Science.gov

Sample records for active interrogation system

  1. Portable active interrogation system.

    SciTech Connect

    Moss, C. E.; Brener, M. W.; Hollas, C. L.; Myers, W. L.

    2004-01-01

    The system consists of a pulsed DT neutron generator (5 x 10{sup 7} n/s) and a portable but high intrinsic efficiency, custom-designed, polyethylene-moderated {sup 3}He neutron detector. A multichannel scaler card in a ruggedized laptop computer acquires the data. A user-friendly LabVIEW program analyzes and displays the data. The program displays a warning message when highly enriched uranium or any other fissionable materials is detected at a specified number of sigmas above background in the delayed region between pulses. This report describes the system and gives examples of the response of the system to highly enriched uranium and some other fissionable materials, at several distances and with various shielding materials.

  2. Layered shielding design for an active neutron interrogation system

    NASA Astrophysics Data System (ADS)

    Whetstone, Zachary D.; Kearfott, Kimberlee J.

    2016-08-01

    The use of source and detector shields in active neutron interrogation can improve detector signal. In simulations, a shielded detector with a source rotated π/3 rad relative to the opening decreased neutron flux roughly three orders of magnitude. Several realistic source and detector shield configurations were simulated. A layered design reduced neutron and secondary photon flux in the detector by approximately one order of magnitude for a deuterium-tritium source. The shield arrangement can be adapted for a portable, modular design.

  3. Active Interrogation for Spent Fuel

    SciTech Connect

    Swinhoe, Martyn Thomas; Dougan, Arden

    2015-11-05

    The DDA instrument for nuclear safeguards is a fast, non-destructive assay, active neutron interrogation technique using an external 14 MeV DT neutron generator for characterization and verification of spent nuclear fuel assemblies.

  4. A portable active interrogation system using a switchable AmBe neutron source

    NASA Astrophysics Data System (ADS)

    Allen, Matthew; Hertz, Kristin; Kunz, Christopher; Mascarenhas, Nicholas

    2005-09-01

    Active neutron interrogation is an effective technique used to locate fissionable material. This paper discusses a portable system that utilizes a AmBe neutron source. The AmBe source consists of an americium alpha source and a beryllium target that can be switched into alignment to turn the source on and out of alignment to turn the source off. This offers a battery operated backpack portable source. The detector system that has been fabricated for use with this source is a fifteen tube 3He neutron detector. The results of initial experiments with the detector and MCNP calculations are discussed.

  5. Development and application of a hybrid transport methodology for active interrogation systems

    SciTech Connect

    Royston, K.; Walters, W.; Haghighat, A.; Yi, C.; Sjoden, G.

    2013-07-01

    A hybrid Monte Carlo and deterministic methodology has been developed for application to active interrogation systems. The methodology consists of four steps: i) neutron flux distribution due to neutron source transport and subcritical multiplication; ii) generation of gamma source distribution from (n, 7) interactions; iii) determination of gamma current at a detector window; iv) detection of gammas by the detector. This paper discusses the theory and results of the first three steps for the case of a cargo container with a sphere of HEU in third-density water cargo. To complete the first step, a response-function formulation has been developed to calculate the subcritical multiplication and neutron flux distribution. Response coefficients are pre-calculated using the MCNP5 Monte Carlo code. The second step uses the calculated neutron flux distribution and Bugle-96 (n, 7) cross sections to find the resulting gamma source distribution. In the third step the gamma source distribution is coupled with a pre-calculated adjoint function to determine the gamma current at a detector window. The AIMS (Active Interrogation for Monitoring Special-Nuclear-Materials) software has been written to output the gamma current for a source-detector assembly scanning across a cargo container using the pre-calculated values and taking significantly less time than a reference MCNP5 calculation. (authors)

  6. Active interrogation using energetic protons

    SciTech Connect

    Morris, Christopher L; Chung, Kiwhan; Greene, Steven J; Hogan, Gary E; Makela, Mark; Mariam, Fesseha; Milner, Edward C; Murray, Matthew; Saunders, Alexander; Spaulding, Randy; Wang, Zhehui; Waters, Laurie; Wysocki, Frederick

    2010-01-01

    Energetic proton beams provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because they have large fission cross sections, long mean free paths and high penetration, and they can be manipulated with magnetic optics. We have measured time-dependent cross sections and neutron yields for delayed neutrons and gamma rays using 800 MeV and 4 GeV proton beams with a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Measurements of neutron energies yield suggest a signature unique to fissile material. Results are presented in this paper.

  7. Personnel Dose Assessment during Active Interrogation

    SciTech Connect

    Miller, Thomas Martin; Akkurt, Hatice; Patton, Bruce W

    2010-01-01

    A leading candidate in the detection of special nuclear material (SNM) is active interrogation (AI). Unlike passive interrogation, AI uses a source to enhance or create a detectable signal from SNM (usually fission), particularly in shielded scenarios or scenarios where the SNM has a low activity. The use of AI thus makes the detection of SNM easier or, in some scenarios, even enables previously impossible detection. During the development of AI sources, significant effort is put into determining the source strength required to detect SNM in specific scenarios. Usually during this process, but not always, an evaluation of personnel dose is also completed. In this instance personnel dose could involve any of the following: (1) personnel performing the AI; (2) unknown stowaways who are inside the object being interrogated; or (3) in clandestine interrogations, personnel who are known to be inside the object being interrogated but are unaware of the interrogation. In most instances, dose to anyone found smuggling SNM will be a secondary issue. However, for the organizations performing the AI, legal if not moral considerations should make dose to the personnel performing the AI, unknown stowaways, or innocent bystanders in clandestine interrogations a serious concern.

  8. Active interrogation of highly enriched uranium

    SciTech Connect

    Moss, C. E.; Hollas, C. L.; Myers, W. L.

    2004-01-01

    Active interrogation techniques provide reliable detection of highly enriched uranium (HEU) even when passive detection is difficult. We use 50-Hz pulsed beams of bremsstrahlung photons from a 10-MeV linac or 14-MeV neutrons from a neutron generator for interrogation, thus activating the HEU. Detection of neutrons between pulses is a positive indicator of the presence of fissionable material. We detect the neutrons with three neutron detector designs based on {sup 3}He tubes. This report shows examples of the responses in these three detectors, for unshielded and shielded kilogram quantities of HEU, in containers as large as cargo containers.

  9. 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.

  10. Interrogator system for identifying electrical circuits

    DOEpatents

    Jatko, W.B.; McNeilly, D.R.

    1988-04-12

    A system for interrogating electrical leads to correctly ascertain the identity of equipment attached to remote ends of the leads is disclosed. The system includes a source of a carrier signal generated in a controller/receiver to be sent over the leads and an identifier unit at the equipment. The identifier is activated by command of the carrier and uses a portion of the carrier to produce a supply voltage. Each identifier is uniquely programmed for a specific piece of equipment, and causes the impedance of the circuit to be modified whereby the carrier signal is modulated according to that program. The modulation can be amplitude, frequency or phase modulation. A demodulator in the controller/receiver analyzes the modulated carrier signal, and if a verified signal is recognized displays and/or records the information. This information can be utilized in a computer system to prepare a wiring diagram of the electrical equipment attached to specific leads. Specific circuit values are given for amplitude modulation, and the system is particularly described for use with thermocouples. 6 figs.

  11. Interrogator system for identifying electrical circuits

    DOEpatents

    Jatko, William B.; McNeilly, David R.

    1988-01-01

    A system for interrogating electrical leads to correctly ascertain the identity of equipment attached to remote ends of the leads. The system includes a source of a carrier signal generated in a controller/receiver to be sent over the leads and an identifier unit at the equipment. The identifier is activated by command of the carrier and uses a portion of the carrier to produce a supply voltage. Each identifier is uniquely programmed for a specific piece of equipment, and causes the impedance of the circuit to be modified whereby the carrier signal is modulated according to that program. The modulation can be amplitude, frequency or phase modulation. A demodulator in the controller/receiver analyzes the modulated carrier signal, and if a verified signal is recognized displays and/or records the information. This information can be utilized in a computer system to prepare a wiring diagram of the electrical equipment attached to specific leads. Specific circuit values are given for amplitude modulation, and the system is particularly described for use with thermocouples.

  12. Active interrogation of highly enriched uranium

    NASA Astrophysics Data System (ADS)

    Fairrow, Nannette Lea

    Safeguarding special nuclear material (SNM) in the Department of Energy Complex is vital to the national security of the United States. Active and passive nondestructive assays are used to confirm the presence of SNM in various configurations ranging from waste to nuclear weapons. Confirmation measurements for nuclear weapons are more challenging because the design complicates the detection of a distinct signal for highly enriched uranium. The emphasis of this dissertation was to investigate a new nondestructive assay technique that provides an independent and distinct signal to confirm the presence of highly enriched uranium (HEU). Once completed and tested this assay method could be applied to confirmation measurements of nuclear weapons. The new system uses a 14-MeV neutron source for interrogation and records the arrival time of neutrons between the pulses with a high efficiency detection system. The data is then analyzed by the Feynman reduced variance method. The analysis determined the amount of correlation in the data and provided a unique signature of correlated fission neutrons. Measurements of HEU spheres were conducted at Los Alamos with the new system. Then, Monte Carlo calculations were performed to verify hypothesis made about the behavior of the neutrons in the experiment. Comparisons of calculated counting rates by the Monte Carlo N-Particle Transport Code (MCNP) were made with the experimental data to confirm that the measured response reflected the desired behavior of neutron interactions in the highly enriched uranium. In addition, MCNP calculations of the delayed neutron build-up were compared with the measured data. Based on the results obtained from this dissertation, this measurement method has the potential to be expanded to include mass determinations of highly enriched uranium. Although many safeguards techniques exist for measuring special nuclear material, the number of assays that can be used to confirm HEU in shielded systems is

  13. Pulsed photoneutron interrogation: The GNT demonstration system

    SciTech Connect

    Jones, J.L.; Harker, Y.D.; Yoon, W.Y.; Hoggan, J.M.; McManus, G.J.

    1994-10-01

    The Idaho National Engineering Laboratory (INEL) has developed and tested an active photon interrogation technique to support the Department of Energy`s (DOE) Office of National Security and Nonproliferation (NN) mission related to verification technologies development. The INEL concept, referred to as the Gamma-Neutron Threshold (GNT) technology, uses a transportable, field-deployable, selective-energy (2 to 10 MeV), pulsed, electron accelerator to produce energetic X-rays having a bremsstrahlung spectrum. The energetic X-rays induce neutrons in many proliferation-limited items via direct photoneutron/photofission interactions. The time-dependent neutron response, as a function of the electron beam energy, is measured with a tripod-mounted, detector assembly and a portable data acquisition system. The portable detector assembly has been specifically designed to operate in very intense, pulsed X-ray environments. The GNT technique measures both the prompt and delayed neutron emission after each accelerator pulse. This report fully describes each component of this system and presents various signature results based on these emissions.

  14. Addressing Different Active Neutron Interrogation Signatures from Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2009-10-01

    In a continuing effort to examine portable methods for implementing active neutron interrogation for detecting shielded fissionable material research is underway to investigate the utility of analyzing multiple time-correlated signatures. Time correlation refers here to the existence of unique characteristics of the fission interrogation signature related to the start and end of an irradiation, as well as signatures present in between individual pulses of an irradiating source. Traditional measurement approaches in this area have typically worked to detect die-away neutrons after the end of each pulse, neutrons in between pulses related to the decay of neutron emitting fission products, or neutrons or gamma rays related to the decay of neutron emitting fission products after the end of an irradiation exposure. In this paper we discus the potential weaknesses of assessing only one signature versus multiple signatures and make the assertion that multiple complimentary and orthogonal measurements should be used to bolster the performance of active interrogation systems, helping to minimize susceptibility to the weaknesses of individual signatures on their own. Recognizing that the problem of detection is a problem of low count rates, we are exploring methods to integrate commonly used signatures with rarely used signatures to improve detection capabilities for these measurements. In this paper we will discuss initial activity in this area with this approach together with observations of some of the strengths and weaknesses of using these different signatures.

  15. Active Neutron Interrogation to Detect Shielded Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2009-05-01

    Portable electronic neutron generators (ENGs) may be used to interrogate suspicious items to detect, characterize, and quantify the presence fissionable material based upon the measurement of prompt and/or delayed emissions of neutrons and/or photons resulting from fission. The small size (<0.2 m3), light weight (<12 kg), and low power consumption (<50 W) of modern ENGs makes them ideally suited for use in field situations, incorporated into systems carried by 2-3 individuals under rugged conditions. At Idaho National Laboratory we are investigating techniques and portable equipment for performing active neutron interrogation of moderate sized objects less than ~2-4 m3 to detect shielded fissionable material. Our research in this area relies upon the use of pulsed deuterium-tritium ENGs and the measurement of die-away prompt fission neutrons and other neutron signatures in-between neutron pulses from the ENG and after the ENG is turned off.

  16. Interrogations, confessions, and adolescent offenders' perceptions of the legal system.

    PubMed

    Arndorfer, Andrea; Malloy, Lindsay C; Cauffman, Elizabeth

    2015-10-01

    The potential consequences of interrogations and false confessions have been discussed primarily in terms of the risk for wrongful conviction, especially among adolescents and other vulnerable populations. However, it is possible that such experiences influence adolescents' perceptions of the legal system more generally. In the present study, we examined whether incarcerated male juvenile offenders' (n = 193) perceptions of police and the courts were related to their confession and interrogation experiences. High-pressure interrogation experiences and self-reported false confessions to police were associated with more negative perceptions of police. However, self-reported true confessions were not significantly associated with youths' perceptions of the police. Neither interrogation nor confession experiences (true or false) were related to youths' perceptions of the courts. Results provide additional support for policy reform of interrogation practices with young suspects. A more developmentally appropriate approach to criminal interrogations with youth may simultaneously improve police-youth relations and protect vulnerable suspects in the interrogation room. PMID:26011040

  17. SNM detection by active muon interrogation

    SciTech Connect

    Jason, Andrew J; Miyadera, Haruo; Turchi, Peter J

    2010-01-01

    Muons are charged particles with mass between the electron and proton and can be produced indirectly through pion decay by interaction of a charged-particle beam with a target. There are several distinct features of the muon interaction with matter attractive as a probe for detection of SNM at moderate ranges. These include muon penetration of virtually any amount of material without significant nuclear interaction until stopped by ionization loss in a short distance. When stopped, high-energy penetrating x-rays (in the range of 6 MeV for uranium,) unique to isotopic composition are emitted in the capture process. The subsequent interaction with the nucleus produces additional radiation useful in assessing SNM presence. A focused muon beam can be transported through the atmosphere, at a range limited mainly by beam-size growth through scattering. A muonbeam intensity of > 10{sup 9} /second is required for efficient interrogation and, as in any other technique, dose limits are to be respected. To produce sufficient muons a high-energy (threshold {approx}140 MeV) high-intensity (<1 mA) proton or electron beam is needed implying the use of a linear accelerator to bombard a refractory target. The muon yield is fractionally small, with large angle and energy dispersion, so that efficient collection is necessary in all dimensions of phase space. To accomplish this Los Alamos has proposed a magnetic collection system followed by a unique linear accelerator that provides the requisite phase-space bunching and allows an energy sweep to successively stop muons throughout a large structure such as a sea-going vessel. A possible maritime application would entail fitting the high-gradient accelerators on a large ship with a helicopter-borne detection system. We will describe our experimental results for muon effects and particle collection along with our current design and program for a muon detection system.

  18. Rattling Nucleons: New Developments in Active Interrogation of Special Nuclear Material

    SciTech Connect

    Robert C. Runkle; David L. Chichester; Scott J. Thompson

    2012-01-01

    Active interrogation is a vigorous area of research and development due to its promise of offering detection and characterization capabilities of special nuclear material in environments where passive detection fails. The primary value added by active methods is the capability to penetrate shielding - special nuclear material itself, incidental materials, or intentional shielding - and advocates hope that active interrogation will provide a solution to the problem of detecting shielded uranium, which is at present the greatest obstacle to interdiction efforts. The technique also provides a unique benefit for quantifying nuclear material in high background-radiation environments, an area important for nuclear material safeguards and material accountancy. Progress has been made in the field of active interrogation on several fronts, most notably in the arenas of source development, systems integration, and the integration and exploitation of multiple fission and non-fission signatures. But penetration of interrogating radiation often comes at a cost, not only in terms of finance and dose but also in terms of induced backgrounds, system complexity, and extended measurement times (including set up and acquisition). These costs make the calculus for deciding to implement active interrogation more subtle than may be apparent. The purpose of this review is thus to examine existing interrogation methods, compare and contrast their attributes and limitations, and identify missions where active interrogation may hold the most promise.

  19. Repetitive Interrogation of 2-Level Quantum Systems

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Chung, Sang K.

    2010-01-01

    Trapped ion clocks derive information from a reference atomic transition by repetitive interrogations of the same quantum system, either a single ion or ionized gas of many millions of ions. Atomic beam frequency standards, by contrast, measure reference atomic transitions in a continuously replenished "flow through" configuration where initial ensemble atomic coherence is zero. We will describe some issues and problems that can arise when atomic state selection and preparation of the quantum atomic system is not completed, that is, optical pumping has not fully relaxed the coherence and also not fully transferred atoms to the initial state. We present a simple two-level density matrix analysis showing how frequency shifts during the state-selection process can cause frequency shifts of the measured clock transition. Such considerations are very important when a low intensity lamp light source is used for state selection, where there is relatively weak relaxation and re-pumping of ions to an initial state and much weaker 'environmental' relaxation of the atomic coherence set-up in the atomic sample.

  20. Single transmission line interrogated multiple channel data acquisition system

    DOEpatents

    Fasching, George E.; Keech, Jr., Thomas W.

    1980-01-01

    A single transmission line interrogated multiple channel data acquisition system is provided in which a plurality of remote station/sensor circuits each monitors a specific process variable and each transmits measurement values over a single transmission line to a master interrogating station when addressed by said master interrogating station. Typically, as many as 330 remote stations may be parallel connected to the transmission line which may exceed 7,000 feet. The interrogation rate is typically 330 stations/second. The master interrogating station samples each station according to a shared, charging transmit-receive cycle. All remote station address signals, all data signals from the remote stations/sensors and all power for all of the remote station/sensors are transmitted via a single continuous terminated coaxial cable. A means is provided for periodically and remotely calibrating all remote sensors for zero and span. A provision is available to remotely disconnect any selected sensor station from the main transmission line.

  1. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    SciTech Connect

    DR. Stephen Croft; Mr. David Martancik; Dr. Brian Young; Dr. Patrick MJ Chard; Dr. Robert J Estop; Sheila Melton; Gaetano J. Arnone

    2003-01-13

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nuclide and isotopic compositions Assay of high density matrices (both high-Z and high moderator contents)Correction for radioactive material physical form - such as self shielding or multiplication effects due to large accumulations of radioactive materials.Calibration with a minimal set of reference standards and representative matrices.THis document summarizes the conceptual design parameters of the IBIS and indicates areas key to the success of the project where development is to be centered. The work presented here is a collaborative effort between scientific staff within Canberra and within the NIS-6 group at LANL.

  2. Improved Fission Neutron Data Base for Active Interrogation of Actinides

    SciTech Connect

    Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

    2013-11-06

    This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

  3. Simulation Of A Photofission-Based Cargo Interrogation System

    SciTech Connect

    King, Michael; Gozani, Tsahi; Stevenson, John; Shaw, Timothy

    2011-06-01

    A comprehensive model has been developed to characterize and optimize the detection of Bremsstrahlung x-ray induced fission signatures from nuclear materials hidden in cargo containers. An effective active interrogation system should not only induce a large number of fission events but also efficiently detect their signatures. The proposed scanning system utilizes a 9-MV commercially available linear accelerator and the detection of strong fission signals i.e. delayed gamma rays and prompt neutrons. Because the scanning system is complex and the cargo containers are large and often highly attenuating, the simulation method segments the model into several physical steps, representing each change of radiation particle. Each approximation is carried-out separately, resulting in a major reduction in computational time and a significant improvement in tally statistics. The model investigates the effect on the fission rate and detection rate by various cargo types, densities and distributions. Hydrogenous and metallic cargos, homogeneous and heterogeneous, as well as various locations of the nuclear material inside the cargo container were studied. We will show that for the photofission-based interrogation system simulation, the final results are not only in good agreement with a full, single-step simulation but also with experimental results, further validating the full-system simulation.

  4. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    NASA Astrophysics Data System (ADS)

    Ludewigt, B. A.; Antolak, A. J.; Henestroza, E.; Kwan, J. W.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.

    2009-03-01

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,γ)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,γ)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 μs long pulses, and a 1% duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  5. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    SciTech Connect

    Ludewigt, Bernhard A.; Antolak, A.J.; Henestroza, E.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.; Kwan, J.W.

    2008-08-01

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,gamma)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 mu s long pulses, and a 1percent duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  6. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    SciTech Connect

    Ludewigt, B. A.; Henestroza, E.; Kwan, J. W.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.; Antolak, A. J.

    2009-03-10

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the {sup 11}B(p,{gamma}){sup 12}C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the {sup 11}B(p,{gamma}){sup 12}C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB{sub 6} tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 {mu}s long pulses, and a 1% duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  7. Thermal Neutron Imaging in an Active Interrogation Environment

    SciTech Connect

    Vanier, Peter E.; Forman, Leon; Norman, Daren R.

    2009-03-10

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutron-emitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  8. Thermal neutron imaging in an active interrogation environment

    SciTech Connect

    Vanier,P.E.; Forman, L., and Norman, D.R.

    2009-03-10

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of xcitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  9. Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Kempen, Cornelia; Lopatin, Craig

    2007-04-01

    This paper describes recent progress conducted towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense TM) microchip technology. The hybrid InOSense TM microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogator systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The FBG-Transceiver system uses active optoelectronic components monolithically integrated to the InOSense TM microchip, a microprocessor controlled signal processing electronics board capable of processing the FBG sensors signals related to stress-strain and temperature as well as vibration and acoustics. The FBG-Transceiver TM system represents a new, reliable, highly robust technology that can be used to accurately monitor the status of an array of distributed fiber optic Bragg grating sensors installed in critical infrastructures. Its miniature package, low power operation, and state-of-the-art data communications architecture, all at a very affordable price makes it a very attractive solution for a large number of SHM/NDI applications in aerospace, naval and maritime industry, civil structures like bridges, buildings and dams, the oil and chemical industry, and for homeland security applications. The miniature, cost-efficient FBG-Transceiver TM system is poised to revolutionize the field of structural health monitoring and nondestructive inspection market. The sponsor of this program is NAVAIR under a DOD SBIR contract.

  10. Active-Interrogation Measurements of Fast Neutrons from Induced Fission in Low-Enriched Uranium

    SciTech Connect

    J. L. Dolan; M. J. Marcath; M. Flaska; S. A. Pozzi; D. L. Chichester; A. Tomanin; P. Peerani

    2014-02-01

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre (JRC) in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutron to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials.

  11. System design considerations for fast-neutron interrogation systems

    SciTech Connect

    Micklich, B.J.; Curry, B.P.; Fink, C.L.; Smith, D.L.; Yule, T.J.

    1993-10-01

    Nonintrusive interrogation techniques that employ fast neutrons are of interest because of their sensitivity to light elements such as carbon, nitrogen, and oxygen. The primary requirement of a fast-neutron inspection system is to determine the value of atomic densities, or their ratios, over a volumetric grid superimposed on the object being interrogated. There are a wide variety of fast-neutron techniques that can provide this information. The differences between the various nuclear systems can be considered in light of the trade-offs relative to the performance requirements for each system`s components. Given a set of performance criteria, the operational requirements of the proposed nuclear systems may also differ. For instance, resolution standards will drive scanning times and tomographic requirements, both of which vary for the different approaches. We are modelling a number of the fast-neutron interrogation techniques currently under consideration, to include Fast Neutron Transmission Spectroscopy (FNTS), Pulsed Fast Neutron Analysis (PFNA), and its variant, 14-MeV Associated Particle Imaging (API). The goals of this effort are to determine the component requirements for each technique, identify trade-offs that system performance standards impose upon those component requirements, and assess the relative advantages and disadvantages of the different approaches. In determining the component requirements, we will consider how they are driven by system performance standards, such as image resolution, scanning time, and statistical uncertainty. In considering the trade-offs between system components, we concentrate primarily on those which are common to all approaches, for example: source characteristics versus detector array requirements. We will then use the analysis to propose some figures-of-merit that enable performance comparisons between the various fast-neutron systems under consideration. The status of this ongoing effort is presented.

  12. Micro-size optical fibre strain interrogation system

    NASA Astrophysics Data System (ADS)

    Mrad, Nezih; Xiao, Gaozhi; Guo, Honglei

    2008-03-01

    Within several countries, the military is undergoing significant economic pressure to extend the use of its air fleet beyond its established design life. The availability of low weight, small size, reliable and cost-effective technologies to detect and monitor incipient damage and to alert prior to catastrophic failures is critical to sustain operational effectiveness. To enable the implementation of distributed and highly multiplexed optical fiber sensors networks to aerospace platforms, the data acquisition (interrogation) system has to meet small size and low weight requirements. This paper reports on our current development of micro-sized Echelle Diffractive Gratings (EDG) based interrogation system for strain monitoring of serially multiplexed fibre Bragg grating sensors. The operation principle of the interrogator and its suitability for strain measurements is demonstrated. Static load measurements obtained using this system are compared to those acquired using a optical multi-wavelength meter and are found to have strong correlation.

  13. Active Interrogation Using Electronic Neutron Generators for Nuclear Safeguards Applications

    NASA Astrophysics Data System (ADS)

    Chichester, D. L.; Seabury, E. H.

    2009-03-01

    Active interrogation, a measurement technique which uses a radiation source to probe materials and generate unique signatures useful for characterizing those materials, is a powerful tool for assaying special nuclear material. The most commonly used technique for performing active interrogation is to use an electronic neutron generator as the probe radiation source. Exploiting the unique operating characteristics of these devices, including their monoenergetic neutron emissions and their ability to operate in pulsed modes, presents a number of options for performing prompt and delayed signature analyses using both photon and neutron sensors. A review of literature in this area shows multiple applications of the active neutron interrogation technique for performing nuclear nonproliferation measurements. Some examples include measuring the plutonium content of spent fuel, assaying plutonium residue in spent fuel hull claddings, assaying plutonium in aqueous fuel reprocessing process streams, and assaying nuclear fuel reprocessing facility waste streams to detect and quantify fissile material. This paper discusses the historical use of this technique and examines its context within the scope and challenges of next-generation nuclear fuel cycles and advanced concept nuclear fuel cycle facilities.

  14. Active Interrogation Using Electronic Neutron Generators for Nuclear Safeguards Applications

    SciTech Connect

    David L. Chichester; Edward H. Seabury

    2008-08-01

    Active interrogation, a measurement technique which uses a radiation source to probe materials and generate unique signatures useful for characterizing those materials, is a powerful tool for assaying special nuclear material. The most commonly used technique for performing active interrogation is to use an electronic neutron generator as the probe radiation source. Exploiting the unique operating characteristics of these devices, including their monoenergetic neutron emissions and their ability to operate in pulsed modes, presents a number of options for performing prompt and delayed signature analyses using both photon and neutron sensors. A review of literature in this area shows multiple applications of the active neutron interrogation technique for performing nuclear nonproliferation measurements. Some examples include measuring the plutonium content of spent fuel, assaying plutonium residue in spent fuel hull claddings, assaying plutonium in aqueous fuel reprocessing process streams, and assaying nuclear fuel reprocessing facility waste streams to detect and quantify fissile material. This paper discusses the historical use of this technique and examines its context within the scope and challenges of next-generation nuclear fuel cycles and advanced concept nuclear fuel cycle facilities.

  15. Ask Systems: Interrogative Access to Multiple Ways of Thinking

    ERIC Educational Resources Information Center

    Jonassen, David H.

    2011-01-01

    The purpose of this paper is to familiarize instructional designers and researchers with a useful design and research paradigm known as "Ask Systems." Ask Systems are interrogative interfaces to information and learning environments that model conversations with a skilled, reflective practitioner (Schon, The reflective practitioner, "1983") or…

  16. An optogenetic system for interrogating the temporal dynamics of Akt

    PubMed Central

    Katsura, Yoshihiro; Kubota, Hiroyuki; Kunida, Katsuyuki; Kanno, Akira; Kuroda, Shinya; Ozawa, Takeaki

    2015-01-01

    The dynamic activity of the serine/threonine kinase Akt is crucial for the regulation of diverse cellular functions, but the precise spatiotemporal control of its activity remains a critical issue. Herein, we present a photo-activatable Akt (PA-Akt) system based on a light-inducible protein interaction module of Arabidopsis thaliana cryptochrome2 (CRY2) and CIB1. Akt fused to CRY2phr, which is a minimal light sensitive domain of CRY2 (CRY2-Akt), is reversibly activated by light illumination in several minutes within a physiological dynamic range and specifically regulates downstream molecules and inducible biological functions. We have generated a computational model of CRY2-Akt activation that allows us to use PA-Akt to control the activity quantitatively. The system provides evidence that the temporal patterns of Akt activity are crucial for generating one of the downstream functions of the Akt-FoxO pathway; the expression of a key gene involved in muscle atrophy (Atrogin-1). The use of an optical module with computational modeling represents a general framework for interrogating the temporal dynamics of biomolecules by predictive manipulation of optogenetic modules. PMID:26423353

  17. Neutron Interrogation System For Underwater Threat Detection And Identification

    SciTech Connect

    Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C.

    2009-03-10

    Wartime and terrorist activities, training and munitions testing, dumping and accidents have generated significant munitions contamination in the coastal and inland waters in the United States and abroad. Although current methods provide information about the existence of the anomaly (for instance, metal objects) in the sea bottom, they fail to identify the nature of the found objects. Field experience indicates that often in excess of 90% of objects excavated during the course of munitions clean up are found to be non-hazardous items (false alarm). The technology to detect and identify waterborne or underwater threats is also vital for protection of critical infrastructures (ports, dams, locks, refineries, and LNG/LPG). We are proposing a compact neutron interrogation system, which will be used to confirm possible threats by determining the chemical composition of the suspicious underwater object. The system consists of an electronic d-T 14-MeV neutron generator, a gamma detector to detect the gamma signal from the irradiated object and a data acquisition system. The detected signal then is analyzed to quantify the chemical elements of interest and to identify explosives or chemical warfare agents.

  18. Neutron Interrogation System For Underwater Threat Detection And Identification

    NASA Astrophysics Data System (ADS)

    Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C.

    2009-03-01

    Wartime and terrorist activities, training and munitions testing, dumping and accidents have generated significant munitions contamination in the coastal and inland waters in the United States and abroad. Although current methods provide information about the existence of the anomaly (for instance, metal objects) in the sea bottom, they fail to identify the nature of the found objects. Field experience indicates that often in excess of 90% of objects excavated during the course of munitions clean up are found to be non-hazardous items (false alarm). The technology to detect and identify waterborne or underwater threats is also vital for protection of critical infrastructures (ports, dams, locks, refineries, and LNG/LPG). We are proposing a compact neutron interrogation system, which will be used to confirm possible threats by determining the chemical composition of the suspicious underwater object. The system consists of an electronic d-T 14-MeV neutron generator, a gamma detector to detect the gamma signal from the irradiated object and a data acquisition system. The detected signal then is analyzed to quantify the chemical elements of interest and to identify explosives or chemical warfare agents.

  19. The Pulsed Interrogation Neutron and Gamma (PING) inspection system

    SciTech Connect

    Schultz, F.J.; Hensley, D.C.; Coffey, D.E.; Chapman, J.A.; Caylor, B.A.; Bailey, R.D. ); Vourvopoulos, G. ); Kehayias, J. . USDA Human Nutrition Research Center on Aging at Tufts Univ.)

    1991-01-01

    Explosives and chemical warfare (CW) agents possess elements and characteristic elemental ratios not commonly found in significant quantities in other items. These elements include nitrogen, oxygen, fluorine, phosphorus, sulfur, and chlorine. The research described herein discusses the results to date of the development of a pulsed-neutron interrogation and gamma ({gamma})-ray system for detecting concealed explosives and for discriminating munitions containing CW agents and conventional explosives. Preliminary experimental data has suggested that distinct classes of chemical agents could also be distinguished, for example, nerve agents and mustard gases. Based on there results, the system is currently being designed for the detection of explosives concealed, for example, in airline luggage. Nuclear and x-ray technologies possess unique characteristics to quickly and reliably search for explosives. Both oxygen and nitrogen, present in sufficient concentrations, when detected, uniquely determine the presence of explosives. Carbon would be a third element that is common in all explosives, although it does not correlate uniquely with all known explosives. A system which identifies and quantifies all three elements would provide more reliable information about the interrogated material. We have previously demonstrated that the technique described in this paper can identify certain elements through fast- and slow-neutron interrogation and subsequent prompt- and delayed-{gamma}-ray detection. The identification of CW agent elements such as chlorine, phosphorus, sulfur, and fluorine, is also accomplished through the detection of characteristic capture {gamma}-rays. The Pulsed Interrogation Neutron and Gamma (PING) inspection system is based upon technology developed over twelve years for the determination of fissile mass quantities in radioactive waste, for the determination of sulfur in coal, and for in-vivo body composition measurements.

  20. The Pulsed Interrogation Neutron and Gamma (PING) inspection system

    SciTech Connect

    Schultz, F.J.; Hensley, D.C.; Coffey, D.E.; Chapman, J.A.; Caylor, B.A.; Bailey, R.D.; Vourvopoulos, G.; Kehayias, J.

    1991-12-31

    Explosives and chemical warfare (CW) agents possess elements and characteristic elemental ratios not commonly found in significant quantities in other items. These elements include nitrogen, oxygen, fluorine, phosphorus, sulfur, and chlorine. The research described herein discusses the results to date of the development of a pulsed-neutron interrogation and gamma ({gamma})-ray system for detecting concealed explosives and for discriminating munitions containing CW agents and conventional explosives. Preliminary experimental data has suggested that distinct classes of chemical agents could also be distinguished, for example, nerve agents and mustard gases. Based on there results, the system is currently being designed for the detection of explosives concealed, for example, in airline luggage. Nuclear and x-ray technologies possess unique characteristics to quickly and reliably search for explosives. Both oxygen and nitrogen, present in sufficient concentrations, when detected, uniquely determine the presence of explosives. Carbon would be a third element that is common in all explosives, although it does not correlate uniquely with all known explosives. A system which identifies and quantifies all three elements would provide more reliable information about the interrogated material. We have previously demonstrated that the technique described in this paper can identify certain elements through fast- and slow-neutron interrogation and subsequent prompt- and delayed-{gamma}-ray detection. The identification of CW agent elements such as chlorine, phosphorus, sulfur, and fluorine, is also accomplished through the detection of characteristic capture {gamma}-rays. The Pulsed Interrogation Neutron and Gamma (PING) inspection system is based upon technology developed over twelve years for the determination of fissile mass quantities in radioactive waste, for the determination of sulfur in coal, and for in-vivo body composition measurements.

  1. Methods and systems using encapsulated tracers and chemicals for reservoir interrogation and manipulation

    SciTech Connect

    Roberts, Jeffery; Aines, Roger D; Duoss, Eric B; Spadaccini, Christopher M

    2014-11-04

    An apparatus, method, and system of reservoir interrogation. A tracer is encapsulating in a receptacle. The receptacle containing the tracer is injected into the reservoir. The tracer is analyzed for reservoir interrogation.

  2. Performance report for a small package counter that uses active neutron interrogation

    SciTech Connect

    Harlan, R.A.; Wishard, B.E.; Santopietro, R.D.; Anderson, B.P.

    1993-07-07

    An active neutron interrogation system utilizing the differential die-away technique (DDT), was built to assay fissile material in small waste packages for a variety of matrices. Within minutes the system can make a ``go/no-go`` decision for sorting low-level waste (LLW) from transuranic waste (TRUW). It can also provide gram-level accountability of weapons-grade (WG) Pu in TRUW providing lumps of self-shielding fissile material are absent.

  3. Investigation of active interrogation techniques to detect special nuclear material in maritime environments: Boarded search of a cargo container ship

    NASA Astrophysics Data System (ADS)

    Grogan, Brandon R.; Henkel, James J.; Johnson, Jeffrey O.; Mihalczo, John T.; Miller, Thomas M.; Patton, Bruce W.

    2013-12-01

    The detonation of a terrorist nuclear weapon in the United States would result in the massive loss of life and grave economic damage. Even if a device was not detonated, its known or suspected presence aboard a cargo container ship in a U.S. port would have major economic and political consequences. One possible means to prevent this threat would be to board a ship at sea and search for the device before it reaches port. The scenario considered here involves a small Coast Guard team with strong intelligence boarding a container ship to search for a nuclear device. Using active interrogation, the team would nonintrusively search a block of shipping containers to locate the fissile material. Potential interrogation source and detector technologies for the team are discussed. The methodology of the scan is presented along with a technique for calculating the required interrogation source strength using computer simulations. MCNPX was used to construct a computer model of a container ship, and several search scenarios were simulated. The results of the simulations are presented in terms of the source strength required for each interrogation scenario. Validation measurements were performed in order to scale these simulation results to expected performance. Interrogations through the short (2.4 m) axis of a standardized shipping container appear to be feasible given the entire range of container loadings tested. Interrogations through several containers at once or a single container through its long (12.2 m) axis do not appear to be viable with a portable interrogation system.

  4. Capabilities of the INL ZPPR to Support Active Interrogation Research with SNM

    NASA Astrophysics Data System (ADS)

    Chichester, D. L.; Seabury, E. H.; Turnage, J. A.; Brush, B. A.; Perry, E. F.

    2009-03-01

    For over 40 years Idaho National Laboratory (INL) and its predecessor organizations have maintained and operated the Zero-Power Physics Reactor (ZPPR) as a test bed for studying reactor physics and nuclear reactor design. Although ZPPR is no longer operated as an active research reactor, its infrastructure (radiation shielding, safety systems, physical safeguards) and special nuclear material (SNM) inventory (variably enriched uranium and plutonium fuels available in metallic, oxide, alloy, and other forms) still make the facility a unique national resource for research and development activities involving the use of SNM. Recently INL has utilized this resource to serve as a test and evaluation facility for active interrogation research and development. This facility is currently hosting scoping experiments using neutron and x-ray radiation sources to characterize SNM active interrogation signatures and to develop tools and techniques to detect and identify shielded SNM. This paper presents an overview of the facility's infrastructure and assets and describes recent active interrogation experiments that have taken place using high-energy x-ray sources and compact electronic neutron generators.

  5. Capabilities of the INL ZPPR to Support Active Interrogation Research with SNM

    SciTech Connect

    David L. Chichester; Edward H. Seabury; Jennifer A. Turnage; Bevin A. Brush; Eugene F. Perry

    2008-08-01

    For over 40 years Idaho National Laboratory (INL) and its predecessor organizations have maintained and operated the Zero-Power Physics Reactor (ZPPR) as a test bed for studying reactor physics and nuclear reactor design. Although the ZPPR is no longer operated as an active research reactor, it’s infrastructure (radiation shielding, safety systems, physical safeguards) and special nuclear material (SNM) inventory (variably enriched uranium and plutonium fuels available in metallic, oxide, alloy, and other forms) still makes the facility a unique national resource for research and development activities involving the use of SNM. Recently INL has utilized this facility to serve as a test and evaluation facility for active interrogation research and development. This facility is currently hosting scoping experiments using neutron and x-ray radiation sources to characterize SNM active interrogation signatures and to develop tools and techniques to detect and identify shielded SNM. This paper presents an overview of the facility’s infrastructure and assets and describes recent active interrogation experiments that have taken place using high-energy x-ray sources and compact electronic neutron generators.

  6. An implantable pressure sensing system with electromechanical interrogation scheme.

    PubMed

    Kim, Albert; Powell, C R; Ziaie, Babak

    2014-07-01

    In this paper, we report on the development of an implantable pressure sensing system that is powered by mechanical vibrations in the audible acoustic frequency range. This technique significantly enhances interrogation range, alleviates the misalignment issues commonly encountered with inductive powering, and simplifies the external receiver circuitry. The interrogation scheme consists of two phases: a mechanical vibration phase and an electrical radiation phase. During the first phase, a piezoelectric cantilever acts as an acoustic receiver and charges a capacitor by converting sound vibration harmonics occurring at its resonant frequency into electrical power. In the subsequent electrical phase, when the cantilever is not vibrating, the stored electric charge is discharged across an LC tank whose inductor is pressure sensitive; hence, when the LC tank oscillates at its natural resonant frequency, it radiates a high-frequency signal that is detectable using an external receiver and its frequency corresponds to the measured pressure. The pressure sensitive inductor consists of a planar coil (single loop of wire) with a ferrite core whose distance to the coil varies with applied pressure. A prototype of the implantable pressure sensor is fabricated and tested, both in vitro and in vivo (swine bladder). A pressure sensitivity of 1 kHz/cm H2O is achieved with minimal misalignment sensitivity (26% drop at 90° misalignment between the implanted device and acoustic source; 60% drop at 90° misalignment between the implanted device and RF receiver coil). PMID:24800754

  7. Active Interrogation of Sensitive Nuclear Material Using Laser Driven Neutron Beams

    SciTech Connect

    Favalli, Andrea; Roth, Markus

    2015-05-01

    An investigation of the viability of a laser-driven neutron source for active interrogation is reported. The need is for a fast, movable, operationally safe neutron source which is energy tunable and has high-intensity, directional neutron production. Reasons for the choice of neutrons and lasers are set forth. Results from the interrogation of an enriched U sample are shown.

  8. Active interrogation of helicopter main rotor faults using trailing edge flap actuation

    NASA Astrophysics Data System (ADS)

    Stevens, Patricia Lynn

    Over the past decade, the helicopter community has become increasingly interested in health monitoring. The rotor system, however, is not sufficiently covered in the current Health and Usage Monitoring Systems (HUMS). This dissertation describes the development and evaluation of a new approach for detecting helicopter rotor faults in which active trailing edge flaps are used to interrogate the system. This work is based on the presumption that trailing edge flaps would be installed for the primary purpose of vibration and/or noise control; health monitoring is a secondary use. Using this approach, the blade is excited by an interrogation signal, which is a low amplitude oscillation at a few discrete frequencies. The blade response is measured and the health of the system is determined using a frequency domain damage identification algorithm. Damage detection and location are achieved via the residual force vector. The residual force vector, coupled with an understanding of the system physics, also provides nature characterization. Quantification of damage extent is achieved via a frequency domain adaptation of the Asymmetric Minimum Rank Perturbation Theory. The active interrogation system is evaluated using an aeroelastic finite element model of the rotor system in hover, including an advanced unsteady aerodynamic model to predict the trailing edge flap loads. Realistic damage models, including distributed bending stiffness damage, torsional stiffness damage, control system stiffness damage, cracks and ballistic damage, are seeded in the rotor system model. Results demonstrate detection, location and quantification of extent of all of the faults tested. The effects of noise and modeling errors are discussed and mitigation techniques are developed. Additionally, a measurability study is included. Benefits of this work include both improved health monitoring for rotorcraft as well as insights into the application of structural damage detection algorithms to a

  9. FY09 Advanced Instrumentation and Active Interrogation Research for Safeguards

    SciTech Connect

    D. L. Chichester; S. A. Pozzi; E. H. Seabury; J. L. Dolan; M. Flaska; J. T. Johnson; S. M. Watson; J. Wharton

    2009-08-01

    Multiple small-scale projects have been undertaken to investigate advanced instrumentation solutions for safeguard measurement challenges associated with advanced fuel cycle facilities and next-generation fuel reprocessing installations. These activities are in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and its Materials Protection, Accounting, and Control for Transmutation (MPACT) campaign. 1) Work was performed in a collaboration with the University of Michigan (Prof. Sara Pozzi, co-PI) to investigate the use of liquid-scintillator radiation detectors for assaying mixed-oxide (MOX) fuel, to characterize its composition and to develop advanced digital pulse-shape discrimination algorithms for performing time-correlation measurements in the MOX fuel environment. This work included both simulations and experiments and has shown that these techniques may provide a valuable approach for use within advanced safeguard measurement scenarios. 2) Work was conducted in a collaboration with Oak Ridge National Laboratory (Dr. Paul Hausladen, co-PI) to evaluate the strengths and weaknesses of the fast-neutron coded-aperture imaging technique for locating and characterizing fissile material, and as a tool for performing hold-up measurements in fissile material handling facilities. This work involved experiments at Idaho National Laboratory, using MOX fuel and uranium metal, in both passive and active interrogation configurations. A complete analysis has not yet been completed but preliminary results suggest several potential uses for the fast neutron imaging technique. 3) Work was carried out to identify measurement approaches for determining nitric acid concentration in the range of 1 – 4 M and beyond. This work included laboratory measurements to investigate the suitability of prompt-gamma neutron activation analysis for this measurement and product reviews of other commercial solutions. Ultrasonic density analysis appears to be

  10. Ultrasonic beamforming system for interrogating multiple implantable sensors.

    PubMed

    Dongjin Seo; Hao-Yen Tang; Carmena, Jose M; Rabaey, Jan M; Alon, Elad; Boser, Bernhard E; Maharbiz, Michel M

    2015-08-01

    In this paper, we present an ultrasonic beamforming system capable of interrogating individual implantable sensors via backscatter in a distributed, ultrasound-based recording platform known as Neural Dust [1]. A custom ASIC drives a 7 × 2 PZT transducer array with 3 cycles of 32V square wave with a specific programmable time delay to focus the beam at the 800mm neural dust mote placed 50mm away. The measured acoustic-to-electrical conversion efficiency of the receive mote in water is 0.12% and the overall system delivers 26.3% of the power from the 1.8V power supply to the transducer drive output, consumes 0.75μJ in each transmit phase, and has a 0.5% change in the backscatter per volt applied to the input of the backscatter circuit. Further miniaturization of both the transmit array and the receive mote can pave the way for a wearable, chronic sensing and neuromodulation system. PMID:26736842

  11. Irradiation Effects for the Pulsed Fast Neutron Analysis (PFNA) Cargo Interrogation System

    SciTech Connect

    Slater, C.O.

    2001-02-02

    At the request of Safety and Ecology Corporation of Tennessee, radiation effects of the proposed Pulsed Fast Neutron Analysis (PFNA) Cargo Interrogation System have been examined. First, fissile cargo were examined to determine if a significant neutron signal would be observable during interrogation. Results indicated that ample multiplication would be seen for near critical bare targets. The water-reflected sphere showed relatively little multiplication. By implication, a fissile target shielded by hydrogenous cargo might not be detectable by neutron interrogation, particularly if reliance is placed on the neutron signal. The cargo may be detectable if use can be made of the ample increase in the photon signal. Second, dose rates were calculated at various locations within and just outside the facility building. These results showed that some dose rates may be higher than the target dose rate of 0.05 mrem/h. However, with limited exposure time, the total dose may be well below the allowed total dose. Lastly, estimates were made of the activation of structures and typical cargo. Most cargo will not be exposed long enough to be activated to levels of concern. On the other hand, portions of the structure may experience buildup of some radionuclides to levels of concern.

  12. Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system for use in aerospace and automotive health monitoring systems

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Kempen, Cornelia; Panahi, Allan; Lopatin, Craig

    2007-09-01

    Fiber Bragg grating sensors (FBGs) have gained rapid acceptance in aerospace and automotive structural health monitoring applications for the measurement of strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky and heavy bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense) microchip technology. The hybrid InOSense microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The sponsor of this program is NAVAIR under a DOD SBIR contract.

  13. Illicit substance detection using fast-neutron interrogation systems

    SciTech Connect

    Yule, T.J.; Micklich, B.J.; Fink, C.L.; Smith, D.L.

    1994-06-01

    Fast-neutron interrogation techniques are of interest for detecting illicit substances such as explosives and drugs because of their ability to identify light elements such as carbon, nitrogen, and oxygen, which are the primary constituents of these materials. Two particular techniques, Fast-Neutron Transmission Spectroscopy and Pulsed Fast-Neutron Analysis, are discussed. Examples of modeling studies are provided which illustrate the applications of these two techniques.

  14. INL Active Interrogation Testing In Support of the GNEP Safeguards Campaign

    SciTech Connect

    David L. Chichester

    2008-04-01

    Active interrogation, a measurement technique which uses a radiation source to probe materials and generate unique signatures useful for characterizing those materials, is a powerful tool for assaying special nuclear material. Work at Idaho National Laboratory (INL) in the area of active interrogation, using neutron and photon sources, has been under way for many years to develop methods for detecting and quantifying nuclear material for national and homeland security research areas. This research knowledge base is now being extended to address nuclear safeguards and process monitoring issues related to the Global Nuclear Energy Partnership (GNEP). As a first step in this area preliminary scoping studies have been performed to investigate the usefulness of using active neutron interrogation, with a low-power electronic neutron generator, to assay Department of Transportation 6M shipping drums containing uranium oxide fuel rodlets from INL’s zero power physics reactor. Using the paired-counting technique during the die-away time period of interrogation, a lower detection limit of approximately 4.2 grams of enriched uranium (40% 235U) was calculated for a 40 minute measurement using a field portable 2.5 MeV neutron source and an array of 16 moderated helium-3 neutron tubes. Future work in this area, including the use of a more powerful neutron source and a better tailored detector array, would likely improve this limit to a much lower level. Further development work at INL will explore the applicability of active interrogation in association with the nuclear safeguards and process monitoring needs of the advanced GNEP facilities under consideration. This work, which will include both analyses and field demonstrations, will be performed in collaboration with colleagues at INL and elsewhere that have expertise in nuclear fuel reprocessing as well as active interrogation and its use for nuclear material analyses.

  15. Active Neutron Interrogation of Non-Radiological Materials with NMIS

    SciTech Connect

    Walker, Mark E; Mihalczo, John T

    2012-02-01

    The Nuclear Materials Identification System (NMIS) at Oak Ridge National Laboratory (ORNL), although primarily designed for analyzing special nuclear material, is capable of identifying nonradiological materials with a wide range of measurement techniques. This report demonstrates four different measurement methods, complementary to fast-neutron imaging, which can be used for material identification: DT transmission, DT scattering, californium transmission, and active time-tagged gamma spectroscopy. Each of the four techniques was used to evaluate how these methods can be used to identify four materials: aluminum, polyethylene, graphite, and G-10 epoxy. While such measurements have been performed individually in the past, in this project, all four measurements were performed on the same set of materials. The results of these measurements agree well with predicted results. In particular, the results of the active gamma spectroscopy measurements demonstrate the technique's applicability in a future version of NMIS which will incorporate passive and active gamma-ray spectroscopy. This system, designated as a fieldable NMIS (FNMIS), is under development by the US Department of Energy Office of Nuclear Verification.

  16. Interrogation of Patient Smartphone Activity Tracker to Assist Arrhythmia Management.

    PubMed

    Rudner, Joshua; McDougall, Carol; Sailam, Vivek; Smith, Monika; Sacchetti, Alfred

    2016-09-01

    A 42-year-old man presented to the emergency department (ED) with newly diagnosed atrial fibrillation of unknown duration. Interrogation of the patient's wrist-worn activity tracker and smartphone application identified the onset of the arrhythmia as within the previous 3 hours, permitting electrocardioversion and discharge of the patient from the ED. PMID:27045694

  17. Investigation of Active Interrogation Techniques to Detect Special Nuclear Material in Maritime Environments

    SciTech Connect

    Miller, Thomas Martin; Patton, Bruce W

    2010-01-01

    The detection and interdiction of special nuclear material (SNM) is still a high-priority focus area for many organizations around the world. One method that is commonly considered a leading candidate in the detection of SNM is active interrogation (AI). AI is different from its close relative, passive interrogation, in that an active source is used to enhance or create a detectable signal (usually fission) from SNM, particularly in shielded scenarios or scenarios where the SNM has a low activity. The use of AI thus makes the detection of SNM easier or, in some scenarios, even enables previously impossible detection. In this work the signal from prompt neutrons and photons as well as delayed neutrons and photons will be combined, as is typically done in AI. In previous work AI has been evaluated experimentally and computationally. However, for the purposes of this work, past scenarios are considered lightly shielded and tightly coupled spatially. At most, the previous work interrogated the contents of one standard cargo container (2.44 x 2.60 x 6.10 m) and the source and detector were both within a few meters of the object being interrogated. A few examples of this type of previous work can be found in references 1 and 2. Obviously, more heavily shielded AI scenarios will require larger source intensities, larger detector surface areas (larger detectors or more detectors), greater detector efficiencies, longer count times, or some combination of these.

  18. Implementation of interrogation systems for fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Varghese P, Benjamin; Kumar R, Dinesh; Raju, Mittu; Madhusoodanan, K. N.

    2013-09-01

    The development of two simple methods for wavelength-optical intensity modulation techniques for fiber Bragg grating (FBG) sensors is presented. The performance is evaluated by measuring the strain and temperature. The first method consists of a narrow band source, an optical circulator, an FBG, and a power meter. The source and Bragg reflected signal from the FBG need to be matched to get linear results with good power levels. The source spectral power levels are very critical in this study. The power reflected from a matched reference FBG is fed into the measuring FBG in the second method. Since the FBGs are matched, the entire power is reflected back initially. During the measurement, the change in the measurand causes the reflected power from the sensing FBG to vary. A costly high resolution spectrum analyzer is required only during the characterization of the FBG and source. The performances of two interrogators are compared by measuring the strain and temperature. In the second method, the strain measurements can be made insensitive to the temperature variation by selecting a source with a flat spectrum at the measurement range. Highlights of these methods are the portability, cost effectiveness and better resolution.

  19. A Study of 3He detectors for Active Interrogation

    SciTech Connect

    E.H. Seabury; D.L. Chichester

    2009-10-01

    3He proportional counters have long been used as neutron detectors for both passive and active detection of Special Nuclear Material (SNM). The optimal configuration of these detectors as far as gas pressure, amount of moderating material, and size are concerned is highly dependent on what neutron signatures are being used to detect and identify SNM. We present here a parametric study of the neutron capture response of 3He detectors, based on Monte Carlo simulations using the MCNPX radiation transport code. The neutron capture response of the detectors has been modeled as a function of time after an incident neutron pulse.

  20. Caged compounds for multichromic optical interrogation of neural systems

    PubMed Central

    Amatrudo, Joseph M.; Olson, Jeremy P.; Agarwal, Hitesh K.; Ellis-Davies, Graham C.R.

    2014-01-01

    Caged compounds have widely used by neurophysiologists to study many aspects of cellular signaling in glia and neurons. Biologically inert before irradiation, they can be loaded into cells via patch pipette or topically applied in situ to a defined concentration, photolysis releases the caged compound in a very rapid and spatially defined way. Since caged compounds are exogenous optical probes, they include not only natural products such neurotransmitters, calcium and IP3, but non-natural products such as fluorophores, drugs and antibodies. In this Technical Spotlight we provide a short introduction to the uncaging technique by discussing the nitroaromatic caging chromophores most widely used in such experiments (e.g. CNB1, DMNB, MNI and CDNI). We show that recently developed caging chromophores (RuBi and DEAC450) that are photolyzed with blue light (ca. 430–480 nm range) can be combined with traditional nitroaromatic caged compounds to enable two-color optical probing of neuronal function. For example, one-photon uncaging of either RuBi-GABA or DEAC450-GABA with a 473-nm laser is facile, and can block non-linear currents (dendritic spikes or action potentials) evoked by two-photon uncaging of CDNI-Glu at 720 nm. We also show that two-photon uncaging of DEAC450-Glu and CDNI-GABA at 900 and 720 nm, respectively, can be used to fire and block action potentials. Our experiments illustrate that recently developed chromophores have taken uncaging out of the “monochrome era”, in which it has existed since 1978, so as to enable multichromic interrogation of neuronal function with single synapse precision. PMID:25471355

  1. Design and development of a low power, low cost, portable fiber Bragg grating (FBG) sensor interrogation system

    NASA Astrophysics Data System (ADS)

    Cai, Zhaohui; Phua, Jiliang; Hao, Jianzhong; Dong, Bo; Wang, Xian; Meng, Yu Song; Chiam, Tat Meng

    2012-01-01

    In this paper, the design and development of a low power, low cost and portable FBG Interrogation System is presented. The FBG interrogator consists of a spectral analyzer module, a photo detection module, and an electronic processing module. By using volume holographic phase grating as the continuous dispersion spectral element, our interrogator can achieve a maximum scanning frequency as high as 5 KHz for a single channel with a total power requirement of 25 W.

  2. Design and development of a low power, low cost, portable fiber Bragg grating (FBG) sensor interrogation system

    NASA Astrophysics Data System (ADS)

    Cai, Zhaohui; Phua, Jiliang; Hao, Jianzhong; Dong, Bo; Wang, Xian; Meng, Yu Song; Chiam, Tat Meng

    2011-11-01

    In this paper, the design and development of a low power, low cost and portable FBG Interrogation System is presented. The FBG interrogator consists of a spectral analyzer module, a photo detection module, and an electronic processing module. By using volume holographic phase grating as the continuous dispersion spectral element, our interrogator can achieve a maximum scanning frequency as high as 5 KHz for a single channel with a total power requirement of 25 W.

  3. Active Interrogation Observables for Enrichment Determination of DU Shielded HEU Metal Assemblies with Limited Geometrical Information

    SciTech Connect

    Pena, Kirsten E; McConchie, Seth M; Crye, Jason Michael; Mihalczo, John T

    2011-01-01

    Determining the enrichment of highly enriched uranium (HEU) metal assemblies shielded by depleted uranium (DU) proves a unique challenge to currently employed measurement techniques. Efforts to match time-correlated neutron distributions obtained through active interrogation to Monte Carlo simulations of the assemblies have shown promising results, given that the exact geometries of both the HEU metal assemblies and DU shields are known from imaging and fission site mapping. In certain situations, however, it is desirable to obtain enrichment with limited or no geometrical information of the assemblies being measured. This paper explores the possibility that the utilization of observables in the interrogation of assemblies by time-tagged D-T neutrons, including time-correlated distribution of neutrons and gammas using liquid scintillators operating on the fission chain time scale, can lead to enrichment determination without a complete set of geometrical information.

  4. Numerical modelling of interrogation systems for optical fibre Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Oswald, Daniel; Richardson, Steven; Wild, Graham

    2011-12-01

    There are a number of interrogation methods that can be used in optical Fibre Bragg Grating (FBG) sensing system. For very high frequency signals interrogating the sensor signal from an FBG is limited to two intensiometric methods, edge filter detection and power detection. In edge filter detection, a broadband light source illuminates an FBG, the reflected spectrum is then passed through a spectral filter. In power detection, a narrowband light source with a wavelength corresponding to the 3dB point of the FBG is filtered by the FBG itself. Both methods convert the spectral shift of the FBG into intensity signals. These two categories each have a number of variations, all with different performance characteristics. In this work we present a numerical model for all of these interrogation systems. The numerical model is based on previous analytical modelling, which could only be utilised for perfect Gaussian profiles. However, interrogation systems can make use of non Gaussian shaped filters, or sources. The numerical modelling enables the different variations to be compared using identical component performance, showing the relative strengths and weakness of the systems in terms of useful parameters, including, signal-to-noise ratio, sensitivity, and dynamic resolution. The two different detection methods can also be compared side-by-side using the same FBG. Since the model is numerical, it enables real spectral data to be used for the various components (FBG, light source, filters). This has the added advantage of increasing the accuracy and usefulness of the model, over previous analytical work.

  5. Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

    NASA Astrophysics Data System (ADS)

    Rose, P. B.; Erickson, A. S.

    2015-11-01

    Active interrogation of cargo containers using monoenergetic photons offers a rapid and low-dose approach to search for shielded special nuclear materials. Cherenkov detectors can be used for imaging of the cargo provided that gamma ray energies used in interrogation are well resolved, as the case in 11B(d,n-γ)12C reaction resulting in 4.4 MeV and 15.1 MeV photons. While an array of Cherenkov threshold detectors reduces low energy background from scatter while providing the ability of high contrast transmission imaging, thus confirming the presence of high-Z materials, these detectors require a special approach to energy calibration due to the lack of resolution. In this paper, we discuss the utility of Cherenkov detectors for active interrogation with monoenergetic photons as well as the results of computational and experimental studies of their energy calibration. The results of the studies with sources emitting monoenergetic photons as well as complex gamma ray spectrum sources, for example 232Th, show that calibration is possible as long as the energies of photons of interest are distinct.

  6. DOSE PROFILE MODELING OF IDAHO NATIONAL LABORATORY’S ACTIVE NEUTRON INTERROGATION TEST FACILITY

    SciTech Connect

    D. L. Chichester; E. H. Seabury; J. M. Zabriskie; J. Wharton; A. J. Caffrey

    2009-06-01

    A new research and development laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for DT fusion (14.1 MeV) neutron generators (2 x 108 neutrons per second), DD fusion (2.5 MeV) neutron generators (up to 2 x 106 neutrons per second), and 252Cf spontaneous fission neutron sources (6.7 x 107 neutrons per second, 30 micrograms). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault. The larger vault is designed to allow operation of the DT generator and has walls 3.8 m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for 252Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield wall and entrance maze and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.

  7. Proton interrogation

    SciTech Connect

    Morris, Christopher L

    2008-01-01

    Energetic proton beams may provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because: they have large fission cross sections, long mean free paths and high penetration, and proton beams can be manipulated with magnetic optics. We have measured time-dependent cross sections for delayed neutrons and gamma-rays using the 800 MeV proton beam from the Los Alamos Neutron Science Center for a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Results will be presented.

  8. Design and initial application of the extended aircraft interrogation and display system: Multiprocessing ground support equipment for digital flight systems

    NASA Technical Reports Server (NTRS)

    Glover, Richard D.

    1987-01-01

    A pipelined, multiprocessor, general-purpose ground support equipment for digital flight systems has been developed and placed in service at the NASA Ames Research Center's Dryden Flight Research Facility. The design is an outgrowth of the earlier aircraft interrogation and display system (AIDS) used in support of several research projects to provide engineering-units display of internal control system parameters during development and qualification testing activities. The new system, incorporating multiple 16-bit processors, is called extended AIDS (XAIDS) and is now supporting the X-29A forward-swept-wing aircraft project. This report describes the design and mechanization of XAIDS and shows the steps whereby a typical user may take advantage of its high throughput and flexible features.

  9. Guidelines to indirectly measure and enhance detection efficiency of stationary PIT tag interrogation systems in streams

    USGS Publications Warehouse

    Connolly, Patrick J.

    2010-01-01

    With increasing use of passive integrated transponder (PIT) tags and reliance on stationary PIT tag interrogation systems to monitor fish populations, guidelines are offered to inform users how best to use limited funding and human resources to create functional systems that maximize a desired level of detection and precision. The estimators of detection efficiency and their variability as described by Connolly et al. (2008) are explored over a span of likely performance metrics. These estimators were developed to estimate detection efficiency without relying on a known number of fish passing the system. I present graphical displays of the results derived from these estimators to show the potential efficiency and precision to be gained by adding an array or by increasing the number of PIT-tagged fish expected to move past an interrogation system.

  10. A knowledge based application of the extended aircraft interrogation and display system

    NASA Technical Reports Server (NTRS)

    Glover, Richard D.; Larson, Richard R.

    1991-01-01

    A family of multiple-processor ground support test equipment was used to test digital flight-control systems on high-performance research aircraft. A unit recently built for the F-18 high alpha research vehicle project is the latest model in a series called the extended aircraft interrogation and display system. The primary feature emphasized monitors the aircraft MIL-STD-1553B data buses and provides real-time engineering units displays of flight-control parameters. A customized software package was developed to provide real-time data interpretation based on rules embodied in a highly structured knowledge database. The configuration of this extended aircraft interrogation and display system is briefly described, and the evolution of the rule based package and its application to failure modes and effects testing on the F-18 high alpha research vehicle is discussed.

  11. Structural and molecular interrogation of intact biological systems.

    PubMed

    Chung, Kwanghun; Wallace, Jenelle; Kim, Sung-Yon; Kalyanasundaram, Sandhiya; Andalman, Aaron S; Davidson, Thomas J; Mirzabekov, Julie J; Zalocusky, Kelly A; Mattis, Joanna; Denisin, Aleksandra K; Pak, Sally; Bernstein, Hannah; Ramakrishnan, Charu; Grosenick, Logan; Gradinaru, Viviana; Deisseroth, Karl

    2013-05-16

    Obtaining high-resolution information from a complex system, while maintaining the global perspective needed to understand system function, represents a key challenge in biology. Here we address this challenge with a method (termed CLARITY) for the transformation of intact tissue into a nanoporous hydrogel-hybridized form (crosslinked to a three-dimensional network of hydrophilic polymers) that is fully assembled but optically transparent and macromolecule-permeable. Using mouse brains, we show intact-tissue imaging of long-range projections, local circuit wiring, cellular relationships, subcellular structures, protein complexes, nucleic acids and neurotransmitters. CLARITY also enables intact-tissue in situ hybridization, immunohistochemistry with multiple rounds of staining and de-staining in non-sectioned tissue, and antibody labelling throughout the intact adult mouse brain. Finally, we show that CLARITY enables fine structural analysis of clinical samples, including non-sectioned human tissue from a neuropsychiatric-disease setting, establishing a path for the transmutation of human tissue into a stable, intact and accessible form suitable for probing structural and molecular underpinnings of physiological function and disease. PMID:23575631

  12. Dose profile modeling of Idaho National Laboratory's active neutron interrogation laboratory.

    PubMed

    Chichester, D L; Seabury, E H; Zabriskie, J M; Wharton, J; Caffrey, A J

    2009-06-01

    A new laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for deuterium-tritium (DT) fusion (14.1 MeV) neutron generators (2 x 10(8) n/s), deuterium-deuterium (DD) fusion (2.5 MeV) neutron generators (1 x 10(7) n/s), and (252)Cf spontaneous fission neutron sources (6.96 x 10(7) n/s, 30 microg). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault. The larger vault is designed to allow operation of the DT generator and has walls 3.8m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for (252)Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield walls and entrance mazes and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults. PMID:19217792

  13. Extended step-out length fiber Bragg grating interrogation system for condition monitoring of electrical submersible pumps

    NASA Astrophysics Data System (ADS)

    Fusiek, G.; Niewczas, Pawel; McDonald, James R.

    2005-03-01

    We present details of the design and laboratory evaluation of the fiber Bragg grating (FBG) interrogation system developed specifically for condition monitoring of electrical submersible pumps (ESPs). The system, based on the microelectromechanical systems (MEMS) Fabry-Pérot tunable filter, is capable of interrogating several FBG sensors placed around an ESP unit and configured to measure static and dynamic parameters, e.g., temperature, vibration signature and/or instantaneous voltage, and current. Sensor interrogation over the extended step-out length distance of 24 km is demonstrated in the laboratory in a simple experiment of multipoint dynamic strain monitoring in a vibrated cantilever beam.

  14. Non-invasive biosensor and wilreless interrogating system for hypoglycemia

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.; Whitchurch, Ashwin K.; Saukesi, K.

    2002-11-01

    Hypoglycemia - abnormal decrease in blood sugar - is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This paper presents the development of a non-invasive sensor with miniaturized telemetry device in a wrist-watch for monitoring glucose concentration in blood. The sensor concept is based on optical chiralit of glucose level in the interstitial fluid. The wrist watch consists of a laser power source of the wavelength compatible with the glucose. A nanofilm with specific chirality is placed at the bottom of the watch. The light then passes through the film and illuminates a small area on the skin.It has been documented that there is certain concentration of sugar level is taken by the intertitial fluid from the blood stream and deposit a portion of it at the dead skin. The wrist-watch when in contact with the outer skin of the human will thus monitor the glucose concentration. A wireless monitoring system in the watch then downloads the data from the watch to a Palm or laptop computer.

  15. Noninvasive biosensor and wireless interrogating system for glucose in blood

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.; Whitchurch, Ashwin K.; Sarukesi, K.

    2003-07-01

    Hypoglycemia-abnormal decrease in blood sugar-is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This paper presents the development of a non-invasive sensor with miniaturized telemetry device in a wrist-watch for monitoring glucose concentration in blood. The sensor concept is based on optical chirality of glucose level in the interstitial fluid. The wrist watch consists of a laser power source of the wavelength compatible with the glucose. A nanofilm with specific chirality is placed at the bottom of the watch. The light then passes through the film and illuminates a small area on the skin. It has been documented that there is certain concentration of sugar level is taken by the intertitial fluid from the blood stream and deposit a portion of it at the dead skin. The wrist-watch when in contact with the outer skin of the human will thus monitor the glucose concentration. A wireless monitoring system in the watch then downloads the data from the watch to a Palm or a laptop computer.

  16. Live Interrogation and Visualization of Earth Systems (LIVES)

    NASA Astrophysics Data System (ADS)

    Nunn, J. A.; Anderson, L. C.

    2007-12-01

    Twenty tablet PCs and associated peripherals acquired through a HP Technology for Teaching grant are being used to redesign two freshman laboratory courses as well as a sophomore geobiology course in Geology and Geophysics at Louisiana State University. The two introductory laboratories serve approximately 750 students per academic year including both majors and non-majors; the geobiology course enrolls about 35 students/year and is required for majors in the department's geology concentration. Limited enrollments and 3 hour labs make it possible to incorporate hands-on visualization, animation, GIS, manipulation of data and images, and access to geological data available online. Goals of the course redesigns include: enhancing visualization of earth materials, physical/chemical/biological processes, and biosphere/geosphere history; strengthening student's ability to acquire, manage, and interpret multifaceted geological information; fostering critical thinking, the scientific method, and earth-system science/perspective in ancient and modern environments (such as coastal erosion and restoration in Louisiana or the Snowball Earth hypothesis); improving student communication skills; and increasing the quantity, quality, and diversity of students pursuing Earth Science careers. IT resources available in the laboratory provide students with sophisticated visualization tools, allowing them to switch between 2-D and 3-D reconstructions more seamlessly, and enabling them to manipulate larger integrated data- sets, thus permitting more time for critical thinking and hypothesis testing. IT resources also enable faculty and students to simultaneously work with simulation software to animate earth processes such as plate motions or groundwater flow and immediately test hypothesis formulated in the data analysis. Finally, tablet PCs make it possible for data gathering and analysis outside a formal classroom. As a result, students will achieve fluency in using visualization

  17. Estimation of the Performance of Multiple Active Neutron Interrogation Signatures for Detecting Shielded HEU

    SciTech Connect

    David L. Chichester; Scott J. Thompson; Scott M. Watson; James T. Johnson; Edward H. Seabury

    2012-10-01

    A comprehensive modeling study has been carried out to evaluate the utility of multiple active neutron interrogation signatures for detecting shielded highly enriched uranium (HEU). The modeling effort focused on varying HEU masses from 1 kg to 20 kg; varying types of shields including wood, steel, cement, polyethylene, and borated polyethylene; varying depths of the HEU in the shields, and varying engineered shields immediately surrounding the HEU including steel, tungsten, and cadmium. Neutron and gamma-ray signatures were the focus of the study and false negative detection probabilities versus measurement time were used as a performance metric. To facilitate comparisons among different approaches an automated method was developed to generate receiver operating characteristic (ROC) curves for different sets of model variables for multiple background count rate conditions. This paper summarizes results or the analysis, including laboratory benchmark comparisons between simulations and experiments. The important impact engineered shields can play towards degrading detectability and methods for mitigating this will be discussed.

  18. High-speed and long-time FBG interrogation system using wavelength swept laser

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tatsuya; Shinoda, Yukitaka

    2015-05-01

    The purpose of this research is the development of a system for fabricating high-speed and long-time measurements of wide-band vibration using fiber Bragg gratings (FBGs) to determine the health of structures. We developed a real-time FBG interrogation system using wavelength swept laser. This system can perform real-time measurement of reflected wavelength from a multiple FBG at a temporal resolution of 0.1 ms. The authors also constructed a database system for managing the data obtained from high-speed and long-time measurement. This database system manages data using a relational database and transfers information on FBG reflected wavelengths obtained from this measurement system via the local network. We have demonstrated that this system is able to measure reflected wavelengths from a multipoint FBG at a temporal resolution of 0.1 ms over 24 hours, it was shown that this system could also monitor instantaneously applied high-speed vibrations.

  19. Methods and systems for Raman and optical cross-interrogation in flow-through silicon membranes

    SciTech Connect

    Bond, Tiziana C.; Letant, Sonia E.

    2014-09-09

    Cross-interrogating photonic detection systems and methods are shown. A flow through photonic crystal membrane with a surface enhanced Raman scattering (SERS) substrate is provided with pores which are distributed along multiple regions. The pores of one region have walls to which a first type of target specific anchor can be attached, while pores of another region have walls to which a second type of target specific anchor can be attached. An optical arrangement out-of-plane to the SERS substrate is also provided for enhanced sensitivity and identification of target organisms.

  20. Linearized interrogation of FDML FBG sensor system using PMF Sagnac interferometer

    NASA Astrophysics Data System (ADS)

    Lee, Hwi Don; Jung, Eun Joo; Jeong, Myung Yung; Kim, Chang-Seok

    2009-10-01

    A novel linearized interrogation method is presented for Fourier-domain mode locked (FDML) fiber Bragg grating (FBG) sensor system. In the ultra high-speed regime over 10 kHz modulation, only sine wave is available to scan a center wavelength of FDML wavelength-swept laser instead of conventional triangular wave. However, sine wave modulation has been suffered an exaggerated nonlinear filter response in demodulating the time-encoded parameter into the absolute wavelength. The linearized demodulation is demonstrated by the third order polynomial conversion of filter between the time-encoded parameter and wavelength-encoded parameter based on the spectral information of polarization maintaining fiber (PMF) Sagnac interferometer.

  1. Assessment of effectiveness of geologic isolation systems: the feasibility of computer interrogation of experts for WISAP

    SciTech Connect

    Wight, L.H.

    1980-05-01

    Simulation of the response of a waste repository to events that could initiate a fault tree to breach and failure is currently a keystone to the Battelle Waste Isolation Safety Assessment Program (WISAP). The repository simulation, which is part of the Disruptive Event Analysis Task, models the repository for its entire design life, one million years. This is clearly a challenging calculation, requiring input unlike any other response analysis by virtue of the long design life of the facility. What technology will provide design criteria for a million year design life. Answers to questions like this can, to some extent, be based on data, but always require some subjective judgments. The subjectivity, which is sometimes driven by inadequate or incomplete data or by a lack of understanding of the physical process, is therefore a crucial ingredient in an analysis of initiating events. Because of the variety of possible initiating events (glaciation, man-caused disruption, volcanism, etc.), many expert opinions will be solicited as input. The complexity of the simulation, the variety of experts involved, and the volume of applicable data all suggest that there may be a more direct, economical method to solicit the expert opinion. This report addresses the feasibility of such a system. Background information is presented that demonstrates the advantages of a computer interrogation system over conventional interrogation and assessment techniques. In the subsequent three sections the three elements - structure and decomposition, scaling, and synthesis - that are basic to any interrogation and assessment technique are reviewed. The interrelationship are schematically illustrated between these three fundamental elements and, therefore, serves as a useful guide to these three sections. Each of these three sections begins with a recommended approach to the particular element and ends with an illustration of representative dialogue.

  2. Monitoring system including an electronic sensor platform and an interrogation transceiver

    DOEpatents

    Kinzel, Robert L.; Sheets, Larry R.

    2003-09-23

    A wireless monitoring system suitable for a wide range of remote data collection applications. The system includes at least one Electronic Sensor Platform (ESP), an Interrogator Transceiver (IT) and a general purpose host computer. The ESP functions as a remote data collector from a number of digital and analog sensors located therein. The host computer provides for data logging, testing, demonstration, installation checkout, and troubleshooting of the system. The IT transmits signals from one or more ESP's to the host computer to the ESP's. The IT host computer may be powered by a common power supply, and each ESP is individually powered by a battery. This monitoring system has an extremely low power consumption which allows remote operation of the ESP for long periods; provides authenticated message traffic over a wireless network; utilizes state-of-health and tamper sensors to ensure that the ESP is secure and undamaged; has robust housing of the ESP suitable for use in radiation environments; and is low in cost. With one base station (host computer and interrogator transceiver), multiple ESP's may be controlled at a single monitoring site.

  3. High-throughput spectral system for interrogation of dermally-implanted luminescent sensors.

    PubMed

    Long, Ruiqi; McShane, Mike

    2012-01-01

    Ratiometric luminescent microparticle sensors have been developed for sensing biochemical targets such as glucose in interstitial fluid, enabling use of dermal implants for on-demand monitoring. For these sensor systems to be deployed in vivo, a matched optoelectronic system for interrogation of dermally-implanted sensors was previously designed, constructed, and evaluated experimentally. During evaluation experiments, it revealed that the system efficiency was compromised by losses due to fiber connections of a commercial spectrometer. In this work, a high-throughput spectral system was presented to solve the photon loss problem. This system was designed, constructed, and tested. The throughput was around hundred time more than the previous system we used, and it was cost-effective, as well. It enables use of an integrated system for excitation, collection and measurement of luminescent emission, and will be used as a tool for in vivo studies with animal models or human subjects. PMID:23366396

  4. High-resolution spectrally-resolved fiber optic sensor interrogation system based on a standard DWDM laser module.

    PubMed

    Njegovec, Matej; Donlagic, Denis

    2010-11-01

    This paper presents a spectrally-resolved integration system suitable for the reading of Bragg grating, all-fiber Fabry-Perot, and similar spectrally-resolved fiber-optic sensors. This system is based on a standard telecommunication dense wavelength division multiplexing transmission module that contains a distributed feedback laser diode and a wavelength locker. Besides the transmission module, only a few additional opto-electronic components were needed to build an experimental interrogation system that demonstrated over a 2 nm wide wavelength interrogation range, and a 1 pm wavelength resolution. When the system was combined with a typical Bragg grating sensor, a strain resolution of 1 με and temperature resolution of 0.1 °C were demonstrated experimentally. The proposed interrogation system relies entirely on Telecordia standard compliant photonic components and can thus be straightforwardly qualified for use within the range of demanding applications. PMID:21164765

  5. Integrated FBG sensors interrogator in silicon photonic platform using active interferometer monitoring

    NASA Astrophysics Data System (ADS)

    Marin, Y. E.; Nannipieri, T.; Di Pasquale, F.; Oton, C. J.

    2016-05-01

    We experimentally demonstrate the feasibility of Fiber Bragg Grating sensors interrogation using integrated unbalanced Mach-Zehnder Interferometers (MZI) and phase sensitive detection in silicon-on-insulator (SOI) platform. The Phase- Generated Carrier (PGC) demodulation technique is used to detect phase changes, avoiding signal fading. Signal processing allows us to extract the wavelength shift from the signal patterns, allowing accurate dynamic FBG interrogation. High resolution and low cost chips with multiple interrogators and photodetectors on board can be realized by exploiting the advantages of large scale fabrication capabilities of well-established silicon based industrial infrastructures. Simultaneous dynamic reading of a large number of FBG sensors can lead to large volume market applications of the technology in several strategic industrial fields. The performance of the proposed integrated FBG interrogator is validated by comparing with a commercial FBG readout based on a spectrometer and used as a reference.

  6. A Fiber Bragg Grating Sensor Interrogation System Based on a Linearly Wavelength-Swept Thermo-Optic Laser Chip

    PubMed Central

    Lee, Hyung-Seok; Lee, Hwi Don; Kim, Hyo Jin; Cho, Jae Du; Jeong, Myung Yung; Kim, Chang-Seok

    2014-01-01

    A linearized wavelength-swept thermo-optic laser chip was applied to demonstrate a fiber Bragg grating (FBG) sensor interrogation system. A broad tuning range of 11.8 nm was periodically obtained from the laser chip for a sweep rate of 16 Hz. To measure the linear time response of the reflection signal from the FBG sensor, a programmed driving signal was directly applied to the wavelength-swept laser chip. The linear wavelength response of the applied strain was clearly extracted with an R-squared value of 0.99994. To test the feasibility of the system for dynamic measurements, the dynamic strain was successfully interrogated with a repetition rate of 0.2 Hz by using this FBG sensor interrogation system. PMID:25177803

  7. Insight into GATA1 transcriptional activity through interrogation of cis elements disrupted in human erythroid disorders.

    PubMed

    Wakabayashi, Aoi; Ulirsch, Jacob C; Ludwig, Leif S; Fiorini, Claudia; Yasuda, Makiko; Choudhuri, Avik; McDonel, Patrick; Zon, Leonard I; Sankaran, Vijay G

    2016-04-19

    Whole-exome sequencing has been incredibly successful in identifying causal genetic variants and has revealed a number of novel genes associated with blood and other diseases. One limitation of this approach is that it overlooks mutations in noncoding regulatory elements. Furthermore, the mechanisms by which mutations in transcriptionalcis-regulatory elements result in disease remain poorly understood. Here we used CRISPR/Cas9 genome editing to interrogate three such elements harboring mutations in human erythroid disorders, which in all cases are predicted to disrupt a canonical binding motif for the hematopoietic transcription factor GATA1. Deletions of as few as two to four nucleotides resulted in a substantial decrease (>80%) in target gene expression. Isolated deletions of the canonical GATA1 binding motif completely abrogated binding of the cofactor TAL1, which binds to a separate motif. Having verified the functionality of these three GATA1 motifs, we demonstrate strong evolutionary conservation of GATA1 motifs in regulatory elements proximal to other genes implicated in erythroid disorders, and show that targeted disruption of such elements results in altered gene expression. By modeling transcription factor binding patterns, we show that multiple transcription factors are associated with erythroid gene expression, and have created predictive maps modeling putative disruptions of their binding sites at key regulatory elements. Our study provides insight into GATA1 transcriptional activity and may prove a useful resource for investigating the pathogenicity of noncoding variants in human erythroid disorders. PMID:27044088

  8. Insight into GATA1 transcriptional activity through interrogation of cis elements disrupted in human erythroid disorders

    PubMed Central

    Wakabayashi, Aoi; Ulirsch, Jacob C.; Ludwig, Leif S.; Fiorini, Claudia; Yasuda, Makiko; Choudhuri, Avik; McDonel, Patrick; Zon, Leonard I.; Sankaran, Vijay G.

    2016-01-01

    Whole-exome sequencing has been incredibly successful in identifying causal genetic variants and has revealed a number of novel genes associated with blood and other diseases. One limitation of this approach is that it overlooks mutations in noncoding regulatory elements. Furthermore, the mechanisms by which mutations in transcriptional cis-regulatory elements result in disease remain poorly understood. Here we used CRISPR/Cas9 genome editing to interrogate three such elements harboring mutations in human erythroid disorders, which in all cases are predicted to disrupt a canonical binding motif for the hematopoietic transcription factor GATA1. Deletions of as few as two to four nucleotides resulted in a substantial decrease (>80%) in target gene expression. Isolated deletions of the canonical GATA1 binding motif completely abrogated binding of the cofactor TAL1, which binds to a separate motif. Having verified the functionality of these three GATA1 motifs, we demonstrate strong evolutionary conservation of GATA1 motifs in regulatory elements proximal to other genes implicated in erythroid disorders, and show that targeted disruption of such elements results in altered gene expression. By modeling transcription factor binding patterns, we show that multiple transcription factors are associated with erythroid gene expression, and have created predictive maps modeling putative disruptions of their binding sites at key regulatory elements. Our study provides insight into GATA1 transcriptional activity and may prove a useful resource for investigating the pathogenicity of noncoding variants in human erythroid disorders. PMID:27044088

  9. Using Electronic Neutron Generators in Active Interrogation to Detect Shielded Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2008-10-01

    Experiments have been performed at Idaho National Laboratory to study methodology and instrumentation for performing neutron active interrogation die-away analyses for the purpose of detecting shielded fissionable material. Here we report initial work using a portable DT electronic neutron generator with a He-3 fast neutron detector to detect shielded fissionable material including >2 kg quantities of enriched uranium and plutonium. Measurements have been taken of bare material as well as of material hidden within a large plywood cube. Results from this work have demonstrated the efficacy of the die-away neutron measurement technique for quickly detecting the presence of special nuclear material hidden within plywood shields by analyzing the time dependent neutron signals in-between neutron generator pulses. Using a DT electronic neutron generator operating at 300 Hz with a yield of approximately 0.36 x 10**8 neutrons per second, 2.2 kg of enriched uranium hidden within a 0.60 m x 0.60 m x 0.70 m volume of plywood was positively detected with a measurement signal 2-sigma above the passive background within 1 second. Similarly, for a 500 second measurement period a lower detection limit of approaching the gram level could be expected with the same simple set-up.

  10. Non-destructive assay of fissile materials through active neutron interrogation technique using pulsed neutron (plasma focus) device

    NASA Astrophysics Data System (ADS)

    Tomar, B. S.; Kaushik, T. C.; Andola, Sanjay; Ramniranjan; Rout, R. K.; Kumar, Ashwani; Paranjape, D. B.; Kumar, Pradeep; Ramakumar, K. L.; Gupta, S. C.; Sinha, R. K.

    2013-03-01

    Pulsed neutrons emitted from a plasma focus (PF) device have been used for the first time for the non-destructive assay of 235U content in different chemical forms (oxide and metal). The PF device generates (1.2±0.3)×109 D-D fusion neutrons per shot with a pulse width of 46±5 ns. The method involves the measurement of delayed neutrons from an irradiated sample 50 ms after exposure to the neutron pulse for a time of about 100 s in the multichannel scaling (MCS) mode. The calibration of the active interrogation delayed neutron counter (AIDNEC) system was carried out by irradiating U3O8 samples of varying amounts (0.1-40 g) containing enriched 235U (14.8%) in the device. The delayed neutrons were monitored using a bank of six 3He detectors. The sensitivity of the system was found to be about 100 counts/s/g over the accumulation time of 25 s per neutron pulse of ˜109. The detection limit of the system is estimated to be 18 mg of 235U. The system can be suitably modified for applications toward non-destructive assay of fissile content in waste packets.

  11. Leveraging dialog systems research to assist biomedical researchers' interrogation of Big Clinical Data.

    PubMed

    Hoxha, Julia; Weng, Chunhua

    2016-06-01

    The worldwide adoption of electronic health records (EHR) promises to accelerate clinical research, which lies at the heart of medical advances. However, the interrogation of such Big Data by clinical researchers can be laborious and error-prone, involving iterative and ineffective communication of data requests to data analysts. Research on this communication process is rare. There also exists no contemporary system that offers intelligent solutions to assist clinical researchers in their quest for clinical data. In this article, we first provide a detailed characterization of the challenges encountered in this communication space. Second, we identify promising synergies between fields studying human-to-human and human-machine communication that can shed light on biomedical data query mediation. We propose a mixed-initiative dialog-based approach to support autonomous clinical data access and recommend needed technology development and communication study for accelerating clinical research. PMID:27067901

  12. Simulation of a high-speed superimposed fiber Bragg gratings interrogation system.

    PubMed

    Ma, Youchun; Mills, James K; Xiong, Jijun; Zhang, Wendong; Tan, Qiuling

    2015-09-01

    This paper presents a simulation of high-speed nonuniform random sampling in a superimposed fiber Bragg gratings (SFBGs) interrogation system. The simulated Gauss SFBGs are used to generate a nonuniform sensing pulse train during each scanning cycle. Six different conditions that can cause nonuniform sampling are simulated, and a random sine-wave driving method to improve the driving speed is proposed. An 11.8 kHz dynamic strain is measured by generating an additive nonuniform randomly distributed 12 kHz optical sensing pulse train from a mean 2 kHz sinusoidal periodically changing scanning frequency and three SFBGs. Four conditions that can improve the sampling results are also simulated. PMID:26368898

  13. Parametric Evaluation of Active Neutron Interrogation for the Detection of Shielded Highly-Enriched Uranium in the Field

    SciTech Connect

    D. L. Chcihester; E. H. Seabury; S. J. Thompson; R. R. C. Clement

    2011-10-01

    Parametric studies using numerical simulations are being performed to assess the performance capabilities and limits of active neutron interrogation for detecting shielded highly enriched uranium (HEU). Varying the shield material, HEU mass, HEU depth inside the shield, and interrogating neutron source energy, the simulations account for both neutron and photon emission signatures from the HEU with resolution in both energy and time. The results are processed to represent different irradiation timing schemes and several different classes of radiation detectors, and evaluated using a statistical approach considering signal intensity over background. This paper describes the details of the modeling campaign and some preliminary results, weighing the strengths of alternative measurement approaches for the different irradiation scenarios.

  14. High resolution interrogation system for fiber Bragg grating (FBG) sensor application using radio frequency spectrum analyser

    NASA Astrophysics Data System (ADS)

    Muhammad, F. D.; Zulkifli, M. Z.; Harun, S. W.; Ahmad, H.

    2013-05-01

    In this paper, we propose a fiber Bragg grating (FBG) interrogation system for high resolution sensor application based on radio frequency (RF) generation technique by beating a single longitudinal mode (SLM) fiber ring laser with an external tunable laser source (TLS). The external TLS provides a constant wavelength (CW), functioning as the reference signal for the frequency beating technique. The TLS used has a constant output power and wavelength over time. The sensor signal is provided by the reflected wavelength of a typical fiber Bragg grating (FBG) in the SLM fiber ring laser, which consists of a 1 m long highly doped Erbium doped fiber as the gain medium. The key to ensure the SLM laser oscillation is the role of graphene as saturable absorber which is opposed to the commonly used unpumped erbiumdoped fiber and this consequently contributes to the simple and short cavity design of our proposed system. The signal from the SLM fiber ring laser, which is generated by the FBG in response to external changes, such as temperature, strain, air humidity and air movement, is heterodyned with the CW signal from the TLS at a 6 GHz photodetector using a 3-dB fused coupler to generate the frequency beating. This proposed system is experimentally demonstrated as a temperature sensor and the results shows that the frequency response of the system towards the changes in temperature is about 1.3 GHz/°C, taking into account the resolution bandwidth of 3 MHz of the radio frequency spectrum analyzer (RFSA).

  15. Rewiring Cells: Synthetic biology as a tool to interrogate the organizational principles of living systems

    PubMed Central

    Bashor, Caleb J.; Horwitz, Andrew A.; Peisajovich, Sergio G.; Lim, Wendell A.

    2010-01-01

    The living cell is an incredibly complex entity, and the goal of predictively and quantitatively understanding its function is one of the next great challenges in biology. Much of what we know about the cell concerns its constituent parts, but to a great extent, we have yet to decode how these parts are organized to yield complex physiological function. Classically, we have learned about the organization of cellular networks by perturbing them through genetic or chemical means. The emerging discipline of synthetic biology offers an additional, powerful way to study systems. By rearranging the parts that comprise existing networks, we can gain valuable insight into the hierarchical logic of the networks and identify the modular building blocks that evolution uses to generate innovative function. Additionally, by building minimal “toy” networks, one can systematically explore the relationship between network space (linkages and parameters) and functional space (the system's physiological behavior). Here, we outline recent work that uses synthetic biology approaches to investigate the organization and function of cellular networks, and describe a vision for a synthetic biology toolkit that could be used to interrogate the design principles of diverse systems. PMID:20192780

  16. Optimal sensor placement for active guided wave interrogation of complex metallic components

    NASA Astrophysics Data System (ADS)

    Coelho, Clyde K.; Kim, Seung Bum; Chattopadhyay, Aditi

    2011-04-01

    With research in structural health monitoring (SHM) moving towards increasingly complex structures for damage interrogation, the placement of sensors is becoming a key issue in the performance of the damage detection methodologies. For ultrasonic wave based approaches, this is especially important because of the sensitivity of the travelling Lamb waves to material properties, geometry and boundary conditions that may obscure the presence of damage if they are not taken into account during sensor placement. The framework proposed in this paper defines a sensing region for a pair of piezoelectric transducers in a pitch-catch damage detection approach by taking into account the material attenuation and probability of false alarm. Using information about the region interrogated by a sensoractuator pair, a simulated annealing optimization framework was implemented in order to place sensors on complex metallic geometries such that a selected minimum damage type and size could be detected with an acceptable probability of false alarm anywhere on the structure. This approach was demonstrated on a lug joint to detect a crack and on a large Naval SHM test bed and resulted in a placement of sensors that was able to interrogate all parts of the structure using the minimum number of transducers.

  17. FBG based high sensitive pressure sensor and its low-cost interrogation system with enhanced resolution

    NASA Astrophysics Data System (ADS)

    Pachava, Vengal Rao; Kamineni, Srimannarayana; Madhuvarasu, Sai Shankar; Putha, Kishore; Mamidi, Venkata Reddy

    2015-12-01

    A fiber Bragg grating (FBG) pressure sensor with high sensitivity and resolution has been designed and demonstrated. The sensor is configured by firmly fixing the FBG with a metal bellows structure. The sensor works by means of measuring the Bragg wavelength shift of the FBG with respect to pressure change. From the experimental results, the pressure sensitivity of the sensor is found to be 90.6 pm/psi, which is approximately 4000 times as that of a bare fiber Bragg grating. A very good linearity of 99.86% is observed between the Bragg wavelength of the FBG and applied pressure. The designed sensor shows good repeatability with a negligible hysteresis error of ± 0.29 psi. A low-cost interrogation system that includes a long period grating (LPG) and a photodiode (PD) accompanied with simple electronic circuitry is demonstrated for the FBG sensor, which enables the sensor to attain high resolution of up to 0.025 psi. Thermal-strain cross sensitivity of the FBG pressure sensor is compensated using a reference FBG temperature sensor. The designed sensor can be used for liquid level, specific gravity, and static/dynamic low pressure measurement applications.

  18. High Pressure Sensing and Dynamics Using High Speed Fiber Bragg Grating Interrogation Systems

    SciTech Connect

    Rodriguez, G.; Sandberg, R. L.; Lalone, B. M.; Marshall, B. R.; Grover, M.; Stevens, G. D.; Udd, E.

    2014-06-01

    Fiber Bragg gratings (FBGs) are developing into useful sensing tools for measuring high pressure dynamics in extreme environments under shock loading conditions. Approaches using traditional diode array coupled FBG interrogation systems are often limited to readout speeds in the sub-MHz range. For shock wave physics, required detection speeds approaching 100 MHz are desired. We explore the use of two types of FBG sensing systems that are aimed at applying this technology as embedded high pressure probes for transient shock events. Both approaches measure time resolved spectral shifts in the return light from short (few mm long) uniform FBGs at 1550 nm. In the first approach, we use a fiber coupled spectrometer to demultiplex spectral channels into an array (up to 12) of single element InGaAs photoreceivers. By monitoring the detectors during a shock impact event with high speed recording, we are able to track the pressure induced spectral shifting in FBG down to a time resolution of 20 ns. In the second approach, developed at the Special Technologies Lab, a coherent mode-locked fiber laser is used to illuminate the FBG sensor. After the sensor, wavelength-to-time mapping is accomplished with a chromatic dispersive element, and entire spectra are sampled using a single detector at the modelocked laser repetition rate of 50 MHz. By sampling with a 12 GHz InGaAs detector, direct wavelength mapping in time is recorded, and the pressure induced FBG spectral shift is sampled at 50 MHz. Here, the sensing systems are used to monitor the spectral shifts of FBGs that are immersed into liquid water and shock compressed using explosives. In this configuration, the gratings survive to pressures approaching 50 kbar. We describe both approaches and present the measured spectral shifts from the shock experiments.

  19. Analysis and performance evaluation of an all-fiber wide range interrogation system for a Bragg grating sensor array

    NASA Astrophysics Data System (ADS)

    Rajan, Ginu; Semenova, Yuliya; Farrell, Gerald

    2009-05-01

    Analysis and performance evaluation of a macro-bend fiber based interrogation system for a Bragg grating sensor array is presented. Due to the characteristic properties of the macro-bend fiber filter such as polarization and temperature dependence and the total noise associated with the ratiometric system, a best fit ratio slope is required to interrogate multiple fiber Bragg gratings (FBGs) whose peak wavelengths are spread over a wide wavelength range, rather than the optimal slope for individual FBGs. In this study, we have used an FBG array with 5 FBGs with peak reflected wavelengths lying between 1525 and 1575 nm. The analysis of the system is carried out and a fiber filter with a slope which covers a wavelength range of 1525-1575 nm is selected which ensures a resolution and accuracy for all the FBG sensors in the array as close as possible to that which would be achieved with a filter with an optimal slope for each FBG. Performance evaluation of the system is carried out and the static strain, dynamic strain, and temperature are measured with the developed interrogation system.

  20. Impact of electrolyte composition on the reactivity of a redox active polymer studied through surface interrogation and ion-sensitive scanning electrochemical microscopy.

    PubMed

    Burgess, Mark; Hernández-Burgos, Kenneth; Cheng, Kevin J; Moore, Jeffrey S; Rodríguez-López, Joaquín

    2016-06-21

    Elucidating the impact of interactions between the electrolyte and electroactive species in redox active polymers is key to designing better-performing electrodes for electrochemical energy storage and conversion. Here, we present on the improvement of the electrochemical activity of poly(para-nitrostyrene) (PNS) in solution and as a film by exploiting the ionic interactions between reduced PNS and K(+), which showed increased reactivity when compared to tetrabutylammonium (TBA(+))- and Li(+)-containing electrolytes. While cyclic voltammetry enabled the study of the effects of cations on the electrochemical reversibility and the reduction potential of PNS, scanning electrochemical microscopy (SECM) provided new tools to probe the ionic and redox reactivity of this system. Using an ion-sensitive Hg SECM tip allowed to probe the ingress of ions into PNS redox active films, while surface interrogation SECM (SI-SECM) measured the specific kinetics of PNS and a solution phase mediator in the presence of the tested electrolytes. SI-SECM measurements illustrated that the interrogation kinetics of PNS in the presence of K(+) compared to TBA(+) and Li(+) are greatly enhanced under the same surface concentration of adsorbed radical anion, exhibiting up to a 40-fold change in redox kinetics. We foresee using this new application of SECM methods for elucidating optimal interactions that enhance polymer reactivity for applications in redox flow batteries. PMID:27064026

  1. Datgan, a reusable software system for facile interrogation and visualization of complex transcription profiling data

    PubMed Central

    2011-01-01

    Background We introduce Glaucoma Discovery Platform (GDP), an online environment for facile visualization and interrogation of complex transcription profiling datasets for glaucoma. We also report the availability of Datgan, the suite of scripts that was developed to construct GDP. This reusable software system complements existing repositories such as NCBI GEO or EBI ArrayExpress as it allows the construction of searchable databases to maximize understanding of user-selected transcription profiling datasets. Description Datgan scripts were used to construct both the underlying data tables and the web interface that form GDP. GDP is populated using data from a mouse model of glaucoma. The data was generated using the DBA/2J strain, a widely used mouse model of glaucoma. The DBA/2J-Gpnmb+ strain provided a genetically matched control strain that does not develop glaucoma. We separately assessed both the retina and the optic nerve head, important tissues in glaucoma. We used hierarchical clustering to identify early molecular stages of glaucoma that could not be identified using morphological assessment of disease. GDP has two components. First, an interactive search and retrieve component provides the ability to assess gene(s) of interest in all identified stages of disease in both the retina and optic nerve head. The output is returned in graphical and tabular format with statistically significant differences highlighted for easy visual analysis. Second, a bulk download component allows lists of differentially expressed genes to be retrieved as a series of files compatible with Excel. To facilitate access to additional information available for genes of interest, GDP is linked to selected external resources including Mouse Genome Informatics and Online Medelian Inheritance in Man (OMIM). Conclusion Datgan-constructed databases allow user-friendly access to datasets that involve temporally ordered stages of disease or developmental stages. Datgan and GDP are

  2. Nimbus 4/IRLS Balloon Interrogation Package (BIP)

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The balloon interrogation package (BIP), an integral part of the overall interrogation, recording, and location subsystems (IRLS) for the Nimbus 4 program, is described. The BIP is a self-contained, integrated transponder designed to be carried aloft by a constant altitude, superpressure balloon to an altitude of 67,000 or 78,000 feet. After launch the BIP senses high-altitude balloon overpressure and temperature, and upon receipt of an interrogated command from the IRLS aboard the Nimbus 4 satellite, the BIP enodes the data on a real-time basis into a pulse-code modulation (PCM) format and transmits this data to the satellite. A summary of the program activity to produce 30 BIP systems and to support balloon launches from Ascension Island is presented.

  3. An ultra-stable referenced interrogation system in the deep ultraviolet for a mercury optical lattice clock

    NASA Astrophysics Data System (ADS)

    Dawkins, S. T.; Chicireanu, R.; Petersen, M.; Millo, J.; Magalhães, D. V.; Mandache, C.; Le Coq, Y.; Bize, S.

    2010-04-01

    We have developed an ultra-stable source in the deep ultraviolet, suitable to fulfil the interrogation requirements of a future fully-operational lattice clock based on neutral mercury. At the core of the system is a Fabry-Pérot cavity which is highly impervious to temperature and vibrational perturbations. The mirror substrate is made of fused silica in order to exploit the comparatively low thermal noise limits associated with this material. By stabilizing the frequency of a 1062.6 nm Yb-doped fiber laser to the cavity, and including an additional link to LNE-SYRTE’s fountain primary frequency standards via an optical frequency comb, we produce a signal which is both stable at the 10-15 level in fractional terms and referenced to primary frequency standards. The signal is subsequently amplified and frequency-doubled twice to produce several milliwatts of interrogation signal at 265.6 nm in the deep ultraviolet.

  4. Coherent pulse interrogation system for fiber Bragg grating sensing of strain and pressure in dynamic extremes of materials.

    PubMed

    Rodriguez, George; Jaime, Marcelo; Balakirev, Fedor; Mielke, Chuck H; Azad, Abul; Marshall, Bruce; La Lone, Brandon M; Henson, Bryan; Smilowitz, Laura

    2015-06-01

    A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain and pressure sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber is used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor are detected as a pulsed time domain waveform shift after encoding by the chromatic dispersive line. Signals are recorded using a single 35 GHz photodetector and a 50 G Samples per second, 25 GHz bandwidth, digitizing oscilloscope. Application of this approach to high-speed strain sensing in magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts are used to study magnetic field driven magnetostriction effects in LaCoO3. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ΔL/L<10-4) in the material. A second application used FBG sensing of pressure dynamics to nearly 2 GPa in the thermal ignition of the high explosive PBX-9501 is also demonstrated. Both applications demonstrate the use of this FBG interrogation system in dynamical extreme conditions that would otherwise not be possible using traditional FBG interrogation approaches that are deemed too slow to resolve such events. PMID:26072789

  5. Linear Accelerator-Based Active Interrogation For Detection of Highly Enriched Uranium

    SciTech Connect

    Moss, C.E.; Goulding, C.A.; Hollas, C.L.; Myers, W.L.

    2003-08-26

    Photofissions were induced in samples of highly enriched uranium (HEU) with masses up to 22 kg using bremsstrahlung photons from a pulsed 10-MeV electron linear accelerator (linac). Neutrons were detected between pulses by large 3He detectors, and the data were analyzed with the Feynman variance-to-mean method. The effects of shielding materials, such as lead and polyethylene, and the variation of the counting rate with distance for several configurations were measured. For comparison, a beryllium block was inserted in the beam to produce neutrons that were also used for interrogation. Because both high-energy photons and neutrons are very penetrating, both approaches can be used to detect shielded HEU; the choice of approach depends on the details of the configuration and the shielding.

  6. A wireless interrogation system exploiting narrowband acoustic resonator for remote physical quantity measurement

    NASA Astrophysics Data System (ADS)

    Friedt, J.-M.; Droit, C.; Martin, G.; Ballandras, S.

    2010-01-01

    Monitoring physical quantities using acoustic wave devices can be advantageously achieved using the wave characteristic dependence to various parametric perturbations (temperature, stress, and pressure). Surface acoustic wave (SAW) resonators are particularly well suited to such applications as their resonance frequency is directly influenced by these perturbations, modifying both the phase velocity and resonance conditions. Moreover, the intrinsic radio frequency (rf) nature of these devices makes them ideal for wireless applications, mainly exploiting antennas reciprocity and piezoelectric reversibility. In this paper, we present a wireless SAW sensor interrogation unit operating in the 434 MHz centered ISM band—selected as a tradeoff between antenna dimensions and electromagnetic wave penetration in dielectric media—based on the principles of a frequency sweep network analyzer. We particularly focus on the compliance with the ISM standard which reveals complicated by the need for switching from emission to reception modes similarly to radar operation. In this matter, we propose a fully digital rf synthesis chain to develop various interrogation strategies to overcome the corresponding difficulties and comply with the above-mentioned standard. We finally assess the reader interrogation range, accuracy, and dynamics.

  7. Measuring the performance of two stationary interrogation systems for detecting downstream and upstream movement of PIT-tagged salmonids

    USGS Publications Warehouse

    Connolly, P.J.; Jezorek, I.G.; Martens, K.D.; Prentice, E.F.

    2008-01-01

    We tested the performance of two stationary interrogation systems designed for detecting the movement of fish with passive integrated transponder (PIT) tags. These systems allowed us to determine the direction of fish movement with high detection efficiency and high precision in a dynamic stream environment. We describe an indirect method for deriving an estimate for detection efficiency and the associated variance that does not rely on a known number of fish passing the system. By using six antennas arranged in a longitudinal series of three arrays, we attained detection efficiencies for downstream- and upstream-moving fish exceeding 96% during high-flow periods and approached 100% during low-flow periods for the two interrogation systems we tested. Because these systems did not rely on structural components, such as bridges or culverts, they were readily adaptable to remote, natural stream sites. Because of built-in redundancy, these systems were able to perform even with a loss of one or more antennas owing to dislodgement or electrical failure. However, the reduction in redundancy resulted in decreased efficiency and precision and the potential loss of ability to determine the direction of fish movement. What we learned about these systems should be applicable to a wide variety of other antenna configurations and to other types of PIT tags and transceivers.

  8. Active interrogation of plasma-liquid boundary using 2D plasma-in-liquid apparatus

    NASA Astrophysics Data System (ADS)

    Lai, Janis; Foster, John

    2015-09-01

    Plasma medicine and plasma-based water purification technologies rely on the production and transport of plasma-derived (direct or indirect) reactive species into the bulk medium. This interaction takes place at the interface between the gas phase plasma and the liquid medium. The nature of radical production and subsequent radical transport from this region or boundary layer is not well understood due to the difficulty of implementing diagnostics to interrogate this region. We present a 2-D plasma-in-liquid water apparatus that makes the interface region assessable to optical diagnostics. Using colorimetric chemical probes, acidification and oxidation fronts are tracked using high-speed imaging and spectroscopy. Additionally, observed, plasma-induced fluid dynamical effects are also discussed. Forces at the interface can play a key role in the transport of radicals into the bulk solution. The role of plasma-driven interfacial forces as well as that of the applied, local electric field on chemical front propagation velocity and induced circulation are also discussed. Supported by grants NSF CBET 1336375 and DOE DE-SC0001939.

  9. SARConnect: A Tool to Interrogate the Connectivity Between Proteins, Chemical Structures and Activity Data

    PubMed Central

    Eriksson, Mats; Nilsson, Ingemar; Kogej, Thierry; Southan, Christopher; Johansson, Martin; Tyrchan, Christian; Muresan, Sorel; Blomberg, Niklas; Bjäreland, Marcus

    2012-01-01

    Abstract The access and use of large-scale structure-activity relationships (SAR) is increasing as the range of targets and availability of bioactive compound-to-protein mappings expands. However, effective exploitation requires merging and normalisation of activity data, mappings to target classifications as well as visual display of chemical structure relationships. This work describes the development of the application “SARConnect” to address these issues. We discuss options for delivery and analysis of large-scale SAR data together with a set of use-cases to illustrate the design choices and utility. The main activity sources of ChEMBL,1 GOSTAR2 and AstraZeneca’s internal system IBIS, had already been integrated in Chemistry Connect.3 For target relationships we selected human UniProtKB/Swiss-Prot4 as our primary source of a heuristic target classification. Similarly, to explore chemical relationships we combined several methods for framework and scaffold analysis into a unified, hierarchical classification where ease of navigation was the primary goal. An application was built on TIBCO Spotfire to retrieve data for visual display. Consequently, users can explore relationships between target, activity and structure across internal, external and commercial sources that encompass approximately 3 million compounds, 2000 human proteins and 10 million activity values. Examples showing the utility of the application are given. PMID:23308082

  10. Interrogating an insect society

    PubMed Central

    Gadagkar, Raghavendra

    2009-01-01

    Insect societies such as those of ants, bees, and wasps consist of 1 or a small number of fertile queens and a large number of sterile or nearly sterile workers. While the queens engage in laying eggs, workers perform all other tasks such as nest building, acquisition and processing of food, and brood care. How do such societies function in a coordinated and efficient manner? What are the rules that individuals follow? How are these rules made and enforced? These questions are of obvious interest to us as fellow social animals but how do we interrogate an insect society and seek answers to these questions? In this article I will describe my research that was designed to seek answers from an insect society to a series of questions of obvious interest to us. I have chosen the Indian paper wasp Ropalidia marginata for this purpose, a species that is abundantly distributed in peninsular India and serves as an excellent model system. An important feature of this species is that queens and workers are morphologically identical and physiologically nearly so. How then does an individual become a queen? How does the queen suppress worker reproduction? How does the queen regulate the nonreproductive activities of the workers? What is the function of aggression shown by different individuals? How and when is the queen's heir decided? I will show how such questions can indeed be investigated and will emphasize the need for a whole range of different techniques of observation and experimentation. PMID:19487678

  11. Aircraft interrogation and display system: A ground support equipment for digital flight systems

    NASA Technical Reports Server (NTRS)

    Glover, R. D.

    1982-01-01

    A microprocessor-based general purpose ground support equipment for electronic systems was developed. The hardware and software are designed to permit diverse applications in support of aircraft flight systems and simulation facilities. The implementation of the hardware, the structure of the software, describes the application of the system to an ongoing research aircraft project are described.

  12. Solving problems by interrogating sets of knowledge systems: Toward a theory of multiple knowledge systems

    NASA Technical Reports Server (NTRS)

    Dekorvin, Andre

    1989-01-01

    The main purpose is to develop a theory for multiple knowledge systems. A knowledge system could be a sensor or an expert system, but it must specialize in one feature. The problem is that we have an exhaustive list of possible answers to some query (such as what object is it). By collecting different feature values, in principle, it should be possible to give an answer to the query, or at least narrow down the list. Since a sensor, or for that matter an expert system, does not in most cases yield a precise value for the feature, uncertainty must be built into the model. Also, researchers must have a formal mechanism to be able to put the information together. Researchers chose to use the Dempster-Shafer approach to handle the problems mentioned above. Researchers introduce the concept of a state of recognition and point out that there is a relation between receiving updates and defining a set valued Markov Chain. Also, deciding what the value of the next set valued variable is can be phrased in terms of classical decision making theory such as minimizing the maximum regret. Other related problems are examined.

  13. Fast fiber Bragg grating interrogation system with scalability to support monitoring of large structures in harsh environments

    NASA Astrophysics Data System (ADS)

    Moslehi, Behzad; Black, Richard J.; Costa, Joannes M.; Edwards, Elizabeth H.; Faridian, Fereydoun; Sotoudeh, Vahid

    2014-04-01

    Fiber optic sensor systems can alleviate certain challenges faced by electronics sensors faced when monitoring structures subject to marine and other harsh environments. Challenges in implementation of such systems include scalability, interconnection and cabling. We describe a fiber Bragg grating (FBG) sensor system architecture based that is scalable to support over 1000 electromagnetic interference immune sensors at high sampling rates for harsh environment applications. A key enabler is a high performance FBG interrogator supporting subsection sampling rates ranging from kHz to MHz. Results are presented for fast dynamic switching between multiple structural sections and the use of this sensing system for dynamic load monitoring as well as the potential for acoustic emission and ultrasonic monitoring on materials ranging from aluminum and composites to concrete subject to severe environments.

  14. A flag-based algorithm and associated neutron interrogation system for the detection of explosives in sea-land cargo containers

    NASA Astrophysics Data System (ADS)

    Lehnert, A. L.; Kearfott, K. J.

    2015-07-01

    Recent efforts in the simulation of sea-land cargo containers in active neutron interrogation scenarios resulted in the identification of several flags indicating the presence of conventional explosives. These flags, defined by specific mathematical manipulations of the neutron and photon spectra, have been combined into a detection algorithm for screening cargo containers at international borders and seaports. The detection algorithm's steps include classifying the cargo type, identifying containers filled with explosives, triggering in the presence of concealed explosives, and minimizing the number of false positives due to cargo heterogeneity. The algorithm has been implemented in a system that includes both neutron and photon detectors. This system will take about 10 min to scan a container and cost approximately 1M to construct. Dose calculations resulted in estimates of less than 0.5 mSv for a person hidden in the container, and an operator annual dose of less than 0.9 mSv.

  15. Interrogating the activities of conformational deformed enzyme by single-molecule fluorescence-magnetic tweezers microscopy.

    PubMed

    Guo, Qing; He, Yufan; Lu, H Peter

    2015-11-10

    Characterizing the impact of fluctuating enzyme conformation on enzymatic activity is critical in understanding the structure-function relationship and enzymatic reaction dynamics. Different from studying enzyme conformations under a denaturing condition, it is highly informative to manipulate the conformation of an enzyme under an enzymatic reaction condition while monitoring the real-time enzymatic activity changes simultaneously. By perturbing conformation of horseradish peroxidase (HRP) molecules using our home-developed single-molecule total internal reflection magnetic tweezers, we successfully manipulated the enzymatic conformation and probed the enzymatic activity changes of HRP in a catalyzed H2O2-amplex red reaction. We also observed a significant tolerance of the enzyme activity to the enzyme conformational perturbation. Our results provide a further understanding of the relation between enzyme behavior and enzymatic conformational fluctuation, enzyme-substrate interactions, enzyme-substrate active complex formation, and protein folding-binding interactions. PMID:26512103

  16. Interrogating the activities of conformational deformed enzyme by single-molecule fluorescence-magnetic tweezers microscopy

    PubMed Central

    Guo, Qing; He, Yufan; Lu, H. Peter

    2015-01-01

    Characterizing the impact of fluctuating enzyme conformation on enzymatic activity is critical in understanding the structure–function relationship and enzymatic reaction dynamics. Different from studying enzyme conformations under a denaturing condition, it is highly informative to manipulate the conformation of an enzyme under an enzymatic reaction condition while monitoring the real-time enzymatic activity changes simultaneously. By perturbing conformation of horseradish peroxidase (HRP) molecules using our home-developed single-molecule total internal reflection magnetic tweezers, we successfully manipulated the enzymatic conformation and probed the enzymatic activity changes of HRP in a catalyzed H2O2–amplex red reaction. We also observed a significant tolerance of the enzyme activity to the enzyme conformational perturbation. Our results provide a further understanding of the relation between enzyme behavior and enzymatic conformational fluctuation, enzyme–substrate interactions, enzyme–substrate active complex formation, and protein folding–binding interactions. PMID:26512103

  17. Implementation of advanced matrix corrections for active interrogation of waste drums using the CTEN instrument

    SciTech Connect

    Melton, S.; Estep, R.; Hollas, C.

    1998-12-31

    The combined thermal/epithermal neutron instrument (CTEN) was designed at Los Alamos to improve measurement accuracy and mitigate self shielding effects inherent in the differential dieaway technique (DDT). A major goal in this research effort has been the development of a calibration technique that incorporates recently developed matrix and self-shielding corrections using data generated from additional detectors and new acquisition techniques. A comprehensive data set containing both active and passive measurements was generated using 26 different matrices and comprising a total of 1,400 measurements. In all, 31 flux-and-matrix-dependent parameters, 24 positional parameters, two dieaway times, and a correlated ratio were determined from each of the over 1,400 measurements. A reduced list of matrix indicators, prioritized using the alternating conditional expectation (ACE) algorithm, was used to train a neural network using a generalized regression technique (GRNN) to determine matrix- and position-corrected calibration factors. This paper describes the experimental, analytical, and empirical techniques used to determine the corrected calibration factor for an unknown waste drum. Results from a range of cases are compared with those obtained using a mobile DDT instrument and traditional DDT algorithms.

  18. A Systems-Level Interrogation Identifies Regulators of Drosophila Blood Cell Number and Survival

    PubMed Central

    Makhijani, Kalpana; Alexander, Brandy; Perrimon, Norbert; Brückner, Katja

    2015-01-01

    In multicellular organisms, cell number is typically determined by a balance of intracellular signals that positively and negatively regulate cell survival and proliferation. Dissecting these signaling networks facilitates the understanding of normal development and tumorigenesis. Here, we study signaling by the Drosophila PDGF/VEGF Receptor (Pvr) in embryonic blood cells (hemocytes) and in the related cell line Kc as a model for the requirement of PDGF/VEGF receptors in vertebrate cell survival and proliferation. The system allows the investigation of downstream and parallel signaling networks, based on the ability of Pvr to activate Ras/Erk, Akt/TOR, and yet-uncharacterized signaling pathway/s, which redundantly mediate cell survival and contribute to proliferation. Using Kc cells, we performed a genome wide RNAi screen for regulators of cell number in a sensitized, Pvr deficient background. We identified the receptor tyrosine kinase (RTK) Insulin-like receptor (InR) as a major Pvr Enhancer, and the nuclear hormone receptors Ecdysone receptor (EcR) and ultraspiracle (usp), corresponding to mammalian Retinoid X Receptor (RXR), as Pvr Suppressors. In vivo analysis in the Drosophila embryo revealed a previously unrecognized role for EcR to promote apoptotic death of embryonic blood cells, which is balanced with pro-survival signaling by Pvr and InR. Phosphoproteomic analysis demonstrates distinct modes of cell number regulation by EcR and RTK signaling. We define common phosphorylation targets of Pvr and InR that include regulators of cell survival, and unique targets responsible for specialized receptor functions. Interestingly, our analysis reveals that the selection of phosphorylation targets by signaling receptors shows qualitative changes depending on the signaling status of the cell, which may have wide-reaching implications for other cell regulatory systems. PMID:25749252

  19. The development of multi incident angles and multi points measurement phase image interrogation surface plasmon resonance system

    NASA Astrophysics Data System (ADS)

    Liao, Jyun; Lee, Shu-Sheng; Lin, Shih-Yuan

    2015-05-01

    Surface plasmon resonance (SPR) is one of the recent applied technologies in bio-medical detection, and it is gradually accepted by the researchers. However, it is still not adopted widely and needs more efforts to improve. In our research work, a previous developed phase interrogation SPR detection system is modified and the concept of multi-incident angles of detecting light is used for obtaining more data. Besides, using the focusing characteristic of a cylindrical elliptic reflective mirror to have more than one measuring areas, and this can provide a control reaction accompanied with the experimental reaction on the chip at the same time. The phase variation of the sample variation with different detecting incident angle can provide more data and can reduce the errors, increase the resolution, and raise the detection ability. To acquire the inference fringes images of the phase, the time-stepped quadrature phase shifting method has been introduced, which required fewer images to retrieve the phase than the five-stepped phase shifting method. The data processing time can be reduced and our system would have the potential to measure the reaction in real-time. Finally, sodium chloride-water solution and Ethanol-water solution in different concentration has been measured to verify our system is workable.

  20. Experimental Validation of an Optical System for Interrogation of Dermally-Implanted Microparticle Sensors

    PubMed Central

    Long, Ruiqi; McShane, Mike

    2013-01-01

    Dermally-implanted microparticle sensors are being developed for on-demand monitoring of blood sugar levels. For these to be deployed in vivo, a matched opto-electronic system for delivery of excitation, collection and analysis of escaping fluorescent signal is needed. Previous studies predicted the characteristics of fluorescence from microparticle sensors to facilitate design of hardware system. Based on the results of simulations, we designed and constructed the optical part of this opto-electronic system. This study experimentally verified the simulation results and tested the capability of the designed optical system. Reliable skin phantoms sufficient for future dynamic tests were developed. Skin phantoms with different thicknesses were made and the optical properties of skin phantoms were determined with an integrating sphere system and Inverse Adding-Doubling method. Measurements of sensor emission spectrum through phantoms with different thicknesses were done with the designed optical system. Simulations for the experiment situation were performed. The experimental measurements agreed well with simulations in most cases. The results of hardware experiment and validation with skin phantoms provided us with critical information for future dynamic tests and animal experiments. PMID:19964925

  1. Classifying threats with a 14-MeV neutron interrogation system.

    PubMed

    Strellis, Dan; Gozani, Tsahi

    2005-01-01

    SeaPODDS (Sea Portable Drug Detection System) is a non-intrusive tool for detecting concealed threats in hidden compartments of maritime vessels. This system consists of an electronic neutron generator, a gamma-ray detector, a data acquisition computer, and a laptop computer user-interface. Although initially developed to detect narcotics, recent algorithm developments have shown that the system is capable of correctly classifying a threat into one of four distinct categories: narcotic, explosive, chemical weapon, or radiological dispersion device (RDD). Detection of narcotics, explosives, and chemical weapons is based on gamma-ray signatures unique to the chemical elements. Elements are identified by their characteristic prompt gamma-rays induced by fast and thermal neutrons. Detection of RDD is accomplished by detecting gamma-rays emitted by common radioisotopes and nuclear reactor fission products. The algorithm phenomenology for classifying threats into the proper categories is presented here. PMID:15985373

  2. Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

    DOEpatents

    Slaughter, Dennis R.; Pohl, Bertram A.; Dougan, Arden D.; Bernstein, Adam; Prussin, Stanley G.; Norman, Eric B.

    2008-04-15

    A system for inspecting cargo for the presence of special nuclear material. The cargo is irradiated with neutrons. The neutrons produce fission products in the special nuclear material which generate gamma rays. The gamma rays are detecting indicating the presence of the special nuclear material.

  3. High-resolution all-optical photoacoustic imaging system for remote interrogation of biological specimens

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin

    2014-05-01

    Conventional photoacoustic imaging (PAI) employs light pulses to produce a photoacoustic (PA) effect and detects the resulting acoustic waves using an ultrasound transducer acoustically coupled to the target tissue. The resolution of conventional PAI is limited by the sensitivity and bandwidth of the ultrasound transducer. We have developed an all-optical versatile PAI system for characterizing ex vivo and in vivo biological specimens. The system employs noncontact interferometric detection of the acoustic signals that overcomes limitations of conventional PAI. A 532-nm pump laser with a pulse duration of 5 ns excited the PA effect in tissue. Resulting acoustic waves produced surface displacements that were sensed using a 532-nm continuous-wave (CW) probe laser in a Michelson interferometer with a GHz bandwidth. The pump and probe beams were coaxially focused using a 50X objective giving a diffraction-limited spot size of 0.48 μm. The phase-encoded probe beam was demodulated using a homodyne interferometer. The detected time-domain signal was time reversed using k-space wave-propagation methods to produce a spatial distribution of PA sources in the target tissue. Performance was assessed using PA images of ex vivo rabbit lymph node specimens and human tooth samples. A minimum peak surface displacement sensitivity of 0.19 pm was measured. The all-optical PAI (AOPAI) system is well suited for assessment of retinal diseases, caries lesion detection, skin burns, section less histology and pressure or friction ulcers.

  4. R-MASTIF: robotic mobile autonomous system for threat interrogation and object fetch

    NASA Astrophysics Data System (ADS)

    Das, Aveek; Thakur, Dinesh; Keller, James; Kuthirummal, Sujit; Kira, Zsolt; Pivtoraiko, Mihail

    2013-01-01

    Autonomous robotic "fetch" operation, where a robot is shown a novel object and then asked to locate it in the field, re- trieve it and bring it back to the human operator, is a challenging problem that is of interest to the military. The CANINE competition presented a forum for several research teams to tackle this challenge using state of the art in robotics technol- ogy. The SRI-UPenn team fielded a modified Segway RMP 200 robot with multiple cameras and lidars. We implemented a unique computer vision based approach for textureless colored object training and detection to robustly locate previ- ously unseen objects out to 15 meters on moderately flat terrain. We integrated SRI's state of the art Visual Odometry for GPS-denied localization on our robot platform. We also designed a unique scooping mechanism which allowed retrieval of up to basketball sized objects with a reciprocating four-bar linkage mechanism. Further, all software, including a novel target localization and exploration algorithm was developed using ROS (Robot Operating System) which is open source and well adopted by the robotics community. We present a description of the system, our key technical contributions and experimental results.

  5. Monolithic integrated optic fiber Bragg grating sensor interrogator

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian

    2010-04-01

    Fiber Bragg gratings (FBGs) are a mature sensing technology that has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. Fiber Bragg grating sensors can be use for a variety of measurements including strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky, heavy, and costly bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-TransceiverTM) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables the monolithic integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation.

  6. Small-diameter optical fiber and high-speed wavelength interrogator for FBG/PZT hybrid sensing system

    NASA Astrophysics Data System (ADS)

    Komatsuzaki, Shinji; Kojima, Seiji; Hongo, Akihito; Takeda, Nobuo; Sakurai, Takeo

    2007-04-01

    We have been developing a sensing system for checking the health of aircraft structures made of composite materials. In this system, lead zirconium titanate (PZT) actuators generate elastic waves that travel through the composite material and are received by embedded fiber Bragg grating (FBG) sensors. By analyzing the change in received waveforms, we can detect various kinds of damage. The frequency of the elastic waves is several hundred kHz, which is too high for a conventional optical spectrum analyzer to detect the wavelength change. Moreover, a conventional single-mode optical fiber cannot be used for an embedded FBG sensor because it is so thick that it induces defects in the composite material structure when it is embedded. We are thus developing a wavelength interrogator with an arrayed waveguide grating (AWG) that can detect the high-speed wavelength change and a small-diameter optical fiber (cladding diameter of 40µm) that does not induce defects. We use an AWG to convert the wavelength change into an output power change by using the wavelength dependency of the AWG transmittance. For this conversion, we previously used two adjacent output ports that cover the reflection spectrum of an FBG sensor. However, this requires controlling the temperature of the AWG because the ratio of the optical power change to the wavelength change is very sensitive to the relationship of the center wavelengths between an FBG sensor and the output ports of the AWG. We have now investigated the use of a denser AWG and six adjacent output ports, which covers the reflection spectrum of an FBG sensor, for detecting the elastic waves. Experimental results showed that this method can suppress the sensitivity of the power change ratio to the relationship of the center wavelengths between an FBG sensor and the output ports. Although our improved small-diameter optical fiber does not induce structural defects in the composite material when it is embedded, there is some micro or macro

  7. Modeling and Interrogative Strategies.

    ERIC Educational Resources Information Center

    Denney, Douglas R.

    Three studies to determine the effects of adult models on interrogative strategies of children (ages 6-11) are reviewed. Two issues are analyzed: (1) the comparative effectiveness of various types of modeling procedures for changing rule-governed behaviors, and (2) the interaction between observational learning and the developmental level of the…

  8. Evaluation of Fish Movements, Migration Patterns, and Population Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

    SciTech Connect

    Zydlewski, Gayle; Winter, Christiane; McClanahan, Dee

    2003-02-01

    Two remote Streamwidth PIT tag Interrogation systems (SPIs) were operated continuously for over one year to test the feasibility of these systems for generating movement, migration, survival and smolt production estimates for salmonids. A total of 1,588 juvenile (< 100 mm FL) naturally produced salmonids (7 coho salmon, 482 cutthroat trout, and 1,099 steelhead) were PIT tagged above the upstream-most SPI (9 sites approximately 1 linear km each) in Fall 2001. Age at tagging for wild caught cutthroat and steelhead was 1 year. SPIs were operating before any PIT tagged fish were released in the creek. Over 390,000 detections were recorded from October 2001 to 31 July 2002. Efficiencies were site dependent, but overall detection efficiency for the creek was 97% with 95% confidence intervals of 91-100%. PIT tag detection efficiency ranged from 55-100% depending on the SPI and varied throughout the year with average efficiencies of 73% and 89%. SPI efficiency of PIT tag detection was not completely dependent on electronics noise levels or environmental conditions. Fish from all tagging locations were detected at the SPIs. Steelhead and cutthroat trout were primarily detected moving in the Spring (April-June) coincident with the anticipated smolt migration. Steelhead were also detected moving past SPIs at lower numbers in the Fall and Winter. Travel time between SPIs (downstream movement) was highly dependent on time of year. Travel time in the Spring was significantly faster (34.4 {+-} 7.0 hours) for all species than during any other time of year (763.1 {+-} 267.0 hours). Steelhead and cutthroat migrating in the Spring were the same age as those that did not migrate in the Spring. Peak of steelhead migration recorded at the two SPIs was 5/11 and 5/12 and the peak in the screw trap was recorded on 5/17. Steelhead smolt production estimates using SPIs (3,802 with 95% confidence intervals of 3,440 - 4,245) was similar to those using more standard screw trap methods

  9. Evaluation of Fish Movements, Migration Patterns and Populations Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

    SciTech Connect

    Zydlewski, Gayle B.; Casey, Sean

    2003-02-01

    Two remote Streamwidth PIT tag Interrogation systems (SPIs) were operated continuously for over one year to test the feasibility of these systems for generating movement, migration, survival and smolt production estimates for salmonids. A total of 1,588 juvenile (< 100 mm FL) naturally produced salmonids (7 coho salmon, 482 cutthroat trout, and 1,099 steelhead) were PIT tagged above the upstream-most SPI (9 sites approximately 1 linear km each) in Fall 2001. Age at tagging for wild caught cutthroat and steelhead was 1 year. SPIs were operating before any PIT tagged fish were released in the creek. Over 390,000 detections were recorded from October 2001 to 31 July 2002. Efficiencies were site dependent, but overall detection efficiency for the creek was 97% with 95% confidence intervals of 91-100%. PIT tag detection efficiency ranged from 55-100% depending on the SPI and varied throughout the year with average efficiencies of 73% and 89%. SPI efficiency of PIT tag detection was not completely dependent on electronics noise levels or environmental conditions. Fish from all tagging locations were detected at the SPIs. Steelhead and cutthroat trout were primarily detected moving in the Spring (April-June) coincident with the anticipated smolt migration. Steelhead were also detected moving past SPIs at lower numbers in the Fall and Winter. Travel time between SPIs (downstream movement) was highly dependent on time of year. Travel time in the Spring was significantly faster (34.4 {+-} 7.0 hours) for all species than during any other time of year (763.1 {+-} 267.0 hours). Steelhead and cutthroat migrating in the Spring were the same age as those that did not migrate in the Spring. Peak of steelhead migration recorded at the two SPIs was 5/11 and 5/12 and the peak in the screw trap was recorded on 5/17. Steelhead smolt production estimates using SPIs (3,802 with 95% confidence intervals of 3,440-4,245) was similar to those using more standard screw trap methods

  10. Proof-of-Concept Assessment of a Photofission-Based Interrogation System for the Detection of Shielded Nuclear Material

    SciTech Connect

    Jones, J. L.; Yoon, W. Y.; Harker, Y. D.; Hoggan, J. M.; Haskell, K. J.; VanAusdeln, L. A.

    2000-11-01

    A photonuclear interrogation method was experimentally assessed for the detection of shielded nuclear materials. Proof-of-Concept assessment was performed at the Los Alamos National Laboratory (LANL) TA-18 facility and used the INEEL VARITRON electron accelerator. Experiments were performed to assess and characterize the delayed neutron emission responses for different nuclear materials with various shield configurations using three ''nominal'' electron beam energies; 8-, 10-, and 11-MeV. With the exception of highly enriched uranium (HEU), the nuclear materials assessed represent material types commonly encountered in commerce. The specific nuclear materials studied include a solid 4.8-kg HEU sphere, a 5-kg multiple-object, depleted uranium (DU) [uranium with about 0.2% enrichment with U-235] target, and two 11-kg thorium disks. The shield materials selected include polyethylene, borated-polyethylene, and lead. Experimental results, supported with numerical predictions, have shown that the photonuclear interrogation technique is quite capable of detecting shielded nuclear material via the direct measurement of the photofission-induced delayed neutron emissions. To identify or discriminate between nuclear material types (i.e., depleted uranium, HEU, and thorium), a ratio of delayed neutron counts at two different beam energies is utilized. This latter method, referred to as the dual-beam energy ratio Figure-of-Merit, allows one to differentiate among the three nuclear material types.

  11. Monte Carlo Simulation for LINAC Standoff Interrogation of Nuclear Material

    SciTech Connect

    Clarke, Shaun D; Flaska, Marek; Miller, Thomas Martin; Protopopescu, Vladimir A; Pozzi, Sara A

    2007-06-01

    The development of new techniques for the interrogation of shielded nuclear materials relies on the use of Monte Carlo codes to accurately simulate the entire system, including the interrogation source, the fissile target and the detection environment. The objective of this modeling effort is to develop analysis tools and methods-based on a relevant scenario-which may be applied to the design of future systems for active interrogation at a standoff. For the specific scenario considered here, the analysis will focus on providing the information needed to determine the type and optimum position of the detectors. This report describes the results of simulations for a detection system employing gamma rays to interrogate fissile and nonfissile targets. The simulations were performed using specialized versions of the codes MCNPX and MCNP-PoliMi. Both prompt neutron and gamma ray and delayed neutron fluxes have been mapped in three dimensions. The time dependence of the prompt neutrons in the system has also been characterized For this particular scenario, the flux maps generated with the Monte Carlo model indicate that the detectors should be placed approximately 50 cm behind the exit of the accelerator, 40 cm away from the vehicle, and 150 cm above the ground. This position minimizes the number of neutrons coming from the accelerator structure and also receives the maximum flux of prompt neutrons coming from the source. The lead shielding around the accelerator minimizes the gamma-ray background from the accelerator in this area. The number of delayed neutrons emitted from the target is approximately seven orders of magnitude less than the prompt neutrons emitted from the system. Therefore, in order to possibly detect the delayed neutrons, the detectors should be active only after all prompt neutrons have scattered out of the system. Preliminary results have shown this time to be greater than 5 ?s after the accelerator pulse. This type of system is illustrative of a

  12. Uniform spacing interrogation of a Fourier domain mode-locked fiber Bragg grating sensor system using a polarization-maintaining fiber Sagnac interferometer

    NASA Astrophysics Data System (ADS)

    Lee, Hwi Don; Jung, Eun Joo; Jeong, Myung Yung; Chen, Zhongping; Kim, Chang-Seok

    2013-06-01

    A novel linearized interrogation method is presented for a Fourier domain mode-locked (FDML) fiber Bragg grating (FBG) sensor system. In a high speed regime over several tens of kHz modulations, a sinusoidal wave is available to scan the center wavelength of an FDML wavelength-swept laser, instead of a conventional triangular wave. However, sinusoidal wave modulation suffers from an exaggerated non-uniform wavelength-spacing response in demodulating the time-encoded parameter to the absolute wavelength. In this work, the calibration signal from a polarization-maintaining fiber Sagnac interferometer shares the FDML wavelength-swept laser for FBG sensors to convert the time-encoded FBG signal to the wavelength-encoded uniform-spacing signal.

  13. Uniform spacing interrogation of a Fourier domain mode-locked fiber Bragg grating sensor system using a polarization-maintaining fiber Sagnac interferometer

    PubMed Central

    Lee, Hwi Don; Jung, Eun Joo; Jeong, Myung Yung; Chen, Zhongping; Kim, Chang-Seok

    2014-01-01

    A novel linearized interrogation method is presented for a Fourier domain mode-locked (FDML) fiber Bragg grating (FBG) sensor system. In a high speed regime over several tens of kHz modulations, a sinusoidal wave is available to scan the center wavelength of an FDML wavelength-swept laser, instead of a conventional triangular wave. However, sinusoidal wave modulation suffers from an exaggerated non-uniform wavelength-spacing response in demodulating the time-encoded parameter to the absolute wavelength. In this work, the calibration signal from a polarization-maintaining fiber Sagnac interferometer shares the FDML wavelength-swept laser for FBG sensors to convert the time-encoded FBG signal to the wavelength-encoded uniform-spacing signal. PMID:24489440

  14. The dynamic nature of interrogation.

    PubMed

    Kelly, Christopher E; Miller, Jeaneé C; Redlich, Allison D

    2016-06-01

    Building on a substantial body of literature examining interrogation methods employed by police investigators and their relationship to suspect behaviors, we analyzed a sample of audio and video interrogation recordings of individuals suspected of serious violent crimes. Existing survey research has focused on the tactics reportedly used, at what rate, and under what conditions; observational studies detail which methods are actually employed. With a few notable exceptions, these foundational studies were static examinations of interrogation methods that documented the absence or presence of various approaches. In the present study, we cast interrogation as a dynamic phenomenon and code the recordings in 5-min intervals to examine how interrogation methods and suspect cooperation change over time. Employing the interrogation taxonomy framework, particularly 4 discrete domains-rapport and relationship building, emotion provocation, presentation of evidence, and confrontation/competition-we found that the emphasis of the domains varied across interrogations and were significantly different when suspects confessed versus when they denied involvement. In regression models, suspect cooperation was positively influenced by the rapport and relationship building domain, though it was negatively impacted by presentation of evidence and confrontation/competition. Moreover, we found that the negative effects of confrontation/competition on suspect cooperation lasted for up to 15 min. The implications of the findings for practice and future research include the benefits of a rapport-based approach, the deleterious effects of accusatorial methods, and the importance of studying when, not just if, certain interrogation techniques are employed. (PsycINFO Database Record PMID:26651622

  15. Interrogation of Global Active Site Occupancy of a Fungal Iterative Polyketide Synthase Reveals Strategies for Maintaining Biosynthetic Fidelity

    PubMed Central

    Vagstad, Anna L.; Bumpus, Stefanie B.; Belecki, Katherine; Kelleher, Neil L.; Townsend, Craig A.

    2012-01-01

    Nonreducing iterative polyketide synthases (NR-PKSs) are responsible for assembling the core of fungal aromatic natural products with diverse biological properties. Despite recent advances in the field, many mechanistic details of polyketide assembly by these megasynthases remain unknown. To expand our understanding of substrate loading, polyketide elongation, cyclization, and product release, active site occupancy and product output were explored by Fourier transform mass spectrometry using the norsolorinic acid anthrone-producing polyketide synthase, PksA, from the aflatoxin biosynthetic pathway in Aspergillus parasiticus. Here we report the simultaneous observation of covalent intermediates from all catalytic domains of PksA from in vitro reconstitution reactions. The data provide snapshots of iterative catalysis and reveal an underappreciated editing function for the C-terminal thioesterase domain beyond its recently established synthetic role in Claisen/Dieckmann cyclization and product release. The specificity of thioesterase catalyzed hydrolysis was explored using biosynthetically relevant protein-bound and small molecule acyl substrates, and demonstrated activity against hexanoyl and acetyl, but not malonyl. Processivity of polyketide extension was supported by the inability of a nonhydrolyzable malonyl analog to trap products of intermediate chain lengths and by the detection of only fully extended species observed covalently bound to, and as the predominant products released by, PksA. High occupancy of the malonyl transacylase domain and fast relative rate of malonyl transfer compared to starter unit transfer indicate that rapid loading of extension units onto the carrier domain facilitates efficient chain extension in a manner kinetically favorable to ultimate product formation. PMID:22452347

  16. Integrated nanoscale tools for interrogating living cells

    NASA Astrophysics Data System (ADS)

    Jorgolli, Marsela

    The development of next-generation, nanoscale technologies that interface biological systems will pave the way towards new understanding of such complex systems. Nanowires -- one-dimensional nanoscale structures -- have shown unique potential as an ideal physical interface to biological systems. Herein, we focus on the development of nanowire-based devices that can enable a wide variety of biological studies. First, we built upon standard nanofabrication techniques to optimize nanowire devices, resulting in perfectly ordered arrays of both opaque (Silicon) and transparent (Silicon dioxide) nanowires with user defined structural profile, densities, and overall patterns, as well as high sample consistency and large scale production. The high-precision and well-controlled fabrication method in conjunction with additional technologies laid the foundation for the generation of highly specialized platforms for imaging, electrochemical interrogation, and molecular biology. Next, we utilized nanowires as the fundamental structure in the development of integrated nanoelectronic platforms to directly interrogate the electrical activity of biological systems. Initially, we generated a scalable intracellular electrode platform based on vertical nanowires that allows for parallel electrical interfacing to multiple mammalian neurons. Our prototype device consisted of 16 individually addressable stimulation/recording sites, each containing an array of 9 electrically active silicon nanowires. We showed that these vertical nanowire electrode arrays could intracellularly record and stimulate neuronal activity in dissociated cultures of rat cortical neurons similar to patch clamp electrodes. In addition, we used our intracellular electrode platform to measure multiple individual synaptic connections, which enables the reconstruction of the functional connectivity maps of neuronal circuits. In order to expand and improve the capability of this functional prototype device we designed

  17. Interrogating personhood and dementia

    PubMed Central

    Higgs, Paul; Gilleard, Chris

    2016-01-01

    ABSTRACT Objectives: To interrogate the concept of personhood and its application to care practices for people with dementia. Method: We outline the work of Tom Kitwood on personhood and relate this to conceptualisations of personhood in metaphysics and in moral philosophy. Results: The philosophical concept of personhood has a long history. The metaphysical tradition examines the necessary and sufficient qualities that make up personhood such as agency, consciousness, identity, rationality and second-order reflexivity. Alternative viewpoints treat personhood as a matter of degree rather than as a superordinate category. Within moral philosophy personhood is treated as a moral status applicable to some or to all human beings. Conclusion: In the light of the multiple meanings attached to the term in both metaphysics and moral philosophy, personhood is a relatively unhelpful concept to act as the foundation for developing models and standards of care for people with dementia. Care, we suggest, should concentrate less on ambiguous and somewhat abstract terms such as personhood and focus instead on supporting people's existing capabilities, while minimising the harmful consequences of their incapacities. PMID:26708149

  18. Gamma source for active interrogation

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2009-09-29

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  19. Gamma source for active interrogation

    SciTech Connect

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  20. DIGGING DEEPER INTO DEEP DATA: MOLECULAR DOCKING AS A HYPOTHESIS-DRIVEN BIOPHYSICAL INTERROGATION SYSTEM IN COMPUTATIONAL TOXICOLOGY.

    EPA Science Inventory

    Developing and evaluating prediactive strategies to elucidate the mode of biological activity of environmental chemicals is a major objective of the concerted efforts of the US-EPA's computational toxicology program.

  1. Determination of the plutonium content in a spent fuel assembly by passive and active interrogation using a differential die-away instrument

    NASA Astrophysics Data System (ADS)

    Henzl, V.; Croft, S.; Richard, J.; Swinhoe, M. T.; Tobin, S. J.

    2013-06-01

    In this paper, we present a novel approach to estimating the total plutonium content in a spent fuel assembly (SFA) that is based on combining information from a passive measurement of the total neutron count rate (PN) of the assayed SFA and a measure of its multiplication. While PN can be measured essentially with any non-destructive assay (NDA) technique capable of neutron detection, the measure of multiplication is, in our approach, determined by means of active interrogation using an instrument based on the Differential Die-Away technique (DDA). The DDA is a NDA technique developed within the U.S. Department of Energy's Next Generation Safeguards Initiative (NGSI) project focused on the utilization of NDA techniques to determine the elemental plutonium content in commercial nuclear SFA's [1]. This approach was adopted since DDA also allows determination of other SFA characteristics, such as burnup, initial enrichment, and cooling time, and also allows for detection of certain types of diversion of nuclear material. The quantification of total plutonium is obtained using an analytical correlation function in terms of the observed PN and active multiplication. Although somewhat similar approaches relating Pu content with PN have been adopted in the past, we demonstrate by extensive simulation of the fuel irradiation and NDA process that our analytical method is independent of explicit knowledge of the initial enrichment, burnup, and an absolute value of the SFA's reactivity (i.e. multiplication factor). We show that when tested with MCNPX™ simulations comprising the 64 SFA NGSI Spent Fuel Library-1 we were able to determine elemental plutonium content, using just a few calibration parameters, with an average variation in the prediction of around 1-2% across the wide dynamic range of irradiation history parameters used, namely initial enrichment (IE=2-5%), burnup (BU=15-60 GWd/tU) and cooling time (CT=1-80 y). In this paper we describe the basic approach and the

  2. Systems report on the analysis of spent, highly enriched U-235 reactor fuel by delayed neutron interrogation

    SciTech Connect

    Piper, T.C.; Kirkham, R.J.

    1990-05-01

    Design aspects are briefly given of a neutron source shuffler used to measure fissile material content of spent, highly enriched reactor fuel. The mode of operation used, results of analyzing 176 fuel packages and recommended system improvements are discussed. Four measurements were made on each of the fuel packages with the mean of the 176 standard deviations being 2.03 percent of value. The maximum individual standard deviation was 9.27 percent. Appendixes concerning imprecisions introduced by counting statistics and crane speed irregularities are given. Use of an improved neutron source shuffler, an improved fuel package motion system and modernized computer system should permit system performance to be limited mainly by counting statistics, to about 1.5 percent of measured value. A stronger source could then be installed to further enhance system operation. 16 figs., 3 tabs.

  3. Multi-channel monolithic integrated optic fiber Bragg grating sensor interrogator

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Zongjian

    2011-09-01

    Fiber Bragg grating (FBG) is a mature sensing technology for the measurement of strain, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion. It has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. The most prominent advantages of FBG are: small size and light weight, distributed array of FBG transducers on a single fiber, and immunity to radio frequency interference. However, a major disadvantage of FBG technology is that conventional state-of-the-art FBG interrogation system is typically bulky, heavy, and costly bench top instruments that are typically assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the industrial need for a compact FBG interrogation system, this paper describes recent progress towards the development of miniature fiber Bragg grating sensor interrogator (FBG-Transceiver™) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables monolithic integration of all functionalities, both passive and active, of conventional bench top FBG sensor interrogator system, packaged in a miniaturized, low power operation, 2 cm×5 cm small form factor (SFF) package suitable for long-term structural health monitoring in applications where size, weight, and power are critical for operation.

  4. Programmable DNA Nanosystem for Molecular Interrogation

    PubMed Central

    Mathur, Divita; Henderson, Eric R.

    2016-01-01

    We describe a self-assembling DNA-based nanosystem for interrogating molecular interactions. The nanosystem contains a rigid supporting dumbbell-shaped frame, a cylindrical central core, and a mobile ring that is coaxial with the core. Motion of the ring is influenced by several control elements whose force-generating capability is based on the transition of single-stranded DNA to double-stranded DNA. These forces can be directed to act in opposition to adhesive forces between the ring and the frame thereby providing a mechanism for molecular detection and interrogation at the ring-frame interface. As proof of principle we use this system to evaluate base stacking adhesion and demonstrate detection of a soluble nucleic acid viral genome mimic. PMID:27270162

  5. Programmable DNA Nanosystem for Molecular Interrogation

    NASA Astrophysics Data System (ADS)

    Mathur, Divita; Henderson, Eric R.

    2016-06-01

    We describe a self-assembling DNA-based nanosystem for interrogating molecular interactions. The nanosystem contains a rigid supporting dumbbell-shaped frame, a cylindrical central core, and a mobile ring that is coaxial with the core. Motion of the ring is influenced by several control elements whose force-generating capability is based on the transition of single-stranded DNA to double-stranded DNA. These forces can be directed to act in opposition to adhesive forces between the ring and the frame thereby providing a mechanism for molecular detection and interrogation at the ring-frame interface. As proof of principle we use this system to evaluate base stacking adhesion and demonstrate detection of a soluble nucleic acid viral genome mimic.

  6. Software Development to Assist in the Processing and Analysis of Data Obtained Using Fiber Bragg Grating Interrogation Systems

    NASA Technical Reports Server (NTRS)

    Hicks, Rebecca

    2010-01-01

    A fiber Bragg grating is a portion of a core of a fiber optic stand that has been treated to affect the way light travels through the strand. Light within a certain narrow range of wavelengths will be reflected along the fiber by the grating, while light outside that range will pass through the grating mostly undisturbed. Since the range of wavelengths that can penetrate the grating depends on the grating itself as well as temperature and mechanical strain, fiber Bragg gratings can be used as temperature and strain sensors. This capability, along with the light-weight nature of the fiber optic strands in which the gratings reside, make fiber optic sensors an ideal candidate for flight testing and monitoring in which temperature and wing strain are factors. A team of NASA Dryden engineers has been working to advance the fiber optic sensor technology since the mid 1990 s. The team has been able to improve the dependability and sample rate of fiber optic sensor systems, making them more suitable for real-time wing shape and strain monitoring and capable of rivaling traditional strain gauge sensors in accuracy. The sensor system was recently tested on the Ikhana unmanned aircraft and will be used on the Global Observer unmanned aircraft. Since a fiber Bragg grating sensor can be placed every halfinch on each optic fiber, and since fibers of approximately 40 feet in length each are to be used on the Global Observer, each of these fibers will have approximately 1,000 sensors. A total of 32 fibers are to be placed on the Global Observer aircraft, to be sampled at a rate of about 50 Hz, meaning about 1.6 million data points will be taken every second. The fiber optic sensors system is capable of producing massive amounts of potentially useful data; however, methods to capture, record, and analyze all of this data in a way that makes the information useful to flight test engineers are currently limited. The purpose of this project is to research the availability of software

  7. Interrogation of an object for dimensional and topographical information

    DOEpatents

    McMakin, Doug L [Richland, WA; Severtsen, Ronald H [Richland, WA; Hall, Thomas E [Richland, WA; Sheen, David M [Richland, WA

    2003-01-14

    Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine one or more body measurements at least partially covered by the individual's clothing. The invention further includes techniques to interrogate an object with electromagnetic radiation in the millimeter and/or microwave range to provide a volumetric representation of the object. This representation can be used to display images and/or determine dimensional information concerning the object.

  8. Interrogation of an object for dimensional and topographical information

    DOEpatents

    McMakin, Douglas L.; Severtsen, Ronald H.; Hall, Thomas E.; Sheen, David M.; Kennedy, Mike O.

    2004-03-09

    Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine one or more body measurements at least partially covered by the individual's clothing. The invention further includes techniques to interrogate an object with electromagnetic radiation in the millimeter and/or microwave range to provide a volumetric representation of the object. This representation can be used to display images and/or determine dimensional information concerning the object.

  9. Interrogation Methods and Terror Networks

    NASA Astrophysics Data System (ADS)

    Baccara, Mariagiovanna; Bar-Isaac, Heski

    We examine how the structure of terror networks varies with legal limits on interrogation and the ability of authorities to extract information from detainees. We assume that terrorist networks are designed to respond optimally to a tradeoff caused by information exchange: Diffusing information widely leads to greater internal efficiency, but it leaves the organization more vulnerable to law enforcement. The extent of this vulnerability depends on the law enforcement authority’s resources, strategy and interrogation methods. Recognizing that the structure of a terrorist network responds to the policies of law enforcement authorities allows us to begin to explore the most effective policies from the authorities’ point of view.

  10. Groundwater Visualisation System (GVS): A software framework for integrated display and interrogation of conceptual hydrogeological models, data and time-series animation

    NASA Astrophysics Data System (ADS)

    Cox, Malcolm E.; James, Allan; Hawke, Amy; Raiber, Matthias

    2013-05-01

    Valley, and the Surat Basin, a large sedimentary basin of confined artesian aquifers. This latter example required more detail in the hydrostratigraphy, correlation of formations with drillholes and visualisation of simulation piezometric surfaces. Both alluvial system GVS models were developed during drought conditions to support government strategies to implement groundwater management. The Surat Basin model was industry sponsored research, for coal seam gas groundwater management and community information and consultation. The "virtual" groundwater systems in these 3D GVS models can be interactively interrogated by standard functions, plus production of 2D cross-sections, data selection from the 3D scene, rear end database and plot displays. A unique feature is that GVS allows investigation of time-series data across different display modes, both 2D and 3D. GVS has been used successfully as a tool to enhance community/stakeholder understanding and knowledge of groundwater systems and is of value for training and educational purposes. Projects completed confirm that GVS provides a powerful support to management and decision making, and as a tool for interpretation of groundwater system hydrological processes. A highly effective visualisation output is the production of short videos (e.g. 2-5 min) based on sequences of camera 'fly-throughs' and screen images. Further work involves developing support for multi-screen displays and touch-screen technologies, distributed rendering, gestural interaction systems. To highlight the visualisation and animation capability of the GVS software, links to related multimedia hosted online sites are included in the references.

  11. Development of fast FBG interrogator with wavelength-swept laser

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tatsuya; Shinoda, Yukitaka

    2015-05-01

    The objective of this research is the construction of a structural health monitoring system that uses fiber Bragg grating (FBG) to determine the health of structures. We develop fast FBG interrogator for real-time measurement of the reflected wavelength of a multipoint FBG to monitor the broadband vibration of a structure. This FBG interrogator, which combines a wavelength-swept laser and a real-time measurement system is capable of measuring wavelength within a standard deviation of 2×10-3 nm or less. We have demonstrated that the FBG interrogator is able to measure vibration that has a resonance frequency of 440 Hz at intervals of 0.1 ms with a multipoint FBG.

  12. AWG Filter for Wavelength Interrogator

    NASA Technical Reports Server (NTRS)

    Black, Richard J. (Inventor); Costa, Joannes M. (Inventor); Faridian, Fereydoun (Inventor); Moslehi, Behzad (Inventor); Sotoudeh, Vahid (Inventor)

    2015-01-01

    A wavelength interrogator is coupled to a circulator which couples optical energy from a broadband source to an optical fiber having a plurality of sensors, each sensor reflecting optical energy at a unique wavelength and directing the reflected optical energy to an AWG. The AWG has a detector coupled to each output, and the reflected optical energy from each grating is coupled to the skirt edge response of the AWG such that the adjacent channel responses form a complementary pair response. The complementary pair response is used to convert an AWG skirt response to a wavelength.

  13. SMS fiber structure with a multimode fiber graded index type for a temperature measurement using an intensity-based interrogation system

    NASA Astrophysics Data System (ADS)

    Mufarrikha, Ainun; Hatta, Agus M.; Koentjoro, Sekartedjo

    2015-01-01

    Temperature sensing based on a singlemode-multimode-singlemode (SMS) fiber structure with a graded index multimode fiber (GI-MMF) type using an intensity-based interrogation has been investigated numerically and experimentally. The effect of temperature on the SMS fiber structure with the MMF-GI type was modeled using a modal propagation analysis (MPA). The SMS fiber structures for temperature sensor was fabricated and tested with the MMF length of 57 mm. It is demonstrated experimentally, and supported with numerical results, that the sensor showed a sensitivity of 0.063 dB/°C with a temperature measurement range of 175-325°C. This sensor offers simple configuration and low cost of fabrication for the temperature measurement applications.

  14. Interrogating Transcriptional Regulatory Sequences in Tol2-Mediated Xenopus Transgenics

    PubMed Central

    Loots, Gabriela G.; Bergmann, Anne; Hum, Nicholas R.; Oldenburg, Catherine E.; Wills, Andrea E.; Hu, Na; Ovcharenko, Ivan; Harland, Richard M.

    2013-01-01

    Identifying gene regulatory elements and their target genes in vertebrates remains a significant challenge. It is now recognized that transcriptional regulatory sequences are critical in orchestrating dynamic controls of tissue-specific gene expression during vertebrate development and in adult tissues, and that these elements can be positioned at great distances in relation to the promoters of the genes they control. While significant progress has been made in mapping DNA binding regions by combining chromatin immunoprecipitation and next generation sequencing, functional validation remains a limiting step in improving our ability to correlate in silico predictions with biological function. We recently developed a computational method that synergistically combines genome-wide gene-expression profiling, vertebrate genome comparisons, and transcription factor binding-site analysis to predict tissue-specific enhancers in the human genome. We applied this method to 270 genes highly expressed in skeletal muscle and predicted 190 putative cis-regulatory modules. Furthermore, we optimized Tol2 transgenic constructs in Xenopus laevis to interrogate 20 of these elements for their ability to function as skeletal muscle-specific transcriptional enhancers during embryonic development. We found 45% of these elements expressed only in the fast muscle fibers that are oriented in highly organized chevrons in the Xenopus laevis tadpole. Transcription factor binding site analysis identified >2 Mef2/MyoD sites within ∼200 bp regions in 6 of the validated enhancers, and systematic mutagenesis of these sites revealed that they are critical for the enhancer function. The data described herein introduces a new reporter system suitable for interrogating tissue-specific cis-regulatory elements which allows monitoring of enhancer activity in real time, throughout early stages of embryonic development, in Xenopus. PMID:23874664

  15. Variation in Miami Cuban Spanish Interrogative Intonation

    ERIC Educational Resources Information Center

    Alvord, Scott M.

    2010-01-01

    The interrogative intonation of Cubans and Cuban Americans living in Miami is investigated. Two different intonation patterns are used in this variety of Spanish to convey absolute interrogative meaning: one with a falling final contour, as has been observed in Cuban Spanish, and one with a rising final contour, as is used in American English and…

  16. 8 CFR 343b.3 - Interrogation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Interrogation. 343b.3 Section 343b.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY NATIONALITY REGULATIONS SPECIAL CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.3 Interrogation. When Form N-565 presents a prima...

  17. Tunable microring based on-chip interrogator for wavelength-modulated optical sensors

    NASA Astrophysics Data System (ADS)

    Shen, Ao; Qiu, Chen; Yang, Longzhi; Dai, Tingge; Li, Yubo; Yu, Hui; Hao, Yinlei; Jiang, Xiaoqing; Yang, Jianyi

    2015-04-01

    An interrogation system for wavelength-modulated optical sensors based on tunable microring filter has been proposed and demonstrated both theoretically and experimentally. The wavelength shift of the sensors can be readout from the shift of the peak optical output of the system by scanning the resonant wavelength of the microring filter. We fabricate the interrogator on the silicon-on-insulator platform and a fiber Bragg grating sensor (FBG) is precisely interrogated. The Lorentz spectrum of the microring filter can de-flatten the output spectrum of the FBG and improve the interrogating resolution efficiently. Such a technique potentially provides a compact (only 50×50 μm2), low-cost, and high-performance (1 pm resolution) approach for the interrogation of the wavelength-modulated sensor and distributed sensor arrays.

  18. Active mode calibration of the combined thermal epithermal neutron (CTEN) system

    SciTech Connect

    Veilleux, J. M.

    2001-01-01

    The Combined Thermal Epithermal Neutron (CTEN) system was developed by the Los Alamos National Laboratory to perform active and passive neutron interrogation of waste. The higher energy epithermal neutrons are able to penetrate further into the matrix and active material, thus reducing matrix attenuation and self-shielding effects compared to a thermal neutron pulse alone. The developmental unit was installed in 2001 at the Los Alamos Non-Destructive Assay (NDA) facility to characterize waste for the TRU Waste Characterization Project (TWCP). This paper summarizes the active mode certification results. National Institute of Standards and Technology (NIST) traceable standards were used to determine the system response as a function of mass. Finally, NIST-traceable verification standards were used to verify the calibration in the range 30 milligrams to 25 g of weapons grade plutonium although self-shielding limits the upper active interrogation to 10 g.

  19. Are the American Psychological Association’s Detainee Interrogation Policies Ethical and Effective?

    PubMed Central

    Pope, Kenneth S.

    2011-01-01

    After 9–11, the United States began interrogating detainees at settings such as Abu Ghraib, Bagram, and Guantanamo. The American Psychological Association (APA) supported psychologists’ involvement in interrogations, adopted formal policies, and made an array of public assurances. This article’s purpose is to highlight key APA decisions, policies, procedures, documents, and public statements in urgent need of rethinking and to suggest questions that may be useful in a serious assessment, such as, “However well intended, were APA’s interrogation policies ethically sound?”; “Were they valid, realistic, and able to achieve their purpose?”; “Were other approaches available that would address interrogation issues more directly, comprehensively, and actively, that were more ethically and scientifically based, and that would have had a greater likelihood of success?”; and “Should APA continue to endorse its post-9–11 detainee interrogation policies?” PMID:22096660

  20. 32 CFR 637.21 - Recording interviews and interrogations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel...

  1. 32 CFR 637.21 - Recording interviews and interrogations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel...

  2. 32 CFR 637.21 - Recording interviews and interrogations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel...

  3. 32 CFR 637.21 - Recording interviews and interrogations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel...

  4. 32 CFR 637.21 - Recording interviews and interrogations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel...

  5. The synchronous active neutron detection assay system

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-08-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ``lock-in`` amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design.

  6. Active optical zoom system

    DOEpatents

    Wick, David V.

    2005-12-20

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  7. A MHz speed wavelength sweeping for ultra-high speed FBG interrogation

    NASA Astrophysics Data System (ADS)

    Kim, Gyeong Hun; Lee, Hwi Don; Eom, Tae Joong; Jeong, Myung Yung; Kim, Chang-Seok

    2015-09-01

    We demonstrated a MHz speed wavelength-swept fiber laser based on the active mode locking (AML) technique and applied to interrogation system of an array of fiber Bragg grating (FBG) sensors. MHz speed wavelength sweeping of wavelength-swept fiber laser can be obtained by programmable frequency modulation of the semiconductor optical amplifier (SOA) without any wavelength tunable filter. Both static and dynamic strain measurement of FBG sensors were successfully characterized with high linearity of an R-square value of 0.9999 at sweeping speed of 50 kHz.

  8. Distributed audio recording using OFDR with double interrogation

    NASA Astrophysics Data System (ADS)

    Gabai, Haniel; Eyal, Avishay

    2014-05-01

    We introduce a phase sensitive, dynamic and long range fiber-optic sensing system with fully distributed audio recording capabilities. The proposed system implements a recently developed OFDR design, which is based on double interrogation of a sensing fiber with equally-spaced discrete reflectors. In this paper, the ability of each sensing segment to operate as an independent, purely optical audio recorder with little cross-talk artifacts is demonstrated.

  9. Interrogation of MDM2 phosphorylation in p53 activation using native chemical ligation: the functional role of Ser17 phosphorylation in MDM2 reexamined

    PubMed Central

    Zhan, Changyou; Varney, Kristen; Yuan, Weirong; Zhao, Le; Lu, Wuyuan

    2012-01-01

    The E3 ubiquitin ligase MDM2 functions as a crucial negative regulator of the p53 tumor suppressor protein by antagonizing p53 transactivation activity and targeting p53 for degradation. Cellular stress activates p53 by alleviating MDM2-mediated functional inhibition, even though the molecular mechanisms of stress-induced p53 activation still remain poorly understood. Two opposing models have been proposed to describe the functional and structural role in p53 activation of Ser17 phosphorylation in the N-terminal “lid” (residues 1–24) of MDM2. Using the native chemical ligation technique, we synthesized the p53-binding domain (1–109)MDM2 and its Ser17-phosphorylated analog (1–109)MDM2 pS17 as well as (1–109)MDM2 S17D and (25–109)MDM2, and comparatively characterized their interactions with a panel of p53-derived peptide ligands using surface plasmon resonance, fluorescence polarization, and NMR and CD spectroscopic techniques. We found that the lid is partially structured in apo-MDM2 and occludes p53 peptide binding in a ligand size-dependent manner. Binding of (1–109)MDM2 by the (15–29)p53 peptide fully displaces the lid and renders it completely disordered in the peptide-protein complex. Importantly, neither Ser17 phosphorylation nor the phospho-mimetic mutation S17D has any functional impact on p53 peptide binding to MDM2. Although Ser17 phosphorylation or its mutation to Asp contributes marginally to the stability of the lid conformation in apo-MDM2, neither modification stabilizes apo-MDM2 globally or the displaced lid locally. Our findings demonstrate that Ser17 phosphorylation is functionally neutral with respect to p53 binding, suggesting that MDM2 phosphorylation at a single site is unlikely to play a dominant role in stress-induced p53 activation. PMID:22444248

  10. Fissile mass estimation by pulsed neutron source interrogation

    NASA Astrophysics Data System (ADS)

    Israelashvili, I.; Dubi, C.; Ettedgui, H.; Ocherashvili, A.; Pedersen, B.; Beck, A.; Roesgen, E.; Crochmore, J. M.; Ridnik, T.; Yaar, I.

    2015-06-01

    Passive methods for detecting correlated neutrons from spontaneous fissions (e.g. multiplicity and SVM) are widely used for fissile mass estimations. These methods can be used for fissile materials that emit a significant amount of fission neutrons (like plutonium). Active interrogation, in which fissions are induced in the tested material by an external continuous source or by a pulsed neutron source, has the potential advantages of fast measurement, alongside independence of the spontaneous fissions of the tested fissile material, thus enabling uranium measurement. Until recently, using the multiplicity method, for uranium mass estimation, was possible only for active interrogation made with continues neutron source. Pulsed active neutron interrogation measurements were analyzed with techniques, e.g. differential die away analysis (DDA), which ignore or implicitly include the multiplicity effect (self-induced fission chains). Recently, both, the multiplicity and the SVM techniques, were theoretically extended for analyzing active fissile mass measurements, made by a pulsed neutron source. In this study the SVM technique for pulsed neutron source is experimentally examined, for the first time. The measurements were conducted at the PUNITA facility of the Joint Research Centre in Ispra, Italy. First promising results, of mass estimation by the SVM technique using a pulsed neutron source, are presented.

  11. OFDR with double interrogation for dynamic quasi-distributed sensing.

    PubMed

    Am, Adva Bar; Arbel, Dror; Eyal, Avishay

    2014-02-10

    A method for phase sensitive quasi-distributed vibration and acoustical sensing is presented. The method is based on double optical frequency domain reflectometry interrogation of a sensing fiber with an array of discrete weak reflectors. Two replicas of the interrogation signal are launched into the sensing fiber. The time delay between the replicas is equal to the roundtrip time between two consecutive reflectors. Each peak in the spectrum of the returning signal is made from a coherent addition of the reflections of two consecutive reflectors. Its magnitude is highly sensitive to the optical phase in the fiber segment between the reflectors. The system was used to detect and locate the fall of a paperclip from height of 40 cm onto a sandbox where a 15 cm segment of the fiber was buried. In a different experiment the system successfully detected and located minute vibrations at 440 Hz that were induced by touching the fiber with a tuning fork. PMID:24663522

  12. Methow and Columbia Rivers studies: summary of data collection, comparison of database structure and habitat protocols, and impact of additional PIT tag interrogation systems to survival estimates, 2008-2012

    USGS Publications Warehouse

    Martens, Kyle D.; Tibbits, Wesley T.; Watson, Grace A.; Newsom, Michael A.; Connolly, Patrick J.

    2014-01-01

    designed to show some initial analysis and to disseminate summary information that could potentially be used in ongoing modeling efforts by USGS, Reclamation, and University of Idaho. The second chapter documents the database of fish and habitat data collected by USGS from 2004 through 2012 and compares USGS habitat protocols to the Columbia Habitat Monitoring Program (CHaMP) protocol. The third chapter is a survival analysis of fish moving through Passive Integrated Transponder (PIT) tag interrogation systems in the Methow and Columbia Rivers. It examines the effects of adding PIT tags and/or PIT tag interrogation systems on survival estimates of juvenile steelhead and Chinook salmon.

  13. L'Interrogation Indirecte (Indirect Interrogation). Montreal Working Papers in Linguistics, Vol. 4.

    ERIC Educational Resources Information Center

    Nieger, Monique; Paradis, Monique

    This study is divided into two sections: the first examines Standard French indirect interrogation, noting several distinct verb classes which are discussed in terms of permutations of WH-words, reduction, multiple WH-words, cleavage, semantic compatibility, and the "que-" completive; the second part focuses on indirect interrogation and relatives…

  14. High speed hybrid active system

    NASA Astrophysics Data System (ADS)

    Gonzalez, Ignacio F.; Chang, Fu-Kuo; Qing, Peter X.; Kumar, Amrita; Zhang, David

    2005-05-01

    A novel piezoelectric/fiber-optic system is developed for long-term health monitoring of aerospace vehicles and structures. The hybrid diagnostic system uses the piezoelectric actuators to input a controlled excitation to the structure and the fiber optic sensors to capture the corresponding structural response. The aim of the system is to detect changes in structures such as those found in aerospace applications (damage, cracks, aging, etc.). This system involves the use of fiber Bragg gratings, which may be either bonded to the surface of the material or embedded within it in order to detect the linear strain component produced by the excitation waves generate by an arbitrary waveform generator. Interrogation of the Bragg gratings is carried out using a high speed fiber grating demodulation unit and a high speed data acquisition card to provide actuation input. With data collection and information processing; is able to determine the condition of the structure. The demands on a system suitable for detecting ultrasonic acoustic waves are different than for the more common strain and temperature systems. On the one hand, the frequency is much higher, with typical values for ultrasonic frequencies used in non-destructive testing ranging from 100 kHz up to several MHz. On the other hand, the related strain levels are much lower, normally in the μstrain range. Fiber-optic solutions for this problem do exist and are particularly attractive for ultrasonic sensing as the sensors offer broadband detection capability.

  15. Solar cell activation system

    SciTech Connect

    Apelian, L.

    1983-07-05

    A system for activating solar cells involves the use of phosphorescent paint, the light from which is amplified by a thin magnifying lens and used to activate solar cells. In a typical system, a member painted with phosphorescent paint is mounted adjacent a thin magnifying lens which focuses the light on a predetermined array of sensitive cells such as selenium, cadmium or silicon, mounted on a plastic board. A one-sided mirror is mounted adjacent the cells to reflect the light back onto said cells for purposes of further intensification. The cells may be coupled to rechargeable batteries or used to directly power a small radio or watch.

  16. Polarization multiplexed interrogation technique for FBG sensor array

    NASA Astrophysics Data System (ADS)

    Sikdar, Debabrata; Tiwari, Vinita; Soni, Anupam; Jaiswal, Ritesh; Bhanot, Surekha

    2015-09-01

    This paper proposes a polarization multiplexed interrogation technique for fiber Bragg grating (FBG) sensor array. The novelty of the proposed model is its ability to reduce interference and cross talk, thus allowing larger number of FBG sensors to be interrogated in an array. The calibration technique has been illustrated in this work for the FBG sensor array, where data from each sensor are linearly polarized and multiplexed before co-propagation, to find out the tapping points that enable identification of each sensor data uniquely. Simulation has been carried out for odd number and even number of sensors in an array. Even with interfering input, this proposed scheme can interrogate and distinctively identify each sensor data using appropriate tuning of polarization-splitter, polarization-rotator, and polarization-attenuator at the detector end during the calibration process. The significance of the proposed method is its compact size, which makes this calibration system ready to be deployed in real-time sensing applications and data acquisition from the FBG sensor array.

  17. Holographic fiber bundle system for patterned optogenetic activation of large-scale neuronal networks.

    PubMed

    Farah, Nairouz; Levinsky, Alexandra; Brosh, Inbar; Kahn, Itamar; Shoham, Shy

    2015-10-01

    Optogenetic perturbation has become a fundamental tool in controlling activity in neurons. Used to control activity in cell cultures, slice preparations, anesthetized and awake behaving animals, optical control of cell-type specific activity enables the interrogation of complex systems. A remaining challenge in developing optical control tools is the ability to produce defined light patterns such that power-efficient, precise control of neuronal populations is obtained. Here, we describe a system for patterned stimulation that enables the generation of structured activity in neurons by transmitting optical patterns from computer-generated holograms through an optical fiber bundle. The system couples the optical system to versatile fiber bundle configurations, including coherent or incoherent bundles composed of hundreds of up to several meters long fibers. We describe the components of the system, a method for calibration, and a detailed power efficiency and spatial specificity quantification. Next, we use the system to precisely control single-cell activity as measured by extracellular electrophysiological recordings in ChR2-expressing cortical cell cultures. The described system complements recent descriptions of optical control systems, presenting a system suitable for high-resolution spatiotemporal optical control of wide-area neural networks in vitro and in vivo, yielding a tool for precise neural system interrogation. PMID:26793741

  18. Unified system for 3D holographic displacement and velocity measurements in fluid and solid mechanics: design and construction of the recording camera and interrogation assembly

    NASA Astrophysics Data System (ADS)

    Barnhart, Donald H.; Chan, Victor S. S.; Halliwell, Neil A.; Coupland, Jeremy M.

    1999-10-01

    This paper introduces a new approach to 3D displacement and velocity measurements that unifies the disciplines of holographic interferometry and holographic particle image velocimetry (HPIV). Equally applicable to fluid and solid mechanics, the overall system enables quantitative displacement measurements between two holographically recorded events from either particle or surface scattering sites, working with both pulsed and continuous-wave laser systems. The resulting measurements exhibit an accuracy corresponding to interferometric system, but with a dynamic range found with PIV systems. Most importantly, this paper introduces the novel use of an optical fiber to specify the measurement points, remove optical aberrations of windows, and eliminate directional ambiguity. An optical fiber is used to probe the recorded holographic image space at each 3D measurement point in order to extract the 3D displacement vectors. This fiber system also employs a novel optical image shifting method to eliminate the problem of directional ambiguity. In addition, the reported system uses 3D complex optical correlation rather than 2D real digital correlation. It is therefore a simple matter to directly obtain 3D displacement and velocity measurements at precisely known 3D locations in the object space. By correlating both the amplitude and phase information in the holographic image, this system can measure spatial distributions of displacements even when the presence of severe aberrations preclude the detection of sharp images.

  19. Production Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Gallaway, Ann, Ed.

    This production systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, domains and objectives, a course description, and a content outline. The guide contains 30 modules on the following topics: production…

  20. Communication Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This communication systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 32 modules on the following topics: story…

  1. A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force

    NASA Astrophysics Data System (ADS)

    Yoon, Sangpil; Aglyamov, Salavat; Karpiouk, Andrei; Emelianov, Stanislav

    2012-08-01

    A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young’s moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed.

  2. Explosives (and other threats) detection using pulsed neutron interrogation and optimized detectors

    NASA Astrophysics Data System (ADS)

    Strellis, Dan A.; Elsalim, Mashal; Gozani, Tsahi

    2011-06-01

    We have previously reported results from a human-portable system using neutron interrogation to detect contraband and explosives. We summarized our methodology for distinguishing threat materials such as narcotics, C4, and mustard gas in the myriad of backgrounds present in the maritime environment. We are expanding our mission for the Domestic Nuclear Detection Office (DNDO) to detect Special Nuclear Material (SNM) through the detection of multiple fission signatures without compromising the conventional threat detection performance. This paper covers our initial investigations into using neutrons from compact pulsed neutron generators via the d(D,n)3He or d(T,n)α reactions with energies of ~2.5 and 14 MeV, respectively, for explosives (and other threats) detection along with a variety of gamma-ray detectors. Fast neutrons and thermal neutrons (after successive collisions) can stimulate the emission of various threat detection signatures. For explosives detection, element-specific gamma-ray signatures via the (n,n'γ) inelastic scattering reaction and the (n,'γ) thermal capture reaction are detected. For SNM, delayed gamma-rays following fission can be measured with the same detector. Our initial trade-off investigations of several gamma-ray detectors types (NaI, CsI, LaBr3, HPGe) for measuring gamma-ray signatures in a pulsed neutron environment for potential application in a human-portable active interrogation system are covered in this paper.

  3. High-energy Laser-accelerated Electron Beams for Long-range Interrogation

    SciTech Connect

    Cunningham, Nathaniel J.; Banerjee, Sudeep; Ramanathan, Vidya; Powers, Nathan; Chandler-Smith, Nate; Umstadter, Donald; Vane, Randy; Schultz, David; Beene, James; Pozzi, Sara; Clarke, Shaun

    2009-03-10

    We are studying the use of 0.1-1.0 GeV laser-accelerated electron beams as active interrogation probes for long-standoff radiography or nuclear activation of concealed special nuclear material. Use of beams in this energy range is largely unexplored, but such beams could provide notable advantages over lower-energy beams and x-rays. High-energy laser-accelerated electrons exhibit large penetration range through air and solids, and low beam divergence for both direct beams and secondary Bremsstrahlung x-rays. We present laboratory measurements of radiography and activation, using the high-power Diodes laser system at the University of Nebraska, as well as MCNP and GEANT Monte Carlo simulation results used to aid experiment design and interpretation.

  4. High-Energy Laser-Accelerated Electron Beams for Long-Range Interrogation

    SciTech Connect

    Cummingham, N. J.; Banerjee, Sudeep; Ramanathan, Vidya; Powell, Nathan; Chandler-Smith, Nate; Vane, C Randy; Schultz, David Robert; Pozzi, Sara; Clarke, Shaun; Beene, James R; Umstadter, Donald

    2009-01-01

    We are studying the use of 0.1 1.0 GeV laser-accelerated electron beams as active interrogation probes for long-standoff radiography or nuclear activation of concealed special nuclear material. Use of beams in this energy range is largely unexplored, but such beams could provide notable advantages over lower-energy beams and x-rays. High-energy laser-accelerated electrons exhibit large penetration range through air and solids, and low beam divergence for both direct beams and secondary Bremsstrahlung x-rays. We present laboratory measurements of radiography and activation, using the high-power Diodes laser system at the University of Nebraska, as well as MCNP and GEANT Monte Carlo simulation results used to aid experiment design and interpretation.

  5. Interrogating Racism in Qualitative Research Methodology. Counterpoints.

    ERIC Educational Resources Information Center

    Lopez, Gerardo R., Ed.; Parker, Laurence, Ed.

    This book explores the link between critical race theory and qualitative research methodology, interrogating how race connects and conflicts with other areas of difference and is never entirely absent from the research process. After an introduction, "Critical Race Theory in Education: Theory, Praxis, and Recommendations" (Sylvia R. Lazos Vargas),…

  6. Temperature-compensated strain measurement of full-scale small aircraft wing structure using low-cost FBG interrogator

    NASA Astrophysics Data System (ADS)

    Kim, J. H.; Lee, Y. G.; Park, Y.; Kim, C. G.

    2013-04-01

    Recently, health and usage monitoring systems (HUMS) are being studied to monitor the real-time condition of aircrafts during flight. HUMSs can prevent aircraft accidents and reduce inspection time and cost. Fiber Bragg grating (FBG) sensors are widely used for aircraft HUMSs with many advantages such as light weight, small size, easy-multiplexing, and EMI immunity. However, commercial FBG interrogators are too expensive to apply for small aircrafts. Generally the cost of conventional FBG interrogators is over 20,000. Therefore, cost-effective FBG interrogation systems need to be developed for small aircraft HUMSs. In this study, cost-effective low speed FBG interrogator was applied to full-scale small aircraft wing structure to examine the operational applicability of the low speed FBG interrogator to the monitoring of small aircrafts. The cost of the developed low speed FBG interrogator was about 10,000, which is an affordable price for a small aircraft. 10 FBG strain sensors and 1 FBG temperature sensor were installed on the surface of the full-scale wing structure. Load was applied to the tip of the wing structure, and the low speed interrogator detected the change in the center wavelength of the FBG sensors at the sampling rate of 10Hz. To assess the applicability of the low-cost FBG interrogator to full-scale small aircraft wing structure, a temperature-compensated strain measurement algorithm was verified experimentally under various loading conditions of the wing structure with temperature variations.

  7. Novel applications of fast neutron interrogation methods

    NASA Astrophysics Data System (ADS)

    Gozani, Tsahi

    1994-12-01

    The development of non-intrusive inspection methods for contraband consisting primarily of carbon, nitrogen, oxygen, and hydrogen requires the use of fast neutrons. While most elements can be sufficiently well detected by the thermal neutron capture process, some important ones, e.g., carbon and in particular oxygen, cannot be detected by this process. Fortunately, fast neutrons, with energies above the threshold for inelastic scattering, stimulate relatively strong and specific gamma ray lines from these elements. The main lines are: 6.13 for O, 4.43 for C, and 5.11, 2.31 and 1.64 MeV for N. Accelerator-generated neutrons in the energy range of 7 to 15 MeV are being considered as interrogating radiations in a variety of non-intrusive inspection systems for contraband, from explosives to drugs and from coal to smuggled, dutiable goods. In some applications, mostly for inspection of small items such as luggage, the decision process involves a rudimentary imaging, akin to emission tomography, to obtain the localized concentration of various elements. This technique is called FNA — Fast Neutron Analysis. While this approach offers improvements over the TNA (Thermal Neutron Analysis), it is not applicable to large objects such as shipping containers and trucks. For these challenging applications, a collimated beam of neutrons is rastered along the height of the moving object. In addition, the neutrons are generated in very narrow nanosecond pulses. The point of their interaction inside the object is determined by the time of flight (TOF) method, that is measuring the time elapsed from the neutron generation to the time of detection of the stimulated gamma rays. This technique, called PFNA (Pulsed Fast Neutron Analysis), thus directly provides the elemental, and by inference, the chemical composition of the material at every volume element (voxel) of the object. The various neutron-based techniques are briefly described below.

  8. ADASY (Active Daylighting System)

    NASA Astrophysics Data System (ADS)

    Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

    2009-08-01

    The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

  9. Notes on SAW Tag Interrogation Techniques

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2010-01-01

    We consider the problem of interrogating a single SAW RFID tag with a known ID and known range in the presence of multiple interfering tags under the following assumptions: (1) The RF propagation environment is well approximated as a simple delay channel with geometric power-decay constant alpha >/= 2. (2) The interfering tag IDs are unknown but well approximated as independent, identically distributed random samples from a probability distribution of tag ID waveforms with known second-order properties, and the tag of interest is drawn independently from the same distribution. (3) The ranges of the interfering tags are unknown but well approximated as independent, identically distributed realizations of a random variable rho with a known probability distribution f(sub rho) , and the tag ranges are independent of the tag ID waveforms. In particular, we model the tag waveforms as random impulse responses from a wide-sense-stationary, uncorrelated-scattering (WSSUS) fading channel with known bandwidth and scattering function. A brief discussion of the properties of such channels and the notation used to describe them in this document is given in the Appendix. Under these assumptions, we derive the expression for the output signal-to-noise ratio (SNR) for an arbitrary combination of transmitted interrogation signal and linear receiver filter. Based on this expression, we derive the optimal interrogator configuration (i.e., transmitted signal/receiver filter combination) in the two extreme noise/interference regimes, i.e., noise-limited and interference-limited, under the additional assumption that the coherence bandwidth of the tags is much smaller than the total tag bandwidth. Finally, we evaluate the performance of both optimal interrogators over a broad range of operating scenarios using both numerical simulation based on the assumed model and Monte Carlo simulation based on a small sample of measured tag waveforms. The performance evaluation results not only

  10. Encapsulated microsensors for reservoir interrogation

    DOEpatents

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  11. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  12. Wirelessly Interrogated Position or Displacement Sensors

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Taylor, Bryant D.

    2007-01-01

    Two simple position or displacement sensors based on inductance-capacitance resonant circuits have been conceived. These sensors are both powered and interrogated without use of wires and without making contact with other objects. Instead, excitation and interrogation are accomplished by means of a magnetic-field-response recorder. Both of the present position or displacement sensors consist essentially of variable rectangular parallel-plate capacitors electrically connected in series with fixed inductors. Simple inductance-capacitance circuits of the type used in these sensors are inherently robust; their basic mode of operation does not depend on maintenance of specific environmental conditions. Hence, these sensors can be used under such harsh conditions as cryogenic temperatures, high pressures, and radioactivity.

  13. Wirelessly Interrogated Wear or Temperature Sensors

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Taylor, Bryant D.

    2010-01-01

    Sensors for monitoring surface wear and/or temperature without need for wire connections have been developed. Excitation and interrogation of these sensors are accomplished by means of a magnetic-field-response recorder. In a sensor of the present type as in the previously reported ones, the capacitance and, thus, the resonance frequency, varies as a known function of the quantity of interest that one seeks to determine. Hence, the resonance frequency is measured and used to calculate the quantity of interest.

  14. European Neutron Activation System.

    2013-01-11

    Version 03 EASY-2010 (European Activation System) consists of a wide range of codes, data and documentation all aimed at satisfying the objective of calculating the response of materials irradiated in a neutron flux. The main difference from the previous version is the upper energy limit, which has increased from 20 to 60 MeV. It is designed to investigate both fusion devices and accelerator based materials test facilities that will act as intense sources of high-energymore » neutrons causing significant activation of the surrounding materials. The very general nature of the calculational method and the data libraries means that it is applicable (with some reservations) to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV. EASY can be divided into two parts: data and code development tools and user tools and data. The former are required to develop the latter, but EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source). The complete EASY package contains the FISPACT-2007 inventory code, the EAF-2003, EAF-2005, EAF-2007 and EAF-2010 libraries, and the EASY User Interface for the Window version. The activation package EASY-2010 is the result of significant development to extend the upper energy range from 20 to 60 MeV so that it is capable of being used for IFMIF calculations. The EAF-2010 library contains 66,256 reactions, almost five times more than in EAF-2003 (12,617). Deuteron-induced and proton-induced cross section libraries are also included, and can be used with EASY to enable calculations of the activation due to deuterons and proton [2].« less

  15. Progress in miniaturization of a multichannel optical fiber Bragg grating sensor interrogator

    NASA Astrophysics Data System (ADS)

    Lopatin, Craig M.; Mahmood, Shah; Mendoza, Edgar; Moslehi, Behzad; Black, Richard; Chau, Kelvin; Oblea, Levy

    2007-07-01

    An effort to develop a miniaturized multichannel optical fiber Bragg grating sensor interrogator was initiated in 2006 under the Small Business Innovative Research (SBIR) program. The goal was to develop an interrogator that would be sufficiently small and light to be incorporated into a health monitoring system for use on tactical missiles. Two companies, Intelligent Fiber Optic Systems Corporation (IFOS) and Redondo Optics, were funded in Phase I, and this paper describes the prototype interrogators that were developed. The two companies took very different approaches: IFOS focused on developing a unit that would have a high channel count and high resolution, using off-the-shelf components, while Redondo Optics chose to develop a unit that would be very small and lightweight, using custom designed integrated optical chips. It is believed that both approaches will result in interrogators that will be significantly small, lighter, and possibly even more precise than what is currently commercially available. This paper will also briefly describe some of the sensing concepts that may be used to interrogate the health of the solid rocket motors used in many missile systems. The sponsor of this program was NAVAIR PMA 280.

  16. INL Neutron Interrogation R&D: FY2010 MPACT End of Year Report

    SciTech Connect

    D. L. Chichester; E. H. Seabury; J. Wharton; S. M. Watson

    2010-08-01

    Experiments have been carried out to investigate the feasibility and utility of using neutron interrogation and small-scale, portable prompt gamma-ray neutron activation analysis (PGNAA) instruments for assaying uranium for safeguards applications. Prior work has shown the potential of the PGNAA technique for assaying uranium using reactor-based neutron sources and high-yield electronic neutron generators (ENGs). In this project we adapted Idaho National Laboratory's portable isotopic neutron spectroscopy (PINS) PGNAA system for measuring natural-enrichment uranium yellowcake and metallic depleted uranium and highly enriched uranium. This work used 252Cf as well as deuterium-deuterium (DD) and deuterium-tritium (DT) ENGs. For PGNAA measurements a limiting factor when assaying large objects is the detector dead time due to fast-neutron scattering off of the uranium; this limits the maximum useable neutron source strength to O(107) neutrons per second. Under these conditions the low PGNAA reaction cross sections for uranium prohibited the collection of useful uranium PGNAA signatures from either the yellowcake or metallic uranium samples. Measurement of the decay product activation in these materials following irradiation in the PGNAA geometry similarly did not produce useful uranium activation product – fission product signatures. A customized irradiation geometry tailored to optimally thermalize the interrogation neutron source, intended only for generating long-lived activation products – fission products and not intended for PGNAA measurements, might be possible using small scale ENGs but an application need and a modeling and simulation exercise would be recommended before advancing to experiments. Neutron interrogation PGNAA using a DT-ENG was found to be a quick and useful qualitative method for detecting the presence of oxygen in natural-enrichment uranium yellowcake. With a low effort of development work it would be reasonable to expect this measurement

  17. 48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF...

  18. 48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF...

  19. 48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF...

  20. 48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF...

  1. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    DOEpatents

    Schultz, Frederick J.; Caldwell, John T.

    1993-01-01

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

  2. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    DOEpatents

    Schultz, F.J.; Caldwell, J.T.

    1993-04-06

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

  3. Ion-induced gammas for photofission interrogation of HEU.

    SciTech Connect

    Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); Antolak, Arlyn J.; Morse, Daniel H.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM)

    2006-03-01

    High-energy photons and neutrons can be used to actively interrogate for heavily shielded special nuclear material (SNM), such as HEU (highly enriched uranium), by detecting prompt and/or delayed induced fission signatures. In this work, we explore the underlying physics for a new type of photon source that generates high fluxes of mono-energetic gamma-rays from low-energy (<500 keV) proton-induced nuclear reactions. The characteristic energies (4- to 18-MeV) of the gamma-rays coincide with the peak of the photonuclear cross section. The source could be designed to produce gamma-rays of certain selected energies, thereby improving the probability of detecting shielded HEU or providing a capability to determine enrichment inside sealed containers. The fundamental physics of such an interrogation source were studied in this LDRD through scaled ion accelerator experiments and radiation transport modeling. The data were used to assess gamma and neutron yields, background, and photofission-induced signal levels from several (p,{gamma}) target materials under consideration.

  4. FBG interrogation method based on wavelength-swept laser

    NASA Astrophysics Data System (ADS)

    Qin, Chuan; Zhao, Jianlin; Jiang, Biqiang; Rauf, Abdul; Wang, Donghui; Yang, Dexing

    2013-06-01

    Wavelength-swept laser technique is an active demodulation method which integrates laser source and detecting circuit together to achieve compact size. The method also has the advantages such as large demodulation range, high accuracy, and comparatively high speed. In this paper, we present a FBG interrogation method based on wavelength-swept Laser, in which an erbium-doped fiber is used as gain medium and connected by a WDM to form a ring cavity, a fiber FP tunable filter is inserted in the loop for choosing the laser frequency and a gas absorption cell is adopted as a frequency reference. The laser wavelength is swept by driving the FP filter. If the laser wavelength matches with that of FBG sensors, there will be some strong reflection peak signals. Detecting such signals with the transmittance signal after the gas absorption cell synchronously and analyzing them, the center wavelengths of the FBG sensors are calculated out at last. Here, we discuss the data processing method based on the frequency reference, and experimentally study the swept laser characteristics. Finally, we adopt this interrogator to demodulate FBG stress sensors. The results show that, the demodulation range almost covers C+L band, the resolution and accuracy can reach about 1pm or less and 5pm respectively. So it is very suitable for most FBG measurements.

  5. Hand Held Device for Wireless Powering and Interrogation of Biomems Sensors and Actuators

    NASA Technical Reports Server (NTRS)

    Miranda, Felix Antonio (Inventor); Simons, Rainee N (Inventor)

    2007-01-01

    A compact, hand-held device for wireless powering, interrogation and data retrieval from at least one implanted sensor. The hand-held device includes an antenna for powering an implanted sensor and for receiving data from the implanted sensor to the hand-held device for at least one of storage, display or analysis. The hand-held device establishes electromagnetic coupling with a low radiating radio frequency power inductor in the implanted sensor at a predefined separation and the antenna geometry allows for the antenna to power, interrogate and retrieve data from the implanted sensor without strapping the hand-held device to a human body housing the implanted sensor The hand-held device optionally allows for activation of the implanted sensor only during interrogation and data retrieval.

  6. An Evaluation of "Miranda" Rights and Interrogation in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Salseda, Lindsay M.; Dixon, Dennis R.; Fass, Tracy; Miora, Deborah; Leark, Robert A.

    2011-01-01

    The primary deficits present in autism spectrum disorders (ASD) may lead to increased susceptibility to involvement in the criminal justice system. The same deficits may also cause individuals with ASD to be more vulnerable to interrogation techniques and other aspects of the legal system. Due to the increased level of vulnerability as well as…

  7. Interrogating scarcity: how to think about 'resource-scarce settings'.

    PubMed

    Schrecker, Ted

    2013-07-01

    The idea of resource scarcity permeates health ethics and health policy analysis in various contexts. However, health ethics inquiry seldom asks-as it should-why some settings are 'resource-scarce' and others not. In this article I describe interrogating scarcity as a strategy for inquiry into questions of resource allocation within a single political jurisdiction and, in particular, as an approach to the issue of global health justice in an interconnected world. I demonstrate its relevance to the situation of low- and middle-income countries (LMICs) with brief descriptions of four elements of contemporary globalization: trade agreements; the worldwide financial marketplace and capital flight; structural adjustment; imperial geopolitics and foreign policy. This demonstration involves not only health care, but also social determinants of health. Finally, I argue that interrogating scarcity provides the basis for a new, critical approach to health policy at the interface of ethics and the social sciences, with specific reference to market fundamentalism as the value system underlying contemporary globalization. PMID:22899597

  8. Technology Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Brame, Ray; And Others

    This guide contains 43 modules of laboratory activities for technology education courses. Each module includes an instructor's resource sheet and the student laboratory activity. Instructor's resource sheets include some or all of the following elements: module number, course title, activity topic, estimated time, essential elements, objectives,…

  9. Narcotics detection using fast-neutron interrogation

    SciTech Connect

    Micklich, B.J.; Fink, C.L.

    1995-12-31

    Fast-neutron interrogation techniques are being investigated for detection of narcotics in luggage and cargo containers. This paper discusses two different fast-neutron techniques. The first uses a pulsed accelerator or sealed-tube source to produce monoenergetic fast neutrons. Gamma rays characteristic of carbon and oxygen are detected and the elemental densities determined. Spatial localization is accomplished by either time of flight or collimators. This technique is suitable for examination of large containers because of the good penetration of the fast neutrons and the low attenuation of the high-energy gamma rays. The second technique uses an accelerator to produce nanosecond pulsed beams of deuterons that strike a target to produce a pulsed beam of neutrons with a continuum of energies. Elemental distributions are obtained by measuring the neutron spectrum after the source neutrons pass through the items being interrogated. Spatial variation of elemental densities is obtained by tomographic reconstruction of projection data obtained for three to five angles and relatively low (2 cm) resolution. This technique is best suited for examination of luggage or small containers with average neutron transmissions greater than about 0.01. Analytic and Monte-Carlo models are being used to investigate the operational characteristics and limitations of both techniques.

  10. The synchronous active neutron detection system for spent fuel assay

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-10-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed {open_quotes}lock-in{close_quotes} amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound.

  11. Long fiber Bragg grating sensor interrogation using discrete-time microwave photonic filtering techniques.

    PubMed

    Ricchiuti, Amelia Lavinia; Barrera, David; Sales, Salvador; Thevenaz, Luc; Capmany, José

    2013-11-18

    A novel technique for interrogating photonic sensors based on long fiber Bragg gratings (FBGs) is presented and experimentally demonstrated, dedicated to detect the presence and the precise location of several spot events. The principle of operation is based on a technique used to analyze microwave photonics (MWP) filters. The long FBGs are used as quasi-distributed sensors. Several hot-spots can be detected along the FBG with a spatial accuracy under 0.5 mm using a modulator and a photo-detector (PD) with a modest bandwidth of less than 1 GHz. The proposed interrogation system is intrinsically robust against environmental changes. PMID:24514329

  12. High-sensitivity transuranic waste assay by simultaneous proton and thermal-neutron interrogation using an electron linear accelerator

    SciTech Connect

    Franks, L.A.; Pigg, J.L.; Caldwell, J.T.; Cates, M.R.; Kunz, W.E.; Noel, B.W.

    1982-01-01

    Simultaneous photon and neutron interrogation from electron linear accelerator pulses is used as the basis for a unique assay technique for transuranics. Both prompt and delayed neutrons from the induced fissions are counted on a single detection system, and the contributions from each interrogating flux are resolved. Detection limits (3 sigma) for /sup 239/Pu were estimated to be 3 mg for prompt fission neutrons and 6 mg for delayed neutrons. The technique also provides a clear distinction between fissile and fertile nuclides.

  13. Adaptive dynamic FBG interrogation utilising erbium-doped fibre

    NASA Astrophysics Data System (ADS)

    John, R. N.; Read, I.; MacPherson, W. N.

    2013-04-01

    A dynamic fibre Bragg grating interrogation scheme is investigated using two-wave mixing in erbium-doped fibre, capable of adapting to quasistatic strain and temperature drifts. An interference pattern set up in the erbium-doped fibre creates, due to the photorefractive effect, a dynamic grating capable of wavelength demodulating the FBG signal. The presence of a dynamic grating was verified and then dynamic strain signals from a fibre stretcher were measured. The adaptive nature of the technique was successfully demonstrated by heating the FBG while it underwent dynamic straining leading to detection unlike an alternative arrayed waveguide grating system which simultaneously failed detection. Two gratings were then wavelength division multiplexed with the signal grating receiving approximately 30dB greater signal showing that there was little cross talk in the system.

  14. Design and characterisation of a pulsed neutron interrogation facility.

    PubMed

    Favalli, A; Pedersen, B

    2007-01-01

    The Joint Research Centre recently obtained a license to operate a new experimental device intended for research in the field of nuclear safeguards. The research projects currently being planned for the new device includes mass determination of fissile materials in matrices and detection of contraband non-nuclear materials. The device incorporates a commercial pulsed neutron generator and a large graphite mantle surrounding the sample cavity. In this configuration, a relatively high thermal neutron flux with a long lifetime is achieved inside the sample cavity. By pulsing the neutron generator, a sample may be interrogated by a pure thermal neutron flux during repeated time periods. The paper reports on the design of the new device and the pulsed fast and thermal neutron source. The thermal neutron flux caused by the neutron generator and the graphite structure has been characterised by foil activation, fission chamber and (3)He proportional counter measurements. PMID:17496298

  15. Laser interrogation of latent vehicle registration number

    SciTech Connect

    Russo, R.E. |; Pelkey, G.E.; Grant, P.; Whipple, R.E.; Andresen, B.D.

    1994-09-01

    A recent investigation involved automobile registration numbers as important evidentiary specimens. In California, as in most states, small, thin metallic decals are issued to owners of vehicles each year as the registration is renewed. The decals are applied directly to the license plate of the vehicle and typically on top of the previous year`s expired decal. To afford some degree of security, the individual registration decals have been designed to tear easily; they cannot be separated from each other, but can be carefully removed intact from the metal license plate by using a razor blade. In September 1993, the City of Livermore Police Department obtained a blue 1993 California decal that had been placed over an orange 1992 decal. The two decals were being investigated as possible evidence in a case involving vehicle registration fraud. To confirm the suspicion and implicate a suspect, the department needed to known the registration number on the bottom (completely covered) 1992 decal. The authors attempted to use intense and directed light to interrogate the colored stickers. Optical illumination using a filtered white-light source partially identified the latent number. However, the most successful technique used a tunable dye laser pumped by a pulsed Nd:YAG laser. By selectively tuning the wavelength and intensity of the dye laser, backlit illumination of the decals permitted visualization of the underlying registration number through the surface of the top sticker. With optimally-tuned wavelength and intensity, 100% accuracy was obtained in identifying the sequence of latent characters. The advantage of optical techniques is their completely nondestructive nature, thus preserving the evidence for further interrogation or courtroom presentation.

  16. Optimization of coil design for near uniform interrogating field generation

    NASA Astrophysics Data System (ADS)

    Su, Z.; Efremov, A.; Safdarnejad, M.; Tamburrino, A.; Udpa, L.; Udpa, S. S.

    2015-03-01

    The detection of a crack under fastener heads (CUF) in a multi-layered aircraft structure remains a challenge in non-destructive evaluation (NDE). An EC-GMR system using a linear eddy current (EC) coil with giant magnetoresistive (GMR) sensors located on the axis of symmetry is proposed for detecting discontinuities in conducting materials. The signal received from sensors is greatly influenced by the interrogating field. This paper describes a detailed parametric study, using a finite element model predicted signals in conjunction with a multi-parameter optimization problem for coil design. The sensor performance is assessed using quantitative measures based on Probability of detection (POD) with respect to different crack geometries.

  17. Laser interrogation of surface agents (LISA) for chemical agent reconnaissance

    NASA Astrophysics Data System (ADS)

    Higdon, N. S.; Chyba, Thomas H.; Richter, Dale A.; Ponsardin, Patrick L.; Armstrong, Wayne T.; Lobb, C. T.; Kelly, Brian T.; Babnick, Robert D.; Sedlacek, Arthur J., III

    2002-06-01

    Laser Interrogation of Surface Agents (LISA) is a new technique which exploits Raman scattering to provide standoff detection and identification of surface-deposited chemical agents. ITT Industries, Advanced Engineering and Sciences Division is developing the LISA technology under a cost-sharing arrangement with the US Army Soldier and Biological Chemical Command for incorporation on the Army's future reconnaissance vehicles. A field-engineered prototype LISA-Recon system is being designed to demonstrate on-the- move measurements of chemical contaminants. In this article, we will describe the LISA technique, data form proof-of- concept measurements, the LISA-Recon design, and some of the future realizations envisioned for military sensing applications.

  18. Resolution-improved in situ DNA hybridization detection based on microwave photonic interrogation.

    PubMed

    Cao, Yuan; Guo, Tuan; Wang, Xudong; Sun, Dandan; Ran, Yang; Feng, Xinhuan; Guan, Bai-ou

    2015-10-19

    In situ bio-sensing system based on microwave photonics filter (MPF) interrogation method with improved resolution is proposed and experimentally demonstrated. A microfiber Bragg grating (mFBG) is used as sensing probe for DNA hybridization detection. Different from the traditional wavelength monitoring technique, we use the frequency interrogation scheme for resolution-improved bio-sensing detection. Experimental results show that the frequency shift of MPF notch presents a linear response to the surrounding refractive index (SRI) change over the range of 1.33 to 1.38, with a SRI resolution up to 2.6 × 10(-5) RIU, which has been increased for almost two orders of magnitude compared with the traditional fundamental mode monitoring technique (~3.6 × 10(-3) RIU). Due to the high Q value (about 27), the whole process of DNA hybridization can be in situ monitored. The proposed MPF-based bio-sensing system provides a new interrogation method over the frequency domain with improved sensing resolution and rapid interrogation rate for biochemical and environmental measurement. PMID:26480367

  19. Photoneutron interrogation of low-enriched uranium induced by bremsstrahlung from a 4 MeV linac

    NASA Astrophysics Data System (ADS)

    Lakosi, L.; Tam Nguyen, C.; Bagi, J.

    2008-01-01

    Revealing smuggled nuclear material by passive γ-detection is hindered, because the weak radiation can easily be shielded. Neutrons, as penetrate shielding, represent a detection potential, by inducing fission in the nuclear material. A 4 MeV linear accelerator was used as a pulsed neutron source for active interrogation of U-bearing material. Produced in heavy water by bremsstrahlung, neutrons subsequently induced fissions in UO2 samples. Delayed fission neutrons were detected in a neutron collar built up by 3He counters in a polyamide container. The counters were gated to be detached from high voltage during the electron pulse. Irradiation-measurement cycles were carried out with a 25 Hz pulse repetition rate as optimum setting. The time analyser start-up was externally triggered and synchronised by the electron beam pulse. The response of the system was studied as a function of the intensity of the electron current, the amount of heavy water, U enrichment, and total U content. Sensitivity limit was achieved as 0.5 g 235U and/or 30 g 238U in a 20 s measurement time (500 cycles) with the amount of heavy water of 100 g and a mean electron current of 2 μA. Because of the long decay time of the prompt (interrogating and fission) neutron pulse, about a half of the time interval (40 ms) between pulses is only available for counting delayed neutrons.

  20. Optically powered and interrogated rotary position sensor for aircraft engine control applications

    NASA Astrophysics Data System (ADS)

    Spillman, W. B.; Crowne, D. H.; Woodward, D. W.

    A throttle level angle (TLA) sensing system is described that utilizes a capacitance based rotary position transducer that is powered and interrogated via light from a single multimode optical fiber. The system incorporates a unique GaAs device that serves as both a power converter and optical data transmitter. Design considerations are discussed, and the fabrication and performance of the sensor system are detailed.

  1. Monte Carlo parametric studies of neutron interrogation with the Associated Particle Technique for cargo container inspections

    NASA Astrophysics Data System (ADS)

    Deyglun, Clément; Carasco, Cédric; Pérot, Bertrand

    2014-06-01

    The detection of Special Nuclear Materials (SNM) by neutron interrogation is extensively studied by Monte Carlo simulation at the Nuclear Measurement Laboratory of CEA Cadarache (French Alternative Energies and Atomic Energy Commission). The active inspection system is based on the Associated Particle Technique (APT). Fissions induced by tagged neutrons (i.e. correlated to an alpha particle in the DT neutron generator) in SNM produce high multiplicity coincidences which are detected with fast plastic scintillators. At least three particles are detected in a short time window following the alpha detection, whereas nonnuclear materials mainly produce single events, or pairs due to (n,2n) and (n,n'γ) reactions. To study the performances of an industrial cargo container inspection system, Monte Carlo simulations are performed with the MCNP-PoliMi transport code, which records for each neutron history the relevant information: reaction types, position and time of interactions, energy deposits, secondary particles, etc. The output files are post-processed with a specific tool developed with ROOT data analysis software. Particles not correlated with an alpha particle (random background), counting statistics, and time-energy resolutions of the data acquisition system are taken into account in the numerical model. Various matrix compositions, suspicious items, SNM shielding and positions inside the container, are simulated to assess the performances and limitations of an industrial system.

  2. FTIR-based airborne spectral imagery for target interrogation

    NASA Astrophysics Data System (ADS)

    Smithson, Tracy L.; St. Germain, Daniel; Nadeau, Denis

    2007-09-01

    DRDC Valcartier is continuing to developed infrared spectral imagery systems for a variety of military applications. Recently a hybrid airborne spectral imager / broadband imager system has been developed for ground target interrogation (AIRIS). This system employs a Fourier Transform Interferometer system coupled to two 8x8 element detector arrays to create spectral imagery in the region from 2.0 to 12 microns (830 to 5000 cm -1) at a spectral resolution of up to 1 cm -1. In addition, coupled to this sensor are three broadband imagers operating in the visible, mid-wave and long-wave infrared regions. AIRIS uses an on-board tracking capability to: dwell on a target, select multiple targets sequentially, or build a mosaic description of the environment around a specified target point. Currently AIRIS is being modified to include real-time spectral imagery calibration and application processing. In this paper the flexibility of the AIRIS system will be described, its concept of operation discussed and examples of measurements will be shown.

  3. Combined Photoneutron And X Ray Interrogation Of Containers For Nuclear Materials

    SciTech Connect

    Gozani, Tsahi; Shaw, Timothy; King, Michael J.; Stevenson, John; Elsalim, Mashal; Brown, Craig; Condron, Cathie

    2011-06-01

    Effective cargo inspection systems for nuclear material detection require good penetration by the interrogating radiation, generation of a sufficient number of fissions, and strong and penetrating detection signatures. Inspection systems need also to be sensitive over a wide range of cargo types and densities encountered in daily commerce. Thus they need to be effective with highly hydrogenous cargo, where neutron attenuation is a major limitation, as well as with dense metallic cargo, where x-ray penetration is low. A system that interrogates cargo with both neutrons and x-rays can, in principle, achieve high performance over the widest range of cargos. Moreover, utilizing strong prompt-neutron ({approx}3 per fission) and delayed-gamma ray ({approx}7 per fission) signatures further strengthens the detection sensitivity across all cargo types. The complementary nature of x-rays and neutrons, used as both probing radiation and detection signatures, alleviates the need to employ exceedingly strong sources, which would otherwise be required to achieve adequate performance across all cargo types, if only one type of radiation probe were employed. A system based on the above principles, employing a commercially-available 9 MV linac was developed and designed. Neutrons are produced simultaneously with x-rays by the photonuclear interaction of the x-ray beam with a suitable converter. A total neutron yield on the order of 10{sup 11} n/s is achieved with an average electron beam current of 100 {mu}A. If fissionable material is present, fissions are produced both by the high-energy x-ray beam and by the photoneutrons. Photofission and neutron fission dominate in hydrogenous and metallic cargos, respectively. Neutron-capture gamma rays provide information on the cargo composition. The prompt neutrons resulting from fission are detected by two independent detector systems: by very efficient Differential Die Away Analysis (DDAA) detectors, and by direct detection of neutrons

  4. Active Response Gravity Offload System

    NASA Technical Reports Server (NTRS)

    Valle, Paul; Dungan, Larry; Cunningham, Thomas; Lieberman, Asher; Poncia, Dina

    2011-01-01

    The Active Response Gravity Offload System (ARGOS) provides the ability to simulate with one system the gravity effect of planets, moons, comets, asteroids, and microgravity, where the gravity is less than Earth fs gravity. The system works by providing a constant force offload through an overhead hoist system and horizontal motion through a rail and trolley system. The facility covers a 20 by 40-ft (approximately equals 6.1 by 12.2m) horizontal area with 15 ft (approximately equals4.6 m) of lifting vertical range.

  5. Design concept for the microwave interrogation structure in PARCS

    NASA Technical Reports Server (NTRS)

    Dick, G. J.; Klipstein, W. M.; Heavner, T. P.; Jefferts, S. R.

    2002-01-01

    In this paper we will describe key aspects of the conceptual design of the microwave interrogation structure in the laser-cooled cesium frequency standard that is part of the Primary Atomic Reference Clock in Space (PARCS) experiment.

  6. High performance FBG interrogation technology with scan fiber laser

    NASA Astrophysics Data System (ADS)

    Yang, Yuanhong; Ma, Youchun; Yang, Minwei

    2010-11-01

    A Fiber Bragg gratings (FBG) Interrogation scheme with scan fiber laser was demonstrated. The ring cavity scan fiber laser was investigated and the scan fiber laser module was made and test, the 200Hz scan frequency, ~0.02nm line width, more than 40nm scan range and more than 1 mW output power were obtained. A 12 channels, 20 FBGs per channel FBG interrogator was made with this laser module and the high speed signal process circuit base on FPGA. The centroid finding method which has advantage on interrogation speed and accurate was taken for finding the peak of the return FBG spectrum. The FBG interrogator was test and less than 3pm standard deviation with 200Hz scan frequency were obtained.

  7. The role of abusive states of being in interrogation.

    PubMed

    Putnam, Frank W

    2013-01-01

    Interrogation, the questioning of persons detained by police, military, or intelligence organizations, is designed to extract information that a subject may resist disclosing. Interrogation techniques are frequently predicated on inducing mental states of despair, dread, dependency, and debility that weaken an individual's resistance. Descriptions of techniques from 2 Central Intelligence Agency training manuals are illustrated by examples from interviews of and writings by Murat Kurnaz, who was held at Guantánamo Bay Detention Camp for 5 years. Interrogation techniques are designed to create a destabilizing sense of shock; undermine an individual's grasp on reality; and provoke internal psychological division, self-conflict, and confusion. The long-term effects of interrogation often include posttraumatic stress disorder as well as states of anxiety, depression, and depersonalization. PMID:23406220

  8. Determining plutonium mass in spent fuel using Cf-252 interrogation with prompt neutron detection

    SciTech Connect

    Hu, Jianwei; Tobin, Stephen J; Menlove, Howard O; Croft, Stephen

    2010-01-01

    {sup 252}Cf Interrogation with Prompt Neutron (CIPN) detection is proposed as one of 14 NDA techniques to determine Pu mass in spent fuel assemblies (FAs). CIPN is a low-cost and portable instrument, and it looks like a modified fork detector combined with an active interrogation source. Fission chamber (FC) is chosen as neutron detector because of its insensitivity to {gamma} radiation. The CIPN assay is comprised of two measurements, a background count and an active count, without and with the {sup 252}Cf source next to the fuel respectively. The net signal above background is primarily due to the multiplication of Cf source neutrons caused by the fissile content. The capability of CIPN to detect diversion and to determine fissile content was quantified using MCNPX simulations. New schemes were proposed (such as burnup and cooling time correction, etc.) and the results show that the fissile content of a target spent fuel assembly can be determined using CIPN signal.

  9. Interrogations, confessions, and guilty pleas among serious adolescent offenders.

    PubMed

    Malloy, Lindsay C; Shulman, Elizabeth P; Cauffman, Elizabeth

    2014-04-01

    In the present study, we examined (a) the prevalence and characteristics of youths' true and false admissions (confessions and guilty pleas), (b) youths' interrogation experiences with police and lawyers, and (c) whether youths' interrogation experiences serve as situational risk factors for true and false admissions. We interviewed 193 14- to 17-year-old males (M = 16.4) incarcerated for serious crimes. Over 1/3 of the sample (35.2%) claimed to have made a false admission to legal authorities (17.1% false confession; 18.1% false guilty plea), and 2/3 claimed to have made a true admission (28.5% true confession; 37.3% true guilty plea). The majority of youth said that they had experienced high-pressure interrogations (e.g., threats), especially with police officers. Youth who mentioned experiencing "police refusals" (e.g., of a break to rest) were more likely to report having made both true and false confessions to police, whereas only false confessions were associated with claims of long interrogations (>2 hr) and being questioned in the presence of a friend. The number of self-reported high-pressure lawyer tactics was associated with false, but not true, guilty pleas. Results suggest the importance of conducting specialized trainings for those who interrogate youth, recording interrogations, placing limits on lengthy and manipulative techniques, and exploring alternative procedures for questioning juvenile suspects. PMID:24127891

  10. A utilitarian argument against torture interrogation of terrorists.

    PubMed

    Arrigo, Jean Maria

    2004-07-01

    Following the September 2001 terrorist attacks on the United States, much support for torture interrogation of terrorists has emerged in the public forum, largely based on the "ticking bomb" scenario. Although deontological and virtue ethics provide incisive arguments against torture, they do not speak directly to scientists and government officials responsible for national security in a utilitarian framework. Drawing from criminology, organizational theory, social psychology, the historical record, and my interviews with military professionals, I assess the potential of an official U.S. program of torture interrogation from a practical perspective. The central element of program design is a sound causal model relating input to output. I explore three principal models of how torture interrogation leads to truth: the animal instinct model, the cognitive failure model, and the data processing model. These models show why torture interrogation fails overall as a counterterrorist tactic. They also expose the processes that lead from a precision torture interrogation program to breakdowns in key institutions-health care, biomedical research, police, judiciary, and military. The breakdowns evolve from institutional dynamics that are independent of the original moral rationale. The counterargument, of course, is that in a society destroyed by terrorism there will be nothing to repair. That is why the actual causal mechanism of torture interrogation in curtailing terrorism must be elucidated by utilitarians rather than presumed PMID:15362710

  11. Signal predictions for a proposed fast neutron interrogation method

    SciTech Connect

    Sale, K.E.

    1992-12-01

    We have applied the Monte Carlo radiation transport code COG) to assess the utility of a proposed explosives detection scheme based on neutron emission. In this scheme a pulsed neutron beam is generated by an approximately seven MeV deuteron beam incident on a thick Be target. A scintillation detector operating in the current mode measures the neutrons transmitted through the object as a function of time. The flight time of unscattered neutrons from the source to the detector is simply related to the neutron energy. This information along with neutron cross section excitation functions is used to infer the densities of H, C, N and O in the volume sampled. The code we have chosen to use enables us to create very detailed and realistic models of the geometrical configuration of the system, the neutron source and of the detector response. By calculating the signals that will be observed for several configurations and compositions of interrogated object we can investigate and begin to understand how a system that could actually be fielded will perform. Using this modeling capability many early on with substantial savings in time and cost and with improvements in performance. We will present our signal predictions for simple single element test cases and for explosive compositions. From these studies it is dear that the interpretation of the signals from such an explosives identification system will pose a substantial challenge.

  12. The JET Neutron Activation System

    NASA Astrophysics Data System (ADS)

    Roquemore, A. L.; Bertalot, L.; Esposito, B.; Jarvis, O. N.; Loughlin, M. J.; Sadler, G.; van Belle, P.

    1997-11-01

    The JET activation system provides the absolute value of the neutron yields as well as a check on the linearity of other neutron detector systems. The total neutron yield is standardized to one irradiation end reentrant in the top of the vessel, while the results from the other seven irradiation ends are normalized to this standard end and provide redundancy as well as information on the plasma position. A pneumatic transfer system is used to transfer up to five capsules containing elemental foils for a single discharge on JET. Eleven different elemental foils have been utilized to determine the yields from both DD and DT plasmas. By placing several different foils with different activation energy thresholds in a single capsule for one DT discharge, neutron spectral information has been obtained by use of the SAND-II unfolding code. A description of the activation system hardware and calibration of the activation detector system will be presented along with the results from the DT neutron calibration campaign.

  13. Optogenetic interrogation of neural circuits: technology for probing mammalian brain structures

    PubMed Central

    Zhang, Feng; Gradinaru, Viviana; Adamantidis, Antoine R; Durand, Remy; Airan, Raag D; de Lecea, Luis; Deisseroth, Karl

    2015-01-01

    Elucidation of the neural substrates underlying complex animal behaviors depends on precise activity control tools, as well as compatible readout methods. Recent developments in optogenetics have addressed this need, opening up new possibilities for systems neuroscience. Interrogation of even deep neural circuits can be conducted by directly probing the necessity and sufficiency of defined circuit elements with millisecond-scale, cell type-specific optical perturbations, coupled with suitable readouts such as electrophysiology, optical circuit dynamics measures and freely moving behavior in mammals. Here we collect in detail our strategies for delivering microbial opsin genes to deep mammalian brain structures in vivo, along with protocols for integrating the resulting optical control with compatible readouts (electrophysiological, optical and behavioral). The procedures described here, from initial virus preparation to systems-level functional readout, can be completed within 4–5 weeks. Together, these methods may help in providing circuit-level insight into the dynamics underlying complex mammalian behaviors in health and disease. PMID:20203662

  14. Detection of Special Nuclear Material in Cargo Containers Using Neutron Interrogation

    SciTech Connect

    Slaughter, D; Accatino, M; Bernstein, A; Candy, J; Dougan, A; Hall, J; Loshak, A; Manatt, D; Meyer, A; Pohl, B; Prussin, S; Walling, R; Weirup, D

    2003-08-01

    The goal of the work reported here is to develop a concept for an active neutron interrogation system that can detect small targets of SNM contraband in cargo containers, roughly 5 kg HEU or 1 kg Pu, even when well shielded by a thick cargo. It is essential that the concept be reliable and have low false-positive and false-negative error rates. It also must be rapid to avoid interruption of commerce, completing the analysis in minutes. A new radiation signature unique to SNM has been identified that utilizes high-energy (E{sub {gamma}} = 3-7 MeV) fission product {gamma}-ray emission. Fortunately, this high-energy {gamma}-ray signature is robust in that it is very distinct compared to normal background radiation where there is no comparable high-energy {gamma}-ray radiation. Equally important, it has a factor of 10 higher yield than delayed neutrons that are the basis of classical interrogation technique normally used on small unshielded specimens of SNM. And it readily penetrates two meters of low-Z and high-Z cargo at the expected density of {approx} 0.5 gm/cm{sup 3}. Consequently, we expect that in most cases the signature flux at the container wall is at least 2-3 decades more intense than delayed neutron signals used historically and facilitates the detection of SNM even when shielded by thick cargo. Experiments have verified this signature and its predicted characteristics. However, they revealed an important interference due to the activation of {sup 16}O by the {sup 16}O(n,p){sup 16}N reaction that produces a 6 MeV {gamma}-ray following a 7-sec {beta}-decay of the {sup 16}N. This interference is important when irradiating with 14 MeV neutrons but is eliminated when lower energy neutron sources are utilized since the reaction threshold for {sup 16}O(n,p){sup 16}N is 10 MeV. The signature {gamma}-ray fluxes exiting a thick cargo can be detected in large arrays of scintillation detectors to produce useful signal count rates of 2-4 x 10{sup 4} cps. That is high

  15. Modeling approaches for active systems

    NASA Astrophysics Data System (ADS)

    Herold, Sven; Atzrodt, Heiko; Mayer, Dirk; Thomaier, Martin

    2006-03-01

    To solve a wide range of vibration problems with the active structures technology, different simulation approaches for several models are needed. The selection of an appropriate modeling strategy is depending, amongst others, on the frequency range, the modal density and the control target. An active system consists of several components: the mechanical structure, at least one sensor and actuator, signal conditioning electronics and the controller. For each individual part of the active system the simulation approaches can be different. To integrate the several modeling approaches into an active system simulation and to ensure a highly efficient and accurate calculation, all sub models must harmonize. For this purpose, structural models considered in this article are modal state-space formulations for the lower frequency range and transfer function based models for the higher frequency range. The modal state-space formulations are derived from finite element models and/or experimental modal analyses. Consequently, the structure models which are based on transfer functions are directly derived from measurements. The transfer functions are identified with the Steiglitz-McBride iteration method. To convert them from the z-domain to the s-domain a least squares solution is implemented. An analytical approach is used to derive models of active interfaces. These models are transferred into impedance formulations. To couple mechanical and electrical sub-systems with the active materials, the concept of impedance modeling was successfully tested. The impedance models are enhanced by adapting them to adequate measurements. The controller design strongly depends on the frequency range and the number of modes to be controlled. To control systems with a small number of modes, techniques such as active damping or independent modal space control may be used, whereas in the case of systems with a large number of modes or with modes that are not well separated, other control

  16. Characterization of FBG sensor interrogation based on a FDML wavelength swept laser

    PubMed Central

    Jung, Eun Joo; Kim, Chang-Seok; Jeong, Myung Yung; Kim, Moon Ki; Jeon, Min Yong; Jung, Woonggyu; Chen, Zhongping

    2012-01-01

    In this study, we develop an ultra-fast fiber Bragg grating sensor system that is based on the Fourier domain mode-locked (FDML) swept laser. A FDML wavelength swept laser has many advantages compared to the conventional wavelength swept laser source, such as high-speed interrogation, narrow spectral sensitivity, and high phase stability. The newly developed FDML wavelength swept laser shows a superior performance of a high scan rate of 31.3 kHz and a broad scan range of over 70 nm simultaneously. The performance of the grating sensor interrogating system using a FDML wavelength swept laser is characterized in both static and dynamic strain responses. PMID:18852764

  17. Demonstration of an ultrasensitive refractive-index plasmonic sensor by enabling its quadrupole resonance in phase interrogation.

    PubMed

    Lee, Hsin-Cheng; Li, Chung-Tien; Chen, How-Foo; Yen, Ta-Jen

    2015-11-15

    We present an ultrasensitive plasmonic sensing system by introducing a nanostructured X-shaped plasmonic sensor (XPS) and measuring its localized optical properties in phase interrogation. Our tailored XPS exhibits two major resonant modes of a low-order dipole and a high-order quadrupole, between which the quadrupole resonance allows an ultrahigh sensitivity, due to its higher quality factor. Furthermore, we design an in-house common-path phase-interrogation system, in contrast to conventional wavelength-interrogation methods, to achieve greater sensing capability. The experimental measurement shows that the sensing resolution of the XPS reaches 1.15×10(-6) RIU, not only two orders of magnitude greater than the result of the controlled extinction measurement (i.e., 9.90×10(-5) RIU), but also superior than current reported plasmonic sensors. PMID:26565822

  18. Remotely-interrogated high data rate free space laser communications link

    DOEpatents

    Ruggiero, Anthony J.

    2007-05-29

    A system and method of remotely extracting information from a communications station by interrogation with a low power beam. Nonlinear phase conjugation of the low power beam results in a high power encoded return beam that automatically tracks the input beam and is corrected for atmospheric distortion. Intracavity nondegenerate four wave mixing is used in a broad area semiconductor laser in the communications station to produce the return beam.

  19. PRESTO-Tango as an open-source resource for interrogation of the druggable human GPCRome.

    PubMed

    Kroeze, Wesley K; Sassano, Maria F; Huang, Xi-Ping; Lansu, Katherine; McCorvy, John D; Giguère, Patrick M; Sciaky, Noah; Roth, Bryan L

    2015-05-01

    G protein-coupled receptors (GPCRs) are essential mediators of cellular signaling and are important targets of drug action. Of the approximately 350 nonolfactory human GPCRs, more than 100 are still considered to be 'orphans' because their endogenous ligands remain unknown. Here, we describe a unique open-source resource that allows interrogation of the druggable human GPCRome via a G protein-independent β-arrestin-recruitment assay. We validate this unique platform at more than 120 nonorphan human GPCR targets, demonstrate its utility for discovering new ligands for orphan human GPCRs and describe a method (parallel receptorome expression and screening via transcriptional output, with transcriptional activation following arrestin translocation (PRESTO-Tango)) for the simultaneous and parallel interrogation of the entire human nonolfactory GPCRome. PMID:25895059

  20. Performance of a Compact Gamma Tube Interrogation Source

    SciTech Connect

    King, Michael J.; Antolak, Arlyn J.; Morse, Dan H.; Raber, Thomas N.; Leung, Ka-Ngo; Doyle, Barney L.

    2009-03-10

    Active interrogation with high-energy monoenergetic gammas can induce photofission signals in fissile materials while minimizing absorbed radiation dose and background from surrounding materials. A first-generation axial-type gamma generator has been developed that utilizes the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction at a 163 keV resonance to produce monoenergetic 12-MeV gamma-rays. The gamma tube employs a water-cooled cylindrical radio frequency (if) induction ion source capable of producing a proton current density of up to 100 mA/cm{sup 2}. The extracted proton beam bombards a lanthanum hexaboride (LaB{sub 6}) target at energies up to 200 keV. The 12-MeV gamma intensity was measured as a function of proton energy, beam current, and angle. Photofission-induced neutrons from depleted uranium (DU) were measured and compared to MCNPX calculations. After extended operation, the high power density of the proton beam was observed to cause damage to the LaB{sub 6} target and the gamma tube improvements currently being made to mitigate this damage are discussed.

  1. Pulsed neutron interrogation for detection of concealed special nuclear materials

    NASA Astrophysics Data System (ADS)

    Ruddy, Frank; Seidel, John; Flammang, Robert; Petrović, Bojan; Dulloo, Abdul; Congedo, Thomas

    2006-05-01

    A new neutron interrogation technique for detection of concealed Special Nuclear Material (SNM) is described. This technique is a combination of timing techniques from pulsed prompt gamma neutron activation analysis with silicon carbide (SiC) semiconductor fast neutron detector technology. SiC detectors are a new class of radiation detectors that are ultra-fast and capable of processing high count rates. SiC detectors can operate during and within nanoseconds of the end of an intense neutron pulse, providing the ability to detect the prompt neutron emissions from fission events produced by the neutrons in concealed SNM on a much faster pulsing time scale than has been achieved by other techniques. Neutron-induced fission neutrons in 235U have been observed in the time intervals between pulses of 14-MeV neutrons from a deuterium-tritium electronic neutron generator. Initial measurements have emphasized the detection of SNM using thermal-neutron induced fission. Neutron pulsing and time-sequenced neutron counts were carried out on a hundreds of microseconds time scale, enabling the observation of prompt fission neutrons induced by the die-away of thermal neutrons following the 14-MeV pulse. A discussion of pulsed prompt-neutron measurements and of SiC detectors as well as initial measurement results will be presented.

  2. The activation system EASY-2007

    NASA Astrophysics Data System (ADS)

    Forrest, R. A.; Kopecky, J.

    2009-04-01

    Safety and waste management of materials for ITER, IFMIF and future power plants require knowledge of the activation caused by irradiation with neutrons, or in the case of IFMIF, deuterons. The European Activation System has been developed for such calculations and a new version was released earlier this year. This contains a large amount of nuclear data in the European Activation File covering neutron-, deuteron- and proton-induced cross sections. These data are input to the FISPACT code for activation calculations. EASY-2007 is being validated using integral and differential measurements. However, only a minority of reactions have experimental support and a statistical method is described that can test the complete library. Importance diagrams are useful in finding the dominant nuclides formed following irradiation and the reactions responsible for their production. These diagrams now cover energies above 20 MeV and examples of new dominant nuclides and reactions relevant to IFMIF are given.

  3. Molecular techniques to interrogate and edit the Chlamydomonas nuclear genome.

    PubMed

    Jinkerson, Robert E; Jonikas, Martin C

    2015-05-01

    The success of the green alga Chlamydomonas reinhardtii as a model organism is to a large extent due to the wide range of molecular techniques that are available for its characterization. Here, we review some of the techniques currently used to modify and interrogate the C. reinhardtii nuclear genome and explore several technologies under development. Nuclear mutants can be generated with ultraviolet (UV) light and chemical mutagens, or by insertional mutagenesis. Nuclear transformation methods include biolistic delivery, agitation with glass beads, and electroporation. Transforming DNA integrates into the genome at random sites, and multiple strategies exist for mapping insertion sites. A limited number of studies have demonstrated targeted modification of the nuclear genome by approaches such as zinc-finger nucleases and homologous recombination. RNA interference is widely used to knock down expression levels of nuclear genes. A wide assortment of transgenes has been successfully expressed in the Chlamydomonas nuclear genome, including transformation markers, fluorescent proteins, reporter genes, epitope tagged proteins, and even therapeutic proteins. Optimized expression constructs and strains help transgene expression. Emerging technologies such as the CRISPR/Cas9 system, high-throughput mutant identification, and a whole-genome knockout library are being developed for this organism. We discuss how these advances will propel future investigations. PMID:25704665

  4. Multiplicity Analysis during Photon Interrogation of Fissionable Material

    SciTech Connect

    Clarke, Shaun D; Pozzi, Sara A; Padovani, Enrico; Downar, Thomas J

    2007-01-01

    Simulation of multiplicity distributions with the Monte Carlo method is difficult because each history is treated individually. In order to accurately model the multiplicity distribution, the intensity and time width of the interrogation pulse must be incorporated into the calculation. This behavior dictates how many photons arrive at the target essentially simultaneously. In order to model the pulse width correctly, a Monte Carlo code system consisting of modified versions of the codes MCNPX and MCNP-PoliMi has been developed in conjunction with a post-processing algorithm to operate on the MCNP-PoliMi output file. The purpose of this subroutine is to assemble the interactions into groups corresponding to the number of interactions which would occur during a given pulse. The resulting multiplicity distributions appear more realistic and capture the higher-order multiplets which are a product of multiple reactions occurring during a single accelerator pulse. Plans are underway to gather relevant experimental data to verify and validate the methodology developed and presented here. This capability will enable the simulation of a large number of materials and detector geometries. Analysis of this information will determine the feasibility of using multiplicity distributions as an identification tool for special nuclear material.

  5. Time-Dependent Delayed Signatures From Energetic Photon Interrogations

    SciTech Connect

    D. R. Norman; J. L. Jones; B. W. Blackburn; S. M. Watson; K. J. Haskell

    2006-08-01

    A pulsed photonuclear interrogation environment is rich with time-dependent, material specific, radiation signatures. Exploitation of these signatures in the delayed time regime (>1us after the photon flash) has been explored through various detection schemes to identify both shielded nuclear material and nitrogen-based explosives. Prompt emission may also be invaluable for these detection methods. Numerical and experimental results, which utilize specially modified neutron and HpGe detectors, are presented which illustrate the efficacy of utilizing these time-dependent signatures. Optimal selection of the appropriate delayed time window is essential to these pulsed inspection systems. For explosive (ANFO surrogate) detection, both numerical models and experimental results illustrate that nearly all 14N(n,y) reactions have occurred within l00 us after the flash. In contrast, however, gamma-ray and neutron signals for nuclear material detection require a delay of several milliseconds after the photon pulse. In this case, any data collected too close to the photon flash results in a spectrum dominated by high energy signals which make it difficult to discern signatures from nuclear material. Specifically, two short-lived, high-energy fission fragments (97Ag(T1/2=5.1 s) and 94Sr(T1/2=75.2 s)) were measured and identified as indicators of the presence of fissionable material. These developments demonstrate that a photon inspection environment can be exploited for time-dependent, material specific signatures through the proper operation of specially modified detectors.

  6. Monte Carlo Modeling of Photon Interrogation Methods for Characterization of Special Nuclear Material

    SciTech Connect

    Pozzi, Sara A; Downar, Thomas J; Padovani, Enrico; Clarke, Shaun D

    2006-01-01

    This work illustrates a methodology based on photon interrogation and coincidence counting for determining the characteristics of fissile material. The feasibility of the proposed methods was demonstrated using a Monte Carlo code system to simulate the full statistics of the neutron and photon field generated by the photon interrogation of fissile and non-fissile materials. Time correlation functions between detectors were simulated for photon beam-on and photon beam-off operation. In the latter case, the correlation signal is obtained via delayed neutrons from photofission, which induce further fission chains in the nuclear material. An analysis methodology was demonstrated based on features selected from the simulated correlation functions and on the use of artificial neural networks. We show that the methodology can reliably differentiate between highly enriched uranium and plutonium. Furthermore, the mass of the material can be determined with a relative error of about 12%. Keywords: MCNP, MCNP-PoliMi, Artificial neural network, Correlation measurement, Photofission

  7. Identifying Robust and Sensitive Frequency Bands for Interrogating Neural Oscillations

    PubMed Central

    Shackman, Alexander J.; McMenamin, Brenton W.; Maxwell, Jeffrey S.; Greischar, Lawrence L.; Davidson, Richard J.

    2010-01-01

    Recent years have seen an explosion of interest in using neural oscillations to characterize the mechanisms supporting cognition and emotion. Oftentimes, oscillatory activity is indexed by mean power density in predefined frequency bands. Some investigators use broad bands originally defined by prominent surface features of the spectrum. Others rely on narrower bands originally defined by spectral factor analysis (SFA). Presently, the robustness and sensitivity of these competing band definitions remains unclear. Here, a Monte Carlo-based SFA strategy was used to decompose the tonic (“resting” or “spontaneous”) electroencephalogram (EEG) into five bands: delta (1–5Hz), alpha-low (6–9Hz), alpha-high (10–11Hz), beta (12–19Hz), and gamma (>21Hz). This pattern was consistent across SFA methods, artifact correction/rejection procedures, scalp regions, and samples. Subsequent analyses revealed that SFA failed to deliver enhanced sensitivity; narrow alpha sub-bands proved no more sensitive than the classical broadband to individual differences in temperament or mean differences in task-induced activation. Other analyses suggested that residual ocular and muscular artifact was the dominant source of activity during quiescence in the delta and gamma bands. This was observed following threshold-based artifact rejection or independent component analysis (ICA)-based artifact correction, indicating that such procedures do not necessarily confer adequate protection. Collectively, these findings highlight the limitations of several commonly used EEG procedures and underscore the necessity of routinely performing exploratory data analyses, particularly data visualization, prior to hypothesis testing. They also suggest the potential benefits of using techniques other than SFA for interrogating high-dimensional EEG datasets in the frequency or time-frequency (event-related spectral perturbation, event-related synchronization / desynchronization) domains. PMID

  8. Engineering intracellular active transport systems as in vivo biomolecular tools.

    SciTech Connect

    Bachand, George David; Carroll-Portillo, Amanda

    2006-11-01

    Active transport systems provide essential functions in terms of cell physiology and metastasis. These systems, however, are also co-opted by invading viruses, enabling directed transport of the virus to and from the cell's nucleus (i.e., the site of virus replication). Based on this concept, fundamentally new approaches for interrogating and manipulating the inner workings of living cells may be achievable by co-opting Nature's active transport systems as an in vivo biomolecular tool. The overall goal of this project was to investigate the ability to engineer kinesin-based transport systems for in vivo applications, specifically the collection of effector proteins (e.g., transcriptional regulators) within single cells. In the first part of this project, a chimeric fusion protein consisting of kinesin and a single chain variable fragment (scFv) of an antibody was successfully produced through a recombinant expression system. The kinesin-scFv retained both catalytic and antigenic functionality, enabling selective capture and transport of target antigens. The incorporation of a rabbit IgG-specific scFv into the kinesin established a generalized system for functionalizing kinesin with a wide range of target-selective antibodies raised in rabbits. The second objective was to develop methods of isolating the intact microtubule network from live cells as a platform for evaluating kinesin-based transport within the cytoskeletal architecture of a cell. Successful isolation of intact microtubule networks from two distinct cell types was demonstrated using glutaraldehyde and methanol fixation methods. This work provides a platform for inferring the ability of kinesin-scFv to function in vivo, and may also serve as a three-dimensional scaffold for evaluating and exploiting kinesin-based transport for nanotechnological applications. Overall, the technology developed in this project represents a first-step in engineering active transport system for in vivo applications. Further

  9. Multi-isotopic transuranic waste interrogation using delayed neutron nondestructive assay and iterative quadratic programming techniques

    NASA Astrophysics Data System (ADS)

    Wu, Cheng-Wei

    1997-11-01

    Nuclear safeguards for Special Nuclear Materials is to protect the nuclear materials against malevolent use and to insure their peaceful usage. The nondestructive assay technique (NDA) offers an efficient and proliferation resistance method for nuclear safeguards technology. NDA techniques were investigated for multi-isotopic transuranic waste interrogation. This work was originally intended for the Integral Fast Reactor (IFR) under development at Argonne National Laboratory. One major feature of the IFR is its integral fuel cycle based on a pyrometallurgical process. More than 99% of transuranics produced in the fuel are returned to the makeup fuel and burned in the reactor. With the long-lived actinides removed from the waste stream, the waste produced will decay sufficiently in 300 years dropping below the cancer risk level of natural uranium ore and easing the perceived waste management problem. The feasibility of using nondestructive assay techniques for the IFR fuel cycle waste interrogation were studied. A special DNNDA experimental device was designed and analysis techniques were developed. The DNNDA technique uses the delayed neutrons emitted after the activation of a 14 MeV neutron source as the characteristic signature for each fissionable isotope. A tantalum/polyethylene filter was employed to enhance the discrimination between the fissile and the fissionable isotopes. Spontaneous fissions from 240Pu were also measured to assist the mass assay. A nonlinear overdetermined system was established based on the DNNDA measurements. An Iterative Quadratic Programming (IQP) method was applied to perform the estimates. The IQP method has several advantages over the linear least squares and Kalman filter methods, it has the flexibility of adding additional constraints, it has superlinear global convergence and it can be utilized for nonlinear problems. The results show that using the IQP method with the DNNDA technique is quite promising for multi-isotopic assay

  10. Insight into fiber Bragg sensor response at 100-MHz interrogation rates under various dynamic loading conditions

    NASA Astrophysics Data System (ADS)

    Rodriguez, George; Jaime, Marcelo; Mielke, Chuck H.; Balakirev, Fedor F.; Azad, Abul; Sandberg, Richard L.; Marshall, Bruce; La Lone, Brandon M.; Henson, Bryan F.; Smilowitz, Laura; Marr-Lyon, Mark; Sandoval, Tom

    2015-05-01

    A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain, pressure, and shock position sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber was used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor were detected as a pulsed time domain waveform shift after encoding by the chromatic dispersive line. Signals were recorded using a single 35 GHz photodetector and a 25 GHz bandwidth digitizing oscilloscope. Application of this approach to high-speed strain sensing of magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts were used to study magnetic field driven magnetostriction effects in LaCoO3. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ΔL/L<10-4) in the material. A second application to FBG sensing of pressure dynamics to nearly 2 GPa in the thermal ignition of the high explosive PBX-9501 is also demonstrated. Then, as final demonstration, we use a chirped FBG (CFBG) to resolve shock propagation dynamics in 1-D from an explosive detonation that produces fragmentation in an inert confinement vessel. These applications demonstrate the use of this FBG interrogation system in dynamical extreme conditions that would otherwise not be possible using traditional FBG interrogation approaches that are deemed too slow to resolve such events.

  11. Hood River PIT-tag interrogation system efficiency study. Annual report of U.S. Geological Survey activities: November 2010-October 2011

    USGS Publications Warehouse

    Jezorek, Ian G.; Connolly, Patrick J.

    2012-01-01

    An additional USGS-CRRL task, under contract number 50150, was to build three antennas for use with Destron-Fearing 2001F-ISO PIT tag readers. These antennas would be 5 used at the East Fork Hood River Acclimation site. They would be placed in the outflow channel to inform managers about the number of PIT tagged steelhead smolts released to the Hood River after a period of acclimation when some mortality and predation might occur. 

  12. X-ray and neutron interrogation of air cargo for mobile applications

    NASA Astrophysics Data System (ADS)

    Van Liew, Seth

    2015-06-01

    A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated.

  13. Subthreshold neutron interrogator for detection of radioactive materials

    DOEpatents

    Evans, Michael L.; Menlove, Howard O.; Baker, Michael P.

    1980-01-01

    A device for detecting fissionable material such as uranium in low concentrations by interrogating with photoneutrons at energy levels below 500 keV, and typically about 26 keV. Induced fast neutrons having energies above 500 keV by the interrogated fissionable material are detected by a liquid scintillator or recoil proportional counter which is sensitive to the induced fast neutrons. Since the induced fast neutrons are proportional to the concentration of fissionable material, detection of induced fast neutrons indicate concentration of the fissionable material.

  14. Design, integration, and testing of a compact FBG interrogator, based on an AWG spectrometer

    NASA Astrophysics Data System (ADS)

    Trita, Andrea; Vickers, Garrie; Mayordomo, Iker; van Thourhout, Dries; Vermeiren, Jan

    2014-05-01

    Fiber Bragg Grating or FBG sensors are gaining more and more interest in structural health monitoring of composite materials. Often, the weakest point in such a system is the ingress point of the fiber sensing chain into the composite material. For this reason we have developed a strongly miniaturized FBG interrogator unit with wireless power and data transmission, which can be incorporated in the composite structure. The interrogator is based on an arrayed waveguide grating (AWG) filter fabricated in a SOI technology, which is tailored in such a way to give large cross-talk between neighboring channels. The AWG signals are read by a linear 128 pixel InGaAs array flip-chipped on top of the Photonic Circuit (PIC). The spectrometer unit is completed with a ROIC mounted on the same substrate. The SLED and remaining electronics are integrated on a small and thin substrate and surrounded by the wireless antenna. The interrogator has an overall dimension of 100 mm diameter by max 7 mm height. The power dissipation of the electronics unit is limited to 1.5 W. The unit is capable of measuring strain values as low as 5 micro-strain.

  15. Interrogative suggestibility, confabulation, and acquiescence in people with mild learning disabilities (mental handicap): implications for reliability during police interrogations.

    PubMed

    Clare, I C; Gudjonsson, G H

    1993-09-01

    In order to assess a criminal suspect's ability to make a reliable statement, performance on three measures--interrogative suggestibility, confabulation and acquiescence--may be used. This paper presents preliminary data on these measures for people with mild learning disabilities (Full Scale IQ [FSIQ]: 57-75). It was found that they were more suggestible than their average ability counterparts (FSIQ: 83-111) because they were much more susceptible to 'leading questions'. They also confabulated more and were more acquiescent. Overall, the data emphasized their potential vulnerability to giving erroneous testimony during interrogations. PMID:8251959

  16. Photonic Interrogation and Control of Nano Processes

    NASA Technical Reports Server (NTRS)

    Jassemnejad, Baha

    2003-01-01

    My research activities for the summer of 2003 consisted of two projects: One project was concerned with determining a method for predicting the static and dynamic assembly properties of nano-structures using laser tweezers. The other project was to investigate the generation of Laguerre-Gaussian modes using a spatial light modulator incorporated into an optical tweezers system. Concerning the first project, I initially pursued the approach suggested by my NASA colleague Dr. Art Decker. This approach involved mimicking the model of the structure of atomic nucleus for the assembly of 1 to 100 atoms using allowed quadruple transitions induced by orbital angular momentums of a Laguerre- Gaussian (Doughnut) laser mode. After realizing the inaptness of the nuclear model with the nanostructure model as far as the binding forces and transitions were concerned, I focused on using quantum dot modei. This model was not attuned also for the host lattice influences the electronic structure of the quantum dot. Thus one other option that I decided to pursue was the approach of molecular quantum mechanics. In this approach the nanostructure is treated as a large (10-100 nm) molecule constructed from single element or multi-elements. Subsequent to consultation with Dr. Fred Morales, a chemical engineer at NASA GRC, and Dr. David Ball, a computational chemist at Cleveland State University, I acquired a molecular-quantum computation software, Hyperchem 7.0. This software allows simulation of different molecular structures as far as their static and dynamic behaviors are concerned. The time that I spent on this project was about eight weeks. Once this suitable approach was identified, I realized the need to collaborate with a computational quantum chemist to pursue searching for stable nanostructures in the range of 10-100 nm that we can be assembled using laser tweezers. The second project was about generating laser tweezers that possess orbital angular momentum. As shown, we were

  17. High-energy photon interrogation for nonproliferation applications

    NASA Astrophysics Data System (ADS)

    Jones, J. L.; Blackburn, B. W.; Watson, S. M.; Norman, D. R.; Hunt, A. W.

    2007-08-01

    There is an immediate need for technologies that can successfully address homeland security challenges related to the inspection of commercial rail, air and maritime-cargo container inspections for nuclear and radiological devices. The pulsed photonuclear assessment (PPA) technology, developed through collaboration between Idaho National Laboratory (INL), Los Alamos National Laboratory (LANL) and the Idaho Accelerator Center (IAC) has demonstrated the ability to detect shielded/unshielded nuclear material primarily through the analysis of delayed neutrons and gamma-rays produced via photonuclear reactions. Because of current food irradiation limitations, however, most active photon (i.e. bremsstrahlung) interrogation studies have been performed with electron beam energies at or below 10 MeV. While this energy limit currently applies to cargo inspections, the World Health Organization has indicated that higher energy electron beam operations could be considered for future operations. Clinical applications using photon energies well in excess of 10 MeV are already well established. Notwithstanding the current limitation of 10 MeV, there is a definite advantage in using higher photon energies for cargo inspections. At higher energies, several phenomena contribute to increased sensitivity in regards to detecting shielded nuclear material. Two of the most important are: (1) increased ability for source photons to penetrate shielding; and (2) enhanced signature production via increased (γ,n) and (γ,f) cross-sections in materials such as 235U and 239Pu directly leading to faster inspection throughput. Experimental assessments have been conducted for various electron beam energies from 8 to 25 MeV. Increases of up to three orders of magnitude in delayed signatures have been measured over these energy ranges. Through the continued investigation into PPA-based inspection applications using photon energies greater than 10 MeV, higher detection sensitivities with potentially

  18. Remote file inquiry (RFI) system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    System interrogates and maintains user-definable data files from remote terminals, using English-like, free-form query language easily learned by persons not proficient in computer programming. System operates in asynchronous mode, allowing any number of inquiries within limitation of available core to be active concurrently.

  19. Teacher Epistemology and Collective Narratives: Interrogating Teaching and Diversity

    ERIC Educational Resources Information Center

    Adler, Susan Matoba

    2011-01-01

    This action research study interrogates how one teacher educator analyzed her pedagogy and engaged her students in writing narratives about working with children, families, and co-workers who are racially and ethnically different from themselves. Data were collected from a special topic graduate course entitled, Epistemology, Diversity and…

  20. Microwave interrogation cavity for the rubidium space cold atom clock

    NASA Astrophysics Data System (ADS)

    Wei, Ren; Yuan-Ci, Gao; Tang, Li; De-Sheng, Lü; Liang, Liu

    2016-06-01

    The performance of space cold atom clocks (SCACs) should be improved thanks to the microgravity environment in space. The microwave interrogation cavity is a key element in a SCAC. In this paper, we develop a microwave interrogation cavity especially for the rubidium SCAC. The interrogation cavity has two microwave interaction zones with a single feed-in source, which is located at the center of the cavity for symmetric coupling excitation and to ensure that the two interaction zones are in phase. The interrogation cavity has a measured resonance frequency of 6.835056471 GHz with a loaded quality factor of nearly 4200, which shows good agreement with simulation results. We measure the Rabi frequency of the clock transition of the rubidium atom in each microwave interaction zone, and subsequently demonstrate that the distributions of the magnetic field in the two interaction zones are the same and meet all requirements of the rubidium SCAC. Project supported by the National Natural Science Foundation of China (Grant No. 11034008), the Fund from the Ministry of Science and Technology of China (Grant No. 2013YQ09094304), and the Youth Innovation Promotion Association, Chinese Academy of Sciences.

  1. "Enhanced" interrogation of detainees: do psychologists and psychiatrists participate?

    PubMed

    Halpern, Abraham L; Halpern, John H; Doherty, Sean B

    2008-01-01

    After revelations of participation by psychiatrists and psychologists in interrogation of prisoners at Guantánamo Bay and Central Intelligence Agency secret detention centers, the American Psychiatric Association and the American Psychological Association adopted Position Statements absolutely prohibiting their members from participating in torture under any and all circumstances, and, to a limited degree, forbidding involvement in interrogations. Some interrogations utilize very aggressive techniques determined to be torture by many nations and organizations throughout the world. This paper explains why psychiatrists and psychologists involved in coercive interrogations violate the Geneva Conventions and the laws of the United States. Whether done with ignorance of professional ethical obligations or not, these psychiatrists and psychologists have crossed an ethical barrier that may best be averted from re-occurring by teaching medical students and residents in all medical specialties about the ethics principles stemming from the 1946-1947 Nuremberg trials and the Geneva Conventions, together with the Ethics Codes of the World Medical Association and the American Medical Association; and, with regard to psychiatric residents and psychological trainees, by the teaching about The Principles of Medical Ethics With Annotations Especially Applicable to Psychiatry and the Ethical Principles of Psychologists and Code of Conduct, respectively. In this way, all physicians and psychologists will clearly understand that they have an absolute moral obligation to "First, do no harm" to the human beings they professionally encounter. PMID:18817568

  2. Learning about Posterior Probability: Do Diagrams and Elaborative Interrogation Help?

    ERIC Educational Resources Information Center

    Clinton, Virginia; Alibali, Martha W.; Nathan, Mitchell J.

    2016-01-01

    To learn from a text, students must make meaningful connections among related ideas in that text. This study examined the effectiveness of two methods of improving connections--elaborative interrogation and diagrams--in written lessons about posterior probability. Undergraduate students (N = 198) read a lesson in one of three questioning…

  3. Interview and Interrogation Training using a Computer-Simulated Subject.

    ERIC Educational Resources Information Center

    Olsen, Dale E.

    Interactive, multimedia software involving a simulated subject has been created to help trainees develop interview and interrogation techniques using personal computers, because practice interviews are not always realistic and are too expensive. New and experienced law enforcement agents, among others, need such extensive training in techniques…

  4. "Enhanced" interrogation of detainees: do psychologists and psychiatrists participate?

    PubMed Central

    Halpern, Abraham L; Halpern, John H; Doherty, Sean B

    2008-01-01

    After revelations of participation by psychiatrists and psychologists in interrogation of prisoners at Guantánamo Bay and Central Intelligence Agency secret detention centers, the American Psychiatric Association and the American Psychological Association adopted Position Statements absolutely prohibiting their members from participating in torture under any and all circumstances, and, to a limited degree, forbidding involvement in interrogations. Some interrogations utilize very aggressive techniques determined to be torture by many nations and organizations throughout the world. This paper explains why psychiatrists and psychologists involved in coercive interrogations violate the Geneva Conventions and the laws of the United States. Whether done with ignorance of professional ethical obligations or not, these psychiatrists and psychologists have crossed an ethical barrier that may best be averted from re-occurring by teaching medical students and residents in all medical specialties about the ethics principles stemming from the 1946–1947 Nuremberg trials and the Geneva Conventions, together with the Ethics Codes of the World Medical Association and the American Medical Association; and, with regard to psychiatric residents and psychological trainees, by the teaching about The Principles of Medical Ethics With Annotations Especially Applicable to Psychiatry and the Ethical Principles of Psychologists and Code of Conduct, respectively. In this way, all physicians and psychologists will clearly understand that they have an absolute moral obligation to "First, do no harm" to the human beings they professionally encounter. PMID:18817568

  5. Interrogating Our Practices of Integrating Spirituality into Workplace Education

    ERIC Educational Resources Information Center

    English, Leona M.; Fenwick, Tara J.; Parsons, Jim

    2005-01-01

    Workplace education's interest in spirituality is examined, with an emphasis placed on why this interest might be increasing and what challenges it presents. This article interrogates commonplace strategies to integrate spirituality in workplace education,--providing holistic education, creating sacred spaces and mentoring--questions each approach…

  6. Absolute Interrogative Intonation Patterns in Buenos Aires Spanish

    ERIC Educational Resources Information Center

    Lee, Su Ar

    2010-01-01

    In Spanish, each uttered phrase, depending on its use, has one of a variety of intonation patterns. For example, a phrase such as "Maria viene manana" "Mary is coming tomorrow" can be used as a declarative or as an absolute interrogative (a yes/no question) depending on the intonation pattern that a speaker produces. Patterns of usage also…

  7. Some Remarks on Interrogative and Relative Pronouns in English

    ERIC Educational Resources Information Center

    Lewandowska, Barbara

    1973-01-01

    An analysis is made of three "wh" words -- what, which, and who -- which are most frequently used as interrogative and relative pronouns in English. An attempt is made to find some formal syntactic markers distinguishing these two uses and consequently to postulate distinct feature matrices for them. (Available from: See FL 508 214.) (Author/RM)

  8. Optimized performance for neutron interrogation to detect SNM

    SciTech Connect

    Slaughter, D R; Asztalos, S J; Biltoft, P J; Church, J A; Descalle, M; Hall, J M; Luu, T C; Manatt, D R; Mauger, G J; Norman, E B; Petersen, D C; Pruet, J A; Prussin, S G

    2007-02-14

    A program of simulations and validating experiments was utilized to evaluate a concept for neutron interrogation of commercial cargo containers that would reliably detect special nuclear material (SNM). The goals were to develop an interrogation system capable of detecting a 5 kg solid sphere of high-enriched uranium (HEU) even when deeply embedded in commercial cargo. Performance goals included a minimum detection probability, P{sub d} {ge} 95%, a maximum occurrence of false positive indications, P{sub fA} {le} 0.001, and maximum scan duration of t {le} 1 min. The conditions necessary to meet these goals were demonstrated in experimental measurements even when the SNM is deeply buried in any commercial cargo, and are projected to be met successfully in the most challenging cases of steel or hydrocarbons at areal density {rho}L {le} 150 g/cm{sup 2}. Optimal performance was obtained with a collimated ({Delta}{Theta} = {+-} 15{sup o}) neutron beam at energy E{sub n} = 7 MeV produced by the D(d,n) reaction with the deuteron energy E{sub d} = 4 MeV. Two fission product signatures are utilized to uniquely identify SNM, including delayed neutrons detected in a large array of polyethylene moderated 3He proportional counters and high energy {beta}-delayed fission product {gamma}-radiation detected in a large array of 61 x 61 x 25 cm{sup 3} plastic scintillators. The latter detectors are nearly blind to normal terrestrial background radiation by setting an energy threshold on the detection at E{sub min} {ge} 3 MeV. Detection goals were attained with a low beam current (I{sub d} = 15-65 {micro}A) source up to {rho}L = 75 g/cm{sup 2} utilizing long irradiations, T = 30 sec, and long counting times, t = 30-100 sec. Projecting to a higher beam current, I{sub d} {ge} 600 {micro}A and larger detector array the detection and false alarm goals would be attained even with intervening cargo overburden as large as {rho}L {le} 150 g/cm{sup 2}. The latter cargo thickness corresponds to

  9. Active thermal control system evolution

    NASA Technical Reports Server (NTRS)

    Petete, Patricia A.; Ames, Brian E.

    1991-01-01

    The 'restructured' baseline of the Space Station Freedom (SSF) has eliminated many of the growth options for the Active Thermal Control System (ATCS). Modular addition of baseline technology to increase heat rejection will be extremely difficult. The system design and the available real estate no longer accommodate this type of growth. As the station matures during its thirty years of operation, a demand of up to 165 kW of heat rejection can be expected. The baseline configuration will be able to provide 82.5 kW at Eight Manned Crew Capability (EMCC). The growth paths necessary to reach 165 kW have been identified. Doubling the heat rejection capability of SSF will require either the modification of existing radiator wings or the attachment of growth structure to the baseline truss for growth radiator wing placement. Radiator performance can be improved by enlarging the surface area or by boosting the operating temperature with a heat pump. The optimal solution will require both modifications. The addition of growth structure would permit the addition of a parallel ATCS using baseline technology. This growth system would simplify integration. The feasibility of incorporating these growth options to improve the heat rejection capacity of SSF is under evaluation.

  10. Radiological risks of neutron interrogation of food.

    PubMed

    Albright, S; Seviour, R

    2015-09-01

    In recent years there has been growing interest in the use of neutron scanning techniques for security. Neutron techniques with a range of energy spectra including thermal, white and fast neutrons have been shown to work in different scenarios. As international interest in neutron scanning increases the risk of activating cargo, especially foodstuffs must be considered. There has been a limited amount of research into the activation of foods by neutron beams and we have sought to improve the amount of information available. In this paper we show that for three important metrics; activity, ingestion dose and Time to Background there is a strong dependence on the food being irradiated and a weak dependence on the energy of irradiation. Previous studies into activation used results based on irradiation of pharmaceuticals as the basis for research into activation of food. The earlier work reports that (24)Na production is the dominant threat which motivated the search for (24)Na(n,γ)(24)Na in highly salted foods. We show that (42)K can be more significant than (24)Na in low sodium foods such as Bananas and Potatoes. PMID:26083976

  11. A multi-mode sensing system for corrosion detection using piezoelectric wafer active sensors

    NASA Astrophysics Data System (ADS)

    Yu, Lingyu; Giurgiutiu, Victor; Pollock, Patrick

    2008-03-01

    As an emerging technology for in-situ damage detection and nondestructive evaluation, structural health monitoring with active sensors (active SHM) plays as a promising candidate for the pipeline inspection and diagnosis. Piezoelectric wafer active sensor (PWAS), as an active sensing device, can be permanently attached to the structure to interrogate it at will and can operate in propagating wave mode or electromechanical impedance mode. Its small size and low cost (about $10 each) make itself a potential and unique technology for in-situ SHM application. The objective of the research in this paper is to develop a permanently installed in-situ "multi-mode" sensing system for the corrosion monitoring and prediction of critical pipeline systems. Such a system is used during in-service period, recording and monitoring the changes of the pipelines over time, such as corrosion, wall thickness, etc. Having the real-time data available, maintenance strategies based on these data can then be developed to ensure a safe and less expensive operation of the pipeline systems. After a detailed review of PWAS SHM methods, including ultrasonic, impedance, and thickness measurement, we introduce the concept of PWAS-based multi-mode sensing approach for corrosion detection in pipelines. Particularly, we investigate the potential for using PWAS waves for in thickness mode experimentally. Finally, experiments are conducted to verify the corrosion detection ability of the PWAS network in both metallic plate and pipe in a laboratory setting. Results show successful corrosion localization in both tests.

  12. Engagement with Language: Interrogating a Construct

    ERIC Educational Resources Information Center

    Svalberg, Agneta Marie-Louise

    2009-01-01

    In "Language awareness and language learning" (Svalberg, 2007) I concluded that the otherwise diverse and multidisciplinary field of language awareness (LA) is given coherence by its focus on engagement with language. I argued that LA is seen as active and not merely as a state of conscious awareness or sensitivity. This paper goes one step…

  13. All-Optical Interrogation of Neural Circuits

    PubMed Central

    2015-01-01

    There have been two recent revolutionary advances in neuroscience: First, genetically encoded activity sensors have brought the goal of optical detection of single action potentials in vivo within reach. Second, optogenetic actuators now allow the activity of neurons to be controlled with millisecond precision. These revolutions have now been combined, together with advanced microscopies, to allow “all-optical” readout and manipulation of activity in neural circuits with single-spike and single-neuron precision. This is a transformational advance that will open new frontiers in neuroscience research. Harnessing the power of light in the all-optical approach requires coexpression of genetically encoded activity sensors and optogenetic probes in the same neurons, as well as the ability to simultaneously target and record the light from the selected neurons. It has recently become possible to combine sensors and optical strategies that are sufficiently sensitive and cross talk free to enable single-action-potential sensitivity and precision for both readout and manipulation in the intact brain. The combination of simultaneous readout and manipulation from the same genetically defined cells will enable a wide range of new experiments as well as inspire new technologies for interacting with the brain. The advances described in this review herald a future where the traditional tools used for generations by physiologists to study and interact with the brain—stimulation and recording electrodes—can largely be replaced by light. We outline potential future developments in this field and discuss how the all-optical strategy can be applied to solve fundamental problems in neuroscience. SIGNIFICANCE STATEMENT This review describes the nexus of dramatic recent developments in optogenetic probes, genetically encoded activity sensors, and novel microscopies, which together allow the activity of neural circuits to be recorded and manipulated entirely using light. The

  14. Causal Interrogation of Neuronal Networks and Behavior through Virally Transduced Ivermectin Receptors.

    PubMed

    Obenhaus, Horst A; Rozov, Andrei; Bertocchi, Ilaria; Tang, Wannan; Kirsch, Joachim; Betz, Heinrich; Sprengel, Rolf

    2016-01-01

    The causal interrogation of neuronal networks involved in specific behaviors requires the spatially and temporally controlled modulation of neuronal activity. For long-term manipulation of neuronal activity, chemogenetic tools provide a reasonable alternative to short-term optogenetic approaches. Here we show that virus mediated gene transfer of the ivermectin (IVM) activated glycine receptor mutant GlyRα1 (AG) can be used for the selective and reversible silencing of specific neuronal networks in mice. In the striatum, dorsal hippocampus, and olfactory bulb, GlyRα1 (AG) promoted IVM dependent effects in representative behavioral assays. Moreover, GlyRα1 (AG) mediated silencing had a strong and reversible impact on neuronal ensemble activity and c-Fos activation in the olfactory bulb. Together our results demonstrate that long-term, reversible and re-inducible neuronal silencing via GlyRα1 (AG) is a promising tool for the interrogation of network mechanisms underlying the control of behavior and memory formation. PMID:27625595

  15. Causal Interrogation of Neuronal Networks and Behavior through Virally Transduced Ivermectin Receptors

    PubMed Central

    Obenhaus, Horst A.; Rozov, Andrei; Bertocchi, Ilaria; Tang, Wannan; Kirsch, Joachim; Betz, Heinrich; Sprengel, Rolf

    2016-01-01

    The causal interrogation of neuronal networks involved in specific behaviors requires the spatially and temporally controlled modulation of neuronal activity. For long-term manipulation of neuronal activity, chemogenetic tools provide a reasonable alternative to short-term optogenetic approaches. Here we show that virus mediated gene transfer of the ivermectin (IVM) activated glycine receptor mutant GlyRα1AG can be used for the selective and reversible silencing of specific neuronal networks in mice. In the striatum, dorsal hippocampus, and olfactory bulb, GlyRα1AG promoted IVM dependent effects in representative behavioral assays. Moreover, GlyRα1AG mediated silencing had a strong and reversible impact on neuronal ensemble activity and c-Fos activation in the olfactory bulb. Together our results demonstrate that long-term, reversible and re-inducible neuronal silencing via GlyRα1AG is a promising tool for the interrogation of network mechanisms underlying the control of behavior and memory formation. PMID:27625595

  16. Intravital Microscopic Interrogation of Peripheral Taste Sensation

    PubMed Central

    Choi, Myunghwan; Lee, Woei Ming; Yun, Seok Hyun

    2015-01-01

    Intravital microscopy is a powerful tool in neuroscience but has not been adapted to the taste sensory organ due to anatomical constraint. Here we developed an imaging window to facilitate microscopic access to the murine tongue in vivo. Real-time two-photon microscopy allowed the visualization of three-dimensional microanatomy of the intact tongue mucosa and functional activity of taste cells in response to topically administered tastants in live mice. Video microscopy also showed the calcium activity of taste cells elicited by small-sized tastants in the blood circulation. Molecular kinetic analysis suggested that intravascular taste sensation takes place at the microvilli on the apical side of taste cells after diffusion of the molecules through the pericellular capillaries and tight junctions in the taste bud. Our results demonstrate the capabilities and utilities of the new tool for taste research in vivo. PMID:25726964

  17. Intravital Microscopic Interrogation of Peripheral Taste Sensation

    NASA Astrophysics Data System (ADS)

    Choi, Myunghwan; Lee, Woei Ming; Yun, Seok Hyun

    2015-03-01

    Intravital microscopy is a powerful tool in neuroscience but has not been adapted to the taste sensory organ due to anatomical constraint. Here we developed an imaging window to facilitate microscopic access to the murine tongue in vivo. Real-time two-photon microscopy allowed the visualization of three-dimensional microanatomy of the intact tongue mucosa and functional activity of taste cells in response to topically administered tastants in live mice. Video microscopy also showed the calcium activity of taste cells elicited by small-sized tastants in the blood circulation. Molecular kinetic analysis suggested that intravascular taste sensation takes place at the microvilli on the apical side of taste cells after diffusion of the molecules through the pericellular capillaries and tight junctions in the taste bud. Our results demonstrate the capabilities and utilities of the new tool for taste research in vivo.

  18. Neutron interrogation of shielded/unshielded uranium by a 4 MeV linac.

    PubMed

    Lakosi, L; Nguyen, C Tam; Serf, E

    2011-09-01

    A non-destructive active assay method was developed for revealing illicit trafficking of uranium. Photoneutrons produced in beryllium or heavy water by bremsstrahlung from a linac induced fission in the samples. Delayed fission neutrons were detected by a neutron collar built up of (3)He counters embedded in polyethylene moderator. High-enriched uranium samples shielded and unshielded by lead up to 14 mm thickness were detected, with a performance practically unaltered. 25 mg (235)U can be revealed in a 1 min interrogation time. PMID:21507663

  19. 29 CFR 18.611 - Mode and order of interrogation and presentation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Mode and order of interrogation and presentation. 18.611... of interrogation and presentation. (a) Control by judge. The judge shall exercise reasonable control... interrogation and presentation effective for the ascertainment of the truth, (2) Avoid needless consumption...

  20. Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials

    SciTech Connect

    Tinsley, J.R., Hurley, J.P., Trainham, R., Keegan, R.P.

    2008-11-14

    In an extension of the Associated Particle Imaging technique that is used for the detection and imaging of hidden explosives, the present measurements use a beam of tagged 14.1 MeV neutrons in coincidence with two or more gammas to probe for the presence of fissionable materials. We have measured neutron-gamma-gamma coincidences with targets of depleted uranium, tungsten, lead, iron, and carbon and will present results that show the multiple-coincidence counting rate for the depleted uranium is substantially higher than any of the non-fissionable materials. In addition, the presence of coincidences involving delayed particle spectra provides a signature for fissionable materials that is distinct from that for non-fissionable ones. Information from the tagged neutron involved in the coincidence event is used to compute the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is compact and portable, and produces relatively low levels of background radiation. Simultaneous measurements on packages of interest for both explosives and fissionable materials are now feasible.

  1. Fissile interrogation using gamma rays from oxygen

    DOEpatents

    Smith, Donald; Micklich, Bradley J.; Fessler, Andreas

    2004-04-20

    The subject apparatus provides a means to identify the presence of fissionable material or other nuclear material contained within an item to be tested. The system employs a portable accelerator to accelerate and direct protons to a fluorine-compound target. The interaction of the protons with the fluorine-compound target produces gamma rays which are directed at the item to be tested. If the item to be tested contains either a fissionable material or other nuclear material the interaction of the gamma rays with the material contained within the test item with result in the production of neutrons. A system of neutron detectors is positioned to intercept any neutrons generated by the test item. The results from the neutron detectors are analyzed to determine the presence of a fissionable material or other nuclear material.

  2. Interrogating selectivity in catalysis using molecular vibrations

    NASA Astrophysics Data System (ADS)

    Milo, Anat; Bess, Elizabeth N.; Sigman, Matthew S.

    2014-03-01

    The delineation of molecular properties that underlie reactivity and selectivity is at the core of physical organic chemistry, and this knowledge can be used to inform the design of improved synthetic methods or identify new chemical transformations. For this reason, the mathematical representation of properties affecting reactivity and selectivity trends, that is, molecular parameters, is paramount. Correlations produced by equating these molecular parameters with experimental outcomes are often defined as free-energy relationships and can be used to evaluate the origin of selectivity and to generate new, experimentally testable hypotheses. The premise behind successful correlations of this type is that a systematically perturbed molecular property affects a transition-state interaction between the catalyst, substrate and any reaction components involved in the determination of selectivity. Classic physical organic molecular descriptors, such as Hammett, Taft or Charton parameters, seek to independently probe isolated electronic or steric effects. However, these parameters cannot address simultaneous, non-additive variations to more than one molecular property, which limits their utility. Here we report a parameter system based on the vibrational response of a molecule to infrared radiation that can be used to mathematically model and predict selectivity trends for reactions with interlinked steric and electronic effects at positions of interest. The disclosed parameter system is mechanistically derived and should find broad use in the study of chemical and biological systems.

  3. Interrogating selectivity in catalysis using molecular vibrations.

    PubMed

    Milo, Anat; Bess, Elizabeth N; Sigman, Matthew S

    2014-03-13

    The delineation of molecular properties that underlie reactivity and selectivity is at the core of physical organic chemistry, and this knowledge can be used to inform the design of improved synthetic methods or identify new chemical transformations. For this reason, the mathematical representation of properties affecting reactivity and selectivity trends, that is, molecular parameters, is paramount. Correlations produced by equating these molecular parameters with experimental outcomes are often defined as free-energy relationships and can be used to evaluate the origin of selectivity and to generate new, experimentally testable hypotheses. The premise behind successful correlations of this type is that a systematically perturbed molecular property affects a transition-state interaction between the catalyst, substrate and any reaction components involved in the determination of selectivity. Classic physical organic molecular descriptors, such as Hammett, Taft or Charton parameters, seek to independently probe isolated electronic or steric effects. However, these parameters cannot address simultaneous, non-additive variations to more than one molecular property, which limits their utility. Here we report a parameter system based on the vibrational response of a molecule to infrared radiation that can be used to mathematically model and predict selectivity trends for reactions with interlinked steric and electronic effects at positions of interest. The disclosed parameter system is mechanistically derived and should find broad use in the study of chemical and biological systems. PMID:24622199

  4. An FBG sensor interrogation technique based on a precise optical recirculating frequency shifter driven by RF signals

    NASA Astrophysics Data System (ADS)

    Wang, Zifei; Yang, Tianxin; Jia, Dongfang; Wang, Zhaoying; Sang, Mei

    2013-03-01

    Fiber Bragg grating (FBG) sensors have numerous advantages to sense multi-physical quantities such as the temperature and strain simultaneously by monitoring the shift of the returned "Bragg" wavelength resulting from changes in these quantities. Several FBG interrogation systems have been set up using photo detectors instead of an optical spectrum analyzer (OSA) to convert wavelength to time measurements. However, in those systems, it is necessary to use mechanical tuning components to generate fast-speed wavelength-swept light sources for high-precision FBG interrogation. In this paper, a low-cost and delicate wavelength-shift detection system, without any mechanical scanning parts, is proposed and demonstrated. The wavelength scanning system is a recirculating frequency shifter (RFS) which consists of an optical amplifier, an under test FBG sensor and an optical single-sideband (SSB) modulator driven by RF signals at 10 GHz. The measurement accuracy of this system is 0.08nm.

  5. A Web Architecture to Geographically Interrogate CHIRPS Rainfall and eMODIS NDVI for Landuse Change

    NASA Astrophysics Data System (ADS)

    Burks, J. E.; Limaye, A. S.

    2014-12-01

    Monitoring of rainfall and vegetation over the continent of Africa is important for assessing the status of crop health and agriculture, along with long-term changes in land use change. These issues can be addressed through examination of long-term precipitation (rainfall) data sets and remote sensing of land surface vegetation and land use types. Two products have been used previously to address these goals: the Climate Hazard Group Infrared Precipitation with Stations (CHIRPS) rainfall data, and multi-day composites of Normalized Difference Vegetation Index (NDVI) from the FEWS NET's eMODIS product. Combined, these are very large data sets that require unique tools and architecture to facilitate a variety of data analysis methods or data exploration by the end user community. To address these needs, a web-enabled system has been developed to allow end-users to interrogate CHIRPS rainfall and eMODIS NDVI data over the continent of Africa. The architecture allows end-users to use custom defined geometries, or the use of predefined political boundaries in their interrogation of the data. The massive amount of data interrogated by the system allows the end-users with only a web browser to extract vital information in order to investigate land use change and its causes. The system can be used to generate daily, monthly and yearly averages over a geographical area and range of dates of interest to the user. It also provides analysis of trends in precipitation or vegetation change for times of interest. The data provided back to the end-user is displayed in graphical form and can be exported for use in other, external tools. The development of this tool has significantly decreased the investment and requirements for end-users to use these two important datasets, while also allowing the flexibility to the end-user to limit the search to the area of interest.

  6. Interrogation of duplicitous stars with an APT

    NASA Technical Reports Server (NTRS)

    Bopp, Bernard W.

    1992-01-01

    Preliminary results from intensive spectroscopic and APT monitoring of two interacting binary systems are presented. Both V644 Mon (Be + K:) and HD 37453 (F5 II + B) show complex, composite, and variable spectral. APT observations extending over three years show both stars to vary by 0.1-0.2 mag in V. The photometric variability of V644 Mon appears to be irregular, though there is some evidence for periodic behavior in the 50-60 day range. HD 37453 has an orbital period of 66.75 days; the best-fit photometric period is not quite half this value, indicating the star is an ellipsoidal variable.

  7. Manually controlled neutron-activation system

    NASA Astrophysics Data System (ADS)

    Johns, R. A.; Carothers, G. A.

    1982-01-01

    A manually controlled neutron activation system, the Manual Reactor Activation System, was designed and built and has been operating at one of the Savannah River Plant's production reactors. With this system, samples can be irradiated for up to 24 hours and pneumatically transferred to a shielded repository for decay until their activity is low enough for them to be handled at a radiobench. The Manual Reactor Activation System was built to provide neutron activation of solid waste forms for the Alternative Waste Forms Leach Testing Program. Neutron activation of the bulk sample prior to leaching permits sensitive multielement radiometric analyses of the leachates.

  8. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

    A wave activated power generation system of the float type is disclosed, comprising at least one piston-cylinder device having an anchored cylinder and a piston slidable in the cylinder and cooperating with the cylinder to form a pumping chamber above the piston and a low pressure chamber below the piston. The cylinder has an intake port and an exhaust port both formed at an upper port thereof to communicate with the pumping chamber and each provided with a check valve. A float is connected through a cable to the piston of the piston- cylinder device. A pair of fluid storages are connected to the intake port and the exhaust port of the pumping chamber, respectively. A waterwheel generator is driven by the fluid flowing from one of the fluid storages to another. A pressure regulating device is connected to the low pressure chamber so as to maintain the low pressure chamber at a pressure lower than the pressure in the pumping chamber, the difference in pressure ceaselessly applying a downward force on the piston to keep the cable in a tensed condition.

  9. Interrogating trees as archives of sulphur deposition

    NASA Astrophysics Data System (ADS)

    Wynn, P. M.; Loader, N. J.; Fairchild, I. J.

    2012-04-01

    A principal driver of climatic variability over the past 1,000 years and essential forcing mechanism for climate, are the changes in atmospheric composition resulting from sulphur aerosols. Natural and anthropogenic aerosols released into the atmosphere disrupt the radiative balance through backscattering and absorption of incoming solar radiation and increase cloud albedo by acting as condensation nuclei. Understanding the impact of sulphur emissions upon climate beyond the last few hundred years however is not straightforward and natural archives of environmental information must be explored. Tree-rings represent one such archive as they are widely distributed and preserve environmental information within a precisely dateable, annually resolved timescale. Until recently the sulphur contained within tree-rings has largely remained beyond the reach of environmental scientists and climate modelers owing to difficulties associated with the extraction of a robust signal and uncertainties regarding post-depositional mobility. Our recent work using synchrotron radiation has established that the majority of non-labile sulphur in two conifer species is preserved within the cellular structure of the woody tissue after uptake and demonstrates an increasing trend in sulphur concentration during the 20th century and during known volcanic events. Due to the clear isotopic distinction between marine (+21), geological (+10 to +30), atmospheric pollution (-3 to +9 ) and volcanic sources of sulphur (0 to +5), isotopic ratios provide a diagnostic tool with which changes in the source of atmospheric sulphur can be detected in a more reliable fashion than concentration alone. Sulphur isotopes should thereby provide a fingerprint of short lived events including volcanic activity when extracted at high resolution and in conjunction with high resolution S concentrations defining the event. Here we present methodologies associated with extracting the sulphur isotopic signal from tree

  10. Novel RF interrogation of a fiber Bragg grating sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator.

    PubMed

    Choi, Sang-Jin; Mao, Wankai; Pan, Jae-Kyung

    2013-01-01

    We propose and experimentally demonstrate the novel radio-frequency (RF) interrogation of a fiber Bragg grating (FBG) sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR) at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications. PMID:23820744

  11. Novel RF Interrogation of a Fiber Bragg Grating Sensor Using Bidirectional Modulation of a Mach-Zehnder Electro-Optical Modulator

    PubMed Central

    Choi, Sang-Jin; Mao, Wankai; Pan, Jae-Kyung

    2013-01-01

    We propose and experimentally demonstrate the novel radio-frequency (RF) interrogation of a fiber Bragg grating (FBG) sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR) at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications. PMID:23820744

  12. Microwave photonics filtering technique for interrogating long weak fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Ricchiuti, Amelia Lavinia; Barrera, David; Sales, Salvador; Thévenaz, Luc; Capmany, José

    2014-05-01

    A system to interrogate photonic sensors based on long weak fiber Bragg gratings (FBGs) is presented and experimentally demonstrated, dedicated to measure the precise location of several spot events. The principle of operation is based on a technique used to analyze microwave photonics (MWP) filters. The long weak FBGs are used as quasi-distributed sensors. Several events can be detected along the FBG device with a spatial accuracy under 1 mm using a modulator and a photo-detector (PD) with a modest bandwidth of less than 500 MHz. The simple proposed scheme is intrinsically robust against environmental changes and easy to reconfigure.

  13. Interrogation of a cascaded FBG sensor using a wavelength-to-delay mapping technique

    NASA Astrophysics Data System (ADS)

    Clement, Juan; Hervás, Javier; Fernández-Pousa, Carlos R.; Barrera, David; Pastor, Daniel; Sales, Salvador; Capmany, José

    2015-09-01

    An optical fiber sensor composed of six standard FBGs in cascade is interrogated by use of a technique based on wavelength to delay mapping. A microwave-modulated optical signal enters the FBG cascade and, after being sliced and reflected, experiences dispersion in standard single-mode fiber. The Bragg wavelengths of the FBGs are mapped into the delays that determine the peaks in the system's electrical impulse response. The Bragg wavelength shifts are calculated from the difference of the delays undergone by FBGs samples. A resolution of 9.2 pm in Bragg wavelength shift is demonstrated.

  14. Time dependent measurements of induced fission for SNM interrogation

    NASA Astrophysics Data System (ADS)

    Beck, A.; Israelashvili, I.; Wengrowicz, U.; Caspi, E. N.; Yaar, I.; Osovizki, A.; Ocherashvili, A.; Rennhofer, H.; Pedersen, B.; Crochemore, J.-M.; Roesgen, E.

    2013-08-01

    Gammas from induced fissions were measured and separated into prompt and delayed particles. To this end, a dedicated detector was realized, based on a plastic scintillator, a wavelength shifter fiber and a silicon photomultiplier (SiPM). Results are presented from the interrogation of Special Nuclear Materials (SNM), employing a pulsed neutron generator in the PUNITA graphite moderator incorporating the above detector assembly. The detector response is presented, as well as the sensitivities for prompt and delayed processes within the same experimental setup.

  15. Scanning electrochemical microscopy: surface interrogation of adsorbed hydrogen and the open circuit catalytic decomposition of formic acid at platinum.

    PubMed

    Rodríguez-López, Joaquín; Bard, Allen J

    2010-04-14

    The surface interrogation mode of scanning electrochemical microscopy (SECM) is extended to the in situ quantification of adsorbed hydrogen, H(ads), at polycrystalline platinum. The methodology consists of the production, at an interrogator electrode, of an oxidized species that is able to react with H(ads) on the Pt surface and report the amounts of this adsorbate through the SECM feedback response. The technique is validated by comparison to the electrochemical underpotential deposition (UPD) of hydrogen on Pt. We include an evaluation of electrochemical mediators for their use as oxidizing reporters for adsorbed species at platinum; a notable finding is the ability of tetramethyl-p-phenylenediamine (TMPD) to oxidize (interrogate) H(ads) on Pt at low pH (0.5 M H(2)SO(4) or 1 M HClO(4)) and with minimal background effects. As a case study, the decomposition of formic acid (HCOOH) in acidic media at open circuit on Pt was investigated. Our results suggest that formic acid decomposes at the surface of unbiased Pt through a dehydrogenation route to yield H(ads) at the Pt surface. The amount of H(ads) depended on the open circuit potential (OCP) of the Pt electrode at the time of interrogation; at a fixed concentration of HCOOH, a more negative OCP yielded larger amounts of H(ads) until reaching a coulomb limiting coverage close to 1 UPD monolayer of H(ads). The introduction of oxygen into the cell shifted the OCP to more positive potentials and reduced the quantified H(ads); furthermore, the system was shown to be chemically reversible, as several interrogations could be run consecutively and reproducibly regardless of the path taken to reach a given OCP. PMID:20225806

  16. NeuroArray: a universal interface for patterning and interrogating neural circuitry with single cell resolution.

    PubMed

    Li, Wei; Xu, Zhen; Huang, Junzhe; Lin, Xudong; Luo, Rongcong; Chen, Chia-Hung; Shi, Peng

    2014-01-01

    Recreation of neural network in vitro with designed topology is a valuable tool to decipher how neurons behave when interacting in hierarchical networks. In this study, we developed a simple and effective platform to pattern primary neurons in array formats for interrogation of neural circuitry with single cell resolution. Unlike many surface-chemistry-based patterning methods, our NeuroArray technique is specially designed to accommodate neuron's polarized morphologies to make regular arrays of cells without restricting their neurite outgrowth, and thus allows formation of freely designed, well-connected, and spontaneously active neural network. The NeuroArray device was based on a stencil design fabricated using a novel sacrificial-layer-protected PDMS molding method that enables production of through-structures in a thin layer of PDMS with feature sizes as small as 3 µm. Using the NeuroArray along with calcium imaging, we have successfully demonstrated large-scale tracking and recording of neuronal activities, and used such data to characterize the spiking dynamics and transmission within a diode-like neural network. Essentially, the NeuroArray is a universal patterning platform designed for, but not limited to neuron cells. With little adaption, it can be readily interfaced with other interrogation modalities for high-throughput drug testing, and for building neuron culture based live computational devices. PMID:24759264

  17. NeuroArray: A Universal Interface for Patterning and Interrogating Neural Circuitry with Single Cell Resolution

    NASA Astrophysics Data System (ADS)

    Li, Wei; Xu, Zhen; Huang, Junzhe; Lin, Xudong; Luo, Rongcong; Chen, Chia-Hung; Shi, Peng

    2014-04-01

    Recreation of neural network in vitro with designed topology is a valuable tool to decipher how neurons behave when interacting in hierarchical networks. In this study, we developed a simple and effective platform to pattern primary neurons in array formats for interrogation of neural circuitry with single cell resolution. Unlike many surface-chemistry-based patterning methods, our NeuroArray technique is specially designed to accommodate neuron's polarized morphologies to make regular arrays of cells without restricting their neurite outgrowth, and thus allows formation of freely designed, well-connected, and spontaneously active neural network. The NeuroArray device was based on a stencil design fabricated using a novel sacrificial-layer-protected PDMS molding method that enables production of through-structures in a thin layer of PDMS with feature sizes as small as 3 µm. Using the NeuroArray along with calcium imaging, we have successfully demonstrated large-scale tracking and recording of neuronal activities, and used such data to characterize the spiking dynamics and transmission within a diode-like neural network. Essentially, the NeuroArray is a universal patterning platform designed for, but not limited to neuron cells. With little adaption, it can be readily interfaced with other interrogation modalities for high-throughput drug testing, and for building neuron culture based live computational devices.

  18. Identifying work related injuries: comparison of methods for interrogating text fields

    PubMed Central

    2010-01-01

    Background Work-related injuries in Australia are estimated to cost around $57.5 billion annually, however there are currently insufficient surveillance data available to support an evidence-based public health response. Emergency departments (ED) in Australia are a potential source of information on work-related injuries though most ED's do not have an 'Activity Code' to identify work-related cases with information about the presenting problem recorded in a short free text field. This study compared methods for interrogating text fields for identifying work-related injuries presenting at emergency departments to inform approaches to surveillance of work-related injury. Methods Three approaches were used to interrogate an injury description text field to classify cases as work-related: keyword search, index search, and content analytic text mining. Sensitivity and specificity were examined by comparing cases flagged by each approach to cases coded with an Activity code during triage. Methods to improve the sensitivity and/or specificity of each approach were explored by adjusting the classification techniques within each broad approach. Results The basic keyword search detected 58% of cases (Specificity 0.99), an index search detected 62% of cases (Specificity 0.87), and the content analytic text mining (using adjusted probabilities) approach detected 77% of cases (Specificity 0.95). Conclusions The findings of this study provide strong support for continued development of text searching methods to obtain information from routine emergency department data, to improve the capacity for comprehensive injury surveillance. PMID:20374657

  19. What Is an Activity? Appropriating an Activity-Centric System

    NASA Astrophysics Data System (ADS)

    Yarosh, Svetlana; Matthews, Tara; Moran, Thomas P.; Smith, Barton

    Activity-Centric Computing (ACC) systems seek to address the fragmentation of office work across tools and documents by allowing users to organize work around the computational construct of an Activity. Defining and structuring appropriate Activities within a system poses a challenge for users that must be overcome in order to benefit from ACC support. We know little about how knowledge workers appropriate the Activity construct. To address this, we studied users’ appropriation of a production-quality ACC system, Lotus Activities, for everyday work by employees in a large corporation. We contribute to a better understanding of how users articulate their individual and collaborative work in the system by providing empirical evidence of their patterns of appropriation. We conclude by discussing how our findings can inform the design of other ACC systems for the workplace.

  20. Concept and design of an FBG emulator for a scanning laser-based fiber optic interrogator

    NASA Astrophysics Data System (ADS)

    Kuhenuri, Nader; Putzer, Philipp; Koch, Alexander W.; Obermaier, Johannes; Schweyer, Sebastian; Hurni, Andreas

    2014-06-01

    The Hybrid Sensor Bus is a space-borne temperature monitoring system for telecommunication satellites com­ bining electrical and fiber-optical Fiber Bragg Grating (FBG) sensors. Currently, there is no method available for testing the functionality and robustness of the system without setting up an actual sensor-network implying numerous FBG sensors in which each has to be heated/cooled individually. As a verification method of the mentioned system, FBG reflection based scanning laser interrogator, an FBG­ emulator is implemented to emulate the necessary FBG sensors. It is capable of immediate emulation of any given FBG spectrum, thus, any temperature. The concept provides advantages like emulating different kinds of FBGs with any peak shape, variable Bragg-wavelength λB, maximal-reflectivity τmax, spectral-width and degradation characteristics. Further, it facilitates an efficient evaluation of different interrogator peak-finding algorithms and the capability of emulating up to 10000 sample points per second is achieved. In the present paper, different concepts will be discussed and evaluated yielding to the implementation of a Variable Optical Attenuator (VOA) as the main actuator of the emulator. The actuator choice is further restricted since the emulator has to work with light in unknown polarization state. In order to implement a fast opto-ceramic VOA, issues like temperature dependencies, up to 200 V driving input and capacitive load have to be overcome. Furthermore, a self-calibration procedure mitigates problems like attenuation losses and long-term drift.

  1. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton Richard J.

    2012-01-01

    For many NASA missions, remote sensing is a critical application that supports activities such as environmental monitoring, planetary science, structural shape and health monitoring, non-destructive evaluation, etc. The utility of the remote sensing devices themselves is greatly increased if they are passive V that is, they do not require any on-board power supply such as batteries V and if they can be identified uniquely during the sensor interrogation process. Additional passive sensor characteristics that enable greater utilization in space applications are small size and weight, long read ranges with low interrogator power, ruggedness, and operability in extreme environments (vacuum, extreme high/low temperature, high radiation, etc.) In this paper, we consider one very promising passive sensor technology, called surface acoustic wave (SAW) radio-frequency identification (RFID), that satisfies all of these criteria. In general, RFID is a method of identifying items using radio waves to interrogate tags encoded with a unique identifier that are affixed to the items of interest. In the case of passive tags, only the interrogator, which transmits power to the tags in the form of radio-frequency electromagnetic radiation, requires access to a power supply. Passive RFID technologies are used today in many applications, including asset tracking and management, security and access control, and remote sensing. To date, most of the development and application in RFID technology has focused on either asset/inventory tracking and control or security and access control because these are the largest commercial application areas. Recently however, there has been growing interest in using passive RFID technology for remote sensing applications, and SAW devices are at the forefront of RFID sensing technology development. Although SAW RFID tags have great potential for use in numerous space-based remote sensing applications, the limited collision resolution capability of

  2. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2011-01-01

    For many NASA missions, remote sensing is a critical application that supports activities such as environmental monitoring, planetary science, structural shape and health monitoring, non-destructive evaluation, etc. The utility of the remote sensing devices themselves is greatly increased if they are passive that is, they do not require any on-board power supply such as batteries and if they can be identified uniquely during the sensor interrogation process. Additional passive sensor characteristics that enable greater utilization in space applications are small size and weight, long read ranges with low interrogator power, ruggedness, and operability in extreme environments (vacuum, extreme high/low temperature, high radiation, etc.) In this paper, we consider one very promising passive sensor technology, called surface acoustic wave (SAW) radio-frequency identification (RFID), that satisfies all of these criteria. Although SAW RFID tags have great potential for use in numerous space-based remote sensing applications, the limited collision resolution capability of current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? What are the

  3. Wavelength-switched phase interrogator for extrinsic Fabry-Perot interferometric sensors.

    PubMed

    Xia, Ji; Xiong, Shuidong; Wang, Fuyin; Luo, Hong

    2016-07-01

    We report on phase interrogation of extrinsic Fabry-Perot interferometric (EFPI) sensors through a wavelength-switched unit with a polarization-maintaining fiber Bragg grating (PMFBG). The measurements at two wavelengths are first achieved in one total-optical path. The reflected peaks of the PMFBG with two natural wavelengths are in mutually perpendicular polarization detection, and they are switched through an electro-optic modulator at a high switching speed of 10 kHz. An ellipse fitting differential cross multiplication (EF-DCM) algorithm is proposed for interrogating the variation of the gap length of the EFPI sensors. The phase demodulation system has been demonstrated to recover a minimum phase of 0.42  μrad/Hz at the test frequency of 100 Hz with a stable intensity fluctuation level of ±0.8  dB. Three EFPI sensors with different cavity lengths are tested at the test frequency of 200 Hz, and the results indicate that the system can achieve the demodulation of EFPI sensors with different cavity lengths stably. PMID:27367107

  4. Data base management systems activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The Data Management System-1100 is designed to operate in conjunction with the UNIVAC 1100 Series Operating System on any 1100 Series computer. DMS-1100 is divided into the following four major software components: (1) Data Definition Languages (DDL); (2) Data Management Routine (DMR); (3) Data Manipulation Languages (DML); and (4) Data Base Utilities (DBU). These software components are described in detail.

  5. Orbiter active thermal control system description

    NASA Technical Reports Server (NTRS)

    Laubach, G. E.

    1975-01-01

    A brief description of the Orbiter Active Thermal Control System (ATCS) including (1) major functional requirements of heat load, temperature control and heat sink utilization, (2) the overall system arrangement, and (3) detailed description of the elements of the ATCS.

  6. Experiment system of LAMOST active optics

    NASA Astrophysics Data System (ADS)

    Cui, Xiangqun; Su, Ding; Li, Guoping; Yao, Zhengqiu; Zhang, Zhengcao; Li, Yeping; Zhang, Yong; Wang, You; Xu, Xinqi; Wang, Hai

    2004-10-01

    Active optics is the most difficult part in LAMOST project. Especially for the segmented reflecting Schmidt plate Ma, in which both segmented mirror active optics and thin mirror (or deformable mirror) active optics are applied. To test and optimize the thin mirror active optics of Ma, and to approach the reality of operating environment of the telescope, an outdoor experiment system has been established. This experiment system is also a `small LAMOST" with one sub-mirror of the primary mirror Mb and one sub-mirror of the Schmidt plate Ma, and with full scale in spacing (40 meters) between Ma and Mb. many parts of LAMOST were tested in the experiment system except segmented mirror active optics. Especially for force actuators, thin mirror support system, friction driving of the alt-azimuth mounting and its control system, wave front test along such a long optical path. This paper presents the experiment system, research and developments, and some experiment results.

  7. Modeling Cytoskeletal Active Matter Systems

    NASA Astrophysics Data System (ADS)

    Blackwell, Robert

    Active networks of filamentous proteins and crosslinking motor proteins play a critical role in many important cellular processes. One of the most important microtubule-motor protein assemblies is the mitotic spindle, a self-organized active liquid-crystalline structure that forms during cell division and that ultimately separates chromosomes into two daughter cells. Although the spindle has been intensively studied for decades, the physical principles that govern its self-organization and function remain mysterious. To evolve a better understanding of spindle formation, structure, and dynamics, I investigate course-grained models of active liquid-crystalline networks composed of microtubules, modeled as hard spherocylinders, in diffusive equilibrium with a reservoir of active crosslinks, modeled as hookean springs that can adsorb to microtubules and and translocate at finite velocity along the microtubule axis. This model is investigated using a combination of brownian dynamics and kinetic monte carlo simulation. I have further refined this model to simulate spindle formation and kinetochore capture in the fission yeast S. pombe. I then make predictions for experimentally realizable perturbations in motor protein presence and function in S. pombe.

  8. Concise Review: Patient-Specific Stem Cells to Interrogate Inherited Eye Disease.

    PubMed

    Giacalone, Joseph C; Wiley, Luke A; Burnight, Erin R; Songstad, Allison E; Mullins, Robert F; Stone, Edwin M; Tucker, Budd A

    2016-02-01

    Whether we are driving to work or spending time with loved ones, we depend on our sense of vision to interact with the world around us. Therefore, it is understandable why blindness for many is feared above death itself. Heritable diseases of the retina, such as glaucoma, age-related macular degeneration, and retinitis pigmentosa, are major causes of blindness worldwide. The recent success of gene augmentation trials for the treatment of RPE65-associated Leber congenital amaurosis has underscored the need for model systems that accurately recapitulate disease. With the advent of patient-specific induced pluripotent stem cells (iPSCs), researchers are now able to obtain disease-specific cell types that would otherwise be unavailable for molecular analysis. In the present review, we discuss how the iPSC technology is being used to confirm the pathogenesis of novel genetic variants, interrogate the pathophysiology of disease, and accelerate the development of patient-centered treatments. Significance: Stem cell technology has created the opportunity to advance treatments for multiple forms of blindness. Researchers are now able to use a person's cells to generate tissues found in the eye. This technology can be used to elucidate the genetic causes of disease and develop treatment strategies. In the present review, how stem cell technology is being used to interrogate the pathophysiology of eye disease and accelerate the development of patient-centered treatments is discussed. PMID:26683869

  9. [INVITED] Cascade FBGs distributed sensors interrogation using microwave photonics filtering techniques

    NASA Astrophysics Data System (ADS)

    Ricchiuti, Amelia L.; Hervás, Javier; Sales, Salvador

    2016-03-01

    Systems to interrogate photonic sensors based on long fiber Bragg gratings (FBGs) are illustrated and experimentally validated. The FBGs-based devices are used as quasi-distributed sensors and have demonstrated their ability to detect and measure the precise location of several spot events. The principle of operation is based on a technique used to analyze microwave photonics (MWP) filters. The overall idea beyond this work has been borne out and demonstrated step by step starting from preliminary test that have led to the development of a very-long distributed sensor based on an array of 500 equal and weak FBGs. Firstly, we have demonstrated the feasibility of the MWP filtering technique to interrogate a 10 cm-long high reflectivity (≈99%) FBG. Then, a pair of low-reflectivity (<6%) FBGs has been employed as sensing device. The latter has laid the foundation for the development and implementation of a 5 m-long fiber optic sensor based on 500 very weak FBGs. Spot events have been detected with a good spatial accuracy of less than 1 mm using a modulator and a photo-detector (PD) with a modest bandwidth of only 500 MHz. The simple proposed schemes result cost effective, intrinsically robust against environmental changes and easy to reconfigure.

  10. Concise Review: Patient-Specific Stem Cells to Interrogate Inherited Eye Disease

    PubMed Central

    Giacalone, Joseph C.; Wiley, Luke A.; Burnight, Erin R.; Songstad, Allison E.; Mullins, Robert F.; Stone, Edwin M.

    2016-01-01

    Whether we are driving to work or spending time with loved ones, we depend on our sense of vision to interact with the world around us. Therefore, it is understandable why blindness for many is feared above death itself. Heritable diseases of the retina, such as glaucoma, age-related macular degeneration, and retinitis pigmentosa, are major causes of blindness worldwide. The recent success of gene augmentation trials for the treatment of RPE65-associated Leber congenital amaurosis has underscored the need for model systems that accurately recapitulate disease. With the advent of patient-specific induced pluripotent stem cells (iPSCs), researchers are now able to obtain disease-specific cell types that would otherwise be unavailable for molecular analysis. In the present review, we discuss how the iPSC technology is being used to confirm the pathogenesis of novel genetic variants, interrogate the pathophysiology of disease, and accelerate the development of patient-centered treatments. Significance Stem cell technology has created the opportunity to advance treatments for multiple forms of blindness. Researchers are now able to use a person’s cells to generate tissues found in the eye. This technology can be used to elucidate the genetic causes of disease and develop treatment strategies. In the present review, how stem cell technology is being used to interrogate the pathophysiology of eye disease and accelerate the development of patient-centered treatments is discussed. PMID:26683869

  11. Interrogating scarcity: how to think about ‘resource-scarce settings’

    PubMed Central

    Schrecker, Ted

    2013-01-01

    The idea of resource scarcity permeates health ethics and health policy analysis in various contexts. However, health ethics inquiry seldom asks—as it should—why some settings are ‘resource-scarce’ and others not. In this article I describe interrogating scarcity as a strategy for inquiry into questions of resource allocation within a single political jurisdiction and, in particular, as an approach to the issue of global health justice in an interconnected world. I demonstrate its relevance to the situation of low- and middle-income countries (LMICs) with brief descriptions of four elements of contemporary globalization: trade agreements; the worldwide financial marketplace and capital flight; structural adjustment; imperial geopolitics and foreign policy. This demonstration involves not only health care, but also social determinants of health. Finally, I argue that interrogating scarcity provides the basis for a new, critical approach to health policy at the interface of ethics and the social sciences, with specific reference to market fundamentalism as the value system underlying contemporary globalization. PMID:22899597

  12. Dynamic Sensor Interrogation Using Wavelength-Swept Laser with a Polygon-Scanner-Based Wavelength Filter

    PubMed Central

    Kwon, Yong Seok; Ko, Myeong Ock; Jung, Mi Sun; Park, Ik Gon; Kim, Namje; Han, Sang-Pil; Ryu, Han-Cheol; Park, Kyung Hyun; Jeon, Min Yong

    2013-01-01

    We report a high-speed (∼2 kHz) dynamic multiplexed fiber Bragg grating (FBG) sensor interrogation using a wavelength-swept laser (WSL) with a polygon-scanner-based wavelength filter. The scanning frequency of the WSL is 18 kHz, and the 10 dB scanning bandwidth is more than 90 nm around a center wavelength of 1,540 nm. The output from the WSL is coupled into the multiplexed FBG array, which consists of five FBGs. The reflected Bragg wavelengths of the FBGs are 1,532.02 nm, 1,537.84 nm, 1,543.48 nm, 1,547.98 nm, and 1,553.06 nm, respectively. A dynamic periodic strain ranging from 500 Hz to 2 kHz is applied to one of the multiplexed FBGs, which is fixed on the stage of the piezoelectric transducer stack. Good dynamic performance of the FBGs and recording of their fast Fourier transform spectra have been successfully achieved with a measuring speed of 18 kHz. The signal-to-noise ratio and the bandwidth over the whole frequency span are determined to be more than 30 dB and around 10 Hz, respectively. We successfully obtained a real-time measurement of the abrupt change of the periodic strain. The dynamic FBG sensor interrogation system can be read out with a WSL for high-speed and high-sensitivity real-time measurement. PMID:23899934

  13. Linearity enhancement of scale factor in an optical interrogated micromechanical accelerometer.

    PubMed

    Zhang, Yu; Feng, Lishuang; Wang, Xiao; Wang, Yang

    2016-08-01

    A method to reduce the residual stress of support arms in an optical interrogated micromechanical accelerometer is proposed in order to enhance the linearity of the scale factor of the accelerometer. First, the behavior of residual stress in support arms is analyzed in detail, and the simulation of shape curvature caused by residual stress in aluminum-made support arms is completed using finite element analysis. Then, by comparing two different materials of support arms (aluminum-made and silicon-made support arms), a modified fabrication is introduced in order to reduce the unexpected residual stress in support arms. Finally, based on contrast experiments, the linearity of the scale factor of accelerometers with aluminum-made and silicon-made support arms is measured using the force feedback test system, respectively. Results show that the linearity of the scale factor of the accelerometer with silicon-made support arms is 0.85%, which is reduced about an order of magnitude compared to that of the accelerometer with aluminum-made support arms with the linearity of scale factor of 7.48%; linearity enhancement of the scale factor is validated. This allows accuracy improvement of the optical interrogated micromechanical accelerometer in the application of inertial navigation and positioning. PMID:27505396

  14. Characterization of lipid films by an angle-interrogation surface plasmon resonance imaging device.

    PubMed

    Liu, Linlin; Wang, Qiong; Yang, Zhong; Wang, Wangang; Hu, Ning; Luo, Hongyan; Liao, Yanjian; Zheng, Xiaolin; Yang, Jun

    2015-04-01

    Surface topographies of lipid films have an important significance in the analysis of the preparation of giant unilamellar vesicles (GUVs). In order to achieve accurately high-throughput and rapidly analysis of surface topographies of lipid films, a homemade SPR imaging device is constructed based on the classical Kretschmann configuration and an angle interrogation manner. A mathematical model is developed to accurately describe the shift including the light path in different conditions and the change of the illumination point on the CCD camera, and thus a SPR curve for each sampling point can also be achieved, based on this calculation method. The experiment results show that the topographies of lipid films formed in distinct experimental conditions can be accurately characterized, and the measuring resolution of the thickness lipid film may reach 0.05 nm. Compared with existing SPRi devices, which realize detection by monitoring the change of the reflective-light intensity, this new SPRi system can achieve the change of the resonance angle on the entire sensing surface. Thus, it has higher detection accuracy as the traditional angle-interrogation SPR sensor, with much wider detectable range of refractive index. PMID:25697808

  15. Special nuclear material detection using pulsed neutron interrogation

    NASA Astrophysics Data System (ADS)

    Ruddy, Frank H.; Seidel, John G.; Flammang, Robert W.

    2007-04-01

    Pulsed neutron interrogation methods for detection of Special Nuclear Materials are being developed. Fast prompt neutrons from thermal neutron-induced fissions are detected in the time intervals following 100-μs neutron bursts from a pulsed D-T neutron generator operating at 1000 pulses per second. Silicon Carbide semiconductor neutron detectors are used to detect fission neutrons in the 30-840 μs time intervals following each 14-MeV D-T neutron pulse. Optimization of the neutron detectors has led to dramatic reduction of detector background and improvement of the signal-to-noise ratio for Special Nuclear Material detection. Detection of Special Nuclear Materials in the presence of lead, cadmium and plywood shielding has been demonstrated. Generally, the introduction of shielding leads to short thermal neutron die-away times of 100-200 μs or less. The pulsed neutron interrogation method developed allows detection of the neutron signal even when the die-away time is less than 100 μs.

  16. Remotely Interrogated Passive Polarizing Dosimeter (RIPPeD).

    SciTech Connect

    Kemme, Shanalyn A.; Buller, Daniel L.; Dirk, Shawn M.; Boye, Robert R.; Samora, Sally; Washburn, Cody M.; Wheeler, David Roger

    2008-09-01

    Conductive polymers have become an extremely useful class of materials for many optical applications. We have developed an electrochemical growth method for depositing highly conductive ({approx}100 S/cm) polypyrrole. Additionally, we have adapted advanced fabrication methods for use with the polypyrrole resulting in gratings with submicron features. This conductive polymer micro-wire grid provides an optical polarizer with unique properties. When the polymer is exposed to ionizing radiation, its conductivity is affected and the polarization properties of the device, specifically the extinction ratio, change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. The result is a passive radiation-sensitive sensor with very low optical visibility. The ability to interrogate the device from a safe standoff distance provides a device useful in potentially dangerous environments. Also, the passive nature of the device make it applicable in applications where external power is not available. We will review the polymer deposition, fabrication methods and device design and modeling. The characterization of the polymer's sensitivity to ionizing radiation and optical testing of infrared polarizers before and after irradiation will also be presented. These experimental results will highlight the usefulness of the conductive infrared polarizer to many security and monitoring applications.

  17. Centrally activated pipe snubbing system

    DOEpatents

    Cawley, William E.

    1985-01-01

    An electromechanical pipe snubbing system and an electromechanical pipe snubber. In the system, each pipe snubber, in a set of pipe snubbers, has an electromechanical mechanism to lock and unlock the snubber. A sensor, such as a seismometer, measures a quantity related to making a snubber locking or unlocking decision. A control device makes an electrical connection between a power supply and each snubber's electromechanical mechanism to simultaneously lock each snubber when the sensor measurement indicates a snubber locking condition. The control device breaks the connection to simultaneously unlock each snubber when the sensor measurement indicates a snubber unlocking condition. In the snubber, one end of the shaft slides within a bore in one end of a housing. The other end of the shaft is rotatably attached to a pipe; the other end of the housing is rotatively attached to a wall. The snubber's electromechanical mechanism locks the slidable end of the shaft to the housing and unlocks that end from the housing. The electromechanical mechanism permits remote testing and lockup status indication for each snubber.

  18. Police interviewing and interrogation of juvenile suspects: a descriptive examination of actual cases.

    PubMed

    Cleary, Hayley M D

    2014-06-01

    Although empirical attention to police interrogation has gained traction in recent years, comparatively few studies have examined interrogation of juvenile suspects, and virtually none have examined actual interrogations. Despite a growing literature on youths' interrogation-related capacities, we still know very little about what actually transpires when police question youth. The present study examines electronically recorded police interviews with juveniles to describe the characteristics, processes, and outcomes that occur in actual juvenile interrogations, including interview duration, individuals present, and confessions. Fifty-seven electronic recordings from 17 police departments were analyzed using observational research software. The median juvenile interrogation lasted 46 min, though the range was extensive (6 min to nearly 5 hr). Youth frequently submitted to questioning without a parent or advocate present, and disruptions to the interview process were common. Interrogation outcomes varied and included full confessions, partially incriminating admissions, and denials of guilt. Results from this study provide context for interrogation research using other methods and suggest that youth may frequently consent to interrogation in the absence of important legal protections. PMID:24377911

  19. 48 CFR 252.237-7010 - Prohibition on interrogation of detainees by contractor personnel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... personnel or DoD contractor personnel being held for law enforcement purposes. Interrogation of detainees... obtaining reliable information to satisfy foreign intelligence collection requirements. (b)...

  20. Active microrheology in active matter systems: Mobility, intermittency, and avalanches.

    PubMed

    Reichhardt, C; Reichhardt, C J Olson

    2015-03-01

    We examine the mobility and velocity fluctuations of a driven particle moving through an active matter bath of self-mobile disks for varied density or area coverage and varied activity. We show that the driven particle mobility can exhibit nonmonotonic behavior that is correlated with distinct changes in the spatiotemporal structures that arise in the active media. We demonstrate that the probe particle velocity distributions exhibit specific features in the different dynamic regimes and identify an activity-induced uniform crystallization that occurs for moderate activity levels and is distinct from the previously observed higher activity cluster phase. The velocity distribution in the cluster phase has telegraph noise characteristics produced when the probe particle moves alternately through high-mobility areas that are in the gas state and low-mobility areas that are in the dense phase. For higher densities and large activities, the system enters what we characterize as an active jamming regime. Here the probe particle moves in intermittent jumps or avalanches that have power-law-distributed sizes that are similar to the avalanche distributions observed for nonactive disk systems near the jamming transition. PMID:25871116

  1. PASS: Creating Physically Active School Systems

    ERIC Educational Resources Information Center

    Ciotto, Carol M.; Fede, Marybeth H.

    2014-01-01

    PASS, a Physically Active School System, is a program by which school districts and schools utilize opportunities for school-based physical activity that enhance overall fitness and cognition, which can be broken down into four integral parts consisting of connecting, communicating, collaborating, and cooperating. There needs to be an…

  2. Active impedance matching of complex structural systems

    NASA Technical Reports Server (NTRS)

    Macmartin, Douglas G.; Miller, David W.; Hall, Steven R.

    1991-01-01

    Viewgraphs on active impedance matching of complex structural systems are presented. Topics covered include: traveling wave model; dereverberated mobility model; computation of dereverberated mobility; control problem: optimal impedance matching; H2 optimal solution; statistical energy analysis (SEA) solution; experimental transfer functions; interferometer actuator and sensor locations; active strut configurations; power dual variables; dereverberation of complex structure; dereverberated transfer function; compensators; and relative power flow.

  3. Simultaneous interrogation of interferometric and Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Brady, G.; Kalli, K.; Webb, D. J.; Jackson, D. A.; Reekie, L.; Archambault, J. L.

    1995-06-01

    We propose a new method for the simultaneous interrogation of conventional two-beam interferometers and Bragg grating sensors. The technique employs an unbalanced Mach-Zehnder interferometer illuminated by a single low-coherence source, which acts as a wavelength-tunable source for the grating and as a path-matched filter for the Fizeau interferometer, thus providing a high phase resolution output for each sensor. The grating sensor demonstrates a dynamic strain resolution of \\similar 0.05 mu 3 / \\radical Hz \\end-radical at 20 Hz, while the interferometric phase resolution is better than 1mrad/ \\radical Hz \\end-radical at 20 Hz, corresponding to an rms mirror displacement of 0.08 nm.

  4. An Optical Fiber Displacement Sensor Using RF Interrogation Technique

    PubMed Central

    Kim, Hyeon-Ho; Choi, Sang-Jin; Jeon, Keum Soo; Pan, Jae-Kyung

    2016-01-01

    We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed sensor showed a sensitivity of 456 kHz/mm or 1.043 kHz/V in a measurement range of 7 mm. The displacement resolution of the proposed sensor depends on the linewidth and the power of the optical source. Resolution better than 0.05 μm would be achieved if an optical source which has a linewidth narrower than 1.5 nm and a received power larger than −36 dBm is used. Also, the multiplexing characteristic of the proposed sensor was experimentally validated. PMID:26927098

  5. Scoping studies - photon and low energy neutron interrogation

    SciTech Connect

    Becker, G.; Harker, Y.; Jones, J.; Harmon, F.

    1997-11-01

    High energy photon interrogation of waste containers, with the aim of producing photo nuclear reactions, in specific materials, holds the potential of good penetration and rapid analysis. Compact high energy ({le} 10 MeV) photon sources in the form of electron linacs producing bremstrahlung radiation are readily available. Work with the Varitron variable energy accelerator at ISU will be described. Advantages and limitations of the technique will be discussed. Using positive ion induced neutron producing reactions, it is possible to generate neutrons in a specific energy range. By this means, variable penetration and specific reactions can be excited in the assayed material. Examples using the {sup 3}H(p,n) and {sup 7}Li(p,n) reactions as neutron sources will be discussed. 4 refs., 7 figs.

  6. An Optical Fiber Displacement Sensor Using RF Interrogation Technique.

    PubMed

    Kim, Hyeon-Ho; Choi, Sang-Jin; Jeon, Keum Soo; Pan, Jae-Kyung

    2016-01-01

    We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed sensor showed a sensitivity of 456 kHz/mm or 1.043 kHz/V in a measurement range of 7 mm. The displacement resolution of the proposed sensor depends on the linewidth and the power of the optical source. Resolution better than 0.05 μm would be achieved if an optical source which has a linewidth narrower than 1.5 nm and a received power larger than -36 dBm is used. Also, the multiplexing characteristic of the proposed sensor was experimentally validated. PMID:26927098

  7. Time-Dependent Delayed Signatures from Energetic Photon Interrogations

    SciTech Connect

    Daren R. Norman; James L. Jones; Brandon W. Blackburn; Kevin J. Haskell; James T. Johnson; Scott M. Watson; Alan W. Hunt; Randy Spaulding; Frank Harmon

    2007-08-01

    Pulsed photonuclear interrogation environments generated by 8–24 MeV electron linac are rich with time-dependent, material-specific, radiation signatures. Nitrogen-based explosives and nuclear materials can be detected by exploiting these signatures in different delayed-time regions. Numerical and experimental results presented in this paper show the unique time and energy dependence of these signatures. It is shown that appropriate delayed-time windows are essential to acquire material-specific signatures in pulsed photonuclear assessment environments. These developments demonstrate that pulsed, high-energy, photon-inspection environments can be exploited for time-dependent, material-specific signatures through the proper operation of specialized detectors and detection methods.

  8. Time-Dependent Delayed Signatures from Energetic Photon Interrogations

    SciTech Connect

    Daren R. Norman; James L. Jones; Brandon W. Blackburn; Kevin J. Haskell; James T. Johnson; Scott M. Watson; Alan W. Hunt; Randy Spaulding; Frank Harmon

    2007-08-01

    Pulsed photonuclear interrogation environments generated by 8–24 MeV electron linac are rich with time-dependent, material-specific, radiation signatures. Nitrogen-based explosives and nuclear materials can be detected by exploiting these signatures in different delayed-time regions. Numerical and experimental results presented in this paper show the unique time and energy dependence of these signatures. It is shown that appropriate delayed-time windows are essential to acquire material-specific signatures in the pulsed photonuclear assessment (PPA) environments. These developments demonstrate that pulsed, high-energy, photon- inspection environments can be exploited for time-dependent, material-specific signatures through the proper operation of specialized detectors and detection methods.

  9. Activated systemic inflammatory response at diagnosis reduces lymph node count in colonic carcinoma

    PubMed Central

    Kennelly, Rory P; Murphy, Brenda; Larkin, John O; Mehigan, Brian J; McCormick, Paul H

    2016-01-01

    AIM To investigate a link between lymph node yield and systemic inflammatory response in colon cancer. METHODS A prospectively maintained database was interrogated. All patients undergoing curative colonic resection were included. Neutrophil lymphocyte ratio (NLR) and albumin were used as markers of SIR. In keeping with previously studies, NLR ≥ 4, albumin < 35 was used as cut off points for SIR. Statistical analysis was performed using 2 sample t-test and χ2 tests where appropriate. RESULTS Three hundred and two patients were included for analysis. One hundred and ninety-five patients had NLR < 4 and 107 had NLR ≥ 4. There was no difference in age or sex between groups. Patients with NLR of ≥ 4 had lower mean lymph node yields than patients with NLR < 4 [17.6 ± 7.1 vs 19.2 ± 7.9 (P = 0.036)]. More patients with an elevated NLR had node positive disease and an increased lymph node ratio (≥ 0.25, P = 0.044). CONCLUSION Prognosis in colon cancer is intimately linked to the patient’s immune response. Assuming standardised surgical technique and sub specialty pathology, lymph node count is reduced when systemic inflammatory response is activated. PMID:27574555

  10. Active and passive mode calibration of the Combined Thermal Epithermal Neutron (CTEN) system

    SciTech Connect

    Veilleux, J. M.

    2002-06-01

    The Combined Thermal/Epithermal Neutron (CTEN) non-destructive assay (NDA) system was designed to assay transuranic waste by employing an induced active neutron interrogation and/or a spontaneous passive neutron measurement. This is the second of two papers, and focuses on the passive mode, relating the net double neutron coincidence measurement to the plutonium mass via the calibration constant. National Institute of Standards and Technology (NIST) calibration standards were used and the results verified with NIST-traceable verification standards. Performance demonstration program (PDP) 'empty' 208-L matrix drum was used for the calibration. The experimentally derived calibration constant was found to be 0.0735 {+-} 0.0059 g {sup 240}Pu effective per unit response. Using this calibration constant, the Waste Isolation Pilot Plant (WIPP) criteria was satisfied with five minute waste assays in the range from 3 to 177g Pu. CTEN also participated in the PDP Cycle 8A blind assay with organic sludge and metal matrices and passed the criteria for accuracy and precision in both assay modes. The WIPP and EPA audit was completed March 1, 2002 and full certification is awaiting the closeout of one finding during the audit. With the successful closeout of the audit, the CTEN system will have shown that it can provide very fast assays (five minutes or less) of waste in the range from the minimum detection limit (about 2 mg Pu) to 177 g Pu.

  11. Phase Transitions in Model Active Systems

    NASA Astrophysics Data System (ADS)

    Redner, Gabriel S.

    The amazing collective behaviors of active systems such as bird flocks, schools of fish, and colonies of microorganisms have long amazed scientists and laypeople alike. Understanding the physics of such systems is challenging due to their far-from-equilibrium dynamics, as well as the extreme diversity in their ingredients, relevant time- and length-scales, and emergent phenomenology. To make progress, one can categorize active systems by the symmetries of their constituent particles, as well as how activity is expressed. In this work, we examine two categories of active systems, and explore their phase behavior in detail. First, we study systems of self-propelled spherical particles moving in two dimensions. Despite the absence of an aligning interaction, this system displays complex emergent dynamics, including phase separation into a dense active solid and dilute gas. Using simulations and analytic modeling, we quantify the phase diagram and separation kinetics. We show that this nonequilibrium phase transition is analogous to an equilibrium vapor-liquid system, with binodal and spinodal curves and a critical point. We also characterize the dense active solid phase, a unique material which exhibits the structural signatures of a crystalline solid near the crystal-hexatic transition point, as well as anomalous dynamics including superdiffusive motion on intermediate timescales. We also explore the role of interparticle attraction in this system. We demonstrate that attraction drastically changes the phase diagram, which contains two distinct phase-separated regions and is reentrant as a function of propulsion speed. We interpret this complex situation with a simple kinetic model, which builds from the observed microdynamics of individual particles to a full description of the macroscopic phase behavior. We also study active nematics, liquid crystals driven out of equilibrium by energy-dissipating active stresses. The equilibrium nematic state is unstable in these

  12. Active imaging system with Faraday filter

    DOEpatents

    Snyder, J.J.

    1993-04-13

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  13. Active imaging system with Faraday filter

    DOEpatents

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  14. And I Want to Thank You Barbie: Barbie as a Site for Cultural Interrogation.

    ERIC Educational Resources Information Center

    Mitchell, Claudia; Reid-Walsh, Jacqueline

    1995-01-01

    Barbie is presented as the perfect cultural site for interrogating margins, borders, and contradictions in females' lives. This article illuminates such issues by interrogating the "cumulative cultural text of Barbie." Texts criticized are: Barbie collector cards; "Barbie" and "Barbie Fashion" comic books; "Barbie, The Magazine for Girls"; and the…

  15. 29 CFR 18.614 - Calling and interrogation of witnesses by judge.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Calling and interrogation of witnesses by judge. 18.614... HEARINGS BEFORE THE OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.614 Calling and interrogation of witnesses by judge. (a) Calling by the judge. The judge may, on the judge's own motion or...

  16. Using Elaborative Interrogation Enhanced Worked Examples to Improve Chemistry Problem Solving

    ERIC Educational Resources Information Center

    Pease, Rebecca Simpson

    2012-01-01

    Elaborative interrogation, which prompts students to answer why-questions placed strategically within informational text, has been shown to increase learning comprehension through reading. In this study, elaborative interrogation why-questions requested readers to explain why paraphrased statements taken from a reading were "true."…

  17. Detection and interrogation of biomolecules via nanoscale probes: From fundamental physics to DNA sequencing

    NASA Astrophysics Data System (ADS)

    Zwolak, Michael

    2013-03-01

    A rapid and low-cost method to sequence DNA would revolutionize personalized medicine, where genetic information is used to diagnose, treat, and prevent diseases. There is a longstanding interest in nanopores as a platform for rapid interrogation of single DNA molecules. I will discuss a sequencing protocol based on the measurement of transverse electronic currents during the translocation of single-stranded DNA through nanopores. Using molecular dynamics simulations coupled to quantum mechanical calculations of the tunneling current, I will show that the DNA nucleotides are predicted to have distinguishable electronic signatures in experimentally realizable systems. Several recent experiments support our theoretical predictions. In addition to their possible impact in medicine and biology, the above methods offer ideal test beds to study open scientific issues in the relatively unexplored area at the interface between solids, liquids, and biomolecules at the nanometer length scale. http://mike.zwolak.org

  18. Absolute Bragg wavelength and dispersion determination in dispersive incoherent OFDR interrogators

    NASA Astrophysics Data System (ADS)

    Clement, J.; Torregrosa, G.; Hervás, J.; Fernández-Pousa, C. R.

    2016-05-01

    We report on an incoherent OFDR interrogator of FBG arrays based on the concept of dispersive wavelength to time delay mapping. The system is specifically designed to show stability to environmental thermal variations by the incorporation of a composite dispersive delay and weak broadband reflectors for delay and dispersion monitoring. Dispersion is imparted by the combination of a fiber coil and an athermally-packaged chirped fiber Bragg grating for dispersion compensation. Using differential measurements over a single acquisition trace, the values of Bragg wavelengths and dispersion are determined from the delays experienced by the FBGs and by additional reference wavelengths reflected in the broadband reflectors. The results show maximum deviations of 20 pm and 0.2 ps/nm with respect to OSA measurements of Bragg wavelengths and nominal dispersion values, respectively.

  19. System for objective assessment of fetal activity.

    PubMed

    Kaluzynski, K J; Kret, T; Czajkowski, K; Sieńko, J; Zmigrodzki, J

    2011-07-01

    Fetal activity is an important indicator of fetal well-being. It is proposed to assess this activity using the pulsed wave Doppler method to collect fetal activity data and dedicated software for on-line processing. The system, addressed to 3rd trimester pregnancies, provides information on presence of pseudobreathing, the heart rate trace, the fetal movement trace, the movement velocity spectrogram, histograms of the velocity and acceleration of both the body movements and pseudobreathing, parameters of these histograms (mean values, standard deviations, shape descriptors), and cumulative counts of the velocity histograms. These parameters form the feature vector of the fetal activity. The system was validated by simultaneous echographic and cardiotocographic recordings and during oxytocin challenge tests. Feature vectors obtained from 1h recordings in 61 pregnancies were submitted to multivariate analysis of variance. Activity patterns of physiological cases and "borderline pathologies" were discriminated using reduced feature vectors, containing cumulative counts of velocity histograms. PMID:21277248

  20. Active containment systems incorporating modified pillared clays

    SciTech Connect

    Lundie, P. |; McLeod, N.

    1997-12-31

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation.

  1. Lies and coercion: why psychiatrists should not participate in police and intelligence interrogations.

    PubMed

    Janofsky, Jeffrey S

    2006-01-01

    Police interrogators routinely use deceptive techniques to obtain confessions from criminal suspects. The United States Executive Branch has attempted to justify coercive interrogation techniques in which physical or mental pain and suffering may be used during intelligence interrogations of persons labeled unlawful combatants. It may be appropriate for law enforcement, military, or intelligence personnel who are not physicians to use such techniques. However, forensic psychiatry ethical practice requires honesty, striving for objectivity, and respect for persons. Deceptive and coercive interrogation techniques violate these moral values. When a psychiatrist directly uses, works with others who use, or trains others to use deceptive or coercive techniques to obtain information in police, military, or intelligence interrogations, the psychiatrist breaches basic principles of ethics. PMID:17185476

  2. A New DREADD Facilitates the Multiplexed Chemogenetic Interrogation of Behavior

    PubMed Central

    Vardy, Eyal; Robinson, J. Elliott; Li, Chia; Olsen, Reid H. J.; DiBerto, Jeffrey F.; Giguere, Patrick M.; Sassano, Flori M.; Huang, Xi-Ping; Zhu, Hu; Urban, Daniel J.; White, Kate L.; Rittiner, Joseph E.; Crowley, Nicole A.; Pleil, Kristen E.; Mazzone, Christopher M.; Mosier, Philip D.; Song, Juan; Kash, Thomas L.; Malanga, C. J.; Krashes, Michael J.; Roth, Bryan L.

    2015-01-01

    DREADDs are chemogenetic tools widely used to remotely control cellular signaling, neuronal activity and behavior. Here we used a structure-based approach to develop a new Gi coupled DREADD using the kappa-opioid receptor as template (KORD) that is activated by the pharmacologically inert ligand salvinorin B (SALB). Activation of virally-expressed KORD in several neuronal contexts robustly attenuated neuronal activity and modified behaviors. Additionally, co-expression of the KORD and the Gq coupled M3-DREADD within the same neuronal population facilitated the sequential and bi-directional remote control of behavior. The availability of DREADDs activated by different ligands provides enhanced opportunities for investigating diverse physiological systems using multiplexed chemogenetic actuators. PMID:25937170

  3. Protection of Active Distribution Systems with DGs

    NASA Astrophysics Data System (ADS)

    Akila, Abdelrahman Ahmed; Helal, Ahmed; Eldesouki, Hussein

    2015-10-01

    Distribution systems are traditionally designed as radial passive systems fed from a single source. Protection coordination of such systems has been easily established assuming the system radiality. Insertion of distributed generators (DGs) into distribution systems makes the distribution system to be more active which causes redistribution of fault currents magnitudes and directions. This causes negative impacts on the original protection system coordination, since the distribution system losses its radiality and passiveness. Recently protection coordination in the presence of distributed generation has been paid a great attention. Researchers proposed various solutions to solve the protection coordination problem caused by adding DG into the distribution network. In this paper, the proposed solutions for the protection coordination problem considering the DG insertion will be illustrated, classified, and criticized.

  4. Aging assessment for active fire protection systems

    SciTech Connect

    Ross, S.B.; Nowlen, S.P.; Tanaka, T.

    1995-06-01

    This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

  5. Active Displacement Control of Active Magnetic Bearing System

    NASA Astrophysics Data System (ADS)

    Kertész, Milan; Kozakovič, Radko; Magdolen, Luboš; Masaryk, Michal

    2014-12-01

    The worldwide energy production nowadays is over 3400 GW while storage systems have a capacity of only 90 GW [1]. There is a good solution for additional storage capacity in flywheel energy storage systems (FES). The main advantage of FES is its relatively high efficiency especially with using the active magnetic bearing system. Therefore there exist good reasons for appropriate simulations and for creating a suitable magneto-structural control system. The magnetic bearing, including actuation, is simulated in the ANSYS parametric design language (APDL). APDL is used to create the loops of transient simulations where boundary conditions (BC) are updated based upon a "gap sensor" which controls the nodal position values of the centroid of the shaft and the current density inputs onto the copper windings.

  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. Assessing the feasibility of interrogating nuclear waste storage silos using cosmic-ray muons

    NASA Astrophysics Data System (ADS)

    Ambrosino, F.; Bonechi, L.; Cimmino, L.; D'Alessandro, R.; Ireland, D. G.; Kaiser, R.; Mahon, D. F.; Mori, N.; Noli, P.; Saracino, G.; Shearer, C.; Viliani, L.; Yang, G.

    2015-06-01

    Muon radiography is a fast growing field in applied scientific research. In recent years, many detector technologies and imaging techniques using the Coulomb scattering and absorption properties of cosmic-ray muons have been developed for the non-destructive assay of various structures across a wide range of applications. This work presents the first results that assess the feasibility of using muon radiography to interrogate waste silos within the U.K. Nuclear Industry. Two such approaches, using different techniques that exploit each of these properties, have previously been published, and show promising results from both simulation and experimental data for the detection of shielded high-Z materials and density variations from volcanic assay. Both detection systems used are based on scintillator and photomultiplier technologies. Results from dedicated simulation studies using both these proven technologies and image reconstruction techniques are presented for an intermediate-sized legacy nuclear waste storage facility filled with concrete and an array of uranium samples. Both results highlight the potential to identify uranium objects of varying thicknesses greater than 5 cm within real-time durations of several weeks. Increased contributions from Coulomb scattering within the concrete matrix of the structure hinder the ability of both approaches to resolve similar objects of 2 cm dimensions even with increased statistics. These results are all dependent on both the position of the objects within the facility and the locations of the detectors. Results for differing thicknesses of concrete, which reflect the non-standard composition of these complex, legacy structures under interrogation, are also presented alongside studies performed for a series of data collection durations. It is anticipated that with further research and optimisation of detector technologies and geometries, muon radiography in one, or both of these forms, will play a key role in future

  9. Gamma Band Activity in the Reticular Activating System

    PubMed Central

    Urbano, Francisco J.; Kezunovic, Nebojsa; Hyde, James; Simon, Christen; Beck, Paige; Garcia-Rill, Edgar

    2012-01-01

    This review considers recent evidence showing that cells in three regions of the reticular activating system (RAS) exhibit gamma band activity, and describes the mechanisms behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanisms behind this ceiling effect have been recently elucidated. We describe recent findings showing that every cell in the PPN have high-threshold, voltage-dependent P/Q-type calcium channels that are essential, while N-type calcium channels are permissive, to gamma band activity. Every cell in the Pf also showed that P/Q-type and N-type calcium channels are responsible for this activity. On the other hand, every SubCD cell exhibited sodium-dependent subthreshold oscillations. A novel mechanism for sleep–wake control based on well-known transmitter interactions, electrical coupling, and gamma band activity is described. The data presented here on inherent gamma band activity demonstrates the global nature of sleep–wake oscillation that is orchestrated by brainstem–thalamic mechanism, and questions the undue importance given to the hypothalamus for regulation of sleep–wakefulness. The discovery of gamma band activity in the RAS follows recent reports of such activity in other subcortical regions like the hippocampus and cerebellum. We hypothesize that, rather than participating in the temporal binding of sensory events as seen in the cortex, gamma band activity manifested in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking and paradoxical sleep. Most of our thoughts and actions are driven by pre-conscious processes. We speculate that continuous sensory input will induce gamma band activity in the RAS that could participate in the processes of

  10. Traveling and Resting Crystals in Active Systems

    NASA Astrophysics Data System (ADS)

    Menzel, Andreas M.; Löwen, Hartmut

    2013-02-01

    A microscopic field theory for crystallization in active systems is proposed which unifies the phase-field-crystal model of freezing with the Toner—Tu theory for self-propelled particles. A wealth of different active crystalline states are predicted and characterized. In particular, for increasing strength of self-propulsion, a transition from a resting crystal to a traveling crystalline state is found where the particles migrate collectively while keeping their crystalline order. Our predictions, which are verifiable in experiments and in particle-resolved computer simulations, provide a starting point for the design of new active materials.

  11. Distributed control system for active mirrors

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ramos, Luis F.; Williams, Mark R.; Castro, Javier; Cruz, A.; Gonzalez, Juan C.; Mack, Brian; Martin, Carlos; Pescador, German; Sanchez, Vicente; Sosa, Nicolas A.

    1994-06-01

    This paper presents the IAC (Instituto de Astrofisica de Canaries, Spain) proposal of a distributed control system intended for the active support of a 8 m mirror. The system incorporates a large number of compact `smart' force actuators, six force definers, and a mirror support computer (MSC) for interfacing with the telescope control system and for general housekeeping. We propose the use of a network for the interconnection of the actuators, definers and the MSC, which will minimize the physical complexity of the interface between the mirror support system and the MSC. The force actuator control electronics are described in detail, as is the system software architecture of the actuator and the MSC. As the network is a key point for the system, we also detail the evaluation of three candidates, before electing the CAN bus.

  12. Modular System to Enable Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2011-01-01

    The ability to perform extravehicular activity (EVA), both human and robotic, has been identified as a key component to space missions to support such operations as assembly and maintenance of space system (e.g. construction and maintenance of the International Space Station), and unscheduled activities to repair an element of the transportation and habitation systems that can only be accessed externally and via unpressurized areas. In order to make human transportation beyond lower earth orbit (BLEO) practical, efficiencies must be incorporated into the integrated transportation systems to reduce system mass and operational complexity. Affordability is also a key aspect to be considered in space system development; this could be achieved through commonality, modularity and component reuse. Another key aspect identified for the EVA system was the ability to produce flight worthy hardware quickly to support early missions and near Earth technology demonstrations. This paper details a conceptual architecture for a modular extravehicular activity system (MEVAS) that would meet these stated needs for EVA capability that is affordable, and that could be produced relatively quickly. Operational concepts were developed to elaborate on the defined needs and define the key capabilities, operational and design constraints, and general timelines. The operational concept lead to a high level design concept for a module that interfaces with various space transportation elements and contains the hardware and systems required to support human and telerobotic EVA; the module would not be self-propelled and would rely on an interfacing element for consumable resources. The conceptual architecture was then compared to EVA Systems used in the Shuttle Orbiter, on the International Space Station to develop high level design concepts that incorporate opportunities for cost savings through hardware reuse, and quick production through the use of existing technologies and hardware designs

  13. Active Annuloplasty System for Mitral Valve Insufficiency

    NASA Astrophysics Data System (ADS)

    Díaz Lantada, Andrés; Lafont, Pilar; Rada, Ignacio; Jiménez, Antonio; Hernández, José Luis; Lorenzo-Yustos, Héctor; Muñoz-García, Julio

    Active materials are capable of responding in a controlled way to different external physical or chemical stimuli by changing some of their properties. These materials can be used to design and develop sensors, actuators and multifunctional systems with a large number of applications for developing medical devices.

  14. METALS DISTRIBUTIONS IN ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    This project developed models to predict the distribution of metals in activated sludge system process streams. The data used to develop the models were obtained through extended pilot studies from a previous project. The objectives of the study were to evaluate the effects of wa...

  15. Supporting Classroom Activities with the BSUL System

    ERIC Educational Resources Information Center

    Ogata, Hiroaki; Saito, Nobuji A.; Paredes J., Rosa G.; San Martin, Gerardo Ayala; Yano, Yoneo

    2008-01-01

    This paper presents the integration of ubiquitous computing systems into classroom settings, in order to provide basic support for classrooms and field activities. We have developed web application components using Java technology and configured a classroom with wireless network access and a web camera for our purposes. In this classroom, the…

  16. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed. PMID:12906279

  17. Targeted activation in deterministic and stochastic systems

    NASA Astrophysics Data System (ADS)

    Eisenhower, Bryan; Mezić, Igor

    2010-02-01

    Metastable escape is ubiquitous in many physical systems and is becoming a concern in engineering design as these designs (e.g., swarms of vehicles, coupled building energetics, nanoengineering, etc.) become more inspired by dynamics of biological, molecular and other natural systems. In light of this, we study a chain of coupled bistable oscillators which has two global conformations and we investigate how specialized or targeted disturbance is funneled in an inverse energy cascade and ultimately influences the transition process between the conformations. We derive a multiphase averaged approximation to these dynamics which illustrates the influence of actions in modal coordinates on the coarse behavior of this process. An activation condition that predicts how the disturbance influences the rate of transition is then derived. The prediction tools are derived for deterministic dynamics and we also present analogous behavior in the stochastic setting and show a divergence from Kramers activation behavior under targeted activation conditions.

  18. A Web Architecture to Geographically Interrogate CHIRPS Rainfall and eMODIS NDVI for Land Use Change

    NASA Technical Reports Server (NTRS)

    Burks, Jason E.; Limaye, Ashutosh

    2014-01-01

    Monitoring of rainfall and vegetation over the continent of Africa is important for assessing the status of crop health and agriculture, along with long-term changes in land use change. These issues can be addressed through examination of long-term precipitation (rainfall) data sets and remote sensing of land surface vegetation and land use types. Two products have been used previously to address these goals: the Climate Hazard Group Infrared Precipitation with Stations (CHIRPS) rainfall data, and multi-day composites of Normalized Difference Vegetation Index (NDVI) from the USGS eMODIS product. Combined, these are very large data sets that require unique tools and architecture to facilitate a variety of data analysis methods or data exploration by the end user community. To address these needs, a web-enabled system has been developed to allow end-users to interrogate CHIRPS rainfall and eMODIS NDVI data over the continent of Africa. The architecture allows end-users to use custom defined geometries, or the use of predefined political boundaries in their interrogation of the data. The massive amount of data interrogated by the system allows the end-users with only a web browser to extract vital information in order to investigate land use change and its causes. The system can be used to generate daily, monthly and yearly averages over a geographical area and range of dates of interest to the user. It also provides analysis of trends in precipitation or vegetation change for times of interest. The data provided back to the end-user is displayed in graphical form and can be exported for use in other, external tools. The development of this tool has significantly decreased the investment and requirements for end-users to use these two important datasets, while also allowing the flexibility to the end-user to limit the search to the area of interest.

  19. Green Bank Telescope active surface system

    NASA Astrophysics Data System (ADS)

    Lacasse, Richard J.

    1998-05-01

    During the design phase of the Green Bank Telescope (GBT), various means of providing an accurate surface on a large aperture paraboloid, were considered. Automated jacks supporting the primary reflector were selected as the appropriate technology since they promised greater performance and potentially lower costs than a homologous or carbon fiber design, and had certain advantages over an active secondary. The design of the active surface has presented many challenges. Since the actuators are mounted on a tipping structure, it was required that they support a significant side-load. Such devices were not readily available commercially so they had to be developed. Additional actuator requirements include low backlash, repeatable positioning, and an operational life of at least 230 years. Similarly, no control system capable of controlling the 2209 actuators was commercially available. Again a prime requirement was reliability. Maintaining was also a very important consideration. The system architecture is tree-like. An active surface 'master-computer' controls interaction with the telescope control system, and controls ancillary equipment such as power supplies and temperature monitors. Two slave computers interface with the master- computer, and each closes approximately 1100 position loops. For simplicity, the servo is an 'on/off' type, yet achieves a positioning resolution of 25 microns. Each slave computer interfaces with 4 VME I/O cards, which in turn communicate with 140 control modules. The control modules read out the positions of the actuators every 0.1 sec and control the actuators' DC motors. Initial control of the active surface will be based on an elevation dependant structural model. Later, the model will be improved by holographic observations.Surface accuracy will be improved further by using laser ranging system which will actively measure the surface figure. Several tests have been conducted to assure that the system will perform as desired when

  20. Active gated imaging in driver assistance system

    NASA Astrophysics Data System (ADS)

    Grauer, Yoav

    2014-04-01

    In this paper, we shall present the active gated imaging system (AGIS) in relation to the automotive field. AGIS is based on a fast-gated camera and pulsed illuminator, synchronized in the time domain to record images of a certain range of interest. A dedicated gated CMOS imager sensor and near infra-red (NIR) pulsed laser illuminator, is presented in this paper to provide active gated technology. In recent years, we have developed these key components and learned the system parameters, which are most beneficial to nighttime (in all weather conditions) driving in terms of field of view, illumination profile, resolution, and processing power. We shall present our approach of a camera-based advanced driver assistance systems (ADAS) named BrightEye™, which makes use of the AGIS technology in the automotive field.

  1. Benchmark for Peak Detection Algorithms in Fiber Bragg Grating Interrogation and a New Neural Network for its Performance Improvement

    PubMed Central

    Negri, Lucas; Nied, Ademir; Kalinowski, Hypolito; Paterno, Aleksander

    2011-01-01

    This paper presents a benchmark for peak detection algorithms employed in fiber Bragg grating spectrometric interrogation systems. The accuracy, precision, and computational performance of currently used algorithms and those of a new proposed artificial neural network algorithm are compared. Centroid and gaussian fitting algorithms are shown to have the highest precision but produce systematic errors that depend on the FBG refractive index modulation profile. The proposed neural network displays relatively good precision with reduced systematic errors and improved computational performance when compared to other networks. Additionally, suitable algorithms may be chosen with the general guidelines presented. PMID:22163806

  2. Measurement of uranium and plutonium in solid waste by passive photon or neutron counting and isotopic neutron source interrogation

    SciTech Connect

    Crane, T.W.

    1980-03-01

    A summary of the status and applicability of nondestructive assay (NDA) techniques for the measurement of uranium and plutonium in 55-gal barrels of solid waste is reported. The NDA techniques reviewed include passive gamma-ray and x-ray counting with scintillator, solid state, and proportional gas photon detectors, passive neutron counting, and active neutron interrogation with neutron and gamma-ray counting. The active neutron interrogation methods are limited to those employing isotopic neutron sources. Three generic neutron sources (alpha-n, photoneutron, and /sup 252/Cf) are considered. The neutron detectors reviewed for both prompt and delayed fission neutron detection with the above sources include thermal (/sup 3/He, /sup 10/BF/sub 3/) and recoil (/sup 4/He, CH/sub 4/) proportional gas detectors and liquid and plastic scintillator detectors. The instrument found to be best suited for low-level measurements (< 10 nCi/g) is the /sup 252/Cf Shuffler. The measurement technique consists of passive neutron counting followed by cyclic activation using a /sup 252/Cf source and delayed neutron counting with the source withdrawn. It is recommended that a waste assay station composed of a /sup 252/Cf Shuffler, a gamma-ray scanner, and a screening station be tested and evaluated at a nuclear waste site. 34 figures, 15 tables.

  3. Modular System to Enable Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2012-01-01

    The ability to perform extravehicular activity (EVA), both human and robotic, has been identified as a key component to space missions to support such operations as assembly and maintenance of space systems (e.g. construction and maintenance of the International Space Station), and unscheduled activities to repair an element of the transportation and habitation systems that can only be accessed externally and via unpressurized areas. In order to make human transportation beyond lower Earth orbit (LEO) practical, efficiencies must be incorporated into the integrated transportation systems to reduce system mass and operational complexity. Affordability is also a key aspect to be considered in space system development; this could be achieved through commonality, modularity and component reuse. Another key aspect identified for the EVA system was the ability to produce flight worthy hardware quickly to support early missions and near Earth technology demonstrations. This paper details a conceptual architecture for a modular EVA system that would meet these stated needs for EVA capability that is affordable, and that could be produced relatively quickly. Operational concepts were developed to elaborate on the defined needs, and to define the key capabilities, operational and design constraints, and general timelines. The operational concept lead to a high level design concept for a module that interfaces with various space transportation elements and contains the hardware and systems required to support human and telerobotic EVA; the module would not be self-propelled and would rely on an interfacing element for consumable resources. The conceptual architecture was then compared to EVA Systems used in the Space Shuttle Orbiter, on the International Space Station to develop high level design concepts that incorporate opportunities for cost savings through hardware reuse, and quick production through the use of existing technologies and hardware designs. An upgrade option

  4. Optically Active Porphyrin and Phthalocyanine Systems.

    PubMed

    Lu, Hua; Kobayashi, Nagao

    2016-05-25

    This review highlights and summarizes various optically active porphyrin and phthalocyanine molecules prepared using a wide range of structural modification methods to improve the design of novel structures and their applications. The induced chirality of some illustrative achiral bis-porphyrins with a chiral guest molecule is introduced because these systems are ideal for the identification and separation of chiral biologically active substrates. In addition, the relationship between CD signal and the absolute configuration of the molecule is analyzed through an analysis of the results of molecular modeling calculations. Possible future research directions are also discussed. PMID:27186902

  5. Control Systems Cyber Security Standards Support Activities

    SciTech Connect

    Robert Evans

    2009-01-01

    The Department of Homeland Security’s Control Systems Security Program (CSSP) is working with industry to secure critical infrastructure sectors from cyber intrusions that could compromise control systems. This document describes CSSP’s current activities with industry organizations in developing cyber security standards for control systems. In addition, it summarizes the standards work being conducted by organizations within the sector and provides a brief listing of sector meetings and conferences that might be of interest for each sector. Control systems cyber security standards are part of a rapidly changing environment. The participation of CSSP in the development effort for these standards has provided consistency in the technical content of the standards while ensuring that information developed by CSSP is included.

  6. Advanced extravehicular activity systems requirements definition study

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A study to define the requirements for advanced extravehicular activities (AEVA) was conducted. The purpose of the study was to develop an understanding of the EVA technology requirements and to map a pathway from existing or developing technologies to an AEVA system capable of supporting long-duration missions on the lunar surface. The parameters of an AEVA system which must sustain the crewmembers and permit productive work for long periods in the lunar environment were examined. A design reference mission (DRM) was formulated and used as a tool to develop and analyze the EVA systems technology aspects. Many operational and infrastructure design issues which have a significant influence on the EVA system are identified.

  7. Active State Model for Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Park, Han; Chien, Steve; Zak, Michail; James, Mark; Mackey, Ryan; Fisher, Forest

    2003-01-01

    The concept of the active state model (ASM) is an architecture for the development of advanced integrated fault-detection-and-isolation (FDI) systems for robotic land vehicles, pilotless aircraft, exploratory spacecraft, or other complex engineering systems that will be capable of autonomous operation. An FDI system based on the ASM concept would not only provide traditional diagnostic capabilities, but also integrate the FDI system under a unified framework and provide mechanism for sharing of information between FDI subsystems to fully assess the overall health of the system. The ASM concept begins with definitions borrowed from psychology, wherein a system is regarded as active when it possesses self-image, self-awareness, and an ability to make decisions itself, such that it is able to perform purposeful motions and other transitions with some degree of autonomy from the environment. For an engineering system, self-image would manifest itself as the ability to determine nominal values of sensor data by use of a mathematical model of itself, and selfawareness would manifest itself as the ability to relate sensor data to their nominal values. The ASM for such a system may start with the closed-loop control dynamics that describe the evolution of state variables. As soon as this model was supplemented with nominal values of sensor data, it would possess self-image. The ability to process the current sensor data and compare them with the nominal values would represent self-awareness. On the basis of self-image and self-awareness, the ASM provides the capability for self-identification, detection of abnormalities, and self-diagnosis.

  8. APSTNG: neutron interrogation for detection of explosives, drugs, and nuclear and chemical warfare materials

    NASA Astrophysics Data System (ADS)

    Rhodes, Edgar A.; Peters, Charles W.

    1993-02-01

    A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed-portal requirements for nondestructive detection, including monitoring of contraband explosives, drugs, and weapon materials, and treaty verification of sealed munitions. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14- MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron reactions identify nuclides associated with all major chemicals in explosives, drugs, and chemical warfare agents, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from detection times of the gamma-rays and alpha-particles yield a separate coarse tomographic image of each identified nuclide. The APSTNG also forms the basis for a compact fast-neutron transmission imaging system that can be used along with or instead of the emission imaging system. Proof-of-concept experiments have been performed under laboratory conditions for simulated nuclear and chemical warfare munitions and for explosives and drugs. The small and relatively inexpensive APSTNG exhibits high reliability and can be quickly replaced. Surveillance systems based on APSTNG technology can avoid the large physical size, high capital and operating expenses, and reliability problems associated with complex accelerators.

  9. Research on an Active Seat Belt System

    NASA Astrophysics Data System (ADS)

    Kawashima, Takeshi

    In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the active shock control system is proposed. The semi-active control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.

  10. Multipurpose active/passive motion compensation system

    SciTech Connect

    Sullivan, R.A.; Clements, R.E.; Davenport, M.R.

    1984-05-01

    A microprocessor-controlled active/passive motion compensation system has been developed for deploying a variety of geotechnical in-situ testing devices with mobile drilling rigs from low-cost service vessels. The light-weight rotary heave compensator incorporates a hydraulic motor as the compensator actuator and a servo-controlled closed loop pump to reduce the air storage and power requirements. Unique features of the system are the use of inertial sensors to measure three components of boat motion, the ability to run the system in active/passive or passive modes, and the ability to automatically lower the drillstring at a constant velocity while maintaining motion compensation. Quantitative measurements made during sea trials offshore California yielded motion compensation accuracy approaching 98 percent which is much better than the compensation achieved with passive systems. Results are presented from offshore in-situ testing with a cone penetrometer, a vane shear device, and a suspension PS logger. The system can also be used for other offshore applications.

  11. Active laser system for sea ice control

    NASA Astrophysics Data System (ADS)

    Evtikhiev, Nickolay N.; Gaponov, Alexandr E.; Kuluba, Yury N.; Matous, Vladislav I.; Radominov, Oleg E.; Tuzikov, Vladimir Z.; Vargaftic, Vasiliy N.

    1997-01-01

    The airborne systems are used for complex investigations of coastline very successfully, for example it can be used to measure the depth of the sea, to discover the reefs and so on. Such information may be used in navigation too. The specific conditions of navigation in the North and Pole seas defines the necessity of exact knowledge about the ice cracks in order to find the possible direction of the ship movement. The active optical system, working in the near IR region, has many advantages before the passive one, especially if it is necessary to work during the polar night and at bad weather conditions. In this article we discuss the demands to the laser active airborne systems, that given the accurate picture of the ice with high resolution in the daytime and nighttime conditions. Such system based on the laser, mechanical scanner and avalanche photodiode is very compact, reliable and informative. The picture of the ice surface can be shown on the TV monitor, can be written to the memory and can be delivered to the processing center by the radiochannel. The experimental results are shown together with results of this system probing in the conditions of the North Pole Ocean.

  12. PCM Passive Cooling System Containing Active Subsystems

    NASA Technical Reports Server (NTRS)

    Blanding, David E.; Bass, David I.

    2005-01-01

    A multistage system has been proposed for cooling a circulating fluid that is subject to intermittent intense heating. The system would be both flexible and redundant in that it could operate in a basic passive mode, either sequentially or simultaneously with operation of a first, active cooling subsystem, and either sequentially or simultaneously with a second cooling subsystem that could be active, passive, or a combination of both. This flexibility and redundancy, in combination with the passive nature of at least one of the modes of operation, would make the system more reliable, relative to a conventional cooling system. The system would include a tube-in-shell heat exchanger, within which the space between the tubes would be filled with a phase-change material (PCM). The circulating hot fluid would flow along the tubes in the heat exchanger. In the basic passive mode of operation, heat would be conducted from the hot fluid into the PCM, wherein the heat would be stored temporarily by virtue of the phase change.

  13. Active Aircraft Pylon Noise Control System

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Czech, Michael J (Inventor); Elmiligui, Alaa A. (Inventor)

    2015-01-01

    An active pylon noise control system for an aircraft includes a pylon structure connecting an engine system with an airframe surface of the aircraft and having at least one aperture to supply a gas or fluid therethrough, an intake portion attached to the pylon structure to intake a gas or fluid, a regulator connected with the intake portion via a plurality of pipes, to regulate a pressure of the gas or fluid, a plenum chamber formed within the pylon structure and connected with the regulator, and configured to receive the gas or fluid as regulated by the regulator, and a plurality of injectors in communication with the plenum chamber to actively inject the gas or fluid through the plurality of apertures of the pylon structure.

  14. Spontaneous activity in the developing auditory system.

    PubMed

    Wang, Han Chin; Bergles, Dwight E

    2015-07-01

    Spontaneous electrical activity is a common feature of sensory systems during early development. This sensory-independent neuronal activity has been implicated in promoting their survival and maturation, as well as growth and refinement of their projections to yield circuits that can rapidly extract information about the external world. Periodic bursts of action potentials occur in auditory neurons of mammals before hearing onset. This activity is induced by inner hair cells (IHCs) within the developing cochlea, which establish functional connections with spiral ganglion neurons (SGNs) several weeks before they are capable of detecting external sounds. During this pre-hearing period, IHCs fire periodic bursts of Ca(2+) action potentials that excite SGNs, triggering brief but intense periods of activity that pass through auditory centers of the brain. Although spontaneous activity requires input from IHCs, there is ongoing debate about whether IHCs are intrinsically active and their firing periodically interrupted by external inhibitory input (IHC-inhibition model), or are intrinsically silent and their firing periodically promoted by an external excitatory stimulus (IHC-excitation model). There is accumulating evidence that inner supporting cells in Kölliker's organ spontaneously release ATP during this time, which can induce bursts of Ca(2+) spikes in IHCs that recapitulate many features of auditory neuron activity observed in vivo. Nevertheless, the role of supporting cells in this process remains to be established in vivo. A greater understanding of the molecular mechanisms responsible for generating IHC activity in the developing cochlea will help reveal how these events contribute to the maturation of nascent auditory circuits. PMID:25296716

  15. Massively Parallel Interrogation of Aptamer Sequence, Structure and Function

    SciTech Connect

    Fischer, N O; Tok, J B; Tarasow, T M

    2008-02-08

    Optimization of high affinity reagents is a significant bottleneck in medicine and the life sciences. The ability to synthetically create thousands of permutations of a lead high-affinity reagent and survey the properties of individual permutations in parallel could potentially relieve this bottleneck. Aptamers are single stranded oligonucleotides affinity reagents isolated by in vitro selection processes and as a class have been shown to bind a wide variety of target molecules. Methodology/Principal Findings. High density DNA microarray technology was used to synthesize, in situ, arrays of approximately 3,900 aptamer sequence permutations in triplicate. These sequences were interrogated on-chip for their ability to bind the fluorescently-labeled cognate target, immunoglobulin E, resulting in the parallel execution of thousands of experiments. Fluorescence intensity at each array feature was well resolved and shown to be a function of the sequence present. The data demonstrated high intra- and interchip correlation between the same features as well as among the sequence triplicates within a single array. Consistent with aptamer mediated IgE binding, fluorescence intensity correlated strongly with specific aptamer sequences and the concentration of IgE applied to the array. The massively parallel sequence-function analyses provided by this approach confirmed the importance of a consensus sequence found in all 21 of the original IgE aptamer sequences and support a common stem:loop structure as being the secondary structure underlying IgE binding. The microarray application, data and results presented illustrate an efficient, high information content approach to optimizing aptamer function. It also provides a foundation from which to better understand and manipulate this important class of high affinity biomolecules.

  16. Active neutron methods for nuclear safeguards applications using Helium-4 gas scintillation detectors

    NASA Astrophysics Data System (ADS)

    Lewis, Jason M.

    Active neutron methods use a neutron source to interrogate fissionable material. In this work a 4He gas scintillation fast neutron detection system is used to measure neutrons created by the interrogation. Three new applications of this method are developed: spent nuclear fuel assay, fission rate measurement, and special nuclear material detection. Three active neutron methods are included in this thesis. First a non-destructive plutonium assay technique called Multispectral Active Neutron Interrogation Analysis is developed. It is based on interrogating fuel with neutrons at several different energies. The induced fission rates at each interrogation energy are compared with results from a neutron transport model of the irradiation geometry in a system of equations to iteratively solve the inverse problem for isotopic composition. The model is shown to converge on the correct composition for a material with 3 different fissionable components, a representative neutron absorber, and any neutron transparent material such as oxygen in a variety of geometries. Next an experimental fission rate measurement technique is developed using 4He gas scintillation fast neutron detector. Several unique features of this detector allow it to detect and provide energy information on fast neutrons with excellent gamma discrimination efficiency. The detector can measure induced fission rate by energetically differentiating between interrogation neutrons and higher energy fission neutrons. The detector response to a mono-energetic deuterium-deuterium fusion neutron generator and a 252Cf source are compared to examine the difference in detected energy range. Finally we demonstrate a special nuclear material detection technique by detecting an unambiguous fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium neutron generator and a high pressure 4He gas fast neutron scintillation detector. Energy histograms resulting from this

  17. Voice activity detection for speaker verification systems

    NASA Astrophysics Data System (ADS)

    Borowski, Filip

    2008-01-01

    Complex algorithm for speech activity detection was presented in this article. It is based on speech enhancement, features extraction and final detection algorithm. The first one was published in ETSI standard as a module of "Advanced front-end feature extraction algorithm" in distributed speech recognition system. It consists of two main parts, noise estimatiom and Wiener filtering. For the final detection modified linear prediction coefficients and spectral entropy features are extracted form denoised signal.

  18. Light and immune systems: activation of immunological activities

    NASA Astrophysics Data System (ADS)

    Huang, Zheng; Liu, Hong; Chen, Wei R.

    2006-02-01

    Light has been used to treat diseases for hundreds of years. Convenient and powerful light sources such as lasers make photomedicine a major branch in diseases treatment and detection. Originally, light was often used for local treatment, using photomechanical, photochemical, photothermal reactions and photomodulation as the major mechanisms. More and more investigators have become interested in the systemic effects of light, particularly in its effects on immune systems. Much work has been done to activate and/or enhance the host immune system to combat cancer, either using light as a direct tool or as an adjuvant method. Light has long been used for assisting disease detection and diagnosis. Advances in light technology have made photo-diagnostics ever more precise spatially and temporally. Many techniques facilitate observation of bio-molecule interactions and other biological processes at the cellular level, hence providing opportunities to detect and monitor immune activities. This manuscript will review recent photo-immunological research in treatment of cancer. The recent development of combination therapies involving lasers will be presented. Specifically, the results of cancer treatment using laser photothermal interaction, either with or without additional immunological stimulation will be discussed. The immunological effects of photodynamic therapy (PDT), and of its combination with immunotherapy in cancer treatment will also be discussed. Much interest has been recently concentrated in the immunological responses after laser treatment. Such responses at cellular and molecular levels will be discussed. The effect of these treatment modalities on the distant metastases also showed promise of light induced antitumor immunity. The combination therapy and induced immunological responses appear to be the key for long-term control of tumors.

  19. A multi-parameter optical fiber sensor with interrogation and discrimination capabilities

    NASA Astrophysics Data System (ADS)

    Zhan, Yage; Wu, Hua; Yang, Qinyu; Pei, Jincheng; Yang, Xichun

    2009-11-01

    A multi-parameter and multi-function, but low-cost, optical fiber grating sensor with self-interrogation and self-discrimination capabilities is presented theoretically and experimentally. The sensor bases on three fiber Bragg gratings (FBG) and one fiber long period grating (LPG). Strain, vibration, pressure, ordinary temperature (-10 to 100 °C) and high temperature (100-800 °C) can be measured by the sensor. When high temperature (100-800 °C) is measured, the LPG is used as a high temperture sensor head and FBG 1 is used as an interrogation element. Alternatively, when one of the other four measurands is measured, FBG 1 (or FBG 2) is used as a sensor head and LPG is used as an interrogation element. When two of the other four measurands are measured simultaneously, FBG 1 and FBG 2 are used as sensor heads and LPG is used as a shared interrogation element. FBG 3 is used as a reference element to eliminate the errors resulted from light source fluctuation and the cross-sensitivity between measurand and environmental temperature. The measurands can be interrogated according to the signals of the photodiodes (PDs), which are related to the relative wavelength shift of the LPG and the FBGs. Experimental results agree well with theoretical analyses. The interrogation scheme is immune to light source fluctuation and the cross-sensitivity between measurands and enviromental temperature, and also the dynamic range is large.

  20. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  1. Global Positioning System Synchronized Active Light Autonomous Docking System

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor); Bell, Joseph L. (Inventor)

    1996-01-01

    A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprising at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

  2. Global Positioning System Synchronized Active Light Autonomous Docking System

    NASA Technical Reports Server (NTRS)

    Howard, Richard (Inventor)

    1994-01-01

    A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprises at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

  3. Passive position-adaptive radar modes for non-LOS interrogation of embedded targets

    NASA Astrophysics Data System (ADS)

    Mitra, Atindra K.

    2004-08-01

    A position-adaptive radar system concept is presented for purposes of interrogating difficult and obscured targets via the application of low-altitude smart or robotic-type UAV platforms. Under this concept, a high-altitude radiating platform is denoted as a HUAV and a low-altitude "position-adaptive" platform is denoted as a LUAV. The system concept is described by two modes. In Mode-1, real-time onboard LUAV computation of a phase parameter denoted as "signal differential path length" allows the LUAV to position-adaptively isolate a "signal leakage point", for example, between two buildings. After the LUAV position-adaptively converges to an optimum location, the system enters Mode-2. Under this Mode-2 concept, a technique denoted as "exploitation of leakage signals via path trajectory diversity" (E-LS-PTD) is developed. This technique is based on modulating scattering centers on embedded objects by implementing a fast trajectory on the HUAV while the LUAV is hovering in front of an "obscuration channel." Analytical results include sample outputs from an initial set numerical electromagnetic simulations.

  4. APSTNG: Neutron interrogation for detection of nuclear and CW weapons, explosives, and drugs

    SciTech Connect

    Rhodes, E.; Dickerman, C.E.; De Volpi, A. ); Peters, C.W. )

    1992-01-01

    A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image of each identified nuclide. The APSTNG also forms the basis for a compact fast-neutron transmission imaging system that can be used along with or instead of the emission imaging system; a collimator is not required since scattered neutrons are removed by electronic collimation'' (detected neutrons not having the proper flight time to be uncollided are discarded). The small and relatively inexpensive APSTNG exhibits high reliability and can be quickly replaced. Proof-of-concept experiments have been performed under laboratory conditions for simulated nuclear and chemical warfare munitions and for explosives and drugs.

  5. APSTNG: Neutron interrogation for detection of nuclear and CW weapons, explosives, and drugs

    SciTech Connect

    Rhodes, E.; Dickerman, C.E.; De Volpi, A.; Peters, C.W.

    1992-07-01

    A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image of each identified nuclide. The APSTNG also forms the basis for a compact fast-neutron transmission imaging system that can be used along with or instead of the emission imaging system; a collimator is not required since scattered neutrons are removed by ``electronic collimation`` (detected neutrons not having the proper flight time to be uncollided are discarded). The small and relatively inexpensive APSTNG exhibits high reliability and can be quickly replaced. Proof-of-concept experiments have been performed under laboratory conditions for simulated nuclear and chemical warfare munitions and for explosives and drugs.

  6. Dislocation boundaries and active slip systems

    SciTech Connect

    Wert, J.A.; Hansen, N.

    1995-11-01

    Part of the dislocations which have participated in the plastic deformation of a polycrystalline metal are stored in dislocation boundaries in a two- or three-dimensional arrangement. The dislocation in such boundaries can be analyzed by determining the misorientation between neighboring crystallites and the boundary orientation. Information about the dislocations in the boundaries can also be obtained by an analysis of active slip systems based on the crystallite orientation and the imposed stress or strain state in combination with appropriate constraint conditions. In the present paper an analysis of the boundary dislocation structure and of the slip systems has been conducted for pure aluminium cold-rolled to a von Mises strain of 0.41. The results show that a substantial majority of dislocations in different types of dislocation boundaries are from the primary and conjugate slip system in the adjoining crystallites. A basis is therefore provided for integrating deformation structure observations with plastic deformation behavior.

  7. Extravehicular Activity (EVA) 101: Constellation EVA Systems

    NASA Technical Reports Server (NTRS)

    Jordan, Nicole C.

    2007-01-01

    A viewgraph presentation on Extravehicular Activity (EVA) Systems is shown. The topics include: 1) Why do we need space suits? 2) Protection From the Environment; 3) Primary Life Support System (PLSS); 4) Thermal Control; 5) Communications; 6) Helmet and Extravehicular Visor Assy; 7) Hard Upper Torso (HUT) and Arm Assy; 8) Display and Controls Module (DCM); 9) Gloves; 10) Lower Torso Assembly (LTA); 11) What Size Do You Need?; 12) Boot and Sizing Insert; 13) Boot Heel Clip and Foot Restraint; 14) Advanced and Crew Escape Suit; 15) Nominal & Off-Nominal Landing; 16) Gemini Program (mid-1960s); 17) Apollo EVA on Service Module; 18) A Bold Vision for Space Exploration, Authorized by Congress; 19) EVA System Missions; 20) Configurations; 21) Reduced Gravity Program; and 22) Other Opportunities.

  8. Multi-level RF identification system

    DOEpatents

    Steele, Kerry D.; Anderson, Gordon A.; Gilbert, Ronald W.

    2004-07-20

    A radio frequency identification system having a radio frequency transceiver for generating a continuous wave RF interrogation signal that impinges upon an RF identification tag. An oscillation circuit in the RF identification tag modulates the interrogation signal with a subcarrier of a predetermined frequency and modulates the frequency-modulated signal back to the transmitting interrogator. The interrogator recovers and analyzes the subcarrier signal and determines its frequency. The interrogator generates an output indicative of the frequency of the subcarrier frequency, thereby identifying the responding RFID tag as one of a "class" of RFID tags configured to respond with a subcarrier signal of a predetermined frequency.

  9. Active Thermal Control System Development for Exploration

    NASA Technical Reports Server (NTRS)

    Westheimer, David

    2007-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has been actively developing technologies that will enable future missions or will provide significant improvements over the state of the art technologies. These technologies have are targeted for application on the Crew Exploration Vehicle (CEV), or Orion, and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  10. Advanced Active Thermal Control Systems Architecture Study

    NASA Technical Reports Server (NTRS)

    Hanford, Anthony J.; Ewert, Michael K.

    1996-01-01

    The Johnson Space Center (JSC) initiated a dynamic study to determine possible improvements available through advanced technologies (not used on previous or current human vehicles), identify promising development initiatives for advanced active thermal control systems (ATCS's), and help prioritize funding and personnel distribution among many research projects by providing a common basis to compare several diverse technologies. Some technologies included were two-phase thermal control systems, light-weight radiators, phase-change thermal storage, rotary fluid coupler, and heat pumps. JSC designed the study to estimate potential benefits from these various proposed and under-development thermal control technologies for five possible human missions early in the next century. The study compared all the technologies to a baseline mission using mass as a basis. Each baseline mission assumed an internal thermal control system; an external thermal control system; and aluminum, flow-through radiators. Solar vapor compression heat pumps and light-weight radiators showed the greatest promise as general advanced thermal technologies which can be applied across a range of missions. This initial study identified several other promising ATCS technologies which offer mass savings and other savings compared to traditional thermal control systems. Because the study format compares various architectures with a commonly defined baseline, it is versatile and expandable, and is expected to be updated as needed.

  11. Noninvasive ambulatory measurement system of cardiac activity.

    PubMed

    Pino, Esteban J; Chavez, Javier A P; Aqueveque, Pablo

    2015-08-01

    This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown. PMID:26738057

  12. Velocity distribution in active particles systems

    PubMed Central

    Marconi, Umberto Marini Bettolo; Gnan, Nicoletta; Paoluzzi, Matteo; Maggi, Claudio; Di Leonardo, Roberto

    2016-01-01

    We derive an analytic expression for the distribution of velocities of multiple interacting active particles which we test by numerical simulations. In clear contrast with equilibrium we find that the velocities are coupled to positions. Our model shows that, even for two particles only, the individual velocities display a variance depending on the interparticle separation and the emergence of correlations between the velocities of the particles. When considering systems composed of many particles we find an analytic expression connecting the overall velocity variance to density, at the mean-field level, and to the pair distribution function valid in the limit of small noise correlation times. Finally we discuss the intriguing analogies and main differences between our effective free energy functional and the theoretical scenario proposed so far for phase-separating active particles. PMID:27001289

  13. Velocity distribution in active particles systems

    NASA Astrophysics Data System (ADS)

    Marconi, Umberto Marini Bettolo; Gnan, Nicoletta; Paoluzzi, Matteo; Maggi, Claudio; di Leonardo, Roberto

    2016-03-01

    We derive an analytic expression for the distribution of velocities of multiple interacting active particles which we test by numerical simulations. In clear contrast with equilibrium we find that the velocities are coupled to positions. Our model shows that, even for two particles only, the individual velocities display a variance depending on the interparticle separation and the emergence of correlations between the velocities of the particles. When considering systems composed of many particles we find an analytic expression connecting the overall velocity variance to density, at the mean-field level, and to the pair distribution function valid in the limit of small noise correlation times. Finally we discuss the intriguing analogies and main differences between our effective free energy functional and the theoretical scenario proposed so far for phase-separating active particles.

  14. Methods for Characterization of Batteries Using Acoustic Interrogation

    NASA Astrophysics Data System (ADS)

    Bhadra, Shoham

    Batteries are a ubiquitous form of electrochemical energy storage, but thus far the methods for measuring the mechanical properties of batteries and their component materials in operando have lagged far behind the methods for measuring the corresponding electrical properties. In this thesis, I demonstrate methods for determining the changes in materials properties of an electrochemical energy storage cell both ex situ and in operando.. I begin by establishing the impact of micro-scale morphology changes on the macro-scale dynamic mechanical response in commercial alkaline AA cells. Using a bounce test, the coefficient of restitution (COR) of the cell is shown to increase non-linearly as a function of state of charge (SOC). I show that the reason for the increase in the COR stems from the spatially-dependent oxidation of the Zn anode, with an initial increase corresponding to the formation of a percolation pathway of ZnO-clad Zn particles spanning the radius of the anode. The subsequent saturation of the COR is shown to result from the ultimate solidification and desiccation of the Zn anode. Building from this, I present a generalized in operando solution for materials characterization in batteries using ultrasonic interrogation. The materials properties of battery components change during charge and discharge, resulting in a change in the sound speed of the materials. By attaching transducers to a battery during cycling and sending ultrasonic pulses through each cell I observe the changes in the time of flight (ToF) of the pulses, both in reflection and transmission. I show that the changes in ToF correspond to both SOC and state of health (SOH) in a variety of battery chemistries and geometries, and detail a corresponding acoustic conservation law model framework. Finally, I perform these electrochemical acoustic time of flight (EAToF) experiments on commercial alkaline AA cells. By correlating the results with energy dispersive x-ray diffraction (EDXRD) data and

  15. Chemical Mutagens, Transposons, and Transgenes to Interrogate Gene Function in Drosophila melanogaster

    PubMed Central

    Venken, Koen J.T.; Bellen, Hugo J.

    2014-01-01

    The study of genetics, genes, and chromosomal inheritance was initiated by Thomas Morgan in when the first visible mutations were identified in fruit flies. The field expanded upon the work initiated by Herman Muller in 1926 when he used X-rays to develop the first balancer chromosomes. Today, balancers are still invaluable to maintain mutations and transgenes but the arsenal of tools has expanded vastly and numerous new methods have been developed, many relying on the availability of the genome sequence and transposable elements. Forward genetic screens based on chemical mutagenesis or transposable elements have resulted in the unbiased identification of many novel players involved in processes probed by specific phenotypic assays. Reverse genetic approaches have relied on the availability of a carefully selected set of transposon insertions spread throughout the genome to allow the manipulation of the region in the vicinity of each insertion. Lastly, the ability to transform Drosophila with single copy transgenes using transposons or site-specific integration using the ΦC31 integrase has allowed numerous manipulations, including the ability to create and integrate genomic rescue constructs, generate duplications, RNAi knock-out technology, binary expression systems like the GAL4/UAS system as well as other methods. Here, we will discuss the most useful methodologies to interrogate the fruit fly genome in vivo focusing on chemical mutagenesis, transposons and transgenes. Genome engineering approaches based on nucleases and RNAi technology are discussed in following chapters. PMID:24583113

  16. A Group Recommender System for Tourist Activities

    NASA Astrophysics Data System (ADS)

    Garcia, Inma; Sebastia, Laura; Onaindia, Eva; Guzman, Cesar

    This paper introduces a method for giving recommendations of tourist activities to a group of users. This method makes recommendations based on the group tastes, their demographic classification and the places visited by the users in former trips. The group recommendation is computed from individual personal recommendations through the use of techniques such as aggregation, intersection or incremental intersection. This method is implemented as an extension of the e-Tourism tool, which is a user-adapted tourism and leisure application, whose main component is the Generalist Recommender System Kernel (GRSK), a domain-independent taxonomy-driven search engine that manages the group recommendation.

  17. Influenza virus activation of the interferon system

    PubMed Central

    Killip, Marian J.; Fodor, Ervin; Randall, Richard E.

    2015-01-01

    The host interferon (IFN) response represents one of the first barriers that influenza viruses must surmount in order to establish an infection. Many advances have been made in recent years in understanding the interactions between influenza viruses and the interferon system. In this review, we summarise recent work regarding activation of the type I IFN response by influenza viruses, including attempts to identify the viral RNA responsible for IFN induction, the stage of the virus life cycle at which it is generated and the role of defective viruses in this process. PMID:25678267

  18. System and method for monitoring cellular activity

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Fraser, Scott E. (Inventor); Lansford, Russell D. (Inventor)

    2002-01-01

    A system and method for monitoring cellular activity in a cellular specimen. According to one embodiment, a plurality of excitable markers are applied to the specimen. A multi-photon laser microscope is provided to excite a region of the specimen and cause fluorescence to be radiated from the region. The radiating fluorescence is processed by a spectral analyzer to separate the fluorescence into respective wavelength bands. The respective bands of fluorescence are then collected by an array of detectors, with each detector receiving a corresponding one of the wavelength bands.

  19. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1991-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six-inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. The experimental results for those component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials and extreme-infrared reflectivity of black paints show unexpected changes.

  20. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  1. System and method for monitoring cellular activity

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Fraser, Scott E. (Inventor); Lansford, Russell D. (Inventor)

    2004-01-01

    A system and method for monitoring cellular activity in a cellular specimen. According to one embodiment, a plurality of excitable markers are applied to the specimen. A multi-photon laser microscope is provided to excite a region of the specimen and cause fluorescence to be radiated from the region. The radiating fluorescence is processed by a spectral analyzer to separate the fluorescence into respective wavelength bands. The respective bands of fluorescence are then collected by an array of detectors, with each detector receiving a corresponding one of the wavelength bands.

  2. Analog VLSI system for active drag reduction

    SciTech Connect

    Gupta, B.; Goodman, R.; Jiang, F.; Tai, Y.C.; Tung, S.; Ho, C.M.

    1996-10-01

    In today`s cost-conscious air transportation industry, fuel costs are a substantial economic concern. Drag reduction is an important way to reduce costs. Even a 5% reduction in drag translates into estimated savings of millions of dollars in fuel costs. Drawing inspiration from the structure of shark skin, the authors are building a system to reduce drag along a surface. Our analog VLSI system interfaces with microfabricated, constant-temperature shear stress sensors. It detects regions of high shear stress and outputs a control signal to activate a microactuator. We are in the process of verifying the actual drag reduction by controlling microactuators in wind tunnel experiments. We are encouraged that an approach similar to one that biology employs provides a very useful contribution to the problem of drag reduction. 9 refs., 21 figs.

  3. Spontaneous Oscillations in an Active Matter System

    NASA Astrophysics Data System (ADS)

    Hayes, Robert; Tsang, Boyce; Granick, Steve

    Active matter (which consumes energy to move about) can organize into dynamic structures more interesting than those possible at steady-state. Here we show spontaneous periodic self-assembly in a simple three-component system of water, oil phase, and surfactant at constant room temperature, with emphasis on one model system. Benchtop experiments show that liquid crystal oil droplets spontaneously and collectively oscillate like a `beating heart' for several hours; contract, relax, and subsequently re-contract in a petri dish at a rate of a few `beats' per minute. These oscillations, emergent from the cooperative interaction of the three components, are driven by the competition between positive and negative feedback processes. This illustration of feedback in action reveals a new way to program self-assembled structures to vary with time.

  4. Actively controlled vibration welding system and method

    SciTech Connect

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  5. Active alignment/contact verification system

    DOEpatents

    Greenbaum, William M.

    2000-01-01

    A system involving an active (i.e. electrical) technique for the verification of: 1) close tolerance mechanical alignment between two component, and 2) electrical contact between mating through an elastomeric interface. For example, the two components may be an alumina carrier and a printed circuit board, two mating parts that are extremely small, high density parts and require alignment within a fraction of a mil, as well as a specified interface point of engagement between the parts. The system comprises pairs of conductive structures defined in the surfaces layers of the alumina carrier and the printed circuit board, for example. The first pair of conductive structures relate to item (1) above and permit alignment verification between mating parts. The second pair of conductive structures relate to item (2) above and permit verification of electrical contact between mating parts.

  6. Active balance system and vibration balanced machine

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  7. Phase Interrogation Used for a Wireless Passive Pressure Sensor in an 800 °C High-Temperature Environment

    PubMed Central

    Zhang, Huixin; Hong, Yingping; Liang, Ting; Zhang, Hairui; Tan, Qiulin; Xue, Chenyang; Liu, Jun; Zhang, Wendong; Xiong, Jijun

    2015-01-01

    A wireless passive pressure measurement system for an 800 °C high-temperature environment is proposed and the impedance variation caused by the mutual coupling between a read antenna and a LC resonant sensor is analyzed. The system consists of a ceramic-based LC resonant sensor, a readout device for impedance phase interrogation, heat insulating material, and a composite temperature-pressure test platform. Performances of the pressure sensor are measured by the measurement system sufficiently, including pressure sensitivity at room temperature, zero drift from room temperature to 800 °C, and the pressure sensitivity under the 800 °C high temperature environment. The results show that the linearity of sensor is 0.93%, the repeatability is 6.6%, the hysteretic error is 1.67%, and the sensor sensitivity is 374 KHz/bar. The proposed measurement system, with high engineering value, demonstrates good pressure sensing performance in a high temperature environment. PMID:25690546

  8. GWAS Central: a comprehensive resource for the comparison and interrogation of genome-wide association studies.

    PubMed

    Beck, Tim; Hastings, Robert K; Gollapudi, Sirisha; Free, Robert C; Brookes, Anthony J

    2014-07-01

    To facilitate broad and convenient integrative visualization of and access to GWAS data, we have created the GWAS Central resource (http://www.gwascentral.org). This database seeks to provide a comprehensive collection of summary-level genetic association data, structured both for maximal utility and for safe open access (i.e., non-directional signals to fully preclude research subject identification). The resource emphasizes on advanced tools that allow comparison and discovery of relevant data sets from the perspective of genes, genome regions, phenotypes or traits. Tested markers and relevant genomic features can be visually interrogated across up to 16 multiple association data sets in a single view, starting at a chromosome-wide view and increasing in resolution down to individual bases. In addition, users can privately upload and view their own data as temporary files. Search and display utility is further enhanced by exploiting phenotype ontology annotations to allow genetic variants associated with phenotypes and traits of interest to be precisely identified, across all studies. Data submissions are accepted from individual researchers, groups and consortia, whereas we also actively gather data sets from various public sources. As a result, the resource now provides over 67 million P-values for over 1600 studies, making it the world's largest openly accessible online collection of summary-level GWAS association information. PMID:24301061

  9. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    NASA Astrophysics Data System (ADS)

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-03-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  10. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-05-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  11. Expanding applications for surface-contaminant sensing using the laser interrogation of surface agents (LISA) technique

    NASA Astrophysics Data System (ADS)

    Ponsardin, Patrick L.; Higdon, N. S.; Chyba, Thomas H.; Armstrong, Wayne T.; Sedlacek, Arthur J., III; Christesen, Steven D.; Wong, Anna

    2004-02-01

    Laser Interrogation of Surface Agents (LISA) is a UV-Raman technique that provides short-range standoff detection and identification of surface-deposited chemical agents. ITT Industries, Advanced Engineering and Sciences Division, is currently developing and expanding the LISA technology under several programs that span a variety of missions for homeland defense. We will present and discuss some of these applications, while putting in perspective the overall evolution undergone by the technique within the last years. These applications include LISA-Recon (now called the Joint Contaminated Surface Detector--JCSD) which was developed under a cost-sharing arrangement with the U.S. Army Soldier and Biological Chemical Command (SBCCOM) for incorporation on the Army"s future reconnaissance vehicles, and designed to demonstrate single-shot on-the-move measurements of chemical contaminants at concentration levels below the Army's requirements. In parallel, LISA-Shipboard is being developed to optimize the sensor technique for detection of surface contaminants in the operational environment of a ship. The most recently started activity is LISA-Inspector that is being developed to provide a transportable sensor in a 'cart-like' configuration.

  12. DNA interrogation by the CRISPR RNA-guided endonuclease Cas9

    PubMed Central

    Sternberg, Samuel H.; Redding, Sy; Jinek, Martin; Greene, Eric C.; Doudna, Jennifer A.

    2014-01-01

    The CRISPR-associated enzyme Cas9 is an RNA-guided endonuclease that uses RNA:DNA base-pairing to target foreign DNA in bacteria. Cas9:guide RNA complexes are also effective genome engineering agents in animals and plants. Here we use single-molecule and bulk biochemical experiments to determine how Cas9:RNA interrogates DNA to find specific cleavage sites. We show that both binding and cleavage of DNA by Cas9:RNA require recognition of a short trinucleotide protospacer adjacent motif (PAM). Non-target DNA binding affinity scales with PAM density, and sequences fully complementary to the guide RNA but lacking a nearby PAM are ignored by Cas9:RNA. DNA strand separation and RNA:DNA heteroduplex formation initiate at the PAM and proceed directionally towards the distal end of the target sequence. Furthermore, PAM interactions trigger Cas9 catalytic activity. These results reveal how Cas9 employs PAM recognition to quickly identify potential target sites while scanning large DNA molecules, and to regulate dsDNA scission. PMID:24476820

  13. A Catheter-Based Acoustic Interrogation Device for Monitoring Motility Dynamics of the Lower Esophageal Sphincter

    PubMed Central

    Lu, Qian; Yadid-Pecht, Orly; Sadowski, Daniel C.; Mintchev, Martin P.

    2014-01-01

    This paper presents novel minimally-invasive, catheter-based acoustic interrogation device for monitoring motility dynamics of the lower esophageal sphincter (LES). A micro-oscillator actively emitting sound wave at 16 kHz is located at one side of the LES, and a miniature microphone is located at the other side of the sphincter to capture the sound generated from the oscillator. Thus, the dynamics of the opening and closing of the LES can be quantitatively assessed. In this paper, experiments are conducted utilizing an LES motility dynamics simulator. The sound strength is captured by the microphone and is correlated to the level of LES opening and closing controlled by the simulator. Measurements from the simulator model show statistically significant (p < 0.05) Pearson correlation coefficients (0.905 on the average in quiet environment and 0.736 on the average in noisy environment, D.O.F. = 9). Measuring the level of LES opening and closing has the potential to become a valuable diagnostic technique for understanding LES dysfunction and the disorders associated with it. PMID:25120160

  14. DNA interrogation by the CRISPR RNA-guided endonuclease Cas9

    NASA Astrophysics Data System (ADS)

    Sternberg, Samuel H.; Redding, Sy; Jinek, Martin; Greene, Eric C.; Doudna, Jennifer A.

    2014-03-01

    The clustered regularly interspaced short palindromic repeats (CRISPR)-associated enzyme Cas9 is an RNA-guided endonuclease that uses RNA-DNA base-pairing to target foreign DNA in bacteria. Cas9-guide RNA complexes are also effective genome engineering agents in animals and plants. Here we use single-molecule and bulk biochemical experiments to determine how Cas9-RNA interrogates DNA to find specific cleavage sites. We show that both binding and cleavage of DNA by Cas9-RNA require recognition of a short trinucleotide protospacer adjacent motif (PAM). Non-target DNA binding affinity scales with PAM density, and sequences fully complementary to the guide RNA but lacking a nearby PAM are ignored by Cas9-RNA. Competition assays provide evidence that DNA strand separation and RNA-DNA heteroduplex formation initiate at the PAM and proceed directionally towards the distal end of the target sequence. Furthermore, PAM interactions trigger Cas9 catalytic activity. These results reveal how Cas9 uses PAM recognition to quickly identify potential target sites while scanning large DNA molecules, and to regulate scission of double-stranded DNA.

  15. Experimental investigations on implementing different PGC algorithms for interrogation of fiber optic hydrophones

    NASA Astrophysics Data System (ADS)

    Sham Kumar, S.; C. V., Sreehari; Vivek, K.; T. V., Praveen; Moosad, K. P. B.; Rajesh, R.

    2015-06-01

    This paper discusses the detailed experimental investigations on the performance of interferometer based fiber optic hydrophones with different Phase Generated Carrier (PGC) demodulation algorithms for their interrogation. The study covers the effect on different parametric variations in the PGC implementations by comparison through Signal to Noise And Distortion (SINAD) and Total Harmonic Distortion (THD) analysis. This paper discusses experiments on most popular algorithms based on PGC like Arctangent, Differential Cross Multiplication (DCM) and Ameliorated PGC. A Distributed Feed-Back Fiber Lasers (DFB-FL) based fiber optic hydrophone, with Mach-Zehnder Interferometer having active phase modulator in reference arm and mechanism to cater polarization related intensity fading were used for the experiments. Experiments were carried out to study the effects of various parameters like the type and configuration of low pass filter, frequency of the modulation signal, frequency of acoustic signal etc. It is observed that all the three factors viz. the type of low pass filter, frequency of modulating and acoustic signal plays important role in retrieving the acoustic signal, based on the type of algorithms used and are discussed here.

  16. Active, Non-Intrusive Inspection Technologies for Homeland Defense

    SciTech Connect

    James L. Jones

    2003-06-01

    Active, non-intrusive inspection or interrogation technologies have been used for 100 years - with the primary focus being radiographic imaging. During the last 50 years, various active interrogation systems have been investigated and most have revealed many unique and interesting capabilities and advantages that have already benefited the general public. Unfortunately, except for medical and specific industrial applications, these unique capabilities have not been widely adopted, largely due to the complexity of the technology, the overconfident reliance on passive detection systems to handle most challenges, and the unrealistic public concerns regarding radiation safety issues for a given active inspection deployment. The unique homeland security challenges facing the United States today are inviting more "out-of-the-box" solutions and are demanding the effective technological solutions that only active interrogation systems can provide. While revolutionary new solutions are always desired, these technology advancements are rare, and when found, usually take a long time to fully understand and implement for a given application. What's becoming more evident is that focusing on under-developed, but well-understood, active inspection technologies can provide many of the needed "out-of-the-box" solutions. This paper presents a brief historical overview of active interrogation. It identifies some of the major homeland defense challenges being confronted and the commercial and research technologies presently available and being pursued. Finally, the paper addresses the role of the Idaho National Engineering and Environmental Laboratory and its partner, the Idaho Accelerator Center at Idaho State University, in promoting and developing active inspection technologies for homeland defense.

  17. Next Generation Active Buffet Suppression System

    NASA Technical Reports Server (NTRS)

    Galea, Stephen C.; Ryall, Thomas G.; Henderson, Douglas A.; Moses, Robert W.; White, Edward V.; Zimcik, David G.

    2003-01-01

    Buffeting is an aeroelastic phenomenon that is common to high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. These loads result in significant random stresses, which may cause fatigue damage leading to restricted capabilities and availability of the aircraft. This paper describes an international collaborative research activity among Australia, Canada and the United States involving the use of active structural control to alleviate the damaging structural response to these loads. The research program is being co-ordinated by the Air Force Research Laboratory (AFRL) and is being conducted under the auspices of The Technical Cooperative Program (TTCP). This truly unique collaborative program has been developed to enable each participating country to contribute resources toward a program that coalesces a broad range of technical knowledge and expertise into a single investigation. This collaborative program is directed toward a full-scale test of an F/A-18 empennage, which is an extension of an earlier initial test. The current program aims at applying advanced directional piezoactuators, the aircraft rudder, switch mode amplifiers and advanced control strategies on a full-scale structure to demonstrate the enhanced performance and capability of the advanced active BLA control system in preparation for a flight test demonstration.

  18. The synchronous active neutron detection assay system

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-09-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. They are using a Schlumberger neutron generator for the direct measurement of the fissile material content in spent fuel, in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics for the detection of very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ``lock-in`` amplifiers. They have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The results to data are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference.

  19. Systemic lupus erythematosus activity. An operational definition.

    PubMed

    Liang, M H; Stern, S; Esdaile, J M

    1988-04-01

    Improved diagnosis and treatment have reduced mortality from SLE and present us with an opportunity to consider SLE in finer distinctions than alive or dead. Although much has been learned about SLE without a gold standard of disease activity or a universally agreed-upon definition of SLE activity, standardization of one or more measures would greatly enhance our ability to compare results from different centers and to communicate more precisely. It is unlikely that any of the existing measures or any ones to be developed will completely satisfy everyone's needs but it is pointless to proliferate new ones without testing their metric properties. Some differences in concept are desirable, particularly for investigators who have specialized interests or insights, but each should meet criteria of reliability and validity and have explicit definitions of terms, rules for their ascertainment, and the time period covered. Moreover, agreement on minimum essential elements of any SLE activity measure and their operational definitions would be a boon. SLE activity is one dimension in the disease pathway of lupus and implies a continuous phenomena that is potentially reversible. Organ damage, another point in the path of causation, connotes irreversible disease. We recommend that minimum essential elements be based on their frequency of occurrence, biological sensibleness, and the likelihood that degrees of activity can be rated reliably to show a change in a clinical state. The rating should be independent of whether a therapy is employed. Since activity is always considered with severity, the two dimensions could be recognized in the scale. Severity can be used to expand a scale's gradations if a symptom or sign is present. Severity could be rated by the need to treat with immunosuppressive agents, the need to follow the patient more closely, or the functional or prognostic consequences of the manifestation. For every organ system clinical judgment should be used to decide

  20. Intense combined source of neutrons and photons for interrogation based on compact deuteron RF accelerator

    SciTech Connect

    Kurennoy, S. S.; Garnett, R. W.; Rybarcyk, L. J.

    2015-06-18

    Interrogation of special nuclear materials can benefit from mobile sources providing significant fluxes of neutrons (108/s at 2.5 MeV, 1010/s at 14.1 MeV) and of photons (>1012/s at 1-3 MeV). We propose a source that satisfies these requirements simultaneously plus also provides, via the reaction 11B(d,n)12C(γ15.1), a significant flux of 15-MeV photons, which are highly penetrating and optimal for inducing photo-fission in actinides. The source is based on a compact (< 5 m) deuteron RF accelerator that delivers an average current of a few mA of deuterons at 3-4 MeV to a boron target. The accelerator consists of a short RFQ followed by efficient inter-digital H-mode structures with permanent-magnet-quadrupole beam focusing [Kurennoy et al. (2012)], which suit perfectly for deuteron acceleration at low energies. Our estimates, based on recent measurements, indicate that the required fluxes of both neutrons and photons can be achieved at ~1 mA of 4-MeV deuterons. The goal of the proposed study is to confirm feasibility of the approach and develop requirements for future full system implementation.

  1. Intense combined source of neutrons and photons for interrogation based on compact deuteron RF accelerator

    DOE PAGESBeta

    Kurennoy, S. S.; Garnett, R. W.; Rybarcyk, L. J.

    2015-06-18

    Interrogation of special nuclear materials can benefit from mobile sources providing significant fluxes of neutrons (108/s at 2.5 MeV, 1010/s at 14.1 MeV) and of photons (>1012/s at 1-3 MeV). We propose a source that satisfies these requirements simultaneously plus also provides, via the reaction 11B(d,n)12C(γ15.1), a significant flux of 15-MeV photons, which are highly penetrating and optimal for inducing photo-fission in actinides. The source is based on a compact (< 5 m) deuteron RF accelerator that delivers an average current of a few mA of deuterons at 3-4 MeV to a boron target. The accelerator consists of a shortmore » RFQ followed by efficient inter-digital H-mode structures with permanent-magnet-quadrupole beam focusing [Kurennoy et al. (2012)], which suit perfectly for deuteron acceleration at low energies. Our estimates, based on recent measurements, indicate that the required fluxes of both neutrons and photons can be achieved at ~1 mA of 4-MeV deuterons. The goal of the proposed study is to confirm feasibility of the approach and develop requirements for future full system implementation.« less

  2. Low-level transuranic waste assay by photon interrogation and neutron counting

    SciTech Connect

    Lyoussi, A.; Edeline, J.C.; Romeyer-Dherbey, J.; Buisson, A.

    1993-12-31

    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 (TRU) in bulk solid wastes. This report describes the method being developed to assay high density TRU waste packages using photon interrogation. The system uses a pulsed electron beam from a linear accelerator (LINAC) to produce high-energy photon bursts from a metallic converter. The photons induce fissions in TRU. 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. The authors give here the results from counting photofission-induced delayed neutrons from {sup 239}Pu, {sup 235}U and {sup 238}U in sample matrices. They counted delayed neutrons emitted after each pulse of the LINAC. This enhances the available counts by a factor about 20 compared with the counting of delayed neutrons only after the irradiation period. The electron linear accelerator operates at 15 MeV, 140 mA, and 2.5 {mu}s wide pulse at a 50 Hz rate. The dynamics of photofission and delayed neutron production, use of an electron linear accelerator as a particle source, experimental and electronics details, and a future experimental works are discussed.

  3. Nanoscale bio-platforms for living cell interrogation: current status and future perspectives

    NASA Astrophysics Data System (ADS)

    Chang, Lingqian; Hu, Jiaming; Chen, Feng; Chen, Zhou; Shi, Junfeng; Yang, Zhaogang; Li, Yiwen; Lee, Ly James

    2016-02-01

    The living cell is a complex entity that dynamically responds to both intracellular and extracellular environments. Extensive efforts have been devoted to the understanding intracellular functions orchestrated with mRNAs and proteins in investigation of the fate of a single-cell, including proliferation, apoptosis, motility, differentiation and mutations. The rapid development of modern cellular analysis techniques (e.g. PCR, western blotting, immunochemistry, etc.) offers new opportunities in quantitative analysis of RNA/protein expression up to a single cell level. The recent entries of nanoscale platforms that include kinds of methodologies with high spatial and temporal resolution have been widely employed to probe the living cells. In this tutorial review paper, we give insight into background introduction and technical innovation of currently reported nanoscale platforms for living cell interrogation. These highlighted technologies are documented in details within four categories, including nano-biosensors for label-free detection of living cells, nanodevices for living cell probing by intracellular marker delivery, high-throughput platforms towards clinical current, and the progress of microscopic imaging platforms for cell/tissue tracking in vitro and in vivo. Perspectives for system improvement were also discussed to solve the limitations remains in current techniques, for the purpose of clinical use in future.

  4. Nanoscale bio-platforms for living cell interrogation: current status and future perspectives.

    PubMed

    Chang, Lingqian; Hu, Jiaming; Chen, Feng; Chen, Zhou; Shi, Junfeng; Yang, Zhaogang; Li, Yiwen; Lee, Ly James

    2016-02-14

    The living cell is a complex entity that dynamically responds to both intracellular and extracellular environments. Extensive efforts have been devoted to the understanding intracellular functions orchestrated with mRNAs and proteins in investigation of the fate of a single-cell, including proliferation, apoptosis, motility, differentiation and mutations. The rapid development of modern cellular analysis techniques (e.g. PCR, western blotting, immunochemistry, etc.) offers new opportunities in quantitative analysis of RNA/protein expression up to a single cell level. The recent entries of nanoscale platforms that include kinds of methodologies with high spatial and temporal resolution have been widely employed to probe the living cells. In this tutorial review paper, we give insight into background introduction and technical innovation of currently reported nanoscale platforms for living cell interrogation. These highlighted technologies are documented in details within four categories, including nano-biosensors for label-free detection of living cells, nanodevices for living cell probing by intracellular marker delivery, high-throughput platforms towards clinical current, and the progress of microscopic imaging platforms for cell/tissue tracking in vitro and in vivo. Perspectives for system improvement were also discussed to solve the limitations remains in current techniques, for the purpose of clinical use in future. PMID:26745513

  5. A new melanoma diagnosis active support system.

    PubMed

    Fiorini, R A; Dacquino, G; Laguteta, G

    2004-01-01

    The aim of this paper is to present the operational performance of a new MDASS (Melanoma Diagnosis Active Support System) prototype able to distil optimal knowledge from acquired data to automatically capture and reliably discriminate and quantify the stage of disease evolution. Automated classification dermatoscopical parameters can be divided into two main classes: Size Descriptor (point size, local, and global) and Intrinsic Descriptor (morphological, geometrical, chromatic, others). Usually elementary geometric shape robust and effective characterization, invariant to environment and optical geometry transformations, on a rigorous mathematical level is a key and computational intensive problem. MDASS uses GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Moment Invariants for shape/texture effective description. MDASS main results show robust disease classification procedure with distillation of minimal reference grids for pathological cases and they ultimately achieve effective early diagnosis of melanocytic lesion. System results are validated by carefully designed experiments with certified clinical reference database. Overall system operational performance is presented. Finally, MDASS error analysis and computational complexity are addressed and discussed. PMID:17270962

  6. Iterative key-residues interrogation of a phytase with thermostability increasing substitutions identified in directed evolution.

    PubMed

    Shivange, Amol V; Roccatano, Danilo; Schwaneberg, Ulrich

    2016-01-01

    Bacterial phytases have attracted industrial interest as animal feed supplement due to their high activity and sufficient thermostability (required for feed pelleting). We devised an approach named KeySIDE,  an iterative Key-residues interrogation of the wild type with Substitutions Identified in Directed Evolution for improving Yersinia mollaretii phytase (Ymphytase) thermostability by combining key beneficial substitutions and elucidating their individual roles. Directed evolution yielded in a discovery of nine positions in Ymphytase and combined iteratively to identify key positions. The "best" combination (M6: T77K, Q154H, G187S, and K289Q) resulted in significantly improved thermal resistance; the residual activity improved from 35 % (wild type) to 89 % (M6) at 58 °C and 20-min incubation. Melting temperature increased by 3 °C in M6 without a loss of specific activity. Molecular dynamics simulation studies revealed reduced flexibility in the loops located next to helices (B, F, and K) which possess substitutions (Helix-B: T77K, Helix-F: G187S, and Helix-K: K289E/Q). Reduced flexibility in the loops might be caused by strengthened hydrogen bonding network (e.g., G187S and K289E/K289Q) and a salt bridge (T77K). Our results demonstrate a promising approach to design phytases in food research, and we hope that the KeySIDE might become an attractive approach for understanding of structure-function relationships of enzymes. PMID:26403922

  7. A novel method for active fissile mass estimation with a pulsed neutron source

    NASA Astrophysics Data System (ADS)

    Dubi, C.; Ridnik, T.; Israelashvili, I.; Pedersen, B.

    2013-07-01

    Neutron interrogation facilities for mass evaluation of Special Nuclear Materials (SNM) samples are divided into two main categories: passive interrogation, where all neutron detections are due to spontaneous events, and active interrogation, where fissions are induced on the tested material by an external neutron source. While active methods are, in general, faster and more effective, their analysis is much harder to carry out. In the paper, we will introduce a new formalism for analyzing the detection signal generated by a pulsed source active interrogation facility. The analysis is aimed to distinct between fission neutrons from the main neutron source in the system, and the surrounding "neutron noise". In particular, we derive analytic expressions for the first three central moments of the number of detections in a given time interval, in terms of the different neutron sources. While the method depends on exactly the same physical assumptions as known models, the simplicity of the suggested formalism allows us to take into account the variance of the external neutron source—an effect that was so far neglected.

  8. Activity systems in the inquiry classroom

    NASA Astrophysics Data System (ADS)

    Wortham, Donald William

    Inquiry science, as called for by reform-minded organizations such as the National Research Council (1996), offers a platform with the potential for introducing all students to the practice of science while maintaining focus on key concepts and theories. This project followed two small groups as they completed an inquiry unit on genetics at a Midwestern high school. I investigated whether levels of student-to-teacher, student-to-student, student-apparatus, and student-concept connections were approximately equal across all students in each of the two groups. I found differences among students in levels of student-to-teacher, student-to-student, and student-concept connections. From a situated idiopathic perspective, these differences may indicate different levels of opportunity-to-learn. At a more abstract (nomothetic) level, these differences may be due to emergent divisions of labor (roles) within the two groups. From the perspective of Activity Theory (Leont'ev, 1978; Engestrom, 1987), roles serve as important mediators that simultaneously allow the social unit to accomplish its objectives, while shaping the development of participants. I describe three roles that capture modes of participation for students interacting in the small groups, and that may contribute to what Engestrom (2001) calls subject-producing activity systems: networked contributor, social member, and isolate. This paper also describes tools for teachers and researchers to use in identifying levels of mediation and roles as they occur in small groups.

  9. ROVER: A prototype active vision system

    NASA Astrophysics Data System (ADS)

    Coombs, David J.; Marsh, Brian D.

    1987-08-01

    The Roving Eyes project is an experiment in active vision. We present the design and implementation of a prototype that tracks colored balls in images from an on-line charge coupled device (CCD) camera. Rover is designed to keep up with its rapidly changing environment by handling best and average case conditions and ignoring the worst case. This allows Rover's techniques to be less sophisticated and consequently faster. Each of Rover's major functional units is relatively isolated from the others, and an executive which knows all the functional units directs the computation by deciding which jobs would be most effective to run. This organization is realized with a priority queue of jobs and their arguments. Rover's structure not only allows it to adapt its strategy to the environment, but also makes the system extensible. A capability can be added to the system by adding a functional module with a well defined interface and by modifying the executive to make use of the new module. The current implementation is discussed in the appendices.

  10. Split Hopkinson bar measurement using high-speed full-spectrum fiber Bragg grating interrogation.

    PubMed

    Seng, Frederick; Hackney, Drew; Goode, Tyler; Shumway, LeGrand; Hammond, Alec; Shoemaker, George; Pankow, Mark; Peters, Kara; Schultz, Stephen

    2016-09-01

    The development and validation of a high-speed, full-spectrum measurement technique is described for fiber Bragg grating (FBG) sensors. A FBG is surface-mounted to a split-Hopkinson tensile bar specimen to induce high strain rates. The high strain gradients and large strains that indicate material failure are analyzed under high strain rates up to 500  s-1. The FBG is interrogated using a high-speed full-spectrum solid-state interrogator with a repetition rate of 100 kHz. The captured deformed spectra are analyzed for strain gradients using a default interior point algorithm in combination with the modified transfer matrix approach. This paper shows that by using high-speed full-spectrum interrogation of an FBG and the modified transfer matrix method, highly localized strain gradients and discontinuities can be measured without a direct line of sight. PMID:27607299

  11. Compact, low-cost, and high-resolution interrogation unit for optical sensors

    SciTech Connect

    Kiesel, Peter; Schmidt, Oliver; Mohta, Setu; Johnson, Noble; Malzer, Stefan

    2006-11-13

    Compact wavelength detectors that resolve wavelength changes in the subpicometer range over a broad spectral range are presented. A photodiode array or position sensor device is coated with a linear variable filter that converts the wavelength of the incident light into a spatial intensity distribution. The centroid of the spatial distribution is determined by a differential readout of the two elements of the photodiode array or the position sensor device. The device can interrogate any optical sensor that produces a wavelength shift in response to a stimulus. The potential of this device was tested by interrogating fiber-Bragg-grating sensors.

  12. Electrodermal responsivity to interrogation questions and its relation to self-reported emotional disturbance.

    PubMed

    Gudjonsson, G H

    1982-01-01

    The relationship between skin resistance responses (SRRs) and self-reported emotional disturbance was studied in 24 males and 24 females. SRRs to seven interrogation questions were recorded and subjects were requested to rate on visual analogue scales how disturbing they had found each question. The mean within subject correlations were significant for both groups, suggesting that electrodermal responses to interrogation questions are significantly related to the extent to which the subjects find such questions disturbing. A particular question may elicit disturbance for a number of reasons including embarrassment, conflict over how to answer the question, and fear of the consequences of possible detection. PMID:7126718

  13. Accelerator requirements for fast-neutron interrogation of luggage and cargo

    SciTech Connect

    Micklich, B.J.; Fink, C.L.; Yule, T.J.

    1995-05-01

    Several different fast-neutron based techniques are being studied for the detection of contraband substances in luggage and cargo containers. The present work discusses the accelerator requirements for fast-neutron transmission spectroscopy (FNTS), pulsed fast-neutron analysis (PFNA), and 14-MeV neutron interrogation. These requirements are based on the results of Monte-Carlo simulations of neutron or gamma detection rates. Accelerator requirements are driven by count-rate considerations, spatial resolution and acceptable uncertainties in elemental compositions. The authors have limited their analyses to luggage inspection with FNTS and to cargo inspection with PFNA or 14-MeV neutron interrogation.

  14. Spectral Doppler interrogation of the patent foramen ovale-a window to left heart hemodynamics.

    PubMed

    Fadel, Bahaa M; Husain, Aysha; Bakarman, Hatem; Dahdouh, Ziad; Salvo, Giovanni Di; Mohty, Dania

    2015-02-01

    Spectral Doppler interrogation of flow across a patent foramen ovale (PFO) allows recording of the instantaneous pressure gradient between left and right atrium (RA). The assessment of RA pressure using the size and collapsibility of the inferior vena cava would thus allow estimation of left atrial (LA) pressure. In this article, we illustrate the value of spectral Doppler interrogation of flow across the PFO by transthoracic echocardiography as a novel and simple tool for the assessment of LA pressure and left cardiac hemodynamics in addition to the conventional noninvasive parameters. PMID:25130954

  15. Integrated Software Systems for Crew Management During Extravehicular Activity in Planetary Terrain Exploration

    NASA Technical Reports Server (NTRS)

    Kuznetz, Lawrence; Nguen, Dan; Jones, Jeffrey; Lee, Pascal; Merrell, Ronald; Rafiq, Azhar

    2008-01-01

    Initial planetary explorations with the Apollo program had a veritable ground support army monitoring the safety and health of the 12 astronauts who performed lunar surface extravehicular activities (EVAs). Given the distances involved, this will not be possible on Mars. A spacesuit for Mars must be smart enough to replace that army. The next generation suits can do so using 2 software systems serving as virtual companions, LEGACI (Life support, Exploration Guidance Algorithm and Consumable Interrogator) and VIOLET (Voice Initiated Operator for Life support and Exploration Tracking). The system presented in this study integrates data inputs from a suite of sensors into the MIII suit s communications, avionics and informatics hardware for distribution to remote managers and data analysis. If successful, the system has application not only for Mars but for nearer term missions to the Moon, and the next generation suits used on ISS as well. Field tests are conducted to assess capabilities for next generation spacesuits at Johnson Space Center (JSC) as well as the Mars and Lunar analog (Devon Island, Canada). LEGACI integrates data inputs from a suite of noninvasive biosensors in the suit and the astronaut (heart rate, suit inlet/outlet lcg temperature and flowrate, suit outlet gas and dewpoint temperature, pCO2, suit O2 pressure, state vector (accelerometry) and others). In the Integrated Walkback Suit Tests held at NASA-JSC and the HMP tests at Devon Island, communication and informatics capabilities were tested (including routing by satellite from the suit at Devon Island to JSC in Houston via secure servers at VCU in Richmond, VA). Results. The input from all the sensors enable LEGACI to compute multiple independent assessments of metabolic rate, from which a "best" met rate is chosen based on statistical methods. This rate can compute detailed information about the suit, crew and EVA performance using test-derived algorithms. VIOLET gives LEGACI voice activation

  16. Inadvertent hypnosis during interrogation: false confession due to dissociative state; mis-identified multiple personality and the Satanic cult hypothesis.

    PubMed

    Ofshe, R J

    1992-07-01

    Induction of a dissociative state followed by suggestion during interrogation caused a suspect to develop pseudo-memories of raping his daughters and of participation in a baby-murdering Satanic cult. The pseudo-memories coupled with influence from authority figures convinced him of his guilt for 6 months. During this time, the suspect, the witnesses, and all the evidence in the case were studied. No evidence supported an inference of guilt and substantial evidence supported the conclusion that no crime had been committed. An experiment demonstrated the suspect's extreme suggestibility. The conclusion reached was that the cult did not exist and the suspect's confessions were coerced-internalized false confessions. During the investigation, 2 psychologists diagnosed the suspect as suffering from a dissociative disorder similar to multiple personality. Both psychologists were predisposed to find Satanic cult activity. Each concluded that the disorder was due to "programming" by the non-existent Satanic cult. PMID:1399152

  17. Interrogating Meanings of Work in Children's Literature

    ERIC Educational Resources Information Center

    Wieland, Stacey M. B.; Bauer, Janell C.

    2015-01-01

    In this article, Wieland and Bauer discuss a teaching activity that helps students understand how meanings of work (MOW) are socially constructed through commonplace texts: children's books. The activity helps students consider how children's books shape future workers' understandings of what work is, what kinds of work are most…

  18. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  19. Can You Believe It? 12-Month-Olds Use Word Order to Distinguish between Declaratives and Polar Interrogatives

    ERIC Educational Resources Information Center

    Geffen, Susan; Mintz, Toben H.

    2015-01-01

    Word order is a core mechanism for conveying syntactic structure, yet interrogatives usually disrupt canonical word orders. For example, in English, polar interrogatives typically invert the subject and auxiliary verb and insert an utterance-initial "do" if no auxiliary is present. These word order patterns result from differences in the…

  20. A Syntactic Bias in Scope Ambiguity Resolution in the Processing of English-French Cardinality Interrogatives: Evidence for Informational Encapsulation

    ERIC Educational Resources Information Center

    Dekydtspotter, Laurent; Outcalt, Samantha D.

    2005-01-01

    This article presents a reading-time study of scope resolution in the interpretation of ambiguous cardinality interrogatives in English-French and in English and French native sentence processing. Participants were presented with a context, a self-paced segment-by-segment presentation of a cardinality interrogative, and a numerical answer that…

  1. Genome-Wide Mapping and Interrogation of the Nmp4 Antianabolic Bone Axis

    PubMed Central

    Childress, Paul; Stayrook, Keith R.; Alvarez, Marta B.; Wang, Zhiping; Shao, Yu; Hernandez-Buquer, Selene; Mack, Justin K.; Grese, Zachary R.; He, Yongzheng; Horan, Daniel; Pavalko, Fredrick M.; Warden, Stuart J.; Robling, Alexander G.; Yang, Feng-Chun; Allen, Matthew R.; Krishnan, Venkatesh; Liu, Yunlong

    2015-01-01

    PTH is an osteoanabolic for treating osteoporosis but its potency wanes. Disabling the transcription factor nuclear matrix protein 4 (Nmp4) in healthy, ovary-intact mice enhances bone response to PTH and bone morphogenetic protein 2 and protects from unloading-induced osteopenia. These Nmp4−/− mice exhibit expanded bone marrow populations of osteoprogenitors and supporting CD8+ T cells. To determine whether the Nmp4−/− phenotype persists in an osteoporosis model we compared PTH response in ovariectomized (ovx) wild-type (WT) and Nmp4−/− mice. To identify potential Nmp4 target genes, we performed bioinformatic/pathway profiling on Nmp4 chromatin immunoprecipitation sequencing (ChIP-seq) data. Mice (12 w) were ovx or sham operated 4 weeks before the initiation of PTH therapy. Skeletal phenotype analysis included microcomputed tomography, histomorphometry, serum profiles, fluorescence-activated cell sorting and the growth/mineralization of cultured WT and Nmp4−/− bone marrow mesenchymal stem progenitor cells (MSPCs). ChIP-seq data were derived using MC3T3-E1 preosteoblasts, murine embryonic stem cells, and 2 blood cell lines. Ovx Nmp4−/− mice exhibited an improved response to PTH coupled with elevated numbers of osteoprogenitors and CD8+ T cells, but were not protected from ovx-induced bone loss. Cultured Nmp4−/− MSPCs displayed enhanced proliferation and accelerated mineralization. ChIP-seq/gene ontology analyses identified target genes likely under Nmp4 control as enriched for negative regulators of biosynthetic processes. Interrogation of mRNA transcripts in nondifferentiating and osteogenic differentiating WT and Nmp4−/− MSPCs was performed on 90 Nmp4 target genes and differentiation markers. These data suggest that Nmp4 suppresses bone anabolism, in part, by regulating IGF-binding protein expression. Changes in Nmp4 status may lead to improvements in osteoprogenitor response to therapeutic cues. PMID:26244796

  2. Genome-Wide Mapping and Interrogation of the Nmp4 Antianabolic Bone Axis.

    PubMed

    Childress, Paul; Stayrook, Keith R; Alvarez, Marta B; Wang, Zhiping; Shao, Yu; Hernandez-Buquer, Selene; Mack, Justin K; Grese, Zachary R; He, Yongzheng; Horan, Daniel; Pavalko, Fredrick M; Warden, Stuart J; Robling, Alexander G; Yang, Feng-Chun; Allen, Matthew R; Krishnan, Venkatesh; Liu, Yunlong; Bidwell, Joseph P

    2015-09-01

    PTH is an osteoanabolic for treating osteoporosis but its potency wanes. Disabling the transcription factor nuclear matrix protein 4 (Nmp4) in healthy, ovary-intact mice enhances bone response to PTH and bone morphogenetic protein 2 and protects from unloading-induced osteopenia. These Nmp4(-/-) mice exhibit expanded bone marrow populations of osteoprogenitors and supporting CD8(+) T cells. To determine whether the Nmp4(-/-) phenotype persists in an osteoporosis model we compared PTH response in ovariectomized (ovx) wild-type (WT) and Nmp4(-/-) mice. To identify potential Nmp4 target genes, we performed bioinformatic/pathway profiling on Nmp4 chromatin immunoprecipitation sequencing (ChIP-seq) data. Mice (12 w) were ovx or sham operated 4 weeks before the initiation of PTH therapy. Skeletal phenotype analysis included microcomputed tomography, histomorphometry, serum profiles, fluorescence-activated cell sorting and the growth/mineralization of cultured WT and Nmp4(-/-) bone marrow mesenchymal stem progenitor cells (MSPCs). ChIP-seq data were derived using MC3T3-E1 preosteoblasts, murine embryonic stem cells, and 2 blood cell lines. Ovx Nmp4(-/-) mice exhibited an improved response to PTH coupled with elevated numbers of osteoprogenitors and CD8(+) T cells, but were not protected from ovx-induced bone loss. Cultured Nmp4(-/-) MSPCs displayed enhanced proliferation and accelerated mineralization. ChIP-seq/gene ontology analyses identified target genes likely under Nmp4 control as enriched for negative regulators of biosynthetic processes. Interrogation of mRNA transcripts in nondifferentiating and osteogenic differentiating WT and Nmp4(-/-) MSPCs was performed on 90 Nmp4 target genes and differentiation markers. These data suggest that Nmp4 suppresses bone anabolism, in part, by regulating IGF-binding protein expression. Changes in Nmp4 status may lead to improvements in osteoprogenitor response to therapeutic cues. PMID:26244796

  3. Analytical investigation of a novel interrogation approach of fiber Bragg grating sensors using Optical Frequency Domain Reflectometry

    NASA Astrophysics Data System (ADS)

    Yüksel, Kivilcim; Pala, Deniz

    2016-06-01

    This work presents a novel approach in interrogating Polarization Dependent Loss (PDL) of cascaded identical FBGs using Optical Frequency Domain Reflectometer (OFDR). The fundamentals of both polarisation properties of uniform FBGs and polarisation-sensitive OFDR are explained and the benefits of this novel approach in measuring transversal load are discussed. The numerical programs computing the spectral evolution of PDL of the FBGs in the array as a function of grating parameters (grating length and birefringence) are presented. Our simulation results show an excellent agreement with the previously reported simulation (and experimental) results in the literature obtained on a single FBG by using classical state-of-the-art measurement techniques. As an envisaged application, the proposed system shows the feasibility of measuring the residual stresses during manufacturing process of composite materials which is not straightforward by amplitude spectrum measurements and/or considering only the axial strains.

  4. Interrogating Institutionalized Establishments: Urban-Rural Inequalities in China's Higher Education

    ERIC Educational Resources Information Center

    Li, Mei; Yang, Rui

    2013-01-01

    China's urban-rural disparities are a fundamental source of China's overall educational inequalities. This article addresses the issue with data collected through interviews with members at various Chinese higher education institutions. It interrogates China's current policies together with the socio-political institutional…

  5. Scripting, Ritualising and Performing Leadership: Interrogating Recent Policy Developments in Australia

    ERIC Educational Resources Information Center

    Fitzgerald, Tanya; Savage, Julia

    2013-01-01

    In this article, we argue that leadership of schools is a form of performance that has become ritualised and routinised through the official scripting of policy texts that mandate how leadership of schools should occur. Our interrogation of recent policy scripts in Australia reveals that there is limited scope for leadership in schools to occur as…

  6. CEL_INTERROGATOR: A FREE AND OPEN SOURCE PACKAGE FOR AFFYMETRIX CEL FILE PARSING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CEL_Interrogator Package is a suite of programs designed to extract the average probe intensity and other information for each probe sequence from an Affymetrix GeneChip CEL file and unite them with their human-readable Affymetrix consensus sequence names. The resulting text file is suitable for di...

  7. Examining Adolescents' and Their Parents' Conceptual and Practical Knowledge of Police Interrogation: A Family Dyad Approach

    ERIC Educational Resources Information Center

    Woolard, Jennifer L.; Cleary, Hayley M. D.; Harvell, Samantha A. S.; Chen, Rusan

    2008-01-01

    This study examines whether parents have the prerequisite knowledge about police interrogation that would allow them to compensate for youths' knowledge deficits, protect their interests, and buffer against their vulnerability to coercion. A racially diverse urban/suburban convenience sample of 77 11- to 13-year-olds, 46 14- to 15-year-olds, and…

  8. Double Jeopardy in the Interrogation Room for Youths with Mental Illness

    ERIC Educational Resources Information Center

    Redlich, Allison D.

    2007-01-01

    Comments on the article by J. Owen-Kostelnik, N. D. Reppucci, and J. R. Meyer (see record 2006-05893-002) which reviewed the issues surrounding the police interrogation of minors. This commentary expands on the review by addressing the mental health status of youths who come into contact with police. It stems from two immutable facts: (a) The…

  9. Reading Resistance: The Record of Tsunesaburo Makiguchi's Interrogation by Wartime Japan's "Thought Police"

    ERIC Educational Resources Information Center

    Ito, Takao

    2009-01-01

    This article examines the record of Tsunesaburo Makiguchi's interrogation as a thought criminal following his arrest in July, 1943. By comparing and contrasting his responses and statements against the official government positions, I hope to clarify the nature of his critique of the wartime fascist regime. Makiguchi himself was an educator, and…

  10. Interrogative Suggestibility among Adolescent Boys and Its Relationship with Intelligence, Memory, and Cognitive Set.

    ERIC Educational Resources Information Center

    Singh, Krishna K.; Gudjonsson, Gisli H.

    1992-01-01

    Investigated hypotheses generated by Gudjonsson and Clark model of interrogative suggestibility. Adolescent boys (n=40) completed Gudjonsson Suggestibility Scale and measures of intellectual skills, memory, field-dependence, hostility, and attitudes toward persons in authority. Suggestibility correlated negatively with intelligence quotient and…

  11. Radio-frequency unbalanced M-Z interferometer for wavelength interrogation of fiber Bragg grating sensors.

    PubMed

    Zhou, Jiaao; Xia, Li; Cheng, Rui; Wen, Yongqiang; Rohollahnejad, Jalal

    2016-01-15

    The optical unbalanced Mach-Zehnder interferometer (UMZI) has attracted significant interests for interrogation of FBG sensors owing to its excellent advantages in sensitivity, resolution, and demodulation speed. But this method is still limited to dynamic measurements due to its poor stability and reliability when used for quasi-static detections. Here, we propose for the first time, to the best of our knowledge, a radio-frequency unbalanced M-Z interferometer (RF-UMZI) for interrogation of FBG sensors, which, owing to its operation in an incoherent rather than a coherent regime, provides an ideal solution for the existing stability problem of the conventional UMZI, with remarkable features of adjustable resolution and potentially extremely high sensitivity. A dispersion compensation fiber (DCF) and single-mode fiber (SMF) with a small length difference are served as the two unbalanced arms of the RF interferometer. The induced differential chromatic dispersion transfers the wavelength shift of the FBG to the change of the RF phase difference between the two interferometric carriers, which ultimately leads to the variation of the RF signal intensity. An interrogation of a strain-turned FBG was accomplished and a maximum sensitivity of 0.00835  a.u./με was obtained, which can easily be further improved by more than two orders of magnitude through various fiber dispersion components. Finally, the stability of the interrogation was tested. PMID:26766702

  12. Asking for Action or Information? Crosslinguistic Comparison of Interrogative Functions in Early Child Cantonese and Mandarin

    ERIC Educational Resources Information Center

    Li, Hui; Wong, Eileen Chin Mei; Tse, Shek Kam; Leung, Shing On; Ye, Qianling

    2015-01-01

    Request for information (RfI) is believed to be the universally dominant function of young children's questioning, whereas request for action (RfA) has been reported to be the leading interrogative form used in early child Cantonese. The possibility of crosslinguistic variability prompts further research and comparison with additional languages.…

  13. Correlation between Question Intonation and Focus of Interrogation--Evidence from French Dislocated Questions.

    ERIC Educational Resources Information Center

    Shen, Xiao-nan

    This study explores the relationship between question intonation patterns in French using dislocated questions and question-focus (Q- focus). A dislocated question is defined as an interrogative sentence whose sequence is interrupted by the topicalization of a constituent at the left ("Toi, tu viens?"), at the right (Tu viens, toi?"), or in the…

  14. A High-Temperature Fiber Sensor Using a Low Cost Interrogation Scheme

    PubMed Central

    Barrera, David; Sales, Salvador

    2013-01-01

    Regenerated Fibre Bragg Gratings have the potential for high-temperature monitoring. In this paper, the inscription of Fibre Bragg Gratings (FBGs) and the later regeneration process to obtain Regenerated Fiber Bragg Gratings (RFBGs) in high-birefringence optical fiber is reported. The obtained RFBGs show two Bragg resonances corresponding to the slow and fast axis that are characterized in temperature terms. As the temperature increases the separation between the two Bragg resonances is reduced, which can be used for low cost interrogation. The proposed interrogation setup is based in the use of optical filters in order to convert the wavelength shift of each of the Bragg resonances into optical power changes. The design of the optical filters is also studied in this article. In first place, the ideal filter is calculated using a recursive method and defining the boundary conditions. This ideal filter linearizes the output of the interrogation setup but is limited by the large wavelength shift of the RFBG with temperature and the maximum attenuation. The response of modal interferometers as optical filters is also analyzed. They can be easily tuned shifting the optical spectrum. The output of the proposed interrogation scheme is simulated in these conditions improving the sensitivity. PMID:24008282

  15. Dynamic interrogator for elastic wave sensing using Fabry Perot filters based on fiber Bragg gratings.

    PubMed

    Harish, Achar V; Varghese, Bibin; Rao, Babu; Balasubramaniam, Krishnan; Srinivasan, Balaji

    2015-07-01

    Use of in-fiber Fabry-Perot (FP) filters based on fiber Bragg gratings as both sensor as well as an interrogator for enhancing the detection limit of elastic wave sensing is investigated in this paper. The sensitivity of such a demodulation scheme depends on the spectral discrimination of the sensor and interrogator gratings. Simulations have shown that the use of in-fiber FP filters with high finesse provide better performance in terms of sensitivity compared to the demodulation using fiber Bragg gratings. Based on these results, a dynamic interrogator capable of sensing acoustic waves with amplitude of less than 1 micro-strain over frequencies of 10 kHz to several 100 kHz has been implemented. Frequency response of the fiber Bragg gratings in the given experimental setup has been compared to that of the conventional piezo sensors demonstrating that fiber Bragg gratings can be used over a relatively broad frequency range. Dynamic interrogator has been packaged in a compact box without any degradation in its performance. PMID:25783780

  16. The Impact of Caregivers' Interrogative Styles in English and Japanese on Early Bilingual Development

    ERIC Educational Resources Information Center

    Nakamura, Janice; Quay, Suzanne

    2012-01-01

    This study examines the relationship between caregivers' conversational styles in One-Person-One-Language (OPOL) settings and early bilingual development. In particular, it attempts to demonstrate that interrogative styles may have an impact on bilingual children's responsiveness in two language contexts. It is based on longitudinal data of a…

  17. Questioning Masculinities: Interrogating Boys' Capacities for Self-Problematization in Schools

    ERIC Educational Resources Information Center

    Kehler, Michael; Martino, Wayne

    2007-01-01

    In drawing on selected interviews with adolescent boys from both Australia and North America, we present an analysis of boys' own capacities for interrogating gender normalisation in their school lives. We set this analysis against a critique of the public media debates about boys' education, which continue to be fuelled by a moral panic about the…

  18. Monte-Carlo simulations of neutron-induced activation in a Fast-Neutron and Gamma-Based Cargo Inspection System

    NASA Astrophysics Data System (ADS)

    Bromberger, B.; Bar, D.; Brandis, M.; Dangendorf, V.; Goldberg, M. B.; Kaufmann, F.; Mor, I.; Nolte, R.; Schmiedel, M.; Tittelmeier, K.; Vartsky, D.; Wershofen, H.

    2012-03-01

    An air cargo inspection system combining two nuclear reaction based techniques, namely Fast-Neutron Resonance Radiography and Dual-Discrete-Energy Gamma Radiography is currently being developed. This system is expected to allow detection of standard and improvised explosives as well as special nuclear materials. An important aspect for the applicability of nuclear techniques in an airport inspection facility is the inventory and lifetimes of radioactive isotopes produced by the neutron radiation inside the cargo, as well as the dose delivered by these isotopes to people in contact with the cargo during and following the interrogation procedure. Using MCNPX and CINDER90 we have calculated the activation levels for several typical inspection scenarios. One example is the activation of various metal samples embedded in a cotton-filled container. To validate the simulation results, a benchmark experiment was performed, in which metal samples were activated by fast-neutrons in a water-filled glass jar. The induced activity was determined by analyzing the gamma spectra. Based on the calculated radioactive inventory in the container, the dose levels due to the induced gamma radiation were calculated at several distances from the container and in relevant time windows after the irradiation, in order to evaluate the radiation exposure of the cargo handling staff, air crew and passengers during flight. The possibility of remanent long-lived radioactive inventory after cargo is delivered to the client is also of concern and was evaluated.

  19. Interrogating Commonly Applied Initial Condition Assumptions in Geospeedometry using NanoSIMS

    NASA Astrophysics Data System (ADS)

    Till, C. B.; Boyce, J. W.

    2014-12-01

    The geologically short (days to centuries) timescales associated with thermochemical changes in magma chambers during the prelude to eruption are typically beyond the resolution of long-lived radioisotopic geochronometers but can be resolved by "geospeedometry" that quantifies the relatively rapid diffusional relaxation of compositional zoning in igneous phenocrysts. When combined with absolute dating, geospeedometry can reveal long-term chronologies of compositional and thermal oscillations in magma chambers. The ability to accurately constrain timescales via geospeedometry is limited in part by the spatial resolution of commonly used analytical techniques and the derivative chemical profiles, especially in the case of very short timescales or very slow diffusing elements, where the chemical profile is often approximated as a step-function. We present geospeedometry of chemical profiles collected with the NanoSIMS ion microprobe in multi-collection mode with sub-micron resolution (e.g., 0.3 micron spacing). This data facilitates a comparison of how well the timescales calculated with the different experimentally-determined diffusivities and collected along the same profile agree and an interrogation of commonly made model assumptions in geospeedometry. For example, electron probe profiles across internal sanidine zone boundaries from a ca. 250 ka rhyolite lava from Yellowstone Caldera reveal a step function in anorthite content at 10 micron spacing and evidence for earlier dissolution prior to new zone growth, yet we find no observable difference in the width of Ba, Sr and Mg diffusion profiles collected via NanoSIMS for the same profile. These observations support the hypothesis that very little to no diffusive relaxation has affected the initial concentration profile that was produced by crystal growth during magma mixing. Our results highlight the need to quantitatively constrain initial conditions when applying geospeedometry to intermediate to silicic

  20. Police training in interviewing and interrogation methods: A comparison of techniques used with adult and juvenile suspects.

    PubMed

    Cleary, Hayley M D; Warner, Todd C

    2016-06-01

    Despite empirical progress in documenting and classifying various interrogation techniques, very little is known about how police are trained in interrogation methods, how frequently they use various techniques, and whether they employ techniques differentially with adult versus juvenile suspects. This study reports the nature and extent of formal (e.g., Reid Technique, PEACE, HUMINT) and informal interrogation training as well as self-reported technique usage in a diverse national sample (N = 340) of experienced American police officers. Officers were trained in a variety of different techniques ranging from comparatively benign pre-interrogation strategies (e.g., building rapport, observing body language or speech patterns) to more psychologically coercive techniques (e.g., blaming the victim, discouraging denials). Over half the sample reported being trained to use psychologically coercive techniques with both adults and juveniles. The majority (91%) receive informal, "on the job" interrogation training. Technique usage patterns indicate a spectrum of psychological intensity where information-gathering approaches were used most frequently and high-pressure tactics less frequently. Reid-trained officers (56%) were significantly more likely than officers without Reid training to use pre-interrogation and manipulation techniques. Across all analyses and techniques, usage patterns were identical for adult and juvenile suspects, suggesting that police interrogate youth in the same manner as adults. Overall, results suggest that training in specific interrogation methods is strongly associated with usage. Findings underscore the need for more law enforcement interrogation training in general, especially with juvenile suspects, and highlight the value of training as an avenue for reducing interrogation-induced miscarriages of justice. (PsycINFO Database Record PMID:26651619

  1. Activity Systems and Moral Reasoning: An Intervention Study

    ERIC Educational Resources Information Center

    Wardi, Eva; Helkama, Klaus

    2015-01-01

    Seventeen social educator students were taught to analyze their work activity by means of a Vygotsky-inspired method, drawing on Engeström's notion of an activity system. The method aimed at increasing the consciousness of the students of the structure of work activity system. The participants wrote two accounts of their field-work practice…

  2. New approaches to enhance active steering system functionalities: preliminary results

    NASA Astrophysics Data System (ADS)

    Serarslan, Benan

    2014-09-01

    An important development of the steering systems in general is active steering systems like active front steering and steer-by-wire systems. In this paper the current functional possibilities in application of active steering systems are explored. A new approach and additional functionalities are presented that can be implemented to the active steering systems without additional hardware such as new sensors and electronic control units. Commercial active steering systems are controlling the steering angle depending on the driving situation only. This paper introduce methods for enhancing active steering system functionalities depending not only on the driving situation but also vehicle parameters like vehicle mass, tyre and road condition. In this regard, adaptation of the steering ratio as a function of above mentioned vehicle parameters is presented with examples. With some selected vehicle parameter changes, the reduction of the undesired influences on vehicle dynamics of these parameter changes has been demonstrated theoretically with simulations and with real-time driving measurements.

  3. Process of activation of a palladium catalyst system

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-08-02

    Improved processes for activating a catalyst system used for the reduction of nitrogen oxides are provided. In one embodiment, the catalyst system is activated by passing an activation gas stream having an amount of each of oxygen, water vapor, nitrogen oxides, and hydrogen over the catalyst system and increasing a temperature of the catalyst system to a temperature of at least 180.degree. C. at a heating rate of from 1-20.degree./min. Use of activation processes described herein leads to a catalyst system with superior NOx reduction capabilities.

  4. Student Activity Funds: Creating a System of Controls That Work.

    ERIC Educational Resources Information Center

    Cuzzetto, Charles

    1995-01-01

    Although student-activity funds usually represent a small portion of school-system monies, their very nature makes them a high risk. Outlines three steps for maintaining an efficient and effective system of controls over student-activity funds: (1) identifying control issues; (2) designing a control system; and (3) using checks and balances.…

  5. Displaying Knowledge through Interrogatives in Student-Initiated Sequences

    ERIC Educational Resources Information Center

    Solem, Marit Skarbø

    2016-01-01

    This article presents an analysis of student initiatives in whole-class interactions. While prior research on question-answer sequences in classroom interactions has shown students to be rather passive recipients of knowledge, this article focuses on aspects of classroom interaction where students take a more active role. Following a conversation…

  6. Pulsed Bremsstrahlung Interrogation with Photoneutron - Gamma-Ray Spectrometry for Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Jones, James Litton

    A novel photoneutron-based nondestructive evaluation (NDE) technique which does not require a radioactive neutron source is presented. Some unique features of this technique include: 1) pulsed interrogation neutron production within, or very near, an inspected object, 2) spectrum tailoring of the source neutrons, and 3) compatibility with many existing high-energy, commercial x-ray inspection devices. Basic concept feasibility was first established by numerical methods. The pulsed photoneutron inspection technique performs nondestructive elemental analysis using gamma-ray spectrometry. Highly penetrating bremsstrahlung photons are produced by a pulsed electron accelerator capable of producing up to 16-MeV electrons. The photoneutrons are generated by the bremsstrahlung photons interacting with an inspected object and near-by beryllium metal. The interactions of the neutrons within an inspected item result in the emission of elemental characteristic gamma-rays. Spectrometry is performed by analyzing the gamma -rays acquired between accelerator pulses. A unique fast detection and acquisition system, using two 5.08 x 5.08 -cm organic scintillators, acquires gamma-ray emissions within 100 ns of each accelerator pulse. The fast system is capable of processing individual gamma-ray signals at count rates up to 40 MHz between accelerator pulses with a repetition rate up to 1 kHz. The system incorporates a unique x-ray flash recovery method which allows individual gamma-ray detection as soon as 75 ns after the start of each x-ray flash occurring within the detector. Conventional detection and data acquisition systems are used to acquire gamma-ray spectra for the time period between 1000 ns and the next accelerator pulse. Operational tests using a 30-ps pulse width, electron accelerator demonstrated the x-ray flash recovery methodology, gamma-ray detection, and data acquisition. Although, gamma -ray spectrometry performance was limited by x-ray flash -induced gain shifts in

  7. Active fluidization in dense glassy systems.

    PubMed

    Mandal, Rituparno; Bhuyan, Pranab Jyoti; Rao, Madan; Dasgupta, Chandan

    2016-07-20

    Dense soft glasses show strong collective caging behavior at sufficiently low temperatures. Using molecular dynamics simulations of a model glass former, we show that the incorporation of activity or self-propulsion, f0, can induce cage breaking and fluidization, resulting in the disappearance of the glassy phase beyond a critical f0. The diffusion coefficient crosses over from being strongly to weakly temperature dependent as f0 is increased. In addition, we demonstrate that activity induces a crossover from a fragile to a strong glass and a tendency of active particles to cluster. Our results are of direct relevance to the collective dynamics of dense active colloidal glasses and to recent experiments on tagged particle diffusion in living cells. PMID:27380935

  8. Active vibration control of lightweight floor systems

    NASA Astrophysics Data System (ADS)

    Baader, J.; Fontana, M.

    2016-04-01

    Wide-span and lightweight floors are often prone to structural vibrations due to their low resonance frequency and poor material damping. Their dynamic behaviour can be improved using passive, semi-active or active vibration control devices. The following article proposes a novel method for the controller synthesis for active vibration control. An existing passive TMD (tuned mass damper) is modelled and equipped with an actuator in order to provide more efficient damping. Using an iterative optimization approach under constraints, an optimal controller is found which minimizes a quadratic cost function in frequency domain. A simulation of an existing test bench shows that the active vibration control device is able to provide increased damping compared to the passive TMD.

  9. Power System Considerations and Test Activities

    NASA Technical Reports Server (NTRS)

    Miller, J.

    1983-01-01

    The potential benefits of an IPACS system compared to NiCd and/or Regen Fuel Cell systems are summarized. The benefits are: (1) significant life cycle cost savings; (2) total weight to orbit savings (30 yrs) as much as 10 times; (3) end to end efficiency increase results in approximately 10 kW reduction in array size(6%); (4) motor/generator controller regulation during discharge simplifies distribution system; and (5) momentum stored for attitude control increased by 4 times.

  10. Fragmentation and Interrogation as an Approach to Integration

    ERIC Educational Resources Information Center

    Wallick, Karl; Zaretsky, Michael

    2010-01-01

    This article tracks the generative role of research and fragmentation as a means for integrating technology and form within an architecture technology lecture class and a co-requisite design studio. The complexity of teaching building systems integration within a design studio context is achieved by removing any expectation of building design…

  11. Description of data base management systems activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    One of the major responsibilities of the JPL Computing and Information Services Office is to develop and maintain a JPL plan for providing computing services to the JPL management and administrative community that will lead to improved productivity. The CISO plan to accomplish this objective has been titled 'Management and Administrative Support Systems' (MASS). The MASS plan is based on the continued use of JPL's IBM 3032 Computer system for administrative computing and for the MASS functions. The current candidate administrative Data Base Management Systems required to support the MASS include ADABASE, Cullinane IDMS and TOTAL. Previous uses of administrative Data Base Systems have been applied to specific local functions rather than in a centralized manner with elements common to the many user groups. Limited capacity data base systems have been installed in microprocessor based office automation systems in a few Project and Management Offices using Ashton-Tate dBASE II. These experiences plus some other localized in house DBMS uses have provided an excellent background for developing user and system requirements for a single DBMS to support the MASS program.

  12. Using Imaging Methods to Interrogate Radiation-Induced Cell Signaling

    SciTech Connect

    Shankaran, Harish; Weber, Thomas J.; Freiin von Neubeck, Claere H.; Sowa, Marianne B.

    2012-04-01

    There is increasing emphasis on the use of systems biology approaches to define radiation induced responses in cells and tissues. Such approaches frequently rely on global screening using various high throughput 'omics' platforms. Although these methods are ideal for obtaining an unbiased overview of cellular responses, they often cannot reflect the inherent heterogeneity of the system or provide detailed spatial information. Additionally, performing such studies with multiple sampling time points can be prohibitively expensive. Imaging provides a complementary method with high spatial and temporal resolution capable of following the dynamics of signaling processes. In this review, we utilize specific examples to illustrate how imaging approaches have furthered our understanding of radiation induced cellular signaling. Particular emphasis is placed on protein co-localization, and oscillatory and transient signaling dynamics.

  13. Interrogating viral capsid assembly with ion mobility-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Uetrecht, Charlotte; Barbu, Ioana M.; Shoemaker, Glen K.; van Duijn, Esther; Heck, Albert J. R.

    2011-02-01

    Most proteins fulfil their function as part of large protein complexes. Surprisingly, little is known about the pathways and regulation of protein assembly. Several viral coat proteins can spontaneously assemble into capsids in vitro with morphologies identical to the native virion and thus resemble ideal model systems for studying protein complex formation. Even for these systems, the mechanism for self-assembly is still poorly understood, although it is generally thought that smaller oligomeric structures form key intermediates. This assembly nucleus and larger viral assembly intermediates are typically low abundant and difficult to monitor. Here, we characterised small oligomers of Hepatitis B virus (HBV) and norovirus under equilibrium conditions using native ion mobility mass spectrometry. This data in conjunction with computational modelling enabled us to elucidate structural features of these oligomers. Instead of more globular shapes, the intermediates exhibit sheet-like structures suggesting that they are assembly competent. We propose pathways for the formation of both capsids.

  14. High Throughput Interrogation of Behavioral Transitions in C. elegans

    NASA Astrophysics Data System (ADS)

    Liu, Mochi; Shaevitz, Joshua; Leifer, Andrew

    We present a high-throughput method to probe transformations from neural activity to behavior in Caenorhabditis elegans to better understand how organisms change behavioral states. We optogenetically deliver white-noise stimuli to target sensory or inter neurons while simultaneously recording the movement of a population of worms. Using all the postural movement data collected, we computationally classify stereotyped behaviors in C. elegans by clustering based on the spectral properties of the instantaneous posture. (Berman et al., 2014) Transitions between these behavioral clusters indicate discrete behavioral changes. To study the neural correlates dictating these transitions, we perform model-driven experiments and employ Linear-Nonlinear-Poisson cascades that take the white-noise stimulus as the input. The parameters of these models are fitted by reverse-correlation from our measurements. The parameterized models of behavioral transitions predict the worm's response to novel stimuli and reveal the internal computations the animal makes before carrying out behavioral decisions. Preliminary results are shown that describe the neural-behavioral transformation between neural activity in mechanosensory neurons and reversal behavior.

  15. Chemical interrogation of malarial host and parasite kinomes

    PubMed Central

    Zuzarte-Luís, Vanessa; Magalhães, Andreia D.; Kato, Nobutaka; Sanschagrin, Paul C.; Wang, Jinhua; Zhou, Wenjun; Miduturu, Chandrasekhar V.; Mazitschek, Ralph; Sliz, Piotr; Mota, Maria M.; Gray, Nathanael S.

    2014-01-01

    Malaria, an infectious disease caused by eukaryotic parasites from the genus Plasmodium, afflicts hundreds of millions of people every year. Both the parasite and its host utilize protein kinases to regulate essential cellular processes. Bioinformatic analyses of parasite genomes predict at least 65 protein kinases, but their biological functions and therapeutic potential are largely unknown. We profiled 1,358 small molecule kinase inhibitors to evaluate the role of both the human and malaria kinomes in Plasmodium infection of liver cells, the parasites’ obligatory but transient developmental stage that precedes the symptomatic blood stage. The screen identified several small molecules that inhibit parasite load in liver cells, some with nanomolar efficacy, and each compound was subsequently assessed for activity against blood stage malaria. Most of the screening hits inhibited both liver and blood stage malaria parasites, which have dissimilar gene expression profiles and infect different host cells. Evaluation of existing kinase activity profiling data for the library members suggests several kinases are essential to malaria parasites, including cyclin-dependent kinases, glycogen synthase kinases, and phosphoinositide-3-kinases. CDK inhibitors were found to bind to Plasmodium protein kinase 5, but it is likely that these compounds target multiple parasite kinases. The dual stage inhibition of the identified kinase inhibitors makes them useful chemical probes and promising starting points for antimalarial development. PMID:25111632

  16. Hybrid energy storage systems utilizing redox active organic compounds

    DOEpatents

    Wang, Wei; Xu, Wu; Li, Liyu; Yang, Zhenguo

    2015-09-08

    Redox flow batteries (RFB) have attracted considerable interest due to their ability to store large amounts of power and energy. Non-aqueous energy storage systems that utilize at least some aspects of RFB systems are attractive because they can offer an expansion of the operating potential window, which can improve on the system energy and power densities. One example of such systems has a separator separating first and second electrodes. The first electrode includes a first current collector and volume containing a first active material. The second electrode includes a second current collector and volume containing a second active material. During operation, the first source provides a flow of first active material to the first volume. The first active material includes a redox active organic compound dissolved in a non-aqueous, liquid electrolyte and the second active material includes a redox active metal.

  17. Experimental acquisition system for impedance tomography with active electrode approach.

    PubMed

    Rigaud, B; Shi, Y; Chauveau, N; Morucci, J P

    1993-11-01

    An experimental system for impedance tomography has been constructed. The acquisition system uses 16 multifunctional active electrodes, each including a current source and a voltage buffer. Images of active and reactive parts of different target impedances in a phantom filled with liquid have been obtained. The system performance has been compared with those of other systems using either a mesh phantom or rods as point sources used for the determination of the modulation transfer function. PMID:8145585

  18. Practical engineering: control of active systems using the stagnation temperature

    SciTech Connect

    Lunde, P.J.

    1982-04-01

    Solar active systems with flat plate collectors are discussed with reference to the temperature at which the system should be activated. It is concluded that the system should be activated when the stagnation temperature (temperature under the absorber plate when no fluid is circulating) equals the temperature of the fluid in storage. A thermistor Wheatstone bridge control system is described which will eliminate pump relay chatter and the permissible control differential is calculated from the collector efficiency curve. To avoid dedication of an entire collector to house the control system, a method is described for determining the stagnation temperature using a portion of an active collector. For an active solar hot water system, a calculation is carried out to show that a 2/sup 0/F temperature differential (stagnation temperature-storage temperature) is satisfactory. (MJJ)

  19. Electricity/Electronics Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This electricity/electronics guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 35 modules on the following topics: electrical…

  20. Interrogative pressure in simulated forensic interviews: the effects of negative feedback.

    PubMed

    McGroarty, Allan; Baxter, James S

    2007-08-01

    Much experimental research on interrogative pressure has concentrated on the effects of leading questions, and the role of feedback in influencing responses in the absence of leading questions has been neglected by comparison. This study assessed the effect of negative feedback and the presence of a second interviewer on interviewee responding in simulated forensic interviews. Participants viewed a videotape of a crime, answered questions about the clip and were requestioned after receiving feedback. Compared with neutral feedback, negative feedback resulted in more response changes, higher reported state anxiety and higher ratings of interview difficulty. These results are consistent with Gudjonsson and Clark's (1986) model of interrogative suggestibility. The presence and involvement of a second interviewer did not significantly affect interviewee responding, although trait anxiety scores were elevated when a second interviewer was present. The theoretical and applied implications of these findings are considered. PMID:17535467

  1. ZnO-coated SMS structure interrogated by a fiber ring laser for chemical sensing

    NASA Astrophysics Data System (ADS)

    Wen, X. Y.; Huang, J.; Xiao, H.; Yang, M. H.

    2014-11-01

    A zinc oxide (ZnO)-coated single mode-multimode-single mode fiber (SMS) structure interrogated by a fiber ring laser has been developed as a chemical sensor. Response to relative humidity (RH) and ethanol volatilization was evaluated by tracking the wavelength shifts of the output laser line in different moisture environments and ethanol solutions, respectively. For humidity sensing a linear response with a measurement range of 4-96% RH, and a sensitivity of 0.06 nm per %RH were obtained. As for ethanol volatilization sensing obvious wavelength blue shift was observed for the sensor immersed in 50% and 62% ethanol solution, while no variation could be detected in pure ethanol solution (purity larger than 97%). With the advantages of low cost, ease of fabrication and sensitive response, ZnO-coated SMS interrogated with a fiber ring laser was demonstrated to be an effective sensor for humidity and ethanol volatilization sensing.

  2. Interrogation of fibre Bragg gratings through a fibre optic rotary joint on a geotechnical centrifuge

    NASA Astrophysics Data System (ADS)

    Correia, Ricardo; James, Stephen W.; Marshall, Alec; Heron, Charles; Korposh, Sergiy

    2016-05-01

    The monitoring of an array of fibre Bragg gratings (FBGs) strain sensors was performed through a single channel, single mode fibre optic rotary joint (FORJ) mounted on a geotechnical centrifuge. The array of three FBGs was attached to an aluminum plate that was anchored at the ends and placed on the model platform of the centrifuge. Acceleration forces of up to 50g were applied and the reflection signal of the monitored FBGs recorded dynamically using a 2.5kHz FBG interrogator placed outside the centrifuge. The use of a FORJ allowed the monitoring of the FBGs without submitting the FBG interrogator to the high g-forces experienced in the centrifuge.

  3. Direct fissile assay of enriched uranium using random self-interrogation and neutron coincidence response

    DOEpatents

    Menlove, Howard O.; Stewart, James E.

    1986-01-01

    Apparatus and method for the direct, nondestructive evaluation of the .sup.235 U nuclide content of samples containing UF.sub.6, UF.sub.4, or UO.sub.2 utilizing the passive neutron self-interrogation of the sample resulting from the intrinsic production of neutrons therein. The ratio of the emitted neutron coincidence count rate to the total emitted neutron count rate is determined and yields a measure of the bulk fissile mass. The accuracy of the method is 6.8% (1.sigma.) for cylinders containing UF.sub.6 with enrichments ranging from 6% to 98% with measurement times varying from 3-6 min. The samples contained from below 1 kg to greater than 16 kg. Since the subject invention relies on fast neutron self-interrogation, complete sampling of the UF.sub.6 takes place, reducing difficulties arising from inhomogeneity of the sample which adversely affects other assay procedures.

  4. Direct fissile assay of enriched uranium using random self-interrogation and neutron coincidence response

    DOEpatents

    Menlove, H.O.; Stewart, J.E.

    1985-02-04

    Apparatus and method for the direct, nondestructive evaluation of the /sup 235/U nuclide content of samples containing UF/sub 6/, UF/sub 4/, or UO/sub 2/ utilizing the passive neutron self-interrogation of the sample resulting from the intrinsic production of neutrons therein. The ratio of the emitted neutron coincidence count rate to the total emitted neutron count rate is determined and yields a measure of the bulk fissile mass. The accuracy of the method is 6.8% (1sigma) for cylinders containing UF/sub 6/ with enrichments ranging from 6% to 98% with measurement times varying from 3-6 min. The samples contained from below 1 kg to greater than 16 kg. Since the subject invention relies on fast neutron self-interrogation, complete sampling of the UF/sub 6/ takes place, reducing difficulties arising from inhomogeneity of the sample which adversely affects other assay procedures. 4 figs., 1 tab.

  5. Interrogation cradle and insertable containment fixture for detecting birefringent microcrystals in bile

    DOEpatents

    Darrow, Chris; Seger, Tino

    2003-09-30

    A transparent flow channel fluidly communicates a fluid source and a collection reservoir. An interrogating light beam passes through a first polarizer having a first plane of polarization. The flow channel is orthogonal to the light beam. The light beam passes through a fluid sample as it flows through the flow channel, and is then filtered through a second polarizer having a second plane of polarization rotated 90.degree. from the first plane of polarization. An electronic photo-detector is aligned with the light beam, and signals the presence of birefringent microcrystals in the fluid sample by generating voltage pulses. A disposable containment fixture includes the flow channel and the collection reservoir. The fixture is adapted for removable insertion into an interrogation cradle that includes optical and data processing components. The cradle rigidly positions the centerline of the flow channel orthogonal to the light beam.

  6. Enhanced-locality fiber-optic two-photon-fluorescence live-brain interrogation

    SciTech Connect

    Fedotov, I. V.; Doronina-Amitonova, L. V.; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Anokhin, K. V.; Kilin, S. Ya.; Sakoda, K.; Zheltikov, A. M.

    2014-02-24

    Two-photon excitation is shown to substantially enhance the locality of fiber-based optical interrogation of strongly scattering biotissues. In our experiments, a high-numerical-aperture, large-core-are fiber probe is used to deliver the 200-fs output of a 100-MHz mode-locked ytterbium fiber laser to samples of live mouse brain, induce two-photon fluorescence of nitrogen–vacancy centers in diamond markers in brain sample. Fiber probes with a high numerical aperture and a large core area are shown to enable locality enhancement in fiber-laser–fiber-probe two-photon brain excitation and interrogation without sacrificing the efficiency of fluorescence response collection.

  7. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  8. Sharpening Precision Medicine by a Thorough Interrogation of Metabolic Individuality

    PubMed Central

    Beebe, Kirk; Kennedy, Adam D.

    2016-01-01

    Precision medicine is an active component of medical practice today, but aspirations are to both broaden its reach to a greater diversity of individuals and improve its “precision” by enhancing the ability to define even more disease states in combination with associated treatments. Given complexity of human phenotypes, much work is required. In this review, we deconstruct this challenge at a high level to define what is needed to move closer toward these aspirations. In the context of the variables that influence the diverse array of phenotypes across human health and disease – genetics, epigenetics, environmental influences, and the microbiome – we detail the factors behind why an individual's biochemical (metabolite) composition is increasingly regarded as a key element to precisely defining phenotypes. Although an individual's biochemical (metabolite) composition is generally regarded, and frequently shown, to be a surrogate to the phenotypic state, we review how metabolites (and therefore an individual's metabolic profile) are also functionally related to the myriad of phenotypic influencers like genetics and the microbiota. We describe how using the technology to comprehensively measure an individual's biochemical profile – metabolomics – is integrative to defining individual phenotypes and how it is currently being deployed in efforts to continue to elaborate on human health and disease in large population studies. Finally, we summarize instances where metabolomics is being used to assess individual health in instances where signatures (i.e. biomarkers) have been defined. PMID:26929792

  9. PEGASUS: Designing a System for Supporting Group Activity

    ERIC Educational Resources Information Center

    Kyprianidou, Maria; Demetriadis, Stavros; Pombortsis, Andreas; Karatasios, George

    2009-01-01

    Purpose: The purpose of this paper is to present the design and first results of the integration of a web-based system person-centred group-activity support system (PEGASUS) in university instruction, as a means for advancing person-centred learning by supporting group activity. The PEGASUS is expected to help students and teachers in two distinct…

  10. Applying an Activity System to Online Collaborative Group Work Analysis

    ERIC Educational Resources Information Center

    Choi, Hyungshin; Kang, Myunghee

    2010-01-01

    This study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer-mediated communication.…

  11. Entry-Level Activities in System Consultation

    ERIC Educational Resources Information Center

    Hylander, Ingrid

    2014-01-01

    System-level consultation or organizational development in schools is an area in great need of theoretical models and definitions. The three articles in this special issue provide a unique learning opportunity not only for consultation across borders but also for consultation within the same nation. In my commentary, I limit my remarks to a few…

  12. Methodology for the systems engineering process. Volume 1: System functional activities

    NASA Technical Reports Server (NTRS)

    Nelson, J. H.

    1972-01-01

    Systems engineering is examined in terms of functional activities that are performed in the conduct of a system definition/design, and system development is described in a parametric analysis that combines functions, performance, and design variables. Emphasis is placed on identification of activities performed by design organizations, design specialty groups, as well as a central systems engineering organizational element. Identification of specific roles and responsibilities for doing functions, and monitoring and controlling activities within the system development operation are also emphasized.

  13. Optical fiber sensors using hollow glass spheres and CCD spectrometer interrogator

    NASA Astrophysics Data System (ADS)

    Dakin, John P.; Ecke, Wolfgang; Schroeder, Kerstin; Reuter, Martin

    2009-10-01

    Hollow glass micro-spheres, firstly used to make fiber optic sensors for high hydrostatic pressure, have been interrogated using a high-resolution CCD-based spectrometer, to give far better precision than conventional spectrometric read out. It is found that these simple, low-cost micro-sensors have excellent sensitivity to both static and dynamic pressure, and have the advantage of being hermetically sealed. Many other application areas are foreseen for these low-cost sensors.

  14. Interrogative suggestibility among adolescent boys and its relationship with intelligence, memory, and cognitive set.

    PubMed

    Singh, K K; Gudjonsson, G H

    1992-06-01

    This study investigates some of the hypotheses generated by the Gudjonsson and Clark model of interrogative suggestibility. The subjects were 40 adolescent boys (11-16 years), who completed the Gudjonsson Suggestibility Scale and instruments measuring intellectual skills, memory, field-dependence, hostility, and attitudes towards persons in authority. Suggestibility correlated negatively with I.Q. and memory capacity, and positively with field-dependence. PMID:1527249

  15. Cellular Interrogation: Exploiting Cell-to-Cell Variability to Discriminate Regulatory Mechanisms in Oscillatory Signalling

    PubMed Central

    Gibson, Daniel; Chang, Frederick; Gnad, Florian; Gunawardena, Jeremy

    2016-01-01

    The molecular complexity within a cell may be seen as an evolutionary response to the external complexity of the cell’s environment. This suggests that the external environment may be harnessed to interrogate the cell’s internal molecular architecture. Cells, however, are not only nonlinear and non-stationary, but also exhibit heterogeneous responses within a clonal, isogenic population. In effect, each cell undertakes its own experiment. Here, we develop a method of cellular interrogation using programmable microfluidic devices which exploits the additional information present in cell-to-cell variation, without requiring model parameters to be fitted to data. We focussed on Ca2+ signalling in response to hormone stimulation, which exhibits oscillatory spiking in many cell types and chose eight models of Ca2+ signalling networks which exhibit similar behaviour in simulation. We developed a nonlinear frequency analysis for non-stationary responses, which could classify models into groups under parameter variation, but found that this question alone was unable to distinguish critical feedback loops. We further developed a nonlinear amplitude analysis and found that the combination of both questions ruled out six of the models as inconsistent with the experimentally-observed dynamics and heterogeneity. The two models that survived the double interrogation were mathematically different but schematically identical and yielded the same unexpected predictions that we confirmed experimentally. Further analysis showed that subtle mathematical details can markedly influence non-stationary responses under parameter variation, emphasising the difficulty of finding a “correct” model. By developing questions for the pathway being studied, and designing more versatile microfluidics, cellular interrogation holds promise as a systematic strategy that can complement direct intervention by genetics or pharmacology. PMID:27367445

  16. Making Bunyaviruses Talk: Interrogation Tactics to Identify Host Factors Required for Infection

    PubMed Central

    Riblett, Amber M.; Doms, Robert W.

    2016-01-01

    The identification of host cellular genes that act as either proviral or antiviral factors has been aided by the development of an increasingly large number of high-throughput screening approaches. Here, we review recent advances in which these new technologies have been used to interrogate host genes for the ability to impact bunyavirus infection, both in terms of technical advances as well as a summary of biological insights gained from these studies. PMID:27187446

  17. Cellular Interrogation: Exploiting Cell-to-Cell Variability to Discriminate Regulatory Mechanisms in Oscillatory Signalling.

    PubMed

    Estrada, Javier; Andrew, Natalie; Gibson, Daniel; Chang, Frederick; Gnad, Florian; Gunawardena, Jeremy

    2016-07-01

    The molecular complexity within a cell may be seen as an evolutionary response to the external complexity of the cell's environment. This suggests that the external environment may be harnessed to interrogate the cell's internal molecular architecture. Cells, however, are not only nonlinear and non-stationary, but also exhibit heterogeneous responses within a clonal, isogenic population. In effect, each cell undertakes its own experiment. Here, we develop a method of cellular interrogation using programmable microfluidic devices which exploits the additional information present in cell-to-cell variation, without requiring model parameters to be fitted to data. We focussed on Ca2+ signalling in response to hormone stimulation, which exhibits oscillatory spiking in many cell types and chose eight models of Ca2+ signalling networks which exhibit similar behaviour in simulation. We developed a nonlinear frequency analysis for non-stationary responses, which could classify models into groups under parameter variation, but found that this question alone was unable to distinguish critical feedback loops. We further developed a nonlinear amplitude analysis and found that the combination of both questions ruled out six of the models as inconsistent with the experimentally-observed dynamics and heterogeneity. The two models that survived the double interrogation were mathematically different but schematically identical and yielded the same unexpected predictions that we confirmed experimentally. Further analysis showed that subtle mathematical details can markedly influence non-stationary responses under parameter variation, emphasising the difficulty of finding a "correct" model. By developing questions for the pathway being studied, and designing more versatile microfluidics, cellular interrogation holds promise as a systematic strategy that can complement direct intervention by genetics or pharmacology. PMID:27367445

  18. A microscopic field theoretical approach for active systems

    NASA Astrophysics Data System (ADS)

    Alaimo, F.; Praetorius, S.; Voigt, A.

    2016-08-01

    We consider a microscopic modeling approach for active systems. The approach extends the phase field crystal (PFC) model and allows us to describe generic properties of active systems within a continuum model. The approach is validated by reproducing results obtained with corresponding agent-based and microscopic phase field models. We consider binary collisions, collective motion and vortex formation. For larger numbers of particles we analyze the coarsening process in active crystals and identify giant number fluctuation in a cluster formation process.

  19. Determination of optical probe interrogation field of near-infrared reflectance: phantom and Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Bahadur, Ali N.; Giller, Cole A.; Kashyap, Dheerendra; Liu, Hanli

    2007-08-01

    An optical probe used to localize human brain tissues in vivo has been reported previously. It was able to sense the underlying tissue structure with an optical interrogation field, termed as "look ahead distance" (LAD). A new side-firing probe has been designed with its optical window along its side. We have defined the optical interrogation field of the new side probe as "look aside distance" (LASD). The purpose of this study is to understand the dependence of the LAD and LASD on the optical properties of tissue, the light source intensity, and the integration time of the detector, using experimental and computational methods. The results show that a decrease in light intensity does decrease the LAD and LASD and that an increase in integration time of detection may not necessarily improve the depths of LAD and LASD. Furthermore, Monte Carlo simulation results suggest that the LAD/LASD decreases with an increase in reduced scattering coefficient to a point, after which the LAD/LASD remains constant. We expect that an optical interrogation field of a tip or side probe is approximately 1-2 mm in white matter and 2-3.5 mm in gray matter. These conclusions will help us optimally manipulate the parameter settings during surgery and determine the spatial resolution of the probe.

  20. Facilitating biomedical researchers' interrogation of electronic health record data: Ideas from outside of biomedical informatics.

    PubMed

    Hruby, Gregory W; Matsoukas, Konstantina; Cimino, James J; Weng, Chunhua

    2016-04-01

    Electronic health records (EHR) are a vital data resource for research uses, including cohort identification, phenotyping, pharmacovigilance, and public health surveillance. To realize the promise of EHR data for accelerating clinical research, it is imperative to enable efficient and autonomous EHR data interrogation by end users such as biomedical researchers. This paper surveys state-of-art approaches and key methodological considerations to this purpose. We adapted a previously published conceptual framework for interactive information retrieval, which defines three entities: user, channel, and source, by elaborating on channels for query formulation in the context of facilitating end users to interrogate EHR data. We show the current progress in biomedical informatics mainly lies in support for query execution and information modeling, primarily due to emphases on infrastructure development for data integration and data access via self-service query tools, but has neglected user support needed during iteratively query formulation processes, which can be costly and error-prone. In contrast, the information science literature has offered elaborate theories and methods for user modeling and query formulation support. The two bodies of literature are complementary, implying opportunities for cross-disciplinary idea exchange. On this basis, we outline the directions for future informatics research to improve our understanding of user needs and requirements for facilitating autonomous interrogation of EHR data by biomedical researchers. We suggest that cross-disciplinary translational research between biomedical informatics and information science can benefit our research in facilitating efficient data access in life sciences. PMID:26972838