Science.gov

Sample records for on-line radiation detection

  1. Development of an on-line radiation detection and measurements laboratory course

    NASA Astrophysics Data System (ADS)

    Kopp, Derick G.

    An on-line radiation detection and measurements lab is being developed with a grant from the U.S. Nuclear Regulatory Commission. The on-line laboratory experiments are designed to provide a realistic laboratory experience and will be offered to students at colleges/universities where such a course is not offered. This thesis presents four web-based experiments: 1) nuclear electronics, 2) gamma-ray spectroscopy with scintillation detectors, 3) gamma-ray attenuation in matter and external dosimetry, and 4) alpha spectroscopy and absorption in matter. The students access the experiments through a broad-band internet connection. Computer-controlled instrumentation developed in National Instruments (NI) LabVIEW(TM) communicates with the URSA-II (SE International, Inc.) data acquisition system, which controls the detector bias voltage, pulse shaping, amplifier gain, and ADC. Detector and amplifier output pulses can be displayed with other instrumentation developed in LabVIEW(TM) for the digital oscilloscope (USB-5132, NI). Additional instrumentation developed in LabVIEW(TM) is used to control the positions of all sources with stepper motor controllers (VXM-1, Velmex, Inc.) and to adjust pressure in the alpha chamber with a digital vacuum regulator (Model 200, J-KEM, Inc.). Unique interactive interfaces are created by integrating all of the necessary instrumentation to conduct each lab. These interfaces provide students with seamless functionality for data acquisition, experimental control, and live data display with real-time updates for each experiment. A webcam is set up to stream the experiment live so the student can observe the physical instruments and receive visual feedback from the system in real time.

  2. Detection of radiation-induced hydrocarbons in Camembert irradiated before and after the maturing process-comparison of florisil column chromatography and on-line coupled liquid chromatography-gas chromatography

    SciTech Connect

    Schulzki, G.; Spiegelberg, A.; Schreiber, G.A.

    1995-02-01

    The influence of the maturing process on the detection of radiation-induced volatile hydrocarbons in the fat of Camembert has been investigated. Two analytical methods for separation of the hydrocarbon fraction from the lipid were applied: Florisil column chromatography with subsequent gas chromatographic-mass spectrometric (GC-MS) determination as well as on-line coupled liquid chromatography-GC-MS. The maturing process had no influence on the detection of radiation-induced volatiles. Comparable results were achieved with both analytical methods. However, preference is given to the more effective on-line coupled LC-GC method. 17 refs., 5 figs., 2 tabs.

  3. ASIMUT on line radiative transfer code

    NASA Astrophysics Data System (ADS)

    Vandaele, A. C.; Neary, L.; Robert, S.; Letocart, V.; Giuranna, M.; Kasaba, Y.

    2015-10-01

    The CROSS DRIVE project aims to develop an innovative collaborative workspace infrastructure for space missions that will allow distributed scientific and engineering teams to collectively analyse and interpret scientific data as well as execute operations of planetary spacecraft. ASIMUT will be one of the tools that will be made available to the users. Here we describe this radiative transfer code and how it will be integrated into the virtual environment developed within CROSS DRIVE.

  4. Condenser on-line leak-detection system development

    SciTech Connect

    Not Available

    1991-11-01

    Condenser tube leaks have been the number one source of impurities in most utility steam cycles. The impurities lead to corrosion of feedwater systems, boilers, and turbines. EPRI recommends sodium in the condensate be less than 3 ppb, which means less than one gallon leakage per day in some cases. The location of leaks requires isolation of the condenser water box and is costly because of power reduction. On-line detection using tracer can cut down the isolation time and, therefore, offers cost advantages to utilities. The on-line leak detection technique utilizes the concepts developed by EPRI for targeted chlorination''. Sulfur hexafluoride (SF{sub 6}), helium gases, and perfluorocarbon liquid were considered as tracers. Laboratory studies were conducted to evaluate the practicability of injecting water with dissolved SF{sub 6} gas, SF{sub 6} bubbles, and dissolved SF{sub 6} gas in perfluorocarbon liquid. Both static and dynamic tests were conducted in a condenser model. It was determined that water entrained with SF{sub 6} bubbles offered the most practical method of injection, followed by dissolved SF{sub 6} gas in perfluorocarbon. A conceptual design was developed that utilizes a water lance, a swivel arrangement in the waterbox manhole cover, a tracer targeting and mixing system, and a tracer gas detection system at the air ejector exhaust. A successful demonstration of targeted leak detection using a waterjet lance with SF{sub 6} was conducted at Carolina Power Light Company's Asheville Steam Electric Station Unit 1. A measurable artificially created leak was detected and located using this system with the condenser on-line. 2 refs., 39 figs., 6 tabs.

  5. Research of on-line detection system for power capacitor

    NASA Astrophysics Data System (ADS)

    Yao, Junda; Qian, Zheng; Yu, Hao; Xia, Jiuyun

    2016-01-01

    The hidden danger exists in the power capacitor of power system due to long-time operation under the environment of high voltage. Thus, it is possible to induce serious fault, and the on-line detection system is urgently required. In this paper, two methods of the on-line detection system are compared in order to realize the better real-time condition detection. The first method is based on the STM microprocessor with an internal 12 bit A/D converter, which converts analog signals which is arrived from the sample circuit into digital signals, and then the FFT algorithm is used to accomplish the measurement of the voltage and current values of the capacitor. The second method is based on the special electric energy metering IC, which can obtain RMS (Root Mean Square) of voltage and current by processing the sampled data of the voltage and current, and store RMS of voltage and current in its certain registers. The operating condition of the capacitor can be obtained after getting the values of voltage and current. By comparing the measuring results of two methods, the second method could achieve a higher measurement accuracy and more simple construction.

  6. Based on line scan CCD print image detection system

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Xie, Kai; Li, Tong

    2015-12-01

    In this paper, a new method based on machine vision is proposed for the defects of the traditional manual inspection of the quality of printed matter. With the aid of on line array CCD camera for image acquisition, using stepper motor as a sampling of drive circuit. Through improvement of driving circuit, to achieve the different size or precision image acquisition. In the terms of image processing, the standard image registration algorithm then, because of the characteristics of CCD-image acquisition, rigid body transformation is usually used in the registration, so as to achieve the detection of printed image.

  7. High-pressure on-line photolysis with NMR detection

    SciTech Connect

    Yonker, C.R.; Wallen, S.L.

    1996-06-01

    The investigation of the photoreversible fulgide Aberchrome-540 as a function of pressure and temperature with the use of nuclear magnetic resonance (NMR) detection is described. This technique demonstrates the novel combination of high-pressure NMR and laser photolysis with the use of fiber optics for the conversion of the fulgide on-line in the instrument. Investigation of the photolysis of Aberchrome-540 to 2.0 kbar and 120 degrees C is reported. Extension of this technique should allow the investigation of photo-initiated reaction kinetics and equilibria as a function of pressure and temperature with simultaneous structural characterization with NMR. {copyright} {ital 1996} {ital Society for Applied Spectroscopy}

  8. On-Line Loss of Control Detection Using Wavelets

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J. (Technical Monitor); Thompson, Peter M.; Klyde, David H.; Bachelder, Edward N.; Rosenthal, Theodore J.

    2005-01-01

    Wavelet transforms are used for on-line detection of aircraft loss of control. Wavelet transforms are compared with Fourier transform methods and shown to more rapidly detect changes in the vehicle dynamics. This faster response is due to a time window that decreases in length as the frequency increases. New wavelets are defined that further decrease the detection time by skewing the shape of the envelope. The wavelets are used for power spectrum and transfer function estimation. Smoothing is used to tradeoff the variance of the estimate with detection time. Wavelets are also used as front-end to the eigensystem reconstruction algorithm. Stability metrics are estimated from the frequency response and models, and it is these metrics that are used for loss of control detection. A Matlab toolbox was developed for post-processing simulation and flight data using the wavelet analysis methods. A subset of these methods was implemented in real time and named the Loss of Control Analysis Tool Set or LOCATS. A manual control experiment was conducted using a hardware-in-the-loop simulator for a large transport aircraft, in which the real time performance of LOCATS was demonstrated. The next step is to use these wavelet analysis tools for flight test support.

  9. Evaluation of Shiryaev-Roberts Procedure for On-line Environmental Radiation Monitoring

    NASA Astrophysics Data System (ADS)

    Watson, Mara Mae

    An on-line radiation monitoring system that simultaneously concentrates and detects radioactivity is needed to detect an accidental leakage from a nuclear waste disposal facility or clandestine nuclear activity. Previous studies have shown that classical control chart methods can be applied to on-line radiation monitoring data to quickly detect these events as they occur; however, Bayesian control chart methods were not included in these studies. This work will evaluate the performance of a Bayesian control chart method, the Shiryaev-Roberts (SR) procedure, compared to classical control chart methods, Shewhart 3-sigma and cumulative sum (CUSUM), for use in on-line radiation monitoring of 99Tc in water using extractive scintillating resin. Measurements were collected by pumping solutions containing 0.1-5 Bq/L of 99Tc, as 99T cO4-, through a flow cell packed with extractive scintillating resin coupled to a Beta-RAM Model 5 HPLC detector. While 99T cO4- accumulated on the resin, simultaneous measurements were acquired in 10-s intervals and then re-binned to 100-s intervals. The Bayesian statistical method, Shiryaev-Roberts procedure, and classical control chart methods, Shewhart 3-sigma and cumulative sum (CUSUM), were applied to the data using statistical algorithms developed in MATLAB RTM. Two SR control charts were constructed using Poisson distributions and Gaussian distributions to estimate the likelihood ratio, and are referred to as Poisson SR and Gaussian SR to indicate the distribution used to calculate the statistic. The Poisson and Gaussian SR methods required as little as 28.9 mL less solution at 5 Bq/L and as much as 170 mL less solution at 0.5 Bq/L to exceed the control limit than the Shewhart 3-sigma method. The Poisson SR method needed as little as 6.20 mL less solution at 5 Bq/L and up to 125 mL less solution at 0.5 Bq/L to exceed the control limit than the CUSUM method. The Gaussian SR and CUSUM method required comparable solution volumes for test

  10. Radiation detection system

    DOEpatents

    Nelson, Melvin A.; Davies, Terence J.; Morton, III, John R.

    1976-01-01

    A radiation detection system which utilizes the generation of Cerenkov light in and the transmission of that light longitudinally through fiber optic wave guides in order to transmit intelligence relating to the radiation to a remote location. The wave guides are aligned with respect to charged particle radiation so that the Cerenkov light, which is generated at an angle to the radiation, is accepted by the fiber for transmission therethrough. The Cerenkov radiation is detected, recorded, and analyzed at the other end of the fiber.

  11. Note: On-line weak signal detection via adaptive stochastic resonance

    SciTech Connect

    Lu, Siliang; He, Qingbo Kong, Fanrang

    2014-06-15

    We design an instrument with a novel embedded adaptive stochastic resonance (SR) algorithm that consists of a SR module and a digital zero crossing detection module for on-line weak signal detection in digital signal processing applications. The two modules are responsible for noise filtering and adaptive parameter configuration, respectively. The on-line weak signal detection can be stably achieved in seconds. The prototype instrument exhibits an advance of 20 dB averaged signal-to-noise ratio and 5 times averaged adjust R-square as compared to the input noisy signal, in considering different driving frequencies and noise levels.

  12. Link community detection based on line graphs with a novel link similarity measure

    NASA Astrophysics Data System (ADS)

    Wang, Guishen; Huang, Lan; Wang, Yan; Pang, Wei; Ma, Qin

    2016-02-01

    Link community gradually unfolds its capacity in complex network research. In this paper, a novel link similarity measure on line graphs is proposed. This measure can be adapted to different types of networks with an adjustable parameter. We prove its value converges to a limit on line graphs with the relationship of the nonneighbor links taken into account. Based on this similarity measure, we propose a novel link community detection algorithm for link clustering on line graphs. The detection algorithm combines the novel link similarity measure with the classic Markov Cluster (MCL) Algorithm and determines the link community partitions by calculating an extended modularity measure. Extensive experiments on two types of complex networks demonstrate the effectiveness, reliability and rationality of our solution in contrast to the other two classical algorithms.

  13. On-Line Hyperspectral Transmittance Imaging for Internal Defect Detection of Pickling Cucumbers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imaging technique under transmittance mode was investigated for detection of internal defect in pickling cucumbers such as carpel suture separation or hollow cucumbers caused by mechanical stress. A prototype of on-line hyperspectral transmittance imaging system was developed for real...

  14. RADIATION WAVE DETECTION

    DOEpatents

    Wouters, L.F.

    1960-08-30

    Radiation waves can be detected by simultaneously measuring radiation- wave intensities at a plurality of space-distributed points and producing therefrom a plot of the wave intensity as a function of time. To this end. a detector system is provided which includes a plurality of nuclear radiation intensity detectors spaced at equal radial increments of distance from a source of nuclear radiation. Means are provided to simultaneously sensitize the detectors at the instant a wave of radiation traverses their positions. the detectors producing electrical pulses indicative of wave intensity. The system further includes means for delaying the pulses from the detectors by amounts proportional to the distance of the detectors from the source to provide an indication of radiation-wave intensity as a function of time.

  15. On-line failure detection and damping measurement of aerospace structures by random decrement signatures

    NASA Technical Reports Server (NTRS)

    Cole, H. A., Jr.

    1973-01-01

    Random decrement signatures of structures vibrating in a random environment are studied through use of computer-generated and experimental data. Statistical properties obtained indicate that these signatures are stable in form and scale and hence, should have wide application in one-line failure detection and damping measurement. On-line procedures are described and equations for estimating record-length requirements to obtain signatures of a prescribed precision are given.

  16. OLTARIS: On-Line Tool for the Assessment of Radiation in Space

    NASA Technical Reports Server (NTRS)

    Singleterry, Robert C., Jr.; Blattnig, Steve R.; Clowdsley, Martha S.; Qualls, Garry D.; Sandridge, Christopher A.; Simonsen, Lisa C.; Norbury, John W.; Slaba, Tony C.; Walker, Steven A.; Badavi, Francis F.; Spangler, Jan L.; Aumann, Aric R.; Zapp, E. Neal; Rutledge, Robert D.; Lee, Kerry T.; Norman, Ryan B.

    2010-01-01

    The On-Line Tool for the Assessment of Radiation In Space (OLTARIS) is a World Wide Web based tool that assesses the effects of space radiation on humans and electronics in items such as spacecraft, habitats, rovers, and spacesuits. This document explains the basis behind the interface and framework used to input the data, perform the assessment, and output the results to the user as well as the physics, engineering, and computer science used to develop OLTARIS. The transport and physics is based on the HZETRN and NUCFRG research codes. The OLTARIS website is the successor to the SIREST website from the early 2000's. Modifications have been made to the code to enable easy maintenance, additions, and configuration management along with a more modern web interface. Overall, the code has been verified, tested, and modified to enable faster and more accurate assessments.

  17. OLTARIS: On-Line Tool for the Assessment of Radiation in Space

    NASA Technical Reports Server (NTRS)

    Sandridge, Chris A.; Blattnig, Steve R.; Clowdsley, Martha S.; Norbury, John; Qualis, Garry D.; Simonsen, Lisa C.; Singleterry, Robert C.; Slaba, Tony C.; Walker, Steven A.; Badavi, Francis F.; Spangler, Jan L.; Aumann, Aric R.; Lee, Kerry T.; Rutledge, Robert D.; Zapp, E. Neal

    2009-01-01

    The effects of ionizing radiation on humans in space is a major technical challenge for exploration to the moon and beyond. The radiation shielding team at NASA Langley Research Center has been working for over 30 years to develop techniques that can efficiently assist the engineer throughout the entire design process. OLTARIS: On-Line Tool for the Assessment of Radiation in Space is a new NASA website (http://oltaris.larc.nasa.gov) that allows engineers and physicists to access a variety of tools and models to study the effects of ionizing space radiation on humans and shielding materials. The site is intended to be an analysis and design tool for those working radiation issues for current and future manned missions, as well as a research tool for developing advanced material and shielding concepts. The site, along with the analysis tools and models within, have been developed using strict software practices to ensure reliable and reproducible results in a production environment. They have also been developed as a modular system so that models and algorithms can be easily added or updated.

  18. Developing an EEG-based on-line closed-loop lapse detection and mitigation system

    PubMed Central

    Wang, Yu-Te; Huang, Kuan-Chih; Wei, Chun-Shu; Huang, Teng-Yi; Ko, Li-Wei; Lin, Chin-Teng; Cheng, Chung-Kuan; Jung, Tzyy-Ping

    2014-01-01

    In America, 60% of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15–20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM) System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments. PMID:25352773

  19. Developing an EEG-based on-line closed-loop lapse detection and mitigation system.

    PubMed

    Wang, Yu-Te; Huang, Kuan-Chih; Wei, Chun-Shu; Huang, Teng-Yi; Ko, Li-Wei; Lin, Chin-Teng; Cheng, Chung-Kuan; Jung, Tzyy-Ping

    2014-01-01

    In America, 60% of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM) System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments. PMID:25352773

  20. Optical on-line method of ethyl mercaptan detection in liquid phase in motor fuels

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-11-01

    The letter reports on the experimental research of the absorption spectra of ethyl mercaptan in liquid phase in various motor fuels (petrol, kerosene, and diesel fuel). The values of ethyl mercaptan absorption sections were obtained in the above-mentioned fuels in the spectral range of 280-475 nm, and the dependences of ethyl mercaptan absorption coefficients on its part in the analyzed mixture with motor fuels were researched. On the basis of the obtained results we propose an optical on-line method of ethyl mercaptan detection in motor fuels. The optimal spectral ranges for the highest sensitivity of ethyl mercaptan detection in various motor fuels were determined.

  1. On-line detection of atmospheric formaldehyde by a conductometric biosensor.

    PubMed

    Vianello, Fabio; Boscolo-Chio, Raffaella; Signorini, Stefano; Rigo, Adelio

    2007-01-15

    Atmospheric formaldehyde (CH(2)O) was detected under continuous flow conditions by an on-line system comprising of a wet scrubber for a continuous transfer of the pollutant to an aqueous solution, a micro-reactor containing immobilized formaldehyde dehydrogenase (FDH) and a conductometric transducer. By this system atmospheric formaldehyde concentrations in the range 0.05-2 ppm were detected with a sensitivity of 20 microS/ppm. In this concentration range the immobilized enzyme oxidized all the sampled formaldehyde molecules to formic acid, avoiding cumbersome calibration procedures. The operational stability of the biosensor was at least 3 months, working continuously 10 h/day at room temperature. PMID:16678399

  2. On-Line Tool for the Assessment of Radiation in Space - Deep Space Mission Enhancements

    NASA Technical Reports Server (NTRS)

    Sandridge, Chris a.; Blattnig, Steve R.; Norman, Ryan B.; Slaba, Tony C.; Walker, Steve A.; Spangler, Jan L.

    2011-01-01

    The On-Line Tool for the Assessment of Radiation in Space (OLTARIS, https://oltaris.nasa.gov) is a web-based set of tools and models that allows engineers and scientists to assess the effects of space radiation on spacecraft, habitats, rovers, and spacesuits. The site is intended to be a design tool for those studying the effects of space radiation for current and future missions as well as a research tool for those developing advanced material and shielding concepts. The tools and models are built around the HZETRN radiation transport code and are primarily focused on human- and electronic-related responses. The focus of this paper is to highlight new capabilities that have been added to support deep space (outside Low Earth Orbit) missions. Specifically, the electron, proton, and heavy ion design environments for the Europa mission have been incorporated along with an efficient coupled electron-photon transport capability to enable the analysis of complicated geometries and slabs exposed to these environments. In addition, a neutron albedo lunar surface environment was also added, that will be of value for the analysis of surface habitats. These updates will be discussed in terms of their implementation and on how OLTARIS can be used by instrument vendors, mission designers, and researchers to analyze their specific requirements.12

  3. Condenser on-line leak-detection system development. Final report

    SciTech Connect

    Not Available

    1991-11-01

    Condenser tube leaks have been the number one source of impurities in most utility steam cycles. The impurities lead to corrosion of feedwater systems, boilers, and turbines. EPRI recommends sodium in the condensate be less than 3 ppb, which means less than one gallon leakage per day in some cases. The location of leaks requires isolation of the condenser water box and is costly because of power reduction. On-line detection using tracer can cut down the isolation time and, therefore, offers cost advantages to utilities. The on-line leak detection technique utilizes the concepts developed by EPRI for ``targeted chlorination``. Sulfur hexafluoride (SF{sub 6}), helium gases, and perfluorocarbon liquid were considered as tracers. Laboratory studies were conducted to evaluate the practicability of injecting water with dissolved SF{sub 6} gas, SF{sub 6} bubbles, and dissolved SF{sub 6} gas in perfluorocarbon liquid. Both static and dynamic tests were conducted in a condenser model. It was determined that water entrained with SF{sub 6} bubbles offered the most practical method of injection, followed by dissolved SF{sub 6} gas in perfluorocarbon. A conceptual design was developed that utilizes a water lance, a swivel arrangement in the waterbox manhole cover, a tracer targeting and mixing system, and a tracer gas detection system at the air ejector exhaust. A successful demonstration of targeted leak detection using a waterjet lance with SF{sub 6} was conducted at Carolina Power & Light Company`s Asheville Steam Electric Station Unit 1. A measurable artificially created leak was detected and located using this system with the condenser on-line. 2 refs., 39 figs., 6 tabs.

  4. On-line automatic detection of wood pellets in pneumatically conveyed wood dust flow

    NASA Astrophysics Data System (ADS)

    Sun, Duo; Yan, Yong; Carter, Robert M.; Gao, Lingjun; Qian, Xiangchen; Lu, Gang

    2014-04-01

    This paper presents a piezoelectric transducer based system for on-line automatic detection of wood pellets in wood dust flow in pneumatic conveying pipelines. The piezoelectric transducer senses non-intrusively the collisions between wood pellets and the pipe wall. Wavelet-based denoising is adopted to eliminate environmental noise and recover the collision events. Then the wood pellets are identified by sliding a time window through the denoised signal with a suitable threshold. Experiments were carried out on a laboratory test rig and on an industrial pneumatic conveying pipeline to assess the effectiveness and operability of the system.

  5. On-line detection of orange soluble solid content using visible and near infrared transmission measurements

    NASA Astrophysics Data System (ADS)

    Fu, Xiaping; Ying, Yibin; Xu, Huirong; Qi, Bing; Xie, Lijuan

    2012-05-01

    A prototype of on-line system developed by ourselves was used to non-destructively inspect orange quality. This system includes three main parts: machine vision part for fruit external quality detection, visible and near infrared (Vis-NIR) spectroscopy part for fruit internal quality detection, and weighing part for fruit weight detection. Fruit scrolled on the roller in the machine vision part, while stopped scrolling before entering the Vis-NIR spectroscopy part. Therefore, fruit positions and directions were inconsistent for spectra acquisition. This paper was aimed to study the influence of fruit detection orientation on spectra variation and model estimation performance using the on-line system. The system was configured to operate at typical grader speeds (0.27m/s or approximately three fruit per second) and detect the light transmitted through oranges. Stepwise multi linear regression models were developed for fruit with consistent directions and inconsistent directions in the wavelength range of 600-950 nm, and gave reasonable calibration correlations R2=0.89-0.92 and low cross validation errors (RMSECV=0.44-0.56%). The calibration model with spherical samples only turned out the best prediction results, which has lowest RMSEP of 0.56%-0.63% for different fruit orientations. It can be seen from the study that fruit shape would influence the fruit orientation for spectra aqcuiring of spherical samples after scrolling, and would further influence the modeling resutls. It is better to acquire spectra and establish models for sampels with different shapes separately and then applying them based on shape detection resutls to improve the soluble solid content (SSC) prediction accuracy.

  6. OLTARIS: On-Line Tool for the Assessment of Radiation in Space

    NASA Technical Reports Server (NTRS)

    Singleterry, Robert C., Jr.; Blattnig, Steve R.; Clowdsley, Martha S.; Qualls, Garry D.; Sandridge, Chris A.; Simonsen, Lisa C.; Norbury, John W.; Slaba, Tony C.; Walker, Steve A.; Badavi, Francis F.; Spangler, Jan L.; Aumann, Aric R.; Zapp, E. Neal; Rutledge, Robert D.; Lee, Kerry T.; Norman, Ryan B.

    2009-01-01

    The On-Line Tool for the Assessment of Radiation In Space (OLTARIS) is a World Wide Web based tool that assesses the effects of space radiation to humans in items such as spacecraft, habitats, rovers, and spacesuits. This document explains the basis behind the interface and framework used to input the data, perform the assessment, and output the results to the user as well as the physics, engineering, and computer science used to develop OLTARIS. The physics is based on the HZETRN2005 and NUCFRG2 research codes. The OLTARIS website is the successor to the SIREST website from the early 2000 s. Modifications have been made to the code to enable easy maintenance, additions, and configuration management along with a more modern web interface. Over all, the code has been verified, tested, and modified to enable faster and more accurate assessments. The next major areas of modification are more accurate transport algorithms, better uncertainty estimates, and electronic response functions. Improvements in the existing algorithms and data occur continuously and are logged in the change log section of the website.

  7. On-line estimation of myoelectric signal spectral parameters and nonstationarities detection.

    PubMed

    D'Alessio, T; Knaflitz, M; Balestra, G; Paggi, S

    1993-09-01

    In this communication, we present a method for detecting nonstationarities of random time series with an approximately Gaussian distribution of amplitudes. This method is suitable for real time implementation. Here we report some results obtained by applying them to a time series of spectral parameters of surface myoelectric signals, collected during voluntary isometric contractions of human muscles. Moreover, we describe the computerized system that we used to implement our detector of nonstationarity. This system is based on the TMS 320C25 DSP chip and realizes on-line estimation and display of spectral parameters, as well as detection of their nonstationarities, featuring a sampling frequency up to 20 k samples/s. A friendly user interface, fully menu driven, allows the user to select different options during the system's operation by means of hot keys. The accuracy of the system was tested by comparing its estimates with those of an off-line system, previously characterized, which we took as a reference. The estimates of spectral parameters obtained by means of the two systems were always consistent. The on-line stationarity detector was able to recognize rates of variation of the spectral parameters as small as 1%/s during contractions lasting 10-15 s. This sensitivity makes it suitable for clinical application. The set of results herein presented has been selected to highlight the main characteristics of the system. PMID:8288289

  8. Nanoscintillators for radiation detection

    NASA Astrophysics Data System (ADS)

    Hall, Ryan Gregory

    In the search for faster, more effective methods for detection of and protection against radiological weapons, advances in materials for radiation detection are a critical component of any successful strategy. This work focuses on producing inexpensive, but highly sensitive, nanoparticle alternatives to existing single-crystal installations. Attention is given to particular types of promising inorganic scintillators: LaF3, yttrium-aluminum-garnet (YAG), and SrF2, each one an inorganic host doped with additional elements that encourage luminescent decay and increase effective Z-value. I examine the possible routes to synthesize these compounds, and the difficulties and benefits of each method. After synthesizing these materials, testing was performed to determine comparative performance against each other and commercial solutions, identify structural and compositional characteristics, and explore routes for fixing the scintillators into a detector assembly. The unifying goal is to develop a scintillating material suitable for consistent dosimetry and radio-isotope identification applications.

  9. A dedicated on-line detecting system for auto air dryers

    NASA Astrophysics Data System (ADS)

    Shi, Chao-yu; Luo, Zai

    2013-10-01

    According to the correlative automobile industry standard and the requirements of manufacturer, this dedicated on-line detecting system is designed against the shortage of low degree automatic efficiency and detection precision of auto air dryer in the domestic. Fast automatic detection is achieved by combining the technology of computer control, mechatronics and pneumatics. This system can detect the speciality performance of pressure regulating valve and sealability of auto air dryer, in which online analytical processing of test data is available, at the same time, saving and inquiring data is achieved. Through some experimental analysis, it is indicated that efficient and accurate detection of the performance of auto air dryer is realized, and the test errors are less than 3%. Moreover, we carry out the type A evaluation of uncertainty in test data based on Bayesian theory, and the results show that the test uncertainties of all performance parameters are less than 0.5kPa, which can meet the requirements of operating industrial site absolutely.

  10. Nanocomposite for radiation detection

    NASA Astrophysics Data System (ADS)

    Sahi, Sunil

    2012-02-01

    Cerium fluoride is among the widely studied inorganic scintillators for radiation detection, because of its high light output and high stopping power. Herein, platelets shape CeF3 nanoparticles for radiation detection was synthesis by bisolvent solvothermal method. The characterization of nanoprticles was done by photoluminescence, XRD and SEM measurement. The synthesized CeF3 nanoparticles have broad emission peak around 330 nm. ZnO is a semiconductor scintillator, having fast decay time. ZnO nanoparticles were synthesized using solvothermal method and UV-Vis, photoluminescence and SEM measurement were done for their characterization. The absorption spectrum of the ZnO nanoparticles is dependent on the size of the nanoparticles. By changing the temperature and the concentration of zinc salt and surfactant, ZnO with absorption spectra overlapping with the emission spectra of CeF3 were made for the purpose of creating nanocomposites, with improved scintillation properties. The energy transfer between two nanoparticles was also studied and the changes in Photoluminescence intensity of the nanocomposites were described.

  11. A distributed fault-detection and diagnosis system using on-line parameter estimation

    NASA Technical Reports Server (NTRS)

    Guo, T.-H.; Merrill, W.; Duyar, A.

    1991-01-01

    The development of a model-based fault-detection and diagnosis system (FDD) is reviewed. The system can be used as an integral part of an intelligent control system. It determines the faults of a system from comparison of the measurements of the system with a priori information represented by the model of the system. The method of modeling a complex system is described and a description of diagnosis models which include process faults is presented. There are three distinct classes of fault modes covered by the system performance model equation: actuator faults, sensor faults, and performance degradation. A system equation for a complete model that describes all three classes of faults is given. The strategy for detecting the fault and estimating the fault parameters using a distributed on-line parameter identification scheme is presented. A two-step approach is proposed. The first step is composed of a group of hypothesis testing modules, (HTM) in parallel processing to test each class of faults. The second step is the fault diagnosis module which checks all the information obtained from the HTM level, isolates the fault, and determines its magnitude. The proposed FDD system was demonstrated by applying it to detect actuator and sensor faults added to a simulation of the Space Shuttle Main Engine. The simulation results show that the proposed FDD system can adequately detect the faults and estimate their magnitudes.

  12. On-Line Database of Vibration-Based Damage Detection Experiments

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Doebling, Scott W.; Kholwad, Tina D.

    2000-01-01

    This paper describes a new, on-line bibliographic database of vibration-based damage detection experiments. Publications in the database discuss experiments conducted on actual structures as well as those conducted with simulated data. The database can be searched and sorted in many ways, and it provides photographs of test structures when available. It currently contains 100 publications, which is estimated to be about 5-10% of the number of papers written to date on this subject. Additional entries are forthcoming. This database is available for public use on the Internet at the following address: http://sdbpappa-mac.larc.nasa.gov. Click on the link named "dd_experiments.fp3" and then type "guest" as the password. No user name is required.

  13. Arsenic and antimony determination by on-line flow hydride generation glow discharge optical emission detection

    NASA Astrophysics Data System (ADS)

    Guillermo Orellana-Velado, Néstor; Fernández, Matilde; Pereiro, Rosario; Sanz-Medel, Alfredo

    2001-01-01

    Hollow cathode (HC) and conventional flat cathode (FC) glow discharge (GD) optical emission spectrometry (OES) were used as detectors for the determination of arsenic and antimony by on-line hydride generation (HG) in a flow system. Both radiofrequency (rf) and direct current (dc) sources were investigated to produce the discharge. The design of the HC and FC and also the parameters governing the discharge (pressure, He flow rate, voltage, current and delivered power) and the HG (sodium borohydride concentration and reagent flow rates) were investigated using both cathodes. The analytical performance characteristics of HG-GD-OES with HC and FC were evaluated for some emission lines of arsenic (193.7, 200.3, 228.8 and 234.9 nm). The best detection limit (0.2 μg l -1) was obtained when the emission line of 228.8 nm was used with FC. Under the same arsenic optimized experimental conditions, the system was evaluated to determine antimony at 259.7, 252.7 and 231.1 nm, 252.7 nm being the emission line which produced the best detection limit (0.7 μg l -1). The rf-HC-GD-OES system was applied successfully to the determination of arsenic in freeze-dried urine in the standard reference material 2670 from NIST. Finally, a flow injection system was assayed to determine arsenic at 228.8 nm, using a dc-GD with both FC and HC. The results indicated that for low volumes of sample, the HC discharge allows better analytical signals than the FC.

  14. DEVELOPMENT OF AN ON-LINE, REAL-TIME ALPHA RADIATION MEASURING INSTRUMENT FOR LIQUID STREAMS

    SciTech Connect

    Unknown

    1999-03-14

    The US Department of Energy (DOE) has expressed a need for an on-line, real-time instrument for assaying alpha-emitting radionuclides (uranium and the transuranics) in effluent waters leaving DOE sites to ensure compliance with regulatory limits. Due to the short range of alpha particles in water ({approximately}40 Im), it is necessary now to intermittently collect samples of water and send them to a central laboratory for analysis. A lengthy and costly procedure is used to separate and measure the radionuclides from each sample. Large variations in radionuclide concentrations in the water may go undetected due to the sporadic sampling. Even when detected, the reading may not be representative of the actual stream concentration. To address these issues, the Advanced Technologies Group of Thermo Power Corporation (a Thermo Electron company) is developing a real-time, field-deployable alpha monitor based on a solid-state silicon wafer semiconductor (US Patent 5,652,013 and pending, assigned to the US Department of Energy). The Thermo Water Alpha Monitor will serve to monitor effluent water streams (Subsurface Contaminants Focus Area) and will be suitable for process control of remediation as well as decontamination and decommissioning (D and D) operations, such as monitoring scrubber or rinse water radioactivity levels (Mixed Waste, Plutonium, and D and D Focus Area). It would be applicable for assaying other liquids, such as oil, or solids after proper preconditioning. Rapid isotopic alpha air monitoring is also possible using this technology. This report details the program's accomplishments to date. Most significantly, the Alpha Monitoring Instrument was successfully field demonstrated on water 100X below the Environmental Protection Agency's proposed safe drinking water limit--down to under 1 pCi/1. During the Field Test, the Alpha Monitoring Instrument successfully analyzed isotopic uranium levels on a total of five different surface water, process water, and

  15. DEVELOPMENT OF AN ON-LINE, REAL-TIME ALPHA RADIATION MEASURING INSTRUMENT FOR LIQUID STREAMS

    SciTech Connect

    1996-11-22

    The Department of Energy (DOE) has expressed a need for an on-line, real-time instrument for assaying alpha-emitting radionuclides (uranium and the transuranics) in effluent waters leaving DOE sites to ensure compliance with regulatory limits. Due to the short range of alpha particles in water ({approximately}40 Tm), it is necessary now to intermittently collect samples of water and send them to a central laboratory for analysis. A lengthy and costly procedure is used to separate and measure the radionuclides from each sample. Large variations in radionuclide concentrations in the water may go undetected due to the sporadic sampling. Even when detected, the reading may not be representative of the actual stream concentration. To address these issues, Tecogen, a division of Thermo Power Corporation, a Thermo Electron company, is developing a real-time, field-deployable, alpha monitor based on a solid-state silicon wafer semiconductor (patent pending, to be assigned to the Department of Energy). The Thermo Alpha Monitor (TAM) will serve to monitor effluent water streams (Subsurface Contaminants Focus Area) and will be suitable for process control of remediation as well as decontamination and decommissioning operations, such as monitoring scrubber or rinse water radioactivity levels (Mixed Waste Focus Area and D&D Focus Area). It would be applicable for assaying other liquids, such as oil, or solids after proper preconditioning. Rapid isotopic alpha air monitoring is also possible using this technology. This instrument for direct counting of alpha-emitters in aqueous streams is presently being developed by Thermo Power under a development program funded by the DOE Environmental Management program (DOE-EM), administered by the Morgantown Energy Technology Center (METC). Under this contract, Thermo Power has demonstrated a solid-state, silicon-based semiconductor instrument, which uses a proprietary film-based collection system to quantitatively extract the

  16. Radiation detection system

    DOEpatents

    Whited, R.C.

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI/sub 2/, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  17. Aerial Radiation Detection

    SciTech Connect

    W. M. Quam

    1999-09-30

    An airborne system designed for the detection of radioactive sources on the soil surface from an aircraft normally senses gamma rays emitted by the source. Gamma rays have the longest path length (least attenuation) through the air of any of the common radioactive emissions and will thus permit source detection at large distances. A secondary benefit from gamma rays detection if that nearly all radioactive isotopes can be identified by the spectrum of gammas emitted. Major gaseous emissions from fuel processing plants emit gammas that may be detected and identified. Some types of special nuclear material also emit neutrons which are also useful for detection at a distance.

  18. DEVELOPMENT OF AN ON-LINE, REAL-TIME ALPHA RADIATION MEASURING INSTRUMENT FOR LIQUID STREAMS

    SciTech Connect

    Unknown

    1999-06-16

    Thermo Power Corporation has proven the technical viability of an on-line, real-time alpha radionuclide instrument for aqueous sample analysis through laboratory and initial field tests of the instrument. The instrument has been shown to be isotonically sensitive to extremely low (ten parts per trillion, or femto Curies per liter) levels of a broad range of radioisotopes. Performance enhancement and other scaling data obtained during the course of this investigation have shown that on-line, real-time operation is possible, with a sub 30-minute response time analyzing 20 ppb (30 pCi/1) natural uranium. Now that these initial field tests in Oak Ridge, Tennessee have been successfully completed, Thermo Power plans to conduct comprehensive field tests of the instrument. The purpose of these endurance tests will be to determine the endurance characteristics of the Thermo Alpha Monitor for Water when it is used by non-Thermo Power personnel in a series of one or more extended field tests. Such endurance testing is the vital next step towards the commercialization of the Alpha Monitor. Subsequently, it will be possible to provide the DOE with an instrument that has the capability of obtaining rapid feedback about the concentrations of alpha-emitting isotope contamination in effluent water streams (Subsurface Contaminants Focus Area). It will also be useful for process control of remediation and D and D operations such as monitoring scrubber/rinse water radioactivity levels (Mixed Waste, Plutonium and D and D Focus Areas).

  19. Radiation Detection from Fission

    SciTech Connect

    Mihalczo, J.

    2004-11-17

    This report briefly describes the neutrons and gamma rays emitted in fission, briefly discusses measurement methods, briefly discusses sources and detectors relevant to detection of shielded HEU in sealand containers, and lists the measurement possibilities for the various sources. The brief descriptions are supplemented by reference.

  20. On-line detection of key radionuclides for fuel-rod failure in a pressurized water reactor.

    PubMed

    Qin, Guoxiu; Chen, Xilin; Guo, Xiaoqing; Ni, Ning

    2016-08-01

    For early on-line detection of fuel rod failure, the key radionuclides useful in monitoring must leak easily from failing rods. Yield, half-life, and mass share of fission products that enter the primary coolant also need to be considered in on-line analyses. From all the nuclides that enter the primary coolant during fuel-rod failure, (135)Xe and (88)Kr were ultimately chosen as crucial for on-line monitoring of fuel-rod failure. A monitoring system for fuel-rod failure detection for pressurized water reactor (PWR) based on the LaBr3(Ce) detector was assembled and tested. The samples of coolant from the PWR were measured using the system as well as a HPGe γ-ray spectrometer. A comparison showed the method was feasible. Finally, the γ-ray spectra of primary coolant were measured under normal operations and during fuel-rod failure. The two peaks of (135)Xe (249.8keV) and (88)Kr (2392.1keV) were visible, confirming that the method is capable of monitoring fuel-rod failure on-line. PMID:27209090

  1. Effects of external radiation fields on line emission—application to star-forming regions

    SciTech Connect

    Chatzikos, Marios; Ferland, G. J.; Williams, R. J. R.; Porter, Ryan; Van Hoof, P. A. M.

    2013-12-20

    A variety of astronomical environments contain clouds irradiated by a combination of isotropic and beamed radiation fields. For example, molecular clouds may be irradiated by the isotropic cosmic microwave background, as well as by a nearby active galactic nucleus. These radiation fields excite atoms and molecules and produce emission in different ways. We revisit the escape probability theorem and derive a novel expression that accounts for the presence of external radiation fields. We show that when the field is isotropic the escape probability is reduced relative to that in the absence of external radiation. This is in agreement with previous results obtained under ad hoc assumptions or with the two-level system, but can be applied to complex many-level models of atoms or molecules. This treatment is in the development version of the spectral synthesis code CLOUDY. We examine the spectrum of a Spitzer cloud embedded in the local interstellar radiation field and show that about 60% of its emission lines are sensitive to background subtraction. We argue that this geometric approach could provide an additional tool toward understanding the complex radiation fields of starburst galaxies.

  2. Radiation detection system

    DOEpatents

    Riedel, Richard A.; Wintenberg, Alan L.; Clonts, Lloyd G.; Cooper, Ronald G.

    2012-02-14

    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.

  3. New correction method for dynamic error in on-line gamma ray thickness detection.

    PubMed

    Liang, Manchun; Yi, Hongchang; Lin, Qian

    2009-11-01

    In this paper, we present a new method to correct dynamic error (DE) in on-line gamma ray thickness measurement, which significantly improves measurement precision over traditional method, in most cases, by one order of magnitude. Theoretical analysis of DE is presented and the correction method is proposed. In order to further prove our theory, Monte Carlo simulation is taken and the performance improvement is given. The method has been successfully applied to our thickness measurement system and brought dramatic improvement to its dynamic precision. PMID:19682915

  4. Developments in on-line, electron-beam emittance measurements using optical transition radiation techniques

    SciTech Connect

    Feldman, R.B.; Lumpkin, A.H. ); Rule, D.W.; Fiorito, R.B. )

    1989-01-01

    We have developed image analysis software to facilitate the analysis of optical transition radiation (OTR) patterns generated by the electron beam from the Los Alamos free-electron laser facility. The software can be used for beam alignment, beam profile and angular divergence measurements, and the programs run on an IBM AT microcomputer. The programs and their use are described and some results shown. 2 refs., 17 figs.

  5. Generally applicable fed-batch culture concept based on the detection of metabolic state by on-line balancing.

    PubMed

    Jobé, Anna Marya; Herwig, Christoph; Surzyn, Martin; Walker, Bernhard; Marison, Ian; von Stockar, Urs

    2003-06-20

    In many microorganisms, flux limitations in oxidative metabolism lead to the formation of overflow metabolites even under fully aerobic conditions. This can be avoided if the specific growth rate is controlled at a low enough value. This is usually accomplished by controlling the substrate feeding profile in a fed-batch process. The present work proposes a control concept which is based on the on-line detection of metabolic state by on-line calculation of mass and elemental balances. The advantages of this method are: 1) the check of measurement consistency based on all of the available measurements, 2) the minimum requirement of a priori knowledge of metabolism, and 3) the exclusive use of simple and established on-line techniques which do not require direct measurement of the metabolite in question. The control concept has been linked to a simple adaptive controller and applied to fed-batch cultures of S. cerevisiae and E. coli, organisms which express different overflow metabolites, ethanol and acetic acid, respectively. Oxidative and oxidoreductive states of S. cerevisiae and E. coli cultures were detected with high precision. As demonstrated by the formation of acetic acid in E. coli cultures, metabolic states could be correctly distinguished for systems for which traditional methods, such as respiratory quotient (RQ), are insensitive. Hence, it could be shown that the control concept allowed avoidance of overflow metabolite formation and operation at maximum oxidative biomass productivity and oxidative conversion of substrate into biomass. Based on mass and elemental balances, the proposed method additionally provides a richness of additional information, such as yield coefficients and estimation of concentrations and specific conversion rates. These data certainly help the operator to additionally evaluate the state of the process on-line. PMID:12673762

  6. Line-scan hyperspectral imaging for real-time on-line poultry fecal detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The preliminary results demonstrated that high speed line-scan hyperspectral imaging system has a potential for real-time online fecal detection during poultry processing. To improve detection accuracy, fully calibrated images both spatially and spectrally were acquired for further processing. In ad...

  7. DEVELOPMENT OF ON-LINE INSTRUMENTATION AND TECHNIQUES TO DETECT AND MEASURE PARTICULATES

    SciTech Connect

    Sheng Wu; Steve Palm; Yongchun Tang; William A. Goddard III

    2003-01-28

    In the first quarter of the project, we reviewed many past references about using light scattering to characterize particulate matters. We also constructed light sources, detection systems and PM synthesizer for the project.

  8. On-line early fault detection and diagnosis of municipal solid waste incinerators

    SciTech Connect

    Zhao Jinsong Huang Jianchao; Sun Wei

    2008-11-15

    A fault detection and diagnosis framework is proposed in this paper for early fault detection and diagnosis (FDD) of municipal solid waste incinerators (MSWIs) in order to improve the safety and continuity of production. In this framework, principal component analysis (PCA), one of the multivariate statistical technologies, is used for detecting abnormal events, while rule-based reasoning performs the fault diagnosis and consequence prediction, and also generates recommendations for fault mitigation once an abnormal event is detected. A software package, SWIFT, is developed based on the proposed framework, and has been applied in an actual industrial MSWI. The application shows that automated real-time abnormal situation management (ASM) of the MSWI can be achieved by using SWIFT, resulting in an industrially acceptable low rate of wrong diagnosis, which has resulted in improved process continuity and environmental performance of the MSWI.

  9. On-line early fault detection and diagnosis of municipal solid waste incinerators.

    PubMed

    Zhao, Jinsong; Huang, Jianchao; Sun, Wei

    2008-11-01

    A fault detection and diagnosis framework is proposed in this paper for early fault detection and diagnosis (FDD) of municipal solid waste incinerators (MSWIs) in order to improve the safety and continuity of production. In this framework, principal component analysis (PCA), one of the multivariate statistical technologies, is used for detecting abnormal events, while rule-based reasoning performs the fault diagnosis and consequence prediction, and also generates recommendations for fault mitigation once an abnormal event is detected. A software package, SWIFT, is developed based on the proposed framework, and has been applied in an actual industrial MSWI. The application shows that automated real-time abnormal situation management (ASM) of the MSWI can be achieved by using SWIFT, resulting in an industrially acceptable low rate of wrong diagnosis, which has resulted in improved process continuity and environmental performance of the MSWI. PMID:18255276

  10. DEVELOPMENT OF ON-LINE INSTRUMENTATION AND TECHNIQUES TO DETECT AND MEASURE PARTICULATES

    SciTech Connect

    Sheng Wu; Steve Palm; Yongchun Tang; William A. Goddard III

    2003-04-01

    In the second quarter of the project, we built the liquid aerosol generator and characterized it. We also constructed and perfected light sources and detection systems. We also designed programs to simulate spherical particle MIE scattering for different wavelengths.

  11. Development of on-line FTIR spectroscopy for siloxane detection in biogas to enhance carbon contactor management.

    PubMed

    Hepburn, C A; Vale, P; Brown, A S; Simms, N J; McAdam, E J

    2015-08-15

    Activated carbon filters are used to limit engine damage by siloxanes when biogas is utilised to provide electricity. However, carbon filter siloxane removal performance is poorly understood as until recently, it had not been possible to measure siloxanes on-line. In this study, on-line Fourier Transform Infrared (FTIR) spectroscopy was developed to measure siloxane concentration in real biogas both upstream (86.1-157.5mg m(-3)) and downstream (2.2-4.3mg m(-3)) of activated carbon filters. The FTIR provided reasonable precision upstream of the carbon vessel with a root mean square error of 10% using partial least squares analysis. However, positive interference from volatile organic carbons was observed in downstream gas measurements limiting precision at the outlet to an RMSE of 1.5mg m(-3) (47.8%). Importantly, a limit of detection of 3.2mg m(-3) was identified which is below the recommended siloxane limit and evidences the applicability of on-line FTIR for this application. PMID:25966392

  12. Method of enhancing radiation response of radiation detection materials

    DOEpatents

    Miller, Steven D.

    1997-01-01

    The present invention is a method of increasing radiation response of a radiation detection material for a given radiation signal by first pressurizing the radiation detection material. Pressurization may be accomplished by any means including mechanical and/or hydraulic. In this application, the term "pressure" includes fluid pressure and/or mechanical stress.

  13. Radiation Detection Computational Benchmark Scenarios

    SciTech Connect

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

    2013-09-24

    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

  14. Automated on-line fecal detection - digital eye guards against fecal contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural Research Service scientists in Athens, GA., have been granted a patent on a method to detect contaminants on food surfaces with imaging systems. Using a real-time imaging system in the processing plant, researchers Bob Windham, Kurt, Lawrence, Bosoon Park, and Doug Smith in the ARS Poul...

  15. On-line Machine Learning and Event Detection in Petascale Data Streams

    NASA Astrophysics Data System (ADS)

    Thompson, David R.; Wagstaff, K. L.

    2012-01-01

    Traditional statistical data mining involves off-line analysis in which all data are available and equally accessible. However, petascale datasets have challenged this premise since it is often impossible to store, let alone analyze, the relevant observations. This has led the machine learning community to investigate adaptive processing chains where data mining is a continuous process. Here pattern recognition permits triage and followup decisions at multiple stages of a processing pipeline. Such techniques can also benefit new astronomical instruments such as the Large Synoptic Survey Telescope (LSST) and Square Kilometre Array (SKA) that will generate petascale data volumes. We summarize some machine learning perspectives on real time data mining, with representative cases of astronomical applications and event detection in high volume datastreams. The first is a "supervised classification" approach currently used for transient event detection at the Very Long Baseline Array (VLBA). It injects known signals of interest - faint single-pulse anomalies - and tunes system parameters to recover these events. This permits meaningful event detection for diverse instrument configurations and observing conditions whose noise cannot be well-characterized in advance. Second, "semi-supervised novelty detection" finds novel events based on statistical deviations from previous patterns. It detects outlier signals of interest while considering known examples of false alarm interference. Applied to data from the Parkes pulsar survey, the approach identifies anomalous "peryton" phenomena that do not match previous event models. Finally, we consider online light curve classification that can trigger adaptive followup measurements of candidate events. Classifier performance analyses suggest optimal survey strategies, and permit principled followup decisions from incomplete data. These examples trace a broad range of algorithm possibilities available for online astronomical data

  16. On-line wall-free cell for laser-induced fluorescence detection in capillary electrophoresis.

    PubMed

    Yu, Chang-Zhu; He, You-Zhao; Xie, Hai-Yang; Gao, Yong; Gan, Wu-Er; Li, Jun

    2009-05-15

    A wall-free detection method based on liquid junction in a capillary gap was proposed for laser-induced fluorescence (LIF) of capillary electrophoresis (CE). The capillary gap of the wall-free cell was fabricated by etching a 10-mm x 50-microm I.D. fused-silica capillary to obtain a polyimide coating sleeve, decoating about 6mm at one end of both 50 microm I.D. separation and liquid junction capillary, inserting the treated capillary ends into the coating sleeve oppositely, fixing the capillaries with a gap distance of 140 microm by epoxy glue and removing the coating sleeve by burning. The theoretical model, experimental results and wall-free cell images indicated that the gap distance and applied voltage were main influence factors on the wall-free detection. Since the wall-free cell increased the absorption light path and avoided the stray light from the capillary wall, it improved the ratio of signal to noise and limit of detection (LOD) of CE-LIF. Three flavin compounds of riboflavin (RF), flavin mononucleotide sodium (FMN) and flavin adenine dinucleotide disodium (FAD) were used to evaluate the wall-free detection method. Compared with on-column cell, the LODs of the wall-free cell were improved 15-, 6- and 9-fold for RF, FMN and FAD, respectively. The linear calibration concentrations of the flavins ranged from 0.005 to 5.0 micromol/L. The column efficiency was in the range from 1.0 x 10(5) to 2.5 x 10(5) plates. The wall-free detection of CE-LIF was applied to the analysis of the flavins in spinach and lettuce leaves. PMID:19329123

  17. CORA—a control program for the ROMA on-line alpha detection apparatus

    NASA Astrophysics Data System (ADS)

    Taut, Steffen; Hübener, S.

    2002-07-01

    This paper reports on the new control program CORA for the ROMA detection device. It was developed as part of the HITGAS apparatus for the study of seaborgium ( Z=106) as oxide hydroxide. CORA runs under Win9x and Win NT. It is object oriented, programmed with Borland C++ Builder. Its main features are high flexibility for various experiment modes, hardware independence to a large extent, and an easy-to-understand user interface.

  18. Sensitive simultaneous determination of three sulfanilamide artificial sweeters by capillary electrophoresis with on-line preconcentration and contactless conductivity detection.

    PubMed

    Yang, Lirong; Zhou, ShengJi; Xiao, Yuezhou; Tang, Yufeng; Xie, Tianyao

    2015-12-01

    A sensitive method followed by capillary electrophoresis with on-line perconcentration and capacitively coupled contactless conductivity detection (CE-C(4)D) was evaluated as a novel approach for the determination of three sulfanilamide artificial sweeteners (acesulfame-K, sodium saccharin and sodium cyclamate) in beverages. The on-line preconcentration technique, namely field-amplified sample injection, coupled with CE-C(4)D were successfully developed and optimized. The separation was achieved within 10 min under the following conditions: an uncoated fused-silica capillary (45 cm × 50 μm i.d., Leff=40 cm), 20 mmol L(-1) HAc as running buffer, separation voltage of -12 kV, electrokinetic injection of -11 kV × 8 s. The detection limits of acesulfame-K, sodium saccharin and sodium cyclamate were 4.4, 6.7 and 8.8 μg L(-1), respectively. The relative standard deviation varied in the range of 3.0-5.0%. Results of this study show a great potential method for the fast screening of these artificial sweeteners contents in commercial beverages. PMID:26041216

  19. On line separation of overlapped signals from multi-time photons for the GEM-based detection system

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Pozniak, K. T.; Chernyshova, M.; Malinowski, K.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zabolotny, W.

    2015-09-01

    The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector for high-resolution X-ray diagnostics of magnetic confinement fusion plasmas. Multi-channel measurement system and serial data acquisition for X-ray energy and position recognition is described. Fundamental characteristics are presented for two dimensional detector structure. Typical signals of ADC - Analog to Digital Converter are considered for charge value and position estimation. Coinciding signals for high flux radiation cause the problem for cluster charge identification. The amplifier with shaper determines time characteristics and limits the pulses frequency. Separation of coincided signals was introduced and verified for simulation experiments. On line separation of overlapped signals was implemented applying the FPGA technology with relatively simple firmware procedure. Representative results for reconstruction of coinciding signals are demonstrated.

  20. Cellular telephone-based radiation detection instrument

    DOEpatents

    Craig, William W.; Labov, Simon E.

    2011-06-14

    A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

  1. Fuzzy logic based on-line fault detection and classification in transmission line.

    PubMed

    Adhikari, Shuma; Sinha, Nidul; Dorendrajit, Thingam

    2016-01-01

    This study presents fuzzy logic based online fault detection and classification of transmission line using Programmable Automation and Control technology based National Instrument Compact Reconfigurable i/o (CRIO) devices. The LabVIEW software combined with CRIO can perform real time data acquisition of transmission line. When fault occurs in the system current waveforms are distorted due to transients and their pattern changes according to the type of fault in the system. The three phase alternating current, zero sequence and positive sequence current data generated by LabVIEW through CRIO-9067 are processed directly for relaying. The result shows that proposed technique is capable of right tripping action and classification of type of fault at high speed therefore can be employed in practical application. PMID:27398278

  2. A New On-Line Detecting Apparatus of the Residual Chlorine in Disinfectant for Fresh-Cut Vegetables

    NASA Astrophysics Data System (ADS)

    Hu, Chao; Su, Shu-Qiang; Li, Bao-Guo; Liu, Meng-Fang

    With the fast development of modern food and beverage industry, fresh-cut vegetables have wider application than before. During the process of sterilization in fresh-cut vegetables, the concentration of chloric disinfectant is usually so high that the common sensor can't be used directly on the product line. In order to solve this problem, we have invented a new detecting apparatus which could detect high concentration of chloric disinfectant directly. In this paper, the working principle, main monitor indicators, application and technical creations of the on-line apparatus have been discussed, and we also carried on the experimental analysis for its performance. The actual demands in factory could be met when the detecting flux is 2L/min, the dilution ratio is 15 and input amount of the disinfectant is 200ml per time, the max of the detecting deviation achieves ±4.8ppm(mg/L). The main detecting range of residual chlorine is 0~300ppm.

  3. Development of On-line Instrumentation and Techniques to Detect and Measure Particulates

    SciTech Connect

    Sheng Wu; Steve Palm; Yongchun Tang; William A. Goddard III

    2005-10-31

    In this final quarter, we have continued to collect more field data. Here, in this report representative data collected in the field with turbine engine are presented. We also made substantial progress in calibration of standard particles using MOUDI. During the 12th quarter of this project, we collected a myriad of field data at our industrial partner's test site. These data verified the system performances. (1) The system could detect light scattering signal for all 9 wavelength lasers under different load conditions--We verified that the ELIS1024 chip could reliably collect light scattering signal from the 9 wavelength lasers, even the weakest wavelength at 355nm, thanks to our effort in improving the signal to noise ratio of the detector. (2) The data collected for each wavelength channel under the same load is consistent and repeatable--Although different wavelength channel has drastically different signal to noise ratio, after certain averages, we are able to repeat the scattering signal under the same engine conditions. (3) The data collected for each channel under different load conditions are qualitatively consistent with prediction--The data collected for each channel under different load conditions change according to the predictions. We are conducting simulation models to simulate the data and use the model to predict the PM emission pattern.

  4. Liquid-chromatographic separation and on-line bioluminescence detection of creatine kinase isoenzymes

    SciTech Connect

    Bostick, W.D.; Denton, M.S.; Dinsmore, S.R.

    1980-01-01

    Isoenzymes of creatine kinase were separated by anion-exchange chromatography, with use of an elution gradient containing lithium acetate (0.1 to 0.6 mol/L). A stream splitter was used to divert a 5% side stream of column effluent, which was subsequently mixed with the reagents necessary for bioluminescence assay of the separated isoenzymes. The use of the stream splitter greatly decreased the rate of consumption of reagent and, when combined with a peristaltic pumping system, permitted independent control of the side-stream flow rate. Thus both the residence interval in a delay coil in which the ATP reaction product is formed and the bioluminescence emission was monitored in a flow-through fluorometer without use of an external light source or filters. Separation and detection of the isoenzymes of creatine kinase were rapid, sensitive, and highly selective. The incremental decrease of bioluminescence response owing to inhibition by the ions in the eluent was less than 31% across the entire gradient.

  5. Rapid dereplication of estrogenic compounds in pomegranate (Punica granatum) using on-line biochemical detection coupled to mass spectrometry.

    PubMed

    van Elswijk, Danny A; Schobel, Uwe P; Lansky, Ephraim P; Irth, Hubertus; van der Greef, Jan

    2004-01-01

    During recent years, phytoestrogens have been receiving an increasing amount of interest, as several lines of evidence suggest a possible role in preventing a range of diseases, including the hormonally dependent cancers. In this context, various parts of the pomegranate fruit (Punica granatum; Punicaceae), e.g. seed oil, juice, fermented juice and peel extract, have been shown to exert suppressive effects on human breast cancer cells in vitro. On-line biochemical detection coupled to mass spectrometry (LC-BCD-MS) was applied to rapidly profile the estrogenic activity in the pomegranate peel extract. The crude mixture was separated by HPLC, after which the presence of biologically active compounds, known or unknown, was detected by means of an on-line beta-estrogen receptor (ER) bioassay. Chemical information, such as molecular weight and MS/MS fingerprint, was obtained in real time by directing part of the HPLC effluent towards a mass spectrometer. Using this approach in total three estrogenic compounds, i.e. luteolin, quercetin and kaempferol, were detected and identified by comparing the obtained molecular weights and negative ion APCI MS/MS spectra with the data of an estrogenic compound library. Although well known in literature and widely distributed in nature, the presence of these phytoestrogenic compounds in pomegranate peel extract was not reported previously. Compared to traditional screening approaches of complex mixtures, often characterized by a repeating cycle of HPLC fractionation and biological screening, LC-BCD-MS was shown to profoundly accelerate the time required for compound description and identification. PMID:14732284

  6. Transuranic waste detection by photon interrogation and on-line delayed neutron counting

    NASA Astrophysics Data System (ADS)

    Lyoussi, A.; Romeyer-Dherbey, J.; Jallu, F.; Payan, E.; Buisson, A.; Nurdin, G.; Allano, J.

    2000-02-01

    A comprehensive program is currently in progress at several laboratories for the development of sensitive, practical, non-destructive assay techniques for the quantification of low-level transuranics (TRUs) in bulk solid wastes. This paper describes the method being developed to assay high density TRU waste packages using photon interrogation. The system uses a pulsed electron beam from an electron linear accelerator to produce high-energy photon bursts from a metallic converter. The photons induce fissions in a TRU waste package which is inside an original neutron separating and counting cavity (NS2C). When fission is induced in trace amounts of TRU contaminants in waste material, it provides “signatures” from fission products that can be used to assay the material before disposal. We give here the results from counting photofission-induced delayed neutrons from 239Pu, 235U and 238U in sample matrices. We counted delayed neutrons emitted after each pulse of the LINAC by using the sequential photon interrogation and neutron counting signatures (SPHINCS) technique which had been developed in the present framework. The SPHINCS method enhances the available counts by a factor of about 20 compared with the counting of delayed neutrons only, after the irradiation period. Furthermore, the use of SPHINCS measurement technique coupled with the NS2C facility improves the signal-to-noise ratio by a factor of about 30. This decreases the detection limit. The electron linear accelerator operates at 15 MeV, 140 mA, and 2.5 μs wide pulse at a 50 and 6.25 Hz rate. The dynamics of photofission and delayed neutron production, NS2C advantages and performances, use of an electron linear accelerator as a particle source, experimental and electronics details, and future experimental works are discussed.

  7. Transuranic waste detection by photon interrogation and on-line delayed neutron counting

    NASA Astrophysics Data System (ADS)

    Lyoussi, A.; Romeyer-Dherbey, J.; Jallu, F.; Payan, E.; Buisson, A.; Nurdin, G.; Allano, J.

    1999-02-01

    A comprehensive program is currently in progress at several laboratories for the development of sensitive, practical, non-destructive assay techniques for the quantification of low-level transuranics (TRUs) in bulk solid wastes. This paper describes the method being developed to assay high density TRU waste packages using photon interrogation. The system uses a pulsed electron beam from an electron linear accelerator to produce high-energy photon bursts from a metallic converter. The photons induce fissions in a TRU waste package which is inside an original neutron separating and counting cavity (NS2C). When fission is induced in trace amounts of TRU contaminants in waste material, it provides "signatures" from fission products that can be used to assay the material before disposal. We give here the results from counting photofission-induced delayed neutrons from 239Pu, 235U and 238U in sample matrices. We counted delayed neutrons emitted after each pulse of the LINAC by using the sequential photon interrogation and neutron counting signatures (SPHINCS) technique which had been developed in the present framework. The SPHINCS method enhances the available counts by a factor of about 20 compared with the counting of delayed neutrons only, after the irradiation period. Furthermore, the use of SPHINCS measurement technique coupled with the NS2C facility improves the signal-to-noise ratio by a factor of about 30. This decreases the detection limit. The electron linear accelerator operates at 15 MeV, 140 mA, and 2.5 μs wide pulse at a 50 and 6.25 Hz rate. The dynamics of photofission and delayed neutron production, NS2C advantages and performances, use of an electron linear accelerator as a particle source, experimental and electronics details, and future experimental works are discussed.

  8. Determination of biothiols by a novel on-line HPLC-DTNB assay with post-column detection.

    PubMed

    Özyürek, Mustafa; Baki, Sefa; Güngör, Nilay; Çelik, S Esin; Güçlü, Kubilay; Apak, Reşat

    2012-10-31

    A novel on-line HPLC-DTNB method was developed for the selective determination of biologically important thiols (biothiols) such as L-cysteine (Cys), glutathione (GSH), homocysteine (HCys), N-acetylcysteine (NAC), and 1,4-dithioerythritol (DTE) in pharmaceuticals and tissue homogenates. The biothiols were separated on C18 column using gradient elution, reacted with the postcolumn reagent, DTNB in 0.5% M-β-CD (w/v) solution at pH 8, to form yellow-colored 5-thio-2-nitrobenzoic acid (TNB), and monitored with a PDA detector (λ=410 nm). With the optimized conditions for chromatography and the post-column derivatization, 40 nM of NAC, 40 nM of Cys, and 50 nM of GSH can be determined. The relative standard deviations of the recommended method were in the range of 3.2-5.4% for 50 μM biothiols. The negative peaks of biothiol constituents were monitored by measuring the increase in absorbance due to TNB chromophore. The detection limits of biothiols at 410 nm (in the range of 0.04-0.58 μM) after post-column derivatization with DTNB+M-β-CD were much lower than those at 205 nm UV-detection without derivatization, and were distinctly lower than those with post-column DTNB alone. The method is rapid, inexpensive, versatile, nonlaborious, uses stable reagents, and enables the on-line qualitative and quantitative estimation of biothiol constituents of biological fluids and pharmaceuticals. PMID:23062438

  9. Development of a biosensor for on-line detection of tributyltin with a recombinant bioluminescent Escherichia coli strain.

    PubMed

    Thouand, G; Horry, H; Durand, M J; Picart, P; Bendriaa, L; Daniel, P; DuBow, M S

    2003-08-01

    A biosensor was developed for the detection of tributyltin (TBT), using a bioluminescent recombinant Escherichia coli:: luxAB strain. Dedicated devices allowed the on-line measurement of bioluminescence, pH and dissolved oxygen values and the feed-back regulation of temperature. Bacterial physiology was monitored by the measurement of the cellular density, respiratory activity and the intracellular level of ATP, glucose and acetate levels. Our results showed that a synthetic glucose medium gave a better TBT detection limit than LB medium (respectively 0.02 micro M and 1.5 micro M TBT). High growth and dilution rates ( D=0.9 h(-1)) allowed maximum light emission from the bacterium. Moreover, simple atmospheric air bubbling was sufficient to provide oxygen for growth and the bioluminescence reaction. Real-time monitoring of bioluminescence after TBT induction occurred with continuous addition of decanal up to 300 micro M, which was not toxic throughout a 7-day experiment. The design of our biosensor and the optimization of the main parameters that influence microbial activity led to the capacity for the detection of TBT. PMID:12883867

  10. Dithizone immobilized silica gel on-line preconcentration of trace copper with detection by flame atomic absorption spectrometry.

    PubMed

    Yu, Hong-Mei; Song, Hua; Chen, Ming-Li

    2011-07-15

    A novel adsorbent-silica gel bound dithizone (H(2)Dz-SG) was prepared and used as solid-phase extraction of copper from complex matrix. The H(2)Dz-SG is investigated by means of FT-IR spectra and the SEM images, demonstrating the bonding of dithizone. The H(2)Dz-SG quantitatively adsorb copper ions, and the retained copper is afterwards collected by elution of 10% (v/v) nitric acid. An on-line flow injection solid-phase extraction procedure was developed for trace copper separation and preconcentration with detection by flame atomic spectrometry. By loading 5.4 mL of sample solution, a liner range of 0.5-120 μg L(-1), an enrichment factor of 42.6, a detection limit of 0.2 μg L(-1) and a precision of 1.7% RSD at the 40 μg L(-1) level (n=11) were obtained, along with a sampling frequency of 47 h(-1). The dynamic sorption capacity of H(2)Dz-SG to Cu(2+) was 0.76 mg g(-1). The accuracy of the proposed procedure was evaluated by determination of copper in reference water sample. The potential applications of the procedure for extraction of trace copper were successfully accomplished in water samples (tap, rain, snow, sea and river). The spiking recoveries within 91-107% are achieved. PMID:21645750

  11. A novel active battery equalization control with on-line unhealthy cell detection and cell change decision

    NASA Astrophysics Data System (ADS)

    Gallardo-Lozano, Javier; Romero-Cadaval, Enrique; Milanes-Montero, M. Isabel; Guerrero-Martinez, Miguel A.

    2015-12-01

    Battery Equalization systems are necessary as cell imbalance can lead to poor performance and safety hazards. In this paper we present a novel active battery equalization control, based on the Shunt Transistor method, which is feasible for EV battery equalization. Unlike the actual Shunt Transistor control methods that can only operate at the end of the charging process, the proposed smart control is able to accomplish the equalization during both driving and charging EV operations (optimizing time and performance) with a high final efficiency. Balancing is not enough when battery aging manifests; therefore, health management is essential. By taking advantage of the proposed system, a novel on-line unhealthy cell detection and cell change decision function is implemented. The proposed health analysis can be performed during normal driving, without the need for numerous charging/discharging cycles, a considerable data set, or complex models or estimations. Simulation results and experimental validation, in a battery pack made up with three cells, first prove the correct equalization during driving (with a real driving profile) and charging/discharging operations, with high efficiency (over 95%); and secondly, validates the cell health analysis, obtaining a cell health map and detecting the unhealthy cell placed on purpose.

  12. Radiation Detection Material Discovery Initiative at PNNL

    NASA Astrophysics Data System (ADS)

    Milbrath, Brian

    2006-05-01

    Today's security threats are being met with 30-year old radiation technology. Discovery of new radiation detection materials is currently a slow and Edisonian process. With heightened concerns over nuclear proliferation, terrorism and unconventional warfare, an alternative strategy for identification and development of potential radiation detection materials must be adopted. Through the Radiation Detection Materials Discovery Initiative, PNNL focuses on the science-based discovery of next generation materials for radiation detection by addressing three ``grand challenges'': fundamental understanding of radiation detection, identification of new materials, and accelerating the discovery process. The new initiative has eight projects addressing these challenges, which will be described, including early work, paths forward and the opportunities for collaboration.

  13. The Trace Analysis of DEET in Water using an On-line Preconcentration Column and Liquid Chromatography with UV Photodiode Array Detection

    EPA Science Inventory

    A method for the detection of trace levels of N,N-diethyl-m-toluamide (DEET) in water is discussed. The method utilizes an on-line preconcentration column in series with high performance liquid chromatography (HPLC) and UV photodiode array detection. DEET, a common insect repel...

  14. Radiation Detection Center on the Front Lines

    SciTech Connect

    Hazi, A

    2005-09-20

    Many of today's radiation detection tools were developed in the 1960s. For years, the Laboratory's expertise in radiation detection resided mostly within its nuclear test program. When nuclear testing was halted in the 1990s, many of Livermore's radiation detection experts were dispersed to other parts of the Laboratory, including the directorates of Chemistry and Materials Science (CMS); Physics and Advanced Technologies (PAT); Defense and Nuclear Technologies (DNT); and Nonproliferation, Arms Control, and International Security (NAI). The RDC was formed to maximize the benefit of radiation detection technologies being developed in 15 to 20 research and development (R&D) programs. These efforts involve more than 200 Laboratory employees across eight directorates, in areas that range from electronics to computer simulations. The RDC's primary focus is the detection, identification, and analysis of nuclear materials and weapons. A newly formed outreach program within the RDC is responsible for conducting radiation detection workshops and seminars across the country and for coordinating university student internships. Simon Labov, director of the RDC, says, ''Virtually all of the Laboratory's programs use radiation detection devices in some way. For example, DNT uses radiation detection to create radiographs for their work in stockpile stewardship and in diagnosing explosives; CMS uses it to develop technology for advancing the detection, diagnosis, and treatment of cancer; and the Energy and Environment Directorate uses radiation detection in the Marshall Islands to monitor the aftermath of nuclear testing in the Pacific. In the future, the National Ignition Facility will use radiation detection to probe laser targets and study shock dynamics.''

  15. Great SEP events and space weather , 4. Principles of on-line radiation hazard forecasting in space, in magnetosphere, and in the atmosphere

    NASA Astrophysics Data System (ADS)

    Dorman, L.

    In report Dorman (2002) w re described how worked automatically the programse "SEP-Research/TimeofEjection","SEP-Research/Source"and"SEP- Research/Diffusion". On the basis of these programs on-line can be determined the time of ejection, diffusion coefficient in the interplanetary space and energy spectrum in source of SEP. Here we show how on the basis of these results can be made forecasting of expected radiation hazard for computers, electronics, solar battaries, technology in space on different distances from the Sun and on different helio-latitudes. We show that the same can be made for satellites on different orbits in the magnetosphere with taking into account the change of cut-off rigidities along the orbits (for people health, solar battaries, computers, electronics, technology). By the method of coupling functions for different altitudes in the atmosphere we describe principles of radiation hazard forecasting on-line for air-planes on regular and non-regular lines in dependence of altitudes and cut-off rigidities, and value of shielding. On-line will be made forecasting of radiation hazard on the ground for people health and technology in dependence from the cut-off rigidity and atmospheric pressure. If for some cases the calculated radiation hazard will be expected higher than some definite level of dangerous, will be on-line send special Alerts. We show how worked these programs on examples of some historical great SEP events. This research is partly supported by INTAS grant 00-0810. REFERENCES: Dorman L.I. " Great SEP events and space weather , 3. Automatically determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum in source.", Report on COSPAR_2002.

  16. RADIATION DETECTING AND TELEMETERING SYSTEM

    DOEpatents

    Richards, H.K.

    1959-12-15

    A system is presented for measuring ionizing radiation at several remote stations and transmitting the measured information by radio to a central station. At each remote station a signal proportioned to the counting rate is applied across an electrical condenser made of ferroelectric material. The voltage across the condenser will vary as a function of the incident radiation and the capacitance of the condenser will vary accordingly. This change in capacitance is used to change the frequency of a crystalcontrolled oscillator. The output of the oscillator is coupled to an antenna for transmitting a signal proportional to the incident radiation.

  17. In-Ground Radiation Detection

    SciTech Connect

    McCormick, Kathleen R.; Stromswold, David C.; Woodring, Mitchell L.; Ely, James H.; Siciliano, Edward R.; Caggiano, Joseph A.; Hensley, Walter K.

    2006-10-29

    Vertically oriented radiation detectors may not provide sufficient screening in rail or aviation applications. Railcars can be heavily shielded on the sides, reducing the sensitivity of vertically mounted monitors. For aviation, the distance required for wingspan clearance reduces a vertical detector’s coverage of the fuselage. To surmount these, and other, challenging operational and sensitivity issues, we have investigated the use of in-ground radiation detectors. (PIET-43741-TM-605).

  18. Indirect detection of radiation sources through direct detection of radiolysis products

    DOEpatents

    Farmer, Joseph C.; Fischer, Larry E.; Felter, Thomas E.

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  19. Device for detecting ionizing radiation

    SciTech Connect

    Anatychuk, L.I.; Kharitonov, J.P.; Kusniruk, V.F.; Meir, V.A.; Melnik, A.P.; Ponomarev, V.S.; Skakodub, V.A.; Sokolov, A.D.; Subbotin, V.G.; Zhukovsky, A.N.

    1980-10-28

    The present invention relates to ionizing radiation sensors, and , more particularly, to semiconductor spectrometers with thermoelectric cooling, and can most advantageously be used in mineral raw material exploration and evaluation under field conditions. The spectrometer comprises a vacuum chamber with an entrance window for passing the radiation therethrough. The vacuum chamber accommodates a thermoelectric cooler formed by a set of peltier elements. A heat conducting plate is mounted on the cold side of the thermoelectric cooler, and its hot side is provided with a radiator. Mounted on the heat conducting plate are sets of peltier elements, integral with the thermoelectric cooler and independent of one another. The peltier elements of these sets are stacked so as to develop the minimum temperature conditions on one set carrying a semiconductor detector and to provide the maximum refrigeration capacity conditions on the other set provided with the field-effect transistor mounted thereon.

  20. Radiation Detection for Homeland Security Applications

    NASA Astrophysics Data System (ADS)

    Ely, James

    2008-05-01

    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

  1. Millimeter wave detection of nuclear radiation - an alternative detection mechanism.

    SciTech Connect

    Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.; Nuclear Engineering Division

    2009-08-01

    We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.

  2. Millimeter wave detection of nuclear radiation: An alternative detection mechanism

    SciTech Connect

    Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.

    2009-08-15

    We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.

  3. Millimeter wave detection of nuclear radiation: an alternative detection mechanism.

    PubMed

    Gopalsami, N; Chien, H T; Heifetz, A; Koehl, E R; Raptis, A C

    2009-08-01

    We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam. PMID:19725673

  4. Millimeter wave detection of nuclear radiation: An alternative detection mechanism

    NASA Astrophysics Data System (ADS)

    Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.

    2009-08-01

    We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.

  5. Environmental radiation detection via thermoluminescence

    DOEpatents

    Miller, S.D.

    1993-03-23

    The method and apparatus of the present invention relate to cryogenically cooling a thermoluminescent material, exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to room temperature'' and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.

  6. Environmental radiation detection via thermoluminescence

    DOEpatents

    Miller, Steven D.

    1993-01-01

    The method and apparatus of the present invention relate to cryogenically cooling a thermoluminescent material, exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to "room temperature", and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.

  7. A history of radiation detection instrumentation.

    PubMed

    Frame, Paul W

    2004-08-01

    A review is presented of the history of radiation detection instrumentation. Specific radiation detection systems that are discussed include the human senses, photography, calorimetry, color dosimetry, ion chambers, electrometers, electroscopes, proportional counters, Geiger Mueller counters, scalers and rate meters, barium platinocyanide, scintillation counters, semiconductor detectors, radiophotoluminescent dosimeters, thermoluminescent dosimeters, optically stimulated luminescent dosimeters, direct ion storage, electrets, cloud chambers, bubble chambers, and bubble dosimeters. Given the broad scope of this review, the coverage is limited to a few key events in the development of a given detection system and some relevant operating principles. The occasional anecdote is included for interest. PMID:15257213

  8. A history of radiation detection instrumentation.

    PubMed

    Frame, Paul W

    2005-06-01

    A review is presented of the history of radiation detection instrumentation. Specific radiation detection systems that are discussed include the human senses, photography, calorimetry, color dosimetry, ion chambers, electrometers, electroscopes, proportional counters, Geiger Mueller counters, scalers and rate meters, barium platinocyanide, scintillation counters, semiconductor detectors, radiophotoluminescent dosimeters, thermoluminescent dosimeters, optically stimulated luminescent dosimeters, direct ion storage, electrets, cloud chambers, bubble chambers, and bubble dosimeters. Given the broad scope of this review, the coverage is limited to a few key events in the development of a given detection system and some relevant operating principles. The occasional anecdote is included for interest. PMID:15891457

  9. Flow injection on-line dilution for zinc determination in human saliva with electrothermal atomic absorption spectrometry detection.

    PubMed

    Burguera-Pascu, Margarita; Rodríguez-Archilla, Alberto; Burguera, José Luis; Burguera, Marcela; Rondón, Carlos; Carrero, Pablo

    2007-09-26

    An automated method is described for the determination of zinc in human saliva by electrothermal atomic absorption spectrometry (ET AAS) after on-line dilution of samples with a significant reduction of sample consumption per analysis (<0.4 mL including the dead volume of the system). In order to fulfill this aim without changing the sample transport conduits during the experiments, a flow injection (FI) dilution system was constructed. Its principal parts are: one propulsion device (peristaltic pump, PP) for either samples, standards or washing solution all located in an autosampler tray and for the surfactant solution (Triton X-100) used as diluent, and a two-position time based solenoid injector (TBSI(1)) which allowed the introduction of 10 microL of either solution in the diluent stream. To avoid unnecessary waste of samples, the TBSI(1) also permitted the recirculation of the solutions to their respective autosampler cups. The downstream diluted solution fills a home made sampling arm assembly. The sequential deposition of 20 microL aliquots of samples or standards on the graphite tube platform was carried out by air displacement with a similar time based solenoid injector (TBSI(2)). The dilution procedure and the injection of solutions into the atomizer are computer controlled and synchronized with the operation of the temperature program. Samples or standards solutions were submitted to two drying steps (at 90 and 130 degrees C), followed by pyrolysis and atomization at 700 and 1700 degrees C, respectively. The aqueous calibration was linear up to 120.0 microgL(-1) for diluted standard solutions/samples and its slope was similar (p>0.05) to the standard addition curve, indicating lack of matrix effect. The precision tested by repeated analysis of real saliva samples was less than 3% and the detection limit (3sigma) was of 0.35 microgL(-1). To test the accuracy of the proposed procedure, recovery tests were performed, obtaining mean recovery of added zinc of

  10. Influence of the gaseous mixture composition on accuracy of molecular iodine on-line detection by laser-induced fluorescence method

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2016-07-01

    This paper informs on research into the influence of the composition of gaseous mixtures analyzed on the accuracy of on-line molecular iodine detection by laser-induced fluorescence in various gaseous media—in atmospheric air and in technological mixtures formed during reprocessing of spent nuclear fuel. The paper shows that by considering the composition of buffer media and parts of its components, the accuracy of iodine content measurement may be increased in several times.

  11. A radio-high-performance liquid chromatography dual-flow cell gamma-detection system for on-line radiochemical purity and labeling efficiency determination.

    PubMed

    Lindegren, S; Jensen, H; Jacobsson, L

    2014-04-11

    In this study, a method of determining radiochemical yield and radiochemical purity using radio-HPLC detection employing a dual-flow-cell system is evaluated. The dual-flow cell, consisting of a reference cell and an analytical cell, was constructed from two PEEK capillary coils to fit into the well of a NaI(Tl) detector. The radio-HPLC flow was directed from the injector to the reference cell allowing on-line detection of the total injected sample activity prior to entering the HPLC column. The radioactivity eluted from the column was then detected in the analytical cell. In this way, the sample will act as its own standard, a feature enabling on-line quantification of the processed radioactivity passing through the system. All data were acquired on-line via an analog signal from a rate meter using chromatographic software. The radiochemical yield and recovery could be simply and accurately determined by integration of the peak areas in the chromatogram obtained from the reference and analytical cells using an experimentally determined volume factor to correct for the effect of different cell volumes. PMID:24630054

  12. GaTe semiconductor for radiation detection

    DOEpatents

    Payne, Stephen A.; Burger, Arnold; Mandal, Krishna C.

    2009-06-23

    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.

  13. Detecting radiation reaction at moderate laser intensities.

    PubMed

    Heinzl, Thomas; Harvey, Chris; Ilderton, Anton; Marklund, Mattias; Bulanov, Stepan S; Rykovanov, Sergey; Schroeder, Carl B; Esarey, Eric; Leemans, Wim P

    2015-02-01

    We propose a new method of detecting radiation reaction effects in the motion of particles subjected to laser pulses of moderate intensity and long duration. The effect becomes sizable for particles that gain almost no energy through the interaction with the laser pulse. Hence, there are regions of parameter space in which radiation reaction is actually the dominant influence on charged particle motion. PMID:25768626

  14. Detection of contraband using microwave radiation

    DOEpatents

    Toth, Richard P.; Loubriel, Guillermo M.; Bacon, Larry D.; Watson, Robert D.

    2002-01-01

    The present invention relates to a method and system for using microwave radiation to detect contraband hidden inside of a non-metallic container, such as a pneumatic vehicle tire. The method relies on the attenuation, retardation, time delay, or phase shift of microwave radiation as it passes through the container plus the contraband. The method is non-invasive, non-destructive, low power, and does not require physical contact with the container.

  15. Sequential on-line C-terminal sequencing of peptides based on carboxypeptidase Y digestion and optically gated capillary electrophoresis with laser-induced fluorescence detection.

    PubMed

    Tian, Miaomiao; Zhang, Ning; Liu, Xiaoxia; Guo, Liping; Yang, Li

    2016-08-12

    We report a novel method for sequential on-line C-terminal sequencing of peptides, which combines carboxypeptidase Y (CPY) digestion with on-line derivatization and optically gated capillary electrophoresis with laser-induced fluorescence detection (OGCE-LIF). Various factors that may affect the C-terminal sequencing were investigated and optimized. High repeatability of on-line derivatization and the sequential OGCE-LIF assay of amino acids (AAs) was achieved with relative standard deviation (RSD) (n=20) less than 1.5% and 3.2% for migration time and peak height, respectively. A total of 13 AAs was efficiently separated in the present study, indicating that the method can be used for sequencing of peptides consisting of the 13 AAs studied. Using two synthesized N-terminally blocked peptides as test examples, we show that the present method can on-line monitor the released AAs with a temporal resolution of 50s during the entire CPY digestion process. The rates of AA release as a function of digestion time were easily measured; thus, the AA sequence of the peptide was determined with just one OGCE assay. Our study indicates the present approach is an effective, reliable, and convenient method for rapid analysis of the C-terminal sequence of peptides, with potential application in peptide analysis and proteome research. PMID:27425760

  16. Bayesian Methods for Radiation Detection and Dosimetry

    SciTech Connect

    Peter G. Groer

    2002-09-29

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model.

  17. Development of a microfluidic confocal fluorescence detection system for the hyphenation of nano-LC to on-line biochemical assays

    PubMed Central

    Heus, Ferry; Giera, Martin; de Kloe, Gerdien E.; van Iperen, Dick; Buijs, Joost; Nahar, Tariq T.; Smit, August B.; Lingeman, Henk; de Esch, Iwan J. P.; Niessen, Wilfried M. A.; Irth, Hubertus

    2010-01-01

    One way to profile complex mixtures for receptor affinity is to couple liquid chromatography (LC) on-line to biochemical detection (BCD). A drawback of this hyphenated screening approach is the relatively high consumption of sample, receptor protein and (fluorescently labeled) tracer ligand. Here, we worked toward minimization of sample and reagent consumption, by coupling nano-LC on-line to a light-emitting diode (LED) based capillary confocal fluorescence detection system capable of on-line BCD with low-flow rates. In this fluorescence detection system, a capillary with an extended light path (bubble cell) was used as a detection cell in order to enhance sensitivity. The technology was applied to a fluorescent enhancement bioassay for the acetylcholine binding protein, a structural analog of the extracellular ligand-binding domain of neuronal nicotinic acetylcholine receptors. In the miniaturized setup, the sensitive and low void volume LED-induced confocal fluorescence detection system operated in flow injection analysis mode allowing the measurement of IC50 values, which were comparable with those measured by a conventional plate reader bioassay. The current setup uses 50 nL as injection volume with a carrier flow rate of 400 nL/min. Finally, coupling of the detection system to gradient reversed-phase nano-LC allowed analysis of mixtures in order to identify the bioactive compounds present by injecting 10 nL of each mixture. Electronic supplementary material The online version of this article (doi:10.1007/s00216-010-4210-x) contains supplementary material, which is available to authorized users. PMID:20872136

  18. Laser-induced fluorescence method for on-line molecular isotopologues of iodine-127, iodine-129, iodine-131 detected in gaseous media using a tunable diode laser

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.; Sobolevsky, I. V.

    2016-06-01

    The letter reports on the development of a laser-induced fluorescence method for on-line selective measurement of 127I2, 129I2, 131I2, 129I127I, 127I131I, 129I131I isotopologue concentrations in gaseous media. The method is based on the excitation of molecular iodine isotopologues’ fluorescence by tunable diode laser (632–637 nm) radiation at three or four wavelengths corresponding to the 127I2, 131I2, 129I127I, 129I131I absorption line centers. Boundary relations for concentrations of simultaneously measured iodine isotopologues is about 10‑5–10‑6.

  19. SU-E-J-92: On-Line Cone Beam CT Based Planning for Emergency and Palliative Radiation Therapy

    SciTech Connect

    Held, M; Morin, O; Pouliot, J

    2014-06-01

    Purpose: To evaluate and develop the feasibility of on-line cone beam CT based planning for emergency and palliative radiotherapy treatments. Methods: Subsequent to phantom studies, a case library of 28 clinical megavoltage cone beam CT (MVCBCT) was built to assess dose-planning accuracies on MVCBCT for all anatomical sites. A simple emergency treatment plan was created on the MVCBCT and copied to its reference CT. The agreement between the dose distributions of each image pair was evaluated by the mean dose difference of the dose volume and the gamma index of the central 2D axial plane. An array of popular urgent and palliative cases was also evaluated for imaging component clearance and field-of-view. Results: The treatment cases were categorized into four groups (head and neck, thorax/spine, pelvis and extremities). Dose distributions for head and neck treatments were predicted accurately in all cases with a gamma index of >95% for 2% and 2 mm criteria. Thoracic spine treatments had a gamma index as low as 60% indicating a need for better uniformity correction and tissue density calibration. Small anatomy changes between CT and MVCBCT could contribute to local errors. Pelvis and sacral spine treatment cases had a gamma index between 90% and 98% for 3%/3 mm criteria. The limited FOV became an issue for large pelvis patients. Imaging clearance was difficult for cases where the tumor was positioned far off midline. Conclusion: The MVCBCT based dose planning and delivery approach is feasible in many treatment cases. Dose distributions for head and neck patients are unrestrictedly predictable. Some FOV restrictions apply to other treatment sites. Lung tissue is most challenging for accurate dose calculations given the current imaging filters and corrections. Additional clinical cases for extremities need to be included in the study to assess the full range of site-specific planning accuracies. This work is supported by Siemens.

  20. Development of On-Line High Performance Liquid Chromatography (HPLC)-Biochemical Detection Methods as Tools in the Identification of Bioactives

    PubMed Central

    Malherbe, Christiaan J.; de Beer, Dalene; Joubert, Elizabeth

    2012-01-01

    Biochemical detection (BCD) methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC) is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays. PMID:22489144

  1. Composite scintillators for detection of ionizing radiation

    DOEpatents

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

    2010-12-28

    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.

  2. Detection of electromagnetic radiation using nonlinear materials

    DOEpatents

    Hwang, Harold Y.; Liu, Mengkun; Averitt, Richard D.; Nelson, Keith A.; Sternbach, Aaron; Fan, Kebin

    2016-06-14

    An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

  3. A fully automated system for analysis of pesticides in water: on-line extraction followed by liquid chromatography-tandem photodiode array/postcolumn derivatization/fluorescence detection.

    PubMed

    Patsias, J; Papadopoulou-Mourkidou, E

    1999-01-01

    A fully automated system for on-line solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with tandem detection with a photodiode array detector and a fluorescence detector (after postcolumn derivatization) was developed for analysis of many chemical classes of pesticides and their major conversion products in aquatic systems. An automated on-line-SPE system (Prospekt) operated with reversed-phase cartridges (PRP-1) extracts analytes from 100 mL acidified (pH = 3) filtered water sample. On-line HPLC analysis is performed with a 15 cm C18 analytical column eluted with a mobile phase of phosphate (pH = 3)-acetonitrile in 25 min linear gradient mode. Solutes are detected by tandem diode array/derivatization/fluorescence detection. The system is controlled and monitored by a single computer operated with Millenium software. Recoveries of most analytes in samples fortified at 1 microgram/L are > 90%, with relative standard deviation values of < 5%. For a few very polar analytes, mostly N-methylcarbamoyloximes (i.e., aldicarb sulfone, methomyl, and oxamyl), recoveries are < 20%. However, for these compounds, as well as for the rest of the N-methylcarbamates except for aldicarb sulfoxide and butoxycarboxim, the limits of detection (LODs) are 0.005-0.05 microgram/L. LODs for aldicarb sulfoxide and butoxycarboxim are 0.2 and 0.1 microgram, respectively. LODs for the rest of the analytes except 4-nitrophenol, bentazone, captan, decamethrin, and MCPA are 0.05-0.1 microgram/L. LODs for the latter compounds are 0.2-1.0 microgram/L. The system can be operated unattended. PMID:10444834

  4. A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus.

    PubMed

    Shangguan, Jingfang; Li, Yuhong; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui

    2015-07-01

    Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (Apt(S.aureus)/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the Apt(S.aureus)/FNP labeled S. aureus. After incubating with S. aureus, the mixture of Apt(S.aureus)/FNP labeled S. aureus and Apt(S.aureus)/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the Apt(S.aureus)/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free Apt(S.aureus)/FNPs flowed away. The signal that came from the Apt(S.aureus)/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported Apt(S.aureus)/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h. PMID:25963028

  5. Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

    NASA Astrophysics Data System (ADS)

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

    1995-02-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

  6. 10 CFR 39.33 - Radiation detection instruments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Radiation detection instruments. 39.33 Section 39.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.33 Radiation detection instruments. (a) The licensee shall keep a calibrated and operable radiation survey instrument capable of detecting...

  7. Monitoring gradient profile on-line in micro- and nano-high performance liquid chromatography using conductivity detection.

    PubMed

    Zhang, Min; Chen, Apeng; Lu, Joann J; Cao, Chengxi; Liu, Shaorong

    2016-08-19

    In micro- or nano-flow high performance liquid chromatography (HPLC), flow-splitters and gradient elutions are commonly used for reverse phase HPLC separations. When a flow splitter was used at a high split-ratio (e.g., 1000:1 or higher), the actual gradient may deviate away from the programmed gradient. Sometimes, mobile phase concentrations can deviate by as much as 5%. In this work, we noticed that the conductivity (σ) of a gradient decreased with the increasing organic-solvent fraction (φ). Based on the relationship between σ and φ, a method was developed for monitoring gradient profile on-line to record any deviations in these HPLC systems. The conductivity could be measured by a traditional conductivity detector or a capacitively coupled contactless conductivity detector (C(4)D). The method was applied for assessing the performance of an electroosmotic pump (EOP) based nano-HPLC. We also observed that σ value of the gradient changed with system pressure; a=0.0175ΔP (R(2)=0.964), where a is the percentage of the conductivity increase and ΔP is the system pressure in bar. This effect was also investigated. PMID:27435687

  8. Radiation sensitive area detection device and method

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor); Hecht, Diana L. (Inventor); Witherow, William K. (Inventor)

    1991-01-01

    A radiation sensitive area detection device for use in conjunction with an X ray, ultraviolet or other radiation source is provided which comprises a phosphor containing film which releases a stored diffraction pattern image in response to incoming light or other electromagnetic wave. A light source such as a helium-neon laser, an optical fiber capable of directing light from the laser source onto the phosphor film and also capable of channelling the fluoresced light from the phosphor film to an integrating sphere which directs the light to a signal processing means including a light receiving means such as a photomultiplier tube. The signal processing means allows translation of the fluoresced light in order to detect the original pattern caused by the diffraction of the radiation by the original sample. The optical fiber is retained directly in front of the phosphor screen by a thin metal holder which moves up and down across the phosphor screen and which features a replaceable pinhole which allows easy adjustment of the resolution of the light projected onto the phosphor film. The device produces near real time images with high spatial resolution and without the distortion that accompanies prior art devices employing photomultiplier tubes. A method is also provided for carrying out radiation area detection using the device of the invention.

  9. Waveshifters and Scintillators for Ionizing Radiation Detection

    SciTech Connect

    B.Baumgaugh; J.Bishop; D.Karmgard; J.Marchant; M.McKenna; R.Ruchti; M.Vigneault; L.Hernandez; C.Hurlbut

    2007-12-11

    Scintillation and waveshifter materials have been developed for the detection of ionizing radiation in an STTR program between Ludlum Measurements, Inc. and the University of Notre Dame. Several new waveshifter materials have been developed which are comparable in efficiency and faster in fluorescence decay than the standard material Y11 (K27) used in particle physics for several decades. Additionally, new scintillation materials useful for fiber tracking have been developed which have been compared to 3HF. Lastly, work was done on developing liquid scintillators and paint-on scintillators and waveshifters for high radiation environments.

  10. Analysis of sucrose acetates in a crude 6-O-acetyl sucrose product by on-line hydrolysis-high-performance liquid chromatography with pulsed amperometric detection.

    PubMed

    Yan, Wenwu; Wang, Nani; Zhang, Peimin; Zhang, Jiajie; Wu, Shuchao; Zhu, Yan

    2016-06-01

    A standard-free and sensitive method was developed for analysis of sucrose acetates in a crude 6-O-acetyl sucrose (S-6-a) product by on-line hydrolysis-high-performance liquid chromatography with pulsed amperometric detection (PAD). Sucrose, three regio-isomers of acetyl sucrose and five regio-isomers of diacetyl sucrose were separated on a C18 column using 3% (v/v) acetonitrile in water as eluent within 25min. After purification with LC followed by semi-preparative HPLC, their chemical structures were identified by 1D, 2D NMR and LC-MS. Moreover, quantification of those regio-isomers was achieved by on-line alkaline hydrolysis to liberate sucrose using a post-column delivery system, and then detected by PAD for indirect estimation of the sucrose acetate content. Under optimal conditions, the linear ranges were from 0.03 to 150μmolL(-1) for sucrose corresponding to sucrose acetates with coefficient of determination as 0.9997 and detection limit as 0.01μmolL(-1) (S/N=3). Good repeatability was obtained (RSD<3%, n=6). Furthermore, this method has been successfully applied to the analysis of sucrose and sucrose acetates in a crude S-6-a product during synthesis, purification and structure elucidation studies. The recoveries were from 94.89% to 102.31% for sucrose and sucrose acetates. PMID:27139218

  11. Cytochrome P450 bio-affinity detection coupled to gradient HPLC: on-line screening of affinities to cytochrome P4501A2 and 2D6.

    PubMed

    Kool, Jeroen; van Liempd, Sebastiaan M; Harmsen, Stefan; Beckman, Joran; van Elswijk, Danny; Commandeur, Jan N M; Irth, Hubertus; Vermeulen, Nico P E

    2007-10-15

    Here we describe novel on-line human CYP1A2 and CYP2D6 Enzyme Affinity Detection (EAD) systems coupled to gradient HPLC. The use of the systems lies in the detection of individual inhibitory ligands in mixtures (e.g. metabolic mixtures or herbal extracts) towards two relevant drug metabolizing human CYPs. The systems can rapidly detect individual compounds in mixtures with affinities to CYP1A2 or 2D6. The HPLC-EAD systems were first evaluated and validated in flow injection analysis mode. IC50 values of known ligands for both CYPs, tested both in flow injection and in HPLC mode, were well comparable with those measured in microplate reader formats. Both EAD systems were also connected to gradient HPLC and used to screen known compound mixtures for the presence of CYP1A2 and 2D6 inhibitors. Finally, the on-line CYP2D6 EAD system was used to screen for the inhibitory activities of stereoisomers of a mixture of five methylenedioxy-alkylamphetamines (XTC analogs) on a chiral analytical column. PMID:17826363

  12. On-line air-tightness and insertion loss simultaneous detection method of high air-tightness fiber optic penetration connector

    NASA Astrophysics Data System (ADS)

    Zhang, Jingchuan; Yang, Xiaoning; Wang, Jing; Jiang, Junfeng

    2015-08-01

    The high air-tightness multicore fiber optic penetration connector is a core component for the optical fiber sensing and communication technologies applied in the space environment simulator under the vacuum thermal environment. High air-tightness and insertion loss are the two key indexes of the fiber optic penetration connector. The air-tightness and insertion loss on-line synchronous detection method was proposed. First, established hardware-in-the-loop testing platform by using the vacuum pumping system, the vacuum vessel, the helium mass spectrometer leak detector and optical time-domain reflectmeter, then, described the air tightness and insertion loss on-line detection principle, finally, designed a detection test scheme and air-tightness and insertion loss were tested. Experimental results indicate that the leakage rate is lower than 1.0×10-7Pa•L/S, the minimum of which is1.0×10-10Pa•L/S and the insertion loss at wave length window 1550 nm is +/-0.07db, which is less than +/-0.1db. It can lay the data basis for the design of opto-mechanical combination and later period fine processing.

  13. On-line molecular iodine isotopologue detection in gaseous media during spent nuclear fuel reprocessing using a laser-induced fluorescence method

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-06-01

    The paper reports on on-line measurement of the {}129{{\\text{I}}2}, 127I129I, and {}127{{\\text{I}}2} concentrations during spent nuclear fuel (SNF) reprocessing using a laser-induced fluorescence method. A He-Ne laser (632.8 nm) was used as a fluorescence excitation source. The detection limits obtained for molecular iodine isotopologue concentrations demonstrate the possibility of using this method for iodine control both in gaseous technological media generated during SNF reprocessing and after passing through the gas purification system (in atmosphere emission).

  14. Covariance Spectroscopy Applied to Nuclear Radiation Detection

    SciTech Connect

    Trainham, R., Tinsley, J., Keegan, R., Quam, W.

    2011-09-01

    Covariance spectroscopy is a method of processing second order moments of data to obtain information that is usually absent from average spectra. In nuclear radiation detection it represents a generalization of nuclear coincidence techniques. Correlations and fluctuations in data encode valuable information about radiation sources, transport media, and detection systems. Gaining access to the extra information can help to untangle complicated spectra, uncover overlapping peaks, accelerate source identification, and even sense directionality. Correlations existing at the source level are particularly valuable since many radioactive isotopes emit correlated gammas and neutrons. Correlations also arise from interactions within detector systems, and from scattering in the environment. In particular, correlations from Compton scattering and pair production within a detector array can be usefully exploited in scenarios where direct measurement of source correlations would be unfeasible. We present a covariance analysis of a few experimental data sets to illustrate the utility of the concept.

  15. Radiation Detection for Active Interrogation of HEU

    SciTech Connect

    Mihalczo, J.T.

    2004-12-09

    This report briefly describes the neutrons and gamma rays emitted by active interrogation of HEU, briefly discusses measurement methods, briefly discusses sources and detectors relevant to detection of shielded HEU in Sealand containers, and lists the measurement possibilities for the various sources. All but one of the measurement methods detect radiation emitted by induced fission in the HEU; the exception utilizes nuclear resonance fluorescence. The brief descriptions are supplemented by references. This report presents some active interrogation possibilities but the status of understanding is not advanced enough to select particular methods. Additional research is needed to evaluate these possibilities.

  16. Network Algorithms for Detection of Radiation Sources

    SciTech Connect

    Rao, Nageswara S; Brooks, Richard R; Wu, Qishi

    2014-01-01

    In support of national defense, Domestic Nuclear Detection Office s (DNDO) Intelligent Radiation Sensor Systems (IRSS) program supported the development of networks of radiation counters for detecting, localizing and identifying low-level, hazardous radiation sources. Industry teams developed the first generation of such networks with tens of counters, and demonstrated several of their capabilities in indoor and outdoor characterization tests. Subsequently, these test measurements have been used in algorithm replays using various sub-networks of counters. Test measurements combined with algorithm outputs are used to extract Key Measurements and Benchmark (KMB) datasets. We present two selective analyses of these datasets: (a) a notional border monitoring scenario that highlights the benefits of a network of counters compared to individual detectors, and (b) new insights into the Sequential Probability Ratio Test (SPRT) detection method, which lead to its adaptations for improved detection. Using KMB datasets from an outdoor test, we construct a notional border monitoring scenario, wherein twelve 2 *2 NaI detectors are deployed on the periphery of 21*21meter square region. A Cs-137 (175 uCi) source is moved across this region, starting several meters from outside and finally moving away. The measurements from individual counters and the network were processed using replays of a particle filter algorithm developed under IRSS program. The algorithm outputs from KMB datasets clearly illustrate the benefits of combining measurements from all networked counters: the source was detected before it entered the region, during its trajectory inside, and until it moved several meters away. When individual counters are used for detection, the source was detected for much shorter durations, and sometimes was missed in the interior region. The application of SPRT for detecting radiation sources requires choosing the detection threshold, which in turn requires a source strength

  17. Radiation detection and wireless networked early warning

    NASA Astrophysics Data System (ADS)

    Burns, David A.; Litz, Marc S.; Carroll, James J.; Katsis, Dimosthenis

    2012-06-01

    We have designed a compact, wireless, GPS-enabled array of inexpensive radiation sensors based on scintillation counting. Each sensor has a scintillator, photomultiplier tube, and pulse-counting circuit that includes a comparator, digital potentiometer and microcontroller. This design provides a high level of sensitivity and reliability. A 0.2 m2 PV panel powers each sensor providing a maintenance-free 24/7 energy source. The sensor can be mounted within a roadway light-post and monitor radiological activity along transport routes. Each sensor wirelessly transmits real-time data (as counts per second) up to 2 miles with a XBee radio module, and the data is received by a XBee receive-module on a computer. Data collection software logs the information from all sensors and provides real-time identification of radiation events. Measurements performed to-date demonstrate the ability of a sensor to detect a 20 μCi source at 3.5 meters when packaged with a PVT (plastic) scintillator, and 7 meters for a sensor with a CsI crystal (more expensive but ~5 times more sensitive). It is calculated that the sensor-architecture can detect sources moving as fast as 130 km/h based on the current data rate and statistical bounds of 3-sigma threshold detection. The sensor array is suitable for identifying and tracking a radiation threat from a dirty bomb along roadways.

  18. Detection and quantification of sulfur in oil products by laser-induced breakdown spectroscopy for on-line analysis

    NASA Astrophysics Data System (ADS)

    Trichard, F.; Forquet, V.; Gilon, N.; Lienemann, C.-P.; Baco-Antoniali, F.

    2016-04-01

    Determination of sulfur in petroleum products is described using Laser Induced breakdown spectroscopy (LIBS). A study of buffer gases employed to improve sulfur IR line detection is presented. Optimisation of the flow rate led to a 1.4 L/min optimal helium flow rate. An adaptation between a typical laboratory setup to a compact system allowed to obtain detection limits in the 0.2% w/w range. Calibration is made under the process conditions (70 °C) and at room temperature. Normalization with a helium emission line compensates for liquid level variations and for the temperature variations. The analysis of a sample over the course of 2 days under the conditions of the industrial process was tested and gave a good repeatability.

  19. A portable and autonomous multichannel fluorescence detector for on-line and in situ explosive detection in aqueous phase.

    PubMed

    Xin, Yunhong; Wang, Qi; Liu, Taihong; Wang, Lingling; Li, Jia; Fang, Yu

    2012-11-21

    A multichannel fluorescence detector used to detect nitroaromatic explosives in aqueous phase has been developed, which is composed of a five-channel sample-sensor unit, a measurement and control unit, a microcontroller, and a communication unit. The characteristics of the detector as developed are mainly embedded in the sensor unit, and each sensor consists of a fluorescent sensing film, a light emitting diode (LED), a multi-pixel photon counter (MPPC), and an optical module with special bandpass optical filters. Due to the high sensitivity of the sensing film, the small size and low cost of LED and MPPC, the developed detector not only has a better detecting performance and small size, but also has a very low cost - it is an alternative to the device made with an expensive high power lamp and photomultiplier tube. The wavelengths of the five sensors covered extend from the upper UV through the visible spectrum, 370-640 nm, and thereby it possesses the potential to detect a variety of explosives and other hazardous materials in aqueous phase. An additional function of the detector is its ability to function via a wireless network, by which the data recorded by the detector can be sent to the host computer, and at the same time the instructions can be sent to the detector from the host computer. By means of the powerful computing ability of the host computer, and utilizing the classical principal component analysis (PCA) algorithm, effective classification of the analytes is achieved. Furthermore, the detector has been tested and evaluated using NB, PA, TNT and DNT as the analytes, and toluene, benzene, methanol and ethanol as interferent compounds (concentration various from 10 and 60 μM). It has been shown that the detector can detect the four nitroaromatics with high sensitivity and selectivity. PMID:23007322

  20. Composition and apparatus for detecting gamma radiation

    DOEpatents

    Hofstetter, K.J.

    1994-08-09

    A gamma radiation detector and a radioluminescent composition for use therein. The detector includes a radioluminescent composition that emits light in a characteristic wavelength region when exposed to gamma radiation, and means for detecting said radiation. The composition contains a scintillant such as anglesite (PbSO[sub 4]) or cerussite (PbCO[sub 3]) incorporated into an inert, porous glass matrix via a sol-gel process. Particles of radiation-sensitive scintillant are added to, a sol solution. The mixture is polymerized to form a gel, then dried under conditions that preserve the structural integrity and radiation sensitivity of the scintillant. The final product is a composition containing the uniformly-dispersed scintillant in an inert, optically transparent and highly porous matrix. The composition is chemically inert and substantially impervious to environmental conditions including changes in temperature, air pressure, and so forth. It can be fabricated in cylinders, blocks with holes therethrough for flow of fluid, sheets, surface coatings, pellets or other convenient shapes. 3 figs.

  1. Composition and apparatus for detecting gamma radiation

    DOEpatents

    Hofstetter, Kenneth J.

    1994-01-01

    A gamma radiation detector and a radioluminiscent composition for use therein. The detector includes a radioluminscent composition that emits light in a characteristic wavelength region when exposed to gamma radiation, and means for detecting said radiation. The composition contains a scintillant such as anglesite (PbSO.sub.4) or cerussite (PbCO.sub.3) incorporated into an inert, porous glass matrix via a sol-gel process. Particles of radiation-sensitive scintillant are added to, a sol solution. The mixture is polymerized to form a gel, then dried under conditions that preserve the structural integrity and radiation sensitivity of the scintillant. The final product is a composition containing the uniformly-dispersed scintillant in an inert, optically transparent and highly porous matrix. The composition is chemically inert and substantially impervious to environmental conditions including changes in temperature, air pressure, and so forth. It can be fabricated in cylinders, blocks with holes therethrough for flow of fluid, sheets, surface coatings, pellets or other convenient shapes.

  2. Selective spectral detection of continuum terahertz radiation

    NASA Astrophysics Data System (ADS)

    Kaufmann, P.; Marcon, R.; Marun, A.; Kudaka, A. S.; Bortolucci, E.; Zakia, M. B.; Diniz, J. A.; Cassiano, M. M.; Pereyra, P.; Godoy, R.; Timofeevsky, A. V.; Nikolaev, V. A.; Pereira Alves da Silva, A. M.; Fernandes, L. O. T.

    2010-07-01

    The knowledge of THz continuum spectra is essential to investigate the emission mechanisms by high energy particle acceleration processes. Technical challenges appear for obtaining selective spectral sensing in the far infrared range to diagnose radiation produced by solar flare burst emissions measured from space as well as radiation produced by high energy electrons in laboratory accelerators. Efforts are been carried out intended for the development of solar flare high cadence radiometers at two THz frequencies to operate outside the terrestrial atmosphere (i.e. at 3 and 7 THz). One essential requirement is the efficient suppression of radiation in the visible and near infrared. Experimental setups have been assembled for testing (a) THz transmission of "low-pass" filters: rough surface mirrors; membranes Zitex G110G and TydexBlack; (b) a fabricated 2.4 THz resonant grid band-pass filter transmission response for polarization and angle of incidence; (c) radiation response from distinct detectors: adapted commercial microbolometer array using HRFZ-Si window, pyroelectric module and Golay cell; qualitative detection of solar radiation at a sub-THz frequency has been tested with a microbolometer array placed at the focus of the 1.5 m reflector for submillimeter waves (SST) at El Leoncito, Argentina Andes.

  3. Automated flow-through amperometric immunosensor for highly sensitive and on-line detection of okadaic acid in mussel sample.

    PubMed

    Dominguez, Rocio B; Hayat, Akhtar; Sassolas, Audrey; Alonso, Gustavo A; Munoz, Roberto; Marty, Jean-Louis

    2012-09-15

    An electrochemical immunosensor for okadaic acid (OA) detection has been developed, and used in an indirect competitive immunoassay format under automated flow conditions. The biosensor was fabricated by injecting OA modified magnetic beads onto screen printed carbon electrode (SPCE) in the flow system. The OA present in the sample competed with the immobilized OA to bind with anti-okadaic acid monoclonal antibody (anti-OA-MAb). The secondary alkaline phosphatase labeled antibody was used to perform electrochemical detection. The current response obtained from the labeled alkaline phosphatase to 1-naphthyl phosphate decreased proportionally to the concentration of free OA in the sample. The calculated limit of detection (LOD) was 0.15 μg/L with a linear range of 0.19-25 μg/L. The good recoveries percentages validated the immunosensor application for real mussel samples. The developed system automatically controlled the incubation, washing and current measurement steps, showing its potential use for OA determination in field analysis. PMID:22967546

  4. The detection of radical scavenging compounds in crude extract of borage (Borago officinalis L.) by using an on-line HPLC-DPPH method.

    PubMed

    Bandoniene, Donata; Murkovic, Michael

    2002-01-01

    The rapid evaluation of antioxidant activity of crude borage (Borago officinalis L.) extract was determined by using DPPH free radical method. This borage extract resulted in a rapid decrease of the absorbance and showed very high hydrogen-donating capacity towards the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical. A new HPLC-DPPH on-line method was applied for a screening of several radical scavenging components in this borage extract as well as for quantitative analysis. This on-line HPLC-DPPH method was developed using a methanolic solution of DPPH-stable radical. The HPLC-separated analytes reacted post-column with the DPPH solution in methanol. The induced bleaching was detected as a negative peak photometrically at 515 nm. The separation of antioxidative components was carried out by gradient HPLC with mobile-phase composition ranging from 2% to 80% acetonitrile with 2% acetic acid in water, UV detection was carried out at 280 nm. The HPLC analysis of borage extract revealed the presence of several radical scavenging components in the borage extract. The results obtained from the chromatograms suggest that some compounds present in the extract possess high radical quenching ability. The dominant antioxidative compound in the crude extract of borage leaves was identified as rosmarinic acid. PMID:12406585

  5. A neural network approach for on-line fault detection of nitrogen sensors in alternated active sludge treatment plants.

    PubMed

    Caccavale, F; Digiulio, P; Iamarino, M; Masi, S; Pierri, F

    2010-01-01

    In this paper, an effective strategy for fault detection of nitrogen sensors in alternated active sludge treatment plants is proposed and tested on a simulated set-up. It is based on two predictive neural networks, which are trained using a historical set of data collected during fault-free operation of a wastewater treatment plant and their ability to predict reduced (ammonium) and oxidized (nitrates and nitrites) nitrogen is tested. The neural networks are also characterized by good generalization ability and robustness with respect to the influent variability with time and weather conditions. Then, simulations have been carried out imposing different kinds of fault on both sensors, as isolated spikes, abrupt bias and increased noise. Processing of residuals, based on the difference between measured concentration values and neural networks predictions, allows a quick revealing of the fault as well as the isolation of the corrupted sensor. PMID:21123904

  6. Bubble Radiation Detection: Current and Future Capability

    SciTech Connect

    AJ Peurrung; RA Craig

    1999-11-15

    Despite a number of noteworthy achievements in other fields, superheated droplet detectors (SDDs) and bubble chambers (BCs) have not been used for nuclear nonproliferation and arms control. This report examines these two radiation-detection technologies in detail and answers the question of how they can be or should be ''adapted'' for use in national security applications. These technologies involve closely related approaches to radiation detection in which an energetic charged particle deposits sufficient energy to initiate the process of bubble nucleation in a superheated fluid. These detectors offer complete gamma-ray insensitivity when used to detect neutrons. They also provide controllable neutron-energy thresholds and excellent position resolution. SDDs are extraordinarily simple and inexpensive. BCs offer the promise of very high efficiency ({approximately}75%). A notable drawback for both technologies is temperature sensitivity. As a result of this problem, the temperature must be controlled whenever high accuracy is required, or harsh environmental conditions are encountered. The primary findings of this work are listed and briefly summarized below: (1) SDDs are ready to function as electronics-free neutron detectors on demand for arms-control applications. The elimination of electronics at the weapon's location greatly eases the negotiability of radiation-detection technologies in general. (2) As a result of their high efficiency and sharp energy threshold, current BCs are almost ready for use in the development of a next-generation active assay system. Development of an instrument based on appropriately safe materials is warranted. (3) Both kinds of bubble detectors are ready for use whenever very high gamma-ray fields must be confronted. Spent fuel MPC and A is a good example where this need presents itself. (4) Both kinds of bubble detectors have the potential to function as low-cost replacements for conventional neutron detectors such as {sup 3}He

  7. Cellular telephone-based wide-area radiation detection network

    DOEpatents

    Craig, William W.; Labov, Simon E.

    2009-06-09

    A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

  8. On-Line Detection of Defects on Fruit by Machinevision Systems Based on Three-Color-Cameras Systems

    NASA Astrophysics Data System (ADS)

    Xul, Qiaobao; Zou, Xiaobo; Zhao, Jiewen

    How to identify apple stem-ends and calyxes from defects is still a challenging project due to the complexity of the process. It is know that the stem-ends and calyxes could not appear at the same image. Therefore, a contaminated apple distinguishing method is developed in this article. That is, if there are two or more doubtful blobs on an applés image, the apple is contaminated one. There is no complex imaging process and pattern recognition in this method, because it is only need to find how many blobs (including the stem-ends and calyxes) in an applés image. Machine vision systems which based 3 color cameras are presented in this article regarding the online detection of external defects. On this system, the fruits placed on rollers are rotating while moving, and each camera which placed on the line grabs 3 images from an apple. After the apple segmented from the black background by multi-thresholds method, defect's segmentation and counting is performed on the applés images. Good separation between normal and contaminated apples was obtained for threecamera system (94.5%), comparing to one-camera system (63.3%), twocamera system (83.7%). The disadvantage of this method is that it could not distinguish different defects types. Defects of apples, such as bruising, scab, fungal growth, and disease, are treated as the same.

  9. Size-tunable Pt nanoparticles assembled on functionalized ordered mesoporous carbon for the simultaneous and on-line detection of glucose and L-lactate in brain microdialysate.

    PubMed

    Yu, Yanyan; Yang, Yan; Gu, Hui; Zhou, Tianshu; Shi, Guoyue

    2013-03-15

    This study presents a facile electrochemical method for simultaneous and selective on-line detection of glucose and L-lactate in the striatum of anesthetic rats through the integration of selective electrochemical detection with in vivo microdialysis system. A positively-charged polyelectrolyte, (diallyldimethylammonium chloride) (PDDA), was attached onto carbon mesoporous material (CMM) through non-covalent interaction, which provided an ideal environment for the assembling and dispersion of nanoparticle electrocatalysts. Platinum nanoparticles with wide loadings from 5 to 50 wt% were successfully self-assembled on PDDA-functionalized CMM via electrostatic interaction. TEM results showed that with the increase in the Pt loadings, both the size and interconnectivity between particles increased, with particle sizes ranging from 3.2±0.4 to 6.8±1.4 nm. Moreover, the electrocatalytic activities of the as-prepared six Pt/PDDA-CMM hybrid nanocomposites were also observed to show an inverted-V-shaped profile as a function of loading amount of Pt NPs. Integrated with glucose oxidase (GOx), L-lactate oxidase (LOD) and the in vivo microdialysis system, the constructed dual oxidase/Pt/PDDA-CMM/Nafion biosensors were successfully applied for the simultaneous and on-line detection of glucose and L-lactate. After post-calibration, the basal level of glucose and L-lactate in the striatum of anesthetic rats was calculated to be 0.27±0.03 and 0.71±0.05 mM (mean ±s.d., n=3), respectively. What is more important, the dual oxidase biosensors almost suffered from little cross-talk, which is characteristic of an excellent sensor with high performance. This property, along with the good linearity and a high stability substantially enables this method promising application in physiology and pathology. PMID:23089326

  10. Redox speciation analysis of dissolved iron in estuarine and coastal waters with on-line solid phase extraction and graphite furnace atomic absorption spectrometry detection.

    PubMed

    Chen, Yaojin; Feng, Sichao; Huang, Yongming; Yuan, Dongxing

    2015-05-01

    An automatic on-line solid phase extraction (SPE) system employing the flow injection (FI) technique directly coupled to a graphite furnace atomic absorption spectrometer (GFAAS) was established for speciation and determination of dissolved iron in estuarine and coastal waters. Fe(II) was mixed with ferrozine solution in a sample stream to form the Fe(II)-ferrozine complex which was extracted onto a C18 SPE cartridge, eluted with eluent and detected with GFAAS. In a parallel flow channel, Fe(III) was reduced to Fe(II) with ascorbic acid and then detected in the same way as Fe(II). The home-made interface between FI-SPE and GFAAS efficiently realized the sample introduction to the furnace in a semi-automated way. Parameters of the FI-SPE system and graphite furnace program were optimized based on a univariate experimental design and an orthogonal array design. The salinity effect on the method sensitivity was investigated. The proposed method provided a detection limit of 1.38 nmol L(-1) for Fe(II) and 1.87 nmol L(-1) for Fe(II+III). With variation of the sample loading volume, a broadened determination range of 2.5-200 nmol L(-1) iron could be obtained. The proposed method was successfully applied to analyze iron species in samples collected from the Jiulongjiang Estuary, Fujian, China. With the 2-cartridge FI-SPE system developed, on-line simultaneous determination of Fe species with GFAAS was achieved for the first time. PMID:25770602

  11. An approach to on-line electrospray mass spectrometric detection of polypeptide antibiotics of enramycin for high-speed counter-current chromatographic separation.

    PubMed

    Inoue, Koichi; Hattori, Yasuko; Hino, Tomoaki; Oka, Hisao

    2010-04-01

    In the field of pharmaceutical and biomedical analysis of peptides, a rapid on-line detection and identification for a methodology have been required for the discovery of new biological active products. In this study, a high-speed counter-current chromatography with electrospray mass spectrometry (HSCCC/ESI-MS) was developed for the on-line detection and purification of polypeptide antibiotics of enramycin-A and -B. The analytes were purified on HSCCC model CCC-1000 (multi-layer coil planet centrifuge) with a volatile solvent of two-phase system composed of n-butanol/hexane/0.05% aqueous trifluoroacetic acid solution (43/7/50, V/V/V), and detected on an LCMS-2010EV quadrupole mass spectrometer fitted with an ESI source system in positive ionization following scan mode (m/z 100-2000). The HSCCC/ESI-MS peaks indicated that enramycin-A (major m/z 786 [M+3H](3+) and minor m/z 1179 [M+2H](2+)) and enramycin-B (major m/z 791 [M+3H](3+) and minor m/z 1185 [M+2H](2+)) have the peak resolution value of 2.9 from 15mg of loaded enramycin powder. The HSCCC collected amounts of the peak fractions were additionally 4.3mg (enramycin-A), and 5.9mg (enramycin-B), respectively. These purified substances were analyzed by LC/ESI-MS with scan positive mode. Based on the LC/ESI-MS chromatograms and spectra of the fractions, enramycin-A and -B were estimated to be over 95% purity. The overall results indicate that this approach of HSCCC/ESI-MS is a powerful technique for the purification and identification of bioactive peptides. PMID:20004073

  12. Automatic determination of phylloquinone in vegetables and fruits using on-line photochemical reduction and fluorescence detection via solid phase extraction and flow injection.

    PubMed

    Pérez-Ruiz, Tomás; Martínez-Lozano, Carmen; Martín, Jesús; García, Maria Dolores

    2006-01-01

    A very simple, rapid and highly sensitive flow injection fluorimetric method was developed for the determination of phylloquinone. The assay was based on the on-line reduction of phylloquinone in dodecylsulfate micelles after irradiation with UV light. The micellar medium enhanced the fluorescence and stability of the reduced phylloquinone. Under optimum experimental conditions, the range of application of the technique was between 0.09 and 45.0 microg mL(-1) and the detection limit was 0.05 microg mL(-1). The sample throughput was 90 injections per hour. The reliability of the method for the routine analysis of phylloquinone in vegetables and fruits is demonstrated. Extractions were made with hexane, and an automated solid phase extraction system was used to purify the sample extracts prior to injection into the flow injection manifold. PMID:16292548

  13. Correction for ‘artificial’ electron disequilibrium due to cone-beam CT density errors: implications for on-line adaptive stereotactic body radiation therapy of lung

    NASA Astrophysics Data System (ADS)

    Disher, Brandon; Hajdok, George; Wang, An; Craig, Jeff; Gaede, Stewart; Battista, Jerry J.

    2013-06-01

    Cone-beam computed tomography (CBCT) has rapidly become a clinically useful imaging modality for image-guided radiation therapy. Unfortunately, CBCT images of the thorax are susceptible to artefacts due to scattered photons, beam hardening, lag in data acquisition, and respiratory motion during a slow scan. These limitations cause dose errors when CBCT image data are used directly in dose computations for on-line, dose adaptive radiation therapy (DART). The purpose of this work is to assess the magnitude of errors in CBCT numbers (HU), and determine the resultant effects on derived tissue density and computed dose accuracy for stereotactic body radiation therapy (SBRT) of lung cancer. Planning CT (PCT) images of three lung patients were acquired using a Philips multi-slice helical CT simulator, while CBCT images were obtained with a Varian On-Board Imaging system. To account for erroneous CBCT data, three practical correction techniques were tested: (1) conversion of CBCT numbers to electron density using phantoms, (2) replacement of individual CBCT pixel values with bulk CT numbers, averaged from PCT images for tissue regions, and (3) limited replacement of CBCT lung pixels values (LCT) likely to produce artificial lateral electron disequilibrium. For each corrected CBCT data set, lung SBRT dose distributions were computed for a 6 MV volume modulated arc therapy (VMAT) technique within the Philips Pinnacle treatment planning system. The reference prescription dose was set such that 95% of the planning target volume (PTV) received at least 54 Gy (i.e. D95). Further, we used the relative depth dose factor as an a priori index to predict the effects of incorrect low tissue density on computed lung dose in regions of severe electron disequilibrium. CT number profiles from co-registered CBCT and PCT patient lung images revealed many reduced lung pixel values in CBCT data, with some pixels corresponding to vacuum (-1000 HU). Similarly, CBCT data in a plastic lung

  14. Correction for 'artificial' electron disequilibrium due to cone-beam CT density errors: implications for on-line adaptive stereotactic body radiation therapy of lung.

    PubMed

    Disher, Brandon; Hajdok, George; Wang, An; Craig, Jeff; Gaede, Stewart; Battista, Jerry J

    2013-06-21

    Cone-beam computed tomography (CBCT) has rapidly become a clinically useful imaging modality for image-guided radiation therapy. Unfortunately, CBCT images of the thorax are susceptible to artefacts due to scattered photons, beam hardening, lag in data acquisition, and respiratory motion during a slow scan. These limitations cause dose errors when CBCT image data are used directly in dose computations for on-line, dose adaptive radiation therapy (DART). The purpose of this work is to assess the magnitude of errors in CBCT numbers (HU), and determine the resultant effects on derived tissue density and computed dose accuracy for stereotactic body radiation therapy (SBRT) of lung cancer. Planning CT (PCT) images of three lung patients were acquired using a Philips multi-slice helical CT simulator, while CBCT images were obtained with a Varian On-Board Imaging system. To account for erroneous CBCT data, three practical correction techniques were tested: (1) conversion of CBCT numbers to electron density using phantoms, (2) replacement of individual CBCT pixel values with bulk CT numbers, averaged from PCT images for tissue regions, and (3) limited replacement of CBCT lung pixels values (LCT) likely to produce artificial lateral electron disequilibrium. For each corrected CBCT data set, lung SBRT dose distributions were computed for a 6 MV volume modulated arc therapy (VMAT) technique within the Philips Pinnacle treatment planning system. The reference prescription dose was set such that 95% of the planning target volume (PTV) received at least 54 Gy (i.e. D95). Further, we used the relative depth dose factor as an a priori index to predict the effects of incorrect low tissue density on computed lung dose in regions of severe electron disequilibrium. CT number profiles from co-registered CBCT and PCT patient lung images revealed many reduced lung pixel values in CBCT data, with some pixels corresponding to vacuum (-1000 HU). Similarly, CBCT data in a plastic lung

  15. 10 CFR 39.33 - Radiation detection instruments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Radiation detection instruments. 39.33 Section 39.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.33 Radiation detection instruments. (a) The licensee shall keep a calibrated and...

  16. 10 CFR 39.33 - Radiation detection instruments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Radiation detection instruments. 39.33 Section 39.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.33 Radiation detection instruments. (a) The licensee shall keep a calibrated and...

  17. Ionizing radiation detection using microstructured optical fiber

    NASA Astrophysics Data System (ADS)

    DeHaven, Stanton

    Ionizing radiation detecting microstructured optical fibers are fabricated, modeled and experimentally measured for X-ray detection in the 10-40 keV energy range. These fibers operate by containing a scintillator material which emits visible light when exposed to ionizing radiation. An X-ray source characterized with a CdTe spectrometer is used to quantify the X-ray detection efficiency of the fibers. The solid state CdTe detector is considered 100% efficient in this energy range. A liquid filled microstructured optical fiber (MOF) is presented where numerical analysis and experimental observation leads to a geometric theory of photon transmission using total internal reflection. The model relates the quantity and energy of absorbed X-rays to transmitted and measured visible light photons. Experimental measurement of MOF photon counts show good quantitative agreement with calculated theoretical values. This work is extended to a solid organic scintillator, anthracene, which shows improved light output due to its material properties. A detailed description of the experimental approach used to fabricate anthracene MOF is presented. The fabrication technique uses a modified Bridgman-Stockbarger crystal growth technique to grow anthracene single crystals inside MOF. The anthracene grown in the MOF is characterized using spectrophotometry, Raman spectroscopy, and X-ray diffraction. These results show the anthracene grown is a high purity crystal with a structure similar to anthracene grown from the liquid, vapor and melt techniques. The X-ray measurement technique uses the same approach as that for liquid filled MOF for efficiency comparison. A specific fiber configuration associated with the crystal growth allows an order of magnitude improvement in X-ray detection efficiency. The effect of thin film external coatings on the measured efficiency is presented and related to the fiber optics. Lastly, inorganic alkali halide scintillator materials of CsI(Tl), CsI(Na), and

  18. Characterisation of phenolic compounds in South African plum fruits (Prunus salicina Lindl.) using HPLC coupled with diode-array, fluorescence, mass spectrometry and on-line antioxidant detection.

    PubMed

    Venter, Alet; Joubert, Elizabeth; de Beer, Dalene

    2013-01-01

    Phenolic compounds are abundant secondary metabolites in plums, with potential health benefits believed to be due to their antioxidant activity, amongst others. Phenolic characterisation of South African Prunus salicina Lindl. plums is necessary to fully evaluate their potential health benefits. An HPLC method using diode-array detection (DAD) for quantification of phenolic compounds was improved and fluorescence detection (FLD) was added for quantification of flavan-3-ols. Validation of the HPLC-DAD-FLD method showed its suitability for quantification of 18 phenolic compounds, including flavan-3-ols using FLD, and phenolic acids, anthocyanins and flavonols using DAD. The method was suitable for characterisation of the phenolic composition of 11 South African plum cultivars and selections, including various types with yellow and red skin and flesh. The method was used in conjunction with mass spectrometry (MS) to identify 24 phenolic compounds. Neochlorogenic acid and cyanidin-3-O-glucoside were the major compounds in most of the plums, while cyanidin-3-O-glucoside was absent in Sun Breeze plums with yellow skin and flesh. Post-column on-line coupling of the ABTS•+ scavenging assay with HPLC-DAD enabled qualitative evaluation of the relative contribution of individual phenolic compounds to the antioxidant activity. The flavan-3-ols, neochlorogenic acid and cyanidin-3-O-glucoside displayed the largest antioxidant response peaks. PMID:23644975

  19. Simultaneous determination of three banned psychiatric drugs in pig feed and tissue using solid-phase reactor on-line oxidizing and HPLC-fluorescence detection.

    PubMed

    Qi, Liang; Duan, Li-Min; Sun, Xiao-Huan; Zhang, Jing; Zhang, Zhi-Qi

    2015-10-01

    The banned addition of psychiatric drugs such as phenothiazines to animal feed and foodstuffs increases the risk of human organ lesion. Phenothiazines usually exhibit weak native fluorescence and can be oxidized to strongly fluorescent compounds. In this study, a novel, sensitive and convenient method of HPLC-fluorescence detection based on post-column on-line oxidizing with lead dioxide solid-phase reactor has been developed for simultaneous determination of three banned psychotropic drugs, promethazine, chlorpromazine and thioridazine. Three compounds were successfully separated on an Agilent TC-C18 column with mobile phase of acetonitrile (A) and water (B), both containing 0.5% (v/v) formic acid. A gradient elution was programmed and fluorimetric detection was performed at λex /λem of 332/373 nm for promethazine, 340/380 nm for chlorpromazine and 352/432 nm for thioridazine. The calibration graphs gave good linearity over the concentration ranges of 30.0-4976.4 µg/L for promethazine, 2.0-2153.2 µg/L for chlorpromazine, and 15.0-3088.0 µg/L for thioridazine, and correlation coefficients (r) were ≥0.995. The method was applied to the determination of phenothiazines in pig feed and pig tissue, and the average spiked recoveries were in the range 69.1-115.4%. PMID:25810380

  20. On-line anion exchange solid-phase extraction coupled to liquid chromatography with fluorescence detection to determine quinolones in water and human urine.

    PubMed

    Lara, Francisco J; Del Olmo-Iruela, Monsalud; García-Campaña, Ana M

    2013-10-01

    An analytical method based on on-line solid-phase extraction coupled to liquid chromatography with fluorescence detection has been developed to determine quinolones in tap water and human urine. A home-made setup was used to percolate 10 mL of sample through a solid-phase extraction column. Analytes were retained onto the sorbent by an anion exchange mechanism which ensures an optimum compatibility with the subsequent chromatographic separation. A C-18 column containing core-shell particles (2.6 μm) was used to achieve peak efficiencies up to 200,000 plates/m, at a flow rate of 1.2 mL/min and without the need for special pumps. The method allowed the determination of 11 quinolones directly in tap water samples in less than 20 min and with limits of detection ranging between 7 and 110 ng/L. The sensitivity achieved made possible the direct determination of 9 quinolones in human urine without any sample treatment, just dilution with water. Relative recoveries between 94 and 109% were obtained meaning that the matrix effect in human urine is negligible after dilution. Satisfactory results were also obtained in terms of precision since relative standard deviations were always below 13%. PMID:23992844

  1. Determination of catechol-O-methyltransferase activity in brain tissue by high-performance liquid chromatography with on-line radiochemical detection

    SciTech Connect

    Nissinen, E.

    1985-01-01

    A sensitive assay for catechol-O-methyltransferase (COMT) activity by high-performance liquid chromatography with on-line radiochemical detection was described. The method was based on the measurement of /sup 3/H- labeled 3-O- and 4-O-methylated products of the substrate, 3,4- dihydroxybenzoic acid, using S-adenosyl-L-(methyl-/sup 3/H)methionine as the methyl donor, or the measurement of /sup 14/C-labeled 3-O- and 4-O-methylated products of the substrate, (7-/sup 14/C)dopamine. The reaction products were determined from the incubation mixture after removal of protein by injecting an aliquot into the liquid chromatograph. The detection limit with counting efficiency of 40% was 0.45 pmol /sup 3/H-labeled product, and 0. 04 pmol /sup 14/C-labeled product with 61% counting efficiency. The method is suitable for assaying membrane-bound and soluble COMT activities in the brain tissue and for calculation of meta/para product ratios.

  2. Ultrasensitive and accelerated detection of ciguatoxin by capillary electrophoresis via on-line sandwich immunoassay with rotating magnetic field and nanoparticles signal enhancement.

    PubMed

    Zhang, Zhaoxiang; Zhang, Chaoying; Luan, Wenxiu; Li, Xiufeng; Liu, Ying; Luo, Xiliang

    2015-08-12

    A sensitive and rapid on-line immunoassay for the determination of ciguatoxin CTX3C was developed based on a capillary mixing system, which was integrated with capillary electrophoresis (CE) separation and electrochemical (EC) detection. In the sandwich immunoassay system, anti-CTX3C-functionalized magnetic nanoparticles were used as immunosensing probes, and horseradish peroxidase (HRP) and anti-CTX3C antibody were bound onto the surface of gold nanoparticles (AuNPs) and used as recognition elements. Online formation of immunocomplex was realized in capillary inlet end with an external rotating magnetic field. Compared with classical HPLC-MS and ELISA, the assay adopting AuNPs as multienzyme carriers and online sandwich immunoassay format with rotating magnetic field exhibited higher sensitivity and shorter assay time. The linear range of the assay for CTX3C was from 0.6 to 150 ng/L with a correlation coefficient of 0.9948 (n = 2), and the detection limit (S/N = 3) was 0.09 ng/L. The developed assay showed satisfying reproducibility and stability, and it was successfully applied for the quantification of CTX3C in fish samples. PMID:26320955

  3. On-line detection of root-induced volatiles in Brassica nigra plants infested with Delia radicum L. root fly larvae.

    PubMed

    Crespo, Elena; Hordijk, Cornelis A; de Graaf, Rob M; Samudrala, Devasena; Cristescu, Simona M; Harren, Frans J M; van Dam, Nicole M

    2012-12-01

    Plants emit various volatile organic compounds (VOCs) upon herbivore attack. These VOC emissions often show temporal dynamics which may influence the behavior of natural enemies using these volatiles as cues. This study analyzes on-line VOC emissions by roots of Brassica nigra plants under attack by cabbage root fly larvae, Delia radicum. Root emitted VOCs were detected using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). These analyses showed that several sulfur containing compounds, such as methanethiol, dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and glucosinolate breakdown products, such as thiocyanates (TC) and isothiocyanates (ITC), were emitted by the roots in response to infestation. The emissions were subdivided into early responses, emerging within 1-6 h after infestation, and late responses, evolving only after 6-12 h. The marker for rapid responses was detected at m/z 60. The ion detected at m/z 60 was identified as thiocyanic acid, which is also a prominent fragment in some TC or ITC spectra. The emission of m/z 60 stopped when the larvae had pupated, which makes it an excellent indicator for actively feeding larvae. Methanethiol, DMS and DMDS levels increased much later in infested roots, indicating that activation of enzymes or genes involved in the production of these compounds may be required. Earlier studies have shown that both early and late responses can play a role in tritrophic interactions associated with Brassica species. Moreover, the identification of these root induced responses will help to design non-invasive analytical procedures to assess root infestations. PMID:22995928

  4. On-line sample processing involving microextraction techniques as a front-end to atomic spectrometric detection for trace metal assays: a review.

    PubMed

    Miró, Manuel; Hansen, Elo Harald

    2013-06-11

    Within the last decade, liquid-phase microextraction (LPME) and micro-solid phase extraction (μSPE) approaches have emerged as substitutes for conventional sample processing procedures for trace metal assays within the framework of green chemistry. This review surveys the progress of the state of the art in simplification and automation of microextraction approaches by harnessing to the various generations of flow injection (FI) as a front end to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS) or inductively coupled plasma atomic emission spectrometry or mass spectrometry (ICP-AES/MS). It highlights the evolution of flow injection analysis and related techniques as vehicles for appropriate sample presentation to the detector and expedient on-line matrix separation and pre-concentration of trace levels of metals in troublesome matrices. Rather than being comprehensive this review is aimed at outlining the pros and cons via representative examples of recent attempts in automating green sample preparation procedures in an FI or sequential injection (SI) mode capitalizing on single-drop microextraction, dispersive liquid-phase microextraction and advanced sorptive materials including carbon and metal oxide nanoparticles, ion imprinted polymers, superparamagnetic nanomaterials and biological/biomass sorbents. Current challenges in the field are identified and the synergetic combination of flow analysis, nanotechnology and metal-tagged biomolecule detection is envisaged. PMID:23708278

  5. Determination of benzoylureas in ground water samples by fully automated on-line pre-concentration and liquid chromatography-fluorescence detection.

    PubMed

    Gil García, M D; Martínez Galera, M; Barranco Martínez, D; Gisbert Gallego, J

    2006-01-27

    An on-line pre-concentration method for the analysis of five benzoylureas (diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron) in ground water samples was evaluated using two C(18) columns, and fluorescence detection after photochemical induced fluorescence (PIF) post-column derivatization. The trace enrichment was carried out with 35 mL of ground water modified with 15 mL of MeOH on a 50 mm x 4.6 mm I.D. first enrichment column (C-1) packed with 5 microm Hypersil Elite C(18). Retention properties of pesticides and humic acids usually contained in ground water were studied on C-1 at concentration levels ranging between 0.04 and 14.00 microg/L in water samples. The results obtained in this study show that the pesticides are pre-concentrated in the first short column while the humic acids contained in the ground water samples are eluted to waste. Pesticides recoveries ranged between 92.3 and 109.5%. The methodology proposed was used to determine benzoylureas in ground water samples at levels lower than 0.1 microg/L (maximum levels established by the European Union). PMID:16337641

  6. On-line coupling of ionic liquid-based single-drop microextraction with capillary electrophoresis for sensitive detection of phenols.

    PubMed

    Wang, Qing; Qiu, Hongdeng; Li, Jing; Liu, Xia; Jiang, Shengxiang

    2010-08-13

    An ionic liquid-based single-drop microextraction (IL-SDME) procedure using IL as an extractant on-line coupled to capillary electrophoresis (CE) is proposed. The method is capable of quantifying trace amounts of phenols in environmental water samples. For the SDME of three phenols, a 2.40 nL IL microdrop was exposed for 10 min to the aqueous sample and then was directly injected into the capillary column for analysis. Extraction parameters such as the extraction time, the IL single-drop volume, pH of the sample solution, ionic strength, volume of the sample solution and the extraction temperature were systematically investigated. Detection limits to three phenols were less than 0.05 microg mL(-1), and their calibration curves were all linear (R(2) > or = 0.9994) in the range from 0.05 to 50 microg mL(-1). And enrichment factors for three phenols were 156, 107 and 257 without agitation, respectively. This method was then utilized to analyze two real environmental samples from Yellow River and tap water, obtaining satisfactory results. Compared with the usual SDME for CE, IL-SDME-CE is a simple, low-cost, fast and environmentally friendly preconcentration technique. PMID:20621300

  7. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes.

    PubMed

    Zhang, Qiang; van der Klift, Elbert J C; Janssen, Hans-Gerd; van Beek, Teris A

    2009-10-23

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high performance liquid chromatography-separated analytes are mixed post-column with a solution of stable free radicals in hexane. Reduced levels of the radical as a result of a reaction with a radical scavenger are detected as negative peaks by an absorbance detector. After investigating a number of different reagents, solvents, concentrations and solution flow rates an optimized instrumental set-up incorporating a superloop for pulse-free delivery of the reagent solution is presented. Both 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-1-ylidene)-p-tolyloxy (galvinoxyl) were used as stable free radicals. The method is suitable for both isocratic and gradient HPLC operation. The method has a simple experimental protocol, uses standard instruments and inexpensive and stable reagents, and accepts any hexane-soluble sample. It can also be used for semi-quantitative analysis. The method was applied to several pure, non-polar natural antioxidants, vegetable oils and lipid-soluble rosemary extract. The limits of detection varied from 0.2 to 176 microg/ml, depending on the compound tested. PMID:19726044

  8. Apparatus and method for detecting gamma radiation

    DOEpatents

    Sigg, Raymond A.

    1994-01-01

    A high efficiency radiation detector for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data.

  9. Apparatus and method for detecting gamma radiation

    DOEpatents

    Sigg, R.A.

    1994-12-13

    A high efficiency radiation detector is disclosed for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data. 4 figures.

  10. Three-dimensional, position-sensitive radiation detection

    DOEpatents

    He, Zhong; Zhang, Feng

    2010-04-06

    Disclosed herein is a method of determining a characteristic of radiation detected by a radiation detector via a multiple-pixel event having a plurality of radiation interactions. The method includes determining a cathode-to-anode signal ratio for a selected interaction of the plurality of radiation interactions based on electron drift time data for the selected interaction, and determining the radiation characteristic for the multiple-pixel event based on both the cathode-to-anode signal ratio and the electron drift time data. In some embodiments, the method further includes determining a correction factor for the radiation characteristic based on an interaction depth of the plurality of radiation interactions, a lateral distance between the selected interaction and a further interaction of the plurality of radiation interactions, and the lateral positioning of the plurality of radiation interactions.

  11. Method for radiation detection and measurement

    DOEpatents

    Miller, Steven D.

    1993-01-01

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength.

  12. Method for radiation detection and measurement

    DOEpatents

    Miller, S.D.

    1993-12-21

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. 9 figures.

  13. APPLICATION OF SAMPLE PRE-OXIDATION OF ARSENITE IN HUMAN URINE PRIOR TO SPECIATON VIA ON-LINE PHOTO-OXIDATION WITH MEMBRANE HYDRIDE GENRATION AND ICP-MS DETECTION

    EPA Science Inventory

    A pre-oxidation procedure which converts arsenite (AS(III)) to arsenate (As(VVV)) was investigated in urinary arsenic speciation prior to on-line photo-oxidation hydride-generation with ICP-MS detection. This sample pre-oxidation method eliminates As(III) and As(V) preservation c...

  14. Stability of arsenic peptides in plant extracts: off-line versus on-line parallel elemental and molecular mass spectrometric detection for liquid chromatographic separation.

    PubMed

    Bluemlein, Katharina; Raab, Andrea; Feldmann, Jörg

    2009-01-01

    The instability of metal and metalloid complexes during analytical processes has always been an issue of an uncertainty regarding their speciation in plant extracts. Two different speciation protocols were compared regarding the analysis of arsenic phytochelatin (As(III)PC) complexes in fresh plant material. As the final step for separation/detection both methods used RP-HPLC simultaneously coupled to ICP-MS and ES-MS. However, one method was the often used off-line approach using two-dimensional separation, i.e. a pre-cleaning step using size-exclusion chromatography with subsequent fraction collection and freeze-drying prior to the analysis using RP-HPLC-ICP-MS and/or ES-MS. This approach revealed that less than 2% of the total arsenic was bound to peptides such as phytochelatins in the root extract of an arsenate exposed Thunbergia alata, whereas the direct on-line method showed that 83% of arsenic was bound to peptides, mainly as As(III)PC(3) and (GS)As(III)PC(2). Key analytical factors were identified which destabilise the As(III)PCs. The low pH of the mobile phase (0.1% formic acid) using RP-HPLC-ICP-MS/ES-MS stabilises the arsenic peptide complexes in the plant extract as well as the free peptide concentration, as shown by the kinetic disintegration study of the model compound As(III)(GS)(3) at pH 2.2 and 3.8. But only short half-lives of only a few hours were determined for the arsenic glutathione complex. Although As(III)PC(3) showed a ten times higher half-life (23 h) in a plant extract, the pre-cleaning step with subsequent fractionation in a mobile phase of pH 5.6 contributes to the destabilisation of the arsenic peptides in the off-line method. Furthermore, it was found that during a freeze-drying process more than 90% of an As(III)PC(3) complex and smaller free peptides such as PC(2) and PC(3) can be lost. Although the two-dimensional off-line method has been used successfully for other metal complexes, it is concluded here that the fractionation and

  15. Radiation and Nuclear Materials Detection Research and Development at ORNL

    SciTech Connect

    Hardy, Jim E; Wright, Michael C

    2009-01-01

    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.

  16. FY05 LDRD Final ReportNanomaterials for Radiation Detection

    SciTech Connect

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

    2006-02-06

    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.

  17. Detection of alpha radiation in a beta radiation field

    DOEpatents

    Mohagheghi, Amir H.; Reese, Robert P.

    2001-01-01

    An apparatus and method for detecting alpha particles in the presence of high activities of beta particles utilizing an alpha spectrometer. The apparatus of the present invention utilizes a magnetic field applied around the sample in an alpha spectrometer to deflect the beta particles from the sample prior to reaching the detector, thus permitting detection of low concentrations of alpha particles. In the method of the invention, the strength of magnetic field required to adequately deflect the beta particles and permit alpha particle detection is given by an algorithm that controls the field strength as a function of sample beta energy and the distance of the sample to the detector.

  18. Detection of nonthermal continuum radiation in Saturn's magnetosphere

    SciTech Connect

    Kuth, W.S.; Scarf, F.L.; Sullivan, J.D.; Gurnett, D.A.

    1982-08-01

    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.

  19. A Correlation of Raman and Single and Multiple Layer Graphene Conductivity As Detected With A Cryogenic Multiprobe AFM With On-line Raman, NSOM and Other SPM Modalities

    NASA Astrophysics Data System (ADS)

    Lewis, Aaron; Zinoviev, Oleg; Komissar, Anatoly; Maayan, Eran; Lewis, David

    2015-03-01

    It is a challenge to study 2D materials, such as Graphene, MoS2, WeSe2, etc. at temperatures down to 10°K when considering the wide variety of physical phenomena that must be applied for a full picture of the functionality of these materials. This involves questions of structure, nanometric photoconductivity, electrical properties, thermal properties, near-field optical in the apertured & scattering modes, Kelvin probe, and Raman. These phenomena are common not only to 2D materials but also to carbon nanotubes and related nanomaterials. This presentation will describe the instrumental development of such a multiprobe cryogenic system that allows for state of the art on-line optical measurements and will also include a review of the probe developments that permit such multifunctional multiprobe operation with on-line full optical access. This system has a completely free optical axis from above and below not obscured by electrical or other probes that have been developed for multiprobe operation. This permits on-line Raman and Tip Enhanced NanoRaman Scattering. With such a system we have investigated graphene and HfO2 using multiprobe electrical, Kelvin probe, NSOM and on-line Raman. The results have yielded new insights into chemical changes correlated to electrical conductivity.

  20. Remote infrared radiation detection using piezoresistive microcantilevers

    SciTech Connect

    Datskos, P.G.; Oden, P.I.; Thundat, T.; Wachter, E.A.; Warmack, R.J.; Hunter, S.R.

    1996-11-01

    A novel micromechanical infrared (IR) radiation sensor has been developed using commercially available piezoresistive microcantilevers. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress between the top layer (coating) and the substrate. The bending causes a change in the piezoresistance and is proportional to the amount of heat absorbed. The microcantilever IR sensor exhibits two distinct thermal responses: a fast one ({lt}ms) and a slower one ({approximately}10 ms). A noise equivalent power (at a modulation frequency of 30 Hz) was estimated to be {approximately}70 nW/Hz{sup 1/2}. This value can be further reduced by designing microcantilevers with better thermal isolation that can allow microcantilevers to be used as uncooled IR radiation detectors. {copyright} {ital 1996 American Institute of Physics.}

  1. Integrating Wireless Networking for Radiation Detection

    NASA Astrophysics Data System (ADS)

    Board, Jeremy; Barzilov, Alexander; Womble, Phillip; Paschal, Jon

    2006-10-01

    As wireless networking becomes more available, new applications are being developed for this technology. Our group has been studying the advantages of wireless networks of radiation detectors. With the prevalence of the IEEE 802.11 standard (``WiFi''), we have developed a wireless detector unit which is comprised of a 5 cm x 5 cm NaI(Tl) detector, amplifier and data acquisition electronics, and a WiFi transceiver. A server may communicate with the detector unit using a TCP/IP network connected to a WiFi access point. Special software on the server will perform radioactive isotope determination and estimate dose-rates. We are developing an enhanced version of the software which utilizes the receiver signal strength index (RSSI) to estimate source strengths and to create maps of radiation intensity.

  2. The use of asymmetrical flow field-flow fractionation with on-line detection in the study of drug retention within liposomal nanocarriers and drug transfer kinetics.

    PubMed

    Hinna, Askell Hvid; Hupfeld, Stefan; Kuntsche, Judith; Brandl, Martin

    2016-05-30

    Due to their solubilizing capabilities, liposomes (phospholipid vesicles) are suited for designing formulations for intravenous administration of drug compounds which are poorly water-soluble. Despite the good in-vitro stability of such formulations with minimal drug leakage, upon i.v. injection there is a risk of premature drug loss due to drug transfer to plasma proteins and cell membranes. Here we report on the refinement of a recently introduced simple in vitro predictive tool by Hinna and colleagues in 2014, which brings small drug loaded (donor) liposomes in contact with large acceptor liposomes, the latter serving as a model mimicking biological sinks in the body. The donor- and acceptor-liposomes were subsequently separated using asymmetrical flow field-flow fractionation (AF4), during which the sample is exposed to a large volume of eluent which corresponds to a dilution factor of approximately 600. The model drug content in the donor- and acceptor fraction was quantified by on-line UV/VIS extinction measurements with correction for turbidity and by off-line HPLC measurements of collected fractions. The refined method allowed for (near) baseline separation of donor and acceptor vesicles as well as reliable quantification of the drug content not only of the donor- but now also of the acceptor-liposomes due to their improved size-homogeneity, colloidal stability and reduced turbidity. This improvement over the previously reported approach allowed for simultaneous quantification of both drug transfer and drug release to the aqueous phase. By sampling at specific incubation times, the release and transfer kinetics of the model compound p-THPP (5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine) was determined. p-THPP is structurally closely related to the photosensitizer temoporfin, which is in clinical use and under evaluation in liposomal formulations. The transfer of p-THPP to the acceptor vesicles followed 1st order kinetics with a half-life of

  3. Bulk semiconducting scintillator device for radiation detection

    DOEpatents

    Stowe, Ashley C.; Burger, Arnold; Groza, Michael

    2016-08-30

    A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI.sub.2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.

  4. Single-electron detection and spectroscopy via relativistic cyclotron radiation

    SciTech Connect

    Asner, David M.; Bradley, Rich; De Viveiros Souza Filho, Luiz A.; Doe, Peter J.; Fernandes, Justin L.; Fertl, M.; Finn, Erin C.; Formaggio, Joseph; Furse, Daniel L.; Jones, Anthony M.; Kofron, Jared N.; LaRoque, Benjamin; Leber, Michelle; MCBride, Lisa; Miller, M. L.; Mohanmurthy, Prajwal T.; Monreal, Ben; Oblath, Noah S.; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Rysewyk, Devyn M.; Sternberg, Michael G.; Tedeschi, Jonathan R.; Thummler, Thomas; VanDevender, Brent A.; Woods, N. L.

    2015-04-01

    It has been understood since 1897 that accelerating charges should emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spectrometer. We observe the cyclotron radiation emitted by individual electrons that are produced with mildly-relativistic energies by a gaseous radioactive source and are magnetically trapped. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work is a proof-of-concept for future neutrino mass experiments using this technique.

  5. Smart Surfaces: New Coatings & Paints with Radiation Detection Functionality

    SciTech Connect

    Farmer, J; Choi, J

    2007-03-12

    Paints are being developed and tested that might ultimately be able to detect radiological agents in the environment by incorporating special pigments into an organic polymeric binder that can be applied as a paint or coatings. These paints detect radioactive sources and contaminants with inorganic or organic scintillation or thermo-luminescent pigments, which are selected based upon the radiation ({alpha}, {beta}, {gamma} or n) to be detected, and are shown in Figure 1.

  6. Review of using gallium nitride for ionizing radiation detection

    NASA Astrophysics Data System (ADS)

    Wang, Jinghui; Mulligan, Padhraic; Brillson, Leonard; Cao, Lei R.

    2015-09-01

    With the largest band gap energy of all commercial semiconductors, GaN has found wide application in the making of optoelectronic devices. It has also been used for photodetection such as solar blind imaging as well as ultraviolet and even X-ray detection. Unsurprisingly, the appreciable advantages of GaN over Si, amorphous silicon (a-Si:H), SiC, amorphous SiC (a-SiC), and GaAs, particularly for its radiation hardness, have drawn prompt attention from the physics, astronomy, and nuclear science and engineering communities alike, where semiconductors have traditionally been used for nuclear particle detection. Several investigations have established the usefulness of GaN for alpha detection, suggesting that when properly doped or coated with neutron sensitive materials, GaN could be turned into a neutron detection device. Work in this area is still early in its development, but GaN-based devices have already been shown to detect alpha particles, ultraviolet light, X-rays, electrons, and neutrons. Furthermore, the nuclear reaction presented by 14N(n,p)14C and various other threshold reactions indicates that GaN is intrinsically sensitive to neutrons. This review summarizes the state-of-the-art development of GaN detectors for detecting directly and indirectly ionizing radiation. Particular emphasis is given to GaN's radiation hardness under high-radiation fields.

  7. Review of using gallium nitride for ionizing radiation detection

    SciTech Connect

    Wang, Jinghui; Mulligan, Padhraic; Cao, Lei R.; Brillson, Leonard

    2015-09-15

    With the largest band gap energy of all commercial semiconductors, GaN has found wide application in the making of optoelectronic devices. It has also been used for photodetection such as solar blind imaging as well as ultraviolet and even X-ray detection. Unsurprisingly, the appreciable advantages of GaN over Si, amorphous silicon (a-Si:H), SiC, amorphous SiC (a-SiC), and GaAs, particularly for its radiation hardness, have drawn prompt attention from the physics, astronomy, and nuclear science and engineering communities alike, where semiconductors have traditionally been used for nuclear particle detection. Several investigations have established the usefulness of GaN for alpha detection, suggesting that when properly doped or coated with neutron sensitive materials, GaN could be turned into a neutron detection device. Work in this area is still early in its development, but GaN-based devices have already been shown to detect alpha particles, ultraviolet light, X-rays, electrons, and neutrons. Furthermore, the nuclear reaction presented by {sup 14}N(n,p){sup 14}C and various other threshold reactions indicates that GaN is intrinsically sensitive to neutrons. This review summarizes the state-of-the-art development of GaN detectors for detecting directly and indirectly ionizing radiation. Particular emphasis is given to GaN's radiation hardness under high-radiation fields.

  8. Multi-sensor radiation detection, imaging, and fusion

    NASA Astrophysics Data System (ADS)

    Vetter, Kai

    2016-01-01

    Glenn Knoll was one of the leaders in the field of radiation detection and measurements and shaped this field through his outstanding scientific and technical contributions, as a teacher, his personality, and his textbook. His Radiation Detection and Measurement book guided me in my studies and is now the textbook in my classes in the Department of Nuclear Engineering at UC Berkeley. In the spirit of Glenn, I will provide an overview of our activities at the Berkeley Applied Nuclear Physics program reflecting some of the breadth of radiation detection technologies and their applications ranging from fundamental studies in physics to biomedical imaging and to nuclear security. I will conclude with a discussion of our Berkeley Radwatch and Resilient Communities activities as a result of the events at the Dai-ichi nuclear power plant in Fukushima, Japan more than 4 years ago.

  9. Single-Electron Detection and Spectroscopy via Relativistic Cyclotron Radiation.

    PubMed

    Asner, D M; Bradley, R F; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thümmler, T; VanDevender, B A; Woods, N L

    2015-04-24

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Although first derived in 1904, cyclotron radiation from a single electron orbiting in a magnetic field has never been observed directly. We demonstrate single-electron detection in a novel radio-frequency spectrometer. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay end point, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments. PMID:25955048

  10. Detecting ionizing radiation with optical fibers down to biomedical doses

    NASA Astrophysics Data System (ADS)

    Avino, S.; D'Avino, V.; Giorgini, A.; Pacelli, R.; Liuzzi, R.; Cella, L.; De Natale, P.; Gagliardi, G.

    2013-10-01

    We report on a passive ionizing radiation sensor based on a fiber-optic resonant cavity interrogated by a high resolution interferometric technique. After irradiation in clinical linear accelerators, we observe significant variations of the fiber thermo-optic coefficient. Exploiting this effect, we demonstrate an ultimate detection limit of 160 mGy with an interaction volume of only 6 × 10-4 mm3. Thanks to its reliability, compactness, and sensitivity at biomedical dose levels, our system lends itself to real applications in radiation therapy procedures as well as in radiation monitoring and protection in medicine, aerospace, and nuclear power plants.

  11. Stand-alone and Network Capable Pocket Radiation Detection System

    SciTech Connect

    R. Aryaeinejad

    2009-03-01

    A multi-functional and networked pocket radiation detection system has been developed at the Idaho National Laboratory (INL) capable of detecting and storing gamma ray and neutron data. The device can be used as a stand-alone device or in conjunction with an array to cover a small or large area. The device has programmable alarm trigger levels that can be modified for specific applications. The data is stored with a date/time stamp and can be transferred and viewed on a PDA via direct connection or, in networked configuration, wireless connection to a remote central facility upon request. Data functional/bench tests have been completed successfully and the device was demonstrated to detect radiation from a 55.6 uCi Cf-252 source at 5 meters and from 1.4 mCi Cf-252 source at 10 meters which exceeds both ANSI and IAEA standards for pocket radiation detection. In terms of sensitivity, this detection system detects neutron and gamma-ray fields down to 10 micro rem/hr levels and therefore can find the location of the radioactive source quickly. The detection system is small enough to be put in a pocket or clipped to a belt.

  12. Simultaneous analysis of aspartame and its hydrolysis products of Coca-Cola Zero by on-line postcolumn derivation fluorescence detection and ultraviolet detection coupled two-dimensional high-performance liquid chromatography.

    PubMed

    Cheng, Cheanyeh; Wu, Shing-Chen

    2011-05-20

    An innovative two-dimensional high-performance liquid chromatography system was developed for the simultaneous analysis of aspartame and its hydrolysis products of Coca-Cola Zero. A C8 reversed-phase chromatographic column with ultraviolet detection was used as the first dimension for the determination of aspartame, and a ligand-exchange chromatographic column with on-line postcolumn derivation fluorescence detection was employed as the second dimension for the analysis of amino acid enantiomers. The fluorimetric derivative reagent of amino acid enantiomers was o-phthaldialdehyde. The hydrolysis of aspartame in Coca-Cola Zero was induced by electric-heating or microwave heating. Aspartame was quantified by the matrix matched external standard calibration curve with a linear concentration range of 0-50 μg mL(-1) (r(2)=0.9984). The limit of detection (LOD) and the limit of quantification (LOQ) were 1.3 μg mL(-1) and 4.3 μg mL(-1), respectively. The amino acid enantiomers was analyzed by the matrix matched internal standard calibration method (D-leucine as the internal standard) with a linear concentration range of 0-10 μg mL(-1) (r(2)=0.9988-0.9997). The LODs and LOQs for L- and D-aspartic acid and L- and D-phenylalanine were 0.16-0.17 μg mL(-1) and 0.52-0.55 μg mL(-1), respectively, that was 12-13 times more sensitive than ultraviolet detection. The overall analysis accuracy for aspartame and amino acid enantiomers was 90.2-99.2% and 90.4-96.2%, respectively. The overall analysis precision for aspartame and amino acid enantiomers was 0.1-1.7% and 0.5-6.7%, respectively. Generally, the extent of aspartame hydrolysis increases with the increase of electro-thermal temperature, microwave power, and the duration of hydrolysis time. D-aspartic acid and D-phenylalanine can be observed with the electro-thermal racemization at the hydrolysis temperature 120°C for 1 day and only D-aspartic acid can be observed at the hydrolysis temperature 90°C for 2 and 3 days. For

  13. Networked gamma radiation detection system for tactical deployment

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Smith, Ethan; Guss, Paul; Mitchell, Stephen

    2015-08-01

    A networked gamma radiation detection system with directional sensitivity and energy spectral data acquisition capability is being developed by the National Security Technologies, LLC, Remote Sensing Laboratory to support the close and intense tactical engagement of law enforcement who carry out counterterrorism missions. In the proposed design, three clusters of 2″ × 4″ × 16″ sodium iodide crystals (4 each) with digiBASE-E (for list mode data collection) would be placed on the passenger side of a minivan. To enhance localization and facilitate rapid identification of isotopes, advanced smart real-time localization and radioisotope identification algorithms like WAVRAD (wavelet-assisted variance reduction for anomaly detection) and NSCRAD (nuisance-rejection spectral comparison ratio anomaly detection) will be incorporated. We will test a collection of algorithms and analysis that centers on the problem of radiation detection with a distributed sensor network. We will study the basic characteristics of a radiation sensor network and focus on the trade-offs between false positive alarm rates, true positive alarm rates, and time to detect multiple radiation sources in a large area. Empirical and simulation analyses of critical system parameters, such as number of sensors, sensor placement, and sensor response functions, will be examined. This networked system will provide an integrated radiation detection architecture and framework with (i) a large nationally recognized search database equivalent that would help generate a common operational picture in a major radiological crisis; (ii) a robust reach back connectivity for search data to be evaluated by home teams; and, finally, (iii) a possibility of integrating search data from multi-agency responders.

  14. Development of a novel gamma probe for detecting radiation direction

    NASA Astrophysics Data System (ADS)

    Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

  15. Characterization of fiber optic Cerenkov radiation sensor for detecting neutrons

    NASA Astrophysics Data System (ADS)

    Jang, K. W.; Yagi, T.; Pyeon, C. H.; Shin, S. H.; Yoo, W. J.; Misawa, T.; Lee, B.

    2013-09-01

    Cerenkov radiation can be observed easily as a shimmer of blue light from the water in boiling- and pressurized-water reactors, or spent fuel storage pools. In this research, we fabricated the fiber-optic Cerenkov radiation sensor using a Gdfoil, rutile crystal and optical fiber for detecting neutrons. Also, the reference sensor for measuring background gammarays was fabricated with the rutile crystal and optical fiber. The neutron fluxes could be obtained by measuring the signal difference between two sensors. To characterize the fiber-optic Cerenkov radiation sensor, we measured neutron fluxes using a Cf-252 neutron source according to depths of polyethylene. As the results, the counts of fiber-optic Cerenkov radiation sensor were higher than those of reference sensor due to additional interactions between Gd-foil and neutrons. Also, the counts of Cerenkov radiation decreased with increasing polyethylene thickness. It is anticipated that the novel and simple fiber-optic Cerenkov radiation sensor using the Cerenkov effect can be widely used to detect the neutrons in hazardous nuclear facilities.

  16. Characterization of mobile radiation detection systems at the Hanford Site

    SciTech Connect

    Antonio, E.J.; Schmidt, J.W.; Gunnink, D.S.; Nelsen, L.A.

    1993-01-01

    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 ft{sup 2}) 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.

  17. Method for detecting radiation dose utilizing thermoluminescent material

    DOEpatents

    Miller, Steven D.; McDonald, Joseph C.; Eichner, Fred N.; Durham, James S.

    1992-01-01

    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.

  18. Apparatuses for large area radiation detection and related method

    DOEpatents

    Akers, Douglas W; Drigert, Mark W

    2015-04-28

    Apparatuses and a related method relating to radiation detection are disclosed. In one embodiment, an apparatus includes a first scintillator and a second scintillator adjacent to the first scintillator, with each of the first scintillator and second scintillator being structured to generate a light pulse responsive to interacting with incident radiation. The first scintillator is further structured to experience full energy deposition of a first low-energy radiation, and permit a second higher-energy radiation to pass therethrough and interact with the second scintillator. The apparatus further includes a plurality of light-to-electrical converters operably coupled to the second scintillator and configured to convert light pulses generated by the first scintillator and the second scintillator into electrical signals. The first scintillator and the second scintillator exhibit at least one mutually different characteristic for an electronic system to determine whether a given light pulse is generated by the first scintillator or the second scintillator.

  19. ANOLE Portable Radiation Detection System Field Test and Evaluation Campaign

    SciTech Connect

    Chris A. Hodge

    2007-07-12

    Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named “Anole,” it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection systems. The campaign also offered manufacturers the opportunity to submit their equipment for independent operationally relevant testing to subsequently improve their detector performance. This paper will present the design, execution, and methodologies of the DHS Anole portable radiation detection system test campaign.

  20. The Detection of Radiated Modes from Ducted Fan Engines

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Nark, Douglas M.; Thomas, Russell H.

    2001-01-01

    The bypass duct of an aircraft engine is a low-pass filter allowing some spinning modes to radiate outside the duct. The knowledge of the radiated modes can help in noise reduction, as well as the diagnosis of noise generation mechanisms inside the duct. We propose a nonintrusive technique using a circular microphone array outside the engine measuring the complex noise spectrum on an arc of a circle. The array is placed at various axial distances from the inlet or the exhaust of the engine. Using a model of noise radiation from the duct, an overdetermined system of linear equations is constructed for the complex amplitudes of the radial modes for a fixed circumferential mode. This system of linear equations is generally singular, indicating that the problem is illposed. Tikhonov regularization is employed to solve this system of equations for the unknown amplitudes of the radiated modes. An application of our mode detection technique using measured acoustic data from a circular microphone array is presented. We show that this technique can reliably detect radiated modes with the possible exception of modes very close to cut-off.

  1. Organic materials and devices for detecting ionizing radiation

    DOEpatents

    Doty, F. Patrick; Chinn, Douglas A.

    2007-03-06

    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.

  2. Passive radiation detection using optically active CMOS sensors

    NASA Astrophysics Data System (ADS)

    Dosiek, Luke; Schalk, Patrick D.

    2013-05-01

    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 β 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.

  3. Ultrafast Radiation Detection by Modulation of an Optical Probe Beam

    SciTech Connect

    Vernon, S P; Lowry, M E

    2006-02-22

    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

  4. Current trends in gamma radiation detection for radiological emergency response

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Guss, Paul; Maurer, Richard

    2011-09-01

    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 inter-disciplinary 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.

  5. Current Trends in Gamma Radiation Detection for Radiological Emergency Response

    SciTech Connect

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

    2011-09-01

    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.

  6. DETERMINATION OF CARBENDAZIM IN WATER BY HIGH-PERFORMANCE IMMUNOAFFINITY CHROMATOGRAPHY ON-LINE WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH DIODE-ARRAY OR MASS SPECTROMETRIC DETECTION

    EPA Science Inventory

    An automated method for the determination of carbendazim in water that combines high-performance immunoaffinity chromatography (HPIAC), high-performance liquid chromatography (HPLC) in the reversed-phase mode, and detection by either UV-Vis diode array detector (DAD) spectroscopy...

  7. Detectivity of gas leakage based on electromagnetic radiation transfer

    NASA Astrophysics Data System (ADS)

    Long, Yunting; Wang, Lingxue; Li, Jiakun; Zhang, Changxing; Zhang, Bei

    2011-05-01

    Standoff detection of gas leakage is a fundamental need in petrochemical and power industries. The passive gas imaging system using thermal imager has been proven to be efficient to visualize leaking gas which is not visible to the naked eye. The detection probability of gas leakage is the basis for designing a gas imaging system. Supposing the performance parameters of the thermal imager are known, the detectivity based on electromagnetic radiation transfer model to image gas leakage is analyzed. This model takes into consideration a physical analysis of the gas plume spread in the atmosphere-the interaction processes between the gas and its surrounding environment, the temperature of the gas and the background, the background surface emissivity, and also gas concentration, etc. Under a certain environmental conditions, through calculating the radiation reaching to the detector from the camera's optical field of view, we obtain an entity "Gas Equivalent Blackbody Temperature Difference (GEBTD)" which is the radiation difference between the on-plume and off-plume regions. Comparing the GEBTD with the Noise Equivalent Temperature Difference (NETD) of the thermal imager, we can know whether the system can image the gas leakage. At last, an example of detecting CO2 gas by JADE MWIR thermal imager with a narrow band-pass filter is presented.

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

    SciTech Connect

    Shaver, Mark W.

    2010-09-27

    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.

  9. Determination of benzoylureas in tomato by high-performance liquid chromatography using continuous on-line post-elution photoirradiation with fluorescence detection.

    PubMed

    Martínez-Galera, M; López-López, T; Gil-García, M D; Martínez-Vidal, J L; Parrilla Vázquez, P

    2001-05-18

    A photochemically induced fluorescence post-column method, with HPLC separation and fluorescence detection, was developed for the determination of five naturally non-fluorescent benzoylurea insecticides: diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron. The applicability of the method to the determination of insecticides in spiked tomato was evaluated. Samples were extracted into ethyl acetate and further cleaned-up by solid-phase extraction using an aminopropyl-bonded silica cartridge. The interferences due to the matrix effect were eliminated using matrix matched standards. Linear dynamic ranges were established over more than two orders of magnitude. The limits of detection ranged from 5 to 21 ng ml(-1) (or 0.5 and 2.1 microg kg(-1) in the vegetable samples), with relative standard deviations lower than 5.0%, using blank tomato extract. Mean recoveries ranged from 79 to 102%. PMID:11403458

  10. On-line and in-situ detection of polycyclic aromatic hydrocarbons (PAH) on aerosols via thermodesorption and laser-induced fluorescence spectroscopy.

    PubMed

    Panne, U; Knöller, A; Kotzick, R; Niessner, R

    2000-02-01

    A fiber optical sensor system for the determination of polycyclic aromatic hydrocarbons (PAH) on aerosols by laser-induced, time-resolved fluorescence is combined with a thermodesorption device. The sensor system is based on an aerosol flow cell, which is fibre-optically coupled to a pulsed nitrogen laser for excitation and the detection system. Time-resolved fluorescence emission spectra are detected by a monochromator equipped with a photomultiplier and a fast digital storage oscilloscope. The analytical figures of merit of the thermodenuder are reported for benzo[a]pyrene, benzo[b]fluoranthene, and benzo[ghi]-perylene on ultrafine soot and NaCl aerosols. By thermodesorption of the PAH, problems due to quenching of the PAH fluorescence by the bulk aerosol material or excimer formation on the aerosol surface were avoided. For the PAH under study, the sensitivity was improved considerably and detection limits between 110 and 850 ng m(-3) were attained, while a response time of 2-3 min was achieved with the thermodenuder. A calibration for PAH on ultrafine soot and NaCl aerosols was established independent of the aerosol substrate. PMID:11220329

  11. Infrared luminescence for real time ionizing radiation detection

    SciTech Connect

    Veronese, Ivan Mattia, Cristina De; Cantone, Marie Claire; Fasoli, Mauro; Chiodini, Norberto; Vedda, Anna; Mones, Eleonora

    2014-08-11

    Radio-luminescence (RL) optical fiber sensors enable a remote, punctual, and real time detection of ionizing radiation. However, the employment of such systems for monitoring extended radiation fields with energies above the Cerenkov threshold is still challenging, since a spurious luminescence, namely, the “stem effect,” is also generated in the passive fiber portion exposed to radiation. Here, we present experimental measurements on Yb-doped silica optical fibers irradiated with photon fields of different energies and sizes. The results demonstrate that the RL of Yb{sup 3+}, displaying a sharp emission line at about 975 nm, is free from any spectral superposition with the spurious luminescence. This aspect, in addition with the suitable linearity, reproducibility, and sensitivity properties of the Yb-doped fibers, paves the way to their use in applications where an efficient stem effect removal is required.

  12. On-line identification of the antifungal constituents of Erythrina vogelii by liquid chromatography with tandem mass spectrometry, ultraviolet absorbance detection and nuclear magnetic resonance spectrometry combined with liquid chromatographic micro-fractionation.

    PubMed

    Queiroz, E F; Wolfender, J L; Atindehou, K K; Traore, D; Hostettmann, K

    2002-10-18

    In our continuing search for new antifungal agents of plant origin, the investigation of Erythrina vogelii Hook. f. (Leguminosae), a plant used in the traditional medicine of Ivory Coast to treat various infectious ailments, was undertaken. In order to rapidly identify the active principles, the crude extract was analysed by low-flow LC-1H nuclear magnetic resonance spectrometry (NMR) which gave a sensitive detection of all the main peaks. LC microfractionation was performed just after LC-NMR detection and all peaks collected were submitted to antifungal bioautography assays against Cladosporium cucumerinum. By this means, the antifungal activity could be efficiently linked to three of the LC peaks. In order to obtain complementary on-line structural information for all peaks of interest, high-resolution LC-MS-MS together with LC-UV with post-column addition of UV shifts reagents was undertaken on the crude extract. This chemical screening strategy with integrated antifungal bioassays has permitted the on-line identification of numerous constituents and has given useful information for an efficient peak-guided isolation procedure. PMID:12458932

  13. Method for detecting radiation dose utilizing thermoluminescent material

    DOEpatents

    Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Durham, J.S.

    1992-08-04

    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. 5 figs.

  14. Method for detecting radiation dose utilizing thermoluminescent material

    DOEpatents

    Miller, Steven D.; McDonald, Joseph C.; Eichner, Fred N.; Tomeraasen, Paul L.

    1991-01-01

    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.

  15. Noninvasive detection of weapons of mass destruction using terahertz radiation

    NASA Astrophysics Data System (ADS)

    Campbell, Matthew B.; Heilweil, Edwin J.

    2003-08-01

    The growing and immediate threat of biological and chemical weapons has placed urgency on the development of chemical and biological warfare agent (CWA/BWA) screening devices. Specifically, the ability to detect CWA/BWA prior to deployment is paramount to mitigating the threat without exposing individuals to its effects. SPARTA, Inc. and NIST are currently investigating the feasibility of using far-infrared radiation, or terahertz (THz, 1 THz = 1012 Hz) radiation, to non-invasively detect biological and chemical agents, explosives and drugs/narcotics inside sealed containers. Small-to-medium sized molecules (3-100 atoms) in gas, liquid and solid phases consistently exhibit identifiable spectral features in the far-IR portion of the spectrum. Many compounds associated with weapons of mass destruction are made up of molecules of this size. The THz portion of the spectrum lies between visible light and radio waves, allowing for partial transmission of 0.3-10.0 THz (30-1000 μm, 10-330 cm-1) light through most common materials. Therefore, transmission measurements of THz light can potentially be used to non-invasively detect the presence of CWA/BWA, explosives and drugs in the pathway of a THz radiation beam.

  16. Monitoring of enzymatic hydrolysis of starch by microdialysis sampling coupled on-line to anion exchange chromatography and integrated pulsed electrochemical detection using post-column switching

    SciTech Connect

    Torto, N.; Gorton, L.; Emneus, J.; Laurell, T.; Marko-Varga, G.; Akerberg, C.; Zacchi, G. |

    1997-12-05

    A quantitative evaluation of the hydrolysis of wheat starch using Termamyl, a thermostable {alpha}-amylase, is reported. Data from the monitoring of the hydrolysis of wheat starch indicated that, after 1 h, glucose and maltooligosaccharides up to DP 7 were the main hydrolysis products and thus enabled optimization of a liquefaction step during the production of L-lactic acid. The monitoring system used, both in the on- and off-line mode, was based on continuous flow microdialysis sampling (CFMS) coupled to anion exchange chromatography and integrated pulsed electrochemical detection (IPED). A microdialysis probe equipped with a 5-mm polysulfone (SPS 4005) membrane, with a molecular-weight cut-off of 5 kDa, was used to sample the hydrolysis products of native wheat starch at 90 C. Characteristic fingerpoint separations were achieved by anion exchange chromatography after enzymatic hydrolysis. Post-column switching improved the detection and, consequently, also quantification of the hydrolysates as fouling of the electrode could be reduced. Maltooligosaccharide standards were used for quantification and to verify the elution of the hydrolysates by spiking the off-line samples.

  17. Energy Transfer Based Nanocomposite Scintillator for Radiation Detection

    NASA Astrophysics Data System (ADS)

    Aslam, Soha; Sahi, Sunil; Chen, Wei; Ma, Lun; Kenarangui, Rasool

    2014-09-01

    Scintillators are the materials that emit light upon irradiation with high energy radiation like X-ray or gamma-ray. Inorganic single crystal and organic (plastic and liquid) are the two most used scintillator types. Both of these scintillator kinds have advantages and disadvantages. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, single crystal scintillator such as NaI and CsI are very hygroscopic. On the other hand, organic scintillators have low density which limits their applications in gamma spectroscopy. Due to high quantum yield and size dependent emission, nanoparticles have attracted interested in various field of research. Here, we have studies the nanoparticles for radiation detection. We have synthesized nanoparticles of Cerium fluoride (CeF3), Zinc Oxide (ZnO), Cadmium Telluride (CdTe), Copper complex and Zinc sulfide (ZnS). We have used Fluorescence Resonance Energy Transfer (FRET) principle to enhance the luminescence properties of nanocomposite scintillator. Nanocomposites scintillators are structurally characterized with X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Optical properties are studied using Photoluminescence, UV-Visible and X-ray. Enhancements in the luminescence are observed under UV and X-ray excitation. Preliminary studies shows nanocomposite scintillators are promising for radiation detection. Scintillators are the materials that emit light upon irradiation with high energy radiation like X-ray or gamma-ray. Inorganic single crystal and organic (plastic and liquid) are the two most used scintillator types. Both of these scintillator kinds have advantages and disadvantages. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, single crystal scintillator such as NaI and CsI are very hygroscopic. On the other hand, organic scintillators have low density which limits their applications in gamma spectroscopy. Due to high quantum

  18. Radiation detection and situation management by distributed sensor networks

    SciTech Connect

    Jan, Frigo; Mielke, Angela; Cai, D Michael

    2009-01-01

    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.

  19. Design of a Mobile Radiation Detection System for Seaports

    SciTech Connect

    Baker, Carl P.

    2006-02-11

    Pacific Northwest National Laboratory (PNNL) has developed a mobile radiation detection system for the U.S. Customs department. Based on the radiation detection instruments currently in use at many border crossings, the mobile radiation portal monitor (mRPM) consists of two Ludlum 4500-3000 detector panels, a package of sensors and a sensor integration module mounted to a medium duty truck chassis. The sensor package detects the presence of scanning targets (containers) and uses this to control operation of the detectors. The mRPM is designed to scan containerized cargo at seaports. A single mRPM can be driven past grounded or chassis-mounted containers (both sides of the container must be scanned for complete coverage), or a pair of mRPM systems can be parked opposite one another to form a relocatable portal. This rapidly reconfigurable system has proven to be very useful for targeted scanning of containers at multiple seaports. Since seaports are frequently space-constrained and contain few chokepoints, mobile systems that can be easily relocated allow customs operators to effectively scan cargo with minimal interference with the flow of commerce. Operators previously trained in the use of the stationary radiation portal monitors require minimal additional training to use the mRPM systems. The medium duty trucks employed are similar to one-ton crew cab pickup trucks, and a commercial driver's license is not required to operate them. In addition to successful deployments at seaports, the mRPM units have proven useful in other applications, such as preliminary characterization of rail cargo and targeted scanning at special events (political conventions).

  20. Assessment of Radiation Background Variation for Moving Detection Systems

    SciTech Connect

    Miller, James Christopher; Rennie, John Alan; Toevs, James Waldo; Wallace, Darrin J.; Abhold, Mark Edward

    2015-07-13

    The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more information for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.

  1. On-line detection of hippuric acid by microextraction with a molecularly-imprinted polysulfone membrane sorbent and liquid chromatography-tandem mass spectrometry.

    PubMed

    Moein, Mohammad Mahdi; El-Beqqali, Aziza; Javanbakht, Mehran; Karimi, Mohammad; Akbari-Adergani, Behrouz; Abdel-Rehim, Mohamed

    2014-10-30

    Destruction of sorbents during consecutive extractions using the micro-extraction by packed sorbent (MEPS) technique is a serious problem. In MEPS the complex matrix such as plasma and blood can affect the sorbent physical properties and the sorbent can be deteriorated after handling of few samples. To overcome this problem, the surface of a polysulfone membrane (PSM) was modified by a molecularly imprinted sol-gel and utilized for online extraction of a lung cancer biomarker, hippuric acid (HA), in biological matrices. The molecularly imprinted polymer membrane provided fast, sensitive, selective and robust sample preparation method for HA in biological fluids. In addition, MIP membrane could be used for up to 50 extractions without a significant change in extraction recovery. To achieve the best results, the parameters that influenced the extraction efficiency were thoroughly investigated. Moreover, for evaluating the performance of the molecularly imprinted sol-gel membrane (MISM), a non-molecularly imprinted sol-gel membrane (NISM) as a blank was prepared. The limits of detection (LOD) and quantification (LOQ) for HA in both plasma and urine samples were 0.30nmolL(-1) and 1.0nmolL(-1), respectively. Standard calibration curves were obtained over the range of 1-1000nmolL(-1) for HA in plasma and urine samples. The coefficients of determination (R(2)) were ≥0.997. The extraction recoveries of HA from human plasma and urine samples were higher than 91%. The precision values for HA in plasma and urine samples were 2.2-4.8% and 1.1-6.7%, respectively. PMID:25468498

  2. A novel mobile system for radiation detection and monitoring

    NASA Astrophysics Data System (ADS)

    Biafore, Mauro

    2014-05-01

    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

  3. Simultaneous detection of antibiotics and other drug residues in the dissolved and particulate phases of water by an off-line SPE combined with on-line SPE-LC-MS/MS: Method development and application.

    PubMed

    Tlili, Ines; Caria, Giovanni; Ouddane, Baghdad; Ghorbel-Abid, Ibtissem; Ternane, Riadh; Trabelsi-Ayadi, Malika; Net, Sopheak

    2016-09-01

    Due to their widespread use in human and animal healthcare, antibiotics and other drug residues are ubiquitous in the aquatic environment. Given their potential impacts on ecosystem functioning and public health, the quantification of environmental drug residues has become a necessity. Various analysis techniques have been found to be suitable for reliable detection of such compounds. However, quantification can be difficult because these compounds are present at trace or ultra-trace levels. Consequently, the accuracy of environmental analyses depends on both the efficiency and the robustness of the extraction and quantification method. In this work, an off-line solid-phase extraction (SPE) combined with on-line SPE-LC-MS/MS was applied to the simultaneous extraction and quantification of 26 pharmaceutical products, including 18 antibiotics, dissolved in a water phase. Optimal conditions were determined and then applied to assess the contamination level of the targeted drug residues in water collected from four sites in Northern France: a river, the input and output of an aerated lagoon, and a wastewater treatment plant. Drug residues associated with suspended solid matter (SSM) were also quantified in this work using pressurized liquid extraction (PLE) combined with an on-line SPE-LC-MS/MS system in order to complete an assessment of the degree of total background pollution. PMID:27151499

  4. Determination of total folate in plant material by chemical conversion into para-aminobenzoic acid followed by high performance liquid chromatography combined with on-line postcolumn derivatization and fluorescence detection.

    PubMed

    Zhang, Guo-Fang; Maudens, Kristof E; Storozhenko, Sergei; Mortier, Kjell A; Van Der Straeten, Dominique; Lambert, Willy E

    2003-12-31

    A procedure involving chemical conversion of all forms of folate present in plant material into para-aminobenzoic acid (PABA) and a liquid chromatographic-fluorimetric determination with on-line postcolumn derivatization is reported. All folates are cleaved with liberation of PABA by hydrogen peroxide followed by acid hydrolysis using concentrated hydrochloric acid (37%) at 110 degrees C for 6 h. The reaction yield for individual folates conversion to PABA ranged from 44.4 to 97.3%. PABA could be determined sensitively by on-line postcolumn derivatization with fluorescamine, the detection limit for PABA being 3.02 nM. On the basis of this principle, a method for the determination of total folate in plant material, including a purification step on an affinity column, is presented, which offers a sufficient sensitivity and selectivity for routine analysis of total folate in natural samples. The total folate contents of tomatoes, carrots, white cabbage, and spinach were determined, and the results were quite comparable to the data reported. The recovery of PABA and the comparison of total folate analysis in spinach on different occasions (over 6 months) are also reported. The method is reliable, universal for all folates, including polyglutamate and monoglutamate forms, and eliminates the need for a deconjugation step and multiple conversion reactions. PMID:14690367

  5. Detection of radiation treatment of beans using DNA comet assay

    NASA Astrophysics Data System (ADS)

    Khan, Ashfaq A.; Khan, Hasan M.; Delincée, Henry

    2002-03-01

    A simple technique of microgel electrophoresis of single cells (DNA Comet Assay) enabled a quick detection of radiation treatment of several kinds of leguminous beans (azuki, black, black eye, mung, pinto, red kidney and white beans). Each variety was exposed to radiation doses of 0.5, 1 and 5kGy covering the permissible limits for insect disinfestation. The cells or nuclei from beans were extracted in cold PBS, embedded in agarose on microscope slides, lysed between 15 and 60min in 2.5% SDS and electrophoresis was carried out at a voltage of 2V/cm for 2-2.5min. After silver staining, the slides were evaluated through an ordinary transmission microscope. In irradiated samples, fragmented DNA stretched towards the anode and the damaged cells appeared as a comet. The density of DNA in the tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short tails only. Hence, the DNA comet assay provides an inexpensive, rapid and relatively simple screening method for the detection of irradiated beans.

  6. Detection, classification, and extraction of helicopter-radiated noise

    NASA Astrophysics Data System (ADS)

    Dwyer, R. F.

    1984-07-01

    Surface ships operating in conjunction with supporting helicopters may experience sonar performance degradation due to the accompanying interference from helicopter-radiated noise. The interference manifests itself in the time domain as impulses due to blade vortex interactions and in the frequency domain as harmonic components from both the main and tail rotors. But these components are not pure sinusoids. In addition, they have non-Gaussian probability distributions. They appear to be caused by frequency modulation due to the rotating blades. The paper discusses detection and classification of helicopter-radiated noise from cumulative distribution function estimates, autocorrelation estimate, spectrum estimates, and from higher-order moment estimates. After the detection and classification problem is discussed a method to extract the interference by implementing a non-linearity in the frequency domain is presented. It is shown with real helicopter-radiated noise data that autocorrelation estimates can be improved by extracting the interfering components. The extracted components are also available as an enhanced time domain representation.

  7. Cellular telephone-based radiation sensor and wide-area detection network

    DOEpatents

    Craig, William W.; Labov, Simon E.

    2006-12-12

    A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

  8. On the detection of other planetary systems - Detection of intrinsic thermal radiation

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1980-01-01

    There is currently no unambiguous observational evidence for the existence of other planetary systems. One possible way to detect and study such systems is infrared observations of continuum blackbody radiation from planets revolving around other stars. It is shown that the effective temperature of large planets revolving around mid- to late-spectral-type main-sequences stars is set by energy sources internal to the planet rather than by equilibrium with the radiation field of the central star, making them easier to detect than had been previously thought. Consideration is given to the two major observational constraints on detecting planetary companions to nearby stars, namely, angular resolution and sensitivity. A comparison is made between the performance of an ambient (T 200 K), single-aperture telescope and a cooled interferometer. In each case the required aperture (baseline) is large (in the 10-m class), but consistent with Shuttle launch capability.

  9. Radiation sensitive devices and systems for detection of radioactive materials and related methods

    DOEpatents

    Kotter, Dale K

    2014-12-02

    Radiation sensitive devices include a substrate comprising a radiation sensitive material and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to resonate responsive to non-ionizing incident radiation. Systems for detecting radiation from a special nuclear material include a radiation sensitive device and a sensor located remotely from the radiation sensitive device and configured to measure an output signal from the radiation sensitive device. In such systems, the radiation sensitive device includes a radiation sensitive material and a plurality of resonance elements positioned on the radiation sensitive material. Methods for detecting a presence of a special nuclear material include positioning a radiation sensitive device in a location where special nuclear materials are to be detected and remotely interrogating the radiation sensitive device with a sensor.

  10. Aging masks detection of radiation-induced brain injury

    PubMed Central

    Shi, Lei; Olson, John; D’Agostino, Ralph; Linville, Constance; Nicolle, Michelle M.; Robbins, Michael E.; Wheeler, Kenneth T.; Brunso-Bechtold, Judy K.

    2011-01-01

    Fractionated partial or whole-brain irradiation (fWBI) is a widely used, effective treatment for primary and metastatic brain tumors, but it also produces radiation-induced brain injury, including cognitive impairment. Radiation-induced neural changes are particularly problematic for elderly brain tumor survivors who also experience age-dependent cognitive impairment. Accordingly, we investigated, i] radiation-induced cognitive impairment, and ii] potential biomarkers of radiation-induced brain injury in a rat model of aging. Fischer 344 × Brown Norway rats received fractionated whole-brain irradiation (fWBI rats, 40 Gy, 8 fractions over 4 wk) or sham-irradiation (Sham-IR rats) at 12 months of age; all analyses were performed at 26–30 months of age. Spatial learning and memory were measured using the Morris water maze (MWM), hippocampal metabolites were measured using proton magnetic resonance spectroscopy (1H MRS), and hippocampal glutamate receptor subunits were evaluated using Western blots. Young rats (7–10 month-old) were included to control for age effects. The results revealed that both Sham-IR and fWBI rats exhibited age-dependent impairments in MWM performance; fWBI induced additional impairments in the reversal MWM. 1H MRS revealed age-dependent decreases in neuronal markers, increases in glial markers, but no detectable fWBI-dependent changes. Western blot analysis revealed age-dependent, but not fWBI-dependent, glutamate subunit declines. Although previous studies demonstrated fWBI-induced changes in cognition, glutamate subunits, and brain metabolites in younger rats, age-dependent changes in these parameters appear to mask their detection in old rats, a phenomenon also likely to occur in elderly fWBI patients >70 years of age. PMID:21338580

  11. Validation of a confirmatory analytical method for the determination of aflatoxins B₁, B₂, G₁ and G₂ in foods and feed materials by HPLC with on-line photochemical derivatization and fluorescence detection.

    PubMed

    Muscarella, Marilena; Iammarino, Marco; Nardiello, Donatella; Magro, Sonia Lo; Palermo, Carmen; Centonze, Diego; Palermo, Domenico

    2009-10-01

    A sensitive and selective analytical method for the simultaneous separation and quantitative determination of aflatoxins B1, B2, G1 and G2 in foodstuffs and materials for feed has been validated. The method is based on high performance liquid chromatography with on-line post-column photochemical derivatization and fluorescence detection. The chromatographic separation of aflatoxins was accomplished using a C18 column eluted with an isocratic mobile phase consisting of water, methanol and acetonitrile. The sample preparation required a simple extraction of aflatoxins with MeOH/H2O (80:20, v/v) and a purification step by immunoaffinity column cleanup. The total analysis time, including sample preparation and chromatographic separation, did not exceed 40 min with a run time of 10 min. The on-line photochemical derivatization ensures better results in terms of simplicity, sensitivity and reproducibility with respect to chemical derivatization techniques, and provides an increase of the peak resolution and an extent of automation in comparison with the electrochemical ones. The procedure for the determination of aflatoxins in food samples and cereals for animal consumption was extensively validated following Regulation (EC) No. 882/2004. Detection limits in wheat bran samples of 0.08 μg kg1 for AFB1, 0.02 μg kg1 for AFB2, 0.16 μg kg1 for AFG1 and 0.04 μg kg1 for AFG2 were attained. The method allows high recovery with mean values ranging from 72 to 94% and it satisfies the necessary requirements for sensitivity, linearity, selectivity, precision and ruggedness, demonstrating the conformity of the method with provisions of Regulation (EC) No. 401/2006. PMID:21462585

  12. High-throughput determination of faropenem in human plasma and urine by on-line solid-phase extraction coupled to high-performance liquid chromatography with UV detection and its application to the pharmacokinetic study.

    PubMed

    Xie, Rui; Wen, Jun; Wei, Hua; Fan, Guorong; Zhang, Dabing

    2010-05-01

    An automated system using on-line solid-phase extraction and HPLC with UV detection was developed for the determination of faropenem in human plasma and urine. Analytical process was performed isocratically with two reversed-phase columns connected by a switching valve. After simple pretreatment for plasma and urine with acetonitrile, a volume of 100microl upper layer of the plasma or urine samples was injected for on-line SPE column switching HPLC-UV analysis. The analytes were retained on the self-made trap column (Lichrospher C(18), 4.6mmx37mm, 25microm) with the loading solvent (20mM NaH(2)PO(4) adjusted pH 3.5) at flow rate of 2mlmin(-1), and most matrix materials were removed from the column to waste. After 0.5min washing, the valve was switched to another position so that the target analytes could be eluted from trap column to analytical column in the back-flush mode by the mobile phase (acetonitrile-20mM NaH(2)PO(4) adjusted pH 3.5, 16:84, v/v) at flow rate of 1.5mlmin(-1), and then separated on the analytical column (Ultimate XB-C(18), 4.6mmx50mm, 5microm).The complete cycle of the on-line SPE preconcentration purification and HPLC separation of the analytes was 5min. Calibration curves with good linearities (r=0.9994 for plasma sample and r=0.9988 for urine sample) were obtained in the range 0.02-5microgml(-1) in plasma and 0.05-10microg ml(-1) in urine for faropenem. The optimized method showed good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy. The method was successfully utilized to quantify faropenem in human plasma and urine to support the clinical pharmacokinetic studies. PMID:20036477

  13. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    DOEpatents

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  14. Photocurrent-based detection of terahertz radiation in graphene

    SciTech Connect

    Tomadin, Andrea Tredicucci, Alessandro; Vitiello, Miriam S.; Polini, Marco; Pellegrini, Vittorio

    2013-11-18

    Graphene is a promising candidate for the development of detectors of Terahertz (THz) radiation. A well-known detection scheme due to Dyakonov and Shur exploits plasma waves in a field-effect transistor (FET), whereby a dc photovoltage is generated in response to a THz field. In the quest for devices with a better signal-to-noise ratio, we theoretically investigate a plasma-wave photodetector in which a dc photocurrent is generated in a graphene FET. The noise equivalent power of our device is shown to be much smaller than that of a Dyakonov-Shur detector in a wide spectral range.

  15. RADIATION PRESSURE DETECTION AND DENSITY ESTIMATE FOR 2011 MD

    SciTech Connect

    Micheli, Marco; Tholen, David J.; Elliott, Garrett T. E-mail: tholen@ifa.hawaii.edu

    2014-06-10

    We present our astrometric observations of the small near-Earth object 2011 MD (H ∼ 28.0), obtained after its very close fly-by to Earth in 2011 June. Our set of observations extends the observational arc to 73 days, and, together with the published astrometry obtained around the Earth fly-by, allows a direct detection of the effect of radiation pressure on the object, with a confidence of 5σ. The detection can be used to put constraints on the density of the object, pointing to either an unexpectedly low value of ρ=(640±330)kg m{sup −3} (68% confidence interval) if we assume a typical probability distribution for the unknown albedo, or to an unusually high reflectivity of its surface. This result may have important implications both in terms of impact hazard from small objects and in light of a possible retrieval of this target.

  16. Generation and Detection of THz Radiation Using Intrinsic Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Irie, Akinobu; Oikawa, Dai; Oya, Gin-ichiro

    We present the generation and detection of terahertz radiation using intrinsic Josephson junctions (IJJs) in Bi2Sr2CaCu2Oy single crystals. This approach allows us to detect THz radiation from large stacks consisting of a few hundred intrinsic Josephson junctions. The lateral dimensions of the fabricated IJJ oscillator mesa range from 290×50 to 290×90 μm2 and the number of IJJs which constitute the mesas is between 100 and 450, while the small mesa with the lateral dimensions of 5 × 5 μm2 is used as the high sensitive THz detector. The largest emission is always observed when the oscillator is biased at the negative resistance region of the current-voltage characteristics. We find that the emission frequency cor-responds to the second harmonics of the in-phase cavity resonance mode. This is consistent with the emission condition of the case of thick IJJ stacks reported previously.

  17. On-line iron-ore slurry monitoring for real-time process control of pellet making processes using laser-induced breakdown spectroscopy: graphitic vs. total carbon detection

    NASA Astrophysics Data System (ADS)

    Barrette, Louis; Turmel, Simon

    2001-06-01

    Chemical composition of iron-ore pellets has a significant impact on their quality and commercial value. Laser-induced breakdown spectroscopy (LIBS) technique has been extensively tested on line, at industrial pelletizing plants. It proved successful at measuring Si, Ca, Mg, Al and graphitic C contents of different iron-ore slurries prior to filtration and pelletizing. For this specific application, the sensitivity of the technique compares with the one obtained from dedicated chemical laboratories. But the real advantage of LIBS technique is that the results are delivered continuously and in real time compared to periodic sampling and standard analytical delays of more than 1 h. Consequently, LIBS gives a more representative reading of the state of the process — particularly when rapid perturbations occur — and allows process optimization and quality improvement. In this work, special attention was given to the fact that the detection system, with specific settings, gives direct measurement for either graphitic carbon (coke breeze) or total carbon (coke breeze, flux and natural carbonate). Graphitic carbon content is a key parameter for both the pellet production cost and its final commercial value. LIBS is a sensitive technique that can detect small variations. But matrix effects affect the spectral lines and it is sometimes difficult to establish universal calibration curve. This problem is partially overcome by the use of a multivariable calibration that corrects for matrix effects and evaluates a confidence level based on expertise for each measurement. Current research is aimed at the development of commercial equipment for continuous industrial use.

  18. Establishment of the Radiation Detection Laboratory at Fisk University

    SciTech Connect

    Arnold Burger, Ph.D.

    2008-02-28

    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}

  19. In-Situ Radiation Detection Demonstration Final Report

    SciTech Connect

    MOHAGHEGHI,AMIR H.; REESE,ROBERT; MILLER,DAVID R.; MILLER,MARK LAVERNE; DUCE,STEPHEN

    2000-06-01

    The Department of Defense (DoD) has hundreds of facilities where radioactive materials have been used or are being used, including firing ranges, low-level radioactive waste disposal areas, and areas where past activities have resulted in environmental contamination. Affected sites range in size from a few acres to square miles. Impact to the DoD comes through military base closure and release to the public. It is important that radioactive contaminants are remediated to levels that result in acceptable risk to the public. Remediation requires characterization studies, e.g., sampling and surveys, to define the affected areas, removal actions, and final confirmatory sampling and surveys. Characterization of surface contamination concentrations has historically been performed using extensive soil sampling programs in conjunction with surface radiation surveys conducted with hand-held radiation monitoring equipment. Sampling is required within the suspect affected area and a large buffer area. Surface soil contaminant characterization using soil sampling and hand held monitoring are costly, time consuming, and result in long delays between submission of samples for analysis and obtaining of final results. This project took an existing, proven radiation survey technology that has had limited exposure and improved its capabilities by documenting correlation factors for various detector/radionuclide geometries that commonly occur in field surveys. With this tool, one can perform characterization and final release surveys much more quickly than is currently possible, and have detection limits that are as good as or better than current technology. This paper will discuss the capabilities of a large area plastic scintillation detector used in conjunction with a global positioning system (GPS) to improve site characterization, remediation, and final clearance surveys of the radioactively contaminated site. Survey results can rapidly identify areas that require remediation as

  20. Improved Detection of Cherenkov Radiation using Wavelength-Shifting Paints

    NASA Astrophysics Data System (ADS)

    Schmookler, Barak; Ou, Longwu

    2014-03-01

    Photomultiplier Tubes (PMTs) are often used to detect Cherenkov radiation in accelerator-based physics experiments. Since the Cherenkov spectrum is inversely proportional to the square of the photon's wavelength, PMTs with relatively good quantum efficiencies in the ultraviolet region can produce on average a higher number of photoelectrons. The application of certain paints, which absorb light at ultraviolet wavelengths and emit in the visible spectrum, to the surface of some PMTs allows for better sampling of the Cherenkov spectrum. The effects of various wavelength-shifting (WLS) paints designed by Eljen Technologies were tested on ET Enterprises, Model: 9390KB PMTs. Using a 106Ru β-source, Cherenkov light was produced in disks of fused silica. The charge spectrums of the PMTs were measured before and after application of the paint. The average number of photoelectrons produced from the Cherenkov radiation could be determined by knowing the value of the single-photoelectron peak and the mean of the charge spectrum. Four paints were tested, and the gain in the number photoelectrons produced varied from 10-35% for the different paints. Work Conducted at Thomas Jefferson National Accelerator Facility.

  1. Biological detection of low radiation doses with integrated photothermal assay

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

    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 γ-radiation and optimal therapeutic doses for cancer treatment. With this assay, the influences of γ 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 γ 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.

  2. Fiber-optic radiation sensor for detection of tritium

    NASA Astrophysics Data System (ADS)

    Jang, K. W.; Cho, D. H.; Yoo, W. J.; Seo, J. K.; Heo, J. Y.; Park, J.-Y.; Lee, B.

    2011-10-01

    The objective of this study is to develop the radiation sensor, which is composed of a scintillator, an optical fiber bundle and a light measuring device to detect the tritium in real-time. In this study, we have fabricated fiber-optic radiation sensors using inorganic scintillators and plastic optical fiber bundles. Each scintillator interacts with electron or beta ray and generates 455-550 nm wavelength of scintillation photons. An optical fiber bundle is usually made of plastic or glass, which is used to guide the light signal from a scintillating probe to light measuring device. For the purpose of selecting the best scintillator with a high efficiency, fiber-optic sensors manufactured using three kinds of inorganic scintillator such as Gd 2O 2S:Tb, Y 3Al 5O 12:Ce and CsI:Tl, and they are tested with a metal hydride type of tritium source. In addition, the scintillation photons are measured as a function of distance between a fiber-optic sensor and source. Finally, we have measured the amounts of scintillation photon with different activities of tritium source and compared the measured results with those obtained using a surface activity monitor.

  3. Study of silicon pixel sensor for synchrotron radiation detection

    NASA Astrophysics Data System (ADS)

    Li, Zhen-Jie; Jia, Yun-Cong; Hu, Ling-Fei; Liu, Peng; Yin, Hua-Xiang

    2016-03-01

    The silicon pixel sensor (SPS) is one of the key components of hybrid pixel single-photon-counting detectors for synchrotron radiation X-ray detection (SRD). In this paper, the design, fabrication, and characterization of SPSs for single beam X-ray photon detection is reported. The designed pixel sensor is a p+-in-n structure with guard-ring structures operated in full-depletion mode and is fabricated on 4-inch, N type, 320 μm thick, high-resistivity silicon wafers by a general Si planar process. To achieve high energy resolution of X-rays and obtain low dark current and high breakdown voltage as well as appropriate depletion voltage of the SPS, a series of technical optimizations of device structure and fabrication process are explored. With optimized device structure and fabrication process, excellent SPS characteristics with dark current of 2 nA/cm2, full depletion voltage < 50 V and breakdown voltage >150 V are achieved. The fabricated SPSs are wire bonded to ASIC circuits and tested for the performance of X-ray response to the 1W2B synchrotron beam line of the Beijing Synchrotron Radiation Facility. The measured S-curves for SRD demonstrate a high discrimination for different energy X-rays. The extracted energy resolution is high (<20% for X-ray photon energy >10 keV) and the linear properties between input photo energy and the equivalent generator amplitude are well established. It confirmed that the fabricated SPSs have a good energy linearity and high count rate with the optimized technologies. The technology is expected to have a promising application in the development of a large scale SRD system for the Beijing Advanced Photon Source. Supported by Prefabrication Research of Beijing Advanced Photon Source (R&D for BAPS) and National Natural Science Foundation of China (11335010)

  4. Radiation resistance of biological reagents for in situ life detection.

    PubMed

    Carr, Christopher E; Rowedder, Holli; Vafadari, Cyrus; Lui, Clarissa S; Cascio, Ethan; Zuber, Maria T; Ruvkun, Gary

    2013-01-01

    Life on Mars, if it exists, may share a common ancestry with life on Earth derived from meteoritic transfer of microbes between the planets. One means to test this hypothesis is to isolate, detect, and sequence nucleic acids in situ on Mars, then search for similarities to known common features of life on Earth. Such an instrument would require biological and chemical components, such as polymerase and fluorescent dye molecules. We show that reagents necessary for detection and sequencing of DNA survive several analogues of the radiation expected during a 2-year mission to Mars, including proton (H-1), heavy ion (Fe-56, O-18), and neutron bombardment. Some reagents have reduced performance or fail at higher doses. Overall, our findings suggest it is feasible to utilize space instruments with biological components, particularly for mission durations of up to several years in environments without large accumulations of charged particles, such as the surface of Mars, and have implications for the meteoritic transfer of microbes between planets. PMID:23330963

  5. On-Line Communications Devices.

    ERIC Educational Resources Information Center

    Sternick, Barbara R.

    These summaries have been compiled to assist users in selecting terminals for use with the National Library of Medicine (NLM) on-line systems. The summaries describe the salient characteristics and approximate prices of a large number of hard copy and display devices. Many of the terminals listed may be modified by the addition of various options…

  6. Simultaneous multi-mycotoxin determination in nutmeg by ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection.

    PubMed

    Kong, Wei-Jun; Liu, Shu-Yu; Qiu, Feng; Xiao, Xiao-He; Yang, Mei-Hua

    2013-05-01

    A simple and sensitive analytical method based on ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with high performance liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection (USLE-IAC-HPLC-PCD-FLD) has been developed for simultaneous multi-mycotoxin determination of aflatoxins B1, B2, G1, G2 (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) in 13 edible and medicinal nutmeg samples marketed in China. AFs and OTA were extracted from nutmeg samples by ultrasonication using a methanol : water (80 : 20, v/v) solution, followed by an IAC clean-up step. Different USL extraction conditions, pre-processing ways for nutmeg sample and clean-up columns for mycotoxins, as well as HPLC-PCD-FLD parameters (mobile phase, column temperature, elution procedure, excitation and emission wavelengths) were optimized. This method, which was appraised for analyzing nutmeg samples, showed satisfactory results with reference to limits of detection (LODs) (from 0.02 to 0.25 μg kg(-1)), limits of quantification (LOQs) (from 0.06 to 0.8 μg kg(-1)), linear ranges (up to 30 ng mL(-1) for AFB1, AFG1 and OTA and 9 ng mL(-1) for AFB2 and AFG2), intra- and inter-day variability (all <2%) and average recoveries (from 79.6 to 90.8% for AFs and from 93.6 to 97.3% for OTA, respectively). The results of the application of developed method in nutmeg samples have elucidated that four samples were detected with contamination of AFs and one with OTA. AFB1 was the most frequently found mycotoxin in 30.8% of nutmeg samples at contamination levels of 0.73-16.31 μg kg(-1). At least two different mycotoxins were co-occurred in three samples, and three AFs were simultaneously detected in one sample. PMID:23486692

  7. Delay-Line Three-Dimensional Position Sensitive Radiation Detection

    NASA Astrophysics Data System (ADS)

    Jeong, Manhee

    High-resistivity silicon(Si) in large volumes and with good charge carrier transport properties has been produced and achieved success as a radiation detector material over the past few years due to its relatively low cost as well as the availability of well-established processing technologies. One application of that technology is in the fabrication of various position-sensing topologies from which the incident radiation's direction can be determined. We have succeeded in developing the modeling tools for investigating different position-sensing schemes and used those tools to examine both amplitude-based and time-based methods, an assessment that indicates that fine position-sensing can be achieved with simpler readout designs than are conventionally deployed. This realization can make ubiquitous and inexpensive deployment of special nuclear materials (SNM) detecting technology becomes more feasible because if one can deploy position-sensitive semiconductor detectors with only one or two contacts per side. For this purpose, we have described the delay-line radiation detector and its optimized fabrication. The semiconductor physics were simulated, the results from which guided the fabrication of the guard ring structure and the detector electrode, both of which included metal-field-plates. The measured improvement in the leakage current was confirmed with the fabricated devices, and the structures successfully suppressed soft-breakdown. We also demonstrated that fabricating an asymmetric strip-line structure successfully minimizing the pulse shaping and increases the distance through which one can propagate the information of the deposited charge distribution. With fabricated delay-line detectors we can acquire alpha spectra (Am-241) and gamma spectra (Ba-133, Co-57 and Cd-109). The delay-line detectors can therefore be used to extract the charge information from both ion and gamma-ray interactions. Furthermore, standard charge-sensitive circuits yield high SNR

  8. Nuisance Source Population Modeling for Radiation Detection System Analysis

    SciTech Connect

    Sokkappa, P; Lange, D; Nelson, K; Wheeler, R

    2009-10-05

    A major challenge facing the prospective deployment of radiation detection systems for homeland security applications is the discrimination of radiological or nuclear 'threat sources' from radioactive, but benign, 'nuisance sources'. Common examples of such nuisance sources include naturally occurring radioactive material (NORM), medical patients who have received radioactive drugs for either diagnostics or treatment, and industrial sources. A sensitive detector that cannot distinguish between 'threat' and 'benign' classes will generate false positives which, if sufficiently frequent, will preclude it from being operationally deployed. In this report, we describe a first-principles physics-based modeling approach that is used to approximate the physical properties and corresponding gamma ray spectral signatures of real nuisance sources. Specific models are proposed for the three nuisance source classes - NORM, medical and industrial. The models can be validated against measured data - that is, energy spectra generated with the model can be compared to actual nuisance source data. We show by example how this is done for NORM and medical sources, using data sets obtained from spectroscopic detector deployments for cargo container screening and urban area traffic screening, respectively. In addition to capturing the range of radioactive signatures of individual nuisance sources, a nuisance source population model must generate sources with a frequency of occurrence consistent with that found in actual movement of goods and people. Measured radiation detection data can indicate these frequencies, but, at present, such data are available only for a very limited set of locations and time periods. In this report, we make more general estimates of frequencies for NORM and medical sources using a range of data sources such as shipping manifests and medical treatment statistics. We also identify potential data sources for industrial source frequencies, but leave the task of

  9. On-line diagnosis of unrestricted faults

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.; Sundstrom, R. J.

    1974-01-01

    A formal model for the study of on-line diagnosis is introduced and used to investigate the diagnosis of unrestricted faults. A fault of a system S is considered to be a transformation of S into another system S' at some time tau. The resulting faulty system is taken to be the system which looks like S up to time tau, and like S' thereafter. Notions of fault tolerance error are defined in terms of the resulting system being able to mimic some desired behavior as specified by a system similar to S. A notion of on-line diagnosis is formulated which involves an external detector and a maximum time delay within which every error caused by a fault in a prescribed set must be detected. It is shown that if a system is on-line diagnosable for the unrestricted set of faults then the detector is at least as complex, in terms of state set size, as the specification. The use of inverse systems for the diagnosis of unrestricted faults is considered. A partial characterization of those inverses which can be used for unrestricted fault diagnosis is obtained.

  10. Lanthanum halide nanoparticle scintillators for nuclear radiation detection

    SciTech Connect

    Guss, Paul; Guise, Ronald; Yuan, Ding; Mukhopadhyay, Sanjoy; O'Brien, Robert; Lowe, Daniel; Kang, Zhitao; Menkara, Hisham; Nagarkar, Vivek V.

    2013-01-01

    Nanoparticles with sizes <10 nm were fabricated and characterized for their nanocomposite radiation detector properties. This work investigated the properties of several nanostructured radiation scintillators, in order to determine the viability of using scintillators employing nanostructured lanthanum tribromide, lanthanum trifluoride, or cerium tribromide. Preliminary results of this investigation are consistent with the idea that these materials have an intrinsic response to nuclear radiation that may be correlated to the energy of the incident radiation.

  11. Lanthanum halide nanoparticle scintillators for nuclear radiation detection

    SciTech Connect

    Guss, Paul; Guise, Ronald; O'Brien, Robert; Lowe, Daniel; Kang Zhitao; Menkara, Hisham; Nagarkar, Vivek V.

    2013-02-14

    Nanoparticles with sizes <10 nm were fabricated and characterized for their nanocomposite radiation detector properties. This work investigated the properties of several nanostructured radiation scintillators, in order to determine the viability of using scintillators employing nanostructured lanthanum trifluoride. Preliminary results of this investigation are consistent with the idea that these materials have an intrinsic response to nuclear radiation that may be correlated to the energy of the incident radiation.

  12. The All Terrain Bio nano Gear for Space Radiation Detection System

    SciTech Connect

    Ummat, Ajay; Mavroidis, Constantinos

    2007-01-30

    This paper discusses about the relevance of detecting space radiations which are very harmful and pose numerous health issues for astronauts. There are many ways to detect radiations, but we present a non-invasive way of detecting them in real-time while an astronaut is in the mission. All Terrain Bio-nano (ATB) gear system is one such concept where we propose to detect various levels of space radiations depending on their intensity and warn the astronaut of probable biological damage. A basic framework for radiation detection system which utilizes bio-nano machines is discussed. This radiation detection system is termed as 'radiation-responsive molecular assembly' (RMA) for the detection of space radiations. Our objective is to create a device which could detect space radiations by creating an environment equivalent to human cells within its structure and bio-chemically sensing the effects induced therein. For creating such an environment and further bio-chemically sensing space radiations bio-nano systems could be potentially used. These bio-nano systems could interact with radiations and signal based on the intensity of the radiations their relative biological effectiveness. Based on the energy and kind of radiation encountered, a matrix of signals has to be created which corresponds to a particular biological effect. The key advantage of such a design is its ability to interact with the radiation at e molecular scale; characterize its intensity based on energy deposition and relate it to the relative biological effectiveness based on the correspondence established through molecular structures and bond strengths of the bio-nano system.

  13. Detecting excess ionizing radiation by electromagnetic breakdown of air

    SciTech Connect

    Granatstein, Victor L.; Nusinovich, Gregory S.

    2010-09-15

    A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

  14. Medium-to-medium transition radiation and the detection of ultrarelativistic charged particles

    NASA Technical Reports Server (NTRS)

    Robbins, D. E.; Mack, J. E.

    1972-01-01

    The use of X-ray transition radiation to distinguish between protons and positrons of equal rigidity was investigated. A formula for the transition radiation spectrum from a medium-to-medium boundary was derived. The formation zone effect was found to limit the detection of transition radiation from ultrarelativistic particles. Curves showing the results of the spectrum calculations are presented.

  15. Luminescent glass fiber sensors for ultraviolet radiation detection by the spectral conversion

    NASA Astrophysics Data System (ADS)

    Agafonova, Darina S.; Kolobkova, Elena V.; Ignatiev, Alexander I.; Nikonorov, Nikolay V.; Shakhverdov, Teimur A.; Shirshnev, Pavel S.; Sidorov, Alexander I.; Vasiliev, Vladimir N.

    2015-11-01

    It is shown that glass fibers doped with luminescent molecular clusters of silver, cadmium and lead chalcogenides, or copper (I) can be used for the efficient radiation conversion of ultraviolet (UV) radiation to the visible spectral region. The advantages of radiation trapping in fibers by the luminescent centers and of spectral conversion are discussed. The excitation and luminescence spectra of luminescent fibers are presented. Analysis of application areas of the luminescent glasses and fibers is performed. The construction of the sensitive element for sensor models for electrical spark and UV radiation detection is described. The characteristics of the models of sensors for electrical spark and UV radiation detection are presented.

  16. High Density Nano-Electrode Array for Radiation Detection

    SciTech Connect

    Mano Misra

    2010-05-07

    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 2.76x1011Ω-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 μCi), 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

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

    SciTech Connect

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

    2012-07-01

    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.

  18. Method for increased sensitivity of radiation detection and measurement

    DOEpatents

    Miller, Steven D.

    1994-01-01

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. Reduced background is accomplished by more thorough annealing and enhanced radiation induced luminescence is obtained by treating the crystalline material to coalesce primary damage centers into secondary damage centers.

  19. Method for detecting moisture in soils using secondary cosmic radiation

    DOEpatents

    Condreva, Kenneth

    2003-12-16

    Water content in a soil is determined by measuring the attenuation of secondary background cosmic radiation as this radiation propagates through a layer of soil and water. By measuring the attenuation of secondary cosmic radiation in the range of 5 MeV-15 MeV it is possible to obtain a relative measure of the water content in a soil layer above a suitable radiation detector and thus establish when and how much irrigation is needed. The electronic circuitry is designed so that a battery pack can be used to supply power.

  20. Fundamental research on a cerenkov radiation sensor based on optical glass for detecting beta-rays

    NASA Astrophysics Data System (ADS)

    Kim, Jae Seok; Jang, Kyoung Won; Shin, Sang Hun; Jeon, Dayeong; Hong, Seunghan; Sim, Hyeok In; Kim, Seon Geun; Yoo, Wook Jae; Lee, Bongsoo; Moon, Joo Hyun; Park, Byung Gi

    2015-01-01

    In this study, a Cerenkov radiation sensor for detecting low-energy beta-particles was fabricated using various Cerenkov radiators such as an aerogel and CaF2-, SiO2-, and Al2O3-based optical glasses. Because the Cerenkov threshold energy (CTE) is determined by the refractive index of the Cerenkov radiator, the intensity of Cerenkov radiation varies according to the refractive indices of the Cerenkov radiators. Therefore, we measured the intensities of Cerenkov radiation induced by beta-particles generated from a radioactive isotope as a function of the refractive indices of the Cerenkov radiators. Also, the electron fluxes were calculated for various Cerenkov radiators by using a Monte Carlo N-Particle extended transport code (MCNPX) to determine the relationship between the intensities of the Cerenkov radiation and the electron fluxes.

  1. Study of radiation detection properties of GaN pn diode

    NASA Astrophysics Data System (ADS)

    Sugiura, Mutsuhito; Kushimoto, Maki; Mitsunari, Tadashi; Yamashita, Kohei; Honda, Yoshio; Amano, Hiroshi; Inoue, Yoku; Mimura, Hidenori; Aoki, Toru; Nakano, Takayuki

    2016-05-01

    Recently, GaN, which has remarkable properties as a material for optical devices and high-power electron devices, has also attracted attention as a material for radiation detectors. We previously suggested the use of BGaN as a neutron detector material. However, the radiation detection characteristics of GaN itself are not yet adequately understood. For realizing a BGaN neutron detector, the understanding of the radiation detection characteristics of GaN, which is a base material of the neutron detector, is important. In this study, we evaluated the radiation detection characteristics of GaN. We performed I-V and energy spectrum measurements under alpha ray, gamma ray, and thermal neutron irradiations to characterize the radiation detection characteristics of a GaN diode. The obtained results indicate that GaN is an effective material for our proposed new BGaN-based neutron detector.

  2. On-line solid-phase enrichment coupled to packed reactor flow injection analysis in a green analytical procedure to determine low levels of folic acid using fluorescence detection

    PubMed Central

    2012-01-01

    Background Analysis of folic acid (FA) is not an easy task because of its presence in lower concentrations, its lower stability under acidic conditions, and its sensitiveness against light and high temperature. The present study is concerned with the development and validation of an automated environmentally friendly pre-column derivatization combined by solid-phase enrichment (SPEn) to determine low levels of FA. Results Cerium (IV) trihydroxyhydroperoxide (CTH) as a packed oxidant reactor has been used for oxidative cleavage of FA into highly fluorescent product, 2-amino-4-hydroxypteridine-6-carboxylic acid. FA was injected into a carrier stream of 0.04 M phosphate buffer, pH 3.4 at a flow-rate of 0.25 mL/min. The sample zone containing the analyte was passed through the CTH reactor thermostated at 40°C, and the fluorescent product was trapped and enriched on a head of small ODS column (10 mm x 4.6 mm i.d., 5 μm particle size). The enriched product was then back-flush eluted by column-switching from the small ODS column to the detector with a greener mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4) in the ratio of 5:95 (v/v). The eluent was monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. The calibration graph was linear over concentrations of FA in the range of 1.25-50 ng/mL, with a detection limit of 0.49 ng/mL. Conclusion A new simple and sensitive green analytical procedure including on-line pre-column derivatization combined by SPEn has been developed for the routine quality control and dosage form assay of FA at very low concentration level. The method was a powerful analytical technique that had excellent sensitivity, sufficient accuracy and required relatively simple and inexpensive instrumentation. PMID:23234331

  3. Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

    NASA Astrophysics Data System (ADS)

    Bero, M. A.; Abukassem, I.

    2009-05-01

    Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

  4. Radiation detector having a multiplicity of individual detecting elements

    DOEpatents

    Whetten, Nathan R.; Kelley, John E.

    1985-01-01

    A radiation detector has a plurality of detector collection element arrays immersed in a radiation-to-electron conversion medium. Each array contains a multiplicity of coplanar detector elements radially disposed with respect to one of a plurality of positions which at least one radiation source can assume. Each detector collector array is utilized only when a source is operative at the associated source position, negating the necessity for a multi-element detector to be moved with respect to an object to be examined. A novel housing provides the required containment of a high-pressure gas conversion medium.

  5. On-line surfactant monitoring

    SciTech Connect

    Mullen, K.I.; Neal, E.E.; Soran, P.D.; Smith, B.

    1995-04-01

    This group has developed a process to extract metal ions from dilute aqueous solutions. The process uses water soluble polymers to complex metal ions. The metal/polymer complex is concentrated by ultrafiltration and the metals are recovered by a pH adjustment that frees the metal ions. The metal ions pass through the ultrafiltration membrane and are recovered in a concentrated form suitable for reuse. Surfactants are present in one of the target waste streams. Surfactants foul the costly ultrafiltration membranes. It was necessary to remove the surfactants before processing the waste stream. This paper discusses an on-line device the authors fabricated to monitor the process stream to assure that all the surfactant had been removed. The device is inexpensive and sensitive to very low levels of surfactants.

  6. SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW AND ON-LINE REDUCTION OF SELENIUM(VI) TO SELENIUM(IV) WITH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRIC DETECTION

    EPA Science Inventory

    Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV') by mixing the CE effluent with concentrated HCl. A microporo...

  7. Apparatus and method for detecting full-capture radiation events

    DOEpatents

    Odell, Daniel M. C.

    1994-01-01

    An apparatus and method for sampling the output signal of a radiation detector and distinguishing full-capture radiation events from Compton scattering events. The output signal of a radiation detector is continuously sampled. The samples are converted to digital values and input to a discriminator where samples that are representative of events are identified. The discriminator transfers only event samples, that is, samples representing full-capture events and Compton events, to a signal processor where the samples are saved in a three-dimensional count matrix with time (from the time of onset of the pulse) on the first axis, sample pulse current amplitude on the second axis, and number of samples on the third axis. The stored data are analyzed to separate the Compton events from full-capture events, and the energy of the full-capture events is determined without having determined the energies of any of the individual radiation detector events.

  8. Detection of coincident radiations in a single transducer by pulse shape analysis

    DOEpatents

    Warburton, William K.; Tan, Hui; Hennig, Wolfgang

    2008-03-11

    Pulse shape analysis determines if two radiations are in coincidence. A transducer is provided that, when it absorbs the first radiation produces an output pulse that is characterized by a shorter time constant and whose area is nominally proportional to the energy of the absorbed first radiation and, when it absorbs the second radiation produces an output pulse that is characterized by a longer time constant and whose area is nominally proportional to the energy of the absorbed second radiation. When radiation is absorbed, the output pulse is detected and two integrals are formed, the first over a time period representative of the first time constant and the second over a time period representative of the second time constant. The values of the two integrals are examined to determine whether the first radiation, the second radiation, or both were absorbed in the transducer, the latter condition defining a coincident event.

  9. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    PubMed Central

    Rana, Sudha; Kumar, Raj; Sultana, Sarwat; Sharma, Rakesh Kumar

    2010-01-01

    Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation. PMID:21829314

  10. Hand-held, mechanically cooled, radiation detection system for gamma-ray spectroscopy

    DOEpatents

    Burks, Morgan Thomas; Eckels, Joel Del

    2010-06-08

    In one embodiment, a radiation detection system is provided including a radiation detector and a first enclosure encapsulating the radiation detector, the first enclosure including a low-emissivity infra-red (IR) reflective coating used to thermally isolate the radiation detector. Additionally, a second enclosure encapsulating the first enclosure is included, the first enclosure being suspension mounted to the second enclosure. Further, a cooler capable of cooling the radiation detector is included. Still yet, a first cooling interface positioned on the second enclosure is included for coupling the cooler and the first enclosure. Furthermore, a second cooling interface positioned on the second enclosure and capable of coupling the first enclosure to a cooler separate from the radiation detection system is included. Other embodiments are also presented.

  11. The Photon Haystack and Emerging Radiation Detection Technology

    SciTech Connect

    Runkle, Robert C.; Smith, Leon E.; Peurrung, Anthony J.

    2009-09-15

    The resources devoted to interdicting special nuclear materials have increased considerably over the last several years in step with growing efforts to counter nuclear proliferation and nuclear terrorism. This changing landscape has led to a great deal of current research and development that aims to improve the effectiveness of technology now deployed worldwide. The interdiction of special nuclear materials is most commonly addressed by detecting and characterizing emitted gamma rays, but modest signature emissions can be obscured by attenuating material and must be differentiated from large and highly variable environmental background. While this makes gamma-ray detection of special nuclear materials a daunting technical challenge, a host of new detection technologies are now emerging. We thus review special nuclear material signatures, the physics of detection approaches, and detection performance metrics. The use of benchmark materials aids our discussion and comparison of detection methods.

  12. Detecting non-Brownian trait evolution in adaptive radiations.

    PubMed

    Freckleton, Robert P; Harvey, Paul H

    2006-11-01

    Many phylogenetic comparative methods that are currently widely used in the scientific literature assume a Brownian motion model for trait evolution, but the suitability of that model is rarely tested, and a number of important factors might affect whether this model is appropriate or not. For instance, we might expect evolutionary change in adaptive radiations to be driven by the availability of ecological niches. Such evolution has been shown to produce patterns of change that are different from those modelled by the Brownian process. We applied two tests for the assumption of Brownian motion that generally have high power to reject data generated under non-Brownian niche-filling models for the evolution of traits in adaptive radiations. As a case study, we used these tests to explore the evolution of feeding adaptations in two radiations of warblers. In one case, the patterns revealed do not accord with Brownian motion but show characteristics expected under certain niche-filling models. PMID:17090217

  13. An investigation of medical radiation detection using CMOS image sensors in smartphones

    NASA Astrophysics Data System (ADS)

    Kang, Han Gyu; Song, Jae-Jun; Lee, Kwonhee; Nam, Ki Chang; Hong, Seong Jong; Kim, Ho Chul

    2016-07-01

    Medical radiation exposure to patients has increased with the development of diagnostic X-ray devices and multi-channel computed tomography (CT). Despite the fact that the low-dose CT technique can significantly reduce medical radiation exposure to patients, the increasing number of CT examinations has increased the total medical radiation exposure to patients. Therefore, medical radiation exposure to patients should be monitored to prevent cancers caused by diagnostic radiation. However, without using thermoluminescence or glass dosimeters, it is hardly measure doses received by patients during medical examinations accurately. Hence, it is necessary to develop radiation monitoring devices and algorithms that are reasonably priced and have superior radiation detection efficiencies. The aim of this study is to investigate the feasibility of medical dose measurement using complementary metal oxide semiconductor (CMOS) sensors in smartphone cameras with an algorithm to extract the X-ray interacted pixels. We characterized the responses of the CMOS sensors in a smartphone with respect to the X-rays generated by a general diagnostic X-ray system. The characteristics of the CMOS sensors in a smartphone camera, such as dose response linearity, dose rate dependence, energy dependence, angular dependence, and minimum detectable activity were evaluated. The high energy gamma-ray of 662 keV from Cs-137 can be detected using the smartphone camera. The smartphone cameras which employ the developed algorithm can detect medical radiations.

  14. Sensitive detection of radiation trapping in cold-atom clouds

    SciTech Connect

    Beeler, Matthew; Stites, Ronald; Kim, Soo; Feeney, Laura; Bali, Samir

    2003-07-01

    In this paper, we calculate the effect of radiation trapping on the photon statistics of the light scattered from optical molasses. We propose that an intensity correlation function measurement may be sensitive to the presence of radiation trapping at an on-resonance optical depth as low as 0.1, more than an order of magnitude less than where effects of multiple scattering in cold-atom clouds have been previously observed [T. Walker, D. Sesko, and C. Wieman, Phys. Rev. Lett. 64, 408 (1990); D. Sesko, T. Walker, and C. Wieman, J. Opt. Soc. Am. B. 8, 946 (1991)].

  15. Nanotechnology-Based Systems for Nuclear Radiation and Chemicl Detection

    SciTech Connect

    Kody Varahramyan; Pedro Derosa; Chester Wilson

    2006-10-11

    This main objectives of this effort are the development and prototyping of a small. sensitive, and low-cost multi-channel nanoparticle scintillation microdevice with integrated waveguides for alpha, beta, gamma, and neutron detection. This research effort has integrated experiments and simulation to determine the combination of process-specific materials for the achievement optimum detection conditions.

  16. Ultra-high sensitivity radiation detection apparatus and method

    DOEpatents

    Gross, Kenneth C.; Valentine, John D.; Markum, Francis; Zawadzki, Mary; Dickerman, Charles

    1999-01-01

    A method and apparatus are provided to concentrate and detect very low levels of radioactive noble gases from the atmosphere. More specifically the invention provides a method and apparatus to concentrate xenon, krypton and radon in an organic fluid and to detect these gases by the radioactive emissions.

  17. High-efficiency scintillation detector for combined detection of thermal and fast neutrons and gamma radiation

    DOEpatents

    Chiles, M.M.; Mihalczo, J.T.; Blakeman, E.D.

    1987-02-27

    A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation event count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

  18. Nuclear Technology Series. Course 11: Radiation Detection and Measurement.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  19. Compact endocavity diagnostic probes for nuclear radiation detection

    DOEpatents

    Cui, Yonggang; James, Ralph; Bolotnikov, Aleksey

    2014-08-26

    This invention relates to the field of radiation imaging. In particular, the invention relates to an apparatus and a method for imaging tissue or an inanimate object using a novel probe that has an integrated solid-state semiconductor detector and complete readout electronics circuitry.

  20. Apparatus for detecting alpha radiation in difficult access areas

    DOEpatents

    Steadman, Peter; MacArthur, Duncan W.

    1997-09-02

    An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure.

  1. Apparatus for detecting alpha radiation in difficult access areas

    DOEpatents

    Steadman, P.; MacArthur, D.W.

    1997-09-02

    An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure is disclosed. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure. 4 figs.

  2. Thermal Stability Analysis for a Heliocentric Gravitational Radiation Detection Mission

    NASA Technical Reports Server (NTRS)

    Folkner, W.; McElroy, P.; Miyake, R.; Bender, P.; Stebbins, R.; Supper, W.

    1994-01-01

    The Laser Interferometer Space Antenna (LISA) mission is designed for detailed studies of low-frequency gravitational radiation. The mission is currently a candidate for ESA's post-Horizon 2000 program. Thermal noise affects the measurement in at least two ways. Thermal variation of the length of the optical cavity to which the lasers are stabilized introduces phase variations in the interferometer signal, which have to be corrected for by using data from the two arms separately.

  3. Theoretical foundations of detection of terahertz radiation in laser-plasma interactions

    SciTech Connect

    Frolov, A. A.

    2013-02-15

    A theory is developed enabling one to calculate the temporal profile and spectrum of a terahertz wave packet from the energy of the second harmonic of optical radiation generated during the nonlinear interaction between terahertz and circularly polarized laser pulses in the skin layer of an overdense plasma. It is shown that the spectral and temporal characteristics of the envelope of the second harmonic of optical radiation coincide with those of the terahertz pulse only at small durations of the detecting laser radiation. For long laser pulses, the temporal profile and spectrum of the second harmonic are mainly determined by the characteristics of optical radiation at the carrier frequency.

  4. Detection of Lyman-beta and Helium Resonance Radiation in the Night Sky.

    PubMed

    Young, J M; Carruthers, G R; Holmes, J C; Johnson, C Y; Patterson, N P

    1968-05-31

    A rocket-borne photometer has detected far ultraviolet night glow radiations that are identified as Lyman-beta (HI 1026 angstroms), and the helium lines at 304 or 584 angstroms, or at both. At an altitude of 227 kilometers the measured intensity for Lyman-beta was about 10 rayleighs. The discrimination characteristics of the broad-band helium radiation filter give helium line intensities, at 227 kilometers, of 4.8 and 12 rayleighs, respectively, pending identification of the wavelength of the radiation as 304 or 584 angstroms. These ultraviolet radiations appear sufficient to maintain the night E and F(1) regions of the ionosphere. PMID:17768892

  5. UTILIZATION OF PHOSWICH DETECTORS FOR SIMULTANEOUS, MULTIPLE RADIATION DETECTION

    SciTech Connect

    William H. Miller; Manuel Diaz de Leon

    2003-04-15

    A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed.

  6. New Spherical Gamma-Ray and Neutron Emitting Sources for Testing of Radiation Detection Instruments

    PubMed Central

    Lucas, L.; Pibida, L.

    2009-01-01

    The National Institute of Standards and Technology (NIST) has developed new gamma-ray and neutron emitting sources for testing radiation detection systems. These radioactive sources were developed for testing of detection systems in maritime applications. This required special source characteristics.

  7. Simulation and modeling for the stand-off radiation detection system (SORDS) using GEANT4

    SciTech Connect

    Hoover, Andrew S; Wallace, Mark; Galassi, Mark; Mocko, Michal; Palmer, David; Schultz, Larry; Tornga, Shawn

    2009-01-01

    A Stand-Off Radiation Detection System (SORDS) is being developed through a joint effort by Raytheon, Los Alamos National Laboratory, Bubble Technology Industries, Radiation Monitoring Devices, and the Massachusetts Institute of Technology, for the Domestic Nuclear Detection Office (DNDO). The system is a mobile truck-based platform performing detection, imaging, and spectroscopic identification of gamma-ray sources. A Tri-Modal Imaging (TMI) approach combines active-mask coded aperture imaging, Compton imaging, and shadow imaging techniques. Monte Carlo simulation and modeling using the GEANT4 toolkit was used to generate realistic data for the development of imaging algorithms and associated software code.

  8. Electro-optic detection of continuous-wave mid-infrared radiation

    NASA Astrophysics Data System (ADS)

    Cao, Hua; Nahata, Ajay

    2002-10-01

    We demonstrate coherent detection of continuous-wave mid-infrared radiation. This radiation is produced by use of conventional difference-frequency mixing and detected via the linear electro-optic effect. The detection process allows for the simultaneous measurement of the amplitude and phase properties of the infrared field. Both processes require an amplitude-modulated optical beam that is derived from the superimposed output of two single-frequency lasers. With appropriate choice of lasers and nonlinear optical crystals, the technique may be applied to any wavelength throughout the far and mid infrared.

  9. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system. Volume 1

    SciTech Connect

    Lawrence, R.S.; Harker, Y.D.; Jones, J.L.; Hoggan, J.M.

    1993-03-01

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data.

  10. Method and apparatus for providing pulse pile-up correction in charge quantizing radiation detection systems

    DOEpatents

    Britton, Jr., Charles L.; Wintenberg, Alan L.

    1993-01-01

    A radiation detection method and system for continuously correcting the quantization of detected charge during pulse pile-up conditions. Charge pulses from a radiation detector responsive to the energy of detected radiation events are converted to voltage pulses of predetermined shape whose peak amplitudes are proportional to the quantity of charge of each corresponding detected event by means of a charge-sensitive preamplifier. These peak amplitudes are sampled and stored sequentially in accordance with their respective times of occurrence. Based on the stored peak amplitudes and times of occurrence, a correction factor is generated which represents the fraction of a previous pulses influence on a preceding pulse peak amplitude. This correction factor is subtracted from the following pulse amplitude in a summing amplifier whose output then represents the corrected charge quantity measurement.

  11. Design of autotrack detecting instrument for solar UV radiation

    NASA Astrophysics Data System (ADS)

    Xia, Jiangtao; Mao, Xiaoli; Zhao, Jing

    2009-11-01

    In order to autotrack the object and detect the solar UV index, a reliable real-time high-precise instrument is proposed in this paper. This instrument involves two subsystems: the autotrack and detecting modules. The autotrack module consists of four-quadrant photo detector, multi-channel signal processing circuit and precise stepping system. The detecting module designed for dada measurement and acquisition is made up of the ultraviolet sensor UV460 and high precision A/D converter MAX1162. The key component of the entire instrument is ultralow-power microprocessor MSP430 which is used for entire system controlling and data processing. The lower system of autotracking and measurement is communicated with upper PC computer by RS232 module. In the experiment, the tracking precision of two-dimensional motion revolving stage is calibrated to be less than 0.05°. Experimental results indicate that the system designed could realize the precise autotracking and detecting function well, and the measure precision of system has reached the desirable target.

  12. A Decision Theoretic Approach to Evaluate Radiation Detection Algorithms

    SciTech Connect

    Nobles, Mallory A.; Sego, Landon H.; Cooley, Scott K.; Gosink, Luke J.; Anderson, Richard M.; Hays, Spencer E.; Tardiff, Mark F.

    2013-07-01

    There are a variety of sensor systems deployed at U.S. border crossings and ports of entry that scan for illicit nuclear material. In this work, we develop a framework for comparing the performance of detection algorithms that interpret the output of these scans and determine when secondary screening is needed. We optimize each algorithm to minimize its risk, or expected loss. We measure an algorithm’s risk by considering its performance over a sample, the probability distribution of threat sources, and the consequence of detection errors. While it is common to optimize algorithms by fixing one error rate and minimizing another, our framework allows one to simultaneously consider multiple types of detection errors. Our framework is flexible and easily adapted to many different assumptions regarding the probability of a vehicle containing illicit material, and the relative consequences of a false positive and false negative errors. Our methods can therefore inform decision makers of the algorithm family and parameter values which best reduce the threat from illicit nuclear material, given their understanding of the environment at any point in time. To illustrate the applicability of our methods, in this paper, we compare the risk from two families of detection algorithms and discuss the policy implications of our results.

  13. Detecting a Non-Gaussian Stochastic Background of Gravitational Radiation

    NASA Astrophysics Data System (ADS)

    Drasco, Steve; Flanagan, Éanna É.

    2002-12-01

    We derive a detection method for a stochastic background of gravitational waves produced by events where the ratio of the average time between events to the average duration of an event is large. Such a signal would sound something like popcorn popping. Our derivation is based on the somewhat unrealistic assumption that the duration of an event is smaller than the detector time resolution.

  14. Solid-State Photomultiplier Development for Radiation Detection

    SciTech Connect

    Baker, Stuart; Brown, Kristina; Curtis, Alden; Young, Jason; Guise, Ronald

    2012-06-12

    We are pursuing the sensitivity of back-thinned silicon (BT Si) with the gain of an SSPM (Baker 2011). Working in collaboration with Radiation Monitoring Devices, Inc., we are designing and fabricating prototype devices. Our original idea spurred from hybrid designs of advanced image sensors that use the sensitivity of BT Si that is then bump bonded to a CMOS readout device. As shown in the graph below (right), the BT Si has a far superior quantum efficiency (QE) than the standard photocathode response available in photomultiplier tubes (PMTs). Collecting as many scintillation photons as possible is the first objective. There has been major concern that the prototype could not deliver the ~105 electronic gain of a PMT. However, recently developed SSPMs do provide the electronic gain needed. We are now pursuing the design of a BTSSPM. With a smaller footprint, the SSPM can potentially lead to a simple, compact deployment package. Because the SSPM can be pixelated and tiled, we foresee developing an imaging detector. Pinhole imaging of radiation sources is a well-exercised technology. Our implementation of the coded aperture (Marks 2010) imager provides a high throughput pinhole imager. We intend to apply miniature coded apertures to minimal pixel count SSPMs to evaluate image quality.

  15. An integrated circuit/microsystem/nano-enhanced four species radiation sensor for inexpensive fissionable material detection

    NASA Astrophysics Data System (ADS)

    Waguespack, Randy Paul

    2011-12-01

    Small scale radiation detectors sensitive to alpha, beta, electromagnetic, neutron radiation are needed to combat the threat of nuclear terrorism and maintain national security. There are many types of radiation detectors on the market, and the type of detector chosen is usually determined by the type of particle to be detected. In the case of fissionable material, an ideal detector needs to detect all four types of radiation, which is not the focus of many detectors. For fissionable materials, the two main types of radiation that must be detected are gamma rays and neutrons. Our detector uses a glass or quartz scintillator doped with 10B nanoparticles to detect all four types of radiation particles. Boron-10 has a thermal neutron cross section of 3,840 barns. The interaction between the neutron and boron results in a secondary charge particle in the form of an alpha particle to be emitted, which is detectable by the scintillator. Radiation impinging on the scintillator matrix produces varying optical pulses dependent on the energy of the particles. The optical pulses are then detected by a photomultiplier (PM) tube, creating a current proportional to the energy of the particle. Current pulses from the PM tube are differentiated by on-chip pulse height spectroscopy, allowing for source discrimination. The pulse height circuitry has been fabricated with discrete circuits and designed into an integrated circuit package. The ability to replace traditional PM tubes with a smaller, less expensive photomultiplier will further reduce the size of the device and enhance the cost effectiveness and portability of the detector.

  16. Simulating and Detecting Radiation-Induced Errors for Onboard Machine Learning

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri L.; Bornstein, Benjamin; Granat, Robert; Tang, Benyang; Turmon, Michael

    2009-01-01

    Spacecraft processors and memory are subjected to high radiation doses and therefore employ radiation-hardened components. However, these components are orders of magnitude more expensive than typical desktop components, and they lag years behind in terms of speed and size. We have integrated algorithm-based fault tolerance (ABFT) methods into onboard data analysis algorithms to detect radiation-induced errors, which ultimately may permit the use of spacecraft memory that need not be fully hardened, reducing cost and increasing capability at the same time. We have also developed a lightweight software radiation simulator, BITFLIPS, that permits evaluation of error detection strategies in a controlled fashion, including the specification of the radiation rate and selective exposure of individual data structures. Using BITFLIPS, we evaluated our error detection methods when using a support vector machine to analyze data collected by the Mars Odyssey spacecraft. We found ABFT error detection for matrix multiplication is very successful, while error detection for Gaussian kernel computation still has room for improvement.

  17. Emulsion chamber with big radiation length for detecting neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Asratyan, A. E.; Davidenko, G. V.; Dolgolenko, A. G.; Kaftanov, V. S.; Kubantsev, M. A.; Verebryusov, V. S.

    2000-08-01

    A conceptual scheme of a hybrid-emulsion spectrometer for investigating various channels of neutrino oscillations is proposed. The design emphasizes detection of τ leptons by detached vertices, reliable identification of electrons, and good spectrometry for all charged particles and photons. A distributed target is formed by layers of low- Z material, emulsion-plastic-emulsion sheets, and air gaps in which τ decays are detected. The tracks of charged secondaries, including electrons, are momentum-analyzed by curvature in magnetic field using hits in successive thin layers of emulsion. The τ leptons are efficiently detected in all major decay channels, including τ-→ e-νν¯. The performance of a model spectrometer, that contains 3 t of nuclear emulsion and 20 t of passive material, is estimated for different experimental environments. When irradiated by the ν μ beam of a proton accelerator over a medium baseline of ˜1 km/ GeV, the spectrometer will efficiently detect either the ν μ→ν τ or the ν μ→ν e transitions in the mass-difference region of Δm 2˜1 eV2, as suggested by the results of LSND. When exposed to the neutrino beam of a muon storage ring over a long baseline of < L/ Eν>˜10- 20 km/ GeV, the model detector will efficiently probe the entire pattern of neutrino oscillations in the region Δ m2˜10 -2- 10 -3 eV2, as suggested by the data on atmospheric neutrinos.

  18. Do satellites detect trends in surface solar radiation?

    PubMed

    Pinker, R T; Zhang, B; Dutton, E G

    2005-05-01

    Long-term variations in solar radiation at Earth's surface (S) can affect our climate, the hydrological cycle, plant photosynthesis, and solar power. Sustained decreases in S have been widely reported from about the year 1960 to 1990. Here we present an estimate of global temporal variations in S by using the longest available satellite record. We observed an overall increase in S from 1983 to 2001 at a rate of 0.16 watts per square meter (0.10%) per year; this change is a combination of a decrease until about 1990, followed by a sustained increase. The global-scale findings are consistent with recent independent satellite observations but differ in sign and magnitude from previously reported ground observations. Unlike ground stations, satellites can uniformly sample the entire globe. PMID:15879215

  19. Enhancing international radiation/nuclear detection training opportunities

    SciTech Connect

    Williams, Thomas L.; Bersell, Bridget M.; Booker, Paul M.; Anderson, Gerald E.; Leitch, Rosalyn M.; Meagher, John B.; Siefken, Rob R.; Spracklen, James L.

    2015-09-23

    The United States has worked domestically to develop and provide radiological and nuclear detection training and education initiatives aimed at interior law enforcement, but the international community has predominantly focused efforts at border and customs officials. The interior law enforcement officials of a State play a critical role in maintaining an effective national-level nuclear detection architecture. To meet this vital need, DNDO was funded by the U.S. Department of State (DOS) to create and deliver a 1-week course at the International Law Enforcement Academy (ILEA) in Budapest, Hungary to inform interior law enforcement personnel of the overall mission, and to provide an understanding of how the participants can combat the threats of radiological and nuclear terrorism through detection efforts. Two courses, with approximately 20 students in each course, were delivered in fiscal year (FY) 2013, two were delivered in FY 2014 and FY 2015, and as of this report’s writing more are planned in FY 2016. However, while the ILEA courses produced measurable success, DNDO requested Pacific Northwest National Laboratory (PNNL) research potential avenues to further increase the course impact.In a multi-phased approach, PNNL researched and analyzed several possible global training locations and venues, and other possible ways to increase the impact of the course using an agreed-to data-gathering format.

  20. Rapid detection of radiation-induced hydrocarbons in cooked ham.

    PubMed

    Barba, C; Santa-María, G; Herraiz, M; Calvo, M M

    2012-03-01

    Solid phase microextraction (SPME) coupled with either gas chromatography-ionization flame detector (CG-FID) or multidimensional gas chromatography-mass spectrometry (MDGC-MS) was evaluated for its ability to detect volatile hydrocarbons produced during the irradiation of cooked ham. The chromatogram of an irradiated sample obtained using GC-FID showed a complex pattern of peaks, with several co-eluting peaks superimposed, indicating that the method was unlikely to resolve adequately the volatile hydrocarbons formed during irradiation. Using SPME-MDGC-MS 1-tetradecene (C(1-14:1)), n-pentadecane (C(15:0)), 1-hexadecene (C(1-16:1)), n-heptadecane (C(17:0)) and 8-heptadecene (C(8-17:1)) were detected in cooked ham irradiated at 0.5, 2, 4 and 8kGy. This method allows the detection of most n-alkanes and n-alkenes produced during the irradiation of the majority of fatty acids in cooked ham, namely oleic acid, stearic acid and palmitic acid. SPME is rapid and inexpensive and does not require organic solvents. The proposed SPME-MDGC-MS method allows the determination of radiolytic markers in cooked ham in less than 115min. PMID:22100714

  1. Digital video system for on-line portal verification

    NASA Astrophysics Data System (ADS)

    Leszczynski, Konrad W.; Shalev, Shlomo; Cosby, N. Scott

    1990-07-01

    A digital system has been developed for on-line acquisition, processing and display of portal images during radiation therapy treatment. A metal/phosphor screen combination is the primary detector, where the conversion from high-energy photons to visible light takes place. A mirror angled at 45 degrees reflects the primary image to a low-light-level camera, which is removed from the direct radiation beam. The image registered by the camera is digitized, processed and displayed on a CRT monitor. Advanced digital techniques for processing of on-line images have been developed and implemented to enhance image contrast and suppress the noise. Some elements of automated radiotherapy treatment verification have been introduced.

  2. Detection system for high-resolution gamma radiation spectroscopy with neutron time-of-flight filtering

    DOEpatents

    Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

    2014-12-30

    A .gamma.-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive .alpha.-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a .gamma.-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the .gamma.-radiation. Subsequently, it is determined whether a coincidence exists between the .alpha.-particles and .gamma.-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the .alpha.-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

  3. Dead time and count loss determination for radiation detection systems in high count rate applications

    NASA Astrophysics Data System (ADS)

    Patil, Amol

    This research is focused on dead time and the subsequent count loss estimation in radiation detection systems. The dead time is the minimum amount of time required between two events to permit detection of those events individually by a radiation detection system. If events occur during the system dead time, they are lost. Such lost information can be important in many applications including high-precision spectroscopy, positron emission tomography (PET), and the scanning of spent nuclear fuel. Understanding of the behavior of radiation detection systems is important; thus this work included a comprehensive review of dead time and pulse pile-up models and methods. The most common way to estimate detector dead time is by one-parameter approximations known as nonparalyzable and paralyzable models. This research proposes a two parameter model that estimates the detector paralysis factor and the dead time based on a graphical method. To determine the two parameters characteristics of a detection system, this work tested a novel technique to saturate the detector using a decaying source. The modified decaying source method, unlike other methods, does not assume the idealized behavior of detection system in use and calculates the overall dead time of the detection system. The paralysis factor for high purity germanium detection system was estimated approaching 100% and the dead time was on the order of 5--10 micros which compares well with the literature.

  4. Using Thermal Radiation in Detection of Negative Obstacles

    NASA Technical Reports Server (NTRS)

    Rankin, Arturo L.; Matthies, Larry H.

    2009-01-01

    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.

  5. Detecting Galaxy Formation with He II Cooling Radiation

    NASA Astrophysics Data System (ADS)

    Yang, Yujin; Zabludoff, Ann; Davé, Romeel; Eisenstein, Daniel

    2006-08-01

    Galaxies obtain material to form their stars from the intergalactic medium, but direct observations of such accretion do not yet exist. Motivated by our theoretical work, we propose the first direct search for gravitational cooling radiation arising from the infall of gas into forming galaxies at z=3. While ``Lyα blobs'' are the best candidates for gas-accreting galaxies at high redshift, and are therefore the focus of our proposed study, their nature remains unknown due to intrinsic difficulties in interpreting their Lyα emission. Here, we propose to survey 10 of the Lyα blobs from the Matsuda et al. sample for He II. Compared to Lyα, Heha is optically thin, less sensitive to the UV background, and less contaminated by the recombination lines from star-forming galaxies, making it an ideal diagnostic line to uncover the processes by which galaxies acquire their baryons. This proposal is a resubmission in which we have explicitly addressed the concerns raised by the TAC last year. This project represents a new approach, which has the potential to revolutionize studies of galaxy formation.

  6. Detecting the Radiative Decay Mode of the Neutron

    PubMed Central

    Fisher, B. M.; Wietfeldt, F. E.; Dewey, M. S.; Gentile, T. R.; Nico, J. S.; Thompson, A. K.; Coakley, K. J.; Beise, E. J.; Kiriluk, K. G.; Byrne, J.

    2005-01-01

    Beta decay of the neutron into a proton, electron, and electron antineutrino is occasionally accompanied by the emission of a photon. Despite decades of detailed experimental studies of neutron beta-decay, this rare branch of a fundamental weak decay has never been observed. An experiment to study the radiative beta-decay of the neutron is currently being developed for the NG-6 fundamental physics endstation at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). The experiment will make use of the existing apparatus for the NIST proton-trap lifetime experiment, which can provide substantial background reduction by providing an electron-proton coincidence trigger. Tests and design of a detector for gamma-rays in the 10 keV to 200 keV range are under development. The need for a large solid-angle gamma-ray detector that can operate in a strong magnetic field and at low temperature has led us to consider scintillating crystals in conjunction with avalanche photodiodes. The motivation and experimental technique will be discussed. PMID:27308161

  7. Radiation resistance of sequencing chips for in situ life detection.

    PubMed

    Carr, Christopher E; Rowedder, Holli; Lui, Clarissa S; Zlatkovsky, Ilya; Papalias, Chris W; Bolander, Jarie; Myers, Jason W; Bustillo, James; Rothberg, Jonathan M; Zuber, Maria T; Ruvkun, Gary

    2013-06-01

    Life beyond Earth may be based on RNA or DNA if such life is related to life on Earth through shared ancestry due to meteoritic exchange, such as may be the case for Mars, or if delivery of similar building blocks to habitable environments has biased the evolution of life toward utilizing nucleic acids. In this case, in situ sequencing is a powerful approach to identify and characterize such life without the limitations or expense of returning samples to Earth, and can monitor forward contamination. A new semiconductor sequencing technology based on sensing hydrogen ions released during nucleotide incorporation can enable massively parallel sequencing in a small, robust, optics-free CMOS chip format. We demonstrate that these sequencing chips survive several analogues of space radiation at doses consistent with a 2-year Mars mission, including protons with solar particle event-distributed energy levels and 1 GeV oxygen and iron ions. We find no measurable impact of irradiation at 1 and 5 Gy doses on sequencing quality nor on low-level hardware characteristics. Further testing is required to study the impacts of soft errors as well as to characterize performance under neutron and gamma irradiation and at higher doses, which would be expected during operation in environments with significant trapped energetic particles such as during a mission to Europa. Our results support future efforts to use in situ sequencing to test theories of panspermia and/or whether life has a common chemical basis. PMID:23734755

  8. An on-line NMR technique with a programmable processor

    SciTech Connect

    Razazian, K.; Dieckman, S.L.; Raptis, A.C.

    1995-07-01

    Nuclear magnetic resonance (NMR) spectroscopy is used to determine molecular content of materials, mainly in laboratory measurements. The reduced cost of fast computer processors, together with recent break throughs in digital signal processor technology, has facilitated the on-line use of NMR by allowing modifications of the available technology. This paper describes a system and an algorithm for improving the on-line operations. It is base on the time-domain NMR signal detected by the controller and some prior knowledge of chemical signal patterns. The desired signal can be separated from a composite signal by using an adaptive line enhancer (ALE) filter. This technique would be useful for upgrading process procedures in on-line manufacturing.

  9. On-Line Assessment: What, Why, How.

    ERIC Educational Resources Information Center

    Natal, Dottie

    Recent increases in the speed and accessibility of computers and networks have made it possible to administer tests on-line. On-line assessment can be conducted in a controlled setting, such as a testing center, or distributed over local area networks or the Internet to libraries and student homes, allowing students the flexibility to complete…

  10. On-line diagnosis of sequential systems

    NASA Technical Reports Server (NTRS)

    Sundstrom, R. J.

    1973-01-01

    A model for on-line diagnosis was investigated for discrete-time systems, and resettable sequential systems. Generalized notions of a realization are discussed along with fault tolerance and errors. Further investigation into the theory of on-line diagnosis is recommended for three levels: binary state-assigned level, logical circuit level, and the subsystem-network level.

  11. Testing Claims for On-Line Conferences.

    ERIC Educational Resources Information Center

    Selfe, Cynthia L.; Meyer, Paul R.

    1991-01-01

    Describes an exploratory study of gender and power relationships on Megabyte University, one particular on-line conference. Finds that, although results of the study are not definite, they do suggest that gender and power are present to some extent even in on-line conferences. (MG)

  12. Application of Terahertz Radiation to the Detection of Corrosion under the Shuttle's Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Madaras, Eric I.; Anastasi, Robert F.; Smith, Stephen W.; Seebo, Jeffrey P.; Walker, James L.; Lomness, Janice K.; Hintze, Paul E.; Kammerer, Catherine C.; Winfree, William P.; Russell, Richard W.

    2007-01-01

    There is currently no method for detecting corrosion under Shuttle tiles except for the expensive process of tile removal and replacement; hence NASA is investigating new NDE methods for detecting hidden corrosion. Time domain terahertz radiation has been applied to corrosion detection under tiles in samples ranging from small lab samples to a Shuttle with positive results. Terahertz imaging methods have been able to detect corrosion at thicknesses of 5 mils or greater under 1" thick Shuttle tiles and 7-12 mils or greater under 2" thick Shuttle tiles.

  13. Radiation detection system for portable gamma-ray spectroscopy

    DOEpatents

    Rowland, Mark S.; Howard, Douglas E.; Wong, James L.; Jessup, James L.; Bianchini, Greg M.; Miller, Wayne O.

    2006-06-20

    A portable gamma ray detection apparatus having a gamma ray detector encapsulated by a compact isolation structure having at least two volumetrically-nested enclosures where at least one is a thermal shield. The enclosures are suspension-mounted to each other to successively encapsulate the detector without structural penetrations through the thermal shields. A low power cooler is also provided capable of cooling the detector to cryogenic temperatures without consuming cryogens, due to the heat load reduction by the isolation structure and the reduction in the power requirements of the cooler. The apparatus also includes a lightweight portable power source for supplying power to the apparatus, including to the cooler and the processing means, and reducing the weight of the apparatus to enable handheld operation or toting on a user's person.

  14. Radiation detection method and system using the sequential probability ratio test

    DOEpatents

    Nelson, Karl E.; Valentine, John D.; Beauchamp, Brock R.

    2007-07-17

    A method and system using the Sequential Probability Ratio Test to enhance the detection of an elevated level of radiation, by determining whether a set of observations are consistent with a specified model within a given bounds of statistical significance. In particular, the SPRT is used in the present invention to maximize the range of detection, by providing processing mechanisms for estimating the dynamic background radiation, adjusting the models to reflect the amount of background knowledge at the current point in time, analyzing the current sample using the models to determine statistical significance, and determining when the sample has returned to the expected background conditions.

  15. Test Report for Cricket Radiation Detection System Used In EPA Port Installations

    SciTech Connect

    Shourbaji, AA

    2004-08-11

    Oak Ridge National Laboratory conducted field radiological measurements at two port locations at the request of the Environmental Protection Agency (EPA). The radiological measurements were performed on five radiation detection systems at the port of Darrow, Louisiana and three systems at the port of Charleston, South Carolina. Darrow was visited on January 20-23, 2004 and Charleston on May 25, 2004. All tested systems are designed to detect radioactive material that might be present in scrap metals as the scrap is being unloaded from ships. All eight systems are commercially known as the Cricket and manufactured by RAD/COMM Systems. Each radiation detection system consists of a detector with two channels and a wireless transmitter, both mounted on the grapple, and a controller located in the crane cab. The cranes at both locations are operated by the Cooper T. Smith Company. The purpose of the radiological measurements was to evaluate the performance of the radiation detection systems in terms of their ability to detect elevated radiation levels, and to develop a routine testing method for all EPA Cricket systems.

  16. Photostimulated luminescence detection and radiation effects on cinnamon (Cinnamomum zeylanicum) spice.

    PubMed

    Marcazzó, J; Sanchez-Barrera, C E; Urbina-Zavala, A; Cruz-Zaragoza, E

    2015-10-01

    The increase of disease borne pathogens in foods has promoted the use of new technologies in order to eliminate these pathogen microorganisms and extend the shelf-life of the foodstuffs. In particular, Cinnamon (Cinnamomum zeylanicum) contains an important number of pathogen microorganisms and it is frequently sterilized by gamma radiation. However, it is important to develop the detection methods for irradiated food in order to keep the dose control and also to analyze the radiation effects in their chemical property. This work reports (i) the photostimulated luminescence (PSL) detection of irradiated cinnamon and thermoluminescence (TL) detection of the inorganic polymineral fraction separated from this spice, and (ii) the proximate chemical analysis carried out on fat, protein and dietetic fiber contents. The detection limits using the PSL and TL methods were 500 Gy and 10 Gy, respectively, and the fat content was increased significantly with the gamma dose that could be related to the lipid oxidation in the cinnamon. PMID:26133665

  17. Solving Inverse Detection Problems Using Passive Radiation Signatures

    SciTech Connect

    Favorite, Jeffrey A.; Armstrong, Jerawan C.; Vaquer, Pablo A.

    2012-08-15

    The ability to reconstruct an unknown radioactive object based on its passive gamma-ray and neutron signatures is very important in homeland security applications. Often in the analysis of unknown radioactive objects, for simplicity or speed or because there is no other information, they are modeled as spherically symmetric regardless of their actual geometry. In these presentation we discuss the accuracy and implications of this approximation for decay gamma rays and for neutron-induced gamma rays. We discuss an extension of spherical raytracing (for uncollided fluxes) that allows it to be used when the exterior shielding is flat or cylindrical. We revisit some early results in boundary perturbation theory, showing that the Roussopolos estimate is the correct one to use when the quantity of interest is the flux or leakage on the boundary. We apply boundary perturbation theory to problems in which spherically symmetric systems are perturbed in asymmetric nonspherical ways. We apply mesh adaptive direct search (MADS) algorithms to object reconstructions. We present a benchmark test set that may be used to quantitatively evaluate inverse detection methods.

  18. Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

    DOEpatents

    Bell, Zane W.

    2000-01-01

    A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

  19. Investigation into Nanostructured Lanthanum Halides and CeBr{sub 3} for Nuclear Radiation Detection

    SciTech Connect

    Guss, P., Guise, R., Mukhopadhyay, S., Yuan, D.

    2011-06-22

    This slide-show presents work on radiation detection with nanostructured lanthanum halides and CeBr{sub 3}. The goal is to extend the gamma energy response on both low and high-energy regimes by demonstrating the ability to detect low-energy x-rays and relatively high-energy activation prompt gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, cerium bromide, or other nanocrystal material. Homogeneous and nano structure cases are compared.

  20. Fast analysis using monolithic columns coupled with high-flow on-line extraction and electrospray mass spectrometric detection for the direct and simultaneous quantitation of multiple components in plasma.

    PubMed

    Zeng, Hang; Deng, Yuzhong; Wu, Jing-Tao

    2003-05-25

    In this work, monolithic columns were used as a fast separation tool for multiple-component quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) assays of drug candidates in biological fluids. A considerably reduced runtime was achieved while maintaining good chromatographic separations. This significantly improved separation speed demanded higher throughput on sample extraction. To this end, monolithic separations were coupled on-line with high-flow extraction, which allowed for the fast extraction and separation of samples containing multiple analytes. An evaluation of this system was performed using a mixture of fenfluramine, temazepam, oxazepam, and tamoxifen in plasma. A total cycle time of 1.2 min was achieved which included both sample extraction and subsequent monolithic column separation via column switching. A total of over 400 plasma samples were analyzed in less than 10 h. The sensitivity and responses were reproducible throughout the run. The system has been routinely used in the authors' laboratory for high-throughput quantitation of compounds in biological fluids in support of drug discovery programs. The assay for samples from a 9-in-1 dog pharmacokinetic study is shown as an example to demonstrate the capability of this system. PMID:12705973

  1. Rapid screening and identification of compounds with DNA-binding activity from Folium Citri Reticulatae using on-line HPLC-DAD-MS(n) coupled with a post column fluorescence detection system.

    PubMed

    Fu, Qingrong; Zhang, Cangman; Lin, Zongtao; Sun, Hongyang; Liang, Yi; Jiang, Haixiu; Song, Zhiling; Wang, Hong; Chen, Shizhong

    2016-02-01

    To study the interactions between natural compounds and deoxyribonucleic acid (DNA), a method has been established combining a high-performance liquid chromatography-diode array detector-multi-stage mass spectrometer with a fluorescence detector (HPLC-DAD-MS(n)-FLD). The FLD was used to monitor fluorescence intensity of the ethidium bromide-DNA (EB-DNA) complex when a compound separated by HPLC was introduced. This novel method was used to simultaneously obtain the HPLC fingerprint, UV spectra, MS(n) fragments and DNA-binding activity profile of various components in Folium Citri Reticulatae. As a result, 35 compounds were identified, of which 25 were found in the extract of Folium Citri Reticulatae for the first time, and 33 compounds showed DNA-binding activities, with the most active being feruloylhexaric and p-coumaroylhexaric acids. In addition, the precision, stability and reproducibility of this method were validated by two positive controls, quercetin and hesperidin. This new on-line method is accurate, precise and reliable for further high-throughput screening of DNA-binding compounds from food samples and other complex matrices. PMID:26304344

  2. Identification of nonvolatile coal derived products via chromatography coupled with on-line FTIR detection. Quarterly progress report, March 1-May 31, 1985. [C/sub 2/H/sub 2/ extracts of ground coal, coffee and paprika

    SciTech Connect

    Taylor, L.T.

    1985-10-01

    Because it has been our goal to interface the supercritical fluid chromatograph with a Fourier transform infrared spectrometer we have initially chosen packed columns due to their increased sample capacities, and supercritical CO/sub 2/ because of its infrared transparency. This paper compares two sampling techniques that can be utilized in packed column supercritical fluid Chromatography (SFC). Traditional sample introduction is accomplished using an injector with a sample loop. The loop is filled with the appropriate amount of material, and subsequently inserted into the mobile phase path. In most cases the sample must be either dissolved or extracted into an appropriate solvent for such sample introduction. Note that unlike HPLC, where the solvent can be the same as the mobile phase, traditional sampling with SFC must use a solvent that is very different from the mobile phase. As a result, solvent peaks are almost always present, especially with universal detectors like FTIR. An alternative method is described here whereby both extraction of the sample and introduction of the extract onto the column is accomplished on-line using only the supercritical fluid mobile phase. This sampling technique is made possible by a simple valving scheme which ties directly the extraction vessel, the injector, the packed column and the detector. This technique has several advantages over the traditional methods, not the least of which is the absence of a large amount of foreign solvent introduced on the column. 11 refs., 7 figs.

  3. Radiation and Electromagnetic Induction Data Fusion for Detection of Buried Radioactive Metal Waste - 12282

    SciTech Connect

    Long, Zhiling; Wei, Wei; Turlapaty, Anish; Du, Qian; Younan, Nicolas H.; Waggoner, Charles

    2012-07-01

    At the United States Army's test sites, fired penetrators made of Depleted Uranium (DU) have been buried under ground and become hazardous waste. Previously, we developed techniques for detecting buried radioactive targets. We also developed approaches for locating buried paramagnetic metal objects by utilizing the electromagnetic induction (EMI) sensor data. In this paper, we apply data fusion techniques to combine results from both the radiation detection and the EMI detection, so that we can further distinguish among DU penetrators, DU oxide, and non- DU metal debris. We develop a two-step fusion approach for the task, and test it with survey data collected on simulation targets. In this work, we explored radiation and EMI data fusion for detecting DU, oxides, and non-DU metals. We developed a two-step fusion approach based on majority voting and a set of decision rules. With this approach, we fuse results from radiation detection based on the RX algorithm and EMI detection based on a 3-step analysis. Our fusion approach has been tested successfully with data collected on simulation targets. In the future, we will need to further verify the effectiveness of this fusion approach with field data. (authors)

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

    SciTech Connect

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

    2010-09-01

    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.

  5. On-Line NDE for Advanced Reactor Designs

    NASA Astrophysics Data System (ADS)

    Nakagawa, N.; Inanc, F.; Thompson, R. B.; Junker, W. R.; Ruddy, F. H.; Beatty, J. M.; Arlia, N. G.

    2003-03-01

    This expository paper introduces the concept of on-line sensor methodologies for monitoring the integrity of components in next generation power systems, and explains general benefits of the approach, while describing early conceptual developments of suitable NDE methodologies. The paper first explains the philosophy behind this approach (i.e. the design-for-inspectability concept). Specifically, we describe where and how decades of accumulated knowledge and experience in nuclear power system maintenance are utilized in Generation IV power system designs, as the designs are being actively developed, in order to advance their safety and economy. Second, we explain that Generation IV reactor design features call for the replacement of the current outage-based maintenance by on-line inspection and monitoring. Third, the model-based approach toward design and performance optimization of on-line sensor systems, using electromagnetic, ultrasonic, and radiation detectors, will be explained. Fourth, general types of NDE inspections that are considered amenable to on-line health monitoring will be listed. Fifth, we will describe specific modeling developments to be used for radiography, EMAT UT, and EC detector design studies.

  6. A new thermal radiation detector using optical heterodyne detection of absorbed energy

    NASA Technical Reports Server (NTRS)

    Davis, C. C.; Petuchowski, S. J.

    1983-01-01

    The operating principles of a new kind of room-temperature thermal radiation detector are described. In this device modulated light heats a gas, either directly or by conduction from a thin absorbing membrane, and the resultant change in density of the gas is detected by optical heterodyning. The performance of a membrane device of this kind agrees well with the predictions of theory.

  7. Operating a Microwave Radiation Detection Monitor. Module 10. Vocational Education Training in Environmental Health Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on operating a microwave radiation detection monitor. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) testing the…

  8. Systems and methods for detecting nuclear radiation in the presence of backgrounds

    DOEpatents

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2005-06-21

    Systems and methods for the simultaneous detection and identification of radiation species, including neutrons, gammas/x-rays and minimum ionizing particles (MIPs). A plurality of rectangular and/or triangularly shaped radiation sensitive scintillators can be configured from a plurality of nano-sized particles, dopants and an extruded plastic material. A wavelength-shifting fiber can then be located within a central hole of each extruded scintillator, wherein the wavelength-shifting fiber absorbs scintillation light and re-emits the light at a longer wavelength, thereby piping the light to a photodetector whose response to the light indicates the presence of radiation The resulting method and system can simultaneously detect neutrons, gamma rays, x-rays and cosmic rays (MIPs) and identify each.

  9. Helicity sensitive terahertz radiation detection by dual-grating-gate high electron mobility transistors

    SciTech Connect

    Faltermeier, P.; Olbrich, P.; Probst, W.; Schell, L.; Ganichev, S. D.; Watanabe, T.; Boubanga-Tombet, S. A.; Otsuji, T.

    2015-08-28

    We report on the observation of a radiation helicity sensitive photocurrent excited by terahertz (THz) radiation in dual-grating-gate (DGG) InAlAs/InGaAs/InAlAs/InP high electron mobility transistors (HEMT). For a circular polarization, the current measured between source and drain contacts changes its sign with the inversion of the radiation helicity. For elliptically polarized radiation, the total current is described by superposition of the Stokes parameters with different weights. Moreover, by variation of gate voltages applied to individual gratings, the photocurrent can be defined either by the Stokes parameter defining the radiation helicity or those for linear polarization. We show that artificial non-centrosymmetric microperiodic structures with a two-dimensional electron system excited by THz radiation exhibit a dc photocurrent caused by the combined action of a spatially periodic in-plane potential and spatially modulated light. The results provide a proof of principle for the application of DGG HEMT for all-electric detection of the radiation's polarization state.

  10. On-line chemical composition analyzer development

    SciTech Connect

    Garrison, A.A.

    1993-01-01

    This report relates to the development of an on-line Raman analyzer for control of a distillation column. It is divided into: program issues, experimental control system evaluation, energy savings analysis, and reliability analysis. (DLC)

  11. On-Line Measurement of Aphasic Speech.

    ERIC Educational Resources Information Center

    Packman, Ann; Ingham, Roger J.

    1978-01-01

    The spontaneous speech of five aphasic Ss (47-70 years old) was rated on-line by four clinicians to test the reliability of seven response categories (devised for the concurrent evaluation of aphasic speech). (Author/PHR)

  12. GaN-Based Heterojunction Structures for Simultaneous Detection of Ultraviolet/Infrared Radiation

    NASA Astrophysics Data System (ADS)

    Jayasinghe, R.; Ariyawansa, G.; Dietz, N.; Perera, A. G. U.; Matsik, S.; Ferguson, I.; Laframboise, S.; Bezinger, A.; Buchanan, M.; Liu, H. C.

    2009-11-01

    Ultraviolet and infrared (UV/IR) dual-band photodetectors have potential applications in various areas, such as fire/flame detection, solar astronomy, military sensing, situational awareness applications, and combustion process monitoring. Since GaN-based UV/IR detectors do not respond to solar or artificial visible lighting, the false detection rate is strongly reduced. Use of a single detector for detecting UV/IR can also eliminate the difficulties of operating several individual detectors with separate electronics and cooling mechanisms. Here, we report a dual-band detector which simultaneously detects UV (250 -- 360 nm) and IR (5 -- 14 μm) regions, showing near zero spectral crosstalk. This allows the detection of both UV and IR incident radiation, separately identifying the relative strength of each photocurrent component. Further improvements for the detector are also discussed.

  13. Design of a spreader bar crane-mounted gamma-ray radiation detection system

    NASA Astrophysics Data System (ADS)

    Grypp, Matthew D.; Marianno, Craig M.; Poston, John W.; Hearn, Gentry C.

    2014-04-01

    Over 95% of imports entering the United States from outside North America arrive by sea at 329 ports of entry. These imports are packaged in more than 11 million cargo containers. Radiation portals monitors routinely scan cargo containers leaving port on specially-designed trucks. To accelerate the process, some commercial entities have placed detection systems on the spreader-bar cranes (SBCs) used to offload. Little is known about the radiation background profiles of systems operating on these cranes. To better understand the operational characteristics of these radiation detection systems; a research team from Texas A&M University (TAMU) mounted three thallium-doped sodium iodide [NaI(Tl)] detectors on an SBC at the Domestic Nuclear Detection Office's (DNDO) test track facility at the Port of Tacoma (PoT). These detectors were used to monitor background radiation levels and continuously recorded data during crane operations using a custom-built software package. Count rates and spectral data were recorded for various crane heights over both land and water. The results of this research created a background profile in which count rate was heavily dependent on position demonstrating how detector readings changed in the operational environment.

  14. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    PubMed

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface. PMID:22349404

  15. Determination of polycyclic aromatic hydrocarbons in food samples by automated on-line in-tube solid-phase microextraction coupled with high-performance liquid chromatography-fluorescence detection.

    PubMed

    Ishizaki, A; Saito, K; Hanioka, N; Narimatsu, S; Kataoka, H

    2010-08-27

    A simple and sensitive automated method, consisting of in-tube solid-phase microextraction (SPME) coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD), was developed for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) in food samples. PAHs were separated within 15 min by HPLC using a Zorbax Eclipse PAH column with a water/acetonitrile gradient elution program as the mobile phase. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 microL of sample using a CP-Sil 19CB capillary column as an extraction device. Low- and high-molecular weight PAHs were extracted effectively onto the capillary coating from 5% and 30% methanol solutions, respectively. The extracted PAHs were readily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. Using the in-tube SPME HPLC-FLD method, good linearity of the calibration curve (r>0.9972) was obtained in the concentration range of 0.05-2.0 ng/mL, and the detection limits (S/N=3) of PAHs were 0.32-4.63 pg/mL. The in-tube SPME method showed 18-47 fold higher sensitivity than the direct injection method. The intra-day and inter-day precision (relative standard deviations) for a 1 ng/mL PAH mixture were below 5.1% and 7.6% (n=5), respectively. This method was applied successfully to the analysis of tea products and dried food samples without interference peaks, and the recoveries of PAHs spiked into the tea samples were >70%. Low-molecular weight PAHs such as naphthalene and pyrene were detected in many foods, and carcinogenic benzo[a]pyrene, at relatively high concentrations, was also detected in some black tea samples. This method was also utilized to assess the release of PAHs from tea leaves into the liquor. PMID:20637468

  16. Magnetic calorimeter with a SQUID for detecting weak radiations and recording the ultralow energy release

    SciTech Connect

    Golovashkin, Aleksander I; Zherikhina, L N; Kuleshova, G V; Tskhovrebov, A M; Izmailov, G N

    2006-12-31

    The scheme of a magnetic calorimeter for recording extremely low energy releases is developed. The calorimeter is activated by the method of adiabatic demagnetisation and its response to the energy release is measured with a superconducting quantum interference device (SQUID). The estimate of the ultimate sensitivity of the calorimeter with the SQUID demonstrates the possibilities of its application for detecting ultralow radiation intensity, recording single X-ray quanta in the proportional regime and other events with ultralow energy releases. The scheme of the calorimeter with the SQUID on matter waves in superfluid {sup 4}He is proposed. (radiation detectors)

  17. Radiation scintillator embedded with a converting medium to detect and discriminate the four species of ionizing radiation

    NASA Astrophysics Data System (ADS)

    Pellegrin, Scott; Wilson, Chester G.

    2010-04-01

    A new nanoparticle loaded plastic scintillator embedded in a glass substrate detects and discriminates all species of radiation emitted from fissionable bomb making materials. The fast electron scintillating resin is doped with tailored charge conversion nanoparticles to produce characteristic optical pulses. The created optical pulses exit the detector, since the nanoparticles are appreciably smaller than the wavelength of light. Microsandblasting is used to etch deep cavities in the glass substrate forming independent optical paths. The doped resin is injected into the cavities and cured. A separate off-the-shelf PM tube linearly amplifies the created light pulse into a usable electrical signal. By using tailored nanoparticles, the physical mechanisms for converting different species of radiation into lower energy electrons allows for pulse height spectroscopy to discriminate between alpha, beta, gamma, and neutron radiation. A 90Sr source was used to test the beta detector, which is loaded with W. The drop in count rates versus distance was found to be similar to traditional detectors. The gamma detector loaded with Pb nanoparticles was tested with a 60Co source. The addition of Pb provided greater sensitivity to the gamma radiation. A 210Pl source was used to test the glass doped scintillator. The count rates remained fairly constant for varying distances since alpha particles tend to travel in straight paths until losing most of their initial energy. The 157Gd loaded scintillator was tested with an Am/Be source. 157Gd has the largest thermal neutron absorption cross section at 255,000 barns and releases a usable characteristic 72keV electron in 39% of the capture reactions.

  18. Radiation anomaly detection algorithms for field-acquired gamma energy spectra

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ron; Guss, Paul; Mitchell, Stephen

    2015-08-01

    The Remote Sensing Laboratory (RSL) is developing a tactical, networked radiation detection system that will be agile, reconfigurable, and capable of rapid threat assessment with high degree of fidelity and certainty. Our design is driven by the needs of users such as law enforcement personnel who must make decisions by evaluating threat signatures in urban settings. The most efficient tool available to identify the nature of the threat object is real-time gamma spectroscopic analysis, as it is fast and has a very low probability of producing false positive alarm conditions. Urban radiological searches are inherently challenged by the rapid and large spatial variation of background gamma radiation, the presence of benign radioactive materials in terms of the normally occurring radioactive materials (NORM), and shielded and/or masked threat sources. Multiple spectral anomaly detection algorithms have been developed by national laboratories and commercial vendors. For example, the Gamma Detector Response and Analysis Software (GADRAS) a one-dimensional deterministic radiation transport software capable of calculating gamma ray spectra using physics-based detector response functions was developed at Sandia National Laboratories. The nuisance-rejection spectral comparison ratio anomaly detection algorithm (or NSCRAD), developed at Pacific Northwest National Laboratory, uses spectral comparison ratios to detect deviation from benign medical and NORM radiation source and can work in spite of strong presence of NORM and or medical sources. RSL has developed its own wavelet-based gamma energy spectral anomaly detection algorithm called WAVRAD. Test results and relative merits of these different algorithms will be discussed and demonstrated.

  19. Some solutions to on-line radiological monitoring of difficult streams

    SciTech Connect

    Bauer, M.L.; Ramsey, J.A.

    1987-01-01

    On-line monitoring for radiological contamination of dirty, but normally not radioactive, streams is difficult. Described are several new, low-fouling units that are intended to replace the existing sensors that monitor both beta and gamma activity. A sensor was designed, using a thin-wall Geiger-Mueller tube for beta and gamma sensitivity, to monitor the influent of the sanitary sewage treatment plant. The new design eliminates dead volumes inherent in the old unit by use of a double-layer, helically wound solenoid made of 5/16-in.-OD thin-wall (0.02-in.) Teflon tubing. A 4-L Marinelli beaker-based system that used a 3 x 3 NaI(Tl) scintillator was replaced with a multilayer solenoid of 5/8-in.-OD Teflon. Two units for the detection of beta radiation are also described. 1 ref., 6 figs., 1 tab.

  20. On-line handwritten text categorization

    NASA Astrophysics Data System (ADS)

    Peña Saldarriaga, Sebastián; Viard-Gaudin, Christian; Morin, Emmanuel

    2009-01-01

    As new innovative devices, accepting or producing on-line documents, emerge, managing facilities for these kinds of documents such as topic spotting are required. This means that we should be able to perform text categorization of on-line documents. The textual data available in on-line documents can be extracted through online recognition, a process which produces noise, i.e. errors, in the resulting text. This work reports experiments on categorization of on-line handwritten documents based on their textual contents. We analyze the effect of the word recognition rate on the categorization performances, by comparing the performances of a categorization system over the texts obtained through on-line handwriting recognition and the same texts available as ground truth. Two categorization algorithms (kNN and SVM) are compared in this work. A subset of the Reuters-21578 corpus consisting of more than 2000 handwritten documents has been collected for this study. Results show that accuracy loss is not significant, and precision loss is only significant for recall values of 60%-80% depending on the noise levels.

  1. An approach for quantitative analysis of vitamins D and B9 and their metabolites in human biofluids by on-line orthogonal sample preparation and sequential mass spectrometry detection.

    PubMed

    Ferreiro-Vera, Carlos; Priego-Capote, Feliciano; Luque de Castro, María Dolores

    2013-04-01

    An approach for quantitative analysis of two vitamins with different polarities (vitamins D and B9) and their metabolites is presented here. The approach is based on an experimental setup based on hyphenation of an automated workstation for preparation of liquid samples and an LC-MS/MS system with a triple quadrupole mass spectrometer. This configuration enabled development of an orthogonal protocol for sequential SPE retention of analytes with different polarities for subsequent elution and chromatographic separation prior to detection. The resulting method was validated by application to three human biofluids. Estimation of recovery factors in the SPE step led to values from 85.2 to 100% for vitamin D and metabolites and from 93.1 to 100% for vitamin B9 and metabolites (folic acid and folates). The influence of sample matrix variability by analysis of human serum, urine and breast milk was minimized with a complete optimization of the SPE step. The utility of the proposed configuration is shown by the sensitivity and precision of the method, expressed as limits of detection (between 0.2 and 0.30 ng mL(-1) or 4 and 60 pg on-column) and within-laboratory reproducibility (lower than 6.7%, as relative standard deviation). The present application represents an example of determination methods involving targeted analysis of compounds with different polarities using a single aliquot of the sample. PMID:23435066

  2. High speed preamplifier circuit, detection electronics, and radiation detection systems therefrom

    DOEpatents

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

    2010-09-21

    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.

  3. Application of DNA comet assay for detection of radiation treatment of grams and pulses.

    PubMed

    Khan, Hasan M; Khan, Ashfaq A; Khan, Sanaullah

    2011-12-01

    Several types of whole pulses (green lentils, red lentils, yellow lentils, chickpeas, green peas, cowpeas and yellow peas) and grams (black grams, red grams and white grams) have been investigated for the identification of radiation treatment using microgel electrophoresis of single cells (DNA comet assay). Pulses and grams were exposed to the radiation doses of 0.5, 1.0 and 5 kGy covering the legalized commercial dose range for protection from insect/pest infestations. All irradiated samples showed comet like stretching of fragmented DNA toward anode, which is expected for irradiated samples. Unirradiated samples showed many intact cells/nuclei in form of round stains or with short faint tails, which is typical for unirradiated food samples. The study shows that DNA comet assay can be used as a rapid, inexpensive and highly effective screening test for the detection of radiation treatment of foods, like pulses and grams. PMID:23572810

  4. Detection and quantification of 8-hydroxydeoxyguanosine adducts in peripheral blood of people exposed to ionizing radiation.

    PubMed Central

    Wilson, V L; Taffe, B G; Shields, P G; Povey, A C; Harris, C C

    1993-01-01

    Ionizing radiation produces a variety of damaging insults to nucleic acids, including the promutagenic lesion 8-hydroxydeoxyguanosine. In the present study, the 8-hydroxydeoxyguanosine content of peripheral blood leukocyte DNA isolated from individuals exposed to therapeutic doses of ionizing radiation was determined by a HPLC-coupled 32P-postlabeling assay. Peripheral blood leukocyte DNA from individuals irradiated with 180-200 cGy were observed to contain 2-4.5 times as much 8-hydroxydeoxyguanosine as that from unexposed individuals. These results were confirmed by the use of a HPLC-coupled electrochemical detection system. Thus, human exposure to ionizing radiation significantly increased the circulating leukocyte DNA content of 8-hydroxydeoxyguanosine. Images FIGURE 2. PMID:8319639

  5. Summary Report for the Radiation Detection for Nuclear Security Summer School 2012

    SciTech Connect

    Runkle, Robert C.; Baciak, James E.; Stave, Jean A.

    2012-08-22

    The Pacific Northwest National Laboratory (PNNL) hosted students from across the United States at the inaugural Radiation Detection for Nuclear Security Summer School from June 11 – 22, 2012. The summer school provided students with a unique understanding of nuclear security challenges faced in the field and exposed them to the technical foundations, analyses, and insight that will be required by future leaders in technology development and implementation. The course heavily emphasized laboratory and field demonstrations including direct measurements of special nuclear material. The first week of the summer school focused on the foundational knowledge required by technology practitioners; the second week focused on contemporary applications. Student evaluations and feedback from student advisors indicates that the summer school achieved its objectives of 1) exposing students to the range of nuclear security applications for which radiation detection is necessary, 2) articulating the relevance of student research into the broader context, and 3) exciting students about the possibility of future careers in nuclear security.

  6. Methods for radiation detection and characterization using a multiple detector probe

    DOEpatents

    Akers, Douglas William; Roybal, Lyle Gene

    2014-11-04

    Apparatuses, methods, and systems relating to radiological characterization of environments are disclosed. Multi-detector probes with a plurality of detectors in a common housing may be used to substantially concurrently detect a plurality of different radiation activities and types. Multiple multi-detector probes may be used in a down-hole environment to substantially concurrently detect radioactive activity and contents of a buried waste container. Software may process, analyze, and integrate the data from the different multi-detector probes and the different detector types therein to provide source location and integrated analysis as to the source types and activity in the measured environment. Further, the integrated data may be used to compensate for differential density effects and the effects of radiation shielding materials within the volume being measured.

  7. Observation of the 3He(n, tp) Reaction by Detection of Far-Ultraviolet Radiation

    PubMed Central

    Thompson, Alan K.; Coplan, Michael A.; Cooper, John W.; Hughes, Patrick P.; Vest, Robert E.; Clark, Charles

    2008-01-01

    We have detected Lyman alpha radiation, 121.6 nm light produced from the n = 2 to n = 1 transition in atomic hydrogen, as a product of the 3He(n, tp) nuclear reaction occurring in a cell of 3He gas. The predominant source of this radiation appears to be decay of the 2p state of tritium produced by charge transfer and excitation collisions with the background 3He gas. Under the experimental conditions reported here we find yields of tens of Lyman alpha photons for every neutron reaction. These results suggest a method of cold neutron detection that is complementary to existing technologies that use proportional counters. In particular, this approach may provide single neutron sensitivity with wide dynamic range capability, and a class of neutron detectors that are compact and operate at relatively low voltages. PMID:27096112

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

    DOEpatents

    Lauf, Robert J.; McElhaney, Stephanie A.; Bates, John B.

    1994-01-01

    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.

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

    DOEpatents

    Lauf, R.J.; McElhaney, S.A.; Bates, J.B.

    1994-07-26

    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.

  10. On-line uranium determination using remote fiber fluorimetry

    NASA Astrophysics Data System (ADS)

    Malstrom, R. A.

    Remote Fiber Fluorimetry (RFF) is being developed at Savannah River Laboratory for the on-line determination of uranium in plant process streams. A prototype system suitable for plant use has been designed and is being built. RFF has four major components: a laser, an optical fiber, an optrode, and a detector. Essentially, an optical fiber carries laser radiation from a laser to a process sampling point. An optrode (the optical analog of an electrode) couples the laser light into a sample solution. Fluorescence from the sample is collected by the optrode and goes back through the same fiber to a detector.

  11. Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer

    PubMed Central

    Borrego-Soto, Gissela; Ortiz-López, Rocío; Rojas-Martínez, Augusto

    2015-01-01

    Abstract Breast cancer is the most common malignancy in women. Radiotherapy is frequently used in patients with breast cancer, but some patients may be more susceptible to ionizing radiation, and increased exposure to radiation sources may be associated to radiation adverse events. This susceptibility may be related to deficiencies in DNA repair mechanisms that are activated after cell-radiation, which causes DNA damage, particularly DNA double strand breaks. Some of these genetic susceptibilities in DNA-repair mechanisms are implicated in the etiology of hereditary breast/ovarian cancer (pathologic mutations in the BRCA 1 and 2 genes), but other less penetrant variants in genes involved in sporadic breast cancer have been described. These same genetic susceptibilities may be involved in negative radiotherapeutic outcomes. For these reasons, it is necessary to implement methods for detecting patients who are susceptible to radiotherapy-related adverse events. This review discusses mechanisms of DNA damage and repair, genes related to these functions, and the diagnosis methods designed and under research for detection of breast cancer patients with increased radiosensitivity. PMID:26692152

  12. Possible standoff detection of ionizing radiation using high-power THz electromagnetic waves

    NASA Astrophysics Data System (ADS)

    Nusinovich, Gregory S.; Sprangle, Phillip; Romero-Talamas, Carlos A.; Rodgers, John; Pu, Ruifeng; Kashyn, Dmytro G.; Antonsen, Thomas M., Jr.; Granatstein, Victor L.

    2012-06-01

    Recently, a new method of remote detection of concealed radioactive materials was proposed. This method is based on focusing high-power short wavelength electromagnetic radiation in a small volume where the wave electric field exceeds the breakdown threshold. In the presence of free electrons caused by ionizing radiation, in this volume an avalanche discharge can then be initiated. When the wavelength is short enough, the probability of having even one free electron in this small volume in the absence of additional sources of ionization is low. Hence, a high breakdown rate will indicate that in the vicinity of this volume there are some materials causing ionization of air. To prove this concept a 0.67 THz gyrotron delivering 200-300 kW power in 10 microsecond pulses is under development. This method of standoff detection of concealed sources of ionizing radiation requires a wide range of studies, viz., evaluation of possible range, THz power and pulse duration, production of free electrons in air by gamma rays penetrating through container walls, statistical delay time in initiation of the breakdown in the case of low electron density, temporal evolution of plasma structure in the breakdown and scattering of THz radiation from small plasma objects. Most of these issues are discussed in the paper.

  13. Apparatus and method for detecting electromagnetic radiation using electron photoemission in a micromechanical sensor

    DOEpatents

    Datskos, Panagiotis G.; Rajic, Slobodan; Datskou, Irene C.; Egert, Charles M.

    2002-01-01

    A micromechanical sensor and method for detecting electromagnetic radiation involve producing photoelectrons from a metal surface in contact with a semiconductor. The photoelectrons are extracted into the semiconductor, which causes photo-induced bending. The resulting bending is measured, and a signal corresponding to the measured bending is generated and processed. A plurality of individual micromechanical sensors can be arranged in a two-dimensional matrix for imaging applications.

  14. Quantum Well Intrasubband Photodetector for Far Infared and Terahertz Radiation Detection

    NASA Technical Reports Server (NTRS)

    Ting, David Z. -Y.; Chang, Yia-Chung; Bandara, Sumith V.; Gunapala, Sarath D.

    2007-01-01

    The authors present a theoretical analysis on the possibility of using the dopant-assisted intrasubband absorption mechanism in quantum wells for normal-incidence far infrared/terahertz radiation detection. The authors describe the proposed concept of the quantum well intrasubband photodetector (QWISP), which is a compact semiconductor heterostructure device compatible with existing GaAs focal-plane array technology, and present theoretical results demonstrating strong normal-incidence absorption and responsivity in the QWISP.

  15. An application of LOH analysis for detecting the genetic influences of space environmental radiation

    NASA Astrophysics Data System (ADS)

    Yatagai, F.; Umebayashi, Y.; Honma, M.; Abe, T.; Suzuki, H.; Shimazu, T.; Ishioka, N.; Iwaki, M.

    To detect the genetic influence of space environmental radiation at the chromosome level we proposed an application of loss of heterozygosity LOH analysis system for the mutations induced in human lymphoblastoid TK6 cells Surprisingly we succeeded the mutation detection in the frozen dells which were exposed to a low-dose 10 cGy of carbon-ion beam irradiation Mutation assays were performed within a few days or after about one month preservation at --80 r C following irradiation The results showed an increase in mutation frequency at the thymidine kinase TK gene locus 1 6-fold 2 5 X 10 -6 to 3 9 X 10 -6 and 2 1-fold 2 5 X 10 -6 to 5 3 X 10 -6 respectively Although the relative distributions of mutation classes were not changed by the radiation exposure in either assay an interesting characteristic was detected using this LOH analysis system two TK locus markers and eleven microsatellite loci spanning chromosome 17 The radiation-specific patterns of interstitial deletions were observed in the hemizygous LOH mutants which were considered as a result of end-joining repair of carbon ion-induced DNA double-strand breaks These results clearly demonstrate that this analysis can be used for the detection of low-dose ionizing radiation effects in the frozen cells In addition we performed so called adaptive response experiments in which TK6 cells were pre-irradiated with low-dose 2 5 sim 10 cGy of X-ray and then exposed to challenging dose 2Gy of X-rays Interestingly the

  16. Water-dispersable colloidal quantum dots for the detection of ionizing radiation.

    PubMed

    Lecavalier, Marie-Eve; Goulet, Mathieu; Allen, Claudine Nì; Beaulieu, Luc; Larivière, Dominic

    2013-12-25

    Fluorescent CdSe-CdS-Cd0.5Zn0.5S-ZnS core-shell colloidal quantum dots (cQDs) dispersed in aqueous and organic solvents have been prepared and used as scintillators for detecting ionizing radiation. Results demonstrate a linear relationship between emitted luminescence and dose-activity. These results suggest that cQDs alone could be used as liquid scintillators for specific environmental and medical applications. PMID:24177415

  17. On-line atomic data access

    NASA Astrophysics Data System (ADS)

    Schultz, David R.; Nash, Jeffrey K.

    1996-07-01

    The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser-produced plasma research, and plasma processing. Modern computer database and communications technology enables this data to be placed on-line and obtained by users over the INTERNET. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

  18. Radiation protection program for early detection of breast cancer in a mammography facility

    NASA Astrophysics Data System (ADS)

    Villagomez Casimiro, Mariana; Ruiz Trejo, Cesar; Espejo Fonseca, Ruby

    2014-11-01

    Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards [1-4]. To achieve this goal, radiation protection and quality control manuals were elaborated [5]. Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (<3 mGy per projection). The image quality test showed that most images (70%)- presented artifacts. A brief summary of the results of quality control tests applied to the equipment and film processor are presented. To maintain an adequate level of quality and safety at FUCAM-AC is necessary that the proposed radiation protection program in this work is applied.

  19. Radiation protection program for early detection of breast cancer in a mammography facility

    SciTech Connect

    Mariana, Villagomez Casimiro E-mail: cesar@fisica.unam.mx; Cesar, Ruiz Trejo E-mail: cesar@fisica.unam.mx; Ruby, Espejo Fonseca

    2014-11-07

    Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards [1–4]. To achieve this goal, radiation protection and quality control manuals were elaborated [5]. Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (<3 mGy per projection). The image quality test showed that most images (70%)– presented artifacts. A brief summary of the results of quality control tests applied to the equipment and film processor are presented. To maintain an adequate level of quality and safety at FUCAM-AC is necessary that the proposed radiation protection program in this work is applied.

  20. On-line object feature extraction for multispectral scene representation

    NASA Technical Reports Server (NTRS)

    Ghassemian, Hassan; Landgrebe, David

    1988-01-01

    A new on-line unsupervised object-feature extraction method is presented that reduces the complexity and costs associated with the analysis of the multispectral image data and data transmission, storage, archival and distribution. The ambiguity in the object detection process can be reduced if the spatial dependencies, which exist among the adjacent pixels, are intelligently incorporated into the decision making process. The unity relation was defined that must exist among the pixels of an object. Automatic Multispectral Image Compaction Algorithm (AMICA) uses the within object pixel-feature gradient vector as a valuable contextual information to construct the object's features, which preserve the class separability information within the data. For on-line object extraction the path-hypothesis and the basic mathematical tools for its realization are introduced in terms of a specific similarity measure and adjacency relation. AMICA is applied to several sets of real image data, and the performance and reliability of features is evaluated.

  1. Low dose detection of γ radiation via solvent assisted fluorescence quenching.

    PubMed

    Han, Ji-Min; Xu, Miao; Wang, Brian; Wu, Na; Yang, Xiaomei; Yang, Haori; Salter, Bill J; Zang, Ling

    2014-04-01

    Development of low cost, easy-to-use chemical sensor systems for low dose detection of γ radiation remains highly desired for medical radiation therapy and nuclear security monitoring. We report herein on a new fluorescence sensor molecule, 4,4'-di(1H-phenanthro[9,10-d]imidazol-2-yl)biphenyl (DPI-BP), which can be dissolved into halogenated solvents (e.g., CHCl3, CH2Cl2) to enable instant detection of γ radiation down to the 0.01 Gy level. The sensing mechanism is primarily based on radiation induced fluorescence quenching of DPI-BP. Pristine DPI-BP is strongly fluorescent in halogenated solvents. When exposed to γ radiation, the halogenated solvents decompose into various radicals, including hydrogen and chlorine, which then combine to produce hydrochloric acid (HCl). This strong acid interacts with the imidazole group of DPI-BP to convert it into a DPI-BP/HCl adduct. The DPI-BP/HCl adduct possesses a more planar configuration than DPI-BP, enhancing the π-π stacking and thus molecular aggregation. The strong molecular fluorescence of DPI-BP gets quenched upon aggregation, due to the π-π stacking interaction (forming forbidden low-energy excitonic transition). Interestingly the quenched fluorescence can be recovered simply by adding base (e.g., NaOH) into the solution to dissociate the DPI-BP/HCl adduct. Such sensing mechanism was supported by systematic investigations based on HCl titration and dynamic light scattering measurements. To further confirm that the aggregation caused fluorescence quenching, a half size analogue of DPI-BP, 2-phenyl-1H-phenanthro[9,10-d]imidazole (PI-Ph), was synthesized and investigated in comparison with the observations of DPI-BP. PI-Ph shares the same imidazole conjugation structure with DPI-BP and is expected to bind the same way with HCl. However, PI-Ph did not show fluorescence quenching upon binding with HCl likely due to the smaller π-conjugation structure, which can hardly enforce the π-π stacking assembly. Combining

  2. Reflections of an On-Line Tutor

    ERIC Educational Resources Information Center

    Towndrow, Phillip

    2004-01-01

    This article investigates the relatively unexplored field of reflective journal writing by an on-line tutor, in this case working with a group of Chinese learners of English attending an intensive communication skills programme at a tertiary-level institution in Singapore. The results reported highlight the role of the reflective journal in…

  3. Student System, On-Line Admissions.

    ERIC Educational Resources Information Center

    White, Stephen R.

    This report provides technical information on an on-line admissions system developed by Montgomery College. Part I, Systems Development, describes the background, objectives and responsibilities, system design, and reports generated by the system. Part II, Operating Instructions, describes input forms and controls, admission system functions, file…

  4. Student System, On-Line Registration.

    ERIC Educational Resources Information Center

    Michael, Mary Ellen

    This report provides technical information on an on-line student registration system developed by Montgomery College. Part I, Systems Development, describes the background, objectives and benefits, system design, and reports generated by the system. Part II, Operating Instructions, describes input forms, registration system functions, file…

  5. LUST ON-LINE CALCULATOR INTRODUCTION

    EPA Science Inventory

    EPA has developed a suite of on-line calculators to assist in performing site assessment and modeling calculations for leaking underground storage tank sites (http://www.epa.gov/athens/onsite). The calculators are divided into four types: parameter estimation, models, scientific...

  6. On-line field measurements of VOC emissions from a spruce tree at SMEAR Estonia

    NASA Astrophysics Data System (ADS)

    Bourtsoukidis, Efstratios; Bonn, Boris; Noe, Steffen

    2013-04-01

    We have investigated VOC emissions from a Norway spruce tree (Picea abies) in a hemi-boreal mixed forest in September and October 2012, using Proton Transfer Reaction Mass Spectrometry and Gas Chromatography - Mass Spectrometry techniques, applied in a dynamic branch enclosure system that was automatically operated with an electrical compressor. Parallel to BVOC measurements a vast amount of atmospheric (CO2, CH4, H2O, CO, particles) and meteorological (temperature, relative humidity, photosynthetic active radiation, wind speed and direction, precipitation) parameters were measured in the ambient atmosphere and inside the cuvette enclosure (temperature, relative humidity, O3). Prior to the measuring period, an innovatory experimental setup was built at Järvselja forest station, in order to accomplish the detection of BVOC and minimize sampling losses. Therefore, a new inlet line, consisting of 19.4m of heated and isolated glass tube was constructed. The new inlet system applied, allowed the on-line detection and calculation of sesquiterpene (SQT) emission rates for the first time in a hemi-boreal forest site. It total, 12 atmospheric relevant BVOCs were continuously monitored for a three week period and the emission rates were derived. Along with diurnal profiles and continuous timeless, some interesting observations showed the possibility of ozone effect on SQT emissions, the possibility of radiation effect on MT emissions, the higher induced emissions due to mechanical stress and the possibility for a valid intercomparison between different spruce trees located in mountain Kleiner Feldberg (Germany) and in Järvseja forest station (Estonia).

  7. Transformation invariant on-line target recognition.

    PubMed

    Iftekharuddin, Khan M

    2011-06-01

    Transformation invariant automatic target recognition (ATR) has been an active research area due to its widespread applications in defense, robotics, medical imaging and geographic scene analysis. The primary goal for this paper is to obtain an on-line ATR system for targets in presence of image transformations, such as rotation, translation, scale and occlusion as well as resolution changes. We investigate biologically inspired adaptive critic design (ACD) neural network (NN) models for on-line learning of such transformations. We further exploit reinforcement learning (RL) in ACD framework to obtain transformation invariant ATR. We exploit two ACD designs, such as heuristic dynamic programming (HDP) and dual heuristic dynamic programming (DHP) to obtain transformation invariant ATR. We obtain extensive statistical evaluations of proposed on-line ATR networks using both simulated image transformations and real benchmark facial image database, UMIST, with pose variations. Our simulations show promising results for learning transformations in simulated images and authenticating out-of plane rotated face images. Comparing the two on-line ATR designs, HDP outperforms DHP in learning capability and robustness and is more tolerant to noise. The computational time involved in HDP is also less than that of DHP. On the other hand, DHP achieves a 100% success rate more frequently than HDP for individual targets, and the residual critic error in DHP is generally smaller than that of HDP. Mathematical analyses of both our RL-based on-line ATR designs are also obtained to provide a sufficient condition for asymptotic convergence in a statistical average sense. PMID:21571610

  8. Feasibility of OCT to detect radiation-induced esophageal damage in small animal models (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jelvehgaran, Pouya; Alderliesten, Tanja; Salguero, Javier; Borst, Gerben; Song, Ji-Ying; van Leeuwen, Ton G.; de Boer, Johannes F.; de Bruin, Daniel M.; van Herk, Marcel B.

    2016-03-01

    Lung cancer survival is poor and radiotherapy patients often suffer serious treatment side effects. The esophagus is particularly sensitive leading to reduced food intake or even fistula formation. Only few direct techniques exist to measure radiation-induced esophageal damage, for which knowledge is needed to improve the balance between risk of tumor recurrence and complications. Optical coherence tomography (OCT) is a minimally-invasive imaging technique that obtains cross-sectional, high-resolution (1-10µm) images and is capable of scanning the esophageal wall up to 2-3mm depth. In this study we investigated the feasibility of OCT to detect esophageal radiation damage in mice. In total 30 mice were included in 4 study groups (1 main and 3 control groups). Mice underwent cone-beam CT imaging for initial setup assessment and dose planning followed by single-fraction dose delivery of 4, 10, 16, and 20Gy on 5mm spots, spaced 10mm apart. Mice were repeatedly imaged using OCT: pre-irradiation and up to 3 months post-irradiation. The control groups received either OCT only, irradiation only, or were sham-operated. We used histopathology as gold standard for radiation-induced damage diagnosis. The study showed edema in both the main and OCT-only groups. Furthermore, radiation-induced damage was primarily found in the highest dose region (distal esophagus). Based on the histopathology reports we were able to identify the radiation-induced damage in the OCT images as a change in tissue scattering related to the type of induced damage. This finding indicates the feasibility and thereby the potentially promising role of OCT in radiation-induced esophageal damage assessment.

  9. Radiation detection with CdTe quantum dots in sol-gel glass and polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Manickaraj, Kavin; Wagner, Brent K.; Kang, Zhitao

    2013-05-01

    Optically based radiation detectors in various fields of science still suffer from low resolution, sensitivity and efficiency that restrict their overall performance. Quantum dots (QD) are well-suited for such detectors due to their unique optical properties. CdTe QDs show fast luminescence decay times, high conversion efficiencies, and have band gaps strongly dependent on the particle radius. Since QD particle sizes are well below the wavelengths of their emissions, they remain optically transparent when incorporated in both polymer and sol-gel based silica glass due to negligible optical scattering. In addition, as these composite materials can greatly improve the mechanical robustness of alpha-particle detectors, conventionally known to have delicate components, CdTe QDs show high promise for radiation sensing applications. These properties are especially advantageous for alpha-particle and potentially neutron detection. In this work, CdTe QD-based glass or polymer matrix nanocomposites were synthesized for use as alpha-particle detection scintillators.. The fast photo-response and decay times provide excellent time resolution. The radiation responses of such nanocomposites in polymer or glass matrices were investigated.

  10. Ultrasound-Detected Thyroid Nodule Prevalence and Radiation Dose from Fallout

    PubMed Central

    Land, C. E.; Zhumadilov, Z.; Gusev, B. I.; Hartshorne, M. H.; Wiest, P. W.; Woodward, P. W.; Crooks, L. A.; Luckyanov, N. K.; Fillmore, C. M.; Carr, Z.; Abisheva, G.; Beck, H. L.; Bouville, A.; Langer, J.; Weinstock, R.; Gordeev, K. I.; Shinkarev, S.; Simon, S. L.

    2014-01-01

    Settlements near the Semipalatinsk Test Site (SNTS) in northeastern Kazakhstan were exposed to radioactive fallout during 1949–1962. Thyroid disease prevalence among 2994 residents of eight villages was ascertained by ultrasound screening. Malignancy was determined by cytopathology. Individual thyroid doses from external and internal radiation sources were reconstructed from fallout deposition patterns, residential histories and diet, including childhood milk consumption. Point estimates of individual external and internal dose averaged 0.04 Gy (range 0–0.65) and 0.31 Gy (0–9.6), respectively, with a Pearson correlation coefficient of 0.46. Ultrasound-detected thyroid nodule prevalence was 18% and 39% among males and females, respectively. It was significantly and independently associated with both external and internal dose, the main study finding. The estimated relative biological effectiveness of internal compared to external radiation dose was 0.33, with 95% confidence bounds of 0.09–3.11. Prevalence of papillary cancer was 0.9% and was not significantly associated with radiation dose. In terms of excess relative risk per unit dose, our dose–response findings for nodule prevalence are comparable to those from populations exposed to medical X rays and to acute radiation from the Hiroshima and Nagasaki atomic bombings. PMID:18363427

  11. Time Resolved Detection of Infrared Synchrotron Radiation at DA{phi}NE

    SciTech Connect

    Bocci, A.; Marcelli, A.; Drago, A.; Guidi, M. Cestelli; Pace, E.; Piccinini, M.; Sali, D.; Morini, P.

    2007-01-19

    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{phi}NE (Double Annular {phi}-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{phi}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.

  12. Synthesis of scintillating metal organic frameworks for the detection of radiation from subatomic particles

    NASA Astrophysics Data System (ADS)

    Ingram, Conrad; Williams, Michael

    2013-04-01

    The objective of this research is to develop fluorescent metal organic frameworks (MOFs) as scintillation materials for more efficient light output and detection of ionizing radiation, such as neutrons, alpha particles or gamma rays, generated by fissile materials. MOFs are multidimensional porous structures, which are synthesized from the covalent bonding of metal ions or metal oxide clusters with organic ligand linkers, such as benzene dicarboxylates. The ligands will be chosen to have fluorescent characteristics, when excited by radiation or energetic sub-atomic particles. We will explore the synthesis of new MOFs, containing carboxylate ligands with unique conjugated chromophores, such as, benzene-1,3,5-triyltris(ethene-2,1-diyl)) tribenzoic acid and 9-hydroxy-9-vinyl-9H-fluorene-2,7-dicarboxylic acid), and doped with heavy metal as triplet-state harvesters, that we are proposing will result in stronger and possibly, unique luminescence spectral features that will allow for the discrimination between different ionizing radiations from subatomic particles. Photo-, catho- and radio-luminescence studies will be conducted on the materials, and radiation mechanism(s) will be investigated.

  13. Multi-parameter on-line coal bulk analysis

    SciTech Connect

    1999-02-01

    This was a four-year grant that was given a no cost extension for one more year. The purpose of the grant was to develop a pulsed neutron-based technique that could measure on-line all the major and minor elements in coal. Such measurements would allow the continuous monitoring of bulk parameters such as coal heating value (BTU/lb), volatile matter, moisture etc., deemed important to the coal industry. Such parameters, along with the continuous measurement of elements such as sulfur and sodium, are of major economic and environmental concern, and their measurement would assist in a more efficient use of the coal-fired boilers, as well as limiting emissions controlled by the 1990 Clean Air Act Amendments. It was hoped that this study would lead to the development of a technique able to create a marketable product, an On-Line Elemental Coal Analyzer. The study was separated in the following major parts: (1) Devise an efficient system for the detection of gamma rays; (2) Prior to experimentation, perform modeling and simulations for items such as detector shielding, coal sample configuration, and neutron tube collimation; (3) Develop a computer code for data reduction and analysis; (4) Measure the elemental composition of various coal samples; and (5) Design a prototype, on-line elemental coal analyzer, based on the PFTNA principle.

  14. On-line handwriting analysis using wavelets

    NASA Astrophysics Data System (ADS)

    Srikantan, Geetha; Srihari, Rohini K.

    1995-09-01

    Speech and Handwriting interfaces to computing devices have received increased attention recently as alternate human-computer media. Automatic recognition of unconstrained handwritten text must be provided as a capability in handwriting computer interfaces. Variation in writing styles of a single writer at different times and between multiple writers makes unconstrained on-line handwriting recognition a challenging task. On-line handwriting is recorded as a sequence of coordinates as the writer's pen moves along the recording device. Isolated character and word recognition have been addressed by several researchers. More recently, attention has been focussed on the recognition of unconstrained text streams. The dynamic changes in handwriting styles observed in everyday use requires development of methods that are adaptive to local variations. We present a novel application of wavelet-based analysis of pen position, velocity and acceleration time-sequences for segmentation and recognition of text components.

  15. On-line controlled documents: Lessons learned

    SciTech Connect

    Cochrell, R.C.; Steele, C.M.

    1995-06-01

    Placing Controlled Documents on-line on a computer network seems like the solution to many problems, one being distribution, with a path toward a paperless office. However, many problems presented themselves as we were designing the system and placing the documents on-line. Although we planned and established a Process Management Team to help work out the bugs, we still encountered many obstacles in the process. This presentation will cover the ``trials and tribulations`` of placing Controlled Documents on a computer network at three different sites. We will discuss the process we went through, the problems we encountered, the software we used, and how we got management to buy into the process.

  16. The EINSTEIN On-Line Service

    NASA Astrophysics Data System (ADS)

    Harris, D. E.; Grant, C. S.; Andernach, H.

    The Einstein On-Line Service (EOLS) is a simple menu-driven system which provides an intuitive method of querying over one hundred database catalogs. In addition, the EOLS contains over 30 CD-ROMs of images from the Einstein X-ray Observatory which are available for downloading. The EOLS provides all of our databases to the NASA Astrophysics Data System (ADS) and our documents which describe each table are written in the ADS format. In conjunction with the IAU working group on Radioastronomical Databases, the EOLS serves as an experimental platform for on-line access to radio source catalogs. The number of entries in these catalogs exceeds half a million.

  17. Detection of Radiation Tracks Recorded on Silver-Salt Photographic Materials by Fluorescence-Labeling Method

    NASA Astrophysics Data System (ADS)

    Kuge, Ken'ichi; Inoue, Ryouhei; Oishi, Yasushi; Yasuda, Nakahiro; Kodaira, Satoshi; Sato, Osamu

    2013-10-01

    We have proposed a new fluorescence-labeling method to detect radiation tracks recorded on silver-salt photographic materials. Fluorescence images of tracks were obtained by converting the developed silver to silver iodide as a mordant by bleaching and selectively adsorbing a fluorescent dye, namely, 3,3'-diethyl-2,2'-oxacyanine iodide, on it. The dye emitted blue and green fluorescent lights in the adsorbed state to silver iodide. Even tracks masked with fake particles could be recognized clearly in the fluorescence images, because the dye was adsorbed only on silver iodide. This new fluorescence-labeling method will facilitate the development of new technologies for the analysis of radiation tracks on the basis of the color information obtained from the tracks.

  18. Impurity Radiation for Detecting Arcs during High Lower Hybrid Power Transmission at JET

    SciTech Connect

    Goniche, M.; Delpech, L.; Ekedahl, A.; Hillairet, J.; Mailloux, J.; Baranov, Y.; Coffey, I.; Kirov, K.; Mayoral, M.-L.; Sergienko, G.; Ongena, J.

    2009-11-26

    During high power commissioning of the JET LH launcher, the radiation and impurity release has been analyzed from various diagnostics: VUV and visible spectroscopy, bolometry. These two last diagnostics have lines-of-sight viewing the launcher and can provide information about the electron and/or impurity source localisation. Using a database of 800 plasmas, it is concluded that the iron contamination (FeXV and FeXXIII) is very low for 94% of the pulses and increases linearly with LH power. During arcs, a strong and fast increase of the radiation along the line-of-sight viewing the launcher is observed. This diagnostic could provide a tool for arc detection complementary to the RF measurements aiming at reducing the metal contamination in the plasma.

  19. Potential Application of Fabricated Sulfide-Based Scintillation Materials for Radiation Detection

    SciTech Connect

    Im, Hee-Jung; Dai, Sheng; Pawel, Michelle D; Brown, Suree

    2010-01-01

    In our laboratories, we have produced ZnS(Ag)/{sup 6}Li sol-gel scintillation materials which produce an excellent light output with an alpha radiation (compared to commercial high temperature lithiated glass; KG-2 and a plastic scintillator; BC-400). However, when tested with a neutron radiation, the opacity of the ZnS(Ag)/{sup 6}Li sol-gel scintillation materials, which were composed of a homogeneous micron-sized ZnS(Ag), prevented a clear neutron energy peak formation, thus making it difficult to set a threshold for neutron-gamma discrimination. In an effort to increase the transparency of the scintillation materials and to develop new technologies to fabricate sulfide-based scintillation materials for neutron detection, we turned to the methods of a chemical bath deposition (CBD) and a nano-particle synthesis for possible solutions.

  20. An analysis of a spreader bar crane mounted gamma-ray radiation detection system

    NASA Astrophysics Data System (ADS)

    Grypp, Matthew David

    Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192 Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 +/- 0.4 microcuries (muCi), 19.3 +/- 1.1 muCi, 11.7 +/- 0.6 muCi, 3.5 +/- 0.3 kilograms (kg), and 30.6 +/- 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.

  1. Patient monitoring: on-line computing

    PubMed Central

    Raison, John C. A.

    1970-01-01

    On-line computing represents a further extension of the senses of attendant staff in intensive care situations. Smaller computers will contribute as scientific processors, by extending the capability of instrumental systems or enabling new means of measurement and calculation. The fullest use of computer-aid will provide systems of data acquisition from multiple sources, rapid processing correlation, analysis in mathematical and diagnostic forms, and resultant output in simply intelligible displays: later, some direct control of therapy may be applied. PMID:5476133

  2. Connecting to On-line Data

    NASA Astrophysics Data System (ADS)

    Eichhorn, G.; Astrophysics Datacenter Executive Committee (ADEC)

    2004-05-01

    The Astrophysics Datacenter Executive Committee (ADEC) is coordinating the development of a system to facilitate the linking to on-line data. This system has three components: 1. Unique dataset identifiers. 2. A verification system for identifiers. 3. Permanent links to on-line data sets. 1. The ADEC has agreed on a naming scheme for data sets that allows for the unique identification of any data set. The ADEC data centers will clearly mark their data with these identifiers to allow the generation of links to these data. 2. Each data center has a utility that can check whether a data set identifier is a valid identifier at that center. A central verifier allows third parties access to these individual verifiers through a single portal. 3. The central verifier also provides permanent links to data sets through a central link forwarding system. This makes it possible to move data sets between data centers while maintaining the permanent links. The ADEC plans to first use this system to implement the linking from the literature to on-line data in a collaboration with the AAS and the University of Chicago Press for the AAS journals.

  3. Tailoring Adjuvant Radiation Therapy by Intraoperative Imaging to Detect Residual Cancer.

    PubMed

    Whitley, Melodi J; Weissleder, Ralph; Kirsch, David G

    2015-10-01

    For many solid cancers, radiation therapy is offered as an adjuvant to surgical resection to lower rates of local recurrence and improve survival. However, a subset of patients treated with surgery alone will not have a local recurrence. Currently, there is no way to accurately determine which patients have microscopic residual disease in the tumor bed after surgery and therefore are most likely to benefit from adjuvant radiation therapy. To address this problem, a number of technologies have been developed to try to improve margin assessment of resected tissue and to detect residual cancer in the tumor bed. Moreover, some of these approaches have been translated from the preclinical arena into clinical trials. Here, we review different types of intraoperative molecular imaging systems for cancer. Optical imaging techniques like epi-illumination, fluorescence molecular tomography and optoacoustic imaging can be coupled with exogenous fluorescent imaging probes that accumulate in tumors passively via the enhanced permeability and retention effect or are targeted to tumor tissues based on affinity or enzyme activity. In these approaches, detection of fluorescence in the tumor bed may indicate residual disease. Protease activated probes have generated great interest because of their potential for leading to high tumor to normal contrast. Recently, the first Phase I clinical trial to assess the safety and activation of a protease activated probe was conducted. Spectroscopic methods like radiofrequency spectroscopy and Raman spectroscopy, which are based on energy absorption and scattering, respectively, have also been tested in humans and are able to distinguish between normal and tumors tissues intraoperatively. Most recently, multimodal contrast agents have been developed that target tumors and contain both fluorescent dyes and magnetic resonance imaging contrast agents, allowing for preoperative planning and intraoperative margin assessment with a single contrast

  4. On-line composition with laser-based techniques

    SciTech Connect

    Finch, F.T.; Hartford, A. Jr.

    1982-01-01

    Current methods for determining the composition of coal gasification streams generally involve sampling, some treatment, and inherent delay times prior to analysis. Optical instrumentation, on the other hand, provides the potential for on-line, rapid-response monitoring of gasifier streams. Among the optical technques that appear quite promising for this application are coherent anti-Stokes Raman scattering (CARS), laser-induced breakdown spectroscopy (LIBS), Fourier transform infrared spectroscopy (FTIR), laser-induced fluorescence (LIF), and synchronous detection of laser-induced fluorescence (SDLIF).

  5. Operation of an on-line substation diagnosis system

    SciTech Connect

    Fujimoto, Y.; Ono, T. ); Ibuki, K.; Taka, S. )

    1988-10-01

    On-line monitoring systems for substation equipment are expected to give an impact on the improvement of the reliability of the power system. A monitoring system was applied to one of the newly built substations. It monitors the 204 kV and 72 kV GIS's and the transformer in their normal operation condition. The basic philosophy of the monitoring system and the principle of the detection of the abnormality is introduced together with the record of its operation in the first year.

  6. Source reduction from chemical plants using on-line optimization

    SciTech Connect

    Zhang, Z.; Pike, R.W.; Hertwig, T.A.

    1995-12-01

    An effective approach for source reduction in chemical plants has been demonstrated using on-line optimization with flowsheeting (ASPEN PLUS) for process optimization and parameter estimation and the Tjao-Biegler algorithm implemented in a mathematical programming language (GAMS/MINOS) for data reconciliation and gross error detection. Results for a Monsanto sulfuric acid plant with a Bailey distributed control system showed a 25% reduction in the sulfur dioxide emissions and a 17% improvement in the profit over the current operating conditions. Details of the methods used are described.

  7. Anisotropic. cap alpha. -emission of on-line separated isotopes

    SciTech Connect

    Wouters, J.; Vandeplassche, D.; van Walle, E.; Severijns, N.; Van Haverbeke, J.; Vanneste, L.

    1987-12-10

    The technical realization of particle detection at very low temperatures (4K) has made it possible to study for the first time the anisotropic ..cap alpha..-decay of oriented nuclei which have been produced, separated and implanted on line. The measured ..cap alpha..-angular distributions reveal surprising new results on nuclear aspects as well as in solid state physics. The nuclear structure information from these data questions the older ..cap alpha..-decay theoretical interpretation and urges for a reaxamination of the earliest work on anisotropic ..cap alpha..-decay.

  8. Sweating the small stuff: pitfalls in the use of radiation detection instruments.

    PubMed

    Prekeges, Jennifer Lynne

    2014-06-01

    Nuclear medicine technologists use nonimaging radiation detection instruments on a daily basis and routinely assess their performance in several ways. These instruments are simple to operate compared with imaging instruments but are also susceptible to misuse. After reviewing the theoretic basis for common mistakes and the importance of routine quality control, this continuing education article discusses pitfalls in the operation of dose calibrators, survey meters, scintillation detectors, and semiconductors. The article also reviews quality control procedures and ways in which these can be performed incorrectly. The goal of the article is to help technologists to spot and correct problems before they lead to errant results. PMID:24627414

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

    NASA Astrophysics Data System (ADS)

    Katayama, I.; Shimosato, H.; Bito, M.; Furusawa, K.; Adachi, M.; Shimada, M.; Zen, H.; Kimura, S.; Yamamoto, N.; Hosaka, M.; Katoh, M.; Ashida, M.

    2012-03-01

    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.

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

    SciTech Connect

    Katayama, I.; Shimosato, H.; Bito, M.; Furusawa, K.; Adachi, M.; Zen, H.; Kimura, S.; Katoh, M.; Shimada, M.; Yamamoto, N.; Hosaka, M.; Ashida, M.

    2012-03-12

    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.

  11. Prospects for detection of gravitational radiation by simultaneous Doppler tracking of several spacecraft

    NASA Technical Reports Server (NTRS)

    Estabrook, F. B.; Wahlquist, H. D.

    1978-01-01

    This paper reports a calculation of the effect of gravitational radiation on the observed Doppler shift of a sinusoidal electromagnetic signal transmitted to, and coherently transponded from, distant spacecraft. It is found that the effect of plane gravitational waves on such observations is not intuitively immediate, and in fact depends sensitively on the spacecraft direction, which suggests the possibility of detecting such plane waves by simultaneous Doppler tracking of several spacecraft. The need for broad band gravitational wave observations, the required stabilities of time keeping standards, and astrophysical sources expected in the Very Low Frequency band are briefly discussed.

  12. Detection scheme for acoustic quantum radiation in Bose-Einstein condensates.

    PubMed

    Schützhold, Ralf

    2006-11-10

    Based on doubly detuned Raman transitions between (meta)stable atomic or molecular states and recently developed atom counting techniques, a detection scheme for sound waves in dilute Bose-Einstein condensates is proposed whose accuracy might reach down to the level of a few or even single phonons. This scheme could open up a new range of applications including the experimental observation of quantum radiation phenomena such as the Hawking effect in sonic black-hole analogues or the acoustic analogue of cosmological particle creation. PMID:17155600

  13. Hybrid emergency radiation detection: a wireless sensor network application for consequence management of a radiological release

    NASA Astrophysics Data System (ADS)

    Kyker, Ronald D.; Berry, Nina; Stark, Doug; Nachtigal, Noel; Kershaw, Chris

    2004-08-01

    The Hybrid Emergency Radiation Detection (HERD) system is a rapidly deployable ad-hoc wireless sensor network for monitoring the radiation hazard associated with a radiation release. The system is designed for low power, small size, low cost, and rapid deployment in order to provide early notification and minimize exposure. The many design tradeoffs, decisions, and challenges in the implementation of this wireless sensor network design will be presented and compared to the commercial systems available. Our research in a scaleable modular architectural highlights the need and implementation of a system level approach that provides flexibility and adaptability for a variety of applications. This approach seeks to minimize power, provide mission specific specialization, and provide the capability to upgrade the system with the most recent technology advancements by encapsulation and modularity. The implementation of a low power, widely available Real Time Operating System (RTOS) for multitasking with an improvement in code maintenance, portability, and reuse will be presented. Finally future design enhancements technology trends affecting wireless sensor networks will be presented.

  14. Applications in Bioastronautics and Bioinformatics: Early Radiation Cataracts Detected by Noninvasive, Quantitative, and Remote Means

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; King, James F.; Giblin, Frank J.

    2000-01-01

    Human exploration of Mars is a key goal in NASA's exploration planning in the next 20 years. Maintaining crew health and good vision is certainly an important aspect of achieving a successful mission. Continuous radiation exposure is a risk factor for radiation-induced cataracts in astronauts because radiation exposure in space travel has the potential of accelerating the aging process (ref. 1). A patented compact device (ref. 2) based on the technique of dynamic light scattering (DLS) was designed for monitoring an astronaut's ocular health during long-duration space travel. This capability of early diagnosis, unmatched by any other clinical technique in use today, may enable prompt initiation of preventive/curative therapy. An Internet web-based system integrating photon correlation data and controlling the hardware to monitor cataract development in vivo at a remote site in real time (teleophthalmology) is currently being developed. The new technology detects cataracts very early (at the molecular level). Cataract studies onboard the International Space Station will be helpful in quantifying any adverse effect of radiation to ocular health. The normal lens in a human eye, situated behind the cornea, is a transparent tissue. It contains 35 wt % protein and 65 wt % water. Aging, disease (e.g., diabetes), smoking, dehydration, malnutrition, and exposure to ultraviolet light and ionizing radiation can cause agglomeration of the lens proteins. Protein aggregation can take place anywhere in the lens, causing lens opacity. The aggregation and opacification could produce nuclear (central portion of the lens) or cortical (peripheral) cataracts. Nuclear and posterior subcapsular (the membrane's capsule surrounds the whole lens) cataracts, being on the visual optical axis of the eye, cause visual impairment that can finally lead to blindness. The lens proteins, in their native state, are small in size. As a cataract develops, this size grows from a few nanometers

  15. A robust hypothesis test for the sensitive detection of constant speed radiation moving sources

    NASA Astrophysics Data System (ADS)

    Dumazert, Jonathan; Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Moline, Yoann; Sannié, Guillaume; Gameiro, Jordan; Normand, Stéphane; Méchin, Laurence

    2015-09-01

    Radiation Portal Monitors are deployed in linear networks to detect radiological material in motion. As a complement to single and multichannel detection algorithms, inefficient under too low signal-to-noise ratios, temporal correlation algorithms have been introduced. Test hypothesis methods based on empirically estimated mean and variance of the signals delivered by the different channels have shown significant gain in terms of a tradeoff between detection sensitivity and false alarm probability. This paper discloses the concept of a new hypothesis test for temporal correlation detection methods, taking advantage of the Poisson nature of the registered counting signals, and establishes a benchmark between this test and its empirical counterpart. The simulation study validates that in the four relevant configurations of a pedestrian source carrier under respectively high and low count rate radioactive backgrounds, and a vehicle source carrier under the same respectively high and low count rate radioactive backgrounds, the newly introduced hypothesis test ensures a significantly improved compromise between sensitivity and false alarm. It also guarantees that the optimal coverage factor for this compromise remains stable regardless of signal-to-noise ratio variations between 2 and 0.8, therefore allowing the final user to parametrize the test with the sole prior knowledge of background amplitude.

  16. Computer-aided detection of radiation-induced cerebral microbleeds on susceptibility-weighted MR images☆

    PubMed Central

    Bian, Wei; Hess, Christopher P.; Chang, Susan M.; Nelson, Sarah J.; Lupo, Janine M.

    2013-01-01

    Recent interest in exploring the clinical relevance of cerebral microbleeds (CMBs) has motivated the search for a fast and accurate method to detect them. Visual inspection of CMBs on MR images is a lengthy, arduous task that is highly prone to human error because of their small size and wide distribution throughout the brain. Several computer-aided CMB detection algorithms have recently been proposed in the literature, but their diagnostic accuracy, computation time, and robustness are still in need of improvement. In this study, we developed and tested a semi-automated method for identifying CMBs on minimum intensity projected susceptibility-weighted MR images that are routinely used in clinical practice to visually identify CMBs. The algorithm utilized the 2D fast radial symmetry transform to initially detect putative CMBs. Falsely identified CMBs were then eliminated by examining geometric features measured after performing 3D region growing on the potential CMB candidates. This algorithm was evaluated in 15 patients with brain tumors who exhibited CMBs on susceptibility-weighted images due to prior external beam radiation therapy. Our method achieved heightened sensitivity and acceptable amount of false positives compared to prior methods without compromising computation speed. Its superior performance and simple, accelerated processing make it easily adaptable for detecting CMBs in the clinic and expandable to a wide array of neurological disorders. PMID:24179783

  17. Effect of ionizing radiation on the quantitative detection of Salmonella using real-time PCR

    NASA Astrophysics Data System (ADS)

    Lim, Sangyong; Jung, Jinwoo; Kim, Minjeong; Ryu, Sangryeol; Kim, Dongho

    2008-09-01

    Food irradiation is an economically viable technology for inactivating foodborne pathogens, but irradiation can mask pathogens in unhygienically prepared food. The aim of this study was to investigate the effect of irradiation treatment on the detection of Salmonella using real-time PCR. Three commercially available kits were tested, of which the InstaGene Matrix procedure was most effective in preparing template DNA from Salmonella exposed to radiation in broth culture. The minimum level of detection by real-time PCR combined with InstaGene Matrix was 3 log units of Salmonella per milliliter. However, when pure cultures of Salmonella were irradiated at 3 and 5 kGy, the cycle threshold ( CT) increased 1-1.5-fold compared to irradiation at 0 and 1 kGy. This indicated that irradiation treatment may result in an underestimation of bacterial counts due to radiation-induced DNA lesions. We also compared CT values in inoculated chicken homogenates before and after irradiation, which in this model caused a 1.3-3.3-fold underestimation of bacterial counts with respect to irradiation dose.

  18. Summary Report for the Radiation Detection for Nuclear Security Summer School 2014

    SciTech Connect

    Runkle, Robert C.; Baciak, James E.; Woodring, Mitchell L.; Jenno, Diana M.

    2014-09-30

    Executive Summary The Pacific Northwest National Laboratory (PNNL) hosted students from across the United States at the 3rd Radiation Detection for Nuclear Security Summer School from 16 – 27 June 2014. The summer school provided students with a unique understanding of nuclear security challenges faced in the field and exposed them to the technical foundations, analyses, and insight that will be required by future leaders in technology development and implementation. The course heavily emphasized laboratory and field demonstrations including direct measurements of special nuclear material. Student evaluations and feedback from student advisors indicates that the summer school achieved its objectives of 1) exposing students to the range of nuclear security applications for which radiation detection is necessary, 2) articulating the relevance of student research into the broader context, and 3) exciting students about the possibility of future careers in nuclear security. In fact, we are beginning to see previous students both enroll in graduate programs (former undergraduates) and complete internships at agencies like the National Nuclear Security Administration.

  19. Effects of Ionizing Radiation on Biological Molecules—Mechanisms of Damage and Emerging Methods of Detection

    PubMed Central

    Reisz, Julie A.; Bansal, Nidhi; Qian, Jiang; Zhao, Weiling

    2014-01-01

    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

  20. Ruggedization of CdZnTe detectors and detector assemblies for radiation detection applications

    NASA Astrophysics Data System (ADS)

    Lu, P. H.; Gomolchuk, P.; Chen, H.; Beitz, D.; Grosser, A. W.

    2015-06-01

    This paper described improvements in the ruggedization of CdZnTe detectors and detector assemblies for use in radiation detection applications. Research included experimenting with various conductive and underfill adhesive material systems suitable for CZT substrates. A detector design with encapsulation patterning was developed to protect detector surfaces and to control spacing between CZT anode and PCB carrier. Robustness of bare detectors was evaluated through temperature cycling and metallization shear testing. Attachment processes using well-chosen adhesives and PCB carrier materials were optimized to improve reliability of detector assemblies, resulted in Improved Attachment Detector Assembly. These detector assemblies were subjected to aggressive temperature cycling, and varying levels of drop/shock and vibration, in accordance with modified JEDEC, ANSI and FedEx testing standards, to assess their ruggedness. Further enhanced detector assembly ruggedization methods were investigated involving adhesive conformal coating, potting and dam filling on detector assemblies, which resulted in the Enhanced Ruggedization Detector Assembly. Large numbers of CZT detectors and detector assemblies with 5 mm and 15 mm thick, over 200 in total, were tested. Their performance was evaluated by exposure to various radioactive sources using comprehensive predefined detector specifications and testing protocols. Detector assemblies from improved attachment and enhanced ruggedization showed stable performances during the harsh environmental condition tests. In conclusion, significant progress has been made in improving the reliability and enhancing the ruggedness of CZT detector assemblies for radiation detection applications deployed in operational environments.

  1. Simultaneous Nonrigid Registration, Segmentation, and Tumor Detection in MRI Guided Cervical Cancer Radiation Therapy

    PubMed Central

    Lu, Chao; Chelikani, Sudhakar; Jaffray, David A.; Milosevic, Michael F.; Staib, Lawrence H.; Duncan, James S.

    2013-01-01

    External beam radiation therapy (EBRT) for the treatment of cancer enables accurate placement of radiation dose on the cancerous region. However, the deformation of soft tissue during the course of treatment, such as in cervical cancer, presents significant challenges for the delineation of the target volume and other structures of interest. Furthermore, the presence and regression of pathologies such as tumors may violate registration constraints and cause registration errors. In this paper, automatic segmentation, nonrigid registration and tumor detection in cervical magnetic resonance (MR) data are addressed simultaneously using a unified Bayesian framework. The proposed novel method can generate a tumor probability map while progressively identifying the boundary of an organ of interest based on the achieved nonrigid transformation. The method is able to handle the challenges of significant tumor regression and its effect on surrounding tissues. The new method was compared to various currently existing algorithms on a set of 36 MR data from six patients, each patient has six T2-weighted MR cervical images. The results show that the proposed approach achieves an accuracy comparable to manual segmentation and it significantly outperforms the existing registration algorithms. In addition, the tumor detection result generated by the proposed method has a high agreement with manual delineation by a qualified clinician. PMID:22328178

  2. A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection

    SciTech Connect

    Ma, Lun; Chen, Wei; Jiang, Ke; Liu, Xiao-tang

    2014-03-14

    We prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583 nm due to the d-d transition of Mn ions, an intense violet emission at 420 nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu{sup 2+} doping but only appears at certain Eu{sup 2+} concentrations. It is found that the intensity of the 420 nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583 nm is not. The ratio of fluorescence intensities at 420 nm and 583 nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420 nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection.

  3. Total on-line purchasing system (TOPS)

    SciTech Connect

    Collins, N.

    1995-11-01

    The Information Management Division (IMD) at LLNL is developing a new purchasing system for the Procurement Department. The first major development of this new system is called, {open_quotes}Total On-Line Purchasing System{close_quotes} (TOPS). TOPS will help speed up the requisitioning process by having requisitions electronically entered by requesters and electronically sent to buyers to be put on Purchase Orders. The new purchasing system will use Electronic Commerce (EC)/Electronic Data Interchange (EDI), to help increase transaction flows for shipping notices, RFQs, Quotes, Purchase Orders, and Invoices. ANSI X.12 is the EDI standard that this new EC will use.

  4. Dairy Herd On-line Information System

    NASA Astrophysics Data System (ADS)

    Takahashi, Satoshi

    As the business circumstances have become worse, computational breeding management based on the scientific matters has been needed for dairy farming in our country. In this connection it was urgent to construct the system which provided data effectively used in the fields for dairy farmers. The Federation has executed to provide dairy farming technical data promptly through its own on-line network being composed of middle sized general-purpose computer (main memory : 5MB, and fixed disk : 1100MB) and 22 terminals.

  5. On-line diagnosis of unrestricted faults

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.; Sundstrom, R. J.

    1975-01-01

    Attention is given to the formal development of the notion of a discrete-time system and the associated concepts of fault, result of a fault, and error. The considered concept of on-line diagnosis is formalized and a diagnosis using inverse machines is discussed. The case of an inverse which is lossless is investigated. It is found that in such a case the class of unrestricted faults can be diagnosed with a delay equal to the delay of losslessness of the inverse system.

  6. Remote Detection of Concealed Radioactive Materials by Using Focused Powerful Terahertz Radiation

    NASA Astrophysics Data System (ADS)

    Nusinovich, Gregory S.

    2016-06-01

    This review paper summarizes the results of studies of a novel concept of the remote detection of concealed radioactive materials by using focused high-power terahertz (THz) radiation. The concept is based on the known fact that the ambient electron density in air is low (one to three free electrons per cubic centimeter). These electrons can serve as seed electrons from which an avalanche breakdown in strong electromagnetic fields starts. When a powerful THz radiation is focused in a small spot, the breakdown-prone volume can be much smaller than a cubic centimeter. So, the probability of having some free electrons in this volume and, hence, the probability of breakdown are low in the absence of additional sources of air ionization. However, in the vicinity of radioactive materials (10-20 m), the electron density can be higher, and, hence, there are always some seed free electrons from which the avalanche ionization will start. Thus, the breakdown rate in this case can be close to 100 %. Realization of this concept requires studies of various physical and technical issues. First, it is necessary to develop a high-power source of (sub-) THz radiation whose power, frequency, and pulse duration are sufficient for realizing this goal. Second, it is necessary to analyze numerous issues important for realizing this concept. Among these issues are (a) enhancement of the ionization level of air molecules in the presence of hidden radioactive materials, (b) estimating the minimum detectable mass of radioactive material, (c) formation of breakdown-prone volumes in focused THz wave beams, and (d) effect of atmospheric conditions on the propagation and focusing of THz wave beams and on the optimal location of the breakdown-prone volume between a container with hidden radioactive material and a THz antenna. The results of these studies are described below.

  7. Metal%3CU%2B2010%3Eorganic frameworks for radiation detection and particle discrimination.

    SciTech Connect

    Allendorf, Mark D.; Doty, F. Patrick; Feng, Patrick L.

    2010-05-01

    Metal-organic frameworks (MOFs) represent a diverse and rapidly expanding class of materials comprising metal ions bridged by organic linker molecules. These robust crystalline structures have been found to exhibit exceptionally large surface areas, paving the way for diverse applications ranging from gas storage and separations to catalysis, drug delivery, and sensing. Less well understood are the intrinsic luminescence properties of MOFs, which arise from the electronic transitions within the hybrid metal-organic structure. Recently, we reported the observation of scintillation in stilbene-based MOFs, representing the discovery of the first completely new class of radiation detection materials since the advent of plastic scintillators in 1950. Photoluminescence and ion-induced luminescence spectroscopy of these materials show that both the luminescence spectrum and its timing can be varied by altering the local environment of the chromophore, establishing critical insight towards the rational design of materials for specific radiation detection applications. In this work, we describe the luminescence and scintillating properties of a series of isoreticular MOFs (IRMOFs), emphasizing the structural and electronic effects associated with systematic modification of the chromophore. Among these structures are IRMOFs based on naphthyl, biphenyl, terphenyl, and stilbene dicarboxylate linkers, for which unique structural changes and optical properties are observed. In addition to chemical changes in the structure, framework interpenetration may also be synthetically controlled, resulting in pairs of catenated and non-catenated IRMOFs based upon the same organic linker. The distinct interchromophore distances and solvate structure in these pairs lead to unique luminescence spectra that are interpreted in terms of energy transfer interactions. These spectral changes provide insight into the mechanism for radiation-induced luminescence, which for MOFs may differ

  8. Integration of On-Line and Off-Line Diagnostic Algorithms for Aircraft Engine Health Management

    NASA Technical Reports Server (NTRS)

    Kobayashi, Takahisa; Simon, Donald L.

    2007-01-01

    This paper investigates the integration of on-line and off-line diagnostic algorithms for aircraft gas turbine engines. The on-line diagnostic algorithm is designed for in-flight fault detection. It continuously monitors engine outputs for anomalous signatures induced by faults. The off-line diagnostic algorithm is designed to track engine health degradation over the lifetime of an engine. It estimates engine health degradation periodically over the course of the engine s life. The estimate generated by the off-line algorithm is used to update the on-line algorithm. Through this integration, the on-line algorithm becomes aware of engine health degradation, and its effectiveness to detect faults can be maintained while the engine continues to degrade. The benefit of this integration is investigated in a simulation environment using a nonlinear engine model.

  9. On-line and Mobil Learning Activities

    NASA Astrophysics Data System (ADS)

    Ackerman, S. A.; Whittaker, T. M.; Jasmin, T.; Mooney, M. E.

    2012-12-01

    Introductory college-level science courses for non-majors are critical gateways to imparting not only discipline-specific information, but also the basics of the scientific method and how science influences society. They are also indispensable for student success to degree. On-line, web-based homework (whether on computers or mobile devices) is a rapidly growing use of the Internet and is becoming a major component of instruction in science, replacing delayed feedback from a few major exams. Web delivery and grading of traditional textbook-type questions is equally effective as having students write them out for hand grading, as measured by student performance on conceptual and problem solving exams. During this presentation we will demonstrate some of the interactive on-line activities used to teach concepts and how scientists approach problem solving, and how these activities have impacted student learning. Evaluation of the activities, including formative and summative, will be discussed and provide evidence that these interactive activities significantly enhance understanding of introductory meteorological concepts in a college-level science course. More advanced interactive activities are also used in our courses for department majors, some of these will be discussed and demonstrated. Bring your mobile devices to play along! Here is an example on teaching contouring: http://profhorn.aos.wisc.edu/wxwise/contour/index.html

  10. The EINSTEIN On-Line Service (EOLS)

    NASA Astrophysics Data System (ADS)

    Harris, D. E.; Stern Grant, C. P.; Andernach, H.

    1994-08-01

    In January 1989, SAO established an on-line service to help astronomers prepare ROSAT proposals by providing access to the preliminary source list from the ``Einstein Observatory Catalog of IPC X-ray Sources''. In the intervening years, we have updated the source list, added to the documentation, included many more Einstein databases as well as a number of tables from other wavebands, provided access to images for downloading from all of the Einstein CDROMs, and installed new software for more sophisticated filtering and retrieval. Although we have improved the functionality and made significant additions to the databases, we still maintain a simple menu interface accessible from any type of terminal. EOLS provides all of our databases to the NASA Astrophysics Data System (ADS) and our documents which describe each table are thus written in the ADS format. In conjunction with the IAU working group on Archiving and Data Bases for Radio Astronomy, EOLS serves as an experimental platform for on-line access to the radio source lists collected by one of us (H.A.). The number of these entries exceeds half a million.

  11. Condenser on-line fouling monitor

    SciTech Connect

    Tsou, J.L.; Garey, J.F.; Wiebe, D.H.

    1994-12-31

    Biological and/or chemical fouling in utility condensers is a major cause of reduced efficiency and substantially affects availability and increases operational costs. Performance losses due to water side fouling are difficult to measure and, usually, quantitative assessment of the economic impact of condenser fouling is impossible. Plant operators typically examine steam backpressure and perform complex calculations for condenser cleanliness. These direct estimates are often imprecise due to inadequate instrumentation. In addition, these data provide information on overall condenser performance which may be influenced by a number of parameters which are independent of water side fouling. Indirect (side-stream) methods are also used to isolate/measure biological or chemical fouling in condensers. This approach is extremely useful to document site/seasonal fouling rates, and for the simultaneous evaluation of treatment options. In collaboration with the Electric Power Research Institute, instrumentation has been developed which meets requirements for the direct, on-line measurement of condenser fouling. This monitor may be installed in any location within the condenser, does not interfere with routine plant operations, including on-line mechanical and chemical treatment methods, and provides continuous, real-time readings of the heat transfer efficiency of the instrumented tube. Three prototype assemblies were installed at the New England Power Company, Brayton Point Generating Station in 1993. This paper discusses the design, construction, preliminary test results, and subsequent data collected in 1994 with a redesigned system.

  12. Open-Source Radiation Exposure Extraction Engine (RE3) with Patient-Specific Outlier Detection.

    PubMed

    Weisenthal, Samuel J; Folio, Les; Kovacs, William; Seff, Ari; Derderian, Vana; Summers, Ronald M; Yao, Jianhua

    2016-08-01

    We present an open-source, picture archiving and communication system (PACS)-integrated radiation exposure extraction engine (RE3) that provides study-, series-, and slice-specific data for automated monitoring of computed tomography (CT) radiation exposure. RE3 was built using open-source components and seamlessly integrates with the PACS. RE3 calculations of dose length product (DLP) from the Digital imaging and communications in medicine (DICOM) headers showed high agreement (R (2) = 0.99) with the vendor dose pages. For study-specific outlier detection, RE3 constructs robust, automatically updating multivariable regression models to predict DLP in the context of patient gender and age, scan length, water-equivalent diameter (D w), and scanned body volume (SBV). As proof of concept, the model was trained on 811 CT chest, abdomen + pelvis (CAP) exams and 29 outliers were detected. The continuous variables used in the outlier detection model were scan length (R (2)  = 0.45), D w (R (2) = 0.70), SBV (R (2) = 0.80), and age (R (2) = 0.01). The categorical variables were gender (male average 1182.7 ± 26.3 and female 1047.1 ± 26.9 mGy cm) and pediatric status (pediatric average 710.7 ± 73.6 mGy cm and adult 1134.5 ± 19.3 mGy cm). PMID:26644157

  13. Optical instrumentation for on-line analysis of chemical processes

    SciTech Connect

    Hartford, A. Jr.; Cremers, D.A.; Loree, T.R.; Quigley, G.P.

    1983-01-01

    Optical diagnostics provide the capability for nonintrusive, on-line, real time analysis of chemical process streams. Several laser-based methods for monitoring fossil energy processes have been evaluated. Among the instrumentation techniques which appear quite promising are coherent anti-Stokes Raman spectroscopy (CARS), laser-induced breakdown spectroscopy (LIBS), and synchronous detection of laser-induced fluorescence (SDLIF). A CARS diagnostic was implemented on a coal gasifier and was successfully employed to measure species concentrations and temperatures within the process stream. The LIBS approach has been used to identify total trace impurities (e.g., Na, K, and S) within a gasifier. Recently, individual components in mixtures of aromatics hydrocarbons have been resolved via the synchronous detection of laser-induced fluorescence. 9 figures.

  14. Near-Infrared Spectroscopy as an Analytical Process Technology for the On-Line Quantification of Water Precipitation Processes during Danhong Injection

    PubMed Central

    Liu, Xuesong; Wu, Chunyan; Geng, Shu; Jin, Ye; Luan, Lianjun; Chen, Yong; Wu, Yongjiang

    2015-01-01

    This paper used near-infrared (NIR) spectroscopy for the on-line quantitative monitoring of water precipitation during Danhong injection. For these NIR measurements, two fiber optic probes designed to transmit NIR radiation through a 2 mm flow cell were used to collect spectra in real-time. Partial least squares regression (PLSR) was developed as the preferred chemometrics quantitative analysis of the critical intermediate qualities: the danshensu (DSS, (R)-3, 4-dihydroxyphenyllactic acid), protocatechuic aldehyde (PA), rosmarinic acid (RA), and salvianolic acid B (SAB) concentrations. Optimized PLSR models were successfully built and used for on-line detecting of the concentrations of DSS, PA, RA, and SAB of water precipitation during Danhong injection. Besides, the information of DSS, PA, RA, and SAB concentrations would be instantly fed back to site technical personnel for control and adjustment timely. The verification experiments determined that the predicted values agreed with the actual homologic value. PMID:26839549

  15. Radiative-SPR platform for the detection of apolipoprotein E for use in medical diagnostics

    NASA Astrophysics Data System (ADS)

    Sciacca, Beniamino; Francois, Alexandre; Penno, Megan A. S.; Brazzatti, Julie A.; Klingler-Hoffmann, Manuela; Hoffmann, Peter; Monro, Tanya M.

    2012-03-01

    Surface Plasmon Resonance (SPR) based sensors enable the rapid, label-free and highly sensitive detection of a large range of biomolecules. We have previously shown that, using silver coated optical fibres with an high surface roughness, a re-scattering of the surface plasmons is possible, turning SPR into a radiative process. This approach overcomes limitations associated with current SPR technologies such as the tight tolerance on the metallic coating thickness, and results in a more compact, versatile, robust and cost-effective approach. However, the specific detection of small molecules is a challenge in SPR systems, regardless of the SPR architecture that is used. This new sensing platform, which has proved effective for the detection of large molecules such as viruses, is now demonstrated to be able to detect small proteins thanks to an improved surface functionalization procedure, a key point for reliable and robust immunosensors. Avidin, a tetrameric biotin-binding protein, was used to link biotinylated antibodies to the biotinylated surface, with a given orientation, to enable efficient sensing of the analyte. This approach may offer significant advantages compared to protein A surface functionalization strategies such as a limited cross reactivity with free IgG antibodies in clinical samples. We demonstrate that by bringing together this novel emission-based fibre SPR platform, with an improved surface functionalization process, is possible to rapidly and specifically detect human apolipoprotein E, a low molecular weight protein (~39kDa) known to be involved in cardiovascular diseases, in Alzheimer's disease and in gastric cancer. The results obtained clearly show that this new sensing platform has the potential to serve as a tool for point-of-decision medical diagnostics.

  16. Impact of precursor purity on optical properties and radiation detection of CsI:Tl scintillators

    NASA Astrophysics Data System (ADS)

    Saengkaew, Phannee; Sanorpim, Sakuntam; Jitpukdee, Manit; Cheewajaroen, Kulthawat; Yenchai, Chadet; Thong-aram, Decho; Yordsri, Visittapong; Thanachayanont, Chanchana; Nuntawong, Noppadon

    2016-08-01

    Cesium iodide doped with thallium (CsI:Tl) crystals was grown to develop the gamma-ray detectors by using low-cost raw materials. Effect of impurities on optical properties and radiation detection performance was investigated. By a modified homemade Bridgman-Stockbarger technique, CsI:Tl samples were grown in two levels of CsI and TlI reactant materials, i.e., having as a very high purity of 99.999 % and a high purity of 99.9 %. XRD measurements indicate CsI:Tl crystals having a good quality with a dominant (110) plane. Having a cubic structure, a lattice constant of CsI crystals of 0.4574 nm and a crystallite size of 43.539 nm were obtained. From the lower-purity raw materials, calcite was found in an orange crystal with a lattice constant of 0.4560 nm and a crystallite size of 43.089 nm. By PL measurements, the optical properties of the CsI:Tl crystals were analyzed. ~540-nm-wavelength PL peak was observed from the colorless high-purity crystal, and ~600-nm-wavelength PL peak was observed from the orange crystal. The brighter PL emission was obtained from the orange crystals suggesting impurities. CsI:Tl surface morphology by SEM exhibited a smooth surface with some parallel crystal facets. For electrical properties of high-quality CsI:Tl crystals, the electrical resistances were 230 ± 16 MΩ in cross-sectional direction and 714 ± 136 MΩ in vertical direction with respect to more homogeneous crystal quality in cross-sectional direction than that in vertical direction. TEM measurement was applied to evaluate the microstructure of colorless CsI:Tl crystal with different patterns of a cubic structure. Both CsI:Tl crystals show good efficiencies and good resolutions. Maintaining the same electronic conditions and amplifications, the colorless CsI:Tl scintillators represented a higher detection efficiency at 122 keV of Co-57 of 78.4 % and the energy resolution of 23.3 % compared to the detection efficiency of 75.9 % and the energy resolution of 34.6 % of the orange

  17. Development of Thin Film Germanium-Gold Thermistors for Calorimetric Detection of Nuclear Radiation.

    NASA Astrophysics Data System (ADS)

    Wang, Xunxie

    1995-01-01

    The present work is to produce thin film semiconductor thermistors which can be directly fabricated on radiation absorbers to act as ultra low-mass, highly sensitive cryogenic phonon sensors for detecting single nuclear radiation interaction invents. The specific application envisioned for these devices is in the search for galactic Dark Matter, which is proposed to exist in the form of weakly interacting massive particles in the galaxy. Thin film Au doped Ge thermistors were directly fabricated on single crystal silicon absorbers using vacuum filament evaporation and microfabrication techniques. The fabrication procedure developed in the present work gives micron-scale thin film GeAu thermistors with highly reproducible characteristics. Electrical and thermal properties of thin film Ge_{rm 1-x}Au _{rm x} for 0.019 < x < 0.17 were studied between room temperature and 0.019K and in magnetic fields up to 4.0T. Measurements indicated that variable-range-hopping dominates the conductivity of GeAu thin film at temperatures below 10K. Metal-insulator transition of the film is found to occur for x > 0.17. The observed magnetoresistance is explained by using a field-dependent hopping exponent proposed in the present work combined with Mott's hopping conductivity theory. A new treatment of electrical field-induced nonlinearity in variable-range-hopping is also given which quantitatively reproduced the observed nonlinear resistivity. Electrical heat pulse and particle detection measurements showed that the total effective heat capacity of the device was dominated by the silicon absorber substrate at a bath temperature of 1.5 K and by electron system of the thermistor itself of the device when the bath temperatures were below 100 mK. Excellent responsivity of GeAu thin film calorimeters has been demonstrated in AC electrical pulse and nuclear radiation detection experiments. At optimal bias power, the responsivity (|DeltaV/ DeltaE|) of the present devices reaches 10^8 V/J at

  18. On-line tritium production monitor

    DOEpatents

    Mihalczo, John T.

    1993-01-01

    A scintillation optical fiber system for the on-line monitoring of nuclear reactions in an event-by-event manner is described. In the measurement of tritium production one or more optical fibers are coated with enriched .sup.6 Li and connected to standard scintillation counter circuitry. A neutron generated .sup.6 Li(n )T reaction occurs in the coated surface of .sup.6 Li-coated fiber to produce energetic alpha and triton particles one of which enters the optical fiber and scintillates light through the fiber to the counting circuit. The coated optical fibers can be provided with position sensitivity by placing a mirror at the free end of the fibers or by using pulse counting circuits at both ends of the fibers.

  19. On-line tritium production monitor

    DOEpatents

    Mihalczo, J.T.

    1993-11-23

    A scintillation optical fiber system for the on-line monitoring of nuclear reactions in an event-by-event manner is described. In the measurement of tritium production one or more optical fibers are coated with enriched {sup 6}Li and connected to standard scintillation counter circuitry. A neutron generated {sup 6}Li(n)T reaction occurs in the coated surface of {sup 6}Li-coated fiber to produce energetic alpha and triton particles one of which enters the optical fiber and scintillates light through the fiber to the counting circuit. The coated optical fibers can be provided with position sensitivity by placing a mirror at the free end of the fibers or by using pulse counting circuits at both ends of the fibers. 5 figures.

  20. On-line process control monitoring system

    DOEpatents

    O'Rourke, Patrick E.; Van Hare, David R.; Prather, William S.

    1992-01-01

    An on-line, fiber-optic based apparatus for monitoring the concentration of a chemical substance at a plurality of locations in a chemical processing system comprises a plurality of probes, each of which is at a different location in the system, a light source, optic fibers for carrying light to and from the probes, a multiplexer for switching light from the source from one probe to the next in series, a diode array spectrophotometer for producing a spectrum from the light received from the probes, and a computer programmed to analyze the spectra so produced. The probes allow the light to pass through the chemical substance so that a portion of the light is absorbed before being returned to the multiplexer. A standard and a reference cell are included for data validation and error checking.

  1. NASDA's Advanced On-Line System (ADOLIS)

    NASA Technical Reports Server (NTRS)

    Yamamoto, Yoshikatsu; Hara, Hideo; Yamada, Shigeo; Hirata, Nobuyuki; Komatsu, Shigenori; Nishihata, Seiji; Oniyama, Akio

    1993-01-01

    Spacecraft operations including ground system operations are generally realized by various large or small scale group work which is done by operators, engineers, managers, users and so on, and their positions are geographically distributed in many cases. In face-to-face work environments, it is easy for them to understand each other. However, in distributed work environments which need communication media, if only using audio, they become estranged from each other and lose interest in and continuity of work. It is an obstacle to smooth operation of spacecraft. NASDA has developed an experimental model of a new real-time operation control system called 'ADOLIS' (ADvanced On-Line System) adopted to such a distributed environment using a multi-media system dealing with character, figure, image, handwriting, video and audio information which is accommodated to operation systems of a wide range including spacecraft and ground systems. This paper describes the results of the development of the experimental model.

  2. On-line resources for Xenopus.

    PubMed

    Bowes, Jeff

    2012-01-01

    Since the advent of computational methods in biology, the quantity of biological data has grown exponentially. These data support genomic, genetic, developmental, and other forms of biological experimentation. The number of on-line resources has kept pace with the growth in data. Xenopus has perhaps lagged some of the other model organisms in developing resources, but is now quickly catching up. There are now a number of well-established and developing resources for Xenopus. This chapter looks beyond the widely known public databases, Genbank and the EBI, and describes how the researcher can use a number of central sites such as Xenbase, UniProtKB, and major genome browsers to navigate to a variety of different resources. PMID:22956109

  3. On-line Resources for Xenopus

    PubMed Central

    Bowes, Jeff

    2015-01-01

    Summary Since the advent of computational methods in biology the quantity of biological data has grown exponentially. These data support genomic, genetic, developmental, and other forms of biological experimentation. The number of on-line resources has kept pace with the growth in data. Xenopus has perhaps lagged some of the other model organisms in developing resources but is now quickly catching up. There are now a number of well-established and developing resources for Xenopus. This chapter looks beyond the widely-known public databases, Genbank and the EBI, and describes how the researcher can use a number of central sites such as Xenbase, UniProtKB, and major genome browsers to navigate to a variety of different resources. PMID:22956109

  4. On-line chemical composition analyzer development

    SciTech Connect

    Roberts, M.J.; Garrison, A.A.; Muly, E.C.; Moore, C.F.

    1992-02-01

    The energy consumed in distillation processes in the United States represents nearly three percent of the total national energy consumption. If effective control of distillation columns can be accomplished, it has been estimated that it would result in a reduction in the national energy consumption of 0.3%. Real-time control based on mixture composition could achieve these savings. However, the major distillation processes represent diverse applications and at present there does not exist a proven on-line chemical composition sensor technology which can be used to control these diverse processes in real-time. This report presents a summary of the findings of the second phase of a three phase effort undertaken to develop an on-line real-time measurement and control system utilizing Raman spectroscopy. A prototype instrument system has been constructed utilizing a Perkin Elmer 1700 Spectrometer, a diode pumped YAG laser, two three axis positioning systems, a process sample cell land a personal computer. This system has been successfully tested using industrially supplied process samples to establish its performance. Also, continued application development was undertaken during this Phase of the program using both the spontaneous Raman and Surface-enhanced Raman modes of operation. The study was performed for the US Department of Energy, Office of Industrial Technologies, whose mission is to conduct cost-shared R D for new high-risk, high-payoff industrial energy conservation technologies. Although this document contains references to individual manufacturers and their products, the opinions expressed on the products reported do not necessarily reflect the position of the Department of Energy.

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

    DOEpatents

    McElhaney, Stephanie A.; Bauer, Martin L.; Chiles, Marion M.

    1992-01-01

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

    DOEpatents

    McElhaney, S.A.; Bauer, M.L.; Chiles, M.M.

    1992-09-22

    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.

  7. Non-Linear Signal Detection Improvement by Radiation Damping in Single-Pulse NMR Spectra

    PubMed Central

    Schlagnitweit, Judith; Morgan, Steven W; Nausner, Martin; Müller, Norbert; Desvaux, Hervé

    2012-01-01

    When NMR lines overlap and at least one of them is affected by radiation damping, the resonance line shapes of all lines are no longer Lorentzian. We report the appearance of narrow signal distortions, which resemble hole-burnt spectra. This new experimental phenomenon facilitates the detection of tiny signals hidden below the main resonance. Theoretical analysis based on modified Maxwell–Bloch equations shows that the presence of strong transverse magnetization creates a feedback through the coil, which influences the magnetization of all spins with overlapping resonance lines. In the time domain this leads to cross-precession terms between magnetization densities, which ultimately cause non-linear behavior. Numerical simulations corroborate this interpretation. PMID:22266720

  8. Current-driven detection of terahertz radiation using a dual-grating-gate plasmonic detector

    SciTech Connect

    Boubanga-Tombet, S. Tanimoto, Y.; Satou, A.; Suemitsu, T.; Otsuji, T.; Wang, Y.; Minamide, H.; Ito, H.; Fateev, D. V.; Popov, V. V.

    2014-06-30

    We report on the detection of terahertz radiation by an on-chip planar asymmetric plasmonic structure in the frequency region above one terahertz. The detector is based on a field-effect transistor that has a dual grating gate structure with an asymmetric unit cell, which provides a geometrical asymmetry within the structure. Biasing the detector with a dc source-to-drain current in the linear region of the current-voltage characteristic introduces an additional asymmetry (electrical asymmetry) that enhances the detector responsivity by more than one order of magnitude (by a factor of 20) as compared with the unbiased case due to the cooperative effect of the geometrical and electrical asymmetries. In addition to the responsivity enhancement, we report a relatively low noise equivalent power and a peculiar non-monotonic dependence of the responsivity on the frequency, which results from the multi-plasmonic-cavity structure of the device.

  9. Detection of Radiation-Exposure Biomarkers by Differential Mobility Prefiltered Mass Spectrometry (DMS-MS)

    PubMed Central

    Coy, Stephen L.; Krylov, Evgeny V.; Schneider, Bradley B.; Covey, Thomas R.; Brenner, David J.; Tyburski, John B.; Patterson, Andrew D.; Krausz, Kris W.; Fornace, Albert J.; Nazarov, Erkinjon G.

    2010-01-01

    Technology to enable rapid screening for radiation exposure has been identified as an important need, and, as a part of a NIH / NIAD effort in this direction, metabolomic biomarkers for radiation exposure have been identified in a recent series of papers. To reduce the time necessary to detect and measure these biomarkers, differential mobility spectrometry – mass spectrometry (DMS-MS) systems have been developed and tested. Differential mobility ion filters preselect specific ions and also suppress chemical noise created in typical atmospheric-pressure ionization sources (ESI, MALDI, and others). Differential-mobility-based ion selection is based on the field dependence of ion mobility, which, in turn, depends on ion characteristics that include conformation, charge distribution, molecular polarizability, and other properties, and on the transport gas composition which can be modified to enhance resolution. DMS-MS is able to resolve small-molecule biomarkers from nearly-isobaric interferences, and suppresses chemical noise generated in the ion source and in the mass spectrometer, improving selectivity and quantitative accuracy. Our planar DMS design is rapid, operating in a few milliseconds, and analyzes ions before fragmentation. Depending on MS inlet conditions, DMS-selected ions can be dissociated in the MS inlet expansion, before mass analysis, providing a capability similar to MS/MS with simpler instrumentation. This report presents selected DMS-MS experimental results, including resolution of complex test mixtures of isobaric compounds, separation of charge states, separation of isobaric biomarkers (citrate and isocitrate), and separation of nearly-isobaric biomarker anions in direct analysis of a bio-fluid sample from the radiation-treated group of a mouse-model study. These uses of DMS combined with moderate resolution MS instrumentation indicate the feasibility of field-deployable instrumentation for biomarker evaluation. PMID:20305793

  10. The High Energy cosmic-Radiation Detection (HERD) Facility onboard China's Future Space Station

    NASA Astrophysics Data System (ADS)

    Wu, Bobing

    2015-08-01

    The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs)from five sides except the bottom. CALO is made of about 10^4 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; 2) electron/proton separation power better than 10^5 ; effective geometrical factors of > 3 m^2 sr for electron and diffuse gamma-rays, > 2 m^2 sr for cosmic ray nuclei. The prototype of about 1/40 of HERD calorimeter is under construction. A beam test in CERN with the prototype is approved and will be carried out in Nov. 2015.

  11. First Satellite-detected Perturbations of Outgoing Longwave Radiation Associated with Blowing Snow Events over Antarctica

    NASA Technical Reports Server (NTRS)

    Yang, Yuekui; Palm, Stephen P.; Marshak, Alexander; Wu, Dong L.; Yu, Hongbin; Fu, Qiang

    2014-01-01

    We present the first satellite-detected perturbations of the outgoing longwave radiation (OLR) associated with blowing snow events over the Antarctic ice sheet using data from Cloud-Aerosol Lidar with Orthogonal Polarization and Clouds and the Earth's Radiant Energy System. Significant cloud-free OLR differences are observed between the clear and blowing snow sky, with the sign andmagnitude depending on season and time of the day. During nighttime, OLRs are usually larger when blowing snow is present; the average difference in OLRs between without and with blowing snow over the East Antarctic Ice Sheet is about 5.2 W/m2 for the winter months of 2009. During daytime, in contrast, the OLR perturbation is usually smaller or even has the opposite sign. The observed seasonal variations and day-night differences in the OLR perturbation are consistent with theoretical calculations of the influence of blowing snow on OLR. Detailed atmospheric profiles are needed to quantify the radiative effect of blowing snow from the satellite observations.

  12. Thermoluminescence of contaminating minerals for the detection of radiation treatment of dried fruits

    NASA Astrophysics Data System (ADS)

    Khan, H. M.; Bhatti, Ijaz A.; Delincée, Henry

    2002-03-01

    Several types of dry fruits (pistachio nut, dried apricot, almond and raisins) have been investigated for detection of their radiation treatment by gamma rays or electron beam using thermoluminescence (TL) measurements. These samples were irradiated to 1.0-3.0 kGy (gamma rays) or 0.75-3.9 kGy (10 MeV electron beam). Thermoluminescence glow curves for the contaminating minerals separated from the dry fruits were recorded between the temperature range of 50°C and 500°C. In all the cases, the intensity of TL signal for the irradiated dry fruits was 1-3 orders of magnitudes higher than the TL intensity of the corresponding unirradiated control samples allowing clear distinction between the irradiated and unirradiated samples. These results were normalized by re-irradiating the mineral grains with a gamma-ray dose of 1.0 kGy, and a second glow curve was recorded. The ratio of intensity of the first glow curve (TL 1) to that after the normalization dose (TL 2), i.e. (TL 1/TL 2) was determined and compared with the recommended threshold values. These parameters, together with comparison of the shape of the first glow curve, gave unequivocal results about the radiation treatment of the dry fruit samples.

  13. High-frequency detection of the formation and stabilization of a radiation-induced defect cluster in semiconductor structures

    SciTech Connect

    Puzanov, A. S.; Obolenskiy, S. V. Kozlov, V. A.; Volkova, E. V.; Paveliev, D. G.

    2015-12-15

    The processes of the formation and stabilization of a radiation-induced defect cluster upon the arrival of a fast neutron to the space-charge region of a semiconductor diode are analyzed. The current pulse formed by secondary electrons is calculated and the spectrum of the signal generated by the diode (detector) under the action of an instantaneous neutron flux of the fission spectrum is determined. The possibility of experimental detection of the picosecond radiation-induced transition processes is discussed.

  14. Detection of some irradiated spices on the basis of radiation induced damage of starch

    NASA Astrophysics Data System (ADS)

    Farkas, J.; Sharif, M. M.; Koncz, Á.

    Untreated and irradiated samples of spices were suspended in water, alkalized, and after heat-gelatinization, the apparent viscosity was determined by a rotational viscometer. Several spices, i.e. white pepper, black pepper, nutmeg and ginger showed considerable loss of viscosity as a function of γ-radiation dose in the dose range required for microbial decontamination of natural spices. Less promising results were obtained with spices such as allspice, garlic powder, and onion powder forming low-viscosity heat-treated suspensions even when unirradiated viscometric studies were also performed with a number of pepper samples of various origin to estimate the "natural" variation of rheological properties. Irradiation and storage studies were performed with ground black pepper samples of moisture contents in equilibrium with air of 25%, 50% and 75% R.H., respectively, either untreated or irradiated with 4, 8, 16 or 32 kGy, to study the effect of equilibrium relative humidity and storage time on detectability of radiation treatment. During the entire storage period of 100 days, statistically significant differences of the apparent viscosities of heat-gelatinized suspensions remained detectable between untreated samples and those irradiated with 8 kGy or higher doses. The apparent viscosity of high-moisture (75% E.R.H.) untreated samples was decreasing during long-term storage. Differences between viscosities of untreated and irradiated samples were enlarged when measured at elevated temperatures such as 50°C in the rotational viscometer, or in the boiling-water bath of a falling number apparatus. Other analytical indices such as onset and peak temperatures of gelatinization endotherms by DSC (damaged starch content), by colorimetry, reducing sugar content, alcohol-induced turbidity of hot water extracts of pepper samples, have been changed less dramatically by irradiation than the apparent viscosity of the gelatinized suspensions

  15. Effects of simulated space radiation on immunoassay components for life-detection experiments in planetary exploration missions.

    PubMed

    Derveni, Mariliza; Hands, Alex; Allen, Marjorie; Sims, Mark R; Cullen, David C

    2012-08-01

    The Life Marker Chip (LMC) instrument is part of the proposed payload on the ESA ExoMars rover that is scheduled for launch in 2018. The LMC will use antibody-based assays to detect molecular signatures of life in samples obtained from the shallow subsurface of Mars. For the LMC antibodies, the ability to resist inactivation due to space particle radiation (both in transit and on the surface of Mars) will therefore be a prerequisite. The proton and neutron components of the mission radiation environment are those that are expected to have the dominant effect on the operation of the LMC. Modeling of the radiation environment for a mission to Mars led to the calculation of nominal mission fluences for proton and neutron radiation. Various combinations and multiples of these values were used to demonstrate the effects of radiation on antibody activity, primarily at the radiation levels envisaged for the ExoMars mission as well as at much higher levels. Five antibodies were freeze-dried in a variety of protective molecular matrices and were exposed to various radiation conditions generated at a cyclotron facility. After exposure, the antibodies' ability to bind to their respective antigens was assessed and found to be unaffected by ExoMars mission level radiation doses. These experiments indicated that the expected radiation environment of a Mars mission does not pose a significant risk to antibodies packaged in the form anticipated for the LMC instrument. PMID:22897155

  16. Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

    PubMed

    Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

    2016-06-10

    Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery. PMID:27178150

  17. Experimental applications for the MARK-1 and MARK-1A pulsed ionizing radiation detection systems. Volume 3

    SciTech Connect

    Harker, Y.D.; Lawrence, R.S.; Yoon, W.Y.; Lones, J.L.

    1993-12-01

    This report is the third volume in a three volume set describing the MARK series of pulsed ionizing radiation detection systems. This volume describes the MARK-1A detection system, compares it with the MARK-1 system, and describes the experimental testing of the detection systems. Volume 1 of this set presents the technical specifications for the MARK-1 detection system. Volume 2 is an operations manual specifically for the MARK-1 system, but it generally applies to the MARK-1A system as well. These detection systems operate remotely and detect photon radiation from a single or a multiple pulsed source. They contain multiple detector (eight in the MARK-1 and ten in the MARK-1A) for determination of does and incident photon effective energy. The multiple detector arrangement, having different detector sizes and shield thicknesses, provides the capability of determining the effective photon energy of the radiation spectrum. Dose measurements using these units are consistent with TLD measurements. The detection range is from 3 nanorads to 90 microrads per source burst; the response is linear over that range. Three units were built and are ready for field deployment.

  18. On-Line Wavelength Calibration of Pulsed Laser for CO2 Differential Absorption LIDAR

    NASA Astrophysics Data System (ADS)

    Xiang, Chengzhi; Ma, Xin; Han, Ge; Liang, Ailin; Gong, Wei

    2016-06-01

    Differential absorption lidar (DIAL) remote sensing is a promising technology for atmospheric CO2 detection. However, stringent wavelength accuracy and stability are required in DIAL system. Accurate on-line wavelength calibration is a crucial procedure for retrieving atmospheric CO2 concentration using the DIAL, particularly when pulsed lasers are adopted in the system. Large fluctuations in the intensities of a pulsed laser pose a great challenge for accurate on-line wavelength calibration. In this paper, a wavelength calibration strategy based on multi-wavelength scanning (MWS) was proposed for accurate on-line wavelength calibration of a pulsed laser for CO2 detection. The MWS conducted segmented sampling across the CO2 absorption line with appropriate number of points and range of widths by using a tunable laser. Complete absorption line of CO2 can be obtained through a curve fitting. Then, the on-line wavelength can be easily found at the peak of the absorption line. Furthermore, another algorithm called the energy matching was introduced in the MWS to eliminate the backlash error of tunable lasers during the process of on-line wavelength calibration. Finally, a series of tests was conducted to elevate the calibration precision of MWS. Analysis of tests demonstrated that the MWS proposed in this paper could calibrate the on-line wavelength of pulsed laser accurately and steadily.

  19. FY06 Annual Report: Amorphous Semiconductors for Gamma Radiation Detection (ASGRAD)

    SciTech Connect

    Johnson, Bradley R.; Riley, Brian J.; Crum, Jarrod V.; Sundaram, S. K.; Henager, Charles H.; Zhang, Yanwen; Shutthanandan, V.

    2007-01-01

    We describe progress in the development of new materials for portable, room-temperature, gamma-radiation detection at Pacific Northwest National Laboratory at the Hanford Site in Washington State. High Z, high resistivity, amorphous semiconductors are being designed for use as solid-state detectors at near ambient temperatures; principles of operation are analogous to single-crystal semiconducting detectors. Amorphous semiconductors have both advantages and disadvantages compared to single crystals, and this project is developing methods to mitigate technical problems and design optimized material for gamma detection. Several issues involved in the fabrication of amorphous semiconductors are described, including reaction thermodynamics and kinetics, the development of pyrolytic coating, and the synthesis of ingots. The characterization of amorphous semiconductors is described, including sectioning and polishing protocols, optical microscopy, X-ray diffraction, scanning electron microscopy, optical spectroscopy, particle-induced X-ram emission, Rutherford backscattering, and electrical testing. Then collaboration with the University of Illinois at Urbana-Champaign is discussed in the areas of Hall-effect measurements and current voltage data. Finally, we discuss the strategy for continuing the program.

  20. Level crossing analysis of cosmic microwave background radiation: a method for detecting cosmic strings

    SciTech Connect

    Movahed, M. Sadegh; Khosravi, Shahram E-mail: khosravi@ipm.ir

    2011-03-01

    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, Gμ, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with Gμ∼>4 × 10{sup −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 Gμ∼>5.8 × 10{sup −9}.

  1. Crystal growth in LiGaSe2 for semiconductor radiation detection applications

    NASA Astrophysics Data System (ADS)

    Stowe, A. C.; Woodward, J.; Tupitsyn, E.; Rowe, E.; Wiggins, B.; Matei, L.; Bhattacharya, P.; Burger, A.

    2013-09-01

    Lithium containing AIBIIICVI semiconductors are being considered as alternative materials for room temperature neutron detection. Materials such as LiGaSe2 have been synthesized for non-linear optical applications; however, when the crystal is grown enriched in the 6Li isotope, it is possible to imagine a radiation detector. A nuclear reaction occurs with 6Li, which can be detected within the semiconductor crystal. As such, high quality crystals are required, which have few defects which prohibit charge collection. One of the primary challenges in growing a high quality crystal is the reactivity of lithium metal. Vacuum purified lithium metal was therefore reacted with gallium to form LiGa as an intermediate to LiGaSe2 synthesis. Vertical and horizontal Bridgman growth was then conducted to determine the optimal growth conditions. Vertical Bridgman growth resulted in more pure crystals. Annealing in lithium metal vapor reduced crystal defects and improved optical and electrical properties of the subsequent LiGaSe2 crystal.

  2. From Exploratory Synthesis to Hard Radiation Detection: Crystal Growth and Characterization of Chalcogenide and Chalcohalide Materials

    NASA Astrophysics Data System (ADS)

    Nguyen, Sandy Linhsa

    In the first half of this thesis work, exploratory synthesis of materials using mixed polychalcogenide fluxes yielded four quaternary mixed Te/S compounds, with the respective chalcogen atoms residing in different crystallographic sites. Two-dimensional thiotellurite compounds (Ag2TeS3) 2·A2S6 (A = Rb, Cs), containing the trigonal pyramidal [TeS 3]2- unit, were synthesized and characterized. These structures are composed of layers of neutral [Ag2TeS3] alternating with charge-balanced salt layers containing the polysulfide chain [S6]2- and alkali metal ions. Using mixed Te/S polychalcogenide fluxes for compound discovery, we then investigated a new set of layered metal dichalcogenides, Ag2Te(MS2)3 (M = V, Nb) crystallizing in the P-62m space group. Ag2Te(MS2)3 contains layers of [Ag2Te] sandwiched between layers of [MS2] (M = V, Nb). The Ag and, more interestingly, Te atoms are linearly coordinated by S atoms in the [MS2] layers. This linear coordination of the Te atom by S atoms is unprecedented in the literature and stabilized by charge transfer within the [Ag2Te] layers. In the latter half, we report the bulk crystal growth and characterization of Tl-based chalcogenide and chalcohalide materials for hard radiation (X- and gamma-ray) detection, which requires high density, wide band gaps, and high resistivity. Lattice hybridization was applied to identify materials with optimal properties for hard radiation detection, resulting in the chalcohalide compound Tl6SI4. Tl6SI4 exhibits low effective mass of carriers, high resistivity, optimal band gap, and large hardness values. The figure of merit mutau products, (mutau) e = 2.1 x 10-3 cm2V-1 and (mutau)h = 2.3 x 10-5 cm2V -1, are comparable to state-of-the-art commercially used materials. Furthermore, high resolution detection of Ag X-rays by Tl6SI 4 was seen at 22 keV (2.6%). Dimensional reduction was used to identify Tl-based chalcogenide materials Tl2MS3 (M = Ge, Sn). Tl2MS3 show great potential for use as hard

  3. Detection of embedded radiation sources using temporal variation of gamma spectral data.

    SciTech Connect

    Shokair, Isaac R.

    2011-09-01

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the isotopes present in a measurement. For low energy resolution detectors, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the isotopes present in the measurement. When many isotopes are present it is difficult to make the correct identification and this process often requires many trial solutions by highly skilled spectroscopists. This report investigates the potential of a new analysis method which uses spatial/temporal information from multiple low energy resolution measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other isotopes present. This method is referred to as targeted principal component analysis (TPCA). For radiation portal monitor applications, multiple measurements of gamma spectra are taken at equally spaced time increments as a vehicle passes through the portal and the TPCA method is directly applicable to this type of measurement. In this report we describe the method and investigate its application to the problem of detection of a radioactive localized source that is embedded in a distributed source in the presence of an ambient background. Examples using simulated spectral measurements indicate that this method works very well and has the potential for automated analysis for RPM applications. This method is also expected to work well for isotopic detection in the presence of spectrally and spatially varying backgrounds as a result of vehicle-induced background suppression. Further work is needed to include effects of shielding, to understand detection limits, setting of thresholds, and to estimate false positive probability.

  4. On-Line Instruction: Are the Outcomes the Same?

    ERIC Educational Resources Information Center

    Warren, Louis L.; Holloman, Harold L., Jr.

    2005-01-01

    Institutions of higher education are offering more and more on-line courses to students. Do students receive the same quality of instruction with an on-line class as an on-campus class? Specifically, is there a difference in students' outcomes between a face-to-face class and on-line class? This study addresses that question by collecting and…

  5. An Evaluation of On-Line Information Retrieval System Techniques.

    ERIC Educational Resources Information Center

    Wolfe, Theodore

    This report presents a review and evaluation of three remote access on-line information retrieval systems and some ideas on what the capabilities of an ideal on-line information retrieval system should be. The three systems reviewed are the DDC Remote On-Line Retrieval System, the National Aeronautics and Space Administration RECON System, and the…

  6. A Distributed System for Learning Programming On-Line

    ERIC Educational Resources Information Center

    Verdu, Elena; Regueras, Luisa M.; Verdu, Maria J.; Leal, Jose P.; de Castro, Juan P.; Queiros, Ricardo

    2012-01-01

    Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the "UVA On-line Judge", an existing on-line…

  7. PHEBUS on-line aerosol monitor development test program

    SciTech Connect

    Sprenger, M.H.; Pentecost, C.G.

    1992-03-01

    EG&G Idaho, Inc. developed an on-line aerosol monitor (OLAM) for the French PHEBUS Fission Product Project. Part of the development was to manufacture and test an OLAM prototype. This report presents the results of the testing which determined the mechanical integrity of the monitor at operating temperature and pressure and performed a preliminary test of the optical system. A series of twenty different tests was conducted during the prototype testing sequence. Since no leaks were detected, the OLAM demonstrated that it could provide a pressure boundary at required test conditions. The optical and electrical system also proved its integrity by exceeding the design requirement of less than 105 optical signal drift during an actual two-hour test sequence.

  8. PHEBUS on-line aerosol monitor development test program

    SciTech Connect

    Sprenger, M.H.; Pentecost, C.G.

    1992-03-01

    EG G Idaho, Inc. developed an on-line aerosol monitor (OLAM) for the French PHEBUS Fission Product Project. Part of the development was to manufacture and test an OLAM prototype. This report presents the results of the testing which determined the mechanical integrity of the monitor at operating temperature and pressure and performed a preliminary test of the optical system. A series of twenty different tests was conducted during the prototype testing sequence. Since no leaks were detected, the OLAM demonstrated that it could provide a pressure boundary at required test conditions. The optical and electrical system also proved its integrity by exceeding the design requirement of less than 105 optical signal drift during an actual two-hour test sequence.

  9. On-line upgrade of program modules

    NASA Technical Reports Server (NTRS)

    Waldrop, Raymond S.; Volz, Richard A.; Smith, Gary W.; Holzbacher-Valero, A. A.; Goldsack, S. J.

    1993-01-01

    This paper presents a taxonomy of problems that must be solved in order to achieve on-line upgradability of long-lived programs, and presents a solution to the fundamental problems in the taxonomy. The solutions are based upon AdaPT, a set of language extensions designed to aid in the distribution of a single Ada program. AdaPT introduces three major units, the public, the partition, and the node. Publics are primarily used to share type information. Partitions are the basic units of distribution while nodes are used to control the configuration of the program. Nodes and partitions can be created dynamically via the allocator. A node-level routine controls the replacement process. The controlling node creates a new instance of the routine being replaced; the run-time system must ensure that the new instance is the updated one. Once access to the new version has been established, all further calls to the module are redirected to the new version and the caller is informed of the change so that it may make subsequent calls directly. When a module is being upgraded, there is a transition period during which both the old and new versions are present. We require that clients of a potentially replaceable module 'check in' with the controlling node. The controlling node keeps track of the number of clients that have been redirected to the replacement. When all have been redirected, the old version can be deallocated.

  10. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation.

    PubMed

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-01-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 10(6), which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results. PMID:26976363

  11. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

    PubMed Central

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-01-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 106, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results. PMID:26976363

  12. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

    NASA Astrophysics Data System (ADS)

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-03-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 106, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results.

  13. The high energy cosmic-radiation detection (HERD) facility onboard China's Space Station

    NASA Astrophysics Data System (ADS)

    Zhang, S. N.; Adriani, O.; Albergo, S.; Ambrosi, G.; An, Q.; Bao, T. W.; Battiston, R.; Bi, X. J.; Cao, Z.; Chai, J. Y.; Chang, J.; Chen, G. M.; Chen, Y.; Cui, X. H.; Dai, Z. G.; D'Alessandro, R.; Dong, Y. W.; Fan, Y. Z.; Feng, C. Q.; Feng, H.; Feng, Z. Y.; Gao, X. H.; Gargano, F.; Giglietto, N.; Gou, Q. B.; Guo, Y. Q.; Hu, B. L.; Hu, H. B.; He, H. H.; Huang, G. S.; Huang, J.; Huang, Y. F.; Li, H.; Li, L.; Li, Y. G.; Li, Z.; Liang, E. W.; Liu, H.; Liu, J. B.; Liu, J. T.; Liu, S. B.; Liu, S. M.; Liu, X.; Lu, J. G.; Mazziotta, M. N.; Mori, N.; Orsi, S.; Pearce, M.; Pohl, M.; Quan, Z.; Ryde, F.; Shi, H. L.; Spillantini, P.; Su, M.; Sun, J. C.; Sun, X. L.; Tang, Z. C.; Walter, R.; Wang, J. C.; Wang, J. M.; Wang, L.; Wang, R. J.; Wang, X. L.; Wang, X. Y.; Wang, Z. G.; Wei, D. M.; Wu, B. B.; Wu, J.; Wu, X.; Wu, X. F.; Xia, J. Q.; Xiao, H. L.; Xu, H. H.; Xu, M.; Xu, Z. Z.; Yan, H. R.; Yin, P. F.; Yu, Y. W.; Yuan, Q.; Zha, M.; Zhang, L.; Zhang, L.; Zhang, L. Y.; Zhang, Y.; Zhang, Y. J.; Zhang, Y. L.; Zhao, Z. G.

    2014-07-01

    The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 104 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10-5; effective geometrical factors of >3 m2sr for electron and diffuse gamma-rays, >2 m2sr for cosmic ray nuclei. R and D is under way for reading out the LYSO signals with optical fiber coupled to image intensified CCD and the prototype of one layer of CALO.

  14. On-line evaluation of multiloop digital controller performance

    NASA Technical Reports Server (NTRS)

    Wieseman, Carol D.

    1993-01-01

    The purpose of this presentation is to inform the Guidance and Control community of capabilities which were developed by the Aeroservoelasticity Branch to evaluate the performance of multivariable control laws, on-line, during wind-tunnel testing. The capabilities are generic enough to be useful for all kinds of on-line analyses involving multivariable control in experimental testing. Consequently, it was decided to present this material at this workshop even though it has been presented elsewhere. Topics covered include: essential on-line analysis requirements; on-line analysis capabilities; on-line analysis software; frequency domain procedures; controller performance evaluation frequency-domain flutter suppression; and plant determination.

  15. A terahertz confocal microscope for far-field thermal radiation detection and near-field sub-wavelength imaging

    NASA Astrophysics Data System (ADS)

    Weng, Qianchun; Yang, Le; Xu, Jie; Qian, Qingbai; Yu, Haochi; Zhang, Bo; An, Zhenghua; Zhu, Ziqiang; Lu, Wei

    2015-11-01

    We present a novel scattering-type scanning near-field optical microscope (s-SNOM) operating in the terahertz (THz) wavelength. A home-made ultra-high sensitive detector named charge sensitive infrared phototransistor (CSIP, detection wavelength ~15 μm) is equipped for spontaneous thermal radiation detection (external illumination should be avoided). Thermal emission from room-temperature objects is collected by a cassegrain objective lens placed above the sample, and focused to a pinhole (d=250 μm) which is kept in liquid-helium (LHe) temperature(4.2 K). With the background radiation from environment efficiently blocked by the low-temperature pinhole, the detector is only sensitive to the THz radiation from a small spot (~λ) on sample surface (the confocal point). As a result, thermal radiation spontaneously emitted by object itself is measured with an excellent spatial resolution of ~14 μm (diffraction-limit). For overcoming the diffraction limit by detecting the near-field evanescent waves, this THz microscope is combined with a home-built atomic-force microscope (AFM). With sharp AFM tip (<100 nm) scattering the evanescent waves with an improved tip-modulation method, we successfully obtained thermal near-field images with a spatial resolution of ~100 nm, which is already less than 1% of the detection wavelength (15 μm). This THz s-SNOM should be a powerful tool for various material research down to the nanometer scale.

  16. Self-checking on-line testable static RAM

    NASA Technical Reports Server (NTRS)

    Chau, Savio N. (Inventor); Rennels, David A. (Inventor)

    1993-01-01

    This is a fault-tolerant random access memory for use in fault-tolerant computers. It comprises a plurality of memory chips each comprising a plurality of on-line testable and correctable memory cells disposed in rows and columns for holding individually addressable binary bits and provision for error detection incorporated into each memory cell for outputting an error signal whenever a transient error occurs therein. In one embodiment, each of the memory cells comprises a pair of static memory sub-cells for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the memory sub-cells to one another and for outputting the error signal whenever the contents do not match. In another embodiment, each of the memory cells comprises a static memory sub-cell and a dynamic memory sub-cell for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the static memory sub-cell to the dynamic memory sub-cell and for outputting the error signal whenever the contents do not match. Capability for correction of errors is also included.

  17. Students On-Line Atmospheric Research

    NASA Astrophysics Data System (ADS)

    Woods, D. C.; Moore, S. W.; Walters, S. C.

    2002-12-01

    Students On-Line Atmospheric Research (SOLAR) is one of NASA's educational outreach programs. SOLAR's primary role is to support educational outreach activities for NASA's Stratospheric Aerosol and Gas Experiment III (SAGE III). SAGE III is the latest version of a series of solar occultation experiments, which include SAGE I and SAGE II. The SAGE III instrument was launched on a Russian METEOR 3M spacecraft in December 2001, and is now monitoring the global distribution of aerosols, ozone, clouds, and other important trace gases in the upper atmosphere. The SAGE measurements are critical to improving the understanding of global climate forcing as well as atmospheric chemical processes in the upper atmosphere. The SAGE experiment addresses interesting science problems related to the Earth's atmosphere. Many exciting science and technology topics from SAGE can be developed and incorporated into K-12 curriculum materials to enhance student interest in science. In addition, technologies employed by the SAGE measurement technique give rise to ideas for science projects that involve student participation. The SOLAR outreach program helps to bring these topics and ideas to the classroom by focusing on helping teachers become familiar with current research in the atmospheric sciences, and helping them integrate SOLAR developed educational materials into their curriculum. SOLAR gives special presentations at national and regional science teacher conferences and conducts an annual summer teacher workshop at the NASA Langley Research Center. Members of the SOLAR team also visit schools give classroom presentations and presentations to special student groups. This poster highlights some of the key features of the SOLAR program and presents descriptions of student projects, teacher workshops, and SOLAR resources.

  18. Subclinical Cardiotoxicity Detected by Strain Rate Imaging up to 14 months After Breast Radiation Therapy

    SciTech Connect

    Erven, Katrien; Florian, Anca; Slagmolen, Pieter; Sweldens, Caroline; Jurcut, Ruxandra; Wildiers, Hans; Voigt, Jens-Uwe; Weltens, Caroline

    2013-04-01

    Purpose: Strain rate imaging (SRI) is a new echocardiographic modality that enables accurate measurement of regional myocardial function. We investigated the role of SRI and troponin I (TnI) in the detection of subclinical radiation therapy (RT)-induced cardiotoxicity in breast cancer patients. Methods and Materials: This study prospectively included 75 women (51 left-sided and 24 right-sided) receiving adjuvant RT to the breast/chest wall and regional lymph nodes. Sequential echocardiographs with SRI were obtained before RT, immediately after RT, and 8 and 14 months after RT. TnI levels were measured on the first and last day of RT. Results: Mean heart and left ventricle (LV) doses were both 9 ± 4 Gy for the left-sided patients and 4 ± 4 Gy and 1 ± 0.4 Gy, respectively, for the right-sided patients. A decrease in strain was observed at all post-RT time points for left-sided patients (−17.5% ± 1.9% immediately after RT, −16.6% ± 1.4% at 8 months, and −17.7% ± 1.9% at 14 months vs −19.4% ± 2.4% before RT, P<.01) but not for right-sided patients. When we considered left-sided patients only, the highest mean dose was given to the anterior left ventricular (LV) wall (25 ± 14 Gy) and the lowest to the inferior LV wall (3 ± 3 Gy). Strain of the anterior wall was reduced after RT (−16.6% ± 2.3% immediately after RT, −16% ± 2.6% at 8 months, and −16.8% ± 3% at 14 months vs −19% ± 3.5% before RT, P<.05), whereas strain of the inferior wall showed no significant change. No changes were observed with conventional echocardiography. Furthermore, mean TnI levels for the left-sided patients were significantly elevated after RT compared with before RT, whereas TnI levels of the right-sided patients remained unaffected. Conclusions: In contrast to conventional echocardiography, SRI detected a regional, subclinical decline in cardiac function up to 14 months after breast RT. It remains to be determined whether these changes are related to clinical

  19. Implementation of an on-line monitoring system for transmitters in a CANDU nuclear power plant

    NASA Astrophysics Data System (ADS)

    Labbe, A.; Abdul-Nour, G.; Vaillancourt, R.; Komljenovic, D.

    2012-05-01

    Many transmitters (pressure, level and flow) are used in a nuclear power plant. It is necessary to calibrate them periodically to ensure that their measurements are accurate. These calibration tasks are time consuming and often contribute to worker radiation exposure. Human errors can also sometimes degrade their performance since the calibration involves intrusive techniques. More importantly, experience has shown that the majority of current calibration efforts are not necessary. These facts motivated the nuclear industry to develop new technologies for identifying drifting instruments. These technologies, well known as on-line monitoring (OLM) techniques, are non-intrusive and allow focusing the maintenance efforts on the instruments that really need a calibration. Although few OLM systems have been implemented in some PWR and BWR plants, these technologies are not commonly used and have not been permanently implemented in a CANDU plant. This paper presents the results of a research project that has been performed in a CANDU plant in order to validate the implementation of an OLM system. An application project, based on the ICMP algorithm developed by EPRI, has been carried out in order to evaluate the performance of an OLM system. The results demonstrated that the OLM system was able to detect the drift of an instrument in the majority of the studied cases. A feasibility study has also been completed and has demonstrated that the implementation of an OLM system at a CANDU nuclear power plant could be advantageous under certain conditions.

  20. On-Line Coolant Chemistry Analysis

    SciTech Connect

    LM Bachman

    2006-07-19

    Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.

  1. Detection and selective avoidance of near ultraviolet radiation by an aquatic annelid: the medicinal leech

    PubMed Central

    Jellies, John

    2014-01-01

    Medicinal leeches are aquatic predators that inhabit surface waters during daylight and also leave the water where they might be exposed to less screened light. Whereas the leech visual system has been shown to respond to visible light, leeches in the genus Hirudo do not appear to be as negatively phototactic as one might expect in order to avoid potential ultraviolet radiation (UVR)-induced damage. I used high intensity light emitting diodes to test the hypothesis that leeches could detect and specifically avoid near UVR (395–405 nm). Groups of unfed juvenile leeches exhibited a robust negative phototaxis to UVR, but had no behavioral response to blue or red and only a slight negative phototaxis to green and white light. Individual leeches also exhibited a vigorous negative phototaxis to UVR; responding in 100% of trials compared with modest negative responses to visible light (responding in ~8% of the trials). The responses in fed and unfed leeches were comparable for UVR stimuli. The responses depended upon the stimulus site: leeches shortened away from UV light to the head, and extended away from UV light to the tail. Electrophysiological nerve recordings showed that the cephalic eyes responded vigorously to UVR. Additionally, individual leech photoreceptors also showed strong responses to UVR, and a higher-order neuron associated with shortening and rapid behavioral responses, the S-cell, was activated by UVR, on both the head and tail. These results demonstrate that the leech can detect UVR and is able to discriminate behaviorally between UVR and visible light. PMID:24265432

  2. Detection of DNA Damage by Space Radiation in Human Fibroblast Cells Flown on the International Space Station

    NASA Technical Reports Server (NTRS)

    Wu, Honglu; Lu, Tao; Wong, Michael; Beno, Jonathan; Countryman, Stefanie; Stodieck, Louis; Karouia, Fathi; Zhang, Ye

    2015-01-01

    Although charged particles in space have been detected with radiation detectors on board spacecraft since the early discovery of the Van Allen Belt, reports on effects of direct exposure to space radiation in biological systems have been limited. Measurement of biological effects of space radiation has been difficult due to the low dose and low dose rate nature of the radiation environment, and the difficulty in separating the radiation effects from microgravity and other space environmental factors. In astronauts, only a small number of changes, such as increased chromosome aberrations in lymphocytes and early onset of cataracts, attributed primarily to the exposure to space radiation. In a recent experiment, human fibroblast cells were flown on the International Space Station (ISS). Cells fixed on Days 3 and 14 after reaching orbit were analyzed for phosphorylation of a histone protein H2AX by immunofluorescent staining of cells, which is a widely used marker for DNA double strand breaks. The 3-dimensional gamma-H2AX foci were captured with a laser confocal microscope. Quantitative analysis revealed a small fraction of foci that were larger and displayed a track pattern in the flight samples in comparison to the ground control. Human fibroblast cells were also exposed to low dose rate gamma rays, as well as to protons and Fe ions. Comparison of the pattern and distribution of the foci after gamma ray and charged particle exposure to our flight results confirmed that the foci found in the flown cells were indeed induced by space radiation.

  3. Improved estimates of boreal Fire Radiative Energy using high temporal resolution data and a modified active fire detection algorithm

    NASA Astrophysics Data System (ADS)

    Barrett, Kirsten

    2016-04-01

    Reliable estimates of biomass combusted during wildfires can be obtained from satellite observations of fire radiative power (FRP). Total fire radiative energy (FRE) is typically estimated by integrating instantaneous measurements of fire radiative power (FRP) at the time of orbital satellite overpass or geostationary observation. Remotely-sensed FRP products from orbital satellites are usually global in extent, requiring several thresholding and filtering operations to reduce the number of false fire detections. Some filters required for a global product may not be appropriate to fire detection in the boreal forest resulting in errors of omission and increased data processing times. We evaluate the effect of a boreal-specific active fire detection algorithm and estimates of FRP/FRE. Boreal fires are more likely to escape detection due to lower intensity smouldering combustion and sub canopy fires, therefore improvements in boreal fire detection could substantially reduce the uncertainty of emissions from biomass combustion in the region. High temporal resolution data from geostationary satellites have led to improvements in FRE estimation in tropical and temperate forests, but such a perspective is not possible for high latitude ecosystems given the equatorial orbit of geostationary observation. The increased density of overpasses in high latitudes from polar-orbiting satellites, however, may provide adequate temporal sampling for estimating FRE.

  4. Self-filling and self-purging apparatus for detecting spontaneous radiation from substances in fluids

    DOEpatents

    Larson, I. Lauren; Chiles, Marion M.; Miller, V. Clint

    1993-01-01

    Disclosed herein is a radiation detector providing for the in situ automatic sampling of fluids containing substances emitting radiation, especially Cerenkov radiation. The detector permits sampling within well casings and is self-purging such that no additional provisions must be established for the storage and disposal of contaminated fluids.

  5. ANSI and IEC standards for, and evaluation of, radiation detection instrumentation

    SciTech Connect

    Chiaro Jr, Peter John

    2008-01-01

    During the last quarter of 2002, an effort was started to develop performance requirements for radiation instrumentation used for the detection of illicit trafficking of radioactive material. Coordinated by the US National Institute of Science and Technology (NIST), a team was formed to establish writing committees for the development of these requirements as American National Standards Institute (ANSI) standards. The core of the new area was developed as ANSI N42, Homeland Security Instruments. A series of standards were developed followed by testing and evaluation (T&E) protocols that would be used for specific testing. Four US National Laboratories provided T&E support and work commenced to test instruments provided by manufacturers at no cost. During this time, discussions began regarding the formation of a new work group within the International Electrotechnical Commission (IEC). This new work group would be located within technical committee (TC) 45 which addresses nuclear instrumentation. This new work group, 15B, also began developing international standards to address the same instrument types. Following development of ANSI standards, the testing and evaluation process began, running for two distinct rounds. The results of the work was consolidated by NIST and released back to individual companies as well as the user community in a controlled manner. This document will provide details regarding the standards and their basis and status, as well as some information regarding the T&E process used in the USA.

  6. Detection of microvasculature alterations by synchrotron radiation in murine with delayed jellyfish envenomation syndrome.

    PubMed

    Wang, Beilei; Zhang, Bo; Huo, Hua; Wang, Tao; Wang, Qianqian; Wu, Yuanlin; Xiao, Liang; Ren, Yuqi; Zhang, Liming

    2014-04-01

    Using the tentacle extract (TE) from the jellyfish Cyanea capillata, we have previously established a delayed jellyfish envenomation syndrome (DJES) model, which is meaningful for clinical interventions against jellyfish stings. However, the mechanism of DJES still remains unclear. Thus, this study aimed to explore its potential mechanism by detecting TE-induced microvasculature alterations in vivo and ex vivo. Using a third-generation synchrotron radiation facility, we, for the first time, directly observed the blood vessel alterations induced by jellyfish venom in vivo and ex vivo. Firstly, microvasculature imaging of whole-body mouse in vivo indicated that the small blood vessel branches in the liver and kidney in the TE-treated group, seemed much thinner than those in the control group. Secondly, 3D imaging of kidney ex vivo showed that the kidneys in the TE-treated group had incomplete vascular trees where distal vessel branches were partly missing and disorderly disturbed. Finally, histopathological analysis found that obvious morphological changes, especially hemorrhagic effects, were also present in the TE-treated kidney. Thus, TE-induced microvasculature changes might be one of the important mechanisms of multiple organ dysfunctions in DJES. In addition, the methods we employed here will probably facilitate further studies on developing effective intervention strategies against DJES. PMID:24508769

  7. Signal Processing and Its Effect on Scanning Efficiencies for a Field Instrument for Detecting Low-energy Radiation.

    PubMed

    Marianno, Craig M

    2015-07-01

    Signal processing within a radiation detector affects detection efficiency. Currently, organizations such as private industry, the U.S. Navy, Army, and Air Force are coupling some detector systems with data collection devices to survey large land areas for radioactive contamination. As detector technology has advanced and analog data collection has turned to digital, signal processing is becoming prevalent in some instruments. Using a NIST traceable (241)Am source, detection efficiency for a field instrument for detecting low-energy radiation (FIDLER) was examined for both a static and scanning mode. Experimental results were compared to Monte Carlo-generated efficiencies. Stationary data compared nicely to the theoretical results. Conversely, scanning detection efficiencies were considerably different from their theoretical counterparts. As speed increased, differences in detection efficiency approached two orders of magnitude. To account for these differences, a quasi time-dependent Monte Carlo simulation was created mimicking the signal processing undertaken by the FIDLER detection system. By including signal processing, experimental results fell within the bounds of the Monte Carlo-generated efficiencies, thus demonstrating the negative effects of such processing on detection efficiencies. PMID:26011500

  8. Development of a Cerenkov radiation sensor to detect low-energy beta-particles.

    PubMed

    Yoo, Wook Jae; Han, Ki-Tek; Shin, Sang Hun; Seo, Jeong Ki; Jeon, Dayeong; Lee, Bongsoo

    2013-11-01

    We fabricated a novel fiber-optic Cerenkov radiation sensor using a Cerenkov radiator for measuring beta-particles. Instead of employing a scintillator, transparent liquids having various refractive indices were used as a Cerenkov radiator to serve as a sensing material. The experimental results showed that the amount of Cerenkov radiation due to the interaction with beta-particles increased as the refractive index of the Cerenkov radiator was increased as a results of a decrease of the Cerenkov threshold energy for electrons. PMID:23582496

  9. Radiation

    NASA Video Gallery

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  10. Rates and characteristics of radiographically detected intracerebral cavernous malformations after cranial radiation therapy in pediatric cancer patients.

    PubMed

    Gastelum, Erica; Sear, Katherine; Hills, Nancy; Roddy, Erika; Randazzo, Dominica; Chettout, Nassim; Hess, Christopher; Cotter, Jennifer; Haas-Kogan, Daphne A; Fullerton, Heather; Mueller, Sabine

    2015-06-01

    Rates and characteristics of intracerebral cavernous malformations after cranial radiation therapy remain poorly understood. Herein we report on intracerebral cavernous malformations detected on follow-up imaging in pediatric cancer patients who received cranial radiation therapy at age ≤18 years from 1980 to 2009. Through chart reviews (n = 362) and phone interviews (n = 104) of a retrospective cohort, we identified 10 patients with intracerebral cavernous malformations. The median latency time for detection of intracerebral cavernous malformations after cranial radiation therapy was 12 years (range 1-24 years) at a median age of 21.4 years (interquartile range = 15-28). The cumulative incidence was 3% (95% confidence interval 1%-8%) at 10 years post cranial radiation therapy and 14% (95% confidence interval 7%-26%) at 15 years. Three patients underwent surgical resection. Two surgical specimens were pathologically similar to sporadically occurring intracerebral cavernous malformations; one was consistent with capillary telangiectasia. Intracerebral cavernous malformations are common after cranial radiation therapy and can show a spectrum of histologic features. PMID:25122111

  11. Oncogene amplification detected by in situ hybridization in radiation induced rat skin tumors. [C-myc:a3

    SciTech Connect

    Yi Jin.

    1991-02-01

    Oncogene activation may play an important role in radiation induced carcinogenesis. C-myc oncogene amplification was detected by in situ hybridization in radiation-induced rat skin tumors, including squamous and basal cell carcinomas. In situ hybridization was performed with a biotinylated human c-myc third exon probe, visualized with an avidin-biotinylated alkaline phosphate detection system. No c-myc oncogene amplification was detected in normal rat skin at very early times after exposure to ionizing radiation, which is consistent with the view that c-myc amplification is more likely to be related to carcinogenesis than to normal cell proliferation. The incorporation of tritiated thymidine into the DNA of rat skin cells showed that the proliferation of epidermal cells reached a peak on the seventh day after exposure to ionizing radiation and then decreased. No connection between the proliferation of epidermal cell and c-myc oncogene amplification in normal or irradiated rat skin was found. The results indicated that c-myc amplification as measured by in situ hybridization was correlated with the Southern bolt results, but only some of the cancer cells were amplified. The c-myc positive cells were distributed randomly within regions of the tumor and exhibited a more uniform nuclear structure in comparison to the more vacuolated c-myc negative cells. No c-myc signal was detected in unirradiated normal skin or in irradiated skin cells near the tumors. C-myc amplification appears to be cell or cell cycle specific within radiation-induced carcinomas. 28 refs., 3 figs., 3 tabs.

  12. On-Line Grammaticality Judgments in French Children and Adults: A Crosslinguistic Perspective

    ERIC Educational Resources Information Center

    Kail, Michele

    2004-01-01

    This study examined the on-line processing of French sentences in a grammaticality judgment experiment. Three age groups of French children (mean age: 6;8, 8;6 and 10;10 years) and a group of adults were asked to detect grammatical violations as quickly as possible. Three factors were studied: the violation type: agreement violations (number and…

  13. Verb Agreements during On-Line Sentence Processing in Alzheimer's Disease and Frontotemporal Dementia

    ERIC Educational Resources Information Center

    Price, C.C.; Grossman, M.

    2005-01-01

    An on-line ''word detection'' paradigm was used to assess the comprehension of thematic and transitive verb agreements during sentence processing in individuals diagnosed with probable Alzheimer's Disease (AD, n=15) and Frontotemporal Dementia (FTD, n=14). AD, FTD, and control participants (n=17) were asked to listen for a word in a sentence.…

  14. EnviroNET: On-line information for LDEF

    NASA Technical Reports Server (NTRS)

    Lauriente, Michael

    1993-01-01

    EnviroNET is an on-line, free-form database intended to provide a centralized repository for a wide range of technical information on environmentally induced interactions of use to Space Shuttle customers and spacecraft designers. It provides a user-friendly, menu-driven format on networks that are connected globally and is available twenty-four hours a day - every day. The information, updated regularly, includes expository text, tabular numerical data, charts and graphs, and models. The system pools space data collected over the years by NASA, USAF, other government research facilities, industry, universities, and the European Space Agency. The models accept parameter input from the user, then calculate and display the derived values corresponding to that input. In addition to the archive, interactive graphics programs are also available on space debris, the neutral atmosphere, radiation, magnetic fields, and the ionosphere. A user-friendly, informative interface is standard for all the models and includes a pop-up help window with information on inputs, outputs, and caveats. The system will eventually simplify mission analysis with analytical tools and deliver solutions for computationally intense graphical applications to do 'What if...' scenarios. A proposed plan for developing a repository of information from the Long Duration Exposure Facility (LDEF) for a user group is presented.

  15. TH-C-BRE-01: IGART: Fast On-Line Planning for IGART

    SciTech Connect

    Oelfke, U; Raaymakers, B; Jia, X; Ahunbay, E; Li, X

    2014-06-15

    Cone beam CT IGRT provides on-line anatomical data of the patient at the treatment couch while new hybrid MRI radiotherapy systems promise to provide this data during the actual radiation delivery itself. To exploit these data, and account for tissue rotations, deformations and tumor regression during radiation therapy delivery, fast, on-line IMRT (re)planning is required.On-line IMRT re-planning needs to re-generate a similar patient specific dose distribution as done in the pre-treatment planning but then for the new state of the anatomy. For this the pre-treatment information has to be propagated to the actual treatment. A fast dose engine is required, which may be, in the case of MRI based IGRT, Monte Carlo based in order to account for the magnetic field induced dose effects. Then robust re-planning methods or class solutions should be available that account efficiently for both rigid and non-rigid anatomical changes while preserving the patient specific pre-treatment dose considerations. Preferably this is all fully automatic, but also fast interactive re-planning is an option, especially in hypo-fractionated (boost) radiotherapy. Learning Objectives: Preservation of pre-treatment prescriptions in the on-line IMRT re-planning Fast re-planning techniques and speed limitations for dose engines Pros and cons of interactive versus automatic re-planning.

  16. On-line monitoring the extract process of Fu-fang Shuanghua oral solution using near infrared spectroscopy and different PLS algorithms

    NASA Astrophysics Data System (ADS)

    Kang, Qian; Ru, Qingguo; Liu, Yan; Xu, Lingyan; Liu, Jia; Wang, Yifei; Zhang, Yewen; Li, Hui; Zhang, Qing; Wu, Qing

    2016-01-01

    An on-line near infrared (NIR) spectroscopy monitoring method with an appropriate multivariate calibration method was developed for the extraction process of Fu-fang Shuanghua oral solution (FSOS). On-line NIR spectra were collected through two fiber optic probes, which were designed to transmit NIR radiation by a 2 mm flange. Partial least squares (PLS), interval PLS (iPLS) and synergy interval PLS (siPLS) algorithms were used comparatively for building the calibration regression models. During the extraction process, the feasibility of NIR spectroscopy was employed to determine the concentrations of chlorogenic acid (CA) content, total phenolic acids contents (TPC), total flavonoids contents (TFC) and soluble solid contents (SSC). High performance liquid chromatography (HPLC), ultraviolet spectrophotometric method (UV) and loss on drying methods were employed as reference methods. Experiment results showed that the performance of siPLS model is the best compared with PLS and iPLS. The calibration models for AC, TPC, TFC and SSC had high values of determination coefficients of (R2) (0.9948, 0.9992, 0.9950 and 0.9832) and low root mean square error of cross validation (RMSECV) (0.0113, 0.0341, 0.1787 and 1.2158), which indicate a good correlation between reference values and NIR predicted values. The overall results show that the on line detection method could be feasible in real application and would be of great value for monitoring the mixed decoction process of FSOS and other Chinese patent medicines.

  17. DOE-EPRI On-Line Monitoring Implementation Guidelines

    SciTech Connect

    E. Davis, R. Bickford

    2003-01-02

    Industry and EPRI experience at several plants has shown on-line monitoring to be very effective in identifying out-of-calibration instrument channels or indications of equipment-degradation problems. The EPRI implementation project for on-line monitoring has demonstrated the feasability of on-line monitoring at several participating nuclear plants. The results have been very enouraging, and substantial progress is anticipated in the coming years.

  18. On-line ultrasonic gas entrainment monitor

    DOEpatents

    Day, Clifford K.; Pedersen, Herbert N.

    1978-01-01

    Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment. One specific embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose.

  19. Resistance of lichens to simulated galactic cosmic radiation: limits of survival capacity and biosignature detection

    NASA Astrophysics Data System (ADS)

    de la Torre Noetzel, Rosa; Miller, Ana Z.; Cubero, Beatriz; Raguse, Marina; Meessen, Joachim

    2016-04-01

    Space constitutes an extremely harmful environment for survival of terrestrial organisms. Amongst extremophiles on Earth, lichens are one of the most resistant organisms to harsh terrestrial environments, as well as some species of microorganisms, such as bacteria (Moeller et al., 2010), criptoendolithic cyanobacteria and lithic fungi (de los Ríos et al. 2004). To study the survival capacity of lichens to the harmful radiation environment of space, we have selected the lichen Circinaria gyrosa, an astrobiological model defined by its high capacity of resistance to space conditions (De la Torre et al. 2010) and to a simulated Mars environment (Sanchez et al., 2012). Samples were irradiated with four types of space-relevant ionizing radiation in the STARLIFE campaign: helium and iron ion doses (up to 2,000 Gy), X-ray doses (up to 5,000 Gy) and ultra-high γ-ray doses (from 6 to 113 kGy). Results on resistance of C. gyrosa to space-relevant ionizing radiation and its post-irradiation viability were obtained by: (i) chlorophyll a fluorescence of photosystem II (PS II); (ii) epifluorescence microscopy; (iii) confocal laser-scanning microscopy (CLSM), and (iv) field emission scanning electron microscopy (FESEM). Results of photosynthetic activity and epifluorescence showed no significant changes on the viability of C. gyrosa with increasing doses of helium and iron ions as well as X-rays. In contrast, γ-irradiation elicited significant dose-correlated effects as revealed by all applied techniques. Relevant is the presence of whewellite-like crystals, detected by FESEM on C. gyrosa thalli after high irradiation doses, which has been also identified in previous Mars simulation studies (Böttcher et al., 2014). These studies contribute to the better understanding of the adaptability of extremophile organisms to harsh environments, as well as to estimate the habitability of a planet's surface, like Mars; they will be important for planning experiments on the search of life

  20. Characterization of amorphous selenium alloy detectors for x-rays and high energy nuclear radiation detection

    NASA Astrophysics Data System (ADS)

    Mandal, Krishna C.; Mehta, Abhinav; Chaudhuri, Sandeep K.; Cui, Yunlong; Groza, Michael; Burger, Arnold

    2013-09-01

    Synthesized amorphous selenium (a-Se) alloy materials have been characterized for room temperature high-energy nuclear radiation detector and x-ray detection applications. The alloy composition has been optimized to ensure good charge transport properties and detector performance. The synthesis of a-Se (As, Cl) alloys has been carried out by thoroughly mixing zone-refined (ZR) Se (~7N) with previously synthesized a-Se(As) and a-Se(Cl) master alloys (MS). The synthesized alloys have been characterized by x-ray diffraction (XRD), glow discharge mass spectroscopy (GDMS), differential scanning calorimetry (DSC), x-ray photoelectron spectroscopy (XPS), and current-voltage (I-V) characteristics measurements. Raman spectroscopy demonstrated that the a-Se(As) master alloy samples were in metastable monoclinic Se8 states, in which seven vibrational modes are located at 40(41), 59(60), 77, 110, 133, 227(228) and 251(252) cm-1. However, a-Se(Cl) master alloy samples are in stable form of trigonal structure of Se8 ring, in which two modes at 142 and 234 cm-1 were found. Both Raman and energy dispersive spectroscopy (EDS) exhibited that a small amount of tellurium (Te) existed in a-Se (As, Cl) master alloy samples. DSC measurements showed that a-Se (Cl) MS and a-Se (As) MS samples have one melting point, located at ~219.6°C, whereas a-Se-As (0.52%)-Cl and Se- As(10.2%)-Cl(60 ppm) both possess two melting points, located at 221 and 220.3°C respectively. The a-Se alloy plate detectors have been fabricated and tested and the results showed high dark resistivity (1012 - 1013 Ω-cm) with good charge transport properties and cost-effective large-area scalability.

  1. New small devices for radiation detection: the Wee Pocket Chirper and the Portable Multichannel Analyzer

    SciTech Connect

    Umbarger, C.J.

    1980-08-01

    Recent events have demonstrated the need for improved capability to monitor the exposure of workers to radiation and, in general, to identify and measure the many forms of radioactive materials found throughout the nuclear industry. Two radiation monitoring devices have been developed that are much smaller than existing instruments, yet exhibit superior performance and a longer battery life. The first instrument, the Wee Pocket Chirper, is a tiny, battery-powered warning device that chirps when exposed to radiation. The second instrument is a portable battery-powered, computer-based, multichannel analyzer that allows the user to examine radiation fields and to identify the types and amounts of radioactive materials present.

  2. Sci—Fri AM: Mountain — 04: Label-free Raman spectroscopy of single tumour cells detects early radiation-induced glycogen synthesis associated with increased radiation resistance

    SciTech Connect

    Matthews, Q; Lum, JJ; Isabelle, M; Harder, S; Jirasek, A; Brolo, AG

    2014-08-15

    Purpose: To use label-free Raman spectroscopy (RS) for early treatment monitoring of tumour cell radioresistance. Methods: Three human tumour cell lines, two radioresistant (H460, SF{sub 2} = 0.57 and MCF7, SF{sub 2} = 0.70) and one radiosensitive (LNCaP, SF{sub 2} = 0.36), were irradiated with single fractions of 2, 4, 6, 8 or 10 Gy. In additional experiments, H460 and MCF7 cells were irradiated under co-treatment with the anti-diabetic drug metformin, a known radiosensitizing agent. Treated and control cultures were analyzed with RS daily for 3 days post-treatment. Single-cell Raman spectra were acquired from 20 live cells per sample, and experiments were repeated in triplicate. The combined data sets were analyzed with principal component analysis using standard algorithms. Cells from each culture were also subjected to standard assays for viability, proliferation, cell cycle, and radiation clonogenic survival. Results: The radioresistant cells (H460, MCF7) exhibited a RS molecular radiation response signature, detectable as early as 1 day post-treatment, of which radiation-induced glycogen synthesis is a significant contributor. The radiosensitive cells (LNCaP) exhibited negligible glycogen synthesis. Co-treatment with metformin in MCF7 cells blocked glycogen synthesis, reduced viability and proliferation, and increased radiosensitivity. Conversely, metformin co-treatment in H460 cells did not produce these same effects; importantly, both radiation-induced synthesis of glycogen and radiosensitivity were unaffected. Conclusions: Label-free RS can detect early glycogen synthesis post-irradiation, a previously undocumented metabolic mechanism associated with tumour cell radioresistance that can be targeted to increase radiosensitivity. RS monitoring of intratumoral glycogen may provide new opportunities for personalized combined modality radiotherapy treatments.

  3. Continuous On-Line Partial Discharge Monitor for Medium-Voltage Cable Feasibility Study

    SciTech Connect

    M. Fenger

    2005-11-30

    Partial discharge (PD) assessment is one method of detecting cable conditions that predict approaching failure. While not all PDs in cable systems lead to failure, PDs within the cable's insulation can lead to relatively rapid failure. Accordingly, on-line PD assessment may be more useful than periodic PD assessment because the period of partial discharging at the end of a cable's life may be quite short. The research described in this report studied the feasibility of developing an on-line PD monitor for assessing both shielded and unshielded MV cables.

  4. Simultaneous detection of ultraviolet and infrared radiation in a single GaN/GaAlN heterojunction.

    PubMed

    Jayasinghe, Ranga C; Ariyawansa, Gamini; Dietz, Nikolaus; Perera, A G Unil; Matsik, Steven G; Yu, Hongbo B; Ferguson, Ian T; Bezinger, Andrew; Laframboise, Sylvain R; Buchanan, Margaret; Liu, Hui Chun

    2008-11-01

    Results are presented for a dual-band detector that simultaneously detects UV radiation in the 250-360 nm and IR radiation in the 5-14 microm regions with near zero spectral cross talk. In this detector having separate UV- and IR-active regions with three contacts (one common contact for both regions) allows the separation of the UV and IR generated photocurrent components, identifying the relative strength of each component. This will be an important development in UV-IR dual-band applications such as fire-flame detection, solar astronomy, and military sensing, eliminating the difficulties of employing several individual detectors with separate electronics-cooling mechanisms. PMID:18978874

  5. Radiation Detection Field Test at the Federal Express (FedEx) Air Cargo Facility at Denver International Airport (DIA)

    SciTech Connect

    Weirup, D; Waters, A; Hall, H; Dougan, A; Trombino, D; Mattesich, G; Hull, E; Bahowick, S; Loshak, A; Gruidl, J

    2004-02-11

    Lawrence Livermore National Laboratory (LLNL) recently conducted a field-test of radiation detection and identification equipment at the air cargo facility of Federal Express (FedEx) located at Denver International Airport (DIA) over a period of two weeks. Comprehensive background measurements were performed and were analyzed, and a trial strategy for detection and identification of parcels displaying radioactivity was implemented to aid in future development of a comprehensive protection plan. The purpose of this project was threefold: {sm_bullet} Quantify background radiation environments at an air cargo facility. {sm_bullet} Quantify and identify ''nuisance'' alarms. {sm_bullet} Evaluate the performance of various isotope identifiers deployed in an operational environment (in this case, the operational environment included the biggest blizzard in over 90 years!).

  6. Mitigation of High Altitude and Low Earth Orbit Radiation Effects on Microelectronics via Shielding or Error Detection and Correction Systems

    NASA Technical Reports Server (NTRS)

    Gupta, Kajal (Technical Monitor); Kirby, Kelvin

    2004-01-01

    The NASA Cooperative Agreement NAG4-210 was granted under the FY2000 Faculty Awards for Research (FAR) Program. The project was proposed to examine the effects of charged particles and neutrons on selected random access memory (RAM) technologies. The concept of the project was to add to the current knowledge of Single Event Effects (SEE) concerning RAM and explore the impact of selected forms of radiation on Error Detection and Correction Systems. The project was established as an extension of a previous FAR awarded to Prairie View A&M University (PVAMU), under the direction of Dr. Richard Wilkins as principal investigator. The NASA sponsored Center for Applied Radiation Research (CARR) at PVAMU developed an electronic test-bed to explore and quantify SEE on RAM from charged particles and neutrons. The test-bed was developed using 486DX microprocessor technology (PC-104) and a custom test board to mount RAM integrated circuits or other electronic devices. The test-bed had two configurations - a bench test version for laboratory experiments and a 400 Hz powered rack version for flight experiments. The objectives of this project were to: 1) Upgrade the Electronic Test-bed (ETB) to a Pentium configuration; 2) Accommodate more than only 8 Mbytes of RAM; 3) Explore Error Detection and Correction Systems for radiation effects; 4) Test modern RAM technologies in radiation environments.

  7. DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENNTIAL FLUORESENCE ASSAY

    EPA Science Inventory

    A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposures...

  8. DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENTIAL FLUORESCENCE ASSAY

    EPA Science Inventory

    A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposur...

  9. Radio-frequency measurements of coherent transition and Cherenkov radiation: Implications for high-energy neutrino detection

    SciTech Connect

    Gorham, Peter W.; Saltzberg, David P.; Schoessow, Paul; Gai, Wei; Power, John G.; Konecny, Richard; Conde, M. E.

    2000-12-01

    We report on measurements of (11--18)-cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultrahigh-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultrahigh-energy neutrinos.

  10. Radio-frequency measurements of coherent transition and cherenkov radiation: implications for high-energy neutrino detection

    PubMed

    Gorham; Saltzberg; Schoessow; Gai; Power; Konecny; Conde

    2000-12-01

    We report on measurements of (11-18)-cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultrahigh-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultrahigh-energy neutrinos. PMID:11138159

  11. Growth and Characterization of alpha-PbO for Room Temperature Radiation Detection

    NASA Astrophysics Data System (ADS)

    Ford, Erin Leigh

    A global trading structure and high throughput of shipping containers into ports around the world increases the chance of nuclear terrorism via cargo containers. Harmless radioactive sources confuse and impede detection of the materials that pose a real threat, making spectroscopy difficult and requiring detectors with high resolution. The current methods that are used to check containers in ports have security flaws, and only 5% of all shipping containers are checked. The development of semiconductor gamma-ray detectors is one of the protocols being advanced to alleviate this risk because they can function at room temperature and they are cost effective, easily produced, and have high resolution. This dissertation has addressed the current lack of "perfect" room temperature detector materials by investigating alpha-PbO, a novel material in this field. This includes the development of a growth process for alpha-PbO thin films, as well as its structural and performance characterization as a detector material. Because we intend alpha-PbO to be a photoconductive detector, it should have certain properties. A photoconductive detector consists of a highly resistive material with a voltage bias across it. It absorbs incident gamma-rays, creating electron-hole pairs that provide a signal. To function well, it must have a high atomic number and a high density in order to absorb high-energy photons via the photoelectric effect. It should also have a large resistivity and a wide band gap to avoid large leakage currents at room temperature. Finally, it must have good charge carrier transport properties and detector resolution in order to be able to determine the characteristic energy peaks of the radiation-emitting source. We chose alpha-PbO because it has a very high Z and a very high density and a band gap in the correct range. It also has a rich history of use as a photoconductor that reaches back to the 1950s. Numerous methods have been used to grow thin films of alpha

  12. Growth and Characterization of alpha-PbO for Room Temperature Radiation Detection

    NASA Astrophysics Data System (ADS)

    Ford, Erin Leigh

    A global trading structure and high throughput of shipping containers into ports around the world increases the chance of nuclear terrorism via cargo containers. Harmless radioactive sources confuse and impede detection of the materials that pose a real threat, making spectroscopy difficult and requiring detectors with high resolution. The current methods that are used to check containers in ports have security flaws, and only 5% of all shipping containers are checked. The development of semiconductor gamma-ray detectors is one of the protocols being advanced to alleviate this risk because they can function at room temperature and they are cost effective, easily produced, and have high resolution. This dissertation has addressed the current lack of "perfect" room temperature detector materials by investigating alpha-PbO, a novel material in this field. This includes the development of a growth process for alpha-PbO thin films, as well as its structural and performance characterization as a detector material. Because we intend alpha-PbO to be a photoconductive detector, it should have certain properties. A photoconductive detector consists of a highly resistive material with a voltage bias across it. It absorbs incident gamma-rays, creating electron-hole pairs that provide a signal. To function well, it must have a high atomic number and a high density in order to absorb high-energy photons via the photoelectric effect. It should also have a large resistivity and a wide band gap to avoid large leakage currents at room temperature. Finally, it must have good charge carrier transport properties and detector resolution in order to be able to determine the characteristic energy peaks of the radiation-emitting source. We chose alpha-PbO because it has a very high Z and a very high density and a band gap in the correct range. It also has a rich history of use as a photoconductor that reaches back to the 1950s. Numerous methods have been used to grow thin films of alpha

  13. On-Line and Off-Line Assessment of Metacognition

    ERIC Educational Resources Information Center

    Saraç, Seda; Karakelle, Sema

    2012-01-01

    The study investigates the interrelationships between different on-line and off-line measures for assessing metacognition. The participants were 47 fifth grade elementary students. Metacognition was assessed through two off-line and two on-line measures. The off-line measures consisted of a teacher rating scale and a self-report questionnaire. The…

  14. 45 CFR 502.8 - Documents on-line.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Documents on-line. 502.8 Section 502.8 Public Welfare Regulations Relating to Public Welfare (Continued) FOREIGN CLAIMS SETTLEMENT COMMISSION OF THE... § 502.8 Documents on-line. Commission documents available in electronic format may be accessed via...

  15. On-Line Administrative Information Systems: A Case Study.

    ERIC Educational Resources Information Center

    Sire, Paul W.

    A case study approach is used to document the on-line information system developed by the Office of Management Information and Computing at the University of Vermont. Stanford University's Project INFO On-Line Administration Information System, OASIS, was chosen as a model. The administrative system is one of two on campus, the other designed for…

  16. Are On-Line Data Bases in Your Library's Future?

    ERIC Educational Resources Information Center

    Deacon, Jim

    1983-01-01

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: Today there are over 900 on-line data banks available for public access. Most microcomputers can use them through the aid of a modem and communication program. Major public information utilities that offer access to these on-line data bases are growing and expanding. The Source, a data base utility…

  17. On-Line Distance Learning: A Model for Developing Countries.

    ERIC Educational Resources Information Center

    Khan, Abdul W.

    2000-01-01

    Discusses issues related to open and distance-learning (ODL) in developing countries, using the virtual campus initiative of the Indira Gandhi National Open University (India) as an example and model of on-line program delivery and on-line, for-profit telelearning centers. Suggests strategies to enable open and distance-learning institutions to…

  18. Issues Affecting Teaching On-Line: An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Thompson, Kelvin

    This annotated bibliography identifies issues affecting the on-line teaching environment by assembling a variety of quantitative and qualitative studies. Studies in the bibliography are divided into two major categories: (1) topical studies, which contain papers that focus primarily on one issue affecting teaching on-line (student…

  19. Chat: The Missing Link in On-Line Instruction.

    ERIC Educational Resources Information Center

    Roberson, Thelma J.; Klotz, Jack

    As more courses in higher education move to an on-line format, a major concern that has arisen is the lack of personal interaction between the professor and student. The literature provides evidence that often on-line courses are configured and delivered in a style more often associated with independent study or correspondence work, i.e., students…

  20. On-Line Library Housekeeping Systems. A Survey

    ERIC Educational Resources Information Center

    McAllister, Caryl

    1971-01-01

    A general discussion of on-line procedures, batch and real-time updating, types of files and indexes, terminals, and the use of a general-purpose data management system as a vehicle for on-line operation is followed by an Appendix giving detailed information on each on the known systems. (14 references) (Author/NH)

  1. System Requirements for On-Line and Batch Retrieval.

    ERIC Educational Resources Information Center

    American Society for Information Science, Washington, DC. Special Interest Group on Computerized Retrieval Services.

    Three papers on system requirements for on-line and batch retrieval presented at the American Society for Information Science (ASIS) annual meeting are included here. At G.D. Searle, data for records related to pharmacology screening are used in a batch system, and an on-line system is used to search information on mutagenic, carcinogenic, and…

  2. On-Line Course Development: Engaging and Retaining Students

    ERIC Educational Resources Information Center

    Bruster, Benita G.

    2015-01-01

    As the number of on-line classes and the demand for on-line education continues to sky-rocket, it is critical that course developers and university faculty have the skills to effectively design curricula, to develop engaging learning opportunities, and to create responsive courses that meet individual student needs. This paper details three…

  3. Evidence on the Effectiveness of On-Line Homework

    ERIC Educational Resources Information Center

    Dillard-Eggers, Jane; Wooten, Tommy; Childs, Brad; Coker, John

    2008-01-01

    The purpose of this research is to evaluate the impact and effectiveness of on-line homework in principles of accounting classes. We surveyed students to determine their degree of satisfaction with on-line homework and their perceptions about its effectiveness in enhancing their learning. We also gathered data to determine the extent of online…

  4. Survival and Germinability of Bacillus subtilis Spores Exposed to Simulated Mars Solar Radiation: Implications for Life Detection and Planetary Protection

    NASA Astrophysics Data System (ADS)

    Tauscher, Courtney; Schuerger, Andrew C.; Nicholson, Wayne L.

    2006-08-01

    Bacterial spores have been considered as microbial life that could survive interplanetary transport by natural impact processes or human spaceflight activity. Deposition of terrestrial microbes or their biosignature molecules onto the surface of Mars could negatively impact life detection experiments and planetary protection measures. Simulated Mars solar radiation, particularly the ultraviolet component, has been shown to reduce spore viability, but its effect on spore germination and resulting production of biosignature molecules has not been explored. We examined the survival and germinability of Bacillus subtilis spores exposed to simulated martian conditions that include solar radiation. Spores of B. subtilis that contain luciferase resulting from expression of an sspB-luxAB gene fusion were deposited on aluminum coupons to simulate deposition on spacecraft surfaces and exposed to simulated Mars atmosphere and solar radiation. The equivalent of 42 min of simulated Mars solar radiation exposure reduced spore viability by nearly 3 logs, while germination-induced bioluminescence, a measure of germination metabolism, was reduced by less than 1 log. The data indicate that spores can retain the potential to initiate germination-associated metabolic processes and produce biological signature molecules after being rendered nonviable by exposure to Mars solar radiation.

  5. Detection of DNA Damage by Space Radiation in Human Fibroblast Cells Flown on the International Space Station

    NASA Technical Reports Server (NTRS)

    Wu, Honglu; Lu, Tao; Wong, Michael; Feiveson, Alan; Stodieck, Louis; Karouia, Fathi; Zhang, Ye

    2016-01-01

    Although charged particles in space have been detected with radiation detectors on board the spacecraft since the early discovery of the Van Allen Belts, reports on the effects of direct exposure to space radiation in biological systems have been limited. Measurement of biological effects of space radiation has been difficult due to the low dose and low dose rate nature of the radiation environment, and the difficulty in separating the radiation effects from microgravity and other space environmental factors. In astronauts, only a few changes, such as increased chromosome aberrations in lymphocytes and early onset of cataracts, attributed primarily to the exposure to space radiation. In a recent experiment, human fibroblast cells were flown on the International Space Station (ISS). Cells were kept at 370 C in space and fixed on Days 3 and 14 after reaching orbit. After returning to the ground, the fixed cells were analyzed for phosphorylation of a histone protein H2AX by immunofluorescent staining of cells, which is a widely used biomarker for DNA double strand breaks. The 3-dimensional gamma-H2AX foci were captured with a laser confocal microscope. Quantitative analysis revealed a small fraction of foci that were larger and displayed a track pattern in the flight samples in comparison to the ground controls. To confirm that the foci data from the flight study was actually induced from space radiation exposure, human fibroblast cells were exposed to low- and high-LET protons and high-LET Fe ions on the ground. High-LET protons and Fe ions were found to induce foci of the pattern that were observed in the flown cells.

  6. Detection of DNA damage by space radiation in human fibroblast cells flown on the International Space Station

    NASA Astrophysics Data System (ADS)

    Wu, Honglu; Feiveson, Alan; Karouia, Fathi; Stodieck, Louis; Zhang, Ye; Lu, Tao; Wong, Michael

    2016-07-01

    Although charged particles in space have been detected with radiation detectors on board the spacecraft since the early discovery of the Van Allen Belts, reports on the effects of direct exposure to space radiation in biological systems have been limited. Measurement of biological effects of space radiation has been difficult due to the low dose and low dose rate nature of the radiation environment, and the difficulty in separating the radiation effects from microgravity and other space environmental factors. In astronauts, only a few changes, such as increased chromosome aberrations in lymphocytes and early onset of cataracts, attributed primarily to the exposure to space radiation. In a recent experiment, human fibroblast cells were flown on the International Space Station (ISS). Cells were kept at 370C in space and fixed on Days 3 and 14 after reaching orbit. After returning to the ground, the fixed cells were analyzed for phosphorylation of a histone protein H2AX by immunofluorescent staining of cells, which is a widely used biomarker for DNA double strand breaks. The 3-dimensional γg-H2AX foci were captured with a laser confocal microscope. Quantitative analysis revealed a small fraction of foci that were larger and displayed a track pattern in the flight samples in comparison to the ground controls. To confirm that the foci data from the flight study was actually induced from space radiation exposure, human fibroblast cells were exposed to low- and high-LET protons and high-LET Fe ions on the ground. High-LET protons and Fe ions were found to induce foci of the pattern that were observed in the flown cells.

  7. Evaluation of a Reactor On-Line Uncertainty Monitoring System

    SciTech Connect

    Edwards, Robert M.; He, Weidong

    2001-06-17

    Robust control designs were developed to better match experimental conditions available in the TRIGA reactor. A first-order weighting function is specified for each operating range in the robust design to limit the maximum tracking error. Inclusion of the performance-weighting function as the on-line filter is discussed as a possible on-line performance-monitoring method. The scheme to evaluate an on-line uncertainty monitoring system for a robust reactor controller is shown. TRIGA reactor experiments were conducted to evaluate on-line performance-monitoring techniques. It is concluded that the observed robust-control performance-monitoring characteristics can be incorporated in an on-line decision-making process to choose appropriate robust control selection and enforcement.

  8. On-line monitoring of methane in sewer air

    PubMed Central

    Liu, Yiwen; Sharma, Keshab R.; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-01-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R2 > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air. PMID:25319343

  9. Gated Treatment Delivery Verification With On-Line Megavoltage Fluoroscopy

    SciTech Connect

    Tai An; Christensen, James D.; Gore, Elizabeth; Khamene, Ali; Boettger, Thomas; Li, X. Allen

    2010-04-15

    Purpose: To develop and clinically demonstrate the use of on-line real-time megavoltage (MV) fluoroscopy for gated treatment delivery verification. Methods and Materials: Megavoltage fluoroscopy (MVF) image sequences were acquired using a flat panel equipped for MV cone-beam CT in synchrony with the respiratory signal obtained from the Anzai gating device. The MVF images can be obtained immediately before or during gated treatment delivery. A prototype software tool (named RTReg4D) was developed to register MVF images with phase-sequenced digitally reconstructed radiograph images generated from the treatment planning system based on four-dimensional CT. The image registration can be used to reposition the patient before or during treatment delivery. To demonstrate the reliability and clinical usefulness, the system was first tested using a thoracic phantom and then prospectively in actual patient treatments under an institutional review board-approved protocol. Results: The quality of the MVF images for lung tumors is adequate for image registration with phase-sequenced digitally reconstructed radiographs. The MVF was found to be useful for monitoring inter- and intrafractional variations of tumor positions. With the planning target volume contour displayed on the MVF images, the system can verify whether the moving target stays within the planning target volume margin during gated delivery. Conclusions: The use of MVF images was found to be clinically effective in detecting discrepancies in tumor location before and during respiration-gated treatment delivery. The tools and process developed can be useful for gated treatment delivery verification.

  10. On-line optical sensors for industrial material inspection

    NASA Astrophysics Data System (ADS)

    Cielo, Paolo G.

    1990-08-01

    In the modem computer-integrated material processing plant statistical process control plays an increasingly important role. A corresponding need for rugged and noninvasive on-line sensors capable of reliable and unattended performance is becoming more and more urgent. Optical sensors are often being adopted for such tasks not only because of their noncontact nature implying an easy adaptability to the automated inspection of continuously moving products at any temperature but also in view of their high response speed intrinsic resolution and increasing ruggedness. Properties which may be probed with optical devices include product features such as geometrical size and shape or surface integrity as well as process parameters such as temperature speed or vibration amplitude. This paper reviews a number of optical sensors which were recently developed at our institute for industrial material online inspection. Examples include surface defect detection 3-D lumber board scanning and infrared temperature measurement either in furnace or during spray deposition. The emphasis is on noncontact techniques well suited to automation and specifically adapted to each particular application with minimum perturbation of the industrial process. 1.

  11. Laser Ultrasonic System for On-Line Steel Tube Gauging

    NASA Astrophysics Data System (ADS)

    Monchalin, Jean-Pierre; Choquet, Marc; Padioleau, Christian; Néron, Christian; Lévesque, Daniel; Blouin, Alain; Corbeil, Christian; Talbot, Richard; Bendada, Abdelhakim; Lamontagne, Mario; Kolarik, Robert V.; Jeskey, Gerald V.; Dominik, Erich D.; Duly, Larry J.; Samblanet, Kenneth J.; Agger, Steven E.; Roush, Kenneth J.; Mester, Michael L.

    2003-03-01

    A laser-ultrasonic system has been installed on a seamless tubing production line of The Timken Company and is being used to measure on-line the wall thickness of tubes during processing. The seamless process consists essentially in forcing a mandrel through a hot cylindrical billet in rotation and typically results in fairly large wall thickness variations that should be minimized and controlled to respect specifications. The system includes a Q-switched Nd-YAG laser for generation of ultrasound by ablation, a long pulse very stable Nd-YAG laser for detection coupled to a confocal Fabry-Perot interferometer, a pyrometer to measure tube temperature and two laser Doppler velocimeters to measure the coordinates of the probing location at the tube surface. The laser, data acquisition and processing units are housed in a cabin off line and connected to a front coupling head located over the passing tube by optical fibers. The system has been integrated into the plant computer network and provides in real time thickness data to the plant operators. It allow much faster mill setups, has been used since its deployment for inspecting more than 100,000 tubes and has demonstrated very significant savings.

  12. On-line monitoring of methane in sewer air

    NASA Astrophysics Data System (ADS)

    Liu, Yiwen; Sharma, Keshab R.; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-10-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R2 > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air.

  13. On-line monitoring of methane in sewer air.

    PubMed

    Liu, Yiwen; Sharma, Keshab R; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-01-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R(2) > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air. PMID:25319343

  14. Detection of a unique antigen on radiation leukemia virus-induced leukemia B6RV2

    SciTech Connect

    Nakayama, E.; Uenaka, A.; Stockert, E.; Obata, Y.

    1984-11-01

    Radiation leukemia virus-induced leukemia of a male C57BL/6 mouse, B6RV2, is immunogenic to female BALB/c X C57BL/6 F1 mice. In these mice, B6RV2 tumors regressed after initial growth, and after tumor regression the mice were resistant to repeated inocula of up to 10(8) B6RV2 cells. Serum from these mice reacted with B6RV2 in mixed hemadsorption or protein A assays, and absorption analysis indicated that the antigen was restricted to B6RV2; it could not be detected in normal thymocytes or spleen concanavalin A blasts from different inbred strains, nor in 16 C57BL/6 or BALB/c leukemias. Spleen cells from mice in which the tumor had regressed were cytotoxic to B6RV2 after in vitro stimulation with B6RV2, as shown by /sup 51/chromium release assay. This cytotoxicity was eliminated by pretreatment of the cells with anti-Thy-1.2, anti-Lyt-2.2, anti-Lyt-3.2, and complement, indicating that the effector cells were T-cells. The specificity of T-cell killing of B6RV2 was examined by competitive inhibition assays with unlabeled cells; only B6RV2 inhibited killing, while eight other C57BL/6 leukemias did not inhibit. Thus, the antigen on B6RV2 defined serologically and by cytotoxic T-cells is a unique antigen. However, it was not revealed by antibody-blocking test whether the unique determinant defined serologically was related to that recognized by T-cells; B6RV2 antiserum did not block lytic activity in the absence of added complement, irrespective of whether the target cells were untreated or anti-H-2b-treated B6RV2. H-2Kb antisera, but not H-2Db antisera, blocked lysis. This indicated that the H-2Kb molecule was exclusively involved in recognition of B6RV2 by cytotoxic T-cell.

  15. Laboratory verification of on-line lithium analysis using ultraviolet absorption spectrometry

    SciTech Connect

    Beemster, B.J.; Schlager, K.J.; Schloegel, K.M.; Kahle, S.J.; Fredrichs, T.L.

    1992-12-31

    Several laboratory experiments were performed to evaluate the capability of absorption spectrometry in the ultraviolet-visible wavelength range with the objective of developing methods for on-line analysis of lithium directly in the primary coolant of Pressurized Water Reactors using optical probes. Although initial laboratory tests seemed to indicate that lithium could be detected using primary absorption (detection of natural spectra unassisted by reagents), subsequent field tests demonstrated that no primary absorption spectra existed for lithium in the ultraviolet-visible wavelength range. A second series of tests that were recently conducted did, however, confirm results reported in the literature to the effect that reagents were available that will react with lithium to form chelates that possess detectable absorption and fluorescent signatures. These results point to the possible use of secondary techniques for on-line analysis of lithium.

  16. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    SciTech Connect

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua; Anastasio, Mark A.; Low, Daniel A.

    2015-02-15

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  17. Radiation detection system using semiconductor detector with differential carrier trapping and mobility

    DOEpatents

    Whited, Richard C.

    1981-01-01

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI.sub.2, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  18. Beta particle detection efficiency of the radiation sensor made from a mixture of polyaniline and titanium oxide

    NASA Astrophysics Data System (ADS)

    Tamura, M.; Miyata, H.; Katsumata, M.; Matsuda, K.; Ueno, T.; Ito, D.; Suzuki, T.

    2016-08-01

    We developed a new real-time radiation sensor using an organic semiconductor and measured its β-particle detection sensitivity. This sensor is fabricated by simply combining a p-type semiconductor, polyaniline (Pani), with an n-type semiconductor, TiO2, and processing the compound. Since Pani and TiO2 are both inexpensive materials, the sensor can be fabricated at a lower cost than inorganic semiconductor sensors. The signal of each fabricated sensor was measured by a charge sensitive ADC for the irradiation of β-particles. The response signal data of the ADC for each irradiation was measured to calculate the detection efficiency of the detector. The maximum detection efficiency measured as β-particle sensitivity of the sensor was 1%. This β-particle sensitivity is higher than that reported of Pani sensors in the past.

  19. On-line preconcentration strategies for analyzing pesticides in fruits and vegetables by micellar electrokinetic chromatography.

    PubMed

    Juan-García, Ana; Font, Guillermina; Picó, Yolanda

    2007-06-15

    Five pesticides (fludioxonil, procymidone, pyriproxyfen, dinoseb and carbendazim) were separated in reversed migration micellar electrokinetic chromatography (RM-MEKC) using 20 mmol l(-1) phosphate buffer at pH 2.3, containing 25 mmol l(-1) sodium dodecylsulfate and 10% methanol. Three on-line concentration strategies, sweeping (SW), normal stacking with reversed migration and a water plug (SRW) and stacking with reverse migration and removal of sample matrix using polarity switching (SRMM), were compared. About 10-, 30- and 50-fold increases in detection sensitivity, compared with standard hydrodynamic injection (5 s at 0.5 psi), were observed with SW, SRW and SRMM, respectively. Limits of detection (LODs) ranged from 0.002 to 0.03 microg ml(-1) using only the on-line preconcentration procedures without any off-line concentration of the extract. A solid-phase extraction (SPE) procedure, for previous isolation and concentration of the analytes, was used in combination with any of the proposed on-line preconcentration strategies, which achieves the determination of pesticides at limits of quantification (LOQs) lower than 0.01 mg kg(-1). The recoveries obtained by SPE in samples spiked at 0.01 mg kg(-1) were between 70 and 100%, with RSDs between 10 and 18% using SRMM. Samples of fruits and vegetables were taken from the market, extracted by the proposed procedure and analyzed with RM-MEKC with the on-line strategies. PMID:17306816

  20. On-Line Allocation Of Robot Resources To Task Plans

    NASA Astrophysics Data System (ADS)

    Lyons, Damian M.

    1989-02-01

    In this paper, I present an approach to representing plans that make on-line decisions about resource allocation. An on-line decision is the evaluation of a conditional expression involving sensory information as the plan is being executed. I use a plan representation called 7ZS10'1 1,12that has been especially designed for the domain of robot programming, and in particular, for the problem of on-line decisions. The resource allocation example is based on the robot assembly cell architecture outlined by Venkataraman and Lyons16. I begin by setting forth a definition of on-line decision making and some arguments as to why this form of decision making is important and useful. To set the context for the resource allocation example, I take some care in categorizing the types of on-line decision making and the approaches adopted by other workers so far. In particular, I justify a plan-based approach to the study of on-line decision making. From that, the focus shifts to one type of decision making: on-line allocation of robot resources to task plans. Robot resources are the physical manipulators (grippers, wrists, arms, feeders, etc) that are available to carry out the task. I formulate the assembly cell architecture of Venkataraman and Lyons16 as an R.S plan schema, and show how the on-line allocation specified in that architecture can be implemented. Finally, I show how considering the on-line allocation of logical resources, that is a physical resource plus some model information, can be used as a non-traditional approach to some problems in robot task planning.