Note: This page contains sample records for the topic quantitative nondestructive evaluation from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Nondestructive pulsed infrared quantitative evaluation of metals  

NASA Astrophysics Data System (ADS)

A nondestructive technique for the quantitative evaluation of defects in metal structures is described. The surface of the metal is irradiated by a short xenon lamp pulse and monitored by a thermal image processor. The analysis relates to the time decay signal of the front face temperature, which contains information on the thermophysical properties and subsurface defects of the material. The time history of the surface temperature is then used to quantify the substructure of the material. Applications for the inspection of aluminum, steel, and turbine blades are presented.

Daniels, Arnold

1996-03-01

2

Towards quantitative non-destructive evaluation of aging aircraft  

NASA Astrophysics Data System (ADS)

Nondestructive testing techniques, as they are practiced in the field of quantitative nondestructive evaluation, are at the basis of a comprehensive approach to secure the safety of aging aircraft. The applications, advantages and disadvantages of the principal NDE techniques are summarized in this paper. It is discussed that measurement models for these techniques, in conjunction with the probability of detection concept, scanning plans, and methods of graphical display, facilitate the selection of optimal procedures for specific inspection problems. These models also suggest NDE standards and calibration techniques, and they can be an important part of inspection system validation and operator training. Four major components of a comprehensive quantitative NDE program for aging aircraft are identified and briefly discussed.

Achenbach, J. D.; Thompson, D. O.

3

The Nuclear Renaissance - Implications on Quantitative Nondestructive Evaluations  

SciTech Connect

The world demand for energy is growing rapidly, particularly in developing countries that are trying to raise the standard of living for billions of people, many of whom do not even have access to electricity. With this increased energy demand and the high and volatile price of fossil fuels, nuclear energy is experiencing resurgence. This so-called nuclear renaissance is broad based, reaching across Asia, the United States, Europe, as well as selected countries in Africa and South America. Some countries, such as Italy, that have actually turned away from nuclear energy are reconsidering the advisability of this design. This renaissance provides the opportunity to deploy more advanced reactor designs that are operating today, with improved safety, economy, and operations. In this keynote address, I will briefly present three such advanced reactor designs in whose development Westinghouse is participating. These designs include the advanced passive PWR, AP1000, which recently received design certification for the US Nuclear Regulatory Commission; the Pebble Bed Modular reactor (PBMR) which is being demonstrated in South Africa; and the International Reactor Innovative and Secure (IRIS), which was showcased in the US Department of Energy's recently announced Global Nuclear Energy Partnership (GNEP), program. The salient features of these designs that impact future requirements on quantitative nondestructive evaluations will be discussed. Such features as reactor vessel materials, operating temperature regimes, and new geometric configurations will be described, and mention will be made of the impact on quantitative nondestructive evaluation (NDE) approaches.

Matzie, Regis A. [Westinghouse Electric Company, 20 International Drive, Windsor, CT 06095 (United States)

2007-03-21

4

Nondestructive evaluation  

Microsoft Academic Search

Nondestructive evaluation (NDE) is to materials what CAT (computerized axial tomography) scanning is to the human body-an attempt to look inside without opening it up. As in CAT scanning, modern NDE requires sophisticated mathematical software to perform its function. This is especially true with regard to quantitative NDE, wherein we attempt to quantify defects, that is, determine their size, location,

H. A. Sabbagh

1994-01-01

5

Nondestructive evaluation  

SciTech Connect

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.

Martz, H.E.

1997-02-01

6

Review of progress in quantitative NDE. [Nondestructive Evaluation (NDE)  

SciTech Connect

This booklet is composed of abstracts from papers submitted at a meeting on quantitative NDE. A multitude of topics are discussed including analysis of composite materials, NMR uses, x-ray instruments and techniques, manufacturing uses, neural networks, eddy currents, stress measurements, magnetic materials, adhesive bonds, signal processing, NDE of mechanical structures, tomography,defect sizing, NDE of plastics and ceramics, new techniques, optical and electromagnetic techniques, and nonlinear techniques. (GHH)

Not Available

1991-01-01

7

QUANTITATIVE NON-DESTRUCTIVE EVALUATION (QNDE) OF THE ELASTIC MODULI OF POROUS TIAL ALLOYS  

SciTech Connect

The elastic moduli of {gamma}-TiA1 were studied in porous samples consolidated by various techniques e.g. cold isostatic pressing (CIP), pressure-less sintering, or hot isostatic pressing (HIP). Porosity linearly affects the dynamic elastic moduli of samples. The results indicate that the sound wave velocities and the elastic moduli affected by the processing route and depend not only on the attained density but also on the consolidation temperature. In this paper we show that there is linear correlation between the shear and the longitudinal sound velocities in porous TiA1. This opens the way to use a single sound velocity as a tool for quantitative non-destructive evaluation (QNDE) of porous TiA1 alloys. Here we demonstrate the applicability of an equation derived from the elastic theory and used previously for porous cubic metals.

Yeheskel, O. [NRCN, PO Box 9001, Beer Sheva, 84190 (Israel)

2008-02-28

8

Quantitative Non-Destructive Evaluation (qnde) of the Elastic Moduli of Porous Tial Alloys  

NASA Astrophysics Data System (ADS)

The elastic moduli of ?-TiA1 were studied in porous samples consolidated by various techniques e.g. cold isostatic pressing (CIP), pressure-less sintering, or hot isostatic pressing (HIP). Porosity linearly affects the dynamic elastic moduli of samples. The results indicate that the sound wave velocities and the elastic moduli affected by the processing route and depend not only on the attained density but also on the consolidation temperature. In this paper we show that there is linear correlation between the shear and the longitudinal sound velocities in porous TiA1. This opens the way to use a single sound velocity as a tool for quantitative non-destructive evaluation (QNDE) of porous TiA1 alloys. Here we demonstrate the applicability of an equation derived from the elastic theory and used previously for porous cubic metals.

Yeheskel, O.

2008-02-01

9

Electromagnetic Nondestructive Evaluation (III)  

Microsoft Academic Search

Within the context of non-destructive testing, the classical `Formulate-Solve-Interpret' model of problem solving becomes `Measure-Recover-Interpret'. But, before one can perform measurements, there must be appropriate instrumentation. In this book on electromagnetic non-destructive evaluation (ENDE) all these aspects (instrumentation, measurement, recovery and interpretation) are treated, though the major emphasis is on the recovery and interpretation aspects. The focus of the book,

R S Anderssen

2000-01-01

10

Simulation and Visualisation for Electromagnetic Nondestructive Evaluation  

Microsoft Academic Search

This paper reviews the state-of-the art of modelling, simulation and visualisation and reviews the recent development of modelling, simulation and visualisation software for Nondestructive Evaluation (NDE). Simulation and visualisation can assist in the design and development of electromagnetic sensing and imaging techniques and systems for nondestructive testing, feature extraction and inverse problems for quantitative nondestructive evaluation. After reviewing the state-of-the

Anthony Simm; Ilham Zainal Abidin; Gui Yun Tian; Wai Lok Woo

2010-01-01

11

Reflection shearography for nondestructive evaluation  

Microsoft Academic Search

Conventional nondestructive evaluation (NDE) techniques include visual inspection, eddy current scanning, ultrasonics, and fluorescent dye penetration. These techniques are limited to local evaluation, often miss small buried defects, and are useful only on polished surfaces. Advanced NDE techniques include laser ultrasonics, holographic interferometry, structural integrity monitoring, shearography, and thermography. A variation of shearography, employing reflective shearographic interferometry, has been developed.

Russell M. Kurtz; Michael A. Piliavin; Ranjit D. Pradhan; Tin M. Aye; Gajendra D. Savant; Tomasz P. Jannson; Steffen Hergert

2004-01-01

12

Bridge Management and Nondestructive Evaluation  

Microsoft Academic Search

The City and County of Denver (CCD) Public Works Department owns, inspects, and maintains 531 bridges in its inventory of which 264 are considered major structures spanning over 6.1 m in length. In this paper, a methodology using the CCD major bridge network for the application of nondestructive evaluation (NDE) methods in bridge inspections is explained. The methodology, called Bridge

Kevin L. Rens; Carnot L. Nogueira; David J. Transue

2005-01-01

13

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

NASA Astrophysics Data System (ADS)

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.

Miller, James G.

1995-03-01

14

Reflection shearography for nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Conventional nondestructive evaluation (NDE) techniques include visual inspection, eddy current scanning, ultrasonics, and fluorescent dye penetration. These techniques are limited to local evaluation, often miss small buried defects, and are useful only on polished surfaces. Advanced NDE techniques include laser ultrasonics, holographic interferometry, structural integrity monitoring, shearography, and thermography. A variation of shearography, employing reflective shearographic interferometry, has been developed. This new shearographic interferometer is discussed, together with models to optimize its performance and experiments demonstrating its use in NDE.

Kurtz, Russell M.; Piliavin, Michael A.; Pradhan, Ranjit D.; Aye, Tin M.; Savant, Gajendra D.; Jannson, Tomasz P.; Hergert, Steffen

2004-09-01

15

Magnetoresistive Sensors for Nondestructive Evaluation  

Microsoft Academic Search

New high-sensitivity solid-state magnetoresistive (MR) sensor technologies offer significant advantages in nondestructive evaluation (NDE) systems. A key advantage of MR sensors is a flat frequency response extending from dc to hundreds of MHz, making them particularly attractive for low-frequency and multi- frequency eddy current detection for deep-flaw detection and depth profiling. MR sensors are mass produced by thin film processing

Albrecht Jander; Carl Smith; Robert Schneider

16

Problems associated with nondestructive evaluation of bridges  

NASA Astrophysics Data System (ADS)

The US has 542,000 bridges that consume billions of dollars per year in construction, rehabilitation, and maintenance funds and which are the lifelines of US commerce. The 1992 ISTEA (Intermodal Surface Transportation Efficiency Act) mandates the implementation of a quantitative computerized bridge management system by 1996. A prime need of such a system are quantitative bridge inspection methods to feed accurate reliable condition information to the huge database of bridges. Nondestructive evaluation (NDE) will fill a critical need in the implementation of effective bridge management. However, many serious barriers exist to the widespread routine application of this technology to bridges. This paper provides an overview of the typical problems associated with applying NDE to bridges.

Prine, David W.

1995-05-01

17

Actively modulated acoustic nondestructive evaluation of concrete  

Microsoft Academic Search

The need in testing concrete is not only the ability to detect large cracks or flaws but also reliably and efficiently to quantify the residual strength. Current nondestructive testing methods are capable only of discriminating high states of damage. This study lays the foundation for an evaluation method that may be significantly more sensitive than traditional nondestructive evaluation (NDE) to

Kraig Warnemuende; Hwai-Chung Wu

2004-01-01

18

Nondestructive Evaluation Program. Progress in 1985  

Microsoft Academic Search

The increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondestructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now under way. This report

G. J. Dau; M. M. Behravesh; S. N. Liu; T. Oldberg; M. J. Jr. Avioli; J. R. Scheibel; D. Sharma; D. M. Norris; S. W. Jr. Tagart; T. J. Griesbach

1986-01-01

19

Reports from the Yayoi symposium on quantitative non-destructive evaluation, (1). Application to the atomic energy; inverse problem and imaging technology.  

National Technical Information Service (NTIS)

The report consists of four parts. The first part deals with nondestructive evaluation in the nuclear power industry, focusing on in-service inspection in nuclear power plant, eddy current crack detection test of steam generator heat-exchanger tube, and n...

1990-01-01

20

Aerostructure Nondestructive Evaluation by Thermal Field Detection. Phase II. Technique Refinement and Quantitative Determination of Flaw Detection Capabilities.  

National Technical Information Service (NTIS)

This report describes the second phase of a program to evaluate and develop methods of flaw detection in laminated fiber composites using infrared radiation detection techniques with application to inspection of aerovehicle structures. Analytical heat tra...

P. V. McLaughlin M. G. Mirchandani

1984-01-01

21

Nondestructive evaluation of oriented strand board exposed to ...  

Treesearch

Description: Stress wave nondestructive evaluation (NDE) technologies are being ... in our laboratory to evaluate the performance properties of engineered wood. ... examined the relationship between nondestructive stress wave transmission, ...

22

Practical applications of nondestructive evaluation for airport pavement analysis  

NASA Astrophysics Data System (ADS)

This paper discusses the equipment and methodologies currently used for nondestructive testing (NDT) and nondestructive evaluation (NDE) of the structural capacity of military and civil airport pavements, including: (1) commonly used equipment and test methods for measuring pavement response to dynamic loads; (2) qualitative and quantitative evaluation of NDT data; (3) methods for back-calculating layer properties from NDT data; (4) layered elastic methods for evaluating pavement performance using processed NDT data; and (5) application of analytical results for developing pavement rehabilitation and management strategies.

McQueen, Roy D.; Guo, Edward

1995-07-01

23

Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics  

Microsoft Academic Search

Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture.

John H. Cantrell

2009-01-01

24

NONDESTRUCTIVE EVALUATION OF METAL FATIGUE USING NONLINEAR ACOUSTICS  

Microsoft Academic Search

Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture.

John H. Cantrell

2009-01-01

25

Novel quantitative non-destructive testing method for composite structures  

Microsoft Academic Search

A novel QNDT (quantitative non-destructive testing) method is developed that is combined with a phase-shifting shearing speckle and thermograph, and, it aims at the detection of faults such as cracks, voids, delamination and weak areas. The technique is immune to ambient noise and is suitable for measuring the in situ environment. Some different depth defects that would produce deformation differing

Jin-long Chen; Yu-wen Qin; Hong-wei Ji; Xin-hua Ji

1998-01-01

26

Nondestructive quantitative stress characterization of wire rope and steel cables  

NASA Astrophysics Data System (ADS)

This paper describes a new approach to nondestructive and quantitative characterization of residual and applied stress (absolute stress) on wire rope and steel cable. Examples are given from both field work as well as laboratory tests, including stress characterization of post-tensioning cables, bridge suspension cables, wire rope and thin strand steel wire. The approach is based on x-ray diffraction techniques. A detailed description of the results and the methodologies used to obtain them are provided.

Brauss, Michael E.; Pineault, James A.; Belassel, M.; Teodoropol, S. I.

1998-03-01

27

An Automated X-Ray Gauge for Nondestructive Quantitative Analysis  

Microsoft Academic Search

An x-ray gauging system is described for nondestructive quantitative analysis. The automated device utilizes the transmission of low-energy x-rays through a material in order to measure the areal density of the material. Under some conditions, one material may be examined in the presence of another. Using digital rather than analog conversion techniques, measurement precision of 0.1% and accuracy near 0.5%

William D. Drotning

1988-01-01

28

Nondestructive Evaluation Program: Progress in 1987  

Microsoft Academic Search

The increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondsetructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now under way. This report

M. J. Jr. Avioli; G. J. Dau; J. Edmonds; S. Gehl; S. N. Liu; J. Stein; R. Viswanathan; C. S. Welty

1988-01-01

29

NONDESTRUCTIVE EVALUATION (NDE) OF DAMAGED STRUCTURAL CERAMICS  

SciTech Connect

A combination of destructive and nondestructive testing methods was utilized to evaluate the impact velocity and energy conditions that caused fracture in alumina structural ceramics. Drop tower testing was used for low velocity impact with a high mass indenter and fragment simulating projectile testing was used for high velocity impact with a low mass projectile. The damaged samples were nondestructively evaluated using digital radiography and ultrasound C-scan imaging. The bulk damage detected by these techniques was compared to surface damage observed by visual inspection.

Brennan, R. E.; Green, W. H.; Sands, J. M.; Yu, J. H. [US Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, MD 21005-5066 (United States)

2009-03-03

30

Knowledge based systems in nondestructive evaluation  

Microsoft Academic Search

This paper dicusses the application of knowledge based systems technology to problems in nondestructive evaluation (NDE). The Saft Image Interpretation Assistant (SIIA) is used as an illustrative example. SIIA is a prototype knowledge based system designed to assist in making the operation of the Synthetic Aperture Focusing Technique (SAFT) Ultrasonic Inspection System more reliable and efficient. The two primary motivations

Melton

1987-01-01

31

Nondestructive Evaluation of FRP Bridge Deck Panels  

Microsoft Academic Search

The purpose of this research was to investigate Infrared Thermography (IRT) as a Non-Destructive Evaluation (NDE) method for glass fiber-reinforced polymer (FRP) composite bridge deck panels. FRP bridge decks are currently being evaluated as a potential replacement for traditional steel-grate or concrete bridge decking. A potential problem with these decks, however, is that structural damage that can occur due to

Phillip Hallam

2012-01-01

32

Techniques for enhancing laser ultrasonic nondestructive evaluation  

SciTech Connect

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.

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

1999-02-16

33

Development of instrumentation for magnetic nondestructive evaluation  

SciTech Connect

The use of failure-prone components in critical applications has been traditionally governed by removing such components from service prior to the expiration of their predicted life expectancy. Such early retirement of materials does not guarantee that a particular sample will not fail in actual usage. The increasing cost of such life expectancy based operation and increased demand for improved reliability in industrial settings has necessitated an alternate form of quality control. Modern applications employ nondestructive evaluation (NDE), also known as nondestructive testing (NDT), as a means of monitoring the levels and growth of defects in a material throughout its operational life. This thesis describes the modifications made to existing instrumentation used for magnetic measurements at the Center for Nondestructive Evaluation at Iowa State University. Development of a new portable instrument is also given. An overview of the structure and operation of this instrumentation is presented. This thesis discusses the application of the magnetic hysteresis and Barkhausen measurement techniques, described in Sections 1.3.1 and 1.3.2 respectively, to a number of ferromagnetic specimens. Specifically, measurements were made on a number of railroad steel specimens for fatigue characterization, and on specimens of Damascus steel and Terfenol-D for materials evaluation. 60 refs., 51 figs., 5 tabs.

Hariharan, S.

1991-09-23

34

Optical Nondestructive Evaluation for Structures  

Microsoft Academic Search

This paper presents a new technique for evaluation of engineering structures, using optical measurement and probabilistic advancing cross-diagnosis. Its application is first computersimulated, and then it is tested in the laboratory. With the cooperation of the U.S. Federal Highway Administration, a recently developed coherent laser radar system was used to measure structural deformation. The data are treated to reduce noise

Gongkang Fu; Adil G. Moosa; Juan Peng

2001-01-01

35

Nondestructive evaluation of steam traps  

NASA Astrophysics Data System (ADS)

Many thermographers have touted infrared thermography as an effective maintenance tool for evaluating steam traps for years. However, several investigators have raised questions about thermal measurement's effectiveness in this application. This paper explores and compares infrared thermography and ultrasonic detection methods for steam trap testing and provides guidelines for a successful trap survey.

Orlove, Gary L.

1999-03-01

36

Nondestructive evaluation of steam traps  

Microsoft Academic Search

Many thermographers have touted infrared thermography as an effective maintenance tool for evaluating steam traps for years. However, several investigators have raised questions about thermal measurement's effectiveness in this application. This paper explores and compares infrared thermography and ultrasonic detection methods for steam trap testing and provides guidelines for a successful trap survey.

Gary L. Orlove

1999-01-01

37

Optical Nondestructive Evaluation for Structures  

Microsoft Academic Search

.    This paper presents a new technique for evaluation of engineering structures, using optical measurement and probabilistic\\u000a advancing cross-diagnosis. Its application is first computer-simulated, and then it is tested in the laboratory. With the\\u000a cooperation of the U.S. Federal Highway Administration, a recently developed coherent laser radar system was used to measure\\u000a structural deformation. The data are treated to

Gongkang Fu; Adil G. Moosa; Juan Peng

2001-01-01

38

Nondestructive evaluation techniques for enhanced bridge inspection  

SciTech Connect

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.

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

1993-10-01

39

Complementary Electromagnetic Non-Destructive Evaluation  

NASA Astrophysics Data System (ADS)

The use of non-destructive evaluation (NDE) for defect detection and failure prediction in structures and specimens is widespread in energy industries, aimed at ageing power plants and pipelines, material degradation, fatigue and radiation damage, etc. At present there are no suitable electromagnetic NDE methods for the measurement and characterization of material degradation, in irradiated samples in particular, which is very important and timely for the nuclear power industry in the UK. This paper reports recent developments in the field of electromagnetic (EM) NDE at Newcastle University, including pulsed eddy current (PEC), pulsed magnetic flux leakage (PMFL), magnetic Barkhausen emission (MBE) and magneto-acoustic emission (MAE). As different EM methods have different strengths, an integrative EM framework is introduced. Case studies through the second round robin tests organized by the Universal Network for Magnetic Non-Destructive Evaluation (UNMNDE), representing eighteen leading research groups worldwide in the area of electromagnetic NDE, are reported. Twelve samples with different ageing times and rolling reduction ratios were tested using different magnetic methods among the UNMNDE members. Based on the studies, the complementary characteristics of electromagnetic techniques for NDE are discussed.

Tian, Gui Yun; Wilson, John; Morozov, Maxim

2011-06-01

40

Nondestructive methods for the structural evaluation of wood floor ...  

Treesearch

Nondestructive techniques for evaluating the structural integrity of wood floor systems in ... ultrasonic, and stress-wave transmission techniques were evaluated in an effort to assess and predict the residual performance of in-place wood floors. ... Nondestructive methods for the structural evaluation of wood floor systems in ...

41

Nondestructive evaluation of nuclear-grade graphite  

NASA Astrophysics Data System (ADS)

The material of choice for the core of the high-temperature gas-cooled reactors being developed by the U.S. Department of Energy's Next Generation Nuclear Plant Program is graphite. Graphite is a composite material whose properties are highly dependent on the base material and manufacturing methods. In addition to the material variations intrinsic to the manufacturing process, graphite will also undergo changes in material properties resulting from radiation damage and possible oxidation within the reactor. Idaho National Laboratory is presently evaluating the viability of conventional nondestructive evaluation techniques to characterize the material variations inherent to manufacturing and in-service degradation. Approaches of interest include x-ray radiography, eddy currents, and ultrasonics.

Kunerth, D. C.; McJunkin, T. R.

2012-05-01

42

Nondestructive evaluation of aircraft fuselage panels with electronic shearography  

Microsoft Academic Search

With the growing number of aging passenger aircraft in the fleet, improve nondestructive inspection (NDI) techniques are being investigated to insure the reliability of the fuselage structures of these aircraft. The Boeing Commercial Airplane Group is evaluating nondestructive testing techniques for detecting disbonds in aircraft structures. One of the techniques under evaluation is electronic shearography. This paper describes the disbond

Morteza Safai

1993-01-01

43

Nondestructive dynamic testing of apples for firmness evaluation  

Microsoft Academic Search

Two nondestructive dynamic test methods, low-mass impact and acoustic response, were tested and compared with destructive compression and penetration tests to evaluate apple firmness. The purpose of the study was to analyze the performance of the impact test methods for nondestructive firmness evaluation, and to assess whether the acoustic tests could add sorting capacity to low-mass impact testing in apples.

I Shmulevich; N Galili; M. S Howarth

2003-01-01

44

Nondestructive evaluation of compacted clayey soils  

Microsoft Academic Search

Compacted clayey soils are analyzed using nondestructive testing methods. Ultrasonic testing and image analysis are used as nondestructive testing techniques. Tests were conducted on three clayey soils with low to high plasticities. The soils are compacted and then allowed to dry or subjected to wetting and drying cycles subsequent to compaction. Ultrasonic tests are performed to determine small strain elastic

Gokhan Inci

2001-01-01

45

Applications of the wavefield transform to nondestructive evaluation  

Microsoft Academic Search

Eddy current nondestructive techniques offer many attractive benefits such as reduced inspection time, low cost and reproducibility. Nevertheless, they are not used in many industrial applications, primarily due to the difficulty associated with the lack of simple and physically meaningful interpretation techniques. In contrast; wave propagation phenomena based non-destructive evaluation (NDE) techniques employ a host of physical intuitive concepts, among

Yong Tian

2005-01-01

46

Nondestructive evaluation development for process control  

SciTech Connect

A joint project between Garrett Ceramic Components (GCC) of Allied Signal Aerospace Corporation and Argonne National Laboratory (ANL) is ongoing to evaluate nondestructive characterization (NDC) methods to detect and measure process-induced variations in ceramic materials. The process methods of current focus on slip-casting and injection molding and the NDC methods being evaluated are microfocus X-ray computed tomography (XCT) and nuclear magnetic resonance computed tomography (MRCT). As part of this work, SiC whisker reinforced Si{sub 3}N{sub 4} (GCC`s GN-10 material) has been pressure slip-cast at two casting pressures, 15 and 40 psi; and at length/diameter ratios of 1.5, 2.5 and 3.0 with whisker contents of 20, 23, 27 and 30 wt %. Three-dimensional microfocus XCT has been used to study density variations in billets produced by different process conditions. Destructive measurement of density variation has been compared to the XCT measurements and correlations established. XCT has been shown to be able to detect <5% variations in as-cast density and these were destructively verified.

Ellingson, W.A.; Holloway, D.L.; Sivers, E.A. [Argonne National Lab., IL (United States); Ling, J. [Chinese Academy of Science, Shanghai SH (China). Inst. for Ceramics; Pollinger, J.P.; Yeh, H.C. [Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.

1991-12-31

47

Nondestructive evaluation development for process control  

SciTech Connect

A joint project between Garrett Ceramic Components (GCC) of Allied Signal Aerospace Corporation and Argonne National Laboratory (ANL) is ongoing to evaluate nondestructive characterization (NDC) methods to detect and measure process-induced variations in ceramic materials. The process methods of current focus on slip-casting and injection molding and the NDC methods being evaluated are microfocus X-ray computed tomography (XCT) and nuclear magnetic resonance computed tomography (MRCT). As part of this work, SiC whisker reinforced Si{sub 3}N{sub 4} (GCC's GN-10 material) has been pressure slip-cast at two casting pressures, 15 and 40 psi; and at length/diameter ratios of 1.5, 2.5 and 3.0 with whisker contents of 20, 23, 27 and 30 wt %. Three-dimensional microfocus XCT has been used to study density variations in billets produced by different process conditions. Destructive measurement of density variation has been compared to the XCT measurements and correlations established. XCT has been shown to be able to detect <5% variations in as-cast density and these were destructively verified.

Ellingson, W.A.; Holloway, D.L.; Sivers, E.A. (Argonne National Lab., IL (United States)); Ling, J. (Chinese Academy of Science, Shanghai SH (China). Inst. for Ceramics); Pollinger, J.P.; Yeh, H.C. (Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.)

1991-01-01

48

Review of progress in quantitative nondestructive evaluation. Vol. 11A; Proceedings of the 18th Annual Review, Bowdoin College, Brunswick, ME, July 28-Aug. 2, 1991  

SciTech Connect

The present volume discusses such topics in quantitative NDE as elastic wave scattering and propagation, eddy currents, X-ray and computed radiography, thermal NDE techniques, optical NDE, developing electromagnetic NDE methods, laser ultrasonics, magnetic resonance imaging, neural networks, imaging and inversion techniques, signal processing, acoustic and ultrasonic sensors, fiber-optic sensors, eddy-current arrays and sensors, corrosion-sensing instruments, and NDE standards. Attention is given to ultrasonic scattering from anisotropic shells, surface-wave propagation in composite laminates, eddy-current testing of carbon-carbon composites, monochromatic X-ray beams for NDT, flying laser spot thermal-wave IR imaging, pulsed lasers for ultrasonic NDE, NMR of advanced composites, and ultrasonic synthetic-aperture holographic imaging.

Thompson, D.O.; Chimenti, D.E.

1992-01-01

49

Nondestructive evaluation of advanced ceramic composite materials  

SciTech Connect

Nondestructive evaluation techniques were developed to characterize performance degrading conditions in continuous fiber-reinforced silicon carbide/silicon carbide composites. Porosity, fiber-matrix interface bond strength, and physical damage were among the conditions studied. The material studied is formed by chemical vapor infiltration (CVI) of the matrix material into a preform of woven reinforcing fibers. Acoustic, ultrasonic, and vibration response techniques were studied. Porosity was investigated because of its inherent presence in the CVI process and of the resultant degradation of material strength. Correlations between porosity and ultrasonic attenuation and velocity were clearly demonstrated. The ability of ultrasonic transmission scanning techniques to map variations in porosity in a single sample was also demonstrated. The fiber-matrix interface bond was studied because of its importance in determining the fracture toughness of the material. Correlations between interface bonding and acoustic and ultrasonic properties were observed. These results are presented along with those obtained form acoustic and vibration response measurements on material samples subjected to mechanical impact damage. This is the final report on research sponsored by the US Department of Energy, Fossil Energy Advanced Research and Technology Development Materials Program. 10 refs., 24 figs., 2 tabs.

Lott, L.A.; Kunerth, D.C.; Walter, J.B.

1991-09-01

50

Nondestructive evaluation of metal and composite targets using an infrared line-scanning technique  

Microsoft Academic Search

A thermal, non-destructive evaluation (NDE) technique has been employed by ThermTech Services, Inc. in cooperation with NASA Langley Research Center that allows for quantitative measurements of wall thickness in steam boilers. By determining the thickness of the walls, one can easily determine how much thinning has occurred due to corrosion. This type of NDE can be applied to the inspection

Christopher Smith; Matthew Rowley; Curt Dvonch; Mary Fulton

2005-01-01

51

Framework for incorporating nondestructive evaluation (NDE) into pavement and bridge management systems  

Microsoft Academic Search

One of the major components of an infrastructure management system is the condition assessment or deterioration modeling. With application to highway pavements and bridges, this paper presents conceptually how nondestructive evaluation (NDE) results can be utilized to provide a quantitative assessment of the infrastructure condition in a format usable for network-level pavement management systems and bridge management systems. NDE techniques

John O. Sobanjo; Kamal S. Tawfiq

1999-01-01

52

Role of nondestructive evaluation in life cycle management.  

National Technical Information Service (NTIS)

This paper provides an overview of some common nondestructive evaluation (NDE) methods and several examples for the use of different NDE techniques throughout the life cycle of a product. NDE techniques are being used to help determine material properties...

H. Martz

1997-01-01

53

Application of Computerized Tomography for Nondestructive Evaluation of Weldments.  

National Technical Information Service (NTIS)

The purpose of this research project has been to investigate the feasibility of applying the Computerized Tomographic (CT) processes to the nondestructive testing and evaluation of weldments. The present study investigates the degree of spatial resolution...

I. L. Morgan S. Gautam

1983-01-01

54

Overview of Mathematical Modeling in Nondestructive Evaluation (NDE).  

National Technical Information Service (NTIS)

This report presents a broad overview of mathematical modeling in nondestructive evaluation (NDE). The primary emphasis is to expand the review of NDE modeling literature covered by previous general works. To provide a starting point for researchers and e...

J. C. Aldrin

2002-01-01

55

Nondestructive Evaluation of Damage in Metal Matrix Composites.  

National Technical Information Service (NTIS)

The basic objectives of this work were: to apply nondestructive evaluation techniques to metal matrix composites; to obtain base line data as to the ability of these techniques to locate, identify and quantify defects in these materials; to determine the ...

E. G. Henneke K. L. Reifsnider W. W. Stinchcomb J. C. Duke

1979-01-01

56

Technologies for Nondestructive Evaluation of Surfaces and Thin Coatings.  

National Technical Information Service (NTIS)

The effort included in this project included several related activities encompassing basic understanding, technological development, customer identification and commercial transfer of several methodologies for nondestructive evaluation of surfaces and thi...

1999-01-01

57

Guided wave nuances for ultrasonic nondestructive evaluation.  

PubMed

Recent developments in guided wave generation, reception, and mode control show that increased penetration power and sensitivity are possible. A tone burst function generator and appropriate signal processing are generally used. Variable angle beam and comb-type transducers are the key to this effort. Problems in tubing, piping, hidden corrosion detection in aging aircraft, adhesive and diffusion bonding, and ice detection are discussed. Additionally, sample configurations, inspection objectives, and logic are being developed for such sample problems as defect detection and analysis in lap splice joints, tear straps, cracks in a second layer, hidden corrosion in multiple layers, cracks from rivet holes, transverse cracking in a beam, and cracks in landing gear assembly. Theoretical and experimental aspects of guided wave analysis include phase velocity, group velocity, and attenuation dispersion curves; boundary element model analysis for reflection and transmission factor analysis; use of wave structure for defect detection sensitivity; source influence on the phase velocity spectrum, and the use of angle beam and comb transducer technology. Probe design and modeling considerations are being explored. Utilization of in-plane and out-of-plane displacement patterns on the surface and longitudinal power distribution across the structural cross-section are considered for improved sensitivity, penetration power, and resolution in nondestructive evaluation. Methods of controlling the phase velocity spectrum for mode and frequency selection are available. Such features as group velocity change, mode cut-off measurements, mode conversion, amplitude ratios of transmission, and reflection factors of specific mode and frequency as input will be introduced for their ability to be used in flaw and material characterization analysis. PMID:18238584

Rose, J L

2000-01-01

58

Nondestructive evaluation of thick-composite fatigue damage  

NASA Astrophysics Data System (ADS)

This paper describes the results of the comparison of a variety of nondestructive evaluation techniques to monitor the development of fatigue damage in thick graphite/epoxy composites. Three inch long, one inch square cross-section test specimens were fatigue tested in compression. Most specimens incorporated stress (strain) concentration notches at their mid- section in order to localize the primary fatigue damage regions in an optimum location for nondestructive monitoring. The nondestructive techniques evaluated were ultrasonic B- and C- scan, ultrasonic velocity and attenuation, ultrasonic second harmonic generation, acoustic microscopy, acoustic emission, thermography, real-time high-speed digital/video laser speckle decorrelation, magnetic resonance imaging, radio-opaque penetrant enhanced x-radiography, and eddy current. Mechanical resonance spectroscopy was used to measure the second order (linear) elastic moduli. Optical and electron microscopy on cut and polished specimens were used to verify the results of the nondestructive tests.

Green, Robert E.

1995-06-01

59

Non-destructive evaluation and quality control of surface treatments  

NASA Astrophysics Data System (ADS)

The ability to detect and quantify beneficial surface and subsurface residual stresses, and operational damage in aerospace materials/structures in a reliable and efficient manner presents significant challenges to existing nondestructive inspection technologies. Induced Positron Analysis (IPA) has demonstrated the ability to nondestructively quantify shot peening/surface treatments and relaxation effects in single crystal superalloys, steels, titanium and aluminum with a single measurement as part of a National Science Foundation SBIR program and in projects with commercial companies. IPA measurement of surface treatment effects provides a demonstrated ability to quantitatively measure initial treatment effectiveness along with the effect of operationally induced changes over the life of the treated component. Use of IPA to nondestructively quantify surface and subsurface residual stresses in turbine engine materials and components has the potential to significantly improve the understanding at the microscale level the effects of surface coatings and treatments on the durability and fatigue life of critical components.

Rideout, Curtis A.; Ritchie, Scott J.

2007-03-01

60

Nondestructive Evaluation of Oriented Strand Board Exposed to Decay Fungi  

Microsoft Academic Search

Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of wood composites exposed to decay fungi. For

Barbara Illman; Vina W. Yang; Robert J. Ross; William J. Nelson

61

Application of nondestructive evaluation techniques on concrete dams  

Microsoft Academic Search

Many mining and civil engineering structures are showing signs of deterioration due to various factors. In recent years, the heavy cost of repairs of concrete infrastructures has been reduced by using nondestructive evaluation (NDE) techniques to pinpoint problem areas. This paper presents the theoretical and practical aspects of the Miniature Seismic Reflection (MSR) system for the evaluation of concrete dams.

F. P. Hassani; P. Guevremont; M. Momayez; A. Sadri; K. Saleh

1997-01-01

62

Nondestructive inspection and evaluation of composite-material flywheels  

SciTech Connect

It has been demonstrated that flywheels made from composite materials are capable of storing energy with a significantly higher energy density than those made from conventional metals. Since composite materials are also very durable and inherently safer for such applications, it would appear that they will play a major role in flywheel energy-storage systems. This report addresses the question of how flywheels made from composite materials can be inspected with nondestructive test methods to establish their initial quality and their subsequent integrity during service. A variety of methods is discussed in the context of special requirements for the examination of composite flywheel structures and the results of several example nondestructive evaluations before and after spin testing are presented. Recommendations for general nondestructive testing and evaluation of composite-material flywheels are made.

Reifsnider, K.L.; Boyd, D.M.; Kulkarni, S.V.

1982-02-24

63

Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics  

NASA Astrophysics Data System (ADS)

Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture. A method based on nonlinear acoustics is shown to provide such a means to assess the state of metal fatigue. The salient features of an analytical model are presented of the microelastic-plastic nonlinearities resulting from the interaction of an acoustic wave with fatigue-generated dislocation substructures and cracks that predictably evolve during the metal fatigue process. The interaction is quantified by the material (acoustic) nonlinearity parameter ? extracted from acoustic harmonic generation measurements. The ? parameters typically increase monotonically by several hundred percent over the fatigue life of the metal, thus providing a unique measure of the state of fatigue. Application of the model to aluminum alloy 2024-T4 and 410 Cb stainless steel specimens fatigued using different loading conditions yields good agreement between theory and experiment. Application of the model and measurement technique to the on-site inspection of steam turbine blades is discussed.

Cantrell, John H.

2009-03-01

64

Proceedings of the Workshop on Structural Composites and Nondestructive Evaluation.  

National Technical Information Service (NTIS)

The problems and opportunities in the nondestructive evaluation of composites are covered in formal papers and a summary of the discussion which took place at a Workshop held in Dayton on February 13-14, 1974. The recommendations arrived at by an National...

1974-01-01

65

Overview of Mathematical Modeling in Nondestructive Evaluation (NDE)  

Microsoft Academic Search

This report presents a broad overview of mathematical modeling in nondestructive evaluation (NDE). The primary emphasis is to expand the review of NDE modeling literature covered by previous general works. To provide a starting point for researchers and engineers, the discussions and references include multiple modeling approaches (analytical, asymptotic, and numerical) for a variety of NDE techniques. A second emphasis

John C. Aldrin

2002-01-01

66

SAW Electromagnetic Transducer Design for Nondestructive Evaluation Applications  

Microsoft Academic Search

Abxrroct-Recent progress in surface acoustic wave (SAW) electromagnetic transducer (EMT) modeling and fabrication techniques have greatly increased EMT versatility for nondestructive evaluation (NDE) applications. Unlike other types of SAW NDE transducers that suffer from variability in manufacture and coupling conditions, virtually identical EMT's can be made that have predictable characteristics. Information is presented for straightforward design on different materials, including

T. L. Szabo; H. M. Frost

1976-01-01

67

Integrated low-temperature superconductor SQUID gradiometers for nondestructive evaluation  

Microsoft Academic Search

We describe an eddy current nondestructive evaluation system using a low-temperature superconductor magnetic field sensor in an electromagnetically unshielded environment. The sensor comprises a niobium dc superconducting quantum interference device (SQUID) integrated with a first-order gradiometric pickup coil to reject spatially uniform interference fields but remain sensitive to flaw induced fields. We demonstrate its use in locating and mapping subsurface

Uho Klein; Morag E. Walker; Chris Carr; D. M. McKirdy; C. M. Pegrum; G. B. Donaldson; A. Cochran; H. Nakane

1997-01-01

68

Optical nondestructive evaluation technique capable of predicting failure  

NASA Astrophysics Data System (ADS)

An optical interferometric nondestructive evaluation technique is introduced. Based on electronic speckle-pattern interferometry and a recent theory of plastic deformation, this technique is capable of visualizing stress concentration and predicting the location and timing of the failure of the object. The operation of the technique is demonstrated for tensile analyses of aluminum alloy samples.

Yoshida, Sanichiro J.; Pardede, M. H.; Siahaan, B.; Pardede, M.; Muhamad, I.; Sijabat, N.; Simangunsong, H.; Simbolon, T.; Adlin; Jubir; Kusnowo, A.

1999-02-01

69

Quantitative non-destructive characterisation (NDC) of plant fibre composites  

NASA Astrophysics Data System (ADS)

Composites made of plant fibres offer a new, environmentally attractive supplement to traditional glass fibre composite materials. Plant fibre composites may have similar mechanical properties as conventional (e.g. glass fibre) composites, with a lower impact strength. Since plant fibre composites constitute a relatively new group of materials, the limitations imposed on the mechanical performance due to flaws are not well known. The subject of this article is the investigation of the structure, the homogeneity and the mechanical properties of jute fibre based composites, and the correlation to quantitative data derived from X-radiography and ultrasonic scanning. The results indicates that parameters such as fibre orientation and fibre volume fraction are very important concerning sample tensile strength. These parameters can be assessed by the considered QNDC techniques. It is also shown that the samples are relatively homogeneous, and that the limitation on mechanical performance cannot by the considered techniques be related to a single defect. From the results it may be further concluded that the NDC techniques can provide quantitative data for an assessment of important manufacturing variables.

Rheinländer, Jørgen; Cendre, Emmanuelle; Debel, Christian; Borum, Kaj K.; Lilholt, Hans

1999-12-01

70

Development of an automated x-ray gauge for nondestructive quantitative analysis  

Microsoft Academic Search

This report describes an x-ray gauging system developed in the Materials Characterization Department at Sandia for nondestructive quantitative analysis. The automated device utilizes the transmission of low-energy x-rays through a material in order to measure the areal density of the material. If the material density is known, the x-ray gauge serves as a non-contacting thickness gauge, typically for micron-range dimensions.

Drotning

1988-01-01

71

Aging management of major LWR components with nondestructive evaluation  

SciTech Connect

Nondestructive evaluation of material damage can contribute to continued safe, reliable, and economical operation of nuclear power plants through their current and renewed license period. The aging mechanisms active in the major light water reactor components are radiation embrittlement, thermal aging, stress corrosion cracking, flow-accelerated corrosion, and fatigue, which reduce fracture toughness, structural strength, or fatigue resistance of the components and challenge structural integrity of the pressure boundary. This paper reviews four nondestructive evaluation methods with the potential for in situ assessment of damage caused by these mechanisms: stress-strain microprobe for determining mechanical properties of reactor pressure vessel and cast stainless materials, magnetic methods for estimating thermal aging damage in cast stainless steel, positron annihilation measurements for estimating early fatigue damage in reactor coolant system piping, and ultrasonic guided wave technique for detecting cracks and wall thinning in tubes and pipes and corrosion damage to embedded portion of metal containments.

Shah, V.N.; MacDonald, P.E.; Akers, D.W.; Sellers, C. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States); Murty, K.L.; Miraglia, P.Q.; Mathew, M.D. [North Carolina State Univ., Raleigh, NC (United States); Haggag, F.M. [Advanced Technology Corp. (United States)

1997-12-31

72

Recent developments in nondestructive evaluation for structural ceramics  

Microsoft Academic Search

Advanced nondestructive evaluation methods are being developed to characterize ceramic materials and allow improvement of process technology. If one can determine porosity, map organic binder\\/plasticizer distributions, measure average through-volume and in-plane density, as well as detect inclusions, then process and machine operations may be modified to enhance the reliabilty of ceramics. Two modes of x-ray tomographic imaging - advanced film

W. A. Ellingson; R. A. Roberts; M. W. Vannier; J. L. Ackerman; B. D. Sawicka; S. Gronemeyer; R. J. Kriz

1987-01-01

73

An Ultrasonic Nondestructive Method for Evaluating Carbon\\/Carbon Composites  

Microsoft Academic Search

In this work, especially carbon\\/carbon (C\\/C) composites are one of the few materials that are suitable for structural applications at high temperature environments. Characterization and integrity of carbon\\/carbon(C\\/C) composite materials should be evaluated because of its inhomogeneity and composite. A C\\/C composite material was nondestructively characterized and a technique was developed to measure ultrasonic velocity in C\\/C composites using automated

K. H. Im; D. K. Hsu; S. J. Song; H. Cho; J. W. Park; Y. S. Kweon; J. K. Sim; I. Y. Yang

2006-01-01

74

Large area terahertz imaging and non-destructive evaluation applications  

Microsoft Academic Search

Abstract: Terahertz (THz) imaging,is being adopted for non-destructive evaluation (NDE) applications in aerospace and other government,and industrial settings [1-3]. NASA is currently employing ,THz reflection NDE to examine ,the space shuttle external tank sprayed on foam insulation (SOFI) for voids and disbonds. Homeland security applications such as the inspection of personnel[2], the detection of concealed explosives[2], biological agents, chemical weapons,

David Zimdars; Jeffrey S. White; G. stuk; A. chernovsky; G. Fichter; S. Williamson

2006-01-01

75

Nondestructive Evaluation and Self-Monitoring Materials.  

National Technical Information Service (NTIS)

This report is a response to a request from DARPA for a JASON study to evaluate existing and novel approaches to condition-based maintenance. Our guidance was to avoid the area of 'smart materials', which is by itself an active area of research with which...

E. Williams N. Lewis H. Abarbanel D. Eardley W. Happer

1999-01-01

76

Nondestructive evaluation of hollow clay tile walls  

SciTech Connect

Experiments have been conducted using sonics, ultrasonics, infrared thermography, and microwave NDE techniques on hollow clay tile masonry construction at the Department of Energy Oak Ridge Y-12 Plant in Oak Ridge, Tennessee. The experiments are part of a major test program to evaluate the seismic and wind load capacity of existing hollow clay tile infilled steel frame buildings at the Y-12 Plant and to recommended the extent of retrofit required to ensure these structures will meet the current requirements for natural hazards survival. Many of the techniques that showed promise in bench top experiments proved to be disappointing for in situ evaluations. For the problem definitions specific to the Y-12 Plant test program, at least two NDE techniques continue to justify funding of further development into a useful methodology: infrared thermography and low power microwave spectrography.

Wynn, C.C.; Fletcher, W.M.; Jones, W.D.

1992-03-12

77

Nondestructive damage evaluation in ceramic matrix composites for aerospace applications.  

PubMed

Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used for the assessment of the material's performance under fatigue. IRT and AE parameters are specifically used for the characterization of the complex damage mechanisms that occur during CMC fracture, and they enable the identification of the micromechanical processes that control material failure, mainly crack formation and propagation. Additionally, these nondestructive parameters help in early prediction of the residual life of the material and in establishing the fatigue limit of materials rapidly and accurately. PMID:23935428

Dassios, Konstantinos G; Kordatos, Evangelos Z; Aggelis, Dimitrios G; Matikas, Theodore E

2013-07-11

78

Evaluation of an electric field sensor for nondestructive material inspection  

NASA Astrophysics Data System (ADS)

An electric field sensor is fabricated on a 125 micron thick flexible dielectric substrate for electromagnetic (EM) nondestructive material inspection at 915 MHz. The sensor consists of an electrically short dipole antenna and a radio frequency (RF) diode detector connected to a pair of high impedance screen printed carbon lines. The DC component of the rectified diode voltage conveyed across the high impedance lines is measured using a data acquisition circuit. Sensor measurements are validated with simulated data for a conformal patch antenna operating at 915 MHz. Sensor performance for EM nondestructive testing (NDT) is evaluated using phantom defects in low loss dielectric slabs. Preliminary results indicate sensor utility for EM NDT and support further testing on realistic defects.

Kalyanasundaram, Kayatri; Arunachalam, Kavitha

2013-01-01

79

Nondestructive methods for quality evaluation of livestock products.  

PubMed

The muscles derived from livestock are highly perishable. Rapid and nondestructive methods are essential for quality assurance of such products. Potential nondestructive methods, which can supplement or replace many of traditional time consuming destructive methods, include colour and computer image analysis, NIR spectroscopy, NMRI, electronic nose, ultrasound, X-ray imaging and biosensors. These methods are briefly described and the research work involving them for products derived from livestock is reviewed. These methods will be helpful in rapid screening of large number of samples, monitoring distribution networks, quick product recall and enhance traceability in the value chain of livestock products. With new developments in the areas of basic science related to these methods, colour, image processing, NIR spectroscopy, biosensors and ultrasonic analysis are expected to be widespread and cost effective for large scale meat quality evaluation in near future. PMID:23729854

Narsaiah, K; Jha, Shyam N

2011-02-17

80

Nondestructive inspection and evaluation of composite-material flywheels  

SciTech Connect

Several composite panels and flywheel designs were evaluated in support of the Mechanical Energy Storage Technology (MEST) project. Conventional nondestructive evaluation (NDE) technology was used on the panels and flywheels. All flywheels and panels were radiographed and, where practical, were also inspected using ultrasonic techniques. The results provided information about the structural features of flywheels and materials. This information is useful for the quality control of fabrication procedures. The detection of apparent flaws in fabrication cannot be related to the ultimate strength until failure mechanisms in composite materials have been fully defined. Therefore, the location of detected flaws should be recorded for later comparison with dynamic and destructive evaluations.

Boyd, D.M.; Maxfield, B.W.; Kulkarni, S.V.; Schwarber, A.J.

1982-02-24

81

Nondestructive Evaluation Quality Procedure: Personnel Qualification and Certification Radiographic Testing-Levels I& II  

SciTech Connect

This Operational Procedure establishes the minimum requirements for the qualification and certification/recertification of Nondestructive Evaluation (NDE) personnel in the nondestructive testing (NDT) radiographic testing (RT) method. This document is in accordance with the American Society for Nondestructive Testing Recommended Practice SNT-TC-1A, 1996, except as amended herein.

Dolan, K; Rikard, R D; Rodriquez, J

2003-07-01

82

Ultrasonic infrared thermal wave nondestructive evaluation for crack detection of several aerospace materials  

Microsoft Academic Search

The applications of ultrasonic infrared thermal wave nondestructive evaluation for crack detection of several materials, which often used in aviation alloy. For instance, steel and carbon fiber. It is difficult to test cracks interfacial or vertical with structure's surface by the traditional nondestructive testing methods. Ultrasonic infrared thermal wave nondestructive testing technology uses high-power and low-frequency ultrasonic as heat source

Weichao Xu; Jingling Shen; Cunlin Zhang; Ning Tao; Lichun Feng

2008-01-01

83

Nondestructive Evaluation of the VSC-17 Cask  

SciTech Connect

In 2003, representatives from the Central Research Institute of Electric Power Industry (CRIEPI) requested development of a project with the objective of determining the performance of a concrete spent nuclear fuel storage cask. Radiation and environmental effects may cause chemical alteration of the concrete that could result in excessive cracking, spalling, and loss of compressive strength. The Idaho National Laboratory (INL) project team and CRIEPI representatives identified the Ventilated Storage Cask (VSC 17) spent nuclear fuel storage cask, originally located at the INL Test Area North, as a candidate to study cask performance because it had been used to store fuel as part of a dry cask storage demonstration project for over 15 years. The project involved investigating the properties of the concrete shield. INL performed a survey of the cask in the summers of 2003 and 2004. The INL team met with the CRIEPI representatives in December of 2004 to discuss the next steps. As a result of that meeting, CRIEPI requested that in the summer 2005 INL perform additional surveys on the VSC 17 cask with participation of CRIEPI scientists. This document summarizes the evaluation methods used on the VSC 17 to evaluate the cask for compressive strength, concrete cracking, concrete thickness, and temperature distribution.

Sheryl Morton; Al Carlson; Cecilia Hoffman; James Rivera; Phil Winston; Koji Shirai; Shin Takahashi; Masaharo Tanaka

2006-01-01

84

Evaluation of Nondestructive Assay/Nondestructive Examination Capabilities for Department of Energy Spent Nuclear Fuel  

SciTech Connect

This report summarizes an evaluation of the potential use of nondestructive assay (NDA) and nondestructive examination (NDE) technologies on DOE spent nuclear fuel (SNF). It presents the NDA/NDE information necessary for the National Spent Nuclear Fuel Program (NSNFP) and the SNF storage sites to use when defining that role, if any, of NDA/NDE in characterization and certification processes. Note that the potential role for NDA/NDE includes confirmatory testing on a sampling basis and is not restricted to use as a primary, item-specific, data collection method. The evaluation does not attempt to serve as a basis for selecting systems for development or deployment. Information was collected on 27 systems being developed at eight DOE locations. The systems considered are developed to some degree, but are not ready for deployment on the full range of DOE SNF and still require additional development. The system development may only involve demonstrating performance on additional SNF, packaging the system for deployment, and developing calibration standards, or it may be as extensive as performing additional basic research. Development time is considered to range from one to four years. We conclude that NDA/NDE systems are capable of playing a key role in the characterization and certification of DOE SNF, either as the primary data source or as a confirmatory test. NDA/NDE systems will be able to measure seven of the nine key SNF properties and to derive data for the two key properties not measured directly. The anticipated performance goals of these key properties are considered achievable except for enrichment measurements on fuels near 20% enrichment. NDA/NDE systems can likely be developed to measure the standard canisters now being considered for co-disposal of DOE SNF. This ability would allow the preparation of DOE SNF for storage now and the characterization and certification to be finalize later.

Luptak, A.J.; Bulmahn, K.D.

1998-09-01

85

Nondestructive evaluation of Ni-Ti shape memory alloy  

SciTech Connect

The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO (United States); Wiezman, A. [Netania (Israel)

2011-06-23

86

Preliminary Evaluation of Several Nondestructive-Evaluation Techniques for Silicon Nitride Gas-Turbine Rotors.  

National Technical Information Service (NTIS)

Several nondestructive-evaluation (NDE) techniques have been examined to establish their effectiveness for detecting critically sized flaws in silicon nitride gas-turbine rotors. Preliminary results have been obtained for holographic interferometry, acous...

D. S. Kupperman C. Sciammarella N. P. Lapinski A. Sather D. Yuhas

1978-01-01

87

Pavement Evaluation Concepts Using Nondestructive Structural Evaluation and Pavement Condition Index.  

National Technical Information Service (NTIS)

A logical method for pavement evaluation utilizing both nondestructive procedures for structural analysis and pavement condition distress to identify maintenance needs is presented. Alternatives for maintaining desired serviceability are categorized as ro...

J. W. Hall

1987-01-01

88

Experimental implementation of reverse time migration for nondestructive evaluation applications  

NASA Astrophysics Data System (ADS)

Reverse time migration (RTM) is a commonly employed imaging technique in seismic applications (e.g., to image reservoirs of oil). Its standard implementation cannot account for multiple scattering/reverberation. For this reason it has not yet found wide application in nondestructive evaluation (NDE). This paper applies RTM imaging to NDE applications in bounded samples, where reverberation is always present. This paper presents a fully experimental implementation of RTM, whereas in seismic applications, only part of the procedure is done experimentally. A modified RTM imaging condition is able to localize scatterers and locations of disbonding. Experiments are conducted on aluminum samples with controlled scatterers.

Le Bas, P.; Anderson, B. E.; Griffa, M.; Ulrich, T. J.; Johnson, P. A.

2011-12-01

89

Experimental implementation of reverse time migration for nondestructive evaluation applications.  

PubMed

Reverse time migration (RTM) is a commonly employed imaging technique in seismic applications (e.g., to image reservoirs of oil). Its standard implementation cannot account for multiple scattering/reverberation. For this reason it has not yet found application in nondestructive evaluation (NDE). This paper applies RTM imaging to NDE applications in bounded samples, where reverberation is always present. This paper presents a fully experimental implementation of RTM, whereas in seismic applications, only part of the procedure is done experimentally. A modified RTM imaging condition is able to localize scatterers and locations of disbonding. Experiments are conducted on aluminum samples with controlled scatterers. PMID:21302980

Anderson, Brian E; Griffa, Michele; Bas, Pierre-Yves Le; Ulrich, Timothy J; Johnson, Paul A

2011-01-01

90

Stress-wave nondestructive evaluation of green veneer: southern yellow pine and Douglas fir  

Microsoft Academic Search

The potential of using stress wave nondestructive evaluation techniques to sort green southern yellow pine and DOuglas fir veneer into stress grades was evaluated. Stress wave nondestructive evaluation was used to separate green veneer into several grades for use in manufacturing engineered wood composites, most notably laminated veneer lumber. The effect of moisture content and preservative treatment on stress wave

Brian K. Brashaw; Robert J. Ross; Roy F. Pellerin

1996-01-01

91

Infrared thermal wave nondestructive testing for rotor blades in wind turbine generators non-destructive evaluation and damage monitoring  

Microsoft Academic Search

The rotor blades are key components in wind turbine generators. A visual inspection of the laminated shells for delaminations, air pockets, missing\\/disoriented fabric etc. is in most cases also not possible due to the manufacturing process, so Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of rotor blades structure are essential to both reduce manufacturing costs

Shi Bin Zhao; Cun-Lin Zhang; Nai-Ming Wu; Yu-Xia Duan; Hao Li

2009-01-01

92

Symposium on Nondestructive Evaluation, 15th, San Antonio, TX, April 23-25, 1985, Proceedings  

SciTech Connect

Papers presented include the application of the electric current perturbation method to the inspection of magnetic materials, the acoustical holographic Siamese image technique for imaging radial cracks in reactor piping, advanced enhancement techniques for digitized images, ultrasonic inspection systems for sonar dome rubber windows, and a novel acoustic coupling device using permeable membranes. Consideration is given to a dry imaging system for radiography, the role of laser technology in materials processing and NDT in the 21st century, a computer controlled array of ultrasonic transducers for the fast inspection of steel pipes, quantitative ultrasonic NDE, and the effect of tensile straining on the magnetic pulses induced during cyclic loading of a ferromagnetic steel. In addition, use of ultrasonics for quantitative nondestructive evaluation, imaging of defects in fiber-reinforced composites, and for determination of principal stress differences in a slightly anisotropic residual stress specimen are discussed.

Matzkanin, G.A.; Moore, D.W.

1986-01-01

93

Active Tagging Non-Destructive Evaluation Techniques for Full-Scale Structural Composite Elements.  

National Technical Information Service (NTIS)

A health monitoring technique is presented for on-site particle tagging non-destructive evaluation (NDE) of a full-scale structural element of advanced composites. Conventional non-destructive evaluation methods are not very effective in monitoring the ma...

C. A. Rogers J. Berman R. Quattrone V. Giurgiutiu Z. Chen

1996-01-01

94

Development of Innovative Nondestructive Evaluation Technologies for the Inspection of Cracking and Corrosion Under Coatings  

NASA Astrophysics Data System (ADS)

Three different innovative nondestructive evaluation technologies were developed and evaluated for the ability to detect fatigue cracks and corrosion hidden under painted aluminum panels. The three technologies included real-time ultrasound imaging, thermal imaging, and near-field microwave imaging. With each of these nondestructive inspection methods, subtasks were performed in order to optimize each methodology.

Lipetzky, Kirsten G.; Novack, Michele R.; Perez, Ignacio; Davis, William R.

2001-11-01

95

Nondestructive Evaluation (NDE) research progress in 1988: Proceedings from the ninth annual EPRI NDE information meeting  

Microsoft Academic Search

The increasing cost of equipment for power generating plants and the potential increases in productivity and safety analysis through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondestructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now underway. This report presents

M. J. Jr. Avioli; G. J. Dau; S. N. Liu; J. Stein; C. S. Welty

1989-01-01

96

Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection  

Microsoft Academic Search

The acousto-ultrasonic method has proven to be a most interesting technique for nondestructive evaluation of the mechanical properties of a variety of materials. Use of the technique or a modification thereof, has led to correlation of the associated stress wave factor with mechanical properties of both metals and composite materials. The method is applied to the nondestructive evaluation of selected

Robert D. Huber; Robert E. Green Jr.

1990-01-01

97

Determination of Space Station on-orbit nondestructive evaluation requirements  

NASA Astrophysics Data System (ADS)

NASA has recently initiated a reassessment of requirements for the performance of in-space nondestructive evaluation (NDE) of the International Space Station Alpha (ISSA) while on- orbit. given the on-orbit operating environment, there is a powerful motivation for avoiding inspection requirements. For example the ISSA maintenance philosophy includes the use of orbital replacement units (ORUs); hardware that is designed to fail without impact on mission assurance or safety. Identification of on-orbit inspection requirements involves review of a complex set of disciplines and considerations such as fracture control, contamination, safety, mission assurance, electrical power, and cost. This paper presents background discussion concerning on-orbit NDE and a technical approach for separating baseline requirements from opportunities.

Salkowski, Charles

1995-07-01

98

Nerva fuel nondestructive evaluation and characterization equipment and facilities  

SciTech Connect

Nuclear Thermal Propulsion (NTP) is one of the technologies that the Space Exploration Initiative (SEI) has identified as essential for a manned mission to Mars. A base or prior work is available upon which to build in the development of nuclear rockets. From 1955 to 1973, the U.S Atomic Energy Commission (AEC) sponsored development and testing of a nuclear rocket engine under Project Rover. The rocket engine, called the Nuclear Engine for Rocket Vehicle Application (NERVA), used a graphite fuel element incorporating coated particle fuel. Much of the NERVA development and manufacturing work was performed at the Oak Ridge Y[minus]12 Plant. This paper gives a general review of that work in the area of nondestructive evaluation and characterization. Emphasis is placed on two key characteristics: uranium content and distribution and thickness profile of metal carbide coatings deposited in the gas passage holes.

Caputo, A.J. (Martin Marietta Energy Systems, Inc., Oak Ridge, Y-12 Plant Oak Ridge, TN 37831 (United States))

1993-01-20

99

Nerva fuel nondestructive evaluation and characterization equipment and facilities  

NASA Astrophysics Data System (ADS)

Nuclear Thermal Propulsion (NTP) is one of the technologies that the Space Exploration Initiative (SEI) has identified as essential for a manned mission to Mars. A base or prior work is available upon which to build in the development of nuclear rockets. From 1955 to 1973, the U.S Atomic Energy Commission (AEC) sponsored development and testing of a nuclear rocket engine under Project Rover. The rocket engine, called the Nuclear Engine for Rocket Vehicle Application (NERVA), used a graphite fuel element incorporating coated particle fuel. Much of the NERVA development and manufacturing work was performed at the Oak Ridge Y-12 Plant. This paper gives a general review of that work in the area of nondestructive evaluation and characterization. Emphasis is placed on two key characteristics: uranium content and distribution and thickness profile of metal carbide coatings deposited in the gas passage holes.

Caputo, Anthony J.

1993-01-01

100

Physical model assisted probability of detection in nondestructive evaluation  

SciTech Connect

Nondestructive evaluation is used widely in many engineering and industrial areas to detect defects or flaws such as cracks inside parts or structures during manufacturing or for products in service. The standard statistical model is a simple empirical linear regression between the (possibly transformed) signal response variables and the (possibly transformed) explanatory variables. For some applications, such a simple empirical approach is inadequate. An important alternative approach is to use knowledge of the physics of the inspection process to provide information about the underlying relationship between the response and explanatory variables. Use of such knowledge can greatly increase the power and accuracy of the statistical analysis and enable, when needed, proper extrapolation outside the range of the observed explanatory variables. This paper describes a set of physical model-assisted analyses to study the capability of two different ultrasonic testing inspection methods to detect synthetic hard alpha inclusion and flat-bottom hole defects in a titanium forging disk.

Li, M.; Meeker, W. Q. [Center for Nondestructive Evaluation and Department of Statistics, Iowa State University, Ames, IA 50011 (United States); Thompson, R. B. [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011 (United States)

2011-06-23

101

Development of nondestructive evaluation methods for ceramic coatings.  

SciTech Connect

Various nondestructive evaluation (NDE) technologies are being developed to advance the knowledge of ceramic coatings for components in the hot gas-path of advanced, low-emission gas-fired turbine engines. The ceramic coating systems being studied by NDE include thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). TBCs are under development for vanes, blades and combustor liners to allow hotter gas path temperatures and EBCs are under development to reduce environmental damage to high temperature components made of ceramic matrix composites (CMCs). Data provided by NDE methods will be used to: (a) provide data to assess reliability of new coating application processes, (b) identify defective components that could cause unscheduled outages (c) track growth rates of defects during use in engines and (d) allow rational judgement for replace/repair/re-use decisions of components.

Sun, J. G. (Nuclear Engineering Division)

2007-01-01

102

Millimeter-wave imaging for nondestructive evaluation of materials  

SciTech Connect

A millimeter-wave imaging system has been developed in the W band (75--110 GHz) for nondestructive evaluation of low-loss materials. The system employs a focused beam to provide spatial resolution of about one wavelength. A plane-wave model is used to calculate the effective reflection (or transmission) coefficient of a multilayer geometry. Theoretical analysis is used to optimize the measurement frequency for higher image contrast and to interpret the experimental results. Both reflection and transmission images, based on backscattered and forward-scattered powers, were made with Kevlar/epoxy samples containing artificially introduced defects such as subsurface voids and disbonds. The results indicate that millimeter wave imaging has high potential for noncontact detection of defects in low-loss materials.

Gopalsami, N; Bakhtiari, S.; Dieckman, S.L.; Raptis, A.C.; Lepper, M.J. (Argonne National Lab., IL (United States). Energy Technology Div.)

1994-03-01

103

Methodology for the Economic Assessment of Nondestructive Evaluation Techniques Used in Aircraft Inspection.  

National Technical Information Service (NTIS)

This report details a methodology for the economic evaluation of emerging nondestructive evaluation (NDE) methods applicable to aircraft inspection. The methodology is based on the economic principle of cost benefit analysis (CBA). CBA measures the future...

V. J. Brechling

1995-01-01

104

Nondestructive evaluation of hydrogel mechanical properties using ultrasound  

PubMed Central

The feasibility of using ultrasound technology as a noninvasive, nondestructive method for evaluating the mechanical properties of engineered weight-bearing tissues was evaluated. A fixture was designed to accurately and reproducibly position the ultrasound transducer normal to the test sample surface. Agarose hydrogels were used as phantoms for cartilage to explore the feasibility of establishing correlations between ultrasound measurements and commonly used mechanical tissue assessments. The hydrogels were fabricated in 1–10% concentrations with a 2–10 mm thickness. For each concentration and thickness, six samples were created, for a total of 216 gel samples. Speed of sound was determined from the time difference between peak reflections and the known height of each sample. Modulus was computed from the speed of sound using elastic and poroelastic models. All ultrasonic measurements were made using a 15 MHz ultrasound transducer. The elastic modulus was also determined for each sample from a mechanical unconfined compression test. Analytical comparison and statistical analysis of ultrasound and mechanical testing data was carried out. A correlation between estimates of compressive modulus from ultrasonic and mechanical measurements was found, but the correlation depended on the model used to estimate the modulus from ultrasonic measurements. A stronger correlation with mechanical measurements was found using the poroelastic rather than the elastic model. Results from this preliminary testing will be used to guide further studies of native and engineered cartilage.

Walker, Jason M.; Myers, Ashley M.; Schluchter, Mark D.; Goldberg, Victor M.; Caplan, Arnold I.; Berilla, Jim A.; Mansour, Joseph M.; Welter, Jean F.

2012-01-01

105

Incorporation of nondestructive evaluation in Pontis Bridge Management System  

NASA Astrophysics Data System (ADS)

The highway system in the United States includes nearly 577,000 bridges, the majority of which were built during two major bridge building periods -- just before World War II (1930s) and in the first two decades of the Cold War (1950s and 1960s). Given the age and increased usage of these bridges over the years, many now require substantial maintenance to satisfy their desired level of service. The complex task of allocating scarce funds for the repair, maintenance, and rehabilitation of this large number of bridges led to the development of several optimization studies and two major bridge management system, namely BRIDGIT and Pontis. Pontis has emerged as the system of choice for all states in the Nation. At this time over 40 highway agencies continue to license, evaluate and implement the current AASHTOWARE Program, Pontis V. 3.2. However, all data currently required by Pontis to assess the structural stability and resulting suggestions for repair and maintenance of bridges are based on visual inspection and judgement. Consequently, all suggestions are based on that visual inspection. This paper discusses development of a plan for how non-destructive evaluation (NDE) data can be used to provide more information than visual inspection.

Hadavi, Ahmad

1998-03-01

106

Nondestructive evaluation of hydrogel mechanical properties using ultrasound.  

PubMed

The feasibility of using ultrasound technology as a noninvasive, nondestructive method for evaluating the mechanical properties of engineered weight-bearing tissues was evaluated. A fixture was designed to accurately and reproducibly position the ultrasound transducer normal to the test sample surface. Agarose hydrogels were used as phantoms for cartilage to explore the feasibility of establishing correlations between ultrasound measurements and commonly used mechanical tissue assessments. The hydrogels were fabricated in 1-10% concentrations with a 2-10 mm thickness. For each concentration and thickness, six samples were created, for a total of 216 gel samples. Speed of sound was determined from the time difference between peak reflections and the known height of each sample. Modulus was computed from the speed of sound using elastic and poroelastic models. All ultrasonic measurements were made using a 15 MHz ultrasound transducer. The elastic modulus was also determined for each sample from a mechanical unconfined compression test. Analytical comparison and statistical analysis of ultrasound and mechanical testing data was carried out. A correlation between estimates of compressive modulus from ultrasonic and mechanical measurements was found, but the correlation depended on the model used to estimate the modulus from ultrasonic measurements. A stronger correlation with mechanical measurements was found using the poroelastic rather than the elastic model. Results from this preliminary testing will be used to guide further studies of native and engineered cartilage. PMID:21773854

Walker, Jason M; Myers, Ashley M; Schluchter, Mark D; Goldberg, Victor M; Caplan, Arnold I; Berilla, Jim A; Mansour, Joseph M; Welter, Jean F

2011-07-20

107

Evaluation of Nondestructive Testing Techniques of Diffusion Coatings.  

National Technical Information Service (NTIS)

Three novel nondestructive testing methods of diffusion coatings were compared with other methods and checked against microscopic examination by subsequent sectioning of suspected defects. Methods used consisted of a beta backscatter, X-ray fluorescence a...

B. E. Arnesen H. B. Karplus R. A. Semmler

1968-01-01

108

Nondestructive Evaluation of Creep-Fatigue Damage: An Interim Report.  

National Technical Information Service (NTIS)

In view of the uncertainties involved in designing against creep-fatigue failure and the consequences of such failures in Class 1 nuclear components that operate at elevated temperature, the possibility of intermittent or even continuous non-destructive e...

R. E. Nickell

1977-01-01

109

Applications of the wavefield transform to nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Eddy current nondestructive techniques offer many attractive benefits such as reduced inspection time, low cost and reproducibility. Nevertheless, they are not used in many industrial applications, primarily due to the difficulty associated with the lack of simple and physically meaningful interpretation techniques. In contrast; wave propagation phenomena based non-destructive evaluation (NDE) techniques employ a host of physical intuitive concepts, among which a prominent one is time-of-flight (TOF), i.e. the time duration between the excitation pulse and its response. TOF not only provides position and other information relating to the flaw in an "explicit" way, but also enables the use of mapping algorithms based on wave propagation. There is thus a clear need to study means in which techniques for analyzing wave propagation based NDE data can be applied to eddy current testing (ECT) data. This research aims at inverting ECT data from the perspective of wave propagation phenomena and presenting the inversion results in the same format as that obtained from wave propagation based testings, thereby facilitating possible future data fusion processes. Towards this goal, it is necessary to obtain a comprehensive understanding of the distinct physical characteristics, incompatible test data formats, and different mathematical tools required for analysis and data processing. To this end, we employ a wavefield transform, also called the Q-transform, a mapping relating wave fields to diffusive fields, to retrieve TOF information from ECT data. In this research, the TOF information is extracted directly from ECT data. Thus, we overcome the instability associated with numerical inversion of the Q-transform, which is widely adopted in traditional Q-transform based TOF extraction methods. In order to demonstrate the effectiveness of the proposed Q-transform approach, we estimate the TOF for a host of canonical examples, in both the time and frequency domain. In addition to demonstrating the merit of these models through numerical simulations, an experimental set-up was built for validating the concept. The measured data shows excellent agreement with theoretical predictions. The experimental data was also used to estimate the source position successfully. The Q-transform based TOF extraction methods presented in this work demonstrates the potential for retrieving the TOF information from test objects with complex geometries. The extracted TOF data possesses the same format as that measured from wave propagation based NDE techniques. This makes it possible to fuse these measurements together for improving inspection accuracy and reliability. In a broader context, the successful development of the Q-transform approach may inspire and encourage future research on methods for addressing ECT conductivity imaging problems.

Tian, Yong

110

Phase-Contrast X-Ray Imaging for Nondestructive Evaluation of Materials  

SciTech Connect

Practical aspects of microfocal X-ray image enhancement utilizing phase-contrast effects are considered. Optimization of the experimental method to achieve phase contrast in the hard X-ray regime is described for application to nondestructive evaluation of materials. To achieve this we simulate the diffraction field in an object from a small finite X-ray source, and investigate effects of geometrical and material parameters on the X-ray phase-contrast image are investigated. Experimental phase-contrast images of porosity and cylindrical pit obtained with a 5 micron microfocal X-ray source are compared with those from computer simulation as a function of geometrical magnification and X-ray energy. The phase-contrast and absorption-contrast images are compared demonstrating quantitative enhancement of image quality. The phase-contrast X-ray imaging provides enhanced contrast, improved edge definition and X-ray phase information.

Zoofan, B.; Kim, J.-Y.; Rokhlin, S.I. [Ohio State University, Nondestructive Evaluation Program, Edison Joining Technology Center, Columbus, OH 43221 (United States); Frankel, G.S. [Ohio State University, Fontana Corrosion Center, Department of Materials Science and Engineering, Columbus, OH 43210 (United States)

2004-02-26

111

Overview of Mathematical Modeling in Nondestructive Evaluation (NDE)  

NASA Astrophysics Data System (ADS)

This report presents a broad overview of mathematical modeling in nondestructive evaluation (NDE). The primary emphasis is to expand the review of NDE modeling literature covered by previous general works. To provide a starting point for researchers and engineers, the discussions and references include multiple modeling approaches (analytical, asymptotic, and numerical) for a variety of NDE techniques. A second emphasis for this report is to present the pertinent modeling software packages for a variety of NDE techniques. Overviews of modeling for four NDE techniques, ultrasonic testing, eddy current testing, radiography, and thermography are presented. In order to present the broad subject of NDE modeling for this report, the discussions of modeling research and software packages are limited in scope; however, numerous references are provided in each section for further study by the reader. Given the inherent depth and importance of the field, special emphasis is given to ultrasonic NDE. Discussions are presented on the generation of ultrasound, wave propagation in elastic solids, scattering from cracks, and waves in guides and at interfaces.

Aldrin, John C.

2002-09-01

112

Development of nondestructive evaluation methods for structural ceramics  

SciTech Connect

Nondestructive evaluation (NDE) methods using three-dimensional microfocus X-ray computed tomographic imaging (3DXCT) were employed to map axial and radial density variations in hot-gas filters and heat exchanger tubes. 3D XCT analysis was conducted on (a) two 38-mm-OD, 6.5-mm wall, SiC/SiC heat exchanger tubes infiltrated by CVI; (b) eight 10 cm diam. oxide/oxide heat exchanger tubes; and (c) one 26-cm-long Nextel fiber/SiC matrix hot-gas filter. The results show that radial and axial density uniformity as well as porosity, can be assessed by 3D XCT. NDE methods are also under development to assess thermal barrier coatings which are under development as methods to protect gas-turbine first-stage hot section metallic substrates. Further, because both shop and field joining of CFCC materials will be necessary, work is now beginning on development of NDE methods for joining.

Ellingson, W.A.; Koehl, R.D.; Wilson, J.A.; Stuckey, J.B. [Argonne National Lab., IL (United States). Energy Technology Div.; Engel, H.P. [Argonne National Lab., IL (United States). Energy Technology Div.]|[Heaviside Science, Inc., Melbourne, FL (United States)

1996-04-01

113

Distinguishing between uncertainty and variability in nondestructive evaluation  

NASA Astrophysics Data System (ADS)

In nondestructive evaluation (NDE), measurement outputs usually involve different sources of variability such as operator variation, flaw-morphology variation, setup and calibration variation, environmental related variations, and measurement error. If an appropriate experiment is conducted, it is possible to estimate the separate effects of different sources of variability. These sources of variability imply that the Probability of Detection (POD) itself is random depending, for example, on the operator assigned to do the inspection. Traditional POD analysis has focused on the estimation of the mean of the POD distribution (i.e., estimating a POD averaged over the different sources of variability reflected in the data), also providing an associated 95% lower confidence bound to reflect statistical uncertainty (i.e., uncertainty due to limited data). Focusing on mean POD obscures the process variability and has the potential to provide an overly optimistic impression of POD when there is considerable variation. An alternative, commonly used in other areas of statistical analysis, such as product reliability, is to make inferences on a lower quantile of the distribution. In this paper, we emphasize the important difference between mean POD and quantile POD and provide guidance about when they should be used.

Li, M.; Spencer, F. W.; Meeker, W. Q.

2012-05-01

114

Non-destructive evaluation of mechanical properties of magnetic materials  

SciTech Connect

A magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

Kankolenski, K.P.; Hua, S.Z.; Yang, D.X.; Hicho, G.E.; Swartzendruber, L.J.; Zang, Z.; Chopra, H.D.

2000-07-01

115

Infrared thermal wave nondestructive testing for rotor blades in wind turbine generators non-destructive evaluation and damage monitoring  

NASA Astrophysics Data System (ADS)

The rotor blades are key components in wind turbine generators. A visual inspection of the laminated shells for delaminations, air pockets, missing/disoriented fabric etc. is in most cases also not possible due to the manufacturing process, so Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of rotor blades structure are essential to both reduce manufacturing costs and out of service time of wind turbine generators due to maintenance. Nowadays, Infrared Thermal Wave Nondestructive Testing (Pulsed thermography) is commonly used for assessing composites. This research work utilizes Infrared Thermal Wave Nondestructive Testing system (EchoTherm, Thermal Wave Imaging, Inc.) to inspect a specimen with embedded defects (i.e. foreign matter and air inclusions) in different depth which is a part of rotor blades in wind turbine generators, we have successfully identified defects including foreign matter and air inclusions, and discovered a defective workmanship. The system software allows us to simultaneously view and analyze the results for an entire transition.

Zhao, Shi Bin; Zhang, Cun-Lin; Wu, Nai-Ming; Duan, Yu-Xia; Li, Hao

2009-07-01

116

Computed Tomography for Non-Destructive Evaluation of Composites: Applications and Correlations.  

National Technical Information Service (NTIS)

The state-of-the-art fabrication techniques for composite materials are such that stringent species-specific acceptance criteria must be generated to insure product reliability. Non-destructive evaluation techniques including computed tomography (CT), X-r...

B. Goldberg L. Hediger E. Noel

1985-01-01

117

Quantitative nondestructive density determinations of very low-density carbon foams  

SciTech Connect

The carbon density and the carbon distribution in low-density foams that were manufactured by a modified salt-replica process were determined by bulk measurements of weight and volume and by x-ray computed tomography (CT). When determining the carbon density, both methods yielded similar results, however, the high spatial resolution of CT was found to yield nondestructive quantitative information on the carbon distribution that was not available from bulk measurements. The highest and lowest foam densities were found to occur at the edges and the interior, respectively. The carbon density at the edge was found to be a few percent up to 20 percent higher than the average foam density. The percentage of carbon buildup at the edge was determined to be inversely proportional to the foal density, and in addition, the gradient compared favorably with calculations from Fick's second low of diffusion. A calculated diffusion coefficient was interpreted in terms of foam manufacturing in the modified salt-replica process. 6 refs., 5 figs., 1 tab.

Moddeman, W.E.; Kramer, D.P.; Firsich, D.W.; Trainer, P.D.; Back, P.S.; Smith, S.D.; Deal, W.R.; Salerno, R.F.; Koehler, F.A. (EG and G Mound Applied Technologies, Miamisburg, OH (United States)); Hughes, M.E.; Yancey, R.N. (Advanced Research and Applications Corp., Dayton, OH (United States))

1991-01-01

118

Development of nondestructive evaluation methods for structural ceramics  

SciTech Connect

Development of nondestructive evaluation (NDE) methods for application to fossil energy systems continues in three areas: (a) mapping axial and radial density gradients in hot gas filters, (b) characterization of the quality of continuous fiber ceramic matrix composite (CFCC) joints and (c) characterization and detection of defects in thermal barrier coatings. In this work, X-ray computed tomographic imaging was further developed and used to map variations in the axial and radial density of two full length (2.3-m) hot gas filters. The two filters differed in through wall density because of the thickness of the coating on the continuous fibers. Differences in axial and through wall density were clearly detected. Through transmission infrared imaging with a highly sensitivity focal plane array camera was used to assess joint quality in two sets of SiC/SiC CFCC joints. High frame rate data capture suggests that the infrared imaging method holds potential for the characterization of CFCC joints. Work to develop NDE methods that can be used to evaluate electron beam physical vapor deposited coatings with platinum-aluminide (Pt-Al) bonds was undertaken. Coatings of Zirconia with thicknesses of 125 {micro}m (0.005 in.), 190 {micro}m (0.0075 in.), and 254 {micro}m (0.010 in.) with a Pt-Al bond coat on Rene N5 Ni-based superalloy were studied by infrared imaging. Currently, it appears that thickness variation, as well as thermal properties, can be assessed by infrared technology.

Ellingson, W.A.; Koehl, R.D.; Stuckey, J.B.; Sun, J.G. [Argonne National Lab., IL (United States). Energy Technology Div.; Engel, H.P. [Heaviside Science, Inc., Melbourne, FL (United States); Smith, R.G. [3M Corp., St. Paul, MN (United States)

1997-06-01

119

Corrosion Evaluation of Carbon Steels Using Nondestructive Technique  

NASA Astrophysics Data System (ADS)

Primary water stress corrosion crack (PWSCC) in the piping used at the nuclear power plant has been one of the major issues for the safety of plant. The major objective in this paper is to clarify the corrosion degree and damage by the PWSCC using nondestructive technique. The instrument of the tube typed reactor with the internal conditions of the temperature of 473K under pressure of 10 MPa was designed for corrosion of the material. The tensile specimens of the same material with the reactor were corroded in the reactor for evaluation of mechanical properties according to the corrosion. The corrosion of the specimen was maintained over one year, and an acoustic emission technique was applied to inspect the corrosion damage of the specimen periodically. A tensile test was performed for the corroded specimen, and then the elastic waves caused the deformation of the corroded specimen were analyzed. With the increase of the corrosion time the elastic waves generated in the specimen due to the tensile load showed a little difference, and these differences of the waves work as a cause of the change of acoustic emission (AE) parameters. The number of AE events at the beginning of the load increased with the corrosion time. AE parameters of amplitude and energy decreased as the corrosion times increased, while the level of duration time and count were increased with the corrosion periods. The velocity and attenuation of the elastic wave were also analyzed for the specimen, and these factors showed a close relation with the corrosion times. In addition, SEM and XRD analysis were performed to evaluate the damage behavior of the carbon steel due to corrosion.

Lee, Jin Kyung; Lee, Sang Pill; Lee, Moon Hee; Lee, Joon Hyun; Park, Jun Young

120

Nondestructive evaluation of concrete dams and other structures  

Microsoft Academic Search

This paper presents an overview of several stress-wave based nondestructive testing methods which can be used to assess the condition of concrete structures such as dams, buildings, and foundations. The specific methods to be presented include the use of the impact echo (IE) and spectral analysis of surface waves (SASW) methods in the assessment of dam concrete condition (including freeze-thaw

Larry D. Olson; Dennis A. Sack

1995-01-01

121

FORENSIC EXAMINATION USING A NONDESTRUCTIVE EVALUATION METHOD FOR SURFACE METROLOGY  

Microsoft Academic Search

The objective of this paper is to describe the use of a new technique of optical profilometry in a nondestructive, non-contact fashion for the comparison of two metallic surfaces, one hard and one soft. When brought in contact with one another, the harder material (i.e. the tool) will impress its surface roughness onto the softer. It is understood that the

David J. Eisenmann; L. Scott Chumbley

2009-01-01

122

Forensic Examination Using a Nondestructive Evaluation Method for Surface Metrology  

Microsoft Academic Search

The objective of this paper is to describe the use of a new technique of optical profilometry in a nondestructive, non-contact fashion for the comparison of two metallic surfaces, one hard and one soft. When brought in contact with one another, the harder material (i.e. the tool) will impress its surface roughness onto the softer. It is understood that the

David J. Eisenmann; L. Scott Chumbley

2009-01-01

123

Preliminary evaluation of several nondestructive-evaluation techniques for silicon nitride gas-turbine rotors  

Microsoft Academic Search

Several nondestructive-evaluation (NDE) techniques have been examined to establish their effectiveness for detecting critically sized flaws in silicon nitride gas-turbine rotors. Preliminary results have been obtained for holographic interferometry, acoustic microscopy, dye-enhanced radiography, acoustic emission, and acoustic-impact testing techniques. This report discusses the relative effectiveness of these techniques in terms of their applicability to the rotor geometry and ability to

D. S. Kupperman; C. Sciammarella; N. P. Lapinski; A. Sather; D. Yuhas; L. Kessler; N. F. Fiore

1978-01-01

124

Quantitative evaluation of nation stability  

Microsoft Academic Search

This paper quantitatively evaluates nation stability, defined as the state of a country's social and economic system as measured by multiple evaluation indicators, and observes its transitions. Data Envelopment Analysis\\/Malmquist Index (DEA\\/MI) methodology is applied to the panel data for 97 countries for the period 1981–2004, although the DEA application is totally different from the DEA efficiency\\/productivity analysis. This analysis

Takao Tsuneyoshi; Akihiro Hashimoto; Shoko Haneda

125

Nondestructive evaluation of composite materials by electrical resistance measurement  

NASA Astrophysics Data System (ADS)

This dissertation investigates electrical resistance measurement for nondestructive evaluation of carbon fiber (CF) reinforced polymer matrix composites. The method involves measuring the DC electrical resistance in either the longitudinal or through thickness direction. The thermal history and thermal properties of thermoplastic/CF composites were studied by longitudinal and through-thickness resistance measurements. The resistance results were consistent with differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) results. The resistance measurements gave more information on the melting of the polymer matrix than TMA. They were more sensitive to the glass transition of the polymer matrix than DSC. The through-thickness resistance decreased as autohesion progressed. The activation energy of autohesion was 21.2 kJ/mol for both nylon-6 and polyphenylene sulfide (PPS)/CF composites. Adhesive bonding and debonding were monitored in real-time by measurement of the through-thickness resistance between the adherends in an adhesive joint during heating and subsequent cooling. Debonding occurred during cooling when the pressure or temperature during prior bonding was not sufficiently high. A long heating time below the melting temperature (T m) was found to be detrimental to subsequent PPS adhesive joint development above Tm, due to curing reactions below Tm and consequent reduced mass flow response above Tm. A high heating rate (small heating time) enhanced the bonding more than a high pressure. The longitudinal resistance measurement was used to investigate the effects of temperature and stress on the interface between a concrete substrate and its epoxy/CF composite retrofit. The resistance of the retrofit was increased by bond degradation, whether the degradation was due to heat or stress. The degradation was reversible. Irreversible disturbance in the fiber arrangement occurred slightly as thermal or load cycling occurred, as indicated by the resistance decreasing cycle by cycle. This dissertation also addresses the use of the electrical resistance method to observe thermal and mechanical damage in real time. A temperature increase caused the interlaminar contact resistance to decrease reversibly within each thermal cycle, while thermal damage caused the resistance to decrease abruptly and irreversibly, due to matrix molecular movement and the consequent increase in the chance of fibers of one lamina touching those of an adjacent lamina. The through-thickness volume resistivity irreversibly and gradually decreased upon mechanical damage, which was probably fiber-matrix debonding. Moreover, it reversibly and abruptly increased upon matrix micro-structural change, which occurred reversibly near the peak stress of a stress cycle.

Mei, Zhen

126

Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials.  

National Technical Information Service (NTIS)

This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were...

R. E. Martin

2010-01-01

127

NDE (Non-Destructive Evaluation) Round Robin. The Evaluation of NDE Techniques for Determining Offshore Structures Integrity.  

National Technical Information Service (NTIS)

The Round Robin Test Program was undertaken to document the abilities of several nondestructive evaluation (NDE) techniques in monitoring the integrity of large, complex structures and, particularly, off-shore oil platforms. The test program required advo...

R. E. Dame H. A. Warren

1983-01-01

128

NDE (Non-Destructive Evaluation) Round Robin. The Evaluation of NDE Techniques for Determining Offshore Structures Integrity Appendices.  

National Technical Information Service (NTIS)

The Round Robin Test Program was undertaken to document the abilities of several nondestructive evaluation (NDE) techniques in monitoring the integrity of large, complex structures and, particularly, off-shore oil platforms. The test program required advo...

R. E. Dame H. A. Warren

1983-01-01

129

Nondestructive evaluation of ceramic matrix composite combustor components.  

SciTech Connect

Combustor liners fabricated from a SiC/SiC composite were nondestructively interrogated before and after combustion rig testing. The combustor liners were inspected by X-ray, ultrasonic and thermographic techniques. In addition, mechanical test results were obtained from witness coupons, representing the as-manufactured liners, and from coupons machined from the components after combustion exposure. Thermography indications were found to correlate with reduced material properties obtained after rig testing. Microstructural examination of the SiC/SiC liners revealed the thermography indications to be delaminations and damaged fiber tows.

Sun, J. G.; Verrilli, M. J.; Stephan, R.; Barnett, T. R.; Ojard, G.

2002-11-08

130

Framework for incorporating nondestructive evaluation (NDE) into pavement and bridge management systems  

NASA Astrophysics Data System (ADS)

One of the major components of an infrastructure management system is the condition assessment or deterioration modeling. With application to highway pavements and bridges, this paper presents conceptually how nondestructive evaluation (NDE) results can be utilized to provide a quantitative assessment of the infrastructure condition in a format usable for network-level pavement management systems and bridge management systems. NDE techniques typically applied to pavements include Visual Rating, Falling Weight Deflectometer, Dynaflect, Seismic Pavement Analyzer, and the Ground Penetrating Radar (GPR). Bridges can also be evaluated using the GPR. NDE is particularly useful at the network level of infrastructure management because of the mobility of conducting the tests. Detailed mechanistic methods have been suggested for NDE interpretation but this method may not be practical at network level. Interpretation of NDE results, through knowledge-based systems and intelligent databases indicate the defects and residual capacity of infrastructures. Measured physical properties and defects in the infrastructure component materials can be correlated to existing scales of condition assessment such as in the NBI and PONTIS formats for bridge management and also to an index or rating such as the PSI in highway pavements.

Sobanjo, John O.; Tawfiq, Kamal S.

1999-02-01

131

Impact Acoustic Non-destructive Evaluation in Noisy Environment Based on Wavelet Packet Decomposition  

Microsoft Academic Search

Impact acoustic is an effective non-destructive evaluation (NDE) method for many applications especially for inspecting the bonding quality of mosaic tile-walls. However, the audio noise can affect the power spectrum density (PSD) distribution of an acquired signal seriously. So, the traditional method of using PSD as the main identification tool is not sufficient. This paper proposes an evaluation method based

Bing L. Luk; Z. D. Jiang; Louis K. P. Liu; F. Tong

2008-01-01

132

Nondestructive 3D confocal laser imaging with deconvolution of seven whole stardust tracks with complementary XRF and quantitative analysis  

SciTech Connect

We present a nondestructive 3D system for analysis of whole Stardust tracks, using a combination of Laser Confocal Scanning Microscopy and synchrotron XRF. 3D deconvolution is used for optical corrections, and results of quantitative analyses of several tracks are presented. The Stardust mission to comet Wild 2 trapped many cometary and ISM particles in aerogel, leaving behind 'tracks' of melted silica aerogel on both sides of the collector. Collected particles and their tracks range in size from submicron to millimeter scale. Interstellar dust collected on the obverse of the aerogel collector is thought to have an average track length of {approx}15 {micro}m. It has been our goal to perform a total non-destructive 3D textural and XRF chemical analysis on both types of tracks. To that end, we use a combination of Laser Confocal Scanning Microscopy (LCSM) and X Ray Florescence (XRF) spectrometry. Utilized properly, the combination of 3D optical data and chemical data provides total nondestructive characterization of full tracks, prior to flattening or other destructive analysis methods. Our LCSM techniques allow imaging at 0.075 {micro}m/pixel, without the use of oil-based lenses. A full textural analysis on track No.82 is presented here as well as analysis of 6 additional tracks contained within 3 keystones (No.128, No.129 and No.140). We present a method of removing the axial distortion inherent in LCSM images, by means of a computational 3D Deconvolution algorithm, and present some preliminary experiments with computed point spread functions. The combination of 3D LCSM data and XRF data provides invaluable information, while preserving the integrity of the samples for further analysis. It is imperative that these samples, the first extraterrestrial solids returned since the Apollo era, be fully mapped nondestructively in 3D, to preserve the maximum amount of information prior to other, destructive analysis.

Greenberg, M.; Ebel, D.S. (AMNH)

2009-03-19

133

Framework for the quantitative modelling of the European methodology for qualification of non-destructive testing  

Microsoft Academic Search

The European methodology for qualification of non-destructive testing has been adopted as the basis of inspection qualifications for nuclear utilities in many European countries. According to this methodology, the inspection qualification is based on a combination of technical justification and practical trials. The methodology is qualitative in nature, and it does not give explicit guidance on how the evidence from

Luca Gandossi; Kaisa Simola

2005-01-01

134

Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography  

Microsoft Academic Search

The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external

D. C. Camp; H. E. Martz

1991-01-01

135

Nondestructive evaluation of thermal spray cathodic protection anodes  

SciTech Connect

The aging of thermal spray (TS) cathodic protection (CP) anodes is usually characterized by the amount of current passing through the anode-concrete interface. This charge, also called electrochemical age, can be correlated to bond strength and eventual failure of TS Zn anodes. Several non-destructive techniques were subsequently applied to aged thermal spray anodes to determine if other property measurements would correlate to electrochemical age and thus to service life. The techniques considered are the circuit resistance of impressed current anodes, the AC resistivity between the rebar and the anode, and the surface resistivity of the TS anodes. All three techniques gave a good correlation of measured property to electrochemical age. Surface resistivity can also be used to calculate the thickness of anode remaining.

Covino, B.S., Jr.; Russell, J.H.; Bullard, S.J.; Holcomb, G.R.; Cramer, S.D.

2000-03-01

136

Ultrasound Nondestructive Evaluation (NDE) Imaging with Transducer Arrays and Adaptive Processing  

PubMed Central

This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated.

Li, Minghui; Hayward, Gordon

2012-01-01

137

Ultrasound nondestructive evaluation (NDE) imaging with transducer arrays and adaptive processing.  

PubMed

This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated. PMID:22368457

Li, Minghui; Hayward, Gordon

2011-12-22

138

Optimization of ISOCS Parameters for Quantitative Non-Destructive Analysis of Uranium in Bulk Form  

NASA Astrophysics Data System (ADS)

Quantitative calculation of the isotopic masses of fissionable U and Pu is important for forensic analysis of nuclear materials. ?-spectrometry is the most commonly applied tool for qualitative detection and analysis of key radionuclides in nuclear materials. Relative isotopic measurement of U and Pu may be obtained from ?-spectra through application of special software such as MGAU (Multi-Group Analysis for Uranium, LLNL) or FRAM (Fixed-Energy Response Function Analysis with Multiple Efficiency, LANL). If the concentration of U/Pu in the matrix is unknown, however, isotopic masses cannot be calculated. At present, active neutron interrogation is the only practical alternative for non-destructive quantification of fissionable isotopes of U and Pu. An active well coincidence counter (AWCC), an alternative for analyses of uranium materials, has the following disadvantages: 1) The detection of small quantities (?100 g) of 235U is not possible in many models; 2) Representative standards that capture the geometry, density and chemical composition of the analyzed unknown are required for precise analysis; and 3) Specimen size is severely restricted by the size of the measuring chamber. These problems may be addressed using modified ?-spectrometry techniques based on a coaxial HPGe-detector and ISOCS software (In Situ Object Counting System software, Canberra). We present data testing a new gamma-spectrometry method uniting actinide detection with commonly utilized software, modified for application in determining the masses of the fissionable isotopes in unknown samples of nuclear materials. The ISOCS software, widely used in radiation monitoring, calculates the detector efficiency curve in a specified geometry and range of photon energies. In describing the geometry of the source-detector, it is necessary to clearly describe the distance between the source and the detector, the material and the thickness of the walls of the container, as well as material, density and chemical composition of the matrix of the specimen. Obviously, not all parameters can be characterized when measuring samples of unknown composition or uranium in bulk form. Because of this, and especially for uranium materials, the IAEA developed an ISOCS optimization procedure. The target values for the optimization are ?matrixfixed, the matrix mass determined by weighing with a known mass container, and ?fixed, the 235U enrichment, determined by MGAU. Target values are fitted by varying the matrix density (?), and the concentration of uranium in the matrix of the unknown (w). For each (?i, wi), an efficiency curve is generated, and the masses of uranium isotopes, ?235Ui and ?238Ui, determined using spectral activity data and known specific activities for U. Finally, fitted parameters are obtained for ?matrixi = ?matrixfixed ± 1?, ?i = ?fixed ± 1?, as well as important parameters (?i, wi, ?235Ui, ?238Ui, ?Ui). We examined multiple forms of uranium (powdered, pressed, and scrap UO2 and U3O8) to test this method for its utility in accurately identifying the mass and enrichment of uranium materials, and will present the results of this research.

Kutniy, D.; Vanzha, S.; Mikhaylov, V.; Belkin, F.

2011-12-01

139

Non-destructive evaluation of aerospace materials with lock-in thermography  

Microsoft Academic Search

The attention of the present study was focused on the aid provided by lock-in thermography for non-destructive evaluation of aerospace materials and structures. The experimental analysis was performed by testing several specimens, which were made of different materials employed in the fabrication of aircraft (composites, hybrid composites, sandwiches, metals) and which included the most commonly encountered kinds of damage (delamination,

Carosena Meola; Giovanni Maria Carlomagno; Antonino Squillace; Antonio Vitiello

2006-01-01

140

Experimental Comparison of Lock-in and Pulsed Thermography for the Nondestructive Evaluation of Aerospace Materials  

Microsoft Academic Search

Infrared thermography is a nondestructive evaluation technique aimed to the detection of surface temperature variations related to the presence of subsurface defects. Several inspection techniques have been developed over the years with basically two approaches, lock-in thermography and pulsed thermography. These two techniques are based on the principle of heat diffusion and thermal wave reflection, but they differ in the

W. Ben Larbi; C. Ibarra-Castanedo; M. Klein; A. Bendada; X. Maldague

141

Recent Developments of Aircraft Nondestructive Evaluation Based on Advanced Sensor Techniques  

Microsoft Academic Search

The safety and structural integrity are of great importa nce to military and commercial aircraft, and the developments of effective nondestruct ive evaluation (NDE) methods are receiving much attention in recent years. The objective o f this paper was to provide the recent developments of aircraft NDE based on advanced sensor t echniques: (a) Ultrasonic testing with piezoceramic sensor arrays,

Gongjin QI; Hong LEI; Rongsheng GENG; Peng JING

142

a Fiber Optic-Based Thermal Acousto-Photonic System for Noncontacting Nondestructive Evaluation  

Microsoft Academic Search

The Thermal Acousto-Photonic (TAP) Nondestructive Evaluation (NDE) system is an optically based ultrasonic testing technique which extends the potential applications of ultrasonic flaw detection beyond the current capabilities of traditional piezoelectric transducer based technology. Laser based excitation and optical interferometric detection of acoustic waves are conducted through flexible noncontacting fiber optic probes, and a combination of these two methods is

Bruce R. Peters

1990-01-01

143

Efficient methods for solving boundary integral equation in diffusive scalar problem and eddy current nondestructive evaluation  

Microsoft Academic Search

Eddy current nondestructive evaluation (NDE) of airframe structures involves the detection of electromagnetic field irregularities due to non-conducting inhomogeneities in an electrically conducting material. Usually, the eddy current NDE problem can be formulated by the boundary integral equations (BIE) and discretized into matrix equations by the method of moments (MoM) or the boundary element method (BEM). The fast multipole method

Ming Yang

2010-01-01

144

Infrared Thermography As A Nondestructive Evaluation Technique For Fiber Composite Bridge Decks  

Microsoft Academic Search

The purpose of this research was to determine the optimal usage of Infrared Thermography (IRT) as a Non-Destructive Evaluation (NDE) method on glass fiber composite bridge decks. For various reasons, fiber bridge decks are a potential for replacing traditional steel-grate or concrete bridge decking. However, the main problem with fiber decks is that there is no proven NDE method. Two

Philip Hallam

2012-01-01

145

New methods for statistical modeling and analysis of nondestructive evaluation data  

Microsoft Academic Search

Statistical methods have a long history of applications in physical sciences and engineering for design of experiments and data analyses. In nondestructive evaluation (NDE) studies, standard statistical methods are described in Military Handbook 1823A as guidelines to analyze the experimental NDE data both in carefully controlled laboratory setup and field studies. However complicated data structures often demand non-traditional statistical approaches.

Ming Li

2010-01-01

146

Nondestructive Integrity Evaluation of PC Pile Using Wigner-Ville Distribution Method  

Microsoft Academic Search

Nondestructive evaluation (NDE) techniques have been used for years to provide a quality control of the construction for both drilled shafts and driven concrete piles. This trace is typically made up of transient pulses reflected from structural features of the pile or changes in its surrounding environment. It is often analyzed in conjunction with the spectral response, mobility curve, arrival

Sheng-Huoo Ni; Kuo-Feng Lo; Yan-Hong Huang

2008-01-01

147

Nondestructive evaluation of the delamination of fine bumps in three-dimensionally stacked flip chip structures  

Microsoft Academic Search

A new nondestructive evaluation method for detecting delamination between a chip and metallic bumps in area-arrayed flip chip structures has been developed by measuring the local surface deformation of a chip, which is caused by the mismatch in mechanical properties between the metallic bumps and underfill. The change of the local deformation was measured by using a high resolution laser

Yuhki Sato; Naokazu Murata; Kinji Tamakawa; Ken Suzuki; Hideo Miura

2010-01-01

148

Nondestructive evaluation of internal maturity of tomatoes using spatially offset Raman spectroscopy  

Technology Transfer Automated Retrieval System (TEKTRAN)

This research explored the use of spatially offset Raman spectroscopy (SORS) for nondestructive evaluation of internal maturity of tomatoes. A Raman spectroscopy system using a 785 nm laser was developed to collect spatially-offset spectra in the wavenumber range of 200 – 2500. The SORS measuremen...

149

Role of nondestructive evaluation in civil aviation: historical development, current status, future challenges  

Microsoft Academic Search

Nondestructive evaluation has been used in civil aviation for 50 years. Until the arrival of the jet era it was mostly applied to component inspection. Since the damage-tolerant design philosophy was introduced by mandate for large transport aircraft, it has become an integral part of their design and maintenance. In the near future its role in the maintenance of aging

Hans J. Weber

1995-01-01

150

Nondestructive evaluation of the preservation state of stone columns in the Hospital Real of Granada  

Microsoft Academic Search

This paper describes the results of the employment of two nondestructive evaluation methods for the diagnostic of the preservation state of stone elements. The first method is based on ultrasonic (US) pulses while the second method uses short electromagnetic pulses. Specifically, these methods were applied to some columns, some of them previously restored. These columns are part of the architectonic

C. Moreno de Jong van Coevorden; C. Cobos Sánchez; A. Rubio Bretones; M. Fernández Pantoja; Salvador G. García; R. Gómez Martín

2012-01-01

151

Design and evaluation of a nondestructive fissile assay device for HTGR fuel samples  

Microsoft Academic Search

Nondestructive assay of fissile material plays an important role in nuclear fuel processing facilities. Information for product quality control, plant criticality safety, and nuclear materials accountability can be obtained from assay devices. All of this is necessary for a safe, efficient, and orderly operation of a production plant. Presented here is a design description and an operational evaluation of a

S. R. McNeany; R. W. Knoll; J. D. Jenkins

1979-01-01

152

Electromagnetic nondestructive evaluation: moving HTS SQUIDs, inducing field nulling and dual frequency measurements  

Microsoft Academic Search

We have previously shown that simple, single layer HTS SQUIDs can be used effectively in electromagnetic nondestructive evaluation (NDE) using eddy current techniques in a magnetically unshielded environment. HTS SQUID systems for NDE applications are expected to be small and portable allowing non-stationary measurements to be carried out in the Earth's field above a stationary sample. Here we present application-oriented

C. Carr; D. Mc A. McKirdy; E. J. Romans; G. B. Donaldson; A. Cochran

1997-01-01

153

Forensic Examination Using a Nondestructive Evaluation Method for Surface Metrology  

NASA Astrophysics Data System (ADS)

The objective of this paper is to describe the use of a new technique of optical profilometry in a nondestructive, non-contact fashion for the comparison of two metallic surfaces, one hard and one soft. When brought in contact with one another, the harder material (i.e. the tool) will impress its surface roughness onto the softer. It is understood that the resulting set of impressions left from a tool tip act in a manner similar to a photographic negative, in that it leaves a reverse, or negative impression on the surface of a plate. If properly inverted and reversed, measurements from the softer material should be identical to the harder indenting object with regard to surface texture and roughness. This assumption is inherent in the area of forensics, where bullets, cartridge cases, and toolmarked surfaces from crime scenes are compared to similar marks made under controlled conditions in the forensic laboratory. This paper will examine the methodology used to compare two surfaces for similarities and dissimilarities, and comment on the applicability of this technique to other studies.

Eisenmann, David J.; Chumbley, L. Scott

2009-03-01

154

Estimate of accuracy requirements for nondestructive evaluation of materials properties  

NASA Astrophysics Data System (ADS)

Research literature documents several nondestructive (NDE) techniques for measuring material properties such as residual stress, embrittlement and fatigue damage. Reports in peer reviewed publications thoroughly describe the experimental measurement techniques and provide a comparison between expected analytical results and experimental measurements. A simple rationale for estimating the required accuracy of NDE to measure residual stress shows that residual stress measurements are acceptable if accurate to within plus or minus 10%. An analysis of the effect of neutron fluence on fracture toughness shows a more complex relationship. At temperature and fluence conditions corresponding to low toughness; fracture toughness is insensitive to fluence and high accuracy for NDE embrittlement is not required. However, for conditions associated with high toughness, changes in fluence have significant effect. Calculations indicate that NDE measurements of irradiation effects should have an accuracy of approximately plus or minus 15% to correspond to a plus or minus 10% change in KIC over the toughness range from about 40 to 100 ksi(root)in.

Gamble, Ronald C.; Taylor, Tom T.

1995-05-01

155

Low velocity impact testing and nondestructive evaluation of transparent materials  

SciTech Connect

Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

Brennan, R. E.; Green, W. H. [U.S. Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, MD 21005-5066 (United States)

2011-06-23

156

Ultrasonic nondestructive material evaluation method and study on texture and cross slip effects under simple and pure shear states  

Microsoft Academic Search

Ultrasonic wave velocities propagating in a plastically deformed medium are known to depend upon its microstructural material properties. Therefore, the authors have proposed the theoretical modeling of an ultrasonic nondestructive method to evaluate plastically deformed states. In the present paper, we verify the proposed theoretical modeling of an ultrasonic nondestructive method and examine its accuracy by comparing the experimental results

Michiaki Kobayashi; Shihua Tang; Setsuo Miura; Kazuya Iwabuchi; Seiichi Oomori; Hiroyuki Fujiki

2003-01-01

157

Nondestructive evaluation of plates using eddy current methods  

Microsoft Academic Search

The problem of determining defects in structures using eddy current methods is investigated. The goal of this work is to assess the extent to which accurate quantitative information about damage can be extracted from the data. For simplicity, we consider the problem of inspecting a plate in two dimensions. Damage is modeled as a change in the plate's conductivity. Electromagnetic

David C. Dobson; Fadil Santosa

1998-01-01

158

Guided plate waves and reflection factor for NDE (Non-Destructive Evaluation) of composite materials  

SciTech Connect

An oblique incidence reflection factor analysis and a guided plate wave approach are being adopted in an attempt to explore the potential of utilizing the abundance of ultrasonic wave modes and particle displacement types for the characterization of the material state in fiber reinforced composite structures. The generation and the propagation of guided plate waves in fiber reinforced composites are demonstrated to qualitatively and quantitatively evaluate material degradation problems such as delamination, porosity, fiber volume fraction changes, hydrothermal degradation and fiber mis-orientation. Several anomaly modeling techniques are coupled in order to describe material degradation in multi-layered composites. The global anomalies in the fiber reinforced laminates are modeled as changes in the effective elastic constants and density. The laminated plate theory is then used to smear the elastic properties over the whole composite structure thus enabling the modeling of different ply lay-ups. A new generalized model for plate wave dispersion in composite plates is introduced to establish the relationships between the material state and wave mode generation. The sensitivity of plate wave modes and several of its features capable of characterizing material state is demonstrated, using both experimental and theoretical evidence. The critical angles and resonant frequencies, which are also related to the existence of plate wave modes also reveal the possibility of using oblique incidence reflection factor analysis in the Non-destructive Evaluation (NDE) field. Another useful derivative from this research is the scientific proof for an increased sensitivity of the oblique incidence longitudinal and the oblique incidence shear waves mode to global anomalies such as porosity in fiber reinforced composite materials, a practical NDE tool.

Balasubramaniam, K.

1989-01-01

159

Nondestructive evaluation of a graphite/aluminum composite space radiator panel. Technical report  

SciTech Connect

Graphite aluminum composites which employ graphite fibers for mechanical reinforcement have applications in the aerospace industry. They are particularly attractive for spacecraft thermal management systems due to their ability to efficiently transport heat. The detection and evaluation of damage in structures fabricated from this material is necessary to the efficiency and application of these materials. This technical report presents research on a graphite fiber reinforced aluminum composite space radiator panel. The panel was evaluated after each of four fabrication stages by four nondestructive techniques: ultrasound, x-ray, dye penetrant, and visual inspection. The results illustrate the importance of nondestructive evaluation (NDE) from the time the composite is fabricated through the time it is implemented into the spacecraft. These NDE technologies will help detect external or internal irregularities (anomalies) at each increment of the fabrication and qualification testing of the composite radiator panel.

Feldman, N.M.; Foltz, J.V.

1991-12-01

160

A report on nondestructive testing and evaluation in India  

SciTech Connect

India is pursuing research and development in various aspects of NDT including in service inspection in fields such as ultrasonic testing, acoustic emission testing, single and multi-frequency eddy current testing, signal analysis, X-ray diffraction, high resolution X-radiography, radiographic image enhancement, laser holography, laser speckle scattering, laser based ultrasonic generation, electromagnetic acoustic transducers, artificial intelligence approaches, and intelligent processing of materials. The emphasis is not only on the methodologies of acquisition of the data but also on the means to analyze them properly so that complete characterization of the type, nature, and size of the defects can be made, as well as their effects on the structural integrity of the components. The approach is comprehensive, the means being total awareness, and the objective is a complete quantitative characterization of defects and other required physical parameters, leading to defect free and safe components and systems.

Raj, B. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Metallurgy and Materials Group; Viswanathan, K. [SHAR, Andhra Pradesh (India); Nair, C.G.K. [Hindustan Aeronautics Limited, Bangalore (India)

1996-11-01

161

Nondestructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method  

NASA Astrophysics Data System (ADS)

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

Mi, Bao; Zhao, Xiaoliang (George); Bayles, Robert

2007-03-01

162

Nondestructive evaluation for remanent life of modified 9Cr-1Mo steel by reversible magnetic permeability  

NASA Astrophysics Data System (ADS)

We present a magnetic and nondestructive method to evaluate the remanent life of modified 9Cr-1Mo steel by measuring the reversible magnetic permeability. Specimens with ten different kinds of aging periods were prepared using an isothermal heat treatment at 690 °C. The Larson-Miller parameter (LMP) was calculated and the peak interval of reversible magnetic permeability (PIRMP) was measured using the surface type probe. PIRMP was inversely proportional to LMP. We can evaluate the remanent life of modified 9Cr-1Mo steel using the relationship between PIRMP and LMP. Also, we present the possibility that the tensile strength and yield strength measured by destructive methods could be estimated by PIRMP measured nondestructively.

Bong, Chung-Jong; Ryu, Kwon-Sang; Nahm, Seung-Hoon; Kyu Kim, Eun

2011-03-01

163

Model-based estimation of ultrasonic echoes. Part II: Nondestructive evaluation applications  

Microsoft Academic Search

For Part I see ibid., vol.48, no.3, pp.787-802 (2001). Accurate estimation of the ultrasonic echo pattern leading to the physical property of the object is desirable for ultrasonic NDE (nondestructive evaluation) applications. In Part I of this study, we have presented a generalized parametric ultrasonic echo model, composed of a number of Gaussian echoes corrupted by noise, and algorithms for

Ramazan Demirli; Jafar Saniie

2001-01-01

164

Real-time nondestructive evaluation for full-scale aircraft fatigue test  

Microsoft Academic Search

Damage identification and fatigue crack inspection during the test is a key foundation for full-scale aircraft fatigue test. It is very important to determine the fatigue life and maintenance period of the aircraft structure. The paper presents a brief introduction about a practical engineering method on real-time non-destructive evaluation (NDE) of aircraft structures for full-scale fatigue test. The content covers

Quanliang Liu; Pengfei Song; Sen Ge; Wanlin Guo

2008-01-01

165

Nondestructive testing ultrasonic immersion probe assessment and uncertainty evaluation according to EN 12668-2:2010.  

PubMed

Ultrasonic beam parameters from nondestructive testing probes and respective measurement uncertainties were calculated according to the Guide to the Expression of Uncertainty in Measurement (BIPM-JCGM-100:2008). The major conclusion of this work is that proper measurements of ultrasonic probes parameters are necessary because each probe has intrinsic construction particularities. Uncertainty evaluation was essential to properly assess the experimental results. PMID:23143583

Silva, Cristiane E R; Alvarenga, André V; Costa-Felix, Rodrigo P B

2012-10-01

166

Nondestructive evaluation of various materials using a SQUID-based eddy-current system  

Microsoft Academic Search

We have investigated the applicability of SQUIDs for nondestructive evaluation of various materials from industrial production. For this purpose, we tested production samples and compared the results with other NDE methods such as conventional eddy-current or ultrasonic testing. The materials investigated included niobium sheets for superconducting resonators and indium-tin-oxide sputtering targets for solar panels. Especially for the case of thick,

Michael Mück; Matthias Korn; Christian Welzel; Stefan Grawunder; Friedhold Schölz

2005-01-01

167

Real-Time Ultrasonic Nondestructive Evaluation of Green State Ceramic Powders during Compaction  

Microsoft Academic Search

A real-time ultrasonic technique for the nondestructive evaluation of ceramic powders during compaction has been demonstrated. Initial results indicate that this technique can detect the presence of hard agglomerates in a spray-dried alumina powder. The proposed sensor could be employed by industry to spot flawed parts prior to removing them from the die, and to provide on-line criteria for control

Martin P. Jones; Gerald V. Blessing

1986-01-01

168

Pulsed Bremsstrahlung Interrogation with Photoneutron - Gamma-Ray Spectrometry for Nondestructive Evaluation  

Microsoft Academic Search

A novel photoneutron-based nondestructive evaluation (NDE) technique which does not require a radioactive neutron source is presented. Some unique features of this technique include: 1) pulsed interrogation neutron production within, or very near, an inspected object, 2) spectrum tailoring of the source neutrons, and 3) compatibility with many existing high-energy, commercial x-ray inspection devices. Basic concept feasibility was first established

James Litton Jones

1996-01-01

169

Nondestructive evaluation of creep-fatigue damage: an interim report. [LMFBR  

Microsoft Academic Search

In view of the uncertainties involved in designing against creep-fatigue failure and the consequences of such failures in Class 1 nuclear components that operate at elevated temperature, the possibility of intermittent or even continuous non-destructive examination of these components has been considered. In this interim report some preliminary results on magnetic force and ultrasonic evaluation of creep-fatigue damage in an

Nickell

1977-01-01

170

Development of a Nondestructive Non-Contact Acousto-Thermal Evaluation Technique for Damage Detection in Materials (Preprint).  

National Technical Information Service (NTIS)

This paper presents the development of a new non-contact acousto- thermal signature (NCATS) nondestructive evaluation (NDE) technique. The physical basis of the method is the measurement of the efficiency of the material to convert acoustic energy into he...

J. T. Welter K. V. Jata N. Schehl S. Sathish T. R. Boehnlein

2011-01-01

171

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics.  

National Technical Information Service (NTIS)

Continuous fiber ceramic matrix composites are being developed for turbine engine components, heat exchangers, and hot-gas filters in fossil energy systems. Reliable application requires nondestructive evaluation (NDE) methods that provide data for qualit...

W. A. Ellingson J. P. Singh E. A. Sivers

1995-01-01

172

Conference on Nondestructive Evaluation of Bridges. Held in Arlington, Virginia on August 25-27, 1992. Proceedings (Documentation).  

National Technical Information Service (NTIS)

On August 25-27, 1992, a major forum of 80 knowledgeable individuals representing researchers, manufacturers, and users of nondestructive evaluation (NDE) methods and equipment for bridges was convened to exchange information and to provide guidance for s...

B. R. Ellingwood K. H. Frank N. P. Jones R. F. Pellerin R. J. Ross

1993-01-01

173

Evaluation of nondestructive assay characterization methods for pipe-over-pack containers  

SciTech Connect

Nondestructive assay (NDA) measurements of Transuranic (TRU) waste at Los Alamos National Laboratory (LANL) packed in Pipe-Over-Pack Containers or POC's exhibit a number of complexities. The POC is highly attenuating to both gamma rays and neutrons which presents a difficult waste matrix for correct quantification of material in the container. Also, chemical and matrix properties of the Pu contaminated waste in the POCs that may affect the measurement result are generally unknown in advance of the measurement. Currently there are a number of POC containers at LANL that require evaluation for shipment to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM. At LANL, a single instrument has been used to explore the appropriateness of both passive neutron and quantitative gamma ray methods for measuring POC's. The instrument, a High Efficiency Neutron Counter (HENC) with an integrated high purity germanium detector incorporates both passive neutron and high resolution gamma counting capabilities. The passive neutron approach uses the Reals coincidence count rate to establish plutonium mass and other parameters of interest for TRU waste. The quantitative gamma ray method assumes a homogeneous distribution of matrix and source material and assays the drum with a calibration based on the known density of the matrix. Both methods are supplemented by a simultaneous gamma isotopic measurement using Multi-Group Analysis (MGA) software to determine the plutonium isotopic composition. If MGA fails to provide a viable isotopic result Fixed energy Response function Analysis with Multiple efficiencies (FRAM) could be used to replace MGA results. Acceptable knowledge (AK) may also be used in certain instances. This report will discuss the two measurement methods in detail for POC analysis. Included in the discussion will be descriptions of the setup parameters and calibration techniques for the instrument. A number of test measurements have been performed to compare HENC data with certified safeguards data. Empty POCs loaded with known sources have also been measured to determine the viability of the technique. Finally, a brief discussion of the conclusions that can be drawn from the tests will be offered. (authors)

Stanfield, S.B.; Wachter, J.R.; Cramer, D.L. [Canberra Instruments Inc., Meriden, CT (United States)

2007-07-01

174

Probabilistic nondestructive evaluation of bonded aluminum honeycomb structures  

NASA Astrophysics Data System (ADS)

Aluminum honeycomb panels fabricated in accordance with spacecraft fracture control guidelines must be evaluated to a 90/95 POD/CL (probability of detection/confidence) level for detection of the critical initial flaw (CIF) size. Severe weight limitations can drive the CIF to a size of one cell diameter, or smaller. Additionally, producibility (low or no type II errors) must be maintained, and inspection costs minimized. To assure these goals, a reliability demonstration program was undertaken on thin skin panels for the Space Station Electric Power System ORU (orbital replacement unit) enclosures. This paper examines the probabilistic NDE process in detail, including: analysis of the manufacturing methodology, expected flaw types, construction of the disbond flaw data base, and the subsequent evaluations and results using laser shearography. The experimental data is then reduced utilizing the statistical methodology outlined in a proposed military standard for NDE reliability demonstrations, and contrasted against conventional through transmission ultrasonic inspection. The effort revealed that substantial gains in system reliability and flaw type discrimination are possible with laser shearography, along with a nearly order of magnitude reduction in inspection time.

Schaefer, Lloyd A.

1995-07-01

175

Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography  

SciTech Connect

The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

Camp, D.C.; Martz, H.E.

1991-11-12

176

Nondestructive evaluation of surface roughness by speckle correlation techniques  

NASA Astrophysics Data System (ADS)

The most established way to inspect surface roughness of machined surfaces is to measure with profilometers. These techniques are not applicable for on-line inspection. A few decades ago, the correlation between laser speckles of different light wavelengths and surface roughness was discovered. Since then several authors have been working on this topic. In measuring systems which are considered in this paper, the surface which is to be inspected is illuminated by a polychromatic laser beam. The scattered light is converted by an optical system, which ensures that the product of wavelength times focal length is constant. In the Fourier plane of each subsystem a CCD-array is installed. The CCD- data are captured by a frame grabber and stored for evaluation in a computer. One major problem in industrial processes where surface roughness measurements had ben tried was that the inspected metal workpieces may be tilted and, therefore, the direction of spectral reflection changes. In the method discussed in this paper an approximate value of the surface roughness can be obtained by determining the difference between the zero orders of the scattering patterns of the wavelengths. This difference can be approximated by the position of the maximum of the 2D- cross correlation function of related speckle patterns. The main benefit of the method described is the feasibility of measuring roughness during machining or other types of continuous or semi-continuous production processes. This is achieved by a synchronous detection of speckle patterns of the different wavelengths used. In the pilot project the shutter sped of the cameras is 1/10000 seconds, therefore, in this case only frequencies above 1kHz disturb the measuring results.

Peters, Jorg; Schoene, Armin

1998-03-01

177

Three new nondestructive evaluation tools based on high flux neutron sources  

SciTech Connect

Nondestructive evaluation methods and systems based on specific attributes of neutron interactions with materials are being developed. The special attributes of neutrons are low attenuation in most engineering materials, strong interaction with low Z elements, and epithermal neutron absorption resonances. The three methods under development at ORNL include neutron based tomography and radiography; through thickness, nondestructive texture mapping; and internal, noninvasive temperature measurement. All three techniques require high flux sources such as the High Flux Isotope Reactor, a steady state source, or the Oak Ridge Electron Linear Accelerator, a pulsed neutron source. Neutrons are quite penetrating in most engineering materials and thus can be useful to detect internal flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant, or a metal hydride, are relatively opaque to neutron transmission and thus neutron based tomography/radiography is ideal to image their presence. Texture, the nonrandom orientation of crystalline grains within materials, can be mapped nondestructively using neutron diffraction methods. Epithermal neutron resonance absorption is being studied as a noncontacting temperature sensor. This paper highlights the underlying physics of the methods, progress in development, and the potential benefits for science and industry of the three facilities.

Hubbard, C.R.; Raine, D.; Peascoe, R.; Wright, M. [and others

1997-03-01

178

Application of internal friction damping as a nondestructive evaluation technique for wire rope  

SciTech Connect

This paper discusses the technical feasibility of applying internal friction damping (IFD) as a nondestructive evaluation (NDE) technique to wire rope. The paper addresses the technical feasibility, laboratory testing on wire rope, and the associated test results on various samples of wire rope. These tests were evaluated in a series of laboratory experiments by measuring the internal friction damping during which several test parameters were changed. The test parameters including the tensile load, frequency of test load, exposure time of rope to load and variations in rope construction are discussed from the standpoint of IFD-NDE measurements.

Hochrein, A.A.; Sherrard, J.R.; Thiruvengadam, A.P.

1983-05-01

179

Nondestructive Evaluation of Flaking-Resistance in Thermal Sprayed Ceramic Coatings with X-ray Diffraction Method  

Microsoft Academic Search

Thermal spraying has emerged as an important tool of increasingly sophisticated surface engineering technology. Therefore, the demand for technology that is checked non-destructively has become more insistent. This paper presents the nondestructive evaluation of fl aking-resistance in thermal sprayed Al2O3, ZrO2 and TiO2 coating. The full-width at half maximum taken from the X-ray diffraction peak profi le was used as

Toru Ito; Toshifumi Kubohori; Jyunji Morimoto

2007-01-01

180

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

PubMed

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. PMID:23020415

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

2012-09-01

181

Parallel three-dimensional acoustic and elastic wave simulation methods with applications in nondestructive evaluation  

NASA Astrophysics Data System (ADS)

In this dissertation, we present two parallelized 3D simulation techniques for three-dimensional acoustic and elastic wave propagation based on the finite integration technique. We demonstrate their usefulness in solving real-world problems with examples in the three very different areas of nondestructive evaluation, medical imaging, and security screening. More precisely, these include concealed weapons detection, periodontal ultrasography, and guided wave inspection of complex piping systems. We have employed these simulation methods to study complex wave phenomena and to develop and test a variety of signal processing and hardware configurations. Simulation results are compared to experimental measurements to confirm the accuracy of the parallel simulation methods.

Rudd, Kevin Edward

182

A DATA FUSION SYSTEM FOR THE NONDESTRUCTIVE EVALUATION OF NON-PIGGABLE PIPES  

SciTech Connect

The objectives of this research project are: (1) To design sensor data fusion algorithms that can synergistically combine defect related information from heterogeneous sensors used in gas pipeline inspection for reliably and accurately predicting the condition of the pipe-wall. (2) To develop efficient data management techniques for signals obtained during multisensor interrogation of a gas pipeline. During this reporting period, Rowan University designed, developed and exercised multisensor data fusion algorithms for identifying defect related information present in magnetic flux leakage, ultrasonic testing and thermal imaging nondestructive evaluation signatures of a test-specimen suite representative of benign and anomalous indications in gas transmission pipelines.

Shreekanth Mandayam; Robi Polikar; John C. Chen

2004-04-01

183

Ultrasonic Excitation by Phase Velocity Scanning of Laser Beam and Application to Nondestructive Evaluation  

NASA Astrophysics Data System (ADS)

It is essential for advanced nondestructive evaluation that single mode of acoustic waves be selectively generated. We have proposed the phase velocity scanning (PVS) method for this purpose. In this work, we improved the PVS method by using an acoustooptic deflector to scan a laser beam at high velocity with high repeatability. In aluminum plates, we succeeded to generate narrow-band single-mode Lamb waves, which propagated a distance more than 1.7 m. We propose to apply this method to detection of defects on large plate structures.

Watanabe, Tomokazu; Cho, Hideo; Yamanaka, Kazushi

2002-05-01

184

Destructive Inspection of Weld Defect and its Nondestructive Evaluation by Photoacoustic Microscopy  

NASA Astrophysics Data System (ADS)

In this study, the nondestructive evaluation (NDE) of an internal defect introduced in the welded region of an aluminum plate has been demonstrated by photoacoustic microscopy (PAM). The internal defect is a blowhole and an incomplete fusion, which were formed in the weld metal during welding. Experiments were carried out at different modulation frequencies. Furthermore, a stereoscopic image of the fractured specimen was obtained by destructive inspection using scanning laser microscopy (SLM) and compared with a photoacoustic (PA) amplitude image. The size of the internal weld defect measured by both methods was approximately the same.

Daijiroh Shiraishi,; Ryosuke Kato,; Haruo Endoh,; Tsutomu Hoshimiya,

2010-07-01

185

GPU based numerical modeling for eddy current non-destructive evaluation  

NASA Astrophysics Data System (ADS)

Numerical models serve an important role in eddy current non-destructive evaluation applications. The results of computational models provide meaningful insight into the underlying physics, help theoretically visualize the field/sample interaction and help optimize sensor design and assist algorithms developing for interpreting the measured signals. However, three dimensional computational models can be time consuming. This paper presents a fast and efficient GPU based numerical model for simulating eddy current testing techniques. The model, based on boundary integral method, uses novel matrix compression techniques to optimize the solver performance on GPU architectures. Validation results of model predictions for a number of sample geometries are presented.

Lei, Naiguang; Udpa, Lalita; Udpa, Satish

2013-01-01

186

Nondestructive Evaluation of Weld Defect by Photoacoustic Microscopy and Its Destructive Inspection Using Replica  

NASA Astrophysics Data System (ADS)

The nondestructive evaluation (NDE) of a surface crack and an internal defect introduced in the welded region of an aluminum plate has been demonstrated by photoacoustic microscopy. The surface crack and internal defect are a blowhole and an incomplete fusion, which were formed in the weld metal during welding. Experiments were carried out at different modulation frequencies. Furthermore, to gather information on the internal defect, the measurement of the size and shape of the weld defect was carried out by the replica technique. A stereoscopic image of the replica specimen was compared with a photoacoustic (PA) amplitude image.

Kato, Ryosuke; Endoh, Haruo; Hoshimiya, Tsutomu

2011-07-01

187

Quantitative evaluation of optical lock-in and pulsed thermography for aluminum foam material  

NASA Astrophysics Data System (ADS)

In this article, quantitative evaluation of optical thermographic techniques relative to the non-destructive inspection of aluminum foam material is studied. For this purpose, a set of aluminum foam specimens with flat-bottom holes (FBH) was inspected by both optical lock-in thermography (LT) and pulsed thermography (PT). Probability of detection (PoD) analysis, as a quantitative method to estimate the capability and reliability of a particular inspection technique, was studied and compared for both optical LT and PT inspection results.

Duan, Yuxia; Huebner, Stefanie; Hassler, Ulf; Osman, Ahmad; Ibarra-Castanedo, Clemente; Maldague, Xavier P. V.

2013-09-01

188

Nondestructive evaluation of orthopaedic implant stability in THA using highly nonlinear solitary waves  

NASA Astrophysics Data System (ADS)

We propose a new biomedical sensing technique based on highly nonlinear solitary waves to assess orthopaedic implant stability in a nondestructive and efficient manner. We assemble a granular crystal actuator consisting of a one-dimensional tightly packed array of spherical particles, to generate acoustic solitary waves. Via direct contact with the specimen, we inject acoustic solitary waves into a biomedical prosthesis, and we nondestructively evaluate the mechanical integrity of the bone-prosthesis interface, studying the properties of the waves reflected from the contact zone between the granular crystal and the implant. The granular crystal contains a piezoelectric sensor to measure the travelling solitary waves, which allows it to function also as a sensor. We perform a feasibility study using total hip arthroplasty (THA) samples made of metallic stems implanted in artificial composite femurs using polymethylmethacrylate for fixation. We first evaluate the sensitivity of the proposed granular crystal sensor to various levels of prosthesis insertion into the composite femur. Then, we impose a sequence of harsh mechanical loading on the THA samples to degrade the mechanical integrity at the stem-cement interfaces, using a femoral load simulator that simulates aggressive, accelerated physiological loading. We investigate the implant stability via the granular crystal sensor-actuator during testing. Preliminary results suggest that the reflected waves respond sensitively to the degree of implant fixation. In particular, the granular crystal sensor-actuator successfully detects implant loosening at the stem-cement interface following violent cyclic loading. This study suggests that the granular crystal sensor and actuator has the potential to detect metal-cement defects in a nondestructive manner for orthopaedic applications.

Yang, Jinkyu; Silvestro, Claudio; Sangiorgio, Sophia N.; Borkowski, Sean L.; Ebramzadeh, Edward; De Nardo, Luigi; Daraio, Chiara

2012-01-01

189

Exploratory Nondestructive Evaluation (NDE) Research for Advanced Materials and Processes. Volume 3: Interactive Multimedia Computer Based Training (IMCBT) for Nondestructive Evaluation/Inspection (NDE/I) Personnel.  

National Technical Information Service (NTIS)

Interactive Multimedia Computer Based Training (IMCBT) for Nondestructive Inspection (NDE/I) Personnel: Computer Based Training (CBT) is a highly effective method for industrial training that has been growing in popularity. Text, graphics, sound, movies a...

Bossi B. Knutson R. Nerenberg L. Deobald J. Nelson

1998-01-01

190

Assessing Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability  

SciTech Connect

A research program on primary water stress corrosion cracking (PWSCC) is being conducted by Pacific Northwest National Laboratory (PNNL). In this program, the material degradation problem in Alloys 600, 182 and 82 is being investigated, with objectives that include compiling a knowledge base on all cracking in nickel-base materials at all degradation sites in nuclear power plants, assessing nondestructive evaluation methods using mockups to quantify the detection, sizing, and characterization of tight cracks, determining the role of material parameters, such as welding processes, in the degradation. This work is being conducted as a part of an international cooperative research project that has been set up to leverage efforts in several countries to address a significant and common problem. The U.S. Nuclear Regulatory Commission is leading this cooperative project to address this generic problem in a systematic manner over the next four years. In this paper, published information on the failure history of Alloys 600, 182, and 82 is compiled and presented. The configurations of the welded assemblies that contain these alloys are shown to be important considerations for NDE reliability measurements. The product forms and the welding processes represented in the degraded components are described. The relevant data on crack morphology parameters such as shape and orientation are presented, and their impact on nondestructive evaluation (NDE) reliability is discussed.

Doctor, Steven R.; Schuster, George J.; Anderson, Michael T.

2005-12-01

191

Computer modeling of eddy current nondestructive testing  

Microsoft Academic Search

Nondestructive evaluation (NDE) is to materials what CAT scanning is to the human body--an attempt to look inside without opening up the body. As in CAT scanning, modern NDE requires sophisticated mathematical software to perform its function. This is especially true with regard to quantitative NDE, wherein an attempt is made to quantify defects, that is, determine their size, location,

H. A. Sabbagh; J. C. Treece; R. K. Murphy; Lai Wan Woo

1993-01-01

192

A Quantitative, Non-Destructive Methodology for Habitat Characterisation and Benthic Monitoring at Offshore Renewable Energy Developments  

PubMed Central

Following governments' policies to tackle global climate change, the development of offshore renewable energy sites is likely to increase substantially over coming years. All such developments interact with the seabed to some degree and so a key need exists for suitable methodology to monitor the impacts of large-scale Marine Renewable Energy Installations (MREIs). Many of these will be situated on mixed or rocky substrata, where conventional methods to characterise the habitat are unsuitable. Traditional destructive sampling is also inappropriate in conservation terms, particularly as safety zones around (MREIs) could function as Marine Protected Areas, with positive benefits for biodiversity. Here we describe a technique developed to effectively monitor the impact of MREIs and report the results of its field testing, enabling large areas to be surveyed accurately and cost-effectively. The methodology is based on a high-definition video camera, plus LED lights and laser scale markers, mounted on a “flying array” that maintains itself above the seabed grounded by a length of chain, thus causing minimal damage. Samples are taken by slow-speed tows of the gear behind a boat (200 m transects). The HD video and randomly selected frame grabs are analysed to quantify species distribution. The equipment was tested over two years in Lyme Bay, UK (25 m depth), then subsequently successfully deployed in demanding conditions at the deep (>50 m) high-energy Wave Hub site off Cornwall, UK, and a potential tidal stream energy site in Guernsey, Channel Islands (1.5 ms?1 current), the first time remote samples from such a habitat have been achieved. The next stage in the monitoring development process is described, involving the use of Remote Operated Vehicles to survey the seabed post-deployment of MREI devices. The complete methodology provides the first quantitative, relatively non-destructive method for monitoring mixed-substrate benthic communities beneath MPAs and MREIs pre- and post-device deployment.

Sheehan, Emma V.; Stevens, Timothy F.; Attrill, Martin J.

2010-01-01

193

A study of active thermography approaches for the non-destructive testing and evaluation of aerospace structures  

Microsoft Academic Search

The prerequisite for more competent and cost effective aircraft has led to the evolution of innovative testing and evaluation procedures. Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of an aircraft structure are essential to both reduce manufacturing costs and out of service time of aircraft due to maintenance. Nowadays, active - transient thermal NDT &

Nicolas P. Avdelidis; Clemente Ibarra-Castanedo; Zaira P. Marioli-Riga; Abdelhakim Bendada; Xavier P. V. Maldague

194

Quantitative method of medication system interface evaluation.  

PubMed

The objective of this study was to develop a quantitative method of evaluating the user interface for medication system software. A detailed task analysis provided a description of user goals and essential activity. A structural fault analysis was used to develop a detailed description of the system interface. Nurses experienced with use of the system under evaluation provided estimates of failure rates for each point in this simplified fault tree. Means of estimated failure rates provided quantitative data for fault analysis. Authors note that, although failures of steps in the program were frequent, participants reported numerous methods of working around these failures so that overall system failure was rare. However, frequent process failure can affect the time required for processing medications, making a system inefficient. This method of interface analysis, called Software Efficiency Evaluation and Fault Identification Method, provides quantitative information with which prototypes can be compared and problems within an interface identified. PMID:17625402

Pingenot, Alleene Anne; Shanteau, James; Pingenot, James D F

195

Nondestructive test methods for evaluating durability of concrete highway structures: experience of Ontario Ministry of Transportation  

NASA Astrophysics Data System (ADS)

There is an urgent need for fast, reliable, non-destructive test methods to measure permeability and resistivity of concrete in the field, in order to assess the performance of concrete structures and confirm the benefits of the use of new materials. The application of high performance concrete for rehabilitation of corrosion-damaged highway structures and for new bridge construction has increased in Ontario over the past few years. High performance concrete, containing supplementary cementing materials such as silica fume, typically has lower permeability and higher electrical resistivity than conventional concrete. Since 1993, the R&D staff of the Ontario Ministry of Transportation (MTO) has been evaluating various non-destructive in-situ techniques to measure the permeability and resistivity of concrete. This paper describes two methods used by MTO to measure the permeability of concrete: surface water absorption and air permeability techniques; and presents the methods used to measure the concrete electrical resistivity, chloride movement in the concrete, and corrosion activity of the embedded steel. Many of the tests were performed on both the conventional and high performance concrete. Some of these techniques can be potentially used as quality assurance tools for assessing the quality, performance and durability of concrete in the field.

Ip, Alan; Berszakiewicz, Beata; Pianca, Frank

1998-03-01

196

A nondestructive method for evaluating in vitro osteoblast differentiation on biomaterials using osteoblast-specific fluorescence.  

PubMed

Transgenic mice with a Col1a1-promoter-driven transgene pOBCol2.3GFP were previously developed to visually identify mature osteoblasts through fluorescent expression. Our goal was to determine if this technology could be used to nondestructively evaluate the in vitro differentiation of osteoprogenitor cells on biomaterials such as biomimetic carbonated hydroxyapatite (cHA). Primary osteoprogenitor cells were harvested from calvaria of neonatal Col2.3GFP transgenic mice and cultured on cHA and a tissue culture polystyrene (TCPS) control. The distribution of intensities and area percentage of green fluorescent protein (GFP)-positive cells were quantified using fluorimetry and image analysis of fluorescent microscopy. At 14 days, an increased area and higher mean intensity of GFP-positive cells was observed on cHA as compared to TCPS, indicating more rapid differentiation on cHA. Notably, there were large continuous regions of GFP-positive osteoblasts on cHA, in contrast to the sparse, nodules of osteoblasts on TCPS, implying that cHA provides an osteogenic cue to cells. Xylenol orange staining was capable of distinguishing osteoblast-initiated mineral from the cHA substrate. With this method the unique pattern of osteoblast differentiation on cHA was clearly observed for the first time. Importantly, the generalized method can be used for rapid, high-throughput, nondestructive screening of biomaterials intended to enhance osteogenic differentiation. PMID:20337515

Kuhn, Liisa T; Liu, Yongxing; Advincula, Maria; Wang, Yu-Hsiung; Maye, Peter; Goldberg, A Jon

2010-05-04

197

Measurement techniques and application of electrical properties for nondestructive quality evaluation of foods-a review.  

PubMed

Non-destructive systems are recent trends for quality evaluation of fruits and vegetables. Information on post-harvest variations in electrical properties is needed to develop new instruments for this purpose. Electrical properties are finding increasing application in agriculture and food processing industries. Knowledge of dielectric properties of foods as a function of moisture content and temperature is essential in the design and control of drying systems. As simple, rapid and non-destructive measuring techniques, dielectric spectroscopy provides information about the dielectric response of materials to electromagnetic field. Electrical properties of agricultural materials have been of interest for many years. The interest in dielectric properties of materials has historically been associated with the design of electrical equipment. This review paper covers theoretical aspects of different electrical properties, their measurement techniques, applications of dielectric properties in agriculture/food processing sector and potential applications of thermal imaging (TI) for quality and safety assessment in food processing. The values of dielectric properties of a number of products including food grains, fruits and vegetables, and meat and meat products are presented in table form. This comprehensive coverage will be useful for academic, scientific and industrial community in treating and applying the facts in developing/testing new processes and products based on electromagnetic energy application. PMID:23572764

Jha, Shyam Narayan; Narsaiah, K; Basediya, A L; Sharma, Rajiv; Jaiswal, Pranita; Kumar, Ramesh; Bhardwaj, Rishi

2011-02-18

198

A finite-element model for eddy-current nondestructive evaluation: Final report  

SciTech Connect

Eddy current nondestructive testing techniques are used widely throughout the utility industry for the early detection of defects in critical power plant components such as steam generator tubing. An important aspect of the testing procedure is the evaluation of the eddy current signals to yield information about defects in the part under test. Research effects are underway to automate this process of defect characterization and hence make it more reliable and faster than currently used techniques involving human operators. One major factor which has limited progress towards development of a viable defect characterization scheme for eddy current testing has been the lack of a general mathematical model capable of predicting the complex electromagnetic field/defect interactions in the part under test. A major objective of this research project has been to develop finite element computer code capable of modeling eddy current NDT phenomena of interest to the utilities. Results of numerical studies are described in this report which clearly show the viability of the finite element technique as a general purpose mathematical model, capable of predicting eddy current probe signals from realistic nondestructive testing situations. 43 refs., 47 figs., 5 tabs.

Lord, W.

1989-06-01

199

First-year evaluation of a nondestructive assay system for the examination of ORNL TRU waste  

SciTech Connect

The Oak Ridge National Laboratory has been selected as the demonstration site for a new transuranic neutron assay system (NAS) developed at the Los Alamos National Laboratory. In addition, in order to meet specific ORNL program objectives, an upgraded segmented gamma-ray drum scanner has been integrated into the nondestructive assay (NDA) system to serve as a radioisotope identifier and as a quantitative assay backup to the NAS. A verification study, wherein selected waste drums will be emptied into glove boxes and their contents sampled and subsequently gamma-ray assayed, will take place in FY 1984. Results will be compared to those obtained from the NDA techniques. The NAS uses pulsed-neutron interrogation (differential- dieaway technique) and passive neutron measurements to determine fissile component and an upper-limit estimate of the total TRU activity contained in each waste drum. Of the 171 waste drums assayed to date, nine drums were determined to contain less than 10 nCi/g TRU isotopes. An additional number of drums (approximately 20%) are expected to be categorized as non-TRU, which is presently defined as less than 100 nCi/g TRU concentration. This requires a detailed analysis of the data which includes waste matrix compensation, systematic qualitative and quantitative gamma-ray analyses, and interpretation of neutron multiplicity data. Reproducibility of the active assay measurements on a single waste drum indicate agreement to +-3% relative error. 14 references, 24 figures, 8 tables.

Schultz, F.J.; Haff, K.W.; Coffey, D.E.; Norris, L.B.; Caldwell, J.T.; Close, D.A.; Kuckertz, T.H.; Kunz, W.E.; Pratt, J.C.

1984-04-01

200

Application of internal friction nondestructive evaluation technique for wire ropes used in mining operations  

SciTech Connect

This report discusses the work done, and results obtained, in a program conducted to determine the feasibility of applying the Internal Friction Damping - Nondestructive Evaluation (IFD-NDE) technique to wire rope. Samples of wire rope were evaluated in laboratory experiments by measuring the internal friction damping while varying several test parameters. These parameters included tensile load, frequency of test, time under load and others. The report includes discussion of wire rope mechanics and application history of NDE. Also included are sections detailing IFD-NDE theory, experimental apparatus, and test technique. The data obtained in the program work is reviewed with several results and conclusions drawn. The report closes with recommendations for further work.

Olver, L.; Brasfield, R.G.; Yeager, L.L.; Thiruvengadam, A.P.

1980-05-01

201

Modified nondestructive colorimetric method to evaluate the variability of oxygen diffusion rate through wine bottle closures.  

PubMed

Some modifications to a previous nondestructive colorimetric method that permits evaluation of the oxygen diffusion rate through wine closures were proposed. The method is based on the reaction of indigo carmine solution with oxygen and the tristimulus measurement of the consequent color change. Simplified preparation and measurement procedures were set up, allowing the analysis of a large number of samples simultaneously. The method was applied to the evaluation of the variability within the lot of 20 different types of stoppers (synthetic, produced by molding, and natural cork). The closures were tested at a storage temperature of 26 degrees C. With regard to oxygen permeability, the natural cork stopper showed a low homogeneity within the lot, especially during the first month after bottling, whereas the synthetic closure showed a greater steadiness in the performance. The limits of the colorimetric method were also analyzed, and three possible causes of degradation of the indigo carmine solution were identified: oxygen, light, and heat. PMID:20187636

Brotto, Laura; Battistutta, Franco; Tat, Lara; Comuzzo, Piergiorgio; Zironi, Roberto

2010-03-24

202

Experimental and numerical studies for nondestructive evaluation of human enamel using laser ultrasonic technique.  

PubMed

In this paper, a nondestructive laser ultrasonic technique is used to generate and detect broadband surface acoustic waves (SAWs) on human teeth with different demineralization treatment. A scanning laser line-source technique is used to generate a series of SAW signals for obtaining the dispersion spectrum through a two-dimensional fast Fourier translation method. The experimental dispersion curves of SAWs are studied for evaluating the elastic properties of the sound tooth and carious tooth. The propagation and dispersion of SAWs in human teeth are also been studied using the finite element method. Results from numerical simulation and experiment are compared and discussed, and the elastic properties of teeth with different conditions are evaluated by combining the simulation and experimental results. PMID:24085203

Sun, Kaihua; Yuan, Ling; Shen, Zhonghua; Zhu, Qingping; Lu, Jian; Ni, Xiaowu

2013-10-01

203

Aerostructure Nondestructive Evaluation by Thermal Field Detection. Phase I. Fundamental Information and Basic Technique Development.  

National Technical Information Service (NTIS)

This report describes the results of efforts to evaluate and develop methods of flaw detection in laminated fiber composite aerovehicle structures using infrared radiation detection techniques. While not exhibiting the quantitative detection capabilities ...

P. V. McLaughlin E. V. McAssey V. R. Emany D. N. Koert J. M. Spitzer

1982-01-01

204

A DATA FUSION SYSTEM FOR THE NONDESTRUCTIVE EVALUATION OF NON-PIGGABLE PIPES  

SciTech Connect

The objectives of this research project are: (1) To design sensor data fusion algorithms that can synergistically combine defect related information from heterogeneous sensors used in gas pipeline inspection for reliably and accurately predicting the condition of the pipe-wall. (2) To develop efficient data management techniques for signals obtained during multisensor interrogation of a gas pipeline. During this reporting period, Rowan University fabricated test specimens with simulated defects for nondestructive evaluation (NDE); designed and developed two versions of a test platform for performing multi-sensor interrogation of test specimens under loaded conditions simulating pressurized gas pipelines; and performed acoustic emission (AE) NDE on the test specimens. The data resulting from this work will be employed for designing multi-sensor data fusion algorithms during the next reporting period.

Dr. Shreekanth Mandayam; Dr. Robi Polikar; Dr. John C. Chen

2003-06-01

205

Nondestructive evaluation of braided carbon fiber composites with artificial defect using HTS-SQUID gradiometer  

NASA Astrophysics Data System (ADS)

Braided carbon fiber reinforced plastics (CFRPs) are one of multifunctional materials with superior properties such as mechanical strength to normal CFRPs since the braided CFRPs have continuous fiber bundles. In this paper, we applied the current-injection-based nondestructive evaluation (NDE) method using a HTS-SQUID gradiometer to the braided CFRP for the detection of the breakage of the bundles. We prepared planar braided CFRP samples with and without artificial cracks of 1 and 2 mm lengths, and measured the current density distribution above the samples using the NDE method. In the measurement results, not only a few completely-cut bundles but also the additional partially-cut bundles were detected from decrease in the measured current density along the cut bundle around the cracks. From these results, we showed that it is possible to inspect a few partially-cut bundles in the braided CFRPs by the NDE method.

Shinyama, Y.; Yamaji, T.; Hatsukade, Y.; Takai, Y.; Aly-Hassan, M. S.; Nakai, A.; Hamada, H.; Tanaka, S.

2011-11-01

206

Neural network-based inversion algorithms in magnetic flux leakage nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Magnetic flux leakage (MFL) methods are commonly used in the nondestructive evaluation (NDE) of ferromagnetic materials. An important problem in MFL NDE is the determination of flaw parameters such as the flaw length, depth, and shape (profile) from the measured values of the flux density B. Commonly used methods use a forward model in a loop to determine B for a given set of flaw parameters. This approach iteratively adjusts the flaw parameters to minimize the error between the measured and predicted values of B. This article proposes the use of neural networks as forward models. The proposed approach uses two neural networks in feedback configuration-a forward network and an inverse network. The second network is used to predict the profile given the measured value of B, and acts to constrain the solution space. Results of applying these methods to MFL data obtained from a two-dimensional finite-element model, with rectangular flaws of various dimensions, are presented.

Ramuhalli, Pradeep; Udpa, Lalita; Udpa, Satish S.

2003-05-01

207

Nondestructive evaluation and characterization of damage and repair to continuous-fiber ceramic composite panels.  

SciTech Connect

Continuous fiber ceramic matrix composites are currently being developed for a variety of high-temperature applications. Because of the high costs of making these components, minor damage incurred during manufacturing or operation must be rewired in order to extend the life of the components. In this study, five ceramic-grade Nicalon{trademark} fiber/SiNC-matrix composite panels were intentionally damaged with a pendulum-type impactor during an impact test. The damaged panels were then repaired at Dow Corning Corporation. Three nondestructive evaluation (NDE) methods were used to study the characteristics of the panels after the damage and again after the panels were repaired. The NDE methods were X-ray radiography, infrared thermal imaging, and air-coupled ultrasound. The results showed that the impact test induced various types of damage in the panels. The NDE data that were obtained by the three NDE methods were correlated with each other.

Sun, J. G.; Petrak, D. R.; Pillai, T. A. K.; Deemer, C.; Ellingson, W. A.

1998-04-01

208

Nondestructive evaluation of junction effects in GaAs avalanche photoconductors  

NASA Astrophysics Data System (ADS)

We have studied the current-voltage-temperature response of off-state NIN GaAs Avalanche Photoconductors. These non-destructive tests, evaluated in terms of thermal activation energies (Ea), and Resistance-Voltage (R-V) characteristics, are found to effectively distinguish between two types of devices. The first type possesses Ea < Egap/2 and resistivity commensurate with bulk SI GaAs; the second demonstrates Ea > Egap/s and R values greatly surpassing those of bulk Semi-Insulating GaAs. These data are consistent with junction effects at both contact-bulk interfaces, arising from the formation of an uncompensated P-type region near the N+ contact layer. We explain the P-type behavior by trapped electron neutralization of the deep compensating donor EL2.

Herman, Michael H.; Positeri, Kenneth M.; Ahern, S. M.; Lewis, Robert A.

1992-05-01

209

PREDICTION OF DISSOLVER LIFETIMES THROUGH NON-DESTRUCTIVE EVALUATION AND LABORATORY TESTING  

SciTech Connect

Non-destructive evaluation was used as the primary method of monitoring the corrosion degradation of nuclear material dissolvers and assessing the remaining lifetimes. Materials were typically processed in nitric acid based (4-14M) solutions containing fluoride concentrations less than 0.2 M. The primary corrosion issue for the stainless steel dissolvers is the occurrence of localized corrosion near the tank bottom and the heat affected zones of the welds. Laboratory data for a range of operational conditions, including solution chemistry and temperature, was used to assess the impact of processing changes on the dissolver corrosion rate. Experimental and NDE-based general corrosion rates were found to be in reasonable agreement for standard dissolution chemistries consisting of nitric acid with fluorides and at temperatures less than 95 C. Greater differences were observed when chloride was present as an impurity and temperatures exceeded 100 C.

Mickalonis, J.; Woodsmall, T.; Hinz, W.; Edwards, T.

2011-10-03

210

A DATA FUSION SYSTEM FOR THE NONDESTRUCTIVE EVALUATION OF NON-PIGGABLE PIPES  

SciTech Connect

The objectives of this research project are: (1) To design sensor data fusion algorithms that can synergistically combine defect related information from heterogeneous sensors used in gas pipeline inspection for reliably and accurately predicting the condition of the pipe-wall. (2) To develop efficient data management techniques for signals obtained during multisensor interrogation of a gas pipeline. During this reporting period, Rowan University designed, developed and exercised multisensor data fusion algorithms for identifying defect related information present in magnetic flux leakage, ultrasonic testing, thermal imaging and acoustic emission nondestructive evaluation signatures of a test-specimen suite representative of benign and anomalous indications in gas transmission pipelines. Specifically, the algorithms presented in the earlier reports were augmented to predict information related to defect depth (severity).

Shreekanth Mandayam; Robi Polikar; John C. Chen

2005-02-01

211

System and method for non-destructive evaluation of surface characteristics of a magnetic material  

DOEpatents

A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.

Jiles, David C. (Ames, IA); Sipahi, Levent B. (Ames, IA)

1994-05-17

212

Robotic 3D SQUID imaging system for practical nondestructive evaluation applications  

NASA Astrophysics Data System (ADS)

A robotic three-dimensional (3D) scanning superconducting quantum interference device (SQUID) imaging system was developed for practical nondestructive evaluation (NDE) applications. The major feature of this SQUID NDE system is that the SQUID sensor itself scans in 3D by traveling over the surface of an object during testing without the need for magnetic shielding. This imaging system consists of (i) DC-SQUID gradiometer for effective movement of the sensor, (ii) SQUID sensor manipulator utilizing an articulated-type robot used in industry, (iii) laser charge-coupled-device (CCD) displacement sensor to measure the 3D coordinates of points on the surface of the object, and (iv) computer-aided numerical interpolation scheme for 3D surface reconstruction of the object. The applicability of this system for NDE was demonstrated by successfully detecting artificial damage of cylindrical-shaped steel tubes.

Isawa, K.; Nakayama, S.; Ikeda, M.; Takagi, S.; Tosaka, S.; Kasai, N.

2005-11-01

213

Performance evaluation of a gamma-ray imaging system for nondestructive testing of welded pipes  

NASA Astrophysics Data System (ADS)

As a continuation of our radiographic testing (RT) R&D, we have developed a gamma-ray imaging system to be suitable for nondestructive testing of welded pipes. The system consists of an imaging detector having a CdTe/CMOS-based pixel array (AJAT, SCAN1000), a collimated 75Se gamma source having about 78.7 Ci activities, a gear track mounted around test pipes for image scan, and a computer-controlled microstep motor for precise control of the scan speed. All the components of the imaging system were assembled tightly by a chain belt. From the imaging system, we obtained useful gamma images of a stainless steel pipe (30 cm in internal diameter and 1 cm in thickness) having a weld line. Using standard techniques for evaluation of the radiography quality, we assessed the imaging characteristics of the detector in terms of the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE).

Cho, H. S.; Oh, J. E.; Choi, S. I.; Cho, H. M.; Park, Y. O.; Hong, D. K.; Lee, M. S.; Yang, Y. J.; Je, U. K.; Kim, D. S.; Woo, T. H.; Lee, B. S.; Lee, H. K.

2011-10-01

214

Quantitative evaluation of angular defects by pulsed eddy current thermography  

Microsoft Academic Search

Pulsed eddy current (PEC) thermography employs a combination of PEC and thermographic non-destructive testing (NDT) techniques. This study considers the capabilities of PEC thermography for obtaining quantitative information about cracks set at an angle to the surface. The investigation is implemented by simulating the transient thermal distribution for angular slots, via time-stepping 3D finite element analysis (FEA), with the experimental

Ilham Zainal Abidin; Gui Yun Tian; John Wilson; Suixian Yang; Darryl Almond

2010-01-01

215

Nondestructive evaluation of the severity of discontinuities in flat conductive materials by an eddy-current transducer with orthogonal coils  

Microsoft Academic Search

This work presents two methods for nondestructive evaluation of the severity of material discontinuities in nonmagnetic conductive plates by eddy currents generated by a transducer with orthogonal coils. The first method deals with long rectilinear discontinuities located beneath the surface under test and having a negligible width. It is based on the geometrical theory of diffraction of electromagnetic waves generated

R. Grimberg; A. Savin; E. Radu; O. Mihalache

2000-01-01

216

Resonant Ultrasound Spectroscopy, as Applied to Nondestructive Evaluation and Characterization of Carbon Fiber Reinforced Epoxy Composite Materials  

Microsoft Academic Search

Resonant ultrasound spectroscopy (RUS) can be an elegantly simple nondestructive evaluation tool. The resonance spectrum of any specimen is dependent on, and sensitive at ppm levels to, its density, geometry, elastic and thermal properties, and boundary conditions. The measurement of spectrum is fast, taking between 15 and 90 seconds with state-of-the-art instrumentation, making it appropriate for following properties as a

Timothy Marvin Whitney

1996-01-01

217

NDE (nondestructive evaluation) and fracture studies of hot-pressed Si/sub 3/N/sub 4/  

SciTech Connect

This paper presents recent correlations of nondestructive evaluation (NDE) and fractography results to establish the relative effectiveness of various NDE techniques in detecting and identifying failure-causing flaws in hot-pressed Si/sub 3/N/sub 4/. Ultrasonic and low-kV x-ray data are compared with fractography results by means of digital image-processing techniques.

Roberts, R.A.; Singh, J.P.; Vaitekunas, J.J.

1987-02-01

218

Unshielded use of thin-film Nb dc superconducting quantum interference devices and integrated asymmetric gradiometers for nondestructive evaluation  

Microsoft Academic Search

Novel nondestructive evaluation measurements made using niobium dc superconducting quantum interference devices with integrated asymmetric first-order gradiometers are described. Comparative theoretical and experimental studies of their spatial response have been described, and it is shown that the gradiometric response makes operation possible in an unshielded and electromagnetically noisy environment. As a demonstration of their capabilities, subsurface defects in a multilayer

M. E. Walker; H. Nakane; A. Cochran; R. G. Weston; U. Klein; C. M. Pegrum; G. B. Donaldson

1997-01-01

219

Nondestructive evaluation of chicken-egg freshness based on its optical properties  

NASA Astrophysics Data System (ADS)

Evaluation of internal quality is very indispensable in storing, circulating and processing of chicken-egg. The potential of the UV/VIS (200-1000nm) transmittance method to evaluate the freshness of intact chicken egg was examined. A total of 350 chicken-eggs were tested and one of 200 eggs were used to spectral measurement in the tracing test. The transmittance spectral characteristics of intact egg were also investigated. The correlation models between transmittance versus wavelengths and the storing time, freshness index (Haugh Unit and Yolk coefficient) and the storing time were established by linear regression analysis of SPSS10.0. The correlation coefficients were 0.86, 0.94, 0.99 and 0.98 respectively. The sensitive wavelength used to evaluate freshness was also found at 465nm and the correlation model between transmittance and freshness was built. The test results show that: Nondestructive evaluation freshness by transmittance properties is feasible in the range of 400 -600nm, while it is impossible to evaluate egg freshness in the range of 200-400nm owing to the low transmittance.

Liu, Yande; Ying, Yibin; Ouyang, Aigou; Qiao, Zhenxian

2004-03-01

220

Direct, non-destructive quantitative measurement of an active pharmaceutical ingredient in an intact capsule formulation using Raman spectroscopy  

Microsoft Academic Search

The active pharmaceutical ingredient (ambroxol) in an intact capsule formulation has been non-destructively quantified using Raman spectroscopy. To improve the problem of insufficient representive sampling inherent in Raman measurements, we have employed a wide area illumination (WAI) scheme that enables much improved sample coverage through a circular excitation laser spot with a 6mm diameter. One of the anticipated sources of

Jaejin Kim; Jaegeun Noh; Hoeil Chung; Young-Ah Woo; Mark S. Kemper; Youngil Lee

2007-01-01

221

Infrared thermography non-destructive evaluation of lithium-ion battery  

NASA Astrophysics Data System (ADS)

The power lithium-ion battery with its high specific energy, high theoretical capacity and good cycle-life is a prime candidate as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Safety is especially important for large-scale lithium-ion batteries, especially the thermal analysis is essential for their development and design. Thermal modeling is an effective way to understand the thermal behavior of the lithium-ion battery during charging and discharging. With the charging and discharging, the internal heat generation of the lithium-ion battery becomes large, and the temperature rises leading to an uneven temperature distribution induces partial degradation. Infrared (IR) Non-destructive Evaluation (NDE) has been well developed for decades years in materials, structures, and aircraft. Most thermographic methods need thermal excitation to the measurement structures. In NDE of battery, the thermal excitation is the heat generated from carbon and cobalt electrodes in electrolyte. A technique named "power function" has been developed to determine the heat by chemical reactions. In this paper, the simulations of the transient response of the temperature distribution in the lithium-ion battery are developed. The key to resolving the security problem lies in the thermal controlling, including the heat generation and the internal and external heat transfer. Therefore, three-dimensional modelling for capturing geometrical thermal effects on battery thermal abuse behaviour is required. The simulation model contains the heat generation during electrolyte decomposition and electrical resistance component. Oven tests are simulated by three-dimensional model and the discharge test preformed by test system. Infrared thermography of discharge is recorded in order to analyze the security of the lithium-ion power battery. Nondestructive detection is performed for thermal abuse analysis and discharge analysis.

Wang, Zi-Jun; Li, Zhi-Qiang; Liu, Qiang

2011-06-01

222

A first evaluation of the usefulness of feathers of nestling predatory birds for non-destructive biomonitoring of persistent organic pollutants  

Microsoft Academic Search

In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway:

Igor Eulaers; Adrian Covaci; Dorte Herzke; Marcel Eens; Christian Sonne; Truls Moum; Lisbeth Schnug; Sveinn Are Hanssen; Trond Vidar Johnsen; Jan Ove Bustnes; Veerle L. B. Jaspers

2011-01-01

223

Nondestructive evaluation of fatigue damage in aluminum 2024 by x-ray diffraction  

NASA Astrophysics Data System (ADS)

Aluminum alloys are widely used in the automobile and aerospace industries. This is due to their attractive low density-high modulus and low density-high strength characteristics. Unfortunately, cyclic stress-strain deformations alter the microstructure of aluminum alloys when they are placed into service. These structural changes can lead to fatigue damage and ultimately service failure. Since x-ray diffraction analysis is known to be a sensitive nondestructive indicator of structural changes due to deformations, this technique is being used to evaluate changes in the microstructure of cycled aluminum 2024 commercial alloys. Line shapes, widths, and positions in an x-ray diffraction pattern depend on microstructural properties such as grain size, grain orientation, residual stress, microstrain, etc. Changes in the microstructure due to fatigue will appear as changes in the diffraction pattern. One parameter used to characterize a reflection in a diffraction pattern is the full width at half maximum (FWHM). Preliminary x-ray diffraction results on cycled Al 2024 indicate that the (111) and (222) reflections of the matrix phase do not show any variations in the FWHM due to an increase in the fatigue cycles. However, the FWHM of the (200) and (400) reflections of the same phase unexpectedly showed a dramatic decrease. These results can be interpreted as due to the relaxation of some initial nonuniform residual stresses in the matrix phase lattice. Further work is in progress to evaluate the FWHM of the second phase of the cycled alloys.

Ferguson, Milton W.

1994-12-01

224

Nondestructive method of evaluating adhesive bond strength in fiberglass reinforced plastic assemblies  

SciTech Connect

An instrument for testing of adhesive bond strength on plastic components, assembled by lap joint glueing, is described. Composite materials bonded joints may be thus inspected by a probe with screen readouts. Quantitative evaluation for shear strength can be accomplished by a simple inspection procedure. 6 refs.

Chapman, G.B. II

1981-01-01

225

Pulsed Bremsstrahlung Interrogation with Photoneutron - Gamma-Ray Spectrometry for Nondestructive Evaluation  

NASA Astrophysics Data System (ADS)

A novel photoneutron-based nondestructive evaluation (NDE) technique which does not require a radioactive neutron source is presented. Some unique features of this technique include: 1) pulsed interrogation neutron production within, or very near, an inspected object, 2) spectrum tailoring of the source neutrons, and 3) compatibility with many existing high-energy, commercial x-ray inspection devices. Basic concept feasibility was first established by numerical methods. The pulsed photoneutron inspection technique performs nondestructive elemental analysis using gamma-ray spectrometry. Highly penetrating bremsstrahlung photons are produced by a pulsed electron accelerator capable of producing up to 16-MeV electrons. The photoneutrons are generated by the bremsstrahlung photons interacting with an inspected object and near-by beryllium metal. The interactions of the neutrons within an inspected item result in the emission of elemental characteristic gamma-rays. Spectrometry is performed by analyzing the gamma -rays acquired between accelerator pulses. A unique fast detection and acquisition system, using two 5.08 x 5.08 -cm organic scintillators, acquires gamma-ray emissions within 100 ns of each accelerator pulse. The fast system is capable of processing individual gamma-ray signals at count rates up to 40 MHz between accelerator pulses with a repetition rate up to 1 kHz. The system incorporates a unique x-ray flash recovery method which allows individual gamma-ray detection as soon as 75 ns after the start of each x-ray flash occurring within the detector. Conventional detection and data acquisition systems are used to acquire gamma-ray spectra for the time period between 1000 ns and the next accelerator pulse. Operational tests using a 30-ps pulse width, electron accelerator demonstrated the x-ray flash recovery methodology, gamma-ray detection, and data acquisition. Although, gamma -ray spectrometry performance was limited by x-ray flash -induced gain shifts in the photomultiplier tubes, the basic NDE concept was successfully demonstrated using a modified high-purity germanium detection system.

Jones, James Litton

226

Nondestructive evaluation for crack, corrosion, and stress detection for metal assemblies and structures  

NASA Astrophysics Data System (ADS)

Magneto-optic imaging based upon Faraday rotation of polarized light has been successfully applied to the problem of non-destructive testing of cracks, stress fractures, corrosion, and other surface and subsurface defects in both ferromagnetic nd nonmagnetic metal structures. Some of these applications have been successfully applied to aircraft fuselage and wing structural examination, as well as to the inspection of tanks and other low-accessibility containers. There are significant needs and opportunities for improving upon the accuracy, sensitivity, portability, and automation of such non-destructive evaluation, particularly for aircraft which are by virtue of age, design, or condition subject to dangerous metal fatigue developments in between scheduled examination. There has been a need for improvement in the basic magneto-optic sensing technology as well as in the image processing of data gathered from the sensor, and in the refinement of crack and corrosion recognition algorithms and methods that can enhance automated and assisted recognition. The current research and development program in non-destructive testing applications at MODIS Corporation has developed several innovations within these areas that enable wider application of magneto-optic imaging. These include new Fe-Ga based thin-film technology resulting in (R, Bi)3(Fe, Ga)5O12 wafers that are demonstratably more sensitive to low-strength magnetic fields. These films contain (Y, Lu, Bi)3 (Fe, Ga)5O12 composition, grown on a transparent single- crystalline substrate of Gd3 Ga5 O12 composition. Other more sensitive films and substrates have been developed as well. These films have uniaxial anisotropy due to crystallographic orientation, although with orientation films can be customized for more spatial resolution and sensitivity due to the almost uniformly planar anisotropy. The MODE sensor technology is incorporated into a modular scanning apparatus that enables the operation of several modes of inspection using replaceable video or digital still camera devices as well as variable optics for magnification. Instead of relying upon tradition eddy current technology for introducing measurable magnetic fields in the sample object being examined, the MODIS apparatus operates with a high-current, micro-burst application to the test surface. The sensitivity of the MODE Fe-Ga wafers has been demonstrated in laboratory experiments to operate with magnetic fields that are weaker than those produced by long-duration high-current eddy currents such as are presently being used in NDT applications. The coupling of higher magneto-optic sensitivity plus a reduction in the eddy current generation and heat dissipation opens a path to a number of variations and extensions of magneto-optic NDT. Algorithms and software developed by MODIS and partners for processing and analysis of the scanner output images reside on a Windows 95/NT computer and are compatible with body- wearable PC systems to enable completely hands-free, mobile inspection and data collection. The recognition algorithm are based upon standard digital image processing and neural network pattern recognition that has been successfully applied in other applications.

Dudziak, Martin J.; Chervonenkis, Andre Y.; Chinarov, Vladimir

1999-01-01

227

Non-Destructive Evaluation of Wind Turbine Blades Using an Infrared Camera  

SciTech Connect

The use of a digital infrared as a non-destructive evaluation thermography camera (NDE) tool was ex- plored in two separate wind turbine blade fatigue tests. The fwst test was a fatigue test of part of a 13.1 meter wood-epoxy-composite blade. The second test was on a 4.25 meter pultruded fiber glass blade section driven at several mechanical resonant frequencies. The digital infrared camera can produce images of either the static temperature distribution on the surface of the specimen, or the dynamic temperature distribution that is in phase with a specific frequency on a vibrating specimen. The dynamic temperature distribution (due to thermoplastic effects) gives a measure of the sum of the principal stresses at each point on the surface. In the wood- epoxy-composite blade fatigue test, the point of ultimate failure was detected long before failure occurred. The mode shapes obtained with the digital infrared camera, from the resonant blade tests, were in very good agree- ment with the finite-element calculations. In addition, the static temperature images of the resonating blade showed two areas that contained cracks. Close-up dy- namic inf%red images of these areas showed the crack structure that agreed with subsequent dye-penetrant analysis.

Beattie, A.G.; Rumsey, M.

1998-12-17

228

Stochastic-integral models for propagation-of-uncertainty problems in nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Generalized polynomical chaos (gPC), the probabilistic collocation method (PCM), and analysis of variance (ANOVA) are finding considerable application to problems of interest to engineers in which random parameters are an essential feature of the mathematical model. So far the applications have been mainly to stochastic partial differential equations, but we extend the method to volume-integral equations, which have met great success in electromagnetic nondestructive evaluation (NDE), especially with eddy-currents. The problems of main interest to the NDE community in this connection are concerned with the issue of `propagation of uncertainty' when the relevant parameters are not well characterized, or are known simply as random variables. We demonstrate the ideas by considering a metallic surface that has undergone a shot-peening treatment to reduce residual stresses, and has, therefore, become a random conductivity field. In particular, we show how ANOVA becomes a very promising method for high-dimensional model representation (HDMR) when there are a large number of random variables present in the problem.

Sabbagh, Elias H.; Murphy, R. Kim; Sabbagh, Harold A.; Aldrin, John C.; Knopp, Jeremy; Blodgett, Mark P.

2013-01-01

229

Phase-contrast x-ray imaging for nondestructive evaluation of materials  

SciTech Connect

Phase-contrast x-ray imaging has been studied intensively in the past, mainly with applications to low density biological materials. In this work experimental and theoretical aspects of phase-contrast microfocus x-ray imaging of structural materials (metals and polymers) are considered. The diffraction field in an object from a point x-ray source is simulated and the effects of geometrical and material parameters on the x-ray phase-contrast image are obtained. It is shown that higher-order terms should be retained in the asymptotic expansion of the Green function in the image plane to accurately image discontinuities in structural materials. Experimental phase-contrast images of small defects are obtained with a 5 {mu}m microfocal x-ray source and compared with those from computer simulation as a function of geometrical magnification and photon energy. The phase-contrast x-ray imaging provides enhanced image contrast and improved edge definition and is important for further development of nondestructive evaluation of structural materials.

Zoofan, B.; Kim, J.-Y.; Rokhlin, S. I.; Frankel, G. S. [Nondestructive Evaluation Program, Edison Joining Technology Center, Ohio State University, Columbus, Ohio 43221 (United States); Fontana Corrosion Center, Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2006-07-01

230

Evaluation of scanners for C-scan imaging in nondestructive inspection of aircraft  

SciTech Connect

The goal of this project was to produce a document that contains information on the usability and performance of commercially available, fieldable, and portable scanner systems as they apply to aircraft NDI inspections. In particular, the scanners are used to generate images of eddy current, ultrasonic, or bond tester inspection data. The scanner designs include manual scanners, semiautomated scanners, and fully automated scanners. A brief description of the functionality of each scanner type, a sketch, and a fist of the companies that support the particular design are provided. Vendors of each scanner type provided hands-on demonstrations of their equipment on real aircraft samples in the FAA Aging Aircraft Nondestructive Inspection Validation Center (AANC) in Albuquerque, NM. From evaluations recorded during the demonstrations, a matrix of scanner features and factors and ranking of the capabilities and limitations of the design, portability, articulation, performance, usability, and computer hardware/software was constructed to provide a quick reference for comparing the different scanner types. Illustrations of C-scan images obtained during the demonstration are shown.

Gieske, J.H.

1994-04-01

231

Laser Doppler technique for nondestructive evaluation of mechanical heart valves kinematics  

NASA Astrophysics Data System (ADS)

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.

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

2004-06-01

232

An examination of nondestructive evaluation techniques for polymer matrix composite sandwich materials  

NASA Astrophysics Data System (ADS)

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 were examined with multiple NDE techniques including thermographic, radiographic, and laser based methods to investigate the manufactured condition of blades and damage induced from play. Hockey blades in an as received condition and damaged blades used in play were investigated with each technique. NDE images from the blades 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. With shearography, structural elements, damaged regions, and other material variations were detected in the hockey blades. Each technique's advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

Cosgriff, Laura M.; Roberts, Gary D.; Averbeck, Timothy; Jeanneau, Philippe; Quddus, Michael

2006-04-01

233

Emission and detection of terahertz radiation using two dimensional plasmons in semiconductor nano-heterostructures for nondestructive evaluations  

NASA Astrophysics Data System (ADS)

This paper reviews recent advances in emission and detection of terahertz radiation using two dimensional (2D) plasmons in semiconductor nano-heterostructures for nondestructive evaluations. The 2D plasmon resonance is introduced as the operation principle for broadband emission and detection of terahertz radiation. The device structure is based on a high-electron mobility transistor and incorporates the authors' original asymmetrically interdigitated dual grating gates. Excellent terahertz emission and detection performances are experimentally demonstrated by using InAlAs/InGaAs/InP and/or InGaP/InGaAs/GaAs heterostructure material systems. Their applications to nondestructive material evaluation based on terahertz imaging are also presented.

Otsuji, Taiichi; Watanabe, Takayuki; Boubanga Tombet, Stephane Albon; Satou, Akira; Ryzhii, Victor; Popov, Vyacheslav; Knap, Wojciech

2013-05-01

234

A comparison of traditional and emerging ultrasonic methods for the nondestructive evaluation of polymer matrix composites subjected to impact damage  

Microsoft Academic Search

This paper presents the results of a comparison study of three ultrasonic nondestructive evaluation (NDE) methods applied to polymer matrix composite (PMC) specimens subjected to impact damage. Samples mainly consisted of various thicknesses of graphite\\/epoxy coupon panels impacted with various energy levels. Traditional pulse-echo and through transmission ultrasonic c-scan techniques were applied to impacted samples and served as the basis

Richard E. Martin; Donald J. Roth; Charles G. Pergantis; Jaswinder S. Sandhu

2004-01-01

235

Non-destructive evaluation of smart materials by using extrinsic Fabry–Perot interferometric and fiber Bragg grating sensors  

Microsoft Academic Search

The real-time non-destructive evaluation (NDE) technologies of engineering structures are very important to assess the performance of in-service structures. It is very difficult to carry out the on-line structural integrity monitoring by using classical NDE methods. Fiber optic sensors in smart structures provide a unique opportunity to real-time monitor the structural health status by using embedded sensors. This paper examines

J. S Leng; A Asundi

2002-01-01

236

Autonomous corrosion detection in gas pipelines: a hybrid-fuzzy classifier approach using ultrasonic nondestructive evaluation protocols  

Microsoft Academic Search

In this paper, a customized classifier is presented for the industry-practiced nondestructive evaluation (NDE) protocols using a hybrid-fuzzy inference system (FIS) to classify the corrosion and distinguish it from the geometric defects or normal\\/healthy state of the steel pipes used in the gas\\/petroleum industry. The presented system is hybrid in the sense that it utilizes both soft computing through fuzzy

U. A. Qidwai

2009-01-01

237

Quantitative evaluation of normal muscle tone.  

PubMed

Forty-eight normal subjects were evaluated for the purpose of objectively quantifying muscle tone. Flexor carpi radialis and extensor digitorum communis electromyographic (EMG) activity was simultaneously recorded during wrist movements imposed by a torque motor. Each session was subdivided into three steps: (1) measurement of the 'intrinsic stiffness index' (ISI) at 10 degrees/s; (2) measurement of the 'total stiffness index' (TSI) at 500 degrees/s; (3) evaluation of the stretch reflex threshold speed (SRTS). No stretch reflex (SR) was found in about half of the subjects, even at the highest speed. ISI was higher in males (p < 0.001); significant differences in TSI were found between subjects with SR and those without (p < 0.02); no statistical differences in SRTS were found for either age or gender. ISI, TSI and SRTS, appear to be reliable indices of the range of normal muscle tone for its quantitative assessment. PMID:8867074

Pisano, F; Miscio, G; Colombo, R; Pinelli, P

1996-02-01

238

APNEA/WIT system nondestructive assay capability evaluation plan for select accessibly stored INEL RWMC waste forms  

SciTech Connect

Bio-Imaging Research Inc. (BIR) and Lockheed Martin Speciality Components (LMSC) are engaged in a Program Research and Development Agreement and a Rapid Commercialization Initiative with the Department of Energy, EM-50. The agreement required BIR and LMSC to develop a data interpretation method that merges nondestructive assay and nondestructive examination (NDA/NDE) data and information sufficient to establish compliance with applicable National TRU Program (Program) waste characterization requirements and associated quality assurance performance criteria. This effort required an objective demonstration of the BIR and LMSC waste characterization systems in their standalone and integrated configurations. The goal of the test plan is to provide a mechanism from which evidence can be derived to substantiate nondestructive assay capability and utility statement for the BIT and LMSC systems. The plan must provide for the acquisition, compilation, and reporting of performance data thereby allowing external independent agencies a basis for an objective evaluation of the standalone BIR and LMSC measurement systems, WIT and APNEA respectively, as well as an expected performance resulting from appropriate integration of the two systems. The evaluation is to be structured such that a statement regarding select INEL RWMC waste forms can be made in terms of compliance with applicable Program requirements and criteria.

Becker, G.K.

1997-01-01

239

The Seebeck effect as used for the nondestructive evaluation of metals  

SciTech Connect

The thermoelectric measurement of conductive materials is being applied increasingly to the nondestructive sorting and identifying of metals and alloys. In theory, thermoelectrics as used for this application has long been recognized as valid. However, only with recent advances in solid state electronics has this method become reliable and practical for field use. In this paper the principle of the Seebeck Effect in measuring the electromotive force created at the heated junctions of dissimilar metals is employed as a technique for nondestructively sorting metals and alloys.

Stuart, C.M.

1983-01-01

240

Review of embedded particle tagging methods for nondestructive evaluation (NDE) of composite materials and structures  

NASA Astrophysics Data System (ADS)

Acceptance of advanced composites in both retrofit applications and new construction necessitates quality control (QC)/quality assurance (QA) and in-service monitoring techniques to ensure the performance and serviceability of the composites. A technology that enhances the inspectability of the advanced composites is the particle tagging method. The concept of particle tagging involves embedding micron-sized particles into materials, such as composites, or adhesive layers to make them an integral part of the host material. When interrogated by suitable instrumentation, the embedded particle sensors interact with their host material and generate certain types of measurable signatures. The signatures can be correlated with the material and structural conditions, such as internal stress states, voids, inclusions, state-of- cure, and delaminations. This paper presents a technology assessment of the current and emerging state-of-the-art tagging methods. The objective of this review is to provide a framework for further understanding the physics and mechanisms involved in using the tagging method for in-field nondestructive evaluation (NDE) of composite materials. Information concerning the development of this technique has been obtained from patents, publications, databases within Newman Library at Virginia Polytechnic Institute and State University (Virginia Tech), and previous work and in-progress research at the Center for Intelligent Material Systems and Structures (CIMSS) at Virginia Tech. This paper includes a historic review of tagging techniques, a description of the tagging systems used for in-situ NDE of composites, and experimental results to date. The current and potential applications of this technique are also addressed. The analysis presented in this paper will assist in further efforts to develop the tagging approach that may be used as a new NDE technique for quality assurance of advanced composites.

Zhou, Su-Wei; Chaudhry, Zaffir A.; Rogers, Craig A.; Quattrone, Robert

1995-04-01

241

Non-destructive microwave evaluation of TBC delamination induced by acute angle laser drilling  

NASA Astrophysics Data System (ADS)

Laser drilling has been applied to the production of cooling holes of various size and angles in the modern aerospace gas turbine components such as turbine blades, nozzle guide vanes, combustion chambers and afterburner. These parts are usually made of heat resistant nickel superalloys. The superalloy substrate is coated with yttria-stabilized zirconia thermal barrier coatings (TBCs) to protect them from reaching excessive temperatures in hot engine environments. Drilling the parts at acute angles to the surface is complicated because (i) multiple layers are being drilled through, (ii) the melt ejection and heat flow patterns around the hole are non-symmetrical and (iii) the drilling distance is greater than when drilling normal to the surface. In a previous investigation by the authors, delamination of TBC was addressed as a main problem of angled drilling and mechanisms involved were discussed. Characterization of delamination cracks was normally performed via metallographic techniques. It involves sectioning the samples using an abrasive cutting machine, grinding with successively finer silicon carbide paper up to the centre of the hole and polishing to allow optical microscopic analysis of the cracks. However, clamping and sectioning process of thermal-spray-coated workpieces can introduce cracks in brittle coatings due to the drag of the cut-off wheels. Hence, it is not possible to decide if the delamination is caused as a result of post-process sectioning or laser drilling. In this paper, a microwave non-destructive testing (NDT) technique is employed to evaluate the integrity of TBC after acute angle laser drilling. An Agilent 8510 XF network analyser operating over the frequency range of 45 MHz to 110 GHz was used to measure the amplitude and phase variations of scattered waves. The results significantly indicated the existence of delamination of 1-1.5 mm long at the TBC/substrate interface on the leading edge part of an acute-angled hole laser drilled using a 400 W Nd:YAG laser.

Sezer, H. K.; Li, Lin; Wu, Z.; Anderson, B.; Williams, P.

2007-01-01

242

Quantitative impulse-thermography as non-destructive testing method in civil engineering – Experimental results and numerical simulations  

Microsoft Academic Search

Impulse-thermography is an active method for quantitative investigation of the near surface region of various structures which has recently been applied to civil engineering. It is well suited for the detection of voids and honeycombing in concrete up to concrete covers of 10cm and more. For quantitative analysis, a computer program for numerical simulation of the heating up and cooling

Ch. Maierhofer; A. Brink; M. Röllig; H. Wiggenhauser

2005-01-01

243

The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds  

NASA Astrophysics Data System (ADS)

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 from the application of both methodologies to laboratory specimens and to samples from production operations are reported herein, and show that bond joint integrity can be evaluated effectively over the range of materials and geometries addressed.

Chapman, Gilbert B., II

244

An evaluation of leaf biomass : length ratio as a tool for nondestructive assessment in eelgrass (Zostera marina L.).  

PubMed

The characterization of biomass and its dynamics provides valuable information for the assessment of natural and transplanted eelgrass populations. The need for simple, nondestructive assessments has led to the use of the leaf biomass-to-length ratio for converting leaf-length measurements, which can be easily obtained, to leaf growth rates through the plastochrone method. Using data on leaf biomass and length collected in three natural eelgrass populations and a mesocosm, we evaluated the suitability of a leaf weight-to-length ratio for nondestructive assessments. For the data sets considered, the isometric scaling that sustains the weight-to-length proxy always produced inconsistent fittings, and for leaf-lengths greater than a threshold value, the conversion of leaf length to biomass generated biased estimations. In contrast, an allometric scaling of leaf biomass and length was highly consistent in all the cases considered. And these nondestructive assessments generated reliable levels of reproducibility in leaf biomass for all the ranges of variability in leaf lengths. We argue that the use of allometric scaling for the representation of leaf biomass in terms of length provides a more reliable approach for estimating eelgrass biomass. PMID:22645432

Echavarria-Heras, Hector; Solana-Arellano, Elena; Lee, Kun-Seop; Hosokawa, Shinya; Franco-Vizcaíno, Ernesto

2012-05-01

245

Nondestructive evaluation for crack, corrosion, and stress detection for metal assemblies and structures  

Microsoft Academic Search

Magneto-optic imaging based upon Faraday rotation of polarized light has been successfully applied to the problem of non-destructive testing of cracks, stress fractures, corrosion, and other surface and subsurface defects in both ferromagnetic nd nonmagnetic metal structures. Some of these applications have been successfully applied to aircraft fuselage and wing structural examination, as well as to the inspection of tanks

Martin J. Dudziak; Andre Y. Chervonenkis; Vladimir Chinarov

1999-01-01

246

Evaluation and correction of readout artifacts from flat panel detectors for non-destructive testing purposes  

Microsoft Academic Search

Flat panel detectors are commonly used for non-destructive testing purposes using X-ray technology. During a series of measurements with high absorbing objects, we observed an unknown kind of artifacts especially apparent with high contrast edges. These artifacts lead to unwanted results in radioscopic and computed tomography inspection. Given the object is fully occupying the lower part and half of the

S. Burtzlaff; V. Voland; M. Salamon; Th. Hofmann; N. Uhlmann

2009-01-01

247

Artificial neural networks for non-destructive evaluation with ultrasonic waves in not accessible pipes  

Microsoft Academic Search

The design of non-destructive testing systems for fault detection in long and not accessible pipelines is an actual task in the industrial and civil environment. At this purpose the diagnosis based on the propagation of guided ultrasonic waves along the pipes offers an attractive solution for the fault identification and classification. The authors studied this problem by means of suitable

Francesca Cau; Alessandra Fanni; Augusto Montisci; Pietro Testoni; Mariangela Usai

2005-01-01

248

Nondestructive evaluation of cementite content in steel and white cast iron using inductive Barkhausen noise  

Microsoft Academic Search

A nondestructive testing method for the determination of the cementite content in iron-carbon steel and white cast iron is presented. The method is based on micromagnetic measuring parameters derived from inductive Barkhausen noise measurements taken under room temperature and with temperatures above the Curie temperature. The influence of different cementite contents and cementite modifications on the micromagnetic measuring quantities for

I. Altpeter

1996-01-01

249

Histopathological evaluation of liver fibrosis: quantitative image analysis vs semi-quantitative scores  

Microsoft Academic Search

Background\\/Aims: Liver fibrosis is mainly evaluated by qualitative histological examination. Although histological semi-quantitative scores and quantitative determination with image analysis are now possible, these methods have not been fully validated and compared. Therefore, we evaluated these two methods prospectively in 243 patients with chronic liver disease.Methods: The semi-quantitative fibrosis score was evaluated by two independent pathologists, using the Knodell fibrosis

Christophe Pilette; Marie Christine Rousselet; Pierre Bedossa; Daniel Chappard; Frédéric Oberti; Hervé Rifflet; Moussa Y. Maïga; Yves Gallois; Paul Calès

1998-01-01

250

A new apparatus for non-destructive evaluation of green-state powder metal compacts using the electrical-resistivity method  

Microsoft Academic Search

This paper presents a new apparatus developed for non-destructive evaluation (NDE) of green-state powder metal compacts. A green-state compact is an intermediate step in the powder metallurgy (PM) manufacturing process, which is produced when a metal powder-lubricant mixture is compacted in a press. This compact is subsequently sintered in a furnace to produce the finished product. Non-destructive material testing is

Gene Bogdanov; Reinhold Ludwig; William R. Michalson

2000-01-01

251

a Fiber Optic-Based Thermal Acousto-Photonic System for Noncontacting Nondestructive Evaluation  

NASA Astrophysics Data System (ADS)

The Thermal Acousto-Photonic (TAP) Nondestructive Evaluation (NDE) system is an optically based ultrasonic testing technique which extends the potential applications of ultrasonic flaw detection beyond the current capabilities of traditional piezoelectric transducer based technology. Laser based excitation and optical interferometric detection of acoustic waves are conducted through flexible noncontacting fiber optic probes, and a combination of these two methods is used to locate and characterize surface flaws in structural components. TAP has several advantages over conventional transducers; it is noncontacting, more sensitive, and permits truer pointwise sensing. These attributes increase the potential for in-situ applications and allows ultrasonic testing to be conducted in remote and inaccessible locations on structural components. This dissertation discusses the initial outcome of what is potentially a long term research project to explore the synthesis of photonics and ultrasonics to develop a reliable and rugged system for NDE. Based on a review of the considerable research done in the area of optical ultrasound, it is shown that, at present, TAP is the only all fiber optic system for laser based NDE. First, the excitation leg of the system is discussed. A high energy laser pulse is guided through a fiber optic to an appropriate location on the surface of the test specimen. The focused light creates a localized thermal shock which, in turn, generates a Rayleigh acoustic wave. When the wave interacts with a flaw in its path, the signal is modified by the defect in a way which can be correlated to the dimensions of the flaw. The modified Rayleigh wave is detected by an optical fiber interferometer (OFI) and analyzed using computational methods. The technique of time domain reflectometry and ultrasonic spectroscopy, are applied to determine the location and the salient features of the flaw, respectively. Finally, laser excitation, interferometric detection and signal processing are combined and tests are conducted to verify the capabilities of the all fiber optic NDE system. A list of recommendations and directions for future research brings the dissertation to its conclusion.

Peters, Bruce R.

1990-01-01

252

Nondestructive Impedance Spectroscopy Evaluation of the Bond Coat Oxidation in Thermal Barrier Coatings  

Microsoft Academic Search

In this paper, the impedance spectroscopy technique was employed to examine nondestructively the isothermal oxidation of air plasma sprayed (APS) thermal barrier coatings (TBCs) in air at 800°C. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also used to characterize the microstructure evolution of TBCs. After oxidation, the thermally grown oxide (TGO), which was mainly composed of alumina

L. Yang; Y. C. Zhou; W. G. Mao; Q. X. Liu

2007-01-01

253

Nondestructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method  

Microsoft Academic Search

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to

Bao Mi; Robert Bayles

2007-01-01

254

NONDESTRUCTIVE IMPEDANCE SPECTROSCOPY EVALUATION OF THE BOND COAT OXIDATION IN THERMAL BARRIER COATINGS  

Microsoft Academic Search

In this paper, the impedance spectroscopy technique was employed to examine nondestructively the isothermal oxidation of air plasma sprayed (APS) thermal barrier coatings (TBCs) in air at 800°C. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also used to characterize the microstructure evolution of TBCs. After oxidation, the thermally grown oxide (TGO), which was mainly composed of alumina

L. YANG; Y. C. ZHOU; W. G. MAO; Q. X. LIU

2007-01-01

255

Simulated aircraft load testing and non-destructive evaluation of bituminous pavements  

Microsoft Academic Search

The US Federal Aviation Administration's National Airport Pavement Test Facility was constructed to generate full-scale accelerated pavement test data for the development of advanced airport pavement design criteria. During the first round of traffic testing, a six-wheel (Boeing 777) landing gear and a four-wheel (Boeing 747) landing gear were trafficked on flexible test pavements until they were deemed failed. Non-destructive

Kasthurirangan Gopalakrishnan; Marshall R. Thompson

2008-01-01

256

In-Situ Non-Destructive Evaluation of Concrete Structures Using Shearography  

Microsoft Academic Search

Building and construction is important industry concerning life safety. Contrary to its importance, the testing techniques\\u000a used in this industry are relatively out-of-date. For example, the accessing of strength of aged concrete still relied heavily\\u000a on the traditional core test, which is laborious, time consuming and destructive. Convenient non-destructive testing methods\\u000a including rebound hammer, ultrasonic pulse velocity and pull-out test

Y. Y. Hung; L. Liu; Y. H. Huang; Edward C. Y. Yiu

257

Non-Destructive Material Homogeneity Evaluation Using Scanning Millimeter Wave Microscopy  

NASA Astrophysics Data System (ADS)

Millimeter wave bridge technique for non-destructive material homogeneity characterization is described. The idea of this technique is the local excitation of the millimeter waves in the testing material and the measurement of the transmitted (reflected) wave amplitude and phase in different places of it, i.e. the material plate is scanned by the beam of the millimeter waves. The results of the homogeneity measurements for dielectric wafers according to dielectric constant anisotropy are presented. The measurement technique sensitivity is discussed.

Laurinavi?ius, A.; Anbinderis, T.; Ikonikova, J.; Prishutov, Yu.

2008-03-01

258

Non-destructive evaluation (NDE) using multi-aperture DSPI system and fast Fourier transform method  

Microsoft Academic Search

Digital speckle pattern interferometry (DSPI) and digital shearography (DS) are two independent whole-field non-contacting optical methods for nondestructive flaw detection and precision measurements. A multi-aperture arrangement in front the imaging lens provides the grid structure within the speckles to yield desired diffraction halos at the Fourier transform plane. A three aperture arrangement in front of the imaging system is proposed

Basanta Bhaduri; N. Krishna Mohan; M. P. Kothiyal

2007-01-01

259

A Simple Nondestructive Evaluation of an Adhesive Layer Using Elastic Wave Velocities  

NASA Astrophysics Data System (ADS)

A curing process of epoxy adhesive layers has been investigated by an ultrasonic pulse spectroscopy and a Brillouin scattering technique. Observed longitudinal elastic wave velocities in the curing layer depended on the velocity in the prepolymer used. From this result, we suggest a simple nondestructive method for the estimation of sample Tg (glass transition temperature) during cure. The estimated Tg values were in good accordance with the Tg values measured by differential scanning calorimetry.

Matsukawa, Mami; Nakayama, Shuhei; Ohtori, Norikazu

2000-05-01

260

Nondestructive testing and crack evaluation of ferromagnetic material by using the linearly integrated hall sensor array  

Microsoft Academic Search

Magnetic flux leakage testing (MFLT), which measures the distribution of a magnetic field on a magnetized specimen by using\\u000a a magnetic sensor such as a Hall sensor, is an effective nondestructive testing (NDT) method for detecting surface cracks\\u000a on magnetized ferromagnetic materials. A scan-type magnetic camera, based on the principle of MFLT, uses an inclined Hall\\u000a sensor array on a

Jinyi Lee; Jiseong Hwang; Jongwoo Jun; Seho Choi

2008-01-01

261

Nondestructive Evaluation of Tissue Engineered Articular Cartilage Using Time-Resolved Fluorescence Spectroscopy and Ultrasound Backscatter Microscopy  

PubMed Central

The goal of this study is to evaluate the ability of a bimodal technique integrating time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM) for nondestructive detection of changes in the biochemical, structural, and mechanical properties of self-assembled engineered articular cartilage constructs. The cartilage constructs were treated with three chemical agents (collagenase, chondroitinase-ABC, and ribose) to induce changes in biochemical content (collagen and glycosaminoglycan [GAG]) of matured constructs (4 weeks); and to subsequently alter the mechanical properties of the construct. The biochemical changes were evaluated using TRFS. The microstructure and the thickness of the engineered cartilage samples were characterized by UBM. The optical and ultrasound results were validated against those acquired via conventional techniques including collagen and GAG quantification and measurement of construct stiffness. Current results demonstrated that a set of optical parameters (e.g., average fluorescence lifetime and decay constants) showed significant correlation (p<0.05) with biochemical and mechanical data. The high-resolution ultrasound images provided complementary cross-section information of the cartilage samples morphology. Therefore, the technique was capable of nondestructively evaluating the composition of extracellular matrix and the microstructure of engineered tissue, demonstrating great potential as an alternative to traditional destructive assays.

Responte, Donald; Xie, Hongtao; Liu, Jing; Fatakdawala, Hussain; Hu, Jerry; Athanasiou, Kyriacos A.

2012-01-01

262

Elastic waves and ultrasonic nondestructive evaluation; Proceedings of the IUTAM Symposium on Elastic Wave Propagation and Ultrasonic Evaluation, University of Colorado, Boulder, CO, July 30-Aug. 3, 1989  

NASA Astrophysics Data System (ADS)

The present conference on elastic waves and ultrasonic nondestructive evaluation encompasses ultrasonic scattering, inverse problems, localization, guided waves in multilayered and composite media, poster representations, and wave propagation in nonhomogeneous and prestressed media and acoustic emission. Specific issues addressed include numerical techniques for wave-propagation study, experimental flaw detection by the scattering of plate waves, the ultrasonic nondestructive evaluation of graphite-epoxy laminates, and the characterization of material deformation and failure responses from ultrasonic measurements. Also addressed are ultrasonic measurements of the deformation of rocks, transient stress waves in anisotropic laminates, piezoelectric surface and interface waves in nonclassical elastic dielectrics, sinusoidal waves in twinned crystals, and a finite element study of diffraction tomography.

Datta, S. K.; Achenbach, J. D.; Rajapakse, Y. S.

263

Quantitative Methods for Evaluating Hospital Designs.  

National Technical Information Service (NTIS)

The study provides an integrated quantitative-qualitative basis for decisions involving the relative locations of functions, and hence facilities, within the individual short-term, general, voluntary hospital. The approach used in attacking the problem wa...

G. L. Delon H. E. Smalley

1970-01-01

264

Quantitative Fit Factor Evaluation of Schistosome Topical Antipenetrant (TAP).  

National Technical Information Service (NTIS)

A quantitative fit factor evaluation was conducted to determine the effect of Schistosome Topical Antipenetrant (TAP) on protective mask face seal leakage. This test was conducted on 16 male soldiers. Three test conditions were evaluated. The control cond...

R. A. Weiss A. G. Pappas

1993-01-01

265

Non-Destructive Evaluation of Material System Using Highly Nonlinear Acoustic Waves  

NASA Astrophysics Data System (ADS)

A chain of granular particles is one of the most studied examples of highly nonlinear systems deriving its response from the nonlinear Hertzian contact interaction between particles. Interest in these systems derives from their tunable dynamic response, encompassing linear, weakly nonlinear, and strongly nonlinear regimes, controlled by varying the static and dynamic load applied. In chains with a very weak (or zero) static precompression, the system supports the formation and propagation of highly nonlinear solitary waves (HNSWs). The dual-nonlinear interaction between particles (i.e., a power-law type contact potential in compression, and zero strength in tension) combined with discreteness of the system, makes the granular system highly tunable. The propagation properties of these waves, such as traveling pulse width, wave speed, number of separated pulses (single or train of pulses), etc., can be controlled by modifying one or many of the parameters, like the particle's dimension, material properties, static and dynamic force amplitude, the type and duration of the initial excitation applied to the system, and/or the periodicity of the chain. The ability to control the wave properties in such chains has been proposed for several different practical engineering applications. The dynamic properties of these granular chains have been conventionally studied using discrete particle models (DPMs) which consider the particles in the chains as point masses connected by nonlinear Hertzian springs with the neighboring particles. Although, this is a good approximation under proper circumstances, it does not capture many features of the three dimensional elastic particles such as the elastic wave propagation within the particles, the local deformation of the particles in the vicinity of the contact point, the corresponding changes in the contact area, and the collective vibrations of the particles among others. This thesis focuses on the development of a finite element model (FEM) using the commercially available software Abaqus, which takes into account many of these characteristic features. The finite element model discretizes particles by considering them as three-dimensional deformable bodies of revolution and describes the nonlinear dynamic response of one-dimensional granular chains composed of particles with various geometries and orientations. We showed that particles' geometries and orientations provide additional design parameters for controlling the dynamic response of the system, compared to chains composed of spherical particles. We also showed that the tunable and compact nature of these waves can be used to tailor the properties of HNSWs for specific application, such as information carriers for actuation and sensing of mechanical properties and boundary effects of adjoining media in Non-Destructive Evaluation (NDE) and Structural Health Monitoring (SHM). Using experiments and numerics, we characterized interface dynamics between granular media and adjoining linear elastic media, and found that the coupling produced temporary localization of the incident waves at the boundaries between the two media and their decomposition into reflected waves. We monitored the formation of reflected solitary waves propagating back from the interface and found that their properties are sensitive to the geometric and material properties of the adjoining media. The work done in this research enhances our understanding of the basic physics and tunability of nonlinear granular media, and further establishes a theoretical and numerical foundation in the applications of HNSWs as information carriers.

Khatri, Devvrath

266

Determining quantitative immunophenotypes and evaluating their implications  

NASA Astrophysics Data System (ADS)

Quantitative immunophenotypes varied widely among > 100 healthy young males but were maintained at characteristic levels within individuals. The initial results (SPIE Proceedings 4260:226) that examined cell numbers and the quantitative expression of adhesion and lineage-specific molecules, e.g., CD2 and CD14, have now been confirmed and extended to include the quantitative expression of inducible molecules such as HLA-DR and perforin (Pf). Some properties, such as the ratio of T helper (Th) to T cytotoxic/suppressor (Tc/s) cells, are known to be genetically determined. Other properties, e.g., the T:B cell ratio, the amount of CD19 per B cell, etc., behaved similarly and may also be inherited traits. Since some patterns observed in these healthy individuals resembled those found in pathological situations we tested whether the patterns could be associated with the occurrence of disease. The current studies shows that there were associations between quantitative immunophenotypes and the subsequent incidence and severity of disease. For example, individuals with characteristically low levels of HLA-DR or B cells or reduced numbers of Pf+ Tc/s cells had more frequent and/or more severe upper respiratory infections. Quantitative immunophenotypes will be more widely measured if the necessary standards are available and if appropriate procedures are made more accessible.

Redelman, Douglas; Hudig, Dorothy; Berner, Dave; Castell, Linda M.; Roberts, Don; Ensign, Wayne

2002-05-01

267

Quantitative evaluation of nonablative laser technology.  

PubMed

A new method for treating facial rhytides and acne scars with nonablative laser and light source techniques has recently been introduced. Given the inherent limitations of photographic and clinical evaluation to assess subtle changes in rhytides and surface topography, new noninvasive, objective instruments were used to accurately assess the outcome of these procedures. This study measures and objectively quantifies facial skin by using 2 novel, noninvasive measuring systems after 3 to 5 treatment sessions with the 1,064 nm QS Nd:YAG laser in patients with photodamage and acne scarring. One system measures the skin surface topography and the other characterizes the biomechanical properties of the skin. Patients undergoing facial rejuvenation procedures were analyzed before and after therapy with a 32 x 32 mm in vivo three-dimensional microtopography imaging system (PRIMOS, GFM, Teltow, Germany). The imaging system projects light on to a specific surface of the skin with a Digital Micromirror Device (DMD; Texas Instruments, Irving, TX) and records the image with a CCD camera. Skin Surface microtopography is reconstructed using temporal phase shift algorithms to generate three-dimensional images. Measurements were taken at baseline, at various times during the treatment protocol, and then at 3 and 6 month follow-up visits. Silicone skin replicas (FLEXICO, Herts, England) were also made before and after the laser treatment protocol for comparison to in vivo acquisition. Skin stiffness and compliance were measured with the BTC-2000 (BTC 2000, S.R.L.I. Inc. Nashville, TN). This instrument measures the response of the skin during dynamic stress created by suction. An infrared targeting laser measures the vertical displacement of the skin during the cycle. Pressure and deformation are graphically displayed on the monitor and embedded biomechanical algorithms determine the aforementioned parameters based on the average of 3 repetitive cycles. Four sites on the face were analyzed and compared including the right and left cheek and the right and left forehead. Measurements were taken at baseline and then at 1-, 3- and 6-month follow-up visits. Skin roughness decreased 11% from baseline in the patient with photodamaged skin, while the patients with acne scarring showed a 33% improvement from baseline after 3 treatment sessions. Six-months after the fifth treatment session, a 26% improvement in skin smoothness was documented in the patients with photodamaged skin, while a 61% improvement was recorded in the subject with acne scarring. Biomechanical analysis of the skin showed a 23% decrease in skin stiffness and a 30% increase in skin compliance at the 6-month follow-up in the patients with photodamage. Alternatively, the patient with acne scarring showed a 50% increase in skin stiffness, and a 30% decrease in skin compliance at the 6-month follow-up. Three-dimensional in vivo optical skin imaging provided a rapid and quantitative assessment of surface topography and facial fine lines after multiple treatment sessions with a 1064-nm QS Nd:YAG laser, correlating with clinical and subjective responses. Biomechanical analysis provided technical understanding of structural changes in photodamaged skin and acne scarring following nonablative laser treatment. Future applications of these devices may include comparison of nonablative laser technology, optimization of treatment regimens, and objective evaluation of other aesthetic procedures performed by dermatologists. PMID:12512649

Friedman, Paul M; Skover, Greg R; Payonk, Greg; Geronemus, Roy G

2002-12-01

268

Quantitative Evaluation of Musical Scale Tunings  

ERIC Educational Resources Information Center

|The acoustical and mathematical basis of the problem of tuning the twelve-tone chromatic scale is reviewed. A quantitative measurement showing how well any tuning succeeds in providing just intonation for any specific piece of music is explained and applied to musical examples using a simple computer program. (DT)|

Hall, Donald E.

1974-01-01

269

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

SciTech Connect

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.

Day, R.A.

1988-12-31

270

Impedance-based non-destructive evaluation of the FRP adhesive joints in corrosive environment with re-usable technique  

NASA Astrophysics Data System (ADS)

In this study, a Non-Destructive Evaluation (NDE) method is introduced for evaluating the effects of FRP adhesive joint bond strength subjected to various environmental conditions using electromechanical impedance (EMI) method. The applicability of Fibre Reinforced Plastics (FRP) as a construction material is being globally recognized for their high stiffness and strength to weight ratio and this method proposes a possibility of detecting any strength loss to the adhesive bond without damaging the structure, such as FRP joint itself. PZT (Lead-Zirconate-Titanate) patches were utilized to detect any changes to the bond strength of the FRP adhesive joint exposed to different kinds of environmental conditions by measuring the electrical admittance of the PZT sensors. In addition, a re-usable technique has been introduced with a utilization of magnet to allow multiple sensing of specimens with a single sensor. The results show a possibility of detecting decrease in the bond strength of FRP adhesive using the EMI method.

Na, S.; Tawie, R.; Lee, H. K.

2011-03-01

271

Quantitative Nondestructive Evaluation and Reliability Assessment of the Aging Aircraft Structure Components.  

National Technical Information Service (NTIS)

The report developed under STTR contract presents the results of work performed on development of a new probabilistic model for reliability assessment of the aging aircraft structural components and nonlinear acoustic instrumentation for collecting the in...

A. Sutin

2000-01-01

272

Pulse thermography for quantitative nondestructive evaluation of sound, de-mineralized and re-mineralized enamel  

NASA Astrophysics Data System (ADS)

Current limitations for diagnosing mineralization state of tooth enamel can lead to improper surgical treatments. A method is investigated by which the tooth health state is characterized according to its thermal response, which is hypothesized to be sensitive to increased porosity in enamel that is caused by demineralization. Several specimens consisting of previously extracted human teeth a re prepared by exposure to Streptococcus mutans A32-2 in trypticase-soy-borth supplemented with 5% sucrose at 37°C for 3 or 6 days to de-mineralize two 1×1mm2-windows on each tooth. One of these windows is then re-mineralized with 250 or 1,100ppm-F as NaF for 10 days by pH-cyclic-model. Pulse thermography is used to measure the thermal response of these sections as well as the sound (healthy) portions of the specimen. A spatial profile of the thermal parameters of the specimens is then extracted from the thermography data and are used to compare the sound, de-mineralized, and re-mineralized areas. Results show that the thermal parameters are sensitive to the mineralization state of the tooth and that this method has the potential to accurately and quickly characterize the mineralization state of teeth, thereby allowing future dentists to make informed decisions regarding the best treatment for teeth that have experienced demineralization.

Ando, Masatoshi; Sharp, Nathan; Adams, Douglas

2012-03-01

273

Magnetomechanical Measurements for Nondestructive Evaluation of Failure in Steel Structural Element  

NASA Astrophysics Data System (ADS)

This research aims to explore magnetomechanical effect as a nondestructive method to monitor the failure process of steel structural elements subjected to compressive loadings. Experiments on steel tubular joints were carried out to study the relationship between the applied load and the magnetomechanical field. Results show that the mechanical response and the magnetomechanical response demonstrate similar behavior to the applied load in the whole loading progress. At the critical load of buckling, the load-magnetic field curve has a bifurcation point corresponding to the traditional bifurcation of load-displacement curve. This research demonstrates that the stress-induced magnetic filed can be utilized as an important indicator of impending failure in steel structural elements.

Bao, Sheng; Xu, Fan; Wang, Jiyang; Lou, Hangfei

2013-05-01

274

Nondestructive evaluation of sputtered-deposited tantalum carbide refractory coatings. Final report  

SciTech Connect

Desirable characteristics of refractory coatings for future projectile launchers include high wear resistance, high melting point, hardness, electrical conductivity, good adhesion, thermal stability, and high plasma resistance properties. Sputtered tantalum and tantalum compounds, such as tantalum nitride and tantalum carbide are being considered as future coatings to endure the high pressure, high temperature, and aggressive chemical environment of the bore. In this work, tantalum and tantalum carbide were reactively sputtered deposited from argon plasmas containing methane. Nondestructive x-ray diffraction analysis determined that body-centered-cubic (bcc) tantalum was deposited at methane concentrations below 20 percent, face-centered-cubic (fcc) tantalum carbide was deposited at methane concentrations above 25 percent, and a mixture of tantalum and tantalum carbide was deposited at the transitional 22 percent methane concentration. Coating composition, crystalline structure, particle size, preferred orientations, deposition rate, Knoop hardness, and temperature coefficient of resistivity are sensitive functions of percentage methane concentration in the sputtering-deposited process.

Lee, S.L.; Heffernan, W.J.; Walden, J.

1995-03-01

275

Nondestructive evaluation of mechanical and fracture characteristics of ferritic steels using automated ball identation testing  

SciTech Connect

Mechanical properties of various ferritic steels commonly used for pressure boundary applications in light water reactors are characterized using a novel portable stress-strain microprobe (SSM) system. The SSM system utilizes an automated ball indentation (ABI) technique to measure yield strength, stress-strain curve, strength coefficient, and strain-hardening-exponent (uniform ductility). The technique is essentially nondestructive, albeit small indentations are left following the tests. These, however, leave surface compressive stresses that could actually retard crack initiation characteristics. The ABI-derived mechanical properties agreed with those obtained using conventional destructive tensile tests. To minimize specimen-to-specimen scatter, the grip/shoulder sections were used for ABI testing. In addition, the fracture properties are characterized in terms of a new fracture parameter, indentation energy to fracture (IEF), derived from the temperature variation of the true stress compared with true strain using the critical-stress-to-fracture concept.

Murty, K.L.; Mathew, M.D.; Miraglia, P.Q. [North Carolina State Univ., Raleigh, NC (United States)] [and others

1997-12-01

276

Magnetic non-destructive evaluation of ruptures of tensile armor in oil risers  

NASA Astrophysics Data System (ADS)

Risers are flexible multilayered pipes formed by an inner flexible metal structure surrounded by polymer layers and spiral wound steel ligaments, also known as armor wires. Since these risers are used to link subsea pipelines to floating oil and gas production installations, and their failure could produce catastrophic consequences, some methods have been proposed to monitor the armor integrity. However, until now there is no practical method that allows the automatic non-destructive detection of individual armor wire rupture. In this work we show a method using magnetic Barkhausen noise that has shown high efficiency in the detection of armor wire rupture. The results are examined under the cyclic and static load conditions of the riser. This work also analyzes the theory behind the singular dependence of the magnetic Barkhausen noise on the applied tension in riser armor wires.

Pérez-Benitez, J. A.; Padovese, L. R.

2012-04-01

277

Non-Destructive Evaluation Method of Pharmaceutical Tablet by Terahertz-Time-Domain Spectroscopy: Application to Sound-Alike Medicines  

NASA Astrophysics Data System (ADS)

To evaluate terahertz time-domain spectroscopy (THz-TDS) as a promising tool for discriminating pharmaceutical tablets, THz-TDS has been applied for discrimination between pharmaceutical tablets with sound-alike names. Two sets of medicine tablets with sound-alike names, that is, Amaryl and Almarl, Zyloric and Zantac, are examined in this study. Based on the difference in THz absorption spectra, we have succeeded in distinguishing between sound-alike medicine tablets clearly for each set. The results in this study suggest that THz-TDS is a useful tool that is indispensable for medical security maintenance, such as a non-destructive way to prevent mix-up of medicine.

Kawase, Masaya; Yamamoto, Kohji; Takagi, Keita; Yasuda, Ryohei; Ogawa, Masafumi; Hatsuda, Yasutoshi; Kawanishi, Sonoyo; Hirotani, Yoshihiko; Myotoku, Michiaki; Urashima, Yoko; Nagai, Katsuhito; Ikeda, Kenji; Konishi, Hiroki; Yamakawa, Junji; Tani, Masahiko

2013-09-01

278

Nondestructive evaluation of acoustic properties of fuel cell proton-exchange membranes by vector contrast acoustic microscopy  

NASA Astrophysics Data System (ADS)

In recent years, the interest in the research and development of "green energy" has increased dramatically, with numerous research grants and investment in the areas of wind power, solar power and fuel cell technology. We present results obtained from the evaluation of the acoustic properties of proton-exchange membranes used in hydrogen fuel cells, which relate directly to the microelastic properties of such membranes. These properties play an important role in the durability and applicability as well as the efficiency of such membranes. DuPont Nafion membranes are the most commonly used polymeric membranes in hydrogen/oxygen fuel cells and are therefore used as examples in this study. The microscope used in this non-destructive characterization study is a vector-contrast version of the scanning acoustic microscope which yields images in magnitude- and phase contrast.

Kamanyi, Albert E.; Grill, Wolfgang

2012-03-01

279

Nondestructive evaluation of ±45° flat-braided carbon-fiber-reinforced polymers with carbon nanofibers using HTS-SQUID gradiometer  

NASA Astrophysics Data System (ADS)

Step-by-step tensile tests were applied to flat-braided carbon-fiber-reinforced polymers with and without added dispersions of carbon nanofibers (CNFs) and with and without sample sides cut off to study their mechanical properties and destructive mechanisms by means of in situ observation and stress-strain measurements. An ex situ nondestructive evaluation technique, using a high-temperature superconductor superconducting quantum interference device gradiometer, was also applied to the samples to study their electrical properties; the relationships between the mechanical and electrical properties by visualizing current maps in the samples during ac current injection was also studied. Clear differences were observed in the mechanical and electrical properties and the destructive mechanisms between the samples with and without CNFs and with and without cut off sides. These differences were mainly attributed to the addition of CNFs, which enhanced the mechanical and electrical connections between the carbon fiber bundles.

Hatsukade, Y.; Shinyama, Y.; Yoshida, K.; Takai, Y.; Aly-Hassan, M. S.; Nakai, A.; Hamada, H.; Adachi, S.; Tanabe, K.; Tanaka, S.

2013-01-01

280

Non-destructive evaluation means and method of flaw reconstruction utilizing an ultrasonic multi-viewing transducer data acquistion system  

DOEpatents

A multi-viewing ultrasound transducer acquisition system for non-destructive evaluation, flaw detection and flaw reconstruction in materials. A multiple transducer assembly includes a central transducer surrounded by a plurality of perimeter transducers, each perimeter transducer having an axis of transmission which can be angularly oriented with respect to the axis of transmission of the central transducer to intersect the axis of transmission of the central transducer. A control apparatus automatically and remotely positions the transducer assembly with respect to the material by a positioning apparatus and adjusts the pe GRANT REFERENCE This invention was conceived and reduced to practice at least in part under a grant from the Department of Energy under Contract No. W-7407-ENG-82.

Thompson, Donald O. (Ames, IA); Wormley, Samuel J. (Ames, IA)

1989-03-28

281

Quantitative damage evaluation of localized deep pitting  

SciTech Connect

Localized deep pitting is considered difficult to precisely measure and evaluate using simple techniques and daily-use analysis approaches. A case study was made of carbon steel heat exchangers in a typical fresh cooling water environment that experienced severe pitting. To effectively and precisely evaluate the encountered pitting damage, a simple measurement and analyses approach was devised. In this article, the pitting measurement technique and the damage evaluation approach are presented and discussed in detail.

Al Beed, A.A.; Al Garni, M.A.

2000-04-01

282

Evaluation of Techniques to Quantitatively Monitor Spiny Lobster Postlarval Recruitment.  

National Technical Information Service (NTIS)

Postlarval spiny lobsters, Panulirus argus, attracted to floating artificial habitats were counted to evaluate quantitative sampling techniques for lobster recruitment to the lower Florida Keys. Sampling was conducted from 27 March 1976 to 13 September 19...

E. J. Little G. R. Milano

1978-01-01

283

Nondestructive evaluation of titanium alloys. ESCA (Electron Spectroscopy for Chemical Analysis), ISS (Ion Scattering Spectroscopy), and SIMS (Secondary Ion Mass Spectrometry) examination of titanium alloy solid surfaces  

Microsoft Academic Search

This report will begin with the description of the basic principles and instrumentation of ESCA (Electron Spectroscopy for Chemical Analysis), ISS (Ion Scattering Spectroscopy), and SIMS (Secondary Ion Mass Spectrometry). Particular emphasis will be placed on those aspects which are of immediate relevance to the nondestructive evaluation of titanium alloys such as: the concept of chemical shift in ESCA, the

G. D. Mateescu; Y. H. Pao

1984-01-01

284

Multicriteria evaluation with mixed qualitative and quantitative data  

Microsoft Academic Search

In this paper attention will be focussed on the development of a new multicriteria evaluation approach for mixed 'quantitative - qualitative' data. First a brief overview is given of the 'state of the art' of multicriteria evaluation in urban and regional planning. In addition, a mixed data evaluation approach will be discussed, which includes three techniques which are all based

H Voogd

1982-01-01

285

Physical principles pertaining to ultrasonic and mechanical properties of anisotropic media and their application to nondestructive evaluation of fiber-reinforced composite materials  

SciTech Connect

The central theme of this thesis is to contribute to the physics underlying the mechanical properties of highly anisotropic materials. The hypothesis is that a fundamental understanding of the physics involved in the interaction of interrogating ultrasonic waves with anisotropic media will provide useful information applicable to quantitative ultrasonic measurement techniques employed for the determination of material properties. The desired characteristics of practical fiber-reinforced composites depend on average mechanical properties achieved by placing fibers at specific angles relative to the external surfaces of the finished part. The author examines the physics underlying the use of ultrasound as an interrogation probe for determination of ultrasonic and mechanical properties of anisotropic materials such as fiber-reinforced composites. Fundamental constituent parameters, such as elastic stiffness coefficients, are experimentally determined from ultrasonic time-of-flight measurements. Mechanical moduli descriptive of the anisotropic mechanical properties of unidirectional graphite/epoxy composites are obtained from the ultrasonically determined stiffness coefficients. Three-dimensional visualizations of the anisotropic ultrasonic and mechanical properties of unidirectional graphite/epoxy composites are generated. A goal of the research is to strengthen the connection between practical ultrasonic nondestructive evaluation methods and the physics underlying quantitative ultrasonic measurements for the assessment of manufactured fiber-reinforced composites. Production defects have proven to be of substantial concern in the manufacturing of composites. The author investigates the applicability of ultrasonic interrogation techniques for the detection and characterization of porosity in graphite/epoxy laminates. Complementary ultrasonic parameters based on the frequency dependence of ultrasonic attenuation and integrated polar backscatter are investigated.

Handley, S.M.

1992-01-01

286

Rapid Nondestructive Plutonium Isotopic Analysis.  

National Technical Information Service (NTIS)

Methods for plutonium isotopic measurements have been evaluated for nuclear safeguards inventory verification. A mobile, real-time, nondestructive assay, gamma-ray spectrometric measurement system has been assembled, moved and operated at several nuclear ...

J. E. Fager F. P. Brauer

1978-01-01

287

Nondestructive evaluation and real-time monitoring of laser surface hardening.  

SciTech Connect

An infrared process monitor was used to monitor in real-time the infrared emissions during laser surface hardening of ferrous alloys. The signals from the monitor were correlated with the hardness and case depth of the laser-treated tracks. Test data show that a linear relationship exists between the monitor output DC level voltage and hardness up to the maximum hardness possible and also between the monitor output DC level voltage and case depth. This simple relationship makes it easy to monitor process hardness, case depth and quality of laser heat-treated workpiece. A calibration test on a prototypic material can be used to determine the upper and lower bounds of the voltage signals for a sound quality treatment. In-process monitoring or real-time nondestructive measurement of the hardness and depth of the laser transformation hardened case can then be achieved. The monitor is also capable of tracking changes in surface quality or flatness of the part that is being treated.

Xu, Z.; Leong, K.; Reed, C.; Nuclear Engineering Division

2008-09-12

288

Large area detector based computed tomography system for production nondestructive evaluation.  

SciTech Connect

We present a system for industrial x-ray computed tomography that has been optimized for all phases of nondestructive component inspection. Data acquisition is greatly enhanced by the use of high resolution, large area, flat-panel amorphous-silicon detectors. The detectors have proven, over several years, to be a robust alternative to CCD-optics and image intensifier CT systems. In addition to robustness, these detectors provide the advantage of area detection as compared with the single slice geometry of linear array systems. Parallel processing provides significant speed improvements for data reconstruction, and is implemented for parallel-beam, fan-beam and Feldkamp conebeam reconstruction algorithms. By clustering ten or more equal-speed computers, reconstruction times are reduced by an order of magnitude. We have also developed interactive software for visualization and interrogation of the full three-dimensional dataset. Inspection examples presented in this paper include an electro-mechanical device, nonliving biological specimens and a turbo-machinery component. We also present examples of everyday items for the benefit of the layperson.

Keating, S. C. (Scott C.); Davis, A. A. (Anthony A.); Claytor, T. N. (Thomas N.)

2001-01-01

289

Comparison of radiation sources and filtering safety glasses for fluorescent nondestructive evaluation  

NASA Astrophysics Data System (ADS)

This study was directed toward the question of whether recent advancements in radiation sources and test media offered significant improvements over the current state of the art. Included were experiments characterizing common penetrant and magnetic particle materials to determine their fluorescent excitation spectra, and a comparison between the fluorescent excitation spectra and the emission spectra of common excitation sources. The relationship between exciter and test medium directly controls the luminance of a defect indication. As indication luminance increases, the probability of it being detected by the inspector increases. Fluorescent penetrant and magnetic particle test media were originally designed around the widely available filtered medium pressure mercury vapor lamp, which remains the standard excitation radiation source. Test media properties, and the types of available excitation sources have changed with time, and it was unclear whether present-day media was still best excited by the historical standard ultraviolet radiation source. Predictions and experimental work was performed to determine the optimal excitation source for fluorescent nondestructive testing, and to determine which safety lens option would offer the highest probability of detection. Improvement in radiation sources was primarily judged by an increase in fluorophore luminance versus background, which led to an increase in signal-to-noise ratio facilitating better indication detectability. Other factors considered were improved health and safety, and ease of use.

Lopez, Richard Daniel

290

Nondestructive three-dimensional evaluation of biocompatible materials by microtomography using synchrotron radiation  

NASA Astrophysics Data System (ADS)

Microtomography based on synchrotron radiation sources is a unique technique for the 3D characterization of different materials with a spatial resolution down to about 1 micrometers . The interface between implant materials (metals, ceramics and polymers) and biological matter is nondestructively accessible, i.e. without preparation artifacts. Since the materials exhibit different x-ray absorption, it can become impossible to visualize implant material and tissue, simultaneously. Here, we show that coating of polymer implants, which are invisible in bone tissue, does not only improve the interfacial properties but also allows the imaging of the interface in detail. Titanium implants, on the other hand, absorb the x-rays stronger than bone tissue. The difference, however, is small enough to quantify the bone formation near interface. Another advantage of microtomography with respect to classical histology is the capability to examine samples in a hydrated state. We demonstrate that ceramic hollow spheres can be imaged before sintering and fibroblasts marked by OsO4 are visible on polymer textiles. Consequently, scaffolds of different materials designed for tissue engineering and implant coatings can be optimized on the basis of the tomograms.

Muller, Bert; Thurner, Philipp; Beckmann, Felix; Weitkamp, Timm; Rau, Christoph; Bernhardt, Ricardo; Karamuk, Erdal; Eckert, Ludwig; Brandt, J.; Buchloh, Stefan; Wintermantel, Erich; Scharnweber, Dieter; Worch, Hartmut

2002-01-01

291

Data recovering techniques for superconducting quantum interference device and its application to nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Recently interest has grown for assessing the structural integrity of materials using superconducting quantum interference device (SQUID). SQUIDs involve an extremely high magnetic flux sensitivity and, as a result, magnetic imaging techniques using SQUIDs have a high spatial resolution. However, due to the high magnetic sensitivity of SQUIDs measurement data are heavily corrupted by various kinds of noise in environmental circumstance. SQUID gradiometer could be expected to be a tough measurement technique for overcoming environmental noise. In this paper, an effective computational method is proposed for recovering data by the data acquisition of SQUID gradiometer. A mathematical model of the recovering process is described by an integro-differential equation in a two dimensional spatial domain. The inversion technique proposed here is formulated as a minimization of the regularized least square problem. A computational algorithm of finding an optimal solution is described by using the finite difference scheme. The proposed scheme is applied to the nondestructive testing for detecting cracks in conductor. The effectiveness and validity of the proposed method are demonstrated through computational experiments with laboratory data. .

Kojima, F.; Kasai, N.

2000-05-01

292

Shearographic and thermographic nondestructive evaluation of the space shuttle structure and thermal protection systems (TPS)  

NASA Astrophysics Data System (ADS)

Shearography and thermography have shown promising results on orbiter structure and external tank (ET) and solid rocket booster (SRB) thermal protection systems (TPS). The orbiter uses a variety of composite structure, the two most prevalent materials being aluminum and graphite-epoxy honeycomb. Both techniques have detected delaminations as small at 0.25 inches diameter in the orbiter payload bay doors graphite-epoxy honeycomb structure. Other applications include the robotic manipulator system (RMS) and the rudder speed brake structure. The ET uses spray-on foam insulation (SOFI) as the TPS and the SRB forward section uses marshall sprayable ablative as the TPS. Debonding SOFI damage to the orbiter 'belly' tile and exposes the ET to thermal loading. Voids in SOFI test panels as small as 0.375 inch were detected in 1.75 inch thick foam using a pressure reduction of not more than 10 inches of water or 0.4 pounds per square inch. Preliminary results of the X33 metallic TPS are presented. Ultrasonic testing approved for orbiter bond integrity testing, is time consuming and problematic. No current non-destructive inspection technique is approved for inspection of ET/SRB TPS or the orbiter RMS honeycomb at Kennedy Space Center. Only visual inspections are routinely performed on orbiter structure. The various successes of these two techniques make them good candidates for the aforementioned applications.

Davis, Christopher K.

1996-11-01

293

Mixed Waste Focus Area/Characterization Monitoring Sensor Technology Nondestructive Waste Assay Capability Evaluation Project End-User Summary Report  

SciTech Connect

The Mixed Waste Focus Area (MWFA) in conjunction with the Characterization Monitoring and Sensor Technology (CMST) crosscut program identified the need to objectively evaluate the capability of nondestructive waste assay (NDA) technologies. This was done because of a general lack of NDA technology performance data with respect to a representative cross section of waste form configurations comprising the Department of Energy (DOE) contact-handled alpha contaminated [e.g., transuranic (TRU) waste]. The overall objective of the Capability Evaluation Project (CEP) was to establish a known and unbiased NDA data and information base that can be used to support end-user decisions with regards to technology system selection and to support technology development organizations in identifying technology system deficiencies. The primary performance parameters evaluated in the CEP were measurement bias and relative precision. The performance of a given NDA technology is a direct function of the attributes represented by the waste matrix configuration. Such attributes include matrix density, matrix elemental composition, radionuclidic composition, radionuclide mass loading, and the spatial variation of these components. Analyzing the manner in which bias and precision vary as a function of test sample attribute and NDA technology provides a foundation for deriving performance capability and limitation statements and determines which waste matrix attributes, or combinations of attributes, are compatible or incompatible with existing technologies. The CEP achieved the stated end-user objective. The data indicate that the nondestructive waste assay systems evaluated have a definite capability to perform assay of contact-handled TRU waste packaged in 55-gallon drums. There is, however, a performance envelope where this capability exists, an area near the envelope boundaries where it is questionable, and a realm outside the envelope where the technologies do not perform. Therefore, the end user must be aware of this envelope and ensure the appropriate technology is selected. This program provides the end user with waste type specific performance data to assist in the assessment and selection of a given waste NDA technology. Additionally, the CEP afforded the private sector participants the opportunity to evaluate system performance using National Institute of Standards and Technology traceable radioactive significant enhancements to their respective systems and supported all participants in attaining DOE-CAO certification. Ultimately, the DOE end users will benefit from these enhancements.

G. K. Becker; M. E. McIlwain; M. J. Connolly

1998-11-01

294

Quantitative evaluation of normal muscle tone  

Microsoft Academic Search

Forty-eight normal subjects were evaluated for the purpose of objectively quantifying muscle tone. Flexor carpi radialis and extensor digitorum communis electromyographic (EMG) activity was simultaneously recorded during wrist movements imposed by a torque motor. Each session was subdivided into three steps: (1) measurement of the ‘intrinsic stiffness index’ (ISI) at 10 °\\/s; (2) measurement of the ‘total stiffness index’ (TSI)

Fabrizio Pisano; Giacinta Miscio; Roberto Colombo; Paolo Pinelli

1996-01-01

295

Ultrasonic nondestructive evaluation of matrix structures and nodularity in cast irons  

NASA Astrophysics Data System (ADS)

The primary purpose of this research was to investigate the nondestructive ultrasonic wave response, in terms of acoustic velocities and attenuation of sound energy, in cast irons with different nodularities and matrix structures and its correlation with mechanical properties. The results indicated that the influences of matrix structures on the acoustic velocities were not apparent in the cast irons investigated. As to the nodularity, when graphites were largely spheroidal in shape ( i. e., nodularity over 80 pct), the velocity of longitudinal waves propagation was about 5300 to 5500 m/s. The velocities seemed to decrease linearly down to nodularity of 25 pct, where velocity was approximately 4800 m/s. Below 25 pct nodularity, the values of acoustic velocity dropped rapidly to about 4000 to 4200 m/s. This represented the velocity of longitudinal waves propagation in gray cast iron, in which the graphites appeared in flake form. The analysis of the attenuation of ultrasonic amplitude indicated that when the nodularity of cast irons is low, the echo sound amplitude will decay more rapidly with respect to distance of echo sound travel. As to the matrix structures, ferritic, bainitic, ferritic-pearlitic (low pearlite content) and tempered martensitic matrix structures were found to have similar ultrasonic attenuation characteristics at the testing frequency of 2 MHz. A higher amount of pearlite (over 90 pct) or fresh martensite in the matrix of cast irons has resulted in faster attenuation of ultrasonic energy, with the fresh martensitic matrix being the fastest. At a testing frequency of 4 MHz, the attenuation of the ultrasonic amplitude in pearlitic and fresh martensitic matrices was found to be even greater than that of 2 MHz. However, other matrices exhibited similar attenuation behavior at both 2 and 4 MHz frequencies. The relationship between the mechanical properties of various cast irons and ultrasonic characteristics was also examined.

Lee, Shen-Chih; Suen, Jia-Ming

1989-11-01

296

Simultaneous sum-frequency and vibro-acoustography imaging for nondestructive evaluation and testing applications  

SciTech Connect

High-resolution ultrasound imaging systems for inspection of defects and flaws in materials are of great demand in many industries. Among these systems, Vibro-acoustography (VA) has shown excellent capabilities as a noncontact method for nondestructive high-resolution imaging applications. This method consists of mixing two confocal ultrasound beams, slightly shifted in frequency, to produce a dynamic (oscillatory) radiation force in the region of their intersection. This force vibrates the object placed at the focus of the confocal transducer. As a result of the applied force, an acoustic emission field at the difference frequency of the primary incident ultrasound beams is produced. In addition to the difference frequency acoustic emission signal, there exists another signal at the sum frequency, formed in the intersection region of the two primary beams. The goal of this study is to investigate the formation of high-resolution images using the sum frequency of ultrasound waves in VA while concurrently forming the conventional difference-frequency VA image, thereby increasing the amount of information acquired during a single scan. A theoretical model describing the sum-frequency wave propagation, including beam forming and image formation in the confocal configuration, is developed and verified experimentally. Moreover, sample experiments are performed on a flawed fiber-reinforced ceramic composite plate. Images at both the difference and sum frequencies are compared and discussed. Results show that the sum-frequency image produces a high-resolution C scan of the plate by which the flaws and structural details of the plate can be detected.

Mitri, F. G.; Silva, G. T.; Greenleaf, J. F.; Fatemi, M. [Department of Physiology and Biomedical Engineering, Ultrasound Research Laboratory, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905 (United States); Instituto Nacional de Matematica Pura e Aplicada-IMPA, Rio de Janeiro, RJ 22460-320 (Brazil); Department of Physiology and Biomedical Engineering, Ultrasound Research Laboratory, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905 (United States)

2007-12-01

297

Millimeter-wave nondestructive evaluation of glass fiber/epoxy composites subjected to impact fatigue  

NASA Astrophysics Data System (ADS)

The useful life of a glass fiber/epoxy composite subjected to impact fatigue loading is an important issue in the future design of numerous industrial components. Lifetime predictions have been a problem particularly due to the difficulties encountered in monitoring damage accumulation in composites. It is hypothesized that there is a build up of micro damage, such as matrix micro-cracks and micro-delaminations, even though there is no apparent change in material compliance. A critical level is finally reached at which time the properties of the composite begin to fall and compliance change is evident. In this study the apparent compliance change and the type of damage accumulation is investigated. To measure the compliance change, a test unit was developed that uses a dynamic load measuring system. The load cell measures the load throughout each impact pulse and the compliance and energy absorbed by the specimen is then related to the recorded curve. Initially no change in the impact pulse was apparent; however, after a finite number of cycles the peak load and area under each impact pulse drop, indicating an increase in compliance. Unfortunately, the impact load does not provide information on the form and degree of damage. Thus, millimeter wave nondestructive investigation is used, in conjunction with impact fatigue tests, to examine microstructural aspects of damage initiation and growth. The millimeter wave scanning technique results in detectable damage growth throughout the impact fatigue test. Damage size and growth patterns specific to composites are obvious, and after significant damage can be related to the observable macro damage. Continued development of these investigative techniques promises to enhance the ability of detecting defects and damage growth in fiber reinforced composite materials as well as improving the understanding of impact fatigue initiation in these complex materials.

Radford, Donald W.; Ganchev, Stoyan I.; Qaddoumi, Nasser; Beauregard, Guy; Zoughi, Reza

1994-09-01

298

NONDESTRUCTIVE EVALUATION OF PLEXIGLAS MATERIALS USING LOCK-IN AND PULSE PHASE INFRARED THERMOGRAPHY  

Microsoft Academic Search

Lock-in and pulse phase infrared thermography measurement techniques have been exploited for quantitative assessment of subsurface defects in a reference specimen made of Plexiglas. Radiometric thermal images were post-processed using a contrast approach in the frequency domain, allowing defect depth location to be resolved with a relative combined standard uncertainty of about 7% for thicknesses above 3 mm. Conversely, significant

R. Montanini; S. Aliquò

2009-01-01

299

Quantitative evaluation of passage retrieval algorithms for question answering  

Microsoft Academic Search

Passage retrieval is an important component common to many question answering systems. Because most evaluations of question answering systems focus on end-to-end performance, comparison of common components becomes difficult. To address this shortcoming, we present a quantitative evaluation of various passage retrieval algorithms for question answering, implemented in a framework called Pauchok. We present three important findings: Boolean querying schemes

Stefanie Tellex; Boris Katz; Jimmy J. Lin; Aaron Fernandes; Gregory Marton

2003-01-01

300

Quantitative evaluation of Ocean Thermal Energy Conversion (OTEC): Executive briefing  

NASA Astrophysics Data System (ADS)

The results of an independent quantitative evaluation of Ocean Thermal Energy Conversion (OTEC) for central station applications are summarized. A central station power plant located in the Gulf of Mexico and delivering power to the mainland United States was emphasized. The evaluation of OTEC is based on three important issues: resource availability, technical feasibility, and cost.

Gritton, E. C.; Pei, R. Y.; Hess, R. W.

1980-08-01

301

Nondestructive Evaluation of Strain Distribution and Fatigue Distribution from Austenitic Stainless Steel by Using Magnetic Sensors  

Microsoft Academic Search

Austenitic stainless steel transforms from austenitic crystal structure to martensitic crystal structure after applying strain or stress. Because martensitic crystal structures have magnetization, strain evaluation and fatigue evaluation can be performed by measuring magnetic properties. This paper describes the measurement of leakage magnetic flux density of remanent magnetization for the strain evaluation and the fatigue evaluation by a typical Hall

Y. Tsuchida; M. Oka; T. Yakushiji; M. Enokizono

2007-01-01

302

Waterless Coupling of Ultrasound from Planar Contact Transducers to Curved and Irregular Surfaces during Non-destructive Ultrasonic Evaluations  

SciTech Connect

The Applied Physics group at the Pacific The Applied Physics group at the Pacific Northwest National Laboratory (PNNL) in Richland, WA has evaluated a method for waterless/liquidless coupling of ultrasonic energy from planar ultrasonic contact transducers to irregular test surfaces for ultrasonic non-destructive evaluation applications. Dry couplant material placed between a planar transducer face and a curved or uneven steel or plastic surface allows for effective sound energy coupling and preserves the integrity of the planar transducer sound field by serving as an acoustic impedance matching layer, providing good surface area contact between geometrically dissimilar surfaces and conforming to rough and unsmooth surfaces. Sound fields radiating from planar ultrasonic contact transducers coupled to curved and uneven surfaces using the dry coupling method were scanned and mapped using a Pinducer receiver connected to a raster scanner. Transducer sound field coverage at several ultrasonic frequencies and several distances from the transducer contact locations were found to be in good agreement with theoretical beam divergence and sound field coverage predictions for planar transducers coupled to simple, planar surfaces. This method is valuable for applications that do not allow for the use of traditional liquid-based ultrasonic couplants due to the sensitivity of the test materials to liquids and for applications that might otherwise require curved transducers or custom coupling wedges. The selection of dry coupling material is reported along with the results of theoretical sound field predictions, the laboratory testing apparatus and the empirical sound field data.

Denslow, Kayte M.; Diaz, Aaron A.; Jones, Anthony M.; Meyer, Ryan M.; Cinson, Anthony D.; Wells, Mondell D.

2012-04-30

303

Amplitude modulated acousto-ultrasonic non-destructive testing: Damage evaluation in concrete  

Microsoft Academic Search

As civil infrastructure ages it is pertinent that existing structures are evaluated on the basis of both performance and durability. Additionally, new materials and construction methods must be similarly evaluated in order to promote research and development in civil engineering. A literature search shows that current practice relies primarily on destructive testing for performance evaluation and life span measurements and\\/or

Kraig Warnemuende

2006-01-01

304

Three dimensional ultrasonic imaging: An aging aircraft nondestructive inspection tool.  

National Technical Information Service (NTIS)

Ultrasonic nondestructive evaluation is a valuable technique for finding defects in aircraft structures. It can detect unbonds, corrosion damage and cracks in various aircraft components. Ultrasonic nondestructive evaluation techniques interrogate materia...

G. H. Thomas S. Benson S. Crawford

1993-01-01

305

Radiation applications in art and archaeometry X-ray fluorescence applications to archaeometry. Possibility of obtaining non-destructive quantitative analyses  

NASA Astrophysics Data System (ADS)

The possibility of obtaining quantitative XRF analysis in archaeometric applications is considered in the following cases: (i) Examinations of metallic objects with irregular surface: coins, for instance. (ii) Metallic objects with a natural or artificial patina on the surface. (iii) Glass or ceramic samples for which the problems for quantitative analysis rise from the non-detectability of matrix low Z elements. The fundamental parameter method for quantitative XRF analysis is based on a numerical procedure involving he relative values of XRF lines intensity. As a consequence it can be applied also to the experimental XRF spectra obtained for metallic objects if the correction for the irregular shape consists only in introducing a constant factor which does not affect the XRF intensity relative value. This is in fact possible in non-very-restrictive conditions for the experimental set up. The finenesses of coins with a superficial patina can be evaluated by resorting to the measurements of Rayleigh to Compton scattering intensity ratio at an incident energy higher than the one of characteristic X-ray. For glasses and ceramics the measurements of the Compton scattered intensity of the exciting radiation and the use of a proper scaling law make possible to evaluate the matrix absorption coefficients for all characteristic X-ray line energies.

Milazzo, Mario

2004-01-01

306

Evaluation of non-destructive methods for estimating biomass in marshes of the upper Texas, USA coast  

Microsoft Academic Search

The estimation of aboveground biomass is important in the management of natural resources. Direct measurements by clipping,\\u000a drying, and weighing of herbaceous vegetation are time-consuming and costly. Therefore, non-destructive methods for efficiently\\u000a and accurately estimating biomass are of interest. We compared two non-destructive methods, visual obstruction and light penetration,\\u000a for estimating aboveground biomass in marshes of the upper Texas, USA

Matthew Whitbeck; James B. Grace

2006-01-01

307

Nondestructive Evaluation of Strain Distribution and Fatigue Distribution from Austenitic Stainless Steel by Using Magnetic Sensors  

SciTech Connect

Austenitic stainless steel transforms from austenitic crystal structure to martensitic crystal structure after applying strain or stress. Because martensitic crystal structures have magnetization, strain evaluation and fatigue evaluation can be performed by measuring magnetic properties. This paper describes the measurement of leakage magnetic flux density of remanent magnetization for the strain evaluation and the fatigue evaluation by a typical Hall element sensor for SUS 304 and SUS 304L and by a high-sensitivity thin-film flux-gate magnetic sensor for SUS 316 and SUS 316L.

Tsuchida, Y.; Enokizono, M. [Department of Electrical and Electronic Engineering, Oita University, 700 Dannoharu, Oita 870-1192 (Japan); Oka, M.; Yakushiji, T. [Department of Computer and Control Engineering, Oita National College of Technology, 1666 Maki, Oita 870-0152 (Japan)

2007-03-21

308

Studies in nondestructive testing with potential for in-service inspection of LMFBRs  

Microsoft Academic Search

A variety of nondestructive examination techniques have been and are ; being developed at ORNL with potential for ISI in LMFBRs. Among these are ; radiographic techniques for radiation environment and image enhancement, advanced ; eddy-current techniques and equipment for flaw detection and thickness ; measurement and ISI of steam generator tubing, and ultrasonic methods for ; quantitative flaw evaluation

McClung

1976-01-01

309

A comparison of traditional and emerging ultrasonic methods for the nondestructive evaluation of polymer matrix composites subjected to impact damage  

NASA Astrophysics Data System (ADS)

This paper presents the results of a comparison study of three ultrasonic nondestructive evaluation (NDE) methods applied to polymer matrix composite (PMC) specimens subjected to impact damage. Samples mainly consisted of various thicknesses of graphite/epoxy coupon panels impacted with various energy levels. Traditional pulse-echo and through transmission ultrasonic c-scan techniques were applied to impacted samples and served as the basis for comparison. Specimens were then inspected using acoustography, a large field ultrasonic inspection technique that is analogous to real-time X-ray imaging. Acoustography utilizes a unique, wide area two-dimensional (2-D) detector, called an acousto-optic (AO) sensor, to directly convert ultrasound into visual images; much like an image intensifier in real-time radiography. Finally, a newly developed guided wave scanning system was utilized to inspect the same set of samples. This system uses two transducers in a pitch catch configuration to examine the total (multi-mode) ultrasonic response in its inspection analysis. Several time- and frequency-domain parameters are calculated from the ultrasonic guided wave signal at each scan location to form images. Results are presented for all of the methods demonstrating each technique's detection capabilities and highlighting their advantages and disadvantages.

Martin, Richard E.; Roth, Donald J.; Pergantis, Charles G.; Sandhu, Jaswinder S.

2004-07-01

310

Nondestructive Evaluation (NDE) Techniques Assessment for Graphite/Epoxy (Gr/Ep) Composite Overwrapped Pressure Vessels.  

National Technical Information Service (NTIS)

NDE methods evaluated included eddy current measurements, ultrasonics, radiography, acoustic emission monitoring, acoustic-ultrasonics, and interferometric (e.g., shearography) methods. The major interest was in the detection of damage to COPVs caused by ...

E. C. Johnson J. P. Nokes

1998-01-01

311

Nondestructive Evaluation of the Structural Condition of Timber Piles. Volumes 1 and 2.  

National Technical Information Service (NTIS)

Condition evaluation of timber piles is currently based on traditional methods of visual inspection and sounding. Unfortunately, this method is vague and in many cases relies on interpretation of information and not on measurable parameters. Because nonde...

C. M. Murphy P. J. Donato S. R. Ranjithan Y. R. Kim

2000-01-01

312

950 keV, 3.95 MeV and 6 MeV X-band linacs for nondestructive evaluation and medicine  

Microsoft Academic Search

We are developing compact X-band linac X-ray sources for nondestructive evaluation and medicine. First, we develop a portable X-ray system by a 950keV 9.4GHz X-band linac to realize on-site inspection. We use a low power (250kW) magnetron as an RF source for compactness of the whole system. Since the RF power source is quite small and the stored energy in

Mitsuru Uesaka; Takuya Natsui; Kiwoo Lee; Katsuhiro Dobashi; Tomohiko Yamamoto; Takeshi Fujiwara; Haito Zhu; Kazuyuki Demachi; Eiji Tanabe; Masashi Yamamoto; Naoki Nakamura; Joichi Kusano; Toshiyasu Higo; Shigeki Fukuda; Mitsuhiro Yoshida; Shuji Matsumoto

2011-01-01

313

Quantitative, Notional, and Comprehensive Evaluations of Spontaneous Engaged Speech  

ERIC Educational Resources Information Center

|This study provides specific evidence regarding the extent to which quantitative measures, common sense notional measures, and comprehensive measures adequately characterize spontaneous, although engaged, speech. As such, the study contributes to the growing body of literature describing the current limits of automatic systems for evaluating

Molholt, Garry; Cabrera, Maria Jose; Kumar, V. K.; Thompsen, Philip

2011-01-01

314

Some Quantitative Evaluations of the Disk of Phaistos Text  

Microsoft Academic Search

The Disk of Phaistos (Minoan, presumably about 1700 BC.) contains the earliest printed text presently known. One century of research on this object has brought about a relative convergence of opinions, but no conclusive answers. The quantitative evaluations of the Disk text presented here give additional clues which support and, in part, question the main opinion and allow one to

Dieter Rumpel

1994-01-01

315

Quantitative vs. Qualitative Approaches to Quality Special Education Program Evaluation.  

ERIC Educational Resources Information Center

|One in a series of issue papers commissioned by the Council of Administrators of Special Education (CASE), this document presents a comparison of contemporary evaluation approaches for special education programs. The first section describes the two approaches to be compared: (1) traditional scientific inquiry which emphasizes quantitative

Council of Administrators of Special Education, Inc.

316

Quantitative design and evaluation of enhancement\\/thresholding edge detectors  

Microsoft Academic Search

Quantitative design and performance evaluation techniques are developed for the enhancement\\/thresholding class of image edge detectors. The design techniques are based on statistical detection theory and deterministic pattern-recognition classification procedures. The performance evaluation methods developed include: a)deterministic measurement of the edge gradient amplitude; b)comparison of the probabilities of correct and false edge detection; and c) figure of merit computation. The

I. E. Abdou; W. K. Pratt

1979-01-01

317

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation  

Microsoft Academic Search

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD

Liang Chen; Xing Li; Xun-Bo Li; Zuo-Ying Huang

2009-01-01

318

Laser modulated scattering as a nondestructive evaluation tool for optical surfaces and thin film coatings  

Microsoft Academic Search

Laser modulated scattering (LMS) is introduced as a non- destruction evaluation tool for defect inspection and characterization of optical surface sand thin film coatings. It allows simultaneous measurement of the DC and AC scattering signals of a probe laser beam from an optical surface. by comparison between the DC and AC scattering signals, one can differentiate absorptive defects from non-

Zhouling Wu; Michael D. Feit; Mark R. Kozlowski; Alexander M. Rubenchik; Lynn M. Sheehan

1999-01-01

319

Design, evaluation and implementation of an automated nondestructive leak test for integrated-circuit assemblies  

Microsoft Academic Search

The paper is concerned with the design and evaluation of an automated electrical conductivity leak test, in which methanol is made to leak into the externally pressurized defective assembly, and evidence of the leak is determined by the increase in the electrical conductance between insulated components of a hermetically sealed IC assembly. The ultimate test involves both transport of matter

R. J. Koftan; E. M. Mielnik; J. S. Ramberg

1977-01-01

320

Nondestructive evaluation of volumetric shrinkage of compacted mixtures using digital image analysis  

Microsoft Academic Search

Adapting image processing technology to engineering disciplines can be useful in the evaluation of the mechanical behavior of materials. Not only characteristics of granular materials, but also particulate levels of colloids can be studied using image analysis. Attempts to identify the volume change of soils or compacted specimens have been made since late 1990s. Some of the previous studies were

Ali Hakan Ören; Okan Önal; Gürkan Özden; Abidin Kaya

2006-01-01

321

Evaluation of Ge(Li) Compton suppression spectrometers for non-destructive radiochemical analysis  

Microsoft Academic Search

Ge(Li) Compton suppression spectrometers are evaluated relative to the specific needs of the analytical radiochemist. Their\\u000a application to the analysis of radionuclides found in neutron activation, fission product, and environmental radionuclide\\u000a analyses is discussed.

J. A. Cooper

1970-01-01

322

Evaluation of a nondestructive diagnostic test for Kudoa thyrsites in farmed Atlantic salmon ( Salmo salar)  

Microsoft Academic Search

Postharvest myoliquefaction (soft flesh) associated with Kudoa thyrsites infections is a concern to the Atlantic salmon (Salmo salar) industry in the Pacific Northwest. Infection with this parasite is not macroscopically visible in salmon, and thus infected fish are not readily detectable on the processing line. Identification of infected fish relies on either histological or whole-mount evaluation of muscle tissue. A

Sophie St-Hilaire; Carl Ribble; David J. Whitaker; Michael L. Kent

1997-01-01

323

NONDESTRUCTIVE EVALUATION OF IN VITRO-STORED PLANTS: A COMPARISON OF VISUAL AND IMAGE ANALYSIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

In vitro plants in slow-growth storage require routine evaluation for assessment of viability and timing of repropagation. Determination of plantlet health by visual assessment is subjective and varies by genus due to variations in growth pattern and plant structure. Developing a standardized syste...

324

Review of Advanced Acoustical Imaging Techniques for Nondestructive Evaluation of Art Objects  

Microsoft Academic Search

Proper preventative diagnosis of different art objects, including wooden, bronze and marble sculptures, frescoes, and paintings (on canvas, wood, metal, and glass), is very important for conservation purposes. Various advanced ultrasonic imaging methods for analysis and assessment of art objects can bring about drastic changes in the regular evaluation and inventory carried out by museums and can bring advanced, powerful,

R. G. Maev; R. E. Green Jr; A. M. Siddiolo

2006-01-01

325

Nondestructive Evaluation of Polarization in LTCC\\/PZT Piezoelectric Modules by Thermal Wave Methods  

Microsoft Academic Search

This work investigates the polarization behavior of low-temperature cofired ceramic (LTCC)\\/PZT sensor-actuator-modules fabricated by packaging of ceramic PZT plates between alumosilicate-corundum LTCC green layers and subsequent sintering at elevated temperatures. Polarization evaluation was done by applying the laser intensity modulation method (LIMM) where a thermal wave travelling into the ferroelectric PZT ceramic plate is generated by an intensity-modulated laser beam.

G. Suchaneck; W. Hu; G. Gerlach; M. Flössel; S. Gebhardt; A. Schönecker

2011-01-01

326

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

NASA Astrophysics Data System (ADS)

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.

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

2000-05-01

327

Guidelines to Evaluate Human Observational Studies for Quantitative Risk Assessment  

PubMed Central

Background Careful evaluation of the quality of human observational studies (HOS) is required to assess the suitability of HOS for quantitative risk assessment (QRA). In particular, the quality of quantitative exposure assessment is a crucial aspect of HOS to be considered for QRA. Objective We aimed to develop guidelines for the evaluation of HOS for QRA and to apply these guidelines to case–control and cohort studies on the relation between exposure to benzene and acute myeloid leukemia (AML). Methods We developed a three-tiered framework specific for the evaluation of HOS for QRA and used it to evaluate HOS on the relation between exposure to benzene and AML. Results The developed framework consists of 20 evaluation criteria. A specific focus of the framework was on the quality of exposure assessment applied in HOS. Seven HOS on the relation of benzene and AML were eligible for evaluation. Of these studies, five were suitable for QRA and were ranked based on the quality of the study design, conduct, and reporting on the study. Conclusion The developed guidelines facilitate a structured evaluation that is transparent in its application and harmonizes the evaluation of HOS for QRA. With the application of the guidelines, it was possible to identify studies suitable for QRA of benzene and AML and rank these studies based on their quality. Application of the guidelines in QRA will be a valuable addition to the assessment of the weight of evidence of HOS for QRA.

Vlaanderen, Jelle; Vermeulen, Roel; Heederik, Dick; Kromhout, Hans

2008-01-01

328

Geometrical optimization of sensors for eddy currents nondestructive testing and evaluation  

SciTech Connect

Design of Non Destructive Testing (NDT) and Non Destructive Evaluation (NDE) sensors is possible by solving Maxwell`s relations with FEM or BIM. But the large number of geometrical and electrical parameters of sensor and tested material implies many results that don`t give necessarily a well adapted sensor. The authors have used a genetic algorithm for automatic optimization. After having tested this algorithm with analytical solution of Maxwell`s relations for cladding thickness measurement, the method has been implemented in finite element package.

Thollon, F.; Burais, N. [Ecole Centrale de Lyon, Ecully (France). Dept. Electrotechnique

1995-05-01

329

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOEpatents

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member. 6 figures.

Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

1995-01-24

330

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOEpatents

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.

Bible, Don W. (Clinton, TN); Crutcher, Richard I. (Knoxville, TN); Sohns, Carl W. (Oak Ridge, TN); Maddox, Stephen R. (Loudon, TN)

1995-01-01

331

Exploratory nondestructive evaluation (NDE) research for advanced materials and processes: Volume 3 -- Interactive multimedia computer based training (IMCBT) for nondestructive evaluation\\/inspection (NDE\\/I) personnel. Final report, 1 July 1995--30 April 1998  

Microsoft Academic Search

Interactive Multimedia Computer Based Training (IMCBT) for Nondestructive Inspection (NDE\\/I) Personnel: Computer Based Training (CBT) is a highly effective method for industrial training that has been growing in popularity. Text, graphics, sound, movies and animation enhance the learning activity. Interactive Multimedia CBT (IMCBT) allows students to learn in an environment where the training material is presented on a computer workstation

Bossi; B. Knutson; R. Nerenberg; L. Deobald; J. Nelson

1998-01-01

332

Analysis of Microstructure Using Thermoelectric Diagnostics for Non-Destructive Evaluation of Materials  

NASA Astrophysics Data System (ADS)

Measurements of Thermoelectric power (TEP) were used to evaluate microstructural analysis in HSLA steel weldments and retained austenite volume fraction for TRIP steel. First, the measurements of TEP for weld microstructure across weldment have shown good correlation with hardness profile. The different TEP values indicated that changes in weld microstructure can be correlated with TEP values measured. Second, it was demonstrated that retained austenite volume fraction were well correlated to TEP measurements for transformation induced plasticity (TRIP) steels. The results suggest that TEP measurements can be correlated to retained austenite volume fraction for TRIP steels, which do not have same chemical composition and thermal heat treatment processes. The retained austenite volume fraction also was measured by X-ray diffraction (XRD) method. With the introduction of these advanced TEP coefficient measurement techniques, the welding and steel industry will be using analytical tools similar to those instruments applied in the semiconductor industry.

Park, Y. D.; Kaydanov, V. I.; Mishra, B.; Olson, D. L.

2005-04-01

333

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics  

SciTech Connect

Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction of component performance and the development of process technology. Knowledge of the degradation extent of fiber tows or monofilament degradation after processing, extent of open porosity before densification, and filament/fiber alignments before and after processing are also examples of important variables to be measured. Work in this program has emphasized continuous fiber ceramic matrix composites (CFCCs) that use chemical vapor infiltration (CVI)-infiltrated SiC/SiC materials, primarily those made of Nicalon satin or plain weave with 16 {times} 16 tows/in. in 2-D layups. All studied samples were provided by Oak Ridge National Laboratory and were made using 100 layers per inch. CVI specimens with 0/30/60, 0/90, and 0/45 were examined by 3-D X-ray microtomography to characterize in-plane fiber orientations. Current information suggests that for Nicalon-type fiber architecture, a {plus minus}2--1/2{degrees} misalignment may not affect mechanical properties. Thus the near-term goal has been to establish a detection capability for angular orientation. By using 512 {times} 512 images from 3-D X-ray CT data with pixel sizes of < 140 {mu}m and a special 2-D fast-Fourier transform image processing analysis, we have shown that fiber orientations to {plus minus}2--1/2{degrees} with SiC/SiC CVI type 2-D weave architecture can be measured.

Ellingson, W.A.; Singh, J.P.; Holloway, D.L.; Dieckman, S.L.; Singh, D.; Sivers, E.A.; Sheen, S.H.; Wheeler, M.J.

1992-05-01

334

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics  

SciTech Connect

Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction of component performance and the development of process technology. Knowledge of the degradation extent of fiber tows or monofilament degradation after processing, extent of open porosity before densification, and filament/fiber alignments before and after processing are also examples of important variables to be measured. Work in this program has emphasized continuous fiber ceramic matrix composites (CFCCs) that use chemical vapor infiltration (CVI)-infiltrated SiC/SiC materials, primarily those made of Nicalon satin or plain weave with 16 {times} 16 tows/in. in 2-D layups. All studied samples were provided by Oak Ridge National Laboratory and were made using 100 layers per inch. CVI specimens with 0/30/60, 0/90, and 0/45 were examined by 3-D X-ray microtomography to characterize in-plane fiber orientations. Current information suggests that for Nicalon-type fiber architecture, a {plus_minus}2--1/2{degrees} misalignment may not affect mechanical properties. Thus the near-term goal has been to establish a detection capability for angular orientation. By using 512 {times} 512 images from 3-D X-ray CT data with pixel sizes of < 140 {mu}m and a special 2-D fast-Fourier transform image processing analysis, we have shown that fiber orientations to {plus_minus}2--1/2{degrees} with SiC/SiC CVI type 2-D weave architecture can be measured.

Ellingson, W.A.; Singh, J.P.; Holloway, D.L.; Dieckman, S.L.; Singh, D.; Sivers, E.A.; Sheen, S.H.; Wheeler, M.J.

1992-05-01

335

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation  

NASA Astrophysics Data System (ADS)

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD method. The EEMD defines the true intrinsic mode function (IMF) components as the mean of an ensemble of trials, each consisting of the signal plus a white noise of finite amplitude. Moreover, sparsity selection restriction was defined. Then, The MFL signal is decomposed into several IMFs used for signal reconstruction. Some modes are selected to reconstruct a new signal considering their sparsity. Finally, the comparison is made with the empirical mode decomposition. At the same time, the comparison of the selection restriction between the sparsity and the energy is described. The results show that the EEMD and the sparsity is an efficient technology with the pipeline flaw extraction.

Chen, Liang; Li, Xing; Li, Xun-Bo; Huang, Zuo-Ying

2009-02-01

336

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation.  

PubMed

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD method. The EEMD defines the true intrinsic mode function (IMF) components as the mean of an ensemble of trials, each consisting of the signal plus a white noise of finite amplitude. Moreover, sparsity selection restriction was defined. Then, The MFL signal is decomposed into several IMFs used for signal reconstruction. Some modes are selected to reconstruct a new signal considering their sparsity. Finally, the comparison is made with the empirical mode decomposition. At the same time, the comparison of the selection restriction between the sparsity and the energy is described. The results show that the EEMD and the sparsity is an efficient technology with the pipeline flaw extraction. PMID:19256676

Chen, Liang; Li, Xing; Li, Xun-bo; Huang, Zuo-ying

2009-02-01

337

Non-Destructive Evaluation of Fatigue Damage for SUS316 by Using Electromagnetic Methods  

NASA Astrophysics Data System (ADS)

There are some fatigue damage estimation methods for an austenitic stainless steel that uses martensitic transformation. For instance, those are the remanent magnetization method, the excitation method using the differential pick-up coil, and so on. We are researching also those two methods in our laboratory now. In the remanent magnetization method, it is well known that the relationship between fatigue damage and the remanent magnetization is simple, clear, and reproducible. In addition, the excitation method can be easily used at the job site because the special magnetizer is unnecessary. But, these methods have some disadvantages shown as follows. For instance, the former needs a special magnetizer and the latter's output signal is small. On the other hand, it is well known that the inductance of a pancake type coil put on the metallic specimen changes according to the electromagnetic properties of the metallic specimen. In this paper, the assessment method of fatigue of an austenitic stainless steel (SUS316) that uses the change by fatigue of the inductance of the pancake type coil measured with the LCR meter is shown. In addition, the fatigue evaluation performance of this method is described.

Oka, M.; Tsuchida, Y.; Yakushiji, T.; Enokizono, M.

2009-03-01

338

Experimental evaluation of electromagnetic-thermal non-destructive inspection by eddy current thermography in square aluminum plates  

Microsoft Academic Search

The performance of electromagnetic-thermal non-destructive inspection is investigated experimentally by eddy current thermography. The experiments concerned the detection of the crack in ten square aluminum plates at various positions and orientations. For the excitation are employed two circular coils with an outer diameter either smaller or comparable to the plate side. Crack detection is based not only on the thermograms,

N. Tsopelas; N. J. Siakavellas

2011-01-01

339

Progress in the Nondestructive Evaluation of CF-18 Composite Flight Controls for Water Ingress and Related Damage.  

National Technical Information Service (NTIS)

In late 1995, the CF Nondestructive Testing Center (NDTC) at the Aerospace and Telecommunications Engineering Support Squadron (ATESS) in CFB trenton arranged for a CF-18 to be sent and tested at the neutron radiography and X-ray facility at McClellan AFB...

B. A. Lepine K. I. McRae

1998-01-01

340

2D and 3D non-destructive evaluation of a wooden panel painting using shearography and terahertz imaging  

Microsoft Academic Search

Structural diagnostics information about artwork is commonly obtained by adapting and applying non-destructive testing techniques from engineering. Shearography is a technique well known for type inspection, and for structural analysis in automotive, aerospace and industrial applications. In art conservation, a limited number of shearography sensors are in use at museums and research institutes throughout the world for detecting surface and

R. M. Groves; B. Pradarutti; E. Kouloumpi; W. Osten; G. Notni

2009-01-01

341

Quantitative Evaluation for Two-Dimensional Electromagnetic Propagation in a Dielectric Medium using Markov Chain Monte Carlo Method (Preprint).  

National Technical Information Service (NTIS)

The motivation of this work is to quantify the degradation of aging electrical cables. The dielectric material parameter of insulation can be correlated with degradation. In this paper, the forward problem is posed as a microwave nondestructive evaluation...

F. Kojima J. S. Knopp

2012-01-01

342

Resonant Ultrasound Spectroscopy, as Applied to Nondestructive Evaluation and Characterization of Carbon Fiber Reinforced Epoxy Composite Materials.  

NASA Astrophysics Data System (ADS)

Resonant ultrasound spectroscopy (RUS) can be an elegantly simple nondestructive evaluation tool. The resonance spectrum of any specimen is dependent on, and sensitive at ppm levels to, its density, geometry, elastic and thermal properties, and boundary conditions. The measurement of spectrum is fast, taking between 15 and 90 seconds with state-of-the-art instrumentation, making it appropriate for following properties as a function of temperature. Parts per million changes in specimen density, geometry, elastic moduli, temperature, and boundary conditions are detected with RUS. A novel apparatus is presented for driving and detecting the mechanical resonance of objects with major dimensions ranging from 0.1 cm to 33 cm. The noise floor of the apparatus is characterized using a high Q titanium alloy and a low Q graphite/epoxy composite. The apparatus is used to measure the amplitude/frequency resonance spectra of right rectangular parallelepiped (RRP) specimens of four different lay-ups of AS4/3501-6 carbon fiber reinforced epoxy (CFRE) composite material at room temperature and at one degree C intervals between -177^circC and 25 ^circC. It is important to know the mechanical properties of this material at low temperatures for underwater, polar, and space applications. The temperature dependence of the second order elastic moduli are calculated from the resonance spectra of the AS4/3501-6 RRPs. High power ultrasound is used to enhance the cure of AS4/3501-6 CFRE composite. Composite panels are insonified through the caul plate, by a high power ultrasonic horn, while curing. Stiffness enhancements of five percent are observed. The resonance spectrum of a steel caul plate is used to monitor the degree of cure of AS4/3501-6 CFRE composite panels in real time. Because the curing composite acts to change the boundary conditions, the resonance spectrum changes as the composite cures. RUS is used to screen a variety of high precision engineered parts for mechanical defects. The second order elastic moduli of poly-crystalline Ti6Al4V alloy and single crystal aluminum are determined using RUS.

Whitney, Timothy Marvin

1996-08-01

343

Quantitative Evaluation of Heat Crack Initiation Condition Under Thermal Shock  

NASA Astrophysics Data System (ADS)

In this paper, we have proposed an evaluation method for the initiation conditions of heat crack under thermal shock using the tensile test of a notched specimen. In some materials, such as hot rolling rolls and dies for aluminum die-casting, there is a problem of heat crack initiation, and the evaluation of heat crack resistance using test pieces was difficult until now. The thermal stress and stress gradient that occurred in such material were analyzed by the finite element method (FEM). The maximum stress when tensile stress was applied to the material with a notch was compared to the stress gradient of the thermal stress. As a result, the quantitative evaluation during the initiation conditions of a heat crack for materials became possible.

Sonoda, Akio; Kashiwagi, Suguru; Hamada, Shigeru; Noguchi, Hiroshi

344

Why Not Enlarge the Non-Destructive Testing (NDT) Experience in Construction Maintenance - Problems, Practice, Ideas etc. ?  

Microsoft Academic Search

In the construction area evaluation visual methods and e xpertise predominate. But modern inspection needs quantitative mechanical parameters non-destructively (ND) received. Many ND techniques are developed in the NDT area. The main problem is that the great success reached in ND T methods development is predominantly for the homogenous materials, as metals, i n the most cases iron products -

Valentin D. VLADIMIROV

345

Nondestructive quantitative analysis of a heavy element in solution or suspension by single-shot computed tomography with a polychromatic X-ray source.  

PubMed

X-ray computed tomography (CT) images obtained with a polychromatic X-ray source were simulated by computer for homogeneous solutions and suspensions containing a heavy element. When the K-edge of the element was near the peak energy of the polychromatic X-ray spectrum, the degree of beam hardening in the simulated CT image strongly depended on the atomic number and molar concentration of the heavy element. We analyzed the beam hardening of a single measured CT image of a CeCl(3) aqueous solution sample, and successfully estimated the atomic number and the molar concentration of Ce simultaneously within a certain error. This single-shot, or single-energy (as opposed to dual-energy), CT method permits quick, nondestructive screening of a hazardous heavy element in a solution or suspension confined in a container. PMID:23232231

Nakashima, Yoshito; Nakano, Tsukasa

2012-01-01

346

Quantitative evaluation of intracellular degradation in Entamoeba invadens.  

PubMed

A quantitative study on digestion of erythrocytes by Entamoeba invadens was attempted. Trophozoites of the IP-1 strain were fed red blood cells for 30 min, and subsequently phagocytosis was stopped by means of osmotic shock; post-phagocytosis incubations for up to 15 h were made in order to evaluate intracellular digestion, after staining the red blood cells with benzidine. Eighty-two per cent of trophozoites were capable of phagocytosing erythrocytes, containing an average of 5.5 erythrocytes per amoeba. Erythrocyte digestion within amoebae was shown by loss of benzidine-stainable material and proceeded with a first-order kinetics, with a t1/2 approximately 7 h. Within 15 h there were no amoebae containing erythrocytes. The procedure described may be useful for the evaluation of intracellular digestion in other Entamoeba species. PMID:2332279

Ramírez-Córdova, J D; Ramírez-Romo, S; Mora-Galindo, J

1990-04-01

347

Computer modeling of eddy current nondestructive testing  

SciTech Connect

Nondestructive evaluation (NDE) is to materials what CAT scanning is to the human body--an attempt to look inside without opening up the body. As in CAT scanning, modern NDE requires sophisticated mathematical software to perform its function. This is especially true with regard to quantitative NDE, wherein an attempt is made to quantify defects, that is, determine their size, location, and even shape rather than just to detect their presence. Low-frequency electromagnetic methods using eddy currents are a traditional mode of doing NDE (approximately 35 percent of NDE uses eddy currents, depending upon the specific application), but the technology still suffers from a lack of algorithms and software to allow its full potential to be realized. In this article the authors will describe a computer code that was developed to alleviate that problem.

Sabbagh, H.A.; Treece, J.C.; Murphy, R.K.; Woo, Lai Wan (Sabbagh Association, Inc., Bloomington, IN (United States))

1993-11-01

348

A first evaluation of the usefulness of feathers of nestling predatory birds for non-destructive biomonitoring of persistent organic pollutants.  

PubMed

In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway: northern goshawks (Accipiter gentilis), white-tailed eagles (Haliaeetus albicilla) and golden eagles (Aquila chrysaetos). We were able to detect a broad spectrum of legacy POPs in the nestling feathers of all three species (? PCBs: 6.78-140ng g(-1); DDE: 3.15-145ng g(-1); ? PBDEs: 0.538-7.56ng g(-1)). However, these concentrations were lower compared to other studies on raptor species, probably due to the aspect of monitoring of nestlings instead of adults. Besides their analytical suitability, nestling feathers also appear to be biologically informative: concentrations of most POPs in nestling feathers showed strong and significant correlations with blood plasma concentrations in all species (p<0.050; 0.775non-destructive biomonitoring strategy for POPs in their ecosystems. PMID:21256594

Eulaers, Igor; Covaci, Adrian; Herzke, Dorte; Eens, Marcel; Sonne, Christian; Moum, Truls; Schnug, Lisbeth; Hanssen, Sveinn Are; Johnsen, Trond Vidar; Bustnes, Jan Ove; Jaspers, Veerle L B

2011-01-21

349

Exploring quantitative methods for evaluation of lip function.  

PubMed

The objective was to explore quantitative methods for the measurement of lip mobility and lip force and to relate these to qualitative assessments of lip function. Fifty healthy adults (mean age 45 years) and 23 adults with diagnoses affecting the facial muscles (mean age 37 years) participated in the study. Diagnoses were Möbius syndrome (n=5), Facioscapulohumeral muscular dystrophy (n=6) and Myotonic dystrophy type 1 (n=12). A system for computerised 3D analysis of lip mobility and a lip force meter were tested, and the results were related to results from qualitative assessments of lip mobility, speech (articulation), eating ability and saliva control. Facial expressions studied were open mouth smile and lip pucker. Normative data and cut-off values for adults on lip mobility and lip force were proposed, and the diagnostic value of these thresholds was tested. The proposed cut-off values could identify all inviduals with moderate or severe impairment of lip mobility but not always the milder cases. There were significant correlations between the results from quantitative measurements and qualitative assessments. The examined instruments for measuring lip function were found to be reliable with an acceptable measuring error. The combination of quantitative and qualitative ways to evaluate lip function made it possible to show the strong relation between lip contraction, lip force, eating ability and saliva control. The same combination of assessments can be used in the future to study if oral motor exercises aimed at improving lip mobility and strength could have a positive effect on lip function. PMID:20969612

Sjögreen, L; Lohmander, A; Kiliaridis, S

2010-10-23

350

Quantitative evaluation of simulated human enamel caries kinetics using photothermal radiometry and modulated luminescence  

Microsoft Academic Search

Photothermal radiometry and modulated luminescence (PTR-LUM) is a non-destructive methodology applied toward the detection, monitoring and quantification of dental caries. The purpose of this study was to evaluate the efficacy of PTRLUM to detect incipient caries lesions and quantify opto-thermophysical properties as a function of treatment time. Extracted human molars (n=15) were exposed to an acid demineralization gel (pH 4.5)

Adam Hellen; Andreas Mandelis; Yoav Finer; Bennett T. Amaechi

2011-01-01

351

Quantitative evaluation of the kinetics of human enamel simulated caries using photothermal radiometry and modulated luminescence  

Microsoft Academic Search

Photothermal radiometry and modulated luminescence (PTR-LUM) is an emerging nondestructive methodology applied toward the characterization and quantification of dental caries. We evaluate the efficacy of PTR-LUM in vitro to detect, monitor, and quantify human enamel caries. Artificial caries are created in extracted human molars (n = 15) using an acidified gel system (pH 4.5) for 10 or 40 days. PTR-LUM

Adam Hellen; Andreas Mandelis; Yoav Finer; Bennett T. Amaechi

2011-01-01

352

Evaluation of Slit Sampler in Quantitative Studies of Bacterial Aerosols  

PubMed Central

Quantitative studies were conducted to evaluate the efficiency of the slit sampler in collecting airborne Serratia marcescens and Bacillus subtilis var. niger, and to compare it with the collecting efficiency of the all-glass impinger AGI-30. The slit sampler was approximately 50% less efficient than the AGI-30. This ratio remained the same whether liquid or dry cultures were disseminated when the sample was taken at 2 min of aerosol cloud life. At 30 min of aerosol cloud life, this ratio was approximately 30% for B. subtilis var. niger. S. marcescens recoveries by the slit sampler were, however, only 17% lower than the AGI-30 at 30 min of cloud age, indicating a possible interaction involving the more labile vegetative cells, aerosol age, and method of collection.

Ehrlich, Richard; Miller, Sol; Idoine, L. S.

1966-01-01

353

Evaluation of slit sampler in quantitative studies of bacterial aerosols.  

PubMed

Quantitative studies were conducted to evaluate the efficiency of the slit sampler in collecting airborne Serratia marcescens and Bacillus subtilis var. niger, and to compare it with the collecting efficiency of the all-glass impinger AGI-30. The slit sampler was approximately 50% less efficient than the AGI-30. This ratio remained the same whether liquid or dry cultures were disseminated when the sample was taken at 2 min of aerosol cloud life. At 30 min of aerosol cloud life, this ratio was approximately 30% for B. subtilis var. niger. S. marcescens recoveries by the slit sampler were, however, only 17% lower than the AGI-30 at 30 min of cloud age, indicating a possible interaction involving the more labile vegetative cells, aerosol age, and method of collection. PMID:4961550

Ehrlich, R; Miller, S; Idoine, L S

1966-05-01

354

Evaluation of statistical approaches in quantitative nursing research.  

PubMed

The purposes of this study were to (a) develop a tool to assess statistical methods and (b) use the tool to evaluate recently published quantitative research. We rated the statistical approaches used in 152 studies published in the 5 top impact-factor nursing research journals from September 2005 to August 2007. Studies were generally of high quality; 45% scored between 80% and 100%, and 22% achieved a score of 100%. Predictors of high scores were interdisciplinary authorship, a statistician coauthor, and the number of aims. The authors conclude that studies published in high impact-factor nursing journals are statistically sound and provide a solid foundation for evidence-based practice. PMID:19448031

Gross Cohn, Elizabeth; Haomiao Jia; Larson, Elaine

2009-05-15

355

Nuclear medicine and imaging research (instrumentation and quantitative methods of evaluation)  

SciTech Connect

This document is the annual progress report for project entitled 'Instrumentation and Quantitative Methods of Evaluation.' Progress is reported in separate sections individually abstracted and indexed for the database. Subject areas reported include theoretical studies of imaging systems and methods, hardware developments, quantitative methods of evaluation, and knowledge transfer: education in quantitative nuclear medicine imaging.

Beck, R.N.; Cooper, M.; Chen, C.T.

1992-07-01

356

A new apparatus for non-destructive evaluation of green-state powder metal compacts using the electrical-resistivity method  

NASA Astrophysics Data System (ADS)

This paper presents a new apparatus developed for non-destructive evaluation (NDE) of green-state powder metal compacts. A green-state compact is an intermediate step in the powder metallurgy (PM) manufacturing process, which is produced when a metal powder-lubricant mixture is compacted in a press. This compact is subsequently sintered in a furnace to produce the finished product. Non-destructive material testing is most cost effective in the green state because early flaw detection permits early intervention in the manufacturing cycle and thus avoids scrapping large numbers of parts. Unfortunately, traditional NDE methods have largely been unsuccessful when applied to green-state PM compacts. A new instrumentation approach has been developed, whereby direct currents are injected into the green-state compact and an array of spring-loaded needle contacts records the voltage distributions on the surface. The voltage distribution is processed to identify potentially dangerous surface and sub-surface flaws. This paper presents the custom-designed hardware and software developed for current injection, voltage acquisition, pre-amplification and flaw detection. In addition, the testing algorithm and measurement results are discussed. The success of flaw detection using the apparatus is established by using controlled samples, which are PM compacts with dielectric inclusions inserted.

Bogdanov, Gene; Ludwig, Reinhold; Michalson, William R.

2000-02-01

357

Quantitative evaluation of activation state in functional brain imaging.  

PubMed

Neuronal activity can evoke the hemodynamic change that gives rise to the observed functional magnetic resonance imaging (fMRI) signal. These increases are also regulated by the resting blood volume fraction (V (0)) associated with regional vasculature. The activation locus detected by means of the change in the blood-oxygen-level-dependent (BOLD) signal intensity thereby may deviate from the actual active site due to varied vascular density in the cortex. Furthermore, conventional detection techniques evaluate the statistical significance of the hemodynamic observations. In this sense, the significance level relies not only upon the intensity of the BOLD signal change, but also upon the spatially inhomogeneous fMRI noise distribution that complicates the expression of the results. In this paper, we propose a quantitative strategy for the calibration of activation states to address these challenging problems. The quantitative assessment is based on the estimated neuronal efficacy parameter [Formula: see text] of the hemodynamic model in a voxel-by-voxel way. It is partly immune to the inhomogeneous fMRI noise by virtue of the strength of the optimization strategy. Moreover, it is easy to incorporate regional vascular information into the activation detection procedure. By combining MR angiography images, this approach can remove large vessel contamination in fMRI signals, and provide more accurate functional localization than classical statistical techniques for clinical applications. It is also helpful to investigate the nonlinear nature of the coupling between synaptic activity and the evoked BOLD response. The proposed method might be considered as a potentially useful complement to existing statistical approaches. PMID:22569644

Hu, Zhenghui; Ni, Pengyu; Liu, Cong; Zhao, Xiaohu; Liu, Huafeng; Shi, Pengcheng

2012-05-09

358

Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants  

SciTech Connect

The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), NDE instrumentation development, universities, commercial NDE services and cable manufacturers, and Electric Power Research Institute (EPRI). The motivation for the R&D roadmap comes from the need to address the aging management of in-containment cables at nuclear power plants (NPPs).

Simmons, Kevin L.; Ramuhalli, Pradeep; Brenchley, David L.; Coble, Jamie B.; Hashemian, Hash; Konnik, Robert; Ray, Sheila

2012-09-14

359

Quantitative metrics to evaluate image quality for computed radiographic images  

NASA Astrophysics Data System (ADS)

Traditional methods of evaluating a computed radiography (CR) imaging system's performance (e.g. the noise power spectrum (NPS), the modulation transfer function (MTF), the detective quantum efficiency (DQE) and contrast-detail analysis) were adapted in order to evaluate the feasibility of identifying a quantitative metric to evaluate image quality for digital radiographic images. The addition of simulated patient scattering media when acquiring the images to calculate these parameters altered their fundamental meaning. To avoid confusion with other research they were renamed the clinical noise power spectrum (NPSC), the clinical modulation transfer function (MTFC), the clinical detective quantum efficiency (DQEC) and the clinical contrast detail score (CDSC). These metrics were then compared to the subjective evaluation of radiographic images of an anthropomorphic phantom representing a one-year old pediatric patient. Computer algorithms were developed to implement the traditional mathematical procedures for calculating the system performance parameters. In order to easily compare these three metrics, the integral up to the system Nyquist frequency was used as the final image quality metric. These metrics are identified as the INPSC, the IMTFC and the IDQEC respectively. A computer algorithm was also developed, based on the results of the observer study, to determine the threshold contrast to noise ratio (CNRT) for objects of different sizes. This algorithm was then used to determine the CDSC by scoring images without the use of observers. The four image quality metrics identified in this study were evaluated to determine if they could distinguish between small changes in image acquisition parameters e.g., current-time product and peak-tube potential. All of the metrics were able to distinguish these small changes in at least one of the image acquisition parameters, but the ability to digitally manipulate the raw image data made the identification of a broad indicator of image quality not possible. The contrast-detail observer study revealed important information about how the noise content in an image affects the low-contrast detectability of different sized objects. Since the CNRT for each object size in the contrast-detail phantoms was almost independent of the exposure level, the minimum CNRT that would be necessary for an object of that size to be 'visible' in a clinical image was identified. Finally, in order to determine more refined CNRT values (due to possible observer biases from the physical construction of the contrast-detail phantoms available for this study) the design of new contrast detail phantoms is proposed.

Pitcher, Christopher D.

360

Application of non-destructive impedance-based monitoring technique for cyclic fatigue evaluation of endodontic nickel-titanium rotary instruments.  

PubMed

This study investigates the application of non-destructive testing based on the impedance theory in the cyclic fatigue evaluation of endodontic Ni-Ti rotary instruments. Fifty Ni-Ti ProTaper instruments were divided into five groups (n=10 in Groups A to E). Groups A to D were subjected to cyclic fatigue within an artificial canal (Group E was the control group). The mean value of the total life limit (TLL), defined as the instrument being rotated until fracture occurred was found to be 104 s in Group A. Each rotary instrument in Groups B, C and D were rotated until the tested instruments reached 80% (84 s), 60% (62 s) and 40% (42 s) of the TLL. After fatigue testing, each rotary instrument was mounted onto a custom-developed non-destructive testing device to give the tip of the instrument a progressive sideways bend in four mutually perpendicular directions to measure the corresponding impedance value (including the resistance and the reactance). The results indicated that the impedance value showed the same trend as the resistance, implying that the impedance was primarily affected by the resistance. The impedance value for the instruments in the 80% and 60% TLL groups increased by about 6 m? (about 7.5%) more than that of the instruments in the intact and 40% TLL groups. The SEM analysis result showed that crack striations were only found at the tip of the thread on the cracked surface of the instrument, consistent with the impedance measurements that found the impedance value of the cracked surface to be significantly different from those in other surfaces. These findings indicate that the impedance value may represent an effective parameter for evaluating the micro-structural status of Ni-Ti rotary instruments subjected to fatigue loading. PMID:21251866

Chang, Yau-Zen; Liu, Mou-Chuan; Pai, Che-An; Lin, Chun-Li; Yen, Kuang-I

2011-01-20

361

Nonlinear acoustic nondestructive testing for concrete durability  

Microsoft Academic Search

Several nondestructive testing methods can be used to determine the damage in a concrete structure. Linear ultrasonic techniques, e.g. pulse-velocity and amplitude attenuation, are very common in nondestructive evaluation. Velocity of propagation is not very sensitive to the degrees of damage unless a great deal of micro-damage having evolving into localized macro-damage. This transition typically takes place around 80% of

Hwai-Chung Wu; Kraig Warnemuende

2000-01-01

362

Critical evaluation of quantitative colocalization analysis in confocal fluorescence microscopy.  

PubMed

Spatial colocalization of fluorescently labeled proteins can reveal valuable information about proteinprotein interactions. Compared to qualitative visual interpretation of dual color images, quantitative colocalization analysis (QCA) provides more objective evaluations to the degree of colocalization. However, the finite resolution power of microscopes and the spatial patterns of intracellular structures may compromise the reliability of many classical QCA methods. In this paper, we discuss the strength and weakness of some mostly used QCA methods. By studying their applications on computer-simulated images and biological images, we show that classical pixel intensity based QCA methods are often vulnerable to coincidental overlapping among resolution elements (resel) distributions and thus not suitable to images with high molecular density or with low resolution. Also, many QCA methods can mistakenly regard long range correlation as colocalization due to protein localization in intracellular structures. The newly developed protein-protein index (PPI) approach is able to reduce the influence from resel overlapping and spatial intracellular pattern compared to previous methods, significantly improving the reliability of QCA. PMID:22392274

Wu, Yong; Zinchuk, Vadim; Grossenbacher-Zinchuk, Olga; Stefani, Enrico

2012-03-06

363

Quantitative evaluation of phase processing approaches in susceptibility weighted imaging  

NASA Astrophysics Data System (ADS)

Susceptibility weighted imaging (SWI) takes advantage of the local variation in susceptibility between different tissues to enable highly detailed visualization of the cerebral venous system and sensitive detection of intracranial hemorrhages. Thus, it has been increasingly used in magnetic resonance imaging studies of traumatic brain injury as well as other intracranial pathologies. In SWI, magnitude information is combined with phase information to enhance the susceptibility induced image contrast. Because of global susceptibility variations across the image, the rate of phase accumulation varies widely across the image resulting in phase wrapping artifacts that interfere with the local assessment of phase variation. Homodyne filtering is a common approach to eliminate this global phase variation. However, filter size requires careful selection in order to preserve image contrast and avoid errors resulting from residual phase wraps. An alternative approach is to apply phase unwrapping prior to high pass filtering. A suitable phase unwrapping algorithm guarantees no residual phase wraps but additional computational steps are required. In this work, we quantitatively evaluate these two phase processing approaches on both simulated and real data using different filters and cutoff frequencies. Our analysis leads to an improved understanding of the relationship between phase wraps, susceptibility effects, and acquisition parameters. Although homodyne filtering approaches are faster and more straightforward, phase unwrapping approaches perform more accurately in a wider variety of acquisition scenarios.

Li, Ningzhi; Wang, Wen-Tung; Sati, Pascal; Pham, Dzung L.; Butman, John A.

2012-02-01

364

Quantitative evaluation of intracellular metabolite extraction techniques for yeast metabolomics.  

PubMed

Accurate determination of intracellular metabolite levels requires well-validated procedures for sampling and sample treatment. Several methods exist for metabolite extraction, but the literature is contradictory regarding the adequacy and performance of each technique. Using a strictly quantitative approach, we have re-evaluated five methods (hot water, HW; boiling ethanol, BE; chloroform-methanol, CM; freezing-thawing in methanol, FTM; acidic acetonitrile-methanol, AANM) for the extraction of 44 intracellular metabolites (phosphorylated intermediates, amino acids, organic acids, nucleotides) from S. cerevisiae cells. Two culture modes were investigated (batch and chemostat) to check for growth condition dependency, and three targeted platforms were employed (two LC-MS and one GC/MS) to exclude analytical bias. Additionally, for the determination of metabolite recoveries, we applied a novel approach based on addition of (13)C-labeled internal standards at different stages of sample processing. We found that the choice of extraction method can drastically affect measured metabolite levels, to an extent that for some metabolites even the direction of changes between growth conditions can be inverted. The best performances, in terms of efficacy and metabolite recoveries, were achieved with BE and CM, which yielded nearly identical levels for the metabolites analyzed. According to our results, AANM performs poorly in yeast and FTM cannot be considered adequate as an extraction method, as it does not ensure inactivation of enzymatic activity. PMID:19653633

Canelas, André B; ten Pierick, Angela; Ras, Cor; Seifar, Reza M; van Dam, Jan C; van Gulik, Walter M; Heijnen, Joseph J

2009-09-01

365

Evaluation of the Virus Counter® for rapid baculovirus quantitation  

PubMed Central

The utility of a new instrument for rapid virus quantitation, the Virus Counter, was evaluated in a blind study conducted at three sites. This instrument is a substantially improved version of the original academic research instrument described previously by Stoffel et al. (2005a). The addition of hydrodynamic focusing, a self-contained fluidics system and customized software for system control and data analysis has resulted in a commercially viable and available design. Baculovirus samples were provided by Protein Sciences Corporation and blinded to InDevR and Baylor College of Medicine. Protein Sciences Corporation and Baylor College of Medicine analyzed the samples by plaque assay and InDevR analyzed the samples using the Virus Counter. Serial dilution of stock viruses into growth media and buffer allowed for comparison of measured versus intended concentrations. Direct log-scale comparison between pooled Virus Counter results and pooled plaque assay results indicated a linear relationship (slope = 1.1 ± 0.2, R2 = 0.86) with statistically significant Pearson correlation (r = 0.93, p < 0.001).

Ferris, Matthew M.; Stepp, Patricia C.; Ranno, Kirk A.; Mahmoud, Wafaa; Ibbitson, Elizabeth; Jarvis, James; Cox, Manon M.J.; Christensen, Kurt; Votaw, Heather; Edwards, Dean P.; Rowlen, Kathy L.

2010-01-01

366

Quantitative Measures for Evaluation of Ultrasound Therapies of the Prostate  

NASA Astrophysics Data System (ADS)

Development of non-invasive techniques for prostate cancer treatment requires implementation of quantitative measures for evaluation of the treatment results. In this paper. we introduce measures that estimate spatial targeting accuracy and potential thermal damage to the structures surrounding the prostate. The measures were developed for the technique of treating prostate cancer with a transurethral ultrasound heating applicators guided by active MR temperature feedback. Variations of ultrasound element length and related MR imaging parameters such as MR slice thickness and update time were investigated by performing numerical simulations of the treatment on a database of ten patient prostate geometries segmented from clinical MR images. Susceptibility of each parameter configuration to uncertainty in MR temperature measurements was studied by adding noise to the temperature measurements. Gaussian noise with zero mean and standard deviation of 0, 1, 3 and 5° C was used to model different levels of uncertainty in MR temperature measurements. Results of simulations for each parameter configuration were averaged over the database of the ten prostate patient geometries studied. Results have shown that for update time of 5 seconds both 3- and 5-mm elements achieve appropriate performance for temperature uncertainty up to 3° C, while temperature uncertainty of 5° C leads to noticeable reduction in spatial accuracy and increased risk of damaging rectal wall. Ten-mm elements lacked spatial accuracy and had higher risk of damaging rectal wall compared to 3- and 5-mm elements, but were less sensitive to the level of temperature uncertainty. The effect of changing update time was studied for 5-mm elements. Simulations showed that update time had minor effects on all aspects of treatment for temperature uncertainty of 0° C and 1° C, while temperature uncertainties of 3° C and 5° C led to reduced spatial accuracy, increased potential damage to the rectal wall, and longer treatment times for update time above 5 seconds. Overall evaluation of results suggested that 5-mm elements showed best performance under physically reachable MR imaging parameters.

Kobelevskiy, Ilya; Burtnyk, Mathieu; Bronskill, Michael; Chopra, Rajiv

2010-03-01

367

[Effects of calcinogenic plants--qualitative and quantitative evaluation].  

PubMed

Different research methods demonstrated the presence of variable quantities of Vitamin D as well as its metabolites in calcinogenic plants. Most of the experiments indicated that the active component most probably should be the metabolite 1,25 (OH)2D3 linked as a glycoside. By this research it was achieved to evaluate the presence of elements with Vitamin D-like activity in the calcinogenic plants Solanum malacoxylon, Cestrum diurnum, Trisetum flavescens and Nierembergia veitchii by testing different extracts of the above plants by oral application to rachitic chicks within the research model "Strontium added Alimentation". After the oral administration of the extracts, the serum was analysed to determine the level of the elements calcium, phosphorus and alkaline phosphatase. The results gained with chicks demonstrated the presence of substances with Vitamin D-like activity in the 4 plants. Solanum malacoxylon and Cestrum diurnum as well contained substances of hydrosoluble character with elevated activity which was indicated by the significant high levels of calcium and phosphorus combined with a reduced activity of the alkaline phosphatase. This indicated the presence of 1,25 (OH)2D3 in both plants. The hydrosoluble character of the active substance in both plants is most probably explained as a compound of the metabolite 1,25 (OH)2D3, combined as a glycoside in the position O-25 of the molecule. Nierembergia veitchii and Trisetum flavescens contained only minor concentration of elements with hydrosoluble characteristics. The results of the 4 analysed plants were evaluated quantitatively as follows: Solanum malycoxylon--82,800 IU of Vitamin D/kg, Cestrum diurnum--63,200 IU of Vitamin D/kg, Nierembergia veitchii--16,400 IU/kg and Trisetum flavescens 12,000 Vitamin D IU/kg. All concentrations are calcinogenic. PMID:9499629

Mello, J R; Habermehl, G G

1998-01-01

368

Evaluation of Sodium Fluorescein for Quantitative Diagnosis of Root Caries  

Microsoft Academic Search

The diagnosis of root caries, in particular the judgment of the activity of a visually observed lesion, is difficult. Quantitative determination of lesion severity would allow the lesion to be monitored with time, so that an indication of lesion activity could be obtained. This paper describes a step in the development of a method that provides such a quantitative determination.

M. H. van der Veen; H. Tsuda; J. Arends; J. J. ten Bosch

1996-01-01

369

Reforming Hungarian agricultural trade policy : a quantitative evaluation  

Microsoft Academic Search

The authors quantitatively assess the consequences of Hungary for three types of policies: removing quantitative import restraints in agriculture, both for all of agriculture and for each of five separate agricultural products; removing the export subsidy program in agriculture; and adopting a European Community type common agricultural policy (CAP) system in Hungary. The authors estimate the consequences of all policies

Morris Morkre; David G. Tarr

1993-01-01

370

A quantitative evaluation of pollution effects on stream communities  

Microsoft Academic Search

1.A quantitative and qualitative biological survey was conducted on the Elkhart and St. Joseph Rivers in the vicinity of Elkhart, Indiana.2.Water quality tests were inconclusive as to the effects of periodic industrial waste discharge on the receiving stream.3.A quantitative biological method, the coefficient of similarity, demonstrated the effect of industrial wastes upon the stream communities.

John Mark Dean; Roy F. Burlington

1963-01-01

371

Exploratory nondestructive evaluation (NDE) research for advanced materials and processes: Volume 3 -- Interactive multimedia computer based training (IMCBT) for nondestructive evaluation/inspection (NDE/I) personnel. Final report, 1 July 1995--30 April 1998  

SciTech Connect

Interactive Multimedia Computer Based Training (IMCBT) for Nondestructive Inspection (NDE/I) Personnel: Computer Based Training (CBT) is a highly effective method for industrial training that has been growing in popularity. Text, graphics, sound, movies and animation enhance the learning activity. Interactive Multimedia CBT (IMCBT) allows students to learn in an environment where the training material is presented on a computer workstation and uses student interaction and feedback in the learning process. This technology has been used in the aerospace industry for aircraft maintenance and flight training and is growing in many operation training areas. The cost of development of IMCBT material is significantly more expensive than traditional training material, but an hour of IMCBT material can contain more information than an hour of traditional training material since information is transferred faster and with higher retention. Because IMCBT delivers training at lower cost, the overall benefit of IMCBT has been found to be in the range of 40% to 60% cost savings. The application of IMCBT for NDE/I training did show an overwhelmingly positive acceptance of the incorporation of IMCBT for NDE/I personnel within existing training structures. A CD-ROM package called INSPECT (Interactive Student Paced Eddy Current Training) has demonstrate various advanced aspects of potential IMCBT lessons. The INSPECT CD demonstration was reviewed by Air Force and industry professionals, as well as a group of high school students to gauge novice response. The prototype was found to be appealing and to have significant potential as a useful teaching tool. A large majority of the professional reviewers stated they would like to have complete CBT modules like INSPECT for some aspect of their NDE/I training.

Bossi; Knutson, B.; Nerenberg, R.; Deobald, L.; Nelson, J.

1998-07-01

372

EVALUATING QUANTITATIVE VARIATION IN THE GENOME OF ZEA MAYS  

Microsoft Academic Search

Genomic diversity within the species Zea mays has been examined by measur- ing the variation in the repetitive component of the nuclear genome among North American inbred lines and varieties. This was done by preparing a set of clones of repetitive maize sequences that differ in function, molecular arrange- ment and multiplicity and then using these as probes for quantitative

CAROL J. RIVIN; CHRISTOPHER A. CULLIS; VIRGINIA WALBOT

1986-01-01

373

A selective review of studies of quantitative evaluations in education  

Microsoft Academic Search

There are many interventions in educational systems around the world designed to help disadvantaged or underperforming groups. Quantitative analyses of the effectiveness of these interventions are not as common. Nonetheless there is now a substantial research literature measuring the impact of programs aimed at increasing progression to -or retention at - higher education as well as other outcomes such as

Kevin Denny; Orla Doyle; Marie Hyland; Patricia O' Reilly; Vincent O' Sullivan

374

Quantitative Evaluation Model for Survivability in Large-Scale MANETs Based on Reliability Theory  

Microsoft Academic Search

We propose a quantitative model to evaluate survivability in large-scale Mobile Ad-hoc NETworks (MANETs). We present modeling for survivability regarding various types of faults and connection states for mobile terminals through continuous time Markov chain. We evaluate the survivability of segment-by-segment routing and multipath routing, introduce reliability theory to perform analysis and quantitative evaluation of survivability and provide a theoretical

Sancheng Peng; Weijia Jia; Guojun Wang

2008-01-01

375

Quantitative autoradiographic microimaging in the development and evaluation of radiopharmaceuticals  

SciTech Connect

Autoradiographic (ARG) microimaging is the method for depicting biodistribution of radiocompounds with highest spatial resolution. ARG is applicable to gamma, positron and negatron emitting radiotracers. Dual or multiple-isotope studies can be performed using half-lives and energies for discrimination of isotopes. Quantitation can be performed by digital videodensitometry and by newer filmless technologies. ARG`s obtained at different time intervals provide the time dimension for determination of kinetics.

Som, P. [Brookhaven National Lab., Upton, NY (United States); Oster, Z.H. [State Univ. of New York, Stony Brook, NY (United States)

1994-04-01

376

A quantitative evaluation of various iterative deconvolution algorithms  

Microsoft Academic Search

Various iterative deconvolution algorithms are evaluated that are commonly used to restore degraded chromatographic or spectroscopic peak data. The evaluation criteria include RMS errors, relative errors in peak areas, peak area variances, and rate of convergence. The iterative algorithms to be evaluated include Van Cittert's method, Van Cittert's method with constraint operators, relaxation based methods, and Gold's ratio method. The

P. B. Crilly

1991-01-01

377

Quantitative and Qualitative Evaluation of Social Studies Textbook Content.  

ERIC Educational Resources Information Center

A model of social studies textbook analysis and evaluation is developed in this paper and is applied to the analysis and evaluation of the content on Hawaii in selected elementary school social studies textbooks. Innovative methods of content analysis and evaluation of textbook presentations were developed and applied to the subject of Hawaii to…

Suh, Bernadyn K.

378

Non-destructive thermographic monitoring of crack evolution of thermal barrier coating coupons during cyclic oxidation aging  

Microsoft Academic Search

The diffused microscopic cracking of the interface between a thick (>300?m) air plasma spray (APS) thermal barrier coating (TBC) and a bond coat cannot be clearly identified by non-destructive evaluation and testing techniques. In this work, a semi-quantitative estimation of cracks at the TBC interface is obtained from thermal diffusivity values measured on coupons subjected to thermal cycling using a

F. Cernuschi; S. Capelli; P. Bison; S. Marinetti; L. Lorenzoni; E. Campagnoli; C. Giolli

2011-01-01

379

A quantitative method for evaluating the performances of hyperspectral image fusion  

Microsoft Academic Search

Hyperspectral image fusion is a key technique of hyperspectral data processing. In recent years, many fusion methods have been proposed, but there is little work concerning evaluation of the performances of different image fusion methods. In this paper, a method called quantitative correlation analysis {(QCA)} is proposed, which provides a quantitative measure of the information transferred by an image fusion

Qiang Wang; Yi Shen; Ye Zhang; Jian Qiu Zhang

2003-01-01

380

Evaluating the Use of Art Therapy with Couples in Counseling; A Qualitative and Quantitative Approach  

Microsoft Academic Search

Few research studies have been conducted specifically focused on change process in marital art therapy. A need for more quantitative research in art therapy has been established. This research study focused on the results of a quasi-experiential study evaluating the use of art therapy with couples in counseling. Both qualitative and quantitative measures were employed to support the use of

Dina Leah Ricco

2007-01-01

381

NON-DESTRUCTIVE SOIL CARBON ANALYZER  

Microsoft Academic Search

This report describes the feasibility, calibration, and safety considerations of a non-destructive, in situ, quantitative, volumetric soil carbon analytical method based on inelastic neutron scattering (INS). The method can quantify values as low as 0.018 gC\\/cc, or about 1.2% carbon by weight with high precision under the instrument's configuration and operating conditions reported here. INS is safe and easy to

L. MITRA; S. HENDREY; G. ORION; I. ROGERS; H. TORBERT; A. PRIOR; S. RUNION

2004-01-01

382

Homogenized tissue phantoms for quantitative evaluation of subsurface fluorescence contrast  

NASA Astrophysics Data System (ADS)

The use of phantoms comprising diluted tissue homogenates with a buried capillary containing quantum dots is demonstrated as a method to investigate the optical and biophysical factors influencing the imaging of subsurface fluorescence contrast agents. Validation of the method is demonstrated using both liquid phantoms of known optical absorption and reduced scattering and Monte Carlo computer simulations of photon transport. Conclusions regarding the optimal excitation wavelength are given and quantified with respect to the tissue optical properties. The tissue homogenate method should be of value for quantitative optimization studies relevant to, for example, endoscopic imaging.

Roy, Mathieu; Kim, Anthony; Dadani, Farhan; Wilson, Brian C.

2011-01-01

383

Homogenized tissue phantoms for quantitative evaluation of subsurface fluorescence contrast.  

PubMed

The use of phantoms comprising diluted tissue homogenates with a buried capillary containing quantum dots is demonstrated as a method to investigate the optical and biophysical factors influencing the imaging of subsurface fluorescence contrast agents. Validation of the method is demonstrated using both liquid phantoms of known optical absorption and reduced scattering and Monte Carlo computer simulations of photon transport. Conclusions regarding the optimal excitation wavelength are given and quantified with respect to the tissue optical properties. The tissue homogenate method should be of value for quantitative optimization studies relevant to, for example, endoscopic imaging. PMID:21280919

Roy, Mathieu; Kim, Anthony; Dadani, Farhan; Wilson, Brian C

384

Development of Nondestructive Testing Techniques for High Performance Ceramics.  

National Technical Information Service (NTIS)

Two ceramic materials, a hot-pressed silicon nitride and a siliconized silicon carbide, were manufactured with seeded particulates to evaluate the effectiveness of existing nondestructive test practices for defect detection in ceramics and to evaluate the...

H. R. Baumgartner R. H. Brockelman P. M. Hanson

1978-01-01

385

Quantitative evaluation of siRNA delivery in vivo.  

PubMed

Effective small interfering RNA (siRNA)-mediated therapeutics require the siRNA to be delivered into the cellular RNA-induced silencing complex (RISC). Quantitative information of this essential delivery step is currently inferred from the efficacy of gene silencing and siRNA uptake in the tissue. Here we report an approach to directly quantify siRNA in the RISC in rodents and monkey. This is achieved by specific immunoprecipitation of the RISC from tissue lysates and quantification of small RNAs in the immunoprecipitates by stem-loop PCR. The method, expected to be independent of delivery vehicle and target, is label-free, and the throughput is acceptable for preclinical animal studies. We characterized a lipid-formulated siRNA by integrating these approaches and obtained a quantitative perspective on siRNA tissue accumulation, RISC loading, and gene silencing. The described methodologies have utility for the study of silencing mechanism, the development of siRNA therapeutics, and clinical trial design. PMID:20940339

Pei, Yi; Hancock, Paula J; Zhang, Hangchun; Bartz, René; Cherrin, Craig; Innocent, Nathalie; Pomerantz, Colin J; Seitzer, Jessica; Koser, Martin L; Abrams, Marc T; Xu, Yan; Kuklin, Nelly A; Burke, Paul A; Sachs, Alan B; Sepp-Lorenzino, Laura; Barnett, Stanley F

2010-10-12

386

Quantitative evaluation of scratch visibility resistance of polymers  

NASA Astrophysics Data System (ADS)

Susceptibility of polymer surfaces to acute visibility upon scratching has presented a serious challenge to the polymer industry for quite some time. The ability to design polymers with good scratch visibility resistance requires extensive knowledge about scratch deformation mechanisms and their propensity for light scattering. After examining the physical nature of human vision and surface optical characteristics, a new methodology is developed to quantitatively determine the onset of scratch visibility of polymers via an inexpensive desktop scanner. Taking into account the sample background color, texture, gloss and feature size, the proposed methodology can consistently and reliably determine polymer scratch visibility resistance regardless of the sample surface characteristics. Good correlation is found between this method and actual human perception. Quantitative analysis of the scratched surface is carried out with scanning laser profiling confocal microscopy and strong correlations among scratch visibility, observation angle and various scratch damage features such as roughness and scratch grooves are established. The proposed approach will greatly assist the development of scratch-resistant polymeric materials where surface aesthetics is of primary concern.

Jiang, Han; Browning, Robert L.; Hossain, Mohammad M.; Sue, Hung-Jue; Fujiwara, Mikihiko

2010-08-01

387

Quantitative Exercise Electrocardiography in the Evaluation of Patients with Early Coronary Artery Disease.  

National Technical Information Service (NTIS)

Computer analysis of treadmill exercise electrocardiographic data has been used in the evaluation of USAF flyers suspected of early coronary artery disease. Quantitative measurements of ST segment slope, depression, area, and spatial vectors were correlat...

F. G. Yanowitz M. O. Lancaster N. Feiser V. F. Froelicher

1974-01-01

388

Non-Destructive Testing: Ultrasonics.  

National Technical Information Service (NTIS)

This bibliography is a compilation of references on Non-Destructive Testing: Ultrasonics in a series of bibliographies on Non-Destructive Testing. Citations were selected from entries processed into the Defense Documentation Center's data bank during the ...

1971-01-01

389

Quantitative Evaluation Methodology for Dynamic, Web-Based Collaboration Tools  

Microsoft Academic Search

One of the primary hurdles to effectively evaluating adaptive software is that its very use alters the system from one moment to the next. Here, we developed and implemented an empirical-evaluation methodology that was successfully tested on an adaptive, web-based collaboration tool. Subjects participated in an \\

Chris Furmanski; David W. Payton; Mike Daily

2004-01-01

390

An evaluation of protein assays for quantitative determination of drugs  

Microsoft Academic Search

We have evaluated the response of six protein assays [the biuret, Lowry, bicinchoninic acid (BCA), Coomassie Brilliant Blue (CBB), Pyrogallol Red–Molybdate (PRM), and benzethonium chloride (BEC)] to 21 pharmaceutical drugs. The drugs evaluated were analgesics (acetaminophen, aspirin, codeine, methadone, morphine and pethidine), antibiotics (amoxicillin, ampicillin, gentamicin, neomycin, penicillin G and vancomycin), antipsychotics (chlorpromazine, fluphenazine, prochlorperazine, promazine and thioridazine) and water-soluble

Katherine M. Williams; Sarah J. Arthur; Gillian Burrell; Fionnuala Kelly; Darren W. Phillips; Thomas Marshall

2003-01-01

391

Quantitative evaluation of magnetic immunoassay with remanence measurement  

NASA Astrophysics Data System (ADS)

Magnetic immunoassays utilizing magnetic markers and a high -Tc SQUID have been performed. The marker was designed so as to generate remanence, and its remanence field was measured with the SQUID. The SQUID system was developed so as to measure 12 samples in one measurement sequence. We first conducted a detection of antigen called human IgE using IgE standard solution, and showed the detection of IgE down to 2 attomol. The binding process between IgE and the marker could be semi-quantitatively explained with the Langmuir-type adsorption model. We also measured IgE in human serums, and demonstrated the usefulness of the present method for practical diagnosis.

Enpuku, K.; Soejima, K.; Nishimoto, T.; Kuma, H.; Hamasaki, N.; Tsukamoto, A.; Saitoh, K.; Kandori, A.

2006-05-01

392

DIFFUSIVE AND PROPAGATIVE WAVE FIELD INVERSION WITH EMPHASIS ON NONDESTRUCTIVE EVALUATION OF MAN-MADE & NATURAL OBJECTS  

Microsoft Academic Search

Inverse scattering problems in the field of electromagnetics and novel, mostly non-linearized solutions thereof are considered. Emphasis is on the retrieval of cylindrical or three-dimensionally bounded obstacles that are buried in a known, planarly layered environment. Numerical illustrations come from three challenging applications, the evaluation of voids in a damaged metal layer at eddy-current frequencies, the characterization of mineral bodies

D. Lesselier; D. Dos Reis; B. Duchêne; M. Lambert; G. Perrusson; C. Ramananjaona

393

Artificial weathering and non-destructive tests for the performance evaluation of consolidation materials applied on porous stones  

Microsoft Academic Search

The evaluation of consolidation treatment efficiency in terms of improving the resistance of treated lithotypes to deterioration\\u000a phenomena caused by soluble salts crystallisation, is taking place through dynamic artificial weathering accelerated tests\\u000a of marine salt spray. Quarried biocalcarenites from Greece and Cyprus have been treated with four consolidation materials\\u000a (diversified according to their deposition mechanism). The materials applied are colloidal

A. Moropoulou; G. Haralampopoulos; Th. Tsiourva; F. Auger; J. M. Birginie

2003-01-01

394

The aged male rat as a model for human osteoporosis: Evaluation by nondestructive measurements and biomechanical testing  

Microsoft Academic Search

Summary Effects of androgen deficiency and androgen replacement on bone density, as measured with dual-energy X-ray absorptiometry (DXA) and single photon absorptiometry (SPA), cortical ratio (cortical thickness\\/outside bone diameter x 100), and biomechanical properties were evaluated in 14-month-old (1 month after orchiectomy (orch) or sham-operation) and in 17-month-old (4 months after orch or sham) male rats. Whole femoral bone mineral

Dirk Vanderschueren; Erik Van Herck; Peter Schot; Elisa Rush; Thomas Einhorn; Piet Geusens; Roger Bouillon

1993-01-01

395

Digital holographic microscopy for quantitative cell dynamic evaluation during laser microsurgery  

PubMed Central

Digital holographic microscopy allows determination of dynamic changes in the optical thickness profile of a transparent object with subwavelength accuracy. Here, we report a quantitative phase laser microsurgery system for evaluation of cellular/ sub-cellular dynamic changes during laser micro-dissection. The proposed method takes advantage of the precise optical manipulation by the laser microbeam and quantitative phase imaging by digital holographic microscopy with high spatial and temporal resolution. This system will permit quantitative evaluation of the damage and/or the repair of the cell or cell organelles in real time.

Yu, Lingfeng; Mohanty, Samarendra; Zhang, Jun; Genc, Suzanne; Kim, Myung K.; Berns, Michael W.; Chen, Zhongping

2010-01-01

396

Quantitative Evaluation of Infant's Nonnutritive and Nutritive Sucking  

Microsoft Academic Search

.   Two important aspects of the clinical feeding evaluation of infants are the assessment of their nonnutritive and nutritive\\u000a sucking skills. Nonnutritive sucking is monitored routinely by using a gloved finger and nutritive sucking by observing infants'\\u000a sucking while bottle feeding. This approach, however, provides only a subjective and descriptive evaluation. In this study,\\u000a we developed a finger pressure device

Chantal Lau; Ingrid Kusnierczyk

2001-01-01

397

Educational ultrasound nondestructive testing laboratory.  

PubMed

The ultrasound nondestructive evaluation (NDE) of materials course was developed for applied engineering technology students at Drexel University's Goodwin College of Professional Studies. This three-credit, hands-on laboratory course consists of two parts: the first part with an emphasis on the foundations of NDE, and the second part during which ultrasound NDE techniques are utilized in the evaluation of parts and materials. NDE applications are presented and applied through real-life problems, including calibration and use of the latest ultrasonic testing instrumentation. The students learn engineering and physical principles of measurements of sound velocity in different materials, attenuation coefficients, material thickness, and location and dimensions of discontinuities in various materials, such as holes, cracks, and flaws. The work in the laboratory enhances the fundamentals taught during classroom sessions. This course will ultimately result in improvements in the educational process ["The greater expectations," national panel report, http://www.greaterexpectations.org (last viewed February, 2008); R. M. Felder and R. Brent "The intellectual development of Science and Engineering Students. Part 2: Teaching to promote growth," J. Eng. Educ. 93, 279-291 (2004)] since industry is becoming increasingly reliant on the effective application of NDE technology and the demand on NDE specialists is increasing. NDE curriculum was designed to fulfill levels I and II NDE in theory and training requirements, according to American Society for Nondestructive Testing, OH, Recommended Practice No. SNT-TC-1A (2006). PMID:19045633

Genis, Vladimir; Zagorski, Michael

2008-09-01

398

Nondestructive examination development and demonstration plan  

SciTech Connect

Nondestructive examination (NDE) of waste matrices using penetrating radiation is by nature very subjective. Two candidate systems of examination have been identified for use in WRAP 1. This test plan describes a method for a comparative evaluation of different x-ray examination systems and techniques.

Weber, J.R.

1991-08-21

399

Preprocessing of Edge of Light images: towards a quantitative evaluation  

NASA Astrophysics Data System (ADS)

A computer vision inspection system, named Edge of Light TM (EOL), was invented and developed at the Institute for Aerospace Research of the National Research Council Canada. One application of interest is the detection and quantitative measurement of "pillowing" caused by corrosion in the faying surfaces of aircraft fuselage joints. To quantify the hidden corrosion, one approach is to relate the average corrosion of a region to the peak-to-peak amplitude between two diagonally adjacent rivet centers. This raises the requirement for automatically locating the rivet centers. The first step to achieve this is the rivet edge detection. In this study, gradient-based edge detection, local energy based feature extraction, and an adaptive threshold method were employed to identify the edge of rivets, which facilitated the first step in the EOL quantification procedure. Furthermore, the brightness profile is processed by the derivative operation, which locates the pillowing along the scanning direction. The derivative curves present an estimation of the inspected surface.

Liu, Zheng; Forsyth, David S.; Marincak, Anton

2003-08-01

400

Non-destructive evaluation of porosity and its effect on mechanical properties of carbon fiber reinforced polymer composite materials  

NASA Astrophysics Data System (ADS)

In this work, an attempt is made to induce porosity of varied levels in carbon fiber reinforced epoxy based polymer composite laminates fabricated using prepregs by varying the fabrication parameters such as applied vacuum, autoclave pressure and curing temperature. Different NDE tools have been utilized to evaluate the porosity content and correlate with measurable parameters of different NDE techniques. Primarily, ultrasonic imaging and real time digital X-ray imaging have been tried to obtain a measurable parameter which can represent or reflect the amount of porosity contained in the composite laminate. Also, effect of varied porosity content on mechanical properties of the CFRP composite materials is investigated through a series of experimental investigations. The outcome of the experimental approach has yielded interesting and encouraging trend as a first step towards developing an NDE tool for quantification of effect of varied porosity in the polymer composite materials.

Bhat, M. R.; Binoy, M. P.; Surya, N. M.; Murthy, C. R. L.; Engelbart, R. W.

2012-05-01

401

Quantitative evaluation of the CEEM soil sampling intercomparison  

Microsoft Academic Search

The aim of the CEEM soil project was to compare and to test the soil sampling and sample preparation guidelines used in the member states of the European Union and Switzerland for investigations of background and large-scale contamination of soils, soil monitoring and environmental risk assessments. The results of the comparative evaluation of the sampling guidelines demonstrated that, in soil

G Wagner; P Lischer; S Theocharopoulos; H Muntau; A Desaules; P. h Quevauviller

2001-01-01

402

Research on the quantitative evaluation system for unmanned ground vehicles  

Microsoft Academic Search

The first Chinese unmanned ground vehicles competition - The 2009 Future Challenge: Intelligent Vehicles and Beyond (FC'09) pushed China's unmanned vehicles out of laboratories and into application environments. In order to further promote the development of unmanned vehicle technologies, the test and evaluation system for unmanned vehicles needs to be studied. The design method of test environment is proposed in

Guangming Xiong; Xijun Zhao; Haiou Liu; Shaobin Wu; Jianwei Gong; Haojie Zhang; Huachun Tan; Huiyan Chen

2010-01-01

403

Visible and near-infrared light transmission: A hybrid imaging method for non-destructive meat quality evaluation  

NASA Astrophysics Data System (ADS)

Visual inspection of the amount of external marbling (intramuscular fat) on the meat surface is the official method used to assign the quality grading level of meat. However, this method is based exclusively on the analysis of the meat surface without any information about the internal content of the meat sample. In this paper, a new method using visible (VIS) and near-infrared (NIR) light transmission is used to evaluate the quality of beef meat based on the marbling detection. It is demonstrated that using NIR light in transmission mode, it is possible to detect the fat not only on the surface, as in traditional methods, but also under the surface. Moreover, in combining the analysis of the two sides of the meat simple, it is possible to estimate the volumetric marbling which is not accessible by visual methods commonly proposed in computer vision. To the best of our knowledge, no similar work or method has been published or developed. The experimental results confirm the expected properties of the proposed method and illustrate the quality of the results obtained.

Ziadi, A.; Maldague, X.; Saucier, L.; Duchesne, C.; Gosselin, R.

2012-09-01

404

Quantitative vertebral compression fracture evaluation using a height compass  

NASA Astrophysics Data System (ADS)

Vertebral compression fractures can be caused by even minor trauma in patients with pathological conditions such as osteoporosis, varying greatly in vertebral body location and compression geometry. The location and morphology of the compression injury can guide decision making for treatment modality (vertebroplasty versus surgical fixation), and can be important for pre-surgical planning. We propose a height compass to evaluate the axial plane spatial distribution of compression injury (anterior, posterior, lateral, and central), and distinguish it from physiologic height variations of normal vertebrae. The method includes four steps: spine segmentation and partition, endplate detection, height compass computation and compression fracture evaluation. A height compass is computed for each vertebra, where the vertebral body is partitioned in the axial plane into 17 cells oriented about concentric rings. In the compass structure, a crown-like geometry is produced by three concentric rings which are divided into 8 equal length arcs by rays which are subtended by 8 common central angles. The radius of each ring increases multiplicatively, with resultant structure of a central node and two concentric surrounding bands of cells, each divided into octants. The height value for each octant is calculated and plotted against octants in neighboring vertebrae. The height compass shows intuitive display of the height distribution and can be used to easily identify the fracture regions. Our technique was evaluated on 8 thoraco-abdominal CT scans of patients with reported compression fractures and showed statistically significant differences in height value at the sites of the fractures.

Yao, Jianhua; Burns, Joseph E.; Wiese, Tatjana; Summers, Ronald M.

2012-02-01

405

Quantitative evaluation of phonetograms in the case of functional dysphonia.  

PubMed

According to the laryngeal clinical findings, figures making up a scale were assigned to vocally trained and vocally untrained persons suffering from different types of functional dysphonia. The different types of dysphonia--from the manifested hypofunctional to the extreme hyperfunctional dysphonia--were classified by means of this scale. Besides, the subjects' phonetograms were measured and approximated by three ellipses, what rendered possible the definition of phonetogram parameters. The combining of selected phonetogram parameters to linear combinations served the purpose of a phonetographic evaluation. The linear combinations were to bring phonetographic and clinical evaluations into correspondence as accurately as possible. It was necessary to use different kinds of linear combinations for male and female singers and nonsingers. As a result of the reclassification of 71 and the new classification of 89 patients, it was possible to graduate the types of functional dysphonia by means of computer-aided phonetogram evaluation with a clinically acceptable error rate. This method proved to be an important supplement to the conventional diagnostics of functional dysphonia. PMID:8353627

Airainer, R; Klingholz, F

1993-06-01

406

Optical system for rapid materials characterization with the transient grating technique: Application to nondestructive evaluation of thin films used in microelectronics  

Microsoft Academic Search

This letter describes a noncontact, automated means for nondestructively measuring the physical (elastic, thermal, electronic, optical) properties of bulk samples, surfaces, supported or unsupported thin films, and multilayer assemblies. The method, which is based on the transient grating technique, uses specially constructed beam-shaping optics to manipulate excitation and probe laser beams for initiating and detecting motions in a sample. We

John A. Rogers; Martin Fuchs; Matthew J. Banet; John B. Hanselman; Randy Logan; Keith A. Nelson

1997-01-01

407

Evaluating Learning Style Personalization in Adaptive Systems: Quantitative Methods and Approaches  

Microsoft Academic Search

It is a widely held assumption that learning style is a useful model for quantifying user characteristics for effective personalized learning. We set out to challenge this assumption by discussing the current state of the art, in relation to quantitative evaluations of such systems and also the methodologies that should be employed in such evaluations. We present two case studies

Elizabeth J. Brown; Timothy J. Brailsford; Tony Fisher; Adam Moore

2009-01-01

408

Numbers and Words: Combining Quantitative and Qualitative Methods in a Single Large-Scale Evaluation Study.  

ERIC Educational Resources Information Center

|Three perspectives on combining quantitative and qualitative methods in one evaluation are reviewed: mutually exclusive; separate but equal; and integrated. Ways to corroborate, elaborate, or initiate findings from the other method are illustrated, using a large-scale, three-year evaluation of regional educational service agencies. (Author/GDC)|

Rossman, Gretchen B.; Wilson, Bruce L.

1985-01-01

409

VADAR: a web server for quantitative evaluation of protein structure quality  

Microsoft Academic Search

VADAR (Volume Area Dihedral Angle Reporter) is a comprehensive web server for quantitative protein structure evaluation. It accepts Protein Data Bank (PDB) formatted files or PDB accession numbers as input and calculates, identifies, graphs, reports and\\/ or evaluates a large number (>30) of key structural parameters both for individual residues and for the entire protein. These include excluded volume, accessible

Leigh Willard; Anuj Ranjan; Haiyan Zhang; Hassan Monzavi; Robert F. Boyko; Brian D. Sykes; David S. Wishart

2003-01-01

410

Quantitative and qualitative evaluation of interactive videodisk instructional modules in preclinical neuropathology education  

Microsoft Academic Search

The purpose of this study was to evaluate the design and implementation of 10 neuropathology interactive videodisk instructional (IVI) modules used by Michigan State University medical students in the College of Osteopathic Medicine and the College of Human Medicine. The evaluation strategy incorporated a mixed?method approach utilizing qualitative and quantitative data to examine (a) levels of student acceptance for the

Kathryn L. Lovell; Perrin E. Parkhurst; Sarah A. Sprafka; Mark W. Hodgins; Patricia Bean

1993-01-01

411

A quantitative approach to evaluation of services: GTM-based visualization and fuzzy AHP approach  

Microsoft Academic Search

With the increasing importance of the service sector to both developed and developing countries, the evaluation of services has been considered as one of critical themes of study. Accordingly, a number of studies for evaluating services have been carried out. However, most of them have been performed in qualitative way due to the paucity of quantitative service data. As a

Changho Son

2012-01-01

412

A quantitative evaluation model of teachers based on the consumer behavior theory  

Microsoft Academic Search

The study of educational evaluation is by now mostly limited within the realm of the science of education itself, and is frequently found to depend on qualitative analysis. Nevertheless, the study of science is apt to combine several subjects and focus on the accuracy and comparability of the analysis. In this project, a quantitative study of educational evaluation is conducted

Xiaofang Zhang; Qinghua Huang

2011-01-01

413

Distance estimation from acceleration for quantitative evaluation of Parkinson tremor.  

PubMed

The purpose of this paper is to assess Parkinson tremor estimating actual distance amplitude. We propose a practical, useful and simple method for evaluating Parkinson tremor with distance value. We measured resting tremor of 7 Parkinson Disease (PD) patients with triaxial accelerometer. Resting tremor of participants was diagnosed by Unified Parkinson's Disease Rating Scale (UPDRS) by neurologist. First, we segmented acceleration signal during 7 seconds from recorded data. To estimate a displacement of tremor, we performed double integration from the acceleration. Prior to double integration, moving average method was used to reduce an error of integral constant. After estimation of displacement, we calculated tremor distance during 1s from segmented signal using Euclidean distance. We evaluated the distance values compared with UPDRS. Averaged moving distance during 1 second corresponding to UPDRS 1 was 11.52 mm, that of UPDRS 2 was 33.58 mm and tremor distance of UPDRS 3 was 382.22 mm. Estimated moving distance during 1s was proportional to clinical rating scale--UPDRS. PMID:22254331

Jeon, Hyoseon; Kim, Sang Kyong; Jeon, BeomSeok; Park, Kwang Suk

2011-01-01

414

Quantitative evaluation of common buckwheat (Fagopyrum esculentum Moench) kernel shape by elliptic Fourier descriptor  

Microsoft Academic Search

Kernel shape of 27 common buckwheat cultivars was evaluated quantitatively by image analysis using elliptic Fourier descriptors\\u000a and their principal components. The relationships between the quantitative information on kernel shape and several agronomic\\u000a characteristics were clarified. The closed contour of each kernel projection was extracted, and 80 elliptic Fourier coefficients\\u000a were calculated for each contour. The Fourier coefficients were standardized

Ryo Ohsawa; Tadahiro Tsutsumi; Hideyuki Uehara; Hyoji Namai; Seishi Ninomiya

1998-01-01

415

Quantitative evaluation of wrist posture and typing performance: A comparative study of 4 computer keyboards  

SciTech Connect

The present study focuses on an ergonomic evaluation of 4 computer keyboards, based on subjective analyses of operator comfort and on a quantitative analysis of typing performance and wrist posture during typing. The objectives of this study are (1) to quantify differences in the wrist posture and in typing performance when the four different keyboards are used, and (2) to analyze the subjective preferences of the subjects for alternative keyboards compared to the standard flat keyboard with respect to the quantitative measurements.

Burastero, S.

1994-05-01

416

Quantitative Evaluation of Continuous Diffractive Baffles for Heliospheric Imagers  

NASA Astrophysics Data System (ADS)

Wide-angle heliospheric imagers such as those carried on the SMEI and STEREO spacecraft require highly effective baffle systems to exclude diffracted light from the solar disk as well as other sources of stray light. Buffington (2000, Appl. Opt. 39, 2683-2686) has proposed replacing multi-vane baffle systems with a curved surface that can be thought of as the limiting case of closely spaced vanes. Buffington's experimental data showed that the diffractive performance of a continuous baffle is consistent with the limiting form expected from multi-vane diffraction on heuristic grounds, but a detailed prediction was not possible because multi-vane diffraction calculations assume that the diffractive edges act independently, an assumption that breaks down for a continuous surface. I present analytic calculations of diffraction from a curved surface and use them to evaluate the effectiveness of continuous-surface baffles for heliospheric imagers.

Rabin, D. M.

2011-12-01

417

Improved field experimental designs and quantitative evaluation of aquatic ecosystems  

SciTech Connect

The paired-station concept and a log transformed analysis of variance were used as methods to evaluate zooplankton density data collected during five years at an electrical generation station on Lake Michigan. To discuss the example and the field design necessary for a valid statistical analysis, considerable background is provided on the questions of selecting (1) sampling station pairs, (2) experimentwise error rates for multi-species analyses, (3) levels of Type I and II error rates, (4) procedures for conducting the field monitoring program, and (5) a discussion of the consequences of violating statistical assumptions. Details for estimating sample sizes necessary to detect changes of a specified magnitude are included. Both statistical and biological problems with monitoring programs (as now conducted) are addressed; serial correlation of successive observations in the time series obtained was identified as one principal statistical difficulty. The procedure reduces this problem to a level where statistical methods can be used confidently. 27 references, 4 figures, 2 tables.

McKenzie, D.H.; Thomas, J.M.

1984-05-01

418

Use of Nondestructive Testing Technique as a Routine Inspection Procedure.  

National Technical Information Service (NTIS)

A feasibility study for utilizing proven nondestructive testing techniques in the routine periodic inspection and evaluation of bridges is presented. The inspection procedure, intended for bridges to be built, will enable engineers to obtain a quantitativ...

M. S. Aggour H. M. Fouad

1991-01-01

419

Non-Destructive Inspection Techniques for Acrylic Canopies.  

National Technical Information Service (NTIS)

The advantages and necessities of non-destructive inspection (NDI) of aircraft structural components have gained wide recognition in the aerospace industry. This extends to evaluation of transparent enclosure materials in which the structural adequacy and...

G. F. Thomas S. I. Shelton

1976-01-01

420

Quantitative Evaluation of Aged AISI 316L Stainless Steel Sensitization to Intergranular Corrosion: Comparison Between Microstructural Electrochemical and Analytical Methods  

NASA Astrophysics Data System (ADS)

The evaluation of the degree of sensitization (DOS) to intergranular corrosion (IGC) of a commercial AISI 316L austenitic stainless steel aged at temperatures ranging from 550 °C to 800 °C during 100 to 80,000 hours was carried out using three different assessment methods. (1) The microstructural method coupled with the Strauss standard test (ASTM A262). This method establishes the kinetics of the precipitation phenomenon under different aging conditions, by transmission electronic microscope (TEM) examination of thin foils and electron diffraction. The subsequent chromium-depleted zones are characterized by X-ray microanalysis using scanning transmission electronic microscope (STEM). The superimposition of microstructural time-temperature-precipitation (TTP) and ASTM A262 time-temperature-sensitization (TTS) diagrams provides the relationship between aged microstructure and IGC. Moreover, by considering the chromium-depleted zone characteristics, sensitization and desensitization criteria could be established. (2) The electrochemical method involving the double loop-electrochemical potentiokinetic reactivation (DL-EPR) test. The operating conditions of this test were initially optimized using the experimental design method on the bases of the reliability, the selectivity, and the reproducibility of test responses for both annealed and sensitized steels. The TTS diagram of the AISI 316L stainless steel was established using this method. This diagram offers a quantitative assessment of the DOS and a possibility to appreciate the time-temperature equivalence of the IGC sensitization and desensitization. (3) The analytical method based on the chromium diffusion models. Using the IGC sensitization and desensitization criteria established by the microstructural method, numerical solving of the chromium diffusion equations leads to a calculated AISI 316L TTS diagram. Comparison of these three methods gives a clear advantage to the nondestructive DL-EPR test when it is used with its optimized operating conditions. This quantitative method is simple to perform; it is fast, reliable, economical, and presents the best ability to detect the lowest DOS to IGC. For these reasons, this method can be considered as a serious candidate for IGC checking of stainless steel components of industrial plants.

Sidhom, H.; Amadou, T.; Sahlaoui, H.; Braham, C.

2007-06-01

421

Nondestructive testing techniques  

NASA Astrophysics Data System (ADS)

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)

Bray, Don E.; McBride, Don

422

SQUIDs: microscopes and nondestructive evaluation  

Microsoft Academic Search

SQUIDs (Superconducting Quantum Interference Devices) are magnetic field sensores with unsurpassed sensitivity. They are amazingly versatile, being able to measure all physical quantities which can be converted to magnetic flux. They are routinely fabricated in thin film technology from two classes of superconducting materials: high-temperature superconductors (HTS) which are usually cooled to 77 K, and low-temperature superconductors (LTS), which have

Michael Mück

2005-01-01

423

Spectral nondestructive evaluation-SNDE  

Microsoft Academic Search

Programmed paint stripping and repainting for commercial and military aircraft inspection consumes a large amount time and money and generates considerable amounts of toxic waste. A technique is required that detects surface cracks and corrosion of metallic aerostructures while leaving the paint coating intact. We have investigated the use of infrared spectral reflectance techniques for seeing through paint coatings to

D. di Marzio; J. S. McLaughlin; S. Chu; N. Fonneland; J. Weir

2001-01-01

424

Spectral nondestructive evaluation-SNDE  

NASA Astrophysics Data System (ADS)

Programmed paint stripping and repainting for commercial and military aircraft inspection consumes a large amount time and money and generates considerable amounts of toxic waste. A technique is required that detects surface cracks and corrosion of metallic aerostructures while leaving the paint coating intact. We have investigated the use of infrared spectral reflectance techniques for seeing through paint coatings to the underlying substrate. Many commercial and milspec primers and topcoats exhibit an optically transparent window in the mid-IR range which permits the extraction of spectral reflectance signatures from as well as allowing imaging of the substrate. Both diffuse reflectance and multispectral IR focal plane imaging is used to successfully detect corrosion and surface morphology of painted metal surfaces. .

di Marzio, D.; McLaughlin, J. S.; Chu, S.; Fonneland, N.; Weir, J.

2001-04-01

425

Inverse Problems in Nondestructive Evaluations.  

National Technical Information Service (NTIS)

With the funding provided by AFOSR, the PI was able to take his sabbatical leave for the period of 1 Sep 91 - 31 Aug 92 at Rutgers University. At Rutgers, the PI collaborated with Prof. Michael Vogelius on several problems. The research resulted in severa...

F. Santosa

1992-01-01

426

Quantitative Evaluation of the Stability of Engineered Water Soluble Nanoparticles  

NASA Astrophysics Data System (ADS)

Stability of nanoparticle solutions is a key factor dictating the bioavailability and transport characteristics of nanoparticles (NPs) in the environment. The synthesis of materials with dimensions less than 100 nm relies on the ability to stabilize surfaces. If the stabilization of the material is disrupted by aggregation, precipitation, or dissolution, the chemical and physical properties often revert to the properties of the bulk material or molecular constituents. We synthesized CdSe and gold NPs, and studied their aggregation rate and the critical coagulation concentration (CCC) using Dynamic Light Scattering (DLS). The chemical and physical properties of our NPs have been characterized by Transmission Electron Microscopy (TEM), UV-VIS spectroscopy, IR spectroscopy, Zeta potential measurements, and Nuclear Magnetic Resonance (NMR) measurements. This comprehensive approach to synthesis and characterization enables the isolation of design parameters with greater precision that can be obtained using commercially available NPs. This research evaluates NP design parameters including composition, size, and surface coating, as a function of concentration, pH, and ionic strength, to determine which factors most affect NP stability. The aggregation characteristics of both gold NPs and cadmium selinide NPs, which are between 2-12 nm in diameter, and have been capped with various ligands, have been studied. While previous work demonstrates that these variables influence stability, it does not systematically compare their relative significance. Our results indicate that changing the ligand shell radically affects the stability of NP as a function of both pH and ionic strength, while changing the material from CdSe to gold has only a moderate influence on the stability and aggregation characteristics of our particles. Additionally, the ligand charge, length, and binding affinity all significantly effect NP stability. Funding was provided by the U.S. Department of Energy, the joint BER-EPA-NSF nanoparticulate research program. Aggregation behavior of gold and CdSe nanoparticles both capped with mercaptoundecanoic acid as a function of ionic strength.

Mulvihill, M. J.; Habas, S.; Mokari, T.; Wan, J.

2009-12-01

427

Evaluation of four genes in rice for their suitability as endogenous reference standards in quantitative PCR.  

PubMed

The genetically modified (GM) food/feed quantification depends on the reliable detection systems of endogenous reference genes. Currently, four endogenous reference genes including sucrose phosphate synthase (SPS), GOS9, phospholipase D (PLD), and ppi phosphofructokinase (ppi-PPF) of rice have been used in GM rice detection. To compare the applicability of these four rice reference genes in quantitative PCR systems, we analyzed the target nucleotide sequence variation in 58 conventional rice varieties from various geographic and phylogenic origins, also their quantification performances were evaluated using quantitative real-time PCR and GeNorm analysis via a series of statistical calculation to get a "M value" which is negative correlation with the stability of genes. The sequencing analysis results showed that the reported GOS9 and PLD taqman probe regions had detectable single nucleotide polymorphisms (SNPs) among the tested rice cultivars, while no SNPs were observed for SPS and ppi-PPF amplicons. Also, poor quantitative performance was detectable in these cultivars with SNPs using GOS9 and PLD quantitative PCR systems. Even though the PCR efficiency of ppi-PPF system was slightly lower, the SPS and ppi-PPF quantitative PCR systems were shown to be applicable for rice endogenous reference assay with less variation among the C(t) values, good reproducibility in quantitative assays, and the low M values by the comprehensive quantitative PCR comparison and GeNorm analysis. PMID:20961039

Wang, Chong; Jiang, Lingxi; Rao, Jun; Liu, Yinan; Yang, Litao; Zhang, Dabing

2010-10-20

428

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

Microsoft Academic Search

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

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

2003-01-01

429

'Stories' or 'snapshots'? A study directed at comparing qualitative and quantitative approaches to curriculum evaluation.  

PubMed

The focus of this paper is a study designed to explore the validity of quantitative approaches of student evaluation in a pre-registration degree programme. As managers of the students' education we were concerned that the quantitative method, which used lecturer criteria, may not fully represent students' views. The approach taken is that of a process-type strategy for curriculum evaluation as described by Parlett and Hamilton (1972). The aim of the study is to produce illuminative data, or students' 'stories' of their educational experiences through use of semi-structured interviews. The results are then compared to the current quantitative measurement tools designed to obtain 'snapshots' of the educational effectiveness of the curriculum. The quantitative measurement tools use Likert scale measurements of teacher-devised criterion statements. The results of the study give a rich source of qualitative data which can be used to inform future curriculum development. However, complete validation of the current quantitative instruments used was not achieved in this study. Student and teacher agendas in respect of important issues pertaining to the course programme were found to differ. Limitations of the study are given. There is discussion of the options open to the management team with regard to future development of curriculum evaluation systems. PMID:10222972

Pateman, B; Jinks, A M

1999-01-01

430

Quantitative evanescent microwave microscopy  

NASA Astrophysics Data System (ADS)

A vast variety of measurement techniques with high spatial resolution exist. However, a nondestructive technique that provides reliable, sensitive measurements of the complex electrical impedance with high spatial resolution was lacking. I contributed to the development of such a novel microscope, namely scanned evanescent microwave probe (SEMP). We developed experimental and theoretical methods for the evaluation of microwave complex impedance, which allows the quantitative imaging of the complex microwave dielectric constant (for insulators) and resistivity (for conductors) on a submicron length scale. In order to improve the spatial resolution and reduce the sample or tip damages, we also developed a means of distance regulation. With future improvement of the technique, resolutions approaching 20 nm may be expected. The microscope allows the measurement of variations in sample electronic properties on microscopic length scales. We demonstrated the capability to image samples varying from superconducting structures, semiconductors to ferroelectric materials. Such microscopes should find broad applications in various scientific areas and the semiconductor industry.

Duewer, Frederick William

2000-10-01

431

Nondestructive material characterization  

DOEpatents

A method and apparatus for nondestructive material characterization, such as identification of material flaws or defects, material thickness or uniformity and material properties such as acoustic velocity. The apparatus comprises a pulsed laser used to excite a piezoelectric (PZ) transducer, which sends acoustic waves through an acoustic coupling medium to the test material. The acoustic wave is absorbed and thereafter reflected by the test material, whereupon it impinges on the PZ transducer. The PZ transducer converts the acoustic wave to electrical impulses, which are conveyed to a monitor.

Deason, Vance A. (Idaho Falls, ID); Johnson, John A. (Idaho Falls, ID); Telschow, Kenneth L. (Idaho Falls, ID)

1991-01-01

432

Validation of a new quantitative coronary angiography analysis system used to evaluate densitometric lumen remodelling  

Microsoft Academic Search

Arterial lumen volume, determined by sequential coronary angiography, could have advantages over more commonly used variables (such as percent stenosis or minimal lumen diameter) as a primary endpoint in clinical trials evaluating post-angioplasty restenosis or atherosclerotic plaque progression. We validated a quantitative coronary angiography analysis (QCA) system aimed at measuring lumen volume from coronary angiography films by a densitometric method.

Michel Lièvre; Gérard Finet; Jean Maupas

1997-01-01

433

Serial Quantitative Coronary Analyses for the Evaluation of One-Year Change in Saphenous Vein Grafts  

Microsoft Academic Search

Background. A paucity of data exists with respect to changes in whole saphenous vein grafts (SVGs) despite accelerated atherosclerosis within grafted saphenous vein conduits. In the present study, we evaluated the one-year change in SVGs by means of quantitative cor- onary analysis. Methods. This study enrolled consecutive 52 patients with 109 SVGs, who underwent coronary artery bypass graft surgery successfully.

Nobuaki Suzuki; Ken Kozuma; Yasunari Ueno; Kensuke Nagaoka; Hiroyuki Kyono; Shuichi Ishikawa; Hidenori Watanabe; Naoyuki Yokoyama; Satoshi Takeshita; Takaaki Isshiki

434

Functional Changes in Articular Cartilage After Meniscal Allograft Transplantation: A Quantitative Histochemical Evaluation in Rabbits  

Microsoft Academic Search

Purpose: To evaluate quantitatively functional changes in articular cartilage after immediate and delayed meniscus transplantation in rabbits. Type of Study: Experimental study. Methods: Thirty rabbits were divided into 5 groups: groups A and C were subjected to meniscectomy only, groups B and D underwent meniscal transplantation immediately after meniscectomy, and group E had delayed transplantation 6 weeks after meniscectomy. Six

Paul C. Rijk; Wikky Tigchelaar-Gutter; Franz-Peter Bernoski; Cornelis J. F. Van Noorden

2006-01-01

435

Quantitative PCR Assay To Evaluate Ampicillin, Ofloxacin, and Doxycycline for Treatment of Experimental Leptospirosis  

Microsoft Academic Search

The susceptibility of Leptospira interrogans serovar icterohaemorrhagiae strain Verdun to selected antibiotics used in medical practice (ampicillin, doxycycline, and ofloxacin) was evaluated in a Syrian hamster model, to determine the efficacy of these antibiotics during the course of the disease. A quantitative PCR assay was used to monitor the density of leptospires in blood and in target organs (liver, kidney,

Johann Truccolo; Françoise Charavay; Fabrice Merien; Philippe Perolat

2002-01-01

436

Evaluating Web-supported Learning Versus Lecture-based Teaching: Quantitative and Qualitative Perspectives  

Microsoft Academic Search

A graduate level research methods and statistics course offered on the World-Wide Web was evaluated relative to the traditional lWith their consent, course members were randomly assigned to the two versions of the course for the first block of sessions. For the second block of sessions the groups crossed over to access the alternative version of the course. Quantitative and

Norah Frederickson; Phil Reed; Viv Clifford

2005-01-01

437

Modeling and visualization application of naval battlefield situation quantitative analysis and evaluation  

Microsoft Academic Search

How to analyze the situation of the battlefield in the modern battle, and help the commander to make correct decision is the major orientation of every countriespsila researches. This paper presents a quantitative analysis and evaluation model of naval battlefield situation and gives a corresponding visual analysis model using isoline technology and potential field theory. This model can not only

Xiaobo Niu; Lujing Yang

2008-01-01

438

Evaluation of a Quantitative Magnetic Resonance Method for Mouse Whole Body Composition Analysis  

Microsoft Academic Search

Objective: To evaluate applicability, precision, and accuracy of a new quantitative magnetic resonance (QMR) analysis for whole body composition of conscious live mice.Research Methods and Procedures: Repeated measures of body composition were made by QMR, DXA, and classic chemical analysis of carcass using live and dead mice with different body compositions. Caloric lean and dense diets were used to produce

Frank C. Tinsley; Gersh Z. Taicher; Mark L. Heiman

2004-01-01

439

Quantitative evaluation of ion signal detection in analytically important Fourier transform ion cyclotron resonance mass spectrometry  

Microsoft Academic Search

Experiments performed in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer are evaluated to produce quantitatively reliable mass spectra in which the ion population in the trapped-ion cell is proportional to the image current. Generation of signal intensity profiles as a function of excitation voltage is described for analyzing ion cloud evolution in response to the effect of system

Riegner

1993-01-01

440

DEVELOPMENT AND EVALUATION OF A QUANTITATIVE ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) FOR POLYCHLORINATED BIPHENYLS  

EPA Science Inventory

A 96-well, microplate-based enzyme linked immunosorbent assay (ELISA) for the quantitative determination of PCBs (as Aroclors) in soil has been developed and evaluated. he method detection limits are 8.95 ug/Kg and 10.5 ug/Kg for Aroclors 1248 and 1242, respectively. he ELISA was...

441

Evaluation of a new assay for HBV DNA quantitation in patients with chronic hepatitis B  

Microsoft Academic Search

Background: The Amplicor™ HBV Monitor Test for quantitative determination of serum hepatitis B virus (HBV) DNA has recently been introduced. This assay is based on PCR and a non-radioactive hybridization and detection system on microwell plates.Objective: The performance of the Amplicor™ HBV Monitor Test was evaluated in a routine diagnostic laboratory. The Amplicor™ HBV Monoitor assay was compared to the

Harald H Kessler; Karen Pierer; Elizabeth Dragon; Herwig Lackner; Brigitte Santner; Doris Stünzner; Evelyn Stelzl; Brigitte Waitzl; Egon Marth

1998-01-01

442

A quantitative evaluation of reliability of passive systems within probabilistic safety assessment framework for VHTR  

Microsoft Academic Search

This article presents a quantitative evaluation of the reliability of passive systems (RoPS) within the probabilistic safety assessment (PSA) framework for very high temperature reactors (VHTR). VHTRs have unfavorable features in regard to defining a robust failure state. From the viewpoint of PSA, the evaluation of the RoPS as a part of VHTR’s PSA should carefully consider the correct status

Seok-Jung Han; Joon-Eon Yang

2010-01-01

443

Quantitative MR evaluation of body composition in patients with Duchenne muscular dystrophy  

Microsoft Academic Search

.   The aim of this study was to propose a quantitative MR protocol with very short acquisition time and good reliability in\\u000a volume construction, for the evaluation of body composition in patients affected by Duchenne muscular dystrophy (DMD). This\\u000a MR protocol was compared with common anthropometric evaluations of the same patients. Nine boys affected by DMD, ranging in\\u000a age from

Anna Pichiecchio; Carla Uggetti; Maria Egitto; Angela Berardinelli; Simona Orcesi; Ksenija Gorni; Cristina Zanardi; Anna Tagliabue

2002-01-01

444

NON-DESTRUCTIVE SOIL CARBON ANALYZER.  

SciTech Connect

This report describes the feasibility, calibration, and safety considerations of a non-destructive, in situ, quantitative, volumetric soil carbon analytical method based on inelastic neutron scattering (INS). The method can quantify values as low as 0.018 gC/cc, or about 1.2% carbon by weight with high precision under the instrument's configuration and operating conditions reported here. INS is safe and easy to use, residual soil activation declines to background values in under an hour, and no radiological requirements are needed for transporting the instrument. The labor required to obtain soil-carbon data is about 10-fold less than with other methods, and the instrument offers a nearly instantaneous rate of output of carbon-content values. Furthermore, it has the potential to quantify other elements, particularly nitrogen. New instrumentation was developed in response to a research solicitation from the U.S. Department of Energy (DOE LAB 00-09 Carbon Sequestration Research Program) supporting the Terrestrial Carbon Processes (TCP) program of the Office of Science, Biological and Environmental Research (BER). The solicitation called for developing and demonstrating novel techniques for quantitatively measuring changes in soil carbon. The report includes raw data and analyses of a set of proof-of-concept, double-blind studies to evaluate the INS approach in the first phase of developing the instrument. Managing soils so that they sequester massive amounts of carbon was suggested as a means to mitigate the atmospheric buildup of anthropogenic CO{sub 2}. Quantifying changes in the soils' carbon stocks will be essential to evaluating such schemes and documenting their performance. Current methods for quantifying carbon in soil by excavation and core sampling are invasive, slow, labor-intensive and locally destroy the system being observed. Newly emerging technologies, such as Laser Induced Breakdown Spectroscopy and Near-Infrared Spectroscopy, offer soil-carbon analysis; however, these also are invasive and destructive techniques. The INS approach permits quantification in a relatively large volume of soil without disrupting the measurement site. The technique is very fast and provides nearly instantaneous results thereby reducing the cost, and speeding up the rate of analysis. It also has the potential to cover large areas in a mobile scanning mode. These capabilities will significantly advance the tracking carbon sequestration and offer a tool for research in agronomy, forestry, soil ecology and biogeochemistry.

WIELOPOLSKI,L.MITRA,S.HENDREY,G.ORION,I.ROGERS,H.TORBERT,A.PRIOR,S.RUNION,B.

2004-02-01

445

Quantitative evaluation of electrodes for external urethral sphincter electromyography during bladder-to-urethral guarding reflex  

Microsoft Academic Search

Purpose  Accuracy in the recording of external urethral sphincter (EUS) electromyography (EMG) is an important goal in the quantitative\\u000a evaluation of urethral function. The aim of this study was to quantitatively compare electrode recordings taken during tonic\\u000a activity and leak point pressure (LPP) testing.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Several electrodes, including the surface electrode (SE), concentric electrode (CE), and wire electrode (WE), were placed\\u000a on

James E. Steward; Jessica D. Clemons; Paul J. Zaszczurynski; Robert S. Butler; Margot S. Damaser; Hai-Hong Jiang

2010-01-01

446

Nondestructive sensing and stress transferring evaluation of carbon nanotube, nanofiber, and Ni nanowire strands/polymer composites using an electro-micromechanical technique  

NASA Astrophysics Data System (ADS)

Nondestructive damage sensing and load transfer mechanisms of carbon nanotube (CNT), nanofiber (CNF), and Ni nanowire strands/epoxy composites were investigated using electro-micromechanical technique. Electrospun PVDF nanofiber was also prepared as a piezoelectric sensor. High volume% CNT/epoxy composites showed significantly higher tensile properties than neat and low volume% CNT/epoxy composites. CNF /epoxy composites with smaller aspect ratio showed higher apparent modulus due to high volume content in case of shorter aspect ratio. Using Ni nanowire strands/silicone composites with different content, load sensing response of electrical contact resistivity was investigated under tensile and compression condition. The mechanical properties of Ni nanowire strands with different type and content/epoxy composites were indirectly measured apparent modulus using uniformed cyclic loading and electro-pullout test. CNT or Ni nanowire strands/epoxy composites showed humidity and temperature sensing within limited ranges, 20 vol% reinforcement. Thermal treated electrospun PVDF nanofiber showed higher mechanical properties than the untreated case due to increased crystallization, whereas load sensing decreased in heat treated case. Electrospun PVDF nanofiber web also responded the sensing effect on humidity and temperature. Nanocomposites using CNT, CNF, Ni nanowire strands, and electrospun PVDF nanofiber web can be applicable practically for multifunctional applications nondestructively.

Park, Joung-Man; Kim, Sung-Ju; Jung, Jin-Gyu; Hansen, George; Yoon, Dong-Jin

2006-04-01

447

Business Scenario Evaluation Method Using Monte Carlo Simulation on Qualitative and Quantitative Hybrid Model  

NASA Astrophysics Data System (ADS)

We propose a business scenario evaluation method using qualitative and quantitative hybrid model. In order to evaluate business factors with qualitative causal relations, we introduce statistical values based on propagation and combination of effects of business factors by Monte Carlo simulation. In propagating an effect, we divide a range of each factor by landmarks and decide an effect to a destination node based on the divided ranges. In combining effects, we decide an effect of each arc using contribution degree and sum all effects. Through applied results to practical models, it is confirmed that there are no differences between results obtained by quantitative relations and results obtained by the proposed method at the risk rate of 5%.

Samejima, Masaki; Akiyoshi, Masanori; Mitsukuni, Koshichiro; Komoda, Norihisa

448

Quantitative chemical evaluation of dilute GaNAs using ADF STEM: avoiding surface strain induced artifacts.  

PubMed

The high angle annular dark field intensity (HAADF) in scanning transmission electron microscopy (STEM) can be used for a quantitative evaluation of the chemical composition in dilute GaNAs quantum wells by comparison with simulated intensities. As the scattered intensity is highly sensitive to surface strain fields originating from the quantum wells embedded in GaAs, the HAADF intensity is difficult to evaluate in a quantitative way as long as strain contrast cannot be distinguished from chemical contrast. We present a method to achieve full 2D HAADF STEM compositional mapping of GaNAs/GaAs quantum well systems by making use of information from two different camera lengths. PMID:23542584

Grieb, Tim; Müller, Knut; Fritz, Rafael; Grillo, Vincenzo; Schowalter, Marco; Volz, Kerstin; Rosenauer, Andreas

2013-02-16

449

Quantitative Evaluation of the Effectiveness of Idea Generation in the Wild  

Microsoft Academic Search

\\u000a New ideas are the primary building blocks in attempts to produce novel interactive technology. Numerous idea generation methods\\u000a such as Brainstorming have been introduced to support this process, but there is mixed evidence regarding their effectiveness.\\u000a In this paper we describe an experimental, quantitative methodology from the domain of product design research for evaluating\\u000a different idea generation methods. We present

Lassi A. Liikkanen; Matti M. Hämäläinen; Anders Häggman; Tua Björklund; Mikko P. Koskinen

450

[The quantitative evaluation of capacity of opportunistic pathogenic microorganisms to form biofilms in experiment].  

PubMed

The article discusses the technique of quantitative evaluation of capacity of opportunistic pathogenic microorganisms to form biofilm by means of measuring the contact angle of moistening of its surface. The specific rates of biofilm formation by hospital strains of microorganisms are determined. It is demonstrated that P. aeruginosa form biofilm on surface of glass plate better than S. aureus and C. albicans do. PMID:23265060

Leonov, V V

2012-10-01

451

Evaluation of hepatitis C virus RNA RT\\/PCR qualitative and quantitative second generation assays  

Microsoft Academic Search

Hepatitis C virus (HCV) RNA qualitative and quantitative second generation assays (Amplicor HCV v2.0 and Amplicor HCV Monitor v2.0, respectively) were evaluated by testing serum samples from 132 blood donors anti-HCV positive HCV RNA negative by first generation qualitative assay and 326 viremic patients. An HCV RNA transcript was synthesized and ten-fold dilutions were used to assess sensitivity. Second generation

Fco J. Castro; Silvia Sauleda; J. I. Esteban; L. Viladomiu; M. Martell; E. Dragon; R. Esteban; J. Guardia

2001-01-01

452

Quantitative evaluation of altered hepatic spaces and membrane transport in fibrotic rat liver  

Microsoft Academic Search

Four animal models were used to quantitatively evaluate hepatic alterations in this study: (1) a carbon tetrachloride control group (phenobarbital treatment only), (2) a CCl4-treated group (phenobarbital with CCl4 treatment), (3) an alcohol-treated group (liquid diet with alcohol treatment), and (4) a pair-fed alcohol control group (liquid diet only). At the end of induction, single-pass perfused livers were used to

Daniel Y. Hung; Ping Chang; Kee Cheung; Clay Winterford; Michael S. Roberts

2002-01-01

453

Quantitative and Statistical Performance Evaluation of Arbiter Physical Unclonable Functions on FPGAs  

Microsoft Academic Search

The quantitative performance indicators of Physical Unclonable Functions (PUFs)-Randomness, Steadiness, Correctness, Diffuseness and Uniqueness-are strictly defined and applied to the evaluation of 45 arbiter PUFs on Virtex-5 FPGAs. The indicators effectively reflect the characteristics of PUFs ranging from 0 to 1 with 1 being the highest performance. The indicators enable the easy measurement and intuitive understanding of PUF performances. The

Yohei Hori; Takahiro Yoshida; Toshihiro Katashita; Akashi Satoh

2010-01-01

454

Murine Model of Disseminated Fusariosis: Evaluation of the Fungal Burden by Traditional CFU and Quantitative PCR.  

PubMed

Systemic disease is the most severe clinical form of fusariosis, and the treatment involves a challenge due to the refractory response to antifungals. Treatment for murine Fusarium solani infection has been described in models that employ CFU quantitation in organs as a parameter of therapeutic efficacy. However, CFU counts do not precisely reproduce the amount of cells for filamentous fungi such as F. solani. In this study, we developed a murine model of disseminated fusariosis and compared the fungal burden with two methods: CFU and quantitative PCR. ICR and BALB/c mice received an intravenous injection of 1 × 10(7) conidia of F. solani per mouse. On days 2, 5, 7, and 9, mice from each mice strain were killed. The spleen and kidneys of each animal were removed and evaluated by qPCR and CFU determinations. Results from CFU assay indicated that the spleen and kidneys had almost the same fungal burden in both BALB/c and ICR mice during the days of the evaluation. In the qPCR assay, the spleen and kidney of each mouse strain had increased fungal burden in each determination throughout the entire experiment. The fungal load determined by the qPCR assay was significantly greater than that determined from CFU measurements of tissue. qPCR could be considered as a tool for quantitative evaluation of fungal burden in experimental disseminated F. solani infection. PMID:23943405

González, Gloria M; Márquez, Jazmín; Treviño-Rangel, Rogelio de J; Palma-Nicolás, José P; Garza-González, Elvira; Ceceñas, Luis A; Gerardo González, J

2013-08-13

455

Quantitative oxygen concentration imaging in toluene atmospheres using Dual Imaging with Modeling Evaluation  

NASA Astrophysics Data System (ADS)

Fluorescence lifetimes of toluene as a function of oxygen concentration in toluene/nitrogen/oxygen mixtures have been measured at room temperature using picosecond-laser excitation of the S1-S0 transition at 266 nm. The data satisfy the Stern-Volmer relation with high accuracy, providing an updated value of the Stern-Volmer slope. A newly developed fluorescence lifetime imaging scheme, called Dual Imaging with Modeling Evaluation (DIME), is evaluated and successfully demonstrated for quantitative oxygen concentration imaging in toluene-seeded O2/N2 gas mixtures.

Ehn, Andreas; Jonsson, Malin; Johansson, Olof; Aldén, Marcus; Bood, Joakim

2013-01-01

456

Quantitative oxygen concentration imaging in toluene atmospheres using Dual Imaging with Modeling Evaluation  

NASA Astrophysics Data System (ADS)

Fluorescence lifetimes of toluene as a function of oxygen concentration in toluene/nitrogen/oxygen mixtures have been measured at room temperature using picosecond-laser excitation of the S1-S0 transition at 266 nm. The data satisfy the Stern-Volmer relation with high accuracy, providing an updated value of the Stern-Volmer slope. A newly developed fluorescence lifetime imaging scheme, called Dual Imaging with Modeling Evaluation (DIME), is evaluated and successfully demonstrated for quantitative oxygen concentration imaging in toluene-seeded O2/N2 gas mixtures.

Ehn, Andreas; Jonsson, Malin; Johansson, Olof; Aldén, Marcus; Bood, Joakim

2012-12-01

457

Non-destructive evaluation of the effects of combined bisphosphonate and photodynamic therapy on bone strain in metastatic vertebrae using image registration.  

PubMed

Skeletal metastases most frequently affect the vertebral column and may lead to severe consequences including fracture. Clinical management of skeletal metastases often utilizes a multimodal treatment approach, including bisphosphonates (BPs). Previous work has demonstrated the synergistic potential of photodynamic therapy (PDT) in combination with BP in treating osteolytic disease through structural, histologic, and destructive mechanical testing analyses. Recent work has developed and validated image-based methods that may be used to non-destructively determine mechanical stability in whole bones, and enable their use for additional (i.e. histologic) analysis. In this work we use an intensity-based 3D image registration technique to compare the strain patterns throughout untreated control and BP + PDT treated rnu/rnu rat spinal motion segments with osteolytic metastases. It was hypothesized that the combination treatment will reduce average and maximum strain values and restore the pattern of strain to that of healthy vertebrae. Mean, median, and 90th percentile strains in the control group were significantly higher than the treatment group. High strain areas in both groups were observed around the endplates; in the control group, large areas of high strains were also observed around the lesions and adjacent to the dorsal wall. Absence of high strains adjacent to the dorsal wall (similar to healthy vertebrae) may correspond to a reduced risk of burst fracture following BP + PDT therapy. This study demonstrates the application of non-destructive image analysis to quantify the positive mechanical effects of combined BP + PDT treatment in the metastatic spine. PMID:21818534

Hojjat, Seyed-Parsa; Won, Emily; Hardisty, Michael R; Akens, Margarete K; Wise-Milestone, Lisa M; Whyne, Cari M

2011-08-05