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Sample records for nondestructive technique survey

  1. Nondestructive Technique Survey for Assessing Integrity of Composite Firing Vessel

    SciTech Connect

    Tran, A.

    2000-08-01

    The repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.

  2. Nondestructive testing techniques

    NASA Astrophysics Data System (ADS)

    Bray, Don E.; McBride, Don

    A comprehensive reference covering a broad range of techniques in nondestructive testing is presented. Based on years of extensive research and application at NASA and other government research facilities, the book provides practical guidelines for selecting the appropriate testing methods and equipment. Topics discussed include visual inspection, penetrant and chemical testing, nuclear radiation, sonic and ultrasonic, thermal and microwave, magnetic and electromagnetic techniques, and training and human factors. (No individual items are abstracted in this volume)

  3. Nondestructive evaluation technique guide

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    A total of 70 individual nondestructive evaluation (NDE) techniques are described. Information is presented that permits ease of comparison of the merits and limitations of each technique with respect to various NDE problems. An NDE technique classification system is presented. It is based on the system that was adopted by the National Materials Advisory Board (NMAB). The classification system presented follows the NMAB system closely with the exception of additional categories that have been added to cover more advanced techniques presently in use. The rationale of the technique is explained. The format provides for a concise description of each technique, the physical principles involved, objectives of interrogation, example applications, limitations of each technique, a schematic illustration, and key reference material. Cross-index tabulations are also provided so that particular NDE problems can be referred to appropriate techniques.

  4. Application of nondestructive assay techniques in Kazakstan

    SciTech Connect

    Sprinkle, J.K. Jr.; Butler, G.; Collins, M.

    1997-11-01

    As Kazakstan has transitioned from being part of the Soviet Union to a nonweapons state (Treaty of Nonproliferation of Nuclear Weapons [NPT] signatory) under International Atomic Energy Agency (IAEA) inspections, significant changes have been required. Some of these changes have occurred in nuclear material protection, control, and accounting at the four nuclear facility sites in the Republic of Kazakstan. Specifically, the Republic of Kazakstan has changed from relying primarily on a subset of physical protection methods to a graded safeguards approach using a balance of material control, material accounting, and physical protection. Once more intensive material control and accounting procedures and systems are in place, a necessary step is to supply the accounting systems with measured values of high quality. This need can be met with destructive and nondestructive methods. Material control systems can also use qualitative nondestructive assay information as input. This paper will discuss the nondestructive assay techniques and systems the US Department of Energy (DOE) is providing to Kazakstan under both DOE programs and the Cooperative Threat Reduction Act as part of the nuclear material control and accounting upgrades at four facilities in Kazakstan. 4 refs., 6 figs.

  5. Nondestructive Technique To Assess Embrittlement In Steels

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Yost, William T.; Cantrell, John H.

    1990-01-01

    Recent research at NASA Langley Research Center led to identification of nondestructive technique for detection of temper embrittlement in HY80 steel. Measures magnetoacoustic emission associated with reversible motion of domain walls at low magnetic fields. Of interest to engineers responsible for reliability and safety of various dynamically loaded and/or thermally cycled steel parts. Applications include testing of landing gears, naval vessels, and parts subjected to heat, such as those found in steam-pipe fittings, boilers, turbine rotors, and nuclear pressure vessels.

  6. Nondestructive evaluation techniques for enhanced bridge inspection

    SciTech Connect

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  7. Techniques for enhancing laser ultrasonic nondestructive evaluation

    SciTech Connect

    Candy, J; Chinn, D; Huber, R; Spicer, J; Thomas, G

    1999-02-16

    Ultrasonic nondestructive evaluation is an extremely powerful tool for characterizing materials and detecting defects. A majority of the ultrasonic nondestructive evaluation is performed with piezoelectric transducers that generate and detect high frequency acoustic energy. The liquid needed to couple the high frequency acoustic energy from the piezoelectric transducers restricts the applicability of ultrasonics. For example, traditional ultrasonics cannot evaluate parts at elevated temperatures or components that would be damaged by contact with a fluid. They are developing a technology that remotely generates and detects the ultrasonic pulses with lasers and consequently there is no requirement for liquids. Thus the research in laser-based ultrasound allows them to solve inspection problems with ultrasonics that could not be done before. This technology has wide application in many Lawrence Livermore National Laboratory programs, especially when remote and/or non-contact sensing is necessary.

  8. Complex Archaeological Prospection Using Combination of Non-destructive Techniques

    NASA Astrophysics Data System (ADS)

    Faltýnová, M.; Pavelka, K.; Nový, P.; Šedina, J.

    2015-08-01

    This article describes the use of a combination of non-destructive techniques for the complex documentation of a fabulous historical site called Devil's Furrow, an unusual linear formation lying in the landscape of central Bohemia. In spite of many efforts towards interpretation of the formation, its original form and purpose have not yet been explained in a satisfactory manner. The study focuses on the northern part of the furrow which appears to be a dissimilar element within the scope of the whole Devil's Furrow. This article presents detailed description of relics of the formation based on historical map searches and modern investigation methods including airborne laser scanning, aerial photogrammetry (based on airplane and RPAS) and ground-penetrating radar. Airborne laser scanning data and aerial orthoimages acquired by the Czech Office for Surveying, Mapping and Cadastre were used. Other measurements were conducted by our laboratory. Data acquired by various methods provide sufficient information to determine the probable original shape of the formation and proves explicitly the anthropological origin of the northern part of the formation (around village Lipany).

  9. Non-Destructive Techniques Based on Eddy Current Testing

    PubMed Central

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  10. Non-destructive techniques based on eddy current testing.

    PubMed

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  11. Fault determinations in electroexplosive devices by nondestructive techniques

    NASA Technical Reports Server (NTRS)

    Menichelli, V. J.; Rosenthal, L. A.

    1972-01-01

    Several nondestructive test techniques were developed for electroexplosive devices. The bridgewire responds, when pulsed with a safe level current, by generating a characteristic heating curve. The response is indicative of the electrothermal behavior of the bridgewire-explosive interface. Bridgewires which deviate from the characteristic heating curve were dissected and examined to determine the cause of the abnormality. Deliberate faults were fabricated into squibs. The relationship of the specific abnormality and the fault associated with it is demonstrated.

  12. Potential techniques for non-destructive evaluation of cable materials

    NASA Astrophysics Data System (ADS)

    Gillen, Kenneth T.; Clough, Roger L.; Mattson, Bengt; Stenberg, Bengt; Oestman, Erik

    This paper describes the connection between mechanical degradation of common cable materials, in radiation and elevated temperature environments, and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

  13. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  14. Determining plutonium in spent fuel with nondestructive assay techniques

    SciTech Connect

    Tobin, Stephen J; Charlton, William S; Fensin, Michael L; Menlove, Howard O; Hoover, A S; Quiter, B J; Rajasingam, A; Swinhoe, M T; Thompson, S J; Charlton, W S; Ehinger, M H; Sandoval, N P; Saavedra, S F; Strohmeyer, D

    2009-01-01

    There are a variety of motivations for quantifying plutonium in used (spent) fuel assemblies by means of nondestructive assay including the following: shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories or fuel storage facilities. Twelve NDA techniques were identified that provide information about the composition of an assembly. Unfortunately, none of these techniques is capable of determining the Pu mass in an assembly on its own. However, it is expected that the Pu mass can be quantified by combining a few of the techniques. Determining which techniques to combine and estimating the expected performance of such a system is the purpose of the research effort recently begun. The research presented here is a complimentarily experimental effort. This paper will focus on experimental results of one of the twelve non-destructive assay techniques - passive neutron albedo reactivity. The passive neutron albedo reactivity techniques work by changing the multiplication the pin experiences between two separate measurements. Since a single spent fuel pin has very little multiplication, this is a challenging measurement situation for the technique. Singles and Doubles neutron count rate were measured at Oak Ridge National Laboratory for three different burnup pins to test the capability of the passive neutron albedo reactivity technique.

  15. Development of Nondestructive Measuring Technique of Environmental Radioactive Strontium

    NASA Astrophysics Data System (ADS)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Yoshida, Tatsuru; Murata, Jiro

    The Fukushima first nuclear power plant accident was triggered by the Japanese big earthquake in 2011. The main radioactivity concerned after the accident are I-131 (half-life 8.0 days), Cs-134 (2.1 years) and 137 (30 years), Sr-89 (51 days) and 90 (29 years). We are aiming to establish a new detection technique which enables us to realize quantitative evaluation of the strontium radioactivity by means of nondestructive measurement without chemical separation processing, which is concerned to be included inside foods, environmental water and soil around us, in order to prevent us from undesired internal exposure to the radiation.

  16. Electro-thermography technique for nondestructive testing (NDT) applications

    NASA Astrophysics Data System (ADS)

    Chen, Y. S.; Hung, Y. Y.; Liu, L.

    2008-11-01

    In this paper, Electro-Thermography is introduced in nondestructive testing applications. Electro-Thermography is one of the novel active thermography techniques for nondestructive testing. It gains the advantages from the optical and electromagnetic properties in full-field, non-contact, high inspection speed, and sensitivity in geometry variation. It is mostly applicable to all kind of ferrous-metal, some composites materials. A fundamental difference among electro-thermography and other active thermography techniques are the excitation mechanism. Electro-Thermography is a combination of the electromagnetic induction and surface thermal radiation measuring technique; it used the induction method to excite the object, and then it used the radiation properties to measure the distribution of surface temperature of the object. It detects flaws by the flaw's anomalous heating and heat transfer response. The method of excitation is also different from others irradiation excitation. Electro-Thermography needs an electromagnetic coil to generate eddy current through induction to change the surface and subsurface temperature. Electro-Thermography can detect surface and sub-surface flaws, unless the flaw is too remote and tiny from the surface. Some experiments in flaw detections and other types of inspections are demonstrated.

  17. Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

    SciTech Connect

    Clayton, Dwight A; Barker, Alan M; Santos-Villalobos, Hector J; Albright, Austin P; Hoegh, Kyle; Khazanovich, Lev

    2015-09-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [1]. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.

  18. Study of Beamforming Techniques for Ultrasound Imaging in Nondestructive Testing.

    NASA Astrophysics Data System (ADS)

    Ghorayeb, Sleiman Riad

    Many of the innovations in modern materials testing technology make use of ultrasound. Therefore, the theory and application of ultrasound have become of extreme importance in nondestructive inspection of complete engineered systems. However, despite the fact that most of these ultrasound inspection techniques are based on well-established phenomena, two key problems pertaining to their application still remain unresolved. These problems can be identified as (1) the material being tested is assumed to be isotropic and homogeneous by nature, and (2) the scanning/data collection process, prior to the reconstruction scheme, is very time consuming. As a result, techniques for fast, accurate testing of anisotropic and nonhomogeneous media have been the focus of attention in modern non-destructive testing research. This dissertation first describes the development and implementation of a time domain synthetic aperture focusing technique (SAFT) to reconstruct flaws imbedded within Plexiglass^{rm TM/ } and Graphite/Epoxy samples. A modification to the present SAFT algorithm is then proposed in order to improve the quality of the images produced by SAFT when applied to composites. In addition, since the finite element method (FEM) can be used to solve hyperbolic partial differential equations, which govern wave propagation, FEM solutions are used to mimic a SAFT measurement. That is, the FEM is used to simulate the action of a transducer array. This is done to study the sensitivity of parameters involved in the SAFT algorithm. Using the same FEM model as a test bed, the data independent beamformer, in its basic form, is studied to determine its performance in reducing data acquisition time. It is seen that this technique is capable of adjusting the weights of the interpolating filter (beamformer) to predict an incoming signal from a desired direction while discriminating against other signals from different directions. SAFT results indicate that the FEM model can be used as

  19. Theory and experimental technique for nondestructive evaluation of ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    The important ultrasonic scattering mechanisms for SiC and Si3N4 ceramic composites were identified by examining the interaction of ultrasound with individual fibers, pores, and grains. The dominant scattering mechanisms were identified as asymmetric refractive scattering due to porosity gradients in the matrix material, and symmetric diffractive scattering at the fiber-to-matrix interface and at individual pores. The effect of the ultrasonic reflection coefficient and surface roughness in the ultrasonic evaluation was highlighted. A new nonintrusive ultrasonic evaluation technique, angular power spectrum scanning (APSS), was presented that is sensitive to microstructural variations in composites. Preliminary results indicate that APSS will yield information on the composite microstructure that is not available by any other nondestructive technique.

  20. Non-destructive evaluation of anchorage zones by ultrasonics techniques.

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

    This work aims to evaluate the efficiency and reliability of two Non-Destructive Testing (NDT) methods for damage assessment in bridges' anchorages. The Acousto-Ultrasonic (AU) technique is compared to classical Ultrasonic Testing (UT) in terms of defect detection and structural health classification. The AU technique is firstly used on single seven-wire strands damaged by artificial defects. The effect of growing defects on the waves traveling through the strands is evaluated. Thereafter, three specimens of anchorages with unknown defects are inspected by the AU and UT techniques. Damage assessment results from both techniques are then compared. The structural health conditions of the specimens can be then classified by a damage severity criterion. Finally, a damaged anchorage socket with mastered defects is controlled by the same techniques. The UT allows the detection and localization of damaged wires. The AU technique is used to bring out the effect of defects on acoustic features by comparing a healthy and damaged anchorage sockets. It is concluded that the UT method is suitable for local and crack-like defects, whereas the AU technique enables the assessment of the global structural health of the anchorage zones. PMID:25824342

  1. Multispectral fluorescence imaging techniques for nondestructive food safety inspection

    NASA Astrophysics Data System (ADS)

    Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

    2004-03-01

    The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

  2. Low-frequency electromagnetic technique for nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Dalichaouch, Yacine; Singsaas, Alan L.; Putris, Firas; Perry, Alexander R.; Czipott, Peter V.

    2000-05-01

    We have developed a low frequency electromagnetic technique using sensitive room temperature magnetoresistive (MR) sensors for a variety of nondestructive evaluation (NDE) applications. These applications include the NDE of medical implants and aircraft structures, the detection of cracks and corrosion in metals, the detection of ferromagnetic foreign objects in the eye and the brain, and the noninvasive determination of iron content in the liver. Our technique consists of applying a low frequency ac magnetic field to the sample and detecting the sample response. The low excitation frequency enables us to probe deep into metal structures; the sensitivity of the MR sensor allows us to detect weak responses from the sample without applying too large an excitation field, particularly in the case of human tissue. The MR sensors are small and relatively inexpensive compared to other sensitive magnetic field sensors such as fluxgates and superconducting quantum interference devices or SQUIDs; hence the resulting NDE instrument will be compact and cost-efficient, enabling its commercialization for practical applications. In this paper, we focus primarily on NDE of orthopedic implants.

  3. Nondestructive NMR technique for moisture determination in radioactive materials.

    SciTech Connect

    Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

    1998-12-04

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ({sup 3}H, {sup 3}He, {sup 239}Pu, {sup 241}Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO{sub 2} and UO{sub 2} systems. The total moisture was quantified by means of {sup 1}H NMR detection of H{sub 2}O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96.

  4. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    SciTech Connect

    Clayton, Dwight; Smith, Cyrus

    2014-02-18

    The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R and D Roadmap for Concrete, 'Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap', focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

  5. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight; Smith, Cyrus

    2014-02-01

    The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R&D Roadmap for Concrete, "Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap", focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

  6. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-6, Radiography Inspection.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This sixth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains radiographic inspection as a means of nondestructively examining components, assemblies, structures, and fabricated piping. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  7. [Application of near infrared spectroscopy technique to nondestructive measurement of vegetable quality].

    PubMed

    Xie, Li-Juan; Ying, Yi-Bin; Yu, Hai-Yan; Fu, Xia-Ping

    2007-06-01

    Nondestructive detection techniques of vegetable include electrical properties, optical reflectance and transmission, sonic vibration, nuclear magnetic resonance (NMR), machine vision, aromatic volatile emission, vibration characteristics and others. The most widely employed and successful technique is to use its optical property. Near infrared spectroscopy technique is extremely fast, highly efficient, cheap to implement, of good recurrence and no sample preparation, and is a rapid and non-destructive modern measuring technique that has been widely used in many fields. In the present paper, the application of near infrared spectroscopy technique to nondestructive measurement of vegetable quality was briefly introduced. Some considerable aspects existing in the application were also discussed, and it is pointed out that because of vegetable's diversity and rot-proneness, automation analysis machine should be developed to improve the speed of quality detection, and cooperating with several other nondestructive techniques, such as NMR and machine vision, is the research trend. PMID:17763775

  8. Conceptual Ideas for New Nondestructive UF6 Cylinder Assay Techniques

    SciTech Connect

    Miller, Karen A.

    2012-05-02

    Nondestructive assay (NDA) measurements of uranium cylinders play an important role in helping the International Atomic Energy Agency (IAEA) safeguard uranium enrichment plants. Traditionally, these measurements have consisted of a scale or load cell to determine the mass of UF{sub 6} in the cylinder combined with a gamma-ray measurement of the 186 keV peak from {sup 235}U to determine enrichment. More recently, Los Alamos National Laboratory (LANL) and Pacific Northwest National Laboratory (PNNL) have developed systems that exploit the passive neutron signal from UF{sub 6} to determine uranium mass and/or enrichment. These include the Uranium Cylinder Assay System (UCAS), the Passive Neutron Enrichment Meter (PNEM), and the Hybrid Enrichment Verification Array (HEVA). The purpose of this report is to provide the IAEA with new ideas on technologies that may or may not be under active development but could be useful for UF{sub 6} cylinder assay. To begin, we have included two feasibility studies of active interrogation techniques. There is a long history of active interrogation in the field of nuclear safeguards, especially for uranium assay. Both of the active techniques provide a direct measure of {sup 235}U content. The first is an active neutron method based on the existing PNEM design that uses a correlated {sup 252}Cf interrogation source. This technique shows great promise for UF{sub 6} cylinder assay and is based on advanced technology that could be implemented in the field in the near term. The second active technique is nuclear resonance fluorescence (NRF). In the NRF technique, a bremsstrahlung photon beam could be used to illuminate the cylinder, and high-resolution gamma-ray detectors would detect the characteristic de-excitation photons. The results of the feasibility study show that under certain measurement geometries, NRF is impractical for UF6 cylinder assay, but the 'grazing transmission' and 'secant transmission' geometries have more potential

  9. Nondestructive evaluation: A survey of NASA contributions, chapter 1, Chapter 11, cover page, acknowledgements, and contents

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A survey of nondestructive evaluation (NDE) technology, which is discussed in terms of popular demands for a greater degree of quality, reliability, and safety in industrial products, is presented as an overview of the NDE field to serve the needs of middle management. Three NDE methods are presented: acoustic emission, the use of coherent (laser)light, and ultrasonic holography.

  10. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-2, Leak Tests.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This second in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes the predominantly used leak test methods in nuclear power plants. More specifically, the module describes these test methods, the testing techniques, and the associated quality assurance requirements. The module follows a typical…

  11. Nondestructive evaluation techniques for nickel-cadmium aerospace battery cells

    NASA Technical Reports Server (NTRS)

    Haak, R.; Tench, D.

    1982-01-01

    The ac impedance characteristics of Ni-Cd cells as an in-situ, nondestructive means of determining cell lifetime, particularly with respect to the probability of premature failure were evaluated. Emphasis was on evaluating Ni-Cd cell impedance over a wide frequency range (10,000 to 0.0004 Hz) as the cells were subjected to charge/discharge cycle testing. The results indicate that cell degradation is reflected in the low frequency (Warburg) impedance characteristics associated with diffusion processes. The Warburg slope (W) was found to steadily increase as a function of cell aging for completely discharged cells. In addition, based on data for two cells, a high or rapidly increasing value for W signals imminent cell failure by one mechanism. Degradation by another mechanism is apparently reflected in a fall-off (roll-over) of W at lower frequencies. As a secondary result, the frequency dependence of the absolute cell impedance at low frequencies (5 - 500 mHz) was found to be a good indication of the cell state-of-charge.

  12. NONDESTRUCTIVE TESTING (NDT) TECHNIQUES TO DETECT CONTAINED SUBSURFACE HAZARDOUS WASTE

    EPA Science Inventory

    The project involves the detection of buried containers with NDT (remote-sensing) techniques. Seventeen techniques were considered and four were ultimately decided upon. They were: electromagnetic induction (EMI); metal detection (MD); magnetometer (MAG); and ground penetrating r...

  13. Nondestructive techniques for assaying fuel debris in piping at Three Mile Island Unit 2

    SciTech Connect

    Vinjamuri, K.; McIsaac, C.V.; Beller, L.S.; Isaacson, L.; Mandler, J.W.; Hobbins, R.R. Jr.

    1981-11-01

    Four major categories of nondestructive techniques - ultrasonic, passive gamma ray, infrared detection, and remote video examination - have been determined to be feasible for assaying fuel debris in the primary coolant system of the Three Mile Island Unit 2 (TMI-2) Reactor. Passive gamma ray detection is the most suitable technique for the TMI-2 piping; however, further development of this technique is needed for specific application to TMI-2.

  14. Application of nondestructive gamma-ray and neutron techniques for the safeguarding of irradiated fuel materials

    SciTech Connect

    Phillips, J.R.; Halbig, J.K.; Lee, D.M.; Beach, S.E.; Bement, T.R.; Dermendjiev, E.; Hatcher, C.R.; Kaieda, K.; Medina, E.G.

    1980-05-01

    Nondestructive gamma-ray and neutron techniques were used to characterize the irradiation exposures of irradiated fuel assemblies. Techniques for the rapid measurement of the axial-activity profiles of fuel assemblies have been developed using ion chambers and Be(..gamma..,n) detectors. Detailed measurements using high-resolution gamma-ray spectrometry and passive neutron techniques were correlated with operator-declared values of cooling times and burnup.

  15. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-3, Hydrostatic Tests.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This third in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes the principles and practices associated with hydrostatic testing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student,…

  16. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-5, Fundamentals of Radiography.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This fifth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains the radiographic process, from radiation source selection to equipment and specimen selection and arrangement, and film processing. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  17. Nondestructive Inspection Techniques for Friction Stir Weld Verification on the Space Shuttle External Tank

    NASA Technical Reports Server (NTRS)

    Suits, Michael W.; Leak, Jeffery; Bryson, Craig

    2003-01-01

    Friction Stir Welding (FSW) has gained wide acceptance as a reliable joining process for aerospace hardware as witnessed by its recent incorporation into the Delta Launch vehicle cryotanks. This paper describes the development of nondestructive evaluation methods and techniques used to verify the FSW process for NASA's Space Shuttle.

  18. Nondestructive spectroscopic and imaging techniques for quality evaluation and assessment of fish and fish products.

    PubMed

    He, Hong-Ju; Wu, Di; Sun, Da-Wen

    2015-01-01

    Nowadays, people have increasingly realized the importance of acquiring high quality and nutritional values of fish and fish products in their daily diet. Quality evaluation and assessment are always expected and conducted by using rapid and nondestructive methods in order to satisfy both producers and consumers. During the past two decades, spectroscopic and imaging techniques have been developed to nondestructively estimate and measure quality attributes of fish and fish products. Among these noninvasive methods, visible/near-infrared (VIS/NIR) spectroscopy, computer/machine vision, and hyperspectral imaging have been regarded as powerful and effective analytical tools for fish quality analysis and control. VIS/NIR spectroscopy has been widely applied to determine intrinsic quality characteristics of fish samples, such as moisture, protein, fat, and salt. Computer/machine vision on the other hand mainly focuses on the estimation of external features like color, weight, size, and surface defects. Recently, by incorporating both spectroscopy and imaging techniques in one system, hyperspectral imaging cannot only measure the contents of different quality attributes simultaneously, but also obtain the spatial distribution of such attributes when the quality of fish samples are evaluated and measured. This paper systematically reviews the research advances of these three nondestructive optical techniques in the application of fish quality evaluation and determination and discuss future trends in the developments of nondestructive technologies for further quality characterization in fish and fish products. PMID:24915393

  19. Non-destructive evaluation techniques for chemical weapons destruction

    SciTech Connect

    Hartwell, J.K.; Caffrey, A.J.

    1996-09-01

    fThe safe and verifiable disposition, either by incineration or chemical neutralization of chemical warfare (CW) agents requires correct {ital a priori} identification of each munition or container to be processed. A variety of NDE techniques have been used or tested for the examination and characterization of munitions. In the U.S., three widely used techniques are X-ray radiography, acoustic resonance spectroscopy (ARS), and prompt gamma ray neutron activation analysis (PINS). The technical bases, instrumental implementations, and applications of the U.S. versions of these methods are briefly discussed. 10 refs., 2 figs., 1 tab.

  20. Laryngoscope decontamination techniques: A survey

    PubMed Central

    Chawla, Rajiv; Gupta, Akhilesh; Gupta, Anshu; Kumar, Mritunjay

    2016-01-01

    Background and Aims: India is a vast country with variable, nonuniform healthcare practices. A laryngoscope is an important tool during general anesthesia and resuscitation. The study aimed to determine the current practices of laryngoscope decontamination in India. Material and Methods: An online survey was conducted amongst 100 anesthesiologists to determine the common methods of laryngoscope decontamination adopted in their settings. The survey was done over 6 months after validating the questionnaire. Results: A total of 73 responses were received out of 100. The result of the survey revealed that there is no uniform technique of laryngoscope decontamination. There is marked variability in techniques followed not only among different institutions, but also within the same institution. Conclusion: There are no fixed protocols adopted for laryngoscope decontamination. Thus, there is a need to develop definitive guidelines on this subject, which can be implemented in India. PMID:27006551

  1. Destructive and Non-Destructive Analysis Techniques for Failure Detection of QFN Packages

    NASA Astrophysics Data System (ADS)

    Adhila, M. N.; Wedianti, S.; Suhaimi, W. S. W. M.; Aishah, I.

    2010-03-01

    One of the latest developments in packaging technology is the QFN (Quad Flat Non-Lead) packages, which is both a chip scale package and plastic encapsulated package with lead pad at the bottom. In this paper, different type of commercial QFN single die packages were characterized by using destructive and non-destructive techniques. Non-destructive techniques such as Scanning Acoustic Microscope (SAM) and X-Ray analysis were used to observe package cracking, delamination and other failure mode. Application of SAM include detection of delaminations between lead frame, die face, paddle, heat sink, cracks and plastic encapsulant. In comparison to other techniques, SAM is sensitive to detect beneath the surface of devices which would be inaccessible otherwise by both conventional optical and electron microscopy inspection methods. Destructive technique such as Field Emission Electron Microscopy (FESEM) was implemented to address the failures of the QFN single die packages such as die cracking, lifted ball bonds and other failure mode.

  2. The application of non-destructive techniques to the testing of a wind turbine blade

    SciTech Connect

    Sutherland, H.; Beattie, A.; Hansche, B.; Musial, W.; Allread, J.; Johnson, J.; Summers, M.

    1994-06-01

    NonDestructive Testing (NDT), also called NonDestructive Evaluation (NDE), is commonly used to monitor structures before, during, and after testing. This paper reports on the use of two NDT techniques to monitor the behavior of a typical wind turbine blade during a quasi-static test-to-failure. The two NDT techniques used were acoustic emission and coherent optical. The former monitors the acoustic energy produced by the blade as it is loaded. The latter uses electron shearography to measure the differences in surface displacements between two load states. Typical results are presented to demonstrate the ability of these two techniques to locate and monitor both high damage regions and flaws in the blade structure. Furthermore, this experiment highlights the limitations in the techniques that must be addressed before one or both can be transferred, with a high probability of success, to the inspection and monitoring of turbine blades during the manufacturing process and under normal operating conditions.

  3. Infrared Contrast Analysis Technique for Flash Thermography Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2014-01-01

    The paper deals with the infrared flash thermography inspection to detect and analyze delamination-like anomalies in nonmetallic materials. It provides information on an IR Contrast technique that involves extracting normalized contrast verses time evolutions from the flash thermography infrared video data. The paper provides the analytical model used in the simulation of infrared image contrast. The contrast evolution simulation is achieved through calibration on measured contrast evolutions from many flat bottom holes in the subject material. The paper also provides formulas to calculate values of the thermal measurement features from the measured contrast evolution curve. Many thermal measurement features of the contrast evolution that relate to the anomaly characteristics are calculated. The measurement features and the contrast simulation are used to evaluate flash thermography inspection data in order to characterize the delamination-like anomalies. In addition, the contrast evolution prediction is matched to the measured anomaly contrast evolution to provide an assessment of the anomaly depth and width in terms of depth and diameter of the corresponding equivalent flat-bottom hole (EFBH) or equivalent uniform gap (EUG). The paper provides anomaly edge detection technique called the half-max technique which is also used to estimate width of an indication. The EFBH/EUG and half-max width estimations are used to assess anomaly size. The paper also provides some information on the "IR Contrast" software application, half-max technique and IR Contrast feature imaging application, which are based on models provided in this paper.

  4. Development of a nondestructive vibration technique for bond assessment of Space Shuttle tiles

    NASA Technical Reports Server (NTRS)

    Moslehy, Faissal A.

    1994-01-01

    This final report describes the achievements of the above titled project. The project is funded by NASA-KSC (Grant No. NAG 10-0117) for the period of 1 Jan. to 31 Dec. 1993. The purpose of this project was to develop a nondestructive, noncontact technique based on 'vibration signature' of tile systems to quantify the bond conditions of the thermal protection system) tiles of Space Shuttle orbiters. The technique uses a laser rapid scan system, modal measurements, and finite element modeling. Finite element models were developed for tiles bonded to both clamped and deformable integrated skin-stringer orbiter mid-fuselage. Results showed that the size and location of a disbonded tile can be determined from frequency and mode shape information. Moreover, a frequency response survey was used to quickly identify the disbonded tiles. The finite element results were compared with experimentally determined frequency responses of a 17-tile test panel, where a rapidscan laser system was employed. An excellent degree of correlation between the mathematical simulation and experimental results was realized. An inverse solution for single-tile assemblies was also derived and is being implemented into a computer program that can interact with the modal testing software. The output of the program displays the size and location of disbond. This program has been tested with simulated input (i.e., finite element data), and excellent agreement between predicted and simulated disbonds was shown. Finally, laser vibration imaging and acoustic emission techniques were shown to be well suited for detecting and monitoring the progressive damage in Graphite/Epoxy composite materials.

  5. Development of a nondestructive vibration technique for bond assessment of Space Shuttle tiles

    NASA Astrophysics Data System (ADS)

    Moslehy, Faissal A.

    1994-02-01

    This final report describes the achievements of the above titled project. The project is funded by NASA-KSC (Grant No. NAG 10-0117) for the period of 1 Jan. to 31 Dec. 1993. The purpose of this project was to develop a nondestructive, noncontact technique based on 'vibration signature' of tile systems to quantify the bond conditions of the thermal protection system) tiles of Space Shuttle orbiters. The technique uses a laser rapid scan system, modal measurements, and finite element modeling. Finite element models were developed for tiles bonded to both clamped and deformable integrated skin-stringer orbiter mid-fuselage. Results showed that the size and location of a disbonded tile can be determined from frequency and mode shape information. Moreover, a frequency response survey was used to quickly identify the disbonded tiles. The finite element results were compared with experimentally determined frequency responses of a 17-tile test panel, where a rapidscan laser system was employed. An excellent degree of correlation between the mathematical simulation and experimental results was realized. An inverse solution for single-tile assemblies was also derived and is being implemented into a computer program that can interact with the modal testing software. The output of the program displays the size and location of disbond. This program has been tested with simulated input (i.e., finite element data), and excellent agreement between predicted and simulated disbonds was shown. Finally, laser vibration imaging and acoustic emission techniques were shown to be well suited for detecting and monitoring the progressive damage in Graphite/Epoxy composite materials.

  6. Nondestructive Measurement Material Characterization of Thermal Sprayed Nickel Aluminum Coatings by using Laser Ultrasound Technique

    NASA Astrophysics Data System (ADS)

    Yeh, Cheng Hung; Wu, Tai Chieh; Yang, Che Hua

    This research focused on characterization of mechanical properties in Nickel-Aluminum coating with different thermal technique and processing parameters at high temperature environment up to 295°C. With the laser ultrasound technique (LUT), guided acoustic waves are generated to propagate on the Ni-Al sprayed coatings. By measuring dispersive phase velocity followed by SCE-UA inversion algorithm. The Young's modulus of coatings which fabricated by HVOF technique is higher than APS technique. This technique is potentially useful to probe the material characterization at high temperature environment in a remote and non-destructive way.

  7. Split spectrum technique as a preprocessor for ultrasonic nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Karpur, Prasanna

    Split-spectrum preprocessing (SSP) is shown in light of the present results to process A-scans in a way that allows its incorporation into artificial neural networks and other AI methods, as well as into feature-analysis techniques. SSP is consistently nonlinear in A-scan processing. Attention is given to the results obtained from the use of the magnitude spectra of the SSP-processed A-scans as inputs to a back-propagation artificial neural network.

  8. Comparative testing of nondestructive examination techniques for concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.; Smith, Cyrus M.

    2014-03-01

    A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties, its inexpensiveness, its structural strength, and its ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include containment building, spent fuel pool, and cooling towers. Comparative testing of the various NDE concrete measurement techniques requires concrete samples with known material properties, voids, internal microstructure flaws, and reinforcement locations. These samples can be artificially created under laboratory conditions where the various properties can be controlled. Other than NPPs, there are not many applications where critical concrete structures are as thick and reinforced. Therefore, there are not many industries other than the nuclear power plant or power plant industry that are interested in performing NDE on thick and reinforced concrete structures. This leads to the lack of readily available samples of thick and heavily reinforced concrete for performing NDE evaluations, research, and training. The industry that typically performs the most NDE on concrete structures is the bridge and roadway industry. While bridge and roadway structures are thinner and less reinforced, they have a good base of NDE research to support their field NDE programs to detect, identify, and repair concrete failures. This paper will summarize the initial comparative testing of two concrete samples with an emphasis on how these techniques could perform on NPP concrete structures.

  9. Applications of Advanced Nondestructive Measurement Techniques to Address Safety of Flight Issues on NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

    Advanced nondestructive measurement techniques are critical for ensuring the reliability and safety of NASA spacecraft. Techniques such as infrared thermography, THz imaging, X-ray computed tomography and backscatter X-ray are used to detect indications of damage in spacecraft components and structures. Additionally, sensor and measurement systems are integrated into spacecraft to provide structural health monitoring to detect damaging events that occur during flight such as debris impacts during launch and assent or from micrometeoroid and orbital debris, or excessive loading due to anomalous flight conditions. A number of examples will be provided of how these nondestructive measurement techniques have been applied to resolve safety critical inspection concerns for the Space Shuttle, International Space Station (ISS), and a variety of launch vehicles and unmanned spacecraft.

  10. Quality parameters of mango and potential of non-destructive techniques for their measurement - a review.

    PubMed

    Jha, S N; Narsaiah, K; Sharma, A D; Singh, M; Bansal, S; Kumar, R

    2010-01-01

    The king of fruits "Mango" (Mangifera indica L.) is very nutritious and rich in carotenes. India produces about 50% of the total world's mango. Many researchers have reported the maturity indices and quality parameters for determination of harvesting time and eating quality. The methods currently used for determination of quality of mango are mostly based on the biochemical analysis, which leads to destruction of the fruits. Numerous works are being carried out to explore some non-destructive methods such as Near Infrared (NIR), Nuclear Magnetic Resonance (NMR), X-ray and Computed Tomography (CT), electronic nose, machine vision and ultrasound for quality determination of fruits. This paper deals with some recent work reported on quality parameters, harvesting and post-harvest treatments in relation to quality of mango fruits and reviews on some of the potential non-destructive techniques that can be explored for quality determination of mango cultivars. PMID:23572595

  11. A study of the stress wave factor technique for nondestructive evaluation of composite materials

    NASA Technical Reports Server (NTRS)

    Sarrafzadeh-Khoee, A.; Kiernan, M. T.; Duke, J. C., Jr.; Henneke, E. G., II

    1986-01-01

    The acousto-ultrasonic method of nondestructive evaluation is an extremely sensitive means of assessing material response. Efforts continue to complete the understanding of this method. In order to achieve the full sensitivity of the technique, extreme care must be taken in its performance. This report provides an update of the efforts to advance the understanding of this method and to increase its application to the nondestructive evaluation of composite materials. Included are descriptions of a novel optical system that is capable of measuring in-plane and out-of-plane displacements, an IBM PC-based data acquisition system, an extensive data analysis software package, the azimuthal variation of acousto-ultrasonic behavior in graphite/epoxy laminates, and preliminary examination of processing variation in graphite-aluminum tubes.

  12. Nondestructive characterization of radioactive waste drums by gamma spectrometry: a Monte Carlo technique for efficiency calibration.

    PubMed

    Tzika, Faidra; Savidou, Anastasia; Stamatelatos, Ion E

    2007-11-01

    A semi-empirical non-destructive technique to assay radioactive waste drums is presented. The technique is based on gamma spectrometry performed using a portable NaI detector and Monte Carlo simulations using the MCNP code in order to derive the gamma ray detector efficiency for the volume source. The derivation of detector efficiency was performed assuming homogeneous distribution of the source activity within the matrix material. Moreover, the MCNP model was used to examine the effect of inhomogeneities in activity distribution, variation of matrix material density, and drum filling height on the accuracy of the technique, and to estimate the measurement bias. The technique was verified by estimating radioactivity levels in 25 drums containing ion exchange resin waste, and comparing the results of the non-destructive method against the analytical results of samples obtained from each drum. Satisfactory agreement between the two assay techniques was observed. The discussed technique represents a cost effective technology that can be used to assay low-activity, low-density waste drums provided the contribution to the gamma ray spectrum can be resolved. PMID:18049246

  13. Evaluation of electroexplosive devices by nondestructive test techniques and impulsive waveform firings

    NASA Technical Reports Server (NTRS)

    Menichelli, V. J.

    1972-01-01

    Special requirements of the space industry for more detailed knowledge of the quality and reliability of each electroexplosive device (EED) selected for use aboard a spacecraft are described. Statistical methods do not practically demonstrate the high reliability needed. To close this gap, nondestructive test techniques and instrumentation for 1-W/1-A no-fire devices have been developed. Several lots of squibs have been evaluated using these techniques and instrumentation. They yield data as to the quality and normal behavior of each electroexplosive device without firing or degrading the unit. Performance data were obtained by initiating the EED's with an impulsive waveform and sensing the initiation characteristics, sensitivity, and output.

  14. Nondestructive evaluation

    SciTech Connect

    Martz, H.E.

    1997-02-01

    Research reported in the thrust area of nondestructive evaluation includes: advanced 3-D imaging technologies; new techniques in laser ultrasonic testing; infrared computed tomography for thermal NDE of materials, structures, sources, and processes; automated defect detection for large laser optics; multistatic micropower impulse radar imaging for nondestructive evaluation; and multi-modal NDE for AVLIS pod shielding components.

  15. Nondestructive techniques for characterizing mechanical properties of structural materials - An overview

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1986-01-01

    An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flow detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.

  16. Nondestructive techniques for characterizing mechanical properties of structural materials: An overview

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1985-01-01

    An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flaw detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.

  17. Nondestructive evaluation of notched cracks in mortars by nonlinear ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Ren, Jun; Yin, Tingyuan

    2016-04-01

    In this paper, a nonlinear ultrasonic technique is used to nondestructively characterise concentrated defects in cement-based materials. Cracks are artificially notched in mortar samples and five different crack widths are used to simulate increased damage of samples. The relative ratio of second harmonic amplitude to the square of fundamental ultrasonic signal amplitude is defined as the damage indicator of the nonlinear ultrasonic technique, which is measured for mortar samples in conjunction with a typical linear nondestructive evaluation parameter - ultrasonic pulse velocity. It is found that both linear and nonlinear damage parameters have a good correlation with the change of crack width, while the nonlinearity parameter shows a better sensitivity to the width increase. In addition, the nonlinearity parameter presents an exponential increase with the crack growth, indicating an accelerating nonlinear ultrasonic response of materials to increased internal damage in the late phase. The results demonstrate that the nonlinear ultrasonic technique based on the second harmonic principle keeps the high sensitivity to the isolated cracks in cement-based materials, similarly to the case of distributed cracks in previous studies. The developed technique could thus be a useful experimental tool for the assessment of concentrated damage of concrete structures.

  18. New international Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT)

    NASA Astrophysics Data System (ADS)

    Prokofiev, Iouri; Cumblidge, Stephen E.; Csontos, Aladar A.; Braatz, Brett G.; Doctor, Steven R.

    2013-01-01

    The Nuclear Regulatory Commission established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) to follow on from the successful Program for the Inspection of Nickel alloy Components. The goals of PARENT are to conduct a confirmatory assessment of the reliability of nondestructive evaluation (NDE) techniques for detecting and sizing primary water stress corrosion cracks and apply the lessons learned from PINC to a series of round-robin tests. These open and blind round-robin tests will comprise a new set of typical pressure boundary components including dissimilar metal welds and bottom-mounted instrumentation penetrations. Open round-robin tests will engage research and industry teams worldwide to investigate and demonstrate the reliability of emerging NDE techniques to detect and size flaws with a wide range of lengths, depths, orientations, and locations. Blind round-robin tests will utilize various testing organizations, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from relatively easy to very difficult for detection and sizing. Blind and open round-robin testing started in late 2011 and early 2012, respectively. This paper will present the work scope with reports on progress, NDE methods evaluated, and project timeline for PARENT.

  19. New International Program to Asses the Reliability of Emerging Nondestructive Techniques (PARENT)

    SciTech Connect

    Prokofiev, Iouri; Cumblidge, Stephen E.; Csontos, Aladar A.; Braatz, Brett G.; Doctor, Steven R.

    2013-01-25

    The Nuclear Regulatory Commission (NRC) established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) to follow on from the successful Program for the Inspection of Nickel alloy Components (PINC). The goal of the PARENT is to conduct a confirmatory assessment of the reliability of nondestructive evaluation (NDE) techniques for detecting and sizing primary water stress corrosion cracks (PWSCC) and applying the lessons learned from PINC to a series of round-robin tests. These open and blind round-robin tests will comprise a new set of typical pressure boundary components including dissimilar metal welds (DMWs) and bottom-mounted instrumentation penetrations. Open round-robin tests will engage research and industry teams worldwide to investigate and demonstrate the reliability of emerging NDE techniques to detect and size flaws with a wide range of lengths, depths, orientations, and locations. Blind round-robin tests will utilize various testing organizations, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from relatively easy to very difficult for detection and sizing. Blind and open round-robin testing started in late 2011 and early 2012, respectively. This paper will present the work scope with reports on progress, NDE methods evaluated, and project timeline for PARENT.

  20. Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

    NASA Technical Reports Server (NTRS)

    Tiede, D. A.

    1972-01-01

    A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

  1. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    NASA Astrophysics Data System (ADS)

    Lavers, C.; Franklin, P.; Franklin, P.; Plowman, A.; Sayers, G.; Bol, J.; Shepard, D.; Fields, D.

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  2. A systems approach of the nondestructive evaluation techniques applied to Scout solid rocket motors.

    NASA Technical Reports Server (NTRS)

    Oaks, A. E.

    1971-01-01

    Review and appraisal of the status of the nondestructive tests applied to Scout solid-propellant rocket motors, using analytical techniques to evaluate radiography for detecting internal discontinuities such as voids and unbonds. Information relating to selecting, performing, controlling, and evaluating the results of NDE tests was reduced to a common simplified format. With these data and the results of the analytical studies performed, it was possible to make the basic appraisals of the ability of a test to meet all pertinent acceptance criteria and, where necessary, provide suggestions to improve the situation.

  3. Development of nondestructive non-contact acousto-thermal evaluation technique for damage detection in materials

    NASA Astrophysics Data System (ADS)

    Sathish, Shamachary; Welter, John T.; Jata, Kumar V.; Schehl, Norman; Boehnlein, Thomas

    2012-09-01

    This paper presents the development of a new non-contact acousto-thermal signature (NCATS) nondestructive evaluation technique. The physical basis of the method is the measurement of the efficiency of the material to convert acoustic energy into heat, and a theoretical model has been used to evaluate this. The increase in temperature due to conversion of acoustic energy injected into the material without direct contact was found to depend on the thermal and elastic properties of the material. In addition, it depends on the experimental parameters of the acoustic source power, the distance between sample and acoustic source, and the period of acoustic excitation. Systematic experimental approaches to optimize each of the experimental variables to maximize the observed temperature changes are described. The potential of the NCATS technique to detect microstructural-level changes in materials is demonstrated by evaluating accumulated damage due to plasticity in Ti-6Al-4V and low level thermal damage in polymer matrix composites. The ability of the technique for macroscopic applications in nondestructive evaluation is demonstrated by imaging a crack in an aluminum test sample.

  4. Using the technique of computed tomography for nondestructive analysis of pharmaceutical dosage forms

    NASA Astrophysics Data System (ADS)

    de Oliveira, José Martins, Jr.; Mangini, F. Salvador; Carvalho Vila, Marta Maria Duarte; ViníciusChaud, Marco

    2013-05-01

    This work presents an alternative and non-conventional technique for evaluatingof physic-chemical properties of pharmaceutical dosage forms, i.e. we used computed tomography (CT) technique as a nondestructive technique to visualize internal structures of pharmaceuticals dosage forms and to conduct static and dynamical studies. The studies were conducted involving static and dynamic situations through the use of tomographic images, generated by the scanner at University of Sorocaba - Uniso. We have shown that through the use of tomographic images it is possible to conduct studies of porosity, densities, analysis of morphological parameters and performing studies of dissolution. Our results are in agreement with the literature, showing that CT is a powerful tool for use in the pharmaceutical sciences.

  5. Nondestructive testing and evaluation of composites by non-invasive IR Imaging techniques

    NASA Astrophysics Data System (ADS)

    Mulaveesala, Ravibabu; Siddiqui, Juned A.; Arora, Vanita; Ghali, S. V.; Muniyappa, Amarnath; Takei, Masahiro

    2013-05-01

    InfraRed Thermography (IRT) is one of the promising technique for non-destructive testing method for characterization of materials. This technique relies on evaluation of the surface temperature variations to detect the presence of surface and subsurface anomalies within the material. Due to its whole field and remote testing capabilities, IRT has gained significant importance in testing of Glass Fiber Reinforced Plastic (GFRP) materials. A GFRP sample with defects of various sizes at a given depth was inspected using non-stationary thermographic techniques. In order to highlight the defect detection capabilities of the proposed non-stationary schemes, a comparison has been made using matched excitation energy in frequency domain by taking signal to noise ratio into consideration.

  6. Use of an ultrasonic-acoustic technique for nondestructive evaluation of fiber composite strength

    NASA Technical Reports Server (NTRS)

    Vary, A.; Bowles, K. J.

    1978-01-01

    This report describes the ultrasonic-acoustic technique used to measure a 'Stress Wave Factor'. In a prior study this factor was found effective in evaluating the interlaminar shear strength of fiber-reinforced composites. Details of the method used to measure the stress wave factor are described. In addition, frequency spectra of the stress waves are analyzed in order to clarify the nature of the wave phenomena involved. The stress wave factor can be measured with simple contact probes requiring only one-side access to a part. This is beneficial in nondestructive evaluations because the waves can run parallel to fiber directions and thus measure material properties in directions assumed by actual loads. Moreover, the technique can be applied where conventional through transmission techniques are impractical or where more quantitative data are required. The stress wave factor was measured for a series of graphite/polyimide composite panels and results obtained are compared with through transmission immersion ultrasonic scans.

  7. Non-Destructive Survey of Archaeological Sites Using Airborne Laser Scanning and Geophysical Applications

    NASA Astrophysics Data System (ADS)

    Poloprutský, Z.; Cejpová, M.; Němcová, J.

    2016-06-01

    This paper deals with the non-destructive documentation of the "Radkov" (Svitavy district, Czech Republic) archaeological site. ALS, GPR and land survey mapping will be used for the analysis. The fortified hilltop settlement "Radkov" is an immovable historical monument with preserved relics of anthropogenic origin in relief. Terrain reconnaissance can identify several accentuated objects on site. ALS enables identification of poorly recognizable archaeological objects and their contexture in the field. Geophysical survey enables defunct objects identification. These objects are hidden below the current ground surface and their layout is crucial. Land survey mapping provides technical support for ALS and GPR survey. It enables data georeferencing in geodetic reference systems. GIS can then be used for data analysis. M. Cejpová and J. Němcová have studied this site over a long period of time. In 2012 Radkov was surveyed using ALS in the project "The Research of Ancient Road in Southwest Moravia and East Bohemia". Since 2015 the authors have been examining this site. This paper summarises the existing results of the work of these authors. The digital elevation model in the form of a grid (GDEM) with a resolution 1 m of 2012 was the basis for this work. In 2015 the survey net, terrain reconnaissance and GPR survey of two archaeological objects were done at the site. GDEM was compared with these datasets. All datasets were processed individually and its results were compared in ArcGIS. This work was supported by the Grant Agency of the CTU in Prague, grant No. SGS16/063/OHK1/1T/11.

  8. Application of nondestructive optical techniques in the detection of surface and subsurface defects in sapphire

    NASA Astrophysics Data System (ADS)

    Akwani, Ikerionwu A.; Hibbard, Douglas L.; Jacoby, Keith T.

    2007-04-01

    Advancements in optical manufacturing and testing technologies for sapphire material are required to support the increasing use of large aperture sapphire panels as windscreens for various electro-optical system applications. It is well known that the grinding and polishing operations employed to create optical surfaces leads to the introduction of surface stress and sub-surface damage which can affect critical opto-mechanical performance characteristics such as strength and durability. Traditional methods for measuring these defects are destructive and, therefore, unsuitable as in-process, high volume inspection tools. A number of non-destructive optical techniques were investigated at Exotic Electro-Optics under funding by the Office of Naval Research and the Air Force Research Laboratory including Raman spectroscopy, laser polarimetry and the Twyman effect to characterize process-induced defects in sapphire panels. Preliminary experimental results using these techniques have shown that surface stress and sub-surface damage may be non-destructively measured. Raman spectroscopy has shown promise in quantifying surface stress, laser polarimetry is of questionable utility and the Twyman effect may be used qualitatively to monitor relative stress and sub-surface damage. This information will ultimately provide a better understanding of the overall manufacturing process leading to optimized process time and cost.

  9. Application of non-destructive techniques to assess the state of Hagia Sophia's mosaics

    NASA Astrophysics Data System (ADS)

    Moropoulou, Antonia; Karoglou, Maria; Labropoulos, Kyriakos C.; Delegou, Ekaterini T.; Katsiotis, Nikolaos K.; Karagiannis-Bakolas, Asterios

    2012-04-01

    The church of Hagia Sophia in Istanbul is a world heritage monument that epitomizes the byzantine ecclesiastic architecture. The church is decorated with mosaics from various historic periods. The preservation state of the mosaics is of high importance. In this study, non-destructive techniques (ground penetrating radar, infra-red thermography, fibreoptics microscopy) were employed on south upper gallery mosaic areas. The main aim of this on-site investigation was the evaluation of the preservation state of the mosaics and the previous interventions (materials characterization and decay diagnosis) in order to assess the performance of previous conservation/restoration interventions, as well as to verify the presence of mosaics in layers below the external plaster surfaces. Results indicated that is indeed possible to locate the grid of rendered mosaics. Regarding the preservation state of the mosaics, it was indicated that the main environmental decay factors were the high relative humidity levels with co-action of salt damp as well as the air pollutants. Moreover, it was revealed that previous incompatible restoration/conservation interventions have often accelerated the mosaics' degradation processes. Using non-destructive techniques it was possible to identify areas where the mosaic materials (tesserae and mortars) presented decay problems and in addition identify sub-layers that pose risk of detachment or decay intensification. In this way, NDT can contribute to the development of a strategic planning for mosaics conservation, protection and revealing.

  10. NON-DESTRUCTIVE THERMAL BARRIER COATING SPALLATION PREDICTION BY A LOADBASED MICRO-INDENTATION TECHNIQUE

    SciTech Connect

    J. M. Tannenbaum; K. Lee; B. S.-J. Kang; M.A. Alvin

    2010-11-18

    Currently, the durability and life cycle of thermal barrier coatings (TBC) applied to gas turbine blades and combustor components are limiting the maximum temperature and subsequent efficiency at which gas turbine engines operate. The development of new materials, coating technologies and evaluation techniques is required if enhanced efficiency is to be achieved. Of the current ceramic coating materials used in gas turbine engines, yttria stabilized zirconia (YSZ) is most prevalent, its low thermal conductivity, high thermal expansion coefficient and outstanding mechanical strength make it ideal for use in TBC systems. However, residual stresses caused by coefficients of thermal expansion mismatches within the TBC system and unstable thermally grown oxides are considered the primary causes for its premature and erratic spallation failure. Through finite element simulations, it is shown that the residual stresses generated within the thermally grown oxide (TGO), bond coat (BC), YSZ and their interfaces create slight variations in indentation unloading surface stiffness response prior to spallation failure. In this research, seven air plasma sprayed and one electron beam physical vapor deposition yttria partially stabilized zirconia TBCs were subjected to isothermal and cyclic loadings at 1100°C. The associated coating degradation was evaluated using a non-destructive multiple partial unloading micro-indentation procedure. The results show that the proposed non-destructive micro-indentation evaluation technique can be an effective and specimenindependent TBC failure prediction tool capable of determining the location of initial spallation failure prior to its actual occurrence.

  11. Development of nondestructive-evaluation techniques for high-temperature ceramic heat-exchanger components

    NASA Astrophysics Data System (ADS)

    Kupperman, D. S.; Yuhas, D.; Michaels, T. E.; Michaels, J. E.

    1982-01-01

    An assessment was made of ultrasonic techniques developed to date for nondestructive evaluation of SiC heat exchanger tubes. The results suggest that ultrasonic inspection is a useful and valuable technique for inspecting these tubes, including ceramic butt joints. However, this method alone is currently not sufficiently effective to detect all critical flaws because of (1) the difficulties in following the surface of an out of round tube; (2) the high velocity and thus the large angle of refraction of sound in SiC, which for small diameter tubes leads to significant beam distortion; and (3) insuffient resolution, relative to the small critical flaw size in ceramics, at conventional ultrasonic testing frequencies. The experiments show that higher frequencies (up to 35 MHz) are required for effective wall thickness measurements and detection of laminar type flaws.

  12. Rapid non-destructive assessment of pork edible quality by using VIS/NIR spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Zhang, Leilei; Peng, Yankun; Dhakal, Sagar; Song, Yulin; Zhao, Juan; Zhao, Songwei

    2013-05-01

    The objectives of this research were to develop a rapid non-destructive method to evaluate the edible quality of chilled pork. A total of 42 samples were packed in seal plastic bags and stored at 4°C for 1 to 21 days. Reflectance spectra were collected from visible/near-infrared spectroscopy system in the range of 400nm to 1100nm. Microbiological, physicochemical and organoleptic characteristics such as the total viable counts (TVC), total volatile basic-nitrogen (TVB-N), pH value and color parameters L* were determined to appraise pork edible quality. Savitzky-Golay (SG) based on five and eleven smoothing points, Multiple Scattering Correlation (MSC) and first derivative pre-processing methods were employed to eliminate the spectra noise. The support vector machines (SVM) and partial least square regression (PLSR) were applied to establish prediction models using the de-noised spectra. A linear correlation was developed between the VIS/NIR spectroscopy and parameters such as TVC, TVB-N, pH and color parameter L* indexes, which could gain prediction results with Rv of 0.931, 0.844, 0.805 and 0.852, respectively. The results demonstrated that VIS/NIR spectroscopy technique combined with SVM possesses a powerful assessment capability. It can provide a potential tool for detecting pork edible quality rapidly and non-destructively.

  13. Developing nondestructive techniques for managing conflicts between fisheries and double-crested cormorant colonies

    USGS Publications Warehouse

    Suzuki, Yasuko; Roby, Daniel D.; Lyons, Donald E.; Courtot, Karen; Collis, Ken

    2015-01-01

    Double-crested cormorants (Phalacrocorax auritus) have been identified as the source of significant mortality to juvenile salmonids (Oncorhynchus spp.) in the Columbia River Basin. Management plans for reducing the size of a large colony on East Sand Island (OR, USA) in the Columbia River estuary are currently being developed. We evaluated habitat enhancement and social attraction as nondestructive techniques for managing cormorant nesting colonies during 2004–2007. We tested these techniques on unoccupied plots adjacent to the East Sand Island cormorant colony. Cormorants quickly colonized these plots and successfully raised young. Cormorants also were attracted to nest and raised young on similar plots at 2 islands approximately 25 km from East Sand Island; 1 island had a history of successful cormorant nesting whereas the other was a site where cormorants had previously nested unsuccessfully. On a third island with no history of cormorant nesting or nesting attempts, these techniques were unsuccessful at attracting cormorants to nest. Our results suggest that some important factors influencing attraction of nesting cormorants using these techniques include history of cormorant nesting, disturbance, and presence of breeding cormorants nearby. These techniques may be effective in redistributing nesting cormorants away from areas where fish stocks of conservation concern are susceptible to predation, especially if sites with a recent history of cormorant nesting are available within their foraging or dispersal range. Published 2015. Wiley Periodicals, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.

  14. The eddy-current technique for nondestructive evaluation of generator retaining rings: Feasibility study: Interim report

    SciTech Connect

    Elmo, P.M.; Nottingham, L.D.

    1988-05-01

    An evaluation of the feasibility of using eddy current nondestructive inspection techniques to detect intergranular stress corrosion in generator rotor retaining rings was conducted by the EPRI NDE Center. Experiments were conducted using a bend-bar containing representative stress corrosion damage, a calibration block containing electrical discharge machined (EDM) notches, and four retired retaining rings containing EDM notches and stress corrosion damage. An eddy current transducer transport was designed and fabricated to interface with an existing computer-controlled, two-axis positioner and digital eddy current data acquisition system. Test results of experiments performed with this equipment on the retaining ring test-bed provided experimental validation of the eddy current method's feasibility as a retaining ring inspection method. Details are given of the system and its performance under laboratory and simulated service-inspection conditions. 9 refs., 47 figs.

  15. Electrooptical remote sensing methods as nondestructive testing and measuring techniques in agriculture.

    PubMed

    Myers, V I; Allen, W A

    1968-09-01

    Characteristics of plants that influence reflectance and emission of electromagnetic energy are discussed. Four main spectral regions are influenced by plants. These wavelength bands include the visible region of chlorophyll absorption, very near ir wavelengths, where plant structure is of major importance, the near and middle ir wavelengths, where water and CO(2) absorption predominate, and the far ir region of thermal ir emission. Soil characteristics that influence reflectance and emission of energy are discussed. Nondestructive testing techniques described include laboratory spectrophotometry, field spectrometry, color photography, radiometry, and generation of line scan imagery. Spectrophotometer and spectrometer reflectance data obtained in the laboratory and field are related to interpretation of remote sensing imagery. Model studies that permit predictions of reflectance from plant canopies are described. The principle of multispectral sensing which permits utilization of multiple wavelength channels for establishing unique plant and soil signature is reviewed. PMID:20068888

  16. Nondestructive Evaluation Techniques for Development and Characterization of Carbon Nanotube Based Superstructures

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2014-01-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-toweight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter, defect ratio, and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  17. Nondestructive evaluation techniques for development and characterization of carbon nanotube based superstructures

    NASA Astrophysics Data System (ADS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2015-03-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns [1]. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking [2]. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-to-weight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

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

    NASA Astrophysics Data System (ADS)

    Wu, Cheng-Wei

    1997-11-01

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

  19. An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

    NASA Technical Reports Server (NTRS)

    Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

    2006-01-01

    Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

  20. The application of nondestructive techniques to the testing of a wind turbine blade

    SciTech Connect

    Sutherland, H.J.; Musial, W.

    1993-07-01

    NonDestructive Testing (NDT) is commonly used to monitor structures before, during and after testing. This paper reports on the use of two NDT techniques to monitor the behavior of a typical wind turbine blade during a quasi-static test-to-failure. The test used a three-point spanwise load distribution to load a 7.9-m blade to failure. The two NDT techniques used were acoustic emission and coherent optical. The former monitors the acoustic energy produced by the blade as it is loaded. The latter uses electronic shearography to measure the differences in surface displacements between two load states with an accuracy of a few microns. Typical results are presented to demonstrate the ability of these two techniques to locate and monitor both high damage regions and flaws in the blade structure. Further, this experiment highlights the limitations in the techniques that must be addressed before one or both can be transferred, with a high probability of success, to the inspection and monitoring of turbine blades during the manufacturing process and under normal operating conditions.

  1. A Survey of Shape Parameterization Techniques

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.

    1999-01-01

    This paper provides a survey of shape parameterization techniques for multidisciplinary optimization and highlights some emerging ideas. The survey focuses on the suitability of available techniques for complex configurations, with suitability criteria based on the efficiency, effectiveness, ease of implementation, and availability of analytical sensitivities for geometry and grids. The paper also contains a section on field grid regeneration, grid deformation, and sensitivity analysis techniques.

  2. Exploratory loading techniques. [in holographic nondestructive testing of flat metal plates

    NASA Technical Reports Server (NTRS)

    Martin, A. M., III

    1976-01-01

    Interferometric holographic nondestructive testing of aluminum, copper, and steel flat plates is reported. Structural weaknesses under positive pressure, negative pressure, heating, and cooling are discussed.

  3. Nondestructive measurement of reducing sugar of apples using Vis/NIR spectroscopy techniques

    NASA Astrophysics Data System (ADS)

    Jiang, Yihong; Li, Xiaoli; Bai, Xiujun; He, Yong

    2006-09-01

    In this research, the potential ofusing the Visible/Near Infrared Spectroscopy (VisINIRS) was investigated for measuring the reducing sugar of Fuji apple (from Shanxi of China), and the relationship was established between nondestructive Vis/NIR spectral measurement and the reducing sugar of apple. Intact apple fruit were measured by reflectance Vis/NIR in 325-1075 nm range. The data set as the logarithms of the reflectance reciprocal (absorbance (logl/R)) was analyzed in order to build the best calibration model for this characteristic, using some spectral pretreatments and multivariate calibration techniques such as partial least square regression (PLS). The models for the reducing sugar (r=0.915), standard error ofprediction (SEP) 0.562 with a bias of 0.054; shown the excellent prediction performance. The Vis/NIR spectroscopy technique had significantly greater accuracy for determining the reducing sugar. It was concluded that by using the Vis/NIRS measurement technique, in the spectral range (325-1075 nm), it is possible to assess the reducing sugar content of apple.

  4. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-2, Operation of Ultrasonic Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John

    This second in a series of six modules for a course titled Nondestructive Examination (NDE) II describes specific ultrasonic test techniques and calibration principles. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  5. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-1, Fundamentals of Ultrasonic Testing.

    ERIC Educational Resources Information Center

    Spaulding, Bruce

    This first in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II introduces the student/trainee to the basic behavior of ultrasound, describes ultrasonic test equipment, and outlines the principal methods of ultrasonic testing. The module follows a typical format that includes the following sections: (1)…

  6. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-7, Radiographic Specifications and Code Requirements.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This seventh in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes radiographic specifications and code requirements. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  7. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-5, Fundamentals of Eddy Current Testing.

    ERIC Educational Resources Information Center

    Espy, John

    This fifth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II describes the fundamental concepts applicable to eddy current testing in general. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to…

  8. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-6, Operation of Eddy Current Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John; Selleck, Ben

    This sixth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II details eddy current examination of steam generator tubing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  9. Development of non-destructive quality measurement technique for cabbage seed (Brassica campestris L) using hyperspectral reflectance imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cabbage (Brassica campestris L) is an important crop for Asian countries especially in Korea, Japan and China. In order to achieve uniform and high-yield rate of cabbage product, the seed lot quality needs to be controlled. Non-destructive evaluation of seed viability is an important technique for i...

  10. Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft

    SciTech Connect

    Roach, D.; Walkington, P.

    1998-05-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded composite doubler applications, were highlighted. An array of conventional and advanced NDI techniques were evaluated. Flaw detection sensitivity studies were conducted on applicable eddy current, ultrasonic, X-ray and thermography based devices. The application of these NDI techniques to composite doublers and the results from test specimens, which were loaded to provide a changing flaw profile, are presented in this report. It was found that a team of these techniques can identify flaws in composite doubler installations well before they reach critical size.

  11. Survey of Biochemical Separation Techniques

    ERIC Educational Resources Information Center

    Nilsson, Melanie R.

    2007-01-01

    A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

  12. Determining Plutonium Mass in Spent Fuel with Nondestructive Assay Techniques -- Preliminary Modeling Results Emphasizing Integration among Techniques

    SciTech Connect

    Tobin, S. J.; Fensin, M. L.; Ludewigt, B. A.; Menlove, H. O.; Quiter, B. J.; Sandoval, N. P.; Swinhoe, M. T.; Thompson, S. J.

    2009-08-03

    There are a variety of motivations for quantifying Pu in spent (used) fuel assemblies by means of nondestructive assay (NDA) including the following: strengthen the capabilities of the International Atomic Energy Agencies to safeguards nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at reprocessing facilities and providing quantitative input to burnup credit determination for repositories. For the purpose of determining the Pu mass in spent fuel assemblies, twelve NDA techniques were identified that provide information about the composition of an assembly. A key point motivating the present research path is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the elemental Pu mass of an assembly and (2) detecting the diversion of a significant number of pins. As such, the focus of this work is determining how to best integrate 2 or 3 techniques into a system that can quantify elemental Pu and to assess how well this system can detect material diversion. Furthermore, it is important economically to down-select among the various techniques before advancing to the experimental phase. In order to achieve this dual goal of integration and down-selection, a Monte Carlo library of PWR assemblies was created and is described in another paper at Global 2009 (Fensin et al.). The research presented here emphasizes integration among techniques. An overview of a five year research plan starting in 2009 is given. Preliminary modeling results for the Monte Carlo assembly library are presented for 3 NDA techniques: Delayed Neutrons, Differential Die-Away, and Nuclear Resonance Fluorescence. As part of the focus on integration, the concept of"Pu isotopic correlation" is discussed and the role of cooling time determination.

  13. Laser Doppler technique for nondestructive evaluation of mechanical heart valves kinematics

    NASA Astrophysics Data System (ADS)

    Grigioni, Mauro; Daniele, Carla; Morbiducci, U.; Del Gaudio, C.; D'Avenio, Giuseppe; Di Meo, D.; Barbaro, Vincenzo

    2004-06-01

    Laser techniques for vibration measurement, due to their non-contact nature, represents an interesting alternative investigational tool to be tested in biomedical and clinic fields. A particular application could be as evaluation method in design and quality control of artificial organs. Aim of this study is to investigate the application of laser vibrometry to the study of mechanical heart valves in-vitro, with an ad hoc set-up. A heterodyne laser Doppler vibrometry system, which allows the measurement of both vibrational velocity and displacement was used. Three different approaches have been carried out, in order to stress the limits of the laser vibrometry technique for testing heart valve prostheses. Critical points and difficulties to build up experimental studies in this field were clearly pointed out. In the present study only one laser head was used, the aim of the authors being to test the feasibility of a simplified approach on mechanical cardiac valves. Starting from that analysis a comparison could be made to assess the capability to discriminate between normal and malfunctioning devices. The advantage of the proposed test bench is that it could provide a non-contact, non-destructive analysis of the valve under the same working conditions as those upon implantation. The proposed method could furnish a typical "fingerprint" characterizing each valve behavior in repeatable experimental conditions.

  14. A knowledge-based shell for selecting a nondestructive evaluation technique

    SciTech Connect

    Roberge, P.R.

    1995-02-01

    The complexity of planning a nondestructive evaluation (NDE) program or an inspection schedule for specific problems and available NDE techniques can be drastically reduced by the creation of a knowledge based system that would balance the advantages and limitations of each technique for specific problems. Such a system could incorporate the fundamental knowledge derived from failure analysis and cover topics such as materials vs. defect size and type, probability of failure, and basic reliability information. In order to efficiently organize knowledge of materials degradation, the parameters that control various forms of failure must first be rationalized in a general framework. This framework and their factors would then constitute a quantitative and easily programmable description of the independent variables controlling the intensity of a failure. This article describes such a framework, which could guide the general selection of NDE for materials failure with a particular emphasis on corrosion related failures. The framework architecture itself was constructed using an object-oriented methodology for maximum flexibility because it was anticipated that the materials parameters could easily be described as multidimensional objects.

  15. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1998-01-01

    An overall goal of this research has been to enhance our understanding of the scientific principles necessary to develop advanced ultrasonic nondestructive techniques for the quantitative characterization of advanced composite structures. To this end, we have investigated a thin woven composite (5-harness biaxial weave). We have studied the effects that variations of the physical parameters of the experimental setup can have on the ultrasonic determination of the material properties for this thin composite. In particular, we have considered the variation of the nominal center frequency and the f-number of the transmitting transducer which in turn address issues such as focusing and beam spread of ultrasonic fields. This study has employed a planar, two-dimensional, receiving pseudo-array that has permitted investigation of the diffraction patterns of ultrasonic fields. Distortion of the ultrasonic field due to the spatial anisotropy of the thin composite has prompted investigation of the phenomenon of phase cancellation at the face of a finite-aperture, piezoelectric receiver. We have performed phase-sensitive and phase-insensitive analyses to provide a measure of the amount of phase cancellation at the face of a finite-aperture, piezoelectric receiver. The pursuit of robust measurements of received energy (i.e., those not susceptible to phase cancellation at the face of a finite-aperture, piezoelectric receiver) supports the development of robust techniques to determine material properties from measure ultrasonic parameters.

  16. Feasibility study on nondestructively sensing meat's freshness using light scattering imaging technique.

    PubMed

    Li, Huanhuan; Sun, Xin; Pan, Wenxiu; Kutsanedzie, Felix; Zhao, Jiewen; Chen, Quansheng

    2016-09-01

    Rich nutrient matrix meat is the first-choice source of animal protein for many people all over the world, but it is also highly susceptible to spoilage due to chemical and microbiological activities. In this work, we attempted the feasibility study of rapidly and nondestructively sensing meat's freshness using a light scattering technique. First, we developed the light scattering system for image acquisition. Next, texture analysis was used for extracting characteristic variables from the region of interest (ROI) of a scattering image. Finally, a novel classification algorithm adaptive boosting orthogonal linear discriminant analysis (AdaBoost-OLDA) was proposed for modeling, and compared with two classical classification algorithms linear discriminant analysis (LDA) and support vector machine (SVM). Experimental results showed that classification results by AdaBoost-OLDA algorithm are superior to LDA and SVM algorithms, and eventually achieved 100% classification rate in the calibration and prediction sets. This work demonstrates that the developed light scattering technique has the potential in noninvasively sensing meat's freshness. PMID:27155320

  17. NONDESTRUCTIVE DETECTION OF DELAMINATION IN THERMAL BARRIER COATINGS USING ULTRASONIC TECHNIQUE

    SciTech Connect

    Chen, Roger H. L.; Zhang, Binwei; Alvin, Mary Anne

    2009-06-12

    Nondestructive testing using an acousto-ultrasonic technique has been utilized to detect the change of material properties and provide early warning of failure of thermal barrier coating (TBC) systems. Testing was performed on René N5 and Haynes 230 coupons with an applied NETL-bond coat, as well as on coupons containing both an applied MCrAlY bond coat and 7-YSZ top coat. The coupons were subjected to either cyclic or isothermal testing at 1100ºC. Ultrasonic testing was performed before and after thermal testing using piezoelectric sensors with dry contact on the surface of the coatings. Proof-of-concept test results indicated that changes in the properties of the 40m bond coat can be detected using the proposed technique. Waveforms generated via Pitch/Catch indicated minor changes within the bond coat applied to René N5 substrate after 400500 hours of cyclic oxidation at 1100°C. In contrast, marked differences in waveforms and travel time reflected significant crack formation and spallation of the bond coat from the Haynes 230 substrate. Finite element analysis (FEA) simulation of the wave propagation on a simplified TBC system with nonlinear effects was conducted. FEA results clearly show detection of a small embedded void incorporated to simulate delamination. Comparisons between experimental measurements and finite element simulations were used to estimate the material properties of the coatings and the substrate.

  18. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    NASA Astrophysics Data System (ADS)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (<<10MHz) and a surface displacement sensor that can capture the ultrasonic "return" signal with bandwidth close to 300 MHz. The use of high frequencies enables the detection of smaller defect sites. The technique is time resolved with the sensor and probe as point (>>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

  19. Survey of Header Compression Techniques

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph

    2001-01-01

    This report provides a summary of several different header compression techniques. The different techniques included are: (1) Van Jacobson's header compression (RFC 1144); (2) SCPS (Space Communications Protocol Standards) header compression (SCPS-TP, SCPS-NP); (3) Robust header compression (ROHC); and (4) The header compression techniques in RFC2507 and RFC2508. The methodology for compression and error correction for these schemes are described in the remainder of this document. All of the header compression schemes support compression over simplex links, provided that the end receiver has some means of sending data back to the sender. However, if that return path does not exist, then neither Van Jacobson's nor SCPS can be used, since both rely on TCP (Transmission Control Protocol). In addition, under link conditions of low delay and low error, all of the schemes perform as expected. However, based on the methodology of the schemes, each scheme is likely to behave differently as conditions degrade. Van Jacobson's header compression relies heavily on the TCP retransmission timer and would suffer an increase in loss propagation should the link possess a high delay and/or bit error rate (BER). The SCPS header compression scheme protects against high delay environments by avoiding delta encoding between packets. Thus, loss propagation is avoided. However, SCPS is still affected by an increased BER (bit-error-rate) since the lack of delta encoding results in larger header sizes. Next, the schemes found in RFC2507 and RFC2508 perform well for non-TCP connections in poor conditions. RFC2507 performance with TCP connections is improved by various techniques over Van Jacobson's, but still suffers a performance hit with poor link properties. Also, RFC2507 offers the ability to send TCP data without delta encoding, similar to what SCPS offers. ROHC is similar to the previous two schemes, but adds additional CRCs (cyclic redundancy check) into headers and improves

  20. Non-destructive testing techniques for the forensic engineering investigation of reinforced concrete buildings.

    PubMed

    Hobbs, Brian; Tchoketch Kebir, Mohamed

    2007-04-11

    This study describes in detail the results of a laboratory investigation where the compressive strength of 150mm side-length cubes was evaluated. Non-destructive testing (NDT) was carried out using ultrasonic pulse velocity (UPV) and impact rebound hammer (IRH) techniques to establish a correlation with the compressive strengths of compression tests. To adapt the Schmidt hammer apparatus and the ultrasonic pulse velocity tester to the type of concrete used in Algeria, concrete mix proportions that are recommended by the Algerian code were chosen. The resulting correlation curve for each test is obtained by changing the level of compaction, water/cement ratio and concrete age of specimens. Unlike other works, the research highlights the significant effect of formwork material on surface hardness of concrete where two different mould materials for specimens were used (plastic and wood). A combined method for the above two tests, reveals an improvement in the strength estimation of concrete. The latter shows more improvement by including the concrete density. The resulting calibration curves for strength estimation were compared with others from previous published literature. PMID:16904854

  1. Nondestructive characterization of thermal barrier coating by noncontact laser ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Chen, Jianwei; Zhang, Zhenzhen

    2015-09-01

    We present the application of a laser ultrasonic technique in nondestructive characterization of the bonding layer (BL) in a thermal barrier coating (TBC). A physical mode of a multilayered medium is established to describe the propagation of a longitudinal wave generated by a laser in a TBC system. Furthermore, the theoretical analysis on the ultrasonic transmission in TBC is carried out in order to derive the expression of the BL transmission coefficient spectrum (TCS) which is used to determine the velocity of the longitudinal wave in the BL. We employ the inversion method combined with TCS to ascertain the attenuation coefficient of the BL. The experimental validations are performed with TBC specimens produced by an electron-beam physical vapor deposition method. In those experiments, a pulsed laser with a width of 10 ns is used to generate an ultrasonic signal while a two-wave mixing interferometer is created to receive the ultrasonic signals. By introducing the wavelet soft-threshold method that improves the signal-to-noise ratio, the laser ultrasonic testing results of TBC with an oxidation of 1 cycle, 10 cycles, and 100 cycles show that the attenuation coefficients of the BL become larger with an increase in the oxidation time, which is evident for the scanning electron microscopy observations, in which the thickness of the thermally grown oxide increases with oxidation time.

  2. Survey of data compression techniques

    SciTech Connect

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM`s design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  3. Survey of data compression techniques

    SciTech Connect

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM's design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  4. Monitoring beach changes using GPS surveying techniques

    USGS Publications Warehouse

    Morton, Robert; Leach, Mark P.; Paine, Jeffrey G.; Cardoza, Michael A.

    1993-01-01

    The adaptation of Global Positioning System (GPS) surveying techniques to beach monitoring activities is a promising response to this challenge. An experiment that employed both GPS and conventional beach surveying was conducted, and a new beach monitoring method employing kinematic GPS surveys was devised. This new method involves the collection of precise shore-parallel and shore-normal GPS positions from a moving vehicle so that an accurate two-dimensional beach surface can be generated. Results show that the GPS measurements agree with conventional shore-normal surveys at the 1 cm level, and repeated GPS measurements employing the moving vehicle demonstrate a precision of better than 1 cm. In addition, the nearly continuous sampling and increased resolution provided by the GPS surveying technique reveals alongshore changes in beach morphology that are undetected by conventional shore-normal profiles. The application of GPS surveying techniques combined with the refinement of appropriate methods for data collection and analysis provides a better understanding of beach changes, sediment transport, and storm impacts.

  5. Nondestructive Evaluation of Adhesively Bonded Joints by Acousto-Ultrasonic Technique and Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Nayeb-Hashemi, Hamid; Rossettos, J. N.

    1997-01-01

    Reliable applications of adhesively bonded joints require an effective nondestructive evaluation technique for their bond strength prediction. To properly evaluate factors affecting bond strength, effects of defects such as voids and disbonds on stress distribution in the overlap region must be understood. At the same time, in order to use acousto-ultrasonic (AU) technique to evaluate bond quality, the effect of these defects on dynamic response of single lap joints must be clear. The stress distribution in a single lap joint with and without defects (void or disbond) is analyzed. A bar-Theta parameter which contains adherend and adhesive thickness and properties is introduced. It is shown for bonded joints with bar-Theta greater than 10, that a symmetric void or disbond in the middle of overlap up to the 70 percent of overlap length has negligible effect on bond strength. In contrast frequency response analyses by a finite element technique showed that the dynamic response is affected significantly by the presence of voids or disbonds. These results have direct implication in the interpretations of AU results. Through transmission attenuation and a number of AU parameters for various specimens with and without defects are evaluated. It is found that although void and disbond have similar effects on bond strength (stress distribution), they have completely different effects on wave propagation characteristics. For steel-adhesive-steel specimens with voids, the attenuation changes are related to the bond strength. However, the attenuation changes for specimens with disbond are fairly constant over a disbond range. In order to incorporate the location of defects in AU parameters, a weighting function is introduced. Using an immersion system with focused transducers, a number of AU parameters are evaluated. It is found that by incorporating weighting functions in these parameters better sensitivities (AU parameters vs. bond strength) are achieved. Acoustic emission

  6. The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Chapman, Gilbert B., II

    Demands for improvements in aerospace and automotive energy-efficiency, performance, corrosion resistance, body stiffness and style have increased the use of adhesive bonds to help meet those demands by providing joining technology that accommodates a wider variety of materials and design options. However, the history of adhesive bond performance clearly indicates the need for a robust method of assuring the existence of the required consistent level of adhesive bond integrity in every bonded region. This investigation seeks to meet that need by the development of new, complementary ultrasonic techniques for the evaluation of these bonds, and thus provide improvements over previous methods by extending the range of resolution, speed and applications. The development of a 20 MHz pulse-echo method for nondestructive evaluation of adhesive bonds will accomplish the assessment of bond joints with adhesive as thin as 0.1 mm. This new method advances the state of the art by providing a high-resolution, phase-sensitive procedure that identifies the bond state at each interface of the adhesive with the substrate(s), by the acquisition and analysis of acoustic echoes reflected from interfaces between layers with large acoustic impedance mismatch. Because interface echo amplitudes are marginal when the acoustic impedance of the substrate is close to that of the adhesive, a 25 kHz Lamb wave technique was developed to be employed in such cases, albeit with reduced resolution. Modeling the ultrasonic echoes and Lamb-wave signals was accomplished using mathematical expressions developed from the physics of acoustic transmission, attenuation and reflection in layered media. The models were validated by experimental results from a variety of bond joint materials, geometries and conditions, thereby confirming the validity of the methodology used for extracting interpretations from the phase-sensitive indications, as well as identifying the range and limits of applications. Results

  7. An accurate method for determining residual stresses with magnetic non-destructive techniques in welded ferromagnetic steels

    NASA Astrophysics Data System (ADS)

    Vourna, P.

    2016-03-01

    The scope of the present research work was to investigate the proper selection criteria for developing a suitable methodology for the accurate determination of residual stresses existing in welded parts. Magnetic non-destructive testing took place by the use of two magnetic non-destructive techniques: by the measurement of the magnetic Barkhausen noise and by the evaluation of the magnetic hysteresis loop parameters. The spatial distribution of residual stresses in welded metal parts by both non-destructive magnetic methods and two diffraction methods was determined. The conduction of magnetic measurements required an initial calibration of ferromagnetic steels. Based on the examined volume of the sample, all methods used were divided into two large categories: the first one was related to the determination of surface residual stress, whereas the second one was related to bulk residual stress determination. The first category included the magnetic Barkhausen noise and the X-ray diffraction measurements, while the second one included the magnetic permeability and the neutron diffraction data. The residual stresses determined by the magnetic techniques were in a good agreement with the diffraction ones.

  8. Multi-wave and hybrid imaging techniques: a new direction for nondestructive testing and structural health monitoring.

    PubMed

    Cheng, Yuhua; Deng, Yiming; Cao, Jing; Xiong, Xin; Bai, Libing; Li, Zhaojun

    2013-01-01

    In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physics and principles of multi-wave phenomena and hybrid imaging methods are inherently different. After a brief introduction of nondestructive evaluation (NDE) , structure health monitoring (SHM) and their related challenges, several recent advances that have significantly extended imaging methods from laboratory development into practical applications were summarized, followed by conclusions and discussion on future directions. PMID:24287536

  9. Multi-Wave and Hybrid Imaging Techniques: A New Direction for Nondestructive Testing and Structural Health Monitoring

    PubMed Central

    Cheng, Yuhua; Deng, Yiming; Cao, Jing; Xiong, Xin; Bai, Libing; Li, Zhaojun

    2013-01-01

    In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physics and principles of multi-wave phenomena and hybrid imaging methods are inherently different. After a brief introduction of nondestructive evaluation (NDE), structure health monitoring (SHM) and their related challenges, several recent advances that have significantly extended imaging methods from laboratory development into practical applications were summarized, followed by conclusions and discussion on future directions. PMID:24287536

  10. Preliminary report of the comparison of multiple non-destructive assay techniques on LANL Plutonium Facility waste drums

    SciTech Connect

    Bonner, C.; Schanfein, M.; Estep, R.

    1999-03-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content. The DOE Complex faces the daunting task of measuring nuclear material with both a wide range of masses and matrices. Similarly daunting can be the selection of a non-destructive assay (NDA) technique(s) to efficiently perform the quantitative assay over the entire waste population. In fulfilling its role of a DOE Defense Programs nuclear User Facility/Technology Development Center, the Los Alamos National Laboratory Plutonium Facility recently tested three commercially built and owned, mobile nondestructive assay (NDA) systems with special nuclear materials (SNM). Two independent commercial companies financed the testing of their three mobile NDA systems at the site. Contained within a single trailer is Canberra Industries segmented gamma scanner/waste assay system (SGS/WAS) and neutron waste drum assay system (WDAS). The third system is a BNFL Instruments Inc. (formerly known as Pajarito Scientific Corporation) differential die-away imaging passive/active neutron (IPAN) counter. In an effort to increase the value of this comparison, additional NDA techniques at LANL were also used to measure these same drums. These are comprised of three tomographic gamma scanners (one mobile unit and two stationary) and one developmental differential die-away system. Although not certified standards, the authors hope that such a comparison will provide valuable data for those considering these different NDA techniques to measure their waste as well as the developers of the techniques.

  11. A Survey of Techniques for Approximate Computing

    DOE PAGESBeta

    Mittal, Sparsh

    2016-03-18

    Approximate computing trades off computation quality with the effort expended and as rising performance demands confront with plateauing resource budgets, approximate computing has become, not merely attractive, but even imperative. Here, we present a survey of techniques for approximate computing (AC). We discuss strategies for finding approximable program portions and monitoring output quality, techniques for using AC in different processing units (e.g., CPU, GPU and FPGA), processor components, memory technologies etc., and programming frameworks for AC. Moreover, we classify these techniques based on several key characteristics to emphasize their similarities and differences. Finally, the aim of this paper is tomore » provide insights to researchers into working of AC techniques and inspire more efforts in this area to make AC the mainstream computing approach in future systems.« less

  12. An overview of the nondestructive inspection techniques for coiled tubing and pipe

    SciTech Connect

    Stanley, R.K.

    1996-11-01

    Coiled steel tubing and pipe in the diameter range 20--90 mm (0.75--3.5 in.) are replacing conventional oilfield materials for a variety of purposes including workovers, drilling, production tubing, umbilicals, and flowlines. They offer all the advantages of long tubes with no threaded connections. Because coiled tubing is being produced to high quality standards, it is lasting longer than ever before, and the need has arisen for careful nondestructive inspection at frequent intervals to determine accumulated damage to the string and the need for repair. Currently, derating of used coiled tubing using nondestructive testing (NDT) is not performed. While NDT devices for oilfield tubulars have been well documented, little has been written regarding the NDT of coiled tubing. This paper outlines the current NDT methods used during the manufacture of new tubing and the inspection of used coiled tubing.

  13. Notched graphite polymimide composites at room and notched graphite polymide composites at room and elevated temperatures. [nondestructive test techniques

    NASA Technical Reports Server (NTRS)

    Awerbuch, J.; Perkinson, H. E.; Kamel, I. L.

    1980-01-01

    The fracture behavior in graphite/polyimide (Gr/PI) Celion 6000/PMR-15 composites was characterized. Emphasis was placed on the correlation between the observed failure modes and the deformation characteristics of center-notched Gr/Pl laminates. Crack tip damage growth, fracture strength and notch sensitivity, and the associated characterization methods were also examined. Special attention was given to nondestructive evaluation of internal damage and damage growth, techniques such as acoustic emission, X-ray radiography, and ultrasonic C-scan. Microstructural studies using scanning electron microscopy, photomicrography, and the pulsed nuclear magnetic resonance technique were employed as well. All experimental procedures and techniques are described and a summary of representative results for Gr/Pl laminates is given.

  14. Application of Advanced Nondestructive Evaluation Techniques for Cylindrical Composite Test Samples

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.; Roth, Donald J.; Salem, Jonathan A.

    2013-01-01

    Two nondestructive methods were applied to composite cylinder samples pressurized to failure in order to determine manufacturing quality and monitor damage progression under load. A unique computed tomography (CT) image processing methodology developed at NASA Glenn Research was used to assess the condition of the as-received samples while acoustic emission (AE) monitoring was used to identify both the extent and location of damage within the samples up to failure. Results show the effectiveness of both of these methods in identifying potentially critical fabrication issues and their resulting impact on performance.

  15. Comparison of traditional nondestructive analysis of RERTR fuel plates with digital radiographic techniques

    SciTech Connect

    Davidsmeier, T.; Koehl, R.; Lanham, R.; O'Hare, E.; Wiencek, T

    2008-07-15

    The current design and fabrication process for RERTR fuel plates utilizes film radiography during the nondestructive testing and characterization. Digital radiographic methods offer a potential increases in efficiency and accuracy. The traditional and digital radiographic methods are described and demonstrated on a fuel plate constructed with and average of 51% by volume fuel using the dispersion method. Fuel loading data from each method is analyzed and compared to a third baseline method to assess accuracy. The new digital method is shown to be more accurate, save hours of work, and provide additional information not easily available in the traditional method. Additional possible improvements suggested by the new digital method are also raised. (author)

  16. Development of nondestructive testing techniques for plated-through holes in multilayer printed circuit boards

    NASA Technical Reports Server (NTRS)

    Anthony, P. L.; Mcmurtrey, J. E.

    1971-01-01

    The development of a nondestructive test with the capability to interrogate plated-through holes as small as 0.51 millimeters inside diameter is discussed. The system can detect defects such as holes, voids, cracks, and thin spots that reduce the current carrying capability of plates-through interconnects by 20 percent or more. Efforts were directed toward the design and fabrication of magnetic circuitry mutual coupling probes and to evaluate the effectiveness of these devices for detecting in multilayer board plated-through holes.

  17. Nondestructive biomarkers in ecotoxicology.

    PubMed Central

    Fossi, M C

    1994-01-01

    The aim of this article is to attempt a concise review of the state of the art of the nondestructive biomarkers approach in vertebrates, establishing a consensus on the most useful and sensitive nondestructive biomarker techniques, and proposing research priorities for the development and validation of this promising methodology. The following topics are discussed: the advantages of the use of nondestructive strategies in biomonitoring programs and the research fields in which nondestructive biomarkers can be applied; the biological materials suitable for nondestructive biomarkers and residue analysis in vertebrates; which biomarkers lend themselves to noninvasive techniques; and the validation and implementation strategy of the nondestructive biomarker approach. Examples of applications of this methodology in the hazard assessment of endangered species are also presented. Images Figure 1. C PMID:7713034

  18. Nondestructive technique for the characterization of the pore size distribution of soft porous constructs for tissue engineering.

    PubMed

    Safinia, Laleh; Mantalaris, Athanasios; Bismarck, Alexander

    2006-03-28

    Polymer scaffolds tailored for tissue engineering applications possessing the desired pore structure require reproducible fabrication techniques. Nondestructive, quantitative methods for pore characterization are required to determine the pore size and its distribution. In this study, a promising alternative to traditional pore size characterization techniques is presented. We introduce a quantitative, nondestructive and inexpensive method to determine the pore size distribution of large soft porous solids based on the on the displacement of a liquid, that spreads without limits though a porous medium, by nitrogen. The capillary pressure is measured and related to the pore sizes as well as the pore size distribution of the narrowest bottlenecks of the largest interconnected pores in a porous medium. The measured pore diameters correspond to the narrowest bottleneck of the largest pores connecting the bottom with the top surface of a given porous solid. The applicability and reproducibility of the breakthrough technique is demonstrated on two polyurethane foams, manufactured using the thermally induced phase separation (TIPS) process, with almost identical overall porosity (60-70%) but very different pore morphology. By selecting different quenching temperatures to induce polymer phase separation, the pore structure could be regulated while maintaining the overall porosity. Depending on the quenching temperature, the foams exhibited either longitudinally oriented tubular macropores interconnected with micropores or independent macropores connected to adjacent pores via openings in the pore walls. The pore size and its distribution obtained by the breakthrough test were in excellent agreement to conventional characterization techniques, such as scanning electron microscopy combined with image analysis, BET technique, and mercury intrusion porosimetry. This technique is suitable for the characterization of the micro- and macropore structure of soft porous solids

  19. Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique

    NASA Astrophysics Data System (ADS)

    Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Law, Susan; Swain, Michael; Xue, Jing

    2009-09-01

    Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate broadband surface acoustic wave impulses that are detected with a simplified optical fiber interferometer. The measured surface wave velocity dispersion spectrum is in turn used to characterize the elasticity of the specimen. The NDE system and the analysis technique are validated with measurements of different metal structures and then applied to evaluate human dental enamel. Artificial lesions are prepared on the samples to simulate different states of enamel elasticity. Measurement results for both sound and lesioned regions, as well as lesions of different severity, are clearly distinguishable from each other and fit well with physical expectations and theoretical value. This is the first time, to the best of our knowledge, that a laser-based surface wave velocity dispersion technique is successfully applied on human dental enamel, demonstrating the potential for noncontact, nondestructive in vivo detection of the development of carious lesions.

  20. Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage.

    PubMed

    Mansour, Joseph M; Lee, Zhenghong; Welter, Jean F

    2016-03-01

    In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue. PMID:26817458

  1. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our further development of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns transmitted through water only and transmitted through water and a thin woven composite. All images of diffraction patterns have been included on the accompanying CD-ROM in the JPEG format and Adobe TM Portable Document Format (PDF), in addition to the inclusion of hardcopies of the images contained in this report. In our previous semi-annual Progress Report (NAG 1-1848, December, 1996), we proposed a simple model to simulate the effect of a thin woven composite on an insonifying ultrasonic pressure field. This initial approach provided an avenue to begin development of a robust measurement method for nondestructive evaluation of anisotropic materials. In this Progress Report, we extend that work by performing experimental measurements on a single layer of a five-harness biaxial woven composite to investigate how a thin, yet architecturally complex, material interacts with the insonifying ultrasonic field. In Section 2 of this Progress Report we describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. We also briefly describe the thin composite specimen investigated. Section 3 details the analysis of the experimental data followed by the experimental results in Section 4. Finally, a discussion of the observations and conclusions is found in Section 5.

  2. Non-destructive analysis of didymium and praseodymium molybdate crystals using energy dispersive X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Bhat, C. K.; Joseph, Daisy; Pandita, Sanjay; Kotru, P. N.

    2016-08-01

    Analysis of didymium (Di) and praseodymium molybdate crystals were carried out using energy dispersive X-ray fluorescence (EDXRF). The assigned empirical chemical formulae of the composites were tested and verified by the EDXRF technique by estimating experimental major elemental concentration ratios. On the Basis of these ratios, the established formulae for some of the composite materials have been verified and suggestions made for their refinement. Non-destructive technique used in this analysis enables to retain the original crystal samples and makes rapid simultaneous scan of major elements such as La, Pr, Ned and Mo as well as impurities such as Ce. Absence of samarium(Sm) in the spectrum during analysis of didymium molybdate crystals indicated an incomplete growth of mixed rare earth single crystal. These crystals (e.g.,Di) are shown to be of modified stoichiometry with Ce as trace impurity.

  3. A portable nondestructive real-time detection system for inspection of pork quality attributes using Vis/NIR spectral technique

    NASA Astrophysics Data System (ADS)

    Sun, Hongwei; Peng, Yankun

    2016-05-01

    There are many preferences expressing the quality of pork: color, pH, especially TVB-N content. Different quality pork has different spectral feature (in range of 400 to 1000nm). To detect quality attributes of pork easily, real-time, nondestructively, a portable device based on Vis/NIR spectral technique was developed. The device is mainly made up of four units: light source, spectrometer, controller and display screen. After hardware platform established, reflectance spectra of 44 samples were collected from this system. And their physicochemical characteristics such as color parameters, pH value and the content of total volatile basic-nitrogen (TVB-N) were measured in standard methods. Spectrum data acquired were processed by Savitzky-Golay filter(S-G) for noise removal, and then operated by standard normal variable transformation (SNV) for baseline drifts relieving. The partial least squares regression (PLSR) was used to build prediction models for L*, a*, b* pH* and TVB-N content, which could gain good prediction results with Rp of 0.92, 0.91, 0.92, 0.95 and 0.96 respectively. The results demonstrated that this device could be a promising tool applied to detecting pork quality attributes portably, real-time and nondestructively.

  4. Flat nose low velocity drop-weight impact response of carbon fibre composites using non-destructive damage detection techniques

    NASA Astrophysics Data System (ADS)

    Farooq, Umar; Myler, Peter

    2015-03-01

    This work is mainly concerned with the nondestructive post-impact damage evaluation of carbon fibre reinforced laminated composite panels subject to low velocity drop-weight impact by flat and round nose impactors. Quasi-isotropic laminates consisting of eight-, sixteen-, and twenty-four plies were impacted by flat and round nose impactors at different velocity levels. Load-time history data were recorded and plotted to correlate loaddrop as damage level to the impactor nose profiles. Test produced data, non-destructive damage detection techniques: visual, ultrasonic, and eddy- current, and computer simulations were utilised to identify and quantify status of the impact induced damage. To evaluate damage in relatively thick laminates (consisting of 24-Ply), the damage ratios and deflection quantities were correlated to the corresponding impactor nose profiles. Damage induced by the flat nose impactor to thick laminates was compared against the data produced by the round nose impactor. Results show that relatively thin laminates were largely affected by the impactor nose. Reasonable difference was observed in damage caused by flat and round impactor nose profiles to thick laminates impacted at relatively higher velocity impacts. Resultswere compared and validated against simulation produced data.

  5. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    SciTech Connect

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  6. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    PubMed Central

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G.; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  7. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique.

    PubMed

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  8. Non-destructive techniques used during the restoration of the relief "Madonna and Child" by Jacopo Sansovino

    NASA Astrophysics Data System (ADS)

    Buccolieri, Alessandro; Buccolieri, Giovanni; Castellano, Alfredo; Colosso, Pietro Quarta; Miotto, Lidiana

    2015-08-01

    The characterization of the main pigments present in the papier-mâché relief depicting a " Madonna and Child" by Jacopo Sansovino, preserved at the National Museum of Fine Arts in Budapest, has been carried out using non-destructive techniques. In particular, an XRF portable instrument and an XRD apparatus were used in order to determine the elements and compounds of the pigments, respectively. The experimental results indicate that zinc and barium are present on the relief, and this demonstrates that the artwork has undergone restoration since zinc has been in use since 1840 AD. Moreover, radiographic and stereoradiographic analyses were performed several times in order to assess the condition of the work and, above all, the state of the boards that support the work, the cavity inside the cardboard, the surface and the presence of nails.

  9. Nondestructive evaluation

    SciTech Connect

    Martz, H E

    1998-01-01

    The Nondestructive Evaluation (NDE) thrust area at Lawrence Livermore National Laboratory (LLNL) supports initiatives that advance inspection science and technology. The goal is to provide cutting-edge technologies, that show promise for quantitative inspection and characterization tools two to three years into the future. The NDE thrust area supports a multidisciplinary team, consisting of mechanical and electronics engineers, physicists, materials and computer scientists, chemists, technicians, and radiographers. These team members include personnel that cross departments within LLNL, and some are from academia and industry, within the US and abroad. This collaboration brings together the necessary and diver disciplines to provide the key scientific and technological advancements required to meet LLNL programmatic and industrial NDE challenges. The primary contributions of the NDE thrust area this year are described in these five reports: (1) Image Recovery Techniques for X-Ray Computed Tomography for Limited-Data Environments; (2) Techniques for Enhancing Laser Ultrasonic Nondestructive Evaluation; (3) Optical Inspection of Glass-Epoxy Bonds; (4) Miniature X-Ray Source Development; and (5) Improving Computed Tomography Design and Operation Using Simulation Tools.

  10. New nondestructive techniques for the detection and quantification of corrosion in aircraft structures

    NASA Technical Reports Server (NTRS)

    Winfree, W. P.; Cramer, K. E.; Johnston, P. H.; Namkung, M.

    1995-01-01

    An overview is presented of several techniques under development at NASA Langley Research Center for detection and quantification of corrosion in aircraft structures. The techniques have been developed as part of the NASA Airframe Structural Integrity Program. The techniques focus on the detection of subsurface corrosion in thin laminated structures. Results are presented on specimens with both manufactured defects, for calibration of the techniques, and on specimens removed from aircraft.

  11. Integration of infrared and optical imaging techniques for the nondestructive inspection of aeronautic parts

    NASA Astrophysics Data System (ADS)

    López, F.; Sfarra, S.; Ibarra-Castanedo, C.; Paoletti, D.; Maldague, X.

    2015-05-01

    This work focuses in the implementation of infrared and optical imaging techniques for the inspection of aeronautics parts. To this aim, a helicopter blade with known defects is inspected with four different techniques: long pulse thermography, pulsed thermography, digital speckle photography (DSP) and holographic interferometry (HI). The first two techniques belongs to the group of infrared imaging techniques, which are based on the analysis of the infrared thermal patterns in order to detect internal anomalies in the material; whilst the last two (DSP and HI) corresponds to the optical imaging techniques which make use of visible light to measure the material response to an applied stress. Both techniques were applied using the active approach, i.e. an external stimulation is applied in order to produce a gradient in either, the thermal and/or displacement field of the material. The results are then compared in order to evaluate the advantages and limitations of each technique.

  12. Micro-compression: a novel technique for the nondestructive assessment of local bone failure.

    PubMed

    Müller, R; Gerber, S C; Hayes, W C

    1998-12-01

    Many bones within the axial and appendicular skeleton are subjected to repetitive, cyclic loading during the course of ordinary daily activities. If this repetitive loading is of sufficient magnitude or duration, fatigue failure of the bone tissue may result. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, and are often preceded by buckling and bending of microstructural elements. However, the relative importance of bone density and architecture in the etiology of these fractures is poorly understood. The aim of the study was to investigate failure mechanisms of 3D trabecular bone using micro-computed tomography (microCT). Because of its nondestructive nature, microCT represents an ideal approach for performing not only static measurements of bone architecture but also dynamic measurements of failure initiation and propagation as well as damage accumulation. For the purpose of the study, a novel micro-compression device was devised to measure loaded trabecular bone specimens directly in a micro-tomographic system. The measurement window in the device was made of a radiolucent, highly stiff plastic to enable X-rays to penetrate the material. The micro-compressor has an outer diameter of 19 mm and a total length of 65 mm. The internal load chamber fits wet or dry bone specimens with maximal diameters of 9 mm and maximal lengths of 22 mm. For the actual measurement, first, the unloaded bone is measured in the microCT. Second, a load-displacement curve is recorded where the load is measured with an integrated mini-button load cell and the displacement is computed directly from the microCT scout-view. For each load case, a 3D snap-shot of the structure under load is taken providing 34 microm nominal resolution. Initial measurements included specimens from bovine tibiae and whale spine to investigate the influence of the structure type on the failure mechanism. In a

  13. Recommendations for abortion surveys using the ballot-box technique.

    PubMed

    Medeiros, Marcelo; Diniz, Debora

    2012-07-01

    The article lists recommendations for dealing with methodological aspects of an abortion survey and makes suggestions for testing and validating the survey questionnaire. The recommendations are based on the experience of the Brazilian Abortion Survey (PNA), a random sample household survey that used the ballot-box technique and covered adult women in all urban areas of the country. PMID:22872333

  14. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this

  15. Development and optimization of thermographic techniques for Non-Destructive Evaluation of multilayered structures

    NASA Astrophysics Data System (ADS)

    Gavrilov, Dmitry J.

    Quality control of modern materials is of the utmost importance in science and industry. Methods for nondestructive evaluation of material properties and the presence of defects are numerous. They differ in terms of their sensitivity and applicability in various conditions, and they provide different kinds of data such as the speed of sound in the material, its hardness, radiation absorption, etc. Based on measured characteristics an analyst makes a decision on the material studied. This work addresses a class of methods known as active thermographic analysis. Thermography analyzes the temperature of the surface of the sample under different external conditions. By keeping track of temperature changes at the surface caused by a deposition of heat on the sample one can determine its material properties such as theand processing the data captured it is possible to make decisions on parameters of this sample. Among the data which can be acquired are such important information as the location of internal defects (e.g., detachments, hollows, inclusions), thickness of the material layers, thermal parameters of the material and the location of internal defects (e.g., detachments, hollows, inclusions). The first part of this research investigates a method for analysis of layered composite materials using the approach based on interference of so called temperature waves. As demonstrated using the expressions derived, one can determine the thermal properties of the layers of the sample by applying a harmonically modulated heat flux to the surfaces and measuring the phase of the periodically changing surface temperature. This approach can be of use in the field of designing and analysis of composite thermal insulation coatings. In the second part of this work a method of analyzing objects of fine art was investigated, particularly - detection of subsurface defects. In the process of preserving art it is of primary importance to determine whether restoration is necessary

  16. Pulsed remote eddy current field array technique for nondestructive inspection of ferromagnetic tube

    NASA Astrophysics Data System (ADS)

    Yang, Binfeng; Li, Xuechao

    2010-03-01

    One pick-up coil with a large inner diameter is usually used in pulsed remote field eddy current technique, which decreases the identification ability to defect. With the purpose of overcoming this problem, array pulsed remote field eddy current technique is proposed to enhance the precision in quantification of defect. The finite element method is used to optimise the structure of probe and analyse of the influence effect of response signal with the variation of the defect depths. The results of experimental work confirm that the array pulsed remote field technique has the advantages of high precision and sensitivity, which can be used as an effective method for quantification of defect in tube.

  17. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components

    NASA Astrophysics Data System (ADS)

    1980-10-01

    Detection of electric discharge machined notches in a silicon carbide tube by an ultrasonic bore side probe under microcomputer control was demonstrated. Use of the reflection mode was shown to enhance the sensitivity of flaw detection with an acoustic microscope. In this configuration, the transducer and laser scanned coverslip are both on the tube outer surface, eliminating the need to fill the tube with water. A conceptual design is presented for inspecting tubes up to seven feet long in both through transmission and reflection mode configurations. A comparison of NDE techniques for ceramic butt joints showed holographic interferometry to be generally better than dye-penetrant, radiographic, or ultrasonic techniques for characterizing a crack-like inner wall defect. Pitch catch and pulse echo ultrasonic techniques also indicated the presence of an anomaly in the region identified as flawed via holography, while radiographic and penetrant testing results were ambiguous.

  18. Gpr and Seismic Based Non-Destructive Geophysical Survey for Reinforcement of Historical Fire Tower of Sopron-Hungary

    NASA Astrophysics Data System (ADS)

    Kanli, A. I.; Taller, G.; Nagy, P.; Tildy, P.; Pronay, Z.; Toros, E.

    2013-12-01

    The Fire-Tower which is located in the main square at the hearth of Sopron is the symbol of the city. The museum of Sopron exists in the Storno-house west from the tower. The new city hall stands next to the tower to the east. Funds are from the roman age while the tower was first mentioned in writing in 1409. In 1676, it was burned down to the ground, but re-constructed. In 1894, the old City Hall was deconstucted, but the tower became unstable. István Kiss and Frigyes Schulek saved it by the walling up of the gate. In the year 1928, the scuptures of the main gate which symbolizes the fidelity of the town was sculpted by Zsigmond Kisfaludy Strobl. The old building was deconstructed from its west side, a new concrate museum was built in 1970. After years, important renovation and reinforcement studies had to be needed. For this aim, during the renovation and reinforcement studies, GPR and Seismic based non-destructive geophysical surveys were carried out before and after cement injection to observe the changes of the wall conditions of the historical tower located in Sopron-Hungary for understanding the success of the reinforcements studies. In the GPR survey, 400 MHz and 900 MHz antennas were used. The space between each profiles were taken as 0.5 m for 400 MHz and 0.25m for 900 MHz respectively. After the injection process, reflections from the fractured and porous zones were weakened imaged clearly by GPR data and significant rise of the p-wave velocities were observed.

  19. Survey of Radiographic Requirements and Techniques.

    ERIC Educational Resources Information Center

    Farman, Allan G.; Shawkat, Abdul H.

    1981-01-01

    A survey of dental schools revealed little standardization of student requirements for dental radiography in the United States. There was a high degree of variability as to what constituted a full radiographic survey, which has implications concerning the maximum limits to patient exposure to radiation. (Author/MLW)

  20. Eddy current technique applied to the nondestructive evaluation of turbine blade wall thickness

    NASA Astrophysics Data System (ADS)

    Le Bihan, Yann; Joubert, Pierre-Yves; Placko, Dominique

    2000-05-01

    The high pressure turbine blades of jet engines show internal channels designed for air cooling. These recesses define the internal walls (partitions) and external walls of the blade. The external wall thickness is a critical parameter which has to be systematically checked in order to ensure the blade strength. The thickness evaluation is usually lead by ultrasonic technique or by X-ray tomography. Nevertheless, both techniques present some drawbacks related to measurement speed and automation capability. These drawbacks are bypassed by the eddy current (EC) technique, well known for its robustness and reliability. However, the wall thickness evaluation is made difficult because of the complexity of the blade geometry. In particular, some disturbances appear in the thickness evaluation because of the partitions, which exclude the use of classical EC probes such as cup-core probe. In this paper, we show the main advantages of probes creating an uniformly oriented magnetic field in order to reduce the partition disturbances. Furthermore, we propose a measurement process allowing to separate the wall thickness parameter from the EC signals. Finally, we present some experimental results validating the proposed technique.

  1. Application of ultrasonic technique in nondestructive food quality analysis: a review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quality control and safe storage is important in food processing and storage. Composition of food has more effect on quality in terms of nutritional values, functional properties, commercial values and storage conditions of the food products. Traditional analytical techniques that are used for compo...

  2. Nondestructive Evaluation of Holed CFRP Laminates by a New Technique to Visualize Propagation of Ultrasonic Waves

    NASA Astrophysics Data System (ADS)

    Yashiro, Shigeki; Takatsubo, Junji; Toyama, Nobuyuki; Okabe, Tomonaga; Takeda, Nobuo

    This study investigated damage detection in holed CFRP laminates by using a newly developed technique for visualizing ultrasonic waves. This technique provided a moving diagram of propagating waves with non-contact scanning by a pulsed laser. Its measurement scheme overcame the difficulties of sensitivity in conventional methods and enabled us to observe ultrasonic waves on CFRP laminates. We observed two types of ultrasonic waves propagating on the CFRP laminate in the measured snapshots. These waves were identified as the S0 and the A0 Lamb modes by the dispersion curves, confirming the validity of the visualization technique for composite laminates. Furthermore, ply cracks and delamination, as well as the damage during manufacturing, were observed near the hole in the loaded specimens, and we successfully visualized the Lamb waves scattered by the delamination. The region of wave scattering agreed with the damage observed by soft X-ray radiography. These inspection results demonstrated the usefulness of the visualization technique in inspecting composite laminates.

  3. Non-destructive evaluation techniques, high temperature ceramic component parts for gas turbines

    NASA Technical Reports Server (NTRS)

    Reiter, H.; Hirsekorn, S.; Lottermoser, J.; Goebbels, K.

    1984-01-01

    This report concerns studies conducted on various tests undertaken on material without destroying the material. Tests included: microradiographic techniques, vibration analysis, high-frequency ultrasonic tests with the addition of evaluation of defects and structure through analysis of ultrasonic scattering data, microwave tests and analysis of sound emission.

  4. A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

    SciTech Connect

    Navarro, Jorge

    2013-12-01

    The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method

  5. Summary of nondestructive testing theory and practice

    NASA Technical Reports Server (NTRS)

    Meister, R. P.; Randall, M. D.; Mitchell, D. K.; Williams, L. P.; Pattee, H. E.

    1972-01-01

    The ability to fabricate design critical and man-rated aerospace structures using materials near the limits of their capabilities requires a comprehensive and dependable assurance program. The quality assurance program must rely heavily on nondestructive testing methods for thorough inspection to assess properties and quality of hardware items. A survey of nondestructive testing methods is presented to provide space program managers, supervisors and engineers who are unfamiliar with this technical area with appropriate insight into the commonly accepted nondestructive testing methods available, their interrelationships, used, advantages and limitations. Primary emphasis is placed on the most common methods: liquid penetrant, magnetic particle, radiography, ultrasonics and eddy current. A number of the newer test techniques including thermal, acoustic emission, holography, microwaves, eddy-sonic and exo-electron emission, which are beginning to be used in applications of interest to NASA, are also discussed briefly.

  6. Non-Destructive Techniques in the Tacis and Phare Nuclear Safety Programmes

    SciTech Connect

    Bieth, Michel

    2002-07-01

    Decisions regarding the verification of design plant lifetime and potential license renewal periods involve a determination of the component and circuit condition. In Service Inspection of key reactor components becomes a crucial consideration for continued safe plant operation. The determination of the equipment properties by Non Destructive Techniques during periodic intervals is an important aspect of the assessment of fitness-for-service and safe operation of nuclear power plants The Tacis and Phare were established since 1991 by the European Union as support mechanisms through which projects could be identified and addressed satisfactorily. In Nuclear Safety, the countries mainly concerned are Russia, Ukraine, Armenia, and Kazakhstan for the Tacis programme, and Bulgaria, Czech Republic, Hungary, Slovak Republic, Lithuania, Romania and Slovenia for the Phare programme. The Tacis and Phare programs concerning the Nuclear Power Plants consist of: - On Site Assistance and Operational Safety, - Design Safety, - Regulatory Authorities, - Waste management, and are focused on reactor safety issues, contributing to the improvement in the safety of East European reactors and providing technology and safety culture transfer. The main parts of these programmes are related to the On-Site Assistance and to the Design Safety of VVER and RBMK Nuclear power plants where Non Destructive Techniques for In Service Inspection of the primary circuit components are addressed. (authors)

  7. Effective combination of DIC, AE, and UPV nondestructive techniques on a scaled model of the Belgian nuclear waste container

    NASA Astrophysics Data System (ADS)

    Iliopoulos, Sokratis N.; Areias, Lou; Pyl, Lincy; Vantomme, John; Van Marcke, Philippe; Coppens, Erik; Aggelis, Dimitrios G.

    2015-03-01

    Protecting the environment and future generations against the potential hazards arising from high-level and heat emitting radioactive waste is a worldwide concern. Following this direction, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials has come up with the reference design which considers the geological disposal of the waste in purely indurated clay. In this design the wastes are first post-conditioned in massive concrete structures called Supercontainers before being transported to the underground repositories. The Supercontainers are cylindrical structures which consist of four engineering barriers that from the inner to the outer surface are namely: the overpack, the filler, the concrete buffer and possibly the envelope. The overpack, which is made of carbon steel, is the place where the vitrified wastes and spent fuel are stored. The buffer, which is made of concrete, creates a highly alkaline environment ensuring slow and uniform overpack corrosion as well as radiological shielding. In order to evaluate the feasibility to construct such Supercontainers two scaled models have so far been designed and tested. The first scaled model indicated crack formation on the surface of the concrete buffer but the absence of a crack detection and monitoring system precluded defining the exact time of crack initiation, as well as the origin, the penetration depth, the crack path and the propagation history. For this reason, the second scaled model test was performed to obtain further insight by answering to the aforementioned questions using the Digital Image Correlation, Acoustic Emission and Ultrasonic Pulse Velocity nondestructive testing techniques.

  8. Inspection of the Space Shuttle External Tank SOFI Using Near-Field and Focused Millimeter Wave Nondestructive Testing Techniques

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Hepburn, F.; Walker, J.; Zoughi, R.

    2005-01-01

    The Space Shuttle Columbia's catastrophic failure has been attributed to a piece of external tank SOFI (Spray On Foam Insulation) striking the left wing of the orbiter causing significant damage to some of the reinforced carbon/carbon leading edge wing panels. Subsequently, several nondestructive testing (NDT) techniques have been considered for inspecting the external tank. One such method involves using millimeter waves which have been shown to easily penetrate through the foam and provide high resolution images of its interior structures. This paper presents the results of inspecting three different SOFI covered panels by reflectometers at millimeter wave frequencies, specifically at 100 GHz. Each panel was fitted with various embedded anomalies/inserts representing voids and unbonds of diferent shapes, sizes and locations within each panel. In conjunction with these reJqectome&rs, radiators including a focused lens antenna and a small horn antenna were used. The focused lens antenna provided for a footprint diameter of approximately 1.25 cm (0.5") at 25.4 cm (10") away from the lens surface. The horn antenna was primarily operated in its near-field for obtaining relatively high resolution images. These images were produced using 2 0 scanning mechanisms. Discussions of the difference between the capabilities of these two types of antennas (radiators) for the purpose of inspecting the SOFI as it relates to the produced images are also presented.

  9. A survey of techniques for corrosion monitoring

    SciTech Connect

    Mickalonis, J.I.

    1992-10-01

    Corrosion monitoring techniques have improved with advances in instrumentation technology and corrosion research. Older techniques, such as coupon immersion, generally provide historical information. The new electrochemical techniques, which have not been used widely at SRS, allow on-line monitoring and correlation with process changes. These techniques could improve the corrosion assessment of the waste tanks to be used for In-Tank Precipitation and Extended Sludge Processing. A task was initiated to place an electrochemical probe into tank 48 for testing the utility of this technique for waste tank applications.

  10. Evaluation of bonds in armor plate and other materials using infrared nondestructive testing techniques.

    PubMed

    Vogel, P E

    1968-09-01

    Reported here are the results of using an ir technique in evaluating the bond in hot-roll bonded armor plate, a coating bond, and the bonds in the three-layer construction of a small missile motor. When a specimen is exposed to heat, the heat flows into it at a rate that can be determined. If the flow is interrupted by a void, the inclusion of a material of different conductivity, or any similar thermal barrier, a difference in surface temperature will result that can be defined with an ir radiometer or thermograph. Lack of bond, while not presenting a gross void, is shown here to be a sufficient impediment to be distinguishable. PMID:20068876

  11. Nondestructive determination of plutonium mass in spent fuel: prelliminary modeling results using the passive neutron Albedo reactivity technique

    SciTech Connect

    Evans, Louise G; Tobin, Stephen J; Schear, Melissa A; Menlove, Howard O; Lee, Sang Y; Swinhoe, Martyn T

    2009-01-01

    There are a variety of motivations for quantifying plutonium (Pu) in spent fuel assemblies by means of nondestructive assay (NDA) including the following: strengthening the capability of the International Atomic Energy Agency (LAEA) to safeguard nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at pyrochemical processing facilities, providing quantitative input to burnup credit and final safeguards measurements at a long-term repository. In order to determine Pu mass in spent fuel assemblies, thirteen NDA techniques were identified that provide information about the composition of an assembly. A key motivation of the present research is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the Pu mass of an assembly and (2) detecting the diversion of a significant number of rods. It is therefore anticipated that a combination of techniques will be required. A 5 year effort funded by the Next Generation Safeguards Initiative (NGSI) of the U.S. DOE was recently started in pursuit of these goals. The first two years involves researching all thirteen techniques using Monte Carlo modeling while the final three years involves fabricating hardware and measuring spent fuel. Here, we present the work in two main parts: (1) an overview of this NGSI effort describing the motivations and approach being taken; (2) The preliminary results for one of the NDA techniques - Passive Neutron Albedo Reactivity (PNAR). The PNAR technique functions by using the intrinsic neutron emission of the fuel (primarily from the spontaneous fission of curium) to self-interrogate any fissile material present. Two separate measurements of the spent fuel are made, both with and without cadmium (Cd) present. The ratios of the Singles, Doubles and Triples count rates obtained in each case are analyzed; known as the Cd ratio. The primary differences between the two measurements are the neutron energy spectrum

  12. Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSU research overview and update on 6 NDA techniques

    SciTech Connect

    Tobin, Stephen J; Conlin, Jeremy L; Evans, Louise G; Hu, Jianwei; Blanc, Pauline C; Lafleur, Adrienne M; Menlove, Howard O; Schear, Melissa A; Swinhoe, Martyn T; Croft, Stephen; Fensin, Michael L; Freeman, Corey R; Koehler, William E; Mozin, V; Sandoval, N P; Lee, T H; Cambell, L W; Cheatham, J R; Gesh, C J; Hunt, A; Ludewigt, B A; Smith, L E; Sterbentz, J

    2010-09-15

    This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies [burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)]. The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

  13. X-ray computed tomography imaging: A not-so-nondestructive technique

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.; Sears, Hazel; Ebel, Denton S.; Wallace, Sean; Friedrich, Jon M.

    2016-04-01

    X-ray computed tomography has become a popular means for examining the interiors of meteorites and has been advocated for routine curation and for the examination of samples returned by missions. Here, we report the results of a blind test that indicate that CT imaging deposits a considerable radiation dose in a meteorite and seriously compromises its natural radiation record. Ten vials of the Bruderheim L6 chondrite were placed in CT imager and exposed to radiation levels typical for meteorite studies. Half were retained as controls. Their thermoluminescence (TL) properties were then measured in a blind test. Five of the samples had TL data unaltered from their original (~10 cps) while five had very strong signals (~20,000 cps). It was therefore very clear which samples had been in the CT scanner. For comparison, the natural TL signal from Antarctic meteorites is ~5000-50,000 cps. Using the methods developed for Antarctic meteorites, the apparent dose absorbed by the five test samples was calculated to be 83 ± 5 krad, comparable with the highest doses observed in Antarctic meteorites and freshly fallen meteorites. While these results do not preclude the use of CT scanners when scientifically justified, it should be remembered that the record of radiation exposure to ionizing radiations for the sample will be destroyed and that TL, or the related optically stimulated luminescence, are the primary modern techniques for radiation dosimetry. This is particularly important with irreplaceable samples, such as meteorite main masses, returned samples, and samples destined for archive.

  14. Nondestructive, in-process inspection of inertia friction welding : an investigation into a new sensing technique.

    SciTech Connect

    Hartman, D. A.; Cola, M. J.; Dave, V. R.; Dozhier, N. G.; Carpenter, R. W.

    2002-01-01

    This paper investigates the capabilities of a new sensor for in-process monitoring of quality during friction welding. The non-contact sensor is composed of microphones that are mounted in an aluminum ring which surrounds the weld joint. The sensor collects the acoustical energy (in the form of sound pressure) that is emitted during the plastic deformation and phase transformations (if applicable) in friction welding processes. The focus in this preliminary investigation is to search for and identify features within the acoustical emission that are indicative of bond quality. Bar-to-bar inertia friction welding (one form of friction welding) of copper to 304L stainless steel is used in this proof-of-concept study. This material combination exhibits only marginal weldability and is ideally suited for validating the capabilities of this new sensing technique. A probabilistic neural network is employed in this work to analyze the acoustical emission's frequency spectrum in an attempt to classify acceptable, conditional, and unacceptable welds. Our preliminary findings indicate that quality-based process features do exist within the frequency spectrum of the acoustical signature. The results from this analysis are presented. Future work in improving the sensing and interpretation of the data is discussed in an effort to develop a robust method of quality-based, in-process monitoring of friction welds.

  15. Non-destructive elemental quantification of polymer-embedded thin films using laboratory based X-ray techniques

    NASA Astrophysics Data System (ADS)

    Cordes, Nikolaus L.; Havrilla, George J.; Usov, Igor O.; Obrey, Kimberly A.; Patterson, Brian M.

    2014-11-01

    Thin coatings are important for a variety of industries including energy (e.g., solar cells, batteries), consumer electronics (e.g., LCD displays, computer chips), and medical devices (e.g., implants). These coatings are typically highly uniform layers with thicknesses ranging from a monolayer up to several micrometers. Characterizing these highly uniform coatings for their thickness, elemental composition, and uniformity are all paramount, but obtaining these measurements can be more difficult when the layers are subsurface and must be interrogated non-destructively. The coupling of confocal micro-X-ray fluorescence (confocal MXRF) and nano-scale X-ray computed tomography (nano-CT) together can make these measurements while meeting these sensitivity and resolution specifications necessary for characterizing thin films. Elemental composition, atomic percent, placement, and uniformity can be measured in three dimensions with this integrated approach. Confocal MXRF uses a pair of polycapillary optics to focus and collect X-rays from a material from a 3D spatially restricted confocal volume. Because of the spatial definition, individual layers (of differing composition) can be characterized based upon the elementally characteristic X-ray fluorescence collected for each element. Nano-scale X-ray computed tomography, in comparison, can image the layers at very high resolution (down to 50 nm) to precisely measure the embedded layer thickness. These two techniques must be used together if both the thickness and atomic density of a layer are unknown. This manuscript will demonstrate that it is possible to measure both the atomic percent of an embedded thin film layer and confirm its manufacturing quality. As a proof of principle, a 1.5 atomic percent, 2 μm-thick Ge layer embedded within polymer capsules, used for laser plasma experiments at the Omega Laser Facility and National Ignition Facility, are measured.

  16. Nondestructive atomic compositional analysis of BeMgZnO quaternary alloys using ion beam analytical techniques

    NASA Astrophysics Data System (ADS)

    Zolnai, Z.; Toporkov, M.; Volk, J.; Demchenko, D. O.; Okur, S.; Szabó, Z.; Özgür, Ü.; Morkoç, H.; Avrutin, V.; Kótai, E.

    2015-02-01

    The atomic composition with less than 1-2 atom% uncertainty was measured in ternary BeZnO and quaternary BeMgZnO alloys using a combination of nondestructive Rutherford backscattering spectrometry with 1 MeV He+ analyzing ion beam and non-Rutherford elastic backscattering experiments with 2.53 MeV energy protons. An enhancement factor of 60 in the cross-section of Be for protons has been achieved to monitor Be atomic concentrations. Usually the quantitative analysis of BeZnO and BeMgZnO systems is challenging due to difficulties with appropriate experimental tools for the detection of the light Be element with satisfactory accuracy. As it is shown, our applied ion beam technique, supported with the detailed simulation of ion stopping, backscattering, and detection processes allows of quantitative depth profiling and compositional analysis of wurtzite BeZnO/ZnO/sapphire and BeMgZnO/ZnO/sapphire layer structures with low uncertainty for both Be and Mg. In addition, the excitonic bandgaps of the layers were deduced from optical transmittance measurements. To augment the measured compositions and bandgaps of BeO and MgO co-alloyed ZnO layers, hybrid density functional bandgap calculations were performed with varying the Be and Mg contents. The theoretical vs. experimental bandgaps show linear correlation in the entire bandgap range studied from 3.26 eV to 4.62 eV. The analytical method employed should help facilitate bandgap engineering for potential applications, such as solar blind UV photodetectors and heterostructures for UV emitters and intersubband devices.

  17. Survey of immunoassay techniques for biological analysis

    SciTech Connect

    Burtis, C.A.

    1986-10-01

    Immunoassay is a very specific, sensitive, and widely applicable analytical technique. Recent advances in genetic engineering have led to the development of monoclonal antibodies which further improves the specificity of immunoassays. Originally, radioisotopes were used to label the antigens and antibodies used in immunoassays. However, in the last decade, numerous types of immunoassays have been developed which utilize enzymes and fluorescent dyes as labels. Given the technical, safety, health, and disposal problems associated with using radioisotopes, immunoassays that utilize the enzyme and fluorescent labels are rapidly replacing those using radioisotope labels. These newer techniques are as sensitive, are easily automated, have stable reagents, and do not have a disposal problem. 6 refs., 1 fig., 2 tabs.

  18. Survey of Software Assurance Techniques for Highly Reliable Systems

    NASA Technical Reports Server (NTRS)

    Nelson, Stacy

    2004-01-01

    This document provides a survey of software assurance techniques for highly reliable systems including a discussion of relevant safety standards for various industries in the United States and Europe, as well as examples of methods used during software development projects. It contains one section for each industry surveyed: Aerospace, Defense, Nuclear Power, Medical Devices and Transportation. Each section provides an overview of applicable standards and examples of a mission or software development project, software assurance techniques used and reliability achieved.

  19. Survey of air cargo forecasting techniques

    NASA Technical Reports Server (NTRS)

    Kuhlthan, A. R.; Vermuri, R. S.

    1978-01-01

    Forecasting techniques currently in use in estimating or predicting the demand for air cargo in various markets are discussed with emphasis on the fundamentals of the different forecasting approaches. References to specific studies are cited when appropriate. The effectiveness of current methods is evaluated and several prospects for future activities or approaches are suggested. Appendices contain summary type analyses of about 50 specific publications on forecasting, and selected bibliographies on air cargo forecasting, air passenger demand forecasting, and general demand and modalsplit modeling.

  20. Survey Of High Speed Test Techniques

    NASA Astrophysics Data System (ADS)

    Gheewala, Tushar

    1988-02-01

    The emerging technologies for the characterization and production testing of high-speed devices and integrated circuits are reviewed. The continuing progress in the field of semiconductor technologies will, in the near future, demand test techniques to test 10ps to lOOps gate delays, 10 GHz to 100 GHz analog functions and 10,000 to 100,000 gates on a single chip. Clearly, no single test technique would provide a cost-effective answer to all the above demands. A divide-and-conquer approach based on a judicial selection of parametric, functional and high-speed tests will be required. In addition, design-for-test methods need to be pursued which will include on-chip test electronics as well as circuit techniques that minimize the circuit performance sensitivity to allowable process variations. The electron and laser beam based test technologies look very promising and may provide the much needed solutions to not only the high-speed test problem but also to the need for high levels of fault coverage during functional testing.

  1. Superresolution imaging: a survey of current techniques

    NASA Astrophysics Data System (ADS)

    Cristóbal, G.; Gil, E.; Šroubek, F.; Flusser, J.; Miravet, C.; Rodríguez, F. B.

    2008-08-01

    Imaging plays a key role in many diverse areas of application, such as astronomy, remote sensing, microscopy, and tomography. Owing to imperfections of measuring devices (e.g., optical degradations, limited size of sensors) and instability of the observed scene (e.g., object motion, media turbulence), acquired images can be indistinct, noisy, and may exhibit insuffcient spatial and temporal resolution. In particular, several external effects blur images. Techniques for recovering the original image include blind deconvolution (to remove blur) and superresolution (SR). The stability of these methods depends on having more than one image of the same frame. Differences between images are necessary to provide new information, but they can be almost unperceivable. State-of-the-art SR techniques achieve remarkable results in resolution enhancement by estimating the subpixel shifts between images, but they lack any apparatus for calculating the blurs. In this paper, after introducing a review of current SR techniques we describe two recently developed SR methods by the authors. First, we introduce a variational method that minimizes a regularized energy function with respect to the high resolution image and blurs. In this way we establish a unifying way to simultaneously estimate the blurs and the high resolution image. By estimating blurs we automatically estimate shifts with subpixel accuracy, which is inherent for good SR performance. Second, an innovative learning-based algorithm using a neural architecture for SR is described. Comparative experiments on real data illustrate the robustness and utilization of both methods.

  2. Utilization of nondestructive electrochemical techniques in characterizing microbiologically influenced corrosion (MIC) of API-5L X65 carbon linepipe steel: Laboratory study

    NASA Astrophysics Data System (ADS)

    Al-Abbas, F.; Kakpovbia, A.; Mishra, B.; Olson, D.; Spear, J.

    2012-05-01

    Nondestructive electrochemical techniques were used to investigate the microbiologically influenced corrosion (MIC) by Sulfate Reducing Bacteria (SRB) corrosion of API 5L X65 linepipe steel. These techniques included Electrochemical Impedance Spectroscopy (EIS), open circuit potential (OCP) and linear polarization resistance (Rp). OCP trend showed anodic polarization of 67 mV between the biotic media with reference to abiotic media. These shifts were attributed to the cathodic side reactions produced by the metabolic activity of SRB. Through circuit modeling, EIS results were used to interpret the real time interactions between the electrode, biofilm and solution interfaces.

  3. A survey of data mining techniques

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Karimabadi, H.

    2005-12-01

    Data mining is the act of extracting useful knowledge from a data set. This knowledge can take many forms. It can be in the detection of features of interest. It can be in the form of statistical analysis of data sets. It can be in the form of predictive expressions describing the data or relationships between data. It can be in the form of anomaly detection, serendipitous events which require further investigation. The simplest form of data mining consists of manual inspection of the data sets. This has been the norm in space physics for decades. The most advanced forms of data mining make use of emerging computer science methods, including advances in artificial intelligence. In this presentation we will give a brief introduction to some of the resources that are available for performing advanced data mining. We will focus on giving an overview of some data mining techniques, and how they have been, or could be, applied to space physics problems.

  4. Overview of the program to assess the reliability of emerging nondestructive techniques open testing and study of flaw type effect on NDE response

    NASA Astrophysics Data System (ADS)

    Meyer, Ryan M.; Komura, Ichiro; Kim, Kyung-cho; Zetterwall, Tommy; Cumblidge, Stephen E.; Prokofiev, Iouri

    2016-02-01

    In February 2012, the U.S. Nuclear Regulatory Commission (NRC) executed agreements with VTT Technical Research Centre of Finland, Nuclear Regulatory Authority of Japan (NRA, former JNES), Korea Institute of Nuclear Safety (KINS), Swedish Radiation Safety Authority (SSM), and Swiss Federal Nuclear Safety Inspectorate (ENSI) to establish the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT). The goal of PARENT is to investigate the effectiveness of current emerging and perspective novel nondestructive examination procedures and techniques to find flaws in nickel-alloy welds and base materials. This is done by conducting a series of open and blind international round-robin tests on a set of large-bore dissimilar metal welds (LBDMW), small-bore dissimilar metal welds (SBDMW), and bottom-mounted instrumentation (BMI) penetration weld test blocks. The purpose of blind testing is to study the reliability of more established techniques and included only qualified teams and procedures. The purpose of open testing is aimed at a more basic capability assessment of emerging and novel technologies. The range of techniques applied in open testing varied with respect to maturity and performance uncertainty and were applied to a variety of simulated flaws. This paper will include a brief overview of the PARENT blind and open testing techniques and test blocks and present some of the blind testing results.

  5. NDE: An effective approach to improved reliability and safety. A technology survey. [nondestructive testing of aircraft structures

    NASA Technical Reports Server (NTRS)

    Carpenter, J. L., Jr.; Stuhrke, W. F.

    1976-01-01

    Technical abstracts are presented for about 100 significant documents relating to nondestructive testing of aircraft structures or related structural testing and the reliability of the more commonly used evaluation methods. Particular attention is directed toward acoustic emission; liquid penetrant; magnetic particle; ultrasonics; eddy current; and radiography. The introduction of the report includes an overview of the state-of-the-art represented in the documents that have been abstracted.

  6. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1993-01-01

    In this Progress Report, we describe our current research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of stitched composite materials and bonded aluminum plate specimens. One purpose of this investigation is to identify and characterize specific features of polar backscatter interrogation which enhance the ability of ultrasound to detect flaws in a stitched composite laminate. Another focus is to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize bonded aluminum lap joints. As an approach to implementing quantitative ultrasonic inspection methods to both of these materials, we focus on the physics that underlies the detection of flaws in such materials.

  7. A Survey of Architectural Techniques For Improving Cache Power Efficiency

    SciTech Connect

    Mittal, Sparsh

    2013-01-01

    Modern processors are using increasingly larger sized on-chip caches. Also, with each CMOS technology generation, there has been a significant increase in their leakage energy consumption. For this reason, cache power management has become a crucial research issue in modern processor design. To address this challenge and also meet the goals of sustainable computing, researchers have proposed several techniques for improving energy efficiency of cache architectures. This paper surveys recent architectural techniques for improving cache power efficiency and also presents a classification of these techniques based on their characteristics. For providing an application perspective, this paper also reviews several real-world processor chips that employ cache energy saving techniques. The aim of this survey is to enable engineers and researchers to get insights into the techniques for improving cache power efficiency and motivate them to invent novel solutions for enabling low-power operation of caches.

  8. Pattern recognition techniques in microarray data analysis: a survey.

    PubMed

    Valafar, Faramarz

    2002-12-01

    Recent development of technologies (e.g., microarray technology) that are capable of producing massive amounts of genetic data has highlighted the need for new pattern recognition techniques that can mine and discover biologically meaningful knowledge in large data sets. Many researchers have begun an endeavor in this direction to devise such data-mining techniques. As such, there is a need for survey articles that periodically review and summarize the work that has been done in the area. This article presents one such survey. The first portion of the paper is meant to provide the basic biology (mostly for non-biologists) that is required in such a project. This part is only meant to be a starting point for those experts in the technical fields who wish to embark on this new area of bioinformatics. The second portion of the paper is a survey of various data-mining techniques that have been used in mining microarray data for biological knowledge and information (such as sequence information). This survey is not meant to be treated as complete in any form, since the area is currently one of the most active, and the body of research is very large. Furthermore, the applications of the techniques mentioned here are not meant to be taken as the most significant applications of the techniques, but simply as examples among many. PMID:12594081

  9. Nondestructive and Rapid Concurrent Estimation of Paracetamol and Nimesulide in Their Combined Dosage Form Using Raman Spectroscopic Technique

    PubMed Central

    Lakhwani, Gargi R.; Sherikar, O. D.; Mehta, Priti J.

    2013-01-01

    A rapid, nondestructive Raman spectroscopic method was developed for quantitative estimation of paracetamol and nimesulide in their combined dosage form. A Raman univariate calibration model was developed by measuring the peak intensities of paracetamol and nimesulide at 853 cm−1 and 1336 cm−1, respectively. The developed method was successfully applied for in situ, concurrent estimation of paracetamol and nimesulide in their combined dosage and method was also validated according to International Conference on Harmonisation guidelines. Thus, the developed Raman spectroscopic method can be applied for simultaneous estimation of paracetamol and nimesulide in their combined dosage form as a process analytical technology tool by pharmaceutical industries for routine quality control. PMID:24019571

  10. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    The development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of composite materials requires a better understanding of the physics underlying the interaction of ultrasound with the material. The purpose of this investigation is to identify and characterize the features of complex, three dimensional materials that limit the ability of ultrasound to detect flaws in this broad class of emerging materials. In order to explore the interaction of ultrasound with such complex media, we investigate the characteristics of ultrasonic fields which have propagated through samples with complex geometries and/or internal architecture. We focus on the physics that underlies the detection of flaws in such materials.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  12. Preliminary technique assessment for nondestructive evaluation certification of the NNWSI [Nevada Nuclear Waste Storage Investigations] disposal container closure

    SciTech Connect

    Day, R.A.

    1988-12-31

    Under the direction of the Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM) program, the Nevada Nuclear Waste Storage Investigations (NNWSI) project is evaluating a candidate repository site at Yucca Mountain, Nevada, for permanent disposal of high-level nuclear waste. The Lawrence Livermore National Laboratory (LLNL), a participant in the NNWSI project, is developing waste package designs to meet the NRC requirements. One aspect of this waste package is the nondestructive testing of the final closure of the waste container. The container closure weld can best be nondestructively examined (NDE) by a combination of ultrasonics and liquid penetrants. This combination can be applied remotely and can meet stringent quality control requirements common to nuclear applications. Further development in remote systems and inspection will be required to meet anticipated requirements for flaw detection reliability and sensitivity. New research is not required but might reduce cost or inspection time. Ultrasonic and liquid penetrant methods can examine all closure methods currently being considered, which include fusion welding and inertial welding, among others. These NDE methods also have a history of application in high radiation environments and a well developed technology base for remote operation that can be used to reduce development and design costs. 43 refs., 23 figs., 3 tabs.

  13. [Rapid nondestructive detection of water content in fresh pork based on spectroscopy technique combined with support vector machine].

    PubMed

    Zhang, Hai-Yun; Peng, Yan-Kun; Wang, Wei; Zhao, Song-Wei; Liu, Qiao-Qiao

    2012-10-01

    Visible near infrared reflectance spectra in the range of 350 nm to 1700 nm were collected from 98 pork samples to develop online, rapid and nondestructive detection system for water content in fresh pork Median smoothing filter (M-filter), multiplication scatter correlation (MSC) and first derivative (FD) were used as compound preprocessing method to reduce noise present in the original spectrum. Seventy four samples were randomly selected to develop training model and remaining 24 samples were used to test the model. The optimal punishment parameters for the support vector machine (SVM) were determined by using cross--validation and grid--search in the training set. SVM prediction model was developed with the radial basis function (RBF) and the developed model was compared with the model developed by partial least squares regression (PLSR) method. SVM prediction model based on RBF had the correlation coefficient and root mean standard error of 0.96 and 0.32 respectively in the training set. The model obtained correlation coefficient of 0.87 and root mean square error of 0.67 in the test set. The result thus obtained demonstrates the applicability of SVM model for rapid, nondestructive detection of water content in pork. PMID:23285889

  14. Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

    SciTech Connect

    Braatz, Brett G.; Cumblidge, Stephen E.; Doctor, Steven R.; Prokofiev, Iouri

    2012-12-31

    The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional and phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for

  15. A survey of visual preprocessing and shape representation techniques

    NASA Technical Reports Server (NTRS)

    Olshausen, Bruno A.

    1988-01-01

    Many recent theories and methods proposed for visual preprocessing and shape representation are summarized. The survey brings together research from the fields of biology, psychology, computer science, electrical engineering, and most recently, neural networks. It was motivated by the need to preprocess images for a sparse distributed memory (SDM), but the techniques presented may also prove useful for applying other associative memories to visual pattern recognition. The material of this survey is divided into three sections: an overview of biological visual processing; methods of preprocessing (extracting parts of shape, texture, motion, and depth); and shape representation and recognition (form invariance, primitives and structural descriptions, and theories of attention).

  16. Evaluation of the veracity of one work by the artist Di Cavalcanti through non-destructive techniques: XRF, imaging and brush stroke analysis

    NASA Astrophysics Data System (ADS)

    Kajiya, E. A. M.; Campos, P. H. O. V.; Rizzutto, M. A.; Appoloni, C. R.; Lopes, F.

    2014-02-01

    This paper presents systematic studies and analysis that contributed to the identification of the forgery of a work by the artist Emiliano Augusto Cavalcanti de Albuquerque e Melo, known as Di Cavalcanti. The use of several areas of expertise such as brush stroke analysis ("pinacologia"), applied physics, and art history resulted in an accurate diagnosis for ascertaining the authenticity of the work entitled "Violeiro" (1950). For this work we used non-destructive methods such as techniques of infrared, ultraviolet, visible and tangential light imaging combined with chemical analysis of the pigments by portable X-Ray Fluorescence (XRF) and graphic gesture analysis. Each applied method of analysis produced specific information that made possible the identification of materials and techniques employed and we concluded that this work is not consistent with patterns characteristic of the artist Di Cavalcanti.

  17. Reef Fish Survey Techniques: Assessing the Potential for Standardizing Methodologies.

    PubMed

    Caldwell, Zachary R; Zgliczynski, Brian J; Williams, Gareth J; Sandin, Stuart A

    2016-01-01

    Dramatic changes in populations of fishes living on coral reefs have been documented globally and, in response, the research community has initiated efforts to assess and monitor reef fish assemblages. A variety of visual census techniques are employed, however results are often incomparable due to differential methodological performance. Although comparability of data may promote improved assessment of fish populations, and thus management of often critically important nearshore fisheries, to date no standardized and agreed-upon survey method has emerged. This study describes the use of methods across the research community and identifies potential drivers of method selection. An online survey was distributed to researchers from academic, governmental, and non-governmental organizations internationally. Although many methods were identified, 89% of survey-based projects employed one of three methods-belt transect, stationary point count, and some variation of the timed swim method. The selection of survey method was independent of the research design (i.e., assessment goal) and region of study, but was related to the researcher's home institution. While some researchers expressed willingness to modify their current survey protocols to more standardized protocols (76%), their willingness decreased when methodologies were tied to long-term datasets spanning five or more years. Willingness to modify current methodologies was also less common among academic researchers than resource managers. By understanding both the current application of methods and the reported motivations for method selection, we hope to focus discussions towards increasing the comparability of quantitative reef fish survey data. PMID:27111085

  18. Reef Fish Survey Techniques: Assessing the Potential for Standardizing Methodologies

    PubMed Central

    Caldwell, Zachary R.; Zgliczynski, Brian J.; Williams, Gareth J.; Sandin, Stuart A.

    2016-01-01

    Dramatic changes in populations of fishes living on coral reefs have been documented globally and, in response, the research community has initiated efforts to assess and monitor reef fish assemblages. A variety of visual census techniques are employed, however results are often incomparable due to differential methodological performance. Although comparability of data may promote improved assessment of fish populations, and thus management of often critically important nearshore fisheries, to date no standardized and agreed-upon survey method has emerged. This study describes the use of methods across the research community and identifies potential drivers of method selection. An online survey was distributed to researchers from academic, governmental, and non-governmental organizations internationally. Although many methods were identified, 89% of survey-based projects employed one of three methods–belt transect, stationary point count, and some variation of the timed swim method. The selection of survey method was independent of the research design (i.e., assessment goal) and region of study, but was related to the researcher’s home institution. While some researchers expressed willingness to modify their current survey protocols to more standardized protocols (76%), their willingness decreased when methodologies were tied to long-term datasets spanning five or more years. Willingness to modify current methodologies was also less common among academic researchers than resource managers. By understanding both the current application of methods and the reported motivations for method selection, we hope to focus discussions towards increasing the comparability of quantitative reef fish survey data. PMID:27111085

  19. Non-destructive and non-invasive analyses shed light on the realization technique of ancient polychrome prints.

    PubMed

    Striová, Jana; Coccolini, Gabriele; Micheli, Sara; Lofrumento, Cristiana; Galeotti, Monica; Cagnini, Andrea; Castellucci, Emilio Mario

    2009-08-01

    Five polychrome prints representing famous painters, such as Albrecht Dürer, were analyzed using a non-destructive and non-invasive methodology as required by the artwork typology. The diagnostic strategy includes X-ray fluorescence (XRF), reflectance micro-infrared (microFTIR) and micro-Raman (microRaman) spectroscopy. These prints were realized with a la poupée method that involves application of the polychrome inks on a single copper plate, before the printing process. A broad range of compounds (i.e., cinnabar, red lead, white lead, umber earth, hydrated calcium sulfate, calcium carbonate, amorphous carbon, and Prussian blue) was employed as chalcographic inks, using linseed oil as a binding medium. Gamboge was identified in the delicate finishing brush touches realized in watercolor. PMID:19081288

  20. Non-destructive and non-invasive analyses shed light on the realization technique of ancient polychrome prints

    NASA Astrophysics Data System (ADS)

    Striová, Jana; Coccolini, Gabriele; Micheli, Sara; Lofrumento, Cristiana; Galeotti, Monica; Cagnini, Andrea; Castellucci, Emilio Mario

    2009-08-01

    Five polychrome prints representing famous painters, such as Albrecht Dürer, were analyzed using a non-destructive and non-invasive methodology as required by the artwork typology. The diagnostic strategy includes X-ray fluorescence (XRF), reflectance micro-infrared (μFTIR) and micro-Raman (μRaman) spectroscopy. These prints were realized with a la poupée method that involves application of the polychrome inks on a single copper plate, before the printing process. A broad range of compounds (i.e., cinnabar, red lead, white lead, umber earth, hydrated calcium sulfate, calcium carbonate, amorphous carbon, and Prussian blue) was employed as chalcographic inks, using linseed oil as a binding medium. Gamboge was identified in the delicate finishing brush touches realized in watercolor.

  1. High-resolution X-ray imaging—a powerful nondestructive technique for applications in semiconductor industry

    NASA Astrophysics Data System (ADS)

    Zschech, Ehrenfried; Yun, Wenbing; Schneider, Gerd

    2008-08-01

    The availability of high-brilliance X-ray sources, high-precision X-ray focusing optics and very efficient CCD area detectors has contributed essentially to the development of transmission X-ray microscopy (TXM) and X-ray computed tomography (XCT) with sub-50 nm resolution. Particularly, the fabrication of high aspect ratio Fresnel zone plates with zone widths approaching 15 nm has contributed to the enormous improvement in spatial resolution during the previous years. Currently, Fresnel zone plates give the ability to reach spatial resolutions of 15 to 20 nm in the soft and of about 30 to 50 nm in the hard X-ray energy range. X-ray microscopes with rotating anode X-ray sources that can be installed in an analytical lab next to a semiconductor fab have been developed recently. These unique TXM/XCT systems provide an important new capability of nondestructive 3D imaging of internal circuit structures without destructive sample preparation such as cross sectioning. These lab systems can be used for failure localization in micro- and nanoelectronic structures and devices, e.g., to visualize voids and residuals in on-chip metal interconnects without physical modification of the chip. Synchrotron radiation experiments have been used to study new processes and materials that have to be introduced into the semiconductor industry. The potential of TXM using synchrotron radiation in the soft X-ray energy range is shown for the nondestructive in situ imaging of void evolution in embedded on-chip copper interconnect structures during electromigration and for the imaging of different types of insulating thin films between the on-chip interconnects (spectromicroscopy).

  2. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1994-01-01

    In this Progress Report, we describe our continuing research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the inspection and characterization of complex composite structures. We explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. As an initial step toward the application of linear array imaging technology to the interrogation of a wide range of complex composite structures, we present images obtained using an unmodified medical ultrasonic imaging system of two epoxy-bonded aluminum plate specimens, each with intentionally disbonded regions. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to assess whether these images can detect disbonded regions and provide information regarding the nature of the disbonded region. We present a description of a standoff/delay fixture which has been designed, constructed, and implemented on a Hewlett-Packard SONOS 1500 medical imaging system. This standoff/delay fixture, when attached to a 7.5 MHz linear array probe, greatly enhances our ability to interrogate flat plate specimens. The final section of this Progress Report describes a woven composite plate specimen that has been specially machined to include intentional flaws. This woven composite specimen will allow us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We anticipate the results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology.

  3. Complementary use of the Raman and XRF techniques for non-destructive analysis of historical paint layers

    NASA Astrophysics Data System (ADS)

    Sawczak, M.; Kamińska, A.; Rabczuk, G.; Ferretti, M.; Jendrzejewski, R.; Śliwiński, G.

    2009-03-01

    The portable XRF spectrometer has been applied in situ for the non-destructive elemental mapping of the pigment components of the XV c. mural painting and frescos of the Little Christopher chamber in the Main Town Hall of Gdańsk, Poland. For a sufficiently large data collection the principal component analysis (PCA) was applied in order to associate the most intense lines of the elements Ca, Cu, Fe, Pb, and Hg in the XRF spectra with the palette of colors: white, brown, green, blue, red, yellow, and black observed in the painting. This allowed to limit the number of extractions of the micro-samples for the complementary Raman measurements thus assuring the practically non-destructive character of the entire analysis. The reliable identification of the pigment compositions was based on coincidence of the XRF, PCA and the Raman results which confirmed the presence of the chalk, malachite, azurite, red lead, mars red, mars yellow and candle black in the historical paints, except of the carbon-based black pigment being out of the XRF detection range. Different hues of the green paint were specified and the variety of the red and brown ones was ascribed to compositions of the Pb- and Fe-based red pigments (Fe 2O 3 and Pb 3O 4) with addition of the vermilion (HgS) and carbon black, in agreement with literature. The traces of elements: Ba and Sr, Sb and Mo, and also Cd, were ascribed to the impurities of Ca, those of some ochre pigments, and to the soluble Cd salts, respectively.

  4. Improvement of interfacial adhesion and nondestructive damage evaluation for plasma-treated PBO and Kevlar fibers/epoxy composites using micromechanical techniques and surface wettability.

    PubMed

    Park, Joung-Man; Kim, Dae-Sik; Kim, Sung-Ryong

    2003-08-15

    Comparison of interfacial properties and microfailure mechanisms of oxygen-plasma treated poly(p-phenylene-2,6-benzobisoxazole (PBO, Zylon) and poly(p-phenylene terephthalamide) (PPTA, Kevlar) fibers/epoxy composites were investigated using a micromechanical technique and nondestructive acoustic emission (AE). The interfacial shear strength (IFSS) and work of adhesion, Wa, of PBO or Kevlar fiber/epoxy composites increased with oxygen-plasma treatment, due to induced hydrogen and covalent bondings at their interface. Plasma-treated Kevlar fiber showed the maximum critical surface tension and polar term, whereas the untreated PBO fiber showed the minimum values. The work of adhesion and the polar term were proportional to the IFSS directly for both PBO and Kevlar fibers. The microfibril fracture pattern of two plasma-treated fibers appeared obviously. Unlike in slow cooling, in rapid cooling, case kink band and kicking in PBO fiber appeared, whereas buckling in the Kevlar fiber was observed mainly due to compressive and residual stresses. Based on the propagation of microfibril failure toward the core region, the number of AE events for plasma-treated PBO and Kevlar fibers increased significantly compared to the untreated case. The results of nondestructive AE were consistent with microfailure modes. PMID:16256662

  5. Integrated Surveying Techniques for Sensitive Areas: San Felice Sul Panaro

    NASA Astrophysics Data System (ADS)

    Ballarin, M.; Buttolo, V.; Guerra, F.; Vernier, P.

    2013-07-01

    The last few years have marked an exponential growth in the use of electronic and computing technologies that opened new possibilities and new scenarios in the Geomatic field. This evolution of tools and methods has led to new ways of approaching survey. For what concerns architecture, the new tools for survey acquisition and 3D modelling allow the representation of an object through a digital model, combining the visual potentials of images, normally used for documentation, with the precision of a metric survey. This research focuses on the application of these new technologies and methodologies on sensitive areas, such as portions of the cities affected by earthquakes. In this field the survey is intended to provide a useful support for other structural analysis, in conservation as well as for restoration studies. However, survey in architecture is still a very complex operation both from a methodological and a practical point of view: it requires a critical interpretation of the artefacts and a deep knowledge of the existing techniques and technologies, which often are very different but need to be integrated within a single general framework. This paper describes the first results of the survey conducted on the church of San Geminiano in San Felice sul Panaro (Modena). Here, different tools and methods were used, in order to create a new system that integrates the most recent and cutting-edge technologies in the Geomatic field. The methodologies used were laser scanning, UAV photogrammetry and topography for the definition of the reference system. The present work will focus on the data acquisition and processing whit these techniques and their integration.

  6. Nondestructive imaging of small size voids at Akrotiri archaeological site, Thera Island, Greece, by seismic inversion techniques

    NASA Astrophysics Data System (ADS)

    Louis, Filippos I.; Clark, Roger A.; Louis, Ioannis F.; Makropoulos, Costas C.

    2005-07-01

    High-resolution travel time tomography was used to explore the volcanic basement rock at the Akrotiri archaeological site, Thera (Santorini) Island. The survey was carried out in the context of a large scale project, in which the protective roof cover of old monuments is being replaced by a new environmentally friendly structure, which will be supported by 95 pillars drilled into the volcanic basement rock. Man-made or natural cavities (empty or half-filled with stones), ceramics, and other materials of archaeological interest were unveiled during the excavation of foundation shafts. The objective of this geophysical investigation was the detection of such voids in the vicinity of the excavated shafts, so that the overhead structure can be better supported and protected in the case of an earthquake event. The cross-hole seismic tomography technique was adopted for this purpose. A number of synthetic examples and a calibration experiment at a shaft with a known natural cavity clearly indicated that the tomographic inversion is capable of providing high-resolution 2-D velocity models. High S/N ratios ensured field seismic records of high quality. A set of stability tests was run to check the consistency of the method. Travel time residuals verified the validity of the final velocity depth sections, while model complexity trends showed a consistency between models after a certain number of iterations. The reconstructed velocity fields were quite consistent with the expected velocity structures based on the geologic descriptions of formations encountered during the drilling of the shafts. Impressive low-velocity structures attributed to natural or man-made cavities were reported to the constructing group of engineers, and a remedial action plan was being undertaken to support and improve the ground behavior.

  7. The Importance of Local Surveys for Tying Techniques Together

    NASA Technical Reports Server (NTRS)

    Long, James L.; Bosworth, John M.

    2000-01-01

    The synergistic benefits of combining observations from multiple space geodesy techniques located at a site are a main reason behind the proposal for the establishment of the International Space Geodetic and Gravimetric Network (ISGN). However, the full benefits of inter-comparison are only realized when the spatial relationships between the different space geodetic systems are accurately determined. These spatial relationships are best determined and documented by developing a local reference network of stable ground monuments and conducting periodic surveys to tie together the reference points (for example: the intersection of rotation axes of a VLBI antenna) of the space geodetic systems and the ground monument network. The data obtained from local surveys is vital to helping understand any systematic errors within an individual technique and to helping identify any local movement or deformation of the space geodetic systems over time.

  8. Surveying co-located space geodesy techniques for ITRF computation

    NASA Astrophysics Data System (ADS)

    Sarti, P.; Sillard, P.; Vittuari, L.

    2003-04-01

    We present a comprehensive operational methodology, based on classical geodesy triangulation and trilateration, that allows the determination of reference points of the five space geodesy techniques used in ITRF computation (i.e.: DORIS, GPS, LLR, SLR, VLBI). Most of the times, for a single technique, the reference point is not accessible and measurable directly. Likewise, no mechanically determined ex-center with respect to an external and measurable point is usually given. In these cases, it is not possible to directly measure the sought reference points and it is even less straightforward to obtain the statistical information relating these points for different techniques. We outline the most general practical surveying methodology that permits to recover the reference points of the different techniques regardless of their physical materialization. We also give a detailed analytical approach for less straightforward cases (e.g.: non geodetic VLBI antennae and SLR/LLR systems). We stress the importance of surveying instrumentation and procedure in achieving the best possible results and outline the impact of the information retrieved with our method in ITRF computation. In particular, we will give numerical examples of computation of the reference point of VLBI antennae (Ny Aalesund and Medicina) and the ex-centre vector computation linking co-located VLBI and GPS techniques in Medicina (Italy). A special attention was paid to the rigorous derivation of statistical elements. They will be presented in an other presentation.

  9. Nondestructive analysis and development

    NASA Technical Reports Server (NTRS)

    Moslehy, Faissal A.

    1993-01-01

    This final report summarizes the achievements of project #4 of the NASA/UCF Cooperative Agreement from January 1990 to December 1992. The objectives of this project are to review NASA's NDE program at Kennedy Space Center (KSC) and recommend means for enhancing the present testing capabilities through the use of improved or new technologies. During the period of the project, extensive development of a reliable nondestructive, non-contact vibration technique to determine and quantify the bond condition of the thermal protection system (TPS) tiles of the Space Shuttle Orbiter was undertaken. Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disbond. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility of EMA as a viable technique for tile bond verification. Finally, testing performed on the Space Shuttle Columbia using a laser doppler velocimeter demonstrated the application of EMA, when combined with FE modeling, as a non-contact, non-destructive bond evaluation technique.

  10. Time Delay Integration: A Wide-Field Survey Technique

    NASA Astrophysics Data System (ADS)

    Lapointe, Robert; Hill, E.; Leimer, L.; McMillian, K.; Miller, A.; Prindle, A.

    2009-05-01

    The Advanced Placement Physics class of Orange Lutheran High School has conducted a survey-imaging pro-ject using a Time Delay Integration (TDI) technique. TDI enables very wide-field images to be collected in the form of long strips of the sky. A series of five consecutive nights were captured, calibrated and compared to re-veal possible transient phenomena such as supernovae, asteroids, and other events that have a noticeable change over 24-hour intervals.

  11. Survey of intravitreal injection techniques among retina specialists in Israel

    PubMed Central

    Segal, Ori; Segal-Trivitz, Yael; Nemet, Arie Y; Geffen, Noa; Nesher, Ronit; Mimouni, Michael

    2016-01-01

    Purpose The purpose of this study was to describe antivascular endothelial growth factor intravitreal injection techniques of retinal specialists in order to establish a cornerstone for future practice guidelines. Methods All members of the Israeli Retina Society were contacted by email to complete an anonymous, 19-question, Internet-based survey regarding their intravitreal injection techniques. Results Overall, 66% (52/79) completed the survey. Most (98%) do not instruct patients to discontinue anticoagulant therapy and 92% prescribe treatment for patients in the waiting room. Three quarters wear sterile gloves and prepare the patient in the supine position. A majority (71%) use sterile surgical draping. All respondents apply topical analgesics and a majority (69%) measure the distance from the limbus to the injection site. A minority (21%) displace the conjunctiva prior to injection. A majority of the survey participants use a 30-gauge needle and the most common quadrant for injection is superotemporal (33%). Less than half routinely assess postinjection optic nerve perfusion (44%). A majority (92%) apply prophylactic antibiotics immediately after the injection. Conclusion The majority of retina specialists perform intravitreal injections similarly. However, a relatively large minority performs this procedure differently. Due to the extremely low percentage of complications, it seems as though such differences do not increase the risk. However, more evidence-based medicine, a cornerstone for practice guidelines, is required in order to identify the intravitreal injection techniques that combine safety and efficacy while causing as little discomfort to the patients as possible. PMID:27366050

  12. Digital Survey Techniques for the Documentation of Wooden Shipwrecks

    NASA Astrophysics Data System (ADS)

    Costa, E.; Balletti, C.; Beltrame, C.; Guerra, F.; Vernier, P.

    2016-06-01

    Nowadays, researchers widely employ the acquisition of point clouds as one of the principal type of documentation for cultural heritage. In this paper, different digital survey techniques are employed to document a wooden ancient shipwreck, a particular and difficult kind of archaeological finding due to its material characteristics. The instability of wood and the high costs of restoration do not always offer the opportunity of recovering and showing the hull to researchers and public and three-dimensional surveys are fundamental to document the original conditions of the wood. The precarious conditions of this material in contact with air could modify the structure and the size of the boat, requiring a fast and accurate recording technique. The collaboration between Ca' Foscari University and the Laboratory of Photogrammetry of Iuav University of Venice has given the possibility to demonstrate the utility of these technology. We have surveyed a sewn boat of Roman age through multi-image photogrammetry and laser scanner. Point clouds were compared and a residual analysis was done, to verify the characteristics and the opportunity of the two techniques, both of them have allowed obtaining a very precise documentation from a metrical point of view.

  13. Potential applicability of stress wave velocity method on pavement base materials as a non-destructive testing technique

    NASA Astrophysics Data System (ADS)

    Mahedi, Masrur

    Aggregates derived from natural sources have been used traditionally as the pavement base materials. But in recent times, the extraction of these natural aggregates has become more labor intensive and costly due to resource depletion and environmental concerns. Thus, the uses of recycled aggregates as the supplementary of natural aggregates are increasing considerably in pavement construction. Use of recycled aggregates such as recycled crushed concrete (RCA) and recycled asphalt pavement (RAP) reduces the rate of natural resource depletion, construction debris and cost. Although recycled aggregates could be used as a viable alternative of conventional base materials, strength characteristics and product variability limit their utility to a great extent. Hence, their applicability is needed to be evaluated extensively based on strength, stiffness and cost factors. But for extensive evaluation, traditionally practiced test methods are proven to be unreasonable in terms of time, cost, reliability and applicability. On the other hand, rapid non-destructive methods have the potential to be less time consuming and inexpensive along with the low variability of test results; therefore improving the reliability of estimated performance of the pavement. In this research work, the experimental program was designed to assess the potential application of stress wave velocity method as a non-destructive test in evaluating recycled base materials. Different combinations of cement treated recycled concrete aggregate (RAP) and recycled crushed concrete (RCA) were used to evaluate the applicability of stress wave velocity method. It was found that, stress wave velocity method is excellent in characterizing the strength and stiffness properties of cement treated base materials. Statistical models, based on P-wave velocity were derived for predicting the modulus of elasticity and compressive strength of different combinations of cement treated RAP, Grade-1 and Grade-2 materials. Two

  14. Nondestructive measurement of total volatile basic nitrogen (TVB-N) in pork meat by integrating near infrared spectroscopy, computer vision and electronic nose techniques.

    PubMed

    Huang, Lin; Zhao, Jiewen; Chen, Quansheng; Zhang, Yanhua

    2014-02-15

    Total volatile basic nitrogen (TVB-N) content is an important reference index for evaluating pork freshness. This paper attempted to measure TVB-N content in pork meat using integrating near infrared spectroscopy (NIRS), computer vision (CV), and electronic nose (E-nose) techniques. In the experiment, 90 pork samples with different freshness were collected for data acquisition by three different techniques, respectively. Then, the individual characteristic variables were extracted from each sensor. Next, principal component analysis (PCA) was used to achieve data fusion based on these characteristic variables from 3 different sensors data. Back-propagation artificial neural network (BP-ANN) was used to construct the model for TVB-N content prediction, and the top principal components (PCs) were extracted as the input of model. The result of the model was achieved as follows: the root mean square error of prediction (RMSEP) = 2.73 mg/100g and the determination coefficient (R(p)(2)) = 0.9527 in the prediction set. Compared with single technique, integrating three techniques, in this paper, has its own superiority. This work demonstrates that it has the potential in nondestructive detection of TVB-N content in pork meat using integrating NIRS, CV and E-nose, and data fusion from multi-technique could significantly improve TVB-N prediction performance. PMID:24128472

  15. Characterization and source term assessments of radioactive particles from Marshall Islands using non-destructive analytical techniques

    NASA Astrophysics Data System (ADS)

    Jernström, J.; Eriksson, M.; Simon, R.; Tamborini, G.; Bildstein, O.; Marquez, R. Carlos; Kehl, S. R.; Hamilton, T. F.; Ranebo, Y.; Betti, M.

    2006-08-01

    Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized by non-destructive analytical and microanalytical methods. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector and with wavelength dispersive system as well as a secondary ion mass spectrometer were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups: particles with pure Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogenously distributed. All of the particles were identified as nuclear fuel fragments of exploded weapon components. As containing plutonium with low 240Pu/ 239Pu atomic ratio, less than 0.065, which corresponds to weapons-grade plutonium or a detonation with low fission yield, the particles were identified to originate from the safety test and low-yield tests conducted in the history of Runit Island. The Si/O-rich particles contained traces of 137Cs ( 239 + 240 Pu/ 137Cs activity ratio higher than 2500), which indicated that a minor fission process occurred during the explosion. The average 241Am/ 239Pu atomic ratio in the six particles was 3.7 × 10 - 3 ± 0.2 × 10 - 3 (February 2006), which indicated that plutonium in the different particles had similar age.

  16. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Ninth quarterly report, October-December 1979

    SciTech Connect

    Not Available

    1980-01-01

    Progress in developing and evaluating nondestructive methods for testing ceramic components for high-temperature heat exchangers is reported. The sensitivity of the ultrasonic bore-side probe was demonstrated for detection of 125-..mu..m-deep circumferential EDM notches on ID and OD surfaces of sintered and siliconized tubes. The signal to noise ratios for the ultrasonic echoes are better than 10 to 1, beyond the initial expectations for detection of small reflectors. This results from focussing of the beam in the tube wall. Preliminary data were presented on microprocessor-controlled operation of the ultrasonic probe. Some problems involving the computer interfacing have to be resolved, but detection and recording of an EDM notch located was demonstrated. The acoustic microscope was modified to handle 30-MHz sound waves. This was done to improve the penetration ability of the sound in SiC tube walls. The modification results in less acoustic noise. The ability to detect a notch only 75 ..mu..m in width was demonstrated.

  17. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Astrophysics Data System (ADS)

    Miller, James G.

    1995-03-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  18. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1995-01-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  19. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    PubMed

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  20. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy

    PubMed Central

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  1. Power Management Techniques for Data Centers: A Survey

    SciTech Connect

    Mittal, Sparsh

    2014-07-01

    With growing use of internet and exponential growth in amount of data to be stored and processed (known as ``big data''), the size of data centers has greatly increased. This, however, has resulted in significant increase in the power consumption of the data centers. For this reason, managing power consumption of data centers has become essential. In this paper, we highlight the need of achieving energy efficiency in data centers and survey several recent architectural techniques designed for power management of data centers. We also present a classification of these techniques based on their characteristics. This paper aims to provide insights into the techniques for improving energy efficiency of data centers and encourage the designers to invent novel solutions for managing the large power dissipation of data centers.

  2. A Survey of Architectural Techniques for Near-Threshold Computing

    DOE PAGESBeta

    Mittal, Sparsh

    2015-12-28

    Energy efficiency has now become the primary obstacle in scaling the performance of all classes of computing systems. In low-voltage computing and specifically, near-threshold voltage computing (NTC), which involves operating the transistor very close to and yet above its threshold voltage, holds the promise of providing many-fold improvement in energy efficiency. However, use of NTC also presents several challenges such as increased parametric variation, failure rate and performance loss etc. Our paper surveys several re- cent techniques which aim to offset these challenges for fully leveraging the potential of NTC. By classifying these techniques along several dimensions, we also highlightmore » their similarities and differences. Ultimately, we hope that this paper will provide insights into state-of-art NTC techniques to researchers and system-designers and inspire further research in this field.« less

  3. A Survey of Architectural Techniques for Near-Threshold Computing

    SciTech Connect

    Mittal, Sparsh

    2015-12-28

    Energy efficiency has now become the primary obstacle in scaling the performance of all classes of computing systems. In low-voltage computing and specifically, near-threshold voltage computing (NTC), which involves operating the transistor very close to and yet above its threshold voltage, holds the promise of providing many-fold improvement in energy efficiency. However, use of NTC also presents several challenges such as increased parametric variation, failure rate and performance loss etc. Our paper surveys several re- cent techniques which aim to offset these challenges for fully leveraging the potential of NTC. By classifying these techniques along several dimensions, we also highlight their similarities and differences. Ultimately, we hope that this paper will provide insights into state-of-art NTC techniques to researchers and system-designers and inspire further research in this field.

  4. Survey of Product-line Verification and Validation Techniques

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn

    2007-01-01

    This report presents the results from the first task of the SARP Center Initiative, 'Product Line Verification of Safety-Critical Software.' Task 1 is a literature survey of available techniques for product line verification and validation. Section 1 of the report provides an introduction to product lines and motivates the survey of verification techniques. It describes what is reused in product-line engineering and explains the goal of verifiable conformance of the developed system to its product-line specifications. Section 2 of the report describes six lifecycle steps in product-line verification and validation. This description is based on, and refers to, the best practices extracted from the readings. It ends with a list of verification challenges for NASA product lines (2.7) and verification enablers for NASA product lines (2.8) derived from the survey. Section 3 provides resource lists of related conferences, workshops, industrial and defense industry experiences and case studies of product lines, and academic/industrial consortiums. Section 4 is a bibliography of papers and tutorials with annotated entries for relevant papers not previously discussed in sections 2 or 3.

  5. Literature survey of heat transfer enhancement techniques in refrigeration applications

    SciTech Connect

    Jensen, M.K.; Shome, B.

    1994-05-01

    A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

  6. A Paradigm for the Nondestructive Assay of Spent Fuel Assemblies and Similar Large Objects, with Emphasis on the Role of Photon-Based Techniques

    NASA Astrophysics Data System (ADS)

    Bolind, Alan Michael

    2015-10-01

    The practice of nondestructive assay (NDA) of nuclear materials has, until now, been focused primarily (1) on smaller objects (2) with less fissile material and (3) with less self-generated radiation. The transition to the application of NDA to spent fuel assemblies and similar large objects violates these three conditions, thereby bringing the assumptions and paradigm of traditional NDA practice into question for the new applications. In this paper, a new paradigm for these new applications is presented which is based on the fundamental principles of nuclear engineering. It is shown that the NDA of spent fuel assemblies is mostly a three-dimensional problem that requires the integration of three independent NDA measurements in order to achieve a unique and accurate assay. The only NDA techniques that can avoid this requirement are those that analyze signals that are characteristic to specific isotopes (such as those caused by characteristic resonance interactions), and that are neither distorted nor overly attenuated by the other surrounding material. Some photon-based NDA techniques fall into this exceptional category. Such exceptional NDA techniques become essential to employ when assaying large objects that, unlike spent fuel assemblies, do not have a consistent geometry. With this new NDA paradigm, the advanced photon-based NDA techniques can be put into their proper context, and their development can thereby be properly motivated.

  7. 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.

  8. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  9. Surveying converter lining erosion state based on laser measurement technique

    NASA Astrophysics Data System (ADS)

    Li, Hongsheng; Shi, Tielin; Yang, Shuzi

    1998-08-01

    It is very important to survey the eroding state of the steelmaking converter lining real time so as to optimize technological process, extend converter durability and reduce steelmaking production costs. This paper gives one practical method based on the laser measure technique. It presents the basic principle of the measure technique. It presents the basic principle of the measure method, the composition of the measure system and the researches on key technological problems. The method is based on the technique of the laser range finding to net points on the surface of the surveyed converter lining, and the technology of angle finding to the laser beams. The angle signals would be used to help realizing the automatic scanning function also. The laser signals would be modulated and encoded. In the meantime, we would adopt the wavelet analysis and other filter algorithms, to denoise noisy data and extract useful information. And the main idea of some algorithms such as the net point measuring path planning and the measure device position optimal algorithm would also be given in order to improve the measure precision and real time property of the system.

  10. In situ Raman spectroscopy and confocal microscopy of 2.5-billion-year-old fossil microorganisms: viable nondestructive techniques for the study of returned Martian samples

    NASA Astrophysics Data System (ADS)

    Czaja, A. D.; Lorber, K.

    2014-12-01

    This study presents the discovery of two sets of Archean fossil microorganisms (microfossils) and describes how such a study can be an analogue for a potential Martian sample return mission like that proposed as a follow up to the Mars 2020 mission. Microfossils are not easily preserved and their simple morphologies (made less distinct by taphonomy and diagenesis) can be confused with nonbiological structures. Thus, several lines of evidence are required for a biological interpretation of such remains. Despite this limitation, microfossils represent the most direct and easily illustrated evidence of life, and this will also be true of any microfossils that might be found on Mars. Martian sample return will provide the first chance to apply a full suite of analytical techniques to the study of possible Martian microfossils. Because such precious samples would be of limited quantity, this suite must include nondestructive techniques that are performed in situ and at a micron-scale.The samples studied here were collected from two chert units within the Gamohaan Formation of the Kaapvaal Craton of South Africa. One set was collected from the Tsineng Member near the top of the formation and contains fossils of mat-forming filamentous microorganisms (~15-20 µm in diameter) that were buried in place. The other set comes from a chert bed stratigraphically lower within the Gamohaan Formation. This bed contains shriveled and somewhat compacted spherical microfossils (~100 µm in diameter) and are interpreted to be the remains of planktonic forms that settled from above. Cherts were collected based on a visual identification of their likelihood to contain microfossils. Optical microscopy was used to locate microstructures of interest within thin sections. The biological nature of these structures is supported by analyses of their three dimensional morphologies by confocal laser scanning microscopy (CLSM) as well as their carbonaceous compositions by Raman spectroscopy. Raman

  11. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials

    PubMed Central

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented. PMID:26664356

  12. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials.

    PubMed

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented. PMID:26664356

  13. Comparison of sediment pollution in the rivers of the Hungarian Upper Tisza Region using non-destructive analytical techniques

    NASA Astrophysics Data System (ADS)

    Osán, János; Török, Szabina; Alföldy, Bálint; Alsecz, Anita; Falkenberg, Gerald; Baik, Soo Yeun; Van Grieken, René

    2007-02-01

    The rivers in the Hungarian Upper Tisza Region are frequently polluted mainly due to mining activities in the catchment area. At the beginning of 2000, two major mining accidents occurred in the Romanian part of the catchment area due to the failure of a tailings dam releasing huge amounts of cyanide and heavy metals to the rivers. Surface sediment as well as water samples were collected at six sites in the years 2000-2003, from the northeast-Hungarian section of the Tisza, Szamos and Túr rivers. The sediment pollution of the rivers was compared based on measurements of bulk material and selected single particles, in order to relate the observed compositions and chemical states of metals to the possible sources and weathering of pollution. Non-destructive X-ray analytical methods were applied in order to obtain different kinds of information from the same samples or particles. In order to identify the pollution sources, their magnitude and fate, complementary analyses were carried out. Heterogeneous particulate samples were analyzed from a large geographical territory and a 4-year time period. Individual particles were analyzed only from the "hot" samples that showed elevated concentrations of heavy metals. Particles that were classified as anthropogenic were finally analyzed to identify trace concentrations and chemical states of heavy metals. Although the Tisza river was affected by water pollution due to the two major mining accidents at the beginning of 2000, the concentration of heavy metals in sediments decreased to the mineral background level 1 year after the pollution event. In the tributaries Szamos and Túr, however, no significant decrease of the heavy metal concentrations was observed in the recent years, indicating a continuous pollution. Among the water suspended particles collected from river Túr, fibers of unknown origin were observed by electron microscopy; these particles were aluminosilicates enriched in Zn and Mn. Cd was also concentrated in

  14. Using machine learning techniques to automate sky survey catalog generation

    NASA Technical Reports Server (NTRS)

    Fayyad, Usama M.; Roden, J. C.; Doyle, R. J.; Weir, Nicholas; Djorgovski, S. G.

    1993-01-01

    We describe the application of machine classification techniques to the development of an automated tool for the reduction of a large scientific data set. The 2nd Palomar Observatory Sky Survey provides comprehensive photographic coverage of the northern celestial hemisphere. The photographic plates are being digitized into images containing on the order of 10(exp 7) galaxies and 10(exp 8) stars. Since the size of this data set precludes manual analysis and classification of objects, our approach is to develop a software system which integrates independently developed techniques for image processing and data classification. Image processing routines are applied to identify and measure features of sky objects. Selected features are used to determine the classification of each object. GID3* and O-BTree, two inductive learning techniques, are used to automatically learn classification decision trees from examples. We describe the techniques used, the details of our specific application, and the initial encouraging results which indicate that our approach is well-suited to the problem. The benefits of the approach are increased data reduction throughput, consistency of classification, and the automated derivation of classification rules that will form an objective, examinable basis for classifying sky objects. Furthermore, astronomers will be freed from the tedium of an intensely visual task to pursue more challenging analysis and interpretation problems given automatically cataloged data.

  15. The History of Electromagnetic Induction Techniques in Soil Survey

    NASA Astrophysics Data System (ADS)

    Brevik, Eric C.; Doolittle, Jim

    2014-05-01

    Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales.

  16. Non-destructive Evaluation of Compound Semiconductor Thin-Film Solar Cells by Photothermal Beam Deflection Technique

    NASA Astrophysics Data System (ADS)

    Warrier, Anita R.; Sebastian, Tina; Kartha, C. Sudha; Vijayakumar, K. P.

    2015-01-01

    In this paper, it is demonstrated that the photothermal beam deflection technique can be used for measuring the series resistance, optimum load resistance, and conversion efficiency of thin-film solar cells. This technique is also used for determining the carrier transport properties of an absorber and window layer of -based solar cells during different stages of cell fabrication. Transport properties such as the carrier mobility, lifetime, and surface recombination velocity of the individual absorber and window layer are shown to influence the open-circuit voltage and short-circuit current of the final photovoltaic device. The cell parameters measured using the photothermal technique agree well with the electrical measurements. The principle of the technique is explained on the basis of the "mirage effect" and maximum power transfer theorem.

  17. Integration of Geomatic Techniques for the Urban Cavity Survey

    NASA Astrophysics Data System (ADS)

    Deidda, M.; Sanna, G.

    2013-07-01

    Cagliari, county seat of Sardinia Region (Italy), situated in the southern part of the island, is characterized by a subsoil full of cavities. The excavations in fact, which lasted more than 4000 years, had a great development due also to the special geological characteristics of the city subsoil. The underground voids, which the city is rich in, belong to different classes such as hydraulic structures (aqueducts, cisterns, wells, etc.), settlement works (tunnels, bomb shelters, tombs etc.) and various works (quarries, natural caves, etc.). This paper describes the phases of the survey of a large cavity below a high-traffic square near the Faculty of Engineering in the city of Cagliari, where the research team works. The cave, which is part of a larger complex, is important because it was used in the thirteenth century (known as the Pisan age) as a stone quarry. There are traces of this activity that have to be protected. Moreover, during the last forty years the continuous crossover of vehicles cracked the roof of the cave compromising the stability of the entire area. Consequently a plan was developed to make the whole cavity safe and usable for visits. The study of the safety of the cave has involved different professionals among which geologists, engineers, constructors. The goal of the University of Cagliari geomatic team was to solve two problems: to obtain geometrical information about the void and correctly place the cave in the context of existing maps. The survey and the products, useful for the investigation of the technicians involved, had to comply with tolerances of 3 cm in the horizontal and 5 cm in the vertical component. The approach chosen for this purpose was to integrate different geomatic techniques. The cave was surveyed using a laser scanner (Faro Photon 80) in order to obtain a 3D model of the cave from which all the geometrical information was derived, while both classic topography and GPS techniques were used to include the cave in the

  18. Neutron Resonance Transmission Analysis (NRTA): A Nondestructive Assay Technique for the Next Generation Safeguards Initiative’s Plutonium Assay Challenge

    SciTech Connect

    J. W. Sterbentz; D. L. Chichester

    2010-12-01

    This is an end-of-year report for a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The first-year goals for this project were modest and included: 1) developing a zero-order MCNP model for the NRTA technique, simulating data results presented in the literature, 2) completing a preliminary set of studies investigating important design and performance characteristics for the NRTA measurement technique, and 3) documentation of this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes a nine month period of work.

  19. Nondestructive evaluations

    SciTech Connect

    Kulkarni, S.

    1993-03-01

    This report discusses Nondestructive Evaluation (NDE) thrust area which supports initiatives that advance inspection science and technology. The goal of the NDE thrust area is to provide cutting-edge technologies that have promise of inspection tools three to five years in the future. In selecting projects, the thrust area anticipates the needs of existing and future Lawrence Livermore National Laboratory (LLNL) programs. NDE provides materials characterization inspections, finished parts, and complex objects to find flaws and fabrication defects and to determine their physical and chemical characteristics. NDE also encompasses process monitoring and control sensors and the monitoring of in-service damage. For concurrent engineering, NDE becomes a frontline technology and strongly impacts issues of certification and of life prediction and extension. In FY-92, in addition to supporting LLNL programs and the activities of nuclear weapons contractors, NDE has initiated several projects with government agencies and private industries to study aging infrastructures and to advance manufacturing processes. Examples of these projects are (1) the Aging Airplanes Inspection Program for the Federal Aviation Administration, (2) Signal Processing of Acoustic Signatures of Heart Valves for Shiley, Inc.; and (3) Turbine Blade Inspection for the Air Force, jointly with Southwest Research Institute and Garrett. In FY-92, the primary contributions of the NDE thrust area, described in this report were in fieldable chemical sensor systems, computed tomography, and laser generation and detection of ultrasonic energy.

  20. Defects detection and non-destructive testing (NDT) techniques in paintings: a unified approach through measurements of deformation

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Ibarra-Castanedo, C.; Ambrosini, D.; Paoletti, D.; Bendada, A.; Maldague, X.

    2013-05-01

    The present study is focused on two topics. The first one is a mathematical model, useful to understand the deformation of paintings, which uses straining devices, adjustable and micrometrically controlled via a pin supported in a hollow cylinder. Strains were analyzed by holographic interferometry (HI) technique using an appropriate frame. The second one concerns the need to improve the conservator's knowledge about the defect's detection and defect's propagation in acrylic painting characterized of underdrawings and pentimenti. To fulfill this task, a sample was manufactured to clarify the several uncertainties inherent the influence of external factors on their conservation. Subsurface anomalies were also retrieved by near-infrared reflectography (NIRR) and transmittography (NIRT) techniques, using LED lamps and several narrow-band filters mounted on a CMOS camera, working at different wavelengths each other and in combination with UV imaging. In addition, a sponge glued on the rear side of the canvas was impregnated with a precise amount of water by means of a syringe to verify the "stretcher effect" by the digital speckle photography (DSP) technique (using MatPIV). The same effect also affects the sharp transition of the canvas at the stretcher's edge. In this case, a possible mechanism is a direct mechanical contact between stretcher and canvas that was investigated by HI technique. Finally, advanced algorithms applied to the square heating thermography (SHT) data were very useful to detect three Mylar® inserts simulating different type of defects. These fabricated defects were also identified by optical techniques, while the visual inspection was the only one capable of detecting a biological damage.

  1. Non-destructive evaluation techniques applied to the study of fatigue microcrack growth in steel alloys: Final report

    SciTech Connect

    London, B.; Yuce, H.; Nelson, D.

    1987-10-01

    In Part I of this study, an ultrasonic surface acoustic wave (SAW) technique was used to monitor the depth of surface fatigue microcracks in 300M steel as they grew. This technique also provided information on the stress which must be applied to cause the cracks to fully open. Values of crack opening stress obtained by scanning electron microscope (SEM) measurements of crack tip opening displacements were compared with values determined acoustically. Good agreement was obtained. 300M steel, heat treated to yield strength of 1737 MPa, was tested at two different zero-to-maximum tension stress levels. Effects of residual stresses produced by two different surface preparations on the growth of small cracks were studied. One preparation was electropolishings while the other was stress-relieving followed by diamond paste polishing. Fatigue microcrack growth rate agreed well with that of large cracks in electropolished specimens but, the presence of shallow compressive residual stresses in other specimens caused growth rates as much as an order of magnitude lower than in electropolished specimens. In Part II, four different microstructures of 4140 steel were investigated. Small fatigue crack behavior was monitored using a surface acoustic wave ultrasonic technique to accurately measure crack depth and crack closure stress. Cracks from 50 to 200 ..mu..m in depth in specially designed catilevered bending samples were investigated. 143 refs., 74 figs., 5 tabs.

  2. Nondestructive testing with thermography

    NASA Astrophysics Data System (ADS)

    Ibarra-Castanedo, Clemente; Tarpani, José Ricardo; Maldague, Xavier P. V.

    2013-11-01

    Thermography is a nondestructive testing (NDT) technique based on the principle that two dissimilar materials, i.e., possessing different thermo-physical properties, would produce two distinctive thermal signatures that can be revealed by an infrared sensor, such as a thermal camera. The fields of NDT applications are expanding from classical building or electronic components monitoring to more recent ones such as inspection of artworks or composite materials. Furthermore, thermography can be conveniently used as a didactic tool for physics education in universities given that it provides the possibility of visualizing fundamental principles, such as thermal physics and mechanics among others.

  3. A new, non-destructive, real-time measurement technique of the surface area of aerogel during synthesis

    NASA Astrophysics Data System (ADS)

    Shen, Yang; Lee, Jeongseop A.; Halperin, W. P.

    We have developed a new method of measuring surface area of silica aerogel during the synthesis stage using a standard pulsed NMR setup. The applicability of this method can be extended to a much broader type of chemical reactions yielding a rigid porous condensate whose surface relaxation rate differs substantially from its surrounding liquids. The number of various chemical species involved in the reaction poses little to no limitation to its applicability owing to the physics in the fast exchange limit. This is the main distinguishing feature from a conventional NMR or infrared spectroscopy method in which individual chemical bondings from various reaction intermediaries are tracked in time which is often difficult if not impossible due to complex reactions. The result from this technique yields a surface area that is analogous to the result from a well-established BET (Brunauer-Emmett-Teller) technique, but without the need for extraction or supercritical extraction of the porous medium. This work was supported by the DOE BES under grants No. DE-FG02-05ER46248.

  4. Influence of porosity and relative humidity on consolidation of dolostone with calcium hydroxide nanoparticles: Effectiveness assessment with non-destructive techniques

    SciTech Connect

    Lopez-Arce, P.; Gomez-Villalba, L.S.; Pinho, L.; Fernandez-Valle, M.E.; Alvarez de Buergo, M.; Fort, R.

    2010-02-15

    Slaked lime (Ca(OH){sub 2}) nanoparticles were exposed at 33% and 75% relative humidity (RH) to consolidate dolostone samples used in historical buildings. Non-destructive techniques (NDT) were applied to determine the chemical, morphological, physical and hydric properties of the stone samples, before and after 20 days treatment. Morphological and mineralogical characterisation of the nanoparticles was performed. 75% RH favors the consolidation process studied under Environmental Scanning Electron Microscopy (ESEM-EDS), spectrophotometry, capillarity, water absorption under vacuum, ultrasound velocity, Nuclear Magnetic Resonance (imaging and relaxometry) and Optical Surface Roughness analyses. At 75% RH the nanoparticles fill the pores and inter-crystalline dolomite grain contacts but do not favor calcite re-crystallization as it occurs at 33% RH. The ESEM, XRD and TEM analyses under 75% RH reveal the fast transformation of portlandite (Ca(OH){sub 2}) into vaterite (CaCO{sub 3}), monohydrocalcite (CaCO{sub 3} . H{sub 2}O) and calcite (CaCO{sub 3}), and eventually the physical and hydric properties of the stones significantly improve. New insights are provided for the assessment of consolidation effectiveness of porous carbonate stones with calcium hydroxide nanoparticles under optimum RH conditions combining several NDT.

  5. A survey of CPU-GPU heterogeneous computing techniques

    DOE PAGESBeta

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-07-04

    As both CPU and GPU become employed in a wide range of applications, it has been acknowledged that both of these processing units (PUs) have their unique features and strengths and hence, CPU-GPU collaboration is inevitable to achieve high-performance computing. This has motivated significant amount of research on heterogeneous computing techniques, along with the design of CPU-GPU fused chips and petascale heterogeneous supercomputers. In this paper, we survey heterogeneous computing techniques (HCTs) such as workload-partitioning which enable utilizing both CPU and GPU to improve performance and/or energy efficiency. We review heterogeneous computing approaches at runtime, algorithm, programming, compiler and applicationmore » level. Further, we review both discrete and fused CPU-GPU systems; and discuss benchmark suites designed for evaluating heterogeneous computing systems (HCSs). Furthermore, we believe that this paper will provide insights into working and scope of applications of HCTs to researchers and motivate them to further harness the computational powers of CPUs and GPUs to achieve the goal of exascale performance.« less

  6. A survey of CPU-GPU heterogeneous computing techniques

    SciTech Connect

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-07-04

    As both CPU and GPU become employed in a wide range of applications, it has been acknowledged that both of these processing units (PUs) have their unique features and strengths and hence, CPU-GPU collaboration is inevitable to achieve high-performance computing. This has motivated significant amount of research on heterogeneous computing techniques, along with the design of CPU-GPU fused chips and petascale heterogeneous supercomputers. In this paper, we survey heterogeneous computing techniques (HCTs) such as workload-partitioning which enable utilizing both CPU and GPU to improve performance and/or energy efficiency. We review heterogeneous computing approaches at runtime, algorithm, programming, compiler and application level. Further, we review both discrete and fused CPU-GPU systems; and discuss benchmark suites designed for evaluating heterogeneous computing systems (HCSs). Furthermore, we believe that this paper will provide insights into working and scope of applications of HCTs to researchers and motivate them to further harness the computational powers of CPUs and GPUs to achieve the goal of exascale performance.

  7. Study by non-destructive technique of gilding coat of arms of the Real Alcázar of Seville, Spain

    NASA Astrophysics Data System (ADS)

    Robador, M. D.; Pérez-Rodriguez, J. L.; Muñoz-García, A.; Garófano, I.; Garrote, M. A.; Odriozola, C.; Durán, A.

    2012-04-01

    The Real Alcazar of Seville is a building inscribed in the World Heritage List, being the most ancient Real Palace in Europe still in use. It was built over roman buildings, from the XI century to our days, exceptional buildings and gardens of the highest architectonical, cultural and historic value. High value wall paintings of different periods are located in different places all over the palace. In one of its chamber - the King's bedroom - golden medallions that represent the coat of arms of Leon and Castilla Kingdom appear decorating its walls. The objective of this work was the study of the materials employed in the manufacture of these coats by portable and non-destructive techniques: X-ray diffraction (XDR) and X-ray fluorescence (XRF) and Raman spectroscopy. The support used for gilding was also studied using conventional techniques such as: powder X-ray diffraction (powder XRD), thermal analysis (DTA-TG) and FT-IR spectroscopy. The results obtained by portable XRD, XRF and Raman spectroscopy showed that the polychrome was carried out with gold in all samples studied. Other elements such as silver and cooper were also found in minor proportion. XRF allowed the quantification of the different metal (average composition: Au 79.5 %, Ag 8.1 %, Cu 5 %). There were various ways of adhering the golden leaf to the surface, but for large areas a bole mix of fine earth was typical. For other ornamentations, technique based on an aqueous medium and brushed onto the part to be gilded was used an. For panel and wall paintings, however, oil mordant was commonly used. In our study the gold was adhered to the surface using oil mordant. The powder XRD of the support showed the presence of gypsum and small proportion of anhydrite. However, calcium carbonate was not detected due to low proportion and low diffraction intensity of the mineral. The DTA-TG study confirms the presence of calcite (less than 5%). This technique also revealed the presence of organic compounds (oil

  8. Nondestructive test of regenerative chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Stauffis, R.; Wood, R.

    1972-01-01

    Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

  9. A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique and Three Types of Gamma-ray Detectors

    SciTech Connect

    Jorge Navarro; Rahmat Aryaeinejad,; David W. Nigg

    2011-05-01

    A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique1 Rahmat Aryaeinejad, Jorge Navarro, and David W Nigg Idaho National Laboratory Abstract Effective and efficient Advanced Test Reactor (ATR) fuel management require state of the art core modeling tools. These new tools will need isotopic and burnup validation data before they are put into production. To create isotopic, burn up validation libraries and to determine the setup for permanent fuel scanner system a feasibility study was perform. The study consisted in measuring short and long cooling time fuel elements at the ATR canal. Three gamma spectroscopy detectors (HPGe, LaBr3, and HPXe) and two system configurations (above and under water) were used in the feasibility study. The first stage of the study was to investigate which detector and system configuration would be better suited for different scenarios. The second stage of the feasibility study was to create burnup and cooling time calibrations using experimental isotopic data collected and ORIGEN 2.2 burnup data. The results of the study establish that a better spectra resolution is achieve with an above the water configuration and that three detectors can be used in the permanent fuel scanner system for different situations. In addition it was conclude that a number of isotopic ratios and absolute measurements could be used to predict ATR fuel burnup and cooling times. 1This work was supported by the U.S. Depart¬ment of Energy (DOE) under Battelle Energy Alliance, LLC Contract No. DE-AC07-05ID14517.

  10. Nondestructive Evaluation for Aerospace Composites

    NASA Technical Reports Server (NTRS)

    Leckey, Cara; Cramer, Elliott; Perey, Daniel

    2015-01-01

    Nondestructive evaluation (NDE) techniques are important for enabling NASA's missions in space exploration and aeronautics. The expanded and continued use of composite materials for aerospace components and vehicles leads to a need for advanced NDE techniques capable of quantitatively characterizing damage in composites. Quantitative damage detection techniques help to ensure safety, reliability and durability of space and aeronautic vehicles. This presentation will give a broad outline of NASA's range of technical work and an overview of the NDE research performed in the Nondestructive Evaluation Sciences Branch at NASA Langley Research Center. The presentation will focus on ongoing research in the development of NDE techniques for composite materials and structures, including development of automated data processing tools to turn NDE data into quantitative location and sizing results. Composites focused NDE research in the areas of ultrasonics, thermography, X-ray computed tomography, and NDE modeling will be discussed.

  11. Instruction manuals for radiographic nondestructive testing

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Six new handbooks on the fundamentals of nondestructive test techniques supply recent information for instructing inspectors and technicians, and can be used effectively in shops or laboratories, technical schools, or home study programs.

  12. Importance of integrated results of different non-destructive techniques in order to evaluate defects in panel paintings: the contribution of infrared, optical and ultrasonic techniques

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Theodorakeas, P.; Ibarra-Castanedo, C.; Avdelidis, N. P.; Paoletti, A.; Paoletti, D.; Hrissagis, K.; Bendada, A.; Koui, M.; Maldague, X.

    2011-06-01

    The increasing deterioration of panel paintings can be due to physical processes that take place during exhibition or transit, or as a result of temperature and humidity fluctuations within a building, church or museum. In response to environmental alterations, a panel painting can expand or contract and a new equilibrium state is eventually reached. These adjustments though, are usually accompanied by a change in shape in order to accommodate to the new conditions. In this work, a holographic method for detecting detached regions and micro-cracks is described. Some of these defects are confirmed by Thermographic Signal Reconstruction (TSR) technique. In addition, Pulsed Phase Thermography (PPT) and Principal Component Thermography (PCT) allow to identify with greater contrast two artificial defects in Mylar which are crucial to understand the topic of interest: the discrimination between defect materials. Finally, traditional contact ultrasounds applications, are widely applied for the evaluation of the wood quality in several characterization procedures. Inspecting the specimen from the front side, the natural and artificial defects of the specimen are confirmed. Experimental results derived by the application of the integrated methods on an Italian panel painting reproduction, called The Angel specimen, are presented. The main advantages that these techniques can offer to the conservation and restoration of artworks are emphasized.

  13. AIRBORNE INERTIAL SURVEYING USING LASER TRACKING AND PROFILING TECHNIQUES.

    USGS Publications Warehouse

    Cyran, Edward J.

    1986-01-01

    The U. S. Geological Survey through a contract with the Charles Stark Draper Laboratory has developed the Aerial Profiling of Terrain System. This is an airborne inertial surveying system designed to use a laser tracker to provide position and velocity updates, and a laser profiler to measure terrain elevations. The performance characteristics of the system are discussed with emphasis placed on the performance of the laser devices. The results of testing the system are summarized for both performance evaluation and applications.

  14. Combining Ground Penetrating Radar and Terrestrial Laser Scanning techniques to non-destructively image the 2006 cross-stratified overbank deposits of Tungurahua volcano (Ecuador)

    NASA Astrophysics Data System (ADS)

    Douillet, G. A.; Dujardin, J.; Abolghasem, A.; Kueppers, U.; Bano, M.; Mothes, P. A.; Dingwell, D. B.

    2012-12-01

    Tungurahua volcano (Ecuador) generated Pyroclastic Density Currents (PDCs) in August 2006. The deposits are characterized by two lithofacies: a massive, unsorted, coarse-grained lithofacies confined to the valleys that directed the parent PDCs and interpreted as deposited from dense pyroclastic flows and a finer-grained and better-sorted cross-stratified lithofacies that outcrop on the overbanks of valleys downstream of cliffs and bends in the valleys deposited from dilute PDCs. The pristine surface exhibits a variety of dune-bedform (DBs) shapes. In order to better record the deposits characteristics and constrain the sedimentation processes, a field survey combining terrestrial laser scanner and ground penetrating radars (GPR) was yield. The terrestrial laser scanner records an accurate topography model of the surface of the deposits (<1 cm precision). The shape parameters of the DBs are then analyzed systematically and the size evolution calculated. Three GPR antennas were used (250, 500, 800 MHz). They permit to image the stratification within the deposits at different scales and in a non-destructive way. More than 450 profiles were collected, covering three key sectors of the volcano. A large-scale griding (profiles separated by 20 m and crossing perpendicularly) was executed with the 250 MHz antenna in three main overbank deposition zones (each zone c.a. 50.000 m^2). Of particular interest is a 200 m long ash body with a wedge shape. It has a sharp upstream onset with the shape of a quarter pipe and decreases in thickness downstream with DBs on its surface. Eight layers were identified on the GPR data and interpolated in between the profiles for a 3D image. At least three successive cross-stratified units are found on top of five units that more likely correspond to massive layers. While the cross-stratified units seem to aggrade as stoss-side backstep-strata, the massive layers are either gently thinning downstream or continuous. The data reveal the

  15. Pre-survey feasibility assessment of the persistent scatterer technique

    NASA Astrophysics Data System (ADS)

    Plank, Simon; Singer, John; Thuro, Kurosch

    2013-04-01

    The remote sensing technique persistent scatterer synthetic aperture radar interferometry (PS-InSAR) is a powerful method for detection and monitoring of landslides with accuracy up to a few millimeters. However, precondition for reliable PS-InSAR processing is a stack of at least 15 to 50 SAR images. This makes processing very time-consuming and expensive. Furthermore, successful PS-InSAR application requires a high number of measurement points within the area of interest - so-called persistent scatterers (PS) which are scatterers of high coherent values. But estimation of the number and the distribution of the PS within the site prior to the recording and processing of several SAR images is very complicated. Therefore, we developed three new methods for PS estimation prior to the acquisition of the SAR data. These methods are based on freely available or low-cost optical remote sensing data, land cover data (e.g. GlobCover and CORINE) as well as topographic maps and OpenStreetMap data. By means of empirical approaches these geodata were compared with results of real PS-InSAR processing of several sites. First, the well-known normalized difference vegetation index (NDVI) processed with optical remote sensing data was used in an entirely new approach to estimate PS prior to the SAR data acquisition of the area of interest. Result of this method is an estimation of the probability for each pixel of the NDVI image to get a PS at a certain NDVI value. When using freely available middle spatial resolution optical data (e.g. Landsat and ASTER) this PS estimation procedure works very well in areas of sparse vegetation. World-wide application of this method requires high spatial resolution optical sensors. Then, the NDVI-based PS estimation method can also be applied at areas covered by denser vegetation. The second PS estimation method is based on freely available land cover datasets. Result of this method is an estimation of the PS density (PS/km²) for each type of

  16. Survey of techniques used to preserve biological materials

    NASA Technical Reports Server (NTRS)

    Feinler, E. J.; Hubbard, R. W.

    1972-01-01

    The techniques used to preserve biological materials are documented and summarized. The report is presented in a handbook format that categorizes the most important preservation techniques available, and includes a representative sampling of the thousands of applications of these techniques to biological materials and organisms. Details of the information coverage and method of approach are outlined. Data are given in tabular form, and an index and extensive bibliography are included.

  17. Sampling for Telephone Surveys: Do the Results Depend on Technique?

    ERIC Educational Resources Information Center

    Franz, Jennifer D.

    Two basic methods exist for drawing probability samples to be used in telephone surveys: directory sampling (from alphabetical or street directories) and random digit dialing (RDD). RDD includes unlisted numbers, whereas directory sampling includes only listed numbers. The goal of this paper is to estimate the effect of failure to include…

  18. A Survey of Librarian Perceptions of Information Literacy Techniques

    ERIC Educational Resources Information Center

    Yearwood, Simone L.; Foasberg, Nancy M.; Rosenberg, Kenneth D.

    2015-01-01

    Teaching research competencies and information literacy is an integral part of the academic librarian's role. There has long been debate among librarians over what are the most effective methods of instruction for college students. Library Faculty members at a large urban university system were surveyed to determine their perceptions of the…

  19. Getting Parents and Students Involved: Using Survey and Interview Techniques.

    ERIC Educational Resources Information Center

    Downs, Judy R.

    1993-01-01

    Describes a series of class activities involving student surveys and interviews with parents and other adults. Discusses possible interview topics ranging from important inventions to simulated interviews with historical figures. Reports that student interest improved and parents became more involved with school activities. (CFR)

  20. Nondestructive evaluation of advanced ceramics

    NASA Technical Reports Server (NTRS)

    Klima, Stanley J.; Kautz, Harold E.

    1988-01-01

    A review is presented of Lewis Research Center efforts to develop nondestructive evaluation techniques for characterizing advanced ceramic materials. Various approaches involved the use of analytical ultrasonics to characterize monolythic ceramic microstructures, acousto-ultrasonics for characterizing ceramic matrix composites, damage monitoring in impact specimens by microfocus X-ray radiography and scanning ultrasonics, and high resolution computed X-ray tomography to identify structural features in fiber reinforced ceramics.

  1. Combined use of the non-destructive XRF and low energy micro-XRF techniques for the analysis of silvered nummi belonging to the Treasure of Misurata (Libya)

    NASA Astrophysics Data System (ADS)

    Romano, Francesco Paolo; Garraffo, Salvatore; Pappalardo, Lighea; Rizzo, Francesca

    2013-04-01

    Roman coinage underwent a severe debasement of silver during the time and the production of plated coins became a common practice for giving the impression of a high finesses of the alloy. In 294 AD, Diocletian introduced the nummus, manufactured with the same standard in all the mints by using an internal Cu-Sn-Pb-Ag core and presenting a thin silvered patina (about 2 micron) on its surface. The silver plating of the nummi have been investigated in the past and different methods have been suggested for its manufacturing (e.g. segregation during casting, chemical treatments, mercury-silvering). However, previous analyses were focused on few samples and, consequently, this technological issue remained unresolved. In the present work, the BSC-XRF (Beam Stability Controlled -XRF) and a LE-micro-XRF portable spectrometers developed at the LANDIS laboratory of IBAM-CNR and LNS-INFN in Catania (Italy), have been applied for the in-situ analysis of the silvered nummi belonging to the Misurata Treasure (Museum of Leptis Magna, El-Khomes, Libya). The treasure is composed of 108 thousand coins manufactured in 19 Imperial mints operating in the period 294-333 AD. In order to establish if, and at what extent, the mercury-silvering was used to produce the thin Ag-patina of the nummi, the non-destructive investigation was extended to 1050 well preserved coins. Measurements allowed to explore the presence of Hg and the Hg-Ag correlation at the coin surface. The portable BSC-XRF and the LE-micro XXRF techniques are suited to approach this study. A new version of the BSC-XRF spectrometer, consisting of a compact high-intensity x-ray tube (50 kV; 4 mA) coupled to a 80 mm2 SDD detector (138 eV @ 5.9 keV), was developed for the fast determination of mercury traces in a large number of coins (measurement time is 150 seconds; MDL for Hg is 100 ppm). The investigation allowed to identify the Imperial mints and the periods where the mercury-silvering were probably used. However the BSC

  2. A survey of GPU-based medical image computing techniques.

    PubMed

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming; Wang, Defeng

    2012-09-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine. PMID:23256080

  3. A survey of GPU-based medical image computing techniques

    PubMed Central

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming

    2012-01-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine. PMID:23256080

  4. USES OF MARKETING TECHNIQUES THE U. S. GEOLOGICAL SURVEY.

    USGS Publications Warehouse

    McDermott, Michael P.

    1983-01-01

    The use of marketing techniques by government agencies to provide more efficient and effective dissemination of their information is a fairly recent development. A recessive economy, and increased scrutiny of operations have become a powerful incentive to maximize revenues and minimize expenses wherever possible as long as the primary mission of public service is satisfactorily met.

  5. Survey of Temperature Measurement Techniques For Studying Underwater Shock Waves

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Alderfer, David W.

    2004-01-01

    Several optical methods for measuring temperature near underwater shock waves are reviewed and compared. The relative merits of the different techniques are compared, considering accuracy, precision, ease of use, applicable temperature range, maturity, spatial resolution, and whether or not special additives are required.

  6. Overview of nondestructive evaluation technologies

    SciTech Connect

    Thomas, G.

    1995-04-01

    The infrastructure in the US and the world is aging. There is an increasing awareness of the need to assess the severity of the damage occurring to the infrastructure. Limited resources preclude the replacement of all structures that need repairs or have exceeded their life times. Methods to assess the amount and severity of damage are crucial to implementing a systematic, cost effective approach to repair and/or replace the damaged structures. The challenges of inspecting aging structures without impairing their usefulness rely on a variety of technologies and techniques for nondestructive evaluation (NDE). This paper will briefly describe several nondestructive evaluation technologies that are required for inspecting a variety of systems and structures.

  7. NON-DESTRUCTIVE BEAM MEASUREMENTS.

    SciTech Connect

    BAI,M.

    2004-07-05

    In high energy accelerators, especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is an ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with a Schottky detector, phase advance measurements as well as nonlinear resonance measurements with the ac dipoles in the Brookhaven RHIC.

  8. Watermarking techniques used in medical images: a survey.

    PubMed

    Mousavi, Seyed Mojtaba; Naghsh, Alireza; Abu-Bakar, S A R

    2014-12-01

    The ever-growing numbers of medical digital images and the need to share them among specialists and hospitals for better and more accurate diagnosis require that patients' privacy be protected. As a result of this, there is a need for medical image watermarking (MIW). However, MIW needs to be performed with special care for two reasons. Firstly, the watermarking procedure cannot compromise the quality of the image. Secondly, confidential patient information embedded within the image should be flawlessly retrievable without risk of error after image decompressing. Despite extensive research undertaken in this area, there is still no method available to fulfill all the requirements of MIW. This paper aims to provide a useful survey on watermarking and offer a clear perspective for interested researchers by analyzing the strengths and weaknesses of different existing methods. PMID:24871349

  9. GPR as a Low Impact Paleontogical Survey Technique

    NASA Astrophysics Data System (ADS)

    Sturdevant, G. C.; Leverence, R.; Stewart, R.

    2013-12-01

    The Deweyville Formation, a Pleistocene fluvial sandstone, is a prolific source of megafaunal fossils from periods of low stand environmental conditions. GPR was employed in an environmentally sensitive area in close proximity to a salt dome in Northwest Harris County, Texas as a method of evaluating the probable paleo-depositional environment and to prospect for potential further site development of two distinct fossiliferous zones. The primary zone of interest is a lag gravel bounded sand responsible for producing a regionally unique fossil assemblage including South American megafauna (Lundelius et al, 2013). The secondary zone of interest contains undisturbed mammoth remains housed in coarse white sand emplaced on top of a clay drape which has been hypothesized to represent an oxbow lake formed by the meandering paleo-Brazos river. With an accurate map of the paleo-channel planning future activity can focus on maximizing fossil recovery and minimizing site impact. Pulse EKKO 250 MHz, 400MHz, and 1GHz system was employed in a prospect area proximal to the secondary site to calibrate and evaluate these systems for their resolution and penetration depth in the modern sediments. The data was processed using EKKO Mapper and EKKO View Deluxe software packages, 3d volumes were produced and sliced. Preliminary results from the 250 MHz demonstrate successful imaging of the sand-clay interface. After these surveys were run a small portion of the site was excavated to confirm the estimated velocities, the observed anomalies, and refine our modeling and interpretation, and improve grid design for further surveys. It was confirmed that the sand-clay interface was easily observable using GPR, however the grid spacing proved to be too wide, leading to artifacts in the 3d volume produced.

  10. A survey of reflectometry techniques with applications to TFTR

    SciTech Connect

    Collazo, I.; Stacey, W.M.; Wilgen, J.; Hanson, G.; Bigelow, T.; Thomas, C.E.; Bretz, N.

    1993-12-01

    This report presents a review of reflectometry with particular attention to eXtraordinary mode (X-mode) reflectometry using the novel technique of dual frequency differential phase. The advantage of using an X-mode wave is that it can probe the edge of the plasma with much higher resolution and using a much smaller frequency range than with the Ordinary mode (O-Mode). The general problem with previous full phase reflectometry techniques is that of keeping track of the phase (on the order of 1000 fringes) as the frequency is swept over the band. The dual frequency phase difference technique has the advantage that since it is keeping track of the phase difference of two frequencies with a constant frequency separation, the fringe counting is on the order of only 3 to 5 fringes. This fringe count, combined with the high resolution of the X-mode wave and the small plasma access requirements of reflectometry, make X-mode reflectometry a very attractive diagnostic for today`s experiments and future fusion devices.