is converted to that of a longer wave length, presence and intensity of the radiation rays can be discriminated by the color and the briliancy thereof. Then, an extremely simple and economical radiation detecting and display device, capable of naked eye-observation, and not requiring a power source, a signal processing system and an analyzing system an photoelectronic conversion is not required in a detection section. (N.H.)

1989-12-27

70

Optimizing a method for detection of hepatitis A virus in shellfish and study the effect of gamma radiation on the viral genome  

International Nuclear Information System (INIS)

Our work was aimed at detecting the hepatitis A virus (HAV) in bivalve mollusc collected from five shellfish harvesting areas and from a coastal region in Tunisia using RT-Nested-PCR and studying the effect of gamma radiation on HAV genome. Two methods used to recover HAV from mollusc flesh and two methods of extraction of virus RNA were compared in order to determine the most sensitive method. Glycine extraction and extraction of virus RNA using proteinase K were more convenient and then used in this study for detection of HAV in shellfish. The results of molecular analyses: RT-Nested-PCR using primers targeted at the P1 region revealed that 28 % of the samples were positive for HAV. Doses of gamma irradiation ranging between 5 to 30 kGy were used to study the effect of this radiation on HAV genome after the contamination of mollusc flesh with suspension of HAV (derived from stool specimens). HAV specific genomic band was observed for doses between 5 to 20 kGy. We didn't detect HAV genome with doses 25 and 30 kGy. (Author)

2008-01-01

71

Application of the microbiological method DEFT/APC to detect minimally processed vegetables treated with gamma radiation  

Energy Technology Data Exchange (ETDEWEB)

Marketing of minimally processed vegetables (MPV) are gaining impetus due to its convenience, freshness and apparent health effect. However, minimal processing does not reduce pathogenic microorganisms to safe levels. Food irradiation is used to extend the shelf life and to inactivate food-borne pathogens. In combination with minimal processing it could improve safety and quality of MPV. A microbiological screening method based on the use of direct epifluorescent filter technique (DEFT) and aerobic plate count (APC) has been established for the detection of irradiated foodstuffs. The aim of this study was to evaluate the applicability of this technique in detecting MPV irradiation. Samples from retail markets were irradiated with 0.5 and 1.0 kGy using a {sup 60}Co facility. In general, with a dose increment, DEFT counts remained similar independent of the irradiation while APC counts decreased gradually. The difference of the two counts gradually increased with dose increment in all samples. It could be suggested that a DEFT/APC difference over 2.0 log would be a criteria to judge if a MPV was treated by irradiation. The DEFT/APC method could be used satisfactorily as a screening method for indicating irradiation processing.

Araujo, M.M.; Duarte, R.C.; Silva, P.V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Centro de Tecnologia das Radiacoes, Laboratorio de Deteccao de Alimentos Irradiados, Cidade Universitaria, Av. Prof. Lineu Prestes 2242, Butanta Zip Code 05508-000 Sao Paulo (Brazil); Marchioni, E. [Laboratoire de Chimie Analytique et Sciences de l' Aliment (UMR 7512), Faculte de Pharmacie, Universite Louis Pasteur, 74, route du Rhin, F-67400 Illkirch (France); Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Centro de Tecnologia das Radiacoes, Laboratorio de Deteccao de Alimentos Irradiados, Cidade Universitaria, Av. Prof. Lineu Prestes 2242, Butanta Zip Code 05508-000 Sao Paulo (Brazil)], E-mail: villavic@ipen.br

2009-07-15

72

Means and methods used to check radiation detection, signalling and alarm devices in the centralized environment control systems of the INB of CEN-Saclay  

International Nuclear Information System (INIS)

Having reviewed the prescribed technical measures concerning 'systematic environment controls' in INB (Installations nucleaires de base - basic nuclear facilities) and published in the J.O. (French Official Journal) the authors briefly describe the main radiation detection, signalling and alarm systems at present installed in INB of CEN-Saclay and weigh up the extent to which their characteristics comply with the statutory texts. They then develop the means and methods set up to check on the good working order of these devices which are integrated in centralised one-piece modular analogue or informatics type control systems possible functioning anomalies being classed in two categories: logic type anomalies corresonding to a straightforward breakdown where detection is permanent; developing anomalies corresponding to poor functioning where detection requires a more critical and periodic control. The authors demonstrate the advantages offered by centralised computer type control systems

1979-09-21

73

Radiation delivery system and method  

Energy Technology Data Exchange (ETDEWEB)

A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

2002-01-01

74

Application of the microbiological method DEFT/APC and DNA comet assay to detect ionizing radiation processing of minimally processed vegetables  

International Nuclear Information System (INIS)

Marketing of minimally processed vegetables (MPV) are gaining impetus due to its convenience, freshness and apparent healthy. However, minimal processing does not reduce pathogenic microorganisms to safe levels. Food irradiation is used to extend the shelf life and inactivation of food-borne pathogens, Its combination with minimal processing could improve the safety and quality of MPV. Two different food irradiation detection methods, a biological, the DEFT/APC, and another biochemical, the DNA Comet Assay were applied to MPV in order to test its applicability to detect irradiation treatment. DEFT/APC is a microbiological screening method based on the use of the direct epi fluorescent filter technique (DEFT) and the aerobic plate count (APC). DNA Comet Assay detects DNA damage due to ionizing radiation. Samples of lettuce, chard, watercress, dandelion, kale, chicory, spinach, cabbage from retail market were irradiated O.5 kGy and 1.0 kGy using a 60 Co facility. Irradiation treatment guaranteed at least 2 log cycle reduction for aerobic and psychotropic microorganisms. In general, with increasing radiation doses, DEFT counts remained similar independent of irradiation processing while APC counts decreased gradually. The difference of the two counts gradually increased with dose increment in all samples. It could be suggested that a DEFT/APC difference over 2.0 log would be a criteria to judge if a MPV was treated by irradiation. DNA Comet Assay allowed distinguishing non-irradiated samples from irradiated ones, which showed different types of comets owing to DNA fragmentation. Both DEFT/APC method and DNA Comet Assay would be satisfactorily used as a screening method for indicating irradiation processing. (author)

2008-01-01

75

Underground tank leak detection methods  

Energy Technology Data Exchange (ETDEWEB)

This book presents a description of leak detection methods for testing underground tank systems. Topics covered include: Volumetric leak detection tests, Non-volumetric leak tests, and Leak detection testing methods.

Niaki, S.; Broscious, J.A.

1989-01-01

76

Detection methods of irradiated foodstuffs  

International Nuclear Information System (INIS)

Full text: Food irradiation has, in certain circumstances, an important role to play both in promoting food safety and in reducing food losses. The safety and availability of nutritious food are essential components of primary health care. WHO actively encourages the proper use of food irradiation in the fight against foodborne diseases and food losses. To this end, it collaborates closely with FAO and IAEA. Food irradiation can have a number of beneficial effects, including delay of ripening and prevention of sprouting; control of insects, parasites, helminths, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization, which enables commodities to be stored unrefrigerated for long periods. The 1990s witnessed a significant advancement in food irradiation processing. As a result, progress has been made in commercialization of the technology, culminating in greater international trade in irradiated foods and the implementation of differing regulations relating to its use in many countries. Codex General Standard for Irradiated Foodstuffs and Recommended International Code of Practice for the Operation of Irradiation Facilities Used for the Treatment of Foods regulate food irradiation at international level. At European Union level there are in power Directive 1999/2/EC and Directive1999/3/EC. Every particular country has also its own regulations regarding food irradiation. In Romania, since 2002 the Norms Regarding Foodstuffs and Food Ingredients Treated by Ionizing Radiation are in power. These Norms are in fact the Romanian equivalent law of the European Directives 1999/2/EC and 1999/3/EC. The greater international trade in irradiated foods has led to the demand by consumers that irradiated food should be clearly labeled as such and that methods capable of differentiating between irradiated and nonirradiated products should be available. Thus a practical basis was sought to allow consumers to exercise a free choice as to which food they purchase. If a food is marketed as irradiated or if irradiated goods are sold without the appropriate labeling, then detection tests should be able to prove the authenticity of the product. For the moment in Romania there is not any food control laboratory able to detect irradiated foodstuffs. The Technological Irradiation Department coordinates and co finances a research project aimed to establish the first Laboratory of Irradiated Foodstuffs Detection. The detection methods studied in this project are the ESR methods (for cellulose EN 1787/2000, bone EN 1786/1996 and crystalline sugar EN 13708/2003), the TL method (EN 1788/2001), the PSL method (EN 13751/2002) and the DNA Comet Assay method (EN 13784/2001). The above detection methods will be applied on various foodstuffs such: garlic, onion, potatoes, rice, beans, wheat, maize, pistachio, sunflower seeds, raisins, figs, strawberries, chicken, beef, fish, pepper, paprika, thyme, laurel and mushrooms. As an example of the application of a detection method there are presented the ESR spectra of irradiated and nonirradiated paprika acquired according to ESR detection method for irradiated foodstuffs containing cellulose. First of all it can be noticed that the intensity of the signal of cellulose is much higher for the irradiated sample than that for the nonirradiated one and second that appear two radiation specific signals symmetrical to the cellulose signal. These two radiation specific signals prove the irradiation treatment of paprika. (author)

2005-01-01

77

Deterministic methods in radiation transport  

Energy Technology Data Exchange (ETDEWEB)

The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

Rice, A.F.; Roussin, R.W. (eds.)

1992-06-01

78

Deterministic methods in radiation transport  

International Nuclear Information System (INIS)

The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community

1992-02-04

79

Development of detection/analysis for radiation induced mutations using new DNA analyzing techniques. Construction of effective probe and primer, and their detection method  

International Nuclear Information System (INIS)

An investigation was made on the genome structure of 28 S rDNA in the respect of radiation-induced double strand cleavages in DNA. It has been reported that there is an insertion of retro-transposon in some rDNA. There is a possibility that rDNA may have a specific structure composed of several regions of different sensitivities to radiation exposure. Hence, the structure and the functions of such regions were investigated. This region was as long as 2.5 Mb in length and divided into inserted type and un-inserted one. FISH showed that the inserted regions are composed of mini-clusters and the structure was high-ordered. A new primer was constructed so as to provide PCR products of about 5 Kb in length. When the DNA was exposed to ?-ray (60Co and 137Cs), the amount of PCR products was dose-dependently increased up to 10 Gy and the increase was 15-20 % at the dose. Therefore, it was suggested that PCR amplification was enhanced because of the destruction of higher-ordered structure caused by radiation exposure. The sensitivity of some DNA region to 60Co or 137Cs exposure was different from that of other regions in respect of the formation of double strand cleavage. Therefore, it was thought that such high-ordered genome region could be distinguishable from other regions with the differences in radiation sensitivity of genome DNA. (M.N.)

2000-02-01

80

Method of locating radiation detectors  

International Nuclear Information System (INIS)

Purpose: To avoid direct contact between a detector and radioactive liquid wastes upon on-line measurement of radio activity for radioactive liquid wastes. Method: A by-pass is provided to a pipe through which liquid wastes flow thus making laminar flow of the liquid wastes. A detection portion is provided to the laminar flow portion. In the detection portion, are formed an upper chamber and a lower chamber in contaction to the laminar flow. The upper chamber is filled with a fluid having a specific gravity lower than that of the liquid wastes and insoluble to the liquid wastes, for example, benzene or cyclohexane, which is contacted to the laminar flow. A radiation detector is provided in the above fluid of a low specific gravity. This can prevent the direct contaction between the detector and the liquid wastes and avoid the deposition of oils and scales contained in the liquid wastes to the detector. The above liquid of the lower specific gravity is circulated and cleaned by a pump. In the lower chamber of the pipe, a fluid having a specific gravity higher than that of the liquid wastes and insoluble to the liquid wastes is filled for removing the precipitating substances. (Ikeda, J.)

1979-01-01

 
 
 
 
81

Main Achievements 2003-2004 - Interdisciplinary Research - Radiation detection methods for health, earth and environmental sciences - Thermoluminescence (TL) detectors  

International Nuclear Information System (INIS)

The IFJ has over 35 years of experience in the development, production and application of new types of thermoluminescence (TL) detectors, particularly LiF:Mg,Ti and LiF:Mg,Cu,P. Over 600,000 LiF detectors produced at the IFJ PAN are routinely applied in dosimetry services and hospitals in 30 countries. The current research in the field of thermoluminescence concentrates in space dosimetry and novel 2-dimensional detectors for medical applications. The space project (named Matroshka), organized by the European Space Agency, is one of the most ambitious dosimetry experiments in space. In February 2004 an anatomical model of the human body (a humanoid phantom), equipped with over 3500 dedicated thermoluminescent detectors (TLD), developed and produced at IFJ and tested at the Chiba heavy ion accelerator in Japan, was installed outside the International Space Station (ISS) to determine the cosmic radiation doses absorbed in human organs, which would be experienced by astronauts in open space. The phantom will remain in space for one year, after which the detectors will be returned to the IFJ for analysis

2005-01-01

82

Radiation, ionization, and detection in nuclear medicine  

Energy Technology Data Exchange (ETDEWEB)

Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

Gupta, Tapan K. [Radiation Monitoring Devices Research, Nuclear Medicine, Watertown, MA (United States)

2013-08-01

83

Radiation, ionization, and detection in nuclear medicine  

International Nuclear Information System (INIS)

Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

2013-01-01

84

Atomic bomb radiation dosimetry with ESR method  

International Nuclear Information System (INIS)

The availability of electron spin resonance (ESR) spectroscopy was evaluated in estimating radiation doses in atomic bomb (A-bomb) victims. Teeth, shell button of clothes, and part of the surface of the femur were collected as materials from 7 A-bomb victims. Radiation-induced ESR signals increased in proportional to radiation doses of gamma-rays. A background signal was detected at g value near to the target signal, which was largely different according to the materials. Measurement limits were various. The ESR method allowed small doses of gamma-rays to be estimated with errors of +- 50 % when materials had small background. This method can be used repeatedly because captured electrons are not released by vibration of microwaves. It permits the measurement of living materials which are unmeasurable by thermoluminescence dosimeter, and the estimation of radiation doses even when shielding factors are unknown. (Namekawa, K.)

1984-01-01

85

Electrochemical gas detection method  

Energy Technology Data Exchange (ETDEWEB)

An electrochemical cell comprising an anode, a cathode and a reference electrode operating in an aqueous electrolyte is utilized for detection of noxious gases in air. The gas is oxidized at the anode and detection thereof occurs as a result of the current generated by the reaction. A fixed potential difference is maintained between the anode and the reference electrode to avoid generation of undesired current from reactions involving an oxygen-water redox couple within the cell which would invalidate anode-cathode current for gas detection purposes. The fixed potential is chosen from within the range of about 0.9 to 1.5 volts.

Oswin, H. G.; Blurton, K. F.

1985-06-18

86

Physics and engineering of radiation detection  

CERN Multimedia

Physics and Engineering of Radiation Detection presents an overview of basic physics of radiation and its applications and covers the origins and properties of different kinds of ionizing radiation, their detection and measurement, and the procedures used to protect people and the environment from their potentially harmful effects. Covering both the basic physics of radiation and its applications, it will provide an up-to-date and coherent account of the origins and properties of the different kinds of ionizing radiation, and their detection and measurement. This book will illustrate the basic physical principles with an abundance of practical, worked-out examples, numerical problems, real world applications, and data, including biological effects, radon, risk assessment, and statistics.

Ahmed, Syed Naeem

2007-01-01

87

Method of manufacturing dosemeter detection element  

International Nuclear Information System (INIS)

The invention claims a method of manufacturing the detection element of a radiation dosemeter as described in the Czechoslovak patent document 170016. Patented is the active component of the dosemeter consisting of activated thermoluminescent phosphate glass. The manufacture consists in compacting glass powder consisting of 90 to 99 wt.% of particles of maximally 0.315 mm in diameter. (J.P.)

1973-11-13

88

Special Frisbees Detect Ultraviolet Radiation  

Science.gov (United States)

This experiment helps students understand that ultraviolet (UV) radiation is present in natural outdoor light and that the intensity of the light varies with season and time of day. After completing this activity, students will be able to demonstrate that UV radiation can be blocked or filtered by various substances. The page contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, suggested extensions, assessment ideas, modifications for alternative learners, special notes, and an example lab report format.

2007-12-12

89

Radiation detection and measurement student solutions manual  

CERN Document Server

This is the resource that engineers turn to in the study of radiation detection. The fourth edition takes into account the technical developments that continue to enhance the instruments and techniques available for the detection and spectroscopy of ionizing radiation. New coverage is presented on ROC curves, micropattern gas detectors, new sensors for scintillation light, and the excess noise factor. Revised discussions are also included on TLDs and cryogenic spectrometers, radiation backgrounds, and the VME standard. Engineers will gain a strong understanding of the field with this updated book.

Wehe, David K

2012-01-01

90

Silicon solid state devices and radiation detection  

CERN Multimedia

This book addresses the fundamental principles of interaction between radiation and matter, the principles of working and the operation of particle detectors based on silicon solid state devices. It covers a broad scope with respect to the fields of application of radiation detectors based on silicon solid state devices from low to high energy physics experiments including in outer space and in the medical environment. This book covers stateof- the-art detection techniques in the use of radiation detectors based on silicon solid state devices and their readout electronics, including the latest developments on pixelated silicon radiation detector and their application.

Leroy, Claude

2012-01-01

91

Abnormal glow discharge detection of visible radiation.  

Science.gov (United States)

Extension of abnormal glow discharge detection of electromagnetic radiation to visible wavelengths is observed with inexpensive commercial indicator lamps. The spectral response and mechanisms of detection are discussed and advantages over gas-filled photodiodes noted. Responses from different discharge regions are observed and their implications considered. PMID:20165225

Kopeika, N S; Rosenbaum, J; Kastner, R

1976-06-01

92

Electrets for beta radiation detection  

International Nuclear Information System (INIS)

Electret dosimetry has been reviewed by Gross. A cylindrical electret ionization-chamber type dosimeter has been studied for X and gamma rays and neutrons. The principle of the dosimeter is electret charge compensation due to ionization in the chamber volume. Electret ionization chambers can be designed with one or more electrets and in various shapes. This study is concerned with a simple system, similar to a cylindrical ionization chamber (sensitive volume: 3,5 cm3) using teflon electrets. Aluminum and lucite were used as wall-materials. Other experiences were performed using chambers without wall, i.e., without defined sensitive volume. The teflon electrets were obtained by Corona discharge in the gas surrounding them. The measurement of the electret charge was made by induction using a co-axial insulated metal chamber connected to an electrometer Keithley 610C. By measuring the charge before and after irradiation it is possible to obtain a calibration curve: charge (Q) versus absorbed dose (D) for the dosimeter. The irradiation setup used was the Beta Secondary Standard System of IPEN calibration laboratory with four beta sources: 90Sr90Y (74 and 1850 MBq), 204Tl (18,5 MBq) and 147Pm (518 MBq). In some cases a 85Kr source was also used. The electrets were tested in different radiation field geometries: electret axis parallel and perpendicular to the field. In conclusion, depending on the wall material and radiation field geometry, the teflon electret detector can be used for different dose interval determinations, using beta radiation

1983-02-01

93

Material for ionizing radiation detection  

International Nuclear Information System (INIS)

New scintillation material is claimed, namely, a lead dichloride single crystal activated with europium within 0.01 mol.% and 5 mol.%. For the same size and the same detector-source configuration, the detection efficiency of the PbCl_2(Eu) material is better by up to 40% than the conventional NaI(Tl). Thus, for the same detection efficiency the detector element of the new material can significantly be reduced in size. The PbCl_2(Eu) single crystal was grown by crystallization from the melt, finished into a cylindrical shape and encased in metal with a glass front window. The single crystal is attached to the window using silicone oil. Magnesium oxide powder is used as a reflector between the crystal and the case. (M.D.)

1985-09-05

94

GaTe semiconductor for radiation detection  

Science.gov (United States)

GaTe semiconductor is used as a room-temperature radiation detector. GaTe has useful properties for radiation detectors: ideal bandgap, favorable mobilities, low melting point (no evaporation), non-hygroscopic nature, and availability of high-purity starting materials. The detector can be used, e.g., for detection of illicit nuclear weapons and radiological dispersed devices at ports of entry, in cities, and off shore and for determination of medical isotopes present in a patient.

Payne, Stephen A. (Castro Valley, CA); Burger, Arnold (Nashville, TN); Mandal, Krishna C. (Ashland, MA)

2009-06-23

95

Advanced radiation detection utilizing photostimulated luminescence phenomenon  

International Nuclear Information System (INIS)

This survey of photostimulated luminescence (PSL) has three main thrusts: basic mechanism of PSL phenomenon, photostimulable phosphors as materials for imaging plate (IP) and its application to advanced radiation detection. In the right of the survey, it can be said that the IP utilizing the PSL in alkali halides and II-VI compound phosphors is one of the most attractive candidates for an advanced two-dimensional imaging sensor and a novel dosemeter for ionizing radiation. (author)

1998-01-01

96

A Voltage Quality Detection Method  

DEFF Research Database (Denmark)

This paper presents a voltage quality detection method based on a phase-locked loop (PLL) technique. The technique can detect the voltage magnitude and phase angle of each individual phase under both normal and fault power system conditions. The proposed method has the potential to evaluate various power quality disturbances, such as interruptions, sags and imbalances. Simulation studies have been performed. The effectiveness of the proposed method has been demonstrated under the simulated typical power disturbances.

Chen, Zhe; Wei, Mu

2008-01-01

97

A Voltage Quality Detection Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a voltage quality detection method based on a phase-locked loop (PLL) technique. The technique can detect the voltage magnitude and phase angle of each individual phase under both normal and fault power system conditions. The proposed method has the potential to evaluate various power quality disturbances, such as interruptions, sags and imbalances. Simulation studies have been performed. The effectiveness of the proposed method has been demonstrated under the simulated ty...

Chen, Zhe; Wei, Mu

2008-01-01

98

Technique for stabilization of detected x-radiation flux  

International Nuclear Information System (INIS)

A method for stabilization of recorded X-radiation flux is proposed. Stabilization is attained due to the fact that different signs of changes in comparable counting rates cause changes in the position of the detected radiation flux peak. Use of the proposed method of stabilizing X-radiation has the following advantages: it obviates limitations connected with sealing and thermostatting detectors; enlarges the number of problems which can be solved with the help of X-ray radiometric equipment; increases the lifetime of radioisotope sources. The given stabilization technique may be used in radioisotope instruments when measuring the density, coating thicknesses and dust content

1979-01-01

99

Radiation scatter apparatus and method  

International Nuclear Information System (INIS)

A radiation scatter gauge includes multiple detector locations for developing separate and independent sets of data from which multiple physical characteristics of a thin material and underlying substrate may be determined. In an illustrated embodiment, the apparatus and method of the invention are directed to determining characteristics of resurfaced pavement by nondestructive testing. More particularly, the density and thickness of a thin asphalt overlay and the density of the underlying pavement may be determined

1983-03-22

100

Space Radiation Transport Methods Development  

Science.gov (United States)

Early space radiation shield code development relied on Monte Carlo methods for proton, neutron and pion transport and made important contributions to the space program. More recently Monte Carlo code LAHET has been upgraded to include high-energy multiple-charged light ions for GCR simulations and continues to be expanded in capability. To compensate for low computational efficiency, Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representations of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process and resolving shielding issues usually had a negative impact on the design. We evaluate the implications of these common one-dimensional assumptions on the evaluation of the Shuttle internal radiation field. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary design concepts to the final design. In particular, we will discuss the progress towards a full three-dimensional and computationally efficient deterministic code for which the current HZETRN evaluates the lowest order asymptotic term. HZETRN is the first deterministic solution to the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design practice enabling development of integrated multidisciplinary design optimization methods. A single ray trace in ISS FEM geometry requires 14 milliseconds and severely limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given in terms of reconfigurable computing and could be utilized in the final design as verification of the deterministic method optimized design.

Wilson, J.; Tripathi, R.; Qualls, G.; Cucinotta, F.; Prael, R.; Norbury, J.

 
 
 
 
101

Composite scintillators for detection of ionizing radiation  

Science.gov (United States)

Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

Dai, Sheng (Knoxville, TN) [Knoxville, TN; Stephan, Andrew Curtis (Knoxville, TN) [Knoxville, TN; Brown, Suree S. (Knoxville, TN) [Knoxville, TN; Wallace, Steven A. (Knoxville, TN) [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

2010-12-28

102

Analytical detection methods for irradiated foods  

International Nuclear Information System (INIS)

The present publication is a review of scientific literature on the analytical identification of foods treated with ionizing radiation and the quantitative determination of absorbed dose of radiation. Because of the extremely low level of chemical changes resulting from irradiation or because of the lack of specificity to irradiation of any chemical changes, a few methods of quantitative determination of absorbed dose have shown promise until now. On the other hand, the present review has identified several possible methods, which could be used, following further research and testing, for the identification of irradiated foods. An IAEA Co-ordinated Research Programme on Analytical Detection Methods for Irradiation Treatment of Food ('ADMIT'), established in 1990, is currently investigating many of the methods cited in the present document. Refs and tab

1991-01-01

103

Review of leak detection methods  

International Nuclear Information System (INIS)

The development of the leak-tightness concept and the industrial sectors mainly concerned are reviewed, after which the various methods of leak detection are outlined briefly. The extent to which gases such as ammonia, freon, sulfur hexafluoride and helium are used, generally involving the use of specific detectors, leads to considerations on the principles of leak detection by tracer gas. Practical applications are discussed with regard to criteria of choice, sensitivity required and cost price. Finally the possibilities of using detection methods for industrial purposes are pointed out. They imply that equipment called on to fulfil tightness criteria can be designed to account for certain factors necessary for successful application of the detection methods chosen

1972-05-16

104

Radiation method of chemical analysis  

International Nuclear Information System (INIS)

A new method is described of the radiation analysis of materials using the scattering of accelerated charged particle beams. The material to be analyzed placed on a rotating and/or vibrating target support is exposed at a pressure of 10"-"1 to 10"-"6 torr and cooled to a temperature of down to -250 degC to a beam of accelerated particles applied from a medium at a pressure of 10"-"5 to 10"-"8 torr. The composition of the target material may be determined from the energy spectra or the momentum of the outcoming particles. The method is also suitable for organic substances or organometallic substances subject to pyrolysis. (L.K.)

1973-01-01

105

Plasmonically enhanced thermomechanical detection of infrared radiation.  

Science.gov (United States)

Nanoplasmonics has been an attractive area of research due to its ability to localize and manipulate freely propagating radiation on the nanometer scale for strong light-matter interactions. Meanwhile, nanomechanics has set records in the sensing of mass, force, and displacement. In this work, we report efficient coupling between infrared radiation and nanomechanical resonators through nanoantenna enhanced thermoplasmonic effects. Using efficient conversion of electromagnetic energy to mechanical energy in this plasmo-thermomechanical platform with a nanoslot plasmonic absorber integrated directly on a nanobeam mechanical resonator, we demonstrate room-temperature detection of nanowatt level power fluctuations in infrared radiation. We expect our approach, which combines nanoplasmonics with nanomechanical resonators, to lead to optically controlled nanomechanical systems enabling unprecedented functionality in biomolecular and toxic gas sensing and on-chip mass spectroscopy. PMID:23484543

Yi, Fei; Zhu, Hai; Reed, Jason C; Cubukcu, Ertugrul

2013-04-10

106

Detection of radiation processing in onions  

International Nuclear Information System (INIS)

Two breeds of onions were used for irradiation. Both breeds were divided into two parts - the first was irradiated with a dose of 80 Gy and the second served as a control. The two parts were stored under the same conditions. Conductometry, liquid chromatography and spectrophotometry were used for detecting the radiation processing of the onions. Only from the spectrophotometric determination of 2-desoxysaccharides it was possible to safely distinguish irradiated onions from non-irradiated controls throughout storage time. (E.S.)

1984-11-01

107

Method for detecting biological toxins  

Energy Technology Data Exchange (ETDEWEB)

Biological toxins are indirectly detected by using polymerase chain reaction to amplify unique nucleic acid sequences coding for the toxins or enzymes unique to toxin synthesis. Buffer, primers coding for the unique nucleic acid sequences and an amplifying enzyme are added to a sample suspected of containing the toxin. The mixture is then cycled thermally to exponentially amplify any of these unique nucleic acid sequences present in the sample. The amplified sequences can be detected by various means, including fluorescence. Detection of the amplified sequences is indicative of the presence of toxin in the original sample. By using more than one set of labeled primers, the method can be used to simultaneously detect several toxins in a sample.

Ligler, F.S.; Campbell, J.R.

1992-01-01

108

Neutron Radiation System for Explosives Detection in Cargo Containers  

International Nuclear Information System (INIS)

A measuring inspection system created in VNIIA and intended for active interrogation of cargo containers to detect explosives is presented. The system is based on (a) the 14 MeV 'tagged' neutron method in combination with nanosecond neutron analysis, and (b) the detection of characteristic secondary gamma-radiation from the reaction of inelastic neutron scattering on sample objects. Experimental results for the detection of an explosive simulator - melamine (C3H6N6) are presented for different container loadings (wood, iron) and for different arrangements of the explosive simulator. (author)

2007-11-26

109

New method to detect radiotherapy gamma field  

International Nuclear Information System (INIS)

Full text: This paper describes a novel method, which allows one to measure the intensity distribution of energetic gamma radiation field, used typically in radiation therapy. Traditionally, measurements are based on a detector system of one or more ionization chambers or an array of semiconductor diodes, which are working in the so called current mode. Therefore, in these methods the spatial resolution is limited by the size of the individual chamber- or diode unit and varies typically from one to five centimeters. The improvement in the resolution leads one to decrease the unit size, increase their amount and, consequently, the electronics (amplifiers etc.), because each detection unit needs its own channel. Better resolution is getting more important question together with the generalization of the Intensity Modulated Radiation Therapy (IMRT) but, unfortunately, the improvement in spatial resolution can only be achieved by increasing considerably the total expenses. Our detection method offers a solution to improve the spatial resolution with very low extra costs. It relies on a position sensitive avalanche counter (PSAC), which owns good position resolution and detection efficiency abilities for heavy ions. Due to the extremely high intensity and low ionization properties of gamma radiation, direct monitoring of gamma field with PSAC has not been possible so far. Therefore, a converter with an adequate cross section to photo fission reactions is used to convert the high intensity gamma field to a 'low' intensity field of heavy fission fragments, which then have the intensity distribution similar to the original gammas. The fragments have an excellent capability to ionize the chamber gas and the discrete pulses can easily be sorted out from the background. By this way the resolution of one millimeter in a typical total gamma field area and with a very simple applied electronics can be achieved. The chamber is also very robust against the radiation damages, which is not the case e.g. with the semiconductor diodes. The converter and wire thicknesses, wire voltages and gas pressure are the parameters, which allow one to optimize the operation of the detector for the certain accelerator conditions. In the final paper we will introduce our detection system and its construction in more detail. We also give the first results about the tests we have carried out in the laboratory and in a hospital accelerator and compare the resolutions to the ones existing in the recent detectors. (author)

2008-10-19

110

Methodical principles of radiation safety  

International Nuclear Information System (INIS)

The fundamental principles of radiation safety and the radiation protection are discussing in this book, which is addressed to persons working in the field of radiation safety and, due to their professional obligations, are in contact with ionizing radiations. The authors discuss the specific effects of ionizing radiation on human subjects, as well as the criteria for evaluation and control of the radiation risk, irradiation of peoples being in age of reproduction, planned increase of professional irradiation and accidentally increased professional irradiation (radiation hazards), as well as irradiation of individuals and population groups and irradiation of the total population. All questions treated in this book are interpreted according to the most recent concepts published in the last document of the ICRS. (M.Kh.)

1978-01-01

111

Various Edge Detection Methods for Foreground Detection?  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we study different edge detection techniques, edge detection is one of the mostcommonly used operations in image analysis, and there are probably more algorithms in the literature forenhancing and detecting edges than any other single subject. The goal of edge detection process in a digitalimage is to determine the frontiers of all represented objects based on automatic processing of the colour orgray level information in each present pixel. An edge is the boundary between an object and the background,and indicates the boundary between overlapping objects. This means that if the edges in an image can beidentified accurately, all of the objects can be located and basic properties such as area, perimeter, and shapecan be measured. Since computer vision involves the identification and classification of objects in an image,edge detections is an essential tool.

Gurjeet kaur Seerha

2013-06-01

112

Survey of Anomaly Detection Methods  

Energy Technology Data Exchange (ETDEWEB)

This survey defines the problem of anomaly detection and provides an overview of existing methods. The methods are categorized into two general classes: generative and discriminative. A generative approach involves building a model that represents the joint distribution of the input features and the output labels of system behavior (e.g., normal or anomalous) then applies the model to formulate a decision rule for detecting anomalies. On the other hand, a discriminative approach aims directly to find the decision rule, with the smallest error rate, that distinguishes between normal and anomalous behavior. For each approach, we will give an overview of popular techniques and provide references to state-of-the-art applications.

Ng, B

2006-10-12

113

Landmine detection by neutron methods  

International Nuclear Information System (INIS)

The development of the novel nuclear methods in the field of landmine identification requires a more precise knowledge of microscopic and macroscopic atomic and nuclear data. In addition, the effect of the weight and density of the explosives on the observation of the anomaly in a dry sand environment was examined by different dummy landmines using a hand-held neutron thermalization detector. The concept of the backscattering spectrometry and its possible use for landmine detection are also discussed. (author)

2003-11-05

114

Simple method to demonstrate radiation-inducible radiation resistance in microbial cells  

Energy Technology Data Exchange (ETDEWEB)

A simple method for detection of radiation-inducible radiation resistance was developed by irradiating aliquots (0.01 ml) of cell suspension on agar plates. Part of each experimental plate was subjected to an induction treatment, and subsequent radiation resistance was compared with that of untreated cells on the same plate. The UV radiation resistance of a Micrococcus sp. was increased approximately 1.6 times by an induction treatment. This simple procedure of irradiating cells in a fixed position on agar avoided washing, centrifugation, and cell enumeration required in traditional methods.

Tan, S.T.; Maxcy, R.B.

1986-01-01

115

Pencil-shaped radiation detection ionization chamber  

International Nuclear Information System (INIS)

A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

1979-01-01

116

Method and apparatus for detecting neutrons  

Energy Technology Data Exchange (ETDEWEB)

The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO.sub.2 with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation.

Perkins, Richard W. (Richland, WA); Reeder, Paul L. (Richland, WA); Wogman, Ned A. (Richland, WA); Warner, Ray A. (Benton City, WA); Brite, Daniel W. (Richland, WA); Richey, Wayne C. (Richland, WA); Goldman, Don S. (Orangevale, CA)

1997-01-01

117

Dosimetry methods for the estimation of exposure to ionizing radiation  

International Nuclear Information System (INIS)

Ionizing radiations, by their nature, have required for their detection the use of suitable devices generically referred detecting systems. The detection of secondary particles arising during the processes of ionization and excitation to the passage of radiation in the environment, have constituted the basis of the measurement methods. A detector system is a device that converts the energy of the incident radiation on a signal (electrical, photochemical, etc.) that is easily processable from the technological point of view, but without distorting the original information. These devices have provided qualitative or quantitative information about the radiation of interest. The detector system is a set of a detector together with a processing system. This system has based its operation in methods of: gas ionization, scintillation, semiconductor, film, thermoluminescence, among others. (author)

2012-03-26

118

Calibration method for video and radiation imagers  

Science.gov (United States)

The relationship between the high energy radiation imager pixel (HERIP) coordinate and real-world x-coordinate is determined by a least square fit between the HERIP x-coordinate and the measured real-world x-coordinates of calibration markers that emit high energy radiation imager and reflect visible light. Upon calibration, a high energy radiation imager pixel position may be determined based on a real-world coordinate of a moving vehicle. Further, a scale parameter for said high energy radiation imager may be determined based on the real-world coordinate. The scale parameter depends on the y-coordinate of the moving vehicle as provided by a visible light camera. The high energy radiation imager may be employed to detect radiation from moving vehicles in multiple lanes, which correspondingly have different distances to the high energy radiation imager.

Cunningham, Mark F. (Oak Ridge, TN) [Oak Ridge, TN; Fabris, Lorenzo (Knoxville, TN) [Knoxville, TN; Gee, Timothy F. (Oak Ridge, TN) [Oak Ridge, TN; Goddard, Jr., James S. (Knoxville, TN); Karnowski, Thomas P. (Knoxville, TN) [Knoxville, TN; Ziock, Klaus-peter (Clinton, TN) [Clinton, TN

2011-07-05

119

Detection and identification method employing Mossbauer isotopes  

International Nuclear Information System (INIS)

A detection/identification method for determining the presence of a Mossbauer isotope-containing taggant in a carrier material, e.g., explosives, weapons, currency, tax stamps, or identification documents. The detector includes a Mossbauer isotope-containing detecting substance that is identical to the taggant, and a sensing element responsive to the presence of the tagging substance in the carrier material, provided that the Mossbauer isotope of the tagging substance is in a state of resonance excitation and causes excitation of the Mossbauer isotope of the detecting substance. The sensing element is operatively associated with an indicator for indicating whether or not the sensing element has been actuated. The method is initiated by irradiating the carrier material while in detecting proximity to the detector, with radiation from a radioactive source comprising a Mossbauer isotope-containing substance which corresponds exactly to the taggant. In the case of explosives, identification of the manufacturer, date of manufacture or type of explosive, may be made even after detonation

1982-01-01

120

Detection and identification method employing Mossbauer isotopes  

Energy Technology Data Exchange (ETDEWEB)

A detection/identification method for determining the presence of a Mossbauer isotope-containing taggant in a carrier material, e.g., explosives, weapons, currency, tax stamps, or identification documents. The detector includes a Mossbauer isotope-containing detecting substance that is identical to the taggant, and a sensing element responsive to the presence of the tagging substance in the carrier material, provided that the Mossbauer isotope of the tagging substance is in a state of resonance excitation and causes excitation of the Mossbauer isotope of the detecting substance. The sensing element is operatively associated with an indicator for indicating whether or not the sensing element has been actuated. The method is initiated by irradiating the carrier material while in detecting proximity to the detector, with radiation from a radioactive source comprising a Mossbauer isotope-containing substance which corresponds exactly to the taggant. In the case of explosives, identification of the manufacturer, date of manufacture or type of explosive, may be made even after detonation.

Krevitz, K.; Pytlewski, L.L.; Soberman, R.K.

1982-12-14

 
 
 
 
121

Organic materials and devices for detecting ionizing radiation  

Energy Technology Data Exchange (ETDEWEB)

A .pi.-conjugated organic material for detecting ionizing radiation, and particularly for detecting low energy fission neutrons. The .pi.-conjugated materials comprise a class of organic materials whose members are intrinsic semiconducting materials. Included in this class are .pi.-conjugated polymers, polyaromatic hydrocarbon molecules, and quinolates. Because of their high resistivities (.gtoreq.10.sup.9 ohmcm), these .pi.-conjugated organic materials exhibit very low leakage currents. A device for detecting and measuring ionizing radiation can be made by applying an electric field to a layer of the .pi.-conjugated polymer material to measure electron/hole pair formation. A layer of the .pi.-conjugated polymer material can be made by conventional polymer fabrication methods and can be cast into sheets capable of covering large areas. These sheets of polymer radiation detector material can be deposited between flexible electrodes and rolled up to form a radiation detector occupying a small volume but having a large surface area. The semiconducting polymer material can be easily fabricated in layers about 10 .mu.m to 100 .mu.m thick. These thin polymer layers and their associated electrodes can be stacked to form unique multi-layer detector arrangements that occupy small volume.

Doty, F. Patrick (Livermore, CA); Chinn, Douglas A. (Livermore, CA)

2007-03-06

122

Radiation and thermal characteristics of L5178Y-sensitive cells and usefulness of eosin staining method to detect heat-induced cell death  

International Nuclear Information System (INIS)

Radiosensitivity, thermosensitivity, drug sensitivity and their combined effects were investigated in mouse L5178Y-wild cells (LY-W) and L5178Y-sensitive cells (LY-S). The following results were obtained: LY-S were more radiosensitive than LY-W but were similar in their thermosensitivity. Thermotolerance induction was similar but the decay was faster in LY-W which had a shorter doubling time. The radiosensitizing effect of heating was similar in both cell lines. The thermal enhancement ratio was higher for a longer duration of heating at 42degC than for a shorter duration at 44degC, both of which exhibited a similar level of survival when applied alone. The eosin staining method was useful to detect heat-induced interphase death and thermal sensitizing effects of drugs. In LY-W, interphase death was the main mode of hyperthermic cell killing and was independent of the hyperthermic temperature, whereas in LY-S, the percentage of interphase death increased with the hyperthermic temperature. Procaine and bleomycin sensitized both cells to heat. Survival estimated by the eosin staining method shifted towards that obtained by colony forming method in heated LY-S after procaine. Sensitization to heat by procaine suggests that interphase death after hyperthermia is probably due to membrane damage. Comparison of the present work with previous ones, further suggests that with an increase in thermosensitivity, there is an increase in heat-induced interphase death. (author) 67 refs

1990-01-01

123

Explosives detection system and method  

Science.gov (United States)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Reber, Edward L. (Idaho Falls, ID); Jewell, James K. (Idaho Falls, ID); Rohde, Kenneth W. (Idaho Falls, ID); Seabury, Edward H. (Idaho Falls, ID); Blackwood, Larry G. (Idaho Falls, ID); Edwards, Andrew J. (Idaho Falls, ID); Derr, Kurt W. (Idaho Falls, ID)

2007-12-11

124

Monte Carlo Radiation Hydrodynamics with Implicit Methods  

CERN Document Server

We explore the application of Monte Carlo transport methods to solving coupled radiation-hydrodynamics problems. We use a time-dependent, frequency-dependent, 3-dimensional radiation transport code, that is special relativistic and includes some detailed microphysical interactions such as resonant line scattering. We couple the transport code to two different 1-dimensional (non-relativistic) hydrodynamics solvers: a spherical Lagrangian scheme and a Eulerian Godunov solver. The gas-radiation energy coupling is treated implicitly, allowing us to take hydrodyanimcal time-steps that are much longer than the radiative cooling time. We validate the code and assess its performance using a suite of radiation hydrodynamical test problems, including ones in the radiation energy dominated regime. We also develop techniques that reduce the noise of the Monte Carlo estimated radiation force by using the spatial divergence of the radiation pressure tensor. The results suggest that Monte Carlo techniques hold promise for s...

Roth, Nathaniel

2014-01-01

125

Evaluation of methods to leak test sealed radiation sources  

International Nuclear Information System (INIS)

The methods for the leak testing of sealed radiation sources were reviewed. One hundred and thirty-one equipment vendors were surveyed to identify commercially available leak test instruments. The equipment is summarized in tabular form by radiation type and detector type for easy reference. The radiation characteristics of the licensed sources were reviewed and summarized in a format that can be used to select the most suitable detection method. A test kit is proposed for use by inspectors when verifying a licensee's test procedures. The general elements of leak test procedures are discussed

1987-01-01

126

Aerial Radiation Detection Vehicle Manned and Unmanned Concepts  

International Nuclear Information System (INIS)

We are developing an Unmanned Aerial Radiation Detection Vehicle that will give new abilities to the Manned Aerial Radiation Detection Vehicle, Air-Ram. A comparison between the two systems will be given, and a report to our first Unmanned Aerial Radiation Detection Vehicle flight. Air-Ram The Air-Ram system, figure 1, has been developed to measure and display online radiation level measurements taken above the radiation area with a chopper. The detected radiation levels are presented on a topographical map with the flight path colored with the radiation intensities. The air crew and controllers on the ground are updated every two seconds. It enables first responders to complete and real time picture of a radiological event which is essential in order to be able to activate and direct ground operations if necessary. The system measures radiation levels and produces a spectrum graph used to identify the isotopes

2008-02-19

127

Radiation detection with superconducting granular thin films  

International Nuclear Information System (INIS)

Superconducting granular thin films are considered to be an array of Josephson junctions and can be used as fast, sensitive detectors of microwave and submillimeter wave radiation. This paper describes the experimental results on detection of 10 GHz and HCN laser radiation with tin granular thin films. In order to investigate the relationship between the granular structure and the sensitivity, several kinds of tin granular thin films are made with changing background pressure and substrate temperature which is controlled by a Peltier refrigerator. Optical microscope photographs show that the evaporation at lower background pressure from 10-7 to 10-8 mm Hg makes the tin granules more separate (they are connected to one another by narrow bridges) and that the evaporation with lower substrate temperature makes tin granules smaller. The films having high responsivity are obtained under the condition that the background pressure is 10-4--10-5 mm Hg and the substrate temperature is lowered about 10 K from room temperature. The responsivity values obtained are 9 x 106 V/W at 10 GHz and 270 V/W at 891 GHz

1981-01-01

128

Method of lightening radiation darkened optical elements  

Energy Technology Data Exchange (ETDEWEB)

A method of lightening a radiation-darkened optical element in wich visible optical energy or electromagnetic radiation having a wavelength in the range of from about 2000 to about 20,000 angstroms is directed into the radiation-darkened optical element; the method may be used to lighten radiation-darkened optical element in-situ during the use of the optical element to transmit data by electronically separating the optical energy from the optical output by frequency filtering, data cooling, or interlacing the optic energy between data intervals.

Reich, Frederich R. (Richland, WA); Schwankoff, Albert R. (W. Richland, WA)

1980-01-01

129

Statistical methods in radiation physics  

CERN Multimedia

This statistics textbook, with particular emphasis on radiation protection and dosimetry, deals with statistical solutions to problems inherent in health physics measurements and decision making. The authors begin with a description of our current understanding of the statistical nature of physical processes at the atomic level, including radioactive decay and interactions of radiation with matter. Examples are taken from problems encountered in health physics, and the material is presented such that health physicists and most other nuclear professionals will more readily understand the application of statistical principles in the familiar context of the examples. Problems are presented at the end of each chapter, with solutions to selected problems provided online. In addition, numerous worked examples are included throughout the text.

Turner, James E; Bogard, James S

130

Radiation detection and diagnosis of breast cancer  

International Nuclear Information System (INIS)

The value of mammography in the symptomatic patient has been adequately documented, but its use as a detection procedure remains a question. Risk-benefit ratios, based primarily upon the study carried out by the Health Insurance Plan of Greater New York, have suggested that the technique has little value in individuals under age 50. Emphasis has been placed upon the possible carcinogenic effects of radiation as compared with the efficacy of mammography and the questionable influence of early diagnosis upon end results. Although technical advances have substantially reduced the exposure of the patient to radiation, the possibility of significant information loss as the result of these developments has been considered a potential drawback to their routine use. All of these factors have served to diminish both public and professional acceptance of the examination. Although current data do not allow complete resolution of these problems, certain conclusions may be drawn and trends established. The sum of these may indicate that minimal dose mammography is an accurate, low-risk procedure, capable of significantly altering the natural history of breast cancer. Whether or not the examination should be routinely used in women under age 50 remains open to question since the lack of experimental controls prohibits validation of the technique in terms of reduced mortality rates. Documentation of increased survival rates may partially assist in the established of a reliable risk-benefit ratio, but will not satisfy the statistical requirements of eliminating lead-bias, and self-selection. These questions may be resolved by studies now underway

1981-04-01

131

Particle and photon detection for a neutron radiative decay experiment  

International Nuclear Information System (INIS)

We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons and protons are guided by a 4.6 T magnetic field and detected by a silicon surface barrier detector. Photons with energies between 15 and 750 keV are registered by a detector consisting of a bismuth germanate scintillator coupled to a large area avalanche photodiode. The photon detector operates at a temperature near 80 K in the bore of a superconducting magnet. We discuss CsI as an alternative scintillator, and avalanche photodiodes for direct detection of photons in the 0.1-10 keV range

2007-08-21

132

Detection of radiation in radiographic apparatus  

International Nuclear Information System (INIS)

An apparatus for examining bodies by means of penetrating radiation such as x- or ?-radiation is described. The radiation is directed toward the body in a sectoral-shaped swath and the radiation emergent from the body is collected by detector devices. Each device comprises a scintillator crystal which is arranged to respond to the receipt of the radiation by emitting visible light. The devices are irradiated simultaneously and then interrogated in sequence so that the light emitted by respective ones of the devices, which is in each case indicative of the amount of radiation incident thereon, can be identified as to its origin. 8 claims, 5 drawing figures

1976-01-01

133

Multi-spectral schottky barrier infrared radiation detection array  

Energy Technology Data Exchange (ETDEWEB)

A multi-spectral Schottky barrier infrared detector array in which individual pixels of radiation from a remote radiating object are detected by two or more Schottky barrier infrared radiation detectors each having a different spectral response so as to provide a ''color'' discrimination for the array.

Foss, N.A.

1983-12-27

134

Multi-spectral schottky barrier infrared radiation detection array  

International Nuclear Information System (INIS)

A multi-spectral Schottky barrier infrared detector array in which individual pixels of radiation from a remote radiating object are detected by two or more Schottky barrier infrared radiation detectors each having a different spectral response so as to provide a ''color'' discrimination for the array

1983-01-01

135

Detection of food irradiation with luminescence methods  

International Nuclear Information System (INIS)

Food irradiation is applied as method for the preservation of foods, the prevention of food spoilage and the inhibition of food-borne pathogens. Doses exceeding 10 kGy (10 kJ/kg) are not recommended by the WHO. The different legislation requires methods for the detection and the closimetry of irradiated foods. Among the physical methods based on the radiation-induced changes in inorganic, nonhygroscopic crystalline solids are thermoluminescence (TL), photostimulated luminescence (PSL) and lyoluminescence (LL) measurement. The luminescence methods were tested on natural minerals. Pure quartz, feldspars, calcite, aragonite and dolomite of known origin were irradiated, read out and analyzed to determine the influence of luminescence-activators and deactivators. Carbonate minerals show an orange-red TL easily detectable by blue-sensitive photomultiplier tubes. TIL-inactive carbonate samples may be identified by a lyoluminescence method using the reaction of trapped irradiation-generated charge carriers with the solvent during crystal-lattice breakup. The fine-ground mineral is dissolved in an alkaline complexing agent/chemiluminescence sensitizer/chemiluminescence catalyst (EDTA/luminol/hemin) reagent mixture. The TL and PSL of quartz is too weak to contribute a significant part for the corresponding signals in polymineral dust. Alkali and soda feldspar show intense TL and PSL. The temperature maxima in the TL glow curves allow a clear distinction. PSL does not give this additional information, it suffers from bleaching by ambient light and requires light-protection. Grain disinfestated with low irradiation doses (500 Gy) may not identified by both TL and PSL measurement. The natural TL of feldspar particles may be overlap with the irradiation-induced TL of other minerals. As a routine method, irradiated spices are identified with TL measurement. The dust particles have to be enriched by heavy-liquid flotation and centrifugation. The PSL method allows a clear identification of irradiated spices. The detection of irradiated seafood (mollusks and crustaceans) with TL is only possible for calcitic shells. The EDTA-luminol lyoluminescence is applicable for both calcitic and aragonitic shells, calcitic, amorphous and partially hydroxyapatitic crustacean molts, and poultry bones. The application of chemical methods is much more susceptible to errors.The high-performance liquid chromatography-determination of ortho- and metatyrosine in low-fat poultry and shrimp meat did not allow any positive identification of irradiated samples. (author)

1997-01-01

136

Study of Imaging Plate Radiation Detection Characterization  

International Nuclear Information System (INIS)

Full text: Imaging plate (IP) is an ionizing radiation detector using a photo-stimulated luminescent (PSL) phosphor (BaFBr:Eu2+) crystal. Radiation source for the imaging plate study were Eu-152, S-35 and Am-241 for gamma ray, beta ray and X ray source respectively. Characteristics of photo-stimulated luminescent of IP, such as radiation sensitivity, PSL fading and radiation backscattering of Fuji BAS-MS IP signal were investigated using an IP reader. The PSL signal intensity of IP was proportional to the radiation dose. The exposed IP signal faded away rather quickly as time elapsed

2011-06-06

137

FACE DETECTION USING EIGEN METHOD  

Directory of Open Access Journals (Sweden)

Full Text Available As continual research is being conducted in the area of computer vision, one of the most practical applications under vigorous development is in the construction of a robust face detection system. While the problem of detecting faces under various variations remains largely unsolved, a demonstration system as proof of concept that such systems are now becoming practical have been developed. A system capable of reliable detection, with reduced constraints in regards to the position and orientation of the face and the illumination and background of the image, has been implemented. Those face detection system is based upon “eigenfaces”, which has been separated into three major modules – pre-processing, construction of face space and face localization. A completely robust real-time face detectionsystem is still under heavy investigation and development, the implemented systems are still serving as an extendable foundation for future research.

HASHAAM NAEEM

2012-03-01

138

Detection of radiation-induced changes in electrochemical properties of austenitic stainless steels using miniaturized specimens and the single-loop electrochemical potentiokinetic reactivation method  

Energy Technology Data Exchange (ETDEWEB)

Single-loop electrochemical potentiokinetic reactivation testing of miniaturized (TEM) specimens can provide reliable data comparable to data obtained with larger specimens. Significant changes in electrochemical properties (increased reactivation current and Flade potential) were detected for PCA and type 316 stainless steels irradiated at 200--420{degrees}C up to 7--9 dpa. Irradiations in the FFTF Materials Open Test Assembly and in the Oak Ridge Research Reactor are reported on. 45 figs., 5 tabs., 52 refs.

Inazumi, T.; Bell, G.E.C.; Kenik, E.A.; Kiuchi, K.

1993-01-01

139

Detection of radiation-induced changes in electrochemical properties of austenitic stainless steels using miniaturized specimens and the single-loop electrochemical potentiokinetic reactivation method  

Energy Technology Data Exchange (ETDEWEB)

Single-loop electrochemical potentiokinetic reactivation testing of miniaturized (TEM) specimens can provide reliable data comparable to data obtained with larger specimens. Significant changes in electrochemical properties (increased reactivation current and Flade potential) were detected for PCA and type 316 stainless steels irradiated at 200--420[degrees]C up to 7--9 dpa. Irradiations in the FFTF Materials Open Test Assembly and in the Oak Ridge Research Reactor are reported on. 45 figs., 5 tabs., 52 refs.

Inazumi, T.; Bell, G.E.C.; Kenik, E.A.; Kiuchi, K.

1993-01-01

140

Reducing waste generation and radiation exposure by analytical method modification  

International Nuclear Information System (INIS)

The primary goal of an analytical support laboratory has traditionally been to provide accurate data in a timely and cost effective fashion. Added to this goal is now the need to provide the same high quality data while generating as little waste as possible. At the Savannah River Technology Center (SRTC), we have modified and reengineered several methods to decrease generated waste and hence reduce radiation exposure. These method changes involved improving detection limits (which decreased the amount of sample required for analysis), decreasing reaction and analysis time, decreasing the size of experimental set-ups, recycling spent solvent and reagents, and replacing some methods. These changes had the additional benefits of reducing employee radiation exposure and exposure to hazardous chemicals. In all cases, the precision, accuracy, and detection limits were equal to or better than the replaced method. Most of the changes required little or no expenditure of funds. This paper describes these changes and discusses some of their applications

1996-07-22

 
 
 
 
141

Evaluation of Gamma Radiation Field By Response Matrix Method  

International Nuclear Information System (INIS)

Application of response matrix method for evaluating gamma radiation field in the vicinity of nuclear facilities measured with a NaI(TI) gamma spectrometer is briefly described. Some evaluation results on the elevated exposure in the vicinity of the Radioisotope Production Center and in the RSG-GAS building, as well as concentrations determination of 238U, 232Th, and 40K in the environment are presented. The elevated exposure due to the activity of the Radiation Production Center as low as 0.54 uR/hour could be detected properly by using the response matrix method

1996-08-20

142

Compositions and Methods for Detecting Treponema Pallidum.  

Science.gov (United States)

Methods for the specific and highly sensitive detection of Treponema pallidum infection comprising the use of specific antigenic proteins and peptides unique to Treponema pallidum are provided. In particular, detection assays based recognition of acidic r...

B. Rodes B. M. Steiner H. Liu

2001-01-01

143

Methods of in vivo radiation measurement  

Energy Technology Data Exchange (ETDEWEB)

Methods of and apparatus for in vivo radiation measurements relay on a MOSFET dosimeter of high radiation sensitivity with operates in both the passive mode to provide an integrated dose detector and active mode to provide an irradiation rate detector. A compensating circuit with a matched unirradiated MOSFET is provided to operate at a current designed to eliminate temperature dependence of the device. Preferably, the MOSFET is rigidly mounted in the end of a miniature catheter and the catheter is implanted in the patient proximate the radiation source.

Huffman, Dennis D. (Albuquerque, NM); Hughes, Robert C. (Albuquerque, NM); Kelsey, Charles A. (Albuquerque, NM); Lane, Richard (Galveston, TX); Ricco, Antonio J. (Albuquerque, NM); Snelling, Jay B. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

1990-01-01

144

Terahertz and Mid Infrared Radiation Generation, Detection and Applications  

CERN Document Server

Terahertz (THz) and Mid-Infrared (MIR) radiation  (TERA-MIR) can be transmitted through nearly any material without causing biological harm. Novel and rapid methods of detection can be created with devices operation in these spectral ranges allowing scanning for weapons, detecting hidden explosives (including plastic landmines), controlling the quality of food and a host of other exciting applications.  This book focuses on mathematical and physical aspects of the field, on unifying these two spectral domains (THz and MIR) with regard to common sources, detectors, materials and applications, and on key interdisciplinary topics. The main THz and MIR source is the quantum cascade laser (QCL). Thus significant attention is paid to the challenge of turning this advanced technology into affordable commercial devices so as to exploit its enormous potential. However other alternatives to THz QCLs are also presented, e.g.  sub-terahertz imaging from avalanching GaAs bipolar transistors, Josephson junctions as THz ...

Pereira, Mauro F

2011-01-01

145

Method of failed fuel detection  

International Nuclear Information System (INIS)

Object: To detect with high precision the damage caused to a fuel assembly in a light-water type nuclear reactor by sampling the coolant by means of a water rod provided within the fuel assembly. Structure: A sample extracting tube and a connecting tube are coupled together by a ball joint. Pressurized fluid is supplied to a water rod provided within the fuel assembly and connected to the sample extracting tube by opening a check valve, and it is caused to issue from a number of small holes formed in the peripheral wall of the water rod and agitate the coolant within a channel box in the fuel assembly, and then the agitated coolant is sampled by producing negative pressure within the sampling tube for detecting the concentration of fission products. In this way, damage to a fuel rod within the fuel assembly at any position thereof can be detected with high precision. (Kamimura, M.)

1974-01-01

146

Radiation and Nuclear Materials Detection Research and Development at ORNL  

International Nuclear Information System (INIS)

Research and development is underway to improve radiation and nuclear detection capabilities. This research and development in radiation and nuclear detection includes areas such as advanced materials, applied research and engineering for designing and fabricating customized detection equipment, and theoretical modeling and computational support. Oak Ridge National Laboratory (ORNL) has a distinctive set of detector materials fabrication and characterization capabilities and recently created a Center for Radiation Detection Materials and Systems. Applied research and engineering efforts have led to the development of improved detectors for specific applications including safeguards, treaty monitoring, and science experiments. All sizes, types, and capabilities of detector systems have been addressed from miniature to man-portable and from neutrons to gamma radiation. Dedicated test beds, in-house and in the field, have been established to analyze, characterize, and improve detection systems.

2007-09-16

147

RADIATION and NUCLEAR MATERIALS DETECTION RESEARCH AND DEVELOPMENT AT ORNL  

International Nuclear Information System (INIS)

Research and development is underway to improve radiation and nuclear detection capabilities. This research and development in radiation and nuclear detection includes areas such as advanced materials, applied research and engineering for designing and fabricating customized detection equipment, and theoretical modeling and computational support. Oak Ridge National Laboratory (ORNL) has a distinctive set of detector materials fabrication and characterization capabilities and recently created a Center for Radiation Detection Materials and Systems. Applied research and engineering efforts have led to the development of improved detectors for specific applications including safeguards, treaty monitoring, and science experiments. All sizes, types, and capabilities of detector systems have been addressed from miniature to man-portable and from neutrons to gamma radiation. Dedicated test beds, in-house and in the field, have been established to analyze, characterize, and improve detection systems

2007-09-16

148

Crystallization method employing microwave radiation  

International Nuclear Information System (INIS)

This invention relates to a method of crystallizing materials from aqueous crystallization media. Zeolite materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline metallosilicates having a definite crystalline structure as determined by X-ray diffraction within which there are a number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolite material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of large dimensions, these materials have come to be known as molecular sieves and are utilized in a variety of ways to take advantage of these properties. (author). 3 tabs

1988-09-08

149

FY05 LDRD Final ReportNanomaterials for Radiation Detection  

Energy Technology Data Exchange (ETDEWEB)

We have demonstrated that it is possible to enhance current radiation detection capability by manipulating the materials at the nano level. Fabrication of three-dimensional (3-D) nanomaterial composite for radiation detection has great potential benefits over current semiconductor- and scintillation-based technologies because of the precise control of material-radiation interaction and modulation of signal output. It is also a significant leap beyond current 2-D nanotechnology. Moreover, since we are building the materials using a combination of top-down and bottom-up approaches, this strategy to make radiation detection materials can provide significant improvement to radiation-detection technologies, which are currently based on difficult-to-control bulk crystal growth techniques. We are applying this strategy to tackle two important areas in radiation detection: gamma-rays and neutrons. In gamma-ray detection, our first goal is to employ nanomaterials in the form of quantum-dot-based mixed matrices or nanoporous semiconductors to achieve scintillation output several times over that from NaI(Tl) crystals. In neutron detection, we are constructing a 3-D structure using a doped nanowire ''forest'' supported by a boron matrix and evaluating the detection efficiency of different device geometry with simulation.

Wang, T F; Letant, S E; Nikolic, R J; Chueng, C L

2006-02-06

150

Feasibility of fiber-optic radiation sensor using Cerenkov effect for detecting thermal neutrons.  

Science.gov (United States)

In this research, we propose a novel method for detecting thermal neutrons with a fiber-optic radiation sensor using the Cerenkov effect. We fabricate a fiber-optic radiation sensor that detects thermal neutrons with a Gd-foil, a rutile crystal, and a plastic optical fiber. The relationship between the fluxes of electrons inducing Cerenkov radiation in the sensor probe of the fiber-optic radiation sensor and thermal neutron fluxes is determined using the Monte Carlo N-particle transport code simulations. To evaluate the fiber-optic radiation sensor, the Cerenkov radiation generated in the fiber-optic radiation sensor by irradiation of pure thermal neutron beams is measured according to the depths of polyethylene. PMID:23787645

Jang, Kyoung Won; Yagi, Takahiro; Pyeon, Cheol Ho; Yoo, Wook Jae; Shin, Sang Hun; Misawa, Tsuyoshi; Lee, Bongsoo

2013-06-17

151

Leak detection by vibrational diagnostic methods  

International Nuclear Information System (INIS)

The possibilities and methods of leak detection due to mechanical failures in nuclear power plants are reviewed on the basis of the literature. Great importance is attributed to vibrational diagnostic methods for their adventageous characteristics which enable them to become final leak detecting methods. The problems of noise analysis, e.g. leak detection by impact sound measurements, probe characteristics, gain problems, probe selection, off-line analysis and correlation functions, types of leak noises etc. are summarized. Leak detection based on noise analysis can be installed additionally to power plants. Its maintenance and testing is simple. On the other hand, it requires special training and measuring methods. (Sz.J.)

1983-01-01

152

Luminophor for detecting near-IR radiation  

International Nuclear Information System (INIS)

One of the basic characteristics of a luminophor, which is important for practical applications, is its sensitivity to IR radiation, defined as the magnitude of the change in the brightness of the luminescence of the luminophor under the effect of a unit density of radiation power. This paper develops new sensitive crystal phosphors which convert infrared radiation into visible radiation at wavelengths in the range 0.8-1.7 microm. It is proposed that the rare-earth element Yb, emitting in the nonvisible region of the spectrum in the wavelength range 0.8-1.2 microm, be used as the second activator. The authors synthesized luminophors based on the systems Zns, CdS-Cu, Yb, and Co with different concentration of impurity centers and different ratio of the components of the base in order to obtain a luminophor with maximum sensitivity

1986-09-01

153

Frontal Face Detection Methods –Neural Networks and Aggressive Learning Algorithm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this research work, a face detection method is presented. Face detection is the first step of face Recognition methods. Face detection is a difficult task in Pattern. There are different methods of face detection namely-Knowledge Based Face Detection Methods, Feature Based Face Detection Methods, Template Based Face Detection Methods and Appearnce Based Face Detection Methods. But here we divided basically in two methods for face detection (i) image based methods (ii) feature based methods...

2011-01-01

154

Detection of the strange bodies on the conveyor belt using gamma radiation technique  

International Nuclear Information System (INIS)

The aim of this paper is to present a method for the computation of the activity of a gamma radiation source used in a radiometric assembly designed to detect the strange bodies (iron, stone or wood-made granules) within the textile material on the conveyor belt. The mathematical modelling method based on the Monte Carlo procedure has been used, with different values of the errors of types I and II; the investigation method is the transmission of gamma radiations. (Author)

1990-01-01

155

Nuclear method for materials investigation: Rayleigh scattering of Moessbauer radiation  

International Nuclear Information System (INIS)

In many respects the experiments of Moessbauer radiation Rayleigh scattering are similar to X radiation diffraction experiments. The essential difference consists in possibility of detecting and measuring energy variations as low as 108- 10-9 eV in the scattered radiation by using an adequate nuclear absorbent. If prior to detection the recoil-less radiation emitted by a Moessbauer source encounters a scatterer, due to inelasticity of interaction, a change in the resonant absorption occurs. The Moessbauer linewidth is the main parameter determining the method resolution. From the study of the inelastic component, resulting from incident radiation interaction with the lattice phonons, one can obtain information regarding the motion of scatterer atoms. It is worth mentioning that the sensitivity of this method extends beyond those of neutron quasi-elastic scattering (??10-5 eV). It appears to be an evolutionary step forward of the traditional X ray spectroscopy toward resolutions typical to Moessbauer experiments (??10-8 eV). The experimental setup for measuring the Rayleigh scattered Moessbauer radiation consists in a goniometer, a Moessbauer spectrometer and a computer, ensuring the system control as well as the data acquisition and processing. A layout of the system is presented. Performances of the system were tested on two different crystals, LiF(200) and C(002). In contrast to other experimental systems reported in literature, this system allows smaller horizontal spreads, adjustable between 0.5 deg and 2.8 deg, and Moessbauer sources of lower intensity. Plots for diffraction spectra of the Moessbauer radiation scattered on C(002) crystal are shown, as well as the nuclear resonance absorption spectrum of the Moessbauer radiation scattered from the LiF(200) crystal oriented at ?Bragg=12.365 deg

2001-07-13

156

Detection of nonthermal continuum radiation in Saturn's magnetosphere  

International Nuclear Information System (INIS)

A detailed analysis of high resolution wideband data from the Voyager 1 and 2 plasma wave receivers has revealed the presence of heretofore undiscovered nonthermal continuum radiation trapped within the Saturnian magnetosphere. The discovery of Saturnian trapped continuum radiation fills a disturbing void in the Saturnian radio spectrum. On the basis of observations at both the Earth and Jupiter it was expected that continuum radiation should be a pervasive signature of planetary magnetospheres in general. Special processing of the Voyager 1 plasma wave data at Saturn has now confirmed the existence of weak emissions that have a spectrum characteristic of trapped continuum radiation. Similar radiation was also detected by Voyager 2; however, in this case it is not certain that Saturn was the only source. Considerable evidence exists which suggests that Saturn may have been immersed in the Jovian tail during the Voyager 2 encounter, so that Jupiter may provide an additional source of the continuum radiation detected by Voyager 2

1982-01-01

157

Method for Detecting and Managing Nematode Population.  

Science.gov (United States)

The present invention is directed to methods and apparatus for pest management using remote sensing technology. One aspect of the present invention relates to a method for detecting plant-parasitic nematodes using hyperspectral reflectance data. Another a...

A. T. Kelley G. W. Lawrence J. Vickery R. King

2005-01-01

158

Evaluation of various boar taint detection methods.  

Science.gov (United States)

The aim of this study was to evaluate the performance of various boar taint detection methods, measure the relationship between them and identify possible points of improvement for boar taint detection. The methods used to evaluate boar taint in the carcasses of 448 entire male pigs and 17 barrows were the hot iron method (n = 442), a standardised (n = 323) and home (n = 58) consumer meat-evaluation panel, an expert panel assessment of meat and fat (n = 464) and laboratory analysis of skatole, androstenone and indole in fat (n = 464). The axillary odour of a number of slaughtered entire male pigs was also investigated (n = 231). As correlation coefficients were generally weak, a positive result for one of these detection methods did not per se result in a positive result for all other methods. Results of one detection method could not be generalised. The choice to use one or more detection methods deserves consideration depending on the aim of the study. In this paper, we suggest some possible improvements for evaluating boar taint with a consumer panel based on our results and experience. The home consumer evaluation was correlated with the concentration of indole (r = 0.27) but not with skatole or androstenone. We therefore recommend that lab analyses include indole testing. The hot iron method seems to be an easy and fast detection method, which yields comparable or better correlation coefficients with the other detection methods than an expert panel evaluating fat samples. However, the reliability of the hot iron method depends on the training and reliability of one or two assessors. Efforts should be made to further optimise this method by evaluating the effect of testing conditions. The axillary odour score was moderately correlated with the other detection methods (up to 0.32). More research is needed to evaluate the possibilities of axillary odour as a boar taint detection method. PMID:22717070

Aluwé, M; Tuyttens, F A M; Bekaert, K M; De Smet, S; De Brabander, D L; Millet, S

2012-11-01

159

Statistical Studies on Sequential Probability Ratio Test for Radiation Detection  

International Nuclear Information System (INIS)

A Sequential Probability Ratio Test (SPRT) algorithm helps to increase the reliability and speed of radiation detection. This algorithm is further improved to reduce spatial gap and false alarm. SPRT, using Last-in-First-Elected-Last-Out (LIFELO) technique, reduces the error between the radiation measured and resultant alarm. Statistical analysis determines the reduction of spatial error and false alarm

2007-06-25

160

Small Teleoperated Robot for Nuclear Radiation and Chemical Leak Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In order to meet the actual requirements of nuclear radiation and chemical leak detection, and emergency response, a new small teleoperated robot for nuclear radiation and chemical detection is proposed. A small?size robot is manufactured according to technical requirements and the overall structure and control system is described. Meanwhile, based on the principles of human?robot interaction, a user?friendly human?robot interaction interface is designed to provide a good telepresence...

2012-01-01

 
 
 
 
161

Separation methods of TLD dose compoments for environmental radiation monitoring  

Energy Technology Data Exchange (ETDEWEB)

By using Pb shield of 10 cm thick, new methods were developed to estimate each components of environmental radiation doses measured with CaSO[sub 4]:Tm thermoluminescence dosemeter (TLD-UD 200S). These methods aimed at estimating the air absorbed dose increment due to radioactive materials in the atmosphere or downward radiations released from nuclear facilities. As a preliminary step for the application to detect small dose increments, TLDs preirradiated by 2.2, 3.6 and 7.2 [mu]Gy with a [sup 60]Co source were placed at a location of which background level was 55.5 nGy h[sup -1]. Performance of the TLD system seems to be satisfactory for the practical use since discrepancy between estimated and given doses was less than 30% for a given dose increment of 7.2 [mu]Gy. The responses of the TLDs to cosmic and natural gamma radiations were also investigated with various dosimetric methods. It was found that the responses of the TLDs to natural gamma radiations are in agreement with those inferred from other methods, but their responses to cosmic radiation were definitely lower. (author).

Akhmad, Y.R.; Ikebe, Yukimasa; Iida, Takao (Nagoya Univ. (Japan). Dept. of Nuclear Engineering); Shimo, Michikuni; Obayashi, Haruo; Sakuma, Youichi; Yamanishi, Hirokuni; Kodaira, Jun-ichi

1994-12-01

162

Separation methods of TLD dose compoments for environmental radiation monitoring  

International Nuclear Information System (INIS)

By using Pb shield of 10 cm thick, new methods were developed to estimate each components of environmental radiation doses measured with CaSO4:Tm thermoluminescence dosemeter (TLD-UD 200S). These methods aimed at estimating the air absorbed dose increment due to radioactive materials in the atmosphere or downward radiations released from nuclear facilities. As a preliminary step for the application to detect small dose increments, TLDs preirradiated by 2.2, 3.6 and 7.2 ?Gy with a 60Co source were placed at a location of which background level was 55.5 nGy h-1. Performance of the TLD system seems to be satisfactory for the practical use since discrepancy between estimated and given doses was less than 30% for a given dose increment of 7.2 ?Gy. The responses of the TLDs to cosmic and natural gamma radiations were also investigated with various dosimetric methods. It was found that the responses of the TLDs to natural gamma radiations are in agreement with those inferred from other methods, but their responses to cosmic radiation were definitely lower. (author)

1994-12-01

163

Detection of irradiated pulses by PSL method  

International Nuclear Information System (INIS)

Photostimulated luminescence (PSL) as a screening method is very simple and rapid to detect irradiated foods but various disadvantages (light induced fading of PSL signal or response to clean foods with minerals insensitive to PSL measurement). In this study the characteristics of radiation induced PSL for 10 kinds of pulses (Chinese Soybean and Adzuki bean, Pinto bean, Cowpea, Green gram, Canadian Blue pea and Soybean, American Black-eyed pea and Chickpea, Red Kidney Bean) were investigated. The screening-PSL (s-PSL) cumulate counts of pulses significantly increased with irradiation dose up to 3 kGy. The s-PSL cumulate counts of irradiated pulses gradually decreased with increasing storage periods. The s-PSL cumulate counts of all pulse samples irradiated at a minimum dose of 0.5kGy exceeded considerably the upper screening threshold (5000 counts) regardless of storage period. Calibrated PSL (Cal-PSL) were obtained by re-irradiating the pulse samples with a gamma ray dose of 1 kGy and the PSL ratios (s-PSL/Cal-PSL) were calculated for normalization of sensitivity of the pulse samples. The PSL ratio at each irradiation dose was almost similar regardless of kind of pulses. (author)

2011-09-01

164

Biological methods for marine toxin detection.  

Science.gov (United States)

The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in the legislations of many countries. Most marine toxin groups are detected by animal bioassays worldwide. Although this method has well known ethical and technical drawbacks, it is the official detection method for all regulated phycotoxins except domoic acid. Much effort by the scientific and regulatory communities has been focused on the development of alternative techniques that enable the substitution or reduction of bioassays; some of these have recently been included in the official detection method list. During the last two decades several biological methods including use of biosensors have been adapted for detection of marine toxins. The main advances in marine toxin detection using this kind of technique are reviewed. Biological methods offer interesting possibilities for reduction of the number of biosassays and a very promising future of new developments. PMID:20458470

Vilariño, Natalia; Louzao, M Carmen; Vieytes, Mercedes R; Botana, Luis M

2010-07-01

165

Control volume finite element method for radiation  

International Nuclear Information System (INIS)

In this paper a new methodology is presented by the authors for the numerical treatment of radiative heat transfer in emitting, absorbing and scattering media. This methodology is based on the utilisation of Control Volume Finite Element Method (CVFEM) and the use, for the first time, of matrix formulation of the discretized Radiative Transfer Equation (RTE). The advantages of the proposed methodology is to avoid problems that confronted when previous techniques are used to predict radiative heat transfer, essentially, in complex geometries and when there is scattering and/or non-black boundaries surfaces. Besides, the new formulation of the discretized RTE presented in this paper makes it possible to solve the algebraic system by direct or iterative numerical methods. The theoretical background of CVFEM and matrix formulation is presented in the text. The proposed technique is applied to different test problems, and the results compared favourably against other published works. Moreover this paper discusses in detail the effects of some radiative parameters, such as optical thickness and walls emissivities on the spatial evolution of the radiant heat flux. The numerical simulation of radiative heat transfer for different cases using the algorithm proposed in this work has shown that the developed computer procedure needs an accurate CPU time and is exempt of any numerical oscillations

2005-04-15

166

Radiation transport calculation methods in BNCT  

International Nuclear Information System (INIS)

Boron neutron capture therapy (BNCT) is used as a radiotherapy for malignant brain tumours. Radiation dose distribution is necessary to determine individually for each patient. Radiation transport and dose distribution calculations in BNCT are more complicated than in conventional radiotherapy. Total dose in BNCT consists of several different dose components. The most important dose component for tumour control is therapeutic boron dose DB. The other dose components are gamma dose Dg, incident fast neutron dose Dfastn and nitrogen dose DN. Total dose is a weighted sum of the dose components. Calculation of neutron and photon flux is a complex problem and requires numerical methods, i.e. deterministic or stochastic simulation methods. Deterministic methods are based on the numerical solution of Boltzmann transport equation. Such are discrete ordinates (SN) and spherical harmonics (PN) methods. The stochastic simulation method for calculation of radiation transport is known as Monte Carlo method. In the deterministic methods the spatial geometry is partitioned into mesh elements. In SN method angular integrals of the transport equation are replaced with weighted sums over a set of discrete angular directions. Flux is calculated iteratively for all these mesh elements and for each discrete direction. Discrete ordinates transport codes used in the dosimetric calculations are ANISN, DORT and TORT. In PN method a Legendre expansion for angular flux is used instead of discrete direction fluxes, land the angular dependency comes a property of vector function space itself. Thus, only spatial iterations are required for resulting equations. A novel radiation transport code based on PN method and tree-multigrid technique (TMG) has been developed at VTT (Technical Research Centre of Finland). Monte Carlo method solves the radiation transport by randomly selecting neutrons and photons from a prespecified boundary source and following the histories of selected particles through the geometry. MCNP is a well-known Monte Carlo based computer code that has been used to dosimetric comparison and to study thermal part of neutron energy spectrum. In clinical BNCT dose planning only Monte Carlo based computer codes have been used, such as BNCTRtpe/MCrtt, SERA and NCTPLAN. However, Monte Carlo methods are extremely time consuming. Deterministic methods like TMG would be significantly more effective, especially with improved mesh resolution (author)

2000-03-09

167

Intracavity methods for enhancing laser radiation directivity  

Energy Technology Data Exchange (ETDEWEB)

A systematic review of intracavity methods for improving laser-radiation directivity is presented. Attention is given to methods for the direct improvement of the laser directivity pattern; the prospects of transforming the laser emission into a single-mode beam; and wavefront control. The feasibility of creating solid-state laser with a nearly diffractive directivity at mean powers up to several hundred watts is demonstrated. 28 refs.

Liubimov, V.V.

1990-12-01

168

Crosslinking by Gamma Radiation Uniform Irradiation Method  

International Nuclear Information System (INIS)

With crosslinking it is possible to strengthen the physical properties of thermoplastics such as heat resistance and resistance to other decomposing effects. Crosslinking can be achieved either by chemical methods or using high energy ionizing radiation. In this paper, dosimetry and irradiation methods which are used in crosslinking process of 16 mm radius polietilen under- floor heating pipes are explained. Radiation crosslinkable polietilen pipes of 140-160 meter coils in packed form are under nitrogen. Radiation process takes place in tote boxes where in each tote 4 coils of pipes are placed. In each cycle product absorbs 30 kGy of dose and the total number of cycle varies between 4-4.5 depending on the density .In every two cycles the locations of coils are changed in tote boxes in order to achieve more uniform dose distribution. We found that in the dose range of 130 -140 kGy it is possible to achieve 60 % crosslinking level for this type of pipes manufactured by different companies. Normally in our automatic tote box gamma radiation plant the difference between maximum and minimum dose is 40 %. However thanks to this method this ratio is lowered to 13 %. As a result, the maximum dose of 180 kGy is reduced to the range of 150 kGy that caused a reduction in chain scission effect in molecules

2006-09-23

169

A Fault Detection Method for Reversible Circuits  

Directory of Open Access Journals (Sweden)

Full Text Available This paper represents a redundancy based mechanism for fault detection in reversiblecircuits. In this method reversible circuit has been duplicated for fault detection. This duplication isbased on self complementary feature of reversible circuits. We have used a fully redundant circuitand a comparator for the purpose fault detection. In order to analyze the proposed method, singleand double faults have been investigated in the following four cases: fault tolerant comparator andsingle fault, non-fault tolerant comparator and single fault, fault tolerant comparator and doublefault, non-fault tolerant comparator and double fault. The results show that the proposed techniqueoffers 100%, 83%, 75% and 64% of fault detection respectively.

Maryam Barshan

2011-09-01

170

Rapid methods for detection of bacteria  

DEFF Research Database (Denmark)

Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods: Measurements of Adosine Triphosphate and BactiQuantTM have shown promising results as new monitoring tools, which gives the result within minutes/hours.

Corfitzen, Charlotte B.; Andersen, B.Ã?.

2006-01-01

171

Spectral analysis method for detecting an element  

Science.gov (United States)

A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

2008-02-12

172

A Study on Radiation Detection by Using Optical Fibers  

International Nuclear Information System (INIS)

Optical fiber have been investigated for their potential use as sensor material in various nuclear applications. Several new methods of radiation measurement are being developed using recent optical techniques. Comprehensive overviews of their potential use in nuclear environments can be found in measuring temperature, pressure, void fraction and corrosion in nuclear systems. Optical fibers doped with scintillating components in the core have drawn special interests as potential use for radiation detection. As a radiation detector, a scintillating optical fiber can function for dual purpose: scintillator and light transmitter. When a radiation interacts with the core material, scintillator occurs and the resultant light is transmitted through the fiber to an optoelectronic devices such as a photomultiplier tube. Optical fiber sensors have proven to present several advantages as compared to other conventional sensors. They can be processed very small size and light enough to be easily put into very narrow channels such as between nuclear fuel rods. No electrical power is needed to the sensor part so they are less susceptible to trouble in harsh environments such as underground and underwater. Optical fiber sensor cost relatively cheap to make them more suitable for a multi-point distribution radiation monitoring which can be applied in such as nuclear reactors, accelerators, fusion study facilities. Much effort has been exerted on applying scintillating optical fibers to develop radiation detectors. This study has been conducted to investigate feasibility of using scintillating optical fibers and [CsI(Tl)] for detection of gamma rays emitted 137Cs and 60Co and beta rays form 90Sr. The sensors are constructed of single-stand or multi-stand fibers of 1mm and 0.5mm diameter. The glass scintillating fibers used contains cerium-activated lithium-silicate material in Levy Hill Lab model GS20, GS30 and the plastic scintillating fiber used are commercially available Bicron model BCF-12. We used a mirror and lens to improve the efficiency of the sensor with collecting multi-stand plastic scintillating fibers and light transmitting fibers were tested its bending loss of their types. In this paper, we report the pulse-hight spectra obtained by using these sensors, and analyze them in the aspect of their usability for radiation detectors. Our investigation suggests that the glass scintillating fibers can be used to develop gamma ray detectors which will function in high and low gamma ray flux environments. Use of the sensor for the beta ray detection was not satisfactory. Multi-strand plastic scintillating fiber sensors work satisfactorily for the weak gamma sources, but did produce somewhat promising results for beta ray sources. The inorganic scintillator[CsI(Tl)] works satisfactorily both gamma ray sources and beta ray sources

2002-01-01

173

Detection of gravitational radiation by using laser interferometer  

International Nuclear Information System (INIS)

Methods of experiments aimed at the detection of gravitational radiation by using laser interferometer is reviewed. There are two types of the interferometer; Michelson type with delay lines and Fabry-Perot type with cavities for resonance. In either case very precise and elaborate control system of effective arm length is indispensable. Various noises on the laser interferometer are studied in detail. Theoretical limit to sensitivity for dimensionless amplitude h is determined by laser shot noise in photodetector. For 100 km of beam path length and 1 Watt of laser power, this sensitivity limit is 10"-"2"1 Hzsup(-1/2). The results of the experiments so far in several laboratories are presented. The sensitivity of the order of h = 10"-"1"8 Hzsup(-1/2) has been obtained. (author)

1985-03-01

174

Underground tank leak detection methods  

Energy Technology Data Exchange (ETDEWEB)

In recent years, the increase in leaks from underground gasoline storage tanks has had a significant adverse environmental impact on the US. Current estimates from government and industry sources are that between 1.5 to 3.5 million underground storage tanks exist in the nation. Estimates of the number of leaking tanks range from 75,000 to 100,000; and 350,000 others may develop leaks within the next five years. The 1983 National Petroleum News Factbook Issue forecasts the existence of approximately 140,000 gasoline service stations in the US at the end of 1983. New York State estimates that 19% of its 83,000 active underground gasoline tanks are now leaking. Maine estimates that 25% of its 1,600 retail gasoline underground tanks are leaking approximately 11 million gallons yearly. In Michigan 39% of ground water contamination incidents are attributed to storage tanks. One of the primary causes of tank leakage is corrosion of the storage tanks. Product loss from leaking tanks may cause an adverse effect on the environment, endanger lives, reduce income, and require the expenditure of millions of dollars for cleanup. To prevent or reduce the adverse effects of gasoline leakage, an accurate method must be used to determine whether or not an underground tank is leaking.

Niaki, Shahzad; Broscious, J.A.

1987-01-01

175

Improved GLR method to instrument failure detection  

Energy Technology Data Exchange (ETDEWEB)

The generalized likehood radio(GLR) method performs statistical tests on the innovations sequence of a Kalman-Buchy filter state estimator for system failure detection and its identification. However, the major drawback of the conventional GLR is to hypothesize particular failure type in each case. In this paper, a method to solve this drawback is proposed. The improved GLR method is applied to a PWR pressurizer and gives successful results in detection and identification of any failure. Furthmore, some benefit on the processing time per each cycle of failure detection and its identification can be accompanied.

Jeong, Hak Yeoung; Chang, Soon Heung

1985-06-01

176

Improved GLR method to instrument failure detection  

International Nuclear Information System (INIS)

The generalized likehood radio(GLR) method performs statistical tests on the innovations sequence of a Kalman-Buchy filter state estimator for system failure detection and its identification. However, the major drawback of the convensional GLR is to hypothesize particular failure type in each case. In this paper, a method to solve this drawback is proposed. The improved GLR method is applied to a PWR pressurizer and gives successful results in detection and identification of any failure. Furthmore, some benefit on the processing time per each cycle of failure detection and its identification can be accompanied. (Author)

1985-01-01

177

GMDD: a database of GMO detection methods  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Since more than one hundred events of genetically modified organisms (GMOs have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. Results GMO Detection method Database (GMDD has collected almost all the previous developed and reported GMOs detection methods, which have been grouped by different strategies (screen-, gene-, construct-, and event-specific, and also provide a user-friendly search service of the detection methods by GMO event name, exogenous gene, or protein information, etc. In this database, users can obtain the sequences of exogenous integration, which will facilitate PCR primers and probes design. Also the information on endogenous genes, certified reference materials, reference molecules, and the validation status of developed methods is included in this database. Furthermore, registered users can also submit new detection methods and sequences to this database, and the newly submitted information will be released soon after being checked. Conclusion GMDD contains comprehensive information of GMO detection methods. The database will make the GMOs analysis much easier.

Guo Rong

2008-06-01

178

Determination of the absolute radiation chemical excited state singlet yield in benzene, using a scintillation detection method for excitation energies between 17.5 and 122 keV  

Science.gov (United States)

The absolute yields of excited states formed in benzene solutions by photons with energy varying from 17.5 to 122 keV were determined using a liquid scintillation method with photopeak detection. Radiation energy was accurately defined by using radioactive sources with mono-energetic ?- or X-ray emission. From these results the absolute yields of excited states in pure benzene, G(B*), were calculated for photon energies of 17.5, 32, 59.5, and 122 keV as respectively 0.98, 1.11, 1.12, and 1.15 (100 eV) -1. The ±2? error limits are ±15% with 95% confidence. These results are discussed in comparison with former determinations, taking their dependence on excitation photon energy, due to track effects, into account. The new results used as reference for fluorescence yields in alkanes, namely decalins, lead to a better agreement between earlier measurements of the efficiencies for excited state formation in the decalins from ion recombination and more recent simulation calculations based on spin correlation.

Luthjens, L. H.; Dorenbos, P.; de Haas, J. T. M.; Hummel, A.; van Eijk, C. W. E.

1999-07-01

179

TROL - Solving the underwater radiation detection enigma  

International Nuclear Information System (INIS)

Designed by Fathoms in consultation with UKAEA, Dounreay, to detect buried radiological particles in ground 50m below the sea surface, TROL (Tracked Remote Offshore Logging) is the world's first tracked robotic system capable of delivering gamma spectroscopy in real-time, the genesis of which developed from Fathoms diving and undersea systems technology. This short article examines how an integrated approach to science and technology can be managed through quality processes to deliver superior solutions. The tracked ROV (Remote Operated Vehicle) is designed specifically to meet the challenging demands of real-time subsea particle detection. Positioning of the vehicle by the ultra-short baseline acoustic system was integrated with the surface support vessel's differential GPS navigation system to produce accurate positions of detected particles. (author)

2005-03-01

180

Novelty and change detection radiation physics experiments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis deals with the detection and analysis of low-level natural and induced radioactivity. Using high energy-resolution Ge detectors in low-level counting areas airborne radioactivity’s like Be-7 and Cs-137 have been investigated. The experimental facilities and techniques are described in some detail. One of the aims in this work is the studying of change detection in the amount of the activity received on the earth from events that happen at the solar system. Information about this...

Jabor, Abbas

2007-01-01

 
 
 
 
181

Edge Detection Using Heuristic Search Methods.  

Science.gov (United States)

The paper presents a method for detecting edges in a digitized picture. The problem of edge detection is reduced to the problem of finding an optimal path in a weighted graph. The properties of the edge are embedded in the structure of the graph. Graph se...

A. Martelli

1972-01-01

182

Edge Detection Using Heurisitic Search Methods.  

Science.gov (United States)

The paper presents a method for detecting edges in a digitized picture. The problem of edge detection is reduced to the problem of finding an optimal path in a weighted graph. The properties of the edge are embeded in the structure of the graph. Graph sea...

A. Martelli

1972-01-01

183

Flare loop radiative hydrodynamics. I - Basic methods  

Science.gov (United States)

The study presented here has two goals. The first is to examine the role of energy transport mechanisms in flare dynamics, for instance, thermal cone conduction in the corona and radiative transfer in the chromosphere. The second is to provide diagnostics of flare energization processes by predicting the evolutionary behavior of concurrent emissions from all regions of the flaring atmosphere. To attain these ends, a numerical method is developed for the simultaneous solution of thy continuity, momentum, and energy equations; the time-dependent atomic rate equations describing ionization and excitation; and the radiative transfer equations. With the physical model and computational methods used here, all components of the plasma move as a single fluid and in the initial studies are assumed to have a common kinetic temperature. The plasma is constrained to move in one dimension along the axis of a loop of nonuniform cross section, the geometry of which is defined by a sufficiently strong magnetic field.

Mcclymont, A. N.; Canfield, R. C.

1983-01-01

184

Product control: improved methods - improved radiation protection?  

International Nuclear Information System (INIS)

Many different kinds of methods and installations are applied to the product control of solidified radioactive waste. Over the years they have been modified, adapted and improved. We will use the processing of cemented waste samples and the determination of the fire point of bitumen samples as examples. We will try to show in detail, how minor changes already have a positive influence on reproducibility, working procedures and practical radiation protection. (orig.)

2005-09-20

185

Detection of atrial myxomas by radionuclide methods  

International Nuclear Information System (INIS)

Two cases of right atrial myxomas and one case of left atrial myxoma detected by radionuclide methods are reported. The value of these methods is discussed, as well as the appropriate techniques to be used: the simple sequential gamma-angiocardiography appears sufficient for the detection of right atrial myxomas, whereas the electrocardiographically gated techniques, especially the gated first-pass, are preferable for the diagnosis of left atrial myxomas

1980-01-01

186

On methods of detection of extraterrestrial life.  

Science.gov (United States)

New methods have been developed for detecting microbial growth from the microflora of desert soils. The first is a polarimetric method in which the fall in optical activity due to assimilation of D-glucose is followed. Detectable changes with desert soils were seen in a few hours, and the method can be employed with small amounts of material. The second method is the release of heat from metabolizable substrates as measured by a microcalorimeter. In the presence of glucose a characteristic response from desert soils was found within 24 hours. PMID:12678119

Imshenetsky, A A; Evdokimova, M D; Sotnikov, G G

1976-01-01

187

An Efficient Method of Small Targets Detection in Low SNR  

International Nuclear Information System (INIS)

In this paper, an efficient method based on nonlinear adaptive filtering is proposed to detect the small IR target of low SNR under the complex background. The morphologic filter can be constructed firstly based on the IR radiation traits of low SNR small targets in the complex background and then a morphological method is used to eliminate the influence of the unbalance background to the image segmentation. Next an algorithm of adaptive threshold segmentation is adopted in order to select the small moving target and the noise points. Finally, on the basis of image sequences, the satisfactory targets detection is accomplished after eliminating wrong point targets. The method presented in this paper can effectively suppress the noise and the air background of the original image, enhance the ability of point target detection in single frame

2006-10-01

188

High sensitivity leak detection method and apparatus  

Energy Technology Data Exchange (ETDEWEB)

An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1.times.10.sup.-18 atm cc sec.sup.-1.

Myneni, Ganapatic R. (Grafton, VA)

1994-01-01

189

CVD diamond films for radiation detection  

International Nuclear Information System (INIS)

Diamond films produced by microwave plasma enhanced chemical vapor deposition (CVD) technique have been used to fabricate radiation detectors. The polycrystalline diamond films have a measured resistivity of 10"1"2 ?.cm, a carrier mobility of 280 cm"2/V.s and a carrier lifetime of about 530 ps. The detector response to laser pulses (? = 355, 532 and 1,064 nm), X-ray flux (15--50 keV) and alpha particles ("2"4"1Am, 5.49 MeV) has been investigated. The response speed of the detector is in the 100 ps range. A sensitivity of about 3 x 10"-"1"0 A/V. (Gy/s) was measured under 50 keV X-ray flux. The detector current response to X-ray flux is almost linear. It is also shown that CVD diamond detectors can be used for alpha particle counting

1994-08-01

190

Optimised mounting conditions for poly (ether sulfone) in radiation detection.  

Science.gov (United States)

Poly (ether sulfone) (PES) is a candidate for use as a scintillation material in radiation detection. Its characteristics, such as its emission spectrum and its effective refractive index (based on the emission spectrum), directly affect the propagation of light generated to external photodetectors. It is also important to examine the presence of background radiation sources in manufactured PES. Here, we optimise the optical coupling and surface treatment of the PES, and characterise its background. Optical grease was used to enhance the optical coupling between the PES and the photodetector; absorption by the grease of short-wavelength light emitted from PES was negligible. Diffuse reflection induced by surface roughening increased the light yield for PES, despite the high effective refractive index. Background radiation derived from the PES sample and its impurities was negligible above the ambient, natural level. Overall, these results serve to optimise the mounting conditions for PES in radiation detection. PMID:24930013

Nakamura, Hidehito; Shirakawa, Yoshiyuki; Sato, Nobuhiro; Yamada, Tatsuya; Kitamura, Hisashi; Takahashi, Sentaro

2014-09-01

191

Development of radiation detection and measurement system - Development of scintillation radiation sensor  

Energy Technology Data Exchange (ETDEWEB)

We have been fabricated CsI(Tl) scintillation crystals and plastic scintillators for radiation-based measuring equipment. CsI (Tl) single crystals doped with thallium as an activator were grown using the Czochralski method. The crystal structure of grown CsI(Tl) was bcc, and it was confirmed that its lattice constant was 4,568 A. The spectral range of luminescence of CsI(Tl) was 350 {approx} 700 nm independent of thallium concentration, and the fast component of the luminescence was decreased with increasing thallium concentration. The energy resolution of CsI(Tl) scintillator doped with 0.1 mole% thallium was about 9% for 137 Cs {gamma}-rays. The relation formula of {gamma}-ray energy versus energy resolution was ln(FWHM%)=-0.705ln({epsilon})+6.75. The radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation dosage, and the irradiated crystals were colored reddish. The radiation induced absorption bands appeared around 355, 425, 520 and 555 nm, and their energy level were about 3.50, 2.88, 2.39 and 2.21 eV. Plastic scintillators were fabricated thermal polymerization method. Those were polymerizing at 120 deg. C, during 72 hours, and annealing at 75 deg. C, during 24 hours. When the concentration of 1st solute was 1.5 wt% and concentration of 2nd solute was 0.01 wt%, the characteristics of scintillation were very excellent. Also 3.0 wt% tetraphenyl lead were loaded to improve the detection efficiency of {gamma}-ray. The range of emission spectrum was 400 {approx} 450nm, and the central peak was 415 nm. The radiation damage was not appear under 1*10{sup 3}Gy, but the color of plastic scintillator was changed to brown, over 1*10{sup 4}Gy exposured. 84 refs., 39 figs. (Author)

Kang, Hee Dong; Kim, Wan [Kyungpook National University, Taegu (Korea); Kim, Do Sung [Taegu University, Taegu (Korea)

2000-03-01

192

Radiation-induced thermal noise in optoacoustic detection cells  

International Nuclear Information System (INIS)

When radiation is strongly absorbed in an optoacoustic detection cell, fluctuations in the radiation intensity give rise to thermal noise within the cell. The spectral density of the thermal noise thus generated is dependent on both the frequency response of the cell and the power spectral density of the radiation source. The frequency response function for the spectrophone cell is determined by application of elementary linear response theory to a solution of the heat equation for a uniformly heated cylinder. The power spectral density of coherent and incoherent radiation sources can be determined from their respective intensity autocorrelation functions. Radiation sources are discussed with regard to obtaining the smallest root-mean-square temperature fluctuations in the spectrophone cell. It is shown that optoacoustic noise is minimized by using a stabilized laser operating well above threshold. 15 references, 1 figure, 1 table

1984-10-01

193

Bremstrahlung Detection and Chamber Obstruction Localisation Using Scanning Radiation Detectors  

CERN Multimedia

Radiation monitors consisting of scintillating plastic coupled to photomultipliers are used for diagnostic purposes. By scanning such a detector or a radiation scatterer, two applications are demonstrated: i) Monitoring of vacuum chamber conditioning by monitoring gas Bremstrahlung from residual gas. ii) Localisation of beam interception (beam losses) by longitudinal scanning of a radiation detector. The measurement of gas pressure inside long, small cross section, vacuum vessels is difficult due to the distance between the centre of the vacuum vessel and vacuum gauges (leading to a low vacuum conductance). The narrow beam of gamma Bremstrahlung radiation is intercepted by scanning tungsten blades in the beam line front-end allowing a radiation shower to be detected outside the vacuum vessel proportional to the gas pressure in the corresponding storage ring straight section. A second detector mounted on rails can be moved over a length of 6.5m parallel to the ESRF storage ring so as to localise regions of bea...

Naylor, G A; Robinson, D

2005-01-01

194

Simulated performance of a position sensitive radiation detecting system (COCAE)  

CERN Document Server

Extensive simulations of a portable radiation detecting system have been performed in order to explore important performance parameters. The instrument consists of a stack of ten detecting layers made of pixelated Cadmium Telluride (CdTe) crystals. Its aim is to localize and identify radiation sources, by exploiting the Compton imaging technique. In this paper we present performance parameters based on simulation studies. Specifically the ratio of incompletely absorbed photons, the detector's absolute efficiency as well as its energy and angular resolution are evaluated in a wide range of incident photon energies.

Karafasoulis, K; Seferlis, S; Kaissas, I; Lambropoulos, C; Loukas, D; Poritiriadis, C

2011-01-01

195

Ionizing radiation source detection by personal TLD  

International Nuclear Information System (INIS)

The Laboratory for personal dosimetry has about 3000 workers under control. The most of them work in medicine. Some institutions, as big health centers, have different ionizing radiation sources. It is usefull to analyze what has been the source of irradiation, special when appears a dosimeter with high dose. Personal dosimetry equipment is Harshaw TLD Reader Model 6600 and dosimeters consist of two chips LiF TLD-100 assembled in bar-coded cards which are wearing in holders with one tissue-equivalent filter (to determine H(10)) and skin-equivalent the other (to determine H(0.07)). The calibration dosimeters have been irradiated in holders by different sources: x-ray (for 80keV and 100keV), 60Co, 90Sr (for different distances from beta source) and foton beem (at radiotherapy accelerator by 6MeV, 10MeV and 18MeV). The dose ratio for two LiF cristals was calculated and represented with graphs. So, it is possible to calculate the ratio H(10)/H(0.07) for a personal TLD and analyze what has been the source of irradiation. Also, there is the calibration for determination the time of irradiation, according to glow curve deconvolution

2002-10-08

196

New Method for Classification of Radiation Devices for Industrial Use  

Energy Technology Data Exchange (ETDEWEB)

Every radiation generating devices or devices containing radioactive isotopes (Radiation Devices) should get a design approval from the competent authority, the Ministry of Education, Science and Technology (MEST). Radiation Devices has been sorted and approved according to the design and structural criteria set by regulatory body. New classification method of radiation devices has been suggested to improve the safety control and effectiveness of design approval of radiation devices. Failure Mode and Effects Analysis (FMEA) method was used to evaluate potential accident factors involved in operation of radiation devices. The overall effect of failures on the radiation devices was estimated and the total risk factor for the model radiation device was determined

Cho, Woon Kap; Seo, Kyu Seock; Koo, Bon Cheol [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2010-10-15

197

Radiation detection technique on the fishery foods  

International Nuclear Information System (INIS)

When muscles and myofibril are irradiated by gamma ray, Mg-ATPase activity increased with increasing of dose, but EDTA-ATPase decreased. If dose is very large, Ca-ATPase activity increased. The effects of state of protein on these phenomena were investigated. The muscles, myofibril and myosin B of Tilapia nilotica were used as samples. Change of Ca-ATPase, Mg-ATPase and EDTA-ATPase activity of myosin B by gamma-ray irradiation was the same as myofibril and muscles, but myosin B showed high sensitivity and each ATPase activity was changed by low dose. Accordingly, these values were more difficult to apply to detection technique of irradiation than state of muscle and myofibril. Collagen is known to degenerate and coagulate by gamma-ray irradiation. However, amount of hot water soluble collagen was increased with increasing of dose. (S.Y.)

2000-02-01

198

Spherical harmonics methods for thermal radiation transport  

Science.gov (United States)

An implicit, spherical harmonic (Pn) method for solving thermal transport problems is developed. The method uses a high resolution Riemann solver to produce an upwinded discretization. The high resolution scheme introduces nonlinearities to the radiation transport operator to avoid the creation of artificial oscillations in the solution. By using a minmod limiter a quasi-linear approach to solving this nonlinear system of equations is developed. Through analysis and numerical results it is shown that the quasi-linear approach does suppress artificial oscillations and gives better than first order accuracy and is less computationally demanding than a fully nonlinear solve. The time integration methods considered are the backward Euler method and a high resolution time integration method. Also, reflecting boundary conditions for the Pn equations in three-dimensions are presented. It is shown that the standard Riemann solver is not robust in the diffusion limit. A fix is suggested that scales out the dissipation added by the Riemann solver as spatial cells become optically thick. The Green's function for the one-dimensional P 1 thermal transport equations with Cv ? T3 is derived. The Green's function is used to create the P1 solution to a common benchmark and to a problem of an infinite, pulsed line source. The implicit method was able to produce robust results to thermal transport problems in one and two dimensions. The implicit approach allowed the numerical method to take times steps on the longer material energy time scale rather than the speed of light time scale. In two dimensional problems the Pn solutions contained negative radiation energy densities. These negatives caused the material temperature to become negative as well. The free-streaming limit of the Pn equations is explored and it is shown why in transient problems in multiple-dimensions the Pn solutions can have negative energy densities.

McClarren, Ryan G.

199

Conducted and radiated noise in detection devices  

International Nuclear Information System (INIS)

Conducted and radiated noise is an external noise which affects the quality of the signals of the detectors. An external noise can be reduced, usually, by shielding. This was the situation with 'older fashion' devices which uses boxes and coaxial cables. As the devices becomes more complex, the shielding of the detectors is more and more difficult and the transmission lines evolves from coaxial cables to twisted pair cables which are no more shielded. In such situation, the conducted and radiated noise (C and R noise) becomes important. Due to complexity of a real detector, the main work is based on experiments with components and simulations of some specific problems, associated with CDC detector. The first experiment was done to understand how the C and R noise is propagated. The emission device was a set of coils (between 3 and 5 turns with diameter from 10 to 50 mm) feed by an 74S140 driver. A pulse of about 8 ns width was generated. A coil of reception of about the same physical characteristics was used to see the emitted pulse. When the two coils are separated by about 80 cm, the receiver generated no signal. But, if along the two coils, a conductive material is introduced (a wire for instance), the receiver senses a signal. This signal is not changed too much if the wire is or not connected to ground. The explanation is simple: the pulse in the emitting coil produces an EM pulse which spreads in space. If a conductive material is around, the EM energy is received by that conductor and it is propagated at tens of meters with small attenuation. When this energy reaches the end of the conductor, it is radiated in space. If some other conductors are around, the energy is received and propagated by that conductors. This experiment was done for about 20 kinds of conductors (different coax cables, twisted-pair ribbons, power cables, metallic bars) and with many coils (different diameters and numbers of turns). It was measured the pk-to-pk level, decay constant and frequencies of oscillations (eigen frequencies). Because a Fourier analyzer was not available, the eigen-frequencies were just evaluated by the oscilloscope. The conclusions are: 1. For a 8 ns width pulse, the oscillation is damped in time with a constant between about 100 ns for cooper bars and double-shielded coaxes and up to around 600 ns for twisted-pair ribbons; 2. The frequency of these oscillations depends on the conductor under test and so they are eigen-frequencies of that conductor. For a RG 59BU cable (F and G) the dominant EF was 20 MHZ as for the same RG59U (Amphenol) the EF was 69 MHZ. This is so because the technology to make the shielding is different. For a cooper bar for instance EF was measures as 46 MHz for 3.7 mm diameter and 26 MHz for 2.35 mm diameter. To understand if these EM pulses which propagate everywhere are important or not we have to remind that these pulses propagate on the surface of the conductors. For a shielded coax, they cannot go inside to change the signal. The situation in totally different when such pulse reaches a twisted-pair cable. The signal is superimposed on the useful signal and is propagated as a 'normal' signal. For this situation, the receiver of a twisted pair cable is differential so that the common mode signal could be rejected by a proper designed receiver. This is so only at the receiver side. If such noise propagates toward the source of signal (the output of the preamplifier for instance), when this EM energy goes inside the transmitter, the electronic device reacts at these EM pulses. Its reaction can be a signal which goes back to line and this is impossible to be rejected by receiver because is like a normal differential signal. For a user it looks like being generated by the detector. In an experiment, a real preamplifier, a real ribbon (about 5 meter long) and a real receiver were connected on a table. An 8 ns pulse was inserted somewhere on that 5 meter twisted-pair cable and the signal on the receiver was monitored. The input of the preamplifier was connected to ground. Due to simulated noise, on

2001-01-01

200

Micronuclei: sensitivity for the detection of radiation induced damage  

International Nuclear Information System (INIS)

The in vitro cytokinesis-block (CB) micronucleus (MN) assay for human peripheral blood has been used extensively for the assessment of chromosomal damage induced by ionizing radiation and chemicals and considered a suitable biological dosimeter for estimating in vivo whole body exposures, particularly in the case of large scale radiation accidents. One of the major drawbacks of the MN assay is its reduced sensitivity for the detection of damage induced by low doses of low LET radiation, due to the high variability among the spontaneous MN frequencies. It is suggested that age, smoking habit and sex are the main confounding factors that contribute to the observed variability. Previous work in our laboratory, shows a significant positive correlation of the spontaneous and radiation induced MN frequencies with age and smoking habit, the latter being the strongest confounder. These findings led to in vitro studies of the dose-response relationships for smoking and non smoking donors evaluated separately, using 60Co ? rays. The objectives of the present work are: 1-To increase the amount of data of the dose-response relationships, using ? rays from a 60Co source, for smoking and non smoking donors, in order to find, if applicable, a correction factor for the calibration curve that takes into account the smoking habit of the individual in the case of accidental overexposure dose assessment, particularly in the low dose range. 2-To establish general conclusions on the current state of the technique. The sample for smoking and non smoking calibration curves was enlarged in the range of 0Gy to 2Gy. The fitting of both curves, performed up to the 2Gy dose, resulted in a linear quadratic model. MN distribution among bi nucleated cells was found to be over dispersed with respect to Poisson distribution, the average ratio of variance to mean being 1.13 for non smokers and 1.17 for smokers. Each fitted calibration curve, for smoking and non smoking donors, fell within the 95% confidence curves of the other, with the exception of the spontaneous frequency values of both calibration curves. Thus, for the accidental overexposure dose assessment it seems to be appropriate to use a pooled data (smokers + non smokers) calibration curve and in the case of dose assessment up to 0.5Gy, it is convenient to use the corresponding spontaneous term in the yield equation; associated to the individual smoking habit condition. General conclusions: 1-The high and variable spontaneous MN frequency prevents an adequate dose estimation below 0.2-0.3Gy of low LET radiation. 2-At high doses, of low LET radiation, the sensitivity of the MN test is lower than the conventional aberration methods (dicentrics) due to the smaller squared term in the yield equation. 3-Radiation induced MN tend to be over dispersed with respect to Poisson distribution. Over dispersion increases the standard error on the observed yield and thus the uncertainties on the dose estimation. (author)

1998-10-19

 
 
 
 
201

Characterization of mobile radiation detection systems at the Hanford Site  

International Nuclear Information System (INIS)

The use of vehicle-mounted radiation detection systems for characterizing large areas contaminated with radioactive materials at the Hanford Reservation were examined. Detection capabilities as a function of vehicle speed, detector-source geometry, and source characteristics were evaluated for each of the three systems currently used at the Hanford Site. Large-area radioactive sources (1 ft2) with varying source strengths containing gamma- and beta-emitting radionuclides were used to measure detection-system performance. Detection capability was found to be most influenced by vehicle speed and detector-source geometry. As the vehicle's speed was increased, the probability of detecting a given source decreased dramatically. The probability of detecting a given source was significantly lower under ''poor'' geometry conditions. Each vehicle's monitoring performance was found to compare favorably with portable survey instrument capabilities. The use of vehicle-mounted detectors proves to be far more economical for surveying large surface areas

1993-01-24

202

Three Methods of Detection of Hydrazines  

Science.gov (United States)

Three proposed methods for measuring trace quantities of hydrazines involve ionization and detection of hydrazine derivatives. These methods are intended to overcome the limitations of prior hydrazine- detection methods. Hydrazine (Hz), monomethylhydrazine (MMH), and unsymmetrical dimethylhydrazine (UDMH) are hypergolic fuels and are highly reactive, toxic, and corrosive. A capability to measure concentrations of hydrazines is desirable for detecting leaks and ensuring safety in aerospace settings and in some industrial settings in which these compounds are used. One of the properties (high reactivity) that make it desirable to detect trace amounts of hydrazines also makes it difficult to detect hydrazines and measure their concentrations accurately using prior methods: significant amounts are lost to thermal and catalytic decomposition prior to detection. Further complications arise from the sticky nature of hydrazines: Sample hydrazine molecules tend to become irreversibly adsorbed onto solid surfaces with which they come into contact during transport to detectors, giving rise to drift in detector responses. In each proposed method, the reactive, sticky nature of hydrazines would be turned to advantage by providing a suitably doped substrate surface with which the hydrazines would react. The resulting hydrazine derivatives would be sufficiently less sticky and sufficiently more stable so that fewer molecules would be lost to decomposition or adsorption during transport. Consequently, it would be possible to measure concentration with more sensitivity and less error than in prior techniques. The first proposed method calls for the use of a recently developed technique known as desorption electrospray ionization (DESI), in which a pneumatically assisted micro -electrospray at ambient pressure is directed at a surface of interest. In this case, the surface of interest would be that of a substrate described above.

Griffin, Timothy; Berger, Cristina

2010-01-01

203

DQE as detection probability of the radiation detectors  

Energy Technology Data Exchange (ETDEWEB)

In this paper it is shown that quantum efficiency (DQE), as commonly defined for imaging detectors, can be extended to all radiation detectors with the meaning of detection probability, if Poisson statistics applies. This unified approach is possible in time-domain at zero spatial-frequency.

Zanella, Giovanni [Dipartimento di Fisica ' Galileo Galilei' , Universita di Padova and I.N.F.N., Sezione di Padova, via Marzolo, 8-I-35131 Padova (Italy)], E-mail: zanella@pd.infn.it

2008-02-21

204

DQE as detection probability of the radiation detectors  

International Nuclear Information System (INIS)

In this paper it is shown that quantum efficiency (DQE), as commonly defined for imaging detectors, can be extended to all radiation detectors with the meaning of detection probability, if Poisson statistics applies. This unified approach is possible in time-domain at zero spatial-frequency

2008-02-21

205

Control of irradiated food: recent developments in analytical detection methods  

International Nuclear Information System (INIS)

An overview of recent international efforts, i.e. programmes of ''ADMIT'' (FAO/IAEA) and of BCR (EC) towards the development of analytical detection methods for radiation processed food will be given. Some larger collaborative studies have already taken place, e.g. ESR of bones from chicken, pork, beef, frog legs and fish, thermoluminescence of insoluble minerals isolated from herbs and spices, GC analysis of long-chain hydrocarbons derived from the lipid fraction of chicken and other meats, and the microbiological APC/DEFT procedure for spices. These methods could soon be implemented in international standard protocols. (author)

1993-01-01

206

Detection of radiation from electrochemical cell intensifying beta decay  

International Nuclear Information System (INIS)

The predictions of relic neutrino existence and neutrino anomalous magnetic moment existence, as well as the solution of the Dirac equation for a neutral particle with an anomalous magnetic moment in the Coulomb field imply the existence of neutrino matter component. In this work the radiation intensifying 60Co and 137Cs beta decays by (0.42±0.05)% and (0.160±0.012)% has been detected from the end electrochemical cell. The radiation interaction cross-section with radioactive nuclei is more than 10?30 cm2. - Highlights: ? We supposed that neutrino bound states with nuclei could exist. ? The decay of such bound states could occur during physicochemical processes. ? The radiation intensifying beta decay has been obtained from electrochemical cell. ? The radiation interaction cross-section with radioactive nuclei is >10?30cm2.

2012-08-01

207

Verifying model for statistical hypothesis in detection of noncoherent radiation  

Science.gov (United States)

A mode of quantic detection for noncoherent optical radiation as noise limit is presented. Using the representation on coherent state of density matrix operators ((rho) ) and of detection operators ((pi) ), the detection probability (Qd), false alarm probability (Qo) and signal-noise ratio (S/Z), are estimated, as function of the number of freedom degrees of temporal oscillation modes (Mt) and of the spatial oscillation modes (Ms). A validation algorithm of statistical hypotheses, resulted from noncoherent optical field analysis, is made using Newman-Pearson criterion.

Babin, Vasile D.; Ersen, Simion; Moldovan, Adrian; Iftimia, Nicusor

1998-07-01

208

Novel methods for detecting buried explosive devices  

Energy Technology Data Exchange (ETDEWEB)

Oak Ridge National Laboratory (ORNL) and Quantum Magnetics, Inc. (QM) are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

Kercel, S.W.; Burlage, R.S.; Patek, D.R.; Smith, C.M. [Oak Ridge National Lab., TN (United States); Hibbs, A.D.; Rayner, T.J. [Quantum Magnetics, Inc., San Diego, CA (United States)

1997-04-01

209

A Bayesian method for detecting stellar flares  

CERN Document Server

We present a Bayesian-odds-ratio-based algorithm for detecting stellar flares in light curve data. We assume flares are described by a model in which there is a rapid rise with a half-Gaussian profile, followed by an exponential decay. Our signal model also contains a polynomial background model. This is required to fit underlying light curve variations that are expected in the data, which could otherwise partially mimic a flare. We characterise the false alarm probability and efficiency of this method and compare it with a simpler thresholding method based on that used in Walkowicz et al (2011). We find our method has a significant increase in detection efficiency for low signal-to-noise ratio (S/N) flares. For a conservative false alarm probability our method can detect 95% of flares with S/N less than ~20, as compared to S/N of ~25 for the simpler method. As an example we have applied our method to a selection of stars in Kepler Quarter 1 data. The method finds 687 flaring stars with a total of 1873 flares...

Pitkin, M; Fletcher, L; Grant, S D T

2014-01-01

210

Extraction chromatography method for Sr 90 determination in radiation monitoring  

International Nuclear Information System (INIS)

An idea to combine the up-to-date methods of registration and separation has been applied for the sample operation procedure of Sr 90 determination in crop production and natural water samples. The procedure consists of two basic steps: extraction chromatography separation of strontium from most inactive and radioactive interferences utilizing column with crown ether and radioactivity measurement by gas proportional counter with limit of detection 0,027 Bq per 1 hour. Reference materials were used to test the obtained results. The procedure developed meets the current requirements of radiation monitoring. (authors)

2006-05-01

211

Semiconductor radiation detection device. Handotai hoshasen kenshutsu soshi  

Energy Technology Data Exchange (ETDEWEB)

The semiconductor radiation detection device detects indirectly the [alpha]-ray and Li7 produced by the reaction of B10 and neutron beam after covering the device with the layer containing B10, or an isotope of boron. However, because of high electric resistance of boron, the boron thin film gives rise to a high IR drop, resulting in lowering the sensitivity and resolution performance. This invention solves the problem. The electric resistance is reduced by doping impurities in the born thin film containing B10 in the semiconductor radiation detection device which is covered with boron thin film containing B10 on the surface which is adjacent to the joint to the semiconductor having a joint for forming the vacancy. Reduction of electric resistance in the direction of film thickness of the boron thin film containing B10 by doping impurities makes t possible to reduce the IR drop generated by the leak current occurred at the joint part. 5 figs.

Takahama, S.

1993-10-08

212

Flow cytometric detection method for DNA samples  

Science.gov (United States)

Disclosed herein are two methods for rapid multiplex analysis to determine the presence and identity of target DNA sequences within a DNA sample. Both methods use reporting DNA sequences, e.g., modified conventional Taqman.RTM. probes, to combine multiplex PCR amplification with microsphere-based hybridization using flow cytometry means of detection. Real-time PCR detection can also be incorporated. The first method uses a cyanine dye, such as, Cy3.TM., as the reporter linked to the 5' end of a reporting DNA sequence. The second method positions a reporter dye, e.g., FAM.TM. on the 3' end of the reporting DNA sequence and a quencher dye, e.g., TAMRA.TM., on the 5' end.

Nasarabadi,Shanavaz (Livermore, CA) [Livermore, CA; Langlois, Richard G. (Livermore, CA) [Livermore, CA; Venkateswaran, Kodumudi S. (Round Rock, TX) [Round Rock, TX

2011-07-05

213

Quantitative boron detection by neutron transmission method  

International Nuclear Information System (INIS)

//Quantitative boron detection is mainly performed by chemical methods like colorimetric titration. High neutron absorption cross section of natural boron makes attractive its detection by absorption measurements. This work is an extension of earlier investigations where neutron radiography technique was used for boron detection. In the present investigation, the neutron absorption rate of boron containing solutions is the way to measure quantitatively the boron content of the solutions. The investigation was carried out in Istanbul TRIGA Mark-II reactor. In the end of the experiments, it was observed that even |ppw| grade boron in aqueous solution can be easily detected. The use of this method is certainly very useful for boron utilizing industries like glass and steel industries.The major disadvantage of the method is the obligation to use always aqueous solutions to be able to detect homogeneously the boron content. Then, steel or glass samples have to be put first in an appropriate solution form. The irradiation of steel samples can give the distribution of boron by the help of a imaging and this suggested method will give its quantitative measurement. The superiority of this method are its quick response time and its accuracy. To test this accuracy, a supposed unknown , solution of boric acid is irradiated and then calculated by the help of the calibration curve. The measured value of boric acid was 0.89 mg and the calculated value was found to be 0.98 mg which gives an accuracy of 10 %. It was also seen that the method is more accurate for low concentration. (authors)

1992-10-01

214

Detection of DNA damage induced by space radiation in Mir and space shuttle  

Energy Technology Data Exchange (ETDEWEB)

Although physical monitoring of space radiation hasbeen accomplished, we aim to measure exact DNA damage as caused by space radiation. If DNA damage is caused by space radiation, we can detect DNA damage dependent on the length of the space flight periods byusing post-labeling methods. To detect DNA damage caused by space radiation, we placed fixed human cervical carcinoma (HeLa) cells in the Russian Mir space station for 40 days and in an American space shuttle for 9 days. After landing, we labeled space-radiation-induced DNA strand breaks by enzymatic incorporation of [{sup 3}H]-deoxyadenosine triphosphate (dATP) with terminal deoxyribo-nucleotidyl transferase (TdT). We detected DNA damage as many grains on fixed silver emulsion resulting from {beta}-rays emitted from {sup 3}H-atoms in the nuclei of the cells placed in the Mir-station (J/Mir mission, STS-89), but detected hardly any in the ground control sample. In thespace shuttle samples (S/MM-8), the number of cellshaving many grains was lower than that in the J/Mir mission samples. These results suggest that DNA damage is caused by space radiation and that it is dependent on the length of the space flight. (author)

Ohnishi, Takeo; Ohnishi, Ken; Takahashi, Akihisa [Nara Medical Univ, Kashihara (Japan); Taniguchi, Yoshitaka [Toray Research Center Inc., Kamakura, Kanagawa (Japan); Sato, Masaru; Nakano, Tamotsu [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan); Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences

2002-12-01

215

GMDD: a database of GMO detection methods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. RESULTS: GMO Detec...

Dong, W.; Yang, L.; Shen, K.; Kim, B.; Kleter, G. A.; Marvin, H. J. P.; Guo, R.; Liang, W.; Zhang, D.

2008-01-01

216

GMDD: a database of GMO detection methods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at globa...

2008-01-01

217

Method and apparatus for detecting an analyte  

Energy Technology Data Exchange (ETDEWEB)

We describe the use of coordination polymers (CP) as coatings on microcantilevers for the detection of chemical analytes. CP exhibit changes in unit cell parameters upon adsorption of analytes, which will induce a stress in a static microcantilever upon which a CP layer is deposited. We also describe fabrication methods for depositing CP layers on surfaces.

Allendorf, Mark D. (Pleasanton, CA); Hesketh, Peter J. (Atlanta, GA)

2011-11-29

218

Detection method for nuclear reactor material  

Energy Technology Data Exchange (ETDEWEB)

A fine state of a test piece taken out of a reactor core is analyzed upon periodical inspection, and a new test piece previously reproducing the state described above at the outside of the reactor is disposed to the reactor core upon completion of the periodical inspection. Further, a fine state of the material at a time preceding to the operation time at a certain periodical inspection is forecast, and a test piece reproducing the state at the outside of the reactor is disposed to the reactor core upon the completion of the periodical inspection. Since a test piece previously reproducing the change of the state up to a certain periodical inspection by a method other than irradiation of neutrons is newly disposed, radiation of the test piece is not extremely increased even after an extremely long period of summed up reactor operation time, to provide substantially constant radiation level on every test piece. (T.M.).

Isobe, Yusuke; Hashimoto, Motoyuki

1995-06-23

219

Performance tests of the ORGDP radiation detection instruments  

International Nuclear Information System (INIS)

Tests of the Oak Ridge Gaseous Diffusion Plant (ORGDP) radiation detection instruments were conducted in order to further document compliance with American National Standards Institute standard entitled Criticality Accident Alarm System. Neutron and gamma radiation, similar to that which would be experienced in a criticality accident, was generated by the Health Physics Research Reactor (HPRR)--a small, highly enriched uranium metal reactor. The HPRR was operated in two modes: (1) a burst mode in which yields ranging from 8 to 30 x 1015 fissions were obtained in a small fraction of a second, and (2) a steady-state mode in which smaller yields were obtained over one-minute intervals. The tests demonstrate that at a distance of 225 feet (68 meters), which is the present radius coverage for the ORGDP radiation detection instrument, the minimum criticality accident, as defined by the ANSI standard, could be readily detected. For line-of-sight locations, this radius coverage could be increased to 500 feet. The tests also indicate that the instrument response, in terms of radius coverage, is greater for neutron than for gamma radiation by a factor of about three

1976-01-01

220

Passive radiation detection using optically active CMOS sensors  

Science.gov (United States)

Recently, there have been a number of small-scale and hobbyist successes in employing commodity CMOS-based camera sensors for radiation detection. For example, several smartphone applications initially developed for use in areas near the Fukushima nuclear disaster are capable of detecting radiation using a cell phone camera, provided opaque tape is placed over the lens. In all current useful implementations, it is required that the sensor not be exposed to visible light. We seek to build a system that does not have this restriction. While building such a system would require sophisticated signal processing, it would nevertheless provide great benefits. In addition to fulfilling their primary function of image capture, cameras would also be able to detect unknown radiation sources even when the danger is considered to be low or non-existent. By experimentally profiling the image artifacts generated by gamma ray and ? particle impacts, algorithms are developed to identify the unique features of radiation exposure, while discarding optical interaction and thermal noise effects. Preliminary results focus on achieving this goal in a laboratory setting, without regard to integration time or computational complexity. However, future work will seek to address these additional issues.

Dosiek, Luke; Schalk, Patrick D.

2013-05-01

 
 
 
 
221

Measuring ionizing radiation. Fundamentals and methods. Messung ionisierender Strahlung. Grundlagen und Methoden  

Energy Technology Data Exchange (ETDEWEB)

This condensed textbook first presents a survey of radiation sources, radiation quantities, and the fundamentals of detecting ionizing radiation. Basic knowledge of nuclear physics is required to follow the course. The two main sections of the text deal with technically mature radiation detectors (such as ionization detectors, excitation detectors, solid state nuclear track detectors, chemical detectors), and with well-proven measuring methods (such as particle counting, activity measurement, energy measurement, radioactive half-life measurement, and dose measurement). The information presented primarily has regard for practical measuring problems encountered in medical diagnostics and therapy as well as in civil and military radiation protection.

Stolz, W.

1985-01-01

222

Ultrafast Radiation Detection by Modulation of an Optical Probe Beam  

International Nuclear Information System (INIS)

We describe a new class of radiation sensor that utilizes optical interferometry to measure radiation-induced changes in the optical refractive index of a semiconductor sensor medium. Radiation absorption in the sensor material produces a transient, non-equilibrium, electron-hole pair distribution that locally modifies the complex, optical refractive index of the sensor medium. Changes in the real (imaginary) part of the local refractive index produce a differential phase shift (absorption) of an optical probe used to interrogate the sensor material. In contrast to conventional radiation detectors where signal levels are proportional to the incident energy, signal levels in these optical sensors are proportional to the incident radiation energy flux. This allows for reduction of the sensor form factor with no degradation in detection sensitivity. Furthermore, since the radiation induced, non-equilibrium electron-hole pair distribution is effectively measured ''in place'' there is no requirement to spatially separate and collect the generated charges; consequently, the sensor risetime is of the order of the hot-electron thermalization time (le) 10 fs and the duration of the index perturbation is determined by the carrier recombination time which is of order ? 600 fs in, direct-bandgap semiconductors, with a high density of recombination defects; consequently, the optical sensors can be engineered with sub-ps temporal response. A series of detectors were designed, and incorporated into Mach Zehnder and Fabry-Perot interferometer-based detection systems: proof of concept, lower detection sensitivity, Mach-Zehnder detectors were characterized at beamline 6.3 at SSRL; three generations of high sensitivity single element and imaging Fabry-Perot detectors were measured at the LLNL Europa facility. Our results indicate that this technology can be used to provide x-ray detectors and x-ray imaging systems with single x-ray sensitivity and S/N ? 30 at x-ray energies ? 10 keV

2006-01-01

223

Ultrafast Radiation Detection by Modulation of an Optical Probe Beam  

Energy Technology Data Exchange (ETDEWEB)

We describe a new class of radiation sensor that utilizes optical interferometry to measure radiation-induced changes in the optical refractive index of a semiconductor sensor medium. Radiation absorption in the sensor material produces a transient, non-equilibrium, electron-hole pair distribution that locally modifies the complex, optical refractive index of the sensor medium. Changes in the real (imaginary) part of the local refractive index produce a differential phase shift (absorption) of an optical probe used to interrogate the sensor material. In contrast to conventional radiation detectors where signal levels are proportional to the incident energy, signal levels in these optical sensors are proportional to the incident radiation energy flux. This allows for reduction of the sensor form factor with no degradation in detection sensitivity. Furthermore, since the radiation induced, non-equilibrium electron-hole pair distribution is effectively measured ''in place'' there is no requirement to spatially separate and collect the generated charges; consequently, the sensor risetime is of the order of the hot-electron thermalization time {le} 10 fs and the duration of the index perturbation is determined by the carrier recombination time which is of order {approx} 600 fs in, direct-bandgap semiconductors, with a high density of recombination defects; consequently, the optical sensors can be engineered with sub-ps temporal response. A series of detectors were designed, and incorporated into Mach Zehnder and Fabry-Perot interferometer-based detection systems: proof of concept, lower detection sensitivity, Mach-Zehnder detectors were characterized at beamline 6.3 at SSRL; three generations of high sensitivity single element and imaging Fabry-Perot detectors were measured at the LLNL Europa facility. Our results indicate that this technology can be used to provide x-ray detectors and x-ray imaging systems with single x-ray sensitivity and S/N {approx} 30 at x-ray energies {approx} 10 keV.

Vernon, S P; Lowry, M E

2006-02-22

224

Modified chemical methods applied for radiation dosimetry  

International Nuclear Information System (INIS)

Two chemical methods were studied for radiation dosimetry: the Fricke ferrous sulfate dosimeter, for reference purposes, and the ceric sulfate dosimeter, for routine dosimetric work. In the case of Fricke dosimeter, its main parameters were determined: the wavelength of maximum absorption for the Fe2+ ions, the molar extinction coefficient and the calibration curves as a function of the Fe2+ ions initial concentration. The dose rate determinations were made using ortho-phenanthroline, that acts as a complexant. This dosimeter was used for the dose rate mapping of a 60 Co (185 Tbq) source radiation field, at the irradiation table plane. The ceric sulfate dosimeter was chosen from several possible chemical dosimeters because of its properties as simple preparation, low cost and chemical reagents available at the laboratory. In this work this dosimeter was modified with respect to the use of sodium oxalate instead of arsenic oxide conventionally used for its standardization, in order to minimize its preparation cost. In this case the wavelength for maximum absorption for the Ce4+ ions and calibration curves in function of the Ce4+ ions initial concentration and of the absorbed dose in the dosimeter were determined. The obtained results showed the feasibility of use of this dosimeter between 0,25 and 10 KGy, depending on the initial concentration of Ce4+ ions. (author). 34 refs., 8 figs., 17 tabs

1994-01-01

225

Transport methods and interactions for space radiations  

Science.gov (United States)

This report presents a brief history leading to the involvement of the Langley Research Center of the National Aeronautics and Space Administration (NASA) in space-radiation physics and protection. Indeed, a relatively complete summary of technical capability as of the summer of 1990 is given. The Boltzmann equations for coupled ionic and neutronic fields are presented and inversion techniques for the Boltzmann operator are discussed. Errors generated by the straight ahead approximation are derived and are shown to be negligible for most problems of space-radiation protection. A decoupling of projectile propagation from the target fields greatly simplifies the Boltzmann equations and allows an analytic solution of the target fragment transport. Analytic and numerical methods of solving the projectile transport equations are discussed. The nuclear physics underlying the coefficients in the Boltzmann equation is discussed. A coupled-channel optical model is found as a consequence of the loose binding of nuclear matter and closure of the nuclear states in high-energy reactions. Transport solutions with the developed data base are used with laboratory experiments to validate both the transport code and the data base. Numerical benchmarks and comparison with Monte Carlo calculations are also used for code validation.

Wilson, John W.; Townsend, Lawrence W.; Schimmerling, Walter; Khandelwal, Govind S.; Khan, Ferdous; Nealy, John E.; Cucinotta, Francis A.; Simonsen, Lisa C.; Shinn, Judy L.; Norbury, John W.

1993-01-01

226

Radiation Detection Scenario Analysis Toolbox (RADSAT) Test Case Implementation Final Report  

Energy Technology Data Exchange (ETDEWEB)

Final report for the project. This project was designed to demonstrate the use of the Radiation Detection Scenario Analysis Toolbox (RADSAT) radiation detection transport modeling package (developed in a previous NA-22 project) for specific radiation detection scenarios important to proliferation detection.

Shaver, Mark W.

2010-09-27

227

Current Trends in Gamma Radiation Detection for Radiological Emergency Response  

Energy Technology Data Exchange (ETDEWEB)

Passive and active detection of gamma rays from shielded radioactive materials, including special nuclear materials, is an important task for any radiological emergency response organization. This article reports on the current trends and status of gamma radiation detection objectives and measurement techniques as applied to nonproliferation and radiological emergencies. In recent years, since the establishment of the Domestic Nuclear Detection Office by the Department of Homeland Security, a tremendous amount of progress has been made in detection materials (scintillators, semiconductors), imaging techniques (Compton imaging, use of active masking and hybrid imaging), data acquisition systems with digital signal processing, field programmable gate arrays and embedded isotopic analysis software (viz. gamma detector response and analysis software [GADRAS]1), fast template matching, and data fusion (merging radiological data with geo-referenced maps, digital imagery to provide better situational awareness). In this stride to progress, a significant amount of interdisciplinary research and development has taken place–techniques and spin-offs from medical science (such as x-ray radiography and tomography), materials engineering (systematic planned studies on scintillators to optimize several qualities of a good scintillator, nanoparticle applications, quantum dots, and photonic crystals, just to name a few). No trend analysis of radiation detection systems would be complete without mentioning the unprecedented strategic position taken by the National Nuclear Security Administration (NNSA) to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime transportation–the so-called second line of defense.

Mukhopadhyay, S., Guss, P., Maurer, R.

2011-09-01

228

X-ray tomography detection methods  

International Nuclear Information System (INIS)

The improvement in the performance of X-ray tomographs involves the study of more efficient detectors, hence the important effort now being undertaken by various teams in the design of new detection systems. After defining the parameters which make it possible to select a detection method for an X-ray tomograph, the technical and operating characteristics of the following detectors are briefly reviewed: gas ionization chamber, multiwire grid chambers, ionization chamber with a condensed medium (liquid xenon), scintillation detector (with scintillator and photodetector) and semiconductor detectors (CdTe and HgI2) operating at ambient temperature

1978-06-09

229

Development of detection methods for irradiated foods  

International Nuclear Information System (INIS)

To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats. The analysis of DNA damage made on single cells by agarose gel electrophoresis (DNA 'comet assay') can be used to detect irradiated food. All the samples irradiated with over 0.3 kGy were identified to detect post-irradiation by the tail length of their comets. Irradiated samples showed comets with long tails, and the tail length of the comets increased with the dose, while unirradiated samples showed no or very short tails. As a result of the above experiment, the DNA 'comet assay' might be applied to the detection of irradiated grains as a simple, low-cost and rapid screening test. When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from leic acid. 1,7 hexadecadiene was the highest amount in irradiated beef, pork and chicken. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1,7-hexadecadiene and 8-heptadecen were detected as major compounds. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks

1999-01-01

230

Investigation of antiques with radiation methods  

International Nuclear Information System (INIS)

The authenticity of three European medieval swords had to be proven. In addition, the production techniques used by the medieval smiths were studied. For the assessment of antiques and objects of art, both examination of the material and stylistic studies are required in nearly all cases. In most of these cases, not only one but several essentially different investigation methods have to be applied during the study of the material. Nuclear and radiation techniques are favoured, primarily because these can frequently be carried out non-invasively, which is essential in the study of objects of high value, since taking samples from the objects might devalue them significantly. Using nuclear techniques such as neutron activation analysis (NAA) or photon activation analysis (PAA), large volumes of material can be analysed in many cases, so it is possible to investigate the entire body of the object or large parts of it. Thus meaningful results with a high degree of representativeness can be obtained nondestructively. In activation analysis, the material under study is exposed to irradiation by subatomic particles - neutrons, photons, protons, etc. During bombardment with these, radioactive nuclides are produced through nuclear reactions. The radionuclides decay by emission of different types of radiation. Among these, photons (? or characteristic X rays) are preferred for use in analytical evaluation. The energy distribution of X and ? rays is characteristic for each radionuclide. Measured with an appropriate spectrometer, the spectra can be used for simultaneous multicomponent analyses. Since the method is based upon nuclear reactions, only the element composition can be determined; normally no chemical speciation is possible

2004-10-01

231

Numerical methods in multidimensional radiative transfer  

CERN Document Server

Offers an overview of the numerical modelling of radiation fields in multidimensional geometries. This book covers advances and problems in the mathematical treatment of the radiative transfer equation, a partial integro-differential equation of high dimension that describes the propagation of the radiation in various fields.

Meinköhn, Erik

2008-01-01

232

Calculation methods of internal radiation dose  

International Nuclear Information System (INIS)

A description is made of the methods of calculating the internal radiation dose in man to be put together with the external dose, concerning the guideline dose values of the Atomic Energy Commission of Japan in connection with the principle of keeping the releases of radioactive materials in effluents of light-water-cooled nuclear power reactors to the environment as low as is reasonably achievable. A comparison is then made between the dose calculation methods announced by the Atomic Energy Commission of Japan and those by the U.S. Nuclear Regulatory Commission (Regulatory Guide 1.109). Features of the methods by the Atomic Energy Commission of Japan are: calculation of the doses in individuals of the critical groups outside of the reactors through critical exposure pathways due to major radionuclides in the effluents, usage of calculational models based on specific activities of radionuclides to estimate the doses via seafoods pathways, i.e. radioiodine in seaweed, and presentation of parameters for estimating the doses in Japanese people. (auth.)

1977-06-01

233

Radiation detection using the color changes of lilac spodumene  

International Nuclear Information System (INIS)

The use of radiation in industrial processes currently offers several advantages in the field of sterilization of medical and pharmaceuticals products, the preservation of food, and a variety of other products widely used in modern society. A dosimetry of confidence is a key parameter for the quality assurance of radiation processing and the irradiated products. This work investigates dosimetric properties in natural spodumene, LiAlSi2O6, called kunzite, from Minas Gerais State, Brazil. After X irradiation on the samples in powder form was detected a change in color of the crystal where the dose received. This makes a possible viability of this material is applied in research on development of radiation detectors using the change in color of purple spodumene. (author)

2009-10-02

234

Radiation detection using the color changes of lilac spodumene  

Energy Technology Data Exchange (ETDEWEB)

The use of radiation in industrial processes currently offers several advantages in the field of sterilization of medical and pharmaceuticals products, the preservation of food, and a variety of other products widely used in modern society. A dosimetry of confidence is a key parameter for the quality assurance of radiation processing and the irradiated products. This work investigates dosimetric properties in natural spodumene, LiAlSi{sub 2}O{sub 6}, called kunzite, from Minas Gerais State, Brazil. After X irradiation on the samples in powder form was detected a change in color of the crystal where the dose received. This makes a possible viability of this material is applied in research on development of radiation detectors using the change in color of purple spodumene. (author)

Oliveira, Raquel A.P.; Mello, Ana Carolina S.; Lima, Hestia R.B.R.; Campos, Simara Santos; Souza, Suzana O., E-mail: raoliceira@fisica.ufs.b [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Physics Dept.

2009-07-01

235

Transport methods used for homeland security and non-proliferation detection applications: An overview  

International Nuclear Information System (INIS)

This paper discusses recent investigations in homeland security and non-proliferation research that involve the application, analysis, and experimental validation of transport computations as they are applied to SNM detection scenarios. The use of transport theory methods, particularly 3-D Deterministic radiation transport, as a tool in assessing scenarios involving Special Nuclear Materials (SNM) detection for homeland security and non-proliferation applications has increased in recent years. This is primarily due to the need to optimize detectors and understand radiation signatures to overcome the many challenges associated with SNM detection, and the complex nature of the radiation spectra involving neutron and gamma transport in detection scenarios. Augmenting the effort is the more-ready access and availability of high performance computing. Overall, the valuable information obtained from the application of deterministic and Monte Carlo Transport methods, and how those methods are being used to augment detection capabilities is discussed. (authors)

2009-05-03

236

Position sensitive detection of neutrons in high radiation background field  

Science.gov (United States)

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high ? and e- radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 ?m2) spectroscopic Timepix detector adapted for neutron detection utilizing very thin 10B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10-4.

Vavrik, D.; Jakubek, J.; Pospisil, S.; Vacik, J.

2014-01-01

237

Position sensitive detection of neutrons in high radiation background field  

Energy Technology Data Exchange (ETDEWEB)

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high ? and e{sup ?} radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 ?m{sup 2}) spectroscopic Timepix detector adapted for neutron detection utilizing very thin {sup 10}B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10{sup ?4}.

Vavrik, D., E-mail: vavrik@itam.cas.cz [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, Prague (Czech Republic); Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9 (Czech Republic); Jakubek, J.; Pospisil, S. [Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9 (Czech Republic); Vacik, J. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, 250 68 Prague, Czech Republic (Czech Republic)

2014-01-15

238

Small Teleoperated Robot for Nuclear Radiation and Chemical Leak Detection  

Directory of Open Access Journals (Sweden)

Full Text Available In order to meet the actual requirements of nuclear radiation and chemical leak detection, and emergency response, a new small teleoperated robot for nuclear radiation and chemical detection is proposed. A small?size robot is manufactured according to technical requirements and the overall structure and control system is described. Meanwhile, based on the principles of human?robot interaction, a user?friendly human?robot interaction interface is designed to provide a good telepresence for the operator, helping the operator to perceive and judge the robot’s situation to better assist in making the right decisions and in giving timely operation instructions. The experiment results show the robot system operates reliably and meets the technical requirements.

Kui Qian

2012-09-01

239

Designing metal-organic frameworks for radiation detection  

Energy Technology Data Exchange (ETDEWEB)

Five metal-organic frameworks (MOFs) were synthesized and investigated via steady-state photoluminescence and radioluminescence measurements. Unique spectral features were observed in the 2.5 MeV proton spectra, corresponding to differences in the electronic and crystalline structures of each material. Targeted structural transformations and infiltration with extrinsic dopants were also employed to modify the luminescence of these frameworks, establishing MOFs as a platform to design new radiation detection materials.

Feng, Patrick L. [Sandia National Laboratories, California, 7011 East Ave, Livermore, CA 94550 (United States); Branson, Janelle V.; Hattar, Khalid; Vizkelethy, Gyorgy [Sandia National Laboratories, New Mexico, PO Box 5800, Albuquerque, NM 87185 (United States); Allendorf, Mark D. [Sandia National Laboratories, California, 7011 East Ave, Livermore, CA 94550 (United States); Patrick Doty, F., E-mail: fpdoty@sandia.gov [Sandia National Laboratories, California, 7011 East Ave, Livermore, CA 94550 (United States)

2011-10-01

240

Improved Method for Detection of Starch Hydrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new starch hydrolysis detection method which does not rely on iodine staining or the use of color-complexed starch is described. A linear relationship was obtained with agar-starch plates when net clearing zones around colonies of yeasts were plotted against enzyme levels (semilogarithm scale) produced by the same yeast strains in liquid medium. A similar relationship between starch clearing zones and ?-amylase levels from three different sources was observed. These observations suggest th...

1982-01-01

 
 
 
 
241

Methods of detecting defective nuclear fuel elements  

International Nuclear Information System (INIS)

A method is specified for ultrasonically detecting defective nuclear fuel elements while under water and spaced within a nuclear fuel assembly of the type used in water cooled reactors. The method consists of inserting an ultrasonic search unit having an ultrasonic transducer element into the spaces between the fuel elements; aligning the transducer element with a fuel element to be examined; energising the transducer element to transmit an ultrasonic pulse into the fuel element to be examined; and measuring the ultrasonic echoes reflected. (author)

1980-01-01

242

Improved method for detection of starch hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

A new starch hydrolysis detection method which does not rely on iodine staining or the use of color-complexed starch is described. A linear relationship was obtained with agar-starch plates when net clearing zones around colonies of yeasts were plotted against enzyme levels (semilogarithm scale) produced by the same yeast strains in liquid medium. A similar relationship between starch clearing zones and alpha-amylase levels from three different sources was observed. These observations suggest that the method is useful in mutant isolations, strain improvement programs, and the prediction of alpha-amylase activities in culture filtrates or column effluents. (Refs. 18).

Ohawale, M.R.; Wilson, J.J.; Khachatourians, G.G.; Ingledew, W.M.

1982-09-01

243

Detection Method of TOXOPLASMA GONDII Tachyzoites  

Science.gov (United States)

Tachyzoites are considered to be the most important stage of Toxoplasma gondii which causes toxoplasmosis. T. gondii is, an obligate intracellular parasite which infects a wide range of cells. The present study was designed to develop a method for an early detection of T. gondii tachyzoites. The method comprised of a binding assay which was analyzed using principal component and cluster analysis. Our data showed that glycoconjugates GC1, GC2, GC3 and GC10 exhibit a significantly higher binding affinity for T. gondii tachyzoites as compared to controls (T. gondii only, PAA only, GC 1, 2, 3, and 10 only).

Eassa, Souzan; Bose, Chhanda; Alusta, Pierre; Tarasenko, Olga

2011-06-01

244

Development of automatic analyzing system for radiation-induced mutation. Improvement of its detection efficacy and developments of effective probe and primer, and detection techniques  

International Nuclear Information System (INIS)

From the previous project on high-speed autoanalyzing system for radiation-induced chromosome aberrations, it became possible to easily and certainly identify a centromere by fluorescence staining according to FISH method using a probe with the consensus sequence to ?-satellite DNA. However, this method was thought to be unappropriate for the analysis of dicentric chromosomes because the amount of the satellite DNA on the centromeres was in a wide range, 1-4%. Therefore, development of the detection method for radiation-induced mutation using a new fluorescent material was attempted in this study. First, a detection method using PCR for different genes was developed and a new method for purification of genome DNA from culture cells only with heat treatment was established. Then, real-time detection of genome DNA damaged by radiation was attempted. (M.N.)

1997-02-01

245

Detection and spectral measurements of coherent synchrotron radiation at FLASH  

International Nuclear Information System (INIS)

The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 ?m to 110 ?m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 ?m to 160 ?m were done. (orig.)

2010-01-01

246

Detection and spectral measurements of coherent synchrotron radiation at FLASH  

Energy Technology Data Exchange (ETDEWEB)

The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 {mu}m to 110 {mu}m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 {mu}m to 160 {mu}m were done. (orig.)

Behrens, Christopher

2010-02-15

247

New methods of performing radiation protection inspections in Norway  

Energy Technology Data Exchange (ETDEWEB)

In recent years the Norwegian Radiation Protection Authority (NRPA) has put a lot of effort in working out new national radiation protection legislation. Less time-consuming administration of radiation users and radiation sources was one of the goals of the new legislation, hopefully giving more time for inspections. In the same period NRPA has tested out new methods of performing radiation protection inspections, going beyond the traditionally technical inspections. These methods, and also promising methods used by other regulatory bodies in the Health, Security and Environment (HSE) area in Norway, are described in this paper.

Davidson, T.M.; Finne, I.E. [Norwegian Radiation Protection Authority, Oesteraas (Norway)

2005-09-15

248

Recovering method for radiation shielding material  

Energy Technology Data Exchange (ETDEWEB)

The radioactive shielding material of the present invention comprises a water absorbing resin, water and a radiation shielding material. The water absorbing resin includes, for example, natural polysaccharides such as agar and alginic acid and natural polymer compounds in addition to polymer compounds such as cross-linked polyacrylate materials. The radioactive shielding material includes boron compounds such as boron carbide in addition to boron, iron, lead and cadmium. After irradiating radiation rays to the radiation shielding material, a metal salt such as NaCl is added and water is separated and removed from the radiation shielding material by an appropriate means. (T.M.).

Yamada, Kazuyoshi; Shimomura, Tadao.

1993-06-25

249

Human Portable Radiation Detection System Communications Package Evaluation  

International Nuclear Information System (INIS)

Testing and valuation of the Human Portable Radiation Detection System Communications Package for the US Coast Guard. The main components of the HCP field kit are an Archer Field PC(regsign) and an Iridium satellite phone, along with various charging components and cables. The Archer Field PC has an Enfora Global System for Mobile/General Packet Radio System (GSM/GPRS) wireless cellular modem installed via the compact flash (CF) port. The Iridium satellite phone has a serial communication interface attached. The Archer Field PC is running Windows Mobile(regsign) 5.0 operating system. Included Microsoft products are Excel(regsign) Mobile, PowerPoint(regsign) Mobile, Word(regsign) Mobile, and Internet Explorer(regsign) Mobile. There is an Outlook(regsign) Email program that can be accessed via sending a file or the Messaging link. The Cambridge Computer Corporation vxHpc program is installed to provide a Hyperterm-like software product. vxHpc supports multiple communication protocols. An AT and T SIM card was provided for the GSM wireless cellular modem. A check with AT and T determined the SIM card was not activated to provide cellular service. The Iridium satellite phone did not have a SIM card and has no service. The Archer Field PC boots into a HCP program, displaying the Main Menu. The following actions can be executed by selecting the appropriate box: Spectrum Download, Spectrum Transfer, and Admin Control. The Spectrum Download function uses the serial communication port to download data files from another device, such as a Radiation Isotope Identification Device (RIID). The Spectrum Transfer function uses either the installed wireless cellular modem or the Iridium satellite phone (attached to the serial communication port) to send data files to a computer modem at the Laboratories and Scientific Services (LSS). The Admin Control function allows entering phone numbers and data file deletion. PNNL recommends that DNDO (and/or CG) contact Sanmina and request a demo of the HCP Email data capability. The demo should include at a minimum three spectra data file attachments (background, known source, and unknown source) that are sent in the email package. The data should be sent using both included wireless cell phone hardware and the Iridium sat phone. The HCP has been optimized to operate on the Iridium Satellite Network, so that constraint needs to be factored into the selection of a service provider. It is also suggested that discussions with Sanmina work out the best method for CG personnel to use the HCP without requiring a separate email account for each HCP (e.g., similar to a BlackBerry using the member's email account), which should help make the HCP more user friendly.

2009-01-01

250

Research and development for a high-temperature helium-leak detection system (Joint research). Part 3. Development of radiation sensors  

International Nuclear Information System (INIS)

In the final third stage of the research and development for a high-temperature helium-leak detection system, the radiation sensor was developed in order to detect very small helium leakage. Applying the radiation sensor, we proposed not only the direct detection method which uses the detection of FP gas in helium, but also the active method which uses the difference in the radiation absorption between helium and air. From obtained data it was found that we could detect 0.2 cm3/s leakage within 10 minutes by the active method. (author)

2003-01-01

251

Radiation detection and situation management by distributed sensor networks  

Energy Technology Data Exchange (ETDEWEB)

Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays of low cost, small heterogeneous sensors with the ability to detect the presence of radioactive materials in a moving vehicle over a specific region. In this paper, we report on the use of a heterogeneous, wireless, distributed sensor network for traffic monitoring in a field demonstration. Through wireless communications, the energy spectra from different radiation detectors are combined to improve the detection confidence. In addition, the DSN exploits other sensor technologies and algorithms to provide additional information about the vehicle, such as its speed, location, class (e.g. car, truck), and license plate number. The sensors are in-situ and data is processed in real-time at each node. Relevant information from each node is sent to a base station computer which is used to assess the movement of radioactive materials.

Jan, Frigo [Los Alamos National Laboratory; Mielke, Angela [Los Alamos National Laboratory; Cai, D Michael [Los Alamos National Laboratory

2009-01-01

252

Radiation detection and situation management by distributed sensor networks  

International Nuclear Information System (INIS)

Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays of low cost, small heterogeneous sensors with the ability to detect the presence of radioactive materials in a moving vehicle over a specific region. In this paper, we report on the use of a heterogeneous, wireless, distributed sensor network for traffic monitoring in a field demonstration. Through wireless communications, the energy spectra from different radiation detectors are combined to improve the detection confidence. In addition, the DSN exploits other sensor technologies and algorithms to provide additional information about the vehicle, such as its speed, location, class (e.g. car, truck), and license plate number. The sensors are in-situ and data is processed in real-time at each node. Relevant information from each node is sent to a base station computer which is used to assess the movement of radioactive materials

2009-01-01

253

Failed fuel detection method and detection device therefor  

Energy Technology Data Exchange (ETDEWEB)

The present invention provide a method and a device for detecting a failed fuel, in which the detection sensitivity of delayed neutrons released from fission products leaked from a defective fuel assembly in a FBR type reactor is improved. That is, a fist neutron detector is disposed at a position near an intermediate heat exchanger of the FBR type reactor, where the level of prompt neutrons emitted from a reactor core is low. A second neutron detector is disposed at a place except for the vicinity of the intermediate heat exchanger, where the level of prompt neutrons emitted from the reactor core is also low. A calculation processing section is disposed for outputting a calculated difference signals calculated based on the output signals from the first neutron detector and the output signal from the second neutron detector. With such a constitution, signal components of the failed fuel can be determined at a good sensitivity efficiency based on the calculation difference between both of the signals from the first neutron detector which outputs addition signals for each of components of the failed fuel and the back ground of the reactor and from the second neutron detector which outputs background component signals of the reactor core. (I.S.).

Sudo, Takayuki.

1993-04-27

254

A dual-sided coded-aperture radiation detection system  

Energy Technology Data Exchange (ETDEWEB)

We report the development of a large-area, mobile, coded-aperture radiation imaging system for localizing compact radioactive sources in three dimensions while rejecting distributed background. The 3D Stand-Off Radiation Detection System (SORDS-3D) has been tested at speeds up to 95 km/h and has detected and located sources in the millicurie range at distances of over 100 m. Radiation data are imaged to a geospatially mapped world grid with a nominal 1.25- to 2.5-m pixel pitch at distances out to 120 m on either side of the platform. Source elevation is also extracted. Imaged radiation alarms are superimposed on a side-facing video log that can be played back for direct localization of sources in buildings in urban environments. The system utilizes a 37-element array of 5x5x50 cm{sup 3} cesium-iodide (sodium) detectors. Scintillation light is collected by a pair of photomultiplier tubes placed at either end of each detector, with the detectors achieving an energy resolution of 6.15% FWHM (662 keV) and a position resolution along their length of 5 cm FWHM. The imaging system generates a dual-sided two-dimensional image allowing users to efficiently survey a large area. Imaged radiation data and raw spectra are forwarded to the RadioNuclide Analysis Kit (RNAK), developed by our collaborators, for isotope ID. An intuitive real-time display aids users in performing searches. Detector calibration is dynamically maintained by monitoring the potassium-40 peak and digitally adjusting individual detector gains. We have recently realized improvements, both in isotope identification and in distinguishing compact sources from background, through the installation of optimal-filter reconstruction kernels.

Penny, R.D., E-mail: robert.d.penny@saic.com [Science Applications International Corporation, 10740 Thornmint Rd., San Diego, CA 92124 (United States); Hood, W.E.; Polichar, R.M.; Cardone, F.H.; Chavez, L.G.; Grubbs, S.G.; Huntley, B.P.; Kuharski, R.A.; Shyffer, R.T. [Science Applications International Corporation, 10740 Thornmint Rd., San Diego, CA 92124 (United States); Fabris, L.; Ziock, K.P. [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); Labov, S.E.; Nelson, K. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

2011-10-01

255

A Radiation Dosimetry Method Using Pulsed Optically Stimulated Luminescence  

International Nuclear Information System (INIS)

A method for the determination of absorbed radiation dose is described based on pulsed optically stimulated luminescence (POSL). The method relies upon the stimulation of an irradiated sample with a train of light pulses from a suitable light source (e.g. a laser) using a wavelength which is within the range of wavelengths corresponding to the radiation-induced optical absorption in the irradiated sample. The subsequent emitted light, due to the detrapping of trapped charges and their subsequent recombination with charge of the opposite sign, is synchronously detected in the period between each stimulation pulse. The total luminescence is summed over the desired number of stimulation pulses and this forms the measured POSL signal. By monitoring the emitted light only in the period between stimulation pulses one can reduce the optical filtering required to discriminate between the stimulation light and the emission light; in this way a high measurement efficiency, and, therefore, a high radiation sensitivity (luminescence intensity per unit absorbed dose) is achieved. Key parameters in the method are the intrinsic luminescence lifetime for the material being used as the luminescent detector, the width of the optical stimulation pulse, and the period between pulses. For optimum operation the measurement parameters should be such that both the pulse width and the time between pulses are much less than the luminescence lifetime. By appropriate choice of the power of the optical stimulation, the frequency of the stimulation pulses, and the total stimulation period, one can also re-measure the absorbed dose several times. In this way, a re-read capability is available with the procedure. The method is illustrated using light from a 2nd-harmonic Nd:YAG laser, with irradiated, anion-deficient aluminium oxide as the luminescent detector material. (author)

1999-01-01

256

Coolant leakage detecting method for coolants  

International Nuclear Information System (INIS)

Purpose: To rapidly and surely detect the coolant leakages by determining the level fluctuation rate in the drain sump. Method: The drain sump level in the dry well floor is detected by a ultrasonic level detector and sent to a leakage rate calculating device as a level signal. While on the other hand, a signal indicating the running state of the drain sump pump for the dry well is inputted to a scheduler. The coolant leaking rate calculated in the leaking rate calculator is sent as a signal to a comparator. The comparator judges the state of the signal relative to a limit value and issues an output, depending on the comparison result, to an alarm output device. The alarm output device informs the presence or absence of the coolant leakages. (Seki, T.)

1979-01-01

257

Method of measuring blood flow by radiation  

International Nuclear Information System (INIS)

A method of measuring relative blood flow through at least a part of the body using penetrating radiation comprises transmitting a plurality of rays at an initial angle or initial mean angle through a planar slice of the body to define a first set of rays, transmitting a plurality of further sets of rays at angles or mean angles different from each other and from the initial angle or initial mean angle through the same planar slice of the body to define by the intersection of all such rays a two-dimensional matrix of elements of the body in the slice, measuring for each ray emerging from the body a number of over the period of time at least equal to a pulse interval representing the momentary sum of the transmissions or absorptions of the element of the body intersected by the ray, determining from the momentary signals momentary signals a difference signal representing the maximum difference between the momentary signals for each ray over the period of time, deriving sets of discrete difference signals corresponding to the sets of rays, the difference signals being indicative of the transmission or absorption of blood flowing through each element of the body in the matrix, and calculating from the difference signals resultant signals representing the transmissions or absorptions due to blood flow in the elements of the matrix. These resultant signals may be visually depicted on a cathode ray tube display, as a digital print-out, or as a photograph. 30 claims, 8 figures

1977-01-01

258

A testing and calibration method for channel vehicle radiation monitoring system  

International Nuclear Information System (INIS)

In this paper, a testing and calibration method for channel vehicle radiation monitoring system was presented through experiments on the basisi of the requirements of IAEA technical guidance. The comprehensive performance for channel vehicle radiation monitoring system was studied in aspects of detection threshold, average value of activity response, nonlinearity of activity response, effective detection area and repeatability, and simultaneously, a method for dynamic testing was discussed. The result indicates that the testing and calibration method are feasible, and that there are practical significance for effective preventing the spread of radioactive materials due to monitor system's inaccuracy and malfunction. (authors)

2009-09-01

259

Practical methods for radiation survey in nuclear installations  

International Nuclear Information System (INIS)

This study is placed to those who are responsible to perform radiation survey in the nuclear installations, especially the beginners. Therefore, it gives a comprehensive view to all-important aspects related to their work starting from the structure of atoms to the practical steps for radiation survey works. So, it clarify how to perform personal monitoring, methods for monitoring surface contamination, methods for measuring radioactivity of gases and radioactive aerosols in air, monitoring radiation doses, measuring radiation influences in workplaces and finally measuring internal exposure of radiation workers in nuclear installations. Finally, The study shows some cases of breaches of radiation protection rules in some American nuclear installations and describes the final results of these breaches. The aim of this is to assure that any breach or ignore to radiation protection principles may produce bad results, and there is no leniency in implementing environmental radiation protection principles. (author)

2001-01-01

260

A novel mobile system for radiation detection and monitoring  

Science.gov (United States)

A novel mobile system for real time, wide area radiation surveillance has been developed within the REWARD project, financed within the FP7 programme, theme SEC-2011.1.5-1 (Development of detection capabilities of difficult to detect radioactive sources and nuclear materials - Capability Project). The REWARD sensing units are small, mobile portable units with low energy consumption, which consist of new miniaturized solid-state radiation sensors: a CdZnTe detector for gamma radiation and a high efficiency neutron detector based on novel silicon technologies. The sensing unit is integrated by a wireless communication interface to send the data remotely to a monitoring base station as well as a GPS system to calculate the position of the tag. The system also incorporates middleware and high-level software to provide web-service interfaces for the exchange of information. A central monitoring and decision support system has been designed to process the data from the sensing units and to compare them with historical record in order to generate an alarm when an abnormal situation is detected. A security framework ensures protection against unauthorized access to the network and data, ensuring the privacy of the communications and contributing to the overall robustness and reliability of the REWARD system. The REWARD system has been designed for many different scenarios such as nuclear terrorism threats, lost radioactive sources, radioactive contamination or nuclear accidents. It can be deployed in emergency units and in general in any type of mobile or static equipment, but also inside public/private buildings or infrastructures. The complete system is scalable in terms of complexity and cost and offers very high precision on both the measurement and the location of the radiation. The modularity and flexibility of the system allows for a realistic introduction to the market. Authorities may start with a basic, low cost system and increase the complexity based on their evolving needs and budget constraints. On 24th September 2013, REWARD project received a prize as the best Innovative project related to the Not Conventional Threat (NCT) Chemical Biological Radiological Nuclear explosives (CBRNe) products. A highly distinguished jury stated that "the developed detection and surveillance system offers a perfect solution for end-users to enhance crucial capabilities in RN analysis, risk communication and surveillance in case of a radiation incident". A demonstration of the REWARD system is planned in Naples on September 2014. More information about the REWARD project can be found at www.reward-project.eu.

Biafore, Mauro

2014-05-01

 
 
 
 
261

Development of TOF-PET based on Cherenkov radiation detection  

International Nuclear Information System (INIS)

We have proposed a new Time-of-Flight Positron Emission Tomography (TOF-PET) concept based on Cherenkov radiation detection, where lead glasses and fast micro-channel plate photo-multiplier tubes (MCP-PMTs) were adopted as the Cherenkov radiator and the photo detector, respectively. Through the Monte Carlo simulations and the preliminary experiments, we have estimated the basic performance of this technique. The simulation results have shown that the spatial resolution with TOF information under the time resolution ?T=100ps would be around 4 mm using the Maximum Likelihood-Expectation Maximization (ML-EM) algorithm and also the signal to noise ratio could be about three times better improved by using TOF information. The present detector element combined with the lead glass and MCP-PMT has been experimentally verified to have the time resolution of 170ps, which corresponds to the spatial resolution around 5 mm in the quasi-2D image reconstruction from the 1D experimental data. From these results, it would be concluded that the present technique could be a powerful candidate for the TOF-PET but the detection efficiency should be improved through redesigning the Cherenkov radiator materials and configuration. (author)

2005-11-01

262

Methods of radiation breatment of plastics for decorative aids (review)  

International Nuclear Information System (INIS)

A review deals with different methods of radiation treatment of polymers for formation of various decorative elements. Among them there are radiation treatment of polymer films for formation of images, drawings, radiation treatment of thin-walled polymer products (sheets, panels, plates) for decorative purposes, laser beam and radiation treatment of polymethylmethacrylate for manufacturing decorative products of different sizes with a picture inside the volume

1982-01-01

263

A Parallel Tracking Method for Acoustic Radiation Force Impulse Imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Radiation force-based techniques have been developed by several groups for imaging the mechanical properties of tissue. Acoustic Radiation Force Impulse (ARFI) imaging is one such method that uses commercially available scanners to generate localized radiation forces in tissue. The response of the tissue to the radiation force is determined using conventional B-mode imaging pulses to track micron-scale displacements in tissue. Current research in ARFI imaging is focused on producing real-time...

Dahl, Jeremy J.; Pinton, Gianmarco F.; Mark, L.; Agrawal, Vineet; Nightingale, Kathryn R.; Trahey, Gregg E.

2007-01-01

264

Method and apparatus for detecting explosives  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.

Moore, David Steven (Santa Fe, NM)

2011-05-10

265

Detection of viability: radiopharmacological conditions, methods, indications  

International Nuclear Information System (INIS)

The indication of revascularization in patients with coronary artery disease is mainly based on factors such as coronary anatomy ischemia as well as ventricular function, patient's biological age or accompanying diseases. In general, evidence of vital myocardium plays a secondary role but will be important in patients with hibernating myocardium. Tl-201 scintigraphy with re-injection technique or rest-redistribution-examination is a simple and cost-effective method of the detection or exclusion of hibernation. However, in case of doubt F-18 FDG PET is recommended to guide further therapeutic strategies. (orig.)

1996-07-01

266

Apparatus and method for detecting explosives  

International Nuclear Information System (INIS)

An apparatus is described for use in situations such as airports to detect explosives hidden in containers (for eg. suitcases). The method involves the evaluation of the quantities of oxygen and nitrogen within the container by neutron activation analysis and the determination of whether these quantities exceed predetermined limits. The equipment includes a small sub-critical lower powered reactor for thermal (0.01 to 0.10 eV) neutron production, a radium beryllium primary source, a deuterium-tritium reactor as a high energy (> 1.06 MeV) neutron source and Geiger counter detector arrays. (UK)

1976-01-01

267

Detection of neutral particle radiation with the Mars Science Laboratory (MSL) Radiation Assessment Detector (RAD)  

International Nuclear Information System (INIS)

RAD, the Radiation Assessment Detector on NASA's Mars Science Laboratory (MSL) rover mission is designed to detect a wide range of different particle species at energies up to 100 MeV/nuc. We present the beam testing results for the flight units of the RAD Sensor Head unit (RSH). Neutral particle response, anti-coincidence efficiency as well as behaviour for relativistic high-Z (up to iron) particles are shown. Additionally, we present the response of our RSH GEANT4 model for the expected (simulated) Mars surface radiation environment.

2009-04-02

268

Geiger-mueller radiation detector with means for detecting and indicating the existence of radiation overload  

International Nuclear Information System (INIS)

When subjected to radiation overload existing geiger-mueller counters may give an erroneously low reading, resulting in possible hazard to personnel. The instant invention discloses simple and inexpensive apparatus to remedy this dangerous shortcoming. Depending on the geometry of the detector tube, two possible failure modes have been identified, and circuitry is disclosed to detect the existence of these respective failure modes. The disclosed apparatus indicates the absence of an overload condition, in addition to signaling, by both visible and audible means, the existence of excessive radiation that might result in erroneously low reading of the geiger-mueller counter

1981-01-01

269

Calculation of the radiation exchange in a closed chamber by the method of radiation bands in comparison to the method of the average radiation parameter  

Energy Technology Data Exchange (ETDEWEB)

Two methods for calculating the radiation exchange within a closed chamber with isothermic material, i.e. the classical method of the average emission capacity and the method of the black radiation bands, are compared and approximate auxiliary equations are developed for both methods. The calculation results of the methods investigated differ by approx. 30 to 80 %. The measurements which have been carried out confirm the greater accurracy of the radiation bands method.

Szargut, J.; Wandrasz, J.

1978-08-01

270

Some methods for the detection of fissionable matter; Quelques methodes de detection des corps fissiles  

Energy Technology Data Exchange (ETDEWEB)

A number of equipments or processes allowing to detect uranium or plutonium in industrial plants, and in particular to measure solution concentrations, are studied here. Each method has its own field of applications and has its own performances, which we have tried to define by calculations and by experiments. The following topics have been treated: {gamma} absorptiometer with an Am source, detection test by neutron multiplication, apparatus for the measurement of the {alpha} activity of a solution, fissionable matter detection by {gamma} emission, fissionable matter detection by neutron emission. (author) [French] On examine ici plusieurs appareils ou procedes qui permettent de detecter l'uranium ou le plutonium dans les installations industrielles, et en particulier de mesurer les concentrations de solutions. Chacune des methodes a son domaine d'application et ses performances, qu'on a tente de definir par le calcul et par des experiences. Les sujets traites sont les suivants: absorptiometre {gamma} a source d'americium, essais de detection par multiplication neutronique, appareil de mesure de l'activite {alpha} d'une solution, detection des matieres fissiles par leur emission {gamma}, detection des matieres fissiles par leur emission neutronique. (auteur)

Guery, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-03-01

271

 Methods of detection of selected respiratory viruses  

Directory of Open Access Journals (Sweden)

Full Text Available  Respiratory viruses contribute to significant morbidity and mortality in healthy and immunocompromised individuals and are considered as a significant economic burden in the healthcare system. The similar clinical symptoms in the course of different viral and bacterial respiratory infections make the proper diagnosis difficult. An accurate and prompt diagnostics is crucial for infection control and patient management decisions, especially regarding the use of antibacterial or antiviral therapy and hospitalization. Moreover, the identification of the causative agent eliminates inappropriate use of antibiotics and may reduce the cost of healthcare.A wide variety of diagnostic procedures is applied for the detection of viral agents responsible for respiratory tract infections. For many years, the viral antigen detection and standard isolation technique in cell culture was the main method used in routine diagnostics. However, in recent years the nucleic acid amplification techniques have become widely used and have significantly improved the sensitivity of viral detection in clinical specimens. Molecular diagnostic assays have contributed to revealing high rates of co-infection (multiplex reactions and allow identification of agents that are difficult to culture.This paper discusses a number of technical aspects of the current most commonly used techniques, their general principles, main benefits and diagnostic value, but also some of their limitations.

Ilona Stefa?ska

2012-06-01

272

Leak and Pipe Detection Method and System  

Science.gov (United States)

A method and system for locating leaks of conductive fluids from non-conductive pipes and other structures or for locat- ing non-conductive pipes or structures having conductive fluid contained therein, employ a charge generator to apply a time varying charge to the conductive fluid, and a capaci- tive type detector that can detect the variable charge that is induced in the fluid. The capacitive detector, which prefer- ably includes a handheld housing, employs a large conduc- tive pickup plate that is used to locate the pipe or leak by scanning the plate over the ground and detecting the induced charge that is generated when the plate comes in close proximity to the pipe or leak. If a leak is encountered, the resulting signal will appear over an area larger than expected for a buried pipe, assuming the leak provides an electrically conductive path between the flow and the wet surrounding ground. The detector uses any suitable type of indicator device, such as a pair of headphones that enable an operator to hear the detected signal as a chirping sound, for example.

Youngquist, Robert C. (Inventor)

2003-01-01

273

Detection of irradiated powdered foods using photostimulated luminescence method  

International Nuclear Information System (INIS)

Photostimulated luminescence (PSL) method provides a rapid and markedly sensitive technique to detect of any irradiated food that contain minerals. This method is also convenient as a first screening means in comparison with thermoluminescence (TL) method which requires separating minerals from the food materials. The present study reports the results of PSL measurements for both irradiated and non-irradiated powdered dry leaf vegetable obtained with the prototype of PSL system developed by our groups. This PSL system consists of pulsed Infra-Red (IR) source for photostimulation, single photon counting system for high sensitive detection of luminescence, and computer for data treatments. The PSL intensity of the leaf vegetable increased with increase of gamma radiation dose and show a linear relationship up to a dose of 1kGy. The PSL intensities after four months of storage under light shielding following gamma irradiation (0.49?3.1kGy) decreased to less than half of initial intensities. The PSL intensities of those decreased rapidly for 60 seconds and reached a steady level close to intensity of non-irradiated sample after 300 seconds following photostimulation. We used the information on the shape and slope of PSL intensity curve as a criteria to discriminate whether irradiated foods or not, and possible to detect the irradiation history of food irradiated with a 0.49kGy dose after four months of storage. (author)

2005-09-01

274

Device for the detection or measurement of ionizing radiation  

International Nuclear Information System (INIS)

The semiconductor detector with a 'pin'-structure for detecting e.g. gamma radiation is mounted within a cryostat. Inside the detector is oriented in such manner that the gamma radiation fully hits the zone with intrinsic conduction (side-entry type). In order to be able to neglect the influence of the electrically active layers deposited on the surface of the intrinsically conducting zone the detector is irradiated with light. By this means the pattern of the lines of force at the edge is straightened and the electron-hole pairs generated there contribute to the measurement, too. For the measurement there may be used planar Ge(Li) detectors and lamps of 1.2 watts. (DG)

1978-01-01

275

Platelet antibody: review of detection methods  

International Nuclear Information System (INIS)

The driving force behind development of in vitro methods for platelet antibodies is identification of plasma factors causing platelet destruction. Early methods relied on measurement of platelet activation. Current methods are more specific and use a purified antibody against immunoglobulin or complement, which is usually labeled with 125I or tagged with an enzyme or fluorescein. Comparisons of quantitation of platelet-associated IgG show wide variability between different methods. The disparate results can be related both to differences in binding of secondary antibodies to immunoglobulin in solution compared to immunoglobulins attached to platelets and to the improper assumption that the binding ratio between the secondary detecting and primary antiplatelet antibody is one. Most assays can 1) identify neonatal isoimmune thrombocytopenia and posttransfusion purpura, 2) help to differentiate between immune and nonimmune thrombocytopenias, 3) help to sort out the offending drug when drug-induced thrombocytopenia is suspected, and 4) identify platelet alloantibodies and potential platelet donors via a cross match assay for refractory patients. However, the advantages of quantitative assays over qualitative methods with respect to predictions of patients clinical course and response to different treatments remain to be investigated. 61 references

1988-01-01

276

Method and system for detecting explosives  

Science.gov (United States)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Reber, Edward L. (Idaho Falls, ID); Jewell, James K. (Idaho Falls, ID); Rohde, Kenneth W. (Idaho Falls, ID); Seabury, Edward H. (Idaho Falls, ID); Blackwood, Larry G. (Idaho Falls, ID); Edwards, Andrew J. (Idaho Falls, ID); Derr, Kurt W. (Idaho Falls, ID)

2009-03-10

277

Spectral Analysis Method of Plastic Scintillator-based Radiation Detector against Nuclear/Radiological Terrorism  

Energy Technology Data Exchange (ETDEWEB)

In these days, the threats relating to nuclear or radioactive materials have become a matter of internationally increased grave concern. A plastic scintillation detector in radiation portal monitoring (RPM) application has been used to detect radioactive sources in steel scrap entering reprocessing facilities, and to detect illicit transport of radioactive material across border ports-of-entry. The detection systems for RPM application usually are large and can not easily be moved to a different location. For some situations, an inconspicuous and mobile system for the radioactive or nuclear material during road transport is needed. The mobile radiation detection system has employed a NaI- based radiation detector to detect and identify the material hidden in vehicle. There are some operational constraints - short measuring time, weak activity due to heavy shield of illegal source, long distance - of inspection system in such nuclear security applications. Due to these constraints, large area sensor is required to maximize its sensitivity. Large NaI material, however, is extremely expensive. In designing a radiation detector for prevention of illicit trafficking of nuclear or radioactive materials, the trade-off should be carefully optimized between performance and cost in order to achieve cost-effective inspection system. For the cost-effective mobile radiation detection system, this paper describes new spectral analysis method to use the crude spectroscopic information available from a plastic detector to discriminate other man-made radiation source from NORM.

Kwak, Sung-Woo; Yoo, Ho-Sik; Jang, Sung Soon; Kim, Jung-Soo; Yoon, Wan-Ki [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2008-10-15

278

Spectral Analysis Method of Plastic Scintillator-based Radiation Detector against Nuclear/Radiological Terrorism  

International Nuclear Information System (INIS)

In these days, the threats relating to nuclear or radioactive materials have become a matter of internationally increased grave concern. A plastic scintillation detector in radiation portal monitoring (RPM) application has been used to detect radioactive sources in steel scrap entering reprocessing facilities, and to detect illicit transport of radioactive material across border ports-of-entry. The detection systems for RPM application usually are large and can not easily be moved to a different location. For some situations, an inconspicuous and mobile system for the radioactive or nuclear material during road transport is needed. The mobile radiation detection system has employed a NaI- based radiation detector to detect and identify the material hidden in vehicle. There are some operational constraints - short measuring time, weak activity due to heavy shield of illegal source, long distance - of inspection system in such nuclear security applications. Due to these constraints, large area sensor is required to maximize its sensitivity. Large NaI material, however, is extremely expensive. In designing a radiation detector for prevention of illicit trafficking of nuclear or radioactive materials, the trade-off should be carefully optimized between performance and cost in order to achieve cost-effective inspection system. For the cost-effective mobile radiation detection system, this paper describes new spectral analysis method to use the crude spectroscopic information available from a plastic detector to discriminate other man-made radiation source from NORM

2008-10-01

279

Nick translation detection in situ of cellular DNA strand break induced by radiation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

DNA strand break in HeLa cells induced by radiation was detected using the in situ nick translation method. The cells were exposed to radiation of 3, 6, 12, 18, and 24 Gy in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and [3H]-labeled dTTP. Autoradiographic observation was made of the level of break sites in the DNA. The DNA strand brea...

Maehara, Y.; Anai, H.; Kusumoto, T.; Sakaguchi, Y.; Sugimachi, K.

1989-01-01

280

Measuring equipment for position-sensitive detection of ionizing radiation  

International Nuclear Information System (INIS)

The proportional or Geiger-Mueller counter for X-ray and neutron detection or the surface barrier-layer semiconductor detector has an additional reference electrode parallel to the collector electrode. In order to improve the linearity, the reference electrode gives a signal which has the same rise time independently of the position of the pulse or the exciting radiation. By this means a standardized reference time signal is obtained to be compared with the position-dependent pulse from the highly resistive collector electrode. (DG)

1979-01-01

 
 
 
 
281

SARA (Spectroscopic Ambient Radiation Detection) Spectroscopic Monitoring Systems for Online Environmental Radiation Monitoring Edition 2008  

International Nuclear Information System (INIS)

In the wake of a nuclear incident, it is essential that you can react promptly and provide a completely reliable assessment of the radiological situation. First and foremost, it is vital that your radiation early warning system can automatically detect any man-made isotopes in the environment and identify any changes in the composition of the ambient radiation. Before appropriate countermeasures can be implemented, it is crucial that authorities have accurate information about the type of contamination and its dispersion. TechniData's spectroscopic online monitoring system will improve your existing monitoring systems, provide important information about the composition of ambient radiation during an incident, and therefore help you to make the right decisions

2008-11-15

282

On the net radiation method for heat transfer  

CERN Multimedia

A simplifying approach for calculating the radiant energy is achieved by introducing the concept of net transmittance, resulting in a novel variation of the net radiation method that provides an easy way for solving a variety of situations. In particular, a closed form for the net radiation between two grey plates through a radiation shield formed by a series of partially transparent partially reflecting partially absorbing plates is found. In addition, the method is generalized to cylindrical and spherical geometries.

Micco, C D

2003-01-01

283

Nick translation detection in situ of cellular DNA strand break induced by radiation  

International Nuclear Information System (INIS)

DNA strand break in HeLa cells induced by radiation was detected using the in situ nick translation method. The cells were exposed to radiation of 3, 6, 12, 18, and 24 Gy in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and [3H]-labeled dTTP. Autoradiographic observation was made of the level of break sites in the DNA. The DNA strand break appeared even with a 3 Gy exposure, increased 8.6 times at 24 Gy compared with the control cells, and this level correlated reciprocally to change in cell viability. This nick translation method provides a rapid in situ assay for determining radiation-induced DNA damage of cultured cells, in a semi-quantitative manner

1989-01-01

284

Supersonic wave detection method and supersonic detection device  

International Nuclear Information System (INIS)

The present invention provides a method of and device for a detection suitable to a channel box which is used while covering a fuel assembly of a BWR type reactor. Namely, a probe for transmitting/receiving supersonic waves scans on the surface of the channel box. A data processing device determines an index showing a selective orientation degree of crystal direction of the channel box based on the signals received by the probe. A judging device compares the determined index with a previously determined allowable range to judge whether the channel box is satisfactory or not based on the result of the comparison. The judgement are on the basis that (1) the bending of the channel box is caused by the difference of elongation of opposed surfaces, (2) the elongation due to irradiation is caused by the selective orientation of crystal direction, and (3) the bending of the channel box can be suppressed within a predetermined range by suppressing the index determined by the measurement of supersonic waves having a correlation with the selective orientation of the crystal direction. As a result, the performance of the channel box capable of enduring high burnup region can be confirmed in a nondestructive manner. (I.S.)

1995-05-15

285

A combined optimization method for radiation shielding design in mixed radiation field measurements  

International Nuclear Information System (INIS)

One single shield design was not suitable for all measuring points with different local radiation characters and measurement objects in mixed-radiation field. A new method is needed for quantitative evaluation and automatically optimizing design of radiation shielding to adapt it to various conditions. Based on cost-benefit principle, the authors propose an evaluation method for radiation shielding, and implement a combined optimization method based on genetic algorithm. Experiments show that the evaluation method is consistent with results given by various references and MCNP; in typical condition, influence of noise radiation from optimized design is 44% of the traditional design. The combined optimization method is able to automatically optimize design with certain radiation characters and measuring point parameters that is useful for project design and data analysis. (authors)

2006-01-01

286

Ticor-based scintillation detectors for detection of mixed radiation  

CERN Multimedia

Detection of mixed radiation of thermal neutrons and gamma-rays have been realized using a new ceramic material based on small-crystalline long-wave scintillator alpha-Al sub 2 O sub 3 :Ti (Ticor) and lithium fluoride. Characteristics are presented for scintillators with Si-PIN-PD type photoreceivers and PMT under sup 2 sup 3 sup 9 Pu alpha-particles, sup 2 sup 0 sup 7 Bi internal conversion electrons,as well as sup 2 sup 4 sup 1 Am and sup 1 sup 3 sup 7 Cs gamma-quanta. Detection efficiency of thermal neutron is estimated for composite materials based on Ticor and lithium fluoride.

Litvinov, L A; Kolner, V B; Ryzhikov, V D; Volkov, V G; Tarasov, V A; Zelenskaya, O V

2002-01-01

287

Thermoluminescence method for detection of irradiated food  

Energy Technology Data Exchange (ETDEWEB)

A method of thermoluminescence (TL) analysis was developed for the detection of irradiated foods. The TL method is based on the determination of thermoluminescence of adhering or contaminating minerals separated from foods by wet sieving and treatment with high density liquid. Carbon tetrachloride provided a suitable alternative for foods that form gels with water. Thermoluminescence response of minerals in a first TL measurement is normalised with a second TL measurement of the same mineral sample after calibration irradiation to a dose of 5 kGy. The decision about irradiation is made on the basis of a comparison of the two TL spectra: if the two TL glow curves match in shape and intensity the sample has been irradiated, and if they are clearly different it has not been irradiated. An attractive feature of TL analysis is that the mineral material itself is used for calibration; no reference material is required. Foods of interest in the investigation were herbs, spices, berries and seafood. The presence of minerals in samples is a criterion for application of the method, and appropriate minerals were found in all herbs, spices and berries. The most common minerals in terrestrial food were tecto-silicates - quartz and feldspars - which with their intense and stable thermoluminescence were well suited for the analysis. Mica proved to be useless for detection purposes, whereas carbonate in the form of calcite separated from intestines of seafood was acceptable. Fading of the TL signal is considerable in the low temperature part of the glow curve during a storage of several months after irradiation. However, spices and herbs could easily be identified as irradiated even after two years storage. Conditions for seafood, which is stored in a freezer, are different, and only slight fading was observed after one year. The effect of mineral composition and structure on TL was studied for feldspars. Feldspars originating from subtropical and tropical regions exhibit lower TL intensity than feldspars from cold regions, evidently because a more altered mineral structure is typical in warm water regions. A new autoradiographic method to determine luminescence of irradiated rock surfaces was developed for the study. The method of thermoluminescence analysis has been used for the official control analysis of irradiated food in Finland since 1990. In the course of the study, about 500 analyses were carried out for the Finnish Customs Laboratory. Eighty lots of irradiated herbs or spices and 10 lots of irradiated seafood were found. During the last two years, irradiated green tea in spice mixtures and irradiated frog legs have been detected. No irradiated berry or mushroom products have been found. Screening with a photostimulated luminescence (PSL) instrument, followed by TL analysis to confirm the positive and ambiguous samples, provides a reliable tool for the identification of irradiated food containing adhering or contaminating minerals. The reliability of the TL method was proved in European trials. Standardisation of the method has been undertaken by the European Committee for Standardization (CEN). A TL method based on the determination of TL silicate minerals in dry herbs and spices has recently been accepted as an official CEN standard. (orig.) 55 refs.

Pinnioja, S

1998-12-31

288

Thermoluminescence method for detection of irradiated food  

International Nuclear Information System (INIS)

A method of thermoluminescence (TL) analysis was developed for the detection of irradiated foods. The TL method is based on the determination of thermoluminescence of adhering or contaminating minerals separated from foods by wet sieving and treatment with high density liquid. Carbon tetrachloride provided a suitable alternative for foods that form gels with water. Thermoluminescence response of minerals in a first TL measurement is normalised with a second TL measurement of the same mineral sample after calibration irradiation to a dose of 5 kGy. The decision about irradiation is made on the basis of a comparison of the two TL spectra: if the two TL glow curves match in shape and intensity the sample has been irradiated, and if they are clearly different it has not been irradiated. An attractive feature of TL analysis is that the mineral material itself is used for calibration; no reference material is required. Foods of interest in the investigation were herbs, spices, berries and seafood. The presence of minerals in samples is a criterion for application of the method, and appropriate minerals were found in all herbs, spices and berries. The most common minerals in terrestrial food were tecto-silicates - quartz and feldspars - which with their intense and stable thermoluminescence were well suited for the analysis. Mica proved to be useless for detection purposes, whereas carbonate in the form of calcite separated from intestines of seafood was acceptable. Fading of the TL signal is considerable in the low temperature part of the glow curve during a storage of several months after irradiation. However, spices and herbs could easily be identified as irradiated even after two years storage. Conditions for seafood, which is stored in a freezer, are different, and only slight fading was observed after one year. The effect of mineral composition and structure on TL was studied for feldspars. Feldspars originating from subtropical and tropical regions exhibit lower TL intensity than feldspars from cold regions, evidently because a more altered mineral structure is typical in warm water regions. A new autoradiographic method to determine luminescence of irradiated rock surfaces was developed for the study. The method of thermoluminescence analysis has been used for the official control analysis of irradiated food in Finland since 1990. In the course of the study, about 500 analyses were carried out for the Finnish Customs Laboratory. Eighty lots of irradiated herbs or spices and 10 lots of irradiated seafood were found. During the last two years, irradiated green tea in spice mixtures and irradiated frog legs have been detected. No irradiated berry or mushroom products have been found. Screening with a photostimulated luminescence (PSL) instrument, followed by TL analysis to confirm the positive and ambiguous samples, provides a reliable tool for the identification of irradiated food containing adhering or contaminating minerals. The reliability of the TL method was proved in European trials. Standardisation of the method has been undertaken by the European Committee for Standardization (CEN). A TL method based on the determination of TL silicate minerals in dry herbs and spices has recently been accepted as an official CEN standard. (orig.)

1998-01-01

289

Direct detection of black holes via electromagnetic radiation  

Science.gov (United States)

Many black hole (BH) candidates exist, ranging from supermassive (˜106-1010 M?) to stellar masses (˜1-100 M?), all of them identified by indirect processes. Although there are no known candidate BHs with substellar masses, these might have been produced in the primordial Universe. BHs emit radiation composed of photons, gravitons and, later in their lives, massive particles. We explored the detection of such BHs with present-day masses from 10-22 to 10-11 M?. We determined the maximum distances (d) at which the current best detectors should be placed in order to identify such isolated BHs. Broadly, we conclude that in the visible and ultraviolet BHs can be directly detected at d ? 107 m while in the X-ray band the distances might reach ˜108 m (of the order of the Earth-Moon distance) and in the ?-ray band BHs might even be detected from as far as ˜0.1 pc. Since these results give us realistic hopes of directly detecting BHs, we suggest the scrutiny of current and future space mission data to reach this goal.

Sobrinho, J. L. G.; Augusto, P.

2014-07-01

290

Detection methods at reactor neutrino experiments  

Energy Technology Data Exchange (ETDEWEB)

In 2011 and 2012, the smallest neutrino mixing angle ?{sub 13} was determined to be unexpected large by reactor neutrino experiments Daya Bay, Double Chooz, and RENO, and accelerator experiments T2K and MINOS. The most precise measurement is sin{sup 2}2?{sub 13}=0.089±0.010(stat.)±0.005(syst.), provided by Daya Bay. The measurement of ?{sub 13} opened the gateway to the mass hierarchy and CP phase measurements. It also marked the beginning of precision measurements in neutrino studies. With near-far relative measurement and improvements in detector design, the relative precision of neutrino detectors reached 0.2%. Detection methods for reactor neutrinos are reviewed. The highlighted techniques include gadolinium-doped liquid scintillator, three-layer detectors, functionally identical detectors, reflective panel, background shielding, etc. The next generation reactor neutrino experiment Daya Bay II and its technical challenges are briefly described.

Cao, Jun, E-mail: caoj@ihep.ac.cn

2013-12-21

291

Detection methods at reactor neutrino experiments  

Science.gov (United States)

In 2011 and 2012, the smallest neutrino mixing angle ?13 was determined to be unexpected large by reactor neutrino experiments Daya Bay, Double Chooz, and RENO, and accelerator experiments T2K and MINOS. The most precise measurement is sin22?13=0.089±0.010(stat.)±0.005(syst.), provided by Daya Bay. The measurement of ?13 opened the gateway to the mass hierarchy and CP phase measurements. It also marked the beginning of precision measurements in neutrino studies. With near-far relative measurement and improvements in detector design, the relative precision of neutrino detectors reached 0.2%. Detection methods for reactor neutrinos are reviewed. The highlighted techniques include gadolinium-doped liquid scintillator, three-layer detectors, functionally identical detectors, reflective panel, background shielding, etc. The next generation reactor neutrino experiment Daya Bay II and its technical challenges are briefly described.

Cao, Jun

2013-12-01

292

Material degradation detection by magnetic method  

Energy Technology Data Exchange (ETDEWEB)

To be able to evaluate the life of nuclear power plant becomes inevitable as the plant operating period extends. So, magnetic methods using Barkhausen noise (BHN) and B-H curve were applied to detect the degradation by fatigue and thermal aging. Low alloy steel (SA 508 cl.2) was fatigued, and duplex stainless steel (SCS 14A) was aged at 400 C. For the degradation by thermal aging, BHN and B-H curve were measured and good correlations between magnetic properties and aging time were obtained. For fatigue, BHN was measured at predetermined loading cycles and, at each predetermined cycle, the effect of stress or strain condition in the measurement was evaluated. The results showed that BHN was affected by the stress or strain condition in the measurement, the cause of which seemed to be the change of internal stress condition, and by identifying the measuring condition, good correlation between BHN and fatigue damage was obtained.

Yamaguchi, A.; Maeda, N.; Sugibayashi, T. [Japan Power Engineering and Inspection Corp., Yokohama (Japan)

1995-08-01

293

Reconstruction of radiating sound fields using minimum energy method.  

Science.gov (United States)

A method for reconstructing a pressure field at the surface of a radiating body or source is presented using recording data of a microphone array. The radiation is assumed to consist of many spherical radiators, as microphone positions are present in the array. These monopoles are weighted using a parameter alpha, which broadens or narrows the overall radiation directivity as an effective and highly intuitive parameter of the radiation characteristics. A radiation matrix is built out of these weighted monopole radiators, and for different assumed values of alpha, a linear equation solver reconstructs the pressure field at the body's surface. It appears that from these many arbitrary reconstructions, the correct one minimizes the reconstruction energy. The method is tested, localizing the radiation points of a Balinese suling flute, reconstructing complex radiation from a duff frame drum, and determining the radiation directivity for the first seven modes of an Usbek tambourine. Stability in terms of measurement noise is demonstrated for the plain method, and additional highly effective algorithm is added for a noise level up to 0 dB. The stability of alpha in terms of minimal reconstruction energy is shown over the whole range of possible values for alpha. Additionally, the treatment of unwanted room reflections is discussed, still leading to satisfactory results in many cases. PMID:20058977

Bader, Rolf

2010-01-01

294

Fast microwave detection system for coherent synchrotron radiation study at KEK: Accelerator test facility  

Energy Technology Data Exchange (ETDEWEB)

A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed.

Aryshev, A. [Department of Accelerator-Science, School of High Energy Accelerator Science, Graduate University for Advanced Studies, Shonan International Village, Hayama, Miura, Kanagawa 240-0193 (Japan)], E-mail: alar@post.kek.jp; Araki, S. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Karataev, P. [John Abrams Institute at Royal Holloway, University of London, Egham, Surrey TW20 0EX (United Kingdom); Naito, T.; Terunuma, N.; Urakawa, J. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

2007-10-11

295

A Method for Ultrashort Electron Pulse Shape-Measurement Using Coherent Synchrotron Radiation  

CERN Document Server

In this paper we discuss a method for nondestructive measurements of the longitudinal profile of sub-picosecond electron bunches for X-Ray Free Electron Lasers (XFELs). The method is based on the detection of the Coherent Synchrotron Radiation (CSR) spectrum produced by a bunch passing a dipole magnet system. This work also contains a systematic treatment of synchrotron radiation theory which lies at the basis of CSR. Standard theory of synchrotron radiation uses several approximations whose applicability limits are often forgotten: here we present a systematic discussion about these assumptions. Properties of coherent synchrotron radiation from an electron moving along an arc of a circle are then derived and discussed. We describe also an effective and practical diagnostic technique based on the utilization of an electromagnetic undulator to record the energy of the coherent radiation pulse into the central cone. This measurement must be repeated many times with different undulator resonant frequencies in or...

Geloni, G A; Schneidmiller, E A; Yurkov, M V

2003-01-01

296

Direct detection of Black Holes via electromagnetic radiation  

CERN Document Server

Many black hole (BH) candidates exist, ranging from supermassive ($\\sim10^{6}$--$10^{10}$ M$_{\\odot}$) to stellar masses ($\\sim 1$--$100$ M$_{\\odot}$), all of them identified by indirect processes. Although there are no known candidate BHs with sub-stellar masses, these might have been produced in the primordial Universe. BHs emit radiation composed of photons, gravitons and, later in their lifes, massive particles. We explored the detection of such BHs with present day masses from $10^{-22}$ M$_{\\odot}$ to $10^{-11}$ M$_{\\odot}$. We determined the maximum distances ($d$) at which the current best detectors should be placed in order to identify such isolated BHs. Broadly, we conclude that in the visible and ultraviolet BHs can be directly detected at $d\\lesssim 10^7$ m while in the X-ray band the distances might reach $\\sim10^8$ m (of the order of the Earth-Moon distance) and in the $\\gamma$-ray band BHs might even be detected from as far as $\\sim 0.1$ pc. Since these results give us realistic hopes of direct...

Sobrinho, J L G

2014-01-01

297

A deterministic method to characterize canopy radiative transfer properties  

Science.gov (United States)

Investigations of snowcover dynamics beneath vegetation canopies require either measured or estimated solar and thermal radiation values at the snow surface. A deterministic method is presented that uses portable arrays of pyranometers and pyrgeometers to quantify the amount of incoming radiation at the snow surface. Example solar and thermal radiation datasets are presented from boreal deciduous, boreal coniferous and temperate coniferous forest stands. The data indicate that the canopies transmitted 33% (4-8 March), 15% (6-10 February), and 3% (22-24 September) of the above-canopy radiation. In the boreal deciduous and temperate conifer stands, thermal radiation is increased by 25% and 34% respectively. Thermal gains partially offset solar reduction, such that incoming all-wave radiation is decreased by 22% and 25% respectively for each of these stands. When recorded at a high temporal resolution, array data can estimate below-canopy diffuse solar radiation values for estimation techniques that treat direct and diffuse transmission independently. We provide examples of how radiometer array data are used to derive simple canopy radiation transmissivity parameters for global, beam and diffuse radiation. Radiometer arrays also provide data for detailed investigations to assess within-stand radiation variability, or to investigate radiation variations across land cover discontinuities, to advance our understanding of snowcover energetics in complex environments. Copyright

Link, Timothy E.; Marks, Danny; Hardy, Janet P.

2004-12-01

298

Development of nondestructive evaluation method on radiation damage using micromagnetic methods  

International Nuclear Information System (INIS)

The nuclear reactor pressure vessel is degraded by the high energy neutron bombardments during operation periods. Life extension of existing nuclear power plants requires the development of innovative NDE techniques for inspection of aged components. The magnetic method has been recently demonstrated as a promising technique. One major difficulty in using these particular techniques is to correlate the changes in the measured NDT signals with the microstructural changes occurred in the material due to aging. This problem may be solved through careful microstructural examinations of materials damage and introduction of signal analysis techniques. The NDE and science research center (NDE and S-RC) established in the Iwate University is studying about the application of minor loop method to the radiation damage. The minor loop technique in the detection of radiation damage is complement method of Barkhausen noise which developed in the Korea Atomic Energy Research Institute (KAERI). The cooperation between NDE and S-RC and KAERI are very important in the development of magnetic NDE techniques. The aim of this joint project will be the investigation of the magnetic properties for commen specimens using original methods, establishment of the fundamentals of magnetic NDE technique, and ensuring a safe operation of nuclear power plants

2007-01-01

299

Atoms, radiation and radiation protection  

International Nuclear Information System (INIS)

This text describes basic atomic and nuclear structure as well as the physical processes that result in the emission of ionizing radiation. In addition, external and internal radiation protection criteria, standards and practices are presented from the standpoint of their underlying physical and biological basis. Contents: About atomic physics and radiation. Atomic structure and radiation. The nucleus and nuclear radiation. Interaction of heavy charged particles with matter. Interaction of beta particles with matter. Phenomena associated with charged particle tracks. Interaction of photons with matter. Neutrons, fission, and criticality. Radiation detection methods. Radiation dosimetry. Chemical and biological effects of radiation. Radiation protection criteria and standards. External radiation protection. Internal radiation protection

1986-01-01

300

Using Thermal Radiation in Detection of Negative Obstacles  

Science.gov (United States)

A method of automated detection of negative obstacles (potholes, ditches, and the like) ahead of ground vehicles at night involves processing of imagery from thermal-infrared cameras aimed at the terrain ahead of the vehicles. The method is being developed as part of an overall obstacle-avoidance scheme for autonomous and semi-autonomous offroad robotic vehicles. The method could also be applied to help human drivers of cars and trucks avoid negative obstacles -- a development that may entail only modest additional cost inasmuch as some commercially available passenger cars are already equipped with infrared cameras as aids for nighttime operation.

Rankin, Arturo L.; Matthies, Larry H.

2009-01-01

 
 
 
 
301

Recombination methods in the dosimetry of mixed radiation  

Energy Technology Data Exchange (ETDEWEB)

The work describes the state of art of recombination methods developed for the dosimetry of mixed radiation fields. The existing theories of initial recombination of ions in gases is given. Recombination methods developed in IAE are reviewed in detail. The methods described here can be applied in mixed radiation fields of poorly known composition and practically unlimited energy range. Main dosimetric parameters such as absorbed dose, photon component to the absorbed dose, radiation quality factor, dose equivalent, ambient dose equivalent and some other quantities can be determined in single instrument. A novel method has been developed for determination of the energy loss distribution in the nanometric region. Experimental tests showed that the method is promising not only for radiation protection but also for radiobiological investigations. (author). 166 refs, 62 figs, 16 tabs.

Golnik, N. [Institute of Atomic Energy, Otwock-Swierk (Poland)

1996-12-31

302

Recombination methods in the dosimetry of mixed radiation  

International Nuclear Information System (INIS)

The work describes the state of art of recombination methods developed for the dosimetry of mixed radiation fields. The existing theories of initial recombination of ions in gases is given. Recombination methods developed in IAE are reviewed in detail. The methods described here can be applied in mixed radiation fields of poorly known composition and practically unlimited energy range. Main dosimetric parameters such as absorbed dose, photon component to the absorbed dose, radiation quality factor, dose equivalent, ambient dose equivalent and some other quantities can be determined in single instrument. A novel method has been developed for determination of the energy loss distribution in the nanometric region. Experimental tests showed that the method is promising not only for radiation protection but also for radiobiological investigations. (author). 166 refs, 62 figs, 16 tabs

1996-01-01

303

Radio frequency detection assembly and method for detecting radio frequencies  

Science.gov (United States)

A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

Cown, Steven H. (Rigby, ID); Derr, Kurt Warren (Idaho Falls, ID)

2010-03-16

304

Method and apparatus for sequentially combining pulsed beams of radiation  

International Nuclear Information System (INIS)

Method and apparatus are presented for combining a sequence of radiation pulses in plural beams to provide a common axis output beam of increased repetition rate. An optical correction system is employed to compensate for dynamic angular motion of the output radiation beam over the duration of each pulse. (Auth.)

1974-01-30

305

Linear method as the expansion technique of dynamical capabilities of detecting systems during reactor-physical investigations  

International Nuclear Information System (INIS)

The method giving the possibility to create nuclear radiation detecting systems combining the current apparatus wide-range nature and dynamical capabilities of pulsed detecting systems is proposed. The above method uses peculiarities of the linear method which is based on the refusal of application of nonlinear devices shaping current pulses coming from radiation detectors. The block-diagram of the detecting device ensuring the linear operating regimes is considered. From radiation detector output the current pulses not subjecting to external nonlinear electric circuits shaping enter directly the integrating capacitor and loading. The results of linear detecting systems investigation have shown that the linear method allows by means of a standard fast-response apparatus to develop detecting systems possessing minimum energy threshold and differing by ennanced fast response. The possibilitity to perform measurements with detecting rate up to 1012-1014s-1 has been found experimentally

1980-01-01

306

Establishment of the Radiation Detection Laboratory at Fisk University  

Energy Technology Data Exchange (ETDEWEB)

Synthetic CdZnTe (CZT) semiconducting crystals are highly suitable for the room temperature-based detection of gamma radiation. The surface preparation of Au contacts on surfaces of CZT detectors is typically conducted after (1) polishing to remove artifacts from crystal sectioning and (2) chemical etching, which removes residual mechanical surface damage however etching results in a Te rich surface layer that is prone to oxidize. Our studies show that CZT surfaces that are only polished (as opposed to polished and etched) can be contacted with Au and will yield lower surface currents. Due to their decreased dark currents, these as-polished surfaces can be used in the fabrication of gamma detectors exhibiting a higher performance than polished and etched surfaces with relatively less peak tailing and greater energy resolution.032}

Arnold Burger, Ph.D.

2008-02-28

307

Establishment of the Radiation Detection Laboratory at Fisk University  

International Nuclear Information System (INIS)

Synthetic CdZnTe (CZT) semiconducting crystals are highly suitable for the room temperature-based detection of gamma radiation. The surface preparation of Au contacts on surfaces of CZT detectors is typically conducted after (1) polishing to remove artifacts from crystal sectioning and (2) chemical etching, which removes residual mechanical surface damage however etching results in a Te rich surface layer that is prone to oxidize. Our studies show that CZT surfaces that are only polished (as opposed to polished and etched) can be contacted with Au and will yield lower surface currents. Due to their decreased dark currents, these as-polished surfaces can be used in the fabrication of gamma detectors exhibiting a higher performance than polished and etched surfaces with relatively less peak tailing and greater energy resolution.

2008-02-28

308

A new method for detecting histamine release.  

Science.gov (United States)

Glass microfibres have been found to bind histamine with high affinity and selectivity. A new test for measuring basophil histamine release has been developed using the glass microfibres as a solid phase. Glass microfibres are crushed and fixed to the bottom of microtitre plates with a water-soluble glue. Histamine release is performed in the glass microfibre -prepared microtitre plates by challenging 100 microliter washed blood with 20 microliter antigen per well for 90 min at 37 degrees C. Released histamine is bound with high affinity to the glass microfibres , since 90% of histamine in the solution is adsorbed to the fibres. After incubation the microtitre plate is washed with H2O to remove cells and interfering substances. Fibre-bound histamine is detected by the fluorometric o-phthaldialdehyde method. The sensitivity of the assay is 0.63 ng histamine, 2 HCl and the histamine standard curve is linear up to at least 5 ng histamine, 2 HCl. Optimal conditions for the new assay are described. After challenge with anti-Ige a comparison with the conventional histamine release from Ficoll-Hypaque-isolated leukocytes showed almost identical results. PMID:6203360

Stahl Skov, P; Norn, S; Weeke, B

1984-04-01

309

Biological detection of low radiation doses with integrated photothermal assay  

Science.gov (United States)

The goal of this paper was to evaluate the diagnostic value of integrated photothermal (PT) assay with additional fluorescent and photoacoustic (PA) modules to assess both the "safety limit" of exposure to ionizing ?-radiation and optimal therapeutic doses for cancer treatment. With this assay, the influences of ? irradiation on cancer cells (pancreatic-AR42J and hepatocytes-hepG2) and healthy cells (mouse lymphocytes and erythrocytes) was examined as a function of exposure dose (0.6-5 Gy) and time after irradiation, in vitro and in vivo. Independent verification of data obtained with conventional assays revealed that integrated PT assay allowed us to detect the different stages of radiation impact, including changes in cell metabolism at low dose, or stages related to cell death (apoptosis and necrosis) at high doses with a threshold sensitivity of at least three orders of magnitude better than existing assays. Also, PT assay was capable of quantitatively differentiating the biological action of ? irradiation alone and in combination with drug and nicotine impact. Finally, we demonstrated on an animal model that IPT assay has the potential for use in routine rapid evaluation of biological consequences of low-dose exposure a few days after irradiation.

Zharov, Vladimir P.; Viegas, Mark; Soderberg, Lee S. F.

2005-04-01

310

Detection method for fission product upon failure of nuclear fuels  

International Nuclear Information System (INIS)

The present invention provides a detection method for fission products discharged upon failure of nuclear fuels in an FBR type reactor. Heretofor, the fissile products discharged upon failure of nuclear fuels have been detected by radiometric analysis. Although the radiometric analysis is a highly sensitive detection method, it also detects radioactivity contained in the material, so that the back ground is increased. Moreover, nuclides not having radioactivity can not be detected. The detection method according to the present invention detects fissile products such as xenon, krypton, cesium or the like discharged upon failure of nuclear fuels of the FBR type reactor by multi-photon intensifying ionization method. If gaseous fission products are detected by the multi-photon intensifying ionization method, they can be detected at ultrahigh sensitivity without undergoing influences of the background radioactivity. (I.S.)

1993-04-07

311

Development of detection methods for irradiated foods  

Energy Technology Data Exchange (ETDEWEB)

In 1999, we have been studied (1) on the detection of irradiated foods by ESR spectroscopy, by thermoluminescence, and by viscometry for physical measurements, (2) on the detection of hydrocarbons and 2-alkylcyclobutanones derived from fatty foods by GC/MS for chemical measurements, (3) on the screening and detection of irradiated foods by Comet assay and immunochemical (ELISA) technique for biological or biochemical measurements.

Yang, Jae Seung; Nam, Hye Seon; Oh, Kyong Nam; Woo, Si Ho; Kim, Kyeung Eun; Yi, Sang Duk; Park, Jun Young; Kim, Kyong Su; Hwang, Keum Taek

2000-04-01

312

Development of detection methods for irradiated foods  

International Nuclear Information System (INIS)

In 1999, we have been studied (1) on the detection of irradiated foods by ESR spectroscopy, by thermoluminescence, and by viscometry for physical measurements, (2) on the detection of hydrocarbons and 2-alkylcyclobutanones derived from fatty foods by GC/MS for chemical measurements, (3) on the screening and detection of irradiated foods by Comet assay and immunochemical (ELISA) technique for biological or biochemical measurements

2000-01-01

313

Analysis on Credit Card Fraud Detection Methods  

Directory of Open Access Journals (Sweden)

Full Text Available Due to the theatrical increase of fraud which results in loss of dollars worldwide each year, several modern techniques in detecting fraud are persistently evolved and applied to many business fields. Fraud detection involves monitoring the activities of populations of users in order to estimate, perceive or avoid undesirable behavior. Undesirable behavior is a broad term including delinquency, fraud, intrusion, and account defaulting. This paper presents a survey of current techniques used in credit card fraud detection and telecommunication fraud. The goal of this paper is to provide a comprehensive review of different techniques to detect fraud.

Renu

2014-02-01

314

Method for evaluation of radiative properties of glass samples  

International Nuclear Information System (INIS)

The paper presents a simple calculation method which serves for an evaluation of radiative properties of window glasses. The method is based on a computer simulation model of the energy balance of a thermally insulated box with selected glass samples. A temperature profile of the air inside of the box with a glass sample exposed to affecting radiation was determined for defined boundary conditions. The spectral range of the radiation was considered in the interval between 280 and 2500 nm. This interval is adequate to the spectral range of solar radiation affecting windows in building facades. The air temperature rise within the box was determined in a response to the affecting radiation in the time between the beginning of the radiation exposition and the time of steady-state thermal conditions. The steady state temperature inside of the insulated box serves for the evaluation of the box energy balance and determination of the glass sample radiative properties. These properties are represented by glass characteristics as mean values of transmittance, reflectance and absorptance calculated for a defined spectral range. The data of the computer simulations were compared to experimental measurements on a real model of the insulated box. Results of both the calculations and measurements are in a good compliance. The method is recommended for preliminary evaluation of window glass radiative properties which serve as data for energy evaluation of buildings

2008-04-01

315

Radiation sterilization as compared with another methods of making sterile  

International Nuclear Information System (INIS)

Presentation is devoted to sterilization and hygienization of food, medicinal articles and cosmetics. Radiosterilization is compared with other methods. Advantages of fast electron - and gamma radiation sterilization are stressed

2007-10-11

316

Radiation sterilization as compared with another methods of making sterile  

International Nuclear Information System (INIS)

Presentation is devoted to sterilization and hygienization of food, medicinal articles and cosmetics. Radiosterilization is compared with other methods. Advantages of fast electron- and gamma radiation sterilization are stressed

2007-10-11

317

Application of the microbiological method DEFT/APC and DNA comet assay to detect ionizing radiation processing of minimally processed vegetables; Aplicacao do metodo microbiologico DEFT/APC e do teste do cometa na deteccao do tratamento com radiacao ionizante de hortalicas minimamente processadas  

Energy Technology Data Exchange (ETDEWEB)

Marketing of minimally processed vegetables (MPV) are gaining impetus due to its convenience, freshness and apparent healthy. However, minimal processing does not reduce pathogenic microorganisms to safe levels. Food irradiation is used to extend the shelf life and inactivation of food-borne pathogens, Its combination with minimal processing could improve the safety and quality of MPV. Two different food irradiation detection methods, a biological, the DEFT/APC, and another biochemical, the DNA Comet Assay were applied to MPV in order to test its applicability to detect irradiation treatment. DEFT/APC is a microbiological screening method based on the use of the direct epi fluorescent filter technique (DEFT) and the aerobic plate count (APC). DNA Comet Assay detects DNA damage due to ionizing radiation. Samples of lettuce, chard, watercress, dandelion, kale, chicory, spinach, cabbage from retail market were irradiated O.5 kGy and 1.0 kGy using a {sup 60} Co facility. Irradiation treatment guaranteed at least 2 log cycle reduction for aerobic and psychotropic microorganisms. In general, with increasing radiation doses, DEFT counts remained similar independent of irradiation processing while APC counts decreased gradually. The difference of the two counts gradually increased with dose increment in all samples. It could be suggested that a DEFT/APC difference over 2.0 log would be a criteria to judge if a MPV was treated by irradiation. DNA Comet Assay allowed distinguishing non-irradiated samples from irradiated ones, which showed different types of comets owing to DNA fragmentation. Both DEFT/APC method and DNA Comet Assay would be satisfactorily used as a screening method for indicating irradiation processing. (author)

Araujo, Michel Mozeika

2008-07-01

318

A new solvent suppression method via radiation damping effect  

International Nuclear Information System (INIS)

Radiation damping effects induced by the dominated solvent in a solution sample can be applied to suppress the solvent signal. The precession pathway and rate back to equilibrium state between solute and solvent spins are different under radiation damping. In this paper, a series of pulse sequences using radiation damping were designed for the solvent suppression in nuclear magnetic resonance (NMR) spectroscopy. Compared to the WATERGATE method, the solute signals adjacent to the solvent would not be influenced by using the radiation damping method. The one-dimensional (1D) 1H NMR, two-dimensional (2D) gCOSY, and J-resolved experimental results show the practicability of solvent suppression via radiation damping effects in 1D and 2D NMR spectroscopy. (interdisciplinary physics and related areas of science and technology)

2011-11-01

319

Study on Frequency Control Based on WTTP Frequency Detection Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For improving the precision of power system frequency control under the condition of noise and harmonic interference, a new power system frequency control algorithm is proposed based on WTTP frequency detection method, which is a combination of wavelet transform and three-point frequency detection method. Fundamental component can be extracted from distorted signal by wavelet transform under asynchronous sampling, and then three-point frequency detection method is used to detect fundamental c...

Zhanfeng Ying; Yunyun Chen; Junji Wu

2013-01-01

320

Screening for early detection of radiation-associated thyroid cancer  

International Nuclear Information System (INIS)

In the 1950s, approximately 20,000 Israeli children received scalp irradiation as treatment for tinea capitis (ringworm of the scalp). To evaluate the necessity and feasibility of early screening of these individuals for thyroid cancer, a small pilot program was undertaken. The examination consisted of a thorough palpation of the thyroid gland and the surrounding area. A sup(99m)Tc thyroid scan and thyroid function tests were performed on individuals in whom palpation suggested a nodular abnormality. A multidisciplinary committee then made a recommendation for or against surgery. A total of 443 persons were screened, and nodular abnormalities of the thyroid were detected in 24 (5.4%). Of these persons, nine displayed symptomatology or reported knowledge of a thyroid condition; despite this, three of them were not receiving treatment. This left 18 subjects - 15 new cases and 3 previously untreated patients - needing follow-up care. Altogether nine persons were recommended for surgery, but one refused. All eight of the excised lesions were benign: four colloid nodules and four adenomas. While the screening program was feasible, the fact that no cancers were detected suggested that in a population exposed to a very low dose of radiation, thyroid screening may not be justified on a large scale.

1984-01-01

 
 
 
 
321

Method of radiation degradation of PTFE under vacuum conditions  

International Nuclear Information System (INIS)

A new method of radiation degradation of Polytetrafluoroethylene (PTFE) under vacuum conditions is considered in this report. The combination of glow gas discharge and electrical surface discharge (on surface and inside PTFE) increases the efficiency of thermal-radiation degradation. The main mechanism of this degradation method consists of the breaking of C-C and C-F bonds. The vacuum conditions allow decreasing of the concentration of toxic compounds, such as a HF. Experimental results for degradation of PTFE are presented

2003-09-07

322

The photochemical method for radiation abatement  

International Nuclear Information System (INIS)

This report reviews the underlying chemistry of the photochemical method for removal of radioiodines from air and evaluates the concept with respect to various applications in the nuclear industry. The method uses ultraviolet light (200-300 nm) to convert organic iodides (RI) to elemental iodine (I2). The I2 is then reacted with ozone to form solid iodine oxides (I4O9 or (I2O5), which deposit inside a scrubber. It is concluded that the method is applicable to large-scale systems and would have several advantages over conventional methods of radioiodine abatement

1984-01-01

323

Ultraviolet Radiation Protection Methods (invited paper)  

Energy Technology Data Exchange (ETDEWEB)

Exposure to solar UVR is widespread. Additionally, a small proportion of the population is exposed to artificial sources. There is a clear link between exposure to solar UVR and a range of adverse health effects. The acute and chronic exposure phenomena are different and, in terms of protection, both the measures and success rates will also be different. To reduce risk it is necessary to characterise fully the radiation source, understand the intermediate medium and the biological receptor and then develop appropriate exposure prevention strategies. Protection against occupational exposure to artificial sources should be approached using administrative and engineering control measures. Protective measures against solar UVR are still evolving. A significant decrease in risk can be achieved by changing behaviour through well-designed educational programmes. Personal protection is also important and effective protection is readily available. Avoidance of acute UVR effects and a decrease in skin cancer rates and mortality are the desirable long-term outcomes from such a programme. (author)

Roy, C.R.; Gies, H.P

2000-07-01

324

Background radiation dependence of detection and determination limits for a TLD reading system  

International Nuclear Information System (INIS)

The aim of the work is to study the detection and determination limits dependence of a TLD reading system on the time that dosemeters are exposed to the background radiation.A set of 15 TLD-100 (LiF:Mg,Ti) were exposed to the background radiation for periods of 15, 30, 45, 60, 90 and 180 days; the reading and the standard deviation were evaluated and from these data, using two simple models and the least square fit method, the detection and determination limits time dependence were calculated from the Hirning relations. From a radiation protection point of view when the reading of a dosemeter worn from a worker gives an air-kerma under, it is usually assigned an equivalent dose evaluated from LD so in the most case LD becomes a relevant part of the annual dose of a worker. In the present work we show that for small exposure times LD depends from the intrinsic properties of the system more than from the background radiation: so assigning an equivalent dose from LD we commit a systematic error that can be minimized increasing the time that the dosemeters are on the field. For our dosimetric system, consisting of a TLD-100 set of two-elements dosemeters and an Harshaw Model 6600 reading system, increasing the exposure time from 30 to 180 days can reduce the relative systematic error in the wrong assigned yearly dose from 153% to 13%. (authors)

1997-11-16

325

Development of medical application methods using radiation. Radionuclide therapy  

International Nuclear Information System (INIS)

In this project, we studied following subjects: 1. development of monoclonal antibodies and radiopharmaceuticals 2. clinical applications of radionuclide therapy 3. radioimmunoguided surgery 4. prevention of restenosis with intracoronary radiation. The results can be applied for the following objectives: 1) radionuclide therapy will be applied in clinical practice to treat the cancer patients or other diseases in multi-center trial. 2) The newly developed monoclonal antibodies and biomolecules can be used in biology, chemistry or other basic life science research. 3) The new methods for the analysis of therapeutic effects, such as dosimetry, and quantitative analysis methods of radioactivity, can be applied in basic research, such as radiation oncology and radiation biology

1999-01-01

326

Echo detected EPR as a tool for detecting radiation-induced defect signals in pottery  

International Nuclear Information System (INIS)

Archaeological fragments of pottery have been investigated by using CW-EPR and Echo Detected EPR (EDEPR). EDEPR allows to remove the CW-EPR dominant Fe(III) background spectrum, hiding much weaker signals potentially useful for dating purpose. EDEPR spectra attributed to a methyl radical and to feldspar defects have been recorded at room and low temperature for an Iron Age cooking ware (700 B.C.). A study on the dependence of EDEPR intensity over absorbed dose on a series of ?-irradiated brick samples (estimated age of 562 ± 140 B.C.) has confirmed the potential efficacy of the proposed method for spotting defect signals out of the strong iron background. - Highlights: ? Fe(III) CW-EPR signals cover CW-EPR-detectable defects in ceramics. ? Echo detected EPR gets rid of Fe(III) signals, disclosing defect signals. ? Echo detected EPR detects defect signals even at relatively low doses.

2011-08-01

327

Modification of Gravitational Anomaly Method in Hawking Radiation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We discuss an ambiguity of the derivation of the Hawking radiation through the gravitational anomaly method and propose modifications of this method such that it reproduces the correct thermal fluxes. In this modified gravitational anomaly method, we employ the two-dimensional conformal field theory technique.

Morita, Takeshi

2009-01-01

328

Detection of 90 Sr with Cherenkov radiation and monitoring other radioisotopes in environmental samples  

International Nuclear Information System (INIS)

In emergency situations following major nuclear accidents fast direct method for determination of 90 Sr or at least classification of environmental samples would be very useful. Both 90 Sr and 90 Y being beta emitters cannot be detected by standard gamma spectroscopy. The relatively high end-point energy of 90 Y of the beta spectrum suggest that Cherenkov radiation might be a suitable method to discriminate or at least strongly suppress contributions from other radionuclides. Possibility of increase in the Cherenkov threshold with lower refractive index w of the radiator was examined. Coincidence detector arrangements (aerogel + photomultiplier in coincidence with multiwire proportional chamber) can reach MDA below 1 Bq for high energy beta emitters in thin samples and can discriminate against beta-gamma emitters. Some possible improvements like simultaneous measurements with two aerogels of different refractive index and increase of the solid angle could be checked in the future. (author)

1996-10-06

329

Spectral radiative property control method based on filling solution  

International Nuclear Information System (INIS)

Controlling thermal radiation by tailoring spectral properties of microstructure is a promising method, can be applied in many industrial systems and have been widely researched recently. Among various property tailoring schemes, geometry design of microstructures is a commonly used method. However, the existing radiation property tailoring is limited by adjustability of processed microstructures. In other words, the spectral radiative properties of microscale structures are not possible to change after the gratings are fabricated. In this paper, we propose a method that adjusts the grating spectral properties by means of injecting filling solution, which could modify the thermal radiation in a fabricated microstructure. Therefore, this method overcomes the limitation mentioned above. Both mercury and water are adopted as the filling solution in this study. Aluminum and silver are selected as the grating materials to investigate the generality and limitation of this control method. The rigorous coupled-wave analysis is used to investigate the spectral radiative properties of these filling solution grating structures. A magnetic polaritons mechanism identification method is proposed based on LC circuit model principle. It is found that this control method could be used by different grating materials. Different filling solutions would enable the high absorption peak to move to longer or shorter wavelength band. The results show that the filling solution grating structures are promising for active control of spectral radiative properties. -- Highlights: • A filling solution grating structure is designed to adjust spectral radiative properties. • The mechanism of radiative property control is studied for engineering utilization. • Different grating materials are studied to find multi-functions for grating

2014-01-01

330

Technical improvement and development of automatic detection method for genomic mutation  

Energy Technology Data Exchange (ETDEWEB)

Aiming at automatic detection of genetic mutation, an investigation was made on sample preparing method for automatic detection and automatization of the preparing process. In this year, the second year of this research project, the chromosomal abnormalities in lymphocyte exposed to radiation were analyzed by highly accurate chromosome staining method to clarify the efficacy of the new staining method regarding dose effects, analyzing power for chromosomal abnormalities, etc. by comparing with the conventional method. Chromatin fibers of several hundred {mu} in length were found detectable by FISH, but the method was unsuitable for observation of the fibers in a nanometer level, suggesting that it is needed to prepare much purified samples through more complete deproteinization. Furthermore, primed in situ (PRINS) labelling method which targetted the repeated sequences in Y chromosome was found available for detecting chromatin fibers. (M.N.)

Yamada, Kiyomi; Takai, Setsuo; Togashi, Chikako; Itami, Jun [Research Inst. International Medical Center Japan, Tokyo (Japan)

1998-02-01

331

Technical improvement and development of automatic detection method for genomic mutation  

International Nuclear Information System (INIS)

Aiming at automatic detection of genetic mutation, an investigation was made on sample preparing method for automatic detection and automatization of the preparing process. In this year, the second year of this research project, the chromosomal abnormalities in lymphocyte exposed to radiation were analyzed by highly accurate chromosome staining method to clarify the efficacy of the new staining method regarding dose effects, analyzing power for chromosomal abnormalities, etc. by comparing with the conventional method. Chromatin fibers of several hundred ? in length were found detectable by FISH, but the method was unsuitable for observation of the fibers in a nanometer level, suggesting that it is needed to prepare much purified samples through more complete deproteinization. Furthermore, primed in situ (PRINS) labelling method which targetted the repeated sequences in Y chromosome was found available for detecting chromatin fibers. (M.N.)

1998-02-01

332

EPR spectroscopy for the detection of foods treated with ionising radiation  

International Nuclear Information System (INIS)

The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

1996-01-01

333

EPR spectroscopy for the detection of foods treated with ionising radiation  

Energy Technology Data Exchange (ETDEWEB)

The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author).

Stachowicz, W.; Burlinska, G.; Michalik, J. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Dziedzic-Goclawska, A.; Ostrowski, K. [Medical School, Warsaw (Poland)

1996-12-31

334

Discontinuous Galerkin Methods for Computational Radiation Transport  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This Thesis demonstrates advanced new discretisation technologies that improve the accuracy and stability of the discontinuous Galerkin finite element method applied to the Boltzmann Transport Equation, describing the advective transport of neutral particles such as photons and neutrons within a domain. The discontinuous Galerkin method in its standard form is susceptible to oscillation detrimental to the solution. The discretisation schemes presented in this Thesis enhance the...

Merton, Simon Richard

2012-01-01

335

Study on Frequency Control Based on WTTP Frequency Detection Method  

Directory of Open Access Journals (Sweden)

Full Text Available For improving the precision of power system frequency control under the condition of noise and harmonic interference, a new power system frequency control algorithm is proposed based on WTTP frequency detection method, which is a combination of wavelet transform and three-point frequency detection method. Fundamental component can be extracted from distorted signal by wavelet transform under asynchronous sampling, and then three-point frequency detection method is used to detect fundamental component frequency. For improving the detection precision, error mathematics mechanism of three-point frequency detection method is analyzed and error mitigation method is proposed. Even though there is noise and harmonic interference in feedback loop, power system frequency can be controlled accurately and stably by applying WTTP frequency detection method to power system frequency control. Simulation results demonstrate the feasibility of algorithm.

Zhanfeng Ying

2013-06-01

336

A regularized GMRES method for inverse blackbody radiation problem  

Directory of Open Access Journals (Sweden)

Full Text Available The inverse blackbody radiation problem is focused on determining temperature distribution of a blackbody from measured total radiated power spectrum. This problem consists of solving a first kind of Fredholm integral equation and many numerical methods have been proposed. In this paper, a regularized GMRES method is presented to solve the linear ill-posed problem caused by the discretization of such an integral equation. This method projects the orignal problem onto a lower dimensional subspaces by the Arnoldi process. Tikhonov regularization combined with GCV criterion is applied to stabilize the numerical iteration process. Three numerical examples indicate the effectiveness of the regularized GMRES method.

Wu Jieer

2013-01-01

337

Cationic membrane obtained by radiation grafting method  

International Nuclear Information System (INIS)

A study has been made for the preparation of ion-containing reverse osmosis membranes by the radiation grafting of aqueous acrylic acid onto low density polyethylene films followed by alkaline treatment to confer ionic character in the prepared membranes. The appropriate reaction conditions were selected under which the graft polymerization was carried out successfully. In this grafting system ammonium ferrous sulphate (Mohr's salt) was used as inhibitor to minimize the homopolymerization of AAc, and a suitable concentration of the inhibitor to be added to the reaction medium was found to be 2.5 wt%. The effect of aqueous monomer concentration on the rate and degree of grafting was studied. The dependence of the grafting rate on the monomer concentration was found to be 0.8 order, i.e. almost first order dependence. It was also found that the irradiation atmosphere (air and nitrogen gas) had no significant effect on the grafting yield at given reaction conditions. The prepared graft copolymer films showed good thermal and chemical stability. Gel determination in the grafted films was also investigated and the results indicated that a crosslinked network structure may be formed. The extent of the gelled part in the graft copolymer increased as the degree of grafting increased. (author)

1987-01-01

338

Operation method in high radiation dose area  

International Nuclear Information System (INIS)

Radioactive materials such as 60Co, etc., activated in a reactor core are deposited as cruds to the entire inner surfaces of primary coolant pipeways and vessels in a reactor. Accordingly, the entire inner surfaces of the pipelines and vessels act as radioactive sources, and operators who work in the vicinity suffer from radiation exposure. However, if ?-rays are passed through materials, they interact with molecules and atoms of the materials to be decayed. This decaying effect can be obtained not only by metal materials constituting the pipelines and the vessels but also by inner fluids incorporated therein corresponding to the density thereof. The feature of the present invention is to utilize this shielding effect. That is, a step of filling fluids (for example, water) having the shielding effect into the pipelines and vessels at high radioactive dose is provided prior to operations. In view of the above, the amount of ?-rays from the radioactive materials deposited to the inner surfaces of the pipelines and the vessels can be decayed and the operator's exposure dose can be moderated. (I.S.)

1988-09-26

339

Application of a rapid screening method to detect irradiated meat in Brazil  

Science.gov (United States)

Based on the enormous potential for food irradiation in Brazil, and to ensure free consumer choice, there is a need to find a convenient and rapid method for detection of irradiated food. Since treatment with ionising radiation causes DNA fragmentation, the analysis of DNA damage might be promising. In this paper, the DNA Comet Assay was used to identify exotic meat (boar, jacaré and capybara), irradiated with 60Co gamma rays. The applied radiation doses were 0, 1.5, 3.0 and 4.5 kGy. Analysis of the DNA migration enabled a rapid identification of the radiation treatment.

Villavicencio, A. L. C. H. A. L. C. H.; Mancini-Filho, J. J.; Delincée, H.

2000-03-01

340

Application of a rapid screening method to detect irradiated meat in Brazil  

Energy Technology Data Exchange (ETDEWEB)

Based on the enormous potential for food irradiation in Brazil, and to ensure free consumer choice, there is a need to find a convenient and rapid method for detection of irradiated food. Since treatment with ionising radiation causes DNA fragmentation, the analysis of DNA damage might be promising. In this paper, the DNA Comet Assay was used to identify exotic meat (boar, jacare and capybara), irradiated with {sup 60}Co gamma rays. The applied radiation doses were 0, 1.5, 3.0 and 4.5 kGy. Analysis of the DNA migration enabled a rapid identification of the radiation treatment.

Villavicencio, A.L.C.H. E-mail: villavic@net.ipen.br; Mancini-Filho, J. E-mail: jmancini@usp.br; Delincee, H. E-mail: henrydelincee@bfe.uni-karlsruhe.de

2000-03-01

 
 
 
 
341

Application of a rapid screening method to detect irradiated meat in Brazil  

International Nuclear Information System (INIS)

Complete text of publication follows. Based on the enormous potential for food irradiation in Brazil, and to ensure free consumer choice, there is a need to find a convenient and rapid method for detection of irradiated food. Since treatment with ionizing radiation causes DNA fragmentation, the analysis of DNA damage might be promising. In fact, DNA fragmentation measured in single cells by agarose gel electrophoresis - DNA Comet Assay - has shown to offer great potential as a rapid tool to detect whether a wide variety of foodstuffs has been radiation processed. However, more work is needed to exploit the full potential of this promising technique. In this paper, the DNA Comet Assay was used to identify exotic meat (boar, jacare and capybara), irradiated with 60Co gamma-rays. The applied radiation doses were 0, 1.5, 3.0 and 4.5 kGy. Analysis of the DNA migration enable a rapid identification of the radiation treatment

1998-09-03

342

Leak detection method and method of manufacturing system to be detected  

International Nuclear Information System (INIS)

In a leak detection method, a pH value of water or steams leaked from a system in which a storage vessel for containing water or steams is surrounded by concretes is measured and detected. Further, the surface of the system which has a possibility of causing dew condensation is applied with coating to suppress the contact between condensed water with the concretes. Alternatively, an air layer is formed, the humidity of which is controlled not higher than that of ambient air when the temperature of the air layer is made equal with that of the surface of the system to suppress or prevent occurrence of condensated water on the surface. (N.H.)

1994-06-08

343

Method for non-invasive detection of ocular melanoma  

Energy Technology Data Exchange (ETDEWEB)

There is described an apparatus and method for diagnosing ocular cancer that is both non-invasive and accurate which comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67.

Lambrecht, Richard M. (Quogue, NY); Packer, Samuel (Floral Park, NY)

1984-01-01

344

Improving the detecting performances of radiation portal monitors using matched filter algorithm  

International Nuclear Information System (INIS)

Full text: Introduction: Radiation Portal Monitors (RPM) are used for monitoring transportation of illicit radioactive materials. The application requires detection of radioactive materials while the vehicle is passes through a portal, thus having limited time for monitoring the passing vehicle. The pattern of the RPM detector readings, caused by measuring a moving source versus the background provides an opportunity to employ an algorithm based on matched filter technique for improving the detecting performances. Method: Matched filter is a process used for detecting a known signal in the presence of additive stochastic noise, and thereby maximizing the detected signal to noise ratio (SNR). For RPM's the matched filter is implemented by correlating a known signal, which is distance dependent, with the RPM readings. Convolving those readings, which combine the signal and the noise, with a time-reversed version of the signal, improves the RPM performances. To validate this concept a detection configuration was established according to measuring time limit and Minimal Detectable Activity (MDA) defined by ANSI 42-35 regulation. A mathematical software simulation was performed, followed by an experiment with a scale down configuration in order to confirm the benefits of the suggested algorithm. The experimental setup contained a NaI(Tl) scintillator based radiation detector, a radioactive source located on a moving toy train and a proximity sensor. Results: The detection performances obtained by both the simulation and the experiment with and without the matched filter algorithm were compared. The software simulation has shown a major improvement of up to six-fold decrease in miss alarm rate. Similar results where obtained by the experiments. Conclusions: The implementation of the matched filter in RPM detection algorithm improves its performances. The method provides either a) a higher detection reliability level, b) the ability to detect lower activity level, c) the need for fewer detectors to achieve the same MDA obtained without the matched filter. The proposed method is almost costless for implementation and requires minor hardware modifications. A future research will evaluate the advantage of the matched filter in cases of a spread source and a source which is not located at the center of the moving vehicle. (author)

2009-04-03

345

Radiation methods for liquid waste processing and ecological problems  

International Nuclear Information System (INIS)

Promissing trends in radiation application aimed at rational use of surface waters and their protection from contamination are set forth. Investigations in the USSR, USA and other countries have shown that use of radiation methods for processing allowed to succossfully settle at once several important problems of biosphere basic element conservation. Protection of the natural water reserviors and reduction consumption of fresh water used in industry are possible due to arrangement of water recirculation cycles. Radiation-prolonged adsorption appears to be rather promissing. Attention is paid to radiation processing of industrial and livestock wastes as well as activated sludge of biological sewage works for the pUrpose of their utilization. Radiation processing is used to eliminate waste release into the atmosphere resulting from ''processing'' contaminated effluents containing cancerogenic and toxic agents

1985-01-01

346

An Integrated Radiation Transport Particle-in-Cell Method  

Science.gov (United States)

The study of radiation transport is important to understand the basic physics and to calculate the efficiency in a lamp discharge or laser induced plasma. Many models neglect radiation transport effects in evolving the steady state. In this study, we established a basic model to calculate radiation transport, including the effects of nonuniform ground state density and atomic collisions in one dimensional cylindrical and planar geometries. We coupled radiation transport with the self-consistent kinetic particle-in-cell codes, XPDP1 and XPDC1[1]. We treat electrons and ions with a particle-in-cell method, and the neutral ground and excited states with a fluid model to calculate radiation transport and atomic collisions. The steady state result of this model compares well with the solution of Holstein equation[2]. [1] J. P. Verboncoeur, M. V. Alves, V. Vahedi, and C. K. Birdsall, Journal of Computational Physics 104, 321 (1993). [2] T. Holstein, Phys. Rev. 72, 1213 (1947).

Lee, H. J.; Verboncoeur, J. P.; Smith, H. B.; Parker, G. J.; Birdsall, C. K.

2000-10-01

347

Alterations of mitochondrial DNA: a method for the detection of irradiated beef liver  

International Nuclear Information System (INIS)

The study of the radio degradation of DNA is one of a number of phenomena being investigated to develop methods for identifying irradiated foods. The specific behaviour under radiation of the mitochondrial DNA from beef liver gives the possibility of detecting if the product has been irradiated or not. An identification method could finally be developed. The appraisal of the mitochondrial supercoiled DNA fraction constitutes an unambiguous detection test for beef liver irradiation. A total of 120 different samples were irradiated at 5 different doses. The dose limit of detection is lower than 2 kGy. No effects due to storage conditions were observed. (Author)

1992-12-01

348

Two-Dimensional Change Detection Methods Remote Sensing Applications  

CERN Document Server

Change detection using remotely sensed images has many applications, such as urban monitoring, land-cover change analysis, and disaster management. This work investigates two-dimensional change detection methods. The existing methods in the literature are grouped into four categories: pixel-based, transformation-based, texture analysis-based, and structure-based. In addition to testing existing methods, four new change detection methods are introduced: fuzzy logic-based, shadow detection-based, local feature-based, and bipartite graph matching-based. The latter two methods form the basis for a

Ilsever, Murat

2012-01-01

349

Electric Insulation Detection Method for High-voltage Insulators  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The principle of partial discharge detection is that through partial bridged discharge under high voltage electric field, it detects the inner air-filled cavity of high-voltage insulators. And it is a nondestructive detection method based on discharge magnitude to judge the insulation quality. The detecting system that adopts the partial discharge detection is more rigorous than testing system for electricity products, which must have small discharge capacity and higher sensitivity. This...

Wang Jiajun; Hong Bin; Wang Hongmei

2013-01-01

350

78 FR 64030 - Monitoring Criteria and Methods To Calculate Occupational Radiation Doses  

Science.gov (United States)

...and Methods To Calculate Occupational Radiation Doses AGENCY: Nuclear Regulatory Commission...and Methods to Calculate Occupational Radiation Doses.'' This guide describes methods...monitoring criteria and calculate occupational radiation doses. DATES: Submit comments by...

2013-10-25

351

Approximate design calculation methods for radiation streaming in shield irregularities  

International Nuclear Information System (INIS)

Investigation and assessment are made for approximate design calculation methods of radiation streaming in shield irregularities. Investigation is made for (1) source, (2) definition of streaming radiation components, (3) calculation methods of streaming radiation, (4) streaming formulas for each irregularity, (5) difficulties in application of streaming formulas, etc. Furthermore, investigation is made for simple calculation codes and albedo data. As a result, it is clarified that streaming calculation formulas are not enough to cover various irregularities and their accuracy or application limit is not sufficiently clear. Accurate treatment is not made in the formulas with respect to the radiation behavior for slant incidence, bend part, offset etc., that results in too much safety factors in the design calculation and distrust of the streaming calculation. To overcome the state and improve the accuracy of the design calculation for shield irregularities, it is emphasized to assess existing formulas and develop better formulas based on systematic experimental studies. (author)

1997-01-01

352

Assessment of nonequilibrium radiation computation methods for hypersonic flows  

Science.gov (United States)

The present understanding of shock-layer radiation in the low density regime, as appropriate to hypersonic vehicles, is surveyed. Based on the relative importance of electron excitation and radiation transport, the hypersonic flows are divided into three groups: weakly ionized, moderately ionized, and highly ionized flows. In the light of this division, the existing laboratory and flight data are scrutinized. Finally, an assessment of the nonequilibrium radiation computation methods for the three regimes in hypersonic flows is presented. The assessment is conducted by comparing experimental data against the values predicted by the physical model.

Sharma, Surendra

1993-01-01

353

Pathoanatomy of acute radiation syndrome treated by modern methods  

International Nuclear Information System (INIS)

Changes in morphological picture of acute radiation disease under the effects of modern treatment are studied. 28 case histories of patients exposed to gamma radiation at dose of 6 - 18 Gy are analyzed post mortem. Due to treatment, signs of bone marrow reparation are detected even in patients with the most severe forms. The enteric syndrome was alleviated, and partial epithelialisation of the oral cavity and throat was attained. The hemorrhagic syndrome manifested, in the majority of cases, was no longer life threatening. The most frequent causes of death were infectious complications, primarily mycotic and viral

1999-01-01

354

Method for Early Detection of Infectious Mononucleosis.  

Science.gov (United States)

Early detection of infectious mononucleosis is carried out using a sample of human blood by isolating and identifying the presence of Inmono proteins in the sample from a two-dimensional protein map with the proteins being characterized by having isoelect...

K. E. Willard

1982-01-01

355

Method of Object Detection for Mobile Robot  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: In general, there are two steps of object detection, which are object generation, where the locations of possible objects are in an image and object verification, where tests are performed to verify the presence of object in an image. Approach: The purpose of the proposed object recognition system was to detect the object which is in front the mobile robot so that it can send warnings to avoid possible collision. The information of detected objects can also help to control the robot to travel at an appropriate speed and direction to avoid possible collisions. Results: An object in an image was detected by the two steps of image generation and verification. When object localizations were hypothesized, sub-image of the object was extracted from the image. Gabor features extracted from the sub-image is input into the classifier to verify whether the hypothesized sub-image contain an object or not. Conclusion: Localizations of objects in image are generated and verified. Object generation was implemented by using horizontal and vertical edges on the way region of interest segmented by utilizing color information. The sub-images of object are verified by classifier trained on Gabor features of a training set of images.

Surachai Panich

2010-01-01

356

Radiation detection from phase-locked serial dc SQUID arrays  

DEFF Research Database (Denmark)

We report on synchronous operation of series arrays of inductively coupled superconducting quantum interference devices (SQUIDs). Each array consisted of N=3 or 11 dc SQUIDs with common inductances providing a strong interaction between neighboring cells. Externally shunted (betac[approximately-equal-to]1) trilayer Nbâ??AlOxâ??Nb Josephson junctions were used. Coherent radiation was detected in the frequency range f=67â??73 GHz while the array voltage was VN=NfPhi0 (Phi0=2.07Ã?10â??15 V s). The stability of the coherent state was influenced by the external dc magnetic field. The linewidth depended on the external loading. For small loading it was N times smaller than expected for a single cell. The influence of the inductive coupling mechanism on the operation of discrete Josephson junction circuits and the similarity to the coupling in layered structures of long Josephson junctions is discussed. Journal of Applied Physics is copyrighted by The American Institute of Physics.

Mygind, Jesper; Pedersen, Niels Falsig

1993-01-01

357

Development of thin dosemeters of CaSO_4: Dy for beta radiation detection  

International Nuclear Information System (INIS)

Thin pellets of CaSO: Dy (0,20mm) were produced and tested in beta radiation fields. The Thermolumiscent (TL) characteristics studied were sensitivity, reproducibility, lower detection limit, linearity of TL response with absorved dose energy dependence. The results show the usefulness of this thin pellets in beta radiation detection. (Author)

1987-05-05

358

Alternative method of generation of Cerenkov radiation or shock wave  

CERN Document Server

An alternative method of generation of Cerenkev radiation is proposed over here with the help of a rotating source and a reflector. The principle is that, if we focus a narrow beam of light on to source of light is rotated with certain angular velocity then the light spot on the surface will move with very high velocity which may exceed the velocity of light. As a consequence of this we shall observe an effect very similar to Cerknov radiation.

Halder, A

1997-01-01

359

Efficient Monte Carlo methods for continuum radiative transfer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We discuss the efficiency of Monte Carlo methods in solving continuum radiative transfer problems. The sampling of the radiation field and convergence of dust temperature calculations in the case of optically thick clouds are both studied. For spherically symmetric clouds we find that the computational cost of Monte Carlo simulations can be reduced, in some cases by orders of magnitude, with simple importance weighting schemes. This is particularly true for models consisting...

Juvela, M.

2005-01-01

360

Inertial confinement fusion method producing line source radiation fluence  

Energy Technology Data Exchange (ETDEWEB)

An inertial confinement fusion method in which target pellets are imploded in sequence by laser light beams or other energy beams at an implosion site which is variable between pellet implosions along a line. The effect of the variability in position of the implosion site along a line is to distribute the radiation fluence in surrounding reactor components as a line source of radiation would do, thereby permitting the utilization of cylindrical geometry in the design of the reactor and internal components.

Rose, Ronald P. (Peters Township, Washington County, PA)

1984-01-01

 
 
 
 
361

Radiation monitoring with NORM detection of vehicles at borders at stand-still  

International Nuclear Information System (INIS)

In this report the results of works performed under the Research Contract 12607/R0 are presented. All accomplished works can be divided into three parts: In the first part, the method is described used for radiation control of vehicles crossing customs and border check-points. At detection of the radioactivity in a vehicle, it is detained and the NORM materials and other radioactive materials are identified. The radiation monitor model was developed with realisation of the described vehicle control concept in it. This model was tested on-site on real vehicles crossing the customs check-point of the Republic of Uzbekistan. In the second part, based on the activities conducted in the first part, it was demonstrated that this method can be realised in practice for the purpose of its application at customs and border check-points for detection of nuclear and fissile materials with identification of radioactive isotopes in NORM-materials and other radioactive materials, as well as for decision making upon further possible transportation of such cargo. These results, showed in this report, were analysed and demonstrated that the 100x50 mm NaI(Tl)-crystal based scintillation detector is applicable, so that the identification capabilities become better when such detector is placed at 50 cm distance and closer to the vehicle. Other single crystal can be also used; however, one should take into account its geometry depending on the sizes of the crystal. In the third part, new sophisticated methods for radioactive materials detection were described, and the possibility for creation of radiation monitoring instrumentation based on the described above concept was demonstrated. (author)

2008-07-01

362

Interpolation methods and their use in radiation protection  

International Nuclear Information System (INIS)

The presentation summarizes results of using various interpolation methods for getting spatial data from point measurements. These methods were evaluated within the State Office for Nuclear Safety (SONS) Science and Research Project No. 2/2008 'Methods and Measures to Limit Generation and Liquidation of Consequences of Radioactive Matter Misuse by Terrorists'. Several field tests in which the short life-time radioactive matter was released by explosion were realized and the measured data were processed. The essential goal is to find the most realistic method for radiation events assessment. Within the research project, three methods were used: Multilevel B-Spline, Triangulation and Kriging, using freely available SAGA GIS software. The best solution for this sort of radiation events appears to be the Multilevel B-Spline method. It is quick and produces good quality output data comparable with the much slower Kriging method and allows extrapolation in contrast to Triangulation. (author)

2008-11-01

363

Electric field detection of coherent synchrotron radiation in a storage ring generated using laser bunch slicing  

Energy Technology Data Exchange (ETDEWEB)

The electric field of coherent synchrotron radiation (CSR) generated by laser bunch slicing in a storage ring has been detected by an electro-optic sampling method. The gate pulses for sampling are sent through a large-mode-area photonic-crystal fiber. The observed electric field profile of the CSR is in good agreement with the spectrum of the CSR observed using Fourier transform far-infrared spectrometry, indicating good phase stability in the CSR. The longitudinal density profiles of electrons modulated by laser pulses were evaluated from the electric field profile.

Katayama, I. [Interdisciplinary Research Center, Yokohama National University, Yokohama 240-8501 (Japan); Shimosato, H.; Bito, M.; Furusawa, K. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); Adachi, M.; Zen, H.; Kimura, S.; Katoh, M. [UVSOR, Institute of Molecular Science, Okazaki 444-8585 (Japan); School of Physical Sciences, Graduate Universities for Advanced Studies (SOKENDAI), Okazaki 444-8585 (Japan); Shimada, M. [High Energy Accelerator Research Organization, KEK, Tsukuba 305-0801 (Japan); Yamamoto, N.; Hosaka, M. [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Ashida, M. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); PRESTO, JST (Japan)

2012-03-12

364

Optical detected magnetic resonance in silicon carbide with radiation-induced and thermal defects  

International Nuclear Information System (INIS)

The method of optically detected magnetic resonance (ODMR) was applied to study luminescence observed in SiC crystals containing radiation defects and thermal defects. Crystals of hexagonal silicon carbide 4H-SiC and 6H-SiC with concentration of non-compensated nitrogen equal to 10"1"7-10"1"8 cm"-"3 irradiated by fast reactor neutrons with the dose of 10"1"8 cm"-"2 were investigated. Thermodefects in 3C-SiC crystals resulted from hardening 6H-SiC crystals implanted by aluminium ions were also studied. Spin selection effect through a non-irradiating channel is disclosed

1986-01-01

365

Research on detection method for electron beam irradiation perishable foods  

International Nuclear Information System (INIS)

To develop an applicable detection method and a new detection method the measuring method of the absorbed dose in the food system is examined for perishable foods to which the electron beam is irradiated. It was understood that ESR was a useful detection method, and it had ability enough for the detection of the irradiation food containing a lot of sugar. On the other hand, it is necessary to consider the coverage enough since the ESR signal is easily influenced in the preservation environment for the food. (H. Katsuta)

2004-02-01

366

Anomaly-based Network Intrusion Detection Methods  

Directory of Open Access Journals (Sweden)

Full Text Available The article deals with detection of network anomalies. Network anomalies include everything that is quite different from the normal operation. For detection of anomalies were used machine learning systems. Machine learning can be considered as a support or a limited type of artificial intelligence. A machine learning system usually starts with some knowledge and a corresponding knowledge organization so that it can interpret, analyse, and test the knowledge acquired. There are several machine learning techniques available. We tested Decision tree learning and Bayesian networks. The open source data-mining framework WEKA was the tool we used for testing the classify, cluster, association algorithms and for visualization of our results. The WEKA is a collection of machine learning algorithms for data mining tasks.

Pavel Nevlud

2013-01-01

367

Detection of DNA double-strand break of lymphocytes as a biological marker in radiation injury  

International Nuclear Information System (INIS)

Objective: To investigate the possibility of applying the DNA double strand break and apoptosis of lymphocytes to biological assay in radiation injury. Methods: Comet rates and comet tails were detected using neutral comet assay at 6 h and 24 h following in vitro 0.1-4 Gy ? radiation of whole blood. Results: The comet rates increased in a dose-dependent manner. The dose thresholds of comet rates at 6 h and 24 h were 0.6 Gy and 0.1 Gy, respectively. The correlation coefficients were 0.967 and 0.927, respectively. The comet tails at 6 h also increased dose-dependently with a correlation coefficient of 0.847. Conclusion: The results of neutral comet assay indicates that there is close correlations between doses and comet rates and tails

2004-04-01

368

Odour Detection Methods: Olfactometry and Chemical Sensors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at v...

2011-01-01

369

A Novel Sensor Fault Detection Method  

Directory of Open Access Journals (Sweden)

Full Text Available To detect the sensor faults of the plant with min-disturbance, a weighted least squares interval regression model is proposed. The output of the proposed model is an interval band which can resist the disturbance influence and give correct sensor fault alarm. Additionally, the time complexity of this model is low because only a set of linear equations can determine the parameters. The experiments of fault instance demonstrate the feasibility and effectiveness of the interval regression model.    

Chen Yongqi

2013-07-01

370

Comparing Different Methods for Disfluency Structure Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a number of experiments focusing on assessing the performance of different machine learning methods on the identification of disfluencies and their distinct structural regions over speech data. Several machine learning methods have been applied, namely Naive Bayes, Logistic Regression, Classification and Regression Trees (CARTs), J48 and Multilayer Perceptron. Our experiments show that CARTs outperform the other methods on the identification of the distinct structural d...

Medeiros, Henrique; Batista, Fernando; Moniz, Helena; Trancoso, Isabel; Nunes, Luis

2013-01-01

371

Method of detecting abnormality of control rod  

International Nuclear Information System (INIS)

Purpose: To detect even control rod abnormality even at a low reactivity effect to the reactor core at a high reliability. Constitution: Current signals indicating the neutron density in the reactor core obtained from neutron flux monitors are inputted to a reactivity meter. In the reactivity meter, nuclear dynamic property equations are dissolved by means of the current signals to directly detect the reactivity change in the reactor core, which are them inputted to a judging circuit. The judging circuit compares the inputted reactivity change with a predetermined reactivity change, to always monitor the rapid reactivity change upon control rod abnormality. A signal from a control rod control system may be inputted the judging circuit. In this case, it is possible to judge whether the reactivity change calculated by the reactivity meter is due to the control system operation such as the control rod operation or not. According to this invention, since the neutron flux detector signals are connected to the reactivity meter to thereby always monitor the reactivity change directly, the abnormal state of the control rod can be detected rapidly. (Horiuchi, T.)

1987-02-17

372

Studies on the detection of transition radiation for the e/? separation in the ZEUS experiment  

International Nuclear Information System (INIS)

A transition radiation detector is currently under construction in order to identify single electrons inside hadron-jets of deep inelastic ep-collisions at HERA. We performed measurements with test-modules in mixed particle beams, composed of electrons and pions, at the CERN-PS and -SPS. The transition radiation was generated in polypropylene fibres. The photons were detected in time expansion chambers which were dominantly filled with Xenon. The absorption of transition radiation as well as ?-electrons leads to local ionisation clusters along the track of the ionizing particle. The amplified and shaped chamber signals were digitized by using flash ADCs in order to conserve the time structure of the signal. The tail cancellation due to pulse-shaping improves the recognition of clusters, generated close together along the primary ionisation track. The application of cluster analyzing methods leads to a better electron-pion separation. From the results of one chamber we calculated the peformance of a detector set-up consisting of four modules. Applying such algorithms we obtained a misidentifiaction of pions in the energy range from 2-10 GeV of about 1-2% at 90% electron detection efficiency. (orig.)

1989-01-01

373

High Density Nano-Electrode Array for Radiation Detection  

International Nuclear Information System (INIS)

Bulk single crystals of Cd1-xZnxTe (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd1-xZnxTe with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd1-xZnxTe in an electrochemical route. In this investigation, Cd1-xZnxTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 C. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd0.9Zn0.1Te nanowires were 4.29 x 1013 cm-3, 1.56 eV and 2.76 x 1011 (Omega)-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 (micro)Ci), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The preliminary results indicate that the CZT nanowire arrays can be used as a potential X-ray and low energy gamma ray detector material at room temperature with a much low bias potential (0.7-4V) as against 300-500 V applied in the commercial bulk detector materials.

2010-01-01

374

High Density Nano-Electrode Array for Radiation Detection  

Energy Technology Data Exchange (ETDEWEB)

Bulk single crystals of Cd1-xZnxTe (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd1-xZnxTe with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd1-xZnxTe in an electrochemical route. In this investigation, Cd1-xZnxTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 ºC. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd0.9Zn0.1Te nanowires were 4.29x1013 cm-3, 1.56 eV and 2.76x1011?-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 ?Ci), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The preliminary results indicate that the CZT nanowire arrays can be used as a potential X-ray and low energy gamma ray detector material at room temperature with a much low bias potential (0.7 – 4V) as against 300 – 500 V applied in the commercial bulk detector materials.

Mano Misra

2010-05-07

375

Evaluation of mass spectrometry and radiation detection for the analysis of radionuclides  

International Nuclear Information System (INIS)

Radioactive elements are of increasing importance in the areas of human health and safety, the environment, use in terrorism, and nuclear nonproliferation. Accurate and sensitive measurement of fission products, medical isotopes, and actinide species are a vital part of the job entrusted to the national laboratories. Several competing techniques exist. They can be mainly summarized into two categories: radiation and mass spectrometric detection methods. Traditional radiometric counting methods, which are based on the measurement of natural decay of radionuclides, play an important role in the detection of radionuclides. Fission track analysis, which uses thermal neutron induced fission to detect fissionable isotopes, now reaches a limit of detection (LOD) of 106 atoms. Of the mass spectrometric detection techniques, inductively coupled plasma mass spectrometry, provides the best sensitivity for the cost in low-level determinations of long-lived radionuclides. Other methods, such as thermal ionization mass spec and accelerator mass spec can provide greater sensitivity in some cases but the cost is higher. Depending on the types of mass analyzers, LOD varies from ng/l to pg/l. More importantly, mass spectrometry is capable of offering precise isotopic ratio information that may act as a fingerprint for identifying the origins of nuclear materials. As the technology matures mass techniques now can provide suitable detection of the shorter-lived isotopes. This criterion is critical as the prompt determination of radionuclides is becoming of overriding importance. Radiometric information displayed in a manner that allows for easy comparison to mass counting is provided. The information can then be used as a general guide to determine the most suitable method to use for the prompt determination of radionuclides. (author)

2005-02-01

376

GaN heterostructures for biosensing and radiation detection  

Energy Technology Data Exchange (ETDEWEB)

In this thesis I show the results from our investigation of the interface between gallium nitride wide bandgap semiconductor heterostructures and (bio)molecular systems on their surfaces for biosensing, bioelectronics, and photoelectric applications, with a large emphasis on the processes arising from high energy ionizing irradiation, including heterostructure photoelectric gain mechanisms. Wide bandgap semiconductors, such as gallium nitride, have received increasing attention as potential components in advanced organic/inorganic hybrid systems. Working to further this topic, we determine a new semiconductor alignment required for low energy photo-induced charge transfer ionization of alkyl chains well below the energy normally required for molecular cleavage, show original results of the influence of binding methods on enzyme functionality in conjunction with a novel electrochemical and environmental control system and demonstrate new possibilities to significantly improve upon pH measurements through the use of high sensitivity devices. Furthermore, based on the extension of this work to support future studies of radiation effects on cell systems, we present a detailed characterization of new simultaneous chemical sensing and ionizing radiation dosimetry using single devices. We found that their pH sensitivity was retained during X-ray irradiation and that the fundamental characteristics can be used to separate the irradiation signal from the pH response without compromising operational stability. These data provide clear indications of the separate response mechanism tied to the presence of a two-dimensional electron gas channel. Here, we found new results exhibiting exceptionally high gains and independence of the well-known persistent photoconductivity for soft X-rays and high energy particles in the ultralow dose-rate regime. This material system provides the capability for high sensitivity and resolution real time monitoring, which is competitive with and complements state-of-the-art detectors. Thus, is extremely promising for future applications ranging from advanced organic/inorganic hybrid systems to medical imaging.

Howgate, John D.

2012-12-11

377

GaN heterostructures for biosensing and radiation detection  

International Nuclear Information System (INIS)

In this thesis I show the results from our investigation of the interface between gallium nitride wide bandgap semiconductor heterostructures and (bio)molecular systems on their surfaces for biosensing, bioelectronics, and photoelectric applications, with a large emphasis on the processes arising from high energy ionizing irradiation, including heterostructure photoelectric gain mechanisms. Wide bandgap semiconductors, such as gallium nitride, have received increasing attention as potential components in advanced organic/inorganic hybrid systems. Working to further this topic, we determine a new semiconductor alignment required for low energy photo-induced charge transfer ionization of alkyl chains well below the energy normally required for molecular cleavage, show original results of the influence of binding methods on enzyme functionality in conjunction with a novel electrochemical and environmental control system and demonstrate new possibilities to significantly improve upon pH measurements through the use of high sensitivity devices. Furthermore, based on the extension of this work to support future studies of radiation effects on cell systems, we present a detailed characterization of new simultaneous chemical sensing and ionizing radiation dosimetry using single devices. We found that their pH sensitivity was retained during X-ray irradiation and that the fundamental characteristics can be used to separate the irradiation signal from the pH response without compromising operational stability. These data provide clear indications of the separate response mechanism tied to the presence of a two-dimensional electron gas channel. Here, we found new results exhibiting exceptionally high gains and independence of the well-known persistent photoconductivity for soft X-rays and high energy particles in the ultralow dose-rate regime. This material system provides the capability for high sensitivity and resolution real time monitoring, which is competitive with and complements state-of-the-art detectors. Thus, is extremely promising for future applications ranging from advanced organic/inorganic hybrid systems to medical imaging.

2012-01-01

378

Handbook of engineering control methods for occupational radiation protection  

Energy Technology Data Exchange (ETDEWEB)

Sources of ionizing and non-ionizing radiation are widely used in industrial, medical, military, and other applications. In the workplace, the task of assuring the safety of workers exposed to radiation sources is generally assigned to the safety professional, industrial hygienist, or an engineer in some other discipline. Rarely do employers outside the nuclear industry have the luxury of a staff health physicist in the workplace. Consultants may be called in to provide initial assessments of the hazards and to assist with complex problems, but the day-to-day problem solving is usually a function of the safety professional or other professional with the responsibility for safety. The primary purpose of this book is to provide a practical reference for safety professionals that addresses the application of ionizing and non-ionizing radiation protection standards and the quantitative methods for evaluating and designing engineering controls to meet those standards. Although the emphasis of this book is on control methods, it is necessary to understand the physical nature of the radiation exposure, its units of measure, and its biological effects in order to apply the appropriate control methods. Consequently, a brief treatment of these topics precedes the discussion of control methods for each type of radiation exposure.

Orn, M.K.

1992-01-01

379

Robust Automatic Facial Expression Detection Method  

Directory of Open Access Journals (Sweden)

Full Text Available Recently, the recognition of occluded facial expressions attract more and more people’s attention. Sparse representation based classification (SRC method gives good performance on face recognition (FR and facial expression recognition (FER, well-known for its robustness to occlusion. Histograms of Oriented Gradient (HOG descriptors are very efficient to represent the shape information of different facial expressions and robust to various illumination. Since, this paper proposes a novel method by using HOG descriptors conjunction with SRC framework for FER. Experiment results show that the proposed method gives better performance than the existing state-of-the-art methods. Furthermore, the proposed method is not only robust to assigned occlusions, but also to random occlusions.

Yan OuYang

2013-07-01

380

Development and Establishment of Detection Method of Irradiated Foods  

International Nuclear Information System (INIS)

The present project was related to the development and establishment of the detection techniques for the safety management of gamma-irradiated food and particularly conducted for the establishment of standard detection method for gamma-irradiated dried spices and raw materials, dried meat and fish powder for processed foods, bean paste powder, red pepper paste powder, soy sauce powder, and starch for flavoring ingredients described in 3, 6, 7 section of Korean Food Standard. Since the approvement of gamma-irradiated food items will be enlarged due to the international tendency for gamma-irradiated food, it was concluded that the establishment of detailed detection methods for each food group is not efficient for the enactment and enforcement of related regulations. For this reason, in order to establish the standard detection method, a detection system for gamma-irradiated food suitable for domestic operation was studied using comparative analysis of domestic and foreign research data classified by items and methods and European Standard as a reference. According to the comparative analyses of domestic and foreign research data and regulations of detection for gamma-irradiated food, it was concluded to be desirable that the optimal detection method should be decided after principal detection tests such as physical, chemical, and biological detection methods are established as standard methods and that the specific descriptions such as pre-treatment of raw materials, test methods, and the evaluation of results should be separately prescribed

2004-01-01

 
 
 
 
381

Development and Establishment of Detection Method of Irradiated Foods  

Energy Technology Data Exchange (ETDEWEB)

The present project was related to the development and establishment of the detection techniques for the safety management of gamma-irradiated food and particularly conducted for the establishment of standard detection method for gamma-irradiated dried spices and raw materials, dried meat and fish powder for processed foods, bean paste powder, red pepper paste powder, soy sauce powder, and starch for flavoring ingredients described in 3, 6, 7 section of Korean Food Standard. Since the approvement of gamma-irradiated food items will be enlarged due to the international tendency for gamma-irradiated food, it was concluded that the establishment of detailed detection methods for each food group is not efficient for the enactment and enforcement of related regulations. For this reason, in order to establish the standard detection method, a detection system for gamma-irradiated food suitable for domestic operation was studied using comparative analysis of domestic and foreign research data classified by items and methods and European Standard as a reference. According to the comparative analyses of domestic and foreign research data and regulations of detection for gamma-irradiated food, it was concluded to be desirable that the optimal detection method should be decided after principal detection tests such as physical, chemical, and biological detection methods are established as standard methods and that the specific descriptions such as pre-treatment of raw materials, test methods, and the evaluation of results should be separately prescribed.

Byun, Myung Woo; Lee, Ju Woon; Kim, Dong Ho; Jo, Cheo Run; Kim, Jang Ho; Kim, Kyong Su

2004-12-15

382

Time Resolved Detection of Infrared Synchrotron Radiation at DA?NE  

International Nuclear Information System (INIS)

Synchrotron radiation is characterized by a very wide spectral emission from IR to X-ray wavelengths and a pulsed structure that is a function of the source time structure. In a storage ring, the typical temporal distance between two bunches, whose duration is a few hundreds of picoseconds, is on the nanosecond scale. Therefore, synchrotron radiation sources are a very powerful tools to perform time-resolved experiments that however need extremely fast detectors. Uncooled IR devices optimized for the mid-IR range with sub-nanosecond response time, are now available and can be used for fast detection of intense IR sources such as synchrotron radiation storage rings. We present here different measurements of the pulsed synchrotron radiation emission at DA?NE (Double Annular ?-factory for Nice Experiments), the collider of the Laboratori Nazionali of Frascati (LNF) of the Istituto Nazionale di Fisica Nucleare (INFN), performed with very fast uncooled infrared detectors with a time resolution of a few hundreds of picoseconds. We resolved the emission time structure of the electron bunches of the DA?NE collider when it works in a normal condition for high energy physics experiments with both photovoltaic and photoconductive detectors. Such a technology should pave the way to new diagnostic methods in storage rings, monitoring also source instabilities and bunch dynamics

2007-01-19

383

Frontal Face Detection Methods –Neural Networks and Aggressive Learning Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available In this research work, a face detection method is presented. Face detection is the first step of face Recognition methods. Face detection is a difficult task in Pattern. There are different methods of face detection namely-Knowledge Based Face Detection Methods, Feature Based Face Detection Methods, Template Based Face Detection Methods and Appearnce Based Face Detection Methods. But here we divided basically in two methods for face detection (i image based methods (ii feature based methods. We have developed an intermediate system, using a boosting algorithm to train a classifier which is capable of processing images rapidly while having high detection rates. AdaBoost is a kind of large margin classifiers and is efficient for on-line learning. In order to adapt the AdaBoost algorithm to fast face recognition, the original Adaboost which uses all given features is compared with the boosting along feature dimensions. The comparable results assure the use of the latter, which is faster for classification. The main idea in the building of the detector is a learning algorithm based on boosting: AdaBoost. AdaBoost is an aggressive learning algorithm which produces a strong classifier by choosing visual features in a family of simple classifiers and combining them linearly. The family of simple classifiers contains simple rectangular wavelets which are reminiscent of the Haar basis. Their simplicity and a new image representation called Integral Image allow a very quick computing of these Haarlike features. Then a structure in cascade is introduced in order to reject quickly the easy to classify background regions and focus on the harder to classify windows . For this, classifiers with an increasingly complexity are combined sequentially. This improves both, the detection speed and the detection efficiency. The detection of faces in input images is proceeded using a scanning window at different scales which permits to detect faces of every size without resampling the original image. On the other hand, the structure of the final classifier allows a realtime implementation of the detector. Due to some limitation of neural network based methods we adopt the Adaboost algorithm for face detection. Here we present Some results on real world examples are presented. Our detector found good detection rates with frontal faces and the method can be easily adapted to other object detection tasks by changing the contents of the training dataset.

sushma jaiswal

2011-08-01

384

Frontal Face Detection Methods ???Neural Networks and Aggressive Learning Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available In this research work, a face detection method is presented. Face detection is the first step of face Recognition methods. Face detection is a difficult task in Pattern. There are different methods of face detection namely-Knowledge Based Face Detection Methods, Feature Based Face Detection Methods, Template Based Face Detection Methods and Appearnce Based Face Detection Methods. But here we divided basically in two methods for face detection (i image based methods (ii feature based methods. We have developed an intermediate system, using a boosting algorithm to train a classifier which is capable of processing images rapidly while having high detection rates. AdaBoost is a kind of large margin classifiers and is efficient for on-line learning. In order to adapt the AdaBoost algorithm to fast face recognition, the original Adaboost which uses all given features is compared with the boosting along feature dimensions. The comparable results assure the use of the latter, which is faster for classification. The main idea in the building of the detector is a learning algorithm based on boosting: AdaBoost. AdaBoost is an aggressive learning algorithm which produces a strong classifier by choosing visual features in a family of simple classifiers and combining them linearly. The family of simple classifiers contains simple rectangular wavelets which are reminiscent of the Haar basis. Their simplicity and a new image representation called Integral Image allow a very quick computing of these Haarlike features. Then a structure in cascade is introduced in order to reject quickly the easy to classify background regions and focus on the harder to classify windows . For this, classifiers with an increasingly complexity are combined sequentially. This improves both, the detection speed and the detection efficiency. The detection of faces in input images is proceeded using a scanning window at different scales which permits to detect faces of every size without resampling the original image. On the other hand, the structure of the final classifier allows a realtime implementation of the detector. Due to some limitation of neural network based methods we adopt the Adaboost algorithm for face detection. Here we present Some results on real world examples are presented. Our detector found good detection rates with frontal faces and the method can be easily adapted to other object detection tasks by changing the contents of the training dataset.

Sushma Jaiswal

2011-08-01

385

Method for early detection of infectious mononucleosis  

Energy Technology Data Exchange (ETDEWEB)

Early detection of infectious mononucleosis is carried out using a sample of human blood by isolating and identifying the presence of Inmono proteins in the sample from a two-dimensional protein map with the proteins being characterized by having isoelectric banding as measured in urea of about -16 to -17 with respect to certain isoelectric point standards and molecular mass of about 70 to 75 K daltons as measured in the presence of sodium dodecylsulfate containing polyacrylamide gels, the presence of the Inmono proteins being correlated with the existence of infectious mononucleosis.

Willard, K.E.

1982-08-10

386

Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors  

Energy Technology Data Exchange (ETDEWEB)

A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

Hausladen, Paul [ORNL; Blessinger, Christopher S [ORNL; Guzzardo, Tyler [ORNL; Livesay, Jake [ORNL

2012-07-01

387

Identification of irradiated foods. I. Detection methods based on physical changes induced by irradiation in the food samples  

International Nuclear Information System (INIS)

Food processing by ionizing radiation is an emerging technology capable to extend the shelf-life of foods, to reduce their loses and to improve their hygienic quality. Because the process of food irradiation produces practically no change in appearance, shape, or texture of products, it is controlled mainly by administrative means. Therefore, there is a great interest in supplementing administrative control by developing detection methods for irradiated foods. In recent years, a number of analytical methods for detecting the radiation treatment of foods was developed. All foods can not be identified by a given method, but rather depending on the specific type of food, several methods are applicable. Depending on the detection parameter nature, the methods used may be based on physical, chemical and biological measurements. Physical methods - based on physical changes induced by radiation in food: viscosimetry, dielectric method, ESR spectroscopy, luminescence techniques. Chemical methods - based on chemical changes induced by irradiation in the main food components (proteins, lipids, nucleic acids): gas chromatography - mass spectrometry, liquid chromatography - gas chromatography, electrochemical sensor technique, high performance liquid chromatography, immunochemical detection method, and electrophoretic techniques. Biological methods - based on biological changes in radiation - processed food: microbiological tests (aerobic plate count, direct epi-fluorescence filter technique, Limulus Amoebocyte Lysate test-Gram negative bacterial count) and germination study. In this paper it is not possible to cover all the detection method, so only those which have been most developed will be discussed in detail. (authors)

1996-01-01

388

X-spectrographic method for plutonium detection. Application to contamination measurements in humans  

International Nuclear Information System (INIS)

After reviewing the radio-toxicology of plutonium 239 and conventional detection methods using its ?-radiation, the author considers the measurement of the X emission spectrum of plutonium 239 using a proportional counter filled with argon under pressure. This preliminary work leads to the third part of this research involving the detailed study of the possibilities of applying thin alkali halide crystal scintillators to the detection of soft plutonium X-rays; there follows a systematic study of all the parameters liable to render the detection as sensitive as possible: movement due to the photomultiplier itself and its accessory electronic equipment, nature and size of the crystal scintillator as well as its mode of preparation, shielding against external parasitic radiation. Examples of some applications to the measurement of contamination in humans give an idea of the sensitivity of this method. (author)

1967-01-01

389

Methods and procedures for external radiation dosimetry at ORNL  

International Nuclear Information System (INIS)

Procedures, methods, materials, records, and reports used for accomplishing the personnel, external radiation monitoring program at Oak Ridge National Laboratory are described for the purpose of documenting what is done now for future reference. This document provides a description of the methods and procedures for external radiation metering, monitoring, dosimetry, and records which are in effect at ORNL July 1, 1981. This document does not include procedures for nuclear accident dosimetry except insofar as routine techniques may apply also to nuclear accident dosimetry capability

1981-01-01

390

Measurement of pipe wall local thickness by combined radiation method  

International Nuclear Information System (INIS)

Analytical dependences have been studied which describe radiation fluxes registered by the respective detectors during transmission of a collimated beam of penetrating radiation through a tube over its diameter. The dependences are necessary for engineering designs, analysis of accuracy and other characteristics of radioisotope thickness gaUges using the combined method for measurements of tube wall local thickness. Experimental investigations have been carried out with "1"3"7Cs and "6"0Co sources. The dependence, permitting to determine conditions providing with the preset accuracy of tube wall local thickness measurement by the combined method, has been obtained

1985-01-01

391

Experimental methods of heavy quark detection  

International Nuclear Information System (INIS)

By comparing how b and c were observed we saw that the heavier quark was more difficult to detect. For various reasons the signal was smaller and the signal-to-noise worse. This trend is expected to continue when searching for the still heavier top quark. In fact many detection techniques which worked well for bottom and charm are not viable for top. For masses less than about 60 GeV/c2 top should be visible at the CERN S anti ppS. For larger masses the higher energy of the Fermilab Tevatron will be necessary. At both machines semileptonic decays are the most promising tag. There are background rejection techniques which should result in a fairly clean signal. As there are many possible background sources it is important to carefully estimate the residual background from the data itself. At e+e- machines top will be copiously produced in Z0 decays if M/sub t/ 0//2. In this case it is possible to estimate its mass and study its decay modes. 40 references, 40 figures

1984-08-03

392

Experimental methods of heavy quark detection  

Energy Technology Data Exchange (ETDEWEB)

By comparing how b and c were observed we saw that the heavier quark was more difficult to detect. For various reasons the signal was smaller and the signal-to-noise worse. This trend is expected to continue when searching for the still heavier top quark. In fact many detection techniques which worked well for bottom and charm are not viable for top. For masses less than about 60 GeV/c/sup 2/ top should be visible at the CERN S anti ppS. For larger masses the higher energy of the Fermilab Tevatron will be necessary. At both machines semileptonic decays are the most promising tag. There are background rejection techniques which should result in a fairly clean signal. As there are many possible background sources it is important to carefully estimate the residual background from the data itself. At e/sup +/e/sup -/ machines top will be copiously produced in Z/sup 0/ decays if M/sub t/ < M/sub Z/sup 0///2. In this case it is possible to estimate its mass and study its decay modes. 40 references, 40 figures.

Himel, T.

1984-11-01

393

Knowledge representation methods for early failure detection  

International Nuclear Information System (INIS)

To supervise technical processes like nuclear power plants, it is very important to detect failure modes in an early stage. In the nuclear research center at Karlsruhe an expert system is developed, embedded in a computer network of autonomous computers, which are used for intelligent prepocessing. Events, process data and actual parameter values are stored in slots of special frames in the knowledge base of the expert system. Both rule based and fact based knowledge representations are employed to generate cause consequence chains of failure states. By on-line surveillance of the reactor process, the slots of the frames are dynamically actualized. Immediately after the evaluation, the inference engine starts in the special domain experts (triggered by metarules from a manager) and detects the correspondend failures or anomaly state. Matching the members of the chain and regarding a catalogue of instructions and messages, what is to do by the operator, future failure states can be estimated and propagation can be prohibited. That means qualitative failure prediction based on cause consequence in the static part of the knowledge base. Also, a time series of physical data can be used to predict on analytical way future process state and to continue such a theoretical propagation with matching the cause consuquence chain

1989-10-10

394

PRECISE, AUTOMATIC AND FAST METHOD FOR VANISHING POINT DETECTION  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new approach for vanishing point detection is described. This method is based on the theorem of Thales. The main contribution of this paper is the automatic and simultaneous detection of all vanishing points of the image that consists in detecting circles in a complex cloud of points. This extraction is performed without any prior knowledge of the internal calibration. An analysis of the error propagation is done in order to give quantitative elements on the precision of the detected vanish...

Kalantari, Mahzad; Jung, Franck; Gue?don, Jeanpierre

2009-01-01

395

Comparison between damage detection methods applied to beam structures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Damage detection methods based on the dynamic measurements of structures are one of the most important techniques for damage evaluation in bridges. The methods considered in this study have been recognized as the most promising tools for damage detection in these structures. Some of these methods were applied during the deliberate damage of Z24 Bridge in Switzerland and I-24 Bridge in USA. These methods have been evaluated in different cases and therefore it is difficult to decide which me...

Salgado, R.; Cruz, Paulo J. S.; Ramos, Lui?s F.; Lourenc?o, Paulo B.

2006-01-01

396

Evaluation of radiation detection systems for simultaneous uranium and technetium monitoring at X-326 purge vents  

International Nuclear Information System (INIS)

Vent monitoring methodologies, based on liquid alpha/beta scintillation and sodium iodide gamma-based detection have been evaluated as possible means of improving existing vent monitoring and/or alarm detection capability at the X-326 top and side purge cascade. Of these two methods evaluated, the gamma-based sodium iodide detection system coupled with multi-channel analyses is more promising as a means of overcoming the two key limitations associated with the existing colorimetric analyzers, namely (1) a ten-minute lag time with respect to real time vent conditions, and (2) inability to detect technetium. Response times are reduced to less than one minute at inlet uranium-235 concentrations of approximately 10 ppM and are inversely proportional to concentration increase. Both uranium-235 and technetium-99 are detected by either of the two radiation detection methods but the gamma-based detection system operates with dry trapping agents and is expected to be less labor intensive from a maintenance standpoint because wet scrubbing or associated liquid handling equipment (necessary with the colorimetric uranium analyzers or ?/? liquid scintillation) is not necessary. An option offered by the gamma-based sodium iodide system is the capability to serve as a redundant sampler for convenient confirmation of vent releases or quantity of radionuclides entering the plant trapping system. The gamma-based monitoring system design as described herein is intended for primary application at the X-326 top and side purge vents where uranium-235 assays are above 20% and well known. By further design modifications to enhance sensitivity, the gamma monitoring system could in principle be extended to appropriate lower assay vents. Future technical effort is recommended in refining the gamma-based vent monitoring system (principally in computerizing the data handling) for ultimate replacement of the existing colorimetric uranium analyzers

1986-01-01

397

Scoring methods for implicit Monte Carlo radiation transport  

International Nuclear Information System (INIS)

Analytical and numerical tests were made of a number of possible methods for scoring the energy exchange between radiation and matter in the implicit Monte Carlo (IMC) radiation transport scheme of Fleck and Cummings. The interactions considered were effective absorption, elastic scattering, and Compton scattering. The scoring methods tested were limited to simple combinations of analogue, linear expected value, and exponential expected value scoring. Only two scoring methods were found that produced the same results as a pure analogue method. These are a combination of exponential expected value absorption and deposition and analogue Compton scattering of the particle, with either linear expected value Compton deposition or analogue Compton deposition. In both methods, the collision distance is based on the total scattering cross section

1981-01-01

398

Assessment and comparison of methods for solar ultraviolet radiation measurements  

Science.gov (United States)

In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented.

Leszczynski, K.

1995-06-01

399

Assessment and comparison of methods for solar ultraviolet radiation measurements  

Energy Technology Data Exchange (ETDEWEB)

In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

Leszczynski, K.

1995-06-01

400

Assessment and comparison of methods for solar ultraviolet radiation measurements  

International Nuclear Information System (INIS)

In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

1995-01-01

 
 
 
 
401

High Speed Iris Detection Method for Man-Machine Interface  

Science.gov (United States)

We propose a high speed iris detection method for man-machine interface. In order to communicate between humans and computers comfortably, it is required that high speed processing and adapting the changes of the face direction and the individual variation of the face. Our iris detection method consists of a face detection function, a facial parts extraction function and an iris detection function. The face detection function adapts to individual variation or a light condition by using standard skin color method which decides the standard skin color by a color histogram every frame. The facial parts extraction function adapts to changes of face direction and the individual variation in order to by using the hybrid template matching which consists the four directional features field and the color different features. The iris detection function performs high speed and stable detection by segmentation of iris region using color information and the Hough transform. We conducted the comparison experiment with our past method which uses the least approximation method. By this result, processing time of our method realized equivalent to our past method. In addition, accuracy rate of iris detection with our method improved.

Kashima, Hideki; Hongo, Hitoshi; Kato, Kunihito; Yamamoto, Kazuhiko

402

Islanding Detection Method for Multi-Inverter Distributed Generation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Islanding detection is an essential function for safety and reliability in grid-connected distributed generation (DG) systems. Several methods for islanding detection are proposed, but most of them may fail under multi-source configurations, or they may produce important power quality degradation which gets worse with increasing DG penetration. This paper presents an active islanding detection algorithm for Voltage Source Inverter (VSI) based multi-source DG systems. The proposed method is ba...

Cardenas, Alben; Agbossou, Kodjo; Doumbia, Mamadou Lamine

2009-01-01

403

A simple and efficient eye detection method in color images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we propose a simple and efficient eye detection method for face detection tasks in color images. The algorithm first detects face regions in the image using a skin color model in the normalized RGB color space. Then, eye candidates are extracted within these regions. Finally, using the anthrophological characteristics of human eyes, the pairs of eye regions are selected. The proposed method is simple and fast, since it needs no template matching step for face verification. It is...

Sidibe, Dro Desire; Montesinos, Philippe; Janaqi, Stefan

2006-01-01

404

Gold Cleaning Methods for Electrochemical Detection Applications  

DEFF Research Database (Denmark)

This work investigates methods for obtaining reliably clean gold film surfaces. Nine gold cleaning methods are investigated here: UV ozone photoreactor; potassium hydroxide-hydrogen peroxide; potassium hydroxide potential sweep; sulfuric acid hydrogen peroxide; sulfuric acid potential cycling; hydrochloric acid potential cycling; dimethylamine borane reducing agent solutions at 25 and 65 degrees C; and a dilute form of Aqua Regia. Peak-current potential-differences obtained from cyclic voltammetry and charge transfer resistance obtained from electrochemical impedance spectroscopy, as well as X-ray photo-electron spectroscopy are used to characterize surface cleanliness. A low peak-current potential-difference and charge transfer resistance indicates a cleaner surface, as does a higher percentage of elemental gold on the electrode surface. The potassium hydroxide potential sweep method is found to leave the gold surface the cleanest overall.

Fischer, Lee MacKenzie; Tenje, Maria

2009-01-01

405

On the acoustic leak detection method in piping system  

International Nuclear Information System (INIS)

Periodic inspection is carried out every year on the piping systems in reactor coolant pressure boundary, and leak detecting system is installed in a containment vessel, to confirm the soundness and to detect leak early in nuclear power stations. The leak detecting system comprises the measurements of the flow rate of floor drain and the temperature, humidity and radioactivity in the atmosphere. The method using the radioactivity in air is excellent in its response and detection sensitivity, but the limit of detection is about 100 cc/min, therefore the