Science.gov

Sample records for in-situ verification techniques

  1. Simulation verification techniques study

    NASA Technical Reports Server (NTRS)

    Schoonmaker, P. B.; Wenglinski, T. H.

    1975-01-01

    Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided.

  2. Environmental Technology Verification Program Materials Management and Remediation Center Generic Protocol for Verification of In Situ Chemical Oxidation

    EPA Science Inventory

    The protocol provides generic procedures for implementing a verification test for the performance of in situ chemical oxidation (ISCO), focused specifically to expand the application of ISCO at manufactured gas plants with polyaromatic hydrocarbon (PAH) contamination (MGP/PAH) an...

  3. Mars Atmosphere Resource Verification INsitu (MARVIN) - In Situ Resource Demonstration for the Mars 2020 Mission

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.; Araghi, Koorosh; Ess, Kim M.; Valencia, Lisa M.; Muscatello, Anthony C.; Calle, Carlos I.; Clark, Larry; Iacomini, Christie

    2014-01-01

    The making of oxygen from resources in the Martian atmosphere, known as In Situ Resource Utilization (ISRU), has the potential to provide substantial benefits for future robotic and human exploration. In particular, the ability to produce oxygen on Mars for use in propulsion, life support, and power systems can provide significant mission benefits such as a reducing launch mass, lander size, and mission and crew risk. To advance ISRU for possible incorporation into future human missions to Mars, NASA proposed including an ISRU instrument on the Mars 2020 rover mission, through an announcement of opportunity (AO). The purpose of the the Mars Atmosphere Resource Verification INsitu or (MARVIN) instrument is to provide the first demonstration on Mars of oxygen production from acquired and stored Martian atmospheric carbon dioxide, as well as take measurements of atmospheric pressure and temperature, and of suspended dust particle sizes and amounts entrained in collected atmosphere gases at different times of the Mars day and year. The hardware performance and environmental data obtained will be critical for future ISRU systems that will reduce the mass of propellants and other consumables launched from Earth for robotic and human exploration, for better understanding of Mars dust and mitigation techniques to improve crew safety, and to help further define Mars global circulation models and better understand the regional atmospheric dynamics on Mars. The technologies selected for MARVIN are also scalable for future robotic sample return and human missions to Mars using ISRU.

  4. In situ sensor techniques in modern bioprocess monitoring.

    PubMed

    Beutel, Sascha; Henkel, Steffen

    2011-09-01

    New reactor concepts as multi-parallel screening systems or disposable bioreactor systems for decentralized and reproducible production increase the need for new and easy applicable sensor technologies to access data for process control. These sophisticated reactor systems require sensors to work with the lowest sampling volumes or, even better, to measure directly in situ, but in situ sensors are directly incorporated into a reactor or fermenter within the sterility barrier and have therefore to stand the sterilization procedures. Consequently, these in situ sensor technologies should enable the measurement of multi-analytes simultaneously online and in real-time at a low price for the robust sensing element. Current research therefore focuses on the implementation of noninvasive spectroscopic and optical technologies, and tries to employ them through fiber optics attached to disposable sensing connectors. Spectroscopic methods reach from ultraviolet to infrared and further comprising fluorescence and Raman spectroscopy. Also, optic techniques like microscopy are adapted for the direct use in bioreactor systems (Ulber et al. in Anal Bioanal Chem 376:342-348, 2003) as well as various electrochemical methods (Joo and Brown in Chem Rev 108:638-651, 2008). This review shows the variety of modern in situ sensing principles in bioprocess monitoring with emphasis on spectroscopic and optical techniques and the progress in the adaption to latest reactor concepts. PMID:21785932

  5. Development of geotechnical models for verification of in situ coal conversion impacts

    NASA Astrophysics Data System (ADS)

    Tian, H.; Kempka, T.; Schlüter, R.; Ziegler, M.; Azzam, R.

    2009-04-01

    results of the models; and coupling geotechnical models with multiphase flow models to assess the environmental risk of geological CO2 storage and to provide basic data support for designing and adjusting the in situ conversion process considering impacts of CO2 injection and migration on surrounding rocks. The adapted geotechnical models will be applied for verification of in situ coal conversion impacts on the development of ground subsidence in deep coal deposits as available in Central and Western Europe. A further development of these models will allow a site specific best-fit calculation of the conversion field dimensions aiming at maximum utilization and minimum environmental impact by ground subsidence.

  6. Evaluation of Mesoscale Model Phenomenological Verification Techniques

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred

    2006-01-01

    Forecasters at the Spaceflight Meteorology Group, 45th Weather Squadron, and National Weather Service in Melbourne, FL use mesoscale numerical weather prediction model output in creating their operational forecasts. These models aid in forecasting weather phenomena that could compromise the safety of launch, landing, and daily ground operations and must produce reasonable weather forecasts in order for their output to be useful in operations. Considering the importance of model forecasts to operations, their accuracy in forecasting critical weather phenomena must be verified to determine their usefulness. The currently-used traditional verification techniques involve an objective point-by-point comparison of model output and observations valid at the same time and location. The resulting statistics can unfairly penalize high-resolution models that make realistic forecasts of a certain phenomena, but are offset from the observations in small time and/or space increments. Manual subjective verification can provide a more valid representation of model performance, but is time-consuming and prone to personal biases. An objective technique that verifies specific meteorological phenomena, much in the way a human would in a subjective evaluation, would likely produce a more realistic assessment of model performance. Such techniques are being developed in the research community. The Applied Meteorology Unit (AMU) was tasked to conduct a literature search to identify phenomenological verification techniques being developed, determine if any are ready to use operationally, and outline the steps needed to implement any operationally-ready techniques into the Advanced Weather Information Processing System (AWIPS). The AMU conducted a search of all literature on the topic of phenomenological-based mesoscale model verification techniques and found 10 different techniques in various stages of development. Six of the techniques were developed to verify precipitation forecasts, one

  7. A comparison of software verification techniques

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A controlled experiment performed by the Software Engineering Laboratory (SEL) to compare the effectiveness of code reading, functional testing, and structural testing as software verification techniques is described. The experiment results indicate that code reading provides the greatest error detection capability at the lowest cost, whereas structural testing is the least effective technique. The experiment plan is explained, the experiment results are described, related results from other studies are discussed. The application of these results to the development of software in the flight dynamics environment is considered. Appendices summarize the experiment data and list the test programs.

  8. In Situ Techniques for Mineralogy and Geochemistry of Small Bodies

    NASA Astrophysics Data System (ADS)

    Blacksberg, J.; Rossman, G. R.; Webster, C. R.

    2012-12-01

    In situ exploration of planetary surfaces employs multiple techniques that, when used together, yield important information about their formation histories and evolution. Combined geochemistry and mineralogy measurements reveal the phases present, their composition, morphology, and isotope ratios of constituents. Small and primitive bodies often present a special case where little to no compositional information has been obtained from ground-based or remote measurements. For example, Trojan asteroids and other D-type objects as well as Phobos and Deimos exhibit relatively featureless reflectance spectra as obtained by remote measurements. Yet samples of primitive material in the meteorite collection (e.g. Allende) reveal a fine grained structure with many phases and a wealth of chemical information. On-surface measurements are therefore a necessary component for understanding the origins of these solar system bodies. We will present measurement techniques that could provide microscopic mineralogy and isotope geochemistry. We will discuss instrumentation and measurements relevant to small body exploration - focusing more specifically on our recent results from the techniques of microscopic time-resolved Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS), and Tunable Laser Spectroscopy (TLS). The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). This work was performed in part at the California Institute of Technology for the Keck Institute for Space Studies, which is funded by the W. M. Keck Foundation.

  9. Epoxy nanodielectrics fabricated with in situ and ex situ techniques

    SciTech Connect

    Tuncer, Enis; Polyzos, Georgios; Sauers, Isidor; James, David Randy; Ellis, Alvin R; More, Karren Leslie

    2012-01-01

    In this study, we report fabrication and characterisation of a nanocomposite system composed of a commercial resin and extremely small (several nanometres in diameter) titanium dioxide particles. Nanoparticles were synthesised in situ with particle nucleation occurring inside the resin matrix. In this nanodielectric fabrication method, the nanoparticle precursor was mixed to the resin solution, and the nanoparticles were in situ precipitated. Note that no high shear mixing equipment was needed to improve particle dispersion - nanoparticles were distributed in the polymer matrix uniformly since particle nucleation occurs uniformly throughout the matrix. The properties of in situ nanodielectrics are compared to the unfilled resin and an ex situ nanocomposite. We anticipate that the presented in situ nanocomposite would be employed in high-temperature superconductivity applications. In additions, the improvement shown in the dielectric breakdown indicates that conventional high-voltage components and systems can be reduced in size with novel nanodielectrics.

  10. Development of an in situ loop-mediated isothermal amplification technique for chromosomal localization of DNA sequences

    NASA Astrophysics Data System (ADS)

    Meng, Qinglei; Wang, Shi; Zhang, Lingling; Huang, Xiaoting; Bao, Zhenmin

    2013-01-01

    In situ loop-mediated isothermal amplification (in situ LAMP) combines in situ hybridization and loop-mediated isothermal amplification (LAMP) techniques for chromosomal localization of DNA sequences. In situ LAMP is a method that is generally more specific and sensitive than conventional techniques such as fluorescence in situ hybridization (FISH), primed in situ labeling (PRINS), and cycling primed in situ labeling (C-PRINS). Here, we describe the development and application of in situ LAMP to identify the chromosomal localization of DNA sequences. To benchmark this technique, we successfully applied this technique to localize the major ribosomal RNA gene on the chromosomes of the Zhikong scallop ( Chlamys farreri).

  11. In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition

    SciTech Connect

    Devloo-Casier, Kilian Detavernier, Christophe; Dendooven, Jolien

    2014-01-15

    Atomic layer deposition (ALD) is a thin film deposition technique that has been studied with a variety of in situ techniques. By exploiting the high photon flux and energy tunability of synchrotron based x-rays, a variety of new in situ techniques become available. X-ray reflectivity, grazing incidence small angle x-ray scattering, x-ray diffraction, x-ray fluorescence, x-ray absorption spectroscopy, and x-ray photoelectron spectroscopy are reviewed as possible in situ techniques during ALD. All these techniques are especially sensitive to changes on the (sub-)nanometer scale, allowing a unique insight into different aspects of the ALD growth mechanisms.

  12. Ignition technique for an in situ oil shale retort

    DOEpatents

    Cha, Chang Y.

    1983-01-01

    A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

  13. Single Molecule Techniques for Advanced in situ Hybridization

    SciTech Connect

    Hollars, C W; Stubbs, L; Carlson, K; Lu, X; Wehri, E

    2003-02-03

    One of the most significant achievements of modern science is completion of the human genome sequence, completed in the year 2000. Despite this monumental accomplishment, researchers have only begun to understand the relationships between this three-billion-nucleotide genetic code and the regulation and control of gene and protein expression within each of the millions of different types of highly specialized cells. Several methodologies have been developed for the analysis of gene and protein expression in situ, yet despite these advancements, the pace of such analyses is extremely limited. Because information regarding the precise timing and location of gene expression is a crucial component in the discovery of new pharmacological agents for the treatment of disease, there is an enormous incentive to develop technologies that accelerate the analytical process. Here we report on the use of plasmon resonant particles as advanced probes for in situ hybridization. These probes are used for the detection of low levels of gene-probe response and demonstrate a detection method that enables precise, simultaneous localization within a cell of the points of expression of multiple genes or proteins in a single sample.

  14. In situ pipe coating techniques for building plumbing

    SciTech Connect

    Hock, V.F.; Cardenas, H.E.; Emery, J.R.

    1995-12-01

    Water pipe failures (leaks) within buildings are an ongoing problem at many large installations such as military bases, universities, and industrial complexes. Such failures can cause severe, costly damage to building interiors, personal property, and electronic equipment. Most failures in metallic potable water pipes within buildings are a result of water-side corrosion. Water-side corrosion may be induced by certain constituents in the water and/or poor workmanship practices. Water temperatures, pressures, and velocities are also factors in the corrosion process. In order to mitigate water-side corrosion and comply with the 1986 Safe Drinking Water Act and the National Primary Drinking Water Regulations for lead and copper, 40 CFR 141.82, an alternative to chemical treatment was developed. The preliminary results of in situ pipe coatings for small diameter building plumbing are presented.

  15. Security Verification Techniques Applied to PatchLink COTS Software

    NASA Technical Reports Server (NTRS)

    Gilliam, David P.; Powell, John D.; Bishop, Matt; Andrew, Chris; Jog, Sameer

    2006-01-01

    Verification of the security of software artifacts is a challenging task. An integrated approach that combines verification techniques can increase the confidence in the security of software artifacts. Such an approach has been developed by the Jet Propulsion Laboratory (JPL) and the University of California at Davis (UC Davis). Two security verification instruments were developed and then piloted on PatchLink's UNIX Agent, a Commercial-Off-The-Shelf (COTS) software product, to assess the value of the instruments and the approach. The two instruments are the Flexible Modeling Framework (FMF) -- a model-based verification instrument (JPL), and a Property-Based Tester (UC Davis). Security properties were formally specified for the COTS artifact and then verified using these instruments. The results were then reviewed to determine the effectiveness of the approach and the security of the COTS product.

  16. In Situ Mechanical Testing Techniques for Real-Time Materials Deformation Characterization

    NASA Astrophysics Data System (ADS)

    Rudolf, Chris; Boesl, Benjamin; Agarwal, Arvind

    2016-01-01

    In situ mechanical property testing has the ability to enhance quantitative characterization of materials by revealing the occurring deformation behavior in real time. This article will summarize select recent testing performed inside a scanning electron microscope on various materials including metals, ceramics, composites, coatings, and 3-Dimensional graphene foam. Tensile and indentation testing methods are outlined with case studies and preliminary data. The benefits of performing a novel double-torsion testing technique in situ are also proposed.

  17. Verification of joint input-state estimation for force identification by means of in situ measurements on a footbridge

    NASA Astrophysics Data System (ADS)

    Maes, K.; Nimmen, K. Van; Lourens, E.; Rezayat, A.; Guillaume, P.; Roeck, G. De; Lombaert, G.

    2016-06-01

    This paper presents a verification of a joint input-state estimation algorithm using data obtained from in situ experiments on a footbridge. The estimation of the input and the system states is performed in a minimum-variance unbiased way, based on a limited number of response measurements and a system model. A dynamic model of the footbridge is obtained using a detailed finite element model that is updated using a set of experimental modal characteristics. The joint input-state estimation algorithm is used for the identification of two impact, harmonic, and swept sine forces applied to the bridge deck. In addition to these forces, unknown stochastic forces, such as wind loads, are acting on the structure. These forces, as well as measurement errors, give rise to uncertainty in the estimated forces and system states. Quantification of the uncertainty requires determination of the power spectral density of the unknown stochastic excitation, which is identified from the structural response under ambient loading. The verification involves comparing the estimated forces with the actual, measured forces. Although a good overall agreement is obtained between the estimated and measured forces, modeling errors prohibit a proper distinction between multiple forces applied to the structure for the case of harmonic and swept sine excitation.

  18. Damage Detection and Verification System (DDVS) for In-Situ Health Monitoring

    NASA Technical Reports Server (NTRS)

    Williams, Martha K.; Lewis, Mark; Szafran, J.; Shelton, C.; Ludwig, L.; Gibson, T.; Lane, J.; Trautwein, T.

    2015-01-01

    Project presentation for Game Changing Program Smart Book Release. Detection and Verification System (DDVS) expands the Flat Surface Damage Detection System (FSDDS) sensory panels damage detection capabilities and includes an autonomous inspection capability utilizing cameras and dynamic computer vision algorithms to verify system health. Objectives of this formulation task are to establish the concept of operations, formulate the system requirements for a potential ISS flight experiment, and develop a preliminary design of an autonomous inspection capability system that will be demonstrated as a proof-of-concept ground based damage detection and inspection system.

  19. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

  20. In situ attosecond pulse characterization techniques to measure the electromagnetic phase

    NASA Astrophysics Data System (ADS)

    Spanner, M.; Bertrand, J. B.; Villeneuve, D. M.

    2016-08-01

    A number of techniques have been developed to characterize the attosecond emission from high-order-harmonic sources. These techniques are broadly classified as ex situ, where the attosecond pulse train photoionizes a target gas in the presence of an infrared field, and in situ, where the measurement takes place in the medium in which the attosecond pulses are generated. It is accepted that ex situ techniques measure the characteristics of the electromagnetic field, including the phase of the recombination transition moment of the emitting atom or molecule, when the phase of the second medium is known. However, there is debate about whether in situ techniques measure the electromagnetic field, or only the characteristics of the recolliding electron before recombination occurs. We show numerically that in situ measurements are not sensitive to the recombination phase, when implemented in the perturbative regime as originally envisioned, and that they do not measure the electromagnetic phase of the emission.

  1. Development of an in situ calibration technique for combustible gas detectors

    NASA Technical Reports Server (NTRS)

    Shumar, J. W.; Wynveen, R. A.; Lance, N., Jr.; Lantz, J. B.

    1977-01-01

    This paper describes the development of an in situ calibration procedure for combustible gas detectors (CGD). The CGD will be a necessary device for future space vehicles as many subsystems in the Environmental Control/Life Support System utilize or produce hydrogen (H2) gas. Existing calibration techniques are time-consuming and require support equipment such as an environmental chamber and calibration gas supply. The in situ calibration procedure involves utilization of a water vapor electrolysis cell for the automatic in situ generation of a H2/air calibration mixture within the flame arrestor of the CGD. The development effort concluded with the successful demonstration of in situ span calibrations of a CGD.

  2. A comparison of adjoint and data-centric verification techniques.

    SciTech Connect

    Wildey, Timothy Michael; Cyr, Eric C; Shadid, John N; Pawlowski, Roger P; Smith, Thomas Michael

    2013-03-01

    This document summarizes the results from a level 3 milestone study within the CASL VUQ effort. We compare the adjoint-based a posteriori error estimation approach with a recent variant of a data-centric verification technique. We provide a brief overview of each technique and then we discuss their relative advantages and disadvantages. We use Drekar::CFD to produce numerical results for steady-state Navier Stokes and SARANS approximations. 3

  3. Improved Detection Technique for Solvent Rinse Cleanliness Verification

    NASA Technical Reports Server (NTRS)

    Hornung, S. D.; Beeson, H. D.

    2001-01-01

    The NASA White Sands Test Facility (WSTF) has an ongoing effort to reduce or eliminate usage of cleaning solvents such as CFC-113 and its replacements. These solvents are used in the final clean and cleanliness verification processes for flight and ground support hardware, especially for oxygen systems where organic contaminants can pose an ignition hazard. For the final cleanliness verification in the standard process, the equivalent of one square foot of surface area of parts is rinsed with the solvent, and the final 100 mL of the rinse is captured. The amount of nonvolatile residue (NVR) in the solvent is determined by weight after the evaporation of the solvent. An improved process of sampling this rinse, developed at WSTF, requires evaporation of less than 2 mL of the solvent to make the cleanliness verification. Small amounts of the solvent are evaporated in a clean stainless steel cup, and the cleanliness of the stainless steel cup is measured using a commercially available surface quality monitor. The effectiveness of this new cleanliness verification technique was compared to the accepted NVR sampling procedures. Testing with known contaminants in solution, such as hydraulic fluid, fluorinated lubricants, and cutting and lubricating oils, was performed to establish a correlation between amount in solution and the process response. This report presents the approach and results and discusses the issues in establishing the surface quality monitor-based cleanliness verification.

  4. In situ replication techniques: II. Quantitative methodologies for replicate materials.

    PubMed

    Kusy, R P; Whitley, J Q

    1985-01-01

    Because replicate materials have requirements different from those of recording or impression materials, quantitative methodologies were sought using commercial impression materials. Two satisfactory objective techniques resulted, a laser-scattering and a capillary flow test. Using high-resolution gratings to stimulate tooth detail (less than 1 micron), the reproduction quality of 36 two-stage replicas was determined in diffraction, reflection, and in an unblazed state. Using precision bore glass tubes (0.25, 0.5, 1, and 2 mm diameters) to simulate the high-energy surface of enamel, the flow characteristics of nine elastomers (the first stage replicates) and four epoxies (the second stage replicates) were determined at isobaric conditions. Because the laser spot size was relatively large (0.6 mm) and the pressure differential was small (25 mm Hg), both the global resolution and the low shear rate characteristics could be measured. Of the commercial materials tested, Reprosil Light had the best combination of fluidity and resolution, regardless of which positive material was used. Although Permagum Low, Silene Wash, and Xantopren Blue scored high in one of the two tests, none of these materials could compare to Reprosil Light within the context described herein.

  5. First in situ TOF-PET study using digital photon counters for proton range verification

    NASA Astrophysics Data System (ADS)

    Cambraia Lopes, P.; Bauer, J.; Salomon, A.; Rinaldi, I.; Tabacchini, V.; Tessonnier, T.; Crespo, P.; Parodi, K.; Schaart, D. R.

    2016-08-01

    Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong 15O signal due to its relatively short half-life (~2 min) and high oxygen content in biological tissues, enabling shorter scans that are less sensitive to biological washout. This paper presents the first performance tests of a scaled-down in situ time-of-flight (TOF) PET system based on digital photon counters (DPCs) coupled to Cerium-doped Lutetium Yttrium Silicate (LYSO:Ce) crystals, providing quantitative results representative of a dual-head tomograph that complies with spatial constraints typically encountered in clinical practice (2  ×  50°, of 360°, transaxial angular acceptance). The proton-induced activity inside polymethylmethacrylate (PMMA) and polyethylene (PE) phantoms was acquired within beam pauses (in-beam) and immediately after irradiation by an actively-delivered synchrotron pencil-beam, with clinically relevant 125.67 MeV/u, 4.6  ×  108 protons s-1, and 1010 total protons. 3D activity maps reconstructed with and without TOF information are compared to FLUKA simulations, demonstrating the benefit of TOF-PET to reduce limited-angle artefacts using a 382 ps full width at half maximum coincidence resolving time. The time-dependent contributions from different radionuclides to the total count-rate are investigated. We furthermore study the impact of the acquisition time window on the laterally integrated activity depth-profiles, with emphasis on 2 min acquisitions starting at different time points. The results depend on phantom composition and reflect the differences in relative contributions from the radionuclides originating from carbon and oxygen. We observe very good agreement between the shapes of the simulated and measured activity depth-profiles for post-beam protocols. However, our results also

  6. First in situ TOF-PET study using digital photon counters for proton range verification.

    PubMed

    Cambraia Lopes, P; Bauer, J; Salomon, A; Rinaldi, I; Tabacchini, V; Tessonnier, T; Crespo, P; Parodi, K; Schaart, D R

    2016-08-21

    Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong (15)O signal due to its relatively short half-life (~2 min) and high oxygen content in biological tissues, enabling shorter scans that are less sensitive to biological washout. This paper presents the first performance tests of a scaled-down in situ time-of-flight (TOF) PET system based on digital photon counters (DPCs) coupled to Cerium-doped Lutetium Yttrium Silicate (LYSO:Ce) crystals, providing quantitative results representative of a dual-head tomograph that complies with spatial constraints typically encountered in clinical practice (2  ×  50°, of 360°, transaxial angular acceptance). The proton-induced activity inside polymethylmethacrylate (PMMA) and polyethylene (PE) phantoms was acquired within beam pauses (in-beam) and immediately after irradiation by an actively-delivered synchrotron pencil-beam, with clinically relevant 125.67 MeV/u, 4.6  ×  10(8) protons s(-1), and 10(10) total protons. 3D activity maps reconstructed with and without TOF information are compared to FLUKA simulations, demonstrating the benefit of TOF-PET to reduce limited-angle artefacts using a 382 ps full width at half maximum coincidence resolving time. The time-dependent contributions from different radionuclides to the total count-rate are investigated. We furthermore study the impact of the acquisition time window on the laterally integrated activity depth-profiles, with emphasis on 2 min acquisitions starting at different time points. The results depend on phantom composition and reflect the differences in relative contributions from the radionuclides originating from carbon and oxygen. We observe very good agreement between the shapes of the simulated and measured activity depth-profiles for post-beam protocols. However, our results

  7. First in situ TOF-PET study using digital photon counters for proton range verification

    NASA Astrophysics Data System (ADS)

    Cambraia Lopes, P.; Bauer, J.; Salomon, A.; Rinaldi, I.; Tabacchini, V.; Tessonnier, T.; Crespo, P.; Parodi, K.; Schaart, D. R.

    2016-08-01

    Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong 15O signal due to its relatively short half-life (~2 min) and high oxygen content in biological tissues, enabling shorter scans that are less sensitive to biological washout. This paper presents the first performance tests of a scaled-down in situ time-of-flight (TOF) PET system based on digital photon counters (DPCs) coupled to Cerium-doped Lutetium Yttrium Silicate (LYSO:Ce) crystals, providing quantitative results representative of a dual-head tomograph that complies with spatial constraints typically encountered in clinical practice (2  ×  50°, of 360°, transaxial angular acceptance). The proton-induced activity inside polymethylmethacrylate (PMMA) and polyethylene (PE) phantoms was acquired within beam pauses (in-beam) and immediately after irradiation by an actively-delivered synchrotron pencil-beam, with clinically relevant 125.67 MeV/u, 4.6  ×  108 protons s‑1, and 1010 total protons. 3D activity maps reconstructed with and without TOF information are compared to FLUKA simulations, demonstrating the benefit of TOF-PET to reduce limited-angle artefacts using a 382 ps full width at half maximum coincidence resolving time. The time-dependent contributions from different radionuclides to the total count-rate are investigated. We furthermore study the impact of the acquisition time window on the laterally integrated activity depth-profiles, with emphasis on 2 min acquisitions starting at different time points. The results depend on phantom composition and reflect the differences in relative contributions from the radionuclides originating from carbon and oxygen. We observe very good agreement between the shapes of the simulated and measured activity depth-profiles for post-beam protocols. However, our results also

  8. Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique.

    PubMed

    Wang, Hongchang; Kashyap, Yogesh; Laundy, David; Sawhney, Kawal

    2015-07-01

    In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes. PMID:26134795

  9. Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique.

    PubMed

    Wang, Hongchang; Kashyap, Yogesh; Laundy, David; Sawhney, Kawal

    2015-07-01

    In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes.

  10. The development of an electrochemical technique for in situ calibrating of combustible gas detectors

    NASA Technical Reports Server (NTRS)

    Shumar, J. W.; Lantz, J. B.; Schubert, F. H.

    1976-01-01

    A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector.

  11. Laser Based In Situ Techniques: Novel Methods for Generating Extreme Conditions in TEM Samples

    SciTech Connect

    Taheri, M; Lagrange, T; Reed, B; Armstrong, M; Campbell, G; DeHope, W; Kim, J; King, W; Masiel, D; Browning, N

    2008-02-25

    The Dynamic Transmission Electron Microscope (DTEM) is introduced as a novel tool for in situ processing of materials. Examples of various types of dynamic studies outline the advantages and differences of laser-based heating in the DTEM in comparison to conventional (resistive) heating in situ TEM methods. We demonstrate various unique capabilities of the drive laser, namely, in situ processing of nanoscale materials, rapid and high temperature phase transformations, and controlled thermal activation of materials. These experiments would otherwise be impossible without the use of the DTEM drive laser. Thus, the potential of the DTEM to as a new technique to process and characterize the growth of a myriad of micro and nanostructures is demonstrated.

  12. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    SciTech Connect

    Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

    2015-06-15

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  13. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    NASA Astrophysics Data System (ADS)

    Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

    2015-06-01

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  14. An overview on in situ micronization technique - An emerging novel concept in advanced drug delivery.

    PubMed

    Vandana, K R; Prasanna Raju, Y; Harini Chowdary, V; Sushma, M; Vijay Kumar, N

    2014-09-01

    The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared.

  15. An overview on in situ micronization technique – An emerging novel concept in advanced drug delivery

    PubMed Central

    Vandana, K.R.; Prasanna Raju, Y.; Harini Chowdary, V.; Sushma, M.; Vijay Kumar, N.

    2013-01-01

    The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared. PMID:25161371

  16. Calibration and integrity verification techniques applied to GPS simulators

    NASA Astrophysics Data System (ADS)

    Stulken, D. A.

    Automated calibration and signal verification techniques which are used in GPS simulators to ensure a high level of fidelity of the test stimulus employed in evaluating the performance of GPS receivers have been developed. The present techniques involve satellite signal power levels, jammer signal power levels, time of arrival of satellite signals, and the coordinated timing of simulated satellite signals with respect to the simulation of the host vehicle interface signals. From initial simulation and evaluation system design efforts, a new family of GPS RF signal generators were developed, the multiple channel signal generator and the single channel signal generator.

  17. The development of in situ fracture toughness evaluation techniques in hydrogen environment

    SciTech Connect

    Wang, Jy-An John; Ren, Fei; Tan, Ting; Liu, Ken C

    2014-01-01

    Fracture behavior and fracture toughness are of great interest regarding reliability of hydrogen pipelines and storage tanks, however, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen, in addition to the inherited specimen size effect. Thus it is desired to develop novel in situ fracture toughness evaluation techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, a torsional fixture was developed to utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The in situ testing results indicated that the exposure to H2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.

  18. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    SciTech Connect

    Lovley, Derek R.

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  19. A novel technique for in situ aggregation of Gluconobacter oxydans using bio-adhesive magnetic nanoparticles

    PubMed Central

    Lu, Huimin; Ni, Kefeng; Wang, Cunxun; Black, Kvar C.L.; Wei, Dongzhi; Ren, Yuhong; Messersmith, Phillip B.

    2012-01-01

    Here, we present a novel technique to immobilize magnetic particles onto whole G. oxydans in situ via a synthetic adhesive biomimetic material inspired by the protein glues of marine mussels. Our approach involves simple coating of a cell adherent polydopamine film onto magnetic nanoparticles, followed by conjugation of the polydopamine-coated nanoparticles to G. oxydans which resulted in cell aggregation. After optimization, 21.3 mg (wet cell weight) G. oxydans per milligram of nanoparticle was aggregated and separated with a magnet. Importantly, the G. oxydan aggregates showed high specific activity and good reusability. The facile approach offers the potential advantages of low cost, easy cell separation, low diffusion resistance and high efficiency. Furthermore, the approach is a convenient platform technique for magnetization of cells in situ by direct mixing of nanoparticles with a cell suspension. PMID:22729662

  20. Optical techniques for remote and in-situ characterization of particles pertinent to GEOTRACES

    NASA Astrophysics Data System (ADS)

    Boss, Emmanuel; Guidi, Lionel; Richardson, Mary Jo; Stemmann, Lars; Gardner, Wilford; Bishop, James K. B.; Anderson, Robert F.; Sherrell, Robert M.

    2015-04-01

    Field and laboratory characterization of marine particles is laborious and expensive. Proxies of particle properties have been developed that allow researchers to obtain high frequency distributions of such properties in space or time. We focus on optical techniques used to characterize marine particles in-situ, with a focus on GEOTRACES-relevant properties, such as bulk properties including particle mass, cross-sectional area, particle size distribution, particle shape information, and also single particle optical properties, such as individual particle type and size. We also address the use of optical properties of particles to infer particulate organic or inorganic carbon. In addition to optical sensors we review advances in imaging technology and its use to study marine particles in situ. This review addresses commercially available technology and techniques that can be used as a proxy for particle properties and the associated uncertainties with particular focus to open ocean environments, the focus of GEOTRACES.

  1. Simulation verification techniques study. Subsystem simulation validation techniques

    NASA Technical Reports Server (NTRS)

    Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

    1974-01-01

    Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given.

  2. The development of in situ fracture toughness evaluation techniques in hydrogen environment

    DOE PAGES

    Wang, John Jy-An; Ren, Fei; Tan, Tin; Liu, Ken

    2014-12-19

    Reliability of hydrogen pipelines and storage tanks is significantly influenced by the mechanical performance of the structural materials exposed in the hydrogen environment. Fracture behavior and fracture toughness are of specific interest since they are relevant to many catastrophic failures. However, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen. Thus it is desired to develop novel in situ techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, special testing apparatus were designed to facilitate in situ fracture testing in H2. A torsional fixture was developed to utilizemore » an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The design concepts will be discussed. Preliminary in situ testing results indicated that the exposure to H2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.« less

  3. The development of in situ fracture toughness evaluation techniques in hydrogen environment

    SciTech Connect

    Wang, John Jy-An; Ren, Fei; Tan, Tin; Liu, Ken

    2014-12-19

    Reliability of hydrogen pipelines and storage tanks is significantly influenced by the mechanical performance of the structural materials exposed in the hydrogen environment. Fracture behavior and fracture toughness are of specific interest since they are relevant to many catastrophic failures. However, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen. Thus it is desired to develop novel in situ techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, special testing apparatus were designed to facilitate in situ fracture testing in H2. A torsional fixture was developed to utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The design concepts will be discussed. Preliminary in situ testing results indicated that the exposure to H2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.

  4. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our technology development program at NASA Goddard Space Flight Center's (NASA/GSFC) Astrochemistry Laboratory is to extend the application of neutron interrogation techniques to landed in situ planetary composition measurements by using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies without the need to drill. We are thus working to bring the PING instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets.

  5. Making a Hybrid Microfluidic Platform Compatible for In Situ Imaging by Vacuum-Based Techniques

    SciTech Connect

    Yang, Li; Yu, Xiao-Ying; Zhu, Zihua; Thevuthasan, Suntharampillai; Cowin, James P.

    2011-10-26

    A self-contained microfluidic-based device was designed and fabricated for in situ imaging of aqueous surfaces using vacuum techniques. The device is a hybrid between a microfluidic PDMS block and external accessories, all portable on a small platform (10 cm-8 cm). The key feature is that a small aperture with a diameter of 2-3 micrometers is opened to the vacuum, which serves as a detection window for in situ imaging of aqueous surfaces. Vacuum compatibility and temperature drop due to water vaporization are the two most important challenges in this invention. Theoretical calculations and fabrication strategies are presented from multiple design aspects. In addition, results from the time-of-flight secondary ion mass spectrometry (ToF-SIMS) of aqueous surfaces are presented.

  6. Implementation of In-Situ Impedance Techniques on a Full Scale Aero-Engine System

    NASA Technical Reports Server (NTRS)

    Gaeta, R. J.; Mendoza, J. M.; Jones, M. G.

    2007-01-01

    Determination of acoustic liner impedance for jet engine applications remains a challenge for the designer. Although suitable models have been developed that take account of source amplitude and the local flow environment experienced by the liner, experimental validation of these models has been difficult. This is primarily due to the inability of researchers to faithfully mimic the environment in jet engine nacelles in the laboratory. An in-situ measurement technique, one that can be implemented in an actual engine, is desirable so an accurate impedance can be determined for future modeling and quality control. This paper documents the implementation of such a local acoustic impedance measurement technique that is used under controlled laboratory conditions as well as on full scale turbine engine liner test article. The objective for these series of in-situ measurements is to substantiate treatment design, provide understanding of flow effects on installed liner performance, and provide modeling input for fan noise propagation computations. A series of acoustic liner evaluation tests are performed that includes normal incidence tube, grazing incidence tube, and finally testing on a full scale engine on a static test stand. Lab tests were intended to provide insight and guidance for accurately measuring the impedance of the liner housed in the inlet of a Honeywell Tech7000 turbofan. Results have shown that one can acquire very reasonable liner impedance data for a full scale engine under realistic test conditions. Furthermore, higher fidelity results can be obtained by using a three-microphone coherence technique that can enhance signal-to-noise ratio at high engine power settings. This research has also confirmed the limitations of this particular type of in-situ measurement. This is most evident in the installation of instrumentation and its effect on what is being measured.

  7. Development of a fluorescent in situ hybridization (FISH) technique for visualizing CGMMV in plant tissues.

    PubMed

    Shargil, D; Zemach, H; Belausov, E; Lachman, O; Kamenetsky, R; Dombrovsky, A

    2015-10-01

    Cucumber green mottle mosaic virus (CGMMV), which belongs to the genus Tobamovirus, is a major pathogen of cucurbit crops grown indoors and in open fields. Currently, immunology (e.g., ELISA) and molecular amplification techniques (e.g., RT-PCR) are employed extensively for virus detection in plant tissues and commercial seed lots diagnostics. In this study, a fluorescent in situ hybridization (FISH) technique, using oligonucleotides whose 5'-terminals were labeled with red cyanine 3 (Cy3) or green fluorescein isothiocyanate (FITC), was developed for the visualization of the pathogen in situ. This simple and reliable method allows detection and localization of CGMMV in the vegetative and reproductive tissues of cucumber and melon. When this technique was applied in male flowers, anther tissues were found to be infected; whereas the pollen grains were found to be virus-free. These results have meaningful epidemiological implications for the management of CGMMV, particularly with regard to virus transfer via seed and the role of insects as CGMMV vectors.

  8. In situ identification of bacterial species in marine microfouling films by using an immunofluorescence technique.

    PubMed Central

    Zambon, J J; Huber, P S; Meyer, A E; Slots, J; Fornalik, M S; Baier, R E

    1984-01-01

    An immunofluorescence technique was developed for the in situ identification of specific bacteria in marine microfouling films. Microorganisms adherent to glass plates after 30 days of immersion in a synthetic seawater system were cultured and classified by biochemical tests, flagellar arrangement, and the API 20E system. All isolates were gram-negative aerobic or facultative motile rods, predominantly Pseudomonas spp. Rabbit antisera to the five dominant organisms including Achromobacter spp., Comamonas terrigena, P. putrefaciens, a yellow-pigmented Pseudomonas sp., and Vibrio alginolyticus were prepared. These antisera were shown to be species specific in indirect immunofluorescence assays against a battery of 26 marine isolates from 14 bacterial species, with the exception of antisera to the Pseudomonas spp, which cross-reacted with each other but not with test bacteria of other genera. These immunofluorescent reagents enabled the in situ identification of all five bacterial species in microfouling films. Low-surface-energy test plates had smaller numbers of adherent bacteria in microfouling films than medium-surface-energy test plates, suggesting that the degree of microfouling may be influenced by the surface energy. In addition, the reagents could identify up to 39% of the attached bacteria in microfouling films spontaneously formed on steel plates in flow cells deployed in different areas of the Atlantic Ocean. The microbial composition of the ocean-formed films varied with the geographical area of their formation. The present results indicate that immunofluorescence techniques may provide a rapid and reliable means to identify, in situ, specific bacteria in marine microfouling films. PMID:6393875

  9. Development of Advanced In-Situ Techniques for Chemistry Monitoring and Corrosion Mitigation in SCWO Environments

    SciTech Connect

    Macdonald, D. D.; Lvov, S. N.

    2000-03-31

    This project is developing sensing technologies and corrosion monitoring techniques for use in super critical water oxidation (SCWO) systems to reduce the volume of mixed low-level nuclear waste by oxidizing organic components in a closed cycle system where CO2 and other gaseous oxides are produced, leaving the radioactive elements concentrated in ash. The technique uses water at supercritical temperatures under highly oxidized conditions by maintaining a high fugacity of molecular oxygen in the system, which causes high corrosion rates of even the most corrosive resistant reactor materials. This project significantly addresses the high corrosion shortcoming through development of (a) advanced electrodes and sensors for in situ potentiometric monitoring of pH in high subcritical and supercritical aqueous solutions, (b) an approach for evaluating the association constants for 1-1 aqueous electrolytes using a flow-through electrochemical thermocell; (c) an electrochemical noise sensor for the in situ measurement of corrosion rate in subcritical and supercritical aqueous systems; (d) a model for estimating the effect of pressure on reaction rates, including corrosion reactions, in high subcritical and supercritical aqueous systems. The project achieved all objectives, except for installing some of the sensors into a fully operating SCWO system.

  10. Studies of ferroelectric heterostructure thin films and interfaces via in situ analytical techniques.

    SciTech Connect

    Auciello, O.; Dhote, A.; Gao, Y.; Gruen, D. M.; Im, J.; Irene, E. A.; Krauss, A. R.; Mueller, A. H.; Ramesh, R.

    1999-08-30

    The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMs) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and interface processes, which play critical roles in film microstructure and properties. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed.

  11. Study of techniques for redundancy verification without disrupting systems, phases 1-3

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The problem of verifying the operational integrity of redundant equipment and the impact of a requirement for verification on such equipment are considered. Redundant circuits are examined and the characteristics which determine adaptability to verification are identified. Mutually exclusive and exhaustive categories for verification approaches are established. The range of applicability of these techniques is defined in terms of signal characteristics and redundancy features. Verification approaches are discussed and a methodology for the design of redundancy verification is developed. A case study is presented which involves the design of a verification system for a hypothetical communications system. Design criteria for redundant equipment are presented. Recommendations for the development of technological areas pertinent to the goal of increased verification capabilities are given.

  12. In-situ magnetic gauging technique used at LANL-method and shock information obtained

    NASA Astrophysics Data System (ADS)

    Sheffield, S. A.; Gustavsen, R. L.; Alcon, R. R.

    2000-04-01

    Measuring techniques, including magnetic gauges, quartz gauges, manganin gauges, PVDF gauges, velocity interferometry, piezoelectric pins, shorting pins, flash gaps, etc., have been used over the years in shock experiments in condensed phase materials. The use of a particular technique depends on the measured parameter and the sample material properties. This paper concentrates on in-situ magnetic gauging which is particularly useful in high explosive (HE) shock initiation experiments. A short history of this technique will be given but the main discussion will concentrate on the multiple magnetic gauge technique developed at Los Alamos National Lab. (LANL). Vorthman and Wackerle started the technique development in 1980, concentrating on particle velocity and "impulse" gauges so that Lagrange analysis could be used to map the entire reactive field. Over the years, changes to the gauge design, fabrication, and experimental focus have led to the present LANL technique. During the past two years measurements have tracked the reactive wave evolution resulting from a shock-to-detonation transition in several high explosive materials. Analysis of the data from a single experiment provides: 1) an unreacted Hugoniot point in which both the shock velocity and particle velocity are measured, 2) shock front tracking, 3) ten particle velocity profiles which measure the reactive wave evolution, 4) a "Pop-plot" distance-(time-)to-detonation point, and 5) a 3% measurement of the detonation velocity. Details of the experimental setup and information from several experiments will be discussed.

  13. Calibration of an in-situ BEGe detector using semi-empirical and Monte Carlo techniques.

    PubMed

    Agrafiotis, K; Karfopoulos, K L; Anagnostakis, M J

    2011-08-01

    In the case of a nuclear or radiological accident a rapid estimation of the qualitative and quantitative characteristics of the potential radioactive pollution is needed. For aerial releases the radioactive pollutants are finally deposited on the ground forming a surface source. In this case, in-situ γ-ray spectrometry is a powerful tool for the determination of ground pollution. In this work, the procedure followed at the Nuclear Engineering Department of the National Technical University of Athens (NED-NTUA) for the calibration of an in-situ Broad Energy Germanium (BEGe) detector, for the determination of gamma-emitting radionuclides deposited on the ground surface, is presented. BEGe detectors due to their technical characteristics are suitable for the analysis of photons in a wide energy region. Two different techniques were applied for the full-energy peak efficiency calibration of the BEGe detector in the energy region 60-1600 keV: Full-energy peak efficiencies determined using the two methods agree within statistical uncertainties. PMID:21193317

  14. Simulation verification techniques study: Simulation self test hardware design and techniques report

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The final results are presented of the hardware verification task. The basic objectives of the various subtasks are reviewed along with the ground rules under which the overall task was conducted and which impacted the approach taken in deriving techniques for hardware self test. The results of the first subtask and the definition of simulation hardware are presented. The hardware definition is based primarily on a brief review of the simulator configurations anticipated for the shuttle training program. The results of the survey of current self test techniques are presented. The data sources that were considered in the search for current techniques are reviewed, and results of the survey are presented in terms of the specific types of tests that are of interest for training simulator applications. Specifically, these types of tests are readiness tests, fault isolation tests and incipient fault detection techniques. The most applicable techniques were structured into software flows that are then referenced in discussions of techniques for specific subsystems.

  15. Combustion synthesis of advanced materials. [using in-situ infiltration technique

    NASA Technical Reports Server (NTRS)

    Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

    1992-01-01

    The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

  16. Temperature-dependent properties of silver-poly(methylmethacrylate) nanocomposites synthesized by in-situ technique

    PubMed Central

    2014-01-01

    Ag/PMMA nanocomposites were successfully synthesized by in-situ technique. Transmission electron microscopy (TEM) images show that the particles are spherical in shape and their sizes are dependent on temperature. The smallest particle achieved high stability as indicated from Zeta sizer analysis. The red shift of surface plasmon resonance (SPR) indicated the increases of particle sizes. X-ray diffraction (XRD) patterns exhibit a two-phase (crystalline and amorphous) structure of Ag/PMMA nanocomposites. The complexation of Ag/PMMA nanocomposites was confirmed using Raman spectroscopy. Fourier transform infrared spectroscopy spectra confirmed that the bonding was dominantly influenced by the PMMA and DMF solution. Finally, thermogravimetric analysis (TGA) results indicate that the total weight loss increases as the temperature increases. PMID:24450850

  17. The ID-KArD technique: In-situ dating on Mars

    NASA Astrophysics Data System (ADS)

    Cartwright, J. A.; Farley, K. A.; Hurowitz, J.; Asimow, P. D.; Jacobson, N. S.

    2013-12-01

    The ability to measure absolute ages on the Martian surface is crucial for understanding the planet's evolution. A detailed geological history of the Moon has been determined through analysis of returned samples from specific units, and relative ages calculated by crater counting techniques. However, without returned samples or in-situ dating analyses, we lack absolute age markers for Mars and thus cannot accurately or precisely date its well-documented surface. Instead, we have relied on an estimated Mars/Moon cratering ratio and relative crater counting techniques in an attempt to calculate surface ages and classify geological units. The use of such relative parameters diminishes the precision and accuracy for surface age calculations, and thus highlights the need for independent age determinations from returned samples or in-situ dating. In this research, we describe our technique - ID-KArD (Isotope Dilution K-Ar Dating) - intended for in-situ age dating of geological units on the Martian surface. ID-KArD resolves two challenges that have previously obstructed in-situ age dating on Mars: 1) High fusion temperatures are avoided with the use of a lithium-borate flux; 2) Sample mass measurement is not required, due to the addition of an isotope dilution doubly-spiked glass. The glass has a known 39Ar/41K ratio, which removes the need for concentration measurements. Thus, only isotope ratios are required for a K-Ar age determination. ID-KArD has the potential to address Mars chronology inaccuracies, and would be a suitable technique for consideration on future missions. In the first phase of ID-KArD proof of concept, we selected a Viluy trap basalt (K2O ~ 0.7 wt%), with concordant K-Ar and Ar-Ar ages of 354.3 × 3.5 and 357.7 × 1.4 Ma respectively (Courtillot et al., 2010). An aliquot was combined into a crucible with the flux and the spike glass for separate Ar (MAP 215:50, Caltech), followed by K (KEMS, GRC) isotopic analysis. Combining our results, we obtained

  18. Use of noninvasive geophysical techniques for the In Situ Vitrification Program

    SciTech Connect

    Josten, N.E.; Marts, S.T.; Carpenter, G.S.

    1991-11-01

    In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focuses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results.

  19. In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish.

    PubMed

    Akins, John L; Morris, James A; Green, Stephanie J

    2014-10-01

    Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150

  20. In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish

    PubMed Central

    Akins, John L; Morris, James A; Green, Stephanie J

    2014-01-01

    Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150

  1. An in situ high voltage electron microscopy technique for the study of deformation and fracture: In multilayered materials

    SciTech Connect

    Wall, M.A.; Barbee, T.W. Jr.; Weihs, T.P.

    1995-04-14

    A novel, in situ, high voltage electron microscopy technique for the direct observation of the micromechanisms of tensile deformation and fracture in nanostructured materials is detailed. This technique is particularly well suited for the dynamic observations of deformation and fracture in multilayered materials. The success of this type of in situ technique is highly dependent upon unique specimen preparation procedures and sample design, the importance thereof will be discussed. The initial observations discussed here are expected to aid in the understanding of the mechanical behavior of this new class of atomically engineered materials.

  2. Selective evaluation of high density lipoprotein from mouse small intestine by an in situ perfusion technique[S

    PubMed Central

    Yamaguchi, Satoshi; Zhang, Bo; Tomonaga, Takeshi; Seino, Utako; Kanagawa, Akiko; Segawa, Masaru; Nagasaka, Hironori; Suzuki, Akira; Miida, Takashi; Yamada, Sohsuke; Sasaguri, Yasuyuki; Doi, Takefumi; Saku, Keijiro; Okazaki, Mitsuyo; Tochino, Yoshihiro; Hirano, Ken-ichi

    2014-01-01

    The small intestine (SI) is the second-greatest source of HDL in mice. However, the selective evaluation of SI-derived HDL (SI-HDL) has been difficult because even the origin of HDL obtained in vivo from the intestinal lymph duct of anesthetized rodents is doubtful. To shed light on this question, we have developed a novel in situ perfusion technique using surgically isolated mouse SI, with which the possible filtration of plasma HDL into the SI lymph duct can be prevented. With the developed method, we studied the characteristics of and mechanism for the production and regulation of SI-HDL. Nascent HDL particles were detected in SI lymph perfusates in WT mice, but not in ABCA1 KO mice. SI-HDL had a high protein content and was smaller than plasma HDL. SI-HDL was rich in TG and apo AIV compared with HDL in liver perfusates. SI-HDL was increased by high-fat diets and reduced in apo E KO mice. In conclusion, with our in situ perfusion model that enables the selective evaluation of SI-HDL, we demonstrated that ABCA1 plays an important role in intestinal HDL production, and SI-HDL is small, dense, rich in apo AIV, and regulated by nutritional and genetic factors. PMID:24569139

  3. In-Situ Magnetic Gauging Technique Used at LANL -- Method and Shock Information Obtained

    NASA Astrophysics Data System (ADS)

    Sheffield, Stephen A.

    1999-06-01

    Measuring techniques, including magnetic gauges, quartz gauges, manganin gauges, PVDF gauges, velocity interferometry (VISAR, Fabry-Perot, ORVIS, etc.), piezoelectric pins, shorting pins, flash gaps, etc., have been used over the years to measure shock properties and wave evolution in condensed phase materials. In general, each of these techniques has its own strengths and weaknesses. The use of a particular technique depends on the measured parameter and the sample material properties. This paper will concentrate on in-situ magnetic gauging which is particularly useful in high explosive shock initiation experiments. A short history of this technique will be given but the main discussion will concentrate on the multiple magnetic gauge technique developed at Los Alamos National Lab.(LANL). Vorthman and Wackerle (Vorthman, J.E., ``Facilities for the Study of Shock Induced Decomposition in High Explosive,'' in Shock Waves in Condensed Matter -- 1981, Eds. W. J. Nellis, L. Seaman, and R.A. Graham, AIP Conference Proceedings No. 78 (1982) p. 680.) started developing the technique in 1980, concentrating on particle velocity and ``impulse'' gauges so that Lagrange analysis could be used to map the entire reactive field. Over the years, changes to the gauge design, fabrication, and experimental focus have led to the present LANL capability. During the past two years measurements have tracked the reactive wave evolution resulting from a shock-to-detonation transition in several high explosive materials. The data from a single experiment provides: 1)particle velocity wave profiles from ten to twelve depths in the sample, 2) shock front tracking, 3) an unreacted Hugoniot point (in which both the shock velocity and particle velocity are measured), 4) a ``Pop-plot'' or distance-(time-)to-detonation point, and 5) a 3% measurement of the detonation velocity. Details of the experimental setup and information from several experiments will be discussed.

  4. Evaluation of Select Surface Processing Techniques for In Situ Application During the Additive Manufacturing Build Process

    NASA Astrophysics Data System (ADS)

    Book, Todd A.; Sangid, Michael D.

    2016-07-01

    Although additive manufacturing offers numerous performance advantages for different applications, it is not being used for critical applications due to uncertainties in structural integrity as a result of innate process variability and defects. To minimize uncertainty, the current approach relies on the concurrent utilization of process monitoring, post-processing, and non-destructive inspection in addition to an extensive material qualification process. This paper examines an alternative approach by evaluating the application of select surface process techniques, to include sliding severe plastic deformation (SPD) and fine particle shot peening, on direct metal laser sintering-produced AlSi10Mg materials. Each surface processing technique is compared to baseline as-built and post-processed samples as a proof of concept for surface enhancement. Initial results pairing sliding SPD with the manufacture's recommended thermal stress relief cycle demonstrated uniform recrystallization of the microstructure, resulting in a more homogeneous distribution of strain among the microstructure than as-built or post-processed conditions. This result demonstrates the potential for the in situ application of various surface processing techniques during the layerwise direct metal laser sintering build process.

  5. In Situ Thermal Ion Temperature Measurements in the E Region Ionosphere: Techniques, Results, and Limitations

    NASA Astrophysics Data System (ADS)

    Burchill, J. K.; Archer, W. E.; Clemmons, J. H.; Knudsen, D. J.; Nicolls, M. J.

    2011-12-01

    In situ measurements of thermal ion temperature are rare at E region altitudes, which are too low for satellites. Here we present ion temperature measurements from a Thermal Ion Imager (TII) that flew on NASA sounding rocket 36.234 (the "Joule-2" mission) into the nightside E region ionosphere on 19 January 2007 from Poker Flat, AK. The TII is an electrostatic ion energy/angle imager that provides 2D ion distributions at 8 ms resolution. Ion temperatures are derived at altitudes between 100 km and 190 km by modelling the detector total count rate versus ion bulk flow angle with respect to the plane of the imager's field of view. Modelling this count rate spin profile shows that the analysis technique is robust against a number of error sources, including variability in payload floating potential, ion upflow, and aperture widening due to reflections from electrode surfaces. A significant uncertainty is associated with the average mass of the ions, which is not measured independently. Using the International Reference Ionosphere model to estimate ion mass, we obtain an ion temperature of 1300 K at 125 km, increasing to more than 3000 K at 180 km. These temperatures are much larger than neutral temperatures obtained from an ionization gauge on the same rocket (Tn˜500 K at 125 km, ˜600 K at 180 km), and do not agree with incoherent scatter radar observations in the vicinity of the rocket. These anomalous ion temperatures are, however, consistent with results from an independent analysis of the shape of the ion distribution images from a similar instrument on a separate payload flown 10 minutes earlier [Archer, MSc Thesis, University of Calgary, 2009]. We conclude that the high ion temperature readings are an artifact related to the environment in the vicinity of the probe, and investigate mechanisms for the cause. We discuss the implications of this effect for future in situ attempts to measure ion temperature in the E region ionosphere.

  6. Novel, In-situ NAPL Modification Technique for Persistent Source Zone Control and Remediation

    NASA Astrophysics Data System (ADS)

    Mateas, D. J.; Tick, G. R.; Carroll, K. C.

    2014-12-01

    Non-aqueous phase liquids (NAPLs), such as fuels and solvents, are a major cause of groundwater and soil contamination. This environmental issue has led to concerted efforts to remediate subsurface systems impacted by NAPL pollution, but unfortunately, few of these remediation techniques have succeeded in lowering target contaminant levels below regulatory thresholds. To overcome these limitations, a novel, in-situ source remediation method was tested in the laboratory using equilibrium batch tests and two-dimensional flow cell experiments. The goal of this remediation method was to reduce the aqueous solubility, mass flux, and mass discharge of the target NAPL by the in-situ creation of a NAPL mixture source zone. Predetermined volumes of insoluble n-hexadecane or vegetable oil ("benign" NAPL) were injected into a trichloroethene or toluene ("toxic" NAPL) source zone through a simulated well within the flow cell to form a NAPL mixture. Initial NAPL-aqueous phase batch tests were conducted prior to the flow cell experiments to evaluate the effects of various NAPL mixture ratios on equilibrium aqueous-phase concentrations, and thus, to design optimal benign NAPL injection volumes for the flow cell experiments. Overall, this study indicated that the delivery of benign NAPL into the target, toxic NAPL source zone was effective in significantly reducing contaminant aqueous-phase concentration, mass flux, and mass discharge at intermediate scales. Variations in remediation performance did occur among the various predetermined injection volumes of benign NAPL and the target, toxic NAPL but were consistent to trends observed in batch tests. This novel remediation method may be feasible at larger scales, such as pilot field-scale studies, and may be a cost-effective solution to efficiently mitigate environmental pollution, attain regulatory compliance, and expedite site closure.

  7. Pilot demonstration for containment using in situ soil mixing techniques at a chemical disposal superfund site

    SciTech Connect

    Zarlinski, S.J.; Kingham, N.W.; Semenak, R.

    1997-12-31

    Kiber Environmental Services, Inc. (Kiber), under contract to McLaren-Hart Corporation and the site PRP group, performed technical oversight and on-site sampling and analyses at the confidential site located in Texas. The site consists of 15,000 cubic meters (20,000 cubic yards) of contaminated materials that were to be solidified on-site. The contaminants included heavy metals, PAHs, oil and grease, and volatile organics. Groundwater is less than 1 meter from the surface. Kiber was retained after several unsuccessful efforts to find on-site containment methods that effectively solidified the waste pits while achieving the performance goals. The PRP group then contracted with Kiber to perform the treatability and pilot oversight studies. The full-scale pilot demonstration was performed by Geo-Con. Pilot-scale treatment was performed to evaluate the effectiveness of in situ solidification treatment at achieving the site specific performance criteria, including an unconfined compressive strength of greater than 170 kPa (25 psi) and a permeability of less than 1x10{sup -6} cm/sec. Technical oversight and on-site sampling and analysis were provided to evaluate pilot-scale application of the selected technology and verify treatment effectiveness. The project was divided into several subtasks. First, laboratory treatability testing was conducted to verify that performance specifications were achievable using the proposed reagent formulations. Next, a pilot demonstration was performed by Geo-Con using a Manotowoc 4000 crane equipped with a 1.5-meter diameter auger to evaluate shallow soil mixing. The final task included a comparative study between the performance of test specimens collected using wet sampling techniques versus in situ post-treatment coring.

  8. Establishment of the genomic in situ hybridization (GISH) technique for analysis in interspecific hybrids of Passiflora.

    PubMed

    Melo, C A F; Silva, G S; Souza, M M

    2015-01-01

    The genomic in situ hybridization (GISH) technique was applied to Passiflora interspecific F1 HD13-133 hybrids (Passiflora sublanceolata x Passiflora foetida) and HD15-101 (Passiflora gardineri x Passiflora gibertii), and the backcrossed hybrids (BC1) HD18-106 and HD18-113 (Passiflora sublanceolata x HD13-133). GISH was performed using genomic probes prepared with the DNA from the paternal genitor, whereas the maternal DNA was used as blocking DNA and employed at various concentrations (20X, 40X, 60X, and 100X) in relation to the probe concentration. At the same time, GISH was applied with the use of simultaneous probes from both genomes, paternal and maternal, that were detected with avidin-FITC and anti-digoxigenin-rhodamine, respectively. Both methodologies allowed the distinguishing of the maternal and paternal genomes, thus confirming the hybrid nature of all the analyzed genotypes. Furthermore, the presence of recombinant chromosomes in BC1 hybrids revealed the occurrence of meiotic recombination in HD13 hybrids. This application of the GISH technique is an important step towards genomic analyses of Passiflora hybrids: it can broaden the phylogenetic and evolutionary studies of the genus and, at the same time, contribute to breeding programs. PMID:25867365

  9. Measurement of in-situ stress in salt and rock using NQR techniques

    SciTech Connect

    Schempp, E.; Hirschfeld, T.; Klainer, S.

    1980-12-01

    A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

  10. Identifying reaction intermediates and catalytic active sites through in situ characterization techniques

    SciTech Connect

    Foster, Andrew J.; Lobo, Raul F

    2010-01-01

    This tutorial review centers on recent advances and applications of experimental techniques that help characterize surface species and catalyst structures under in situ conditions. We start by reviewing recent applications of IR spectroscopy of working catalysis, emphasizing newer approaches such as Sum Frequency Generation and Polarization Modulation-infrared reflection absorption spectroscopy. This is followed by a section on solid-state NMR spectroscopy for the detection of surface species and reaction intermediates. These two techniques provide information mainly about the concentration and identity of the prevalent surface species. The following sections center on methods that provide structural and chemical information about the catalyst surface. The increasingly important role of high-pressure X-ray photoelectron spectroscopy in catalyst characterization is evident from the new and interesting information obtained on supported catalysts as presented in recent reports. X-Ray absorption spectroscopy (XANES and EXAFS) is used increasingly under reaction conditions to great advantage, although is inherently limited to systems where the bulk of the species in the sample are surface species. However, the ability of X-rays to penetrate the sample has been used cleverly by a number of groups to understand how changing reaction conditions change the structure and composition of surface atoms on supported catalyst.

  11. Comparison of In Situ Polymerization and Solution-Dispersion Techniques in the Preparation of Polyimide/Montmorillonite (MMT) Nanocomposites

    PubMed Central

    Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd. Sapuan; Hussein, Mohd. Zobir; Shameli, Kamyar

    2011-01-01

    In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3′,4,4′-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique. PMID:22016643

  12. Kinetics and characterization of conducting and insulating polymers by in situ and ex situ techniques

    SciTech Connect

    Fong, Y.K.

    1993-01-01

    The kinetics of polypyrrole, polyaniline, polystyrene and polyurethane syntheses were examined using in-situ techniques. The resulting polymers were analyzed by ex-situ analytical techniques. Comparison of results obtained by different techniques was made. Polypyrrole was synthesized by the chemical oxidative route. The polymerization using polymerization using potassium ferricyanide was monitored by Raman spectroscopy, potentiometry and microelectrode analysis. The kinetics were found to resemble exponential decay. The stoichiometry of the polymerization remained constant throughout the experimental period. The polymerization of aniline by ammonium peroxysulfate was monitored by Raman, potentiometry, calorimetry, quartz crystal microbalance (QCM), conductance measurements, viscometry and visible absorption spectroscopy. QCM and visible absorption spectroscopy were used to probe the nucleation stage. The results showed polymerization occurred following an induction period. The induction period of aniline-peroxysulfate system can be reduced by using mixed oxidizers. Cerium(IV) was used as co-oxidant with peroxysulfate. A significant decrease in the induction period was observed with 0.01% of cerium(IV). This effect can also be achieved by adding polyaniline to provide reaction sites for the monomers. The kinetics of styrene polymerization were monitored by Raman. The decrease in the 1630 cm[sup [minus]1] aliphatic C[double bond]C stretching was interpreted as percent styrene conversion. The 1600 cm[sup [minus]1] aromatic C[double bond]C stretching was used as a standard. UV absorption spectroscopy was used to quantify the amount of styrene in the polymerizing mixture. IR spectroscopy and Raman were used to monitor the reaction of modified diphenylmethane-4-4[prime]-diisocyanate (MDI) and polyether polyol (polyol). In the Raman experiment, the decrease in the 1060 cm[sup [minus]1] peak and the increase in the 1140 cm[sup [minus]1] peak were analyzed.

  13. Towards a more realistic picture of in situ biocide actions: combining physiological and microscopy techniques.

    PubMed

    Speranza, M; Wierzchos, J; De Los Rios, A; Perez-Ortega, S; Souza-Egipsy, V; Ascaso, C

    2012-11-15

    In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment. PMID:23063916

  14. Towards a more realistic picture of in situ biocide actions: combining physiological and microscopy techniques.

    PubMed

    Speranza, M; Wierzchos, J; De Los Rios, A; Perez-Ortega, S; Souza-Egipsy, V; Ascaso, C

    2012-11-15

    In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment.

  15. In-situ turbulence measurement technique using state-of-the-art kite/blimp platforms

    NASA Astrophysics Data System (ADS)

    Balsley, Ben B.; Jensen, Michael L.; Frehlich, Rod G.; Eaton, Frank D.; Bishop, Kenneth P.; Hugo, Ronald J.

    1999-08-01

    Results of a campaign to measure boundary layer/lower troposphere turbulence quantities over New Mexico's Tularosa basin are described in a companion paper. The present contribution outlines the technical developments that enabled these measurements. Basically, instrumented 'payloads' were carried aloft using either a relatively large aerodynamic blimp or a large parafoil kite. The choice between these platforms was dictated by wind velocity. The kite size was determined by the payload weight and the wind velocity. In addition to providing a brief history in CU involvement in kite/blimp atmospheric measurements, we will outline launching methods, tether winching techniques, and payload attachment schemes that were used during the WSMR campaign. Although very low wind conditions during the New Mexico test precluded the use of payloads up and down the kite tether under reasonable wind conditions. We also describe (1) the instrument package designed to measure in- situ temperature and velocity fluctuations, and (2) the 'basic payload' that measures standard atmospheric variables. System operation is illustrated via examples of the resulting data set.

  16. New techniques required to understand the by-stander effect in situ.

    NASA Astrophysics Data System (ADS)

    Britten, Richard

    2008-03-01

    The by-stander effect has been known for nearly a century under various names, of which the abscopal effect is probably the most well known. More recently the by-stander effect has received a lot of attention, and various models have been developed to assess the relative importance of the bystander effect in radiation treatment. It is clear that irradiated cells release factors that lead to alterations in the physiology of adjacent irradiated cells, both via inter-cellular junctions and through systemic factors. Most studies that have sought to identify the systemic factors and the cellular mechanisms that are responsible for the bystander effect have by necessity used in vitro systems. The purpose of this presentation is to alert the audience to the various techniques that are available to study the proteomic changes related to the bystander effect in situ. We shall pay attention to the use of MALDI-imaging to track spatial proteomic changes in tissue that have been exposed to microbeams.

  17. Development of an in situ derivatization technique for rapid analysis of levoglucosan and polar compounds in atmospheric organic aerosol

    NASA Astrophysics Data System (ADS)

    Sheesley, Rebecca J.; Mieritz, Mark; DeMinter, Jeff T.; Shelton, Brandon R.; Schauer, James J.

    2015-12-01

    A novel thermal desorption gas chromatography mass spectrometry (TD-GCMS) technique was developed for the analysis of levoglucosan and other polar compounds in atmospheric organic aerosol. The method employs an in situ derivatization to add tri-methylsilyl groups to alcohol functional groups on simple carbohydrates, like levoglucosan and sterols. The new method was then demonstrated on a set of 40 filter samples collected in Fresno, CA. The results from the in situ silylation TD-GCMS method were compared, using levoglucosan, with a solvent extraction, high-volume injection GCMS method resulting in an r2 = 0.91.

  18. Cyanea capillata Bell Kinematics Analysis through Corrected In Situ Imaging and Modeling Using Strategic Discretization Techniques

    PubMed Central

    Villanueva, Alex A.; Priya, Shashank

    2014-01-01

    Obtaining accurate kinematic data of animals is essential for many biological studies and bio-inspired engineering. Many animals, however, are either too large or too delicate to transport to controlled environments where accurate kinematic data can be easily obtained. Often, in situ recordings are the only means available but are often subject to multi-axis motion and relative magnification changes with time leading to large discrepancies in the animal kinematics. Techniques to compensate for these artifacts were applied to a large jellyfish, Cyanea capillata, freely swimming in ocean waters. The bell kinematics were captured by digitizing exumbrella profiles for two full swimming cycles. Magnification was accounted for by tracking a reference point on the ocean floor and by observing the C. capillata exumbrella arclength in order to have a constant scale through the swimming cycles. A linear fit of the top bell section was used to find the body angle with respect to the camera coordinate system. Bell margin trajectories over two swimming cycles confirmed the accuracy of the correction techniques. The corrected profiles were filtered and interpolated to provide a set of time-dependent points along the bell. Discrete models of the exumbrella were used to analyze the bell kinematics. Exumbrella discretization was conducted using three different methods. Fourier series were fitted to the discretized models and subsequently used to analyze the bell kinematics of the C. capillata. The analysis showed that the bell did not deform uniformly over time with different segments lagging behind each other. Looping of the bell trajectory between contraction and relaxation was also present through most of the exumbrella. The bell margin had the largest looping with an outer path during contraction and inner path during relaxation. The subumbrella volume was approximated based on the exumbrella kinematics and was found to increase during contraction. PMID:25541980

  19. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    NASA Astrophysics Data System (ADS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-03-01

    The Probing in situ with Neutrons and Gamma rays (PING) instrument uses a pulsed neutron generator and neutron and gamma-ray detectors to measure the surface and subsurface elemental composition of planetary bodies without the need for drilling.

  20. The development of sensors and techniques for in situ water quality monitoring

    NASA Technical Reports Server (NTRS)

    Liu, C. C.

    1976-01-01

    Enzyme electrodes and chloride ion electrodes were investigated for in situ monitoring of water quality. Preliminary results show that miniature chloride ion electrodes and a phenol sensor are most promising in determining trace contaminants in water.

  1. In Situ Analytical Strategy for Mars Combining X-Ray and Optical Techniques

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Martin, J. P.; Mason, L. W.; Williamson, D. L.

    2004-03-01

    The “MICA” instrument combines XRD, XRF, and optical analytical methods for in situ analysis of Martian rocks. Optical analysis is critical in rock identification since neither XRD mineralogy nor XRF chemistry can be guaranteed to define lithology.

  2. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

    DOE PAGES

    Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; Tomé, C. N.

    2015-05-14

    In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation andmore » streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.« less

  3. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

    SciTech Connect

    Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; Tomé, C. N.

    2015-05-14

    In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation and streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.

  4. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

    NASA Astrophysics Data System (ADS)

    Morrow, B. M.; Cerreta, E. K.; McCabe, R. J.; Tomé, C. N.

    2015-08-01

    In situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals. Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed. Typically, these processes are characterized postmortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In situ straining in a TEM presents several advantages over conventional postmortem characterization, most notably time resolution of deformation and streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In situ straining is used to study twin boundary motion in hcp magnesium. A twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries; this result suggests that Basinki's dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in situ straining with traditional postmortem characterization yields more detailed information about material behavior during deformation than either technique alone.

  5. Verification of a numerical simulation technique for natural convection

    SciTech Connect

    Gadgil, A.; Bauman, F.; Altmayer, E.; Kammerud, R.C.

    1983-03-01

    The present paper describes a verification of CONVEC2 for single-zone geometries by comparison with the results of two natural convection experiments performed in small-scale rectangular enclosures. These experiments were selected because of the high Rayleigh numbers obtained and the small heat loss through the insulated surfaces. Comparisons are presented for (1) heat transfer rates, (2) fluid temperature profiles, and (3) surface heat flux distributions.

  6. Investigation of Cleanliness Verification Techniques for Rocket Engine Hardware

    NASA Technical Reports Server (NTRS)

    Fritzemeier, Marilyn L.; Skowronski, Raymund P.

    1994-01-01

    Oxidizer propellant systems for liquid-fueled rocket engines must meet stringent cleanliness requirements for particulate and nonvolatile residue. These requirements were established to limit residual contaminants which could block small orifices or ignite in the oxidizer system during engine operation. Limiting organic residues in high pressure oxygen systems, such as in the Space Shuttle Main Engine (SSME), is particularly important. The current method of cleanliness verification for the SSME uses an organic solvent flush of the critical hardware surfaces. The solvent is filtered and analyzed for particulate matter followed by gravimetric determination of the nonvolatile residue (NVR) content of the filtered solvent. The organic solvents currently specified for use (1, 1, 1-trichloroethane and CFC-113) are ozone-depleting chemicals slated for elimination by December 1995. A test program is in progress to evaluate alternative methods for cleanliness verification that do not require the use of ozone-depleting chemicals and that minimize or eliminate the use of solvents regulated as hazardous air pollutants or smog precursors. Initial results from the laboratory test program to evaluate aqueous-based methods and organic solvent flush methods for NVR verification are provided and compared with results obtained using the current method. Evaluation of the alternative methods was conducted using a range of contaminants encountered in the manufacture of rocket engine hardware.

  7. Investigation of cleanliness verification techniques for rocket engine hardware

    NASA Technical Reports Server (NTRS)

    Fritzemeier, Marilyn L.; Skowronski, Raymund P.

    1995-01-01

    Oxidizer propellant systems for liquid-fueled rocket engines must meet stringent cleanliness requirements for particulate and nonvolatile residue. These requirements were established to limit residual contaminants which could block small orifices or ignite in the oxidizer system during engine operation. Limiting organic residues in high pressure oxygen systems is particularly important. The current method of cleanliness verification used by Rocketdyne requires an organic solvent flush of the critical hardware surfaces. The solvent is filtered and analyzed for particulate matter, followed by gravimetric determination of the nonvolatile residue (NVR) content of the filtered solvent. The organic solvents currently specified for use (1,1,1-trichloroethane and CFC-113) are ozone-depleting chemicals slated for elimination by December 1995. A test program is in progress to evaluate alternative methods for cleanliness verification that do not require the use of ozone-depleting chemicals and that minimize or eliminate the use of solvents regulated as hazardous air pollutants or smog precursors. Initial results from the laboratory test program to evaluate aqueous-based methods and organic solvent flush methods for NVR verification are provided and compared with results obtained using the current method. Evaluation of the alternative methods was conducted using a range of contaminants encountered in the manufacture of rocket engine hardware.

  8. A laser GC-IRMS technique for in situ stable isotope analyses of carbonates and phosphates

    NASA Astrophysics Data System (ADS)

    Sharp, Z. D.; Cerling, T. E.

    1996-08-01

    A technique is described whereby in situ carbon and oxygen isotope analyses of carbonates and organic phosphates can be made with the use of a CO 2 laser. The CO 2 gas generated by thermal decarbonation from the laser is entrained in a helium carrier gas, passes through a chromatographic column (GC), and is admitted directly into the isotope ratio mass spectrometer (IRMS). No vacuum systems, pumps, or cryogenic traps are used. All carbonates and biogenic phosphates can be analyzed, no special sample preparation is required and analyses can be made every 3 minutes. The use of a helium carrier gas allows for extremely small samples to be analyzed and the GC column effectively separates CO 2 from any other potential contaminating gases (e.g., SO 2 which is a particular problem in organic apatite). The average reproducibility of calcite, dolomite, magnesite, rhodochrosite, siderite, and smithsonite (ZnCO 3) is 0.29‰ for oxygen and 0.1‰ for carbon (1σ); the most "homogeneous" samples are reproducible to better than 0.1‰ for carbon and 0.2‰ for oxygen. The difference between the laser and conventional values for carbon isotope ratios [Δ 13C (laser-conv)] is 0.05 ± 0.30‰ for all carbonates (excluding siderite). The Δ 18O(laser-conv) value varies from carbonate to carbonate and may be related to the electronegativities of the cations, grain size (or crystallinity), formation of CO and O 2, and reaction with included organic matter. For calcite and rhodochrosite, the Δ 18O(laser-conv) value is 0.3 ± 0.4‰; for siderite, magnesite, and dolomite, the Δ 18O(laser-conv) value is 1.7 ± 0.3‰. The δ 13C values of tooth enamel are the same as those obtained by conventional acid digestion. The laser δ 18O values are equal to the δ 18O values of the phosphate, and approx. 7‰ lighter than the "carbonate" oxygen. The carbonate group in the apatite (equiv. 7.6% oxygen) exchanges with the (PO 4=)-bound oxygen to produce CO 2 with a δ 18O equal to the phosphate

  9. Following the Transient Reactions in Lithium-Sulfur Batteries Using In an In Situ Nuclear Magnetic Resonance Technique

    SciTech Connect

    Xiao, Jie; Hu, Jian Z.; Chen, Honghao; Vijayakumar, M.; Zheng, Jianming; Pan, Huilin; Walter, Eric D.; Hu, Mary Y.; Deng, Xuchu; Feng, Ju; Liaw, Bor Yann; Gu, Meng; Deng, Zhiqun; Lu, Dongping; Xu, Suochang; Wang, Chong M.; Liu, Jun

    2015-05-13

    Li-S batteries hold great potential for next-generation, large-format power source applications; yet, the fundamental understanding of the electrochemical reaction pathways remains lacking to enable their functionality as promised. Here, in situ NMR technique employing a specially designed cylindrical micro battery was used to monitor the chemical environments around Li+ ions during repetitive charge-discharge process and track the transient electrochemical and chemical reactions occurring in the whole Li-S system. The in situ NMR provides real time, quantitative information related to the temporal concentration variations of the polysulfides with various chain lengths, providing important clues for the reaction pathways during both discharge and charge processes. The in-situ technique also reveals that redox reactions may involve transient species that are difficult to detect in ex-situ NMR study. Intermediate species such as charged free radicals may play an important role in the formation of the polysulfide products. Additionally, in situ NMR measurement simultaneously reveals vital information on the 7Li chemical environments in the electrochemical and parasitic reactions on the lithium anode that promotes the understanding of the failure mechanism in the Li-S system. These new insights could help design effective strategies to accelerate the development of Li-S battery technology.

  10. First Results on Visualization and Verification of the STEREO Heliospheric Imager CME Catalogue with In Situ Data from the Heliophysics System Observatory

    NASA Astrophysics Data System (ADS)

    Rollett, T.; Moestl, C.; Boakes, P. D.; Isavnin, A.; Davies, J. A.; Byrne, J.; Barnes, D.; Good, S. W.; Perry, C. H.; Kubicka, M.; Harrison, R. A.; Kilpua, E.; Forsyth, R. J.; Bothmer, V.

    2015-12-01

    The space weather community has recently seen major advances in the prediction of the speed and arrival time of solar coronal mass ejections at Earth and other planets. Since the start of the STEREO mission in 2006, each of the heliospheric imagers (HIs) onboard the Ahead and Behind spacecraft has successfully tracked hundreds of CMEs. The advantage of HI is that CMEs can be followed for a significant part of the inner heliosphere, and the CME evolution in direction and speed is better constrained than by coronagraphs alone. By tracking and cataloguing each of those CMEs in the EU HELCATS project, we can apply geometrical modeling (FPF, HMF, SSEF) techniques on single-spacecraft HI observations to extract the expected planetary impacts of each CME. These arrivals are then verified or refuted by in situ solar wind plasma and magnetic field observations provided by the spacecraft forming the Heliophysics System Observatory (HSO), such as Wind, ACE, Venus Express, MESSENGER, and STEREO-A/B, for which various ICME catalogues are gathered and updated in the course of HELCATS.A first assessment on the relationship between CME HI and in situ observations is discussed, such as occurrence rates, speeds and arrival times and magnetic field strength. We also present visualizations of the HI CME catalogue and the corresponding in situ observations. The presented work has received funding from the European Union Seventh Framework Programme (FP7/ 2007-2013) under grant agreement No. 606692 [HELCATS].

  11. In situ bioremediation technique for sites underlain by silt and clay

    SciTech Connect

    Thacker, B.K.; Ford, C.G.

    1999-12-01

    An in situ trickling filter system, named Trickling Trench, is being used to treat biodegradable organic compounds at a site underlain by silt and clay. This method provides the containment advantages of pump-and-treat remediation with the low-cost benefits of in situ bioremediation. A design method is presented using a conventional trickling filter analytical model with kinetic coefficients for various organic compounds calculated from published data. Performance monitoring data obtained from the Trickling Trench bioreactor are compared to design predictions.

  12. Techniques for Assessing the Performance of In Situ Bioreduction and Immobilization of Metals and Radionuclides in Contaminated Subsurface Environments

    NASA Astrophysics Data System (ADS)

    Watson, D. B.; Jardine, P. M.

    2005-05-01

    monitoring of coupled hydrological, geochemical/geophysical, and microbial processes. In the following presentation we will (1) discuss contaminant fate and transport problems in humid regimes, (2) efforts to immobilize metals and radionuclides in situ via bioremediation, and (3) state-of -the-art techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides. These included (a) in situ solution and solid phase monitoring, (b) in situ and laboratory microbial community analysis, (c) noninvasive geophysical methods, and (d) solid phase speciation via high resolution spectroscopy.

  13. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    SciTech Connect

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    monitoring of coupled hydrological, geochemical/geophysical, and microbial processes. In the following manuscript we will (1) discuss contaminant fate and transport problems in humid regimes, (2) efforts to immobilize metals and radionuclides in situ via bioremediation, and (3) state-of-the-art techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides. These included (a) in situ solution and solid phase monitoring, (b) in situ and laboratory microbial community analysis, (c) noninvasive geophysical methods, and (d) solid phase speciation via high resolution spectroscopy.

  14. European methodology for testing the airborne sound insulation characteristics of noise barriers in situ: experimental verification and comparison with laboratory data

    PubMed

    Garai; Guidorzi

    2000-09-01

    In the frame of the 1994-1997 Standard, Measurement and Testing program, the European Commission funded a research project, named Adrienne, to define new test methods for measuring the intrinsic characteristics of road traffic noise reducing devices in situ. The research team produced innovative methods for testing the sound reflection/absorption and the airborne sound insulation characteristics of noise barriers. These methods are now under consideration at CEN (European Committee for Standardization), to become European standards. The present work reports a detailed verification of the test method for airborne sound insulation over a selection of 17 noise barriers, representative of the Italian and European production. The samples were tested both outdoors, using the new Adrienne method, and in laboratory, following the European standard EN 1793-2. In both cases the single number rating for airborne sound insulation recommended by the European standard was calculated. The new method proved to be easy to use and reliable for all kinds of barriers. It has been found sensitive to quality of mounting, presence of seals, and other details typical of outdoor installations. The comparison between field and laboratory results shows a good correlation, while existing differences can be explained with the different sound fields and mounting conditions between the outdoor and laboratory tests. It is concluded that the Adrienne method is adequate for its intended use. PMID:11008808

  15. Simultaneous in situ Optical Monitoring Techniques during Crystal Growth of ZnSe by Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Su, C.- H.; Feth, S.; Lehoczky, S. L.

    1998-01-01

    ZnSe crystals grown in sealed ampoules by the physical vapor transport method were monitored in situ using three techniques, simultaneously. A Michelson interferometer was set-up to observe the growth rate and surface morphological evolution. An interference pattern (interferogram) is formed by the interaction between the reflection of a HeNe laser (632.8 nm wavelength) off the crystal-vapor interface and a reference beam from the same laser. Preliminary results indicate that the rate of growth/thermal-etching can be calculated using analog data acquisition and simple fringe counting techniques. Gross surface features may also be observed using a digital frame grabber and fringe analysis software. The second in situ technique uses optical absorption to determine the partial pressures of the vapor species. The Se2 and Zn vapor species present in the sealed ampoule absorb light at characteristic wavelengths. The optical absorption is determined by monitoring the light intensity difference between the sample and reference beams. The Se2 Partial pressure profile along the length of the ampoule was estimated from the vibronic absorption peaks at 340.5, 350.8, 361.3 and 379.2 nm using the Beer's law constants established in the calibration runs of pure Se. Finally, because the high temperature crystal growth furnace contains windows, in situ visual observation of the growing crystal is also possible. The use of these techniques not only permits in situ investigation of high temperature vapor growth of semiconductors, but also offers the potential for real time feed back on the growing crystal and allows the possibility of actively controlling the growth process.

  16. Measurement techniques for the verification of excess weapons materials

    SciTech Connect

    Tape, J.W.; Eccleston, G.W.; Yates, M.A.

    1998-12-01

    The end of the superpower arms race has resulted in an unprecedented reduction in stockpiles of deployed nuclear weapons. Numerous proposals have been put forward and actions have been taken to ensure the irreversibility of nuclear arms reductions, including unilateral initiatives such as those made by President Clinton in September 1993 to place fissile materials no longer needed for a deterrent under international inspection, and bilateral and multilateral measures currently being negotiated. For the technologist, there is a unique opportunity to develop the technical means to monitor nuclear materials that have been declared excess to nuclear weapons programs, to provide confidence that reductions are taking place and that the released materials are not being used again for nuclear explosive programs. However, because of the sensitive nature of these materials, a fundamental conflict exists between the desire to know that the bulk materials or weapon components in fact represent evidence of warhead reductions, and treaty commitments and national laws that require the protection of weapons design information. This conflict presents a unique challenge to technologists. The flow of excess weapons materials, from deployed warheads through storage, disassembly, component storage, conversion to bulk forms, and disposition, will be described in general terms. Measurement approaches based on the detection of passive or induced radiation will be discussed along with the requirement to protect sensitive information from release to unauthorized parties. Possible uses of measurement methods to assist in the verification of arms reductions will be described. The concept of measuring attributes of items rather than quantitative mass-based inventory verification will be discussed along with associated information-barrier concepts required to protect sensitive information.

  17. High temperature in-situ observations of multi-segmented metal nanowires encapsulated within carbon nanotubes by in-situ filling technique

    PubMed Central

    2012-01-01

    Multi-segmented one-dimensional metal nanowires were encapsulated within carbon nanotubes (CNTs) through in-situ filling technique during plasma-enhanced chemical vapor deposition process. Transmission electron microscopy (TEM) and environmental TEM were employed to characterize the as-prepared sample at room temperature and high temperature. The selected area electron diffractions revealed that the Pd4Si nanowire and face-centered-cubic Co nanowire on top of the Pd nanowire were encapsulated within the bottom and tip parts of the multiwall CNT, respectively. Although the strain-induced deformation of graphite walls was observed, the solid-state phases of Pd4Si and Co-Pd remain even at above their expected melting temperatures and up to 1,550 ± 50°C. Finally, the encapsulated metals were melted and flowed out from the tip of the CNT after 2 h at the same temperature due to the increase of internal pressure of the CNT. PMID:22873841

  18. A comprehensive approach for the assessment of in-situ pavement density using GPR technique

    NASA Astrophysics Data System (ADS)

    Plati, Christina; Georgiou, Panos; Loizos, Andreas

    2013-04-01

    Proper construction of the asphalt pavement is a prerequisite to developing a long lasting roadway that does not require extensive future maintenance. This goal is achieved by verifying that design specifications are met through the use of quality assurance (QA) practices. The in-situ density is regarded as one of the most important controls used to ensure that a pavement being placed is of high quality because it is a good indicator of future performance. In-situ density is frequently assessed utilizing one or more of the following three methods: cores, nuclear density gauge measurements or non-nuclear density gauge measurements. Each of the above mentioned methods, however, have their distinct disadvantages. Cores, for example, are generally considered to be the most accurate means of measuring in-situ density, however, they are a time consuming and destructive test that introduces a defect into asphalt pavements. Because of the destructive nature associated with coring, contractors and agencies have alternatively used non-destructive nuclear and non-nuclear density gauges for quality control purposes. These instruments allow for a more rapid assessment of the in-situ density, allowing measurements to be taken even during the pavement's construction. The disadvantage of these gauges are that they provide density readings only at discrete locations of the asphalt pavement mat, while no consensus exists among pavement researchers on the proper correlation between the gauges and core density. In recent years, numerous alternative methods have been introduced for the assessment of in-situ density, both during asphalt pavement construction and afterwards. These methods include, amongst others, intelligent compaction, thermal imaging and ground penetrating radar (GPR). Among these methods, GPR has been defined as both a technically feasible and promising method for the nondestructive, rapid, and continuous evaluation of in-situ asphalt pavement density based on

  19. SU-D-BRF-02: In Situ Verification of Radiation Therapy Dose Distributions From High-Energy X-Rays Using PET Imaging

    SciTech Connect

    Zhang, Q; Kai, L; Wang, X; Hua, B; Chui, L; Wang, Q; Ma, C

    2014-06-01

    Purpose: To study the possibility of in situ verification of radiation therapy dose distributions using PET imaging based on the activity distribution of 11C and 15O produced via photonuclear reactions in patient irradiated by 45MV x-rays. Methods: The method is based on the photonuclear reactions in the most elemental composition {sup 12}C and {sup 16}O in body tissues irradiated by bremsstrahlung photons with energies up to 45 MeV, resulting primarily in {sup 11}C and {sup 15}O, which are positron-emitting nuclei. The induced positron activity distributions were obtained with a PET scanner in the same room of a LA45 accelerator (Top Grade Medical, Beijing, China). The experiments were performed with a brain phantom using realistic treatment plans. The phantom was scanned at 20min and 2-5min after irradiation for {sup 11}C and {sup 15}, respectively. The interval between the two scans was 20 minutes. The activity distributions of {sup 11}C and {sup 15}O within the irradiated volume can be separated from each other because the half-life is 20min and 2min for {sup 11}C and {sup 15}O, respectively. Three x-ray energies were used including 10MV, 25MV and 45MV. The radiation dose ranged from 1.0Gy to 10.0Gy per treatment. Results: It was confirmed that no activity was detected at 10 MV beam energy, which was far below the energy threshold for photonuclear reactions. At 25 MV x-ray activity distribution images were observed on PET, which needed much higher radiation dose in order to obtain good quality. For 45 MV photon beams, good quality activation images were obtained with 2-3Gy radiation dose, which is the typical daily dose for radiation therapy. Conclusion: The activity distribution of {sup 15}O and {sup 11}C could be used to derive the dose distribution of 45MV x-rays at the regular daily dose level. This method can potentially be used to verify in situ dose distributions of patients treated on the LA45 accelerator.

  20. Terracotta polychrome sculptures examined before and after their conservation work: contributions from non-invasive in situ analytical techniques.

    PubMed

    Colombo, C; Bevilacqua, F; Brambilla, L; Conti, C; Realini, M; Striova, J; Zerbi, G

    2011-08-01

    The potential of non-invasive in situ analytical techniques such as portable Raman, portable X-ray fluorescence, portable optical microscope and fibre optics reflectance spectroscopy has been shown studying painted layers of Renaissance terracotta polychrome sculptures belonging to the statuary of Santo Sepolcro Church in Milan. The results obtained allowed pointing out the contribution of these techniques to the compositional diagnostic, providing complete information, in some cases, better than micro-destructive techniques, on the kind of pigments used on the external painted layers. Moreover, a comparison with the results obtained before the last conservation work (2009) with micro-destructive techniques allowed ascertaining the removal of the external painted layers during the conservation operations.

  1. Quartz Crystal Microbalance Technique for in Situ Analysis of Supersaturation in Cooling Crystallization.

    PubMed

    Liu, Li-Shang; Kim, Jong-Min; Kim, Woo-Sik

    2016-06-01

    A quartz crystal microbalance (QCM) is used as a novel in situ strategy for analyzing the supersaturation profile during cooling crystallization. The main concept is based on preventing any solid mass loading on the QCM sensor by modifying the sensor surface. As a result, the QCM responses only depend on the solution concentration changes during the crystallization. The proposed strategy is confirmed on the basis of an analysis of sulfamerazine (SMZ) crystallization. When the QCM sensor is modified using 11-amino-1-undecanethiol (AUT), crystal formation on the sensor is completely prevented due to a repulsive interaction between the -NH2 functional groups of the AUT and SMZ crystals. Thus, the QCM responses reflect only the property changes in the solution phase during the crystallization. The supersaturation in the solution is then estimated on the basis of the difference in the frequency shifts between the SMZ solution and a blank solution. The accuracy of the in situ QCM analysis of supersaturation is confirmed using an off-line gravimetric method. PMID:27161190

  2. Studies of ferroelectric heterostructure thin films, interfaces, and device-related processes via in situ analytical techniques.

    SciTech Connect

    Aggarwal, S.; Auciello, O.; Dhote, A. M.; Gao, Y.; Gruen, D. M.; Im, J.; Irene, E. A.; Krauss, A. R.; Muller, A. H.; Ramesh, R.

    1999-06-29

    The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMS) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and device processes relevant to device development. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed. Direct imaging of ferroelectric domains under applied electric fields can provide valuable information to understand domain dynamics in ferroelectric films. We discuss results of piezoresponse scanning force microscopy (SFM) imaging for nanoscale studies of polarization reversal and retention loss in Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT)-based capacitors. Another powerful technique suitable for in situ, real-time characterization of film growth processes and ferroelectric film-based device operation is based on synchrotrons X-ray scattering, which is currently being implemented at Argonne National Laboratory.

  3. Computer-assisted techniques for the verification of the Chebyshev property of Abelian integrals

    NASA Astrophysics Data System (ADS)

    Figueras, Jordi-Lluís; Tucker, Warwick; Villadelprat, Jordi

    We develop techniques for the verification of the Chebyshev property of Abelian integrals. These techniques are a combination of theoretical results, analysis of asymptotic behavior of Wronskians, and rigorous computations based on interval arithmetic. We apply this approach to tackle a conjecture formulated by Dumortier and Roussarie in [F. Dumortier, R. Roussarie, Birth of canard cycles, Discrete Contin. Dyn. Syst. 2 (2009) 723-781], which we are able to prove for q≤2.

  4. Following the transient reactions in lithium-sulfur batteries using an in situ nuclear magnetic resonance technique.

    PubMed

    Xiao, Jie; Hu, Jian Zhi; Chen, Honghao; Vijayakumar, M; Zheng, Jianming; Pan, Huilin; Walter, Eric D; Hu, Mary; Deng, Xuchu; Feng, Ju; Liaw, Bor Yann; Gu, Meng; Deng, Zhiqun Daniel; Lu, Dongping; Xu, Suochang; Wang, Chongmin; Liu, Jun

    2015-05-13

    A fundamental understanding of electrochemical reaction pathways is critical to improving the performance of Li-S batteries, but few techniques can be used to directly identify and quantify the reaction species during disharge/charge cycling processes in real time. Here, an in situ (7)Li NMR technique employing a specially designed cylindrical microbattery was used to probe the transient electrochemical and chemical reactions occurring during the cycling of a Li-S system. In situ NMR provides real time, semiquantitative information related to the temporal evolution of lithium polysulfide allotropes during both discharge/charge processes. This technique uniquely reveals that the polysulfide redox reactions involve charged free radicals as intermediate species that are difficult to detect in ex situ NMR studies. Additionally, it also uncovers vital information about the (7)Li chemical environments during the electrochemical and parasitic reactions on the Li metal anode. These new molecular-level insights about transient species and the associated anode failure mechanism are crucial to delineating effective strategies to accelerate the development of Li-S battery technologies. PMID:25785550

  5. Following the transient reactions in lithium-sulfur batteries using an in situ nuclear magnetic resonance technique.

    PubMed

    Xiao, Jie; Hu, Jian Zhi; Chen, Honghao; Vijayakumar, M; Zheng, Jianming; Pan, Huilin; Walter, Eric D; Hu, Mary; Deng, Xuchu; Feng, Ju; Liaw, Bor Yann; Gu, Meng; Deng, Zhiqun Daniel; Lu, Dongping; Xu, Suochang; Wang, Chongmin; Liu, Jun

    2015-05-13

    A fundamental understanding of electrochemical reaction pathways is critical to improving the performance of Li-S batteries, but few techniques can be used to directly identify and quantify the reaction species during disharge/charge cycling processes in real time. Here, an in situ (7)Li NMR technique employing a specially designed cylindrical microbattery was used to probe the transient electrochemical and chemical reactions occurring during the cycling of a Li-S system. In situ NMR provides real time, semiquantitative information related to the temporal evolution of lithium polysulfide allotropes during both discharge/charge processes. This technique uniquely reveals that the polysulfide redox reactions involve charged free radicals as intermediate species that are difficult to detect in ex situ NMR studies. Additionally, it also uncovers vital information about the (7)Li chemical environments during the electrochemical and parasitic reactions on the Li metal anode. These new molecular-level insights about transient species and the associated anode failure mechanism are crucial to delineating effective strategies to accelerate the development of Li-S battery technologies.

  6. A review of in situ propellant production techniques for solar system exploration

    NASA Technical Reports Server (NTRS)

    Hoffman, S. J.

    1983-01-01

    Representative studies done in the area of extraterrestrial chemical production as it applies to solar system exploration are presented. A description of the In Situ Propellant Production (ISPP) system is presented. Various propellant combinations and direct applications along with the previously mentioned benefits and liens are discussed. A series of mission scenarios is presented which is studied in the greatest detail. A general description of the method(s) of analysis used to study each mission is provided. Each section will be closed by an assessment of the performance advantage, if any, that can be provided by ISPP. A final section briefly summarizes those missions which, as a result of the studies completed thus far, should see a sizable benefit from the use of ISPP.

  7. In situ electrical characterization of palladium-based single electron transistors made by electromigration technique

    SciTech Connect

    Arzubiaga, L.; Llopis, R.; Golmar, F.; Casanova, F.; Hueso, L. E.

    2014-11-15

    We report the fabrication of single electron transistors (SETs) by feedback-controlled electromigration of palladium and palladium-nickel alloy nanowires. We have optimized a gradual electromigration process for obtaining devices consisting of three terminals (source, drain and gate electrodes), which are capacitively coupled to a metallic cluster of nanometric dimensions. This metal nanocluster forms into the inter-electrode channel during the electromigration process and constitutes the active element of each device, acting as a quantum dot that rules the electron flow between source and drain electrodes. The charge transport of the as-fabricated devices shows Coulomb blockade characteristics and the source to drain conductance can be modulated by electrostatic gating. We have thus achieved the fabrication and in situ measurement of palladium-based SETs inside a liquid helium cryostat chamber.

  8. Assembly of amorphous clusters under floating monolayers: a comparison of in situ and ex situ techniques.

    PubMed

    Uysal, Ahmet; Stripe, Benjamin; Lin, Binhua; Meron, Mati; Dutta, Pulak

    2013-11-26

    We report synchrotron X-ray scattering studies of biomimetic crystallization of hydroxyapatite (the primary constituent of bone), using monolayers of fatty acid molecules floating on simulated body fluid (SBF) as well as aqueous solutions of calcium phosphate. A ∼10 Å thick film of amorphous material is observed to form immediately at the molecular monolayer, consistent with the proposed formation of "Posner clusters". This layer becomes denser but not significantly thicker as the subphase concentration and the temperature approach physiological conditions. The amorphous films do not crystallize within 24 h, in contrast to prior reports of more rapid crystallization using electron microscopy on ex situ samples. However, crystallization occurs almost immediately after our films are transferred onto solid substrates. These results illustrate the importance of in situ measurements for model biomineralization experiments. PMID:24164244

  9. Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments.

    PubMed

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    In tissue engineering, non-invasive imaging of biomaterial scaffolds and tissues in living systems is essential to longitudinal animal studies for assessments without interrupting the repair process. Conventional X-ray imaging is inadequate for use in soft tissue engineering due to the limited absorption difference between the soft tissue and biomaterial scaffolds. X-ray phase-based imaging techniques that derive contrast from refraction or phase effects rather than absorption can provide the necessary contrast to see low-density biomaterial scaffolds and tissues in large living systems. This paper explores and compares three synchrotron phase-based X-ray imaging techniques-computed tomography (CT)-diffraction enhanced imaging (DEI), -analyzer based imaging (ABI), and -phase contrast imaging (PCI)-for visualization and characterization of low-density biomaterial scaffolds and tissues in situ for non-invasive soft tissue engineering assessments. Intact pig joints implanted with polycaprolactone scaffolds were used as the model to assess and compare the imaging techniques in terms of different qualitative and quantitative criteria. For long-term in vivo live animal imaging, different strategies for reducing the imaging radiation dose and scan time-reduced number of CT projections, region of interest, and low resolution imaging-were examined with the presented phase-based imaging techniques. The results demonstrated promising capabilities of the phase-based techniques for visualization of biomaterial scaffolds and soft tissues in situ. The low-dose imaging strategies were illustrated effective for reducing the radiation dose to levels appropriate for live animal imaging. The comparison among the imaging techniques suggested that CT-DEI has the highest efficiency in retaining image contrast at considerably low radiation doses.

  10. Verification of Experimental Techniques for Flow Surface Determination

    NASA Technical Reports Server (NTRS)

    Lissenden, Cliff J.; Lerch, Bradley A.; Ellis, John R.; Robinson, David N.

    1996-01-01

    The concept of a yield surface is central to the mathematical formulation of a classical plasticity theory. However, at elevated temperatures, material response can be highly time-dependent, which is beyond the realm of classical plasticity. Viscoplastic theories have been developed for just such conditions. In viscoplastic theories, the flow law is given in terms of inelastic strain rate rather than the inelastic strain increment used in time-independent plasticity. Thus, surfaces of constant inelastic strain rate or flow surfaces are to viscoplastic theories what yield surfaces are to classical plasticity. The purpose of the work reported herein was to validate experimental procedures for determining flow surfaces at elevated temperatures. Since experimental procedures for determining yield surfaces in axial/torsional stress space are well established, they were employed -- except inelastic strain rates were used rather than total inelastic strains. In yield-surface determinations, the use of small-offset definitions of yield minimizes the change of material state and allows multiple loadings to be applied to a single specimen. The key to the experiments reported here was precise, decoupled measurement of axial and torsional strain. With this requirement in mind, the performance of a high-temperature multi-axial extensometer was evaluated by comparing its results with strain gauge results at room temperature. Both the extensometer and strain gauges gave nearly identical yield surfaces (both initial and subsequent) for type 316 stainless steel (316 SS). The extensometer also successfully determined flow surfaces for 316 SS at 650 C. Furthermore, to judge the applicability of the technique for composite materials, yield surfaces were determined for unidirectional tungsten/Kanthal (Fe-Cr-Al).

  11. CT imaging techniques for two-phase and three-phase in-situ saturation measurements

    SciTech Connect

    Sharma, B.C.; Brigham, W.E.; Castanier, L.M.

    1997-06-01

    The aim of this research is to use the SUPRI 3D steam injection laboratory model to establish a reliable method for 3-phase in-situ saturation measurements, and thereafter investigate the mechanism of steamflood at residual oil saturation. Demiral et al. designed and constructed a three dimensional laboratory model that can be used to measure temperature, pressure and heat loss data. The model is also designed so that its construction materials are not a limiting factor for CT scanning. We have used this model for our study. In this study, we saturated the model with mineral oil, and carried out waterflood until residual oil saturation. Steamflood was then carried out. A leak appeared at the bottom of the model. Despite this problem, the saturation results, obtained by using 2-phase and 3-phase saturation equations and obtained from the Cat scanner, were compared with the saturations obtained from material balance. The errors thus obtained were compared with those obtained by an error analysis carried out on the saturation equations. This report gives details of the experimental procedures, the data acquisition and data processing computer programs, and the analysis of a steamflood experiment carried out at residual oil saturation.

  12. Studies on In-situ Chelation/Supercritical Fluid Extraction of Lanthanides and Actinides Using a Radiotracer Technique

    SciTech Connect

    Lin, Yuehe; Wu, Hong; Smart, Neil G.; Wai, Chien M.

    2001-06-01

    Radioisotope tracer techniques were used to study the process of in-situ chelation/supercritical fluid extraction(SFE) of La3+ and Lu3+ from solid matrix using mixed ligand hexafluoroacetylacetone (HFA) and tributylphosphate (TBP) as chelating agents. A lab-built SFE extactor was used in this study and the extractor design was optimized based on the experimental results. Quantitative recovery of La and Lu was achieved when the extrator design was optimized. Extraction of uranium from real world samples was also investigated to demonstrate the capability of this chelation/SFE technology for environmental remediation applications. A novel on-line back extraction technique for the recovery of metal ions and regeneration of ligands is also reported.

  13. In-situ technique for checking the calibration of platinum resistance thermometers

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Dillon-Townes, Lawrence A.

    1987-01-01

    The applicability of the self-heating technique for checking the calibration of platinum resistance thermometers located inside wind tunnels was investigated. This technique is based on a steady state measurement of resistance increase versus joule heating. This method was found to be undesirable, mainly because of the fluctuations of flow variables during any wind tunnel testing.

  14. In situ estimation of soil hydraulic functions using a multistep soil-water extraction technique

    NASA Astrophysics Data System (ADS)

    Inoue, M.; Å Imunek, J.; Hopmans, J. W.; Clausnitzer, V.

    1998-05-01

    Estimation of the retention and unsaturated hydraulic conductivity functions is essential to effectively provide input for water flow and transport simulation and prediction. A parameter optimization procedure is shown as a promising tool to estimate inversely these hydraulic function parameters from transient soil matric potential and cumulative soil solution extraction measurements. Sensitivity analyses from synthetic data generated from forward numerical model simulations showed that optimum tensiometer locations will depend on soil type. Experiments were carried out in both a laboratory column (Columbia sandy loam) and in the field (Yolo silt loam). In both cases a series of vacuum extraction pressures was applied to a ceramic soil solution sampler, and cumulative soil solution extraction volume and matric potentials at various positions near the extraction device were monitored as the soil solution was extracted. In the laboratory a zero-flux boundary condition was maintained at the bottom of the column, whereas matric potential measurements were used in the field to define the lower boundary. In both the field and laboratory experiments, flow at the upper boundary was zero. Cumulative extraction volume and matric potential data were included in the objective function to be minimized to estimate the hydraulic function parameters. We determined that the optimized solution was sensitive to the contact between the ceramic ring and the surrounding soil. By also optimizing the hydraulic resistance of the ceramic ring of the extraction device, optimization improved the fit between measured and optimized flow variables. Comparison of the optimized with the independently measured hydraulic functions indicated that the in situ estimation using a multistep extraction procedure can provide accurate soil hydraulic data.

  15. An injection technique for in-situ remediation of abandoned underground coal mines

    SciTech Connect

    Canty, G.A.; Everett, J.W.

    1998-12-31

    Remediation of underground mines can prove to be a difficult task, given the physical constraints associated with introducing amendments to a subterranean environment. An acid mine abatement project involving in-situ chemical treatment method was conducted by the University of Oklahoma. The treatment method involved the injection of an alkaline coal combustion by-product (CCB) slurry into a flooded mine void (pH 4.4) to create a buffered zone. Injection of the CCB slurry was possible through the use of equipment developed by the petroleum industry for grouting recovery wells. This technology was selected because the CCB slurry could be injected under significant pressure and at a high rate. With higher pressure and rates of injection, a large quantity of slurry can be introduced into the mine within a limited amount of time. Theoretically, the high pressure and rate would improve dispersal of the slurry within the void. In addition, the high pressure is advantageous in fracturing or breaking-down obstructions to injection. During the injection process, a total of 418 tons of CCB was introduced within 15 hours. The mine did not refuse any of the material, and it is likely that a much larger mass could have been added. One injection well was drilled into a pillar of coal. Normally this would pose a problem when introducing a slurry; however, the coal pillar was easily fractured during the injection process. Currently, the pH of the mine discharge is above 6.5 and the alkalinity is approximately 100 mg/L as CACO{sub 3}.

  16. In situ NMR and electrochemical quartz crystal microbalance techniques reveal the structure of the electrical double layer in supercapacitors.

    PubMed

    Griffin, John M; Forse, Alexander C; Tsai, Wan-Yu; Taberna, Pierre-Louis; Simon, Patrice; Grey, Clare P

    2015-08-01

    Supercapacitors store charge through the electrosorption of ions on microporous electrodes. Despite major efforts to understand this phenomenon, a molecular-level picture of the electrical double layer in working devices is still lacking as few techniques can selectively observe the ionic species at the electrode/electrolyte interface. Here, we use in situ NMR to directly quantify the populations of anionic and cationic species within a working microporous carbon supercapacitor electrode. Our results show that charge storage mechanisms are different for positively and negatively polarized electrodes for the electrolyte tetraethylphosphonium tetrafluoroborate in acetonitrile; for positive polarization charging proceeds by exchange of the cations for anions, whereas for negative polarization, cation adsorption dominates. In situ electrochemical quartz crystal microbalance measurements support the NMR results and indicate that adsorbed ions are only partially solvated. These results provide new molecular-level insight, with the methodology offering exciting possibilities for the study of pore/ion size, desolvation and other effects on charge storage in supercapacitors.

  17. Development of in situ and ex situ seed baiting techniques to detect mycorrhizal fungi from terrestrial orchid habitats.

    PubMed

    Brundrett, Mark C; Scade, Ailsa; Batty, Andrew L; Dixon, Kingsley W; Sivasithamparam, Krishnapillai

    2003-10-01

    An innovative ex situ fungal baiting method using soil collected from field sites which allows the simultaneous detection of mycorrhizal fungi for multiple terrestrial orchids is presented. This method demonstrated that coarse organic matter (> 2 mm) in the litter and topsoil was the most important reservoir of inoculum of these fungi. A new in situ seed baiting method using multi-chambered packets to simultaneously assess germination for different orchid species within soil is also introduced. These in situ and ex situ methods are compared using seed of orchids in the genera Monadenia, Microtis, Caladenia, Pterostylis and Diuris, using urban Banksia woodland sites with high or low weed cover. Both these seed baiting methods detected compatible fungi for these orchids, but common orchids germinated more frequently than those which were uncommon at the field sites. Germination rates were not significantly affected by weed cover even though adult orchids were rare in areas with high weed cover. The two new seed baiting methods vary in efficiency and applicability depending on the situation where they are used. However, the ex situ method allowed the time-course of germination to be observed, resulting in the production of more protocorms and facilitation of the isolation of mycorrhizal fungi. These techniques provide valuable new tools for detection of compatible mycorrhizal fungi to assist orchid research and conservation.

  18. Recent trends in non-invasive in situ techniques to monitor bacterial colonies in solid (model) food

    PubMed Central

    Lobete, María M.; Fernandez, Estefania Noriega; Van Impe, Jan F. M.

    2015-01-01

    Planktonic cells typically found in liquid systems, are routinely used for building predictive models or assessing the efficacy of food preserving technologies. However, freely suspended cells often show different susceptibility to environmental hurdles than colony cells in solid matrices. Limited oxygen, water and nutrient availability, metabolite accumulation and physical constraints due to cell immobilization in the matrix, are main factors affecting cell growth. Moreover, intra- and inter-colony interactions, as a consequence of the initial microbial load in solid systems, may affect microbial physiology. Predictive food microbiology approaches are moving toward a more realistic resemblance to food products, performing studies in structured solid systems instead of liquids. Since structured systems promote microbial cells to become immobilized and grow as colonies, it is essential to study the colony behavior, not only for food safety assurance systems, but also for understanding cell physiology and optimizing food production processes in solid matrices. Traditionally, microbial dynamics in solid systems have been assessed with a macroscopic approach by applying invasive analytical techniques; for instance, viable plate counting, which yield information about overall population. In the last years, this approach is being substituted by more mechanistically inspired ones at mesoscopic (colony) and microscopic (cell) levels. Therefore, non-invasive and in situ monitoring is mandatory for a deeper insight into bacterial colony dynamics. Several methodologies that enable high-throughput data collection have been developed, such as microscopy-based techniques coupled with image analysis and OD-based measurements in microplate readers. This research paper provides an overview of non-invasive in situ techniques to monitor bacterial colonies in solid (model) food and emphasizes their advantages and inconveniences in terms of accuracy, performance and output information

  19. Neutron, fluorescence, and optical imaging: An in situ combination of complementary techniques

    SciTech Connect

    Wagner, D.; Egelhaaf, S. U.; Hermes, H. E.; Börgardts, M.; Müller, T. J. J.; Grünzweig, C.; Lehmann, E.

    2015-09-15

    An apparatus which enables the simultaneous combination of three complementary imaging techniques, optical imaging, fluorescence imaging, and neutron radiography, is presented. While each individual technique can provide information on certain aspects of the sample and their time evolution, a combination of the three techniques in one setup provides a more complete and consistent data set. The setup can be used in transmission and reflection modes and thus with optically transparent as well as opaque samples. Its capabilities are illustrated with two examples. A polymer hydrogel represents a transparent sample and the diffusion of fluorescent particles into and through this polymer matrix is followed. In reflection mode, the absorption of solvent by a nile red-functionalized mesoporous silica powder and the corresponding change in fluorescent signal are studied.

  20. Observation of localized heating phenomena during microwave heating of mixed powders using in situ x-ray diffraction technique

    NASA Astrophysics Data System (ADS)

    Sabelström, N.; Hayashi, M.; Watanabe, T.; Nagata, K.

    2014-10-01

    In materials processing research using microwave heating, there have been several observations of various phenomena occurring known as microwave effects. One significant example of such a phenomenon is increased reaction kinetics. It is believed that there is a possibility that this might be caused by localized heating, were some reactants would attain a higher than apparent temperature. To examine whether such thermal gradients are indeed possible, mixed powders of two microwave non-absorbers, alumina and magnesia, were mixed with graphite, a known absorber, and heated in a microwave furnace. During microwave irradiation, the local temperatures of the respective sample constituents were measured using an in situ x-ray diffraction technique. In the case of the alumina and graphite sample, a temperature difference of around 100 °C could be observed.

  1. Chemical composition and the nutritive value of pistachio epicarp (in situ degradation and in vitro gas production techniques)

    PubMed Central

    Bakhshizadeh, Somayeh; Taghizadeh, Akbar; Janmohammadi, Hossein; Alijani, Sadegh

    2014-01-01

    The nutritive value of pistachio epicarp (PE) was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30%) and low in neutral detergent fiber (26.20%). Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr for PE was 122.47 mL g-1DM. As a whole, adding polyethylene glycol (PEG) to PE increased (p < 0.05) gas production volumes, organic matter digestibility and the metabolizable energy that illustrated inhibitory effect of phenolics on rumen microbial fermentation and the positive influence of PEG on digestion PE. The results showed that PE possessed potentials to being used as feed supplements. PMID:25568691

  2. Observation of localized heating phenomena during microwave heating of mixed powders using in situ x-ray diffraction technique

    SciTech Connect

    Sabelström, N. Hayashi, M.; Watanabe, T.; Nagata, K.

    2014-10-28

    In materials processing research using microwave heating, there have been several observations of various phenomena occurring known as microwave effects. One significant example of such a phenomenon is increased reaction kinetics. It is believed that there is a possibility that this might be caused by localized heating, were some reactants would attain a higher than apparent temperature. To examine whether such thermal gradients are indeed possible, mixed powders of two microwave non-absorbers, alumina and magnesia, were mixed with graphite, a known absorber, and heated in a microwave furnace. During microwave irradiation, the local temperatures of the respective sample constituents were measured using an in situ x-ray diffraction technique. In the case of the alumina and graphite sample, a temperature difference of around 100 °C could be observed.

  3. A direct in situ fingerprinting method for acid rock drainage using voltammetric techniques with a single renewable gold microelectrode.

    PubMed

    Nuzzio, Donald B; Zettler, Erik R; Aguilera, Angeles; Amaral-Zettler, Linda A

    2011-04-15

    Electrochemistry allows for rapid identification of multiple metals and other chemical complexes common in acid rock drainage (ARD) systems. Voltammetric scans using a single gold microelectrode of water samples from geochemically distinct areas of the Río Tinto (RT) in southwestern Spain were clearly recognizable in the field and in samples stored at room temperature for over 6 months. Major voltammetric peaks of iron(III) and copper(II) were identified on a single constantly renewable gold microelectrode. Confirmation of these peaks was performed by spiking with standard metal solutions in the laboratory. This voltammetric technique is a rapid, direct and inexpensive in situ method for identification of water sources and their chemical characteristics, as well as an economical way to monitor environmental changes and remediation efforts.

  4. Swept frequency acoustic interferometry technique for chemical weapons verification and monitoring

    SciTech Connect

    Sinha, D.N.; Anthony, B.W.; Lizon, D.C.

    1995-03-01

    Nondestructive evaluation (NDE) techniques are important for rapid on-site verification and monitoring of chemical munitions, such as artillery shells and bulk containers. Present NDE techniques provide only limited characterizations of such munitions. This paper describes the development of a novel noninvasive technique, swept-frequency acoustic interferometry (SFAI), that significantly enhances the capability of munitions characterizations. The SFAI technique allows very accurate and simultaneous determination of sound velocity and attenuation of chemical agents over a large frequency range inside artillery shells, in addition to determining agent density. The frequency-dependent sound velocity and attenuation can, in principle, provide molecular relaxation properties of the chemical agent. The same instrument also enables a direct fill-level measurement in bulk containers. Industrial and other applications of this general-purpose technique are also discussed.

  5. Variation of surface water spectral response as a function of in situ sampling technique

    NASA Technical Reports Server (NTRS)

    Davis, Bruce A.; Hodgson, Michael E.

    1988-01-01

    Tests were carried out to determine the spectral variation contributed by a particular sampling technique. A portable radiometer was used to measure the surface water spectral response. Variation due to the reflectance of objects near the radiometer (i.e., the boat side) during data acquisition was studied. Consideration was also given to the variation due to the temporal nature of the phenomena (i.e., wave activity).

  6. ECR plasma cleaning: an in-situ processing technique for RF cavities

    SciTech Connect

    Wu, G.; Moeller, W-D.; Antoine, C.; Jiang, H.; Pechenezhskiy, I.; Cooley, L.; Khabiboulline, T.; Terechkine, Y.; Edwards, H.; Koeth, T.; Romanenko, A.; /Cornell U., Phys. Dept. /Jefferson Lab

    2008-01-01

    A condition for Electron Cyclotron Resonance (ECR) can be established inside a fully assembled RF cavity without the need for removing high-power couplers. As such, plasma generated by this process can be used as a final cleaning step, or as an alternative cleaning step in place of other techniques. Tests showed filtered dry air plasma can successfully remove sulfur particles on niobium surface while the surface oxygen content remains intact.

  7. Characterization of Cathode Materials for Rechargeable Lithium Batteries using Synchrotron Based In Situ X-ray Techniques

    SciTech Connect

    Yang, Xiao-Qing

    2007-05-23

    not be representative for the full picture of the structural changes during charge (discharge). In other words, the important information might be missed for those charge (discharge) states which were not selected for ex situ XRD studies. Secondly, the structure of the sample may have changed after removed from the cell. Finally, it is impossible to use the ex situ XRD to study the dynamic effects during high rate charge-discharge, which is crucial for the application of lithium-ion batteries for electric vehicle. A few in situ studies have been done using conventional x-ray tube sources. All of the in situ XRD studies using conventional x-ray tube sources have been done in the reflection mode in cells with beryllium windows. Because of the weak signals, data collection takes a long time, often several hundred hours for a single charge-discharge cycle. This long time data collection is not suitable for dynamic studies at all. Furthermore, in the reflection mode, the x-ray beam probes mainly the surface layer of the cathode materials. Iri collaboration with LG Chemical Ltd., BNL group designed and constructed the cells for in situ studies. LG Chemical provided several blended samples and pouch cells to BNL for preliminary in situ study. The LG Chemical provided help on integrate the blended cathode into these cells. The BNL team carried out in situ XAS and XRD studies on the samples and pouch cells provided by LG Chemical under normal charge-discharge conditions at elevated temperature.

  8. Improving carbon cycle models using inverse modelling techniques with in-situ measurements and satellite observations

    NASA Astrophysics Data System (ADS)

    Delahaies, Sylvain; Roulstone, Ian; Nichols, Nancy

    2014-05-01

    Improving our understanding of the carbon cycle is an important component of modelling climate and the Earth system, and a variety of inverse modelling techniques have been used to combine process models with different types of observational data. Model data fusion, or inverse modelling, is the process of best combining our under- standing of the dynamics of a system, observations and our prior knowledge of the state of the system. We consider a simple model for the carbon budget allocation for terrestrial ecosystems, the Data Assimilation-Linked Ecosystem model (DALEC). DALEC is a box model simulating a large range of processes occurring at different time scales from days to millennia. Eddy covariance measurements of net ecosystem exchange of CO2 have been used intensively for over a decade to confront DALEC with real data to estimate model parameters and quantify uncertainty of the model predictions. The REgional FLux Estimation eXperiment (REFLEX), compared the strengths and weaknesses of various inverse modelling strategies (MCMC, ENKF) to estimate parameters and initial stocks for DALEC; most results agreed on the fact that parameters and initial stocks directly related to fast processes were best estimated with narrow confidence intervals, whereas those related to slow processes were poorly estimated with very large uncertainties. While other studies have tried to overcome this difficulty by adding complementary data streams or by considering longer observation windows no systematic analysis has been carried out so far to explain the large differences among results of REFLEX. One of the merits of DALEC is its simplicity that facilitates close mathematical scrutiny. Using variational techniques we quantify the ill-posedness of the inverse problem and we discuss various regularisation techniques. Using the tangent linear model we study the information content of multiple data sources and show how these multiple data sources help constraining initial carbon

  9. A chromism-based assay (CHROBA) technique for in situ detection of protein kinase activity.

    PubMed

    Tomizaki, Kin-ya; Jie, Xu; Mihara, Hisakazu

    2005-03-15

    A unique chromism-based assay technique (CHROBA) using photochromic spiropyran-containing peptides has been firstly established for detection of protein kinase A-catalyzed phosphorylation. The alternative method has advantages that avoid isolation and/or immobilization of kinase substrates to remove excess reagents including nonreactive isotope-labeled ATP or fluorescently-labeled anti-phosphoamino acid antibodies from the reaction mixture. Such a novel protocol based on thermocoloration of the spiropyran moiety in the peptide can offer not only an efficient screening method of potent kinase substrates but also a versatile analytical tool for monitoring other post-translational modification activities. PMID:15745830

  10. Probabilistic risk assessment techniques help in identifying optimal equipment design for in-situ vitrification

    SciTech Connect

    Lucero, V.; Meale, B.M.; Purser, F.E.

    1990-01-01

    The analysis discussed in this paper was performed as part of the buried waste remediation efforts at the Idaho National Engineering Laboratory (INEL). The specific type of remediation discussed herein involves a thermal treatment process for converting contaminated soil and waste into a stable, chemically-inert form. Models of the proposed process were developed using probabilistic risk assessment (PRA) fault tree and event tree modeling techniques. The models were used to determine the appropriateness of the conceptual design by identifying potential hazards of system operations. Additional models were developed to represent the reliability aspects of the system components. By performing various sensitivities with the models, optimal design modifications are being identified to substantiate an integrated, cost-effective design representing minimal risk to the environment and/or public with maximum component reliability. 4 figs.

  11. A novel rocket-based in-situ collection technique for mesospheric and stratospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    Reid, W.; Achtert, P.; Ivchenko, N.; Magnusson, P.; Kuremyr, T.; Shepenkov, V.; Tibert, G.

    2012-11-01

    A technique for collecting aerosol particles between altitudes of 85 and 17 km is described. Collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Each collection sample is exposed over a 50 m to 5 km height range with a total of 45 separate ranges. Post-flight electron microscopy gives size-resolved information on particle number, shape and elemental composition. Each collection probe is equipped with a suite of sensors to capture the probe's status during the fall. Parachute recovery systems along with GPS-based localization ensure that each probe can be located and recovered for post-flight analysis.

  12. Use of Sensitive and Specific Biomolecular and Mass Spectrometric Techniques to Monitor the Performance of In-Situ Hydrocarbon Biodegradation

    NASA Astrophysics Data System (ADS)

    Beller, H. R.; Kane, S. R.; Legler, T. C.

    2008-12-01

    Monitored natural attenuation (MNA) can be a cost-effective and viable approach for remediation of hydrocarbon-contaminated groundwater. However, regulatory acceptance of the approach is often contingent on monitoring that can convincingly demonstrate the role of microbial degradation. Recent advances in anaerobic hydrocarbon biochemistry, analytical chemistry, and molecular biology have fostered the development of powerful techniques that can be applied to MNA of BTEX (benzene, toluene, ethylbenzene, and xylenes). Here, I discuss two independent methods that have been developed to monitor in situ, anaerobic biodegradation of toluene and xylenes. A method has been developed for rapid, sensitive, and highly selective detection of distinctive indicators of anaerobic alkylbenzene metabolism. The target metabolites, benzylsuccinic acid and methylbenzylsuccinic acid isomers, have no known sources other than anaerobic toluene or xylene degradation; thus, their mere presence in groundwater provides definitive evidence of in situ metabolism. The method, which involves small sample size (<1 mL) and no extraction/concentration steps, relies on isotope dilution liquid chromatography/tandem mass spectrometry (LC/MS/MS) with selected reaction monitoring. Detection limits for benzylsuccinates were determined to be ca. 0.3 μg/L and accuracy and precision were favorable in a groundwater matrix. A monitoring method based on quantitative Polymerase Chain Reaction (qPCR) analysis has been developed to specifically quantify populations of anaerobic methylbenzene-degrading bacteria in aquifer sediment. The method targets a catabolic gene (bssA) associated with the first step of anaerobic toluene and xylene degradation. The method has proven to be sensitive (detection limit ca. 5 gene copies) and has a linear range of > 7 orders of magnitude. Application of these two methods in field studies will be discussed in the context of the methods' strengths and limitations. Field data will

  13. In situ mineral identification - Raman technique in future robotic explorations on planetary surfaces

    SciTech Connect

    Wang, A.; Jolliff, B.L.; Haskin, L.A.

    1995-12-31

    Rover and lander missions are being continually planned for the characterization of planetary surface materials. With a series of simulated Raman measurements of lunar soils, rock chips and Martian analogues, we have demonstrated that mineral identification for the main phases in these planetary materials can be unambiguously achieved. We also obtained significant information on composition and structural features of important phases, such as the Mg/(Mg+Fe) ration in olivines, the dominant structural forms of pyroxenes, and the characteristics of hydrous components and cations in carbonates and sulfates, that are very important for Martian geology. Recent developments of Raman spectroscopic instrumentation make it possible to build a small, sensitive, and robust Raman system for rover and lander missions. Compared to other spectroscopic techniques (VIS-NIR, mid-IR and Moessbauer spectroscopy) that have been used or proposed for planetary application, Raman spectroscopy has many advantages, such as sharp, non-overlapping peaks in mineral spectra, no need for spectral deconvolution in order to identify the phases, and operation in visible spectral region. A rover Raman system could work nicely as a mineral indicator in future missions to Mars and Moon.

  14. Study of Formation and Production of Carbon Nanohorns Using Continuous In-Situ Characterization Techniques

    SciTech Connect

    Cheng, Mengdawn; Lee, Doh-Won; Zhao, Bin; Hu, Hui; Styers-Barnett, David J; Puretzky, Alexander A; DePaoli, David W; Geohegan, David B; Ford, Emory; Angelini, Peter

    2007-01-01

    The formation of carbon nanohorns by laser ablation was investigated using a scanning differential mobility analyzer combined with an ultrafine condensation particle counter. The measurement technique provided time-resolved size distributions for the carbon nanoparticles every minute during the course of the production run. The instrument performance was reasonably stable most of the time; however, during laser ablation, shockwave oscillations leading to significant transient flow and pressure variations were shown to disrupt the DMAs ability to measure accurate distributions. On the basis of the general trend observed in the data taken during the laser-ablation experiments, we found that the geometric mean diameter of the produced population shifted to larger particle sizes with increases in pulse width. For a given laser peak power and repetition rate, carbon nanoparticles of mobility diameter close to 100 nm were produced in a large abundance using longer laser pulse lengths (e.g., 10 ms) as compared to the shorter pulse lengths (e.g., 1 ms). A quantitative assessment of the particle size dispersion (using statistics like the geometric standard deviation) in relation to the laser pulse width could not be done with certainty as the shockwave disturbances produced by the laser-ablation process caused significant disruption to SMPS measurements. When laser ablation was not in operation, it was found that carbon nanoparticles with mobility diameters centred at about 20 nm could be produced by thermally desorbing the previously deposited carbon nanoparticles from the reactor wall at temperatures greater than 1300 K.

  15. In-Situ Measurement of Internal Temperature Distribution of Sintered Materials Using Ultrasonic Technique

    NASA Astrophysics Data System (ADS)

    Ihara, I.; Tomomatsu, T.

    2011-03-01

    It is often required to measure internal temperature distribution of a heated material because it is closely related to the materials properties and behavior. In this work, an effective ultrasonic method has been applied to the monitoring of internal temperature distributions of an alumina being heated. The principle of the method is based on the temperature dependence of the velocity of ultrasound propagating through a heated material. In the method, a combined technique of ultrasonic pulse-echo measurements and a finite difference calculation is employed to determine the one-dimensional temperature distribution in a heated material. Shear wave is used for the ultrasonic measurements to improve the accuracy in determining temperature. To verify the feasibility of the method, pulse-echo measurements with a shear wave transducer have been performed for an alumina rod of 14 mm diameter and 25 mm length whose single-end is being heated. The internal temperature distribution and its variation of the alumina are then measured during the heating. The temperature distributions determined by the ultrasonic method almost agree with those obtained by an infrared method. Thus, it is demonstrated that the ultrasonic method has the potential for in-process monitoring of the transient temperature variation of ceramics being processed at high temperatures.

  16. Ambient in-situ immersion freezing measurements - findings from the ZAMBIS 2014 field campaign for three ice nucleation techniques

    NASA Astrophysics Data System (ADS)

    Kohn, Monika; Atkinson, James D.; Lohmann, Ulrike; Kanji, Zamin A.

    2015-04-01

    To estimate the influence of clouds on the Earth's radiation budget, it is crucial to understand cloud formation processes in the atmosphere. A key process, which significantly affects cloud microphysical properties and the initiation of precipitation thus contributing to the hydrological cycle, is the prevailing type of ice nucleation mechanism. In mixed-phase clouds immersion freezing is the dominant ice crystal forming mechanism, whereby ice nucleating particles (INP) first act as cloud condensation nuclei (CCN) and are activated to cloud droplets followed by freezing upon supercooling. There are a number of experimental methods and techniques to investigate the ice nucleating ability in the immersion mode, however most techniques are offline for field sampling or only suitable for laboratory measurements. In-situ atmospheric studies are needed to understand the ice formation processes of 'real world' particles. Laboratory experiments simulate conditions of atmospheric processes like ageing or coating but are still idealized. Our method is able to measure ambient in-situ immersion freezing on single immersed aerosol particles. The instrumental setup consists of the recently developed portable immersion mode cooling chamber (PIMCA) as a vertical extension to the portable ice nucleation chamber (PINC, [1]), where the frozen fraction of activated aerosol particles are detected by the ice optical depolarization detector (IODE, [2]). Two additional immersion freezing techniques based on a droplet freezing array [3,4] are used to sample ambient aerosol particles either in a suspension (fraction larger ~0.6 μm) or on PM10-filters to compare different ice nucleation techniques. Here, we present ambient in-situ measurements at an urban forest site in Zurich, Switzerland held during the Zurich ambient immersion freezing study (ZAMBIS) in spring 2014. We investigated the ice nucleating ability of natural atmospheric aerosol with the PIMCA/PINC immersion freezing setup as

  17. The microwave cavity perturbation technique for contact-free and in situ electrical conductivity measurements in catalysis and materials science.

    PubMed

    Eichelbaum, Maik; Stösser, Reinhard; Karpov, Andrey; Dobner, Cornelia-Katharina; Rosowski, Frank; Trunschke, Annette; Schlögl, Robert

    2012-01-21

    We have developed a noncontact method to probe the electrical conductivity and complex permittivity of single and polycrystalline samples in a flow-through reactor in the temperature range of 20-500 °C and in various gas atmospheres. The method is based on the microwave cavity perturbation technique and allows the simultaneous measurement of microwave conductivity, permittivity and of the catalytic performance of heterogeneous catalysts without any need for contacting the sample with electrodes. The sensitivity of the method towards changes in bulk properties was proven by the investigation of characteristic first-order phase transitions of the ionic conductor rubidium nitrate in the temperature range between 20 and 320 °C, and by studying the temperature dependence of the complex permittivity and conductivity of a niobium(V)-doped vanadium-phosphorous-oxide catalyst for the selective oxidation of n-butane to maleic anhydride. Simultaneously, the catalytic performance was probed by on line GC analysis of evolving product gases making the technique a real in situ method enabling the noninvasive investigation of electronic structure-function relationships.

  18. The application of an in situ karyotyping technique for mesenchymal stromal cells: a validation and comparison study with classical G-banding.

    PubMed

    Hwang, Sang Mee; See, Cha-Ja; Choi, Jungeun; Kim, Seon Young; Choi, Qute; Kim, Jung Ah; Kwon, Jiseok; Park, Si Nae; Im, Kyongok; Oh, Il-Hoan; Lee, Dong Soon

    2013-12-20

    The cytogenetic analysis of mesenchymal stromal cells (MSCs) is essential for verifying the safety and stability of MSCs. An in situ technique, which uses cells grown on coverslips for karyotyping and minimizes cell manipulation, is the standard protocol for the chromosome analysis of amniotic fluids. Therefore, we applied the in situ karyotyping technique in MSCs and compared the quality of metaphases and karyotyping results with classical G-banding and chromosomal abnormalities with fluorescence in situ hybridization (FISH). Human adipose- and umbilical cord-derived MSC cell lines (American Type Culture Collection PCS-500-011, PCS-500-010) were used for evaluation. The quality of metaphases was assessed by analyzing the chromosome numbers in each metaphase, the overlaps of chromosomes and the mean length of chromosome 1. FISH was performed in the interphase nuclei of MSCs for 6q, 7q and 17q abnormalities and for the enumeration of chromosomes via oligo-FISH in adipose-derived MSCs. The number of chromosomes in each metaphase was more variable in classical G-banding. The overlap of chromosomes and the mean length of chromosome 1 as observed via in situ karyotyping were comparable to those of classical G-banding (P=0.218 and 0.674, respectively). Classical G-banding and in situ karyotyping by two personnel showed normal karyotypes for both cell lines in five passages. No numerical or structural chromosomal abnormalities were found by the interphase-FISH. In situ karyotyping showed equivalent karyotype results, and the quality of the metaphases was not inferior to classical G-banding. Thus, in situ karyotyping with minimized cell manipulation and the use of less cells would be useful for karyotyping MSCs.

  19. New in situ solid-state NMR techniques for probing the evolution of crystallization processes: pre-nucleation, nucleation and growth.

    PubMed

    Hughes, Colan E; Williams, P Andrew; Keast, Victoria L; Charalampopoulos, Vasileios G; Edwards-Gau, Gregory R; Harris, Kenneth D M

    2015-01-01

    The application of in situ techniques for investigating crystallization processes promises to yield significant new insights into fundamental aspects of crystallization science. With this motivation, we recently developed a new in situ solid-state NMR technique that exploits the ability of NMR to selectively detect the solid phase in heterogeneous solid-liquid systems (of the type that exist during crystallization from solution), with the liquid phase "invisible" to the measurement. As a consequence, the technique allows the first solid particles produced during crystallization to be observed and identified, and allows the evolution of different solid phases (e.g., polymorphs) present during the crystallization process to be monitored as a function of time. This in situ solid-state NMR strategy has been demonstrated to be a powerful approach for establishing the sequence of solid phases produced during crystallization and for the discovery of new polymorphs. The most recent advance of the in situ NMR methodology has been the development of a strategy (named "CLASSIC NMR") that allows both solid-state NMR and liquid-state NMR spectra to be measured (essentially simultaneously) during the crystallization process, yielding information on the complementary changes that occur in both the solid and liquid phases as a function of time. In this article, we present new results that highlight the application of our in situ NMR techniques to successfully unravel different aspects of crystallization processes, focusing on: (i) the application of a CLASSIC NMR approach to monitor competitive inclusion processes in solid urea inclusion compounds, (ii) exploiting liquid-state NMR to gain insights into co-crystal formation between benzoic acid and pentafluorobenzoic acid, and (iii) applications of in situ solid-state NMR for the discovery of new solid forms of trimethylphosphine oxide and L-phenylalanine. Finally, the article discusses a number of important fundamental issues

  20. The Impact of Chemical Abrasion on Trace Element Analysis of Zircon by In Situ Micro-Analytical Techniques

    NASA Astrophysics Data System (ADS)

    Romanoski, A.; Coint, N.; Cottle, J. M.; Hetherington, C. J.; Barnes, C. G.

    2011-12-01

    Introduction of the chemical abrasion technique has significantly increased the precision and accuracy of ID-TIMS U-Pb dating of zircon. The chemical abrasion technique, coupled with thermal annealing, removes inclusions and metamict domains from zircon reducing the impact of Pb-loss leading to more concordant analyses.In this study, zircon from the Red Bluff Granitic Suite (TX) (ID-TIMS age 1120 ± 35 Ma) has been thermally annealed and chemically abraded prior to SHRIMP-RG and LA-MC-ICP-MS analysis.Chemically abraded zircon gives a date of 1109 ± 22 Ma with an average of 3% discordancy. This compares with dates of 1137 ± 48 Ma with an average of 39% discordancy for non-abraded zircon from the same sample. The dates overlap within uncertainty, but the age from chemically abraded zircon has a lower population uncertainty. Other petrographic and analytical observations of the chemically abraded zircon include brighter CL intensity, lower REE abundances, more consistent (smaller scatter) negative Eu/Eu* anomalies, less scatter in the chondrite-normalized LREE values, and a slightly less-steep chondrite normalized HREE slope. The data show that thermal annealing and chemical abrasion of zircon prior to analysis by in situ ion-beam or laser ablation techniques may result in better accuracy and greater concordance in U-Pb analysis of zircon. However, while improving the quality of some components of the trace element dataset (e.g. Eu anomalies) the process may prejudice the interpretation of zircon trace element data (e.g. HREECN slopes).

  1. Verification Techniques for Parameter Selection and Bayesian Model Calibration Presented for an HIV Model

    NASA Astrophysics Data System (ADS)

    Wentworth, Mami Tonoe

    Uncertainty quantification plays an important role when making predictive estimates of model responses. In this context, uncertainty quantification is defined as quantifying and reducing uncertainties, and the objective is to quantify uncertainties in parameter, model and measurements, and propagate the uncertainties through the model, so that one can make a predictive estimate with quantified uncertainties. Two of the aspects of uncertainty quantification that must be performed prior to propagating uncertainties are model calibration and parameter selection. There are several efficient techniques for these processes; however, the accuracy of these methods are often not verified. This is the motivation for our work, and in this dissertation, we present and illustrate verification frameworks for model calibration and parameter selection in the context of biological and physical models. First, HIV models, developed and improved by [2, 3, 8], describe the viral infection dynamics of an HIV disease. These are also used to make predictive estimates of viral loads and T-cell counts and to construct an optimal control for drug therapy. Estimating input parameters is an essential step prior to uncertainty quantification. However, not all the parameters are identifiable, implying that they cannot be uniquely determined by the observations. These unidentifiable parameters can be partially removed by performing parameter selection, a process in which parameters that have minimal impacts on the model response are determined. We provide verification techniques for Bayesian model calibration and parameter selection for an HIV model. As an example of a physical model, we employ a heat model with experimental measurements presented in [10]. A steady-state heat model represents a prototypical behavior for heat conduction and diffusion process involved in a thermal-hydraulic model, which is a part of nuclear reactor models. We employ this simple heat model to illustrate verification

  2. Deciphering the thermal behavior of lithium rich cathode material by in situ X-ray diffraction technique

    NASA Astrophysics Data System (ADS)

    Muhammad, Shoaib; Lee, Sangwoo; Kim, Hyunchul; Yoon, Jeongbae; Jang, Donghyuk; Yoon, Jaegu; Park, Jin-Hwan; Yoon, Won-Sub

    2015-07-01

    Thermal stability is one of the critical requirements for commercial operation of high energy lithium-ion batteries. In this study, we use in situ X-ray diffraction technique to elucidate the thermal degradation mechanism of 0.5Li2MnO3-0.5LiNi0.33Co0.33Mn0.33O2 lithium rich cathode material in the absence and presence of electrolyte to simulate the real life battery conditions and compare its thermal behavior with the commercial LiNi0.33Co0.33Mn0.33O2 cathode material. We show that the thermal induced phase transformations in delithiated lithium rich cathode material are much more intense compared to similar single phase layered cathode material in the presence of electrolyte. The structural changes in both cathode materials with the temperature rise follow different trends in the absence and presence of electrolyte between 25 and 600 °C. Phase transitions are comparatively simple in the absence of electrolyte, the fully charged lithium rich cathode material demonstrates better thermal stability by maintaining its phase till 379 °C, and afterwards spinel structure is formed. In the presence of electrolyte, however, the spinel structure appears at 207 °C, subsequently it transforms to rock salt type cubic phase at 425 °C with additional metallic, metal fluoride, and metal carbonate phases.

  3. Development of Ground-Based Auroral Photometry Techniques Using In-Situ Electron Precipitation Measurements from the GREECE Mission

    NASA Astrophysics Data System (ADS)

    Grubbs, G. A., II; Samara, M.; Michell, R.; Hampton, D.

    2014-12-01

    The Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment (GREECE) mission successfully launched from Poker Flat, Alaska on 03 March 2014 at 11:09:50 UT and reached an apogee of approximately 335 km during a luminous auroral event. Multiple ground-based electron-multiplying charge-coupled device (EMCCD) imagers were positioned at Venetie, Alaska and aimed along magnetic zenith in order to observe the brightness of different auroral emission lines (427.8, 557.7, and 844.6 nm with a 47 degree field of view) at the magnetic footpoint of the payload, near apogee. Emission line brightness data are presented at the footpoint of the rocket flight and correlated with electron characteristics taken by the Acute Precipitating Electron Spectrometer (APES) on-board instrument. Ratios of different auroral emission lines are also compared to previously published methods and models. This research aims to describe the auroral emissions produced from a known precipitating electron distribution, such that we can more accurately use ground-based imaging and photometry to infer the characteristics of the precipitating electrons. These techniques can then be applied over larger scales and longer times, when only multi-spectral imaging data are available with no corresponding in situ data.

  4. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    SciTech Connect

    Sarma, Abhisakh; Sanyal, Milan K.

    2014-09-15

    In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 10{sup 7}. This value remain almost constant over a frequency range from 1Hz to 10{sup 6} Hz even at 80 K temperature.

  5. X-ray diffraction techniques for in-situ measurements of the dynamic flow stress of shock compressed Ta

    NASA Astrophysics Data System (ADS)

    Wehrenberg, Christopher; Barton, Nathan; Comley, Andrew; McGonegle, David; Maddox, Brian; McNaney, James; Park, Hye-Sook; Plechaty, Chris; Prisbrey, Shon; Remington, Bruce; Rudd, Rob

    2015-06-01

    A range of experimental techniques using in-situ x-ray diffraction have been developed to study the dynamic flow stress and underlying deformation of shock compressed samples. Experiments performed at the Omega and Omega EP facilities can generate both a high pressure drive, ranging from 0.3 Mbar up to and beyond the Hugoniot melt line, while simultaneous providing a short, bright x-ray source. Single crystal samples were studied either by Laue diffraction, using a broadband x-ray source created by an imploding CH capsule, or by Bragg diffraction, using a short pulse driven metal foil backlighter. The strength of polycrystalline samples can be determined using a pinhole camera setup and a quasi-monochromatic source. For highly-textured polycrystalline samples, additional strength information can be inferred from the azimuthal position of the texture spots on the Debye ring. Through measurements of the 1D-to-3D relaxation time or changes in the observed texture, information about the deformation mechanics of shock loading can be inferred. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  6. Development and application of denuder sampling techniques with in situ derivatization for the determination of hydrogenbromide in volcanic plumes

    NASA Astrophysics Data System (ADS)

    Gutmann, Alexandra; Rüdiger, Julian; Hoffmann, Thorsten

    2016-04-01

    The composition of gases in volcanic plumes shifts with subsurface processes inside volcanoes. For monitoring volcanic activity by studying volcanic plumes it is essential to understand the chemical reactions inside the volcanic plume (Bobrowski and Platt, 2013). Measurements of BrO/SO2-ratio already enable insights into magmatic processes (Bobrowski and Giuffrida, 2012). Both, BrO and SO2, are measurable by Remote Sensing Techniques at a safe distance. Models suggest not a direct emission of BrO but formation due to photochemical and multiphase reactions in the gas and particle phase. These model presume HBr as first emitted species (Gerlach, 2004). So HBr is an important connecting link between easily measurable BrO/SO2-ratios and conclusions on a volcanic system. It is of high importance to know if there is a variation in the amount of HBr transformed into BrO and to gain knowledge on the factor of its dependence. Apart from depletion of surrounded ozone also decreasing or depletion of emitted HBr or even HCl could be responsible for the shift (Bobrowski and Giuffrida, 2012). Knowledge about complex processes in volcanic plumes will simplify interpretation and predictions. In this study, first applications of coated gas diffusion denuder (similar to Huang and Hoffmann, 2008) to derivatize gaseous HBr were successful. Due to the lack of adequate remote sensing techniques an in situ method was developed and will be presented in detail. The epoxide of oleic acid was determined as a suitable derivatization agent. The reaction with HBr gives 10-bromo-9-hydroxyoctadecanoic acid. Other hydrogenhalogens give corresponding products. Derivatized analytes were removed from denuder by solvent elution and subsequent analysed with gas chromatography-mass spectrometry. A limit of quantification below 1 ng was achieved. The method was applied on volcanic gas plumes at Mt. Etna in Italy in July and August 2015. The results showed HBr in higher ppt-range. These first proof

  7. In-Situ Characterization of Tissue Blood Flow, Blood Content, and Water State Using New Techniques in Magnetic Resonance Imaging.

    NASA Astrophysics Data System (ADS)

    Conturo, Thomas Edward

    Tissue blood flow, blood content, and water state have been characterized in-situ with new nuclear magnetic resonance imaging techniques. The sensitivities of standard techniques to the physiologic tissue parameters spin density (N_{rm r}) and relaxation times (T_1 and T_2 ) are mathematically defined. A new driven inversion method is developed so that tissue T_1 and T_2 changes produce cooperative intensity changes, yielding high contrast, high signal to noise, and sensitivity to a wider range of tissue parameters. The actual tissue parameters were imaged by automated collection of multiple-echo data having multiple T _1 dependence. Data are simultaneously fit by three-parameters to a closed-form expression, producing lower inter-parameter correlation and parameter noise than in separate T_1 or T_2 methods or pre-averaged methods. Accurate parameters are obtained at different field strengths. Parametric images of pathology demonstrate high sensitivity to tissue heterogeneity, and water content is determined in many tissues. Erythrocytes were paramagnetically labeled to study blood content and relaxation mechanisms. Liver and spleen relaxation were enhanced following 10% exchange of animal blood volumes. Rapid water exchange between intracellular and extracellular compartments was validated. Erythrocytes occupied 12.5% of renal cortex volume, and blood content was uniform in the liver, spleen and kidney. The magnitude and direction of flow velocity was then imaged. To eliminate directional artifacts, a bipolar gradient technique sensitized to flow in different directions was developed. Phase angle was reconstructed instead of intensity since the former has a 2pi -fold higher dynamic range. Images of flow through curves demonstrated secondary flow with a centrifugally-biased laminar profile and stationary velocity peaks along the curvature. Portal vein flow velocities were diminished or reversed in cirrhosis. Image artifacts have been characterized and removed. The

  8. Seasonal variation in methane oxidation in a landfill cover soil as determined by an in situ stable isotope technique

    NASA Astrophysics Data System (ADS)

    Chanton, Jeffrey; Liptay, Karen

    2000-03-01

    Seasonal variations in the oxidation of methane during its transport across the soil cap of a landfill in Leon County, Florida, were determined in situ with a stable isotopic technique. The approach contrasted the δ13C values of emitted and anoxic zone CH4 and utilized measurements of the isotopic fractionation factor α, which varied inversely with temperature from 1.025 to 1.049. Anoxic zone CH4 did not vary seasonally and had a δ13C average value of -55.18 ± 0.15‰. Methane emitted from the landfill soil surface and captured in chambers ranged in δ13C from -54‰ in winter, when emission rates were high, to -40‰ in summer, when emission rates were lower. The antipathetic variation between the δ13C of emitted CH4 and the rate of CH4 emission is consistent with control of the emission rate by bacterial oxidation. Our interpretation of the isotope data indicates that methane oxidation consumed from 3 to 5% of the total flux in winter to a maximum of 43 ± 10% in summer. There was variation in the extent of methane oxidation in soil types, with mulch/topsoil averaging 55 ± 14% and clay averaging 33 ± 13% in summer. The seasonally integrated value for methane oxidation for areas of the landfill covered with mulch/topsoil was 26 ± 4% of the flux toward the soil surface, while for clay soil it was only 14 ± 2%. The overall annual average, which includes both types of soil, was 20 ± 3%. Covering landfills with additional mulch, which can be generated from yard waste, may attenuate methane emission by providing a loose noncompact substrate for bacterial attachment and an environment with moisture, methane, and oxygen. At specific sites within the landfill we studied, temperature was the main factor controlling methane oxidation.

  9. Fabrication of zirconia composite membrane by in-situ hydrothermal technique and its application in separation of methyl orange.

    PubMed

    Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2015-11-01

    The main objective of the work was preparation of zirconia membrane on a low cost ceramic support through an in-situ hydrothermal crystallization technique for the separation of methyl orange dye. To formulate the zirconia film on the ceramic support, hydrothermal reaction mixture was prepared using zirconium oxychloride as a zirconia source and ammonia as a precursor. The synthesized zirconia powder was characterized by X-ray diffractometer (XRD), N2 adsorption/desorption isotherms, Thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), Energy-dispersive X-ray (EDX) analysis and particle size distribution (PSD) to identify the phases and crystallinity, specific surface area, pore volume and pore size distribution, thermal behavior, chemical composition and size of the particles. The porosity, morphological structure and pure water permeability of the prepared zirconia membrane, as well as ceramic support were investigated using the Archimedes' method, Field emission scanning electron microscopy (FESEM) and permeability. The specific surface area, pore volume, pore size distribution of the zirconia powder was found to be 126.58m(2)/g, 3.54nm and 0.3-10µm, respectively. The porosity, average pore size and pure water permeability of the zirconia membrane was estimated to be 42%, 0.66µm and 1.44×10(-6)m(3)/m(2)skPa, respectively. Lastly, the potential of the membrane was investigated with separation of methyl orange by means of flux and rejection as a function of operating pressure and feed concentration. The rejection was found to decrease with increasing the operating pressure and increases with increasing feed concentrations. Moreover, it showed a high ability to reject methyl orange from aqueous solution with a rejection of 61% and a high permeation flux of 2.28×10(-5)m(3)/m(2)s at operating pressure of 68kPa. PMID:25982409

  10. Fabrication of zirconia composite membrane by in-situ hydrothermal technique and its application in separation of methyl orange.

    PubMed

    Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2015-11-01

    The main objective of the work was preparation of zirconia membrane on a low cost ceramic support through an in-situ hydrothermal crystallization technique for the separation of methyl orange dye. To formulate the zirconia film on the ceramic support, hydrothermal reaction mixture was prepared using zirconium oxychloride as a zirconia source and ammonia as a precursor. The synthesized zirconia powder was characterized by X-ray diffractometer (XRD), N2 adsorption/desorption isotherms, Thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), Energy-dispersive X-ray (EDX) analysis and particle size distribution (PSD) to identify the phases and crystallinity, specific surface area, pore volume and pore size distribution, thermal behavior, chemical composition and size of the particles. The porosity, morphological structure and pure water permeability of the prepared zirconia membrane, as well as ceramic support were investigated using the Archimedes' method, Field emission scanning electron microscopy (FESEM) and permeability. The specific surface area, pore volume, pore size distribution of the zirconia powder was found to be 126.58m(2)/g, 3.54nm and 0.3-10µm, respectively. The porosity, average pore size and pure water permeability of the zirconia membrane was estimated to be 42%, 0.66µm and 1.44×10(-6)m(3)/m(2)skPa, respectively. Lastly, the potential of the membrane was investigated with separation of methyl orange by means of flux and rejection as a function of operating pressure and feed concentration. The rejection was found to decrease with increasing the operating pressure and increases with increasing feed concentrations. Moreover, it showed a high ability to reject methyl orange from aqueous solution with a rejection of 61% and a high permeation flux of 2.28×10(-5)m(3)/m(2)s at operating pressure of 68kPa.

  11. Simulation verification techniques study: Simulation performance validation techniques document. [for the space shuttle system

    NASA Technical Reports Server (NTRS)

    Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

    1975-01-01

    Techniques and support software for the efficient performance of simulation validation are discussed. Overall validation software structure, the performance of validation at various levels of simulation integration, guidelines for check case formulation, methods for real time acquisition and formatting of data from an all up operational simulator, and methods and criteria for comparison and evaluation of simulation data are included. Vehicle subsystems modules, module integration, special test requirements, and reference data formats are also described.

  12. Development of in situ observation technique using scanning ion microscopy and demonstration of Mn depletion effect on intragranular ferrite transformation in low-alloy steel.

    PubMed

    Shigesato, Genichi; Sugiyama, Masaaki

    2002-01-01

    An in situ observation technique using scanning ion microscopy (SIM) to investigate the behaviour of phase transformation from austenite to ferrite in low-alloy steel is proposed. The most important advantage of the technique is the combined observation by SIM and fabrication by focused ion beam (FIB) at a wide range of temperature, from room temperature to 1673 K. Using this advantage, we have developed a new technique for observing intragranular ferrite (IGF) transformation in low-alloy steel, which is the phase transformation occurring at an inclusion existing inside a grain of austenite phase. We successfully observed the IGF transformation at 873 K by examining an inclusion exposed to the specimen surface by FIB fabrication at 1073 K during cooling from 1673 K. From the results of the in situ observation, we determined the role of Mn depletion due to precipitation of MnS for IGF transformation in steel.

  13. In situ precision electrospinning as an effective delivery technique for cyanoacrylate medical glue with high efficiency and low toxicity

    NASA Astrophysics Data System (ADS)

    Dong, R. H.; Qin, C. C.; Qiu, X.; Yan, X.; Yu, M.; Cui, L.; Zhou, Y.; Zhang, H. D.; Jiang, X. Y.; Long, Y. Z.

    2015-11-01

    The side effects or toxicity of cyanoacrylate used in vivo have been argued since its first application in wound closure. We propose an airflow-assisted in situ precision electrospinning apparatus as an applicator and make a detailed comparison with traditional spraying via in vitro and in vivo experiments. This novel method can not only improve operational performance and safety by precisely depositing cyanoacrylate fibers onto a wound, but significantly reduce the dosage of cyanoacrylate by almost 80%. A white blood cell count, liver function test and histological analysis prove that the in situ precision electrospinning applicator produces a better postoperative outcome, e.g., minor hepatocyte injury, moderate inflammation and the significant ability for liver regeneration. This in situ precision electrospinning method may thus dramatically broaden both civilian and military applications of cyanoacrylates.

  14. In situ calibration of the foil detector for an infrared imaging video bolometer using a carbon evaporation technique

    NASA Astrophysics Data System (ADS)

    Mukai, K.; Peterson, B. J.; Takayama, S.; Sano, R.

    2016-11-01

    The InfraRed imaging Video Bolometer (IRVB) is a useful diagnostic for the multi-dimensional measurement of plasma radiation profiles. For the application of IRVB measurement to the neutron environment in fusion plasma devices such as the Large Helical Device (LHD), in situ calibration of the thermal characteristics of the foil detector is required. Laser irradiation tests of sample foils show that the reproducibility and uniformity of the carbon coating for the foil were improved using a vacuum evaporation method. Also, the principle of the in situ calibration system was justified.

  15. Dosimetry verification on VMAT and IMRT radiotherapy techniques: In the case of prostate cancer

    NASA Astrophysics Data System (ADS)

    Maulana, A.; Pawiro, S. A.

    2016-03-01

    Radiotherapy treatment depends on the accuracy of the dose delivery to patients, the purpose of the study is to verify the dose in IMRT and VMAT technique in prostate cancer cases correspond to TPS dose using phantom base on ICRU No.50. The dose verification of the target and OAR was performed by placing the TLD Rod LiF100 and EBT2 Gafchromic film at slab hole of pelvic part of the Alderson RANDO phantom for prostate cancer simulation. The Exposed TLDs was evaluated using the TLD Reader Harshaw while EBT2 film was scanned using Epson scanner. The point dose measurements were compared between planned dose and measured dose at target volume and OAR. The result is the dose difference at target volume, bladder and rectum for IMRT and VMAT are less than 5%. On the other hand, the dose difference at the Femoral head is more than 5% for both techniques because the location of OAR already in low gradient dose. Furthermore, the difference dose of the target volume for IMRT technique tends to be smaller than VMAT either for TLD and EBT2 film detectors. From the measurement showed that the delivered dose on the phantom simulation match with ICRU No.50 criteria.

  16. Measurement of Bluetongue Virus Binding to a Mammalian Cell Surface Receptor by an In Situ Immune Fluorescent Staining Technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A quantifiable in situ immune fluorescent assay (IFA) was developed to measure bluetongue virus (BTV) binding to mammalian cells. The utility of the assay was demonstrated with both Chinese hamster ovary (CHO) and bovine pulmonary artery endothelial (CPAE) cells. Since heparin sulfate (HS) has been ...

  17. Ground-based radiometric calibration of the Landsat 8 Operational Land Imager (OLI) using in situ techniques

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, J.

    2013-12-01

    Landsat 8 was successfully launched from Vandenberg Air Force Base in California on 11 February 2013, and was placed into the orbit previously occupied by Landsat 5. Landsat 8 is the latest platform in the 40-year history of the Landsat series of satellites, and it contains two instruments that operate in the solar-reflective and the thermal infrared regimes. The Operational Land Imager (OLI) is a pushbroom sensor that contains eight multispectral bands ranging from 400-2300 nm, and one panchromatic band. The spatial resolution of the multispectral bands is 30 m, which is similar to previous Landsat sensors, and the panchromatic band has a 15-m spatial resolution, which is also similar to previous Landsat sensors. The 12-bit radiometric resolution of OLI improves upon the 8-bit resolution of the Enhanced Thematic Mapper Plus (ETM+) onboard Landsat 7. An important requirement for the Landsat program is the long-term radiometric continuity of its sensors. Ground-based vicarious techniques have been used for over 20 years to determine the absolute radiometric calibration of sensors that encompass a wide variety of spectral and spatial characteristics. This work presents the early radiometric calibration results of Landsat 8 OLI that were obtained using the traditional reflectance-based approach. University of Arizona personnel used five sites in Arizona, California, and Nevada to collect ground-based data. In addition, a unique set of in situ data were collected in March 2013, when Landsat 7 and Landsat 8 were observing the same site within minutes of each other. The tandem overfly schedule occurred while Landsat 8 was shifting to the WRS-2 orbital grid, and lasted only a few days. The ground-based data also include results obtained using the University of Arizona's Radiometric Calibration Test Site (RadCaTS), which is an automated suite of instruments located at Railroad Valley, Nevada. The results presented in this work include a comparison to the L1T at

  18. Detection and typing of human papillomavirus using the Vira Type "in situ" kit: comparison with a conventional dot blot technique.

    PubMed Central

    Faulkner-Jones, B E; Bellomarino, V M; Borg, A J; Orzeszko, K; Garland, S M

    1990-01-01

    A new commercial kit (Vira Type "in situ", Life Technologies, Inc., Molecular Diagnostics Division, Guithersburg, Maryland, USA) for the detection of human papillomavirus (HPV) types 6, 11, 16, 18, 31, 33 and 35 in routinely processed human anogenital tissue was compared with a conventional dot blot assay for HPV 6, 11, 16 and 18. Both systems use double-stranded genomic DNA probes for the detection of type specific HPV DNA. The probes used on the dot blots were labelled with 32P and visualised autoradiographically. The Vira Type probes were labelled with biotin and visualised using a streptavidin-alkaline phosphatase conjugate with NBT-BCIP substrate. Biopsy specimens from the cervix, vagina, and vulva of 46 women were processed by both methods and compared. The histological diagnoses ranged from benign changes, to dysplasia, and invasive carcinoma. Overall, 50% of biopsy specimens were positive for HPV DNA by dot blot hybridisation; only 39% were positive by Vira Type in situ hybridisation. Three of the specimens positive by the Vira Type "in situ" kit showed no cross hybridisation and were the same HPV type as the dot blot. A further 13 showed hybridisation, but the showed cross hybridisation, but the to the dot blot results. One biopsy specimen was positive for different HPV types by the two tests and one was positive by Vira Type and negative by dot blot. Six biopsy specimens were negative by Vira Type but positive by dot blot. It is concluded that the Vira Type "in situ" kit has a similar specificity but lower sensitivity than the dot blot hybridisation method for the detection of HPV DNA. Images PMID:2175755

  19. Vaginal micropapillary lesions are not related to human papillomavirus infection: in situ hybridization and polymerase chain reaction detection techniques.

    PubMed

    Garzetti, G G; Ciavattini, A; Goteri, G; Menzo, S; De Nictolis, M; Clementi, M; Brugia, M; Romanini, C

    1994-01-01

    The objective of this study was to assess the human papillomavirus DNA presence in vaginal papillary lesions, with particular regard to micropapillomatosis to better define their clinical significance. Prospective study: the study population was composed of 62 women who were recruited consecutively from the Colposcopy Centre of the Ancona University, Department of Obstetrics and Gynecology, on the grounds of vaginal papillomatosis or/and typical acuminata warts. Biopsies for routine histology, and for human papillomavirus (HPV) DNA detection by means of in situ hybridization and polymerase chain reaction (PCR) were taken from the papillary lesions and from 24 healthy women, who were selected as controls. Macroscopically, vaginal micropapillomatosis was ascertained in 51 cases (82.3%), while in 11 cases (17.7%) the colposcopic diagnosis was condyloma acuminatum. During in situ hybridization, HPV DNA positivity was observed in 8 (9.4%) out of 85 samples of squamous papillae and in 11 (64.7%) out of 17 samples of condylomata; in control specimens, HPV DNA was detected in 2 (8.3%) out of 24 bioptic samples. The correspondence between in situ hybridization and PCR was 96.1%, with 17.4% more diagnosis obtained by PCR. Vaginal micropapillomatosis may be regarded as a variation in the normal anatomy of the lower genital tract without any significant relationship with HPV infection, and as a lesion easily distinguishable from condylomata acuminata by clinical examination alone. PMID:7959342

  20. Application of the primer in situ DNA synthesis (PRINS) technique to titer recombinant virus and evaluation of the efficiency of viral transduction.

    PubMed

    Claudio, P P; Cinti, C; Giordano, A

    2001-04-01

    Titration is an important and critical step in dosing recombinant virus for gene therapy. We present a relatively fast, convenient, and sensitive method that allows for precise quantification of recombinant retrovirus. The method is based on PCR amplification of a foreign gene by the PRINS (primer in situ DNA synthesis) technique. The PRINS technique is based on the sequence-specific annealing of unlabeled oligonucleotide DNA in situ. This oligonucleotide operates as a primer for in situ chain elongation catalyzed by the Taq I polymerase. Using digoxygenin-labeled nucleotides as a substrate for chain elongation, the neo-synthetic DNA is labeled by an FITC-conjugated anti-digoxygenin antibody. To avoid the possibility of false positives, we amplified the puromycin-resistance gene, which is associated with the transgene in the same viral vector and is not normally present in mammalian cells. The retroviral titer was evaluated by counting fluorescein isothiocyanate-positive cells after PRINS labeling, while knowing the number of plated cells that were transduced with different amounts of viral supernatant. A comparable viral concentration of 1 x 10(7) infectious units/mL was found among the retroviruses.

  1. A Comparison of Clinical Outcomes of Dislocated Intraocular Lens Fixation between In Situ Refixation and Conventional Exchange Technique Combined with Vitrectomy

    PubMed Central

    Eum, Sun Jung; Kim, Myung Jun; Kim, Hong Kyun

    2016-01-01

    Purpose. To evaluate surgical efficacy of in situ refixation technique for dislocated posterior chamber intraocular lens (PCIOL). Methods. This was a single-center retrospective case series. 34 patients (34 eyes) who underwent sclera fixation for dislocated IOLs combined with vitrectomy were studied. Of 34 eyes, 17 eyes underwent IOL exchange and the other 17 eyes underwent in situ refixation. Results. Mean follow-up period was 6 months. Mean logMAR best corrected visual acuity (BCVA) was not significantly different between the groups 6 months after surgery (0.10 ± 0.03 in the IOL exchange group and 0.10 ± 0.05 in the refixation group; p = 0.065). Surgically induced astigmatism (SIA) was significantly lower in the refixation group (0.79 ± 0.41) than in the IOL exchange group (1.29 ± 0.46) (p = 0.004) at 3 months, which persisted to 6 months (1.13 ± 0.18 in the IOL exchange group and 0.74 ± 0.11 in the refixation group; p = 0.006). Postoperative complications occurred in 3 eyes in the IOL exchange group (17.6%) and 2 eyes in the refixation group (11.8%). However, all of the patients were well managed without additional surgery. Conclusion. The in situ refixation technique should be preferentially considered if surgery is indicated since it seemed to produce a sustained less SIA compared to IOL exchange. PMID:27119019

  2. Assessment of aneuploidy for chromosomes 8, 9, 13, 16, and 21 in human sperm by using primed in situ labeling technique

    SciTech Connect

    Pellestor, F.; Girardet, A.; Coignet, L.; Andreo, B.; Charlieu, J.P.

    1996-04-01

    The incidence of aneuploidy was estimated for chromosomes 8, 9, 13, 16, and 21 in mature human spermatozoa by primed in situ (PRINS) labeling technique. This method allows us to perform a chromosome-specific detection by in situ annealing of a centromeric specific primer. A dual color PRINS protocol was adapted to human sperm. The decondensation and the denaturation of sperm nuclei were simultaneously performed by 3-M NaOH treatment. Double labeling of spermatozoa was obtained in < 2 h. A total of 96,292 sperm nuclei were analyzed by two independent observers. The estimates of disomy were 0.31 % for chromosome 8, 0.28% for chromosome 9, 0.28% for chromosome 13, 0.26% for chromosome 16, and 0.32% for chromosome 21. These homogeneous findings suggest an equal distribution of aneuploidies among all autosomal chromosomes in males. 26 refs., 1 fig., 2 tabs.

  3. Experimental verification of a computational technique for determining ground reactions in human bipedal stance.

    PubMed

    Audu, Musa L; Kirsch, Robert F; Triolo, Ronald J

    2007-01-01

    We have developed a three-dimensional (3D) biomechanical model of human standing that enables us to study the mechanisms of posture and balance simultaneously in various directions in space. Since the two feet are on the ground, the system defines a kinematically closed-chain which has redundancy problems that cannot be resolved using the laws of mechanics alone. We have developed a computational (optimization) technique that avoids the problems with the closed-chain formulation thus giving users of such models the ability to make predictions of joint moments, and potentially, muscle activations using more sophisticated musculoskeletal models. This paper describes the experimental verification of the computational technique that is used to estimate the ground reaction vector acting on an unconstrained foot while the other foot is attached to the ground, thus allowing human bipedal standing to be analyzed as an open-chain system. The computational approach was verified in terms of its ability to predict lower extremity joint moments derived from inverse dynamic simulations performed on data acquired from four able-bodied volunteers standing in various postures on force platforms. Sensitivity analyses performed with model simulations indicated which ground reaction force (GRF) and center of pressure (COP) components were most critical for providing better estimates of the joint moments. Overall, the joint moments predicted by the optimization approach are strongly correlated with the joint moments computed using the experimentally measured GRF and COP (0.78 < or = r(2) < or = 0.99,median,0.96) with a best-fit that was not statistically different from a straight line with unity slope (experimental=computational results) for postures of the four subjects examined. These results indicate that this model-based technique can be relied upon to predict reasonable and consistent estimates of the joint moments using the predicted GRF and COP for most standing postures.

  4. EDITORIAL: International Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Verification

    NASA Astrophysics Data System (ADS)

    Verhaegen, Frank; Seuntjens, Jan

    2008-03-01

    Monte Carlo particle transport techniques offer exciting tools for radiotherapy research, where they play an increasingly important role. Topics of research related to clinical applications range from treatment planning, motion and registration studies, brachytherapy, verification imaging and dosimetry. The International Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Verification took place in a hotel in Montreal in French Canada, from 29 May-1 June 2007, and was the third workshop to be held on a related topic, which now seems to have become a tri-annual event. About one hundred workers from many different countries participated in the four-day meeting. Seventeen experts in the field were invited to review topics and present their latest work. About half of the audience was made up by young graduate students. In a very full program, 57 papers were presented and 10 posters were on display during most of the meeting. On the evening of the third day a boat trip around the island of Montreal allowed participants to enjoy the city views, and to sample the local cuisine. The topics covered at the workshop included the latest developments in the most popular Monte Carlo transport algorithms, fast Monte Carlo, statistical issues, source modeling, MC treatment planning, modeling of imaging devices for treatment verification, registration and deformation of images and a sizeable number of contributions on brachytherapy. In this volume you will find 27 short papers resulting from the workshop on a variety of topics, some of them on very new stuff such as graphics processing units for fast computing, PET modeling, dual-energy CT, calculations in dynamic phantoms, tomotherapy devices, . . . . We acknowledge the financial support of the National Cancer Institute of Canada, the Institute of Cancer Research of the Canadian Institutes of Health Research, the Association Québécoise des Physicien(ne)s Médicaux Clinique, the Institute of Physics, and Medical

  5. Spent-fuel verification measurements using passive and active radiation techniques

    SciTech Connect

    Ewing, R.I.; Seager, K.D.

    1996-08-01

    This paper describes an evolutionary development process that will lead to spent fuel measurements that directly measure fissile reactivity. First, the Fork measurement system has been used to verify the burnup of pressurized water reactor (PWR) spent-fuel assemblies at U.S. nuclear utilities. Fork measurements have demonstrated the utility of the passive Fork system to verify reactor records with a single 100-second measurement on each assembly. Second, an Advanced Fork system incorporating collimated gamma-ray spectroscopy has been designed to permit advanced calibration techniques that are independent of reactor burnup records and to allow rapid axial scanning of spent fuel assemblies. Third, an Active Fork system incorporating a neutron source to interrogate spent fuel is proposed to provide the capability to measure fissile reactivity, when compared to measurements on fresh fuel assemblies of the same design. The Advanced and Active Fork systems have wide applicability to spent fuel verification for PWR, boiling water reactor (BWR), and U.S. Department of Energy (DOE) spent fuel.

  6. Theoretical detection threshold of the proton-acoustic range verification technique

    PubMed Central

    Ahmad, Moiz; Xiang, Liangzhong; Yousefi, Siavash; Xing, Lei

    2015-01-01

    Purpose: Range verification in proton therapy using the proton-acoustic signal induced in the Bragg peak was investigated for typical clinical scenarios. The signal generation and detection processes were simulated in order to determine the signal-to-noise limits. Methods: An analytical model was used to calculate the dose distribution and local pressure rise (per proton) for beams of different energy (100 and 160 MeV) and spot widths (1, 5, and 10 mm) in a water phantom. In this method, the acoustic waves propagating from the Bragg peak were generated by the general 3D pressure wave equation implemented using a finite element method. Various beam pulse widths (0.1–10 μs) were simulated by convolving the acoustic waves with Gaussian kernels. A realistic PZT ultrasound transducer (5 cm diameter) was simulated with a Butterworth bandpass filter with consideration of random noise based on a model of thermal noise in the transducer. The signal-to-noise ratio on a per-proton basis was calculated, determining the minimum number of protons required to generate a detectable pulse. The maximum spatial resolution of the proton-acoustic imaging modality was also estimated from the signal spectrum. Results: The calculated noise in the transducer was 12–28 mPa, depending on the transducer central frequency (70–380 kHz). The minimum number of protons detectable by the technique was on the order of 3–30 × 106 per pulse, with 30–800 mGy dose per pulse at the Bragg peak. Wider pulses produced signal with lower acoustic frequencies, with 10 μs pulses producing signals with frequency less than 100 kHz. Conclusions: The proton-acoustic process was simulated using a realistic model and the minimal detection limit was established for proton-acoustic range validation. These limits correspond to a best case scenario with a single large detector with no losses and detector thermal noise as the sensitivity limiting factor. Our study indicated practical proton-acoustic range

  7. Investigation of Advanced Dose Verification Techniques for External Beam Radiation Treatment

    NASA Astrophysics Data System (ADS)

    Asuni, Ganiyu Adeniyi

    Intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) have been introduced in radiation therapy to achieve highly conformal dose distributions around the tumour while minimizing dose to surrounding normal tissues. These techniques have increased the need for comprehensive quality assurance tests, to verify that customized patient treatment plans are accurately delivered during treatment. in vivo dose verification, performed during treatment delivery, confirms that the actual dose delivered is the same as the prescribed dose, helping to reduce treatment delivery errors. in vivo measurements may be accomplished using entrance or exit detectors. The objective of this project is to investigate a novel entrance detector designed for in vivo dose verification. This thesis is separated into three main investigations, focusing on a prototype entrance transmission detector (TRD) developed by IBA Dosimetry, Germany. First contaminant electrons generated by the TRD in a 6 MV photon beam were investigated using Monte Carlo (MC) simulation. This study demonstrates that modification of the contaminant electron model in the treatment planning system is required for accurate patient dose calculation in buildup regions when using the device. Second, the ability of the TRD to accurately measure dose from IMRT and VMAT was investigated by characterising the spatial resolution of the device. This was accomplished by measuring the point spread function with further validation provided by MC simulation. Comparisons of measured and calculated doses show that the spatial resolution of the TRD allows for measurement of clinical IMRT fields within acceptable tolerance. Finally, a new general research tool was developed to perform MC simulations for VMAT and IMRT treatments, simultaneously tracking dose deposition in both the patient CT geometry and an arbitrary planar detector system, generalized to handle either entrance or exit orientations. It was

  8. Theoretical detection threshold of the proton-acoustic range verification technique

    SciTech Connect

    Ahmad, Moiz; Yousefi, Siavash; Xing, Lei; Xiang, Liangzhong

    2015-10-15

    Purpose: Range verification in proton therapy using the proton-acoustic signal induced in the Bragg peak was investigated for typical clinical scenarios. The signal generation and detection processes were simulated in order to determine the signal-to-noise limits. Methods: An analytical model was used to calculate the dose distribution and local pressure rise (per proton) for beams of different energy (100 and 160 MeV) and spot widths (1, 5, and 10 mm) in a water phantom. In this method, the acoustic waves propagating from the Bragg peak were generated by the general 3D pressure wave equation implemented using a finite element method. Various beam pulse widths (0.1–10 μs) were simulated by convolving the acoustic waves with Gaussian kernels. A realistic PZT ultrasound transducer (5 cm diameter) was simulated with a Butterworth bandpass filter with consideration of random noise based on a model of thermal noise in the transducer. The signal-to-noise ratio on a per-proton basis was calculated, determining the minimum number of protons required to generate a detectable pulse. The maximum spatial resolution of the proton-acoustic imaging modality was also estimated from the signal spectrum. Results: The calculated noise in the transducer was 12–28 mPa, depending on the transducer central frequency (70–380 kHz). The minimum number of protons detectable by the technique was on the order of 3–30 × 10{sup 6} per pulse, with 30–800 mGy dose per pulse at the Bragg peak. Wider pulses produced signal with lower acoustic frequencies, with 10 μs pulses producing signals with frequency less than 100 kHz. Conclusions: The proton-acoustic process was simulated using a realistic model and the minimal detection limit was established for proton-acoustic range validation. These limits correspond to a best case scenario with a single large detector with no losses and detector thermal noise as the sensitivity limiting factor. Our study indicated practical proton

  9. Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

    SciTech Connect

    Moody, Neville Reid; Bahr, David F.

    2005-11-01

    This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were calculated using two different numerical methods. The first method utilized a plate bending approach by modeling the thin film as an axisymmetric circular plate on a compliant foundation. The second method measured the applied energy for fracture. The crack extension force and applied stress intensity at fracture was then determined from the energy measurements. Secondly, slip steps form on the free surface around indentations in most crystalline materials when dislocations reach the free surface. Analysis of these slip steps provides information about the deformation taking place in the material. Techniques have now been developed to allow for accurate and consistent measurement of slip steps and the effects of crystal orientation and tip geometry are characterized. These techniques will be described and compared to results from dislocation dynamics simulations.

  10. In situ determination of the hydrothermal properties of a deep fractured medium by a single-well technique

    NASA Astrophysics Data System (ADS)

    Hosanski, J. M.; Ledoux, E.

    1982-03-01

    The recovery of energy from deep hot rock formations with low permeability gives rise to many scientific and technological problems. This paper describes a simple method of in situ analysis of a slightly fissured medium, developed by the Centre d'Informatique Géologique of the Paris School of Mines, during experiments carried out at the site of Mayet de Montagne (Allier, France) between November 1978 and March 1980. These experiments were funded by the Commission of the European Communities and the Institut National d'Astronomie et de Géophysique, and carried out jointly with the Institut de Physique du Globe, Paris. They had a two-fold purpose: (1) Better understanding of the physical phenomena governing the heat exchange between the slightly fissured medium and the injected fluids. (2) Determination in situ of the parameters which control this exchange. This proposed "single-well" method might be suitable as a preliminary test in order to evaluate the life span of a hot dry rock geothermal doublet.

  11. Survey of Verification and Validation Techniques for Small Satellite Software Development

    NASA Technical Reports Server (NTRS)

    Jacklin, Stephen A.

    2015-01-01

    The purpose of this paper is to provide an overview of the current trends and practices in small-satellite software verification and validation. This document is not intended to promote a specific software assurance method. Rather, it seeks to present an unbiased survey of software assurance methods used to verify and validate small satellite software and to make mention of the benefits and value of each approach. These methods include simulation and testing, verification and validation with model-based design, formal methods, and fault-tolerant software design with run-time monitoring. Although the literature reveals that simulation and testing has by far the longest legacy, model-based design methods are proving to be useful for software verification and validation. Some work in formal methods, though not widely used for any satellites, may offer new ways to improve small satellite software verification and validation. These methods need to be further advanced to deal with the state explosion problem and to make them more usable by small-satellite software engineers to be regularly applied to software verification. Last, it is explained how run-time monitoring, combined with fault-tolerant software design methods, provides an important means to detect and correct software errors that escape the verification process or those errors that are produced after launch through the effects of ionizing radiation.

  12. Combination of Fluorescence In Situ Hybridization with Staining Techniques for Cell Viability and Accumulation of PHA and polyP in Microorganisms in Complex Microbial Systems

    NASA Astrophysics Data System (ADS)

    Nielsen, Jeppe Lund; Kragelund, Caroline; Nielsen, Per Halkjær

    Fluorescence in situ hybridization (FISH) can be combined with a number of staining techniques to reveal the relationships between the microorganisms and their function in complex microbial systems with a single-cell resolution. In this chapter, we have focused on staining methods for intracellular storage compounds (polyhydroxyalkanoates, polyphosphate) and a measure for cell viability, reduction of the tetrazolium-based redox stain CTC. These protocols are optimized for the study of microorganisms in waste-water treatment (activated sludge and biofilms), but they may also be used with minor modifications in many other ecosystems.

  13. Development and verification of global/local analysis techniques for laminated composites

    NASA Technical Reports Server (NTRS)

    Thompson, Danniella Muheim; Griffin, O. Hayden, Jr.

    1991-01-01

    A two-dimensional to three-dimensional global/local finite element approach was developed, verified, and applied to a laminated composite plate of finite width and length containing a central circular hole. The resulting stress fields for axial compression loads were examined for several symmetric stacking sequences and hole sizes. Verification was based on comparison of the displacements and the stress fields with those accepted trends from previous free edge investigations and a complete three-dimensional finite element solution of the plate. The laminates in the compression study included symmetric cross-ply, angle-ply and quasi-isotropic stacking sequences. The entire plate was selected as the global model and analyzed with two-dimensional finite elements. Displacements along a region identified as the global/local interface were applied in a kinematically consistent fashion to independent three-dimensional local models. Local areas of interest in the plate included a portion of the straight free edge near the hole, and the immediate area around the hole. Interlaminar stress results obtained from the global/local analyses compares well with previously reported trends, and some new conclusions about interlaminar stress fields in plates with different laminate orientations and hole sizes are presented for compressive loading. The effectiveness of the global/local procedure in reducing the computational effort required to solve these problems is clearly demonstrated through examination of the computer time required to formulate and solve the linear, static system of equations which result for the global and local analyses to those required for a complete three-dimensional formulation for a cross-ply laminate. Specific processors used during the analyses are described in general terms. The application of this global/local technique is not limited software system, and was developed and described in as general a manner as possible.

  14. Development and Experimental Verification of Key Techniques to Validate Remote Sensing Products

    NASA Astrophysics Data System (ADS)

    Li, X.; Wang, S. G.; Ge, Y.; Jin, R.; Liu, S. M.; Ma, M. G.; Shi, W. Z.; Li, R. X.; Liu, Q. H.

    2013-05-01

    Validation of remote sensing land products is a fundamental issue for Earth observation. Ministry of Science and Technology of the People's Republic of China (MOST) has launched a high-tech R&D Program named `Development and experimental verification of key techniques to validate remote sensing products' in 2011. This paper introduces the background, scientific objectives, research contents of this project and research result already achieved. The objectives of this project include (1) to build a technical specification for the validation of remote sensing products; (2) to investigate the performance, we will carry out a comprehensive remote sensing experiment on satellite - aircraft - ground truth and then modify Step 1 until reach the predefined requirement; (3) to establish a validation network of China for remote sensing products. In summer 2012, with support of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER), field observations have been successfully conducted in the central stream of the Heihe River Basin, a typical inland river basin in northwest China. A flux observation matrix composed of eddy covariance (EC) and large aperture scintillometer (LAS), in addition to a densely distributed eco-hydrological wireless sensor network have been established to capture multi-scale heterogeneities of evapotranspiration (ET), leaf area index (LAI), soil moisture and temperature. Airborne missions have been flown with the payloads of imaging spectrometer, light detection and ranging (LiDAR), infrared thermal imager and microwave radiometer that provide various scales of aerial remote sensing observations. Satellite images with high resolution have been collected and pre-processed, e.g. PROBA-CHRIS and TerraSAR-X. Simultaneously, ground measurements have been conducted over specific sampling plots and transects to obtain validation data sets. With this setup complex problems are addressed, e.g. heterogeneity, scaling, uncertainty, and eventually to

  15. Strategies and Techniques to Enhance the In Situ Endothelialization of Small-Diameter Biodegradable Polymeric Vascular Grafts

    PubMed Central

    Hibino, Narutoshi; Fisher, John P.

    2013-01-01

    Due to the lack of success in small-diameter (<6 mm) prosthetic vascular grafts, a variety of strategies have evolved utilizing a tissue-engineering approach. Much of this work has focused on enhancing the endothelialization of these grafts. A healthy, confluent endothelial layer provides dynamic control over homeo-stasis, influencing and preventing thrombosis and smooth muscle cell proliferation that can lead to intimal hyperplasia. Strategies to improve endothelialization of biodegradable polymeric grafts have encompassed both chemical and physical modifications to graft surfaces, many focusing on the recruitment of endothelial and endothelial progenitor cells. This review aims to provide a compilation of current and developing strategies that utilize in situ endothelialization to improve vascular graft outcomes, providing a context for the future directions of vascular tissue-engineering strategies that do not require preprocedural cell seeding. PMID:23252992

  16. Fluorescence in situ hybridization techniques (FISH) to detect changes in CYP19a gene expression of Japanese medaka (Oryzias latipes)

    SciTech Connect

    Park, June-Woo; Tompsett, Amber; Zhang, Xiaowei; Newsted, John L.; Jones, Paul D.; Au, Doris; Kong, Richard; Wu, Rudolf S.S.; Giesy, John P. Hecker, Markus

    2008-10-15

    The aim of this study was to develop a sensitive in situ hybridization methodology using fluorescence-labeled riboprobes (FISH) that allows for the evaluation of gene expression profiles simultaneously in multiple target tissues of whole fish sections of Japanese medaka (Oryzias latipes). To date FISH methods have been limited in their application due to autofluorescence of tissues, fixatives or other components of the hybridization procedure. An optimized FISH method, based on confocal fluorescence microscopy was developed to reduce the autofluorescence signal. Because of its tissue- and gender-specific expression and relevance in studies of endocrine disruption, gonadal aromatase (CYP19a) was used as a model gene. The in situ hybridization (ISH) system was validated in a test exposure with the aromatase inhibitor fadrozole. The optimized FISH method revealed tissue-specific expression of the CYP19a gene. Furthermore, the assay could differentiate the abundance of CYP19a mRNA among cell types. Expression of CYP19a was primarily associated with early stage oocytes, and expression gradually decreased with increasing maturation. No expression of CYP19a mRNA was observed in other tissues such as brain, liver, or testes. Fadrozole (100 {mu}g/L) caused up-regulation of CYP19a expression, a trend that was confirmed by RT-PCR analysis on excised tissues. In a combination approach with gonad histology, it could be shown that the increase in CYP19a expression as measured by RT-PCR on a whole tissue basis was due to a combination of both increases in numbers of CYP19a-containing cells and an increase in the amount of CYP19a mRNA present in the cells.

  17. In-situ stress analysis of the Zr/ZrO2 system as studied by Raman spectroscopy and deflection test in monofacial oxidation techniques

    NASA Astrophysics Data System (ADS)

    Kurpaska, L.; Favergeon, J.; Grosseau-Poussard, J.-L.; Lahoche, L.; Moulin, G.

    2016-11-01

    A comparison of measurements performed in in-situ conditions using Raman spectroscopy and Deflection Test in Monofacial Oxidation techniques were employed to study stress states developed in zirconia films grown at 500 °C is presented. The results show a good correlation between recorded Raman peak displacement and sample deflection angle. Considering analyzed volume of the material, Raman analysis represents a local measurement while the deflection test is a global response of the material. Reported stress components: (i) hydrostatic - resulted from Raman spectroscopy and (ii) in-plane - resulted from deflection test technique have been analyzed in comparison to each of the described techniques and aim to explain the behavior of zirconia at high temperatures.

  18. Single-Tube Reaction Using Perfluorocarbons: A Prerequisite Step Leading to the Whole-Slide In Situ Technique on Histopathological Slides

    PubMed Central

    Chen, Yi-Chang; Teng, Tsung-Han; Tsai, Jane S.-C.; Huang, Hsien-Da; Chang, Yih-Leong

    2016-01-01

    Developing a robust, novel method for performing multiple reactions in a single tube is not only time- and cost-saving but also critical for future high-throughput whole-slide in situ techniques on diseased tissues. In this study, we introduce the use of perfluorocarbons and compound-coated magnetic particles to create pseudochambers in a single tube, allowing different reactions to be performed in different phases. Perfluorocarbons also serve as cell lysis buffer and polymerase chain reaction (PCR) buffer owing to their highly penetrating, repellent and emulsifiable properties. Using this method, nucleic acids can be isolated and purified from various sample types and sizes, followed by PCR, real-time PCR, or multiplex PCR in the same tube. No incubation or enzyme digesting time is needed and the risk of cross-contamination is reduced. Tests can be performed in microemulsions (water-in-oil droplets) containing sequence-specific captures and probes for further high-throughput detection. We present a simple, quick, and robust procedure as a prerequisite step to future high-throughput in situ techniques. PMID:27336363

  19. Application of in situ hybridization, cytochemical and immunocytochemical techniques for the investigation of peroxisomes. A review including novel data. Robert Feulgen Prize Lecture 1997.

    PubMed

    Baumgart, E

    1997-09-01

    In situ hybridization, cytochemical and immunocytochemical techniques have contributed significantly to the understanding of the biology of peroxisomes, since they permit in situ demonstration of the sites of synthesis and distribution of peroxisomal proteins without the necessity of homogenization and subcellular fractionation of tissues or cultured cells. This article reviews the results of research on mammalian peroxisomal metabolism, biogenesis and proliferation in which morphological techniques have played a significant role in the elucidation of the biological problem. Some new data on peroxisomal heterogeneity and morphogenesis are included. The morphological methods applied have made it possible to characterize the differences in distribution of mRNAs encoding peroxisomal proteins in different tissues, as well as to monitor the marked heterogeneity in the protein composition and in the activity of specific enzymes in the peroxisomal population of single cells, or in tissues with complex organization (e.g. liver and kidney). In addition, the dynamic alterations and high plasticity of the peroxisomal compartment--partly dependent on contact of the peroxisomes to the microtubular network-are presented.

  20. Application of in situ hybridization, cytochemical and immunocytochemical techniques for the investigation of peroxisomes. A review including novel data. Robert Feulgen Prize Lecture 1997.

    PubMed

    Baumgart, E

    1997-09-01

    In situ hybridization, cytochemical and immunocytochemical techniques have contributed significantly to the understanding of the biology of peroxisomes, since they permit in situ demonstration of the sites of synthesis and distribution of peroxisomal proteins without the necessity of homogenization and subcellular fractionation of tissues or cultured cells. This article reviews the results of research on mammalian peroxisomal metabolism, biogenesis and proliferation in which morphological techniques have played a significant role in the elucidation of the biological problem. Some new data on peroxisomal heterogeneity and morphogenesis are included. The morphological methods applied have made it possible to characterize the differences in distribution of mRNAs encoding peroxisomal proteins in different tissues, as well as to monitor the marked heterogeneity in the protein composition and in the activity of specific enzymes in the peroxisomal population of single cells, or in tissues with complex organization (e.g. liver and kidney). In addition, the dynamic alterations and high plasticity of the peroxisomal compartment--partly dependent on contact of the peroxisomes to the microtubular network-are presented. PMID:9342614

  1. Single-Tube Reaction Using Perfluorocarbons: A Prerequisite Step Leading to the Whole-Slide In Situ Technique on Histopathological Slides.

    PubMed

    Chen, Yi-Chang; Teng, Tsung-Han; Tsai, Jane S-C; Huang, Hsien-Da; Chang, Yih-Leong; Liang, Cher-Wei

    2016-01-01

    Developing a robust, novel method for performing multiple reactions in a single tube is not only time- and cost-saving but also critical for future high-throughput whole-slide in situ techniques on diseased tissues. In this study, we introduce the use of perfluorocarbons and compound-coated magnetic particles to create pseudochambers in a single tube, allowing different reactions to be performed in different phases. Perfluorocarbons also serve as cell lysis buffer and polymerase chain reaction (PCR) buffer owing to their highly penetrating, repellent and emulsifiable properties. Using this method, nucleic acids can be isolated and purified from various sample types and sizes, followed by PCR, real-time PCR, or multiplex PCR in the same tube. No incubation or enzyme digesting time is needed and the risk of cross-contamination is reduced. Tests can be performed in microemulsions (water-in-oil droplets) containing sequence-specific captures and probes for further high-throughput detection. We present a simple, quick, and robust procedure as a prerequisite step to future high-throughput in situ techniques. PMID:27336363

  2. Laser Ablation in situ (U-Th-Sm)/He and U-Pb Double-Dating of Apatite and Zircon: Techniques and Applications

    NASA Astrophysics Data System (ADS)

    McInnes, B.; Danišík, M.; Evans, N.; McDonald, B.; Becker, T.; Vermeesch, P.

    2015-12-01

    We present a new laser-based technique for rapid, quantitative and automated in situ microanalysis of U, Th, Sm, Pb and He for applications in geochronology, thermochronometry and geochemistry (Evans et al., 2015). This novel capability permits a detailed interrogation of the time-temperature history of rocks containing apatite, zircon and other accessory phases by providing both (U-Th-Sm)/He and U-Pb ages (+trace element analysis) on single crystals. In situ laser microanalysis offers several advantages over conventional bulk crystal methods in terms of safety, cost, productivity and spatial resolution. We developed and integrated a suite of analytical instruments including a 193 nm ArF excimer laser system (RESOlution M-50A-LR), a quadrupole ICP-MS (Agilent 7700s), an Alphachron helium mass spectrometry system and swappable flow-through and ultra-high vacuum analytical chambers. The analytical protocols include the following steps: mounting/polishing in PFA Teflon using methods similar to those adopted for fission track etching; laser He extraction and analysis using a 2 s ablation at 5 Hz and 2-3 J/cm2fluence; He pit volume measurement using atomic force microscopy, and U-Th-Sm-Pb (plus optional trace element) analysis using traditional laser ablation methods. The major analytical challenges for apatite include the low U, Th and He contents relative to zircon and the elevated common Pb content. On the other hand, apatite typically has less extreme and less complex zoning of parent isotopes (primarily U and Th). A freeware application has been developed for determining (U-Th-Sm)/He ages from the raw analytical data and Iolite software was used for U-Pb age and trace element determination. In situ double-dating has successfully replicated conventional U-Pb and (U-Th)/He age variations in xenocrystic zircon from the diamondiferous Ellendale lamproite pipe, Western Australia and increased zircon analytical throughput by a factor of 50 over conventional methods

  3. A Localized In-Situ Hydrogel-Mediated Protein Digestion and Extraction Technique For On-Tissue Analysis

    PubMed Central

    Harris, Glenn A.; Nicklay, Joshua J.; Caprioli, Richard M.

    2013-01-01

    A simultaneous on-tissue proteolytic digestion and extraction method is described for the in-situ analysis of proteins from spatially distinct areas of a tissue section. The digestion occurs on-tissue within a hydrogel network, and peptides extracted from this gel are identified with liquid chromatography tandem MS (LC-MS/MS). The hydrogels are compatible with solubility agents (e.g. chaotropes and detergents) known to improve enzymatic digestion of proteins. Additionally, digestions and extractions are compatible with Imaging Mass Spectrometry (IMS) experiments. As an example application, an initial IMS experiment was conducted to profile lipid species using a traveling wave ion mobility mass spectrometer. On-tissue MS/MS was also performed on the same tissue section to identify lipid ions that showed spatial differences. Subsequently, the section underwent an on-tissue hydrogel digestion to reveal 96 proteins that co-localized to the rat brain cerebellum. Hematoxylin and Eosin (H & E) staining was then performed to provide additional histological information about the tissue structure. This technology provides a versatile workflow that can be used to correlate multiple complementary analytical approaches in the analysis of a single tissue section. PMID:23402265

  4. Innovative Protocols for in SITU MTBE Degradation by Using Molecular Probes-An Enhanced Chemical-Bio Oxidation Technique

    SciTech Connect

    Paul Fallgren

    2009-02-20

    In situ chemical oxidation (ISCO) is a common technology to cleanup petroleum hydrocarbon-contaminated soils and groundwater. Sodium percarbonate (SPC) is an oxidant which is activated by iron (Fe) to produce Fenton-like reactions. Western Research Institute, in conjunction with Regenesis and the U.S. Department of Energy, conducted a study that investigated the performance of a 'safe' oxidant, SPC, to cleanup groundwater and soils contaminated with petroleum hydrocarbons and associated contaminants (e.g., MTBE). Results from a field pilot test in Frenchglen, Oregon showed VOC concentrations in groundwater decreased substantially within 2 weeks after injecting activated SPC (RegenOx). A protocol was established for determining RegenOx TOD in soils and groundwater. Total oxidant demand tests were necessary to determine the correct dosage of RegenOx to apply in the field and sufficiently degrade the contaminants of concern. Bench studies with RegenOx showed this technology was effective in degrading diesel fuel and 1,4-dioxane. The Fe-silica activator (RegenOx Part B) was tested with another oxidant, sodium persulfate. Bench tests results showed the combination of sodium persulfate and RegenOx Part B was effective in reducing PCE, MTBE, benzene, and n-heptane concentrations in water. Overall, the results of this project indicated that most petroleum contaminants in soil and groundwater can be sufficiently degraded using the RegenOx technology.

  5. In-situ gamma spectrometry in environmental monitoring.

    PubMed

    Kluson, J

    2010-01-01

    In-situ gamma spectrometry (scintillation or semiconductor) can be used effectively for monitoring natural and man-made radionuclide concentrations, together with the corresponding photon fields, in the environment and in workplaces. It is applied in operational and emergency monitoring of nuclear facilities, waste storage facilities and the uranium industry, in radioactive contamination measurements and mapping, environmental, radiohygienic and radiation safety studies, etc. Methods for processing and interpreting data, experimental techniques (ground or airborne arrangement), calibration and verification and examples of applications are discussed in this paper. PMID:20022255

  6. Determination of potential groundwater discharge zones into a Salt Lake using remote sensing techniques and in-situ measurements

    NASA Astrophysics Data System (ADS)

    Kilic, Ecenur; Kamil Yilmaz, Koray; Lutfi Suzen, M.

    2015-04-01

    Groundwater and surface water are integral components of the hydrologic system with strong feedback mechanisms and hence should be treated as a single resource. Existence of groundwater discharge into lakes is a very significant factor that affects both the water quantity of the lake as well as its ecological and biological diversity. The degree of interaction is more significant for shallow lakes because of their increased vulnerability due to limited volume and rapid changes in the extent and duration of the wet/dry cycles. The Salt Lake, located in Central Anatolia, Turkey, is a hyper-saline, shallow lake that is ranked as the second largest lake in Turkey. The majority of the lake dries during the late summer season enabling investigation of the lake bottom morphology. Through analysis of the high-resolution satellite images we identified circular features that may indicate possible groundwater seepage locations. The density and shape properties of these features were then investigated via spatial statistics to identify possible trends that can be linked to controlling mechanism(s) such as underlying sediments, geology, hydrogeology and wind patterns. The analysis was supported by field measurement of salt thickness at various locations in a systematic way. Long-term precipitation, lake level and groundwater level data were compared to investigate possible relationships and trends. In this presentation the framework to investigate remotely-sensed and in-situ measurements will be discussed with potential links to the groundwater recharge to the Salt Lake. Future work will focus on installing long-term monitoring networks in the lake.

  7. Automated quantitative analysis of in-situ NaI measured spectra in the marine environment using a wavelet-based smoothing technique.

    PubMed

    Tsabaris, Christos; Prospathopoulos, Aristides

    2011-10-01

    An algorithm for automated analysis of in-situ NaI γ-ray spectra in the marine environment is presented. A standard wavelet denoising technique is implemented for obtaining a smoothed spectrum, while the stability of the energy spectrum is achieved by taking advantage of the permanent presence of two energy lines in the marine environment. The automated analysis provides peak detection, net area calculation, energy autocalibration, radionuclide identification and activity calculation. The results of the algorithm performance, presented for two different cases, show that analysis of short-term spectra with poor statistical information is considerably improved and that incorporation of further advancements could allow the use of the algorithm in early-warning marine radioactivity systems. PMID:21742510

  8. A technique coupling the analyte electrodeposition followed by in-situ stripping with electrothermal atomic absorption spectrometry for analysis of samples with high NaCl contents

    NASA Astrophysics Data System (ADS)

    Čánský, Zdeněk; Rychlovský, Petr; Petrová, Zuzana; Matousek, J. P.

    2007-03-01

    A technique coupling the analyte electrodeposition followed by in-situ stripping with electrothermal atomic absorption spectrometry has been developed for determination of lead and cadmium in samples with high salt contents. To separate the analyte from the sample matrix, the analyte was in-situ quantitatively electrodeposited on a platinum sampling capillary serving as the cathode (sample volume, 20 μL). The spent electrolyte containing the sample matrix was then withdrawn, the capillary with the analyte deposited was washed with deionized water and the analyte was stripped into a chemically simple electrolyte (5 g/L NH 4H 2PO 4) by reversing the polarity of the electrodeposition circuit. Electrothermal atomization using a suitable optimized temperature program followed. A fully automated manifold was designed for this coupled technique and the appropriate control software was developed. The operating conditions for determination of Pb and Cd in samples with high contents of inorganic salts were optimized, the determination was characterized by principal analytical parameters and its applicability was verified on analyses of urine reference samples. The absolute limits of detection for lead and cadmium (3 σ criterion) in a sample containing 30 g/L NaCl were 8.5 pg and 2.3 pg, respectively (peak absorbance) and the RSD values amounted to 1.6% and 1.9% for lead (at the 40 ng mL - 1 level) and cadmium (at the 4.0 ng mL - 1 level), respectively. These values (and also the measuring sensitivity) are superior to the results attained in conventional electrothermal atomic absorption spectrometric determination of Pb and Cd in pure solutions (5 g/L NH 4H 2PO 4). The sensitivity of the Pb and Cd determination is not affected by the NaCl concentration up to a value of 100 g/L, demonstrating an efficient matrix removal during the electrodeposition step.

  9. Infraspinatus/Teres Minor Transfer Biceps In Situ Tenodesis Procedure: Initial Results of a Technique for Massive Cuff Tears

    PubMed Central

    Fletcher, Matt D. A.

    2013-01-01

    Massive rotator cuff tears may not be primarily repairable with salvage options not necessarily providing acceptable results. Extrinsic tendon transfer is a significant undertaking with prolonged rehabilitation and variable outcome. A novel technique for the reconstruction of massive tears, not amenable to primary repair, by performing a transfer of the intrinsic posterior rotator cuff onto an intact, tenodesed long head of biceps tendon acting as a scaffold for the intrinsic transfer is described. The clinical results at short to medium term in 17 initial patients are presented. Encouraging results from this study suggest that this is a viable option for the management of massive rotator cuff tears with an intact posterior cuff with results equal or superior to other reconstructive techniques. PMID:24967113

  10. On line biomonitors used as a tool for toxicity reduction evaluation of in situ groundwater remediation techniques.

    PubMed

    Küster, Eberhard; Dorusch, Falk; Vogt, Carsten; Weiss, Holger; Altenburger, Rolf

    2004-07-15

    Success of groundwater remediation is typically controlled via snapshot analysis of selected chemical substances or physical parameters. Biological parameters, i.e. ecotoxicological assays, are rarely employed. Hence the aim of the study was to develop a bioassay tool, which allows an on line monitoring of contaminated groundwater, as well as a toxicity reduction evaluation (TRE) of different remediation techniques in parallel and may furthermore be used as an additional tool for process control to supervise remediation techniques in a real time mode. Parallel testing of groundwater remediation techniques was accomplished for short and long time periods, by using the energy dependent luminescence of the bacterium Vibrio fischeri as biological monitoring parameter. One data point every hour for each remediation technique was generated by an automated biomonitor. The bacteria proved to be highly sensitive to the contaminated groundwater and the biomonitor showed a long standing time despite the highly corrosive groundwater present in Bitterfeld, Germany. The bacterial biomonitor is demonstrated to be a valuable tool for remediation success evaluation. Dose response relationships were generated for the six quantitatively dominant groundwater contaminants (2-chlortoluene, 1,2- and 1,4-dichlorobenzene, monochlorobenzene, ethylenbenzene and benzene). The concentrations of individual volatile organic chemicals (VOCs) could not explain the observed effects in the bacteria. An expected mixture toxicity was calculated for the six components using the concept of concentration addition. The calculated EC(50) for the mixture was still one order of magnitude lower than the observed EC(50) of the actual groundwater. The results pointed out that chemical analysis of the six most quantitative substances alone was not able to explain the effects observed with the bacteria. Thus chemical analysis alone may not be an adequate tool for remediation success evaluation in terms of

  11. Comparison of the resulting error in data fusion techniques when used with remote sensing, earth observation, and in-situ data sets for water quality applications

    NASA Astrophysics Data System (ADS)

    Ziemba, Alexander; El Serafy, Ghada

    2016-04-01

    Ecological modeling and water quality investigations are complex processes which can require a high level of parameterization and a multitude of varying data sets in order to properly execute the model in question. Since models are generally complex, their calibration and validation can benefit from the application of data and information fusion techniques. The data applied to ecological models comes from a wide range of sources such as remote sensing, earth observation, and in-situ measurements, resulting in a high variability in the temporal and spatial resolution of the various data sets available to water quality investigators. It is proposed that effective fusion into a comprehensive singular set will provide a more complete and robust data resource with which models can be calibrated, validated, and driven by. Each individual product contains a unique valuation of error resulting from the method of measurement and application of pre-processing techniques. The uncertainty and error is further compounded when the data being fused is of varying temporal and spatial resolution. In order to have a reliable fusion based model and data set, the uncertainty of the results and confidence interval of the data being reported must be effectively communicated to those who would utilize the data product or model outputs in a decision making process[2]. Here we review an array of data fusion techniques applied to various remote sensing, earth observation, and in-situ data sets whose domains' are varied in spatial and temporal resolution. The data sets examined are combined in a manner so that the various classifications, complementary, redundant, and cooperative, of data are all assessed to determine classification's impact on the propagation and compounding of error. In order to assess the error of the fused data products, a comparison is conducted with data sets containing a known confidence interval and quality rating. We conclude with a quantification of the performance

  12. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    NASA Astrophysics Data System (ADS)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the

  13. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    NASA Astrophysics Data System (ADS)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the

  14. Advanced Techniques for In-Situ Monitoring of Phase Transformations During Welding Using Synchrotron-Based X-Ray Diffraction

    SciTech Connect

    Elmer, J W; Palmer, T A; Zhang, W; DebRoy, T

    2005-06-05

    Understanding the evolution of microstructure in welds is an important goal of welding research because of the strong correlation between weld microstructure and weld properties. To achieve this goal it is important to develop a quantitative measure of phase transformations encountered during welding in order to ultimately develop methods for predicting weld microstructures from the characteristics of the welding process. To aid in this effort, synchrotron radiation methods have been developed at Lawrence Livermore National Laboratory (LLNL) for direct observation of microstructure evolution during welding. Using intense, highly collimated synchrotron radiation, the atomic structure of the weld heat affected and fusion zones can be probed in real time. Two synchrotron-based techniques, known as spatially resolved (SRXRD) and time resolved (TRXRD) x-ray diffraction, have been developed for these investigations. These techniques have now been used to investigate welding induced phase transformations in titanium alloys, low alloy steels, and stainless steel alloys. This paper will provide a brief overview of these methods and will discuss microstructural evolution during the welding of low carbon (AISI 1005) and medium carbon (AISI 1045) steels where the different levels of carbon influence the evolution of microstructures during welding.

  15. Development of In-Situ Erosion Measurement Techniques for Application to Real-Time Determination of Plasma Thruster Component Lifetimes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This research has resulted in advancing the laser-based diagnostic capability and the ion optics development in the ion propulsion program at NASA GRC. Laser-based plasma diagnostics have been demonstrated in tabletop experiments and, in the case of LDI, on laboratory hollow cathodes. Assessment by GRC of its resources and priorities two years into the grant lead to a refocusing of the research effort away from the development of a real-time erosion rate measurement technique. The extension of the diagnostic techniques to diagnostic tools has been transferred to graduate students under the technical direction of the PI. These diagnostics may facilitate the development of ion thruster with significantly improved throughput capability for lower-power (10 kW) missions High-Isp, Long-lived ion optics development has proceeded from simple extensions of state-of-the-art geometries to radically different geometries and materials. Full-scale testing of these ion optics has demonstrated a significant advance in the throughput capability of ion thrusters enabling significantly more demanding missions. The capability to predict the throughput was developed and will continue to be upgraded. The performance models have been validated via full-scale testing. Partial validation of the throughput prediction will be completed via an upcoming wear test of the ion optics.

  16. Technical Note: A novel rocket-based in situ collection technique for mesospheric and stratospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    Reid, W.; Achtert, P.; Ivchenko, N.; Magnusson, P.; Kuremyr, T.; Shepenkov, V.; Tibert, G.

    2013-03-01

    A technique for collecting aerosol particles between altitudes of 17 and 85 km is described. Spin-stabilized collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Collection samples are exposed over a 50 m to 5 km height range with a total of 45 separate ranges. Post-flight electron microscopy will give size-resolved information on particle number, shape and elemental composition. Each collection probe is equipped with a suite of sensors to capture the probe's status during the fall. Parachute recovery systems along with GPS-based localization will ensure that each probe can be located and recovered for post-flight analysis.

  17. Verification of passive cooling techniques in the Super-FRS beam collimators

    NASA Astrophysics Data System (ADS)

    Douma, C. A.; Gellanki, J.; Najafi, M. A.; Moeini, H.; Kalantar-Nayestanaki, N.; Rigollet, C.; Kuiken, O. J.; Lindemulder, M. F.; Smit, H. A. J.; Timersma, H. J.

    2016-08-01

    The Super FRagment Separator (Super-FRS) at the FAIR facility will be the largest in-flight separator of heavy ions in the world. One of the essential steps in the separation procedure is to stop the unwanted ions with beam collimators. In one of the most common situations, the heavy ions are produced by a fission reaction of a primary 238U-beam (1.5 GeV/u) hitting a 12C target (2.5 g/cm2). In this situation, some of the produced ions are highly charged states of 238U. These ions can reach the collimators with energies of up to 1.3 GeV/u and a power of up to 500 W. Under these conditions, a cooling system is required to prevent damage to the collimators and to the corresponding electronics. Due to the highly radioactive environment, both the collimators and the cooling system must be suitable for robot handling. Therefore, an active cooling system is undesirable because of the increased possibility of malfunctioning and other complications. By using thermal simulations (performed with NX9 of Siemens PLM), the possibility of passive cooling is explored. The validity of these simulations is tested by independent comparison with other simulation programs and by experimental verification. The experimental verification is still under analysis, but preliminary results indicate that the explored passive cooling option provides sufficient temperature reduction.

  18. Applications of a new magnetic monitoring technique to in situ evaluation of fatigue damage in ferrous components

    SciTech Connect

    Jiles, D.C.; Biner, S.B.; Govindaraju, M.R.; Chen, Z.J.

    1994-06-01

    This project consisted of research into the use of magnetic inspection methods for the estimation of fatigue life of nuclear pressure vessel steel. Estimating the mechanical and magnetic properties of ferromagnetic materials are closely interrelated, therefore, measurements of magnetic properties could be used to monitor the evolution of fatigue damage in specimens subjected to cyclic loading. Results have shown that is possible to monitor the fatigue damage nondestructively by magnetic techniques. For example, in load-controlled high-cycle fatigue tests, it has been found that the plastic strain and coercivity accumulate logarithmically during the fatigue process. Thus a quantitative relationship between coercivity and the number of fatigue cycles could be established based on two empirical coefficients, which can be determined from the test conditions and material properties. Also it was found that prediction of the onset of fatigue failure in steels was possible under certain conditions. In strain-controlled low cycle fatigue, critical changes in Barkhausen emissions, coercivity and hysteresis loss occurred in the last ten to twenty percent of fatigue life.

  19. Static in situ calibration of force plates.

    PubMed

    Hall, M G; Fleming, H E; Dolan, M J; Millbank, S F; Paul, J P

    1996-05-01

    An in situ calibration protocol for ground-to-foot force measuring platforms is described. The methodology allows verification of the function of the force plate and allows accurate calibration for three force and moment channels. The effect of cross-sensitivity on recorded data is discussed along with the need for improvements in methodology to quantify this property.

  20. Novel techniques and devices for in-situ film coatings of long, small diameter tubes or elliptical and other surface contours

    SciTech Connect

    Hershcovitch, Ady; Blaskiewicz, Michael; Brennan, Joseph Michael; Fischer, Wolfram; Liaw, Chong -Jer; Meng, Wuzhang; Todd, Robert; Custer, Art; Dingus, Aaron; Erikson, Mark; Jamshidi, Nader; Poole, Henry Joe

    2015-07-30

    In this study, devices and techniques that can, via physical vapor deposition,coat various surface contours or very long small aperture pipes, are described. Recently, a magnetron mole was developed in order to in-situ coat accelerator tube sections of the Brookhaven National Lab relativistic heavy ion collider that have 7.1 cm diameter with access points that are 500 m apart, for copper coat the accelerator vacuum tube in order to alleviate the problems of unacceptable ohmic heating and of electron clouds. A magnetron with a 50 cm long cathode was designed fabricated and successfully operated to copper coat a whole assembly containing a full-size, stainless steel, cold bore, of the accelerator magnet tubing connected to two types bellows, to which two additional pipes made of accelerator tubing were connected. The magnetron is mounted on a carriage with spring loaded wheels that successfully crossed bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. Electrical power and cooling water were fed through a cable bundle. The umbilical cabling system, which is enclosed in a flexible braided metal sleeve, is driven by a motorized spool. To increase cathode lifetime, movable magnet package was developed, and thickest possible cathode was made, with a rather challenging target to substrate distance of less than 1.5 cm. Optimized process to ensure excellent adhesion was developed. Coating thickness of 10 μm Cu passed all industrial tests and even exceeded maximum capability of a 12 kg pull test fixture. Room temperature radio frequency (RF) resistivity measurement indicated that 10 μm Cu coated stainless steel accelerator tube has conductivity close to copper tubing. Work is in progress to repeat the RF resistivity measurement at cryogenic temperatures. Over 20 years ago, a device using multi axis robotic manipulators controlling separate robotic assemblies resulted in nine-axes of motion combined with conformal shape of the

  1. Novel techniques and devices for in-situ film coatings of long, small diameter tubes or elliptical and other surface contours

    DOE PAGES

    Hershcovitch, Ady; Blaskiewicz, Michael; Brennan, Joseph Michael; Fischer, Wolfram; Liaw, Chong -Jer; Meng, Wuzhang; Todd, Robert; Custer, Art; Dingus, Aaron; Erikson, Mark; et al

    2015-07-30

    In this study, devices and techniques that can, via physical vapor deposition,coat various surface contours or very long small aperture pipes, are described. Recently, a magnetron mole was developed in order to in-situ coat accelerator tube sections of the Brookhaven National Lab relativistic heavy ion collider that have 7.1 cm diameter with access points that are 500 m apart, for copper coat the accelerator vacuum tube in order to alleviate the problems of unacceptable ohmic heating and of electron clouds. A magnetron with a 50 cm long cathode was designed fabricated and successfully operated to copper coat a whole assemblymore » containing a full-size, stainless steel, cold bore, of the accelerator magnet tubing connected to two types bellows, to which two additional pipes made of accelerator tubing were connected. The magnetron is mounted on a carriage with spring loaded wheels that successfully crossed bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. Electrical power and cooling water were fed through a cable bundle. The umbilical cabling system, which is enclosed in a flexible braided metal sleeve, is driven by a motorized spool. To increase cathode lifetime, movable magnet package was developed, and thickest possible cathode was made, with a rather challenging target to substrate distance of less than 1.5 cm. Optimized process to ensure excellent adhesion was developed. Coating thickness of 10 μm Cu passed all industrial tests and even exceeded maximum capability of a 12 kg pull test fixture. Room temperature radio frequency (RF) resistivity measurement indicated that 10 μm Cu coated stainless steel accelerator tube has conductivity close to copper tubing. Work is in progress to repeat the RF resistivity measurement at cryogenic temperatures. Over 20 years ago, a device using multi axis robotic manipulators controlling separate robotic assemblies resulted in nine-axes of motion combined with conformal

  2. A crossover adjustment for improving sea surface height mapping from in-situ high rate ship-borne GNSS data using PPP technique

    NASA Astrophysics Data System (ADS)

    Guo, Jinyun; Dong, Zhenghua; Tan, Zhengguang; Liu, Xin; Chen, Chuanfa; Hwang, Cheinway

    2016-08-01

    Ship-borne global navigation satellite system (GNSS) technique can overcome the weakness of satellite altimetry and tide gauge in measuring sea surface heights (SSHs) over coastal seas. Ship-borne GNSS technique can be used to calibrate SSHs determined by the satellite altimetry and tide gauge. The ship-borne GNSS data are processed with the single-epoch precise point positioning (PPP) method to estimate SSHs which are filtered by the Gaussian filter to weaken and/or remove effects of sea wind and wave field. Tidal corrections are also taken into consideration to improve SSHs. One crossover adjustment method is put forward to calculate the bias and drift along the ship route and assess the accuracy of SSHs. We processed the in-situ ship-borne GPS data over the offshore sea around Keelung to compute precisely SSHs with the single-epoch PPP. Statistical results of SSH differences of crossover points indicate that the root mean squares error of SSHs determined by the ship-borne GPS is up to level of 12.9 cm over the offshore sea ~30 km far away to land.

  3. Investigation of the Surface Stress in SiC and Diamond Nanocrystals by In-situ High Pressure Powder Diffraction Technique

    NASA Technical Reports Server (NTRS)

    Palosz, B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Zhao, Y.; Palosz, W.

    2003-01-01

    The real atomic structure of nanocrystals determines key properties of the materials. For such materials the serious experimental problem lies in obtaining sufficiently accurate measurements of the structural parameters of the crystals, since very small crystals constitute rather a two-phase than a uniform crystallographic phase system. As a result, elastic properties of nanograins may be expected to reflect a dual nature of their structure, with a corresponding set of different elastic property parameters. We studied those properties by in-situ high-pressure powder diffraction technique. For nanocrystalline, even one-phase materials such measurements are particularly difficult to make since determination of the lattice parameters of very small crystals presents a challenge due to inherent limitations of standard elaboration of powder diffractograms. In this investigation we used our methodology of the structural analysis, the 'apparent lattice parameter' (alp) concept. The methodology allowed us to avoid the traps (if applied to nanocrystals) of standard powder diffraction evaluation techniques. The experiments were performed for nanocrystalline Sic and GaN powders using synchrotron sources. We applied both hydrostatic and isostatic pressures in the range of up to 40 GPa. Elastic properties of the samples were examined based on the measurements of a change of the lattice parameters with pressure. The results show a dual nature of the mechanical properties (compressibilities) of the materials, indicating a complex, core-shell structure of the grains.

  4. Effect of tissue heterogeneity on an in vivo range verification technique for proton therapy.

    PubMed

    Bentefour, El Hassane; Shikui, Tang; Prieels, Damien; Lu, Hsiao-Ming

    2012-09-01

    It was proposed recently that time-resolved dose measurements during proton therapy treatment by passively scattered beams may be used for in vivo range verification. The method was shown to work accurately in a water tank. In this paper, we further evaluated the potential of the method for more clinically relevant situations where proton beams must pass through regions with significant tissue heterogeneities. Specifically, we considered prostate treatment where the use of anterior or anterior- oblique fields was recently proposed in order to reduce rectal dose by taking advantage of the sharp distal fall-off of the Bragg peak. These beam portals pass through various parts of pubic bone and potential air cavities in the bladder and bowels. Using blocks of materials with densities equivalent to bone, air, etc, arranged in the water tank in relevant configurations, we tested the robustness of the method against range shifting and range mixing. In the former, the beam range is changed uniformly by changes in tissue density in the beam path, while in the latter, variations in tissue heterogeneities across the beam cross section causes the mixing of beam energies downstream, as often occurs when the beam travels along the interface of materials with significantly different densities. We demonstrated that in the region of interest, the method can measure water-equivalent path length with accuracy better than ±0.5 mm for pure range shifting and still reasonable accuracy for range mixing between close beam energies. In situations with range mixing between significantly different beam energies, the dose rate profiles may be simulated for verifying the beam range. We also found that the above performances can be obtained with very small amount of dose (<0.5 cGy), if silicon diodes are used as detectors. This makes the method suitable for in vivo range verification prior to each treatment delivery. PMID:22864304

  5. Optical and Acoustical Techniques for Non-viral Gene Delivery to Mammalian Cells and In-situ Study of Cytoskeletal Mechanics

    NASA Astrophysics Data System (ADS)

    Ma, Zili

    surface acoustic waves, which not only achieved a high efficiency of cells permeabilization in a quick speed, but also allowed us to observe the permeabilization process in real time by microscope. This device is also compatible with biophotonics studies based on fs laser, which can be further developed as a powerful tool for optical gene delivery with the capability of precisely controlling the fluid on-chip by SAW. SAW devices could also achieve exogenous gene delivery through the cell membrane without the need of adding chemical agents. Our results showed that the membrane of mammalian adherent cells could be effectively perforated transiently by applying a SAW. The transfection of pEGFP plasmids into endothelial cells was carried out successfully via this SAW-induced cell perforation. The expression of GFP was observed after 24-hour incubation subsequent to the SAW treatment. In regard to the application of fs lasers in cellular and subcellular level studies, we applied the optical nanoscissoring technique based on fs lasers in biomechanical studies to study the mechanical properties of single SF in-situ. Integrated into a confocal microscope, the fs laser showed great power in manipulating targeted in-situ subcellular structures under real-time imaging without damaging nearby regions. Here, how oxidative challenges would alter the mechanical properties of SFs in myoblasts was firstly investigated using the optical nanoscissoring technique to comprehend the whole picture of muscle tissue injury and repair from the basics. The prestress of stress fibers after the oxidative challenges was found through our modified viscoelastic retraction model and experiment result.

  6. Contraction-by-contraction VO2 and computer-controlled pump perfusion as novel techniques to study skeletal muscle metabolism in situ.

    PubMed

    Hernández, Andrés; Goodwin, Matthew L; Lai, Nicola; Cabrera, Marco E; McDonald, James R; Gladden, L Bruce

    2010-03-01

    The purpose of this research was to develop new techniques to 1) rapidly sample venous O(2) saturation to determine contraction-by-contraction oxygen uptake (Vo(2)), and 2) precisely control the rate and pattern of blood flow adjustment from one chosen steady state to another. An indwelling inline oximeter probe connected to an Oximetrix 3 meter was used to sample venous oxygen concentration ([O(2)]) (via fractional saturation of Hb with O(2)). Data from the Oximetrix 3 were filtered, deconvolved, and processed by a moving average second by second. Computer software and a program written in-house were used to control blood flow with a peristaltic pump. The isolated canine gastrocnemius muscle complex (GS) in situ was utilized to test these techniques. A step change in metabolic rate was elicited by stimulating GS muscles via their sciatic nerves (supramaximal voltage, 8 V; 50 Hz, 0.2-ms pulse width; train duration 200 ms) at a rate of either 1 contraction/2 s, or 2 contractions/3 s. With arterial [O(2)] maintained constant, blood flow and calculated venous [O(2)] were averaged over each contraction cycle and used in the Fick equation to calculate contraction-by-contraction Vo(2). About 5-8 times more data points were obtained with this method compared with traditional manual sampling. Software-controlled pump perfusion enabled the ability to mimic spontaneous blood flow on-kinetics (tau: 14.3 s) as well as dramatically speed (tau: 2.0 s) and slow (tau: 63.3 s) on-kinetics. These new techniques significantly improve on existing methods for mechanistically altering blood flow kinetics as well as accurately measuring muscle oxygen consumption kinetics during transitions between metabolic rates. PMID:20035064

  7. Phylogenetic and taxonomic analysis of Neptunitalea chrysea gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from seawater by using an in situ cultivation technique.

    PubMed

    Yoon, Jaewoo; Kasai, Hiroaki

    2015-09-01

    A novel pale-yellow coloured bacterial strain, designated AM327(T), was isolated by using an in situ cultivation technique from seawater from the coastal zone around a shipyard located in Otsuchi Bay, Japan. The strain was found to be facultatively anaerobic, Gram-stain negative, chemoheterotrophic, non-motile and rod-shaped. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate is affiliated with the family Flavobacteriaceae of the phylum Bacteroidetes and that it shows high sequence similarity (94.7 %) to Frondibacter aureus A5Q-67(T). The strain can be differentiated phenotypically from recognised members of the family Flavobacteriaceae. The DNA G+C content of strain AM327(T) was determined to be 36.2 mol%; MK-6 was identified as the major menaquinone; iso-C15:0 and iso-C17:0 3-OH were identified as the major (>10 %) cellular fatty acids. The polar lipid profile was found to consist of phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid and two unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, strain AM327(T) is considered to represent a novel genus for which the name Neptunitalea chrysea gen. nov., sp. nov. is proposed. The type strain of N. chrysea is AM327(T) (=KCTC 32989(T) = NBRC 110019(T)).

  8. Real-Time Structure Changes during Uniaxial Stretching of Poly (omega-pentadecalactone) by in Situ Synchrotron WAXD/SAXS Techniques

    SciTech Connect

    J Cai; B Hsiao; R Gross

    2011-12-31

    Poly({omega}-pentadecalactone) (PPDL), a model polymer in the poly({omega}-hydroxyl fatty acids) family, is a new biopolymer with monomer synthesized by yeast-catalyzed {omega}-hydroxylation of fatty acids. In this study, deformation-induced structural changes in two PPDL samples with different molecular weights were studied by in situ wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. The high molecular weight PPDL (PPDL-high) sample exhibited notable strain hardening, while the low molecular weight PPDL (PPDL-low) sample did not. The behavior can be explained by the entanglement density concept. The evolution of crystallinity (from WAXD) as a function of strain could be divided into four distinct regions, but their respective mechanisms differ slightly in each sample. During stretching, a mesomorphic phase formed in both samples, bridging between the amorphous and strain-induced crystal phases. The SAXS data verified the effect of molecular weight (or the entanglement density) on the deformation-induced structure of PPDL. The parameters of chain orientation factor (f) calculated from the orthorhombic crystal cell as well as the nonorthorhombic crystal cell proposed by Wilchinsky were used to follow the orientation process during stretching of PPDLs. It was found that the different molecular entanglement network (i.e., PPDL-low versus PPDL-high) led to different crystal orientation behavior, especially in the low strain range.

  9. In-situ investigation of stress conditions during expansion of bare metal stents and PLLA-coated stents using the XRD sin(2)ψ-technique.

    PubMed

    Kowalski, Wolfgang; Dammer, Markus; Bakczewitz, Frank; Schmitz, Klaus-Peter; Grabow, Niels; Kessler, Olaf

    2015-09-01

    Drug eluting stents (DES) consist of platform, coating and drug. The platform often is a balloon-expandable bare metal stent made of the CoCr alloy L-605 or stainless steel 316 L. The function of the coating, typically a permanent polymer, is to hold and release the drug, which should improve therapeutic outcome. Before implantation, DES are compressed (crimped) to allow implantation in the human body. During implantation, DES are expanded by balloon inflation. Crimping, as well as expansion, causes high stresses and high strains locally in the DES struts, as well as in the polymer coating. These stresses and strains are important design criteria of DES. Usually, they are calculated numerically by finite element analysis (FEA), but experimental results for validation are hardly available. In this work, the X-ray diffraction (XRD) sin(2)ψ-technique is applied to in-situ determination of stress conditions of bare metal L-605 stents, and Poly-(L-lactide) (PLLA) coated stents. This provides a realistic characterization of the near-surface stress state and a validation option of the numerical FEA. XRD-results from terminal stent struts of the bare metal stent show an increasing compressive load stress in tangential direction with increasing stent expansion. These findings correlate with numerical FEA results. The PLLA-coating also bears increasing compressive load stress during expansion.

  10. Tailoring copper valence states in CuOδ/γ-Al2O3 catalysts by an in situ technique induced superior catalytic performance for simultaneous elimination of NO and CO.

    PubMed

    Yao, Xiaojiang; Gao, Fei; Cao, Yuan; Tang, Changjin; Deng, Yu; Dong, Lin; Chen, Yi

    2013-09-28

    An in situ technique is employed to tailor the valence states of copper in CuOδ/γ-Al2O3 catalysts with the purpose of inducing superior catalytic performance for simultaneous elimination of NO and CO. The catalyst with zero-valent copper exhibits excellent catalytic performance, which is comparable with the conventional supported noble-metal catalysts. PMID:23925070

  11. Verification of Adaptive Systems

    SciTech Connect

    Pullum, Laura L; Cui, Xiaohui; Vassev, Emil; Hinchey, Mike; Rouff, Christopher; Buskens, Richard

    2012-01-01

    Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance for them. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

  12. Software verification and testing

    NASA Technical Reports Server (NTRS)

    1985-01-01

    General procedures for software verification and validation are provided as a guide for managers, programmers, and analysts involved in software development. The verification and validation procedures described are based primarily on testing techniques. Testing refers to the execution of all or part of a software system for the purpose of detecting errors. Planning, execution, and analysis of tests are outlined in this document. Code reading and static analysis techniques for software verification are also described.

  13. Applicability study of using in-situ gamma-ray spectrometry technique for 137Cs and 210Pb(ex) inventories measurement in grassland environments.

    PubMed

    Li, Junjie; Li, Yong; Wang, Yanglin; Wu, Jiansheng; Funk, Roger; Hoffmann, Carsten

    2010-06-01

    In-situ measurement of fallout radionuclides (137)Cs and (210)Pb(ex) has the potential to assess soil erosion and sedimentation rapidly. In this study, inventories of (137)Cs and (210)Pb(ex) in the soil of Inner Mongolia grassland were measured using an In-situ Object Counting System (ISOCS). The results from the field study indicate that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no extra time is required for sample collection, no reference inventories are required, more economic, prompt availability of the results, the ability to average radionuclide inventory over a large area, and high precision. PMID:20133146

  14. Synergistic Use of SMOS Measurements with SMAP Derived and In-situ Data over Valencia Anchor Station by Using Downscaling Technique

    NASA Astrophysics Data System (ADS)

    Ansari Amoli, Abdolreza; Lopez-Baeza, Ernesto; Mahmoudi, Ali; Mahmoodi, Ali

    2016-07-01

    Synergistic Use of SMOS Measurements with SMAP Derived and In-situ Data over the Valencia Anchor Station by Using a Downscaling Technique Ansari Amoli, A.(1),Mahmoodi, A.(2) and Lopez-Baeza, E.(3) (1) Department of Earth Physics and Thermodynamics, University of Valencia, Spain (2) Centre d'Etudes Spatiales de la BIOsphère (CESBIO), France (3) Department of Earth Physics and Thermodynamics, University of Valencia, Spain Soil moisture products from active sensors are not operationally available. Passive remote sensors return more accurate estimates, but their resolution is much coarser. One solution to overcome this problem is the synergy between radar and radiometric data by using disaggregation (downscaling) techniques. Few studies have been conducted to merge high resolution radar and coarse resolution radiometer measurements in order to obtain an intermediate resolution product. In this paper we present an algorithm using combined available SMAP (Soil Moisture Active and Passive) radar and SMOS (Soil Moisture and Ocean Salinity) radiometer measurements to estimate surface soil moisture over the Valencia Anchor Station (VAS), Valencia, Spain. The goal is to combine the respective attributes of the radar and radiometer observations to estimate soil moisture at a resolution of 3 km. The algorithm disaggregates the coarse resolution SMOS (15 km) radiometer brightness temperature product based on the spatial variation of the high resolution SMAP (3 km) radar backscatter. The disaggregation of the radiometer brightness temperature uses the radar backscatter spatial patterns within the radiometer footprint that are inferred from the radar measurements. For this reason the radar measurements within the radiometer footprint are scaled by parameters that are derived from the temporal fluctuations in the radar and radiometer measurements.

  15. Reconstructing the protracted P-T-t-d path of a giant ultrahigh-pressure terrane: Linking in-situ techniques with multiple methods of conventional geochronology (Invited)

    NASA Astrophysics Data System (ADS)

    Kylander-Clark, A. R.; Hacker, B. R.

    2010-12-01

    The processes that govern the genesis of ultrahigh-pressure (UHP) terranes directly affect those that control the growth and decay of mountain belts, the modification of continental crust, the geochemical evolution of the mantle, and the forces acting on tectonic plates. As such, our understanding of the timing, rates, and/or depths of subduction, exhumation, residence time, deformation, melting and cooling is critical in understanding the aforementioned geologic phenomena. No one sample location or geochronologic technique can properly reconstruct the pressure-temperature-time-deformation history of a terrane, and older terranes are further hampered by the necessity for high-precision geochronologic data that in-situ techniques cannot provide. In this study, we present an array of geochronologic techniques, which allow us to reconstruct much of the P-T-t-d path of the Western Gneiss Region (WGR) UHP terrane, western Norway. These ages can only be linked to specific events by determining the chemical and/or petrologic relation between the chronometer and the whole rock. The Western Gneiss Region was formed in a portion of Baltica that was subducted westward beneath Laurentia during the Caledonian orogeny in the Silurian to Late Devonian. Garnets of eclogites with high-Lu cores (analyzed via LA-ICPMS), yield the oldest Lu-Hf ages, indicating that subduction began by ~420 Ma. Eclogite-facies conditions are commonly linked to zircon ages (ca. 415-400 Ma), although few studies report both petrologic and chemical links to such conditions; rare-earth element data must be compared to either inherited cores or the whole rock. Chemical-abrasion TIMS ages of zircon from weakly- to non-deformed dikes indicate that melting occurred at ca. 400 Ma and subsequent deformation in these areas was minimal. LA-ICPMS data from these melt-related zircons indicate that melting took place at sub-eclogite-facies pressures and thus that initial exhumation of the WGR was rapid. Conventional

  16. Geometric verification

    NASA Technical Reports Server (NTRS)

    Grebowsky, G. J.

    1982-01-01

    Present LANDSAT data formats are reviewed to clarify how the geodetic location and registration capabilities were defined for P-tape products and RBV data. Since there is only one geometric model used in the master data processor, geometric location accuracy of P-tape products depends on the absolute accuracy of the model and registration accuracy is determined by the stability of the model. Due primarily to inaccuracies in data provided by the LANDSAT attitude management system, desired accuracies are obtained only by using ground control points and a correlation process. The verification of system performance with regards to geodetic location requires the capability to determine pixel positions of map points in a P-tape array. Verification of registration performance requires the capability to determine pixel positions of common points (not necessarily map points) in 2 or more P-tape arrays for a given world reference system scene. Techniques for registration verification can be more varied and automated since map data are not required. The verification of LACIE extractions is used as an example.

  17. Concurrent use of flow cytometry and fluorescence in-situ hybridization techniques for detecting faulty meiosis in a human sperm sample.

    PubMed

    Weissenberg, R; Aviram, A; Golan, R; Lewin, L M; Levron, J; Madgar, I; Dor, J; Barkai, G; Goldman, B

    1998-01-01

    Routine semen analysis in an infertile patient revealed severe teratospermia associated with malformation of head and tail in 100% of the sperm cells. Flow cytometry and fluorescence in-situ hybridization (FISH) were shown to supplement routine semen analysis by providing information on the sperm chromatin. Using flow cytometry, propidium iodide-stained spermatozoa from the same sperm sample were compared with a normal reference pool, and with human lymphocytes. The results point to a population of diploid sperm cells rather than to mature haploid spermatozoa. Numerical chromosomal abnormalities of the spermatozoa were subsequently evaluated using FISH. A total of 1000 sperm cells were scored for X and Y chromosomes, and an additional 1128 sperm cells for chromosome 18. Aneuploidy of chromosomes X and Y was revealed in 96.9% of the cells and of chromosome 18 in 90.3% of the cells. Non-disjunction of chromosome X and Y in meiosis I and II occurred in 54.8 and 2.7% of the sperm cells respectively. Non-disjunction in both meiosis I and II occurred in 39.4% of the sperm cells. A normal haploid pattern for chromosomes X and Y was observed in only 3.1%, and for chromosome 18 in 9.7%, of the cells. Using three colour FISH for the sex chromosomes and for chromosome 18, diploidy was demonstrated in 19.4% of 500 sperm cells and aneuploidy in virtually all sperm cells (99.2%). The use of flow cytometry and FISH in cases where genetic and developmental chromatin abnormalities are suspected is a valuable adjunct to other available techniques, and can guide the clinicians to decide which samples are unsuitable for intracytoplasmic injection.

  18. Rapid in situ hybridization technique using 16S rRNA segments for detecting and differentiating the closely related gram-positive organisms Bacillus polymyxa and Bacillus macerans

    NASA Technical Reports Server (NTRS)

    Jurtshuk, R. J.; Blick, M.; Bresser, J.; Fox, G. E.; Jurtshuk, P. Jr

    1992-01-01

    A rapid, sensitive, inexpensive in situ hybridization technique, using 30-mer 16S rRNA probes, can specifically differentiate two closely related Bacillus spp., B. polymyxa and B. macerans. The 16S rRNA probes were labeled with a rhodamine derivative (Texas Red), and quantitative fluorescence measurements were made on individual bacterial cells. The microscopic fields analyzed were selected by phase-contrast microscopy, and the fluorescence imaging analyses were performed on 16 to 67 individual cells. The labeled 16S rRNA probe, POL, whose sequence was a 100% match with B. polymyxa 16S rRNA but only a 60% match with B. macerans 16S rRNA, gave quantitative fluorescence ratio measurements that were 34.8-fold higher for B. polymyxa cells than for B. macerans cells. Conversely, the labeled probe, MAC, which matched B. polymyxa 16S rRNA in 86.6% of its positions and B. macerans 16S rRNA in 100% of its positions, gave quantitative fluorescence measurements that were 59.3-fold higher in B. macerans cells than in B. polymyxa cells. Control probes, whose 16S rRNA sequence segment (P-M) was present in both B. polymyxa and B. macerans as well as a panprokaryotic probe (16S), having a 100% match with all known bacteria, hybridized equally well with both organisms. These latter hybridizations generated very high fluorescence signals, but their comparative fluorescence ratios (the differences between two organisms) were low. The control paneukaryotic probe (28S), which had less than 30% identity for both B. macerans and B. polymyxa, did not hybridize with either organism.

  19. In situ spectrometric and chemical measurements of methane emissions from a natural marine hydrocarbon seep field, Coal Oil Point, California: Validation of methane remote sensing techniques

    NASA Astrophysics Data System (ADS)

    Luyendyk, B. P.; Leifer, I.; Roberts, D.; Margolis, J. S.

    2006-12-01

    Remote sensing techniques can significantly improve our understanding of the sources and sinks of the important greenhouse gas methane. Field and laboratory studies used spectral and in-situ chemical measurements of geologic methane plumes from natural marine seepage and radiative-transfer calculations to test the feasibility of using NASA's Airborne Visual/Infrared Imaging Spectrometer (AVIRIS) for methane remote sensing of this marine source. Based on numerical MODTRAN simulations, the spectral region between 2200 and 2340 nm was chosen for its sensitivity to CH4 with mild sensitivity to water vapor interference. During one marine field study, an intense seep area was repeatedly transected by boat using flame ion detectors (FID) to characterize the methane plume along with detailed meteorological measurements. Based on a Gaussian plume dispersion model for 3 m/s wind speed, methane column-abundances were calculated and showed a plume with methane concentrations greater than 0.5 g/m2 extending downwind 70 m with a 20 m width, much larger than the 3 to 5 m AVIRIS pixel size. Most of the methane was in the lower 10 m. MODTRAN calculations showed this to be well above the noise equivalent detection level of AVIRIS. During a separate field study, FIDs at three heights above the sea surface (2.2, 3.6, and 5 m) measured methane concentrations as high as 200 ppm while transecting an active seep area. Simultaneous spectra were obtained with a field spectrometer. Several plumes were identified from the FID data and a clear relationship was shown between the presence of methane plumes along the incident path and the presence of methane absorption features in spectra. Methane absorption features above atmospheric background were not observed outside the plumes.

  20. Possibilities and limitations of fluorescence in situ hybridization technique in retrospective detection of low dose radiation exposure in post-chernobyl human cohorts.

    PubMed

    Maznyk, N A; Vinnikov, V A

    2005-01-01

    Cytogenetic analysis using the fluorescence in situ hybridisation (FISH) technique was performed late time after the Chernobyl accident in groups of liquidators, evacuees from 30 km exclusive zone, residents of radioactively contaminated areas and control donors age-matched to exposed persons. Stable and unstable chromosome type exchanges were recorded using a hybrid conventional-PAINT nomenclature. The mean yield of stable chromosome exchanges in liquidators did not correlate with registered radiation doses but had a clear negative dependence on the duration of liquidators' staying in Chernobyl zone, that was in a good agreement with early data based on conventional dicentrics plus rings analysis. The overspontaneous excess for stable chromosome exchange level appeared to be higher in evacuees 16-40 years old than that of senior persons, whereas no age-dependent difference occurred for initially induced dicentrics plus rings yields in this cohort. The stable chromosome exchange yield, as well as combined yield of dicentrics plus rings and potentially unstable incomplete translocations in residents of radioactively contaminated areas showed a reasonable positive correlation with levels of 137Cs contamination. The observed yields of stable chromosome exchanges in all three exposed groups appeared to be somewhat lower than those of expected from unstable exchange-based doses which were referred to an in vitro dose response of stable exchanges outcome in human lymphocytes. Thus, FISH analysis can be successfully applied for qualitative cytogenetic indication of past and chronic radiation exposure to low doses but further refinement of FISH-based system for quantitative dose assessment is still required. Some practical approaches of solving this task are discussed.

  1. Verification of the Monte Carlo differential operator technique for MCNP{trademark}

    SciTech Connect

    McKinney, G.W.; Iverson, J.L.

    1996-02-01

    The differential operator perturbation technique has been incorporated into the Monte Carlo N-Particle transport code MCNP and will become a standard feature of future releases. This feature includes first and second order terms of the Taylor series expansion for response perturbations related to cross-section data (i.e., density, composition, etc.). Perturbation and sensitivity analyses can benefit from this technique in that predicted changes in one or more tally responses may be obtained for multiple perturbations in a single run. The user interface is intuitive, yet flexible enough to allow for changes in a specific microscopic cross section over a specified energy range. With this technique, a precise estimate of a small change in response is easily obtained, even when the standard deviation of the unperturbed tally is greater than the change. Furthermore, results presented in this report demonstrate that first and second order terms can offer acceptable accuracy, to within a few percent, for up to 20-30% changes in a response.

  2. Nature Of Pulsed Laser Deposition Technique And In-Situ Processing Of YBa2Cu3O7 Superconducting Thin Films

    NASA Astrophysics Data System (ADS)

    Singh, Rajiv K.; Tiwari, P.; Narayan, Jagdish

    1990-03-01

    The deposition characteristics of YBa2Cu3O7 thin films formed by pulsed laser evaporation (PLE) method have been found to be significantly different from films obtained by other vaporization methods primarily because of very high evaporation flux which absorbs the incoming laser irradiation. Based on the experimentally obtained deposition characteristics, the physics of the PLE process is analyzed, and a hydrodynamic gas expansion model is proposed for the PLE process. In this model, the laser generated partially ionized plasma, initially under high temperature and pressure, expands anisotropically into vacuum. The plasma expansion characteristics determine the nature of the deposition process. Solutions governing the plasma expansion are obtained, and the calculated deposition characteristics are compared with results obtained on PLE deposited YBa2Cu3O7 films on silicon substrates. This model is able to explain most of the salient features of the pulsed laser deposition technique. The non-equilibrium nature of the PLE technique has been utilized for in-situ fabrication of superconducting YBa2Cu3O7 thin films on (100) SrTiO3, (100) YS-ZrO2, and (100) LaA1O3 substrates in the temperature range of 500-650°C. A positively biased ring between the substrate and the target has been found to reduce the processing temperatures to 500°C, although the epitaxial quality of the films deteriorated considerably below 550°C. The films formed on lattice matched SrTiO3 and LaA1O3 substrates are virtually defect-free with minimum channeling yields values equal to the single crystal value. Critical current densities values over 6.0 x 106 amps/cm2 (at 77 K and zero magnetic field) were obtained for epitaxial silver doped films YBa2Cu3O7 films on (100) LaA1O3 substrates. The effect of the processing parameters on the superconducting properties and microstructure of thin films is discussed in detail.

  3. SU-E-T-138: Dosimetric Verification For Volumetric Modulated Arc Therapy Cranio-Spinal Irradiation Technique

    SciTech Connect

    Goksel, E; Bilge, H; Yildiz, Yarar

    2014-06-01

    Purpose: Dosimetric feasibility of cranio-spinal irradiation with volumetric modulated arc therapy (VMAT-CSI) technique in terms of dose distribution accuracy was investigated using a humanlike phantom. Methods: The OARs and PTV volumes for the Rando phantom were generated on supine CT images. Eclipse (version 8.6) TPS with AAA algorithm was used to create the treatment plan with VMAT-CSI technique. RapidArc plan consisted of cranial, upper spinal (US) and lower spinal (LS) regions that were optimized in the same plan. US field was overlapped by 3cm with cranial and LS fields. Three partial arcs for cranium and 1 full arc for each US and LS region were used. The VMAT-CSI dose distribution inside the Rando phantom was measured with thermoluminescent detectors (TLD) and film dosimetry, and was compared to the calculated doses of field junctions, target and OARs. TLDs were placed at 24 positions throughout the phantom. The measured TLD doses were compared to the calculated point doses. Planar doses for field junctions were verified with Gafchromic films. Films were analyzed in PTW Verisoft application software using gamma analysis method with the 4 mm distance to agreement (DTA) and 4% dose agreement criteria. Results: TLD readings demonstrated accurate dose delivery, with a median dose difference of -0.3% (range: -8% and 12%) when compared with calculated doses for the areas inside the treatment portal. The maximum dose difference was 12% higher in testicals that are outside the treatment region and 8% lower in lungs where the heterogeinity was higher. All planar dose verifications for field junctions passed the gamma analysis and measured planar dose distributions demonstrated average 97% agreement with calculated doses. Conclusion: The dosimetric data verified with TLD and film dosimetry shows that VMAT-CSI technique provides accurate dose distribution and can be delivered safely.

  4. Detector power linearity requirements and verification techniques for TMI direct detection receivers

    NASA Technical Reports Server (NTRS)

    Reinhardt, Victor S. (Inventor); Shih, Yi-Chi (Inventor); Toth, Paul A. (Inventor); Reynolds, Samuel C. (Inventor)

    1997-01-01

    A system (36, 98) for determining the linearity of an RF detector (46, 106). A first technique involves combining two RF signals from two stable local oscillators (38, 40) to form a modulated RF signal having a beat frequency, and applying the modulated RF signal to a detector (46) being tested. The output of the detector (46) is applied to a low frequency spectrum analyzer (48) such that a relationship between the power levels of the first and second harmonics generated by the detector (46) of the beat frequency of the modulated RF signal are measured by the spectrum analyzer (48) to determine the linearity of the detector (46). In a second technique, an RF signal from a local oscillator (100) is applied to a detector (106) being tested through a first attenuator (102) and a second attenuator (104). The output voltage of the detector (106) is measured when the first attenuator (102) is set to a particular attenuation value and the second attenuator (104) is switched between first and second attenuation values. Further, the output voltage of the detector (106) is measured when the first attenuator (102) is set to another attenuation value, and the second attenuator (104) is again switched between the first and second attenuation values. A relationship between the voltage outputs determines the linearity of the detector (106).

  5. Verification of image orthorectification techniques for low-cost geometric inspection of masonry arch bridges

    NASA Astrophysics Data System (ADS)

    González-Jorge, Higinio; Riveiro, Belén; Varela, María; Arias, Pedro

    2012-07-01

    A low-cost image orthorectification tool based on the utilization of compact cameras and scale bars is developed to obtain the main geometric parameters of masonry bridges for inventory and routine inspection purposes. The technique is validated in three different bridges by comparison with laser scanning data. The surveying process is very delicate and must make a balance between working distance and angle. Three different cameras are used in the study to establish the relationship between the error and the camera model. Results depict nondependence in error between the length of the bridge element, the type of bridge, and the type of element. Error values for all the cameras are below 4 percent (95 percent of the data). A compact Canon camera, the model with the best technical specifications, shows an error level ranging from 0.5 to 1.5 percent.

  6. Optical fibre techniques for use within tamper indicating enclosures designed for arms control verification purposes

    NASA Astrophysics Data System (ADS)

    Dyer, Thomas C.; Thompson, Alexander W. J.; Wynn, Paul; White, Helen

    2014-10-01

    Ensuring that a future nuclear arms control agreement can be verified is a complex technical challenge. Tamper Indicating Enclosures (TIEs) are likely to be deployed as part of a chain of custody regime, providing an indication of an unauthorised attempt to access an item within the agreement. This paper focuses on the assessment of optical fibre techniques for ensuring boundary control as part of a TIE design. The results of optical fibre damage, subsequent repair attempts, enclosure construction considerations and unique identification features have been evaluated for a selection of fused-silica optical fibres. This paper focuses on detecting a fibre repair attempt, presents a method for increasing repair resistance and a method for uniquely identifying an enclosure using the optical signature from the embedded optical fibre.

  7. Development of experimental verification techniques for non-linear deformation and fracture.

    SciTech Connect

    Moody, Neville Reid; Bahr, David F.

    2003-12-01

    This project covers three distinct features of thin film fracture and deformation in which the current experimental technique of nanoindentation demonstrates limitations. The first feature is film fracture, which can be generated either by nanoindentation or bulge testing thin films. Examples of both tests will be shown, in particular oxide films on metallic or semiconductor substrates. Nanoindentations were made into oxide films on aluminum and titanium substrates for two cases; one where the metal was a bulk (effectively single crystal) material and the other where the metal was a 1 pm thick film grown on a silica or silicon substrate. In both cases indentation was used to produce discontinuous loading curves, which indicate film fracture after plastic deformation of the metal. The oxides on bulk metals fractures occurred at reproducible loads, and the tensile stress in the films at fracture were approximately 10 and 15 GPa for the aluminum and titanium oxides respectively. Similarly, bulge tests of piezoelectric oxide films have been carried out and demonstrate film fracture at stresses of only 100's of MPa, suggesting the importance of defects and film thickness in evaluating film strength. The second feature of concern is film adhesion. Several qualitative and quantitative tests exist today that measure the adhesion properties of thin films. A relatively new technique that uses stressed overlayers to measure adhesion has been proposed and extensively studied. Delamination of thin films manifests itself in the form of either telephone cord or straight buckles. The buckles are used to calculate the interfacial fracture toughness of the film-substrate system. Nanoindentation can be utilized if more energy is needed to initiate buckling of the film system. Finally, deformation in metallic systems can lead to non-linear deformation due to 'bursts' of dislocation activity during nanoindentation. An experimental study to examine the structure of dislocations around

  8. New Insights into the Structure Changes and Interface Properties of Li3VO4 Anode for Lithium-Ion Batteries during the Initial Cycle by in-Situ Techniques.

    PubMed

    Zhou, Li Li; Shen, Shou-Yu; Peng, Xin-Xing; Wu, Li Na; Wang, Qi; Shen, Chong-Heng; Tu, Ting-Ting; Huang, Ling; Li, Jun-Tao; Sun, Shi-Gang

    2016-09-14

    Li3VO4 has been regarded as a new-type anode of lithium-ion batteries in recent years, which has a high theoretical specific capacity of 394 mAh g(-1), a proper potential for Li(+) insertion/deinsertion (∼1 V), and a good rate capacity. However, its low initial Coulombic efficiency, poor conductivity, and poor cycle performance restricts its development. In order to figure out the cause of the low initial Coulombic efficiency of Li3VO4 material, the nanosized Li3VO4 material was synthesized by citric acid-assisted sol-gel method. The lithium storage behaviors of the prepared Li3VO4 material were studied by in-situ XRD and in-situ EIS techniques. In-situ XRD results indicated that there was irreversible phase transformation of Li3VO4 during the initial charging/discharging process. In-situ EIS experiment was performed during the potentiostatic intermittent titration technique (PITT) process to discuss the formation of the solid electrolyte interface (SEI) on the Li3VO4 and the kinetics of lithium-ion diffusion. It is worth pointing out that this is the first time to prove the existence of SEI on Li3VO4 during the initial charging/discharging process by in-situ EIS experiment. It turned out that the irreversible phase transformation and the formation of SEI on Li3VO4 were the two important reasons causing the low initial Coulombic efficiency of Li3VO4 material.

  9. New Insights into the Structure Changes and Interface Properties of Li3VO4 Anode for Lithium-Ion Batteries during the Initial Cycle by in-Situ Techniques.

    PubMed

    Zhou, Li Li; Shen, Shou-Yu; Peng, Xin-Xing; Wu, Li Na; Wang, Qi; Shen, Chong-Heng; Tu, Ting-Ting; Huang, Ling; Li, Jun-Tao; Sun, Shi-Gang

    2016-09-14

    Li3VO4 has been regarded as a new-type anode of lithium-ion batteries in recent years, which has a high theoretical specific capacity of 394 mAh g(-1), a proper potential for Li(+) insertion/deinsertion (∼1 V), and a good rate capacity. However, its low initial Coulombic efficiency, poor conductivity, and poor cycle performance restricts its development. In order to figure out the cause of the low initial Coulombic efficiency of Li3VO4 material, the nanosized Li3VO4 material was synthesized by citric acid-assisted sol-gel method. The lithium storage behaviors of the prepared Li3VO4 material were studied by in-situ XRD and in-situ EIS techniques. In-situ XRD results indicated that there was irreversible phase transformation of Li3VO4 during the initial charging/discharging process. In-situ EIS experiment was performed during the potentiostatic intermittent titration technique (PITT) process to discuss the formation of the solid electrolyte interface (SEI) on the Li3VO4 and the kinetics of lithium-ion diffusion. It is worth pointing out that this is the first time to prove the existence of SEI on Li3VO4 during the initial charging/discharging process by in-situ EIS experiment. It turned out that the irreversible phase transformation and the formation of SEI on Li3VO4 were the two important reasons causing the low initial Coulombic efficiency of Li3VO4 material. PMID:27556414

  10. Verification of the hygienic adequacy of beef carcass cooling processes by microbiological culture and the temperature-function integration technique.

    PubMed

    Jericho, K W; O'Laney, G; Kozub, G C

    1998-10-01

    To enhance food safety and keeping quality, beef carcasses are cooled immediately after leaving the slaughter floor. Within hazard analysis and critical control point (HACCP) systems, this cooling process needs to be monitored by the industry and verified by regulatory agencies. This study assessed the usefulness of the temperature-function integration technique (TFIT) for the verification of the hygienic adequacy of two cooling processes for beef carcasses at one abattoir. The cooling process passes carcasses through a spray cooler for at least 17 h and a holding cooler for at least 7 h. The TFIT is faster and cheaper than culture methods. For spray cooler 1, the Escherichia coli generations predicted by TFIT for carcass surfaces (pelvic and shank sites) were compared to estimated E. coli counts from 120 surface excision samples (rump, brisket, and sacrum; 5 by 5 by 0.2 cm) before and after cooling. Counts of aerobic bacteria, coliforms, and E. coli were decreased after spray cooler 1 (P < or = 0.001). The number of E. coli generations (with lag) at the pelvic site calculated by TFIT averaged 0.85 +/- 0.19 and 0.15 +/- 0.04 after emerging from spray coolers 1 and 2, respectively. The TFIT (with lag) was considered convenient and appropriate for the inspection service to verify HACCP systems for carcass cooling processes. PMID:9798153

  11. GI-13 Integration of Methods for Air Quality and Health Data, Remote Sensed and In-Situ with Disease Estimate Techniques

    EPA Science Inventory

    GI-13 – A brief review of the GEO Work Plan DescriptionGlobal map examples of PM2.5 satellite measuresUS Maps showing examples of fused in-situ and satellite dataNew AQ Monitoring approach with social value – Village Green exampleComputing and Systems Applied in Energ...

  12. Experimental Investigation and High Resolution Simulation of In-Situ Combustion Processes

    SciTech Connect

    Margot Gerritsen; Tony Kovscek

    2008-04-30

    This final technical report describes work performed for the project 'Experimental Investigation and High Resolution Numerical Simulator of In-Situ Combustion Processes', DE-FC26-03NT15405. In summary, this work improved our understanding of in-situ combustion (ISC) process physics and oil recovery. This understanding was translated into improved conceptual models and a suite of software algorithms that extended predictive capabilities. We pursued experimental, theoretical, and numerical tasks during the performance period. The specific project objectives were (i) identification, experimentally, of chemical additives/injectants that improve combustion performance and delineation of the physics of improved performance, (ii) establishment of a benchmark one-dimensional, experimental data set for verification of in-situ combustion dynamics computed by simulators, (iii) develop improved numerical methods that can be used to describe in-situ combustion more accurately, and (iv) to lay the underpinnings of a highly efficient, 3D, in-situ combustion simulator using adaptive mesh refinement techniques and parallelization. We believe that project goals were met and exceeded as discussed.

  13. Spacecraft Communications System Verification Using On-Axis Near Field Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Keating, Thomas; Baugh, Mark; Gosselin, R. B.; Lecha, Maria C.; Krebs, Carolyn A. (Technical Monitor)

    2000-01-01

    Determination of the readiness of a spacecraft for launch is a critical requirement. The final assembly of all subsystems must be verified. Testing of a communications system can mostly be done using closed-circuits (cabling to/from test ports), but the final connections to the antenna require radiation tests. The Tropical Rainfall Measuring Mission (TRMM) Project used a readily available 'near-fleld on-axis' equation to predict the values to be used for comparison with those obtained in a test program. Tests were performed in a 'clean room' environment at both Goddard Space Flight Center (GSFC) and in Japan at the Tanegashima Space Center (TnSC) launch facilities. Most of the measured values agreed with the predicted values to within 0.5 dB. This demonstrates that sometimes you can use relatively simple techniques to make antenna performance measurements when use of the 'far field ranges, anechoic chambers, or precision near-field ranges' are neither available nor practical. Test data and photographs are provided.

  14. A Phase Shift Demodulation Technique: Verification and Application in Fluorescence Phase Based Oxygen Sensors

    NASA Astrophysics Data System (ADS)

    Jia, Chuanwu; Chang, Jun; Wang, Fupeng; Jiang, Hao; Zhu, Cunguang; Wang, Pengpeng

    2016-06-01

    A phase shift demodulation technique based on subtraction capable of measuring 0.03 phase degree limit between sinusoidal signals is presented in this paper. A self-gain module and a practical subtracter act the kernel parts of the phase shift demodulation system. Electric signals in different phases are used to verify the performance of the system. In addition, a new designed optical source, laser fiber differential source (LFDS), capable of generating mini phase is used to further verify the system reliability. R-square of 0.99997 in electric signals and R-square of 0.99877 in LFDS are achieved, and 0.03 degree measurement limit is realized in experiments. Furthermore, the phase shift demodulation system is applied to the fluorescence phase based oxygen sensors to realize the fundamental function. The experimental results reveal that a good repetition and better than 0.02% oxygen concentration measurement accuracy are realized. In addition, the phase shift demodulation system can be easily integrated to other applications.

  15. A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces

    NASA Astrophysics Data System (ADS)

    Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.

    2013-06-01

    A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 °C. The evolved 40Ar∗/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (˜1030 °C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer. Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 ± 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of

  16. Longitudinal mixing in meandering channels: new experimental data set and verification of a predictive technique.

    PubMed

    Boxall, J B; Guymer, I

    2007-01-01

    Evaluation of longitudinal mixing processes in open channel flows is important in environmental management, requiring the quantification of mixing coefficients. Estimates of these coefficients sufficiently accurate for environmental impact assessments cannot be achieved using current theoretical or semi-empirical methods for natural channels. This inaccuracy is caused by a limited understanding and quantification of the interaction of the dominant mechanisms resulting from natural channel features, such as plan form curvature and changes in cross-sectional shape. Experimental results are presented here from studies conducted in three self-formed channels, developed by known discharges. Longitudinal mixing was investigated at various flow rates within each of the channels by monitoring the development of tracer plumes during transit through the channels. Using an optimisation procedure, coefficients required for solution of the one-dimensional advection dispersion equation (1D-ADE) were found in the range 0.02-0.2m(2)/s. The coefficients were found to vary as functions of longitudinal meander location, channel form and discharge. Predictions of these longitudinal mixing coefficients were made using a mathematical technique requiring only channel form properties and flow rate as inputs. Predicted values were typically within 20% of the measured values, although deviation of up to 50% was found for the lowest discharge in each channel. This large error is likely to have been caused by increased dead zone effects associated with channel bathymetry at low discharges that are not captured by the method. The method was shown to be capable of capturing the variation in the longitudinal mixing coefficient with longitudinal meander location, with channel form and with discharge.

  17. Combination of Different In Situ Characterization Techniques and Scanning Electron Microscopy Investigations for a Comprehensive Description of the Tensile Deformation Behavior of a CrMnNi TRIP/TWIP Steel

    NASA Astrophysics Data System (ADS)

    Weidner, Anja; Biermann, Horst

    2015-08-01

    The class of low-carbon, high-alloy CrMnNi steels exhibits outstanding mechanical properties with respect to high strength and ductility due to either transformation-induced plasticity (TRIP) or twinning-induced plasticity (TWIP) effect depending on chemical composition and deformation temperature. However, the ongoing deformation mechanisms like the formation of stacking faults, martensitic phase transformation or deformation-induced twinning are overlapping and the kinetics of the microstructure evolution are quite complex. Therefore, in addition to macroscopic deformation tests and microstructural investigations by scanning electron microscopy, a combination of several in situ characterization techniques with either high lateral and/or temporal resolution as well as providing integral volume information were chosen in order to give a thoroughly and comprehensive description of the deformation behavior of CrMnNi TRIP/TWIP steels. In addition, the complementary in situ techniques like in situ nanoindentation, micro-digital image correlation, and acoustic emission measurements provide excellent possibility for description of materials behavior on a multiscale level from the submicrometer scale up to the macroscopic range. The results obtained by the complementary techniques can support the future modeling of the deformation behavior of TRIP/TWIP steels dependent on chemical composition, temperature, grain size and grain orientation.

  18. Machine-assisted verification of latent fingerprints: first results for nondestructive contact-less optical acquisition techniques with a CWL sensor

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Mario; Kiltz, Stefan; Krapyvskyy, Dmytro; Dittmann, Jana; Vielhauer, Claus; Leich, Marcus

    2011-11-01

    A machine-assisted analysis of traces from crime scenes might be possible with the advent of new high-resolution non-destructive contact-less acquisition techniques for latent fingerprints. This requires reliable techniques for the automatic extraction of fingerprint features from latent and exemplar fingerprints for matching purposes using pattern recognition approaches. Therefore, we evaluate the NIST Biometric Image Software for the feature extraction and verification of contact-lessly acquired latent fingerprints to determine potential error rates. Our exemplary test setup includes 30 latent fingerprints from 5 people in two test sets that are acquired from different surfaces using a chromatic white light sensor. The first test set includes 20 fingerprints on two different surfaces. It is used to determine the feature extraction performance. The second test set includes one latent fingerprint on 10 different surfaces and an exemplar fingerprint to determine the verification performance. This utilized sensing technique does not require a physical or chemical visibility enhancement of the fingerprint residue, thus the original trace remains unaltered for further investigations. No particular feature extraction and verification techniques have been applied to such data, yet. Hence, we see the need for appropriate algorithms that are suitable to support forensic investigations.

  19. Validation and verification of the acoustic emission technique for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Gagar, Daniel Omatsola

    The performance of the Acoustic Emission (AE) technique was investigated to establish its reliability in detecting and locating fatigue crack damage as well as distinguishing between different AE sources in potential SHM applications. Experiments were conducted to monitor the AE signals generated during fatigue crack growth in coupon 2014 T6 aluminium. The influence of stress ratio, stress range, sample geometry and whether or not the load spectrum was of constant or variable amplitude were all investigated. AE signals detected were correlated with values of applied cyclic load throughout the tests. Measurements of time difference of arrival were taken for assessment of errors in location estimates obtained using time of flight algorithms with a 1D location setup. At the onset of crack growth high AE Hit rates were observed for the first few millimetres after which they rapidly declined to minimal values for an extended period of crack growth. Another peak and then decline in AE Hit rates was observed for subsequent crack growth before yet another increase as the sample approached final failure.. AE signals were seen to occur in the lower two-thirds of the maximum load in the first few millimetres of crack growth before occurring at progressively smaller values as the crack length increased. A separate set of AE signals were observed close to the maximum cyclic stress throughout the entire crack growth process. At the failure crack length AE signals were generated across the entire loading range. Novel metrics were developed to statistically characterise variability of AE generation with crack growth and at particular crack lengths across different samples. A novel approach for fatigue crack length estimation was developed based on monitoring applied loads to the sample corresponding with generated AE signals. An acousto-ultrasonic method was used to calibrate the AE wave velocity in a representative wing-box structure which was used to successfully locate the

  20. Applying monitoring, verification, and accounting techniques to a real-world, enhanced oil recovery operational CO2 leak

    USGS Publications Warehouse

    Wimmer, B.T.; Krapac, I.G.; Locke, R.; Iranmanesh, A.

    2011-01-01

    The use of carbon dioxide (CO2) for enhanced oil recovery (EOR) is being tested for oil fields in the Illinois Basin, USA. While this technology has shown promise for improving oil production, it has raised some issues about the safety of CO2 injection and storage. The Midwest Geological Sequestration Consortium (MGSC) organized a Monitoring, Verification, and Accounting (MVA) team to develop and deploy monitoring programs at three EOR sites in Illinois, Indiana, and Kentucky, USA. MVA goals include establishing baseline conditions to evaluate potential impacts from CO2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO2. This paper focuses on the use of MVA techniques in monitoring a small CO2 leak from a supply line at an EOR facility under real-world conditions. The ability of shallow monitoring techniques to detect and quantify a CO2 leak under real-world conditions has been largely unproven. In July of 2009, a leak in the pipe supplying pressurized CO2 to an injection well was observed at an MGSC EOR site located in west-central Kentucky. Carbon dioxide was escaping from the supply pipe located approximately 1 m underground. The leak was discovered visually by site personnel and injection was halted immediately. At its largest extent, the hole created by the leak was approximately 1.9 m long by 1.7 m wide and 0.7 m deep in the land surface. This circumstance provided an excellent opportunity to evaluate the performance of several monitoring techniques including soil CO2 flux measurements, portable infrared gas analysis, thermal infrared imagery, and aerial hyperspectral imagery. Valuable experience was gained during this effort. Lessons learned included determining 1) hyperspectral imagery was not effective in detecting this relatively small, short-term CO2 leak, 2) even though injection was halted, the leak remained dynamic and presented a safety risk concern

  1. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems.

    PubMed

    Chang, Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen, Tainsong

    2009-09-01

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: "The institution should verify the full process of any reconstruction technique employed clinically." Error modeling was also performed to analyze seed-position errors. The "isocentric beam checker" device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roué et al. ["The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy," Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 degrees reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to the isocenter as much as possible. This method could be used to

  2. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems

    SciTech Connect

    Chang Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen Tainsong

    2009-09-15

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: ''The institution should verify the full process of any reconstruction technique employed clinically.'' Error modeling was also performed to analyze seed-position errors. The ''isocentric beam checker'' device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roueet al. [''The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy,'' Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 deg. reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to the isocenter as much as possible. This method could be used

  3. Validation of a deformable image registration technique for cone beam CT-based dose verification

    SciTech Connect

    Moteabbed, M. Sharp, G. C.; Wang, Y.; Trofimov, A.; Efstathiou, J. A.; Lu, H.-M.

    2015-01-15

    Purpose: As radiation therapy evolves toward more adaptive techniques, image guidance plays an increasingly important role, not only in patient setup but also in monitoring the delivered dose and adapting the treatment to patient changes. This study aimed to validate a method for evaluation of delivered intensity modulated radiotherapy (IMRT) dose based on multimodal deformable image registration (DIR) for prostate treatments. Methods: A pelvic phantom was scanned with CT and cone-beam computed tomography (CBCT). Both images were digitally deformed using two realistic patient-based deformation fields. The original CT was then registered to the deformed CBCT resulting in a secondary deformed CT. The registration quality was assessed as the ability of the DIR method to recover the artificially induced deformations. The primary and secondary deformed CT images as well as vector fields were compared to evaluate the efficacy of the registration method and it’s suitability to be used for dose calculation. PLASTIMATCH, a free and open source software was used for deformable image registration. A B-spline algorithm with optimized parameters was used to achieve the best registration quality. Geometric image evaluation was performed through voxel-based Hounsfield unit (HU) and vector field comparison. For dosimetric evaluation, IMRT treatment plans were created and optimized on the original CT image and recomputed on the two warped images to be compared. The dose volume histograms were compared for the warped structures that were identical in both warped images. This procedure was repeated for the phantom with full, half full, and empty bladder. Results: The results indicated mean HU differences of up to 120 between registered and ground-truth deformed CT images. However, when the CBCT intensities were calibrated using a region of interest (ROI)-based calibration curve, these differences were reduced by up to 60%. Similarly, the mean differences in average vector field

  4. Microstructure and Tribological Properties of In Situ Synthesized TiN Reinforced Ni/Ti Alloy Clad Layer Prepared by Plasma Cladding Technique

    NASA Astrophysics Data System (ADS)

    Jin, Guo; Li, Yang; Cui, Huawei; Cui, Xiufang; Cai, Zhaobing

    2016-06-01

    A Ni/Ti composite coating enhanced by an in situ synthesized TiN phase was fabricated on FV520B steel by plasma cladding technology. The in situ formation of the TiN phase was confirmed by XRD, SEM, and TEM. The cladding layer consisted of three regions on going from the top to the bottom, namely, columnar grain regions, columnar dendritic regions, and fine grain regions. The cladding layer was composed of Ni3Ti, TiN, (Fe, Ni), and Ti phases. The dendritic and columnar regions were mainly composed of the Ni3Ti and (Fe, Ni) phases. The Ti phase was observed at the branches of dendrite crystals and columnar grains. The volume fraction of the TiN phase in the cladding layer was about 3.2%. The maximum micro-hardness value of the in situ formed coating (760 HV0.2) was higher than that of the pure coating (537 HV0.2). The cladding layer had a small amount of scratch and wear debris when a load of 20 N was used. As the test load increased, the wear debris in the cladding layer also increased and the massive furrows were not observed.

  5. Poster — Thur Eve — 55: An automated XML technique for isocentre verification on the Varian TrueBeam

    SciTech Connect

    Asiev, Krum; Mullins, Joel; DeBlois, François; Liang, Liheng; Syme, Alasdair

    2014-08-15

    Isocentre verification tests, such as the Winston-Lutz (WL) test, have gained popularity in the recent years as techniques such as stereotactic radiosurgery/radiotherapy (SRS/SRT) treatments are more commonly performed on radiotherapy linacs. These highly conformal treatments require frequent monitoring of the geometrical accuracy of the isocentre to ensure proper radiation delivery. At our clinic, the WL test is performed by acquiring with the EPID a collection of 8 images of a WL phantom fixed on the couch for various couch/gantry angles. This set of images is later analyzed to determine the isocentre size. The current work addresses the acquisition process. A manual WL test acquisition performed by and experienced physicist takes in average 25 minutes and is prone to user manipulation errors. We have automated this acquisition on a Varian TrueBeam STx linac (Varian, Palo Alto, USA). The Varian developer mode allows the execution of custom-made XML script files to control all aspects of the linac operation. We have created an XML-WL script that cycles through each couch/gantry combinations taking an EPID image at each position. This automated acquisition is done in less than 4 minutes. The reproducibility of the method was verified by repeating the execution of the XML file 5 times. The analysis of the images showed variation of the isocenter size less than 0.1 mm along the X, Y and Z axes and compares favorably to a manual acquisition for which we typically observe variations up to 0.5 mm.

  6. A modified rinsing method for the determination of the S, W-S and D + U fraction of protein and starch in feedstuff within the in situ technique.

    PubMed

    de Jonge, L H; van Laar, H; Hendriks, W H; Dijkstra, J

    2013-08-01

    A modified rinsing method for the in situ technique was developed to separate, isolate and characterise the soluble (S), the insoluble washout (W-S) and the non-washout fractions (D + U) within one procedure. For non-incubated bags (t = 0 h), this method was compared with the conventional, Combined Fractionation (CF) method that measures the D + U and S fractions in separate steps and subsequently calculates the W-S fraction. The modified method was based on rinsing of nylon bags in a closed vessel containing a buffer solution (pH 6.2) during 1 h, where shaking speeds of 40, 100, and 160 strokes per minutes (spm) were evaluated, and tested for six feed ingredients (faba beans, maize, oats, peas, soya beans and wheat) and four forages (two ryegrass silages and two maize silages). The average recoveries as the sum of all fractions were 0.972 ± 0.041 for N and 0.990 ± 0.050 for starch (mean ± s.d.). The mean W-S fraction increased with increasing shaking speed and varied between 0.017 (N) and 0.083 (starch) at 40 spm and 0.078 (N) and 0.303 (starch) at 160 spm, respectively. For ryegrass silages, the W-S fraction was absent at all shaking speeds, but was present in the CF method. The modified method, in particular at 40 and 100 spm, reduced the loss of small particles during rinsing, resulting in lower W-S and higher D + U fractions for N and starch compared with the CF method. For soya beans and ryegrass silage, the modified method reduced the S fraction of N compared with the CF method. The results obtained at 160 spm showed the best comparison with those from the CF method. The W-S fraction of the feedstuff obtained at 160 spm contained mainly particles smaller than 40 μm (0.908 ± 0.086). In most feedstuff, starch was the most abundant chemical component in the W-S fraction and its content (726 ± 75 g/kg DM) was higher than in the D + U fraction (405 ± 177 g/kg DM). Alkaline-soluble proteins were the dominant N-containing components in the W-S fraction of

  7. Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes

    NASA Astrophysics Data System (ADS)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2015-04-01

    -mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied on volcanic gas plumes at Mt. Etna and Mt. Stromboli in Italy in July 2014 and on fumarolic gas emissions at Mt. Lastarria in Chile in November 2014. The results show significant amounts of the concerning bromine species (lower ppb range). Comprehensive data evaluation and comparison with results of impinger extraction with NaOH solution as well as chamber experiments are still in progress. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Huang, R.-J. and T. Hoffmann: A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species. Journal of Chromatography A, 1210, 135-141, 2008

  8. In situ zymography: topographical considerations.

    PubMed

    Mungall, B A; Pollitt, C C

    2001-02-26

    In situ gelatin zymography is a simple technique providing valuable information about the cellular and tissue localization of gelatinases. Until recently, the use of this technique has been confined to soft, relatively homogeneous tissue. In this report in situ zymography has been utilized to assess the sub-lamellar location of gelatinases in the hard, semi-keratinized epidermal layer and the adjacent soft connective tissue matrix of the dermis of the equine hoof. We show that alterations in the orientation at which the tissue is dipped and withdrawn from the emulsion cause profound alterations in emulsion thickness. Microscopic variations in the surface topography of frozen tissue sections also influence emulsion thickness making interpretation of the results difficult. Given these results, researchers must be aware of potential variations in zymographic analysis may be influenced by physical tissue parameters in addition to suspected gelatinase activity.

  9. Implementation of an analytical verification technique on three building energy-analysis codes: SUNCAT 2. 4, DOE 2. 1, and DEROB III

    SciTech Connect

    Wortman, D.; O'Doherty, B.; Judkoff, R.

    1981-01-01

    An analytical verification technique for building energy analysis codes has been developed. For this technique, building models are developed that can be both solved analytically and modeled using the analysis codes. The output of the codes is then compared with the analytical solutions. In this way, the accuracy of selected mechanisms in the codes can be verified. The procedure consists of several tests and was run on SUNCAT 2.4, DOE 2.1, and DEROB III. The results are presented and analyzed.

  10. An in-situ K-Ar isochron dating method for planetary landers using a spot-by-spot laser-ablation technique

    NASA Astrophysics Data System (ADS)

    Cho, Yuichiro; Sugita, Seiji; Miura, Yayoi N.; Okazaki, Ryuji; Iwata, Naoyoshi; Morota, Tomokatsu; Kameda, Shingo

    2016-09-01

    Age is essential information for interpreting the geologic record on planetary surfaces. Although crater counting has been widely used to estimate the planetary surface ages, crater chronology in the inner solar system is largely built on radiometric age data from limited sites on the Moon. This has resulted in major uncertainty in planetary chronology. Because opportunities for sample-return missions are limited, in-situ geochronology measurements from one-way lander/rover missions are extremely valuable. Here we developed an in-situ isochron-based dating method using the K-Ar system, with K and Ar in a single rock sample extracted locally by laser ablation and measured using laser-induced breakdown spectroscopy (LIBS) and a quadrupole mass spectrometer (QMS), respectively. We built an experimental system combining flight-equivalent instruments and measured K-Ar ages for mineral samples with known ages (~1.8 Ga) and K contents (1-8 wt%); we achieved precision of 20% except for a mineral with low mechanical strength. Furthermore, validation measurements with two natural rocks (gneiss slabs) obtained K-Ar isochron ages and initial 40Ar consistent with known values for both cases. This result supports that our LIBS-MS approach can derive both isochron ages and contributions of non-in situ radiogenic 40Ar from natural rocks. Error assessments suggest that the absolute ages of key geologic events including the Noachian/Hesperian- and the Hesperian/Amazonian-transition can be dated with 10-20% errors for a rock containing ~1 wt% K2O, greatly reducing the uncertainty of current crater chronology models on Mars.

  11. Improved technique for fluorescence in situ hybridisation analysis of isolated nuclei from archival, B5 or formalin fixed, paraffin wax embedded tissue.

    PubMed

    Schurter, M J; LeBrun, D P; Harrison, K J

    2002-04-01

    Fluorescence in situ hybridisation (FISH) is an effective method to detect chromosomal alterations in a variety of tissue types, including archived paraffin wax embedded specimens fixed in B5 or formalin. However, precipitating fixatives such as B5 have been known to produce unsatisfactory results in comparison with formalin when used for FISH. This study describes an effective nuclear isolation and FISH procedure for B5 and formalin fixed tissue, optimising the nuclear isolation step and nuclei pretreatments using tonsil and mantle cell lymphoma specimens. The protocol presented can be used to isolate nuclei and perform FISH on B5 or formalin fixed, paraffin wax embedded samples from a variety of tissue types.

  12. COMET: a planned airborne mission to simultaneously measure CO2 and CH4 columns using airborne remote sensing and in-situ techniques

    NASA Astrophysics Data System (ADS)

    Fix, A.; Amediek, A.; Büdenbender, C.; Ehret, G.; Wirth, M.; Quatrevalet, M.; Rapp, M.; Gerilowski, K.; Bovensmann, H.; Gerbig, C.; Pfeilsticker, K.; Zöger, M.; Giez, A.

    2013-12-01

    To better predict future trends in the cycles of the most important anthropogenic greenhouse gases, CO2 and CH4, there is a need to measure and understand their distribution and variation on various scales. To address these requirements it is envisaged to deploy a suite of state-of-the-art airborne instruments that will be capable to simultaneously measure the column averaged dry-air mixing ratios (XGHG) of both greenhouse gases along the flight path. As the measurement platform serves the research aircraft HALO, a modified Gulfstream G550, operated by DLR. This activity is dubbed CoMet (CO2 and Methane Mission). The instrument package of CoMet will consist of active and passive remote sensors as well as in-situ instruments to complement the column measurements by highly-resolved profile information. As an active remote sensing instrument CHARM-F, the integrated-path differential absorption lidar currently under development at DLR, will provide both, XCO2 and XCH4, below flight altitude. The lidar instrument will be complemented by MAMAP which is a NIR/SWIR absorption spectrometer developed by University of Bremen and which is also capable to derive XCH4 and XCO2. As an additional passive instrument, mini-DOAS operated by University of Heidelberg will contribute with additional context information about the investigated air masses. In order to compare the remote sensing instruments with integrated profile information, in-situ instrumentation is indispensable. The in-situ package will therefore comprise wavelength-scanned Cavity-Ring-Down Spectroscopy (CRDS) for the detection of CO2, CH4, CO and H2O and a flask sampler for collection of atmospheric samples and subsequent laboratory analysis. Furthermore, the BAsic HALO Measurement And Sensor System (BAHAMAS) will provide an accurate set of meteorological and aircraft state parameters for each scientific flight. Within the frame of the first CoMet mission scheduled for the 2015 timeframe it is planned to concentrate

  13. Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems

    NASA Technical Reports Server (NTRS)

    Hagopian, John G.

    2010-01-01

    A technique was created to measure the pupil alignment of instruments in situ by measuring calibrated pupil alignment references (PARs) in instruments. The PAR can also be measured using an alignment telescope or an imaging system. PAR allows the verification of the science instrument (SI) pupil alignment at the integrated science instrument module (ISIM) level of assembly at ambient and cryogenic operating temperature. This will allow verification of the ISIM+SI alignment, and provide feedback to realign the SI if necessary.

  14. A one-day double-labelling technique for tissue specimens: immunogold-silver staining for in situ hybridization combined with alkaline phosphatase-anti-alkaline phosphatase (APAAP) immunohistochemistry for antigens.

    PubMed

    Müller-Ladner, U; Kriegsmann, J; Gay, R E; Gay, S

    1996-02-01

    An improved technique is described that addresses the problems of sensitivity, specificity, the use of hazardous radioactive equipment and time consumption in immunohistochemical labelling and double labelling of in situ hybridization of tissue specimens. It consists of a two-step protocol in which digoxigenin-uridine triphosphate (UTP) labelled riboprobes in the in situ hybridization step are visualized by the immunogold-silver staining method, and double labelling of tissue antigens is achieved by the application of an alkaline phosphatase-anti-alkaline phosphatase staining step. We tested this protocol using snap-frozen tissue sections of synovial tissue from patients with rheumatoid arthritis. The target mRNA was detected by perforin or cathepsin D riboprobes, the double labelling was performed using anti-collagen type IV and alpha-smooth muscle actin antibodies. It is concluded that, in comparison with an established three- to four-day double-labelling protocol used in many laboratories, this one-day combination is currently the most rapid assay of reliable quality for double labelling of in situ hybridization products and tissue antigens.

  15. Intrinsic stress in ZrN thin films: Evaluation of grain boundary contribution from in situ wafer curvature and ex situ x-ray diffraction techniques

    SciTech Connect

    Koutsokeras, L. E.; Abadias, G.

    2012-05-01

    Low-mobility materials, like transition metal nitrides, usually undergo large residual stress when sputter-deposited as thin films. While the origin of stress development has been an active area of research for high-mobility materials, atomistic processes are less understood for low-mobility systems. In the present work, the contribution of grain boundary to intrinsic stress in reactively magnetron-sputtered ZrN films is evaluated by combining in situ wafer curvature measurements, providing information on the overall biaxial stress, and ex situ x-ray diffraction, giving information on elastic strain (and related stress) inside crystallites. The thermal stress contribution was also determined from the in situ stress evolution during cooling down, after deposition was stopped. The stress data are correlated with variations in film microstructure and growth energetics, in the 0.13-0.42 Pa working pressure range investigated, and discussed based on existing stress models. At low pressure (high energetic bombardment conditions), a large compressive stress is observed due to atomic peening, which induces defects inside crystallites but also promotes incorporation of excess atoms in the grain boundary. Above 0.3-0.4 Pa, the adatom surface mobility is reduced, leading to the build-up of tensile stress resulting from attractive forces between under-dense neighbouring column boundary and possible void formation, while crystallites can still remain under compressive stress.

  16. A technique for recording polycrystalline structure and orientation during in situ deformation cycles of rock analogues using an automated fabric analyser.

    PubMed

    Peternell, M; Russell-Head, D S; Wilson, C J L

    2011-05-01

    Two in situ plane-strain deformation experiments on norcamphor and natural ice using synchronous recording of crystal c-axis orientations have been performed with an automated fabric analyser and a newly developed sample press and deformation stage. Without interrupting the deformation experiment, c-axis orientations are determined for each pixel in a 5 × 5 mm sample area at a spatial resolution of 5 μm/pixel. In the case of norcamphor, changes in microstructures and associated crystallographic information, at a strain rate of ∼2 × 10(-5) s(-1), were recorded for the first time during a complete in situ deformation-cycle experiment that consisted of an annealing, deformation and post-deformation annealing path. In the case of natural ice, slower external strain rates (∼1 × 10(-6) s(-1)) enabled the investigation of small changes in the polycrystal aggregate's crystallography and microstructure for small amounts of strain. The technical setup and first results from the experiments are presented.

  17. An experimental study of the (Ti-6Al-4V)-xH phase diagram using in situ synchrotron XRD and TGA/DSC techniques.

    SciTech Connect

    Sun, Pei; Fang, Z. Zak; Koopman, Mark; Paramore, James D.; Chandran, K. S. Ravi; Ren, Yang; Lu, Jun

    2015-02-01

    Hydrogen has been investigated for decades as a temporary alloying element to refine the microstructure of Ti-6Al-4V, and is now being used in a novel powder metallurgy method known as "hydrogen sintering and phase transformation". Pseudo-binary phase diagrams of (Ti-6Al-4V)-xH have been studied and developed, but are not well established due to methodological limitations. In this paper, in situ studies of phase transformations during hydrogenation and dehydrogenation of (Ti-6Al-4V)-xH alloys were conducted using high-energy synchrotron X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The eutectoid phase transformation of β ↔ α + δ was observed in the (Ti-6Al-4V)-xH alloy via in situ synchrotron XRD at 211 °C with a hydrogen concentration of 37.5 at.% (measured using TGA-DSC). The relationships of hydrogen composition to partial pressure and temperature were investigated in the temperature range 450-900°C. Based on these results, a partial pseudo-binary phase diagram of (Ti-6Al-4V)-xH is proposed for hydrogen compositions up to 60 at.% in the temperature range 100-900°C. Using the data collected in real time under controlled parameters of temperature, composition and hydrogen partial pressure, this work characterizes relevant phase transformations and microstructural evolution for practical titanium-hydrogen technologies of Ti-6Al-4V.

  18. In-Situ and Remote-Sensing Data Fusion Using Machine Learning Techniques to Infer Urban and Fire Related Pollution Plumes

    NASA Technical Reports Server (NTRS)

    Russell, P. B.; Segal-Rozenhaimer, M.; Schmid, B.; Redemann, J.; Livingston, J. M.; Flynn, C.J.; Johnson, R. R.; Dunagan, S. E.; Shinozuka, Y.; Kacenelenbogen, M.; Chatfield, R. B.

    2014-01-01

    Airmass type characterization is key in understanding the relative contribution of various emission sources to atmospheric composition and air quality and can be useful in bottom-up model validation and emission inventories. However, classification of pollution plumes from space is often not trivial. Sub-orbital campaigns, such as SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) give us a unique opportunity to study atmospheric composition in detail, by using a vast suite of in-situ instruments for the detection of trace gases and aerosols. These measurements allow identification of spatial and temporal atmospheric composition changes due to various pollution plumes resulting from urban, biogenic and smoke emissions. Nevertheless, to transfer the knowledge gathered from such campaigns into a global spatial and temporal context, there is a need to develop workflow that can be applicable to measurements from space. In this work we rely on sub-orbital in-situ and total column remote sensing measurements of various pollution plumes taken aboard the NASA DC-8 during 2013 SEAC4RS campaign, linking them through a neural-network (NN) algorithm to allow inference of pollution plume types by input of columnar aerosol and trace-gas measurements. In particular, we use the 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) airborne measurements of wavelength dependent aerosol optical depth (AOD), particle size proxies, O3, NO2 and water vapor to classify different pollution plumes. Our method relies on assigning a-priori ground-truth labeling to the various plumes, which include urban pollution, different fire types (i.e. forest and agriculture) and fire stage (i.e. fresh and aged) using cluster analysis of aerosol and trace-gases in-situ and auxiliary (e.g. trajectory) data and the training of a NN scheme to fit the best prediction parameters using 4STAR measurements as input. We explore our

  19. In situ vadose zone bioremediation.

    PubMed

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

    Contamination of the vadose zone with various pollutants is a world-wide problem, and often technical or economic constraints impose remediation without excavation. In situ bioremediation in the vadose zone by bioventing has become a standard remediation technology for light spilled petroleum products. In this review, focus is given on new in situ bioremediation strategies in the vadose zone targeting a variety of other pollutants such as perchlorate, nitrate, uranium, chromium, halogenated solvents, explosives and pesticides. The techniques for biostimulation of either oxidative or reductive degradation pathways are presented, and biotransformations to immobile pollutants are discussed in cases of non-degradable pollutants. Furthermore, research on natural attenuation in the vadose zone is presented.

  20. Mechanical Failure of Thin Ta and Cu/Ta Layers on Polyimide Substrates: A Synchrotron-Based Technique for In Situ Characterization

    SciTech Connect

    Frank, Stephan; Olliges, Sven; Spolenak, Ralph; Handge, Ulrich A.

    2009-06-18

    In situ synchrotron radiation diffraction and confocal light microscopy is used to study fragmentation and buckling of thin brittle Ta layers with thicknesses of 50 nm, 100 nm and 200 nm on polyimide substrates. Synchrotron-based stress measurements confirm that cracking leads to relaxation of tensile stress. Simultaneously, compressive stress arises in transverse direction, which finally leads to buckling. This behavior can be explained quantitatively by a two-dimensional shear lag model. It is well established that the properties of the coating-substrate interface determine the processes of coating fragmentation and delamination. A possible approach for influencing and controlling these processes is given by the incorporation of a ductile interlayer. It can be observed that the presence of Cu interlayers with thicknesses of 5 nm, 20 nm and 50 nm reduces the fracture strength of brittle Ta coatings on polyimide substrates, whereas the resistance to buckling is increased significantly.

  1. Evidence for Degradation of the Chrome Yellows in Van Gogh's Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron-Radiation-Based X-ray Techniques.

    PubMed

    Monico, Letizia; Janssens, Koen; Hendriks, Ella; Vanmeert, Frederik; Van der Snickt, Geert; Cotte, Marine; Falkenberg, Gerald; Brunetti, Brunetto Giovanni; Miliani, Costanza

    2015-11-16

    This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur-rich PbCr1-x Sx O4 (x≈0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., Cr(III) compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future. PMID:26482035

  2. Molecular Interaction of a New Antibacterial Polymer with a Supported Lipid Bilayer Measured by an in situ Label-Free Optical Technique

    PubMed Central

    Horvath, Robert; Kobzi, Balázs; Keul, Helmut; Moeller, Martin; Kiss, Éva

    2013-01-01

    The interaction of the antibacterial polymer–branched poly(ethylene imine) substituted with quaternary ammonium groups, PEO and alkyl chains, PEI25QI5J5A815–with a solid supported lipid bilayer was investigated using surface sensitive optical waveguide spectroscopy. The analysis of the optogeometrical parameters was extended developing a new composite layer model in which the structural and optical anisotropy of the molecular layers was taken into consideration. Following in situ the change of optical birefringence we were able to determine the composition of the lipid/polymer surface layer as well as the displacement of lipid bilayer by the antibacterial polymer without using additional labeling. Comparative assessment of the data of layer thickness and optical anisotropy helps to reveal the molecular mechanism of antibacterial effect of the polymer investigated. PMID:23648479

  3. Mechanical Failure of Thin Ta and Cu/Ta Layers on Polyimide Substrates: A Synchrotron-Based Technique for In Situ Characterization

    NASA Astrophysics Data System (ADS)

    Frank, Stephan; Handge, Ulrich A.; Olliges, Sven; Spolenak, Ralph

    2009-06-01

    In situ synchrotron radiation diffraction and confocal light microscopy is used to study fragmentation and buckling of thin brittle Ta layers with thicknesses of 50 nm, 100 nm and 200 nm on polyimide substrates. Synchrotron-based stress measurements confirm that cracking leads to relaxation of tensile stress. Simultaneously, compressive stress arises in transverse direction, which finally leads to buckling. This behavior can be explained quantitatively by a two-dimensional shear lag model. It is well established that the properties of the coating-substrate interface determine the processes of coating fragmentation and delamination. A possible approach for influencing and controlling these processes is given by the incorporation of a ductile interlayer. It can be observed that the presence of Cu interlayers with thicknesses of 5 nm, 20 nm and 50 nm reduces the fracture strength of brittle Ta coatings on polyimide substrates, whereas the resistance to buckling is increased significantly.

  4. Molecular interaction of a new antibacterial polymer with a supported lipid bilayer measured by an in situ label-free optical technique.

    PubMed

    Horvath, Robert; Kobzi, Balázs; Keul, Helmut; Moeller, Martin; Kiss, Eva

    2013-01-01

    The interaction of the antibacterial polymer-branched poly(ethylene imine) substituted with quaternary ammonium groups, PEO and alkyl chains, PEI25QI5J5A815-with a solid supported lipid bilayer was investigated using surface sensitive optical waveguide spectroscopy. The analysis of the optogeometrical parameters was extended developing a new composite layer model in which the structural and optical anisotropy of the molecular layers was taken into consideration. Following in situ the change of optical birefringence we were able to determine the composition of the lipid/polymer surface layer as well as the displacement of lipid bilayer by the antibacterial polymer without using additional labeling. Comparative assessment of the data of layer thickness and optical anisotropy helps to reveal the molecular mechanism of antibacterial effect of the polymer investigated. PMID:23648479

  5. Evidence for Degradation of the Chrome Yellows in Van Gogh's Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron-Radiation-Based X-ray Techniques.

    PubMed

    Monico, Letizia; Janssens, Koen; Hendriks, Ella; Vanmeert, Frederik; Van der Snickt, Geert; Cotte, Marine; Falkenberg, Gerald; Brunetti, Brunetto Giovanni; Miliani, Costanza

    2015-11-16

    This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur-rich PbCr1-x Sx O4 (x≈0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., Cr(III) compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future.

  6. Low-Intrusion Techniques and Sensitive Information Management for Warhead Counting and Verification: FY2011 Annual Report

    SciTech Connect

    Jarman, Kenneth D.; Robinson, Sean M.; McDonald, Benjamin S.; Gilbert, Andrew J.; Misner, Alex C.; Pitts, W. Karl; White, Timothy A.; Seifert, Allen; Miller, Erin A.

    2011-09-01

    Future arms control treaties may push nuclear weapons limits to unprecedented low levels and may entail precise counting of warheads as well as distinguishing between strategic and tactical nuclear weapons. Such advances will require assessment of form and function to confidently verify the presence or absence of nuclear warheads and/or their components. Imaging with penetrating radiation can provide such an assessment and could thus play a unique role in inspection scenarios. Yet many imaging capabilities have been viewed as too intrusive from the perspective of revealing weapon design details, and the potential for the release of sensitive information poses challenges in verification settings. A widely held perception is that verification through radiography requires images of sufficient quality that an expert (e.g., a trained inspector or an image-matching algorithm) can verify the presence or absence of components of a device. The concept of information barriers (IBs) has been established to prevent access to relevant weapon-design information by inspectors (or algorithms), and has, to date, limited the usefulness of radiographic inspection. The challenge of this project is to demonstrate that radiographic information can be used behind an IB to improve the capabilities of treaty-verification weapons-inspection systems.

  7. Warm Tropical Sea Surface Temperatures During the Pliocene: a New Record from Mg/Ca and δ18O In Situ Techniques

    NASA Astrophysics Data System (ADS)

    Wycech, J.; Kelly, D.; Kozdon, R.; Fournelle, J.; Valley, J. W.

    2013-12-01

    The Pliocene Warm Period (PWP) was a global warming event that punctuated Earth's climate history ~3 Ma, and study of its geologic record is providing important constraints for models predicting future climate change. Many sea surface temperature (SST) reconstructions for the PWP indicate amplified polar warmth with minimal or absent warming in the tropics - a phenomenon termed the cool tropics paradox. Key pieces of evidence for the lack of tropical warmth are oxygen isotope (δ18O) and Mg/Ca ratios in planktic foraminiferal shells. However, the δ18O data used to reconstruct surface-ocean conditions are derived from whole foraminiferal shells with the assumption that their geochemical compositions are well preserved and homogeneous. To the contrary, most planktic foraminiferal shells found in deep-sea sediments are an aggregate mixture of three carbonate phases (18O-depleted pre-gametogenic calcite, 18O-rich gametogenic calcite added during reproduction, and very 18O-rich diagenetic calcite) that formed under different physiological and/or environmental conditions. Here we report preliminary results of an ongoing study that uses secondary ion mass spectrometry (SIMS) and electron probe microanalysis (EPMA) to acquire in situ δ18O and Mg/Ca data, respectively, from 3-10 μm domains within individual planktic foraminiferal shells (Globigerinoides sacculifer) preserved in a PWP record recovered at ODP Site 806 in the West Pacific Warm Pool. SIMS analyses show that the δ18O of gametogenic calcite is 1-2‰ higher than in the pre-gametogenic calcite of Gs. sacculifer. Mass-balance calculations using the mean δ18O of gametogenic and pre-gametogenic calcites predict a whole-shell δ18O that is ~1.9‰ lower than the published whole-shell δ18O for Gs. sacculifer in this same deep-sea section. Removal of 18O-depleted, pre-gametogenic calcite via dissolution cannot fully account for this isotopic offset since the mean δ18O of whole shells (-1.3‰) is higher than that

  8. In situ mercury stabilization

    SciTech Connect

    Fuhrmann, M.; Kalb, P.; Adams, J.

    2004-09-01

    BNL Royalty Project Internal Status Report. The funds from the allotment of royalty income were used to experimentally explore feasibility of related, potential new techniques based on the Environmental Sciences Department successful technology licensed for the ex situ treatment of mercury. Specifically, this work is exploring the concept of using Sulfur Polymer Cement (SPC) in an in situ application to stabilize and/or remove mercury (Hg) from surficial soil. Patent disclosure forms have been filed for this process. Soil was artificially spiked with 500 ppm Hg and a series of experiments were set up in which SPC rods were placed in the center of a mass of this soil. Some experiments were conducted at 20 C and others at 50 C. After times ranging from 11 to 24 days, these experiments were opened, photographed and the soil was sampled from discrete locations in the containers. The soil and SPC samples were analyzed for Fe and Hg by x-ray fluorescence. The Hg profile in the soil was significantly altered, with concentrations along the outer edge of the soil reduced by as much as 80% from the starting concentration. Conversely, closer to the treatment rod containing SPC, concentrations of Hg were significantly increased over the original concentration. Preliminary results for elevated temperature sample are shown graphically in Figure 2. Apparently the Hg had migrated toward the SPC and reacted with sulfur to form Hg S. This appears to be a reaction between gaseous phases of both S and Hg, with Hg having a greater vapor pressure. The concentration of low solubility HgS (i.e., low leaching properties) developed within 11 days at 50 C and 21 days at 20 C, confirming the potential of this concept.

  9. Detecting In Situ Copepod Diet Diversity Using Molecular Technique: Development of a Copepod/Symbiotic Ciliate-Excluding Eukaryote-Inclusive PCR Protocol

    PubMed Central

    Li, Tao; Carpenter, Edward J.; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

  10. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    PubMed

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

  11. Development of Techniques for the In Situ Observation of OH and HO2 for Studies of the Impact of High-Altitude Supersonic Aircraft on the Stratosphere

    NASA Technical Reports Server (NTRS)

    Anderson, James G.

    1994-01-01

    This three-year project supported the construction, calibration, and deployment of a new instrument to measure the OH and HO2 radicals on the NASA ER-2 aircraft. The instrument has met and exceeded all of its design goals. The instrumentation represents a true quantum leap in performance over that achieved in previous HO(x) instruments built in our group. Sensitivity for OH was enhanced by over two orders of magnitude as the weight fell from approximately 1500 to less than 200 Kg. Reliability has been very high: HO(x) data are available for all flights during the first operational mission, the Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE). The results of that experiment have been reported in the scientific literature and at conferences. Additionally, measurements of H2O and O3 were made and have been reported in the scientific literature. The measurements demonstrate the important role that OH and HO2 play in determining the concentration of ozone in the lower stratosphere. During the SPADE campaign, the measurements demonstrate that the catalytic removal is dominated by processes involving the odd-hydrogen and halogen radical extremely important constraint for photochemical models that are being used to assess the potential deleterious effects of super-sonic aircraft effluent on the burden of stratospheric ozone. A list of the papers that came from this research are included, along with a copy of the paper, 'Aircraft-borne, laser-induced fluorescence instrument for the in situ detection of hydroxyl and hydroperoxyl radicals'.

  12. Defectless Monolithic Low-k/Cu Interconnects Produced by Chemically Controlled Chemical Mechanical Polishing Process with In situ End-Point-Detection Technique

    NASA Astrophysics Data System (ADS)

    Ueki, Makoto; Onodera, Takahiro; Ishikawa, Akira; Hoshino, Susumu; Hayashi, Yoshihiro

    2009-04-01

    Defectless monolithic low-k/Cu interconnects have been obtained for low-power LSIs by a chemically controlled local chemical mechanical polishing (CMP) process to remove a Cu/TaN barrier on hydrophobic SiOCH low-k films. In the first step, Cu-CMP, a unique end-point-detection (EDP) method is implemented to detect a very thin Cu layer (˜100 nm) that remains on the TaN barrier by in situ white-light interferometry, which is implemented in the local CMP apparatus where the wafers undergoing polishing are oriented face-up. In the second step, TaN-CMP, a SiO2 hard-mask (HM) layer on the low-k film is selectively removed to reduce the nonuniformity of the Cu line thickness, and accordingly, those of the resistance and capacitance. Here, a CMP slurry with an oxidizer is used to change the low-k surface from a hydrophobic condition to a hydrophilic condition, improving wettability and reducing the number of scratches and abrasive particles. In the post-CMP cleaning, an alkaline rinse solution with an oxidation-reduction potential (ORP) of less than -0.5 V vs a normal hydrogen electrode (NHE) produces a clean low-k surface resulting in monolithic low-k/Cu interconnects with excellent dielectric properties comparable to those of SiO2/Cu interconnects.

  13. Behavior of Au species in Au/Fe2O3 catalysts characterized by novel in situ heating techniques and aberration-corrected STEM imaging.

    PubMed

    Allard, Lawrence F; Flytzani-Stephanopoulos, Maria; Overbury, Steven H

    2010-08-01

    The recent advent of a novel design of in situ heating technology for electron microscopes has permitted unprecedented control of elevated temperature studies of catalytic materials, particularly when coupled with the sub-Angström imaging performance of a modern aberration-corrected scanning transmission electron microscope (STEM). Using micro-electro-mechanical-systems (MEMS)-based Aduro heating chips from Protochips, Inc. (Raleigh, NC, USA) allows nearly instantaneous heating and cooling of catalyst powders, avoiding effects of temperature ramping as experienced with standard heating stages. The heating technology also provides stable operation limited only by the inherent drift in the microscope stage, thus allowing full image resolution to be achieved even at elevated temperatures. The present study details the use of both the high X-Y spatial resolution in both dark-field and simultaneous bright-field imaging, along with the high resolution in Z (depth sectioning) provided by the large probe incidence semiangle in the aberration-corrected instrument, to characterize the evolution of microstructure in a commercial Au/Fe2O3 water-gas shift catalyst during elevated temperature treatment. The phenomenon of Au diffusion to the surface of hematite support particles to form discrete crystalline Au nanoparticles in the 1-2 nm size range, after a prior leaching treatment to remove surface Au species has been characterized.

  14. Charge collection microscopy of in-situ switchable PRAM line cells in a scanning electron microscope: Technique development and unique observations

    SciTech Connect

    Oosthoek, J. L. M.; Schuitema, R. W.; Brink, G. H. ten; Kooi, B. J.; Gravesteijn, D. J.

    2015-03-15

    An imaging method has been developed based on charge collection in a scanning electron microscope (SEM) that allows discrimination between the amorphous and crystalline states of Phase-change Random Access Memory (PRAM) line cells. During imaging, the cells are electrically connected and can be switched between the states and the resistance can be measured. This allows for electrical characterization of the line cells in-situ in the SEM. Details on sample and measurement system requirements are provided which turned out to be crucial for the successful development of this method. Results show that the amorphous or crystalline state of the line cells can be readily discerned, but the spatial resolution is relatively poor. Nevertheless, it is still possible to estimate the length of the amorphous mark, and also for the first time, we could directly observe the shift of the amorphous mark from one side of the line cell to the other side when the polarity of the applied (50 ns) RESET pulse was reversed.

  15. Direct measurement of toxicants inhaled by water pipe users in the natural environment using a real-time in situ sampling technique.

    PubMed

    Katurji, M; Daher, N; Sheheitli, H; Saleh, R; Shihadeh, A

    2010-11-01

    While narghile water pipe smoking has become a global phenomenon, knowledge regarding its toxicant content and delivery, addictive properties, and health consequences is sorely lagging. One challenge in measuring toxicant content of the smoke in the laboratory is the large number of simplifying assumptions that must be made to model a "typical" smoking session using a smoking machine, resulting in uncertainty over the obtained toxicant yields. In this study, we develop an alternative approach in which smoke generated by a human water pipe user is sampled directly during the smoking session. The method, dubbed real-time in situ sampling (RINS), required developing a self-powered portable instrument capable of automatically sampling a fixed fraction of the smoke generated by the user. Instrument performance was validated in the laboratory, and the instrument was deployed in a field study involving 43 ad libitum water pipe use sessions in Beirut area cafés in which we measured inhaled nicotine, carbon monoxide (CO), and water pipe ma'ssel-derived "tar." We found that users drew a mean of 119 L of smoke containing 150 mg of CO, 4 mg of nicotine, and 602 mg of ma'ssel-derived "tar" during a single use session (mean duration = 61 min). These first direct measurements of toxicant delivery demonstrate that ordinary water pipe use involves inhaling large quantities of CO, nicotine, and dry particulate matter. Results are compared with those obtained using the Beirut method smoking machine protocol. PMID:21062108

  16. Capric Acid Absorption in the Presence of Hydroxypropyl-β-Cyclodextrin in the Rat Ileum using the In Situ Single-Pass Perfusion Technique.

    PubMed

    Hymas, Richard V; Ho, Norman F H; Higuchi, William I

    2015-09-01

    The purpose of the present study was to gain quantitative mechanistic insight into the role cyclodextrin carriers may play in the intestinal absorption of highly lipophilic molecules. The physical model approach was employed to investigate capric acid absorption in the rat ileum using the in situ single-pass method with 2-hydroxypropyl-β-cyclodextrin (HPB) present in the perfusate. Two physical models were examined: the flat surface model in which the intestinal wall was treated as a hollow, smooth, circular cylinder, and the villus model in which the intestinal surface allowed for the presence of villi. Capric acid absorption was found to be essentially 100% aqueous boundary layer controlled at low HPB concentrations and increasingly membrane controlled at the higher HPB concentrations. Theoretical calculations based on the experimental data and model parameters were found to be consistent with: at low HPB concentrations, capric acid was mainly absorbed at the villus tips and there was very little capric acid penetration into the intervillus space; in contrast, at 50 mM HPB, there was considerable capric acid penetration into the intervillus space, this corresponding to around a 4.5-fold increase in the accessible area for absorption when compared with 0 mM HPB.

  17. Charge collection microscopy of in-situ switchable PRAM line cells in a scanning electron microscope: Technique development and unique observations

    NASA Astrophysics Data System (ADS)

    Oosthoek, J. L. M.; Schuitema, R. W.; ten Brink, G. H.; Gravesteijn, D. J.; Kooi, B. J.

    2015-03-01

    An imaging method has been developed based on charge collection in a scanning electron microscope (SEM) that allows discrimination between the amorphous and crystalline states of Phase-change Random Access Memory (PRAM) line cells. During imaging, the cells are electrically connected and can be switched between the states and the resistance can be measured. This allows for electrical characterization of the line cells in-situ in the SEM. Details on sample and measurement system requirements are provided which turned out to be crucial for the successful development of this method. Results show that the amorphous or crystalline state of the line cells can be readily discerned, but the spatial resolution is relatively poor. Nevertheless, it is still possible to estimate the length of the amorphous mark, and also for the first time, we could directly observe the shift of the amorphous mark from one side of the line cell to the other side when the polarity of the applied (50 ns) RESET pulse was reversed.

  18. In situ vitrification large-scale operational acceptance test analysis

    SciTech Connect

    Buelt, J.L.; Carter, J.G.

    1986-05-01

    A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack.

  19. Final report, Ames Mobile Laboratory Project: The development and operation of instrumentation in a mobile laboratory for in situ, real-time screening and characterization of soils using the laser ablation sampling technique

    SciTech Connect

    Anderson, M.S.; Braymen, S.D.

    1995-01-27

    The main focus of the Ames Laboratory`s Technology Integration Program, TIP, from May 1991 through December 1994 was the development, fabrication, and demonstration of a mobile instrumentation laboratory incorporating rapid in situ sampling systems for safe, rapid, and cost effective soil screening/characterization. The Mobile Demonstration Laboratory for Environmental Screening Technologies, MDLEST, containing the analysis instrumentation, along with surface and subsurface sampling probe prototypes employing the laser ablation sampling technique were chosen to satisfy the particular surface and subsurface soil characterization needs of the various Department of Energy facilities for determining the extent of heavy metal and radionuclide contamination. The MDLEST, a 44 foot long 5th wheel trailer, is easily configured for the analysis instrumentation and sampling system required for the particular site work. This mobile laboratory contains all of the utilities needed to satisfy the operating requirements of the various instrumentation installed. These utilities include, an electric generator, a chilled water system, process gases, a heating/air conditioning system, and computer monitoring and automatic operating systems. Once the MDLEST arrives at the job site, the instrumentation is aligned and calibration is completed, sampling and analysis operations begin. The sample is acquired, analyzed and the results reported in as little as 10 minutes. The surface sampling probe is used in two modes to acquire samples for analysis. It is either set directly on the ground over the site to be sampled, in situ sampling, or in a special fixture used for calibrating the sampling analysis system with standard soil samples, having the samples brought to the MDLEST. The surface sampling probe was used to in situ sample a flat concrete surface (nondestructively) with the ablated sample being analyzed by the instrumentation in the MDLEST.

  20. In situ groundwater bioremediation

    SciTech Connect

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  1. Development of an in-situ multi-component reinforced Al-based metal matrix composite by direct metal laser sintering technique — Optimization of process parameters

    SciTech Connect

    Ghosh, Subrata Kumar; Bandyopadhyay, Kaushik; Saha, Partha

    2014-07-01

    In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal laser sintering process. The different mixtures of Al, TiO{sub 2} and B{sub 4}C powders were used to initiate and maintain the self-propagating high-temperature synthesis by laser during the sintering process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and laser power are the significant parameters which influence the porosity. The composition, laser power and layer thickness are the key influencing parameters for microhardness. - Highlights: • The reinforcements such as Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were produced in Al-MMC through SHS. • The density is mainly influenced by the material composition and hatching distance. • Hatching distance is the major influencing parameter on porosity. • The material composition is the significant parameter to enhance the microhardness. • The SEM micrographs reveal the distribution of TiC, TiB{sub 2} and Al{sub 2}O{sub 3} in the composite.

  2. Implementation of neutron counting techniques at US facilities for IAEA verification of excess materials from nuclear weapons production

    SciTech Connect

    Stewart, J.E.; Krick, M.S.; Langner, D.G.; Reilly, T.D.; Theis, W.; Lemaire, R.J.; Xiao, J.

    1995-08-01

    The U.S. Nonproliferation and Export Control Policy, announced by President Clinton before the United Nations General Assembly on September 27, 1993, commits the U.S. to placing under International Atomic Energy Agency (IAEA) Safeguards excess nuclear materials no longer needed for the U.S. nuclear deterrent. As of July 1, 1995, the IAEA had completed Initial Physical Inventory Verification (IPIV) at two facilities: a storage vault in the Oak Ridge Y-12 plant containing highly enriched uranium (HOW) metal and another storage vault in the Hanford Plutonium Finishing Plant (PFP) containing plutonium oxide and plutonium-bearing residues. Another plutonium- storage vault, located at Rocky Flats, is scheduled for the IPIV in the fall of 1995. Conventional neutron coincidence counting is one of the routinely applied IAEA nondestructive assay (ND) methods for verification of uranium and plutonium. However, at all three facilities mentioned above, neutron ND equipment had to be modified or developed for specific facility needs such as the type and configuration of material placed under safeguards. This document describes those modifications and developments.

  3. Studies on parametric optimization for abrasive water jet machining of Al7075-TiB2 in-situ composite

    NASA Astrophysics Data System (ADS)

    Kavya, J. T.; Keshavamurthy, R.; Pradeep Kumar, G. S.

    2016-09-01

    The study focuses on optimization and determination of significant process parameter for Abrasive Water Jet Machining of Al7075-TiB2metal matrix composite. Al-TiB2 metal matrix composite is synthesized by stir casting using in-situ technique. Optimization of machining parameters is done using Taguchi's L25orthogonal array for the experimental trials, with cutting speed, stand-off distance and Abrasive Flow rate as input parameters at five different levels. Analysis Of Variance (ANOVA) method is used for identifying the effect of machining parameters on volumetric material removal rate, surface roughness and dimensional accuracy. Then the results are validated by conducting verification experiments.

  4. GROUND WATER ISSUE: HOW HEAT CAN ENHANCE IN-SITU SOIL AND AQUIFER REMEDIATION: IMPORTANT CHEMICAL PROPERTIES & GUIDANCE ON CHOOSING THE APPROPRIATE TECHNIQUE

    EPA Science Inventory

    The purpose of this Issue Paper and the three companion Issue Papers (Davis, 1997a, b, c) is to provide to those involved in assessing remediation technologies some basic information on the thermal remediation techniques.

  5. In Situ Cometary Cosmochemistry

    NASA Astrophysics Data System (ADS)

    Wright, I. P.; Andrews, D. J.; Barber, S. J.; Sheridan, S.; Morgan, G. H.; Morse, A. D.

    2013-09-01

    In 2014 the Rosetta space mission arrives at comet 67P. Herein we describe the ambitions of one of the instruments, Ptolemy, included on the lander. Our aim is to make in situ measurements of isotopic compositions of elements such as H, C, N and O.

  6. In Situ Processing.

    ERIC Educational Resources Information Center

    Edgar, T. F.; Schechter, R. S.

    1980-01-01

    Describes research on in situ processing to develop necessary theory and understanding of the underground process to facilitate commercialization of a wide range of mineral deposits. Goal is to produce laboratory and computer-based tools to allow site evaluation based on field and laboratory measurements of mineral and associated overburdens.…

  7. In situ reactor

    DOEpatents

    Radtke, Corey William; Blackwelder, David Bradley

    2004-01-27

    An in situ reactor for use in a geological strata, is described and which includes a liner defining a centrally disposed passageway and which is placed in a borehole formed in the geological strata; and a sampling conduit is received within the passageway defined by the liner and which receives a geological specimen which is derived from the geological strata, and wherein the sampling conduit is in fluid communication with the passageway defined by the liner.

  8. Deductive Verification of Cryptographic Software

    NASA Technical Reports Server (NTRS)

    Almeida, Jose Barcelar; Barbosa, Manuel; Pinto, Jorge Sousa; Vieira, Barbara

    2009-01-01

    We report on the application of an off-the-shelf verification platform to the RC4 stream cipher cryptographic software implementation (as available in the openSSL library), and introduce a deductive verification technique based on self-composition for proving the absence of error propagation.

  9. Development of a 3He nuclear spin flip system on an in-situ SEOP 3He spin filter and demonstration for a neutron reflectometer and magnetic imaging technique

    NASA Astrophysics Data System (ADS)

    Hayashida, H.; Oku, T.; Kira, H.; Sakai, K.; Hiroi, K.; Ino, T.; Shinohara, T.; Imagawa, T.; Ohkawara, M.; Ohoyama, K.; Kakurai, K.; Takeda, M.; Yamazaki, D.; Oikawa, K.; Harada, M.; Miyata, N.; Akutsu, K.; Mizusawa, M.; Parker, J. D.; Matsumoto, Y.; Zhang, S.; Suzuki, J.; Soyama, K.; Aizawa, K.; Arai, M.

    2016-04-01

    We have been developing a 3He neutron spin filter (NSF) using the spin exchange optical pumping (SEOP) technique. The 3He NSF provides a high-energy polarized neutron beam with large beam size. Moreover the 3He NSF can work as a π-flipper for a polarized neutron beam by flipping the 3He nuclear spin using a nuclear magnetic resonance (NMR) technique. For NMR with the in-situ SEOP technique, the polarization of the laser must be reversed simultaneously because a non-reversed laser reduces the polarization of the spin-flipped 3He. To change the polarity of the laser, a half-wavelength plate was installed. The rotation angle of the half-wavelength plate was optimized, and a polarization of 97% was obtained for the circularly polarized laser. The 3He polarization reached 70% and was stable over one week. A demonstration of the 3He nuclear spin flip system was performed at the polarized neutron reflectometer SHARAKU (BL17) and NOBORU (BL10) at J-PARC. Off-specular measurement from a magnetic Fe/Cr thin film and magnetic imaging of a magnetic steel sheet were performed at BL17 and BL10, respectively.

  10. Which Microbial Communities Are Present? Using Fluorescence In Situ Hybridisation (FISH): Microscopic Techniques for Enumeration of Troublesome Microorganisms in Oil and Fuel Samples

    NASA Astrophysics Data System (ADS)

    Holmkvist, Lars; Østergaard, Jette Johanne; Skovhus, Torben Lund

    Enumeration of microbes involved in souring of oil fields and microbiologically influenced corrosion (MIC) with culture-based methods, usually yield inadequate and contradictory results. Any cultivation step will almost certainly alter the population structure of the sample and thus the results of cultivation analysis are not a good basis for mitigation decisions. The need for methods that are cultivation independent has over the past 10 years facilitated the development of several analytical methods for determination of bacterial identity, quantity, and to some extent function, applied directly to samples of the native population. In this chapter, we demonstrate the features and benefits of applying microscopic techniques to a situation often encountered in the oil and petroleum industry: Control of microbial growth in fuel storage tanks. The methods described in this chapter will focus on direct counts of specific groups of microorganisms with microscopy and these are based on the detection of genetic material and not on culturing.

  11. In-Situ Burning of Spilled Oil.

    ERIC Educational Resources Information Center

    Allen, Alan A.

    1991-01-01

    Reviews in-situ burning with particular emphasis on how it can be applied in water-related oil spill situations. Presents and discusses the use of nomograms and development of techniques cited for safe and effective ignition and controlled burning of spilled oil. Includes representative oil spill scenarios and possible responses. (15 references)…

  12. Controlled in situ etch-back

    NASA Technical Reports Server (NTRS)

    Mattauch, R. J.; Seabaugh, A. C. (Inventor)

    1981-01-01

    A controlled in situ etch-back technique is disclosed in which an etch melt and a growth melt are first saturated by a source-seed crystal and thereafter etch-back of a substrate takes place by the slightly undersaturated etch melt, followed by LPE growth of a layer by the growth melt, which is slightly supersaturated.

  13. In situ measurement technique for simultaneous detection of K, KCl, and KOH vapors released during combustion of solid biomass fuel in a single particle reactor.

    PubMed

    Sorvajärvi, Tapio; DeMartini, Nikolai; Rossi, Jussi; Toivonen, Juha

    2014-01-01

    A quantitative and simultaneous measurement of K, KCl, and KOH vapors from a burning fuel sample combusted in a single particle reactor was performed using collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) with a time resolution of 0.2 s. The previously presented CPFAAS technique was extended in this work to cover two consecutive fragmentation pulses for the photofragmentation of KCl and KOH. The spectral overlapping of the fragmentation spectra of KCl and KOH is discussed, and a linear equation system for the correction of the spectral interference is introduced. The detection limits for KCl, KOH, and K with the presented measurement arrangement and with 1 cm sample length were 0.5, 0.1, and 0.001 parts per million, respectively. The experimental setup was applied to analyze K, KCl, and KOH release from 10 mg spruce bark samples combusted at the temperatures of 850, 950, and 1050 °C with 10% of O2. The combustion experiments provided data on the form of K vapors and their release during different combustion phases and at different temperatures. The measured release histories agreed with earlier studies of K release. The simultaneous direct measurement of atomic K, KCl, and KOH will help in the impact of both the form of K in the biomass and fuel variables, such as particle size, on the release of K from biomass fuels.

  14. In situ application of stir bar sorptive extraction as a passive sampling technique for the monitoring of agricultural pesticides in surface waters.

    PubMed

    Assoumani, Azziz; Lissalde, Sophie; Margoum, Christelle; Mazzella, Nicolas; Coquery, Marina

    2013-10-01

    Grab sampling and automated sampling are not suitable or logistically too constraining for the monitoring of pesticides in dynamic streams located in agricultural watersheds. In this work, we applied stir bar sorptive extraction (SBSE) Twisters® directly in two small rivers of a French vineyard (herein referred to as "passive SBSE"), for periods of one or two weeks during a month, for the passive sampling of 19 agricultural pesticides. We performed qualitative and semi-quantitative comparisons of the performances of passive SBSE firstly to automated sampling coupled to analytical SBSE, and secondly to the polar organic chemical integrative sampler (POCIS), a well-known passive sampler for hydrophilic micropollutants. Applying passive SBSE in river waters allowed the quantification of more pesticides and in greater amounts than analytical SBSE as shown for samples collected concurrently. Also, passive SBSE and POCIS proved to be complementary techniques in terms of detected molecules; but only passive SBSE was able to integrate a concentration peak triggered by a quick flood event that lasted 5 h. Passive SBSE could be an interesting tool for the monitoring of moderately hydrophobic to hydrophobic organic micropollutants in changing hydrosystems. In this purpose, further studies will focus on the accumulation kinetics of target pesticides and the determination of their sampling rates. PMID:23856404

  15. Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting

    SciTech Connect

    Alstone, Peter; Jacobson, Arne; Mills, Evan

    2010-08-26

    Efforts to promote rechargeable electric lighting as a replacement for fuel-based light sources in developing countries are typically predicated on the notion that lighting service levels can be maintained or improved while reducing the costs and environmental impacts of existing practices. However, the extremely low incomes of those who depend on fuel-based lighting create a need to balance the hypothetically possible or desirable levels of light with those that are sufficient and affordable. In a pilot study of four night vendors in Kenya, we document a field technique we developed to simultaneously measure the effectiveness of lighting service provided by a lighting system and conduct a survey of lighting service demand by end-users. We took gridded illuminance measurements across each vendor's working and selling area, with users indicating the sufficiency of light at each point. User light sources included a mix of kerosene-fueled hurricane lanterns, pressure lamps, and LED lanterns.We observed illuminance levels ranging from just above zero to 150 lux. The LED systems markedly improved the lighting service levels over those provided by kerosene-fueled hurricane lanterns. Users reported that the minimum acceptable threshold was about 2 lux. The results also indicated that the LED lamps in use by the subjects did not always provide sufficient illumination over the desired retail areas. Our sample size is much too small, however, to reach any conclusions about requirements in the broader population. Given the small number of subjects and very specific type of user, our results should be regarded as indicative rather than conclusive. We recommend replicating the method at larger scales and across a variety of user types and contexts. Policymakers should revisit the subject of recommended illuminance levels regularly as LED technology advances and the price/service balance point evolves.

  16. In Situ Fabrication Technologies

    NASA Technical Reports Server (NTRS)

    Rolin, Terry D.; Hammond, Monica

    2005-01-01

    A manufacturing system is described that is internal to controlled cabin environments which will produce functional parts to net shape with sufficient tolerance, strength and integrity to meet application specific needs such as CEV ECLS components, robotic arm or rover components, EVA suit items, unforeseen tools, conformal repair patches, and habitat fittings among others. Except for start-up and shut-down, fabrication will be automatic without crew intervention under nominal scenarios. Off-nominal scenarios may require crew and/or Earth control intervention. System will have the ability to fabricate using both provisioned feedstock materials and feedstock refined from in situ regolith.

  17. Practical application of in situ aerosol measurement

    SciTech Connect

    O`Hern, T.J.; Rader, D.J.

    1993-09-01

    The use of in situ, real-time measurement techniques permits the characterization of airborne droplets and particles under conditions where traditional sampling methods can fail. For example, sampling method rely on the ability to sample and transport particles without biasing the properties of interest, and often are not applicable in harsh environment. Although in situ methods offer unique opportunities in these cases, these techniques introduce new concerns and must be used carefully if accurate measurement are to be made. Several in situ measurement techniques are reviewed here. As the field is rapidly evolving, the discussion is limited to those techniques which: (1) are commercially available, (2) provide real-time output, (3) measure the aerosol size distribution. Discussion is divided between single particle counters (which provide a flux-based or temporal measurement) and ensemble techniques (which provide a concentration-based or spatial measurement). Specific techniques discussed include phase Doppler, Mie scattering, and Fraunhofer diffraction, and commercial instruments based on these techniques.

  18. Three Independent Techniques Localize Expression of Transcript afp-11 and Its Bioactive Peptide Products to the Paired AVK Neurons in Ascaris suum: In Situ Hybridization, Immunocytochemistry, and Single Cell Mass Spectrometry

    PubMed Central

    2012-01-01

    We utilized three independent techniques, immunocytochemistry (ICC), single cell mass spectrometry (MS), and in situ hybridization (ISH), to localize neuropeptides and their transcripts in the nervous system of the nematode Ascaris suum. AF11 (SDIGISEPNFLRFa) is an endogenous peptide with potent paralytic effects on A. suum locomotory behavior. A highly specific antibody to AF11 showed robust immunostaining for AF11 in the paired AVK neurons in the ventral ganglion. We traced the processes from the AVK neurons into the ventral nerve cord and identified them as ventral cord interneurons. MS and MS/MS of single dissected AVKs detected AF11, two previously characterized peptides (AF25 and AF26), seven novel sequence-related peptides, including several sharing a PNFLRFamide C-terminus, and peptide NY, a peptide with an unrelated sequence. Also present in a subset of AVKs was AF2, a peptide encoded by the afp-4 transcript. By sequencing the afp-11 transcript, we discovered that it encodes AF11, all the AF11-related peptides detected by MS in AVK, and peptide NY. ISH detected the afp-11 transcript in AVK neurons, consistent with other techniques. ISH did not detect afp-11 in the ALA neuron, although both ICC and MS found AF11 in ca. 30% of ALAs. All 10 AF11-related peptides reduced acetylcholine-induced muscle contraction, but they differed in their rate of reversal of inhibition after removal of the peptide. PMID:23509978

  19. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    NASA Astrophysics Data System (ADS)

    Romano, F. P.; Garraffo, S.; Pappalardo, L.; Rizzo, F.

    2012-07-01

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-μXRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world.

  20. Three independent techniques localize expression of transcript afp-11 and its bioactive peptide products to the paired AVK neurons in Ascaris suum: in situ hybridization, immunocytochemistry, and single cell mass spectrometry.

    PubMed

    Jarecki, Jessica L; Viola, India R; Andersen, Kari M; Miller, Andrew H; Ramaker, Megan A; Vestling, Martha M; Stretton, Antony O

    2013-03-20

    We utilized three independent techniques, immunocytochemistry (ICC), single cell mass spectrometry (MS), and in situ hybridization (ISH), to localize neuropeptides and their transcripts in the nervous system of the nematode Ascaris suum . AF11 (SDIGISEPNFLRFa) is an endogenous peptide with potent paralytic effects on A. suum locomotory behavior. A highly specific antibody to AF11 showed robust immunostaining for AF11 in the paired AVK neurons in the ventral ganglion. We traced the processes from the AVK neurons into the ventral nerve cord and identified them as ventral cord interneurons. MS and MS/MS of single dissected AVKs detected AF11, two previously characterized peptides (AF25 and AF26), seven novel sequence-related peptides, including several sharing a PNFLRFamide C-terminus, and peptide NY, a peptide with an unrelated sequence. Also present in a subset of AVKs was AF2, a peptide encoded by the afp-4 transcript. By sequencing the afp-11 transcript, we discovered that it encodes AF11, all the AF11-related peptides detected by MS in AVK, and peptide NY. ISH detected the afp-11 transcript in AVK neurons, consistent with other techniques. ISH did not detect afp-11 in the ALA neuron, although both ICC and MS found AF11 in ca. 30% of ALAs. All 10 AF11-related peptides reduced acetylcholine-induced muscle contraction, but they differed in their rate of reversal of inhibition after removal of the peptide.

  1. In Situ Surface Characterization

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Leger, Patrick C.; Yanovsky, Igor

    2011-01-01

    Operation of in situ space assets, such as rovers and landers, requires operators to acquire a thorough understanding of the environment surrounding the spacecraft. The following programs help with that understanding by providing higher-level information characterizing the surface, which is not immediately obvious by just looking at the XYZ terrain data. This software suite covers three primary programs: marsuvw, marsrough, and marsslope, and two secondary programs, which together use XYZ data derived from in situ stereo imagery to characterize the surface by determining surface normal, surface roughness, and various aspects of local slope, respectively. These programs all use the Planetary Image Geometry (PIG) library to read mission-specific data files. The programs themselves are completely multimission; all mission dependencies are handled by PIG. The input data consists of images containing XYZ locations as derived by, e.g., marsxyz. The marsuvw program determines surface normals from XYZ data by gathering XYZ points from an area around each pixel and fitting a plane to those points. Outliers are rejected, and various consistency checks are applied. The result shows the orientation of the local surface at each point as a unit vector. The program can be run in two modes: standard, which is typically used for in situ arm work, and slope, which is typically used for rover mobility. The difference is primarily due to optimizations necessary for the larger patch sizes in the slope case. The marsrough program determines surface roughness in a small area around each pixel, which is defined as the maximum peak-to-peak deviation from the plane perpendicular to the surface normal at that pixel. The marsslope program takes a surface normal file as input and derives one of several slope-like outputs from it. The outputs include slope, slope rover direction (a measure of slope radially away from the rover), slope heading, slope magnitude, northerly tilt, and solar energy

  2. Wind gust warning verification

    NASA Astrophysics Data System (ADS)

    Primo, Cristina

    2016-07-01

    Operational meteorological centres around the world increasingly include warnings as one of their regular forecast products. Warnings are issued to warn the public about extreme weather situations that might occur leading to damages and losses. In forecasting these extreme events, meteorological centres help their potential users in preventing the damage or losses they might suffer. However, verifying these warnings requires specific methods. This is due not only to the fact that they happen rarely, but also because a new temporal dimension is added when defining a warning, namely the time window of the forecasted event. This paper analyses the issues that might appear when dealing with warning verification. It also proposes some new verification approaches that can be applied to wind warnings. These new techniques are later applied to a real life example, the verification of wind gust warnings at the German Meteorological Centre ("Deutscher Wetterdienst"). Finally, the results obtained from the latter are discussed.

  3. Physics-aspects of dose accuracy in high dose rate (HDR) brachytherapy: source dosimetry, treatment planning, equipment performance and in vivo verification techniques

    PubMed Central

    Bradley, David; Nisbet, Andrew

    2012-01-01

    This study provides a review of recent publications on the physics-aspects of dosimetric accuracy in high dose rate (HDR) brachytherapy. The discussion of accuracy is primarily concerned with uncertainties, but methods to improve dose conformation to the prescribed intended dose distribution are also noted. The main aim of the paper is to review current practical techniques and methods employed for HDR brachytherapy dosimetry. This includes work on the determination of dose rate fields around brachytherapy sources, the capability of treatment planning systems, the performance of treatment units and methods to verify dose delivery. This work highlights the determinants of accuracy in HDR dosimetry and treatment delivery and presents a selection of papers, focusing on articles from the last five years, to reflect active areas of research and development. Apart from Monte Carlo modelling of source dosimetry, there is no clear consensus on the optimum techniques to be used to assure dosimetric accuracy through all the processes involved in HDR brachytherapy treatment. With the exception of the ESTRO mailed dosimetry service, there is little dosimetric audit activity reported in the literature, when compared with external beam radiotherapy verification. PMID:23349649

  4. Low-Intrusion Techniques and Sensitive Information Management for Warhead Counting and Verification: FY2012 Annual Report

    SciTech Connect

    Jarman, Kenneth D.; McDonald, Benjamin S.; Robinson, Sean M.; Gilbert, Andrew J.; White, Timothy A.; Pitts, W. Karl; Misner, Alex C.; Seifert, Allen

    2012-11-01

    Progress in the second year of this project is described by the series of technical reports and manuscripts that make up the content of this report. These documents summarize successes in our goals to develop our robust image-hash templating and material-discrimination techniques and apply them to test image data.

  5. Feasibility study on using fast calorimetry technique to measure a mass attribute as part of a treaty verification regime

    SciTech Connect

    Hauck, Danielle K; Bracken, David S; Mac Arthur, Duncan W; Santi, Peter A; Thron, Jonathan

    2010-01-01

    The attribute measurement technique provides a method for determining whether or not an item containing special nuclear material (SNM) possesses attributes that fall within an agreed upon range of values. One potential attribute is whether the mass of an SNM item is larger than some threshold value that has been negotiated as part of a nonproliferation treaty. While the historical focus on measuring mass attributes has been on using neutron measurements, calorimetry measurements may be a viable alternative for measuring mass attributes for plutonium-bearing items. Traditionally, calorimetry measurements have provided a highly precise and accurate determination of the thermal power that is being generated by an item. In order to achieve this high level of precision and accuracy, the item must reach thermal equilibrium inside the calorimeter prior to determining the thermal power of the item. Because the approach to thermal equilibrium is exponential in nature, a large portion of the time spent approaching equilibrium is spent with the measurement being within {approx}10% of its final equilibrium value inside the calorimeter. Since a mass attribute measurement only needs to positively determine if the mass of a given SNM item is greater than a threshold value, performing a short calorimetry measurement to determine how the system is approaching thermal equilibrium may provide sufficient information to determine if an item has a larger mass than the agreed upon threshold. In previous research into a fast calorimetry attribute technique, a two-dimensional heat flow model of a calorimeter was used to investigate the possibility of determining a mass attribute for plutonium-bearing items using this technique. While the results of this study looked favorable for developing a fast calorimetry attribute technique, additional work was needed to determine the accuracy of the model used to make the calculations. In this paper, the results from the current work investigating

  6. Application of the 15N gas-flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    NASA Astrophysics Data System (ADS)

    Sgouridis, Fotis; Stott, Andrew; Ullah, Sami

    2016-03-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilized agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in-house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps and a copper-based reduction furnace, and allows the analysis of small gas injection volumes (4 µL) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Preconcentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N gas-flux method was adapted for application in natural and semi-natural land use types (peatlands, forests, and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. The minimum detectable flux rates were 4 µg N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. Total denitrification rates measured by the acetylene inhibition technique in the same land use types correlated (r = 0.58) with the denitrification rates measured under the 15N gas-flux method, but were underestimated by a factor of 4, and this was partially attributed to the incomplete inhibition of N2O reduction to N2, under a relatively high soil moisture content, and/or the catalytic NO decomposition in the presence of acetylene. Even though relatively robust for in situ denitrification measurements, methodological

  7. In situ DNA-hybridization chain reaction (HCR): a facilitated in situ HCR system for the detection of environmental microorganisms.

    PubMed

    Yamaguchi, Tsuyoshi; Kawakami, Shuji; Hatamoto, Masashi; Imachi, Hiroyuki; Takahashi, Masanobu; Araki, Nobuo; Yamaguchi, Takashi; Kubota, Kengo

    2015-07-01

    In situ detection of microorganisms by fluorescence in situ hybridization (FISH) is a powerful tool for environmental microbiology, but analyses can be hampered by low rRNA content in target organisms, especially in oligotrophic environments. Here, we present a non-enzymatic, hybridization chain reaction (HCR)-based signal amplified in situ whole-cell detection technique (in situ DNA-HCR). The components of the amplification buffer were optimized to polymerize DNA amplifier probes for in situ DNA-HCR. In situ hybridization of initiator probes followed by signal amplification via HCR produced bright signals with high specificity and probe permeation into cells. The detection rates for Bacteria in a seawater sample and Archaea in anaerobic sludge samples were comparable with or greater than those obtained by catalyzed reporter deposition (CARD)-FISH or standard FISH. Detection of multiple organisms (Bacteria, Archaea and Methanosaetaceae) in an anaerobic sludge sample was achieved by simultaneous in situ DNA-HCR. In summary, in situ DNA-HCR is a simple and easy technique for detecting single microbial cells and enhancing understanding of the ecology and behaviour of environmental microorganisms in situ.

  8. Secure verification by multifactor optical validation

    NASA Astrophysics Data System (ADS)

    Millán, María S.; Pérez-Cabré, Elisabet; Javidi, Bahram

    2006-08-01

    We propose a novel multifactor encryption-authentication technique that reinforces optical security by allowing the simultaneous AND-verification of more than one primary image. We describe a method to obtain four-factor authentication. The authenticators are: two different primary images containing signatures or biometric information and two different white random sequences that act as key codes. So far, optical security techniques deal with a single primary image (an object, a signature, or a biometric signal), not combined primary images. Our method involves double random-phase encoding, fully phase-based encryption and a combined nonlinear JTC and a classical 4f-correlator for simultaneous recognition and authentication of multiple images. There is no a priori constraint about the type of primary images to encode. Two reference images, double-phase encoded and encrypted in an ID tag (or card) are compared with the actual input images obtained in situ from the person whose authentication is wanted. The two key phase codes are known by the authentication processor. The complex-amplitude encoded image of the ID tag has a dim appearance that does not reveal the content of any primary reference image nor the key codes. The encoded image function fullfils the general requirements of invisible content, extreme difficulty in counterfeiting and real-time automatic verification. The possibility of introducing nonlinearities in the Fourier plane of the optical processor will be exploited to improve the system performance. This optical technique is attractive for high-security purposes that require multifactor reliable authentication.

  9. In situ measurement system

    DOEpatents

    Lord, D.E.

    1980-11-24

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop hairpin configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. Measurement means are provided for obtaining for each pair the electrical resistance of each element and the difference in electrical resistance of the paired elements, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner means sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  10. Dosimetric Study and Verification of Total Body Irradiation Using Helical Tomotherapy and its Comparison to Extended SSD Technique

    SciTech Connect

    Zhuang, Audrey H.; Liu An; Schultheiss, Timothy E.; Wong, Jeffrey Y.C.

    2010-01-01

    The American College of Radiology practice guideline for total body irradiation (TBI) requires a back-up treatment delivery system. This study investigates the development of helical tomotherapy (HT) for delivering TBI and compares it with conventional extended source-to-surface distance (X-SSD) technique. Four patients' head-to-thigh computed tomographic images were used in this study, with the target defined as the body volume without the left and right lungs. HT treatment plans with the standard TBI prescription (1.2 Gy/fx, 10 fractions) were generated and verified on phantoms. To compare HT plans with X-SSD treatment, the dose distribution of X-SSD technique was simulated using the Eclipse software. The average dose received by 90% of the target volume was 12.3 Gy (range, 12.2-12.4 Gy) for HT plans and 10.3 Gy (range, 10.08-10.58 Gy) for X-SSD plans (p < 0.001). The left and right lung median doses were 5.44 Gy and 5.40 Gy, respectively, for HT plans and 8.34 Gy and 8.95 Gy, respectively, for X-SSD treatment. The treatment planning time was comparable between the two methods. The beam delivery time of HT treatment was longer than X-SSD treatment. In conclusion, HT-based TBI plans have better dose coverage to the target and better dose sparing to the lungs compared with X-SSD technique, which applies dose compensators, lung blocks, and electron boosts. This study demonstrates that HT is possible for delivering TBI. Clinical validation of the feasibility of this approach would be of interest in the future.

  11. Verification of the helioseismology travel-time measurement technique and the inversion procedure for sound speed using artificial data

    SciTech Connect

    Parchevsky, K. V.; Zhao, J.; Hartlep, T.; Kosovichev, A. G.

    2014-04-10

    We performed three-dimensional numerical simulations of the solar surface acoustic wave field for the quiet Sun and for three models with different localized sound-speed perturbations in the interior with deep, shallow, and two-layer structures. We used the simulated data generated by two solar acoustics codes that employ the same standard solar model as a background model, but utilize different integration techniques and different models of stochastic wave excitation. Acoustic travel times were measured using a time-distance helioseismology technique, and compared with predictions from ray theory frequently used for helioseismic travel-time inversions. It is found that the measured travel-time shifts agree well with the helioseismic theory for sound-speed perturbations, and for the measurement procedure with and without phase-speed filtering of the oscillation signals. This testing verifies the whole measuring-filtering-inversion procedure for static sound-speed anomalies with small amplitude inside the Sun outside regions of strong magnetic field. It is shown that the phase-speed filtering, frequently used to extract specific wave packets and improve the signal-to-noise ratio, does not introduce significant systematic errors. Results of the sound-speed inversion procedure show good agreement with the perturbation models in all cases. Due to its smoothing nature, the inversion procedure may overestimate sound-speed variations in regions with sharp gradients of the sound-speed profile.

  12. Multivariate class modeling techniques applied to multielement analysis for the verification of the geographical origin of chili pepper.

    PubMed

    Naccarato, Attilio; Furia, Emilia; Sindona, Giovanni; Tagarelli, Antonio

    2016-09-01

    Four class-modeling techniques (soft independent modeling of class analogy (SIMCA), unequal dispersed classes (UNEQ), potential functions (PF), and multivariate range modeling (MRM)) were applied to multielement distribution to build chemometric models able to authenticate chili pepper samples grown in Calabria respect to those grown outside of Calabria. The multivariate techniques were applied by considering both all the variables (32 elements, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Fe, Ga, La, Li, Mg, Mn, Na, Nd, Ni, Pb, Pr, Rb, Sc, Se, Sr, Tl, Tm, V, Y, Yb, Zn) and variables selected by means of stepwise linear discriminant analysis (S-LDA). In the first case, satisfactory and comparable results in terms of CV efficiency are obtained with the use of SIMCA and MRM (82.3 and 83.2% respectively), whereas MRM performs better than SIMCA in terms of forced model efficiency (96.5%). The selection of variables by S-LDA permitted to build models characterized, in general, by a higher efficiency. MRM provided again the best results for CV efficiency (87.7% with an effective balance of sensitivity and specificity) as well as forced model efficiency (96.5%).

  13. Multivariate class modeling techniques applied to multielement analysis for the verification of the geographical origin of chili pepper.

    PubMed

    Naccarato, Attilio; Furia, Emilia; Sindona, Giovanni; Tagarelli, Antonio

    2016-09-01

    Four class-modeling techniques (soft independent modeling of class analogy (SIMCA), unequal dispersed classes (UNEQ), potential functions (PF), and multivariate range modeling (MRM)) were applied to multielement distribution to build chemometric models able to authenticate chili pepper samples grown in Calabria respect to those grown outside of Calabria. The multivariate techniques were applied by considering both all the variables (32 elements, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Fe, Ga, La, Li, Mg, Mn, Na, Nd, Ni, Pb, Pr, Rb, Sc, Se, Sr, Tl, Tm, V, Y, Yb, Zn) and variables selected by means of stepwise linear discriminant analysis (S-LDA). In the first case, satisfactory and comparable results in terms of CV efficiency are obtained with the use of SIMCA and MRM (82.3 and 83.2% respectively), whereas MRM performs better than SIMCA in terms of forced model efficiency (96.5%). The selection of variables by S-LDA permitted to build models characterized, in general, by a higher efficiency. MRM provided again the best results for CV efficiency (87.7% with an effective balance of sensitivity and specificity) as well as forced model efficiency (96.5%). PMID:27041319

  14. Comparison of conventional culture method and fluorescent in situ hybridization technique for detection of Listeria spp. in ground beef, turkey, and chicken breast fillets in İzmir, Turkey.

    PubMed

    Baysal, Ayse Handan

    2014-12-01

    The occurrence of Listeria species in refrigerated fresh chicken breast fillet, turkey breast fillet, and ground beef was evaluated, comparing the conventional culture method and fluorescent in situ hybridization (FISH). FISH uses hybridization of a nucleic acid sequence target of a microorganism with a specific DNA probe labeled with a fluorochrome and imaging by a fluorescence microscope. First, Listeria was inoculated in chicken breast fillet, turkey breast fillet, or ground beef, and the applicability of the FISH method was evaluated. Second, Listeria was detected in fresh chicken breast fillet, turkey breast fillet, and ground beef by culture and FISH methods. Listeria was isolated from 27 (37.4%) of 216 samples by the standard culture method, whereas FISH detected 25 (24.7%) preenriched samples. Of these isolates, 17 (63%) were L. innocua, 6 (22%) L. welshimeri, and 4 (14.8%) L. seeligeri. Overall, the prevalences of Listeria spp. found with the conventional culture method in chicken breast fillet, turkey breast fillet, and ground beef were 9.7, 6.9, and 20.8%, whereas with the FISH technique these values were 11.1, 6.9, and 16.7%, respectively. The molecular FISH technique appears to be a cheap, sensitive, and time-efficient procedure that could be used for routine detection of Listeria spp. in meat. This study showed that retail raw meats are potentially contaminated with Listeria spp. and are, thus, vehicles for transmitting diseases caused by foodborne pathogens, underlining the need for increased precautions, such as implementation of hazard analysis and critical control points and consumer food safety education.

  15. In situ selective determination of methylmercury in river water by diffusive gradient in thin films technique (DGT) using baker's yeast (Saccharomyces cerevisiae) immobilized in agarose gel as binding phase.

    PubMed

    Tafurt-Cardona, Makenly; Eismann, Carlos Eduardo; Suárez, Carlos Alfredo; Menegário, Amauri Antonio; Luko, Karen Silva; Sargentini Junior, Ézio

    2015-08-01

    Saccharomyces cerevisiae immobilized in agarose gel as binding phase and polyacrylamide as diffusive layer in the diffusive gradient in thin films technique (DGT) was used for selective determination of methylmercury (MeHg). Deployment tests showed good linearity in mass uptake up to 48 h (3276 ng). When coupling the DGT technique with Cold Vapor Atomic Fluorescence Spectrometry, the method has a limit of detection of 0.44 ng L(-1) (pre concentration factor of 11 for 48 h deployment). Diffusion coefficient of 7.03 ± 0.77 × 10(-6) cm(2) s(-1) at 23 °C in polyacrylamide gel (pH = 5.5 and ionic strength = 0.05 mol L(-1) NaCl) was obtained. Influence of ionic strength (from 0.0005 mol L(-1) to 0.1 mol L(-1) NaCl) and pH (from 3.5 to 8.5) on MeHg uptake were evaluated. For these range, recoveries of 84-105% and 84-98% were obtained for ionic strength and pH respectively. Potential interference due to presence of Cu, Fe, Mn, Zn was also assessed showing good recoveries (70-87%). The selectivity of the proposed approach was tested by deployments in solutions containing MeHg and Hg(II). Results obtained showed recoveries of 102-115 % for MeHg, while the uptake of Hg(II) was insignificant. The proposed approach was successfully employed for in situ measurements in the Negro River (Manaus-AM, Brazil).

  16. In situ selective determination of methylmercury in river water by diffusive gradient in thin films technique (DGT) using baker's yeast (Saccharomyces cerevisiae) immobilized in agarose gel as binding phase.

    PubMed

    Tafurt-Cardona, Makenly; Eismann, Carlos Eduardo; Suárez, Carlos Alfredo; Menegário, Amauri Antonio; Luko, Karen Silva; Sargentini Junior, Ézio

    2015-08-01

    Saccharomyces cerevisiae immobilized in agarose gel as binding phase and polyacrylamide as diffusive layer in the diffusive gradient in thin films technique (DGT) was used for selective determination of methylmercury (MeHg). Deployment tests showed good linearity in mass uptake up to 48 h (3276 ng). When coupling the DGT technique with Cold Vapor Atomic Fluorescence Spectrometry, the method has a limit of detection of 0.44 ng L(-1) (pre concentration factor of 11 for 48 h deployment). Diffusion coefficient of 7.03 ± 0.77 × 10(-6) cm(2) s(-1) at 23 °C in polyacrylamide gel (pH = 5.5 and ionic strength = 0.05 mol L(-1) NaCl) was obtained. Influence of ionic strength (from 0.0005 mol L(-1) to 0.1 mol L(-1) NaCl) and pH (from 3.5 to 8.5) on MeHg uptake were evaluated. For these range, recoveries of 84-105% and 84-98% were obtained for ionic strength and pH respectively. Potential interference due to presence of Cu, Fe, Mn, Zn was also assessed showing good recoveries (70-87%). The selectivity of the proposed approach was tested by deployments in solutions containing MeHg and Hg(II). Results obtained showed recoveries of 102-115 % for MeHg, while the uptake of Hg(II) was insignificant. The proposed approach was successfully employed for in situ measurements in the Negro River (Manaus-AM, Brazil). PMID:26320783

  17. In Situ Nuclear Characterization Infrastructure

    SciTech Connect

    James A. Smith; J. Rory Kennedy

    2011-11-01

    To be able to evolve microstructure with a prescribed in situ process, an effective measurement infrastructure must exist. This interdisciplinary infrastructure needs to be developed in parallel with in situ sensor technology. This paper discusses the essential elements in an effective infrastructure.

  18. Verification of threshold activation detection (TAD) technique in prompt fission neutron detection using scintillators containing 19F

    NASA Astrophysics Data System (ADS)

    Sibczynski, P.; Kownacki, J.; Moszyński, M.; Iwanowska-Hanke, J.; Syntfeld-Każuch, A.; Gójska, A.; Gierlik, M.; Kaźmierczak, Ł.; Jakubowska, E.; Kędzierski, G.; Kujawiński, Ł.; Wojnarowicz, J.; Carrel, F.; Ledieu, M.; Lainé, F.

    2015-09-01

    In the present study ⌀ 5''× 3'' and ⌀ 2''× 2'' EJ-313 liquid fluorocarbon as well as ⌀ 2'' × 3'' BaF2 scintillators were exposed to neutrons from a 252Cf neutron source and a Sodern Genie 16GT deuterium-tritium (D+T) neutron generator. The scintillators responses to β- particles with maximum endpoint energy of 10.4 MeV from the n+19F reactions were studied. Response of a ⌀ 5'' × 3'' BC-408 plastic scintillator was also studied as a reference. The β- particles are the products of interaction of fast neutrons with 19F which is a component of the EJ-313 and BaF2 scintillators. The method of fast neutron detection via fluorine activation is already known as Threshold Activation Detection (TAD) and was proposed for photofission prompt neutron detection from fissionable and Special Nuclear Materials (SNM) in the field of Homeland Security and Border Monitoring. Measurements of the number of counts between 6.0 and 10.5 MeV with a 252Cf source showed that the relative neutron detection efficiency ratio, defined as epsilonBaF2 / epsilonEJ-313-5'', is 32.0% ± 2.3% and 44.6% ± 3.4% for front-on and side-on orientation of the BaF2, respectively. Moreover, the ⌀ 5'' EJ-313 and side-on oriented BaF2 were also exposed to neutrons from the D+T neutron generator, and the relative efficiency epsilonBaF2 / epsilonEJ-313-5'' was estimated to be 39.3%. Measurements of prompt photofission neutrons with the BaF2 detector by means of data acquisition after irradiation (out-of-beam) of nuclear material and between the beam pulses (beam-off) techniques were also conducted on the 9 MeV LINAC of the SAPHIR facility.

  19. In situ containment and stabilization of buried waste

    SciTech Connect

    Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

    1992-11-01

    The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

  20. First observations of tropospheric δD data observed by ground- and space-based remote sensing and surface in-situ measurement techniques at MUSICA's principle reference station (Izaña Observatory, Spain)

    NASA Astrophysics Data System (ADS)

    González, Yenny; Schneider, Matthias; Christner, Emanuel; Rodríguez, Omaira E.; Sepúlveda, Eliezer; Dyroff, Christoph; Wiegele, Andreas

    2013-04-01

    The main goal of the project MUSICA (Multiplatform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) is the generation of a quasi global tropospheric water vapor isototopologue dataset of a good and well-documented quality. Therefore, new ground- and space-based remote sensing observations (NDACC-FTIR and IASI/METOP) are combined with in-situ measurements. This work presents the first comparison between in-situ and remote sensing observations made at the Izaña Atmospheric Research Centre (Tenerife, Canary Islands, Spain). The in-situ measurements are made by a Picarro L2120-i water vapor isotopologue analyzer. At Izaña the in-situ data are affected by local small-scale mixing processes: during daylight, the thermally buoyant upslope flow prompts the mixing between the Marine Boundary Layer (MBL) and the low Free Troposphere (FT). However, the remote sensors detect δD values averaged over altitudes that are more representative for the free troposphere. This difference has to be considered for the comparison. In general, a good agreement between the MUSICA remote sensing and the in situ H2O-versus-δD plots is found, which demonstrates that the MUSICA δD remote sensing products add scientifically valuable information to the H2O data.

  1. In Situ Cleanable Alternative HEPA Filter Media

    SciTech Connect

    Adamson, D. J.; Terry, M. T.

    2002-02-28

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of

  2. Application of the 15N-Gas Flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    NASA Astrophysics Data System (ADS)

    Sgouridis, F.; Ullah, S.; Stott, A.

    2015-08-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilised agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps, a copper based reduction furnace, and allows the analysis of small gas injection volumes (4 μL) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Pre-concentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N Gas-Flux method was adapted for application in natural and semi-natural land use types (peatlands, forests and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. For our chamber design (volume / surface = 8:1) and a 20 h incubation period, the minimum detectable flux rates were 4 μg N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. The N2 flux ranged between 2.4 and 416.6 μg N m-2 h-1, and the grassland soils showed on average 3 and 14 times higher denitrification rates than the woodland and organic soils respectively. The N2O flux was on average 20 to 200 times lower than the N2 flux, while the denitrification product ratio (N2O/N2 + N2O) was low, ranging between 0.03 and 13 %. Total denitrification rates measured by the acetylene inhibition technique under the same field conditions

  3. Multibody modeling and verification

    NASA Technical Reports Server (NTRS)

    Wiens, Gloria J.

    1989-01-01

    A summary of a ten week project on flexible multibody modeling, verification and control is presented. Emphasis was on the need for experimental verification. A literature survey was conducted for gathering information on the existence of experimental work related to flexible multibody systems. The first portion of the assigned task encompassed the modeling aspects of flexible multibodies that can undergo large angular displacements. Research in the area of modeling aspects were also surveyed, with special attention given to the component mode approach. Resulting from this is a research plan on various modeling aspects to be investigated over the next year. The relationship between the large angular displacements, boundary conditions, mode selection, and system modes is of particular interest. The other portion of the assigned task was the generation of a test plan for experimental verification of analytical and/or computer analysis techniques used for flexible multibody systems. Based on current and expected frequency ranges of flexible multibody systems to be used in space applications, an initial test article was selected and designed. A preliminary TREETOPS computer analysis was run to ensure frequency content in the low frequency range, 0.1 to 50 Hz. The initial specifications of experimental measurement and instrumentation components were also generated. Resulting from this effort is the initial multi-phase plan for a Ground Test Facility of Flexible Multibody Systems for Modeling Verification and Control. The plan focusses on the Multibody Modeling and Verification (MMV) Laboratory. General requirements of the Unobtrusive Sensor and Effector (USE) and the Robot Enhancement (RE) laboratories were considered during the laboratory development.

  4. IN SITU ENHANCED SOURCE REMOVAL

    EPA Science Inventory

    This html report describes and compares the performance of in situ technologies designed to accelerate the removal of organic contaminants from unconsolidated soils and aquifers. The research was conducted through the Enhanced Source Removal (ESR) Program within the Subsurface Pr...

  5. Acoustofluidic actuation of in situ fabricated microrotors.

    PubMed

    Kaynak, Murat; Ozcelik, Adem; Nama, Nitesh; Nourhani, Amir; Lammert, Paul E; Crespi, Vincent H; Huang, Tony Jun

    2016-09-21

    We have demonstrated in situ fabricated and acoustically actuated microrotors. A polymeric microrotor with predefined oscillating sharp-edge structures is fabricated in situ by applying a patterned UV light to polymerize a photocrosslinkable polyethylene glycol solution inside a microchannel around a polydimethylsiloxane axle. To actuate the microrotors by oscillating the sharp-edge structures, we employed piezoelectric transducers which generate tunable acoustic waves. The resulting acoustic streaming flows rotate the microrotors. The rotation rate is tuned by controlling the peak-to-peak voltage applied to the transducer. A 6-arm microrotor can exceed 1200 revolutions per minute. Our technique is an integration of single-step microfabrication, instant assembly around the axle, and easy acoustic actuation for various applications in microfluidics and microelectromechanical systems (MEMS). PMID:27466140

  6. In situ soil remediation using electrokinetics

    SciTech Connect

    Buehler, M.F.; Surma, J.E.; Virden, J.W.

    1994-11-01

    Electrokinetics is emerging as a promising technology for in situ soil remediation. This technique is especially attractive for Superfund sites and government operations which contain large volumes of contaminated soil. The approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The transport mechanisms include electroosmosis, electromigration, and electrophoresis. The feasibility of using electrokinetics to move radioactive {sup 137}Cs and {sup 60}Co at the Hanford Site in Richland, Washington, is discussed. A closed cell is used to provide in situ measurements of {sup 137}Cs and {sup 60}Co movement in Hanford soil. Preliminary results of ionic movement, along with the corresponding current response, are presented.

  7. In situ nanoparticle sizing with zeptomole sensitivity.

    PubMed

    Batchelor-McAuley, Christopher; Ellison, Joanna; Tschulik, Kristina; Hurst, Philip L; Boldt, Regine; Compton, Richard G

    2015-08-01

    We present the basis for an entirely new approach to in situ nanoparticle sizing. Nanoparticles containing just 12 zeptomoles (1 zeptomole = 10(-21) moles) of silver, are detected via in situ particle coulometry. These stochastic charge measurements correspond to the transfer of only 7000-8000 electrons, yielding direct information relating to the individual nanoparticle volumes. The resulting particle size distribution (average equivalent radius 5 nm) obtained via nanoparticle coulometry is in excellent correspondence with that attained from TEM analysis. Moreover, the measurable particle size limit by this electrochemical method is shown to be significantly below that of more common optical nanoparticle tracking techniques, and as such can be viewed as a potential disruptive nano-technology.

  8. In situ remediation of uranium contaminated groundwater

    SciTech Connect

    Dwyer, B.P.; Marozas, D.C.

    1997-12-31

    In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment - various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field preliminary results are discussed with regard to other potential contaminated groundwater treatment applications.

  9. In Situ Activation of Microcapsules

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2000-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing two or more immiscible liquid phases in which a drug, or a prodrug and a drug activator are partitioned into separate phases. or prevented from diffusing out of the microcapsule by a liquid phase in which the drug is poorly soluble. Also disclosed are methods of using the microcapsules for in situ activation of drugs where upon exposure to an appropriate energy source the internal phases mix and the drug is activated in situ.

  10. Biometric verification with correlation filters.

    PubMed

    Vijaya Kumar, B V K; Savvides, Marios; Xie, Chunyan; Venkataramani, Krithika; Thornton, Jason; Mahalanobis, Abhijit

    2004-01-10

    Using biometrics for subject verification can significantly improve security over that of approaches based on passwords and personal identification numbers, both of which people tend to lose or forget. In biometric verification the system tries to match an input biometric (such as a fingerprint, face image, or iris image) to a stored biometric template. Thus correlation filter techniques are attractive candidates for the matching precision needed in biometric verification. In particular, advanced correlation filters, such as synthetic discriminant function filters, can offer very good matching performance in the presence of variability in these biometric images (e.g., facial expressions, illumination changes, etc.). We investigate the performance of advanced correlation filters for face, fingerprint, and iris biometric verification. PMID:14735958

  11. Advanced and In Situ Analytical Methods for Solar Fuel Materials.

    PubMed

    Chan, Candace K; Tüysüz, Harun; Braun, Artur; Ranjan, Chinmoy; La Mantia, Fabio; Miller, Benjamin K; Zhang, Liuxian; Crozier, Peter A; Haber, Joel A; Gregoire, John M; Park, Hyun S; Batchellor, Adam S; Trotochaud, Lena; Boettcher, Shannon W

    2016-01-01

    In situ and operando techniques can play important roles in the development of better performing photoelectrodes, photocatalysts, and electrocatalysts by helping to elucidate crucial intermediates and mechanistic steps. The development of high throughput screening methods has also accelerated the evaluation of relevant photoelectrochemical and electrochemical properties for new solar fuel materials. In this chapter, several in situ and high throughput characterization tools are discussed in detail along with their impact on our understanding of solar fuel materials.

  12. High accuracy in situ radiometric mapping.

    PubMed

    Tyler, Andrew N

    2004-01-01

    In situ and airborne gamma ray spectrometry have been shown to provide rapid and spatially representative estimates of environmental radioactivity across a range of landscapes. However, one of the principal limitations of this technique has been the influence of changes in the vertical distribution of the source (e.g. 137Cs) on the observed photon fluence resulting in a significant reduction in the accuracy of the in situ activity measurement. A flexible approach for single gamma photon emitting radionuclides is presented, which relies on the quantification of forward scattering (or valley region between the full energy peak and Compton edge) within the gamma ray spectrum to compensate for changes in the 137Cs vertical activity distribution. This novel in situ method lends itself to the mapping of activity concentrations in environments that exhibit systematic changes in the vertical activity distribution. The robustness of this approach has been demonstrated in a salt marsh environment on the Solway coast, SW Scotland, with both a 7.6 cm x 7.6 cm NaI(Tl) detector and a 35% n-type HPGe detector. Application to ploughed field environments has also been demonstrated using HPGe detector, including its application to the estimation of field moist bulk density and soil erosion measurement. Ongoing research work is also outlined.

  13. Swarm Verification

    NASA Technical Reports Server (NTRS)

    Holzmann, Gerard J.; Joshi, Rajeev; Groce, Alex

    2008-01-01

    Reportedly, supercomputer designer Seymour Cray once said that he would sooner use two strong oxen to plow a field than a thousand chickens. Although this is undoubtedly wise when it comes to plowing a field, it is not so clear for other types of tasks. Model checking problems are of the proverbial "search the needle in a haystack" type. Such problems can often be parallelized easily. Alas, none of the usual divide and conquer methods can be used to parallelize the working of a model checker. Given that it has become easier than ever to gain access to large numbers of computers to perform even routine tasks it is becoming more and more attractive to find alternate ways to use these resources to speed up model checking tasks. This paper describes one such method, called swarm verification.

  14. The SeaHorn Verification Framework

    NASA Technical Reports Server (NTRS)

    Gurfinkel, Arie; Kahsai, Temesghen; Komuravelli, Anvesh; Navas, Jorge A.

    2015-01-01

    In this paper, we present SeaHorn, a software verification framework. The key distinguishing feature of SeaHorn is its modular design that separates the concerns of the syntax of the programming language, its operational semantics, and the verification semantics. SeaHorn encompasses several novelties: it (a) encodes verification conditions using an efficient yet precise inter-procedural technique, (b) provides flexibility in the verification semantics to allow different levels of precision, (c) leverages the state-of-the-art in software model checking and abstract interpretation for verification, and (d) uses Horn-clauses as an intermediate language to represent verification conditions which simplifies interfacing with multiple verification tools based on Horn-clauses. SeaHorn provides users with a powerful verification tool and researchers with an extensible and customizable framework for experimenting with new software verification techniques. The effectiveness and scalability of SeaHorn are demonstrated by an extensive experimental evaluation using benchmarks from SV-COMP 2015 and real avionics code.

  15. In situ microbial filter used for bioremediation

    DOEpatents

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  16. In situ nanoindentation in a transmission electron microscope

    SciTech Connect

    Minor, Andrew M.

    2002-12-02

    This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids.

  17. In situ venting of jet fuel-contaminated soil

    SciTech Connect

    Elliott, M.G.; DePaoli, D.W.

    1989-01-01

    The Air Force Engineering and Services center is performing a field demonstration of in situ soil venting at a 27,000-gallon jet fuel spill site at Hill AFB UT. In situ soil venting is a soil cleanup technique which uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminants and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper describes our initial site characterization, the one-vent pilot test, and the design and preliminary results of our full-scale in situ soil venting system. 5 refs., 7 figs.

  18. Triplex in-situ hybridization

    DOEpatents

    Fresco, Jacques R.; Johnson, Marion D.

    2002-01-01

    Disclosed are methods for detecting in situ the presence of a target sequence in a substantially double-stranded nucleic acid segment, which comprises: a) contacting in situ under conditions suitable for hybridization a substantially double-stranded nucleic acid segment with a detectable third strand, said third strand being capable of hybridizing to at least a portion of the target sequence to form a triple-stranded structure, if said target sequence is present; and b) detecting whether hybridization between the third strand and the target sequence has occured.

  19. In situ biofilm coupon device

    DOEpatents

    Peyton, Brent M.; Truex, Michael J.

    1997-01-01

    An apparatus for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements.

  20. In situ biofilm coupon device

    DOEpatents

    Peyton, B.M.; Truex, M.J.

    1997-06-24

    An apparatus is disclosed for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements. 3 figs.

  1. In-Situ Investigation of Advanced Structural Coatings and Composites

    NASA Technical Reports Server (NTRS)

    Ustundag, Ersan

    2003-01-01

    The premise of this project is a comprehensive study that involves the in-situ characterization of advanced coatings and composites by employing both neutron and x-ray diffraction techniques in a complementary manner. The diffraction data would then be interpreted and used in developing or validating advanced micromechanics models with life prediction capability. In the period covered by this report, basic work was conducted to establish the experimental conditions for various specimens and techniques. In addition, equipment was developed that will allow the in-situ studies under a range of conditions (stress, temperature, atmosphere, etc.).

  2. Cleanup Verification Package for the 300 VTS Waste Site

    SciTech Connect

    S. W. Clark and T. H. Mitchell

    2006-03-13

    This cleanup verification package documents completion of remedial action for the 300 Area Vitrification Test Site, also known as the 300 VTS site. The site was used by Pacific Northwest National Laboratory as a field demonstration site for in situ vitrification of soils containing simulated waste.

  3. Biophotonic in situ sensor for plant leaves

    SciTech Connect

    Conejo, Elian; Frangi, Jean-Pierre; Rosny, Gilles de

    2010-04-01

    Knowledge of the water concentration of plants can be helpful in several environmental and agricultural domains. There are many methods for the determination of water content in plant leaves; however, most of them give a relative moisture level or an analytical measure after a previous calibration procedure. Even for other biochemical compounds such as dry matter or chlorophyll, the measurement techniques could be destructive. For this reason, a nondestructive method has been developed to measure the biochemical compounds of a plant leaf, using an infrared spectroscopy technique. One important advantage is the simplicity of the device (RAdiometre portatif de Mesure In Situ, RAMIS) and its capability to perform measurements in situ. The prototype is a leaf-clip configuration and is made of LEDs at five wavelengths (656, 721, 843, 937, and 1550 nm), and a silicon/germanium photosensor. To compute the water content of vegetative leaves, the radiative transfer model PROSPECT was implemented. This model can accurately predict spectral transmittances in the 400 nm to 2500 nm spectral region as a function of the principal leaf biochemical contents: water, dry matter, and chlorophyll. Using the transmittance measured by RAMIS into an inversion procedure of PROSPECT: A Model of Leaf Optical Properties Spectra, we are able to compute the values of water contents that show an agreement with the water contents measured directly using dry weight procedures. This method is presented as a possibility to estimate other leaf biochemical compounds using appropriate wavelengths.

  4. Hydrologic data-verification management program plan

    USGS Publications Warehouse

    Alexander, C.W.

    1982-01-01

    Data verification refers to the performance of quality control on hydrologic data that have been retrieved from the field and are being prepared for dissemination to water-data users. Water-data users now have access to computerized data files containing unpublished, unverified hydrologic data. Therefore, it is necessary to develop techniques and systems whereby the computer can perform some data-verification functions before the data are stored in user-accessible files. Computerized data-verification routines can be developed for this purpose. A single, unified concept describing master data-verification program using multiple special-purpose subroutines, and a screen file containing verification criteria, can probably be adapted to any type and size of computer-processing system. Some traditional manual-verification procedures can be adapted for computerized verification, but new procedures can also be developed that would take advantage of the powerful statistical tools and data-handling procedures available to the computer. Prototype data-verification systems should be developed for all three data-processing environments as soon as possible. The WATSTORE system probably affords the greatest opportunity for long-range research and testing of new verification subroutines. (USGS)

  5. Halogen speciation in volcanic plumes - Development of compact denuder sampling techniques with in-situ derivatization followed by gas chromatography-mass spectrometry and their application at Mt. Etna, Mt. Nyiragongo and Mt. Nyamulagira in 2015.

    NASA Astrophysics Data System (ADS)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2016-04-01

    products. The diffusion denuder technique allows sampling of gaseous compounds exclusively without collecting particulate matter. Solvent elution of the derivatized analytes and subsequent analysis with gas chromatography-mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied in 2015 on volcanic gas plumes at Mt. Etna (Italy), Mt. Nyiragongo and Mt. Nyamulagira (DR Congo) giving reactive bromine mixing ratios from 0.3 ppb (Nyiragongo) up to 22 ppb (Etna, NEC). Compared with total halogen data derived by alkaline trap sampling (Raschig-tube) and ion-chromatography analysis the reactive bromine mixing ratios allow the investigation of the conversion of HBr into reactive species due to plume chemistry with progressing plume age. The new method will be described in detail and the first results on the reactive halogen to total halogen output will be discussed (for bromine and chlorine) and compared to earlier volcanic plume chemistry model studies. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Rüdiger, J., N. Bobrowski, T. Hoffmann (2015), Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes (EGU2015-2392-2), EGU General Assembly 2015

  6. In situ measurement of conductivity during nanocomposite film deposition

    NASA Astrophysics Data System (ADS)

    Blattmann, Christoph O.; Pratsinis, Sotiris E.

    2016-05-01

    Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (Tg) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing Tg. Proper selection of the host polymer in combination with in situ resistance monitoring therefore enable the optimal preparation of conductive nanocomposite films.

  7. In situ soil remediation: Bacteria or fungi?

    SciTech Connect

    Cutright, T.J.; Lee, S.

    1995-07-01

    Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans.

  8. Face verification with balanced thresholds.

    PubMed

    Yan, Shuicheng; Xu, Dong; Tang, Xiaoou

    2007-01-01

    The process of face verification is guided by a pre-learned global threshold, which, however, is often inconsistent with class-specific optimal thresholds. It is, hence, beneficial to pursue a balance of the class-specific thresholds in the model-learning stage. In this paper, we present a new dimensionality reduction algorithm tailored to the verification task that ensures threshold balance. This is achieved by the following aspects. First, feasibility is guaranteed by employing an affine transformation matrix, instead of the conventional projection matrix, for dimensionality reduction, and, hence, we call the proposed algorithm threshold balanced transformation (TBT). Then, the affine transformation matrix, constrained as the product of an orthogonal matrix and a diagonal matrix, is optimized to improve the threshold balance and classification capability in an iterative manner. Unlike most algorithms for face verification which are directly transplanted from face identification literature, TBT is specifically designed for face verification and clarifies the intrinsic distinction between these two tasks. Experiments on three benchmark face databases demonstrate that TBT significantly outperforms the state-of-the-art subspace techniques for face verification.

  9. Design, fabrication, and applications of in situ fluid cell TEM.

    PubMed

    Li, Dongsheng; Nielsen, Michael H; De Yoreo, James J

    2013-01-01

    In situ fluid cell TEM is a powerful new tool for understanding dynamic processes during liquid phase chemical reactions, including mineral formation. This technique, which operates in the high vacuum of a TEM chamber, provides information on crystal structure, phase, morphology, size, aggregation/segregation, and crystal growth mechanisms in real time. In situ TEM records both crystal structure and morphology at spatial resolutions down to the atomic level with high temporal resolution of up to 10(-6)s per image, giving it distinct advantages over other in situ techniques such as optical microscopy, AFM, or X-ray scattering or diffraction. This chapter addresses the design, fabrication, and assembly of TEM fluid cells and applications of fluid cell TEM to understanding mechanisms of mineralization.

  10. Generic Verification Protocol for Verification of Online Turbidimeters

    EPA Science Inventory

    This protocol provides generic procedures for implementing a verification test for the performance of online turbidimeters. The verification tests described in this document will be conducted under the Environmental Technology Verification (ETV) Program. Verification tests will...

  11. Development of in-situ micro-debris measurement system

    NASA Astrophysics Data System (ADS)

    Nakamura, Maki; Kitazawa, Yukihito; Matsumoto, Haruhisa; Okudaira, Osamu; Hanada, Toshiya; Sakurai, Akira; Funakoshi, Kunihiro; Yasaka, Tetsuo; Hasegawa, Sunao; Kobayashi, Masanori

    2015-08-01

    The in-situ debris environment awareness system has been developed. The objective of the system is to measure small debris (between 100 μm and several cm) in orbit. The orbital distribution and the size distribution of the debris are not well understood. The size distribution is difficult to measure from the ground, although the size distribution is very important for the risk evaluation of the impact of debris on spacecraft. The in-situ measurement of the size distribution is useful for: (1) verification of meteoroid and debris environment models, (2) verification of meteoroid and debris environment evolution models, (3) real time detection of unexpected events, such as explosions and/or collisions on an orbit. This paper reports the development study of the in-situ debris measurement system and shows demonstration experiments and their results to describe the performance of the micro-debris sensor system. The sensor system for monitoring micro-debris with sizes ranging from 100 μm to a few mm must have a large detection area, while the constraints of space deployment require that these systems be low in mass, low in power, robust and have low telemetry requirements. For this reason, we have been developing a simple trans-film sensor. Thin and conductive stripes (copper) are formed with fine pitch (100 μm) on a thin film of nonconductive material (12.5-μm thick polyimide). A hypervelocity micro-particle impact is detected when one or more stripes are severed by perforation of the film. We designed a debris detector specialized for measuring the micro-debris size and collision rate. We then manufactured and calibrated the detector.

  12. Integrated in-situ remediation

    SciTech Connect

    Fustos, V.; Lieberman, P.

    1996-01-01

    This article presents an integrated approach to ex-situ and in-situ remediation. A sequence of processes, used successfully in their own right, but used synergistically in this approach, have achieved short-term, economic remediation. In addition the range of contaminants that can be treated is extended. The Process uses ozone, compressed oxygen, water vapor, heat, bioaugmentation and vapor extraction to remediate lower molecular weight hydrocarbons and higher molecular weight hydrocarbons. 3 figs.

  13. Oldest biliary endoprosthesis in situ

    PubMed Central

    Consolo, Pierluigi; Scalisi, Giuseppe; Crinò, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing “irretrievable stones” include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  14. In Situ Depth Profiling of CS-137 Contamination in Soils

    SciTech Connect

    Christopher P. Oertel; John R. Giles; Kenneth C. Thompson; Richard P. Wells

    2004-12-01

    Preremediation characterization of Cs-137 contamination in soils was conducted at the Auxiliary Reactor Area (ARA)-23 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site, located at the Idaho National Engineering and Environmental Laboratory. Characterization activities included verification of the lateral extent of the contaminated area using the INEEL Global Positioning Radiometric Scanner. The vertical extent of the contamination in select areas of the site also was evaluated with an in-situ gamma-ray spectrometer, and depth discrete samples were collected at 2-inch depth intervals down to a depth of 8 inches. A comparison was made between the depth distribution data from the in-situ spectrometric measurements and the physical, depth-discrete samples. The results of the study and of the aforementioned comparison indicate that use of in situ high purity germanium (HpGe) detectors during the remediation of the ARA-23 site will aid in directing the depth of excavation, thereby helping to (a) minimize the amount of soils excavated and removed for disposal, and (b) reduce overall project costs.

  15. In situ TEM of radiation effects in complex ceramics.

    PubMed

    Lian, Jie; Wang, L M; Sun, Kai; Ewing, Rodney C

    2009-03-01

    In situ transmission electron microscopy (TEM) has been extensively applied to study radiation effects in a wide variety of materials, such as metals, ceramics and semiconductors and is an indispensable tool in obtaining a fundamental understanding of energetic beam-matter interactions, damage events, and materials' behavior under intense radiation environments. In this article, in situ TEM observations of radiation effects in complex ceramics (e.g., oxides, silicates, and phosphates) subjected to energetic ion and electron irradiations have been summarized with a focus on irradiation-induced microstructural evolution, changes in microchemistry, and the formation of nanostructures. New results for in situ TEM observation of radiation effects in pyrochlore, A(2)B(2)O(7), and zircon, ZrSiO(4), subjected to multiple beam irradiations are presented, and the effects of simultaneous irradiations of alpha-decay and beta-decay on the microstructural evolution of potential nuclear waste forms are discussed. Furthermore, in situ TEM results of radiation effects in a sodium borosilicate glass subjected to electron-beam exposure are introduced to highlight the important applications of advanced analytical TEM techniques, including Z-contrast imaging, energy filtered TEM (EFTEM), and electron energy loss spectroscopy (EELS), in studying radiation effects in materials microstructural evolution and microchemical changes. By combining ex situ TEM and advanced analytical TEM techniques with in situ TEM observations under energetic beam irradiations, one can obtain invaluable information on the phase stability and response behaviors of materials under a wide range of irradiation conditions.

  16. Land Surface Verification Toolkit (LVT) - A Generalized Framework for Land Surface Model Evaluation

    NASA Technical Reports Server (NTRS)

    Kumar, Sujay V.; Peters-Lidard, Christa D.; Santanello, Joseph; Harrison, Ken; Liu, Yuqiong; Shaw, Michael

    2011-01-01

    Model evaluation and verification are key in improving the usage and applicability of simulation models for real-world applications. In this article, the development and capabilities of a formal system for land surface model evaluation called the Land surface Verification Toolkit (LVT) is described. LVT is designed to provide an integrated environment for systematic land model evaluation and facilitates a range of verification approaches and analysis capabilities. LVT operates across multiple temporal and spatial scales and employs a large suite of in-situ, remotely sensed and other model and reanalysis datasets in their native formats. In addition to the traditional accuracy-based measures, LVT also includes uncertainty and ensemble diagnostics, information theory measures, spatial similarity metrics and scale decomposition techniques that provide novel ways for performing diagnostic model evaluations. Though LVT was originally designed to support the land surface modeling and data assimilation framework known as the Land Information System (LIS), it also supports hydrological data products from other, non-LIS environments. In addition, the analysis of diagnostics from various computational subsystems of LIS including data assimilation, optimization and uncertainty estimation are supported within LVT. Together, LIS and LVT provide a robust end-to-end environment for enabling the concepts of model data fusion for hydrological applications. The evolving capabilities of LVT framework are expected to facilitate rapid model evaluation efforts and aid the definition and refinement of formal evaluation procedures for the land surface modeling community.

  17. In situ sensors for measurements in the global trosposphere

    NASA Technical Reports Server (NTRS)

    Saeger, M. L.; Eaton, W. C.; Wright, R. S.; White, J. H.; Tommerdahl, J. B.

    1981-01-01

    Current techniques available for the in situ measurement of ambient trace gas species, particulate composition, and particulate size distribution are reviewed. The operational specifications of the various techniques are described. Most of the techniques described are those that have been used in airborne applications or show promise of being adaptable to airborne applications. Some of the instruments described are specialty items that are not commercially-available. In situ measurement techniques for several meteorological parameters important in the study of the distribution and transport of ambient air pollutants are discussed. Some remote measurement techniques for meteorological parameters are also discussed. State-of-the-art measurement capabilities are compared with a list of capabilities and specifications desired by NASA for ambient measurements in the global troposphere.

  18. Natural attenuation processes during in situ capping.

    PubMed

    Himmelheber, David W; Pennell, Kurt D; Hughes, Joseph B

    2007-08-01

    Chlorinated solvents are common groundwater contaminants that threaten surface water quality and benthic health when present in groundwater seeps. Aquatic sediments can act as natural biobarriers to detoxify chlorinated solvent plumes via reductive dechlorination. In situ sediment capping, a remedial technique in which clean material is placed at the sediment-water interface, may alter sedimentary natural attenuation processes. This research explores the potential of Anacostia River sediment to naturally attenuate chlorinated solvents under simulated capping conditions. Results of microcosm studies demonstrated that intrinsic dechlorination of dissolved-phase PCE to ethene was possible, with electron donor availability controlling microbial activity. A diverse microbial community was present in the sediment, including multiple Dehalococcoides strains indicated by the amplification of the reductive dehalogenases tceA, vcrA, and bvcA. An upflow column simulating a capped sediment bed subject to PCE-contaminated groundwater seepage lost dechlorination activity with time and only achieved complete dechlorination when microorganisms present in the sediment were provided electron donor. Increases in effluent chloroethene concentrations during the period of biostimulation were attributed to biologically enhanced desorption and the formation of less sorptive dechlorination products. These findings suggest that in situ caps should be designed to account for reductions in natural biobarrier reactivity and for the potential breakthrough of groundwater contaminants. PMID:17822095

  19. Molecular cytogenetics using fluorescence in situ hybridization

    SciTech Connect

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  20. Natural attenuation processes during in situ capping.

    PubMed

    Himmelheber, David W; Pennell, Kurt D; Hughes, Joseph B

    2007-08-01

    Chlorinated solvents are common groundwater contaminants that threaten surface water quality and benthic health when present in groundwater seeps. Aquatic sediments can act as natural biobarriers to detoxify chlorinated solvent plumes via reductive dechlorination. In situ sediment capping, a remedial technique in which clean material is placed at the sediment-water interface, may alter sedimentary natural attenuation processes. This research explores the potential of Anacostia River sediment to naturally attenuate chlorinated solvents under simulated capping conditions. Results of microcosm studies demonstrated that intrinsic dechlorination of dissolved-phase PCE to ethene was possible, with electron donor availability controlling microbial activity. A diverse microbial community was present in the sediment, including multiple Dehalococcoides strains indicated by the amplification of the reductive dehalogenases tceA, vcrA, and bvcA. An upflow column simulating a capped sediment bed subject to PCE-contaminated groundwater seepage lost dechlorination activity with time and only achieved complete dechlorination when microorganisms present in the sediment were provided electron donor. Increases in effluent chloroethene concentrations during the period of biostimulation were attributed to biologically enhanced desorption and the formation of less sorptive dechlorination products. These findings suggest that in situ caps should be designed to account for reductions in natural biobarrier reactivity and for the potential breakthrough of groundwater contaminants.

  1. Noise canceling in-situ detection

    SciTech Connect

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  2. In-situ mechanical testing during X-ray diffraction

    SciTech Connect

    Van Swygenhoven, Helena Van Petegem, Steven

    2013-04-15

    Deforming metals during recording X-ray diffraction patterns is a useful tool to get a deeper understanding of the coupling between microstructure and mechanical behaviour. With the advances in flux, detector speed and focussing techniques at synchrotron facilities, in-situ mechanical testing is now possible during powder diffraction and Laue diffraction. The basic principle is explained together with illustrative examples.

  3. Columbus pressurized module verification

    NASA Technical Reports Server (NTRS)

    Messidoro, Piero; Comandatore, Emanuele

    1986-01-01

    The baseline verification approach of the COLUMBUS Pressurized Module was defined during the A and B1 project phases. Peculiarities of the verification program are the testing requirements derived from the permanent manned presence in space. The model philosophy and the test program have been developed in line with the overall verification concept. Such critical areas as meteoroid protections, heat pipe radiators and module seals are identified and tested. Verification problem areas are identified and recommendations for the next development are proposed.

  4. Verification of VLSI designs

    NASA Technical Reports Server (NTRS)

    Windley, P. J.

    1991-01-01

    In this paper we explore the specification and verification of VLSI designs. The paper focuses on abstract specification and verification of functionality using mathematical logic as opposed to low-level boolean equivalence verification such as that done using BDD's and Model Checking. Specification and verification, sometimes called formal methods, is one tool for increasing computer dependability in the face of an exponentially increasing testing effort.

  5. Regression Verification Using Impact Summaries

    NASA Technical Reports Server (NTRS)

    Backes, John; Person, Suzette J.; Rungta, Neha; Thachuk, Oksana

    2013-01-01

    Regression verification techniques are used to prove equivalence of syntactically similar programs. Checking equivalence of large programs, however, can be computationally expensive. Existing regression verification techniques rely on abstraction and decomposition techniques to reduce the computational effort of checking equivalence of the entire program. These techniques are sound but not complete. In this work, we propose a novel approach to improve scalability of regression verification by classifying the program behaviors generated during symbolic execution as either impacted or unimpacted. Our technique uses a combination of static analysis and symbolic execution to generate summaries of impacted program behaviors. The impact summaries are then checked for equivalence using an o-the-shelf decision procedure. We prove that our approach is both sound and complete for sequential programs, with respect to the depth bound of symbolic execution. Our evaluation on a set of sequential C artifacts shows that reducing the size of the summaries can help reduce the cost of software equivalence checking. Various reduction, abstraction, and compositional techniques have been developed to help scale software verification techniques to industrial-sized systems. Although such techniques have greatly increased the size and complexity of systems that can be checked, analysis of large software systems remains costly. Regression analysis techniques, e.g., regression testing [16], regression model checking [22], and regression verification [19], restrict the scope of the analysis by leveraging the differences between program versions. These techniques are based on the idea that if code is checked early in development, then subsequent versions can be checked against a prior (checked) version, leveraging the results of the previous analysis to reduce analysis cost of the current version. Regression verification addresses the problem of proving equivalence of closely related program

  6. Continued Development of in Situ Geochronology for Planetary Missions

    NASA Technical Reports Server (NTRS)

    Devismes, D.; Cohen, B. A.

    2015-01-01

    The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

  7. The AdaptiV Approach to Verification of Adaptive Systems

    SciTech Connect

    Rouff, Christopher; Buskens, Richard; Pullum, Laura L; Cui, Xiaohui; Hinchey, Mike

    2012-01-01

    Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

  8. Composite with In Situ Plenums

    NASA Technical Reports Server (NTRS)

    Montesano, Mark

    2012-01-01

    A document describes a high-performance thermal distribution panel (TDP) concept using high-conductivity (greater than 800 W/mK) macro composite skin with in situ heat pipes. The processing technologies proposed to build such a panel result in a one-piece, inseparable assembly with high conductance in both the X and Y planes. The TDP configuration can also be used to produce panels with high structural stiffness. The one-piece construction of the TDP eliminates the thermal interface between the cooling plenums and the heat spreader base, and obviates the need for bulky mounting flanges and thick heat spreaders used on baseline designs. The conductivity of the TDP can be configured to exceed 800 W/mK with a mass density below 2.5 grams per cubic centimeter. This material can provide efficient conductive heat transfer between the in situ heat plenums, permitting the use of thinner panel thicknesses. The plenums may be used as heat pipes, loop heat pipes, or liquid cooling channels. The panel technology used in the TDP is a macro-composite comprised of aluminum-encapsulated annealed pyrolytic graphite (APG). APG is highly aligned crystalline graphite with an in-plane thermal conductivity of 1,700 W/mK. APG has low shear strength and does not constrain the encapsulating material. The proposed concept has no thermal interfaces between the heat pipes and the spreader plate, further improving the overall conductance of the system. The in situ plenums can also be used for liquid cooling applications. The process can be used to fabricate structural panels by adding a second thin sheet.

  9. In Situ Mosaic Brightness Correction

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Lorre, Jean J.

    2012-01-01

    In situ missions typically have pointable, mast-mounted cameras, which are capable of taking panoramic mosaics comprised of many individual frames. These frames are mosaicked together. While the mosaic software applies radiometric correction to the images, in many cases brightness/contrast seams still exist between frames. This is largely due to errors in the radiometric correction, and the absence of correction for photometric effects in the mosaic processing chain. The software analyzes the overlaps between adjacent frames in the mosaic and determines correction factors for each image in an attempt to reduce or eliminate these brightness seams.

  10. Mars in Situ Resource Utilization Technology Evaluation

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony C.; Santago-Maldonado, Edgardo

    2012-01-01

    We have examined the technologies required to enable Mars In-Situ Resource Utilization (ISRU) because our understanding of Mars resources has changed significantly in the last five years as a result of recent robotic missions to the red planet. Two major developments, (1) confirmation of the presence of near-surface water in the form of ice in very large amounts at high latitudes by the Phoenix Lander and (2) the likely existence of water at lower latitudes in the form of hydrates or ice in the top one meter of the regolith, have the potential to change ISRU technology selection. A brief technology assessment was performed for the most promising Mars atmospheric gas processing techniques: Reverse Water Gas Shift (RWGS) and Methanation (aka Sabatier), as well as an overview of soil processing technology to extract water from Martian soil.

  11. Repositioning free laser in situ keratomileusis flaps.

    PubMed

    Todani, Amit; Al-Arfaj, Khalid; Melki, Samir A

    2010-02-01

    We describe a protocol for adequate repositioning of free laser in situ keratomileusis (LASIK) corneal flaps created by a Moria M2 microkeratome even in the absence of fiduciary marks. In an enucleated porcine globe, a free flap was created by initially placing a longitudinal incision at the proposed hinge site followed by activating the forward pass of the automated microkeratome. A protocol was devised based on placement of a positioning dot on the free flap before the flap is retrieved from the microkeratome head. Preplaced surgical landmarks were used as a guide to determine the correct alignment of the free flap. Adequate orientation of the free flap to the stromal bed was achieved in 9 porcine eyes using the positioning dot method. The technique is applicable to the Moria M2 microkeratome only and must be validated for other types of keratomes.

  12. Manipulating Bacterial Communities by in situ Microbiome Engineering.

    PubMed

    Sheth, Ravi U; Cabral, Vitor; Chen, Sway P; Wang, Harris H

    2016-04-01

    Microbial communities inhabit our entire planet and have a crucial role in biogeochemical processes, agriculture, biotechnology, and human health. Here, we argue that 'in situ microbiome engineering' represents a new paradigm of community-scale genetic and microbial engineering. We discuss contemporary applications of this approach to directly add, remove, or modify specific sets of functions and alter community-level properties in terrestrial, aquatic, and host-associated microbial communities. Specifically, we highlight emerging in situ genome engineering approaches as tractable techniques to manipulate microbial communities with high specificity and efficacy. Finally, we describe opportunities for technological innovation and ways to bridge existing knowledge gaps to accelerate the development of in situ approaches for microbiome manipulations. PMID:26916078

  13. Strategies for In situ and Sample Return Analyses

    NASA Astrophysics Data System (ADS)

    Papanastassiou, D. A.

    2006-12-01

    There is general agreement that planetary exploration proceeds from orbital reconnaissance of a planet, to surface and near-surface in situ exploration, to sample return missions, which bring back samples for investigations in terrestrial laboratories, using the panoply of state-of-the-art analytical techniques. The applicable techniques may depend on the nature of the returned material and complementary and multi- disciplinary techniques can be used to best advantage. High precision techniques also serve to provide the "ground truth" and calibrate past and future orbital and in situ measurements on a planet. It is also recognized that returned samples may continue to be analyzed by novel techniques as the techniques become developed, in part to address specific characteristics of returned samples. There are geophysical measurements such as those of the moment of inertia of a planet, seismic activity, and surface morphology that depend on orbital and in-situ science. Other characteristics, such as isotopic ages and isotopic compositions (e.g., initial Sr and Nd) as indicators of planetary mantle or crust evolution and sample provenance require returned samples. In situ analyses may be useful for preliminary characterization and for optimization of sample selection for sample return. In situ analyses by Surveyor on the Moon helped identify the major element chemistry of lunar samples and the need for high precision mass spectrometry (e. g., for Rb-Sr ages, based on extremely low alkali contents). The discussion of in-situ investigations vs. investigations on returned samples must be directly related to available instrumentation and to instrumentation that can be developed in the foreseeable future. The discussion of choices is not a philosophical but instead a very practical issue: what precision is required for key investigations and what is the instrumentation that meets or exceeds the required precision. This must be applied to potential in situ instruments and

  14. Whole-mount in situ hybridization using DIG-labeled probes in planarian.

    PubMed

    Rybak-Wolf, Agnieszka; Solana, Jordi

    2014-01-01

    In recent years freshwater flatworms (planarian) have become a powerful model for studies of regeneration and stem cell biology. Whole-mount in situ hybridization (WISH) and fluorescent in situ hybridization (FISH) are key and most commonly used techniques to determine and visualize gene expression patterns in planaria. Here, we present the established version of whole-mount in situ hybridization (WISH) and whole-mount fluorescence in situ hybridization (WFISH) protocol optimized over the last years by several labs from the rapidly growing planaria field and give an overview of recently introduced modifications which can be critical in the study of low abundant transcripts.

  15. The Use of Whole-Mount "in Situ" Hybridization to Illustrate Gene Expression Regulation

    ERIC Educational Resources Information Center

    Llamusí, Beatriz; Muñoz-Soriano, Verónica; Paricio, Nuria; Artero, Rubén

    2014-01-01

    "In situ" hybridization is a widely used technique for studying gene expression. Here, we describe two experiments addressed to postgraduate genetics students in which the effect of transcription factors on gene expression is analyzed in "Drosophila embryos of different genotypes by whole-mount in situ hybridization. In one of the…

  16. [Development of a Dual Detection Method with Fluorescence In Situ Hybridization and Immunostaining on Formalin-Fixed Paraffin-Embedded Tissue Sections--Molecular Pathological Detection Techniques and Their Applications to Pathological Diagnosis].

    PubMed

    Ikeda, Satoshi

    2015-06-01

    Fluorescence in situ hybridization (FISH) has recently become important for pathological diagnosis. However, its practical applications is not widespread because FISH protocol with FFPE specimens is complicated. We report a dual detection method by overlapping FISH with fluorescent immunostaining on FFPE sections. This method is characterized by changing buffers for heat treatment without proteolytic enzyme treatment. Subsequent proteolytic enzyme treatment can be omitted using an antigen activation solution, pH9 (Nichirei Corporation), for heat treatment. After the pretreatment, dual detection was achieved by DNA FISH following RNA FISH and fluorescent immunostaining. This protocol visualized gene abnormalities and protein overexpression on the same sections. Of note, in poorly differentiated tumors containing both normal and tumor cells, the tumor cells were clearly identified on the sections, and FISH signals could be counted in these cells. In addition, HER2 mRNA overexpression and gene amplification were simultaneously detected in HER2-positive gastric cancer. Thus, this method should be widely applicable in clinical settings.

  17. [Development of a Dual Detection Method with Fluorescence In Situ Hybridization and Immunostaining on Formalin-Fixed Paraffin-Embedded Tissue Sections--Molecular Pathological Detection Techniques and Their Applications to Pathological Diagnosis].

    PubMed

    Ikeda, Satoshi

    2015-06-01

    Fluorescence in situ hybridization (FISH) has recently become important for pathological diagnosis. However, its practical applications is not widespread because FISH protocol with FFPE specimens is complicated. We report a dual detection method by overlapping FISH with fluorescent immunostaining on FFPE sections. This method is characterized by changing buffers for heat treatment without proteolytic enzyme treatment. Subsequent proteolytic enzyme treatment can be omitted using an antigen activation solution, pH9 (Nichirei Corporation), for heat treatment. After the pretreatment, dual detection was achieved by DNA FISH following RNA FISH and fluorescent immunostaining. This protocol visualized gene abnormalities and protein overexpression on the same sections. Of note, in poorly differentiated tumors containing both normal and tumor cells, the tumor cells were clearly identified on the sections, and FISH signals could be counted in these cells. In addition, HER2 mRNA overexpression and gene amplification were simultaneously detected in HER2-positive gastric cancer. Thus, this method should be widely applicable in clinical settings. PMID:26548243

  18. In situ photoacoustic spectroscopy of phycobiliproteins in Gracilaria chilensis

    NASA Astrophysics Data System (ADS)

    Saavedra, R.; Figueroa, M.; Wandersleben, T.; Pouchucq, L.; Morales, J. E.; Bunster, M.; Cruz-Orea, A.

    2005-06-01

    Phycobiliproteins, the main polypeptidic components of the phycobilisomes (PBS), are biological macromolecules arranged in complex interaction systems to perform light harvesting and conduction. The optical properties of these systems can hardly be studied by conventional spectroscopic techniques. Furthermore this techniques also involve laborious chemical extraction methods. Photoacoustic (PA) spectroscopy was successfully applied to an in situ study of the phycobiliproteins expression in the eukaryotic red algae: Gracilaria chilensis.

  19. Programmable RET Mask Layout Verification

    NASA Astrophysics Data System (ADS)

    Beale, Daniel F.; Mayhew, Jeffrey P.; Rieger, Michael L.; Tang, Zongwu

    2002-12-01

    Emerging resolution enhancement techniques (RET) and OPC are dramatically increasing the complexity of mask layouts and, in turn, mask verification. Mask shapes needed to achieve required results on the wafer diverge significantly from corresponding shapes in the physical design, and in some cases a single chip layer may be decomposed into two masks used in multiple exposures. The mask verification challenge is to certify that a RET-synthesized mask layout will produce an acceptable facsimile of the design intent expressed in the design layout. Furthermore costs, tradeoffs between mask-complexity, design intent, targeted process latitude, and other factors are playing a growing role in helping to control rising mask costs. All of these considerations must in turn be incorporated into the mask layout verification strategy needed for data prep sign-off. In this paper we describe a technique for assessing the lithographic quality of mask layouts for diverse RET methods while effectively accommodating various manufacturing objectives and specifications. It leverages the familiar DRC paradigm for identifying errors and producing DRC-like error shapes in its output layout. It integrates a unique concept of "check figures" - layer-based geometries that dictate where and how simulations of shapes on the wafer are to be compared to the original desired layout. We will show how this provides a highly programmable environment that makes it possible to engage in "compound" check strategies that vary based on design intent and adaptive simulation with multiple checks. Verification may be applied at the "go/no go" level or can be used to build a body of data for quantitative analysis of lithographic behavior at multiple process conditions or for specific user-defined critical features. In addition, we will outline automated methods that guide the selection of input parameters controlling specific verification strategies.

  20. Overview of the TOPEX/Poseidon Platform Harvest Verification Experiment

    NASA Technical Reports Server (NTRS)

    Morris, Charles S.; DiNardo, Steven J.; Christensen, Edward J.

    1995-01-01

    An overview is given of the in situ measurement system installed on Texaco's Platform Harvest for verification of the sea level measurement from the TOPEX/Poseidon satellite. The prelaunch error budget suggested that the total root mean square (RMS) error due to measurements made at this verification site would be less than 4 cm. The actual error budget for the verification site is within these original specifications. However, evaluation of the sea level data from three measurement systems at the platform has resulted in unexpectedly large differences between the systems. Comparison of the sea level measurements from the different tide gauge systems has led to a better understanding of the problems of measuring sea level in relatively deep ocean. As of May 1994, the Platform Harvest verification site has successfully supported 60 TOPEX/Poseidon overflights.

  1. Formal verification of AI software

    NASA Technical Reports Server (NTRS)

    Rushby, John; Whitehurst, R. Alan

    1989-01-01

    The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms.

  2. Assessment of HER2 Status Using Immunohistochemistry (IHC) and Fluorescence In Situ Hybridization (FISH) Techniques in Mucinous Epithelial Ovarian Cancer: A Comprehensive Comparison between ToGA Biopsy Method and ToGA Surgical Specimen Method

    PubMed Central

    Chao, Wan-Ru; Lee, Ming-Yung; Ruan, Alexandra; Sheng, Huang Pin; Hsu, Jeng-Dong; Han, Chih-Ping; Koo, Chiew-Loon

    2015-01-01

    We aimed to compare the assay performance characteristics of HER2 status in mucinous epithelial ovarian cancer (EOC) by ToGA (Trastuzumab for Gastric Cancer) biopsy versus ToGA surgical specimen methods. Forty-nine tissue microarray (TMA) samples of mucinous EOC from Asian women were analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) tests using ToGA trial HER2 scoring methods. The overall concordance between IHC and FISH by the ToGA surgical specimen method is 97.56% and by the ToGA biopsy specimen method is 97.14%. The agreements of HER2 IHC results under both biopsy and surgical specimen methods were nearly perfect (weighted kappa = 0.845). Additionally, the percentage of Her2 FISH amplification showed increasing trend with increasing HER2 IHC ordinals (negative, equivocal, positive) by both TOGA biopsy (P<0.001) and surgical specimen method (P<0.001). After excluding equivocal cases, the sensitivity (100%), PPV (88.89%) and NPV (100%) of HER2 IHC were unchanged under either surgical specimen method or biopsy method. However, the specificity (96.97%) and accuracy (97.56%) of HER2 IHC was slightly higher under the surgical specimen method than those (specificity 96.30%, accuracy 97.14%) under the biopsy method. Of the total 49 cases, the number (n = 14) of HER2 IHC equivocal results under the ToGA biopsy method was 1.75-fold higher than those (n = 8) under the ToGA surgical specimen method (28.57% vs. 16.32%). Therefore, compared to ToGA surgery specimen method, the ToGA biopsy method caused more equivocal IHC cases to be referred to FISH testing and did not increase the detection rates of Her2 FISH amplification. PMID:26566289

  3. Assessment of HER2 Status Using Immunohistochemistry (IHC) and Fluorescence In Situ Hybridization (FISH) Techniques in Mucinous Epithelial Ovarian Cancer: A Comprehensive Comparison between ToGA Biopsy Method and ToGA Surgical Specimen Method.

    PubMed

    Chao, Wan-Ru; Lee, Ming-Yung; Ruan, Alexandra; Sheng, Huang Pin; Hsu, Jeng-Dong; Han, Chih-Ping; Koo, Chiew-Loon

    2015-01-01

    We aimed to compare the assay performance characteristics of HER2 status in mucinous epithelial ovarian cancer (EOC) by ToGA (Trastuzumab for Gastric Cancer) biopsy versus ToGA surgical specimen methods. Forty-nine tissue microarray (TMA) samples of mucinous EOC from Asian women were analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) tests using ToGA trial HER2 scoring methods. The overall concordance between IHC and FISH by the ToGA surgical specimen method is 97.56% and by the ToGA biopsy specimen method is 97.14%. The agreements of HER2 IHC results under both biopsy and surgical specimen methods were nearly perfect (weighted kappa = 0.845). Additionally, the percentage of Her2 FISH amplification showed increasing trend with increasing HER2 IHC ordinals (negative, equivocal, positive) by both TOGA biopsy (P<0.001) and surgical specimen method (P<0.001). After excluding equivocal cases, the sensitivity (100%), PPV (88.89%) and NPV (100%) of HER2 IHC were unchanged under either surgical specimen method or biopsy method. However, the specificity (96.97%) and accuracy (97.56%) of HER2 IHC was slightly higher under the surgical specimen method than those (specificity 96.30%, accuracy 97.14%) under the biopsy method. Of the total 49 cases, the number (n = 14) of HER2 IHC equivocal results under the ToGA biopsy method was 1.75-fold higher than those (n = 8) under the ToGA surgical specimen method (28.57% vs. 16.32%). Therefore, compared to ToGA surgery specimen method, the ToGA biopsy method caused more equivocal IHC cases to be referred to FISH testing and did not increase the detection rates of Her2 FISH amplification.

  4. Nonaqueous-phase liquid characterization and post-remediation verification sampling

    SciTech Connect

    Tabor, Charles; Juhlin, Randall; Darr, Paul; Caballero, Julian; Daniel, Joseph; Ingle, David

    2004-05-01

    Light and dense nonaqueous-phase liquids (NAPLs) were identified in the surficial aquifer at the Northeast Site of the Young-Rainey Science, Technology, and Research Center located in Largo, Florida. The composition and the horizontal and vertical extent of NAPLs were determined using historical site information, analysis of ground water and soil boring data, and analysis of free product recovered from wells. Trichloroethene, dichloroethene, methylene chloride, toluene, and oils were identified as NAPLs. Calculations were conducted to determine NAPL remediation goals for both soil and ground water. Following completion of in situ thermal remediation activities at a 9,900-cubic-meter NAPL contamination area, a sampling program was implemented to verify the success of the remediation. The program consisted of using hot media sampling techniques to collect soil and ground water samples at randomly chosen locations in three sampling events during a 6- month period. Verification data indicate that the remediation was successful.

  5. Implementation of in situ vitrification for contaminated soils

    SciTech Connect

    Luey, J.; Roberts, J.S.; Timmerman, C.L.

    1993-08-01

    Geosafe Corporation will be implementing the in situ vitrification (ISV) technology commercially at a Superfund site in Michigan. In preparation for the Michigan site, Geosafe Corporation performed two operational acceptance tests (OATs) at the Geosafe Test Site in Richland, Washington. The objectives were to test the performance of the equipment and to train operating personnel. In addition, Geosafe cooperated with the Pacific Northwest Laboratory and the US Department of Energy, Office of Technology Development in a full-scale field data collection effort to obtain data characterizing the dynamic conditions in the soil created by the advancing ISV melt. This full-scale information provides empirical data to support the current understanding of the ISV technology for contaminated soil applications and provides verification of the accuracy of computational modeling tools being used to evaluate the applicability of the ISV technology to different soil sites.

  6. In-situ measurement system

    DOEpatents

    Lord, David E.

    1983-01-01

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop "hairpin" configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. The electrical resistance of each element and the difference in electrical resistance of the paired elements are obtained, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  7. Unintended and in situ amorphisation of pharmaceuticals.

    PubMed

    Priemel, P A; Grohganz, H; Rades, T

    2016-05-01

    Amorphisation of poorly water-soluble drugs is one approach that can be applied to improve their solubility and thus their bioavailability. Amorphisation is a process that usually requires deliberate external energy input. However, amorphisation can happen both unintentionally, as in process-induced amorphisation during manufacturing, or in situ during dissolution, vaporisation, or lipolysis. The systems in which unintended and in situ amorphisation has been observed normally contain a drug and a carrier. Common carriers include polymers and mesoporous silica particles. However, the precise mechanisms by which in situ amorphisation occurs are often not fully understood. In situ amorphisation can be exploited and performed before administration of the drug or possibly even within the gastrointestinal tract, as can be inferred from in situ amorphisation observed during in vitro lipolysis. The use of in situ amorphisation can thus confer the advantages of the amorphous form, such as higher apparent solubility and faster dissolution rate, without the disadvantage of its physical instability. PMID:26724250

  8. In situ permeability testing of rock salt

    SciTech Connect

    Peterson, E.W.; Lagus, P.L.; Broce, R.D.; Lie, K.

    1981-04-01

    Storage of transuranic (TRU) wastes in bedded salt formations requires a knowledge of the in situ permeability of SENM rock salt. Since assumptions for safety assessments have been made in which these wastes could generate gas pressures on the order of the lithostatic pressure over geologic time scales, the permeability of the surrounding formation becomes an important parameter for determining the manner in which the gases will be contained or dispersed. This report describes the series of tests conducted in the AEC-7 borehole, located near the WIPP site, to determine the in situ gas flow characteristics of the bedded salt. In these tests, compressed air was injected into the borehole and flow into the surrounding formation measured. These measured flow rates were interpreted in terms of formation permeabilities and porosities which were, in turn, used as modeling parameters for the repository response analysis. Two series of field tests were performed. The first series consisted of a number of whole-hole flow tests conducted to provide preliminary design information required for future operation of a guarded straddle packer system capable of measuring permeabilities > or = 0.1 ..mu..darcy. The second series of tests were conducted using the Systems, Science and Software (S-Cubed) designed guarded straddle packer system. In these interval permeability tests, 100-foot lengths of borehole were isolated and the flow characteristics of the surrounding formation examined. In this report, a complete description of the test procedures, instrumentation, and measurement techniques is first given. The analytical/numerical methods used for data interpretation are then presented, followed by results of the interval and permeability tests. (The whole-hole tests are summarized in Appendix A.) Conclusions are presented in the final section.

  9. Amplification of chromosomal DNA in situ

    DOEpatents

    Christian, Allen T.; Coleman, Matthew A.; Tucker, James D.

    2002-01-01

    Amplification of chromosomal DNA in situ to increase the amount of DNA associated with a chromosome or chromosome region is described. The amplification of chromosomal DNA in situ provides for the synthesis of Fluorescence in situ Hybridization (FISH) painting probes from single dissected chromosome fragments, the production of cDNA libraries from low copy mRNAs and improved in Comparative Genomic Hybridization (CGH) procedures.

  10. Verification and Validation of Model-Based Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Pecheur, Charles; Koga, Dennis (Technical Monitor)

    2001-01-01

    This paper presents a three year project (FY99 to FY01) on the verification and validation of model based autonomous systems. The topics include: 1) Project Profile; 2) Model-Based Autonomy; 3) The Livingstone MIR; 4) MPL2SMV; 5) Livingstone to SMV Translation; 6) Symbolic Model Checking; 7) From Livingstone Models to SMV Models; 8) Application In-Situ Propellant Production; 9) Closed-Loop Verification Principle; 10) Livingstone PathFinder (LPF); 11) Publications and Presentations; and 12) Future Directions. This paper is presented in viewgraph form.

  11. 77 FR 64596 - Proposed Information Collection (Income Verification) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... AFFAIRS Proposed Information Collection (Income Verification) Activity: Comment Request AGENCY: Veterans... to determine a claimant's entitlement to income- dependent benefits. DATES: Written comments and... techniques or the use of other forms of information technology. Title: Income Verification, VA Form...

  12. Verification of post permanently manned configuration Space Station elements

    NASA Technical Reports Server (NTRS)

    Scully, E. J.; Edwards, M. D.

    1986-01-01

    An account is given of the techniques and ground systems designed to fulfill post permanently manned configuration (PMC) Space Station verification tasks. Consideration is given to analysis using computer math models and computer-aided interface verification systems, testing using simulators and interface mixtures, and special inspection. It is noted that an initial Space Station design that accommodates and facilitates verification is crucial to an effective verification program as well as proper instrumentation, built-in test capability, and a precise configuration management, control and record system. It is concluded that post PMC verification should be accounted for both in the initial Space Station design and in the subsequent development of initial assembly flight verification techniques and capabilities.

  13. In-Situ Exploration of Habitable Environments and Biosignatures in Arctic Cold Springs and Antarctic Paleolakes

    NASA Astrophysics Data System (ADS)

    Sobron, P.; Andersen, D. T.; Pollard, W. H.

    2016-05-01

    We have characterized Artic cold springs and Antarctic paleolakes as high-fidelity analogs to putative inhabited/habitable environments on Mars, using in-situ techniques relevant to the ExoMars 2018 and Mars 2020 missions.

  14. In situ speciation of dissolved inorganic antimony in surface waters and sediment porewaters: development of a thiol-based diffusive gradients in thin films technique for Sb(III).

    PubMed

    Bennett, William W; Arsic, Maja; Welsh, David T; Teasdale, Peter R

    2016-08-10

    Antimony is a priority environmental contaminant typically present as either the trivalent (Sb(III)) or the pentavalent (Sb(V)) oxidation state in aquatic systems. Both the toxicity and mobility of antimony are affected by its speciation, and thus the accurate measurement of antimony speciation is essential for investigating the behaviour of this contaminant in aquatic systems. Here we present a diffusive gradients in thin films (DGT) technique, which utilises a binding layer containing a thiol-based adsorbent (3-mercaptopropyl functionalised silica gel), for the selective measurement of Sb(III) in surface waters and sediment porewaters. We also evaluated the Metsorb DGT technique, which has been previously reported to accurately measure Sb(V), for its ability to accumulate Sb(III) and thus allow the measurement of total inorganic antimony. Both the mercapto-silica and Metsorb DGT techniques showed a high affinity for Sb(III), with uptake efficiencies >97%. Elution efficiencies of 86.9 ± 2.6% and 88.1 ± 1.2% were obtained for mercapto-silica and Metsorb, respectively, with 1 mol L(-1) H2O2 in 1 mol L(-1) NaOH. The accumulation of Sb(III) by these DGT techniques was linear with time (R(2) > 0.99) and unaffected by pH (4.07-8.05), ionic strength (0.001-1.0 mol L(-1) NaCl), bicarbonate (1-15 mmol L(-1)), and an artificial seawater matrix (pH 8.34; salinity 34.8). Finally, the mercapto-silica DGT technique was applied to measure porewater concentrations of Sb(III) and As(III) in a contaminated freshwater sediment at high resolution. PMID:27192548

  15. In situ geomechanics: Climax granite, Nevada Test Site

    SciTech Connect

    Heuze, F.E.; Patrick, W.C.; De la Cruz, R.V.; Voss, C.F.

    1981-04-01

    The in situ modulus of the Climax granite in the Spent Fuel Test (SFT-C) area of the Nevada Test Site was estimated using six different approaches. Our best estimate of field modulus as E/sub f/ = 26 GPa was obtained from a comparison of the various approaches. A best estimate of laboratory modulus acquired by comparing three different sources was E/sub l/ = 70 GPa. Therefore, the modulus reduction factor for the Climax granite appears to be E/sub f//E/sub l/ = 0.37. In turn, our estimate of in situ rock-mass deformability was used to back-calculate in situ values for the normal stiffness of the granite joints. Our analysis of former stress measurements by the US Geological Survey (USGS) shows that the horizontal stresses in the vicinity of SFT-C vary greatly with azimuth. An unexplained feature of the stresses at SFT-C is the fact that the vertical stress appears to be only 65 to 75% of the calculated lithostatic burden. From the three-dimensional stress ellipsoid at mid-length in the tunnels, assuming a plane strain condition, we were able to estimate an in situ Poisson`s ratio of the rock mass as {nu} = 0.246. Two other techniques were applied in an attempt to measure the stresses around the SFT-C heater and canister drifts: the undercoring method and the borehole jack fracturing approach. The former technique appears to have given reasonable estimates of tangential stresses in the roof of the heater drifts; the latter appears to give low results for stresses in the pillars. Specific recommendations are made for future tests to further characterize the mechanical properties of the Climax granite and the in situ stresses at SFT-C.

  16. Chemically enhanced in situ recovery

    SciTech Connect

    Sale, T.; Pitts, M.; Wyatt, K.

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  17. Method for in situ combustion

    DOEpatents

    Pasini, III, Joseph; Shuck, Lowell Z.; Overbey, Jr., William K.

    1977-01-01

    This invention relates to an improved in situ combustion method for the recovery of hydrocarbons from subterranean earth formations containing carbonaceous material. The method is practiced by penetrating the subterranean earth formation with a borehole projecting into the coal bed along a horizontal plane and extending along a plane disposed perpendicular to the plane of maximum permeability. The subterranean earth formation is also penetrated with a plurality of spaced-apart vertical boreholes disposed along a plane spaced from and generally parallel to that of the horizontal borehole. Fractures are then induced at each of the vertical boreholes which project from the vertical boreholes along the plane of maximum permeability and intersect the horizontal borehole. The combustion is initiated at the horizontal borehole and the products of combustion and fluids displaced from the earth formation by the combustion are removed from the subterranean earth formation via the vertical boreholes. Each of the vertical boreholes are, in turn, provided with suitable flow controls for regulating the flow of fluid from the combustion zone and the earth formation so as to control the configuration and rate of propagation of the combustion zone. The fractures provide a positive communication with the combustion zone so as to facilitate the removal of the products resulting from the combustion of the carbonaceous material.

  18. In situ vitrification: A review

    SciTech Connect

    Cole, L.L.; Fields, D.E.

    1989-11-01

    The in situ vitrification process (ISV) converts contaminated soils and sludges to a glass and crystalline product. The process appears to be ideally suited for on site treatment of both wet and dry wastes. Basically, the system requires four molybdenum electrodes, an electrical power system for vitrifying the soil, a hood to trap gaseous effluents, an off-gas treatment system, an off-gas cooling system, and a process control station. Mounted in three transportable trailers, the ISV process can be moved from site to site. The process has the potential for treating contaminated soils at most 13 m deep. The ISV project has won a number of outstanding achievement awards. The process has also been patented with exclusive worldwide rights being granted to Battelle Memorial Institute for nonradioactive applications. While federal applications still belong to the Department of Energy, Battelle transferred the rights of ISV for non-federal government, chemical hazardous wastes to a separate corporation in 1989 called Geosafe. This report gives a review of the process including current operational behavior and applications.

  19. In situ bioremediation in Europe

    SciTech Connect

    Porta, A.; Young, J.K.; Molton, P.M.

    1993-06-01

    Site remediation activity in Europe is increasing, even if not at the forced pace of the US. Although there is a better understanding of the benefits of bioremediation than of other approaches, especially about in situ bioremediation of contaminated soils, relatively few projects have been carried out full-scale in Europe or in the US. Some engineering companies and large industrial companies in Europe are investigating bioremediation and biotreatment technologies, in some cases to solve their internal waste problems. Technologies related to the application of microorganisms to the soil, release of nutrients into the soil, and enhancement of microbial decontamination are being tested through various additives such as surfactants, ion exchange resins, limestone, or dolomite. New equipment has been developed for crushing and mixing or injecting and sparging the microorganisms, as have new reactor technologies (e.g., rotating aerator reactors, biometal sludge reactors, and special mobile containers for simultaneous storage, transportation, and biodegradation of contaminated soil). Some work has also been done with immobilized enzymes to support and restore enzymatic activities related to partial or total xenobiotic decontamination. Finally, some major programs funded by public and private institutions confirm that increasing numbers of firms have a working interest in bioremediation.

  20. In situ microscopy using adjustment-free optics.

    PubMed

    Suhr, Hajo; Herkommer, Alois M

    2015-11-01

    In the past years, in situ microscopy has been demonstrated as a technique for monitoring the concentration and morphology of moving microparticles in agitated suspensions. However, up until now, this technique can only achieve a high resolution if a certain manual or automated effort is established for continuous precise focusing. Therefore, the application of in situ microscopes (ISMs) as sensors is inhibited in the cases where unattended operation is required. Here, we demonstrate a high-resolution ISM which, unlike others, is built as an entirely rigid construction, requiring no adjustments at all. This ISM is based on a specially designed water immersion objective with numerical aperture = 0.75 and a working distance of 15 μm. The objective can be built exclusively from off-the-shelf parts and the front surface directly interfaces with the moving suspension. We show various applications of the system and demonstrate the imaging performance with submicron resolution within moving suspensions of microorganisms.

  1. In situ microscopy using adjustment-free optics

    NASA Astrophysics Data System (ADS)

    Suhr, Hajo; Herkommer, Alois M.

    2015-11-01

    In the past years, in situ microscopy has been demonstrated as a technique for monitoring the concentration and morphology of moving microparticles in agitated suspensions. However, up until now, this technique can only achieve a high resolution if a certain manual or automated effort is established for continuous precise focusing. Therefore, the application of in situ microscopes (ISMs) as sensors is inhibited in the cases where unattended operation is required. Here, we demonstrate a high-resolution ISM which, unlike others, is built as an entirely rigid construction, requiring no adjustments at all. This ISM is based on a specially designed water immersion objective with numerical aperture=0.75 and a working distance of 15 μm. The objective can be built exclusively from off-the-shelf parts and the front surface directly interfaces with the moving suspension. We show various applications of the system and demonstrate the imaging performance with submicron resolution within moving suspensions of microorganisms.

  2. ENGINEERING BULLETIN: IN SITU STEAM EXTRACTION TREATMENT

    EPA Science Inventory

    In situ steam extraction removes volatile and semivolatile hazardous contaminants from soil and groundwater without excavation of the hazardous waste. Waste constituents are removed in situ by the technology and are not actually treated. The use of steam enhances the stripping of...

  3. IN SITU Device for Real-Time Catalyst Deactivation Measurements

    SciTech Connect

    Fossil Energy Research

    2008-03-31

    SCR catalyst management has become an important operations and maintenance activity for coal-fired utility boilers in the United States. To facilitate this activity, a method to determine Catalyst Activity in situ is being developed. This report describes the methodology and presents the results of a two ozone season demonstration conducted at Alabama Power Company's Gorgas Unit 10 during the 2005 and 2006 ozone seasons. The results showed that the in situ measurements are in good agreement with the laboratory measurements and the technique has some advantages over the traditional laboratory method of determining Catalyst Activity and Reactor Potential. SCR Performance is determined by the overall Reactor Potential (the product of the Catalyst Activity and the available surface area per unit of flue gas). The in situ approach provides a direct measurement of Reactor Potential under actual operating conditions, whereas laboratory measurements of Catalyst Activity need to be coupled with estimates of catalyst pluggage and flue gas flowrate in order to assess Reactor Potential. The project also showed that the in situ activity results can easily be integrated into catalyst management software to aid in making informed catalyst decisions.

  4. In situ electron energy-loss spectroscopy in liquids.

    PubMed

    Holtz, Megan E; Yu, Yingchao; Gao, Jie; Abruña, Héctor D; Muller, David A

    2013-08-01

    In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the liquid cell holder shadows the detector and electron energy-loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS in the study of chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap, and thickness of the liquid layer by valence EELS is demonstrated. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio regime as demonstrated for LiFePO4 in an aqueous solution. The potential for the use of valence EELS to understand in situ STEM reactions is demonstrated for beam-induced deposition of metallic copper: as copper clusters grow, EELS develops low-loss peaks corresponding to metallic copper. From these techniques, in situ imaging and valence EELS offer insights into the local electronic structure of nanoparticles and chemical reactions. PMID:23721691

  5. Frontiers of in situ electron microscopy

    DOE PAGES

    Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

    2015-01-01

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore » this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

  6. Towards microfluidic reactors for in situ synchrotron infrared studies

    NASA Astrophysics Data System (ADS)

    Silverwood, I. P.; Al-Rifai, N.; Cao, E.; Nelson, D. J.; Chutia, A.; Wells, P. P.; Nolan, S. P.; Frogley, M. D.; Cinque, G.; Gavriilidis, A.; Catlow, C. R. A.

    2016-02-01

    Anodically bonded etched silicon microfluidic devices that allow infrared spectroscopic measurement of solutions are reported. These extend spatially well-resolved in situ infrared measurement to higher temperatures and pressures than previously reported, making them useful for effectively time-resolved measurement of realistic catalytic processes. A data processing technique necessary for the mitigation of interference fringes caused by multiple reflections of the probe beam is also described.

  7. Microcantilever Sensors for In-Situ Subsurface Characterization

    SciTech Connect

    Thundat, Thomas G.; Zhiyu Hu; Brown, Gilbert M.; Baohua Gu

    2006-06-01

    Real-time, in-situ analysis is critical for decision makers in environmental monitoring, but current techniques for monitoring and characterizing radionuclides rely primarily on liquid scintillation counting, ICP-MS, and spectrofluorimetry, which require sample handling and labor intensive lengthy analytical procedures. Other problems that accompany direct sampling include adherence to strict holding times and record maintenance for QA/QC procedures. Remote, automated sensing with direct connection to automated data management is preferred.

  8. In situ containment and stabilization of buried waste. Annual report FY 1992

    SciTech Connect

    Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

    1992-11-01

    The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

  9. Visualizing T Cell Migration in situ

    PubMed Central

    Benechet, Alexandre P.; Menon, Manisha; Khanna, Kamal M.

    2014-01-01

    Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell–cell and cell–extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen-specific T cells persists as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in situ visualization of T cell responses. Here, we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naïve, effector, and memory T cells. PMID:25120547

  10. Assessment of a biological in situ remediation

    SciTech Connect

    Wuerdemann, H.; Lund, N.C.; Gudehus, G.

    1995-12-31

    A field experiment using a bioventing technique has been conducted at the center of contamination at a former gasworks site for 3 years. The emphasis of this investigation is to determine the efficiency of in situ remediation. Due to an extremely heterogeneous distribution of contamination it was impossible to satisfactorily quantify the reduction of hydrocarbons. However, a comparison of highly contaminated soil samples shows a qualitative alteration. The analyses of pollutant composition reveal a significant decrease of low condensed PAHs up to anthracene. The relative increase of high condensed PAHs in the contaminant composition indicates a PAH degradation of 54%. Soil respiration is used to assess the course of remediation. Continuous monitoring of O{sub 2} and CO{sub 2} in the used air leads to an amount of about 2,400 kg of decomposed organics. Large-scale elution tests show a reduction of the sum parameters for the organic pollution of the flushing water of 80%. The PAHs have dropped about 97%. The Microtox test indicates a detoxification of 98%.

  11. Photonic MEMS for NIR in-situ

    SciTech Connect

    Bond, T C; Cole, G D; Goddard, L L; Behymer, E

    2007-07-03

    We report on a novel sensing technique combining photonics and microelectromechanical systems (MEMS) for the detection and monitoring of gas emissions for critical environmental, medical, and industrial applications. We discuss how MEMS-tunable vertical-cavity surface-emitting lasers (VCSELs) can be exploited for in-situ detection and NIR spectroscopy of several gases, such as O{sub 2}, N{sub 2}O, CO{sub x}, CH{sub 4}, HF, HCl, etc., with estimated sensitivities between 0.1 and 20 ppm on footprints {approx}10{sup -3} mm{sup 3}. The VCSELs can be electrostatically tuned with a continuous wavelength shift up to 20 nm, allowing for unambiguous NIR signature determination. Selective concentration analysis in heterogeneous gas compositions is enabled, thus paving the way to an integrated optical platform for multiplexed gas identification by bandgap and device engineering. We will discuss here, in particular, our efforts on the development of a 760 nm AlGaAs based tunable VCSEL for O{sub 2} detection.

  12. Practical issues related to the application of the electromechanical impedance technique in the structural health monitoring of civil structures: II. Numerical verification

    NASA Astrophysics Data System (ADS)

    Yang, Yaowen; Lim, Yee Yan; Kiong Soh, Chee

    2008-06-01

    This paper, the second in a two-part series, presents various finite element simulations on the interaction between a piezo-impedance transducer (lead zirconate titanate, PZT) and a structure, inclusive of the bonding layer, in the application of the electromechanical impedance (EMI) technique with varying temperature. Simulation of the PZT-structure interaction at the high frequency range (up to 1000 kHz) using the commercially available finite element method (FEM) software, ANSYS version 8.1, was successfully performed. Promising results were found when compared to the experimental results. Advantages over the conventional finite element analysis (FEA) based impedance model and the impedance based analytical models include higher accuracy, direct acquisition of electrical admittance/impedance, and the ability to model the PZT and the bonding layer as well as the ambient temperature. This finite element model also successfully verified some vital experimental observations in part I. This study proves that the FEM could emerge as an excellent alternative to experimentation in the study of the EMI technique.

  13. Extraction of in situ cosmogenic 14C from olivine

    USGS Publications Warehouse

    Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

    2010-01-01

    Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona

  14. Experimental Measurement of In Situ Stress

    NASA Astrophysics Data System (ADS)

    Tibbo, Maria; Milkereit, Bernd; Nasseri, Farzine; Schmitt, Douglas; Young, Paul

    2016-04-01

    The World Stress Map data is determined by stress indicators including earthquake focal mechanisms, in situ measurement in mining, oil and gas boreholes as well as the borehole cores, and geologic data. Unfortunately, these measurements are not only infrequent but sometimes infeasible, and do not provide nearly enough data points with high accuracy to correctly infer stress fields in deep mines around the world. Improvements in stress measurements of Earth's crust is fundamental to several industries such as oil and gas, mining, nuclear waste management, and enhanced geothermal systems. Quantifying the state of stress and the geophysical properties of different rock types is a major complication in geophysical monitoring of deep mines. Most stress measurement techniques involve either the boreholes or their cores, however these measurements usually only give stress along one axis, not the complete stress tensor. The goal of this project is to investigate a new method of acquiring a complete stress tensor of the in situ stress in the Earth's crust. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, and focuses on two boreholes located in this mine. These boreholes are approximately 400 m long with NQ diameters and are located at depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Laboratory experiments have been performed on borehole core samples of varying geologies from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. The apparatus' used for this project are geophysical imaging cells capable

  15. In situ bioremediation using horizontal wells

    SciTech Connect

    1995-04-01

    In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

  16. In situ nanoindentation in a transmission electron microscope

    NASA Astrophysics Data System (ADS)

    Minor, Andrew Murphy

    This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids. Chapter 2 details the unique specimen preparation techniques employed to meet the geometrical constraints of the in situ experiments. These techniques include bulk silicon micromachining and the use of a focused ion beam. In section 2.4 a method of voltage-controlled mechanical testing is derived theoretically and proven experimentally. This method enables the quantification of the mechanical behavior during in situ nanoindentation experiments. Three classes of material systems were studied with this new technique: (1) bulk single crystal, (2) a soft thin film on a harder substrate and (3) a hard thin film on a softer substrate. Section 3.2 provides the first direct evidence of dislocation nucleation in single crystal silicon at room temperature. In contrast to the observation of phase transformations during conventional indentation experiments, the unique geometry employed for the in situ experiments resulted in dislocation plasticity. In section 3.3 results from in situ nanoindentation of Al films on Si substrates are presented. These results include the correlation of the microstructural deformation behavior with load vs. displacement data. It is shown that a sharp change in the force-displacement response at the elastic-to-plastic transition signifies the nucleation of dislocations. Additionally, the softening of sub-micron grains with size is observed. Section 3.4 discussed the influence of the substrate on the indentation response of two thin film/substrate systems where the films were harder than the substrate. Amorphous diamond on Si and epitaxial TiN on MgO (001) systems were studied. It was found that the deformation in the harder films was controlled by the deformation in

  17. Cross-check of ex-situ and in-situ metrology of a bendable temperature stabilized KB mirror

    SciTech Connect

    Yuan, Sheng Sam; Goldberg, Kenneth A.; Yashchuk, Valeriy V.; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory; Macdougall, James; Mochi, Iacopo; Warwick, Tony

    2010-09-15

    At the Advanced Light Source (ALS), we are developing broadly applicable, high-accuracy, in-situ, at-wavelength wavefront slope measurement techniques for Kirkpatrick-Baez (KB) mirror nano-focusing. In this paper, we report an initial cross-check of ex-situ and in-situ metrology of a bendable temperature stabilized KB mirror. This cross-check provides a validation of the in-situ shearing interferometry currently under development at the ALS.

  18. Verification and arms control

    SciTech Connect

    Potter, W.C.

    1985-01-01

    Recent years have witnessed an increased stress upon the verification of arms control agreements, both as a technical problem and as a political issue. As one contribution here points out, the middle ground has shrunk between those who are persuaded that the Soviets are ''cheating'' and those who are willing to take some verification risks for the sake of achieving arms control. One angle, according to a Lawrence Livermore physicist who served as a member of the delegation to the various test-ban treaty negotiations, is the limited effectiveness of on-site inspection as compared to other means of verification.

  19. Ex vivo skin permeation and retention studies on chitosan-ibuprofen-gellan ternary nanogel prepared by in situ ionic gelation technique--a tool for controlled transdermal delivery of ibuprofen.

    PubMed

    Abioye, Amos Olusegun; Issah, Sureya; Kola-Mustapha, Adeola Tawakalitu

    2015-07-25

    The chemical potentials of drug-polymer electrostatic interaction have been utilized to develop a novel ternary chitosan-ibuprofen-gellan nanogel as controlled transdermal delivery tool for ibuprofen. The ternary nanogels were prepared by a combination of electrostatic nanoassembly and ionic gelation techniques. The electrostatic and hydrophobic interactions as well as hydrogen bonding between ibuprofen and chitosan were confirmed with FTIR, while DSC, TGA and SEM confirmed the physical state, thermal and morphological characteristics, respectively. The ex vivo delivery of ibuprofen onto and across the skin was evaluated based on system specific drug release parameters such as steady state permeation rate, permeability coefficient, permeability enhancement ratio, skin/gel partition coefficient, diffusion coefficient, lag time and release rate constant and mechanisms of release were determined using mathematical models. Interaction between ibuprofen and chitosan produced new spherical eutectic nanoconjugates with remarkable decrease in particle size of ibuprofen from 4580 (length-to-breadth aspect ratio) to a minimum of 14.15 nm (324-times), and thermally stable amorphous characteristics. The nanogels exhibited significant elastic and pseudoplastic characteristics dictated by the concentration of chitosan with maximum swelling capacity of 775% w/w at 6.55 mM chitosan compared with 281.16 and 506.50% for plain gellan and control ibuprofen hydrogel, respectively. Chitosan enhanced the skin penetration, permeability and the rate of transdermal release of ibuprofen by a factor of 4, dictated by the extent of ibuprofen-chitosan ionic interaction and its concentration. The major mechanism of ibuprofen release through the pig skin was drug diffusion however drug partition and matrix erosion also occurred. It was evident that ternary nanogels are novel formulations with potential application in controlled transdermal delivery of ibuprofen.

  20. Time-resolved Raman spectroscopy for in situ planetary mineralogy.

    PubMed

    Blacksberg, Jordana; Rossman, George R; Gleckler, Anthony

    2010-09-10

    Planetary mineralogy can be revealed through a variety of remote sensing and in situ investigations that precede any plans for eventual sample return. We briefly review those techniques and focus on the capabilities for on-surface in situ examination of Mars, Venus, the Moon, asteroids, and other bodies. Over the past decade, Raman spectroscopy has continued to develop as a prime candidate for the next generation of in situ planetary instruments, as it provides definitive structural and compositional information of minerals in their natural geological context. Traditional continuous-wave Raman spectroscopy using a green laser suffers from fluorescence interference, which can be large (sometimes saturating the detector), particularly in altered minerals, which are of the greatest geophysical interest. Taking advantage of the fact that fluorescence occurs at a later time than the instantaneous Raman signal, we have developed a time-resolved Raman spectrometer that uses a streak camera and pulsed miniature microchip laser to provide picosecond time resolution. Our ability to observe the complete time evolution of Raman and fluorescence spectra in minerals makes this technique ideal for exploration of diverse planetary environments, some of which are expected to contain strong, if not overwhelming, fluorescence signatures. We discuss performance capability and present time-resolved pulsed Raman spectra collected from several highly fluorescent and Mars-relevant minerals. In particular, we have found that conventional Raman spectra from fine grained clays, sulfates, and phosphates exhibited large fluorescent signatures, but high quality spectra could be obtained using our time-resolved approach.

  1. In situ-based effects measures: considerations for improving methods and approaches.

    PubMed

    Liber, Karsten; Goodfellow, William; den Besten, Pieter; Clements, Will; Galloway, Tamara; Gerhardt, Almut; Green, Andrew; Simpson, Stuart

    2007-04-01

    In situ-based effects measures have gained increased acceptance as a means to improve the link between cause and effect in aquatic ecotoxicological studies. These approaches have primarily been employed where more conventional laboratory tests with field collected samples and routine in-field community surveys have failed to provide reasonable answers with respect to causes of toxicity, primary routes of contaminant exposure, and what constitutes ecotoxicologically relevant contaminant levels, at least at a site-specific level. One of the main advantages provided by in situ tests compared to more conventional field-based monitoring approaches is that they provide better control over stressor exposure to a defined population of test animals under natural or near-natural field conditions. In situ techniques can also be used to avoid artifacts related to sampling, transport and storage of contaminated water and sediment intended for laboratory-based toxicity assessment. In short, they can reduce the need for laboratory to field extrapolation and, when conducted properly, in situ tests can provide improved diagnostic ability and high ecological relevance. This paper provides suggestions and considerations for designing in situ studies, choosing test species and test endpoints, avoiding or minimizing test artifacts, best addressing some of the limitations of in situ test techniques, and generally improving the overall quality of the in situ approach chosen.

  2. Optimization and Analysis of Laser Beam Machining Parameters for Al7075-TiB2 In-situ Composite

    NASA Astrophysics Data System (ADS)

    Manjoth, S.; Keshavamurthy, R.; Pradeep Kumar, G. S.

    2016-09-01

    The paper focuses on laser beam machining (LBM) of In-situ synthesized Al7075-TiB2 metal matrix composite. Optimization and influence of laser machining process parameters on surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy of composites were studied. Al7075-TiB2 metal matrix composite was synthesized by in-situ reaction technique using stir casting process. Taguchi's L9 orthogonal array was used to design experimental trials. Standoff distance (SOD) (0.3 - 0.5mm), Cutting Speed (1000 - 1200 m/hr) and Gas pressure (0.5 - 0.7 bar) were considered as variable input parameters at three different levels, while power and nozzle diameter were maintained constant with air as assisting gas. Optimized process parameters for surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy were calculated by generating the main effects plot for signal noise ratio (S/N ratio) for surface roughness, VMRR and dimensional error using Minitab software (version 16). The Significant of standoff distance (SOD), cutting speed and gas pressure on surface roughness, volumetric material removal rate (VMRR) and dimensional error were calculated using analysis of variance (ANOVA) method. Results indicate that, for surface roughness, cutting speed (56.38%) is most significant parameter followed by standoff distance (41.03%) and gas pressure (2.6%). For volumetric material removal (VMRR), gas pressure (42.32%) is most significant parameter followed by cutting speed (33.60%) and standoff distance (24.06%). For dimensional error, Standoff distance (53.34%) is most significant parameter followed by cutting speed (34.12%) and gas pressure (12.53%). Further, verification experiments were carried out to confirm performance of optimized process parameters.

  3. In-situ determination of radionuclide levels in facilities to be decommissioned using the allowable residual contamination level method

    SciTech Connect

    Arthur, R.J.; Haggard, D.L.

    1989-07-01

    This feasibility study resulted in verification of a direct and two alternate indirect techniques for making in-situ determinations of {sup 90}Sr and other radionuclide levels in a Hanford facility to be decommissioned that was evaluated using the Allowable Residual Contamination Level (ARCL) method. The ARCL method is used to determine the extent of decontamination that will be required before a facility can be decommissioned. A sump in the 1608F Building was chosen for the feasibility study. Hanford decommissioning personnel had previously taken 79 concrete and surface scale samples from the building to be analyzed by radiochemical analysis. The results of the radiochemical analyses compare favorably with the values derived by the in-situ methods presented in this report. Results obtained using a portable spectrometer and thermoluminescent dosimeters (TLDs) were both very close to the radiochemistry results. Surface {sup 90}Sr levels detected on the sump floor were 550 pCi/cm{sup 2} using the spectrometer system and 780 pCi/cm{sup 2} using the TLD data. This compares favorably with the levels determined by radiochemical analyses (i.e., 230 to 730 pCi/cm{sup 2}). Surface {sup 90}Sr levels detected on the sump wall ranged between 10 and 80 pCi/cm{sup 2} using the spectrometer system, compared with a conservative 200 pCi/cm{sup 2} using the TLD data. The radiochemical results ranged between 19 and 77 pCi/cm{sup 2} for the four samples taken from the wall at indeterminate locations. 17 refs., 15 figs., 2 tabs.

  4. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  5. Detection of prokaryotic cells with fluorescence in situ hybridization.

    PubMed

    Zwirglmaier, Katrin

    2010-01-01

    Fluorescence in situ hybridization with rRNA targeted oligonucleotide probes is nowadays one of the core techniques in microbial ecology, allowing the identification and quantification of microbial cells in environmental samples in situ. Next to the classic FISH protocol, which uses fluorescently monolabelled probes, the more sensitive CARD-FISH (also known as TSA-FISH), which involves an enzyme catalyzed signal amplification step, is becoming increasingly popular. This chapter describes protocols for both methods. While classic FISH has the advantage of being relatively cheap and easy to do on morphologically diverse samples, CARD-FISH offers a significantly higher sensitivity, allowing the detection of slow growing or metabolically inactive cells, which are below the detection limit of classic FISH. The drawback here is the considerably higher price for the probes and advanced cell fixation and permeabilization requirements that have to be optimized for different target cells.

  6. In Situ Instrumentation for Sub-Surface Planetary Geochemistry

    NASA Technical Reports Server (NTRS)

    Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    Novel instrumentation is under development at NASA's Goddard Space Flight Center, building upon earth-based techniques for hostile environments, to infer geochemical processes important to formation and evolution of solid bodies in our Solar System. A prototype instrument, the Pulsed Neutron Generator Gamma Ray and Neutron Detectors (PNG-GRAND), has a 14 MeV pulsed neutron generator coupled with gamma ray and neutron detectors to measure quantitative elemental concentrations and bulk densities of a number of major, minor and trace elements at or below the surfaces with approximately a meter-sized spatial resolution down to depths of about 50 cm without the need to drill. PNG-GRAND's in situ a meter-scale measurements and adaptability to a variety of extreme space environments will complement orbital kilometer-scale and in-situ millimeter scale elemental and mineralogical measurements to provide a more complete picture of the geochemistry of planets, moons, asteroids and comets.

  7. Final report: In situ radio frequency heating demonstration

    SciTech Connect

    Jarosch, T.R.; Beleski, R.J.; Faust, D.

    1994-01-05

    A field demonstration of in situ radio frequency heating was performed at the Savannah River Site (SRS) as part of the US Department of Energy-Office of Technology Development`s Integrated Demonstration. The objective of the demonstration was to investigate the effectiveness of in situ radio frequency (RF) heating as an enhancement to vacuum extraction of residual solvents (primarily trichloroethylene and perchloroethylene) held in vadose zone clay deposits. Conventional soil vacuum extraction techniques are mass transfer limited because of the low permeabilities of the clays. By selectively heating the clays to temperatures at or above 100{degrees}C, the release or transport of the solvent vapors will be enhanced as a result of several factors including an increase in the contaminant vapor pressure and diffusivity and an increase in the effective permeability of the formation with the release of water vapor.

  8. Raman spectroscopy for in-situ monitoring of electrode processes

    SciTech Connect

    Varma, R; Cook, G M; Yao, N P

    1982-04-01

    The theoretical and experimental applications of Raman spectroscopic techniques to the study of battery electrode processes are described. In particular, the potential of Raman spectroscopy as an in-situ analytical tool for the characterization of the structure and composition of electrode surface layers at electrode-electrolyte interfaces during electrolysis is examined. It is anticipated that this understanding of the battery electrode processes will be helpful in designing battery active material with improved performance. The applications of Raman spectroscopy to the in-situ study of electrode processes has been demonstrated in a few selected areas, including: (1) the anodic corrosion of lead in sulfuric acid and (2) the anodization and sulfation of tetrabasicleadsulfate in sulfuric acid. Preliminary results on the anodization of iron and on the electrochemical behavior of nickel positive-electrode active material in potassium hydroxide electrolytes are presented in the Appendix.

  9. Monitoring Cocrystal Formation via In Situ Solid-State NMR.

    PubMed

    Mandala, Venkata S; Loewus, Sarel J; Mehta, Manish A

    2014-10-01

    A detailed understanding of the mechanism of organic cocrystal formation remains elusive. Techniques that interrogate a reacting system in situ are preferred, though experimentally challenging. We report here the results of a solid-state in situ NMR study of the spontaneous formation of a cocrystal between a pharmaceutical mimic (caffeine) and a coformer (malonic acid). Using (13)C magic angle spinning NMR, we show that the formation of the cocrystal may be tracked in real time. We find no direct evidence for a short-lived, chemical shift-resolved amorphous solid intermediate. However, changes in the line width and line center of the malonic acid methylene resonance, in the course of the reaction, provide subtle clues to the mode of mass transfer that underlies cocrystal formation.

  10. Methods and systems for in-situ electroplating of electrodes

    DOEpatents

    Zappi, Guillermo Daniel; Zarnoch, Kenneth Paul; Huntley, Christian Andrew; Swalla, Dana Ray

    2015-06-02

    The present techniques provide electrochemical devices having enhanced electrodes with surfaces that facilitate operation, such as by formation of a porous nickel layer on an operative surface, particularly of the cathode. The porous metal layer increases the surface area of the electrode, which may result in increasing the efficiency of the electrochemical devices. The formation of the porous metal layer is performed in situ, that is, after the assembly of the electrodes into an electrochemical device. The in situ process offers a number of advantages, including the ability to protect the porous metal layer on the electrode surface from damage during assembly of the electrochemical device. The enhanced electrode and the method for its processing may be used in any number of electrochemical devices, and is particularly well suited for electrodes in an electrolyzer useful for splitting water into hydrogen and oxygen.

  11. Some implications of in situ uranium mining technology development

    SciTech Connect

    Cowan, C.E.; Parkhurst, M.A.; Cole, R.J.; Keller, D.; Mellinger, P.J.; Wallace, R.W.

    1980-09-01

    The assessment indicates that there do not appear to be any significant demonstrated negative environmental impacts. Moreover, the impacts of in situ mining compare favorably with those impacts expected from conventional mining techniques. Exposure to radioactive elements is less, atmospheric emissions of radioactive and nonradioactive materials are generally less and socioeconomic impacts are decreased. In fact, because of the generally small and unskilled labor forces associated with in-situ mining, development has provided much needed economic stimulus to economically depressed areas of Texas. There are still, however, several areas of unknowns and several areas of inadequate information that will need to be addressed before a complete quantification evaluation of impacts can be made. These areas include levels of radon emissions and groundwater restoration methods and impacts. Several issues mostly relating to the interaction of industry with state and Federal regulators need to be addressed.

  12. In Situ Solid Particle Generator

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.; Vijayakumar, R.

    2013-01-01

    Particle seeding is a key diagnostic component of filter testing and flow imaging techniques. Typical particle generators rely on pressurized air or gas sources to propel the particles into the flow field. Other techniques involve liquid droplet atomizers. These conventional techniques have drawbacks that include challenging access to the flow field, flow and pressure disturbances to the investigated flow, and they are prohibitive in high-temperature, non-standard, extreme, and closed-system flow conditions and environments. In this concept, the particles are supplied directly within a flow environment. A particle sample cartridge containing the particles is positioned somewhere inside the flow field. The particles are ejected into the flow by mechanical brush/wiper feeding and sieving that takes place within the cartridge chamber. Some aspects of this concept are based on established material handling techniques, but they have not been used previously in the current configuration, in combination with flow seeding concepts, and in the current operational mode. Unlike other particle generation methods, this concept has control over the particle size range ejected, breaks up agglomerates, and is gravity-independent. This makes this device useful for testing in microgravity environments.

  13. In situ methods for Li-ion battery research: A review of recent developments

    NASA Astrophysics Data System (ADS)

    Harks, P. P. R. M. L.; Mulder, F. M.; Notten, P. H. L.

    2015-08-01

    A considerable amount of research is being directed towards improving lithium-ion batteries in order to meet today's market demands. In particular in situ investigations of Li-ion batteries have proven extremely insightful, but require the electrochemical cell to be fully compatible with the conditions of the testing method and are therefore often challenging to execute. Advantageously, in the past few years significant progress has been made with new, more advanced, in situ techniques. Herein, a comprehensive overview of in situ methods for studying Li-ion batteries is given, with the emphasis on new developments and reported experimental highlights.

  14. In situ mechanical characterization of the cell nucleus by atomic force microscopy.

    PubMed

    Liu, Haijiao; Wen, Jun; Xiao, Yun; Liu, Jun; Hopyan, Sevan; Radisic, Milica; Simmons, Craig A; Sun, Yu

    2014-04-22

    The study of nuclear mechanical properties can provide insights into nuclear dynamics and its role in cellular mechanotransduction. While several methods have been developed to characterize nuclear mechanical properties, direct intracellular probing of the nucleus in situ is challenging. Here, a modified AFM (atomic force microscopy) needle penetration technique is demonstrated to mechanically characterize cell nuclei in situ. Cytoplasmic and nuclear stiffness were determined based on two different segments on the AFM indentation curves and were correlated with simultaneous confocal Z-stack microscopy reconstructions. On the basis of direct intracellular measurement, we show that the isolated nuclei from fibroblast-like cells exhibited significantly lower Young's moduli than intact nuclei in situ. We also show that there is in situ nucleus softening in the highly metastatic bladder cancer cell line T24 when compared to its less metastatic counterpart RT4. This technique has potential to become a reliable quantitative measurement tool for intracellular mechanics studies.

  15. Verification of RADTRAN

    SciTech Connect

    Kanipe, F.L.; Neuhauser, K.S.

    1995-12-31

    This document presents details of the verification process of the RADTRAN computer code which was established for the calculation of risk estimates for radioactive materials transportation by highway, rail, air, and waterborne modes.

  16. Voltage verification unit

    DOEpatents

    Martin, Edward J.

    2008-01-15

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  17. A Diffusion-Viscous Analysis and Experimental Verification of the Drying Behavior in Nanosilver-Enabled Low-Temperature Joining Technique

    NASA Astrophysics Data System (ADS)

    Xiao, Kewei

    The low-temperature joining technique (LTJT) by silver sintering is being implemented by major manufacturers of power electronics devices and modules for bonding power semiconductor chips. A common die-attach material used with LTJT is a silver paste consisting of silver powder (micron- or nano-size particles) mixed in organic solvent and binder formulation. It is believed that the drying of the paste during the bonding process plays a critical role in determining the quality of the sintered bond-line. In this study, a model based on the diffusion of solvent molecules and viscous mechanics of the paste was introduced to determine the stress and strain states of the silver bond-line. A numerical simulation algorithm of the model was developed and coded in the C++ programming language. The numerical simulation allows determination of the time-dependent physical properties of the silver bond-line as the paste is being dried with a heating profile. The properties studied were solvent concentration, weight loss, shrinkage, stress, and strain. The stress is the cause of cracks in the bond-line and bond-line delamination. The simulated results were verified by complementary experiments in which the formation of cracks in bond-line and interface delamination was observed during the pressure-free drying of a die-attach nanosilver paste. Furthermore, the important drying parameters, such as drying pressure, low temperature drying time and temperature ramp rate of nanosilver LTJT process, are experimentally studied and analyzed with the numerical simulation. The simulated results were consistent with the experimental findings that the quality of sintered silver bond-line increases with increasing external drying pressure, with increasing low temperature drying time, and with decreasing temperature ramp rate. The insight offered by this modeling study can be used to optimize the process profile that enable pressure-free, low-temperature sintering of the die-attach material to

  18. In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry

    SciTech Connect

    Graetz J.; Meng, Y.S.; McGilvray, T.; Yang, M.-C.; Gostovic, D.; Wang, F.; Zeng, D.; Zhu, Y.

    2011-10-31

    Oxides and their tailored structures are at the heart of electrochemical energy storage technologies and advances in understanding and controlling the dynamic behaviors in the complex oxides, particularly at the interfaces, during electrochemical processes will catalyze creative design concepts for new materials with enhanced and better-understood properties. Such knowledge is not accessible without new analytical tools. New innovative experimental techniques are needed for understanding the chemistry and structure of the bulk and interfaces, more importantly how they change with electrochemical processes in situ. Analytical Transmission Electron Microscopy (TEM) is used extensively to study electrode materials ex situ and is one of the most powerful tools to obtain structural, morphological, and compositional information at nanometer scale by combining imaging, diffraction and spectroscopy, e.g., EDS (energy dispersive X-ray spectrometry) and Electron Energy Loss Spectrometry (EELS). Determining the composition/structure evolution upon electrochemical cycling at the bulk and interfaces can be addressed by new electron microscopy technique with which one can observe, at the nanometer scale and in situ, the dynamic phenomena in the electrode materials. In electrochemical systems, for instance in a lithium ion battery (LIB), materials operate under conditions that are far from equilibrium, so that the materials studied ex situ may not capture the processes that occur in situ in a working battery. In situ electrochemical operation in the ultra-high vacuum column of a TEM has been pursued by two major strategies. In one strategy, a 'nano-battery' can be fabricated from an all-solid-state thin film battery using a focused ion beam (FIB). The electrolyte is either polymer based or ceramic based without any liquid component. As shown in Fig. 1a, the interfaces between the active electrode material/electrolyte can be clearly observed with TEM imaging, in contrast to the

  19. In situ freeze-capturing of fracture water using cryogenic coring

    SciTech Connect

    Su, Grace W.; Wang, Joseph S.Y.; Zacny, Kris

    2004-01-29

    Current methods do not allow for sampling of in situ water from unsaturated fractures in low-moisture environments. A novel cryogenic coring technique based on the method developed by Simon and Cooper (1996) is used to collect in situ water in unsaturated fractures. This method uses liquid nitrogen as the drilling fluid, which can freeze the fracture water in place while coring. Laboratory experiments are conducted to demonstrate that water in an unsaturated fracture can be frozen and collected using cryogenic coring.

  20. In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy

    DOEpatents

    Braymen, S.D.

    1996-06-11

    A method and apparatus are disclosed for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present in situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization. 5 figs.

  1. Test/QA Plan for Verification of Nitrate Sensors for Groundwater Remediation Monitoring

    EPA Science Inventory

    A submersible nitrate sensor is capable of collecting in-situ measurements of dissolved nitrate concentrations in groundwater. Although several types of nitrate sensors currently exist, this verification test will focus on submersible sensors equipped with a nitrate-specific ion...

  2. In situ microcosms in aquifer bioremediation studies.

    PubMed

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  3. In situ electron spin resonance and Raman spectroscopic studies of the electrochemical process of conducting polypyrrole films

    SciTech Connect

    Zhong, C.J.; Tian, Z.Q.; Tian, Z.W. )

    1990-03-08

    The electrochemical redox properties of conducting polypyrrole (PPy) films coated on electrodes are investigated in aqueous solutions by use of the in situ techniques of electron spin resonance (ESR) and Raman spectroscopy. Comparisons between the experimental in situ ESR data and a theoretical kinetic prediction on the basis of the polaron-bipolaron model are presented.

  4. Verification of Java Programs using Symbolic Execution and Invariant Generation

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina; Visser, Willem

    2004-01-01

    Software verification is recognized as an important and difficult problem. We present a norel framework, based on symbolic execution, for the automated verification of software. The framework uses annotations in the form of method specifications an3 loop invariants. We present a novel iterative technique that uses invariant strengthening and approximation for discovering these loop invariants automatically. The technique handles different types of data (e.g. boolean and numeric constraints, dynamically allocated structures and arrays) and it allows for checking universally quantified formulas. Our framework is built on top of the Java PathFinder model checking toolset and it was used for the verification of several non-trivial Java programs.

  5. In-situ real time monitoring of the polymerization in gel-cast ceramic processes

    SciTech Connect

    Ahuja, S.; Dieckman, S.L.; Bostrom, G.A.; Waterfield, L.G.; Raptis, A.C.; Omatete, O.O.

    1996-08-01

    Gelcasting requires making a mixture of a slurry of ceramic powder in a solution of organic monomers and casting it in a mold. Gelcasting is different from injection molding in that it separates mold filling from setting during conversion of the ceramic slurry to a formed green part. In this work, NMR spectroscopy and imaging were used for in-situ monitoring of the gelation process and gelcasting of alumina. {sup 1}H NMR spectra and images are obtained during polymerization of a mixture of soluble reactive acrylamide monomers. Polymerization was initiated by adding an initiator and an accelerator to form long- chain, crosslinked polymers. Multidimensional NMR imaging was used for in-situ monitoring of the process and for verification of homogeneous polymerization. Comparison of the modeled intensities with acquired images shows a direction extraction of T{sub 1} data from the images.

  6. A computational model for viscous fluid flow, heat transfer, and melting in in situ vitrification melt pools

    SciTech Connect

    McHugh, P.R.; Ramshaw, J.D.

    1991-11-01

    MAGMA is a FORTRAN computer code designed to viscous flow in in situ vitrification melt pools. It models three-dimensional, incompressible, viscous flow and heat transfer. The momentum equation is coupled to the temperature field through the buoyancy force terms arising from the Boussinesq approximation. All fluid properties, except density, are assumed variable. Density is assumed constant except in the buoyancy force terms in the momentum equation. A simple melting model based on the enthalpy method allows the study of the melt front progression and latent heat effects. An indirect addressing scheme used in the numerical solution of the momentum equation voids unnecessary calculations in cells devoid of liquid. Two-dimensional calculations can be performed using either rectangular or cylindrical coordinates, while three-dimensional calculations use rectangular coordinates. All derivatives are approximated by finite differences. The incompressible Navier-Stokes equations are solved using a new fully implicit iterative technique, while the energy equation is differenced explicitly in time. Spatial derivatives are written in conservative form using a uniform, rectangular, staggered mesh based on the marker and cell placement of variables. Convective terms are differenced using a weighted average of centered and donor cell differencing to ensure numerical stability. Complete descriptions of MAGMA governing equations, numerics, code structure, and code verification are provided. 14 refs.

  7. Growth of HFC-143a (CH3CF3) determined from in-situ observation at AGAGE observatories.

    NASA Astrophysics Data System (ADS)

    O'Doherty, Simon

    2010-05-01

    High frequency, in-situ observation from the Advanced Global Atmospheric Gases Experiment (AGAGE) and System for the Observation of Greenhouse Gases in Europe (SOGE) networks for the period 2004 to 2008 have been used to capture the rapid growth of the HFC-143a (CH3CF3) in the atmosphere. These measurements indicate that the atmospheric accumulation has increased considerably since the only other reported measurements by Culbertson et al. (2004) indicated levels of 2ppt in 1997. The growth rate was 1.1 ppt/year (13%/yr) in 2008. The mole fraction in the lower troposphere in 2008 is estimated to be 8.5 ppt. The rapid increase is the effect of the phaseout of the HCFC compounds under the Montreal Protocol and the increased usage of HFC-143a in mixtures for commercial refrigeration as its main application. The extensive observations have been combined with a range of modelling techniques to derive global and regional emission estimates in a top down approach, which can be compared to bottom up estimates of emissions based on production and consumption data. This independent verification of emissions is vital in assessing the effectiveness of international treaties such as the Kyoto protocol.

  8. 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.

  9. Combining Remote Sensing with in situ Measurements for Riverine Characterization

    NASA Astrophysics Data System (ADS)

    Calantoni, J.; Palmsten, M. L.; Simeonov, J.; Dobson, D. W.; Zarske, K.; Puleo, J. A.; Holland, K. T.

    2014-12-01

    At the U.S. Naval Research Laboratory we are employing a wide variety of novel remote sensing techniques combined with traditional in situ sampling to characterize riverine hydrodynamics and morphodynamics. Surface currents were estimated from particle image velocimetry (PIV) using imagery from visible to infrared bands, from both fixed and airborne platforms. Terrestrial LIDAR has been used for subaerial mapping from a fixed platform. Additionally, LIDAR has been combined with hydrographic surveying (multibeam) in mobile scanning mode using a small boat. Hydrographic surveying (side scan) has also been performed using underwater autonomous vehicles. Surface drifters have been deployed in combination with a remotely operated, floating acoustic Doppler current profiler. Other fixed platform, in situ sensors, such as pencil beam and sector scanning sonars, acoustic Doppler velocimeters, and water level sensors have been deployed. We will present an overview of a variety of measurements from different rivers around the world focusing on validation examples of remotely sensed quantities with more traditional in situ measurements. Finally, we will discuss long-term goals to use remotely sensed data within an integrated environmental modeling framework.

  10. Automated in situ brain imaging for mapping the Drosophila connectome.

    PubMed

    Lin, Chi-Wen; Lin, Hsuan-Wen; Chiu, Mei-Tzu; Shih, Yung-Hsin; Wang, Ting-Yuan; Chang, Hsiu-Ming; Chiang, Ann-Shyn

    2015-01-01

    Mapping the connectome, a wiring diagram of the entire brain, requires large-scale imaging of numerous single neurons with diverse morphology. It is a formidable challenge to reassemble these neurons into a virtual brain and correlate their structural networks with neuronal activities, which are measured in different experiments to analyze the informational flow in the brain. Here, we report an in situ brain imaging technique called Fly Head Array Slice Tomography (FHAST), which permits the reconstruction of structural and functional data to generate an integrative connectome in Drosophila. Using FHAST, the head capsules of an array of flies can be opened with a single vibratome sectioning to expose the brains, replacing the painstaking and inconsistent brain dissection process. FHAST can reveal in situ brain neuroanatomy with minimal distortion to neuronal morphology and maintain intact neuronal connections to peripheral sensory organs. Most importantly, it enables the automated 3D imaging of 100 intact fly brains in each experiment. The established head model with in situ brain neuroanatomy allows functional data to be accurately registered and associated with 3D images of single neurons. These integrative data can then be shared, searched, visualized, and analyzed for understanding how brain-wide activities in different neurons within the same circuit function together to control complex behaviors.

  11. Mobile system for in-situ imaging of cultural objects

    NASA Astrophysics Data System (ADS)

    Zemlicka, J.; Jakubek, J.; Krejci, F.; Hradil, D.; Hradilova, J.; Mislerova, H.

    2012-01-01

    Non-invasive analytical techniques recently developed with the Timepix pixel detector have shown great potential for the inspection of objects of cultural heritage. We have developed new instrumentation and methodology for in-situ X-ray transmission radiography and X-ray fluorescence imaging and successfully tested and evaluated a mobile system for remote terrain tasks. The prototype portable imaging device comprises the radiation source tube and the spectral sensitive X-ray camera. Both components can be moreover mounted on independent motorized positioning systems allowing adaptation of irradiation geometry to the object shape. Both parts are placed onto a pair of universal portable holders (tripods). The detector is placed in a shielded box with exchangeable entrance window (beam filters and pinhole collimator). This adjustable setup allows performing in-situ measurements for both transmission and emission (XRF) radiography. The assembled system has been successfully tested in our laboratory with phantoms and real samples. The obtained and evaluated results are presented in this paper. Future work will include successive adaptation of the current system for real in-situ utilization and preparation of software allowing semi-automatic remote control of measurements.

  12. Complementary technologies for verification of excess plutonium

    SciTech Connect

    Langner, , D.G.; Nicholas, N.J.; Ensslin, N.; Fearey, B.L.; Mitchell, D.J.; Marlow, K.W.; Luke, S.J.; Gosnell, T.B.

    1998-12-31

    Three complementary measurement technologies have been identified as candidates for use in the verification of excess plutonium of weapons origin. These technologies: high-resolution gamma-ray spectroscopy, neutron multiplicity counting, and low-resolution gamma-ray spectroscopy, are mature, robust technologies. The high-resolution gamma-ray system, Pu-600, uses the 630--670 keV region of the emitted gamma-ray spectrum to determine the ratio of {sup 240}Pu to {sup 239}Pu. It is useful in verifying the presence of plutonium and the presence of weapons-grade plutonium. Neutron multiplicity counting is well suited for verifying that the plutonium is of a safeguardable quantity and is weapons-quality material, as opposed to residue or waste. In addition, multiplicity counting can independently verify the presence of plutonium by virtue of a measured neutron self-multiplication and can detect the presence of non-plutonium neutron sources. The low-resolution gamma-ray spectroscopic technique is a template method that can provide continuity of knowledge that an item that enters the a verification regime remains under the regime. In the initial verification of an item, multiple regions of the measured low-resolution spectrum form a unique, gamma-radiation-based template for the item that can be used for comparison in subsequent verifications. In this paper the authors discuss these technologies as they relate to the different attributes that could be used in a verification regime.

  13. Note: High-pressure in situ x-ray laminography using diamond anvil cell.

    PubMed

    Nomura, Ryuichi; Uesugi, Kentaro

    2016-04-01

    A high-pressure in situ X-ray laminography technique was developed using a newly designed, laterally open diamond anvil cell. A low X-ray beam of 8 keV energy was used, aiming at future application to dual energy X-ray chemical imaging techniques. The effects of the inclination angle and the imaging angle range were evaluated at ambient pressure using the apparatus. Sectional images of ruby ball samples were successfully reconstructed at high pressures, up to approximately 50 GPa. The high-pressure in situ X-ray laminography technique is expected to provide new insights into the deep Earth sciences. PMID:27131721

  14. Note: High-pressure in situ x-ray laminography using diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Nomura, Ryuichi; Uesugi, Kentaro

    2016-04-01

    A high-pressure in situ X-ray laminography technique was developed using a newly designed, laterally open diamond anvil cell. A low X-ray beam of 8 keV energy was used, aiming at future application to dual energy X-ray chemical imaging techniques. The effects of the inclination angle and the imaging angle range were evaluated at ambient pressure using the apparatus. Sectional images of ruby ball samples were successfully reconstructed at high pressures, up to approximately 50 GPa. The high-pressure in situ X-ray laminography technique is expected to provide new insights into the deep Earth sciences.

  15. Remedial activities effectiveness verification in tailing areas.

    PubMed

    Kluson, J; Thinova, L; Neznal, M; Svoboda, T

    2015-06-01

    The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement. Results were used for the analysis, design evaluation and verification of the efficiency of the remediation measures. Efficiency of the sludge basin covering by the inert material was modelled using MicroShield code.

  16. In situ characterization of polymer blend mixing

    NASA Astrophysics Data System (ADS)

    Fabian, Zoltan Thomas

    Currently there is great interest in the development of polymer blend morphology arising from processing to control the properties of blends. A non-destructive technique, non-radiative energy transfer (NRET), was utilized to investigate polymer blend mixing ex and in situ . Donor (naphthyl) labeled polymers and acceptor (anthryl) labeled polymers were segregated to either phase domain limiting NRET to the interphase, and therefore permitting superior spatial resolution than obtained by other techniques such as light scattering. Observed donor and acceptor fluorescence intensities were correlated to respective concentrations, sample geometry, and interphase volume using a fluorescence model derived from the Beer-Lambert Law and Forster's description of NRET between a single donor-acceptor chromophore pair. Particular attention was devoted to the phenomena of direct chromophore excitation, NRET, and radiative energy transfer. The model was used to interpret experiments on the two determinant attributes of polymer mixing: interphase thickness and interphase area. Relative interphase thickness comparisons via polymer interdiffusion in a miscible blend of donor-labeled polystyrene and acceptor-labeled polystyrene indicated increasing ratios of acceptor fluorescence to donor fluorescence resulting from (1) longer diffusion time and (2) higher temperatures. Interphase area effects in an immiscible donor-labeled poly(methyl methacrylate)/acceptor-labeled polystyrene blend revealed a linear relationship between interphase area and donor to acceptor fluorescence ratio. Further interphase area investigation revealed that as the ratio of interphase area to sample volume increases, the resulting donor to acceptor fluorescence ratio approaches that of a homogenous mixed sample of equivalent thickness and dye concentration. The observed fluorescence ratio response to mixing was utilized to interpret two commercial applications: interphase contact and random immiscible blend

  17. In Situ Vitrification Treatability Study Work Plan

    SciTech Connect

    Charboneau, B.L.; Landon, J.L.

    1989-03-01

    The Buried Waste Program was established in October, 1987 to accelerate the studies needed to develop a recommended long-term management plan for the buried mixed waste at the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The In Situ Vitrification Project is being conducted in a Comprehensive Environmental Response, Compensation, and Liability Act Feasibility Study format to identify methods for the long-term management of the mixed waste buried. This In Situ Vitrification Treatability Study Work Plan gives a brief description of the site, work breakdown structure, and project organization: the in situ vitrification technology; the purpose of the tests and demonstrations; and the equipment and materials required for the tests and demonstration. 5 refs., 6 figs., 3 tabs.

  18. In situ macromolecular crystallography using microbeams

    PubMed Central

    Axford, Danny; Owen, Robin L.; Aishima, Jun; Foadi, James; Morgan, Ann W.; Robinson, James I.; Nettleship, Joanne E.; Owens, Raymond J.; Moraes, Isabel; Fry, Elizabeth E.; Grimes, Jonathan M.; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S.; Stuart, David I.; Evans, Gwyndaf

    2012-01-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. PMID:22525757

  19. Current management of ductal carcinoma in situ.

    PubMed

    Barth, A; Brenner, R J; Giuliano, A E

    1995-10-01

    Ductal carcinoma in situ represents a biologically and histologically heterogeneous group of lesions characterized by the proliferation of neoplastic epithelial cells confined to the ducts of the breast. Before screening mammography, ductal carcinoma in situ was considered uncommon; patients were usually diagnosed by a breast mass or bloody nipple discharge, and their treatment was mastectomy. Today it represents 20% to 30% of mammographically detected breast cancers and 10% to 15% of all diagnosed breast cancers in the United States. The invariable progression of this cancer to invasive breast cancer requiring mastectomy has been challenged, but because most patients have been treated with mastectomy, knowledge about ductal carcinoma in situ is limited and primarily based on retrospective data. Further insight will emerge from randomized prospective studies that are near completion. Currently available data indicate that breast-conserving treatments are valid alternatives to mastectomy for most patients with this disease. PMID:7483593

  20. Scientific rationale for Saturn's in situ exploration

    NASA Astrophysics Data System (ADS)

    Mousis, O.; Fletcher, L. N.; Lebreton, J.-P.; Wurz, P.; Cavalié, T.; Coustenis, A.; Courtin, R.; Gautier, D.; Helled, R.; Irwin, P. G. J.; Morse, A. D.; Nettelmann, N.; Marty, B.; Rousselot, P.; Venot, O.; Atkinson, D. H.; Waite, J. H.; Reh, K. R.; Simon, A. A.; Atreya, S.; André, N.; Blanc, M.; Daglis, I. A.; Fischer, G.; Geppert, W. D.; Guillot, T.; Hedman, M. M.; Hueso, R.; Lellouch, E.; Lunine, J. I.; Murray, C. D.; O`Donoghue, J.; Rengel, M.; Sánchez-Lavega, A.; Schmider, F.-X.; Spiga, A.; Spilker, T.; Petit, J.-M.; Tiscareno, M. S.; Ali-Dib, M.; Altwegg, K.; Bolton, S. J.; Bouquet, A.; Briois, C.; Fouchet, T.; Guerlet, S.; Kostiuk, T.; Lebleu, D.; Moreno, R.; Orton, G. S.; Poncy, J.

    2014-12-01

    Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases' abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk elemental and isotopic composition would place important constraints on the volatile reservoirs in the protosolar nebula. We also show that the in situ measurement of CO (or any other disequilibrium species that is depleted by reaction with water) in Saturn's upper troposphere may help constraining its bulk O/H ratio. We compare predictions of Jupiter and Saturn's bulk compositions from different formation scenarios, and highlight the key measurements required to distinguish competing theories to shed light on giant planet formation as a common process in planetary systems with potential applications to most extrasolar systems. In situ measurements of Saturn's stratospheric and tropospheric dynamics, chemistry and cloud-forming processes will provide access to phenomena unreachable to remote sensing studies. Different mission architectures are envisaged, which would benefit from strong international collaborations, all based on an entry probe that would descend

  1. Nuclear disarmament verification

    SciTech Connect

    DeVolpi, A.

    1993-12-31

    Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification.

  2. Explaining Verification Conditions

    NASA Technical Reports Server (NTRS)

    Deney, Ewen; Fischer, Bernd

    2006-01-01

    The Hoare approach to program verification relies on the construction and discharge of verification conditions (VCs) but offers no support to trace, analyze, and understand the VCs themselves. We describe a systematic extension of the Hoare rules by labels so that the calculus itself can be used to build up explanations of the VCs. The labels are maintained through the different processing steps and rendered as natural language explanations. The explanations can easily be customized and can capture different aspects of the VCs; here, we focus on their structure and purpose. The approach is fully declarative and the generated explanations are based only on an analysis of the labels rather than directly on the logical meaning of the underlying VCs or their proofs. Keywords: program verification, Hoare calculus, traceability.

  3. Relational String Verification Using Multi-track Automata

    NASA Astrophysics Data System (ADS)

    Yu, Fang; Bultan, Tevfik; Ibarra, Oscar H.

    Verification of string manipulation operations is a crucial problem in computer security. In this paper, we present a new relational string verification technique based on multi-track automata. Our approach is capable of verifying properties that depend on relations among string variables. This enables us to prove that vulnerabilities that result from improper string manipulation do not exist in a given program. Our main contributions in this paper can be summarized as follows: (1) We formally characterize the string verification problem as the reachability analysis of string systems and show decidability/undecidability results for several string analysis problems. (2) We develop a sound symbolic analysis technique for string verification that over-approximates the reachable states of a given string system using multi-track automata and summarization. (3) We evaluate the presented techniques with respect to several string analysis benchmarks extracted from real web applications.

  4. Biotechnology for in situ restoration of ground water contaminated by the petroleum industry.

    PubMed

    Thomas, J M; Ward, C H

    1989-01-01

    As a result of increasing incidents of ground water contamination, several methods to restore polluted aquifers have been developed. These include 1) physical containment, 2) hydrodynamic controls, 3) withdrawal and treatment, 4) in situ physical and chemical treatment, and 5) in situ biological treatment. The fifth technology, in situ biological treatment (in situ biorestoration), is an innovative technique which involves the use of the indigenous subsurface microflora to degrade ground water pollutants. The most important factor in successful application of the process is the presence of metabolically appropriate microorganisms in a perfusable aquifer. As a result of the high levels of carbonaceous material contaminating the subsurface as petroleum waste, nutrients such as oxygen, phosphorus, and nitrogen are often limiting. Stimulation of the microflora is therefore achieved by perfusing the aquifer with the limiting nutrients; the nutrients must be transported to the zone of contamination to be effective. Aquifers with high clay contents and low permeabilities are not good candidates for in situ biorestoration systems nor other treatment strategies which involve plume management using well systems. In conclusion, in situ biorestoration is an innovative technique that can be used to remediate contaminated aquifers which are permeable and contain a metabolically active microflora; in contrast to other remedial methods, the contamination can be completely destroyed rather than transferred to another part of the environment.

  5. In Situ Transmission Electron Microscopy And Spectroscopy Studies Of Rechargeable Batteries Under Dynamic Operating Conditions: A Retrospective And Perspective View

    SciTech Connect

    Wang, Chong M.

    2015-02-14

    Since the advent of the transmission electron microscope (TEM), continuing efforts have been made to image material under native and reaction environments that typically involve liquids, gases, and external stimuli. With the advances of aberration-corrected TEM for improving the imaging resolution, steady progress has been made on developing methodologies that allow imaging under dynamic operating conditions, or in situ TEM imaging. The success of in situ TEM imaging is closely associated with advances in microfabrication techniques that enable manipulation of nanoscale objects around the objective lens of the TEM. This paper summarizes and highlights recent progress involving in situ TEM studies of energy storage materials, especially rechargeable batteries. The paper is organized to cover both the in situ TEM techniques and the scientific discoveries made possible by in situ TEM imaging.

  6. An in situ method for diagnosing phase shifting interferometry

    NASA Astrophysics Data System (ADS)

    Shao, J.; Ma, D.; Zhang, H.; Xie, Y.

    2016-05-01

    Current diagnosing phase shifting interferometry is a time and funds consuming process. Hence a brief and effective method is necessary to satisfy the real-time testing. In this paper, mathematical solutions for errors were deduced from the difference of intensity patterns. Based on the diversity of error distributions, an effective method for distinguishing and diagnosing the error sources is proposed and verified by an elaborative designed simulation. In the actual comparison experiment, vibration, phase-shift error and intensity fluctuation were imposed to demonstrate this method. The results showed that this method can be applied into the real-time measurement and provide an in situ diagnosing technique.

  7. In situ NMR analysis of fluids contained in sedimentary rock

    PubMed

    de Swiet TM; Tomaselli; Hurlimann; Pines

    1998-08-01

    Limitations of resolution and absorption in standard chemical spectroscopic techniques have made it difficult to study fluids in sedimentary rocks. In this paper, we show that a chemical characterization of pore fluids may be obtained in situ by magic angle spinning (MAS) nuclear magnetic resonance (NMR), which is normally used for solid samples. 1H MAS-NMR spectra of water and crude oil in Berea sandstone show sufficient chemical shift resolution for a straightforward determination of the oil/water ratio. Copyright 1998 Academic Press.

  8. In-situ deposition of hydroxyapatite on graphene nanosheets

    PubMed Central

    Neelgund, Gururaj M.; Oki, Aderemi; Luo, Zhiping

    2014-01-01

    Graphene nanosheets were effectively functionalized by in-situ deposition of hydroxyaptite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure. PMID:25110359

  9. In-situ corrosion sensor for coating, testing and screening

    SciTech Connect

    Davis, G.D.; Dacres, C.M.; Krebs, L.A.

    2000-02-01

    An in-situ corrosion censor facilitates coating development and screening by detecting the early stages of corrosion well before degradation is visible. Based on electrochemical impedance spectroscopy (EIS), the sensor extends the use of this established laboratory technique from immersion only to different accelerated test conditions (such as salt fog or humidity) and ambient service environments. By enabling a direct quantitative comparison of the early stages of coating deterioration and substrate corrosion that occur in laboratory accelerated tests and service or field conditions, the laboratory tests can be validated and coatings screened more quickly.

  10. Alkaline fixation drastically improves the signal of in situ hybridization

    PubMed Central

    Basyuk, Eugenia; Bertrand, Edouard; Journot, Laurent

    2000-01-01

    In situ hybridization (ISH) is widely used to detect DNA and RNA sequences within the cell and tissue sections. The important step in performing this technique is tissue fixation. We investigated the influence of the pH of the fixative on the outcome of ISH. Our studies indicate that alkaline formaldehyde dramatically increases the ISH signal with RNA probes. The increase in signal was observed for detection of low as well as for high abundance messages. The sensitivity of the method was increased 5- to 6-fold. PMID:10773094

  11. In-situ scanning transmission X-ray microscopy of catalytic solids and related nanomaterials.

    PubMed

    de Groot, Frank M F; de Smit, Emiel; van Schooneveld, Matti M; Aramburo, Luis R; Weckhuysen, Bert M

    2010-04-01

    The present status of in-situ scanning transmission X-ray microscopy (STXM) is reviewed, with an emphasis on the abilities of the STXM technique in comparison with electron microscopy. The experimental aspects and interpretation of X-ray absorption spectroscopy (XAS) are briefly introduced and the experimental boundary conditions that determine the potential applications for in-situ XAS and in-situ STXM studies are discussed. Nanoscale chemical imaging of catalysts under working conditions is outlined using cobalt and iron Fischer-Tropsch catalysts as showcases. In the discussion, we critically compare STXM-XAS and STEM-EELS (scanning transmission electron microscopy-electron energy loss spectroscopy) measurements and indicate some future directions of in-situ nanoscale imaging of catalytic solids and related nanomaterials.

  12. Recent developments of the in situ wet cell technology for transmission electron microscopies.

    PubMed

    Chen, Xin; Li, Chang; Cao, Hongling

    2015-03-21

    In situ wet cells for transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) allow studying structures and processes in a liquid environment with high temporal and spatial resolutions, and have been attracting increasing research interests in many fields. In this review, we highlight the structural and functional developments of the wet cells for TEM and STEM. One of the key features of the wet cells is the sealing technique used to isolate the liquid sample from the TEM/STEM vacuum environments, thus the existing in situ wet cells are grouped by different sealing methods. In this study, the advantages and shortcomings of each type of in situ wet cells are discussed, the functional developments of different wet cells are presented, and the future trends of the wet cell technology are addressed. It is suggested that in the future the in situ wet cell TEM/STEM technology will have an increasing impact on frontier nanoscale research.

  13. Kinematic analysis of in situ measurement during chemical mechanical planarization process.

    PubMed

    Li, Hongkai; Wang, Tongqing; Zhao, Qian; Meng, Yonggang; Lu, Xinchun

    2015-10-01

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system.

  14. Recent developments of the in situ wet cell technology for transmission electron microscopies

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Li, Chang; Cao, Hongling

    2015-03-01

    In situ wet cells for transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) allow studying structures and processes in a liquid environment with high temporal and spatial resolutions, and have been attracting increasing research interests in many fields. In this review, we highlight the structural and functional developments of the wet cells for TEM and STEM. One of the key features of the wet cells is the sealing technique used to isolate the liquid sample from the TEM/STEM vacuum environments, thus the existing in situ wet cells are grouped by different sealing methods. In this study, the advantages and shortcomings of each type of in situ wet cells are discussed, the functional developments of different wet cells are presented, and the future trends of the wet cell technology are addressed. It is suggested that in the future the in situ wet cell TEM/STEM technology will have an increasing impact on frontier nanoscale research.

  15. Kinematic analysis of in situ measurement during chemical mechanical planarization process

    SciTech Connect

    Li, Hongkai; Wang, Tongqing; Zhao, Qian; Meng, Yonggang; Lu, Xinchun

    2015-10-15

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system.

  16. Performance of in situ soil venting system at jet fuel spill site

    SciTech Connect

    DePaoli, D.W.; Herbes, S.E.; Elliott, M.G.

    1989-01-01

    The Air Force Engineering and Services Center and Oak Ridge National Laboratory (ORNL) are performing a field demonstration of in situ venting at a 27,000-gal jet fuel spill site at Hill Air Force Base (AFB), Utah. In situ soil venting is a soil cleanup techniques that uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminant and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper briefly describes the jet fuel spill site and the design and results to date of our full-scale in situ soil venting system. 8 refs., 9 figs.

  17. In-situ vitrification of waste materials

    DOEpatents

    Powell, J.R.; Reich, M.; Barletta, R.

    1997-10-14

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed. 7 figs.

  18. In situ spectroradiometric quantification of ERTS data

    NASA Technical Reports Server (NTRS)

    Yost, E.

    1973-01-01

    The task of correlating in situ spectral reflectance measurements with ERTS imagery has commenced. A method of additive color analysis of a single multispectral band taken on different dates indicates that ERTS-1 bulk images have sufficient spatial and spectral fidelity to show indications of the presence of soil moisture in desert playas and changes in soil moisture with time. The chain of causality between soil moisture, in situ spectral reflectance, and ERTS multispectral scanner image density remains to be established during the subsequent phases of this study.

  19. In situ hybridization of termite microbes.

    PubMed

    Moriya, Shigeharu; Noda, Satoko; Ohkuma, Moriya; Kudo, Toshiaki

    2007-01-01

    In situ hybridization is one of the most direct and reliable ways to ascertain the origin of the gene from complex mixed cellular systems. This method is essential for studying communities of uncultured microorganism in their natural ecosystem. In this chapter, we introduce our protocols for the in situ hybridization of the messenger RNA of uncultured symbiotic protists of termite hindgut and the ribosomal RNA of the symbiotic bacteria of the protists using nonradioactive labeling protocols. We hope that you will find these protocols useful in your own work to unravel the complex functions and to discover new organisms in the ecosystem.

  20. In-situ vitrification of waste materials

    DOEpatents

    Powell, James R.; Reich, Morris; Barletta, Robert

    1997-11-14

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

  1. Verification and validation benchmarks.

    SciTech Connect

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  2. Verification of Ceramic Structures

    NASA Astrophysics Data System (ADS)

    Behar-Lafenetre, Stephanie; Cornillon, Laurence; Rancurel, Michael; De Graaf, Dennis; Hartmann, Peter; Coe, Graham; Laine, Benoit

    2012-07-01

    In the framework of the “Mechanical Design and Verification Methodologies for Ceramic Structures” contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and instrument structures. It has been written in order to be applicable to most types of ceramic or glass-ceramic materials - typically Cesic®, HBCesic®, Silicon Nitride, Silicon Carbide and ZERODUR®. The proposed guideline describes the activities to be performed at material level in order to cover all the specific aspects of ceramics (Weibull distribution, brittle behaviour, sub-critical crack growth). Elementary tests and their post-processing methods are described, and recommendations for optimization of the test plan are given in order to have a consistent database. The application of this method is shown on an example in a dedicated article [7]. Then the verification activities to be performed at system level are described. This includes classical verification activities based on relevant standard (ECSS Verification [4]), plus specific analytical, testing and inspection features. The analysis methodology takes into account the specific behaviour of ceramic materials, especially the statistical distribution of failures (Weibull) and the method to transfer it from elementary data to a full-scale structure. The demonstration of the efficiency of this method is described in a dedicated article [8]. The verification is completed by classical full-scale testing activities. Indications about proof testing, case of use and implementation are given and specific inspection and protection measures are described. These additional activities are necessary to ensure the required reliability. The aim of the guideline is to describe how to reach the same reliability level as for structures made of more classical materials (metals, composites).

  3. In situ metabolomic mass spectrometry imaging: recent advances and difficulties.

    PubMed

    Miura, Daisuke; Fujimura, Yoshinori; Wariishi, Hiroyuki

    2012-08-30

    MS imaging (MSI) is a remarkable new technology that enables us to determine the distribution of biological molecules present in tissue sections by direct ionization and detection. This technique is now widely used for in situ imaging of endogenous or exogenous molecules such as proteins, lipids, drugs and their metabolites, and it is a potential tool for pathological analysis and the investigation of disease mechanisms. MSI is also thought to be a technique that could be used for biomarker discovery with spatial information. The application of MSI to the study of endogenous metabolites has received considerable attention because metabolites are the result of the interactions of a system's genome with its environment and a total set of these metabolites more closely represents the phenotype of an organism under a given set of conditions. Recent studies have suggested the importance of in situ metabolite imaging in biological discovery and biomedical applications, but several issues regarding the technical application limits of MSI still remained to be resolved. In this review, we describe the capabilities of the latest MSI techniques for the imaging of endogenous metabolites in biological samples, and also discuss the technical problems and new challenges that need to be addressed for effective and widespread application of MSI in both preclinical and clinical settings.

  4. Requirement Assurance: A Verification Process

    NASA Technical Reports Server (NTRS)

    Alexander, Michael G.

    2011-01-01

    Requirement Assurance is an act of requirement verification which assures the stakeholder or customer that a product requirement has produced its "as realized product" and has been verified with conclusive evidence. Product requirement verification answers the question, "did the product meet the stated specification, performance, or design documentation?". In order to ensure the system was built correctly, the practicing system engineer must verify each product requirement using verification methods of inspection, analysis, demonstration, or test. The products of these methods are the "verification artifacts" or "closure artifacts" which are the objective evidence needed to prove the product requirements meet the verification success criteria. Institutional direction is given to the System Engineer in NPR 7123.1A NASA Systems Engineering Processes and Requirements with regards to the requirement verification process. In response, the verification methodology offered in this report meets both the institutional process and requirement verification best practices.

  5. Verification of Autonomous Systems for Space Applications

    NASA Technical Reports Server (NTRS)

    Brat, G.; Denney, E.; Giannakopoulou, D.; Frank, J.; Jonsson, A.

    2006-01-01

    Autonomous software, especially if it is based on model, can play an important role in future space applications. For example, it can help streamline ground operations, or, assist in autonomous rendezvous and docking operations, or even, help recover from problems (e.g., planners can be used to explore the space of recovery actions for a power subsystem and implement a solution without (or with minimal) human intervention). In general, the exploration capabilities of model-based systems give them great flexibility. Unfortunately, it also makes them unpredictable to our human eyes, both in terms of their execution and their verification. The traditional verification techniques are inadequate for these systems since they are mostly based on testing, which implies a very limited exploration of their behavioral space. In our work, we explore how advanced V&V techniques, such as static analysis, model checking, and compositional verification, can be used to gain trust in model-based systems. We also describe how synthesis can be used in the context of system reconfiguration and in the context of verification.

  6. Simulating realistic imaging conditions for in situ liquid microscopy

    SciTech Connect

    Welch, David A.; Faller, Roland; Evans, James E.; Browning, Nigel D.

    2013-12-01

    In situ transmission electron microscopy enables the imaging of biological cells, macromolecular protein complexes, nanoparticles, and other systems in a near-native environment. In order to improve interpretation of image contrast features and also predict ideal imaging conditions ahead of time, new virtual electron microscopic techniques are needed. A technique for virtual fluid-stage high-angle annular dark-field scanning transmission electron microscopy with the multislice method is presented that enables the virtual imaging of model fluid-stage systems composed of millions of atoms. The virtual technique is exemplified by simulating images of PbS nanoparticles under different imaging conditions and the results agree with previous experimental findings. General insight is obtained on the influence of the effects of fluid path length, membrane thickness, nanoparticle position, defocus and other microscope parameters on attainable image quality.

  7. Runtime Verification with State Estimation

    NASA Technical Reports Server (NTRS)

    Stoller, Scott D.; Bartocci, Ezio; Seyster, Justin; Grosu, Radu; Havelund, Klaus; Smolka, Scott A.; Zadok, Erez

    2011-01-01

    We introduce the concept of Runtime Verification with State Estimation and show how this concept can be applied to estimate theprobability that a temporal property is satisfied by a run of a program when monitoring overhead is reduced by sampling. In such situations, there may be gaps in the observed program executions, thus making accurate estimation challenging. To deal with the effects of sampling on runtime verification, we view event sequences as observation sequences of a Hidden Markov Model (HMM), use an HMM model of the monitored program to "fill in" sampling-induced gaps in observation sequences, and extend the classic forward algorithm for HMM state estimation (which determines the probability of a state sequence, given an observation sequence) to compute the probability that the property is satisfied by an execution of the program. To validate our approach, we present a case study based on the mission software for a Mars rover. The results of our case study demonstrate high prediction accuracy for the probabilities computed by our algorithm. They also show that our technique is much more accurate than simply evaluating the temporal property on the given observation sequences, ignoring the gaps.

  8. Experimental verification of an innovative debris detector

    NASA Astrophysics Data System (ADS)

    Bauer, Waldemar; Romberg, Oliver; Putzar, Robin

    2015-12-01

    To analyse the quantity of space debris and micrometeoroids in space, an innovative in-situ impact detection method has been developed at DLR (German Aerospace Center) in Bremen, Germany. The method Solar generator based Impact Detector "SOLID" uses solar panels for impact detection. Since solar panels provide large detection areas, this method allows for the collection of large amounts of data, to be used also for model validation. Furthermore, impact damage can be verified once more to confirm or to refute an impact. Both aspects can significantly improve the quality of model validation by using large amounts of highly reliable data. A verification of the detection method was performed by Hypervelocity Impact (HVI) tests at Fraunhofer EMI, Freiburg, Germany. The HVI tests were conducted using projectiles with a diameter between 500 μm and 2 mm. The impact velocity of those objects ranged from 3.9 km/s to 6.2 km/s. The objective of this investigation was to test the applicability of the developed method concerning in-situ detection of space debris and micrometeoroids. The achieved test results are in agreement with ESA developed damage equations. The ability of the detection method SOLID for impact detection of space debris and micrometeoroids was clearly demonstrated.

  9. ENGINEERING BULLETIN: IN SITU SOIL FLUSHING

    EPA Science Inventory

    In situ soil flushing is the extraction of contaminants from the soil with water or other suitable aqueous solutions. Soil flushing is accomplished by passing the extraction fluid through in-place soils using an injection or infiltration process. Extraction fluids must be recover...

  10. DEMONSTRATION BULLETIN: IN SITU VITRIFICATION - GEOSAFE CORPORATION

    EPA Science Inventory

    in Situ Vitrification (ISV) is designed to treat soils, sludges, sediments, and mine tailings contaminated with organic and inorganic compounds. The process uses electrical current to heat (mett) and vitrify the soil in place. Organic contaminants are decomposed by the extreme h...

  11. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  12. IN SITU LEAD IMMOBILIZATION BY APATITE

    EPA Science Inventory

    Lead contamination is of environmental concern due to its effect on human health. The purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. Hydroxyapatite [Ca10(PO4)6(O...

  13. In-situ denitrification of ponds

    SciTech Connect

    Napier, J.M.

    1984-11-01

    An in-situ biological denitrification process successfully reduced nitrate ion concentrations in four 2.5 million gallon open-air holding ponds from nearly 40,000 mg/L to less than 50 mg/L. Concurrently, heavy metal concentrations were reduced to levels acceptable for discharge. 3 figures.

  14. ENGINEERING BULLETIN: IN SITU VITRIFICATION TREATMENT

    EPA Science Inventory

    In situ vitrification (ISV) uses electrical power to heat and melt soil, sludge, mine tailings, buried wastes, and sediments contaminated with organic, inorganic, and metal-bearing hazardous wastes. The molten material cools to form a hard, monolithic, chemically inert, stable...

  15. Fabrication Capabilities Utilizing In Situ Materials

    NASA Technical Reports Server (NTRS)

    McLemore, Carole A.; Fikes, John C.; Darby, Charles A.; Good, James E.; Gilley, Scott D.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has a Space Exploration Policy that lays out a plan that far exceeds the earlier Apollo goals where landing on the moon and taking those first historic steps fulfilled the mission. The policy states that we will set roots on the moon by establishing an outpost. This outpost will be used as a test bed for residing in more distant locales, such as Mars. In order to become self-sufficient, the occupants must have the capability to fabricate component parts in situ. Additionally, in situ materials must be used to minimize valuable mission upmass and to be as efficient as possible. In situ materials can be found from various sources such as raw lunar regolith whereby specific constituents can be extracted from the regolith (such as aluminum, titanium, or iron), and existing hardware already residing on the moon from past Apollo missions. The Electron Beam Melting (EBM) process lends itself well to fabricating parts, tools, and other necessary items using in situ materials and will be discussed further in this paper.

  16. Parallel In Situ Indexing for Data-intensive Computing

    SciTech Connect

    Kim, Jinoh; Abbasi, Hasan; Chacon, Luis; Docan, Ciprian; Klasky, Scott; Liu, Qing; Podhorszki, Norbert; Shoshani, Arie; Wu, Kesheng

    2011-09-09

    As computing power increases exponentially, vast amount of data is created by many scientific re- search activities. However, the bandwidth for storing the data to disks and reading the data from disks has been improving at a much slower pace. These two trends produce an ever-widening data access gap. Our work brings together two distinct technologies to address this data access issue: indexing and in situ processing. From decades of database research literature, we know that indexing is an effective way to address the data access issue, particularly for accessing relatively small fraction of data records. As data sets increase in sizes, more and more analysts need to use selective data access, which makes indexing an even more important for improving data access. The challenge is that most implementations of in- dexing technology are embedded in large database management systems (DBMS), but most scientific datasets are not managed by any DBMS. In this work, we choose to include indexes with the scientific data instead of requiring the data to be loaded into a DBMS. We use compressed bitmap indexes from the FastBit software which are known to be highly effective for query-intensive workloads common to scientific data analysis. To use the indexes, we need to build them first. The index building procedure needs to access the whole data set and may also require a significant amount of compute time. In this work, we adapt the in situ processing technology to generate the indexes, thus removing the need of read- ing data from disks and to build indexes in parallel. The in situ data processing system used is ADIOS, a middleware for high-performance I/O. Our experimental results show that the indexes can improve the data access time up to 200 times depending on the fraction of data selected, and using in situ data processing system can effectively reduce the time needed to create the indexes, up to 10 times with our in situ technique when using identical parallel settings.

  17. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

  18. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering. PMID:25090251

  19. ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM

    EPA Science Inventory

    This presentation will be given at the EPA Science Forum 2005 in Washington, DC. The Environmental Technology Verification Program (ETV) was initiated in 1995 to speed implementation of new and innovative commercial-ready environemntal technologies by providing objective, 3rd pa...

  20. FPGA Verification Accelerator (FVAX)

    NASA Technical Reports Server (NTRS)

    Oh, Jane; Burke, Gary

    2008-01-01

    Is Verification Acceleration Possible? - Increasing the visibility of the internal nodes of the FPGA results in much faster debug time - Forcing internal signals directly allows a problem condition to be setup very quickly center dot Is this all? - No, this is part of a comprehensive effort to improve the JPL FPGA design and V&V process.