Science.gov

Sample records for non-destructive pollution exposure

  1. Non-destructive method for determining neutron exposure

    DOEpatents

    Gold, R.; McElroy, W.N.

    1983-11-01

    A non-destructive method for determination of neutron exposure in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure at regions of interest within the object.

  2. Non-destructive assessment of polycyclic aromatic hydrocarbon (PAH) exposure by fluorimetric analysis of crab urine.

    PubMed

    Koenig, Samuel; Savage, Candida; Kim, Jonathan P

    2008-12-01

    The detection of urinary polycyclic aromatic hydrocarbon (PAH) metabolites by fluorescence spectrophotometry is particularly effective as a practical means to assess PAH exposure in decapod crabs. However, the practical application of this technique has thus far only been tested for the European shore crab (Carcinus maenas) and only a few field studies have been conducted in heavily polluted areas. The present study evaluated the adaptability of this method as a rapid, cost-effective and non-destructive biomonitoring tool for the New Zealand crab species, Macrophthalmus hirtipes (stalk-eyed mud crab). A field gradient could be detected among the sites and different input sources of PAH contamination could be discerned through the differentiation of pyrogenic and petrogenic PAH signatures. The present study shows that the fluorescence screening method is sensitive to relatively low levels of PAH contamination and more broadly applicable to smaller crab species than C. maenas, for which the technique was developed.

  3. Can predatory bird feathers be used as a non-destructive biomonitoring tool of organic pollutants?

    PubMed Central

    Jaspers, Veerle L.B; Voorspoels, Stefan; Covaci, Adrian; Eens, Marcel

    2006-01-01

    The monitoring of different types of pollutants that are released into the environment and that present risks for both humans and wildlife has become increasingly important. In this study, we examined whether feathers of predatory birds can be used as a non-destructive biomonitor of organic pollutants. We demonstrate that polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and polybrominated diphenyl ethers (PBDEs) are measurable in one single tail feather of common buzzards (Buteo buteo) and that levels in this feather and internal tissues are significantly related to each other (0.35non-destructive biomonitoring of organic pollutants, although further validation may be necessary. PMID:17148383

  4. Non-destructive method for determining neutron exposure and constituent concentrations of a body

    DOEpatents

    Gold, Raymond; McElroy, William N.

    1986-01-01

    A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure or the spatial constituent concentration at regions of interest within the object.

  5. Non-destructive method for determining neutron exposure and constituent concentrations of a body

    DOEpatents

    Gold, R.; McElroy, W.N.

    1984-02-22

    A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure or the spatial constituent concentrations at regions of interest within the object.

  6. Experimental evaluation of the usefulness of feathers as a non-destructive biomonitor for polychlorinated biphenyls (PCBs) using silastic implants as a novel method of exposure.

    PubMed

    Van den Steen, E; Covaci, A; Jaspers, V L B; Dauwe, T; Voorspoels, S; Eens, M; Pinxten, R

    2007-02-01

    Risk assessment of pollutants requires both monitoring studies in the field and experimental exposure studies. In this study, we evaluated silastic implants as an alternative method of exposure for use in toxicological studies and at the same time evaluated the usefulness of feathers as a non-destructive biomonitor for PCBs. European starlings (Sturnus vulgaris) were exposed to different doses (including a control group) of environmentally relevant concentrations of PCB 153 during a 15-week period using silastic implants with both ends/only one end sealed. After implantation, there was a rapid and significant increase in PCB 153 blood concentration in the exposed groups. The significant differences in blood concentrations among the treatment groups show that silastic implants are useful as a method of exposure. Moreover, the ratio between the tissue concentrations of two treatment groups reflected the difference in implantation doses between these groups. There was also a clear difference in tissue concentrations among the treatment groups, although we could not test this statistically due to the small sample sizes. The slow release kinetics for a prolonged period and the relatively stable blood concentrations during the 15-week period render silastic tubes very interesting to study the effects of chronic exposure to pollutants. Our results also revealed that sealing both ends of the implant instead of only one did not significantly affect the exposure. There were strong, significant positive correlations between the blood and the tissues, which confirm the use of blood to monitor PCBs. To evaluate the usefulness of feathers as a non-destructive biomonitor for PCBs, we plucked the original and newly grown wing and tail feathers. We observed strong, significant positive correlations between the concentrations in the newly grown feathers and concentrations in the muscle, liver, brain and blood. PCB 153 concentrations in the newly grown feathers differed among the

  7. A NEW NON-DESTRUCTIVE METHOD FOR CHEMICAL ANALYSIS OF PARTICULATE MATTER FILTERS: THE CASE OF MANGANESE AIR POLLUTION IN VALLECAMONICA (ITALY)

    PubMed Central

    Borgese, Laura; Zacco, Annalisa; Pal, Sudipto; Bontempi, Elza; Lucchini, Roberto; Zimmerman, Neil; Depero, Laura E.

    2011-01-01

    Total Reflection X-ray Fluorescence (TXRF) is a well-established technique for chemical analysis, but it is mainly employed for quality control in the electronics semiconductor industry. The capability to analyze liquid and uniformly thin solid samples makes this technique suitable for other applications, and especially in the very critical field of environmental analysis. Comparison with standard methods like Inductively Coupled Plasma (ICP) and Atomic Absorption Spectroscopy (AAS) show that TXRF is a practical, accurate, and reliable technique in occupational settings. Due to the greater sensitivity necessary in trace heavy metal detection, TXRF is also suitable for environmental chemical analysis. In this paper we show that based on appropriate standards, TXRF can be considered for non-destructive routine quantitative analysis of environmental matrices such as air filters. This work has been developed in the frame of the EU-FP6 PHIME (Public Health Impact of long-term, low-level Mixed element Exposure in susceptible population strata) Integrated Project (www.phime.org). The aim of this work was to investigate Mn air pollution in the area of Vallecamonica (Italy). PMID:21315919

  8. Air Pollution Exposure

    PubMed Central

    Balmes, John R.; Collard, Harold R.

    2015-01-01

    Air pollution exposure is a well-established risk factor for several adverse respiratory outcomes, including airways diseases and lung cancer. Few studies have investigated the relationship between air pollution and interstitial lung disease (ILD) despite many forms of ILD arising from environmental exposures. There are potential mechanisms by which air pollution could cause, exacerbate, or accelerate the progression of certain forms of ILD via pulmonary and systemic inflammation as well as oxidative stress. This article will review the current epidemiologic and translational data supporting the plausibility of this relationship and propose a new conceptual framework for characterizing novel environmental risk factors for these forms of lung disease. PMID:25846532

  9. Non-Destructive Testing Scanner

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Bio-Imaging Research's technology that originated in an aerospace program has come full circle with a new aerospace adaptation called the Advanced Computed Tomography Inspection System, or ACTIS. The medical version of CT scans the human body for tumors or other abnormalities, the ACTIS system finds imperfections in aerospace structures and components, such as castings, assemblies, rocket motors and nozzles. ACTIS is described by its developer as the most versatile CT scanner available for non-destructive testing applications. ACTIS is a variable geometry system. ACTIS source and detectors can be moved closer together or farther apart to optimize the geometry for different sizes of test objects. The combination of variable geometry, three sources, and focusing detectors makes ACTIS cost effective for a broad range of applications. System can scan anything from very small turbine blades to large rocket assemblies.

  10. Non-destructive identification of twisted light.

    PubMed

    Li, Pengyun; Wang, Bo; Song, Xinbing; Zhang, Xiangdong

    2016-04-01

    The non-destructive identification of the orbital angular momentum (OAM) is essential to various applications in the optical information processing. Here, we propose and demonstrate experimentally an efficient method to identify non-destructively the OAM by using a modified Mach-Zehnder interferometer. Our schemes are applicable not only to the case with integer charges, but also to optical vortices with noninteger charges. Our Letter presents the first experimental demonstration of the non-destructive identification of twisted light with integer or noninteger topological charges, which has potential applications in the OAM-based data transmission for optical communications.

  11. Method for non-destructive testing

    DOEpatents

    Akers, Douglas W.

    2011-08-30

    Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

  12. Non-Destructive State Machine Reverse Engineering

    SciTech Connect

    Smith, Jessica L.

    2013-10-10

    Most of the integrated circuits (ICs) that are in electronic systems today are based on state machines. We are taking advantage of this to develop a hardware reverse engineering method that discovers the IC’s underlying state machine, rather than its transistors and gates. While there are other methods for destructively reverse engineering ICs or for non-destructively characterizing ICs, our method offers a fast and accurate analysis while remaining non-destructive. To do this, we present an intelligent brute-force method of exploring the logic of the IC using only the input and outputs designed into the IC - the I/O pins. From this exploration, we can apply a folding algorithm to discover the designed state machine.

  13. Hybrid holographic non-destructive test system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  14. Non-Destructive Evaluation of Aerospace Composites

    DTIC Science & Technology

    2009-03-01

    Master of Science in Materials Science Jeremy D. Johnson, BS Captain, USAF March 2009 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...non-destructive material evaluation (NDE) were used to inspect various forms of damage commonly found in aerospace fiberglass composites: voids...ultrasound, and flash IR thermography were analyzed for the detection of defects. Test results and analysis of each NDE method’s capabilities

  15. FIRST 100 T NON-DESTRUCTIVE MAGNET

    SciTech Connect

    J. R. SIMS; ET AL

    1999-10-01

    The first 100 T non-destructive (100 T ND) magnet and power supplies as currently designed are described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field Laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND magnet will provide a 100 T pulsed field of 5 ms duration (above 90% of full field) in a 15 mm diameter bore once per hour. Magnet operation will be non-destructive. The magnet will consist of a controlled power outer coil set which produces a 47 T platform field in a 225 mm diameter bore. Located within the outer coil set will be a 220 mm outer diameter capacitor powered insert coil. Using inertial energy storage a synchronous motor/generator will provide ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters will energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. The insert will then be energized to produce the balance of the 100 T peak field using a 2.3 MJ, 18 kV (charged to 15 kV), 14.4 mF capacitor bank controlled with solid-state switches. The magnet will be the first of its kind and the first non-destructive, reusable 100 T pulsed magnet. The operation of the magnet will be described along with special features of its design and construction.

  16. Complementary Electromagnetic Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  17. Non-destructive testing method and apparatus

    DOEpatents

    Akers, Douglas W.

    2011-10-04

    Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

  18. NON-DESTRUCTIVE FLAW DETECTION APPARATUS

    DOEpatents

    Stateman, M.J.; Holloway, H.R.

    1957-12-17

    An apparatus is described for the non-destructive detection of flaws in electrical conducting articles. The particular feature of the detection apparatus is that a flaw in the front or back of the test article will not be masked by signals caused by the passage of the end and front of the article through the detection apparatus. The present invention alleviates the above problem by mounting detection coils on directly opposite sides of the test passageway so that the axes of the pickup coils are perpendicular to the axis of an energizing coil through which the article is passed. A flaw in the article will cause a change in the voltage induced in one pickup coil, but passage of the end or front of the article will not produce unequal signals. The signals are compared in appropriate electrical circuitry to actuate a recorder only when unequal signals are present, indicating the presence of a flaw.

  19. Non-destructive evaluation of composites

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip

    1996-01-01

    The composite materials have been used in aerospace industries for quite some time. Several non-destructive evaluation (NDE) methods have been developed to inspect composites in order to detect flaws, matrix cracking, and delamination. These methods include ultrasonics, acoustic emission, shearography, thermography, X-ray, and digital image correlation. The NDE Branch of Marshall Space Flight Center has recently acquired a thermal imaging NDE system. The same system has been used at NASA Langley Research Center for detecting disbonds. In order to compare different NDE methods, three carbon/carbon composite panels were used for experiment using ultrasonic C-scan, shearography, and thermography methods. These panels have teflon inserts to simulate the delamination between plies in a composite panel. All three methods have successfully located the insert. The experiment and results are presented in the following sections.

  20. Exposure measurement for air-pollution epidemiology

    SciTech Connect

    Ferris, B.G.; Ware, J.H.; Spengler, J.D.

    1988-08-01

    The chapter describes the evolution of air-pollution epidemiology over a period when changes in pollution technologies have both lowered total exposures and dispersed them over vastly greater areas. Since personal exposure and microenvironmental measurements are expensive, studies oriented toward measurements of total exposure will be smaller and more intensive. The shift in emphasis to total human exposure also will affect health risk assessment and raise difficult issues in the regulatory domain. Considering that outdoor exposures (for which EPA has a regulatory mandate) occur in the context of exposures from other sources, the potential effect of regulatory action would probably be small. The regulatory issues are even more difficult for particulate air pollution since cigarette smoking is the strongest determinant of indoor levels but the EPA lacks regulatory responsibility for cigarette smoke.

  1. Cryogenic Storage Tank Non-Destructive Evaluation

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2010-01-01

    This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

  2. Non destructive testing of soft body armor

    NASA Astrophysics Data System (ADS)

    Bhise, Karan

    Pristine bullet proof vests are extremely effective at halting pre-determined projectile threats and have saved over 3000 lives. However, the effectiveness of these vests to halt a bullet is seen to decrease over time.Owing to the importance of bullet proof vests over a period of time, tests to determine their effectiveness have been carried out on every batch of vests at the time of inception and at certain time intervals by shooting a bullet through them. A few vests from every batch are picked up and shot at to check for bullet penetration during this process while these results are extrapolated onto the other vests from the batch.One of the main issues with this method is the fact that testing a few jackets among a large set of jackets does not guarantee the safety of every jacket in the entire batch.Further the jackets that are shot-at have the possibility of undergoing substantial damage during the process thus compromising its safety rendering them unsafe for future use.As the vest penetration phenomenon is extremely complex too, there arose a need for a better testing procedure that could not only help ensure more safety, but also save time and money.The new testing procedure proposed a non-destructive evaluation of the jackets that would solve the issues previous faced in testing the vests. This would lead to the building of a portable set up which could be carried to any location to test jackets in a matter of minutes thus saving time and money.

  3. Using magnetic levitation for non-destructive quality control of plastic parts.

    PubMed

    Hennek, Jonathan W; Nemiroski, Alex; Subramaniam, Anand Bala; Bwambok, David K; Yang, Dian; Harburg, Daniel V; Tricard, Simon; Ellerbee, Audrey K; Whitesides, George M

    2015-03-04

    Magnetic levitation (MagLev) enables rapid and non-destructive quality control of plastic parts. The feasibility of MagLev as a method to: i) rapidly assess injection-molded plastic parts for defects during process optimization, ii) monitor the degradation of plastics after exposure to harsh environmental conditions, and iii) detect counterfeit polymers by density is demonstrated.

  4. NON-DESTRUCTIVE SOIL CARBON ANALYZER.

    SciTech Connect

    Wielopolski, Lucian; Hendrey, G.; Orion, I.; Prior, S.; Rogers, H.; Runion, B.; Torbert, A.

    2004-02-01

    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

  5. Personal exposure of children to air pollution

    NASA Astrophysics Data System (ADS)

    Ashmore, M. R.; Dimitroulopoulou, C.

    Changes over recent decades in outdoor concentrations of air pollutants are well documented. However, the impacts of air pollution on an individual's health actually relate not to these outdoor concentrations but to their personal exposure in the different locations in which they spend time. Assessing how personal exposures differ from outdoor concentrations, and how they have changed over recent decades, is challenging. This review focuses on the exposure of children, since they are a particularly sensitive group. Much of children's time is spent indoors, and childhood exposure is closely related to concentrations in the home, at school, and in transport. For this reason, children's personal exposures to air pollutants differ significantly from both those of adults and from outdoor concentrations. They depend on a range of factors, including urbanisation, energy use, building design, travel patterns, and activity profiles; analysis of these factors can identify a wider range of policy measures to reduce children's exposure than direct emission control. There is a very large variation in personal exposure between individual children, caused by differences in building design, indoor and outdoor sources, and activity patterns. Identifying groups of children with high personal exposure, and their underlying causes, is particularly important in regions of the world where emissions are increasing, but there are limited resources for environmental and health protection. Although the science of personal exposure assessment, with the associated measurement and modelling techniques, has developed to maturity in North America and western Europe over the last 50 years, there is an urgent need to apply this science in other parts of the world where the effects of air pollution are now much more serious.

  6. NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.

    SciTech Connect

    BERNDT,M.L.

    2001-03-23

    Non-destructive testing is a key component of optimized plant inspection and maintenance programs. Risk based inspection, condition based maintenance and reliability centered maintenance systems all require detection, location and sizing of defects or flaws by non-destructive methods. Internal damage of geothermal piping by corrosion and erosion-corrosion is an ongoing problem requiring inspection and subsequent maintenance decisions to ensure safe and reliable performance. Conventional manual ultrasonic testing to determine remaining wall thickness has major limitations, particularly when damage is of a random and localized nature. Therefore, it is necessary to explore alternative non-destructive methods that offer potential benefits in terms of accurate quantification of size, shape and location of damage, probability of detection, ability to use on-line over long ranges, and economics. A review of non-destructive methods and their applicability to geothermal piping was performed. Based on this, ongoing research will concentrate on long range guided wave and dynamic methods.

  7. Non-Destructive Classification Approaches for Equilibrated Ordinary Chondrites

    NASA Astrophysics Data System (ADS)

    Righter, K.; Harrington, R.; Schroeder, C.; Morris, R. V.

    2013-09-01

    In order to compare a few non-destructive classification techniques with the standard approaches, we have characterized a group of chondrites from the Larkman Nunatak region using magnetic susceptibility and Mössbauer spectroscopy.

  8. Biomarkers: Non-destructive Method for Predicting Meat Tenderization.

    PubMed

    Singh, Arashdeep; Ahluwalia, Preeti; Rafiq, Aasima; Sharma, Savita

    2015-07-06

    Meat tenderness is the primary and most important quality attribute for the consumers worldwide. Tenderness is the process of breakdown of collagen tissue in meat to make it palatable. The earlier methods of tenderness evaluation like taste panels and shear force methods are destructive, time consuming and ill suited as they requires removing a piece of steak from the carcass for performing the test. Therefore, a non-destructive method for predicting the tenderness would be more desirable. The development of a meat quality grading and guarantee system through muscle profiling research can help to meet this demand. Biomarkers have the ability to identify if an exposure has occurred. Biomarkers of the meat quality are of prime importance for meat industry, which has ability to satisfy consumers' expectations. The biomarkers so far identified have been then sorted and grouped according to their common biological functions. All of them refer to a series of biological pathways including glycolytic and oxidative energy production, cell detoxification, protease inhibition and production of Heat Shock Proteins. On this basis, a detailed analysis of these metabolic pathways helps in identifying tenderization of meat having some domains of interest. It was, therefore, stressed forward that biomarkers can be used to determine meat tenderness. This review article summarizes the uses of several biomarkers for predicting the meat tenderness.

  9. Measurement error in air pollution exposure assessment.

    PubMed

    Navidi, W; Lurmann, F

    1995-01-01

    The exposure of an individual to an air pollutant can be assessed indirectly, with a "microenvironmental" approach, or directly with a personal sampler. Both methods of assessment are subject to measurement error, which can cause considerable bias in estimates of health effects. If the exposure estimates are unbiased and the measurement error is nondifferential, the bias in a linear model can be corrected when the variance of the measurement error is known. Unless the measurement error is quite large, estimates of health effects based on individual exposures appear to be more accurate than those based on ambient levels.

  10. Characterizing climate change impacts on human exposures to air pollutants

    EPA Science Inventory

    Human exposures to air pollutants such as ozone (O3) have the potential to be altered by changes in climate through multiple factors that drive population exposures, including: ambient pollutant concentrations, human activity patterns, population sizes and distributions, and hous...

  11. NonDestructive Evaluation for Industrial & Development Applications

    SciTech Connect

    Hunter, James F.

    2016-10-12

    Provide overview of weld inspection for Non-Destructive Testing at LANL. This includes radiography (RT/DR/CR/CT for x-ray & neutron sources), ultrasonic testing (UT/PAUT), dye penetrant inspection (PT), eddy current inspection (ET) and magnetic particle testing (MT). Facilities and capabilities for weld inspection will be summarized with examples.

  12. Non-destructive methods for food texture assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food texture is important to the successful marketing and profitability of food products. Non-destructive sensing would allow food producers and processors to inspect, sort, grade, or track individual product items, so that they can deliver consistent, superior food products to the marketplace. Over...

  13. Human exposure to urban air pollution.

    PubMed Central

    Boström, C E; Almén, J; Steen, B; Westerholm, R

    1994-01-01

    This study deals with some methods of making human exposure estimates, aimed at describing the human exposure for selected air pollutants in Sweden that are suspected carcinogens. Nitrogen oxides (NOx) have been chosen as an indicator substance for estimating the concentration of the urban plume. Earlier investigations have shown that the traffic in Swedish cities contributes around 85% to the measured NOx concentrations, and that most of the mutagenicity in urban air originates from traffic. The first section of this paper describes measurements in Stockholm of some unregulated light hydrocarbons, such as ethene, ethyne, propane, propene, butane, and isobutane. In addition, measurements of some volatile aromatic hydrocarbons are presented. Simultaneous measurements of carbon monoxide (CO) were made. The ratios between CO and the individual specific compounds were determined by linear regression analysis. By analysis of relationships between CO and NOx, NOx concentrations can be used as a tracer to describe the exposure for these specific compounds. NOx are considered to be a better tracer than CO, because NOx or NO2 values exist for many places over a long time, while CO is measured mostly in streets with high concentrations. At low concentrations, instruments that measure normal CO levels give no detectable signals. Through use of atmospheric dispersion models and models that describe how people live and work in urban areas it has been possible to describe the average exposure to NOx in cities of different sizes. The exposure to NOx for people living in the countryside has also been estimated. In this way, it has been possible to calculate the average exposure dose for NOx for the Swedish population. This figure is 23 micrograms/m3. By use of the relationships between NOx and specific compounds the average dose has been calculated for the following compounds: polyaromatic compounds (PAH); ethene, propene, and butadiene; benzene, toluene, and xylene; formaldehyde

  14. Controlled human exposures to ambient pollutant particles in susceptible populations

    EPA Science Inventory

    Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in suscep...

  15. Non-Destructive Techniques Based on Eddy Current Testing

    PubMed Central

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

    2011-01-01

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

  16. Infrared Thermography for Temperature Measurement and Non-Destructive Testing

    PubMed Central

    Usamentiaga, Rubèn; Venegas, Pablo; Guerediaga, Jon; Vega, Laura; Molleda, Julio; Bulnes, Francisco G.

    2014-01-01

    The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed. PMID:25014096

  17. Infrared thermography for temperature measurement and non-destructive testing.

    PubMed

    Usamentiaga, Rubén; Venegas, Pablo; Guerediaga, Jon; Vega, Laura; Molleda, Julio; Bulnes, Francisco G

    2014-07-10

    The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.

  18. Non-destructive examination system of vitreous body

    NASA Astrophysics Data System (ADS)

    Shibata, Takuma; Gong, Jin; Watanabe, Yosuke; Kabir, M. Hasnat; Masato, Makino; Furukawa, Hidemitsu; Nishitsuka, Koichi

    2014-04-01

    Eyeball plays a quite important role in acquiring the vision. Vitreous body occupies the largest part of the eyeball and consists of biological, elastic, transparent, gel materials. In the present medical examination, the non-destructive examination method of the vitreous body has not been well established. Here, we focus on an application of dynamic light scattering to this topic. We tried to apply our lab-made apparatus, scanning microscopic light scattering (SMILS), which was specially designed for observing the nanometer-scale network structure in gel materials. In order to examine the vitreous body using SMILS method, a commercial apparatus, nano Partica (Horiba Co. Ltd.) was also customized. We analyzed vitreous body using both the SMILS and the customized nano Partica. We successfully examined the vitreous bodies of healthy pigs in non-destructive way.

  19. Non-destructive microstructural analysis with depth resolution

    NASA Astrophysics Data System (ADS)

    Zolotoyabko, E.; Quintana, J. P.

    2003-01-01

    A depth-sensitive X-ray diffraction technique has been developed with the aim of studying microstructural modifications in inhomogeneous polycrystalline materials. In that method, diffraction profiles are measured at different X-ray energies varied by small steps. X-rays at higher energies probe deeper layers of material. Depth-resolved structural information is retrieved by comparing energy-dependent diffraction profiles. The method provides non-destructive depth profiling of the preferred orientation, grain size, microstrain fluctuations and residual strains. This technique is applied to the characterization of seashells. Similarly, energy-variable X-ray diffraction can be used for the non-destructive characterization of different laminated structures and composite materials.

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

    PubMed

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

    2011-01-01

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

  1. Non-destructive NIR FT Raman analysis of plants

    NASA Astrophysics Data System (ADS)

    Schrader, B.; Klump, H. H.; Schenzel, K.; Schulz, H.

    1999-10-01

    Non-destructive analyses of animal and plant cells and tissues by 'classical' Raman spectroscopy with excitation in the visible range have not been possible since the samples are destroyed photochemically or their fluorescence conceals the Raman spectra completely. When excited with the Nd:YAG laser line at 1064 nm fluorescence-free Raman spectra of animal or plant cells and tissues can be recorded without special preparation. In this paper we concentrate on plants and its constituents: essential oils, natural dyes, flavors, spices, alkaloids and fibers can be characterized. The spectra allow the observation of biochemical processes, to observe the distribution of natural products, application to taxonomy, optimizing plant breeding, the harvesting time and control of food—everything non-destructively in living plants!

  2. Embedded Non-Destructive Evaluation for Glass Armor

    DTIC Science & Technology

    2011-12-05

    Unclassified In House NDE and Electromagnetic Compatibility Capabilities Millimeter wave Scanning Imager Phased Array Ultrasound Immersion Tank Low...DISTRIBUTION A: Approved for public release; distribution is unlimited Embedded NDE for Glass Armor Sensor Enhanced Armor- Non-Destructive...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Unclassified Armor Solutions Tested with Ultrasonics NDT/E leading to Sensor Enhanced

  3. Monitoring human exposure to urban air pollutants

    SciTech Connect

    Barale, R.; Barrai, I.; Marrazzini, A.

    1993-10-01

    A multidisciplinary study on a general population exposed to vehicle exhaust was undertaken in Pisa in 1991. Environmental factors such as air pollution and those associated with lifestyle were studied. Meanwhile, biological and medical indicators of health condition were investigated. Chromosomal aberrations, sister chromatid exchanges (SCEs), and micronuclei in lymphocytes were included for the assessment of the genotoxic risk. Because of the large number (3800) of subjects being investigated, standardization of protocols was compulsory. The results on data reproducibility are reported. To assess the reliability of the protocol on a large scale, the population of Porto Tolle, a village located in northeast Italy, was studied and compared to a subset of the Pisa population. Preliminary results showed that probable differences between the two populations and individuals were present in terms of SCE frequencies. The study was potentially able to detect the effects of several factors such as age, smoking, genetics, and environment. The in vitro treatment of lymphocytes with diepoxybutane confirmed the presence of more responsive individuals and permitted us to investigate the genetic predisposition to genetic damage. The possible influence of environmental factors was studied by correlation analyses with external exposure to air pollutants as well as with several lifestyle factors. 10 refs., 5 figs., 1 tab.

  4. Oxidative Stress and Air Pollution Exposure

    PubMed Central

    Lodovici, Maura; Bigagli, Elisabetta

    2011-01-01

    Air pollution is associated with increased cardiovascular and pulmonary morbidity and mortality. The mechanisms of air pollution-induced health effects involve oxidative stress and inflammation. As a matter of fact, particulate matter (PM), especially fine (PM2.5, PM < 2.5 μm) and ultrafine (PM0.1, PM < 0.1 μm) particles, ozone, nitrogen oxides, and transition metals, are potent oxidants or able to generate reactive oxygen species (ROS). Oxidative stress can trigger redox-sensitive pathways that lead to different biological processes such as inflammation and cell death. However, it does appear that the susceptibility of target organ to oxidative injury also depends upon its ability to upregulate protective scavenging systems. As vehicular traffic is known to importantly contribute to PM exposure, its intensity and quality must be strongly relevant determinants of the qualitative characteristics of PM spread in the atmosphere. Change in the composition of this PM is likely to modify its health impact. PMID:21860622

  5. The use of non destructive biomarkers in the study of marine mammals.

    PubMed

    M Cristina Fossi And Letizia Marsili

    1997-01-01

    Marine mammals have been subject to heavy anthropogenic pressure by direct killing and chemical pollution all over the world. Most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting out of a total of 12 cetacean species studied, 45 of the specimens were obtained by sacrificing the animal; out of a total of eight pinniped species studied, 40 of the specimens were obtained by killing. The development of a series of non destructive techniques to evaluate biomarker responses and residue levels is recommended for the hazard assessment and conservation of endangered species of marine mammals. Here we review the current status of the non destructive biomarker approach in marine mammals, describing the biological materials available for non destructive tests in stranded brain, liver, blood, skin, subcutaneous blubber, muscle and fur and free ranging animals blood, skin biopsy, fur and faeces and the respective biomarker techniques mixed function oxidase activity and DNA damage in skin biopsy samples; porphyrins in faeces and fur; esterases, porphyrins, clinical biochemical parameter, vitamin A and micronuclei in blood samples. Residue analysis can be carried out in the various biological materials. We also report the results of applying this methodological approach to cetaceans minke whale Balaenoptera acutorostrata, fin whale-- Balaenoptera physalus, beluga whale-- Delphinapterus leucas, short finned pilot whale-- Globicephala macrorhynchus, harbour porpoise -- Phocoena phocoena, Rissos dolphin-- Risso s Grampus griseus, Dall s porpoise-- Phocoenoides dalli dalli, melon headed whale-- Peponocephala electra, bottlenose dolphin -- Tursiops truncatus, striped dolphin-- Stenella coeruleoalba, spinner dolphin-- Stenella longirostris, killer whale-- Orcinus orca and pinnipeds northern fur seal- Callorhinus ursinus, hooded seal-- Cystophora cristata, grey seal-- Halichoerus grypus, harbour seal-- Phoca vitulina

  6. CHARACTERIZATION OF INDOOR AND OUTDOOR AIR POLLUTION EXPOSURES AND SOURCES

    EPA Science Inventory

    Human exposures to indoor and outdoor pollutants vary depending on the sources and concentrations of pollutants as well as human behavioral factors that determine the extent of an individual's contact with indoor or outdoor pollutants. In general, the older populations spend more...

  7. MODELING INHALATION AND MULTIMEDIA MULTIPATHWAY HUMAN EXPOSURES TO ENVIRONMENTAL POLLUTANTS

    EPA Science Inventory

    Estimation of exposures of children and adults to air toxics or multimedia pollutants require careful consideration of sources and concentrations of pollutants that may be present in different media, as well as various routes and pathways of exposures associated with age-specif...

  8. APPARATUS FOR NON-DESTRUCTIVE INSPECTION OF CANTILEVERED MEMBERS

    DOEpatents

    Taylor, E.R.; Mahoney, C.H.; Lay, C.R.

    1961-10-24

    An apparatus for non-destructive inspection of cantilevered members, such as compressor blades, is described. The member under inspection is vibrated with a regulated source of air under pressure. The amplitude of vibration of the member is maintained at its natural frequency. The frequency of vibration of the member is measured. An indication of an excessive decay or erratic shifting in the measured frequency above an allowable hysteretic decay is provided as an indication of a fault in the member. The member is vibrated for a selected test period. (AEC)

  9. Air pollution exposure prediction approaches used in air pollution epidemiology studies

    EPA Science Inventory

    Epidemiological studies of the health effects of air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and miscla...

  10. Evaluation and Application of Alternative Air Pollution Exposure Metrics in Air Pollution Epidemiology Studies

    EPA Science Inventory

    ABSTRACT: Periodic review, revision and subsequent implementation of the National Ambient Air Quality Standards for criteria air pollutants rely upon various types of scientific air quality, exposure, toxicological dose-response and epidemiological information. Exposure assessmen...

  11. Local defect resonance for sensitive non-destructive testing

    NASA Astrophysics Data System (ADS)

    Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

    2016-02-01

    Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

  12. Laser active thermography for non-destructive testing

    NASA Astrophysics Data System (ADS)

    Semerok, A.; Grisolia, C.; Fomichev, S. V.; Thro, P.-Y.

    2013-11-01

    Thermography methods have found their applications in different fields of human activity. The non-destructive feature of these methods along with the additional advantage by automated remote control and tests of nuclear installations without personnel attendance in the contaminated zone are of particular interest. Laser active pyrometry and laser lock-in thermography for in situ non-destructive characterization of micrometric layers on graphite substrates from European tokamaks were under extensive experimental and theoretical studies in CEA (France). The studies were aimed to obtain layer characterization with cross-checking the layer thermal contact coefficients determined by active laser pyrometry and lock-in thermography. The experimental installation comprised a Nd-YAG pulsed repetition rate laser (1 Hz - 10 kHz repetition rate frequency, homogeneous spot) and a home-made pyrometer system based on two pyrometers for the temperature measurements in 500 - 2600 K range. For both methods, the layer characterization was provided by the best fit of the experimental results and simulations. The layer thermal contact coefficients determined by both methods were quite comparable. Though there was no gain in the measurements accuracy, lock-in measurements have proved their advantage as being much more rapid. The obtained experimental and theoretical results are presented. Some practical applications and possible improvements of the methods are discussed.

  13. Non destructive testing of works of art by terahertz analysis

    NASA Astrophysics Data System (ADS)

    Bodnar, Jean-Luc; Metayer, Jean-Jacques; Mouhoubi, Kamel; Detalle, Vincent

    2013-11-01

    Improvements in technologies and the growing security needs in airport terminals lead to the development of non destructive testing devices using terahertz waves. Indeed, these waves have the advantage of being, on one hand, relatively penetrating. They also have the asset of not being ionizing. It is thus potentially an interesting contribution in the non destructive testing field. With the help of the VISIOM Company, the possibilities of this new industrial analysis method in assisting the restoration of works of art were then approached. The results obtained within this framework are presented here and compared with those obtained by infrared thermography. The results obtained show first that the THZ method, like the stimulated infrared thermography allows the detection of delamination located in murals paintings or in marquetries. They show then that the THZ method seems to allow detecting defects located relatively deeply (10 mm) and defects potentially concealed by other defects. It is an advantage compared to the stimulated infra-red thermography which does not make it possible to obtain these results. Furthermore, they show that the method does not seem sensitive to the various pigments constituting the pictorial layer, to the presence of a layer of "Japan paper" and to the presence of a layer of whitewash. It is not the case of the stimulated infrared thermography. It is another advantage of the THZ method. Finally, they show that the THZ method is limited in the detection of low-size defects. It is a disadvantage compared to the stimulated infrared thermography.

  14. Reducing indoor residential exposures to outdoor pollutants

    SciTech Connect

    Sherman, Max H.; Matson, Nance E.

    2003-07-01

    The basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants. This report reviews the impacts that typical outdoor air pollutants can have on the indoor environment and provides design and operational guidance for mitigating them. Poor quality air cannot be used for diluting indoor contaminants, but more generally it can become an indoor contaminant itself. This paper discusses strategies that use the building as protection against potentially hazardous outdoor pollutants, including widespread pollutants, accidental events, and potential attacks.

  15. Non-Destructive Classification Approaches for Equilbrated Ordinary Chondrites

    NASA Technical Reports Server (NTRS)

    Righter, K.; Harrington, R.; Schroeder, C.; Morris, R. V.

    2013-01-01

    Classification of meteorites is most effectively carried out by petrographic and mineralogic studies of thin sections, but a rapid and accurate classification technique for the many samples collected in dense collection areas (hot and cold deserts) is of great interest. Oil immersion techniques have been used to classify a large proportion of the US Antarctic meteorite collections since the mid-1980s [1]. This approach has allowed rapid characterization of thousands of samples over time, but nonetheless utilizes a piece of the sample that has been ground to grains or a powder. In order to compare a few non-destructive techniques with the standard approaches, we have characterized a group of chondrites from the Larkman Nunatak region using magnetic susceptibility and Moessbauer spectroscopy.

  16. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    SciTech Connect

    Gajdacz, Miroslav; Pedersen, Poul L.; Mørch, Troels; Hilliard, Andrew J.; Arlt, Jan; Sherson, Jacob F.

    2013-08-15

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration, to demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. This demonstrates that the method is a useful tool for the characterization of static and dynamically changing properties of ultracold atomic clouds.

  17. Non-destructive evaluation method employing dielectric electrostatic ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    2003-01-01

    An acoustic nonlinearity parameter (.beta.) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members novelly employs a loosely mounted dielectric electrostatic ultrasonic transducer (DEUT) to receive and convert ultrasonic energy into an electrical signal which can be analyzed to determine the .beta. of the test material. The dielectric material is ferroelectric with a high dielectric constant .di-elect cons.. A computer-controlled measurement system coupled to the DEUT contains an excitation signal generator section and a measurement and analysis section. As a result, the DEUT measures the absolute particle displacement amplitudes in test material, leading to derivation of the nonlinearity parameter (.beta.) without the costly, low field reliability methods of the prior art.

  18. Non-destructive monitoring of river embankments using GPR

    NASA Astrophysics Data System (ADS)

    di Prinzio, Monica; Bittelli, Marco; Castellarin, Attilio; Rossi Pisa, Paola

    2010-05-01

    Non-destructive investigations and controls of civil structures are improving day by day, however the scientific literature reports only a few documented cases of Ground Penetrating Radar (GPR) applications to the detection of voids and discontinuities in hydraulic defense structures such as river embankments and levee systems. GPR can assist decision making in a number of fields by enhancing our knowledge of subsurface features. We applied successfully GPR to the monitoring of river levees for the detectioning of animal burrows in river levees, which may trigger levee failures by piping. The manageability and the non-invasivity of GPR have resulted to be particularly suitable for this application. First because GPR is an extensive investigation method that enables one to rapidly cover a wide area, locating voids that are difficult and costly to locate using other intrusive methods. Second, GPR returns detailed information about the possible presence of voids and discontinuities within river embankments.

  19. Non-destructive evaluation of water ingress in photovoltaic modules

    DOEpatents

    Bora, Mihail; Kotovsky, Jack

    2017-03-07

    Systems and techniques for non-destructive evaluation of water ingress in photovoltaic modules include and/or are configured to illuminate a photovoltaic module comprising a photovoltaic cell and an encapsulant with at least one beam of light having a wavelength in a range from about 1400 nm to about 2700 nm; capture one or more images of the illuminated photovoltaic module, each image relating to a water content of the photovoltaic module; and determine a water content of the photovoltaic module based on the one or more images. Systems preferably include one or more of a light source, a moving mirror, a focusing lens, a beam splitter, a stationary mirror, an objective lens and an imaging module.

  20. Non-destructive shadowgraph imaging of ultra-cold atoms.

    PubMed

    Wigley, P B; Everitt, P J; Hardman, K S; Hush, M R; Wei, C H; Sooriyabandara, M A; Manju, P; Close, J D; Robins, N P; Kuhn, C C N

    2016-10-15

    An imaging system is presented that is capable of far-detuned non-destructive imaging of a Bose-Einstein condensate with the signal proportional to the second spatial derivative of the density. Whilst demonstrated with application to Rb85, the technique generalizes to other atomic species and is shown to be capable of a signal-to-noise of ∼25 at 1 GHz detuning with 100 in-trap images showing no observable heating or atom loss. The technique is also applied to the observation of individual trajectories of stochastic dynamics inaccessible to single shot imaging. Coupled with a fast optical phase locked loop, the system is capable of dynamically switching to resonant absorption imaging during the experiment.

  1. Non-destructive shadowgraph imaging of ultra-cold atoms

    NASA Astrophysics Data System (ADS)

    Wigley, P. B.; Everitt, P. J.; Hardman, K. S.; Hush, M. R.; Wei, C. H.; Sooriyabandara, M. A.; Manju, P.; Close, J. D.; Robins, N. P.; Kuhn, C. C. N.

    2016-10-01

    An imaging system is presented that is capable of far-detuned non-destructive imaging of a Bose-Einstein condensate with the signal proportional to the second spatial derivative of the density. Whilst demonstrated with application to $^{85}\\text{Rb}$, the technique generalizes to other atomic species and is shown to be capable of a signal to noise of ${\\sim}25$ at $1$GHz detuning with $100$ in-trap images showing no observable heating or atom loss. The technique is also applied to the observation of individual trajectories of stochastic dynamics inaccessible to single shot imaging. Coupled with a fast optical phase lock loop, the system is capable of dynamically switching to resonant absorption imaging during the experiment.

  2. Non-destructive photoacoustic imaging of metal surface defects

    NASA Astrophysics Data System (ADS)

    Jeon, Seungwan; Kim, Jeesu; Yun, Jong Pil; Kim, Chulhong

    2016-11-01

    The detection of metal surface defects is important in achieving the goals of product quality enhancement and manufacturing cost reduction. Identifying the defects with visual inspection is difficult, inaccurate, and time-consuming. Thus, several inspection methods using line cameras, magnetic field, and ultrasound have been proposed. However, identifying small defects on metal surfaces remains a challenge. To deal with this problem, we propose the use of photoacoustic imaging (PAI) as a new non-destructive imaging tool to detect metal surface defects. We successfully visualized two types of cracks (i.e., unclassified and seam cracks) in metal plate samples using PAI. In addition, we successfully extracted cracked edges from height-encoded photoacoustic maximum amplitude projection images using the Laplacian of Gaussian filtering method, and then, quantified the detected edges for a statistical analysis. We concluded that PAI can be useful in detecting metal surface defects reducing the defect rate and manufacturing cost during metal production.

  3. Effects of Ambient Air Pollution Exposure on Olfaction: A Review

    PubMed Central

    Ajmani, Gaurav S.; Suh, Helen H.; Pinto, Jayant M.

    2016-01-01

    Background: Olfactory dysfunction affects millions of people worldwide. This sensory impairment is associated with neurodegenerative disease and significantly decreased quality of life. Exposure to airborne pollutants has been implicated in olfactory decline, likely due to the anatomic susceptibility of the olfactory nerve to the environment. Historically, studies have focused on occupational exposures, but more recent studies have considered effects from exposure to ambient air pollutants. Objectives: To examine all relevant human data evaluating a link between ambient pollution exposure and olfaction and to review supporting animal data in order to examine potential mechanisms for pollution-associated olfactory loss. Methods: We identified and reviewed relevant articles from 1950 to 2015 using PubMed and Web of Science and focusing on human epidemiologic and pathophysiologic studies. Animal studies were included only to support pertinent data on humans. We reviewed findings from these studies evaluating a relationship between environmental pollutant exposure and olfactory function. Results: We identified and reviewed 17 articles, with 1 additional article added from a bibliography search, for a total of 18 human studies. There is evidence in human epidemiologic and pathologic studies that increased exposure to ambient air pollutants is associated with olfactory dysfunction. However, most studies have used proxies for pollution exposure in small samples of convenience. Human pathologic studies, with supporting animal work, have also shown that air pollution can contact the olfactory epithelium, translocate to the olfactory bulb, and migrate to the olfactory cortex. Pollutants can deposit at each location, causing direct damage and disruption of tissue morphology or inducing local inflammation and cellular stress responses. Conclusions: Ambient air pollution may impact human olfactory function. Additional studies are needed to examine air pollution

  4. Non-destructive diffraction enhanced imaging of seeds.

    PubMed

    Young, Lester W; Parham, Christopher; Zhong, Zhong; Chapman, Dean; Reaney, Martin J T

    2007-01-01

    Techniques that make possible the non-destructive continuous observation of plant anatomy and developmental processes provide novel insights into these phenomena. Non-destructive imaging of seeds was demonstrated using the synchrotron-based X-ray imaging technique, diffraction enhanced imaging (DEI). The seed images obtained had good contrast and definition, allowing anatomical structures and physiological events to be observed. Structures such as hypocotyl-root axes, cotyledons, seed coats, air cavities, and embryo-less Brassica napus L. seeds were readily observed using DEI. Embryo axes, scutella, pericarp furrows, coleoptiles, and roots were observable over a time-course in individual germinating Triticum aestivum L. caryopses. Novel anatomical and physiological observations were also made that would have been difficult to make continuously using other techniques. The physical principles behind DEI make it a unique imaging technique. Contrast in DEI is the result of X-ray refraction at the density differences occurring at tissue boundaries, scatter caused by regions containing ordered molecules such as cellulose fibres, and attenuation. Sectioning of samples and the infusion of stains or other contrast agents are not necessary. Furthermore, as high-energy X-rays are used (30-40 keV), little X-ray absorption occurs, resulting in low levels of radiation damage. Consequently, studies of developmental processes may be performed on individuals. Individual germinating B. napus and T. aestivum seeds were imaged at several time points without incurring any apparent radiation damage. DEI offers a unique way of examining plant anatomy, development, and physiology, and provides images that are complementary to those obtained through other techniques.

  5. Bicycle messengers: energy expenditure and exposure to air pollution.

    PubMed

    Bernmark, Eva; Wiktorin, Christina; Svartengren, Magnus; Lewné, Marie; Aberg, Samuel

    2006-11-15

    The purpose of the study was to determine the level of energy expenditure and exposure to air pollution for bicycle messengers. Relationships between heart rate (HR) and oxygen uptake, and between HR and pulmonary ventilation (VE) for each participant were established in laboratory tests. Air pollution and HR were measured during one working day. The total oxygen uptake was then described as the total energy expenditure in Joule (J) and in multiples of the energy expenditure at rest (MET). The mean energy expenditure during a working day (8 h) was 12 MJ, (4.8 MET). The level of air pollution exposure when cycling seemed to be comparable with the levels of exposure when sitting inside a vehicle. The VE during cycling was four times higher than resting value. Increased VE led to increased exposure to air pollution.

  6. Air Pollution Exposure Model for Individuals (EMI) in Health Studies

    EPA Science Inventory

    In health studies, traffic-related air pollution is associated with adverse respiratory effects. Due to cost and participant burden of personal measurements, health studies often estimate exposures using local ambient air monitors. Since outdoor levels do not necessarily reflect ...

  7. Novel Approaches for Estimating Human Exposure to Air Pollutants

    EPA Science Inventory

    Numerous health studies have used measurements from a few central-site ambient monitors to characterize air pollution exposures. Relying on solely on central-site ambient monitors does not account for the spatial-heterogeneity of ambient air pollution patterns, the temporal varia...

  8. Air pollution exposure prediction approaches used in air pollution epidemiology studies.

    PubMed

    Özkaynak, Halûk; Baxter, Lisa K; Dionisio, Kathie L; Burke, Janet

    2013-01-01

    Epidemiological studies of the health effects of outdoor air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and misclassification of exposures for pollutants that are spatially heterogeneous, such as those associated with traffic emissions (e.g., carbon monoxide, elemental carbon, nitrogen oxides, and particulate matter). We review alternative air quality and human exposure metrics applied in recent air pollution health effect studies discussed during the International Society of Exposure Science 2011 conference in Baltimore, MD. Symposium presenters considered various alternative exposure metrics, including: central site or interpolated monitoring data, regional pollution levels predicted using the national scale Community Multiscale Air Quality model or from measurements combined with local-scale (AERMOD) air quality models, hybrid models that include satellite data, statistically blended modeling and measurement data, concentrations adjusted by home infiltration rates, and population-based human exposure model (Stochastic Human Exposure and Dose Simulation, and Air Pollutants Exposure models) predictions. These alternative exposure metrics were applied in epidemiological applications to health outcomes, including daily mortality and respiratory hospital admissions, daily hospital emergency department visits, daily myocardial infarctions, and daily adverse birth outcomes. This paper summarizes the research projects presented during the symposium, with full details of the work presented in individual papers in this journal issue.

  9. Confounding and exposure measurement error in air pollution epidemiology.

    PubMed

    Sheppard, Lianne; Burnett, Richard T; Szpiro, Adam A; Kim, Sun-Young; Jerrett, Michael; Pope, C Arden; Brunekreef, Bert

    2012-06-01

    Studies in air pollution epidemiology may suffer from some specific forms of confounding and exposure measurement error. This contribution discusses these, mostly in the framework of cohort studies. Evaluation of potential confounding is critical in studies of the health effects of air pollution. The association between long-term exposure to ambient air pollution and mortality has been investigated using cohort studies in which subjects are followed over time with respect to their vital status. In such studies, control for individual-level confounders such as smoking is important, as is control for area-level confounders such as neighborhood socio-economic status. In addition, there may be spatial dependencies in the survival data that need to be addressed. These issues are illustrated using the American Cancer Society Cancer Prevention II cohort. Exposure measurement error is a challenge in epidemiology because inference about health effects can be incorrect when the measured or predicted exposure used in the analysis is different from the underlying true exposure. Air pollution epidemiology rarely if ever uses personal measurements of exposure for reasons of cost and feasibility. Exposure measurement error in air pollution epidemiology comes in various dominant forms, which are different for time-series and cohort studies. The challenges are reviewed and a number of suggested solutions are discussed for both study domains.

  10. A Novel Application of Non-Destructive Readout Technology to Localisation Microscopy

    NASA Astrophysics Data System (ADS)

    Barnett, Samuel F. H.; Snape, Mary; Hunter, C. Neil; Juárez, Miguel A.; Cadby, Ashley J.

    2017-02-01

    The fitting precision in localisation microscopy is highly dependent on the signal to noise ratio. To increase the quality of the image it is therefore important to increase the signal to noise ratio of the measurements. We present an imaging system for localisation microscopy based on non-destructive readout camera technology that can increase the signal to noise ratio of localisation based microscopy. This approach allows for much higher frame rates through subsampling a traditional camera frame. By matching the effective exposure to both the start time and duration of a single molecule we diminish the effects of read noise and temporal noise. We demonstrate the application of this novel method to localisation microscopy and show both an increase in the attainable signal to noise ratio of data collection and an increase in the number of detected events.

  11. A Novel Application of Non-Destructive Readout Technology to Localisation Microscopy

    PubMed Central

    Barnett, Samuel F. H.; Snape, Mary; Hunter, C. Neil; Juárez, Miguel A.; Cadby, Ashley J.

    2017-01-01

    The fitting precision in localisation microscopy is highly dependent on the signal to noise ratio. To increase the quality of the image it is therefore important to increase the signal to noise ratio of the measurements. We present an imaging system for localisation microscopy based on non-destructive readout camera technology that can increase the signal to noise ratio of localisation based microscopy. This approach allows for much higher frame rates through subsampling a traditional camera frame. By matching the effective exposure to both the start time and duration of a single molecule we diminish the effects of read noise and temporal noise. We demonstrate the application of this novel method to localisation microscopy and show both an increase in the attainable signal to noise ratio of data collection and an increase in the number of detected events. PMID:28195127

  12. Pollution exposure on marine protected areas: A global assessment.

    PubMed

    Partelow, Stefan; von Wehrden, Henrik; Horn, Olga

    2015-11-15

    Marine protected areas (MPAs) face many challenges in their aim to effectively conserve marine ecosystems. In this study we analyze the extent of pollution exposure on the global fleet of MPAs. This includes indicators for current and future pollution and the implications for regionally clustered groups of MPAs with similar biophysical characteristics. To cluster MPAs into characteristic signature groups, their bathymetry, baseline biodiversity, distance from shore, mean sea surface temperature and mean sea surface salinity were used. We assess the extent at which each signature group is facing exposure from multiple pollution types. MPA groups experience similar pollution exposure on a regional level. We highlight how the challenges that MPAs face can be addressed through governance at the appropriate scale and design considerations for integrated terrestrial and marine management approaches within regional level networks. Furthermore, we present diagnostic social-ecological indicators for addressing the challenges facing unsuccessful MPAs with practical applications.

  13. Metal Pollutant Exposure and Behavior Disorders: Implications for School Practices.

    ERIC Educational Resources Information Center

    Marlowe, Mike

    1986-01-01

    The article summarizes research on relationships between low (below metal poisoning) metal exposure and childhood behavior disorders. Symptoms, assessment techniques (hair analysis), and environmental and dietary factors that may increase the risk of metal pollutant exposure are described. School programs emphasizing education and the role of…

  14. Non-destructive compositional analysis of historic organ reed pipes

    NASA Astrophysics Data System (ADS)

    Manescu, A.; Fiori, F.; Giuliani, A.; Kardjilov, N.; Kasztovszky, Z.; Rustichelli, F.; Straumal, B.

    2008-03-01

    In order to be able to reproduce historic organ reed pipes, a bulk non-destructive chemical composition analysis was performed on the tongues and shallots, focusing mainly on the ratio between copper and zinc and on the presence of lead. Prompt gamma activation analysis results allowed us to observe for the first time that the ratio between the two main components of the brass alloy changed from Cu:Zn = 3:1 for the old tongues and shallots to Cu:Zn = 2:1 around the middle of the 18th century, which is typical also for the modern alloys offered to the organ builders nowadays. We also discovered that the Pb content in the old historic brass alloy diminished until the middle of 18th century when the brass alloy became mainly Pb free. The non-uniform lead distribution inside one of the shallots obtained from a prompt gamma activation analysis (PGAA) experiment was studied by neutron tomography. It gave us a three-dimensonal (3D) distribution of the lead inclusions inside the shallots. The lead particles are concentrated towards the base of the shallot.

  15. Non-destructive testing of the MEGAPIE target

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Wohlmuther, M.; Boutellier, V.; Hahl, S.; Lagotzki, A.; Leu, H.; Linder, H. P.; Schwarz, R.; Spahr, A.; Zanini, L.; Kuster, D.; Gavillet, D.; Wagner, W.

    2016-01-01

    Non-destructive testing (NDT) is one important part of the post-irradiation examination (PIE) of the MEGAPIE target. It includes visual inspection and ultrasonic measurement of the beam window of the T91 LBE container and gamma mapping of the beam window of the AlMg3 safety-container. The visual inspection showed no visible failure in the proton beam window area of the T91 LBE container. The ultrasonic measurement demonstrated no detectable change in the wall thickness of the T91 beam window, which implies no severe corrosion effect induced by flowing LBE during the four-month irradiation period. The gamma mapping provided the distribution of 22Na, a spallation product, in the proton beam window area of the AlMg3 safety-container. The result was used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. A maximum proton fluence of 1.9 × 1025 p/m2 was deduced. The corresponding displacement damage degree in the T91 beam window was 7.1 dpa.

  16. A novel thermosonic imaging system for non-destructive testing

    NASA Astrophysics Data System (ADS)

    Willey, C. L.; Xiang, D.; Long, M.

    2017-02-01

    Thermosonic infrared (Sonic IR) imaging is a new non-destructive testing (NDT) technique that uses high-frequency sonic excitation together with infrared (IR) detection to image surface and subsurface defects. A conventional Sonic IR imaging system employs an ultrasonic welder, which is designed to operate at a single frequency. This single frequency ultrasonic source has been found to yield a "blind zone" for NDT due to the formation of standing waves inside the test piece. To overcome this limitation, a spring loaded ultrasonic transducer was used to generate the desired multi-frequency acoustic chaos in the test object [1]. The limitation of the spring loaded ultrasonic transducer is its repeatability and reproducibility for field applications. In this work, we present the development of a novel thermosonic imaging system, which is capable of exciting the ultrasonic transducer at difflerent frequencies for thermosonic NDT to overcome the limitations associated with a single frequency power source as well as the spring loaded transducer design. A comparison of experimental results will be made between the single frequency and the developed multi-frequency thermosonic NDT systems.

  17. Non-Destructive Evaluation of Materials via Ultraviolet Spectroscopy

    NASA Technical Reports Server (NTRS)

    Pugel, Betsy

    2008-01-01

    A document discusses the use of ultraviolet spectroscopy and imaging for the non-destructive evaluation of the degree of cure, aging, and other properties of resin-based composite materials. This method can be used in air, and is portable for field use. This method operates in reflectance, absorbance, and luminescence modes. The ultraviolet source is used to illuminate a composite surface of interest. In reflectance mode, the reflected response is acquired via the imaging system or via the spectrometer. The spectra are analyzed for organic compounds (conjugated organics) and inorganic compounds (semiconducting band-edge states; luminescing defect states such as silicates, used as adhesives for composite aerospace applications; and metal oxides commonly used as thermal coating paints on a wide range of spacecraft). The spectra are compared with a database for variation in conjugation, substitution, or length of molecule (in the case of organics) or band edge position (in the case of inorganics). This approach is useful in the understanding of material quality. It lacks the precision in defining the exact chemical structure that is found in other materials analysis techniques, but it is advantageous over methods such as nuclear magnetic resonance, infrared spectroscopy, and chromatography in that it can be used in the field to assess significant changes in chemical structure that may be linked to concerns associated with weaknesses or variations in structural integrity, without disassembly of or destruction to the structure of interest.

  18. Evaluation of Transportation Options for Intermediate Non-destructive Examinations

    SciTech Connect

    Case, Susan; Hoggard, Gary

    2013-11-01

    Idaho National Laboratory (INL) shipments of irradiated experiments from the Advanced Test Reactor (ATR) to the Hot Fuels Examination Facility (HFEF) have historically been accomplished using the General Electric Model 2000 (GE 2000) Type B shipping container. Battelle Energy Alliance (BEA) concerns regarding the future availability and leasing and handling costs associated with the GE 2000 cask have warranted an evaluation of alternative shipping options. One or more of these shipping options may be utilized to perform non-destructive examinations (NDE) such as neutron radiography and precision gamma scans of irradiated experiments at HFEF and then return the experiments to ATR for further irradiation, hereafter referred to as “intermediate NDE.” This evaluation includes transportation options for intermediate NDE using the GE 2000 cask, BEA Research Reactor (BRR) package, Dry Transfer Cubicle (DTC) insert, and the General Electric Model 100 (GE 100) cask. The GE 2000 cask is the only Type B shipping container currently in use for shipments of irradiated material (exceeding Type A quantities) from ATR to HFEF; therefore it is included as one of the four shipping options in this evaluation. Cost and schedule estimates are provided for performing neutron radiography and precision gamma scans of a five-capsule drop-in-type ATR experiment for each transportation option. All costs provided in this evaluation are rough order-of-magnitude costs based on input from knowledgeable vendor employees and individuals at INL facilities.

  19. A non-destructive method for dating human remains

    USGS Publications Warehouse

    Lail, Warren K.; Sammeth, David; Mahan, Shannon; Nevins, Jason

    2013-01-01

    The skeletal remains of several Native Americans were recovered in an eroded state from a creek bank in northeastern New Mexico. Subsequently stored in a nearby museum, the remains became lost for almost 36 years. In a recent effort to repatriate the remains, it was necessary to fit them into a cultural chronology in order to determine the appropriate tribe(s) for consultation pursuant to the Native American Grave Protection and Repatriation Act (NAGPRA). Because the remains were found in an eroded context with no artifacts or funerary objects, their age was unknown. Having been asked to avoid destructive dating methods such as radiocarbon dating, the authors used Optically Stimulated Luminescence (OSL) to date the sediments embedded in the cranium. The OSL analyses yielded reliable dates between A.D. 1415 and A.D. 1495. Accordingly, we conclude that the remains were interred somewhat earlier than A.D. 1415, but no later than A.D. 1495. We believe the remains are from individuals ancestral to the Ute Mouache Band, which is now being contacted for repatriation efforts. Not only do our methods contribute to the immediate repatriation efforts, they provide archaeologists with a versatile, non-destructive, numerical dating method that can be used in many burial contexts.

  20. Non-destructive evaluation of mechanical properties of magnetic materials

    SciTech Connect

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

    2000-07-01

    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.

  1. Non-destructive acoustic defect detection in drug tablets.

    PubMed

    Akseli, Ilgaz; Mani, Girindra N; Cetinkaya, Cetin

    2008-08-06

    For physical defect detection in drug tablets, a non-destructive and non-contact technique based on air coupled excitation and interferometric detection is presented. Physical properties and mechanical integrity of drug tablets can often affect their therapeutic and structural functions. The monitoring for defects and the characterization of tablet mechanical properties therefore have been of practical interest for solid oral dosage forms. The presented monitoring approach is based on the analysis of the transient vibrational responses of an acoustically excited tablet in both in temporal and spectral domains. The pulsed acoustic field exciting the tablet is generated by an air-coupled transducer. Using a laser vibrometer, the out-of-plane vibrational transient response of the tablet is detected and acquired in a non-contact manner. The physical state of the tablet is evaluated based on the spectral properties of these transient responses. In the current study, the effectiveness of three types of simple similarity measures is evaluated for their potential uses as defect detection norms, and for their potential use in quantifying the extent of tablet defect is discussed. It is found that these quantities can not only be used for identification of defective tablets, but could also provide a measure for the extent of the damage.

  2. Non-destructive investigation of thermoplastic reinforced composites

    DOE PAGES

    Hassen, Ahmed; Taheri, Hossein; Vaidya, Uday

    2016-05-09

    This paper studies various manufacturing defects in glass fiber/Polypropylene (PP) composite parts and their methods of detection. Foreign Object Inclusion (FOI) of different shapes, sizes, and materials were placed in a glass fiber/PP panel made by compression molding. The paper aims to characterize the fiber orientation and fiber related defects such as fiber waviness in the composite specimen. Comprehensive investigation for different Non Destructive Evaluation (NDE) techniques, namely X-ray radiography and Ultrasonic Testing (UT) techniques to trace and characterize the embedded defects and the composite texture are presented. Conventional X-ray radiography successfully identified the fiber orientation in two dimension (2-D)more » plane; however, information for the sample depth was not captured. The radiography techniques showed low relative errors for the defect size measurements (maximum error was below 9.5%) when compared to the ultrasonic techniques. Ultrasonic techniques were able to map all the embedded artificial defects. Phase Array (PA) ultrasonic technique was able to precisely locate the FOI in the glass fiber/PP specimen. Nerveless, the shape and size of the defects were not accurately determined due to the high signal attenuation and distortion characteristics of the E-glass fiber.« less

  3. Non-destructive investigation of thermoplastic reinforced composites

    SciTech Connect

    Hassen, Ahmed; Taheri, Hossein; Vaidya, Uday

    2016-05-09

    This paper studies various manufacturing defects in glass fiber/Polypropylene (PP) composite parts and their methods of detection. Foreign Object Inclusion (FOI) of different shapes, sizes, and materials were placed in a glass fiber/PP panel made by compression molding. The paper aims to characterize the fiber orientation and fiber related defects such as fiber waviness in the composite specimen. Comprehensive investigation for different Non Destructive Evaluation (NDE) techniques, namely X-ray radiography and Ultrasonic Testing (UT) techniques to trace and characterize the embedded defects and the composite texture are presented. Conventional X-ray radiography successfully identified the fiber orientation in two dimension (2-D) plane; however, information for the sample depth was not captured. The radiography techniques showed low relative errors for the defect size measurements (maximum error was below 9.5%) when compared to the ultrasonic techniques. Ultrasonic techniques were able to map all the embedded artificial defects. Phase Array (PA) ultrasonic technique was able to precisely locate the FOI in the glass fiber/PP specimen. Nerveless, the shape and size of the defects were not accurately determined due to the high signal attenuation and distortion characteristics of the E-glass fiber.

  4. Non-Destructive Assay of Curium Contaminated Transuranic Waste Drums

    SciTech Connect

    Foster, L.A.

    1998-11-01

    At the Plutonium Facility at Los Alamos National Laboratory, a series of non-destructive assays were performed on five transuranic waste (TRU) drums containing non-plutonium scrap metal that was potentially contaminated with weapons grade plutonium and trace quantities of curium. Typically, waste drums containing metal matrices are assayed for plutonium content using passive neutron coincidence counting techniques. The presence of trace quantities of Cm-244 prevents this type of analysis because of the strong coincidence signal created by spontaneous fission of Cm-244. To discriminate between the plutonium and curium materials present, an active neutron measurement technique was used. A Cf shuffler designed for measurement of uranium bearing materials was calibrated for plutonium in the active mode. The waste drums were then assayed for plutonium content in the shuffler using the active-mode calibration. The curium contamination levels were estimated from the difference between the active-mode measurement in the shuffler and a passive assay in a neutron coincidence counter. Far field gamma-ray measurements were made to identify additional radioactive contaminants and to corroborate the plutonium measurement results obtained from the active-mode assay. This report describes in detail the measurement process used for characterization of these waste drums. The measurement results and the estimated uncertainty will be presented.

  5. FIRST 100 T NON-DESTRUCTIVE MAGNET OUTER COIL SET

    SciTech Connect

    J. BACON; A. BACA; ET AL

    1999-09-01

    The controlled power outer coil set of the first 100 T non-destructive (100 T ND) magnet is described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND controlled power outer coil set consists of seven nested, mechanically independent externally reinforced coils. These coils, in combination, will produce a 47 T platform field in a 225-mm diameter bore. Using inertial energy storage a synchronous motor/generator provides ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. Each coil consists of a multi-layer winding of high strength conductor supported by an external high strength stainless steel shell. Coils with the highest magnetic loads will utilize a reinforcing shell fabricated from highly cold worked 301 stainless steel strip. The autofrettage conditioning method will be used to pre-stress the coils and thereby limit conductor and reinforcement strains to the elastic range. The purpose of pre-stressing the coils is to attain a design life of 10,000 full field pulses. The operation and conditioning of the coil set will be described along with special features of its design, magnetic and structural analyses and construction.

  6. Non-Destructive Evaluation (NDE) Applications of THz Radiation

    NASA Astrophysics Data System (ADS)

    Zimdars, David

    2005-03-01

    The technology and applications of time domain terahertz (THz) imaging to non-destructive evaluation (NDE) will be discussed. THz imaging has shown great promise in 2 and 3 dimensional non-contact inspection of non-conductive materials such as plastics, foam, composites, ceramics, paper, wood and glass. THz imaging employs safe low power non-ionizing electromagnetic pulses, with lateral resolution < 200 um, and depth resolution < 50 um. THz pulses can be analyzed spectroscopically to reveal chemical content. Recently, highly integrated turn-key THz imaging systems have been introduced commercially. We will demonstrate the detection of voids and disbonds intentionally incorporated within the sprayed on foam insulation of a space shuttle external tank mock-up segments. An industrially hardened THz scanning system which has been deployed to scan the space shuttle tank with small remote transceiver will be described. Additional terahertz security imaging applications for the detection of weapons and explosives will also be discussed, as well as the application of terahertz sensors for high speed industrial process monitoring and quality control.

  7. Non-destructive sub-THz CW imaging

    NASA Astrophysics Data System (ADS)

    Karpowicz, Nicholas; Zhong, Hua; Xu, Jingzhou; Lin, Kuang-I.; Hwang, Jenn-Shyong; Zhang, Xi-Cheng

    2005-03-01

    A simple, compact CW sub-THz imaging system, utilizing a 0.2 and 0.6 THz Gunn diode source is presented. A silicon beam lead diode detector and a Golay cell are used for the detection. Various results are presented, which show that the CW THz imaging modality is suitable for diverse applications, such as non-destructive testing and security. The key components of the system include the Gunn diode assembly, an optical chopper, a polyethylene lens, a detector, a lock-in amplifier, and two translation stages. The beam from the Gunn diode is focused on the sample being imaged by the polyethylene lens, the transmitted or reflected beam is measured by the detector. The energy transmitted through the sample at each point in the plane of the sample is detected. Since the system has relatively few components compared to pulsed THz imaging systems, it is less expensive and easier to design and operate, although it does not provide depth or spectral information about the sample. Since no time-delay scans take place, scanning can be done quickly compared to a time-domain system, limited by the maximum velocity of the translation stages and response of the detectors. It provides information about the macroscopic features of hidden structures within materials that are transparent to sub THz radiation, such as space shuttle insulating foam, articles of clothing, and luggage.

  8. Non-destructive characterization of archaeological glasses by neutron tomography

    NASA Astrophysics Data System (ADS)

    Fiori, F.; Giunta, G.; Hilger, A.; Kardjilov, N.; Rustichelli, F.

    2006-11-01

    The present work is carried out in the framework of a National Italian Project, whose aim is the assessment of innovative physical non-destructive techniques applied to archaeology. Towards this end, some archaeological artefacts have been studied by our group, in collaboration with the National Museum of Altino (VE) and EniTecnologie S.p.A. The objects come from the excavations in Altino, near Venice, where at least three different historical layers are present, corresponding to ages starting from approximately VII century B.C. In particular, in this work the results of neutron tomography investigations on three I-II century A.D. glass fragments are reported. The experiments were performed at the cold neutron radiography facility CONRAD at HMI (Berlin). For the 3D tomographical reconstruction of the sample, 200 projections were collected while the sample was rotated around a defined axis. The rotation interval was 180 degrees. The results show that the technique is able to reconstruct well the structural features of the investigated objects such as, in particular, highly absorbing zones and the presence of defects in the bulk.

  9. Method of non-destructively inspecting a curved wall portion

    DOEpatents

    Fong, James T.

    1996-01-01

    A method of non-destructively inspecting a curved wall portion of a large and thick walled vessel for a defect by computed tomography is provided. A collimated source of radiation is placed adjacent one side of the wall portion and an array of detectors for the radiation is placed on the other side adjacent the source. The radiation from the source passing through the wall portion is then detected with the detectors over a limited angle, dependent upon the curvature of the wall of the vessel, to obtain a dataset. The source and array are then coordinately moved relative to the wall portion in steps and a further dataset is obtained at each step. The plurality of datasets obtained over the limited angle is then processed to produce a tomogram of the wall portion to determine the presence of a defect therein. In a preferred embodiment, the curved wall portion has a center of curvature so that the source and the array are positioned at each step along a respective arc curved about the center. If desired, the detector array and source can be reoriented relative to a new wall portion and an inspection of the new wall portion can be easily obtained. Further, the source and detector array can be indexed in a direction perpendicular to a plane including the limited angle in a plurality of steps so that by repeating the detecting and moving steps at each index step, a three dimensional image can be created of the wall portion.

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

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

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

  11. Data fusion for automated non-destructive inspection

    PubMed Central

    Brierley, N.; Tippetts, T.; Cawley, P.

    2014-01-01

    In industrial non-destructive evaluation (NDE), it is increasingly common for data acquisition to be automated, driving a recent substantial increase in the availability of data. The collected data need to be analysed, typically necessitating the painstaking manual labour of a skilled operator. Moreover, in automated NDE a region of an inspected component is typically interrogated several times, be it within a single data channel due to multiple probe passes, across several channels acquired simultaneously or over the course of repeated inspections. The systematic combination of these diverse readings is recognized to offer an opportunity to improve the reliability of the inspection, but is not achievable in a manual analysis. This paper describes a data-fusion-based software framework providing a partial automation capability, allowing component regions to be declared defect-free to a very high probability while readily identifying defect indications, thereby optimizing the use of the operator's time. The system is designed to applicable to a wide range of automated NDE scenarios, but the processing is exemplified using the industrial ultrasonic immersion inspection of aerospace turbine discs. Results obtained for industrial datasets demonstrate an orders-of-magnitude reduction in false-call rates, for a given probability of detection, achievable using the developed software system. PMID:25002828

  12. An empirical assessment of exposure measurement error and effect attenuation in bi-pollutant epidemiologic models

    EPA Science Inventory

    Background: Using multipollutant models to understand combined health effects of exposure to multiple pollutants is becoming more common. However, complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates f...

  13. An empirical assessment of exposure measurement errors and effect attenuation in bi-pollutant epidemiologic models

    EPA Science Inventory

    Using multipollutant models to understand the combined health effects of exposure to multiple pollutants is becoming more common. However, the complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates from ...

  14. Non-destructive detection of corrosion for life management

    NASA Astrophysics Data System (ADS)

    Bruce, David A.

    1995-01-01

    In recent years, aircraft operators have been driven to increased use of Non-Destructive Evaluation (NDE) to ensure airworthiness during life extensions for ageing aircraft or as an integral part of a damage tolerant lifting philosophy. Major airframe static and fatigue tests are routinely used to highlight problem areas on airframes where design limitations or changes of usage may lead to early failures. The results of such tests become progressively less reliable as the age of the airframe increases and the operating conditions diverge from those under which the tests were conducted. Increased inspection, whether by visual or other means is usually the only alternative to wholesale refurbishment or replacement of aircraft or components. Almost all of the development to date of NDE techniques for corrosion detection and characterization has been concentrated on existing airframe materials, principally Aluminum alloys and steels. The current capabilities of corrosion detection techniques will be reviewed and current research aimed at areas where there is a requirement for improved detection capability will be described. New materials, such as Polymer Matrix Composites, will experience different types of 'corrosive' deterioration. The capability of NDE methods to detect material degradation in new composite materials will be discussed. Finally, reliance on NDE, choice of NDE technique and optimal scheduling of inspections all require an assessment of the reliability of NDE methods. It will be shown that a range of NDE techniques with differing capabilities and characteristics will be required to ensure compatibility with maintenance schedules if full use is to be made of NDE for life management of structures which may be subject to corrosion.

  15. Geophysical Methods for Non-Destructive Testing in Civil Engineering

    NASA Astrophysics Data System (ADS)

    Niederleithinger, E.

    2013-12-01

    Many non-destructive testing (NDT) methods for civil engineering (e. g. ultrasonics, radar) are similar to geophysical techniques. They just differ in scale, material under investigation and vocabulary used. In spite of the fact that the same principles of physics and mathematics apply to both fields, exchange has been limited in the past. But since a few years more and more geophysical knowledge is used in civil engineering. One of the focal points in research is to improve ultrasonic testing of concrete to be able to image the inside even of large, complex structures and to detect any deterioration as early as possible. One of the main issues is the heterogeneity of concrete, including aggregates, reinforcement, cracks and many other features. Our current research focuses on three points. One is the application of state of the art geophysical migration techniques as Reverse Time Migration (RTM) to image vertical faces or the backside of voids and ducts in thick concrete structures, which isn't possible with conventional techniques used in NDT. Second, we have started to use seismic interferometric techniques to interpolate ultrasonic traces, which can't be measured directly for technical reasons. Third, we are using coda wave interferometry to detect concrete degradation due to load, fatigue, temperature or other influences as early as possible. Practical examples of the application of these techniques are given and potential future research directions will be discussed. It will be shown, how a subset of these techniques can be used for innovative monitoring systems for civil infrastructure. Imaging the interior of a concrete body by ultrasonics and reverse time migration(simulated data).

  16. Recent advances in the use of non-destructive near infrared spectroscopy on intact olive fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this review is to illustrate the state of the art in the use of non-destructive near infrared (NIR) spectroscopy for quality evaluation of intact fruit in the olive industry. First, the most recent studies regarding the application of non-destructive NIR spectroscopy methods to asse...

  17. MANAGING EXPOSURES TO NEUROTOXIC AIR POLLUTANTS.

    EPA Science Inventory

    Researchers at EPA's National Health and Environmental Effects Research Laboratory are developing a biologically-based dose-response model to describe the neurotoxic effects of exposure to volatile organic compounds (VOCs). The model is being developed to improve risk assessment...

  18. Thermal history sensors for non-destructive temperature measurements in harsh environments

    SciTech Connect

    Pilgrim, C. C.; Heyes, A. L.; Feist, J. P.

    2014-02-18

    The operating temperature is a critical physical parameter in many engineering applications, however, can be very challenging to measure in certain environments, particularly when access is limited or on rotating components. A new quantitative non-destructive temperature measurement technique has been proposed which relies on thermally induced permanent changes in ceramic phosphors. This technique has several distinct advantages over current methods for many different applications. The robust ceramic material stores the temperature information allowing long term thermal exposures in harsh environment to be measured at a convenient time. Additionally, rare earth dopants make the ceramic phosphorescent so that the temperature information can be interpreted by automated interrogation of the phosphorescent light. This technique has been demonstrated by application of YAG doped with dysprosium and europium as coatings through the air-plasma spray process. Either material can be used to measure temperature over a wide range, namely between 300°C and 900°C. Furthermore, results show that the material records the peak exposure temperature and prolonged exposure at lower temperatures would have no effect on the temperature measurement. This indicates that these materials could be used to measure peak operating temperatures in long-term testing.

  19. Assessment of human exposure to gaseous pollutants

    SciTech Connect

    Baskin, L.B.; Falco, J.W. )

    1989-09-01

    A mathematical model to aid in assessment of human environmental exposure to volatile organic substances is presented. The model simulates the convective and diffusive transport of gas from the ambient environment into the human body by way of the respiratory and circulatory systems. Data required include easily obtained physical and chemical properties of substances as well as several estimated or measured physiological parameters. Transient and steady-state tissue concentrations resulting from an input atmospheric partial pressure are predicted. From these concentrations, an effective dose may be calculated, allowing for the determination of an exposure-response relationship based upon independently obtained dose-response data. The model's results compare favorably to experimental data on oxygen and halothane. Steady-state conditions are reached very rapidly. These results suggest that uptake of these substances is limited by both ventilation and perfusion. Rates are demonstrated to be essentially linear within the current neighborhoods. Conditions in which the primary processes of ventilation, diffusion, perfusion, and elimination limit uptake of gases are considered. Expressions describing the conditions necessary for a single process to limit gas uptake are derived. Accompanying equations for estimating tissue concentrations under these limiting conditions are presented.

  20. Assessment of planctomycetes cell viability after pollutants exposure.

    PubMed

    Flores, Carlos; Catita, José A M; Lage, Olga Maria

    2014-08-01

    In this study, the growth of six different planctomycetes, a particular ubiquitous bacterial phylum, was assessed after exposure to pollutants. In addition and for comparative purposes, Pseudomonas putida, Escherichia coli and Vibrio anguillarum were tested. Each microorganism was exposed to several concentrations of 21 different pollutants. After exposure, bacteria were cultivated using the drop plate method. In general, the strains exhibited a great variation of sensitivity to pollutants in the order: V. anguillarum > planctomycetes > P. putida > E. coli. E. coli showed resistance to all pollutants tested, with the exception of phenol and sodium azide. Copper, Ridomil® (fungicide), hydrazine and phenol were the most toxic pollutants. Planctomycetes were resistant to extremely high concentrations of nitrate, nitrite and ammonium but they were the only bacteria sensitive to Previcur N® (fungicide). Sodium azide affected the growth on plates of E. coli, P. putida and V. anguillarum, but not of planctomycetes. However, this compound affected planctomycetes cell respiration but with less impact than in the aforementioned bacteria. Our results provide evidence for a diverse response of bacteria towards pollutants, which may influence the structuring of microbial communities in ecosystems under stress, and provide new insights on the ecophysiology of planctomycetes.

  1. Approaches to characterize inequities in air pollution exposures

    EPA Science Inventory

    Certain populations bear a disproportionate burden of air pollutant exposures resulting in inequity of risk. This may be due to proximity to outdoor sources such as major roadways and industry or increased prevalence of indoor sources such as cigarette smoking or gas stoves. Ther...

  2. RESPIRATORY EPIDEMIOLOGY OF HOUSEHOLD AIR POLLUTION EXPOSURES IN DEVELOPING COUNTRIES

    EPA Science Inventory

    Acute and chronic respiratory diseases impose a huge public health burden in the developing world. A large and growing body of scientific evidence indicates that household air pollution exposures contribute substantially to this burden. The most important source of indoor air p...

  3. The Evaluation of Alternative Exposure Metrics for Traffic-related Air Pollutant Exposure in North Carolina

    EPA Science Inventory

    Transportation plays an important role in the modern society but can cause significant health impacts. To quantify the associated health impacts, an appropriate traffic-related air pollution exposure metric is required. In this study, we evaluate the suitability of four exposure ...

  4. A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology.

    PubMed

    Cao, Yue; Qu, Hao; Xiong, Can; Liu, Changhong; Zheng, Lei

    2017-03-31

    Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage. More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields.

  5. A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology

    PubMed Central

    Cao, Yue; Qu, Hao; Xiong, Can; Liu, Changhong; Zheng, Lei

    2017-01-01

    Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage. More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields. PMID:28361876

  6. Exposure scenarios and guidance values for urban soil pollutants.

    PubMed

    Boyd, H B; Pedersen, F; Cohr, K H; Damborg, A; Jakobsen, B M; Kristensen, P; Samsøe-Petersen, L

    1999-12-01

    In general, risk assessments of urban soil pollution are prepared by comparing the levels of pollutants with soil quality criteria. However, large urban areas are contaminated with concentrations of pollutants far exceeding the existing soil quality criteria and would consequently be considered to be of potential risk to humans. This is, however, a rather rigid approach, and for risk management purposes it would be desirable to have more than just one level of soil quality criteria. Therefore, a generic risk assessment model was developed for five different use scenarios: child-care centers, kitchen gardens, ornamental gardens, parks, and sports grounds. In each of the scenarios, three different types of expected behavior are described for children and adults, respectively, resulting in different levels of exposure to the pollutants. For risk management purposes, various guidance values can then be derived for each use scenario. Below a lower guidance value, a free use of the area according to the defined use is possible without an unacceptable risk to the public. Above an upper value, a cutoff of the exposure is necessary. In between, the use may be regulated by different types of advice. The model is still preliminary but was, however, used for derivation of guidance values for five commonly found soil pollutants, of which the results for benzo[a]pyrene and lead are presented.

  7. Modeling Air Pollution Exposure Metrics for the Diabetes and Environment Panel Study (DEPS)

    EPA Science Inventory

    Air pollution health studies of fine particulate matter (PM) often use outdoor concentrations as exposure surrogates. To improve exposure assessments, we developed and evaluated an exposure model for individuals (EMI), which predicts five tiers of individual-level exposure metric...

  8. Simultaneous Exposure to Multiple Air Pollutants Influences Alveolar Epithelial Cell Ion Transport

    EPA Science Inventory

    Purpose. Air pollution sources generally release multiple pollutants simultaneously and yet, research has historically focused on the source-to-health linkages of individual air pollutants. We recently showed that exposure of alveolar epithelial cells to a combination of particul...

  9. A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP)

    EPA Science Inventory

    The Pilot Study of Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) investigated the aggregate exposures of 257 preschool children and their primary adult caregivers to pollutants commonly detected in their everyday environments. ...

  10. Socioeconomic Disparities and Air Pollution Exposure: A Global Review

    PubMed Central

    Hsia, Charlene; O’Neill, Marie S.

    2015-01-01

    The existing reviews and meta-analyses addressing unequal exposure of environmental hazards on certain populations have focused on several environmental pollutants or on the siting of hazardous facilities. This review updates and contributes to the environmental inequality literature by focusing on ambient criteria air pollutants (including NOx), by evaluating studies related to inequality by socioeconomic status (as opposed to race/ethnicity) and by providing a more global perspective. Overall, most North American studies have shown that areas where low socioeconomic status (SES) communities dwell experience higher concentrations of criteria air pollutants, while European research has been mixed. Research from Asia, Africa and other parts of the world has shown a general trend similar to that of North America, but research in these parts of the world is limited. PMID:26381684

  11. Socioeconomic Disparities and Air Pollution Exposure: a Global Review.

    PubMed

    Hajat, Anjum; Hsia, Charlene; O'Neill, Marie S

    2015-12-01

    The existing reviews and meta-analyses addressing unequal exposure of environmental hazards on certain populations have focused on several environmental pollutants or on the siting of hazardous facilities. This review updates and contributes to the environmental inequality literature by focusing on ambient criteria air pollutants (including NOx), by evaluating studies related to inequality by socioeconomic status (as opposed to race/ethnicity) and by providing a more global perspective. Overall, most North American studies have shown that areas where low-socioeconomic-status (SES) communities dwell experience higher concentrations of criteria air pollutants, while European research has been mixed. Research from Asia, Africa, and other parts of the world has shown a general trend similar to that of North America, but research in these parts of the world is limited.

  12. Commuter exposure to aerosol pollution on public transport in Singapore

    NASA Astrophysics Data System (ADS)

    Tan, S.; Velasco, E.; Roth, M.; Norford, L.

    2013-12-01

    Personal exposure to aerosol pollutants in the transport microenvironment of Singapore has not been well documented. Studies from many cities suggest that brief periods of exposure to high concentrations of airborne pollutants may have significant health impacts. Thus, a large proportion of aerosol exposure may be experienced during daily commuting trips due to the proximity to traffic. A better understanding of the variability across transport modes is therefore needed to design transport policies that minimize commuters' exposure. In light of this, personal exposure measurements of PM10 and PM2.5, particle number (PN), black carbon (BC), carbon monoxide (CO), particle-bound polycyclic aromatic hydrocarbons (pPAH), and active surface area (SA) were conducted on a selected route in downtown Singapore. Portable and real-time monitoring instruments were carried onto three different modes of public transport (bus, taxi, subway) and by foot. Simultaneous measurements were taken at a nearby park to capture the background concentrations. Large variability was observed amongst the various transport modes investigated. For example, the particle number concentration was on average 1.5, 1.6, 0.8, and 2.2 times higher inside buses, taxis, subway and by foot, respectively, than at the background site. Based on the results, it is possible to come up with a ranking of the 'cleanest' transport mode for Singapore.

  13. Theoretical neutron damage calculations in industrial robotic manipulators used for non-destructive imaging applications

    DOE PAGES

    Hashem, Joseph; Schneider, Erich; Pryor, Mitch; ...

    2017-01-01

    Our paper describes how to use MCNP to evaluate the rate of material damage in a robot incurred by exposure to a neutron flux. The example used in this work is that of a robotic manipulator installed in a high intensity, fast, and collimated neutron radiography beam port at the University of Texas at Austin's TRIGA Mark II research reactor. Our effort includes taking robotic technologies and using them to automate non-destructive imaging tasks in nuclear facilities where the robotic manipulator acts as the motion control system for neutron imaging tasks. Simulated radiation tests are used to analyze the radiationmore » damage to the robot. Once the neutron damage is calculated using MCNP, several possible shielding materials are analyzed to determine the most effective way of minimizing the neutron damage. Furthermore, neutron damage predictions provide users the means to simulate geometrical and material changes, thus saving time, money, and energy in determining the optimal setup for a robotic system installed in a radiation environment.« less

  14. Theoretical neutron damage calculations in industrial robotic manipulators used for non-destructive imaging applications

    SciTech Connect

    Hashem, Joseph; Schneider, Erich; Pryor, Mitch; Landsberger, Sheldon

    2017-01-01

    Our paper describes how to use MCNP to evaluate the rate of material damage in a robot incurred by exposure to a neutron flux. The example used in this work is that of a robotic manipulator installed in a high intensity, fast, and collimated neutron radiography beam port at the University of Texas at Austin's TRIGA Mark II research reactor. Our effort includes taking robotic technologies and using them to automate non-destructive imaging tasks in nuclear facilities where the robotic manipulator acts as the motion control system for neutron imaging tasks. Simulated radiation tests are used to analyze the radiation damage to the robot. Once the neutron damage is calculated using MCNP, several possible shielding materials are analyzed to determine the most effective way of minimizing the neutron damage. Furthermore, neutron damage predictions provide users the means to simulate geometrical and material changes, thus saving time, money, and energy in determining the optimal setup for a robotic system installed in a radiation environment.

  15. Air pollution exposure: An activity pattern approach for active transportation

    NASA Astrophysics Data System (ADS)

    Adams, Matthew D.; Yiannakoulias, Nikolaos; Kanaroglou, Pavlos S.

    2016-09-01

    In this paper, we demonstrate the calculation of personal air pollution exposure during trips made by active transportation using activity patterns without personal monitors. We calculate exposure as the inhaled dose of particulate matter 2.5 μg or smaller. Two modes of active transportation are compared, and they include cycling and walking. Ambient conditions are calculated by combining mobile and stationary monitoring data in an artificial neural network space-time model. The model uses a land use regression framework and has a prediction accuracy of R2 = 0.78. Exposure is calculated at 10 m or shorter intervals during the trips using inhalation rates associated with both modes. The trips are children's routes between home and school. The average dose during morning cycling trips was 2.17 μg, during morning walking trips was 3.19 μg, during afternoon cycling trips was 2.19 μg and during afternoon walking trips was 3.23 μg. The cycling trip dose was significantly lower than the walking trip dose. The air pollution exposure during walking or cycling trips could not be strongly predicted by either the school or household ambient conditions, either individually or in combination. Multiple linear regression models regressing both the household and school ambient conditions against the dose were only able to account for, at most, six percent of the variance in the exposure. This paper demonstrates that incorporating activity patterns when calculating exposure can improve the estimate of exposure compared to its calculation from ambient conditions.

  16. Improving estimates of air pollution exposure through ubiquitous sensing technologies

    PubMed Central

    de Nazelle, Audrey; Seto, Edmund; Donaire-Gonzalez, David; Mendez, Michelle; Matamala, Jaume; Nieuwenhuijsen, Mark J; Jerrett, Michael

    2013-01-01

    Traditional methods of exposure assessment in epidemiological studies often fail to integrate important information on activity patterns, which may lead to bias, loss of statistical power or both in health effects estimates. Novel sensing technologies integrated with mobile phones offer potential to reduce exposure measurement error. We sought to demonstrate the usability and relevance of the CalFit smartphone technology to track person-level time, geographic location, and physical activity patterns for improved air pollution exposure assessment. We deployed CalFit-equipped smartphones in a free living-population of 36 subjects in Barcelona, Spain. Information obtained on physical activity and geographic location was linked to space-time air pollution mapping. For instance, we found on average travel activities accounted for 6% of people’s time and 24% of their daily inhaled NO2. Due to the large number of mobile phone users, this technology potentially provides an unobtrusive means of collecting epidemiologic exposure data at low cost. PMID:23416743

  17. Ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants.

    PubMed

    Eulaers, Igor; Jaspers, Veerle L B; Bustnes, Jan O; Covaci, Adrian; Johnsen, Trond V; Halley, Duncan J; Moum, Truls; Ims, Rolf A; Hanssen, Sveinn A; Erikstad, Kjell E; Herzke, Dorte; Sonne, Christian; Ballesteros, Manuel; Pinxten, Rianne; Eens, Marcel

    2013-07-01

    contamination). In conclusion, the combined analysis of POPs and stable isotopes in body feathers from fully-grown nestlings has identified ecological and spatial factors that may drive POP exposure over the larger part of the nestling stage. This methodological approach further promotes the promising use of nestling predatory bird body feathers as a non-destructive sampling strategy to integrate various toxicological and ecological proxies.

  18. Estimates of health risk from exposure to radioactive pollutants

    SciTech Connect

    Sullivan, R.E.; Nelson, N.S.; Ellett, W.H.; Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.; Eckerman, K.F.

    1981-11-01

    A dosimetric and health effects analysis has been performed for the Office of Radiation Programs of the Environmental Protection Agency (EPA) to assess potential hazards from radioactive pollutants. Contemporary dosimetric methods were used to obtain estimates of dose rates to reference organs from internal exposures due to either inhalation of contaminated air or ingestion of contaminated food, or from external exposures due to either immersion in contaminated air or proximity to contaminated ground surfaces. These dose rates were then used to estimate the number of premature cancer deaths arising from such exposures and the corresponding number of years of life lost in a cohort of 100,000 persons, all simultaneously liveborn and all going through life with the same risks of dying from competing causes. The risk of dying from a competing cause for a given year was taken to be the probability of dying from all causes as given in a recent actuarial life table for the total US population.

  19. Evaluation of noise pollution level based upon community exposure and response data

    NASA Technical Reports Server (NTRS)

    Edmiston, R. D.

    1972-01-01

    The results and procedures are reported from an evaluation of noise pollution level as a predictor of annoyance, based on aircraft noise exposure and community response data. The measures of noise exposure presented include composite noise rating, noise exposure forecast, noise and number index. A proposed measure as a universal noise exposure measure for noise pollution level (L sub NP) is discussed.

  20. Air pollution in moderately polluted urban areas: How does the definition of "neighborhood" impact exposure assessment?

    PubMed

    Tenailleau, Quentin M; Mauny, Frédéric; Joly, Daniel; François, Stéphane; Bernard, Nadine

    2015-11-01

    Environmental health studies commonly quantify subjects' pollution exposure in their neighborhood. How this neighborhood is defined can vary, however, leading to different approaches to quantification whose impacts on exposure levels remain unclear. We explore the relationship between neighborhood definition and exposure assessment. NO2, benzene, PM10 and PM2.5 exposure estimates were computed in the vicinity of 10,825 buildings using twelve exposure assessment techniques reflecting different definitions of "neighborhood". At the city scale, its definition does not significantly influence exposure estimates. It does impact levels at the building scale, however: at least a quarter of the buildings' exposure estimates for a 400 m buffer differ from the estimated 50 m buffer value (±1.0 μg/m(3) for NO2, PM10 and PM2.5; and ±0.05 μg/m(3) for benzene). This variation is significantly related to the definition of neighborhood. It is vitally important for investigators to understand the impact of chosen assessment techniques on exposure estimates.

  1. Method and Apparatus for Non-Destructive Evaluation of Materials

    NASA Technical Reports Server (NTRS)

    Goldfine, Neil J. (Inventor); Washabaugh, Andrew P. (Inventor); Lyons, Robert (Inventor); Thomas, Zachary (Inventor); Jablonski, David A. (Inventor); Martin, Christopher (Inventor)

    2015-01-01

    Methods and apparatus for characterizing composite materials for manufacturing quality assurance (QA), periodic inspection during the useful life, or for forensic analysis/material testing. System are provided that relate eddy-current sensor responses to the fiber layup of a composite structure, the presence of impact damage on a composite structure with or without a metal liner, volumetric stress within the composite, fiber tow density, and other NDE inspection requirements. Also provided are systems that determine electromagnetic material properties and material dimensions of composite materials from capacitive sensor inspection measurements. These properties are related to the presence of buried defects in non-conductive composite materials, moisture ingress, aging of the material due to service or environmental/thermal exposure, or changes in manufacturing quality.

  2. Non-destructive lichen biomass estimation in northwestern Alaska: a comparison of methods.

    PubMed

    Rosso, Abbey; Neitlich, Peter; Smith, Robert J

    2014-01-01

    Terrestrial lichen biomass is an important indicator of forage availability for caribou in northern regions, and can indicate vegetation shifts due to climate change, air pollution or changes in vascular plant community structure. Techniques for estimating lichen biomass have traditionally required destructive harvesting that is painstaking and impractical, so we developed models to estimate biomass from relatively simple cover and height measurements. We measured cover and height of forage lichens (including single-taxon and multi-taxa "community" samples, n = 144) at 73 sites on the Seward Peninsula of northwestern Alaska, and harvested lichen biomass from the same plots. We assessed biomass-to-volume relationships using zero-intercept regressions, and compared differences among two non-destructive cover estimation methods (ocular vs. point count), among four landcover types in two ecoregions, and among single-taxon vs. multi-taxa samples. Additionally, we explored the feasibility of using lichen height (instead of volume) as a predictor of stand-level biomass. Although lichen taxa exhibited unique biomass and bulk density responses that varied significantly by growth form, we found that single-taxon sampling consistently under-estimated true biomass and was constrained by the need for taxonomic experts. We also found that the point count method provided little to no improvement over ocular methods, despite increased effort. Estimated biomass of lichen-dominated communities (mean lichen cover: 84.9±1.4%) using multi-taxa, ocular methods differed only nominally among landcover types within ecoregions (range: 822 to 1418 g m-2). Height alone was a poor predictor of lichen biomass and should always be weighted by cover abundance. We conclude that the multi-taxa (whole-community) approach, when paired with ocular estimates, is the most reasonable and practical method for estimating lichen biomass at landscape scales in northwest Alaska.

  3. Assessment of exposure to mixture pollutants in Mexican indigenous children.

    PubMed

    Flores-Ramírez, R; Pérez-Vázquez, F J; Cilia-López, V G; Zuki-Orozco, B A; Carrizales, L; Batres-Esquivel, L E; Palacios-Ramírez, A; Díaz-Barriga, F

    2016-05-01

    The aim of the present work was to complete an exposure assessment in three Mexican indigenous communities using the community-based health risk assessment, which is the first step in the CHILD framework. We used 1-hydroxypyrene (1-OHP) as an exposure biomarker to polycyclic aromatic hydrocarbons (PAHs) and trans, trans-muconic acid (t,t-MA) as an exposure biomarker to benzene, persistent organic pollutants (POPs), lead, manganese, arsenic, and fluoride. Anthropometric measurements were also taken. In these communities, high percentages of children with chronic malnutrition were found (28 to 49 %) based on their weight and age. All communities showed a high percentage of children with detectable levels of four or more compounds (70 to 82 %). Additionally, our results showed that in indigenous communities, children are exposed to elevated levels of certain environmental pollutants, including manganese with 17.6, 16.8, and 7.3 μg/L from SMP, TOC, and CUA, respectively. Lead and HCB levels were similar in the indigenous communities (2.5, 3.1, and 4.2 μg/dL and 2.5, 3.1, and 3.7 ng/mL, respectively). 1-OHP and t,t-MA levels were higher in TOC (0.8 μmol/mol of creatinine, 476 μg/g of creatinine, respectively) when compared with SMP (0.1 μmol/mol of creatinine, 215.5 μg/g of creatinine, respectively) and CUA (0.1 μmol/mol of creatinine, 185.2 μg/g of creatinine, respectively). DDE levels were 30.7, 26.9, and 9.6 ng/mL in CUA, SMP, and TOC, respectively. The strength of this study is that it assesses exposure to pollutants with indications for the resultant risk before an intervention is made by the CHILD program to manage this risk in the indigenous communities. Considering the large number of people, especially children, exposed to multiple pollutants, it is important to design effective intervention programs that reduce exposure and the resultant risk in the numerous indigenous communities in Mexico.

  4. Prediction of Eggshell Ultrastructure via Some Non-destructive and Destructive Measurements in Fayoumi Breed.

    PubMed

    Radwan, Lamiaa M; Galal, A; Shemeis, A R

    2015-07-01

    Possibilities of predicting eggshell ultrastructure from direct non-destructive and destructive measurements were examined using 120 Fayoumi eggs collected from the flock at 45 weeks of age. The non-destructive measurements included weight, length and width of the egg. The destructive measurements were breaking strength and shell thickness. The eggshell ultrastructure traits involved the total thickness of eggshell layer, thickness of palisade layer, cone layer and total score. Prediction of total thickness of eggshell layer based on non-destructive measurements individually or simultaneously was not possible (R(2) = 0.01 to 0.16). The destructive measurements were far more accurate than the non-destructive in predicting total thickness of eggshell layer. Prediction based on breaking strength alone was more accurate (R(2) = 0.85) than that based on shell thickness alone (R(2) = 0.72). Adding shell thickness to breaking strength (the best predictor) increased the accuracy of prediction by 5%. The results obtained indicated that both non-destructive and destructive measurements were not useful in predicting the cone layer (R(2) not exceeded 18%). The maximum accuracy of prediction of total score (R(2) = 0.48) was obtained from prediction based on breaking strength alone. Combining shell thicknesses and breaking strength into one equation was no help in improving the accuracy of prediction.

  5. Satellite-aided evaluation of population exposure to air pollution

    NASA Technical Reports Server (NTRS)

    Todd, W. J.; George, A. J., Jr.; Bryant, N. A.

    1979-01-01

    The evaluation of population exposure to air pollution through the computer processing of Landsat digital land use data, along with total suspended particulate estimates and population data by census tracts, is demonstrated. Digital image processing was employed to analyze simultaneously data from Landsat MSS bands 4 through 7 in order to extract land use and land cover information. The three data sets were spatially registered in a digital format, compatible with integrated computer processing, and cross-tabulated. A map illustrating relative air quality by 2-sq km cells for the residential population in the Portland, Oregon area is obtained.

  6. Non-Destructive Testing A Developing Tool in Science and Engineering

    SciTech Connect

    Lin, Lianshan

    2013-01-01

    Non-destructive testing (NDT), sometimes also known as non-destructive inspection (NDI) or non-destructive examination (NDE), has been applied to solve a wide range of science and industry problems including construction, aerospace, nuclear engineering, manufacturing, space exploration, art objects, forensic studies, biological and medical fields, etc. Without any permanent changing or alteration of testing objects, NDT methods provide great advantages such as increased testing reliability, efficiency, and safety, as well as reduced time and cost. Since the second half of the 20th century, NDT technology has seen significant growth. Depending on the physical properties being measured, NDT techniques can be classified into several branches. This article will provide a brief overview of commonly used NDT methods and their up-to-date progresses including optical examination, radiography, acoustic emission, ultrasonic testing and eddy current testing. For extended reviews on many presently used NDT methods, please refer to articles by Mullins [1, 2].

  7. Non-destructive testing of composite materials using terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Yakovlev, Egor V.; Zaytsev, Kirill I.; Chernomyrdin, Nikita V.; Gavdush, Arsenii A.; Zotov, Arsen K.; Nikonovich, Maxim Y.; Yurchenko, Stanislav O.

    2016-04-01

    Development of novel methods for non-destructive evaluation of composite materials (CMs) at manufacturing and operational stages remains challenging problem of applied physics, optics and material science. In this paper, we have considered the ability to use the terahertz (THz) time-domain spectroscopy (TDS) for non-destructive evaluation of CMs. By combining the TDS technique with appropriate methods of solving the inverse ill-posed problems, we have shown that TDS could be applied for CM testing. At first, we have demonstrated that TDS could be used to control the polymerization process and, as a consequence, the CM binder curing. Secondary, we have shown the ability to detect the internal defects (non-impregnated voids) inside the CMs via the TDS-based THz time-of-flight tomography. Thereby, the results of our study allow highlighting the prospective of non-destructive evaluation of CMs using the TDS.

  8. Human nasal mucosal changes after exposure to urban pollution.

    PubMed Central

    Calderon-Garcidueñas, L; Rodriguez-Alcaraz, A; Garcia, R; Sanchez, G; Barragan, G; Camacho, R; Ramirez, L

    1994-01-01

    Millions of people worldwide are living in areas where ozone (O3) concentrations exceed health standards (an hourly average of 235 micrograms/m3/0.12 ppm, not to be exceeded more than once per year). Ozone induces acute nasal inflammatory responses and significant epithelial lesions in experimental animals and humans. To determine the nasal effects of a 15-day exposure to an urban polluted atmosphere with O3 as the main pollutant, we studied a population of healthy, young males newly arrived to southwest metropolitan Mexico City (SWMMC). The study included 49 non-smoking residents in an unpolluted port, Veracruz City; 14 subjects stayed in the port and served as controls, while 35 subjects traveled to SWMMC and had serial nasal lavages at different times after arriving in SWMMC. Subjects had exposures to ambient O3 an average of 10.2 hr/day, with a total cumulative O3 exposure of 10.644 ppm.hr. Nasal inflammatory responses, polymorphonuclear leukocyte PMN-CD11b surface expression, rhinoscopic changes, and respiratory symptoms were evaluated. Exposed subjects had massive nasal epithelial shedding and significant responses in PMN nasal influx (p < 0.00001) and in PMN-CD11b expression (p < 0.05). Cumulative O3 exposure correlated with respiratory symptoms, PMNs (rs = 0.2374, p < 0.01), and CD11b (rs = 0.3094, p < 0.01); 94% of exposed subjects experienced respiratory symptoms, and 97% left the city with an abnormal nasal mucosa by rhinoscopy. Nasal epithelial changes persisted 2 weeks after the exposed subjects returned to their nonpolluted environment. Exposure to an urban polluted atmosphere induces significant and persistent nasal epithelial alterations in healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1. Figure 2. A Figure 2. B Figure 2. C Figure 2. D Figure 2. E Figure 2. F Figure 3. A Figure 3. B Figure 4. A Figure 4. B Figure 5. A Figure 5. B PMID:7713020

  9. Acute Air Pollution Exposure and Risk of Suicide Completion

    PubMed Central

    Bakian, Amanda V.; Huber, Rebekah S.; Coon, Hilary; Gray, Douglas; Wilson, Phillip; McMahon, William M.; Renshaw, Perry F.

    2015-01-01

    Research into environmental factors associated with suicide has historically focused on meteorological variables. Recently, a heightened risk of suicide related to short-term exposure to airborne particulate matter was reported. Here, we examined the associations between short-term exposure to nitrogen dioxide, particulate matter, and sulfur dioxide and completed suicide in Salt Lake County, Utah (n = 1,546) from 2000 to 2010. We used a time-stratified case-crossover design to estimate adjusted odds ratios for the relationship between suicide and exposure to air pollutants on the day of the suicide and during the days preceding the suicide. We observed maximum heightened odds of suicide associated with interquartile-range increases in nitrogen dioxide during cumulative lag 3 (average of the 3 days preceding suicide; odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.04, 1.39) and fine particulate matter (diameter ≤2.5 μm) on lag day 2 (day 2 before suicide; OR = 1.05, 95% CI: 1.01, 1.10). Following stratification by season, an increased suicide risk was associated with exposure to nitrogen dioxide during the spring/fall transition period (OR = 1.35, 95% CI: 1.09, 1.66) and fine particulate matter in the spring (OR = 1.28, 95% CI: 1.01, 1.61) during cumulative lag 3. Findings of positive associations between air pollution and suicide appear to be consistent across study locations with vastly different meteorological, geographical, and cultural characteristics. PMID:25673816

  10. X-ray phase scanning setup for non-destructive testing using Talbot-Lau interferometer

    NASA Astrophysics Data System (ADS)

    Bachche, S.; Nonoguchi, M.; Kato, K.; Kageyama, M.; Koike, T.; Kuribayashi, M.; Momose, A.

    2016-09-01

    X-ray grating interferometry has a great potential for X-ray phase imaging over conventional X-ray absorption imaging which does not provide significant contrast for weakly absorbing objects and soft biological tissues. X-ray Talbot and Talbot-Lau interferometers which are composed of transmission gratings and measure the differential X-ray phase shifts have gained popularity because they operate with polychromatic beams. In X-ray radiography, especially for nondestructive testing in industrial applications, the feasibility of continuous sample scanning is not yet completely revealed. A scanning setup is frequently advantageous when compared to a direct 2D static image acquisition in terms of field of view, exposure time, illuminating radiation, etc. This paper demonstrates an efficient scanning setup for grating-based Xray phase imaging using laboratory-based X-ray source. An apparatus consisting of an X-ray source that emits X-rays vertically, optical gratings and a photon-counting detector was used with which continuously moving objects across the field of view as that of conveyor belt system can be imaged. The imaging performance of phase scanner was tested by scanning a long continuous moving sample at a speed of 5 mm/s and absorption, differential-phase and visibility images were generated by processing non-uniform moire movie with our specially designed phase measurement algorithm. A brief discussion on the feasibility of phase scanner with scanning setup approach including X-ray phase imaging performance is reported. The successful results suggest a breakthrough for scanning objects those are moving continuously on conveyor belt system non-destructively using the scheme of X-ray phase imaging.

  11. Edward's sword? - A non-destructive study of a medieval king's sword

    SciTech Connect

    Segebade, Chr.

    2013-04-19

    Non-destructive and instrumental methods including photon activation analysis were applied in an examination of an ancient sword. It was tried to find indication of forgery or, if authentic, any later processing and alteration. Metal components of the hilt and the blade were analysed by instrumental photon activation. Non-destructive metallurgical studies (hardness measurements, microscopic microstructure analysis) are briefly described, too. The results of these investigations did not yield indication of non-authenticity. This stood in agreement with the results of stylistic and scientific studies by weapon experts.

  12. Occupational Exposure to Urban Air Pollution and Allergic Diseases

    PubMed Central

    Vimercati, Luigi; Gatti, Maria Franca; Baldassarre, Antonio; Nettis, Eustachio; Favia, Nicola; Palma, Marco; Martina, Gabriella Lucia Maria; Di Leo, Elisabetta; Musti, Marina

    2015-01-01

    Exposure to air pollution is associated with increased morbidity from cardiovascular diseases, lung cancer, respiratory and allergic diseases. The aim of this study was to investigate allergic diseases in 111 traffic wardens compared to a control group of 101 administrative employees. All participating subjects underwent a physical examination, in which a complete medical history was taken and a dedicated allergological questionnaire administered. Spirometry, Specific IgE dosage (RAST) and skin prick tests (SPT) were done. Diagnostic investigations such as the nasal cytology, a specific nasal provocation test and rhinomanometry were also performed. Statistical analyses were performed using STATA version 11. The percentage of subjects with a diagnosis of allergy was higher in the exposed workers than in the controls. As regards the clinical tests, the positivity was higher for the group of exposed subjects. Among the exposed workers, those who worked on foot or motorcycle had a higher positivity in clinical trials compared to the traffic wardens who used the car. Our study showed a higher percentage of allergic subjects in the group of workers exposed to outdoor pollutants than in the controls. These results suggest that allergological tests should be included in the health surveillance protocols for workers exposed to outdoor pollutants. PMID:26501303

  13. Novel computational identification of highly selective biomarkers of pollutant exposure.

    PubMed

    Weisman, David; Liu, Hong; Redfern, Jessica; Zhu, Liya; Colón-Carmona, Adán

    2011-06-15

    The use of in vivo biosensors to acquire environmental pollution data is an emerging and promising paradigm. One major challenge is the identification of highly specific biomarkers that selectively report exposure to a target pollutant, while remaining quiescent under a diverse set of other, often unknown, environmental conditions. This study hypothesized that a microarray data mining approach can identify highly specific biomarkers, and, that the robustness property can generalize to unforeseen environmental conditions. Starting with Arabidopsis thaliana microarray data measuring responses to a variety of treatments, the study used the top scoring pair (TSP) algorithm to identify mRNA transcripts that respond uniquely to phenanthrene, a model polycyclic aromatic hydrocarbon. Subsequent in silico analysis with a larger set of microarray data indicated that the biomarkers remained robust under new conditions. Finally, in vivo experiments were performed with unforeseen conditions that mimic phenanthrene stress, and the biomarkers were assayed using qRT-PCR. In these experiments, the biomarkers always responded positively to phenanthrene, and never responded to the unforeseen conditions, thereby supporting the hypotheses. This data mining approach requires only microarray or next-generation RNA-seq data, and, in principle, can be applied to arbitrary biomonitoring organisms and chemical exposures.

  14. Modeling exposure to air pollution from the WTC disaster based on reports of perceived air pollution.

    PubMed

    Lederman, Sally Ann; Becker, Mark; Sheets, Stephen; Stein, Janet; Tang, Deliang; Weiss, Lisa; Perera, Frederica P

    2008-04-01

    We examined the utility of a newly developed perceived air pollution (PAP) scale and of a modeled air pollution (MAP) scale derived from it for predicting previously observed birth outcomes of pregnant women enrolled following September 11, 2001. Women reported their home and work locations in the four weeks after September 11, 2001 and the PAP at each site on a four-point scale designed for this purpose. Locations were geocoded and their distance from the World Trade Center (WTC) site determined. PAP values were used to develop a model of air pollution for a 20-mile radius from the WTC site. MAP values were assigned to each geocoded location. We examined the relationship of PAP and MAP values to maternal characteristics and to distance of home and work sites from the WTC site. Both PAP and MAP values were highly correlated with distance from the WTC. Maternal characteristics that were associated with PAP values reported for home or work sites (race, demoralization, material hardship, first trimester on September 11) were not associated with modeled MAP values. Relationships of several birth outcomes to proximity to the WTC, which we previously reported using this data set, were also seen when MAP values were used as the measure of exposure, instead of proximity. MAP developed from reports of PAP may be useful to identify high-risk areas and predict health outcomes when there are multiple sources of pollution and a "distance from source" analysis is impossible.

  15. ADDRESSING HUMAN EXPOSURES TO AIR POLLUTANTS AROUND BUILDINGS IN URBAN AREAS WITH COMPUTATIONAL FLUID DYNAMICS MODELS

    EPA Science Inventory

    This paper discusses the status and application of Computational Fluid Dynamics (CFD) models to address challenges for modeling human exposures to air pollutants around urban building microenvironments. There are challenges for more detailed understanding of air pollutant sour...

  16. Design and use of an exposure chamber for air pollution studies on microarthropods

    SciTech Connect

    Andre, H.M.

    1982-10-01

    An exposure chamber for studying the effects of air pollution on microarthropods is described. The chamber was tested on a corticolous mite, Humerobates rostrolamellatus Grandjean (Acari: Oribatida). In the absence of pollutants, the overall mortality was about 2.5%.

  17. Spatial resolution requirements for traffic-related air pollutant exposure evaluations

    EPA Science Inventory

    Vehicle emissions represent one of the most important air pollution sources in most urban areas, and elevated concentrations of pollutants found near major roads have been associated with many adverse health impacts. To understand these impacts, exposure estimates should reflect ...

  18. MANAGING EXPOSURE TO INDOOR AIR POLLUTANTS IN RESIDENTIAL AND OFFICE ENVIRONMENTS

    EPA Science Inventory

    The paper discusses the factors to be considered in managing indoor air pollutants in residential and office environments to reduce occupant exposures. Techniques for managing indoor air pollution sources include: source elimination, substitution, modification, and pretreatment a...

  19. Development and Evaluation of Alternative Metrics of Ambient Air Pollution Exposure for Use in Epidemiologic Studies

    EPA Science Inventory

    Population-based epidemiologic studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available outdoor concentrations from central monitoring sites. This practice may in...

  20. Effects of travel mode on exposures to particulate air pollution.

    PubMed

    Briggs, David J; de Hoogh, Kees; Morris, Chloe; Gulliver, John

    2008-01-01

    Monitoring was carried out of particulate concentrations whilst simultaneously walking and driving 48 routes in London, UK. Monitoring was undertaken during May and June 2005. Route lengths ranged from 601 to 1351 m, and most routes were travelled in both directions. Individual journey times ranged from 1.5 to 15 min by car (average 3.7 min) and 7.3 to 30 min (average 12.8 min) whilst walking; car trips were therefore repeated up to 5 times for each single walking trip and the results averaged for the route. Car trips were made with windows closed and the ventilation system on a moderate setting. Results show that mean exposures while walking are greatly in excess of those while driving, by a factor 4.7 for the coarse particle mass (PM10-PM2.5), 2.2 for the fine particle mass (PM2.5-PM1), 1.9 for the very fine particle mass (exposures appear to occur largely because the filtration system helps to prevent ingress of particles, so that the vehicle acts as a more-or-less independent micro-environment, insulated against much of air pollution present in the street. When account is also taken of the additional travel time involved in walking, these excesses are further increased: to factors of 15.6, 7.4, 6.5 and 4.4, respectively. Individuals who change their travel mode from car to walking in response to policies aimed at encouraging a modal shift in travel behavior are thus likely to experience considerably increased journey-time personal exposures to traffic-related air pollution. More effort is consequently needed to increase separation between road vehicles and pedestrians if negative effects of these policies are to be avoided.

  1. Research on non-destructive testing method of silkworm cocoons based on image processing technology

    NASA Astrophysics Data System (ADS)

    Gan, Yong; Kong, Qing-hua; Wei, Li-fu

    2008-03-01

    The major studied in this dissertation is the non-destructive testing method of silkworm cocoon's quality, based on the digital image processing and photoelectricity technology. Through the images collection and the data analysis, procession and calculation of the tested silkworm cocoons with the non-destructive testing technology, internet applications automatically reckon all items of the classification indexes. Finally we can conclude the classification result and the purchase price of the silkworm cocoons. According to the domestic classification standard of the silkworm cocoons, the author investigates various testing methods of silkworm cocoons which are used or have been explored at present, and devices a non-destructive testing scheme of the silkworm cocoons based on the digital image processing and photoelectricity technology. They are dissertated about the project design of the experiment. The precisions of all the implements are demonstrated. I establish Manifold mathematic models, compare them with each other and analyze the precision with technology of databank to get the best mathematic model to figure out the weight of the dried silkworm cocoon shells. The classification methods of all the complementary items are designed well and truly. The testing method has less error and reaches an advanced level of the present domestic non-destructive testing technology of the silkworm cocoons.

  2. Non-destructive assessment of human ribs mechanical properties using quantitative ultrasound.

    PubMed

    Mitton, David; Minonzio, Jean-Gabriel; Talmant, Maryline; Ellouz, Rafaa; Rongieras, Frédéric; Laugier, Pascal; Bruyère-Garnier, Karine

    2014-04-11

    Advanced finite element models of the thorax have been developed to study, for example, the effects of car crashes. While there is a need for material properties to parameterize such models, specific properties are largely missing. Non-destructive techniques applicable in vivo would, therefore, be of interest to support further development of thorax models. The only non-destructive technique available today to derive rib bone properties would be based on quantitative computed tomography that measures bone mineral density. However, this approach is limited by the radiation dose. Bidirectional ultrasound axial transmission was developed on long bones ex vivo and used to assess in vivo health status of the radius. However, it is currently unknown if the ribs are good candidates for such a measurement. Therefore, the goal of this study is to evaluate the relationship between ex vivo ultrasonic measurements (axial transmission) and the mechanical properties of human ribs to determine if the mechanical properties of the ribs can be quantified non-destructively. The results show statistically significant relationships between the ultrasonic measurements and mechanical properties of the ribs. These results are promising with respect to a non-destructive and non-ionizing assessment of rib mechanical properties. This ex vivo study is a first step toward in vivo studies to derive subject-specific rib properties.

  3. Non-Destructive Damping Measurement for Wafer-Level Packaged Microelectromechanical System (MEMS) Acceleration Switches

    DTIC Science & Technology

    2014-09-01

    Non-destructive Damping Measurement for Wafer-level Packaged Microelectromechanical System (MEMS) Acceleration Switches by Ryan Knight and...Microelectromechanical System (MEMS) Acceleration Switches Ryan Knight and Evan Cheng Sensors and Electron Devices Directorate, ARL...Damping Measurement for Wafer-level Packaged Microelectromechanical System (MEMS) Acceleration Switches 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  4. Non-destructive method for inward leakage detection of a plate evaporator

    NASA Astrophysics Data System (ADS)

    Hribernik, Ales

    2007-05-01

    A new non-destructive method was developed for the detection of refrigerant leakage at an evaporator's inflow. Nitrogen and oxygen gas were successively blown through the evaporator. A gas analyser was applied at the outflow of the evaporator and the oxygen concentration measured. It was possible to detect any leakage by investigating the oxygen concentration-time history diagram.

  5. Satellite-aided evaluation of population exposure to air pollution

    USGS Publications Warehouse

    Todd, William J.; George, Anthony J.; Bryant, Nevin A.

    1979-01-01

    The Clean Air Act Amendments of 1977 set schedules for states to implement regional, spatial assessments of air quality impacts. Accordingly, the U.S. Environmental Protection Agency recently published guidelines for quantifying population exposure to adverse air quality impact by using air quality and population data by census tracts. Our research complements the EPA guidelines in that it demonstrates the ability to determine population exposure to air pollution through computer processing that utilizes Landsat satellite-derived land use information. Three variables-a 1985 estimate of total suspended particulates for 2-km2 grid cells, Landsat-derived residential land cover data for 0.45-ha cells, and population totals for census tracts-were spatially registered and cross-tabulated to produce tabular and map products illustrating relative air quality exposure for residential population by 2-km2 cells. It would cost $20,000 to replicate our analysis for an area similar in size to the 4000-km2 Portland area. Once completed, the spatially fine, computer-compatible air quality and population data are amenable to the timely and efficient generation of population-at-risk tabular and map information on a continuous or periodic basis.

  6. Windsor, Ontario Exposure Assessment Study: Design and Methods Validation of Personal, Indoor and Outdoor Air Pollution Monitoring

    EPA Science Inventory

    The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures...

  7. Air Quality Modeling in Support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related a...

  8. Systematic review and metaanalysis of air pollution exposure and risk of diabetes.

    PubMed

    Janghorbani, Mohsen; Momeni, Fatemeh; Mansourian, Marjan

    2014-04-01

    The present systematic review and metaanalysis of published observational studies was conducted to assess the health effects of exposure to air pollution on diabetes risk. Online databases were searched through January 2013, and the reference lists of pertinent articles reporting observational studies in humans were examined. Pooled relative risks and 95 % confidence intervals were calculated with a random-effects model. Exposure to air pollution was associated with slight increase in risk of diabetes and susceptibility of people with diabetes to air pollution. These results were consistent between time-series, case-crossover and cohort studies and between studies conducted in North America and Europe. The association between exposure to air pollution and diabetes was stronger for gaseous pollutants than for particulate matter. Our metaanalysis suggests that exposure to air pollution may be a risk factor for diabetes and increase susceptibility of people with diabetes to air pollution.

  9. Development and evaluation of alternative approaches for exposure assessment of multiple air pollutants in Atlanta, Georgia

    EPA Science Inventory

    Measurements from central site (CS) monitors are often used as estimates of exposure in air pollution epidemiological studies. As these measurements are typically limited in their spatiotemporal resolution, true exposure variability within a population is often obscured, leading ...

  10. COOPERATIVE RESEARCH AND DEVELOPMENT FOR APPLICATION OF CFD TO ESTIMATING HUMAN EXPOSURES TO ENVIRONMENTAL POLLUTANTS

    EPA Science Inventory

    Under a Cooperative Research and Development Agreement (CRADA), Fluent, Inc. and the US EPA National Exposure Research Laboratory (NERL) propose to improve the ability of environmental scientists to use computer modeling for environmental exposure to air pollutants in human exp...

  11. Identifying exposure disparities in air pollution epidemiology specific to adverse birth outcomes

    NASA Astrophysics Data System (ADS)

    Geer, Laura A.

    2014-10-01

    More than 147 million people in the US live in areas where pollutant levels are above regulatory limits and pose a risk to health. Most of the vast network of air pollutant monitors in the US are located in places with higher pollution levels and a higher density of pollutant sources (e.g., point sources from industrial pollution). Vulnerable populations are more likely to live closer to pollutant sources, and thus closer to pollutant monitors. These differential exposures have an impact on maternal and child health; maternal air pollutant exposures have been linked to adverse outcomes such as preterm birth and infant low birth weight. Several studies are highlighted that address methodological approaches in the study of air pollution and health disparities.

  12. Metal Pollutants and Cardiovascular Disease: Mechanisms and Consequences of Exposure

    PubMed Central

    Solenkova, Natalia V.; Newman, Jonathan D.; Berger, Jeffrey S.; Thurston, George; Hochman, Judith S.; Lamas, Gervasio A.

    2014-01-01

    Introduction There is epidemiological evidence that metal contaminants may play a role in the development of atherosclerosis and its complications. Moreover, a recent clinical trial of a metal chelator had a surprisingly positive result in reducing cardiovascular events in a secondary prevention population, strengthening the link between metal exposure and cardiovascular disease (CVD). This is, therefore, an opportune moment to review evidence that exposure to metal pollutants, such as arsenic, lead, cadmium, and mercury, are significant risk factors for CVD. Methods We reviewed the English-speaking medical literature to assess and present the epidemiological evidence that 4 metals having no role in the human body (xenobiotic), mercury, lead, cadmium, and arsenic, have epidemiologic and mechanistic links to atherosclerosis and CVD. Moreover, we briefly review how the results of the Trial to Assess Chelation Therapy strengthen the link between atherosclerosis and xenobiotic metal contamination in humans. Conclusions There is strong evidence that xenobiotic metal contamination is linked to atherosclerotic disease and is a modifiable risk factor. PMID:25458643

  13. Air pollution dispersion models for human exposure predictions in London.

    PubMed

    Beevers, Sean D; Kitwiroon, Nutthida; Williams, Martin L; Kelly, Frank J; Ross Anderson, H; Carslaw, David C

    2013-01-01

    The London household survey has shown that people travel and are exposed to air pollutants differently. This argues for human exposure to be based upon space-time-activity data and spatio-temporal air quality predictions. For the latter, we have demonstrated the role that dispersion models can play by using two complimentary models, KCLurban, which gives source apportionment information, and Community Multi-scale Air Quality Model (CMAQ)-urban, which predicts hourly air quality. The KCLurban model is in close agreement with observations of NO(X), NO(2) and particulate matter (PM)(10/2.5), having a small normalised mean bias (-6% to 4%) and a large Index of Agreement (0.71-0.88). The temporal trends of NO(X) from the CMAQ-urban model are also in reasonable agreement with observations. Spatially, NO(2) predictions show that within 10's of metres of major roads, concentrations can range from approximately 10-20 p.p.b. up to 70 p.p.b. and that for PM(10/2.5) central London roadside concentrations are approximately double the suburban background concentrations. Exposure to different PM sources is important and we predict that brake wear-related PM(10) concentrations are approximately eight times greater near major roads than at suburban background locations. Temporally, we have shown that average NO(X) concentrations close to roads can range by a factor of approximately six between the early morning minimum and morning rush hour maximum periods. These results present strong arguments for the hybrid exposure model under development at King's and, in future, for in-building models and a model for the London Underground.

  14. Synergistic effects of exposure to concentrated ambient fine pollution particles and nitrogen dioxide in humans

    EPA Science Inventory

    Exposure to single pollutants such as ambient particulate matter (PM) is associated with adverse health effects. It is unclear, however, if simultaneous exposure to multiple air pollutants (e.g. PM and ozone or nitrogen dioxide), a more real world scenario, results in non-additiv...

  15. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam.

    PubMed

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A; Vick, Andrew J

    2016-09-02

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices.

  16. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam

    NASA Astrophysics Data System (ADS)

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A.; Vick, Andrew J.

    2016-09-01

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices.

  17. Photoacoustic Spectroscopy as a Non-destructive Tool for Quantification of Pesticide Residue in Apple Cuticle

    NASA Astrophysics Data System (ADS)

    Liu, Lixian; Wang, Yafei; Gao, Chunming; Huan, Huiting; Zhao, Binxing; Yan, Laijun

    2015-06-01

    Photoacoustic spectroscopy (PAS), the non-destructive method to detect residue of dimethyl-dichloro-vinyl-phosphate (DDVP) pesticide in a cuticle of apple, is described. After constructing the PA experimental setup and identifying three characteristic peaks of DDVP in the near ultraviolet region, the PA spectra of an apple cuticle contaminated with DDVP were collected. The artificial neural network method was then applied to analyze data quantitatively. The results show a correlation coefficient exceeding 0.99 and a detection limit of 0.2 ppm, which is within the national food safety standard for maximum residue limits for pesticides in food (GB 2763-2012). This fact and the non-destructive character of PAS make the approach promising for detection of pesticide residue in fruits.

  18. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam

    PubMed Central

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A.; Vick, Andrew J.

    2016-01-01

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices. PMID:27586090

  19. Microwaving Blood as a Non-Destructive Technique for Haemoglobin Measurements on Microlitre Samples

    PubMed Central

    Basey-Fisher, Toby H.; Guerra, Nadia; Triulzi, Chiara; Gregory, Andrew; Hanham, Stephen M.; Stevens, Molly M.; Maier, Stefan A.; Klein, Norbert

    2016-01-01

    The non-destructive ex vivo determination of haemoglobin (Hgb) concentration offers the capability to conduct multiple red blood cell haematological measurements on a single sample, an advantage that current optical techniques are unable to offer. Here, a microwave method and device for the accurate and non-destructive determination of Hgb concentration in microlitre blood samples are described. Using broadband microwave spectroscopy, a relationship is established between the dielectric properties of murine blood and Hgb concentration that is utilized to create a technique for the determination of Hgb concentration. Subsequently, a microwave dielectric resonator-microfluidic system is implemented in the analysis of 52 murine samples with microlitre volumes and Hgb concentrations ranging from 0 to 17 g dL−1. Using the characterized relationship, independent and minimally invasive Hgb measurements are made on nine healthy mice as well as seven with mutations in the Adenomatous polyposis coli (APC) gene that leads to colorectal cancer and consequently anaemia. PMID:24002989

  20. PANDA—A novel instrument for non-destructive sample analysis

    NASA Astrophysics Data System (ADS)

    Turunen, Jani; Peräjärvi, Kari; Pöllänen, Roy; Toivonen, Harri

    2010-01-01

    An instrument known as PANDA (Particles And Non-Destructive Analysis) for non-destructive sample analysis has been designed and built at the Finnish Radiation and Nuclear Safety Authority (STUK). In PANDA the measurement techniques and instruments designed for the basic research are applied to the analysis of environmental samples. PANDA has two vacuum chambers, one for loading samples and the other for measurements. In the measurement chamber there are two individual measurement positions. Currently the first one hosts an HPGe gamma detector and a position-sensitive alpha detector. The second measurement position is intended for precise characterization of found particles. PANDA's data are recorded in event mode and events are timestamped. In the present article the technical design of PANDA is presented in detail. In addition, its performance using depleted uranium particles and an air filter is demonstrated.

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

    SciTech Connect

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

    1994-06-01

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

  2. Multi-pollutant exposure profiles associated with term low birth weight in Los Angeles County.

    PubMed

    Coker, Eric; Liverani, Silvia; Ghosh, Jo Kay; Jerrett, Michael; Beckerman, Bernardo; Li, Arthur; Ritz, Beate; Molitor, John

    2016-05-01

    Research indicates that multiple outdoor air pollutants and adverse neighborhood conditions are spatially correlated. Yet health risks associated with concurrent exposure to air pollution mixtures and clustered neighborhood factors remain underexplored. Statistical models to assess the health effects from pollutant mixtures remain limited, due to problems of collinearity between pollutants and area-level covariates, and increases in covariate dimensionality. Here we identify pollutant exposure profiles and neighborhood contextual profiles within Los Angeles (LA) County. We then relate these profiles with term low birth weight (TLBW). We used land use regression to estimate NO2, NO, and PM2.5 concentrations averaged over census block groups to generate pollutant exposure profile clusters and census block group-level contextual profile clusters, using a Bayesian profile regression method. Pollutant profile cluster risk estimation was implemented using a multilevel hierarchical model, adjusting for individual-level covariates, contextual profile cluster random effects, and modeling of spatially structured and unstructured residual error. Our analysis found 13 clusters of pollutant exposure profiles. Correlations between study pollutants varied widely across the 13 pollutant clusters. Pollutant clusters with elevated NO2, NO, and PM2.5 concentrations exhibited increased log odds of TLBW, and those with low PM2.5, NO2, and NO concentrations showed lower log odds of TLBW. The spatial patterning of pollutant cluster effects on TLBW, combined with between-pollutant correlations within pollutant clusters, imply that traffic-related primary pollutants influence pollutant cluster TLBW risks. Furthermore, contextual clusters with the greatest log odds of TLBW had more adverse neighborhood socioeconomic, demographic, and housing conditions. Our data indicate that, while the spatial patterning of high-risk multiple pollutant clusters largely overlaps with adverse contextual

  3. Early life exposure to air pollution induces adult cardiac dysfunction

    PubMed Central

    Gorr, Matthew W.; Velten, Markus; Nelin, Timothy D.; Youtz, Dane J.; Sun, Qinghua

    2014-01-01

    Exposure to ambient air pollution contributes to the progression of cardiovascular disease, particularly in susceptible populations. The objective of the present study was to determine whether early life exposure to air pollution causes persistent cardiovascular consequences measured at adulthood. Pregnant FVB mice were exposed to filtered (FA) or concentrated ambient particulate matter (PM2.5) during gestation and nursing. Mice were exposed to PM2.5 at an average concentration of 51.69 μg/m3 from the Columbus, OH region for 6 h/day, 7 days/wk in utero until weaning at 3 wk of age. Birth weight was reduced in PM2.5 pups compared with FA (1.36 ± 0.12 g FA, n = 42 mice; 1.30 ± 0.15 g PM2.5, n = 67 P = 0.012). At adulthood, mice exposed to perinatal PM2.5 had reduced left ventricular fractional shortening compared with FA-exposed mice (43.6 ± 2.1% FA, 33.2 ± 1.6% PM2.5, P = 0.001) with greater left ventricular end systolic diameter. Pressure-volume loops showed reduced ejection fraction (79.1 ± 3.5% FA, 35.5 ± 9.5% PM2.5, P = 0.005), increased end-systolic volume (10.4 ± 2.5 μl FA, 39.5 ± 3.8 μl PM2.5, P = 0.001), and reduced dP/dt maximum (11,605 ± 200 μl/s FA, 9,569 ± 800 μl/s PM2.5, P = 0.05) and minimum (−9,203 ± 235 μl/s FA, −7,045 ± 189 μl/s PM2.5, P = 0.0005) in PM2.5-exposed mice. Isolated cardiomyocytes from the hearts of PM2.5-exposed mice had reduced peak shortening (%PS, 8.53 ± 2.82% FA, 6.82 ± 2.04% PM2.5, P = 0.003), slower calcium reuptake (τ, 0.22 ± 0.09 s FA, 0.26 ± 0.07 s PM2.5, P = 0.048), and reduced response to β-adrenergic stimulation compared with cardiomyocytes isolated from mice that were exposed to FA. Histological analyses revealed greater picro-sirius red-positive-stained areas in the PM2.5 vs. FA group, indicative of increased collagen deposition. We concluded that these data demonstrate the detrimental role of early life exposure to ambient particulate air pollution in programming of adult cardiovascular

  4. Coded excitation for infrared non-destructive testing of carbon fiber reinforced plastics.

    PubMed

    Mulaveesala, Ravibabu; Venkata Ghali, Subbarao

    2011-05-01

    This paper proposes a Barker coded excitation for defect detection using infrared non-destructive testing. Capability of the proposed excitation scheme is highlighted with recently introduced correlation based post processing approach and compared with the existing phase based analysis by taking the signal to noise ratio into consideration. Applicability of the proposed scheme has been experimentally validated on a carbon fiber reinforced plastic specimen containing flat bottom holes located at different depths.

  5. A novel quadruple excitation in high-Tc SQUID-based non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Kong, X. Y.; Ren, Y. F.; Li, J. W.; Yu, H. W.; Chen, G. H.; Yang, Q. S.

    2006-02-01

    A high-Tc SQUID-based non-destructive evaluation (NDE) system has been set up in our laboratory. The SQUID was made on a 24° bicystal SrTiO3 substrate. A novel quadruple excitation coil was proposed for the first time and applied in the artificial holes in the aluminium multilayer structure in a noisy unshielded environment. The experimental data shows that it has good balance and is very effective at detecting small hole defects.

  6. Conceptual design of non-destructive, time profile monitor for femtosecond-long electron bunches

    NASA Astrophysics Data System (ADS)

    Konoplev, I. V.; Harrison, H.; Lancaster, A. J.; Taheri, F. Bakkali; Doucas, G.; Aryshev, A.; Lekomtsev, K.; Shevelev, M.; Terunuma, N.; Urakawa, J.

    2017-03-01

    The main objective of the project is to build a high resolution time-profile monitor for femtosecond electron beams, based on the spectral analysis of coherent Smith-Purcell radiation (cSPr). The monitor will be capable of determining the electron bunch time profile non-destructively and on a shot-by-shot basis. The results of recent experimental and theoretical studies are presented, and the conceptual design of the monitor is discussed.

  7. Feasibility Study of Non-Destructive Techniques to Measure Corrosion in SAVY Containers

    SciTech Connect

    Davenport, Matthew Nicholas

    2016-07-15

    Stainless Steel SAVY containers are used to transport and store nuclear material. They are prone to interior corrosion in the presence of certain chemicals and a low-oxygen environment. SAVY containers also have relatively thin walls to reduce their weight, making their structural integrity more vulnerable to the effects of corrosion. A nondestructive evaluation system that finds and monitors corrosion within containers in use would improve safety conditions and preclude hazards. Non-destructive testing can determine whether oxidation or corrosion is occurring inside the SAVY containers, and there are a variety of non-destructive testing methods that may be viable. The feasibility study described will objectively decide which method best fits the requirements of the facility and the problem. To improve efficiency, the containers cannot be opened during the non-destructive examination. The chosen technique should also be user-friendly and relatively quick to apply. It must also meet facility requirements regarding wireless technology and maintenance. A feasibility study is an objective search for a new technology or product to solve a particular problem. First, the design, technical, and facility feasibility requirements are chosen and ranked in order of importance. Then each technology considered is given a score based upon a standard ranking system. The technology with the highest total score is deemed the best fit for a certain application.

  8. Non-destructively reading out information embedded inside real objects by using far-infrared light

    NASA Astrophysics Data System (ADS)

    Okada, Ayumi; Silapasuphakornwong, Piyarat; Suzuki, Masahiro; Torii, Hideyuki; Takashima, Youichi; Uehira, Kazutake

    2015-09-01

    This paper presents a technique that can non-destructively read out information embedded inside real objects by using far-infrared-light. We propose a technique that can protect the copyrights of digital content for homemade products using digital fabrication technologies such as those used in 3D printers. It embeds information on copyrights inside real objects produced by 3D printers by forming fine structures inside the objects as a watermark that cannot be observed from the outside. Fine structures are formed near the surface inside real objects when they are being fabricated. Information embedded inside real objects needs to be read out non-destructively. We used a technique that could non-destructively read out information from inside real objects by using far-infrared light. We conducted experiments where we structured fine cavities inside objects. The disposition of the fine domain contained valuable information. We used the flat and curved surfaces of the objects to identify them. The results obtained from the experiments demonstrated that the disposition patterns of the fine structures appeared on the surface of objects as a temperature profile when far-infrared light was irradiated on their surface. Embedded information could be read out successfully by analyzing the temperature profile images of the surface of the objects that were captured with thermography and these results demonstrated the feasibility of the technique we propose.

  9. Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy

    PubMed Central

    McDonald, S. A.; Reischig, P.; Holzner, C.; Lauridsen, E. M.; Withers, P. J.; Merkle, A. P.; Feser, M.

    2015-01-01

    The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance. PMID:26494523

  10. Non-destructive analysis of extracellular matrix development in cardiovascular tissue-engineered constructs.

    PubMed

    Tuemen, M; Nguyen, D V A; Raffius, J; Flanagan, T C; Dietrich, M; Frese, J; Schmitz-Rode, T; Jockenhoevel, S

    2013-05-01

    In the field of tissue engineering, there is an increasing demand for non-destructive methods to quantify the synthesis of extracellular matrix (ECM) components such as collagens, elastin or sulphated glycosaminoglycans (sGAGs) in vitro as a quality control before clinical use. In this study, procollagen I carboxyterminal peptide (PICP), procollagen III aminoterminal peptide (PIIINP), tropoelastin and sGAGs are investigated for their potential use as non-destructive markers in culture medium of statically cultivated cell-seeded fibrin gels. Measurement of PICP as marker for type I collagen synthesis, and PIIINP as marker of type III collagen turnover, correlated well with the hydroxyproline content of the fibrin gels, with a Pearson correlation coefficient of 0.98 and 0.97, respectively. The measurement of tropoelastin as marker of elastin synthesis correlated with the amount of elastin retained in fibrin gels with a Pearson correlation coefficient of 0.99. sGAGs were retained in fibrin gels, but were not detectable in culture medium at any time of measurement. In conclusion, this study demonstrates the potential of PICP and tropoelastin as non-destructive culture medium markers for collagen and elastin synthesis. To our knowledge, this is the first study in cardiovascular tissue engineering investigating the whole of here proposed biomarkers of ECM synthesis to monitor the maturation process of developing tissue non-invasively, but for comprehensive assessment of ECM development, these biomarkers need to be investigated in further studies, employing dynamic cultivation conditions and more complex tissue constructs.

  11. Non-destructive single-pass low-noise detection of ions in a beamline

    SciTech Connect

    Schmidt, Stefan; Murböck, Tobias; Birkl, Gerhard; Andelkovic, Zoran; Vogel, Manuel; Nörtershäuser, Wilfried; Stahl, Stefan

    2015-11-15

    We have conceived, built, and operated a device for the non-destructive single-pass detection of charged particles in a beamline. The detector is based on the non-resonant pick-up and subsequent low-noise amplification of the image charges induced in a cylindrical electrode surrounding the particles’ beam path. The first stage of the amplification electronics is designed to be operated from room temperature down to liquid helium temperature. The device represents a non-destructive charge counter as well as a sensitive timing circuit. We present the concept and design details of the device. We have characterized its performance and show measurements with low-energy highly charged ions (such as Ar{sup 13+}) passing through one of the electrodes of a cylindrical Penning trap. This work demonstrates a novel approach of non-destructive, low noise detection of charged particles which is, depending on the bunch structure, suitable, e.g., for ion traps, low-energy beamlines or accelerator transfer sections.

  12. Non-destructive single-pass low-noise detection of ions in a beamline.

    PubMed

    Schmidt, Stefan; Murböck, Tobias; Andelkovic, Zoran; Birkl, Gerhard; Nörtershäuser, Wilfried; Stahl, Stefan; Vogel, Manuel

    2015-11-01

    We have conceived, built, and operated a device for the non-destructive single-pass detection of charged particles in a beamline. The detector is based on the non-resonant pick-up and subsequent low-noise amplification of the image charges induced in a cylindrical electrode surrounding the particles' beam path. The first stage of the amplification electronics is designed to be operated from room temperature down to liquid helium temperature. The device represents a non-destructive charge counter as well as a sensitive timing circuit. We present the concept and design details of the device. We have characterized its performance and show measurements with low-energy highly charged ions (such as Ar(13+)) passing through one of the electrodes of a cylindrical Penning trap. This work demonstrates a novel approach of non-destructive, low noise detection of charged particles which is, depending on the bunch structure, suitable, e.g., for ion traps, low-energy beamlines or accelerator transfer sections.

  13. [Study on Non-Destructive Testing of Guqin Interior Structure Based on Computed Tomography].

    PubMed

    Zhao, De-da; Liu, Xing-e; Yang, Shu-min; Yu, Shenz; Tian, Gen-lin; Ma, Jian-feng; Wang, Qing-ping

    2015-12-01

    The wood property and production process affect quality of Guqin. At the same time, Guqin shape with cavity layout relations to the improvement of Guqin technology and inheritance, so it's very important to get the internal cavity characteristics and parameters on the condition of non-destructive the structure of Guqin. The image of interior structure in Guqin was investigated by overall scanning based on non-destructive testing technology of computed tomography, which texture of faceplate, connection method between faceplate and soleplate and interior defects were studied. The three-dimensional reconstruction of Guqin cavity was achieved through Mimics software of surface rendering method and put the two-dimensional CT tomography images convert into three-dimensional, which more complete show interior structural form in Guqin, and finally the parameter of cavity dimensions was obtained. Experimental research shows that there is significant difference in Guqin interior structure between Zhong-ni and Luo-xia type, in which the fluctuation of the interior surfacein Zhong-ni type's is larger than that in Luo-xia type; the interior volume of Zhong-ni typeis less than that of Luo-xia type, especially in Guqin neck. The accurate internal information of Guqin obtained through the computed tomography (CT) technology will provide technical support for the Guqin manufacture craft and the quality examination, as well as provide the reference in the aspect of non-destructive testing for other traditional precious internal structure research.

  14. A new non-destructive readout by using photo-recovered surface potential contrast.

    PubMed

    Wang, Le; Jin, Kui-juan; Gu, Jun-xing; Ma, Chao; He, Xu; Zhang, Jiandi; Wang, Can; Feng, Yu; Wan, Qian; Shi, Jin-an; Gu, Lin; He, Meng; Lu, Hui-bin; Yang, Guo-zhen

    2014-11-10

    Ferroelectric random access memory is still challenging in the feature of combination of room temperature stability, non-destructive readout and high intensity storage. As a non-contact and non-destructive information readout method, surface potential has never been paid enough attention because of the unavoidable decay of the surface potential contrast between oppositely polarized domains. That is mainly due to the recombination of the surface movable charges around the domain walls. Here, by introducing a laser beam into the combination of piezoresponse force microscopy and Kelvin probe force microscopy, we demonstrate that the surface potential contrast of BiFeO3 films can be recovered under light illumination. The recovering mechanism is understood based on the redistribution of the photo-induced charges driven by the internal electric field. Furthermore, we have created a 12-cell memory pattern based on BiFeO3 films to show the feasibility of such photo-assisted non-volatile and non-destructive readout of the ferroelectric memory.

  15. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions.

    PubMed

    Jiménez, Juan de la Cruz; Cardoso, Juan A; Leiva, Luisa F; Gil, Juanita; Forero, Manuel G; Worthington, Margaret L; Miles, John W; Rao, Idupulapati M

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress.

  16. Giant Magnetoresistance Sensors: A Review on Structures and Non-Destructive Eddy Current Testing Applications.

    PubMed

    Rifai, Damhuji; Abdalla, Ahmed N; Ali, Kharudin; Razali, Ramdan

    2016-02-26

    Non-destructive eddy current testing (ECT) is widely used to examine structural defects in ferromagnetic pipe in the oil and gas industry. Implementation of giant magnetoresistance (GMR) sensors as magnetic field sensors to detect the changes of magnetic field continuity have increased the sensitivity of eddy current techniques in detecting the material defect profile. However, not many researchers have described in detail the structure and issues of GMR sensors and their application in eddy current techniques for nondestructive testing. This paper will describe the implementation of GMR sensors in non-destructive testing eddy current testing. The first part of this paper will describe the structure and principles of GMR sensors. The second part outlines the principles and types of eddy current testing probe that have been studied and developed by previous researchers. The influence of various parameters on the GMR measurement and a factor affecting in eddy current testing will be described in detail in the third part of this paper. Finally, this paper will discuss the limitations of coil probe and compensation techniques that researchers have applied in eddy current testing probes. A comprehensive review of previous studies on the application of GMR sensors in non-destructive eddy current testing also be given at the end of this paper.

  17. Non-destructive techniques for determining the material characteristics of Cr-Mo-V rotor steel

    SciTech Connect

    Goto, Toru; Kadoya, Yoshikuni; Konishi, Takashi; Kamimura, Takeo; Suyama, Shouji; Haruki, Nirou; Ikuno, Takeshi; Yoshimura, Kouji

    1994-12-31

    Long-term service causes material deterioration, such as the accumulation of creep and fatigue damage, as well as softening and embrittlement, in the high-temperature components of fossil fuel power plants. Therefore, in order to extend plant life at minimum cost without any accidental outages, it is important to observe the material state, especially of rotors and conduct necessary repairs or replace them at the most appropriate time. Therefore, there is a need for non-destructive techniques to evaluate the material characteristics of Cr-Mo-V rotors under service. In this paper, a comparative report of non-destructive techniques using artificially aged and crept Cr-Mo-V steel specimens is given. The techniques tested include replication, hardness measurement, electro-magnetic and ultrasonic techniques, and conventional metallurgical techniques, which have been here to fore usable only in the laboratory, but due to expected advances in the non-destructive sampling of material from service rotors these techniques are now usable in the field. As a result of the studies, the features of each technique are well recognized and the suggestions for the further development of NDE methods for the evaluation of creep damage in Cr-Mo-V rotors are presented.

  18. Giant Magnetoresistance Sensors: A Review on Structures and Non-Destructive Eddy Current Testing Applications

    PubMed Central

    Rifai, Damhuji; Abdalla, Ahmed N.; Ali, Kharudin; Razali, Ramdan

    2016-01-01

    Non-destructive eddy current testing (ECT) is widely used to examine structural defects in ferromagnetic pipe in the oil and gas industry. Implementation of giant magnetoresistance (GMR) sensors as magnetic field sensors to detect the changes of magnetic field continuity have increased the sensitivity of eddy current techniques in detecting the material defect profile. However, not many researchers have described in detail the structure and issues of GMR sensors and their application in eddy current techniques for nondestructive testing. This paper will describe the implementation of GMR sensors in non-destructive testing eddy current testing. The first part of this paper will describe the structure and principles of GMR sensors. The second part outlines the principles and types of eddy current testing probe that have been studied and developed by previous researchers. The influence of various parameters on the GMR measurement and a factor affecting in eddy current testing will be described in detail in the third part of this paper. Finally, this paper will discuss the limitations of coil probe and compensation techniques that researchers have applied in eddy current testing probes. A comprehensive review of previous studies on the application of GMR sensors in non-destructive eddy current testing also be given at the end of this paper. PMID:26927123

  19. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions

    PubMed Central

    Jiménez, Juan de la Cruz; Cardoso, Juan A.; Leiva, Luisa F.; Gil, Juanita; Forero, Manuel G.; Worthington, Margaret L.; Miles, John W.; Rao, Idupulapati M.

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress. PMID:28243249

  20. A new non-destructive readout by using photo-recovered surface potential contrast

    PubMed Central

    Wang, Le; Jin, Kui-juan; Gu, Jun-xing; Ma, Chao; He, Xu; Zhang, Jiandi; Wang, Can; Feng, Yu; Wan, Qian; Shi, Jin-an; Gu, Lin; He, Meng; Lu, Hui-bin; Yang, Guo-zhen

    2014-01-01

    Ferroelectric random access memory is still challenging in the feature of combination of room temperature stability, non-destructive readout and high intensity storage. As a non-contact and non-destructive information readout method, surface potential has never been paid enough attention because of the unavoidable decay of the surface potential contrast between oppositely polarized domains. That is mainly due to the recombination of the surface movable charges around the domain walls. Here, by introducing a laser beam into the combination of piezoresponse force microscopy and Kelvin probe force microscopy, we demonstrate that the surface potential contrast of BiFeO3 films can be recovered under light illumination. The recovering mechanism is understood based on the redistribution of the photo-induced charges driven by the internal electric field. Furthermore, we have created a 12-cell memory pattern based on BiFeO3 films to show the feasibility of such photo-assisted non-volatile and non-destructive readout of the ferroelectric memory. PMID:25381929

  1. A Comparison of Exposure Metrics for Traffic-Related Air Pollutants: Application to Epidemiology Studies in Detroit, Michigan

    EPA Science Inventory

    Vehicles are major sources of air pollutant emissions, and individuals living near large roads endure high exposures and health risks associated with traffic-related air pollutants. Air pollution epidemiology, health risk, environmental justice, and transportation planning studi...

  2. In vitro mucus transportability, cytogenotoxicity, and hematological changes as non-destructive physiological biomarkers in fish chronically exposed to metals.

    PubMed

    Seriani, Robson; Abessa, Denis M S; Moreira, Lucas B; Cabrera, Joana P G; Sanches, Juliana Q; Silva, Carolina L S; Amorim, Francisca A; Rivero, Dolores H R F; Silva, Flavia L; Fitorra, Lilian S; Carvalho-Oliveira, Regiani; Macchione, Mariangela; Ranzani-Paiva, Maria J T

    2015-02-01

    The biomonitoring of fish using biomarkers represents a useful tool for the assessment of aquatic pollution. This study evaluated the sublethal toxic effects of aquatic pollution on fish collected from a site contaminated by metals. Water and fish (Oreochromis niloticus) samples were collected from a pond in the Parque Ecológico do Tietê (PET) that lies along the Tietê River (São Paulo, Brazil), and from a control site (an experimental fish farm). The metal content of the water was evaluated, and fish were used to examine the properties of gill mucus and blood. The PET fish were evaluated for alterations in the in vitro transportability of mucus and changes in blood properties (e.g., cell volume, hemoglobin concentration, red blood cells, and white blood cell count). The results of the water analyzes indicated metal levels above the legal standards for Fe (0.71 mg/L), Ni (0.06 mg/L), Mn (0.11 mg/L), and Pb (0.48 mg/L). Compared to the controls, the hematologic parameter analyzes of PET fish revealed significantly higher numbers of erythrocytes (RBC), leukocytes (WBC), lymphocytes, erythroblasts, and Mean Corpuscular Volume (MCV); however, the hemoglobin content and Mean Corpuscular Hemoglobin Concentration (MCHC) values were significantly lower. The frequencies of nuclear abnormalities and micronuclei were significantly higher and the mucociliary transport was significantly lower in PET fish than in the controls. These results suggest that fish from the contaminated site exhibit a series of physiological responses, which probably indicate health disturbances. Furthermore, the results suggest that blood and mucus are promising, non-destructive targets for use in the monitoring of pollution.

  3. Non-destructive testing on aramid fibres for the long-term assessment of interventions on heritage structures

    NASA Astrophysics Data System (ADS)

    Ceravolo, R.; De Marchi, A.; Pinotti, E.; Surace, C.; Zanotti Fragonara, L.

    2015-07-01

    High strength fibre reinforced polymers (FRPs) are composite materials made of fibres such as carbon, aramid and/or glass, and a resin matrix. FRPs are commonly used for structural repair and strengthening interventions and exhibit high potential for applications to existing constructions, including heritage buildings. In regard to aramid fibres, uncertainties about the long-term behaviour of these materials have often made the designers reluctant to use them in structural engineering. The present study describes simple and non-destructive nonlinearity tests for assessing damage or degradation of structural properties in Kevlar fibres. This was obtained by using high precision measurements to detect small deviations in the dynamic response measured on fibres and ropes. The change in dynamic properties was then related to a damage produced by exposure of the sample to UV rays for a defined time period, which simulated long-term sun exposure. In order to investigate the sensitivity of such an approach to damage detection, non-linearity characterisation tests were conducted on aramid fibres in both damaged and undamaged states. With the purpose of carrying out dynamic tests on small fibre specimens, a dedicated instrumentation was designed and built in cooperation with the Metrology Laboratory of the Department of Electronics at the Politecnico di Torino.

  4. EXPOSURE VERSION 2 - A COMPUTER MODEL FOR ANALYZING THE EFFECTS OF INDOOR AIR POLLUTANT SOURCES ON INDIVIDUAL EXPOSURE

    EPA Science Inventory

    The report presents a model for calculating individual exposure to indoor pollutants from sources. The model calculates exposure due to individual, as opposed to population, activity patterns and source use. The model uses data on source emissions, room- to- room air flows, air e...

  5. Case report: Atrial fibrillation following exposure to ambient air pollution particles

    EPA Science Inventory

    CONTEXT: Exposure to air pollution can result in the onset of atrial fibrillation. CASE PRESENTATION: We present a case of a 58 year old woman who volunteered to participate in a controlled exposure to concentrated ambient particles (CAPs). Twenty minutes into the exposure, there...

  6. Exposure prediction approaches used in air pollution epidemiology studies: Keyfindings and future recommendations

    EPA Science Inventory

    Many epidemiologic studies of the health effects of exposure to ambient air pollution use measurements from central-site monitors as their exposure estimate. However, measurements from central-site monitors may lack the spatial and temporal resolution required to capture exposure...

  7. Application of alternative spatiotemporal metrics of ambient air pollution exposure in a time-series epidemiological study in Atlanta

    EPA Science Inventory

    Exposure error in studies of ambient air pollution and health that use city-wide measures of exposure may be substantial for pollutants that exhibit spatiotemporal variability. Alternative spatiotemporal metrics of exposure for traffic-related and regional pollutants were applied...

  8. Development and evaluation of alternative approaches for exposure assessment of multiple air pollutants in Atlanta, Georgia.

    PubMed

    Dionisio, Kathie L; Isakov, Vlad; Baxter, Lisa K; Sarnat, Jeremy A; Sarnat, Stefanie Ebelt; Burke, Janet; Rosenbaum, Arlene; Graham, Stephen E; Cook, Rich; Mulholland, James; Özkaynak, Halûk

    2013-01-01

    Measurements from central site (CS) monitors are often used as estimates of exposure in air pollution epidemiological studies. As these measurements are typically limited in their spatiotemporal resolution, true exposure variability within a population is often obscured, leading to potential measurement errors. To fully examine this limitation, we developed a set of alternative daily exposure metrics for each of the 169 ZIP codes in the Atlanta, GA, metropolitan area, from 1999 to 2002, for PM(2.5) and its components (elemental carbon (EC), SO(4)), O(3), carbon monoxide (CO), and nitrogen oxides (NOx). Metrics were applied in a study investigating the respiratory health effects of these pollutants. The metrics included: (i) CS measurements (one CS per pollutant); (ii) air quality model results for regional background pollution; (iii) local-scale AERMOD air quality model results; (iv) hybrid air quality model estimates (a combination of (ii) and (iii)); and (iv) population exposure model predictions (SHEDS and APEX). Differences in estimated spatial and temporal variability were compared by exposure metric and pollutant. Comparisons showed that: (i) both hybrid and exposure model estimates exhibited high spatial variability for traffic-related pollutants (CO, NO(x), and EC), but little spatial variability among ZIP code centroids for regional pollutants (PM(2.5), SO(4), and O(3)); (ii) for all pollutants except NO(x), temporal variability was consistent across metrics; (iii) daily hybrid-to-exposure model correlations were strong (r>0.82) for all pollutants, suggesting that when temporal variability of pollutant concentrations is of main interest in an epidemiological application, the use of estimates from either model may yield similar results; (iv) exposure models incorporating infiltration parameters, time-location-activity budgets, and other exposure factors affect the magnitude and spatiotemporal distribution of exposure, especially for local pollutants. The

  9. Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

    SciTech Connect

    Dhondt, Stijn; Beckx, Carolien; Degraeuwe, Bart; Lefebvre, Wouter; Kochan, Bruno; Bellemans, Tom; Int Panis, Luc; Macharis, Cathy; Putman, Koen

    2012-09-15

    In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO{sub 2} and O{sub 3} using only home addresses were compared with models that integrate all time-activity patterns-including time in commute-for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO{sub 2} using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: Black-Right-Pointing-Pointer Exposure to ambient air pollution was assessed integrating population mobility. Black-Right-Pointing-Pointer This dynamic exposure was integrated into a health impact assessment. Black-Right-Pointing-Pointer Differences between the dynamic and residential exposure were quantified. Black-Right-Pointing-Pointer Modest differences in health impact were found at a regional level. Black

  10. Evaluation of Mechanical Properties of Nuclear Materials Using Non-Destructive Ball Indentation Technique

    SciTech Connect

    Mathew, M.D.; Linga Murty, K.

    2002-07-01

    Integrity of structural components depends on the deformation and fracture behavior of materials. For evaluating the material condition in-service, it is generally not feasible or practical or advisable to cut samples from operating structures. Non-destructive testing (NDT) techniques are required to evaluate the mechanical properties. Although several NDT techniques such as ultrasound, magnetic strength, Barkhausen noise, microhardness etc., are employed for estimating the mechanical property degradation, these methodologies are generally empirical and indirect. Automated Ball Indentation (ABI) is a non-destructive testing technique for direct measurement of mechanical and fracture properties of metallic engineering materials. Because of the small area over which the test is carried out, it is possible to determine point to point variations in the mechanical and fracture properties, such as those that exist in weldments. Although ABI technique is non-intrusive, it is a state-of-the-art mechanical test that measures directly the current/local deformation behavior of the material. In this paper, we present results from studies on the application of ABI technique to determine tensile and fracture properties of ferritic steels, an austenitic stainless steel, a nickel base superalloy and Zircaloy in different thermo-mechanical conditions. The effects of aging and cold work on these properties were determined from the ABI tests. Gradients in mechanical properties of ferritic steel welds, particularly in the narrow heat-affected zone, were clearly established. ABI technique was found to be useful in determining the anisotropy in the tensile properties of Zircaloy cladding tubes. The technique has potential as a non-destructive method for assessing structural integrity of aged components. (authors)

  11. Non-destructive Assessment of Engineered Cartilage Composition by Near Infrared Spectroscopy

    PubMed Central

    McGoverin, Cushla M.; Hanifi, Arash; Palukuru, Uday P.; Yousefi, Farzad; Glenn, Padraig B. M.; Shockley, Michael; Spencer, Richard G.; Pleshko, Nancy

    2016-01-01

    Tissue engineering presents a strategy to overcome the limitations of current tissue healing methods. Scaffolds, cells, external growth factors and mechanical input are combined in an effort to obtain constructs with properties that mimic native tissues. However, engineered constructs developed using similar culture environments can have very different matrix composition and biomechanical properties. Accordingly, a non-destructive technique to assess constructs during development such that appropriate compositional endpoints can be defined is desirable. Near infrared spectroscopy (NIRS) analysis is a modality being investigated to address the challenges associated with current evaluation techniques, which includes non-destructive compositional assessment. In the present study, cartilage tissue constructs were grown using chondrocytes seeded onto polyglycolic acid (PGA) scaffolds in similar environments in three separate tissue culture experiments and monitored using NIRS. Multivariate partial least squares (PLS) analysis models of NIR spectra were calculated and used to predict tissue composition, with biochemical assay information used as the reference data. Results showed that for combined data from all tissue culture experiments, PLS models were able to assess composition with significant correlations to reference values, including engineered cartilage water (at 5200 cm−1, R = 0.68, p = 0.03), proteoglycan (at 4310 cm−1, R = 0.82, p = 0.007), and collagen (at 4610 cm−1, R = 0.84, p = 0.005). In addition, degradation of PGA was monitored using specific NIRS frequencies. These results demonstrate that NIR spectroscopy combined with multivariate analysis provides a non-destructive modality to assess engineered cartilage, which could provide information to determine the optimal time for tissue harvest for clinical applications. PMID:26817457

  12. Research Performed within the Non-Destructive Evaluation Team at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Burns, Erin A.

    2004-01-01

    Non-destructive testing is essential in many fields of manufacturing and research in order to perform reliable examination of potentially damaged materials and parts without destroying the inherent structure of the materials. Thus, the Non-Destructive Evaluation (NDE) Team at NASA Glenn Research Center partakes in various projects to improve materials testing equipment as well as analyze materials, material defects, and material deficiencies. Due to the array of projects within the NDE Team at this time, five research aims were supplemental to some current projects. A literature survey of "DE and testing methodologies as related to rocks was performed. Also, Mars Expedition Rover technology was assessed to understand the requirements for instrumentation in harsh space environments (e.g. temperature). Potential instrumentation and technologies were also considered and documented. The literature survey provided background and potential sources for a proposal to acquire funding for ultrasonic instrumentation on board a future Mars expedition. The laboratory uses a Santec Systems AcousticScope AS200 acoustography system. Labview code was written within the current program in order to improve the current performance of the acoustography system. A sample of Reinforced Carbon/Carbon (RCC) material from the leading edge of the space shuttle underwent various non-destructive tests (guided wave scanning, thermography, computed tomography, real time x-ray, etc.) in order to characterize its structure and examine possible defects. Guided wave scan data of a ceramic matrix composite (CMC) panel was reanalyzed utilizing image correlations and signal processing variables. Additional guided wave scans and thermography were also performed on the CMC panel. These reevaluated data and images will be used in future presentations and publications. An additional axis for the guided wave scanner was designed, constructed, and implemented. This additional axis allowed incremental spacing

  13. Non-destructive estimation of foliar carotenoid content of tree species using merged vegetation indices.

    PubMed

    Fassnacht, Fabian E; Stenzel, Stefanie; Gitelson, Anatoly A

    2015-03-15

    Leaf pigment content is an important indicator of plant status and can serve to assess the vigor and photosynthetic activity of plants. The application of spectral information gathered from laboratory, field and remote sensing-based spectrometers to non-destructively assess total chlorophyll (Chl) content of higher plants has been demonstrated in earlier studies. However, the precise estimation of carotenoid (Car) content with non-destructive spectral measurements has so far not reached accuracies comparable to the results obtained for Chl content. Here, we examined the potential of a recently developed angular vegetation index (AVI) to estimate total foliar Car content of three tree species. Based on an iterative search of all possible band combinations, we identified a best candidate AVIcar. The identified index showed quite close but essentially not linear relation with Car contents of the examined species with increasing sensitivity to high Car content and a lack of sensitivity to low Car content for which earlier proposed vegetation indices (VI) performed better. To make use of the advantages of both VI types, we developed a simple merging procedure, which combined the AVIcar with two earlier proposed carotenoid indices. The merged indices had close linear relationship with total Car content and outperformed all other examined indices. The merged indices were able to accurately estimate total Car content with a percental root mean square error (%RMSE) of 8.12% and a coefficient of determination of 0.88. Our findings were confirmed by simulations using the radiative transfer model PROSPECT-5. For simulated data, the merged indices again showed a quasi linear relationship with Car content. This strengthens the assumption that the proposed merged indices have a general ability to accurately estimate foliar Car content. Further examination of the proposed merged indices to estimate foliar Car content of other plant species is desirable to prove the general

  14. A Monte Carlo approach applied to ultrasonic non-destructive testing

    NASA Astrophysics Data System (ADS)

    Mosca, I.; Bilgili, F.; Meier, T.; Sigloch, K.

    2012-04-01

    Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and architectural structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to combine non-destructive testing with a theoretical data analysis and hence to contribute to conservation strategies of archaeological and architectural structures. We analyze ultrasonic waveforms measured at the surface of a variety of samples, and define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface

  15. Additive Manufacturing (AM) Activities and Non-Destructive Evaluation (NDE) at GSFC

    NASA Technical Reports Server (NTRS)

    Jones, Justin S.

    2017-01-01

    NASA personnel will be meeting with a delegation from the Japan Aerospace Exploration Agency (JAXA) Office of Safety and Mission Assurance (OSMA) at Langley Research Center on 2217 through 3217. The purpose of the meeting is a technical interchange between NASA and JAXA to discuss Non-Destructive Evaluation (NDE) of Additive Manufacturing (AM) parts and the HALT process (relates to accelerated life testing). The visitors will be a small group of Japanese citizens. Goddard Space Flight Center (GSFC) has been asked to participate in the meeting, either in person or via teleconference. This presentation covers NDE efforts at GSFC and provides a cursory overview of AM and lab capabilities.

  16. Computed tomography for non-destructive evaluation of composites: Applications and correlations

    NASA Technical Reports Server (NTRS)

    Goldberg, B.; Hediger, L.; Noel, E.

    1985-01-01

    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-ray radiography (RT), and ultrasonic scanning (UT) are investigated and compared to determine their applicability and limitations to graphite epoxy, carbon-carbon, and carbon-phenolic materials. While the techniques appear complementary, CT is shown to provide significant, heretofore unattainable data. Finally, a correlation of NDE techniques to destructive analysis is presented.

  17. Non-destructive terahertz imaging of illicit drugs using spectral fingerprints

    NASA Astrophysics Data System (ADS)

    Kawase, Kodo; Ogawa, Yuichi; Watanabe, Yuuki; Inoue, Hiroyuki

    2003-10-01

    The absence of non-destructive inspection techniques for illicit drugs hidden in mail envelopes has resulted in such drugs being smuggled across international borders freely. We have developed a novel basic technology for terahertz imaging, which allows detection and identification of drugs concealed in envelopes, by introducing the component spatial pattern analysis. The spatial distributions of the targets are obtained from terahertz multispectral transillumination images, using absorption spectra measured with a tunable terahertz-wave source. The samples we used were methamphetamine and MDMA, two of the most widely consumed illegal drugs in Japan, and aspirin as a reference.

  18. [NIR spectrometer for non-destruction measurement of oil contents in a corn seed].

    PubMed

    Cui, Zhi-li; Xie, Jin-chun; Wang, Nan; Pan, Ling-ling; Song, Tong-ming; Zhang, Ye-hui; Xu, Xiao-jie

    2005-11-01

    NIR spectromneter for non-destruction measurement of oil contents in an integrated kernel of corn was manufactured. Using LED (light emitting diode) as the light source and six filters as the monochromator, the specifications of the instrument are compared with those of the commercial instruments. The regression coefficient, the standard error, and the relative error of measuring oil contents in an integrated kernel of corn are 0.9688, 0.72 and 0.062 respectively. The results meet the demand of high-oil corn breeding.

  19. Methods for Non-destructive Temperature Measurements in a Magneto-Optical Trap

    NASA Astrophysics Data System (ADS)

    Narducci, Frank A.; Duncan, Dwight; White, Grady R.; Lough, James; Davis, Jon P.

    2009-05-01

    Certain practical applications for precision measurements by atom interferometers require knowledge of the input atom cloud's temperature from realization to realization. Recent work [1,2] has shown how to measure the temperature of atoms in a magneto-optical trap in a non-destructive, in situ manner. We discuss an alternate, simpler method for the nondestructive measurement of the temperature of an atom cloud and compare our method with earlier techniques. [4pt] [1] T. Brzozowski, M. Brzozowska, J. Zachorowski, M. Zawada, W. Gawlik, PRA, 71, 013401 (2005).[0pt] [2] M. Brzozowska, T. Brzozowski J. Zachorowski, W. Gawlik, PRA, 72, 061401(R), (2005).

  20. Non-destructive qualification tests for ITER cryogenic axial insulating breaks

    SciTech Connect

    Kosek, Jacek; Lopez, Roberto; Tommasini, Davide; Rodriguez-Mateos, Felix

    2014-01-29

    In the ITER superconducting magnets the dielectric separation between the CICC (Cable-In-Conduit Conductors) and the helium supply pipes is made through the so-called insulating breaks (IB). These devices shall provide the required dielectric insulation at a 30 kV level under different types of stresses and constraints: thermal, mechanical, dielectric and ionizing radiations. As part of the R and D program, the ITER Organization launched contracts with industrial companies aimed at the qualification of the manufacturing techniques. After reviewing the main functional aspects, this paper describes and discusses the protocol established for non-destructive qualification tests of the prototypes.

  1. The development of non destructive remote measurement method of concrete contamination

    SciTech Connect

    Stepanov, V E; Potapov, V N; Ivanov, O P

    2013-07-01

    In the frame of the decommissioning of nuclear power plants or laboratories, the penetration depth of the contamination in concrete surfaces: walls, floor, is unknown. Its knowledge requires sample analysis, that is time consuming and expensive. The main goal of the work is to define and evaluate a non-destructive measurement technique for the evaluation of the contamination depth in concrete. Estimation of accuracy of measurements for different contamination levels, time of measurement, value of natural radionuclides (NRN) concentration in concrete and background radiation dose were carried out. The type of relevant detector depends of selected limiting sensitivity, the weight and sizes of the device. (authors)

  2. Delayed Gamma-ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    SciTech Connect

    Mozin, Vladimir; Ludewigt, Bernhard; Campbell, Luke; Favalli, Andrea; Hunt, Alan

    2014-10-09

    This project addresses the need for improved non-destructive assay techniques for quantifying the actinide composition of spent nuclear fuel and for the independent verification of declared quantities of special nuclear materials at key stages of the fuel cycle. High-energy delayed gamma-ray spectroscopy following neutron irradiation is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Other potential applications include determination of MOX fuel composition, characterization of nuclear waste packages, and challenges in homeland security and arms control verification.

  3. Non-destructive testing of biaxial stress state in ferromagnetic materials

    NASA Astrophysics Data System (ADS)

    Vengrinovich, V. L.; Vintov, D. A.; Dmitrovich, D. V.

    2014-02-01

    The technique for biaxial stress state quantitative non destructive testing using magnetic, namely Barkhausen Noise, measurements is developed and checked experimentally. The main elaboration concerns the application of uni-axial calibration data for bi-axial stress measurement in the material which treatment pre-history is not definitely known. The article is aimed to get over difficulties, accompanying factual nondestructive stress evaluation, implied from its tensor nature. The developed technique of stress calibration and measurement assumes the bi-axial stress components recovery from uni-axial magnetic and Barkhausen noise measurement results. The complete technology, based on new calibration procedure with grid diagrams is considered in the article.

  4. Fast Non-Destructive Evaluation of Superconducting Magnet Wires using a Flow-Through SQUID Microscope

    NASA Astrophysics Data System (ADS)

    Matthews, John; Wellstood, Frederick; Weinstock, Harold

    2006-03-01

    We have developed a cryocooled high-Tc SQUID microscope for fast non-destructive evaluation (NDE) of long wires, designed for detecting defects in superconducting magnet wire. A feedthrough mechanism pulls the wire at speeds of up to 20 cm/s through a thin mylar tube that separates the room temperature wire from the SQUID. We present results on test wires where we detect defects down to about 0.3 mm diameter. We discuss how we extract information from the data, such as defect size and location, and also outline a method for fast automated detection of defects in long wires.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

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

  6. Non-Destructive Evaluation Method and Apparatus for Measuring Acoustic Material Nonlinearity

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    An acoustic non-linearity parameter (beta) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members obviates the need for electronic calibration of the measuring equipment. Unlike known substitutional measuring techniques requiring elaborate calibration procedures, the electrical outputs of the capacitive detector of a sample with known beta and the test sample of unknown beta are compared to determine the unknown beta. In order to provide the necessary stability of the present-inventive reference-based approach, the bandpass filters of the measurement system are maintained in a temperature-controlled environment, and the line voltage supplied to said amplifiers is well-regulated.

  7. Application of magnetic resonance imaging to non-destructive void detection in watermelon

    NASA Astrophysics Data System (ADS)

    Saito, K.; Miki, T.; Hayashi, S.; Kajikawa, H.; Shimada, M.; Kawate, Y.; Nishizawa, T.; Ikegaya, D.; Kimura, N.; Takabatake, K.; Sugiura, N.; Suzuki, M.

    A novel application of magnetic resonance imaging (MRI) is described. The possibility of utilizing MRI for non-destructive quality evaluation of watermelons was studied. In this study, we applied MRI to the detection of internal voids in watermelons. In order to increase the measurement rate, we employed a one-dimensional projection profile method instead of observing a two-dimensional cross-sectional image. The void detection was carried out with this technique over 30 samples and 28 samples were correctly evaluated. The measurement rate was 900 ms per sample, which is an acceptable speed for a sorting machine in the agricultural field.

  8. Non-destructive Testing by Infrared Thermography Under Random Excitation and ARMA Analysis

    NASA Astrophysics Data System (ADS)

    Bodnar, J. L.; Nicolas, J. L.; Candoré, J. C.; Detalle, V.

    2012-11-01

    Photothermal thermography is a non-destructive testing (NDT) method, which has many applications in the field of control and characterization of thin materials. This technique is usually implemented under CW or flash excitation. Such excitations are not adapted for control of fragile materials or for multi-frequency analysis. To allow these analyses, in this article, the use of a new control mode is proposed: infrared thermography under random excitation and auto regressive moving average analysis. First, the principle of this NDT method is presented. Then, the method is shown to permit detection, with low energy constraints, of detachments situated in mural paintings.

  9. Minimizing Air Pollution Exposure: A Practical Policy to Protect Vulnerable Older Adults from Death and Disability

    PubMed Central

    Woodward, Nick; Levine, Morgan

    2015-01-01

    Air pollution causes an estimated 200,000 deaths per year in the United States alone. Older adults are at greater risk of mortality caused by air pollution. Here we quantify the number of older adult facilities in Los Angeles County that are exposed to high levels of traffic derived air pollution, and propose policy solutions to reduce pollution exposure to this vulnerable subgroup. Distances between 20,362 intersections and 858 elder care facilities were estimated, and roads or highways within 500 of facilities were used to estimate traffic volume exposure. Of the 858 facilities, 54 were located near at least one major roadway, defined as a traffic volume over 100,000 cars/day. These 54 facilities house approximately 6,000 older adults. Following standards established for schools, we recommend legislation mandating the placement of new elder care facilities a minimum of 500 feet from major roadways in order to reduce unnecessary mortality risk from pollution exposure. PMID:26640413

  10. Rapid microRNA changes in airways of human volunteers after controlled exposure to air pollutants

    EPA Science Inventory

    Introduction/Rationale: Exposure to air pollutants, including ozone and diesel exhaust (DE) are known to cause acute cardiopulmonary dysfunction; however, the molecular mechanisms underlying these changes remain elusive. One mechanism for rapid regulation of multiple genes is a...

  11. Prenatal Exposure to Air Pollutants Raises Risk of ADHD-Related Problems in Childhood

    EPA Pesticide Factsheets

    Researchers at the EPA/NIEHS Columbia Center for Children’s Environmental Health found that prenatal exposure to air pollutants can increase the risk of behavioral problems related to attention deficit hyperactivity disorder (ADHD) in children.

  12. Vascular function and short-term exposure to fine particulate air pollution.

    PubMed

    Pope, C Arden; Hansen, Jaron C; Kuprov, Roman; Sanders, Matthew D; Anderson, Michael N; Eatough, Delbert J

    2011-08-01

    Exposure to fine particulate air pollution has been implicated as a risk factor for cardiopulmonary disease and mortality. Proposed biological pathways imply that particle-induced pulmonary and systemic inflammation play a role in activating the vascular endothelium and altering vascular function. Potential effects of fine particulate pollution on vascular function are explored using controlled chamber exposure and uncontrolled ambient exposure. Research subjects included four panels with a total of 26 healthy nonsmoking young adults. On two study visits, at least 7 days apart, subjects spent 3 hr in a controlled-exposure chamber exposed to 150-200 microg/m3 of fine particles generated from coal or wood combustion and 3 hr in a clean room, with exposure and nonexposure periods alternated between visits. Baseline, postexposure, and post-clean room reactive hyperemia-peripheral arterial tonometry (RH-PAT) was conducted. A microvascular responsiveness index, defined as the log of the RH-PAT ratio, was calculated. There was no contemporaneous vascular response to the few hours of controlled exposure. Declines in vascular response were associated with elevated ambient exposures for the previous 2 days, especially for female subjects. Cumulative exposure to real-life fine particulate pollution may affect vascular function. More research is needed to determine the roles of age and gender, the effect of pollution sources, the importance of cumulative exposure over a few days versus a few hours, and the lag time between exposure and response.

  13. PREFACE: III All-Russian Scientific and Practical Conference on Innovations in Non-Destructive Testing (SibTest 2015)

    NASA Astrophysics Data System (ADS)

    2016-01-01

    This issue of the journal is devoted to the research and studies presented at the III All-Russian Scientific and Practical Conference on Innovations in Non-Destructive Testing SibTest. The conference was held in Altai, Russia, on 27-31 July 2015. The conference brought together experts from different countries and organizations who had a great opportunity to share knowledge during oral and poster presentations and to initiate discussions on topics that are of interest to the conference attendees. The conference aimed to discuss innovative methods and the application of advanced technologies in non-destructive testing. The conference also attempted to bring together university, academic and industrial science, to expand the co-operation of scientists from different countries in research and development and the commercialization of innovative technologies in non-destructive testing. The key themes of the conference were: ultrasonic and acoustic testing; electromagnetic and thermal testing; various types of radiation non-destructive testing; passive and active testing techniques. The conference organizers are the Institute of Non-Destructive Testing, Tomsk Polytechnic University, with the assistance of the Russian Society for Non-Destructive Testing and Technical Diagnostics, Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, National Research Tomsk State University, Moscow State Institute of Radio Engineering, Electronics and Automation.

  14. Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy.

    PubMed

    Ammann, Dominic; Becker, Roland; Kohl, Anka; Hänisch, Jessica; Nehls, Irene

    2014-11-01

    The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000-1100 cm(-1) indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm(-1) associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples.

  15. A Behavioral Intervention to Reduce Child Exposure to Indoor Air Pollution: Identifying Possible Target Behaviors

    ERIC Educational Resources Information Center

    Barnes, Brendon R.; Mathee, Angela; Shafritz, Lonna B.; Krieger, Laurie; Zimicki, Susan

    2004-01-01

    Indoor air pollution has been causally linked to acute lower respiratory infections in children younger than 5. The aim of this study was to identify target behaviors for a behavioral intervention to reduce child exposure to indoor air pollution by attempting to answer two research questions: Which behaviors are protective of child respiratory…

  16. CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP): AN OVERVIEW

    EPA Science Inventory

    Young children may have greater exposures to pollutants in their everyday environments than do adults. Because of their immaturity, rapid development, and smaller body masses, children may also be more susceptible to the effects of these pollutants. Recent federal health init...

  17. "Development of Model-Based Air Pollution Exposure Metrics for use in Epidemiologic Studies"

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  18. DEVELOPMENT OF MODEL-BASED AIR POLLUTION EXPOSURE METRICS FOR USE IN EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  19. EXPOSURE TO PARTICULATE MATTER, VOLATILE ORGANIC COMPOUNDS, AND OTHER AIR POLLUTANTS INSIDE PATROL CARS

    EPA Science Inventory

    People driving in a vehicle might receive an enhanced dose of mobile source pollutants that are considered a potential risk for cardiovascular diseases. The exposure to components of air pollution in highway patrol vehicles, at an ambient, and a roadside location was determined d...

  20. Exposure to Air Pollution Enhances the Generation of Vascular Microparticles

    EPA Science Inventory

    Epidemiological studies associate exposure to ambient levels of particulate matter (PM) with cardiovascular morbidity and mortality. The biological mechanisms by which PM exposure induces cardiovascular effects remain to be elucidated. One important limitation is the lack of sens...

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  2. Non-destructive on-chip cell sorting system with real-time microscopic image processing.

    PubMed

    Takahashi, Kazunori; Hattori, Akihiro; Suzuki, Ikurou; Ichiki, Takanori; Yasuda, Kenji

    2004-06-03

    Studying cell functions for cellomics studies often requires the use of purified individual cells from mixtures of various kinds of cells. We have developed a new non-destructive on-chip cell sorting system for single cell based cultivation, by exploiting the advantage of microfluidics and electrostatic force. The system consists of the following two parts: a cell sorting chip made of poly-dimethylsiloxane (PDMS) on a 0.2-mm-thick glass slide, and an image analysis system with a phase-contrast/fluorescence microscope. The unique features of our system include (i) identification of a target from sample cells is achieved by comparison of the 0.2-microm-resolution phase-contrast and fluorescence images of cells in the microchannel every 1/30 s; (ii) non-destructive sorting of target cells in a laminar flow by application of electrostatic repulsion force for removing unrequited cells from the one laminar flow to the other; (iii) the use of agar gel for electrodes in order to minimize the effect on cells by electrochemical reactions of electrodes, and (iv) pre-filter, which was fabricated within the channel for removal of dust contained in a sample solution from tissue extracts. The sorting chip is capable of continuous operation and we have purified more than ten thousand cells for cultivation without damaging them. Our design has proved to be very efficient and suitable for the routine use in cell purification experiments.

  3. Non destructive examination of UN / U-Si fuel pellets using neutrons (preliminary assessment)

    SciTech Connect

    Bourke, Mark Andrew; Vogel, Sven C.; Voit, Stewart Lancaster; Mcclellan, Kenneth James; Losko, Adrian S.; Tremsin, Anton

    2016-03-31

    Tomographic imaging and diffraction measurements were performed on nine pellets; four UN/ U Si composite formulations (two enrichment levels), three pure U3Si5 reference formulations (two enrichment levels) and two reject pellets with visible flaws (to qualify the technique). The U-235 enrichments ranged from 0.2 to 8.8 wt.%. The nitride/silicide composites are candidate compositions for use as Accident Tolerant Fuel (ATF). The monophase U3Si5 material was included as a reference. Pellets from the same fabrication batches will be inserted in the Advanced Test Reactor at Idaho during 2016. The goal of the Advanced Non-destructive Fuel Examination work package is the development and application of non-destructive neutron imaging and scattering techniques to ceramic and metallic nuclear fuels. Data reported in this report were collected in the LANSCE run cycle that started in September 2015 and ended in March 2016. Data analysis is ongoing; thus, this report provides a preliminary review of the measurements and provides an overview of the characterized samples.

  4. Study of concrete drilling for automated non-destructive evaluation and rehabilitation system for bridge decks

    NASA Astrophysics Data System (ADS)

    Trkov, Mitja; Liu, Fei; Yi, Jingang; Baruh, Haim

    2011-04-01

    Robotic drilling is the basic process for the non-destructive rehabilitation (NDR) system in the Automated Non-destructive Evaluation and Rehabilitation System (ANDERS) for bridge decks. In this paper, we present a study and testing of a concrete drilling process that is used for robotic drilling process for bridge decks repair. We first review the ANDERS and NDR design. Then we present the experimental setup for the drilling process study. A set of testing experiments are performed considering drilling process parameters such as drill bit size, drill rotating speed, drill thrust force and types of concrete composites. Based on the experiments and analysis, we identify and find that the optimal set of drilling process parameters for the ANDERS application is 1/4-inch bit size, drill rotational speed of 1500 rpm and thrust force around 35 lbs. We also demonstrate that the monitoring of drill feeding displacement and thrust force cannot be used to detect and identify the cracks in bridge decks.

  5. Non-invasive and non-destructive measurements of confluence in cultured adherent cell lines

    PubMed Central

    Busschots, Steven; O’Toole, Sharon; O’Leary, John J.; Stordal, Britta

    2014-01-01

    Many protocols used for measuring the growth of adherent monolayer cells in vitro are invasive, destructive and do not allow for the continued, undisturbed growth of cells within flasks. Protocols often use indirect methods for measuring proliferation. Microscopy techniques can analyse cell proliferation in a non-invasive or non-destructive manner but often use expensive equipment and software algorithms. In this method images of cells within flasks are captured by photographing under a standard inverted phase contract light microscope using a digital camera with a camera lens adaptor. Images are analysed for confluence using ImageJ freeware resulting in a measure of confluence known as an Area Fraction (AF) output. An example of the AF method in use on OVCAR8 and UPN251 cell lines is included. • Measurements of confluence from growing adherent cell lines in cell culture flasks is obtained in a non-invasive, non-destructive, label-free manner. • The technique is quick, affordable and eliminates sample manipulation. • The technique provides an objective, consistent measure of when cells reach confluence and is highly correlated to manual counting with a haemocytometer. The average correlation co-efficient from a Spearman correlation (n = 3) was 0.99 ± 0.008 for OVCAR8 (p = 0.01) and 0.99 ± 0.01 for UPN251 (p = 0.01) cell lines. PMID:26150966

  6. Non-destructive sampling of rock-dwelling microbial communities using sterile adhesive tape.

    PubMed

    Cutler, Nick A; Oliver, Anna E; Viles, Heather A; Whiteley, Andrew S

    2012-12-01

    Building stone provides a habitat for an array of microorganisms, many of which have been demonstrated to have a deleterious effect on the appearance and/or structural integrity of stone masonry. It is essential to understand the composition and structure of stone-dwelling (lithobiontic) microbial communities if successful stone conservation strategies are to be applied, particularly in the face of global environmental change. Ideally, the techniques used to sample such assemblages should be non-destructive due to the sensitive conservation status of many stone buildings. This paper quantitatively assesses the performance of sterile adhesive tape as a non-destructive sampling technique and compares the results of tape sampling with an alternative, destructive, sampling method. We used DNA fingerprinting (TRFLP) to characterise the algal, fungal and bacterial communities living on a stone slab. Our results demonstrate that tape sampling may be used to collect viable quantities of microbial DNA from environmental samples. This technique is ideally suited to the sampling of microbial biofilms, particularly when these communities are dominated by green algae. It provides a good approximation of total community diversity (i.e. the aggregate diversity of epilithic and endolithic communities). Tape sampling is straightforward, rapid and cost effective. When combined with molecular analytical techniques, this sampling method has the potential to make a major contribution to efforts to understand the structure of lithobiontic microbial communities and our ability to predict the response of such communities to future environmental change.

  7. Non-destructive forensic latent fingerprint acquisition with chromatic white light sensors

    NASA Astrophysics Data System (ADS)

    Leich, Marcus; Kiltz, Stefan; Dittmann, Jana; Vielhauer, Claus

    2011-02-01

    Non-destructive latent fingerprint acquisition is an emerging field of research, which, unlike traditional methods, makes latent fingerprints available for additional verification or further analysis like tests for substance abuse or age estimation. In this paper a series of tests is performed to investigate the overall suitability of a high resolution off-the-shelf chromatic white light sensor for the contact-less and non-destructive latent fingerprint acquisition. Our paper focuses on scanning previously determined regions with exemplary acquisition parameter settings. 3D height field and reflection data of five different latent fingerprints on six different types of surfaces (HDD platter, brushed metal, painted car body (metallic and non-metallic finish), blued metal, veneered plywood) are experimentally studied. Pre-processing is performed by removing low-frequency gradients. The quality of the results is assessed subjectively; no automated feature extraction is performed. Additionally, the degradation of the fingerprint during the acquisition period is observed. While the quality of the acquired data is highly dependent on surface structure, the sensor is capable of detecting the fingerprint on all sample surfaces. On blued metal the residual material is detected; however, the ridge line structure dissolves within minutes after fingerprint placement.

  8. Non-destructive measurement of soil liquefaction density change by crosshole radar tomography, Treasure Island, California

    USGS Publications Warehouse

    Kayen, Robert E.; Barnhardt, Walter A.; Ashford, Scott; Rollins, Kyle

    2000-01-01

    A ground penetrating radar (GPR) experiment at the Treasure Island Test Site [TILT] was performed to non-destructively image the soil column for changes in density prior to, and following, a liquefaction event. The intervening liquefaction was achieved by controlled blasting. A geotechnical borehole radar technique was used to acquire high-resolution 2-D radar velocity data. This method of non-destructive site characterization uses radar trans-illumination surveys through the soil column and tomographic data manipulation techniques to construct radar velocity tomograms, from which averaged void ratios can be derived at 0.25 - 0.5m pixel footprints. Tomograms of void ratio were constructed through the relation between soil porosity and dielectric constant. Both pre- and post-blast tomograms were collected and indicate that liquefaction related densification occurred at the site. Volumetric strains estimated from the tomograms correlate well with the observed settlement at the site. The 2-D imagery of void ratio can serve as high-resolution data layers for numerical site response analysis.

  9. Non-destructive high-throughput DNA extraction and genotyping methods for cotton seeds and seedlings.

    PubMed

    Zheng, Xiuting; Hoegenauer, Kevin A; Maeda, Andrea B V; Wang, Fei; Stelly, David M; Nichols, Robert L; Jones, Don C

    2015-05-01

    Extensive use of targeted PCR-based genotyping is precluded for many plant research laboratories by the cost and time required for DNA extraction. Using cotton (Gossypium hirsutum) as a model for plants with medium-sized seeds, we report here manual procedures for inexpensive non-destructive high-throughput extraction of DNA suitable for PCR-based genotyping of large numbers of individual seeds and seedlings. By sampling only small amounts of cotyledon tissue of ungerminated seed or young seedlings, damage is minimized, and viability is not discernibly affected. The yield of DNA from each seed or seedling is typically sufficient for 1000 or 500 PCR reactions, respectively. For seeds, the tissue sampling procedure relies on a modified 96-well plate that is used subsequently for seed storage. For seeds and seedlings, the DNA is extracted in a strongly basic DNA buffer that is later neutralized and diluted. Extracts can be used directly for high-throughput PCR-based genotyping. Any laboratory can thus extract DNA from thousands of individual seeds/seedlings per person-day at a very modest cost for consumables (~$0.05 per sample). Being non-destructive, our approach enables a wide variety of time- and resource-saving applications, such as marker-assisted selection (MAS), before planting, transplanting, and flowering.

  10. Early non-destructive biofouling detection and spatial distribution: Application of oxygen sensing optodes.

    PubMed

    Farhat, N M; Staal, M; Siddiqui, A; Borisov, S M; Bucs, Sz S; Vrouwenvelder, J S

    2015-10-15

    Biofouling is a serious problem in reverse osmosis/nanofiltration (RO/NF) applications, reducing membrane performance. Early detection of biofouling plays an essential role in an adequate anti-biofouling strategy. Presently, fouling of membrane filtration systems is mainly determined by measuring changes in pressure drop, which is not exclusively linked to biofouling. Non-destructive imaging of oxygen concentrations (i) is specific for biological activity of biofilms and (ii) may enable earlier detection of biofilm accumulation than pressure drop. The objective of this study was to test whether transparent luminescent planar O2 optodes, in combination with a simple imaging system, can be used for early non-destructive biofouling detection. This biofouling detection is done by mapping the two-dimensional distribution of O2 concentrations and O2 decrease rates inside a membrane fouling simulator (MFS). Results show that at an early stage, biofouling development was detected by the oxygen sensing optodes while no significant increase in pressure drop was yet observed. Additionally, optodes could detect spatial heterogeneities in biofouling distribution at a micro scale. Biofilm development started mainly at the feed spacer crossings. The spatial and quantitative information on biological activity will lead to better understanding of the biofouling processes, contributing to the development of more effective biofouling control strategies.

  11. Compressive strength evaluation of structural lightweight concrete by non-destructive ultrasonic pulse velocity method.

    PubMed

    Bogas, J Alexandre; Gomes, M Glória; Gomes, Augusto

    2013-07-01

    In this paper the compressive strength of a wide range of structural lightweight aggregate concrete mixes is evaluated by the non-destructive ultrasonic pulse velocity method. This study involves about 84 different compositions tested between 3 and 180 days for compressive strengths ranging from about 30 to 80 MPa. The influence of several factors on the relation between the ultrasonic pulse velocity and compressive strength is examined. These factors include the cement type and content, amount of water, type of admixture, initial wetting conditions, type and volume of aggregate and the partial replacement of normal weight coarse and fine aggregates by lightweight aggregates. It is found that lightweight and normal weight concretes are affected differently by mix design parameters. In addition, the prediction of the concrete's compressive strength by means of the non-destructive ultrasonic pulse velocity test is studied. Based on the dependence of the ultrasonic pulse velocity on the density and elasticity of concrete, a simplified expression is proposed to estimate the compressive strength, regardless the type of concrete and its composition. More than 200 results for different types of aggregates and concrete compositions were analyzed and high correlation coefficients were obtained.

  12. Non-destructive detection of pesticide residues in cucumber using visible/near-infrared spectroscopy.

    PubMed

    Jamshidi, Bahareh; Mohajerani, Ezeddin; Jamshidi, Jamshid; Minaei, Saeid; Sharifi, Ahmad

    2015-01-01

    The feasibility of using visible/near-infrared (Vis/NIR) spectroscopy was assessed for non-destructive detection of diazinon residues in intact cucumbers. Vis/NIR spectra of diazinon solution and cucumber samples without and with different concentrations of diazinon residue were analysed at the range of 450-1000 nm. Partial least squares-discriminant analysis (PLS-DA) models were developed based on different spectral pre-processing techniques to classify cucumbers with contents of diazinon below and above the MRL as safe and unsafe samples, respectively. The best model was obtained using a first-derivative method with the lowest standard error of cross-validation (SECV = 0.366). Moreover, total percentages of correctly classified samples in calibration and prediction sets were 97.5% and 92.31%, respectively. It was concluded that Vis/NIR spectroscopy could be an appropriate, fast and non-destructive technology for safety control of intact cucumbers by the absence/presence of diazinon residues.

  13. Non-invasive and non-destructive measurements of confluence in cultured adherent cell lines.

    PubMed

    Busschots, Steven; O'Toole, Sharon; O'Leary, John J; Stordal, Britta

    2015-01-01

    Many protocols used for measuring the growth of adherent monolayer cells in vitro are invasive, destructive and do not allow for the continued, undisturbed growth of cells within flasks. Protocols often use indirect methods for measuring proliferation. Microscopy techniques can analyse cell proliferation in a non-invasive or non-destructive manner but often use expensive equipment and software algorithms. In this method images of cells within flasks are captured by photographing under a standard inverted phase contract light microscope using a digital camera with a camera lens adaptor. Images are analysed for confluence using ImageJ freeware resulting in a measure of confluence known as an Area Fraction (AF) output. An example of the AF method in use on OVCAR8 and UPN251 cell lines is included. •Measurements of confluence from growing adherent cell lines in cell culture flasks is obtained in a non-invasive, non-destructive, label-free manner.•The technique is quick, affordable and eliminates sample manipulation.•The technique provides an objective, consistent measure of when cells reach confluence and is highly correlated to manual counting with a haemocytometer. The average correlation co-efficient from a Spearman correlation (n = 3) was 0.99 ± 0.008 for OVCAR8 (p = 0.01) and 0.99 ± 0.01 for UPN251 (p = 0.01) cell lines.

  14. Processes for non-destructive transfer of graphene: widening the bottleneck for industrial scale production.

    PubMed

    Zaretski, Aliaksandr V; Lipomi, Darren J

    2015-06-14

    The exceptional charge-transport, mechanical, and barrier properties of graphene are well known. High-quality films of single-layer graphene produced over large areas, however, are extremely expensive. The high cost of graphene precludes its use in industries-such as transparent electrodes and flexible packaging-that might take full advantage of its properties. This minireview presents several strategies for the transfer of graphene from the substrates used for growth to substrates used for the final application. Each strategy shares the characteristic of being non-destructive: that is, the growth substrate remains reusable for further synthesis of new graphene. These processes have the potential to lower significantly the costs of manufacturing graphene, to increase production yields, and to minimize environmental impact. This article is divided into sections on (i) the synthesis of high-quality single-layer graphene and (ii) its non-destructive transfer to a host substrate. Section (ii) is further divided according to the substrate from which graphene is transferred: single-crystalline wafers or flexible copper foils. We also comment, wherever possible, on defects produced as a result of the transfer, and potential strategies to mitigate these defects. We conclude that several methods for the green synthesis and transfer of graphene have several of the right characteristics to be useful in industrial scale production.

  15. A Spatially Offset Raman Spectroscopy Method for Non-Destructive Detection of Gelatin-Encapsulated Powders.

    PubMed

    Chao, Kuanglin; Dhakal, Sagar; Qin, Jianwei; Peng, Yankun; Schmidt, Walter F; Kim, Moon S; Chan, Diane E

    2017-03-18

    Non-destructive subsurface detection of encapsulated, coated, or seal-packaged foods and pharmaceuticals can help prevent distribution and consumption of counterfeit or hazardous products. This study used a Spatially Offset Raman Spectroscopy (SORS) method to detect and identify urea, ibuprofen, and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785-nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. As the offset distance was increased, the spectral contribution from the subsurface powder gradually outweighed that of the surface capsule layers, allowing for detection of the encapsulated powders. Containing mixed contributions from the powder and capsule, the SORS spectra for each sample were resolved into pure component spectra using self-modeling mixture analysis (SMA) and the corresponding components were identified using spectral information divergence values. As demonstrated here for detecting chemicals contained inside thick capsule layers, this SORS measurement technique coupled with SMA has the potential to be a reliable non-destructive method for subsurface inspection and authentication of foods, health supplements, and pharmaceutical products that are prepared or packaged with semi-transparent materials.

  16. Non-destructive Testing of Forged Metallic Materials by Active Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Maillard, S.; Cadith, J.; Bouteille, P.; Legros, G.; Bodnar, J. L.; Detalle, V.

    2012-11-01

    Nowadays, infrared thermography is considered as the reference method in many applications such as safety, the inspection of electric installations, or the inspection of buildings' heat insulation. In recent years, the evolution of both material and data-processing tools also allows the development of thermography as a real non-destructive testing method. Thus, by subjecting the element to be inspected to an external excitation and by analyzing the propagation of heat in the examined zone, it is possible to highlight surface or subsurface defects such as cracks, delaminations, or corrosion. One speaks then about active infrared thermography. In this study, some results obtained during the collective studies carried out by CETIM and the University of Reims for the forging industry are presented. Various experimental possibilities offered by active thermography are presented and the interest in this method in comparison with the traditional non-destructive testing methods (penetrant testing and magnetic particle inspection) is discussed. For example, comparative results on a forged cracked hub, a steering joint, and a threaded rod are presented. They highlight the interest of infrared thermography stimulated by induction for forged parts.

  17. Non-destructive inspection in industrial equipment using robotic mobile manipulation

    NASA Astrophysics Data System (ADS)

    Maurtua, Iñaki; Susperregi, Loreto; Ansuategui, Ander; Fernández, Ane; Ibarguren, Aitor; Molina, Jorge; Tubio, Carlos; Villasante, Cristobal; Felsch, Torsten; Pérez, Carmen; Rodriguez, Jorge R.; Ghrissi, Meftah

    2016-05-01

    MAINBOT project has developed service robots based applications to autonomously execute inspection tasks in extensive industrial plants in equipment that is arranged horizontally (using ground robots) or vertically (climbing robots). The industrial objective has been to provide a means to help measuring several physical parameters in multiple points by autonomous robots, able to navigate and climb structures, handling non-destructive testing sensors. MAINBOT has validated the solutions in two solar thermal plants (cylindrical-parabolic collectors and central tower), that are very demanding from mobile manipulation point of view mainly due to the extension (e.g. a thermal solar plant of 50Mw, with 400 hectares, 400.000 mirrors, 180 km of absorber tubes, 140m height tower), the variability of conditions (outdoor, day-night), safety requirements, etc. Once the technology was validated in simulation, the system was deployed in real setups and different validation tests carried out. In this paper two of the achievements related with the ground mobile inspection system are presented: (1) Autonomous navigation localization and planning algorithms to manage navigation in huge extensions and (2) Non-Destructive Inspection operations: thermography based detection algorithms to provide automatic inspection abilities to the robots.

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

    SciTech Connect

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

    2010-11-18

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

  19. A Spatially Offset Raman Spectroscopy Method for Non-Destructive Detection of Gelatin-Encapsulated Powders

    PubMed Central

    Chao, Kuanglin; Dhakal, Sagar; Qin, Jianwei; Peng, Yankun; Schmidt, Walter F.; Kim, Moon S.; Chan, Diane E.

    2017-01-01

    Non-destructive subsurface detection of encapsulated, coated, or seal-packaged foods and pharmaceuticals can help prevent distribution and consumption of counterfeit or hazardous products. This study used a Spatially Offset Raman Spectroscopy (SORS) method to detect and identify urea, ibuprofen, and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785-nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. As the offset distance was increased, the spectral contribution from the subsurface powder gradually outweighed that of the surface capsule layers, allowing for detection of the encapsulated powders. Containing mixed contributions from the powder and capsule, the SORS spectra for each sample were resolved into pure component spectra using self-modeling mixture analysis (SMA) and the corresponding components were identified using spectral information divergence values. As demonstrated here for detecting chemicals contained inside thick capsule layers, this SORS measurement technique coupled with SMA has the potential to be a reliable non-destructive method for subsurface inspection and authentication of foods, health supplements, and pharmaceutical products that are prepared or packaged with semi-transparent materials. PMID:28335453

  20. Non-destructive 3D shape measurement of transparent and black objects with thermal fringes

    NASA Astrophysics Data System (ADS)

    Brahm, Anika; Rößler, Conrad; Dietrich, Patrick; Heist, Stefan; Kühmstedt, Peter; Notni, Gunther

    2016-05-01

    Fringe projection is a well-established optical method for the non-destructive contactless three-dimensional (3D) measurement of object surfaces. Typically, fringe sequences in the visible wavelength range (VIS) are projected onto the surfaces of objects to be measured and are observed by two cameras in a stereo vision setup. The reconstruction is done by finding corresponding pixels in both cameras followed by triangulation. Problems can occur if the properties of some materials disturb the measurements. If the objects are transparent, translucent, reflective, or strongly absorbing in the VIS range, the projected patterns cannot be recorded properly. To overcome these challenges, we present a new alternative approach in the infrared (IR) region of the electromagnetic spectrum. For this purpose, two long-wavelength infrared (LWIR) cameras (7.5 - 13 μm) are used to detect the emitted heat radiation from surfaces which is induced by a pattern projection unit driven by a CO2 laser (10.6 μm). Thus, materials like glass or black objects, e.g. carbon fiber materials, can be measured non-destructively without the need of any additional paintings. We will demonstrate the basic principles of this heat pattern approach and show two types of 3D systems based on a freeform mirror and a GOBO wheel (GOes Before Optics) projector unit.

  1. A Distributive, Non-Destructive, Real-Time Approach to Snowpack Monitoring

    NASA Technical Reports Server (NTRS)

    Frolik, Jeff; Skalka, Christian

    2012-01-01

    This invention is designed to ascertain the snow water equivalence (SWE) of snowpacks with better spatial and temporal resolutions than present techniques. The approach is ground-based, as opposed to some techniques that are air-based. In addition, the approach is compact, non-destructive, and can be communicated with remotely, and thus can be deployed in areas not possible with current methods. Presently there are two principal ground-based techniques for obtaining SWE measurements. The first is manual snow core measurements of the snowpack. This approach is labor-intensive, destructive, and has poor temporal resolution. The second approach is to deploy a large (e.g., 3x3 m) snowpillow, which requires significant infrastructure, is potentially hazardous [uses a approximately equal to 200-gallon (approximately equal to 760-L) antifreeze-filled bladder], and requires deployment in a large, flat area. High deployment costs necessitate few installations, thus yielding poor spatial resolution of data. Both approaches have limited usefulness in complex and/or avalanche-prone terrains. This approach is compact, non-destructive to the snowpack, provides high temporal resolution data, and due to potential low cost, can be deployed with high spatial resolution. The invention consists of three primary components: a robust wireless network and computing platform designed for harsh climates, new SWE sensing strategies, and algorithms for smart sampling, data logging, and SWE computation.

  2. Non-destructive analysis for the investigation of decomposition phenomena of historical manuscripts and prints

    NASA Astrophysics Data System (ADS)

    Faubel, Werner; Staub, Susanne; Simon, Rolf; Heissler, Stefan; Pataki, Andrea; Banik, Gerhard

    2007-07-01

    As a contribution to the increasing efforts to preserve cultural heritage, historical books as well as illuminated manuscripts endangered by corrosive writing and printing materials or destructive coloring matters, non-destructive analytical methods are highly desirable enabling an in-situ examination of the surface status of an object. The development and application of a novel combination of non-destructive analytic methods based on (a) synchrotron radiation induced micro-X-ray fluorescence (SR-μXRF) and (b) Fourier transform infrared (FTIR) microscope allows to investigate the state as well as the effectiveness of conservation procedures for historical manuscripts. Examples of measurements include (1) an iron gall ink manuscript of a historical memo on legal land description of the year 1769, (2) an original hand colored herbal of the years 1536/38 from the Senckenbergische Bibliothek, Frankfurt, and (3) the incunabula Johannes von Saaz: "Der Ackermann aus Boehmen" fated from 1463 and printed by Albrecht Pfister, Bamberg, owned by the Herzog August Bibliothek, Wolfenbuettel.

  3. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    SciTech Connect

    B.Mi; X. Zhao; R. Bayles

    2006-05-26

    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 different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

  4. Non-destructive investigation of a time capsule using neutron radiography and X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    MacDonald, B. L.; Vanderstelt, J.; O'Meara, J.; McNeill, F. E.

    2016-01-01

    Non-destructive analytical techniques are becoming increasingly important for the study of objects of cultural heritage interest. This study applied two techniques: X-ray fluorescence and neutron radiography, for the investigation of a capped, tubular metal object recovered from an urban construction site in Gore Park, Hamilton, Canada. The site is an urban park containing a World War I commemorative monument that underwent renovation and relocation. Historical documentation suggested that the object buried underneath the monument was a time capsule containing a paper document listing the names of 1800 Canadians who died during WWI. The purpose of this study was to assess the condition of the object, and to verify if it was what the historical records purported. XRF analysis was used to characterize the elemental composition of the metal artifact, while neutron radiography revealed that its contents were congruent with historical records and remained intact after being interred for 91 years. Results of this study demonstrate the value of non-destructive techniques for the analysis and preservation of cultural heritage.

  5. Are those bugs reflective? Non-destructive biofilm imaging with white light interferometry

    SciTech Connect

    Larimer, Curtis J.; Brann, Michelle R.; Suter, Jonathan D.; Bonheyo, George T.; Addleman, Raymond S.

    2016-08-28

    White light interferometry (WLI) is not typically used to image bacterial biofilms that are immersed in water because there is insufficient refractive index contrast to induce reflection from the biofilm’s interface. The soft structure and water-like bulk properties of hydrated biofilms make them difficult to characterize in situ by any means, especially in a non-destructive manner. Here we describe a new method for measuring and monitoring the thickness and topology of live biofilms using a WLI microscope. A microfluidic system was used to create a reflective interface on the surface of biofilms. Live biofilm samples were monitored non-destructively over time. The method enables surface metrology measurements (roughness, surface area) and a novel approach to measuring thickness of the thin hydrated biofilms. Increase in surface roughness preceded observable increase in biofilm thickness, indicating that this measure may be used to predict future development of biofilms. We have also developed a flow cell that enables WLI biofilm imaging in a dynamic environment. We have used this flow cell to observe changes in biofilm structure in response to changes in environmental conditions - flow velocity, availability of nutrients, and presence of biocides.

  6. Non-destructive Magnetic Evaluation of Laser Weld Quality in Hot Rolled Coils

    NASA Astrophysics Data System (ADS)

    Mohapatra, J. N.; Chakradhar, I.; Rao, K. R. C.; Rao, V. V. L.; Kaza, Marutiram

    2015-06-01

    Weld quality evaluation was conducted on laser welded thin sectsions (2 mm) of hot-rolled (HR) low-carbon steel coils during cold rolling process. The analysis revealed that the poor welds consisting of the weld defects like incomplete fusion, cluster of porosity, and large difference in hardness between the weld zone and base metal were responsible for the weld failures. Experiments were conducted by varying the welding parameters; laser power and welding speed to optimize the parameters for minimizing the weld defects. The optimized weld process parameters have helped elimination of weld defects and the results are verified with microscopy and microhardness measurements. As destructive evaluation techniques are time consuming and not always permitted in industrial applications, attempts have been made in the present investigation for the utilization of suitable non-destructive techniques for the evaluation of weld quality. Non-destructive magnetic techniques of magnetic hysteresis loop and magnetic Barkhausen emissions were used in the present investigation to establish possible correlations of magnetic properties across the weld seam with the mechanical property (microhardness) for evaluation of weld quality. It is inferred that the magnetic properties of coercivity and inverse of root mean square voltage can be effectively utilized to determine weld quality in HR steel coils.

  7. Non-destructive dielectric assessment of water permeation in composite structures

    SciTech Connect

    Boinard, P.; Boinard, E.; Pethrick, R.A.; Banks, W.M.; Crane, R.L.

    2000-07-01

    Over the last ten years, the application of high frequency dielectric spectroscopy techniques for the assessment of composite structures has been investigated. Novel approaches to assess non-destructively the evolution during ageing of adhesively bonded carbon fiber reinforced plastic (CFRP) structures and bulk glass fiber reinforced plastic (GRP) structures are presented in this paper and the results are critically assessed. The applicability and limitations of dielectric measurements, in both frequency and time domain, to the monitoring of water ingress at 30 C and 60 C are examined. The correlation between gravimetric and high frequency dielectric spectroscopy data demonstrates the suitability of the techniques regarding the assessment of water uptake in composites structures and illustrates its potential as a non-destructive evaluation (NDE) technique. The dielectric time domain response (TDR) study of adhesively bonded structures indicates a new way to assess such structures. The approach for frequency domain analysis of bulk GRP using a coaxial probe technique indicates the potential portability of the technique for in-situ measurements.

  8. Are those bugs reflective? non-destructive biofilm imaging with white light interferometry

    NASA Astrophysics Data System (ADS)

    Larimer, Curtis; Brann, Michelle; Suter, Jonathan D.; Bonheyo, George; Addleman, R. Shane

    2016-08-01

    White light interferometry (WLI) is not typically used to image bacterial biofilms that are immersed in water because there is insufficient refractive index contrast to induce reflection from the biofilm's interface. The soft structure and water-like bulk properties of hydrated biofilms make them difficult to characterize in situ by any means, especially in a non-destructive manner. Here we describe a new method for measuring and monitoring the thickness and topology of live biofilms using a WLI microscope. A microfluidic system was used to create a reflective interface on the surface of biofilms. Live biofilm samples were monitored non-destructively over time. The method enables surface metrology measurements (roughness, surface area) and a novel approach to measuring thickness of the thin hydrated biofilms. Increase in surface roughness preceded observable increase in biofilm thickness, indicating that this measure may be used to predict future development of biofilms. We have also developed a flow cell that enables WLI biofilm imaging in a dynamic environment. We have used this flow cell to observe changes in biofilm structure in response to changes in environmental conditions - flow velocity, availability of nutrients, and presence of biocides.

  9. Neural network and principal component regression in non-destructive soluble solids content assessment: a comparison*

    PubMed Central

    Chia, Kim-seng; Abdul Rahim, Herlina; Abdul Rahim, Ruzairi

    2012-01-01

    Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR) (a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data. Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR. PMID:22302428

  10. Non-Destructive Evaluation of Grain Structure Using Air-Coupled Ultrasonics

    SciTech Connect

    Belvin, A. D.; Burrell, R. K.; Cole, E.G.

    2009-08-01

    Cast material has a grain structure that is relatively non-uniform. There is a desire to evaluate the grain structure of this material non-destructively. Traditionally, grain size measurement is a destructive process involving the sectioning and metallographic imaging of the material. Generally, this is performed on a representative sample on a periodic basis. Sampling is inefficient and costly. Furthermore, the resulting data may not provide an accurate description of the entire part's average grain size or grain size variation. This project is designed to develop a non-destructive acoustic scanning technique, using Chirp waveforms, to quantify average grain size and grain size variation across the surface of a cast material. A Chirp is a signal in which the frequency increases or decreases over time (frequency modulation). As a Chirp passes through a material, the material's grains reduce the signal (attenuation) by absorbing the signal energy. Geophysics research has shown a direct correlation with Chirp wave attenuation and mean grain size in geological structures. The goal of this project is to demonstrate that Chirp waveform attenuation can be used to measure grain size and grain variation in cast metals (uranium and other materials of interest). An off-axis ultrasonic inspection technique using air-coupled ultrasonics has been developed to determine grain size in cast materials. The technique gives a uniform response across the volume of the component. This technique has been demonstrated to provide generalized trends of grain variation over the samples investigated.

  11. Air pollution exposure: Who is at high risk?

    NASA Astrophysics Data System (ADS)

    Peled, Ronit

    2011-04-01

    This article reviews the sub-population groups who are at high risk and first to be harmed by air pollution coming from anthropogenic combustions. Epidemiological studies from the last few decades contributed to the understanding of the different levels of susceptibility to air pollution. Older people and young infants, people who suffer from allergies, pulmonary and heart diseases, pregnant women and newborn babies, and deprived populations that suffer from low socio-economic status have all been described as populations at risk. A better understanding of the role of air pollution on large as well as specific populations' health, will promote a better protection policy.

  12. A review of traffic-related air pollution exposure assessment studies in the developing world.

    PubMed

    Han, Xianglu; Naeher, Luke P

    2006-01-01

    Exposure assessment studies in the developing world are important. Although recent years have seen an increasing number of traffic-related pollution exposure studies, exposure assessment data on this topic are still limited. Differences among measuring methods and a lack of strict quality control in carrying out exposure assessment make it difficult to generalize and compare findings between studies. In this article, exposure assessment studies carried out in the developing world on several traffic-related air pollutants are reviewed. These pollutants include particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). In addition, it discusses advantages and disadvantages of various monitoring methods (ambient fixed-site monitoring, microenvironment monitoring, and personal exposure assessment using portable samplers) for these pollutants in exposure assessment studies. Also included in this paper is a brief introduction of standards for these pollutants in ambient air or in occupational settings established by the United States Environmental Protection Agency (USEPA), the United States Occupational Safety and Health Administration (OSHA) and the World Health Organization (WHO). The review ends with a summary of the limitations and gaps in recent studies and suggestions for future research in the developing world.

  13. Exposure to Moderate Air Pollution during Late Pregnancy and Cord Blood Cytokine Secretion in Healthy Neonates

    PubMed Central

    Latzin, Philipp; Frey, Urs; Armann, Jakob; Kieninger, Elisabeth; Fuchs, Oliver; Röösli, Martin; Schaub, Bianca

    2011-01-01

    Background/Objectives Ambient air pollution can alter cytokine concentrations as shown in vitro and following short-term exposure to high air pollution levels in vivo. Exposure to pollution during late pregnancy has been shown to affect fetal lymphocytic immunophenotypes. However, effects of prenatal exposure to moderate levels of air pollutants on cytokine regulation in cord blood of healthy infants are unknown. Methods In a birth cohort of 265 healthy term-born neonates, we assessed maternal exposure to particles with an aerodynamic diameter of 10 µm or less (PM10), as well as to indoor air pollution during the last trimester, specifically the last 21, 14, 7, 3 and 1 days of pregnancy. As a proxy for traffic-related air pollution, we determined the distance of mothers' homes to major roads. We measured cytokine and chemokine levels (MCP-1, IL-6, IL-10, IL-1ß, TNF-α and GM-CSF) in cord blood serum using LUMINEX technology. Their association with pollution levels was assessed using regression analysis, adjusted for possible confounders. Results Mean (95%-CI) PM10 exposure for the last 7 days of pregnancy was 18.3 (10.3–38.4 µg/m3). PM10 exposure during the last 3 days of pregnancy was significantly associated with reduced IL-10 and during the last 3 months of pregnancy with increased IL-1ß levels in cord blood after adjustment for relevant confounders. Maternal smoking was associated with reduced IL-6 levels. For the other cytokines no association was found. Conclusions Our results suggest that even naturally occurring prenatal exposure to moderate amounts of indoor and outdoor air pollution may lead to changes in cord blood cytokine levels in a population based cohort. PMID:21826232

  14. Disrupted Nitric Oxide Metabolism from Type II Diabetes and Acute Exposure to Particulate Air Pollution.

    PubMed

    Pettit, Ashley P; Kipen, Howard; Laumbach, Robert; Ohman-Strickland, Pamela; Kelly-McNeill, Kathleen; Cepeda, Clarimel; Fan, Zhi-Hua; Amorosa, Louis; Lubitz, Sara; Schneider, Stephen; Gow, Andrew

    2015-01-01

    Type II diabetes is an established cause of vascular impairment. Particulate air pollution is known to exacerbate cardiovascular and respiratory conditions, particularly in susceptible populations. This study set out to determine the impact of exposure to traffic pollution, with and without particle filtration, on vascular endothelial function in Type II diabetes. Endothelial production of nitric oxide (NO) has previously been linked to vascular health. Reactive hyperemia induces a significant increase in plasma nitrite, the proximal metabolite of NO, in healthy subjects, while diabetics have a lower and more variable level of response. Twenty type II diabetics and 20 controls (ages 46-70 years) were taken on a 1.5 hr roadway traffic air pollution exposure as passengers. We analyzed plasma nitrite, as a measure of vascular function, using forearm ischemia to elicit a reactive hyperemic response before and after exposure to one ride with and one without filtration of the particle components of pollution. Control subjects displayed a significant increase in plasma nitrite levels during reactive hyperemia. This response was no longer present following exposure to traffic air pollution, but did not vary with whether or not the particle phase was filtered out. Diabetics did not display an increase in nitrite levels following reactive hyperemia. This response was not altered following pollution exposure. These data suggest that components of acute traffic pollution exposure diminish vascular reactivity in non-diabetic individuals. It also confirms that type II diabetics have a preexisting diminished ability to appropriately respond to a vascular challenge, and that traffic pollution exposure does not cause a further measureable acute change in plasma nitrite levels in Type II diabetics.

  15. Characterization of protein expression of Platanus pollen following exposure to gaseous pollutants and vehicle exhaust particles.

    PubMed

    Lu, Senlin; Ren, Jingjin; Hao, Xiaojie; Liu, Dingyu; Zhang, Rongci; Wu, Minghong; Yi, Fei; Lin, Jun; Shinich, Yonemochi; Wang, Qingyue

    2014-01-01

    Being major ornamental street trees, species of Platanus are widely planted in the Shanghai urban area. A great deal of allergenic Platanus pollen is released from the trees and suspended in the atmosphere during its flowering season, ultimately causing allergic respiratory diseases. Few papers have focused on the distribution of this type of pollen and its expression of allergenic proteins. In order to investigate any differences in protein expression in Platanus pollen following exposure to gaseous and particulate pollutants, a special apparatus was designed. Exposure condition (such as temperature, humidity, and exposure time) of Platanus pollen and gaseous pollutants can be simulated using of this apparatus. Fresh Platanus orientalis pollen, pollutant gases (NO2, SO2, NH3), and typical urban ambient particles (vehicle exhaust particles, VEPs) were mixed in this device to examine possible changes that might occur in ambient airborne urban pollen following exposure to such pollutants. Our results showed that the fresh P. orientalis pollen became swollen, and new kinds of particles could be found on the surface of the pollen grains after exposure to the pollutants. The results of SDS-PAGE showed that five protein bands with molecular weights of 17-19, 34, 61, 82, and 144 kDa, respectively, were detected and gray scale of these brands increased after the pollen exposure to gaseous pollutants. The two-dimensional gel electrophoresis analysis demonstrated that a Platanus pollen allergenic protein (Pla a1, with a molecular weight of 18 kDa) increased in abundance following exposure to pollutant gases and VEPs, implying that air pollutants may exacerbate the allergenicity of pollen.

  16. Disrupted Nitric Oxide Metabolism from Type II Diabetes and Acute Exposure to Particulate Air Pollution

    PubMed Central

    Pettit, Ashley P.; Kipen, Howard; Laumbach, Robert; Ohman-Strickland, Pamela; Kelly-McNeill, Kathleen; Cepeda, Clarimel; Fan, Zhi-Hua; Amorosa, Louis; Lubitz, Sara; Schneider, Stephen; Gow, Andrew

    2015-01-01

    Type II diabetes is an established cause of vascular impairment. Particulate air pollution is known to exacerbate cardiovascular and respiratory conditions, particularly in susceptible populations. This study set out to determine the impact of exposure to traffic pollution, with and without particle filtration, on vascular endothelial function in Type II diabetes. Endothelial production of nitric oxide (NO) has previously been linked to vascular health. Reactive hyperemia induces a significant increase in plasma nitrite, the proximal metabolite of NO, in healthy subjects, while diabetics have a lower and more variable level of response. Twenty type II diabetics and 20 controls (ages 46–70 years) were taken on a 1.5hr roadway traffic air pollution exposure as passengers. We analyzed plasma nitrite, as a measure of vascular function, using forearm ischemia to elicit a reactive hyperemic response before and after exposure to one ride with and one without filtration of the particle components of pollution. Control subjects displayed a significant increase in plasma nitrite levels during reactive hyperemia. This response was no longer present following exposure to traffic air pollution, but did not vary with whether or not the particle phase was filtered out. Diabetics did not display an increase in nitrite levels following reactive hyperemia. This response was not altered following pollution exposure. These data suggest that components of acute traffic pollution exposure diminish vascular reactivity in non-diabetic individuals. It also confirms that type II diabetics have a preexisting diminished ability to appropriately respond to a vascular challenge, and that traffic pollution exposure does not cause a further measureable acute change in plasma nitrite levels in Type II diabetics. PMID:26656561

  17. A novel approach for exposure assessment in air pollution epidemiological studies using neuro-fuzzy inference systems: Comparison of exposure estimates and exposure-health associations.

    PubMed

    Blanes-Vidal, Victoria; Cantuaria, Manuella Lech; Nadimi, Esmaeil S

    2017-04-01

    Many epidemiological studies have used proximity to sources as air pollution exposure assessment method. However, proximity measures are not generally good surrogates because of their complex non-linear relationship with exposures. Neuro-fuzzy inference systems (NFIS) can be used to map complex non-linear systems, but its usefulness in exposure assessment has not been extensively explored. We present a novel approach for exposure assessment using NFIS, where the inputs of the model were easily-obtainable proximity measures, and the output was residential exposure to an air pollutant. We applied it to a case-study on NH3 pollution, and compared health effects and exposures estimated from NFIS, with those obtained from emission-dispersion models, and linear and non-linear regression proximity models, using 10-fold cross validation. The agreement between emission-dispersion and NFIS exposures was high (Root-mean-square error (RMSE) =0.275, correlation coefficient (r)=0.91) and resulted in similar health effect estimates. Linear models showed poor performance (RMSE=0.527, r=0.59), while non-linear regression models resulted in heterocedasticity, non-normality and clustered data. NFIS could be a useful tool for estimating individual air pollution exposures in epidemiological studies on large populations, when emission-dispersion data are not available. The tradeoff between simplicity and accuracy needs to be considered.

  18. Ambient air pollution exposure and the incidence of related health effects among racial/ethnic minorities

    SciTech Connect

    Nieves, L.A.; Wernette, D.R.

    1997-02-01

    Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure to air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.

  19. Effect of geocoding errors on traffic-related air pollutant exposure and concentration estimates

    EPA Science Inventory

    Exposure to traffic-related air pollutants is highest very near roads, and thus exposure estimates are sensitive to positional errors. This study evaluates positional and PM2.5 concentration errors that result from the use of automated geocoding methods and from linearized approx...

  20. Critical Evaluation of Air-Liquid Interface Exposure Devices for In Vitro Assessment of Atmospheric Pollutants

    EPA Science Inventory

    Exposure of cells to atmospheric pollutants at the air-liquid interface (ALI) is a more realistic approach than exposures of attached cells submerged in liquid medium. However, there is still limited understanding of the ideal ALI device design features that permit reproducible a...

  1. Evaluation of air-liquid interface exposure systems for in vitro assessment of airborne pollutants

    EPA Science Inventory

    Exposure of cells to airborne pollutants at the air-liquid interface (ALI) is a more realistic approach than exposures of submerged cells. The published literature, however, describes irreproducible and/or unrealistic experimental conditions using ALI systems. We have compared fi...

  2. (CZ)BIOMARKERS OF EXPOSURE TO PARTICULATE AIR POLLUTION IN THE CZECH REPUBLIC

    EPA Science Inventory

    The use of biomarkers in the Teplice Program, provided a key tool to relate health outcomes to individual personal exposures and to provide measures of confounding exposures. This research program on the health effects of air pollution studied a population living in the heavil...

  3. (PRAGUE)BIOMARKERS OF EXPOSURE TO PARTICULATE AIR POLLUTION IN THE CZECH REPUBLIC

    EPA Science Inventory

    The use of biomarkers in the Teplice Program, provided a key tool to relate health outcomes to individual personal exposures and to provide measures of confounding exposures. This research program on the health effects of air pollution studied a population living in the heavil...

  4. Susceptibility Factors Relevant for the Association Between Long-Term Air Pollution Exposure and Incident Asthma.

    PubMed

    Burte, Emilie; Nadif, Rachel; Jacquemin, Bénédicte

    2016-03-01

    In this review, we identified 15 studies in children and 10 studies in adults that assessed the association between long-term exposure to air pollution and incident asthma and that conducted stratified analyses to explore potential susceptibility factors. Overall, adult never-/former smokers seem to be at higher risk of incident asthma due to air pollution. Children without atopy and children from low socioeconomic status families also seem to be at higher risk of incident asthma due to air pollution. While interaction between air pollution and genes involved in the response to oxidative stress pathways have been explored, results are somewhat inconsistent and in need of replication. To evaluate interactions, large sample sizes are necessary, and much more research, including data pooling from existing studies, is needed to further explore susceptibility factors for asthma incidence due to long-term air pollution exposure.

  5. Non-destructive infrared analyses: a method for provenance analyses of sandstones

    NASA Astrophysics Data System (ADS)

    Bowitz, Jörg; Ehling, Angela

    2008-12-01

    Infrared spectroscopy (IR spectroscopy) is commonly applied in the laboratory for mineral analyses in addition to XRD. Because such technical efforts are time and cost consuming, we present an infrared-based mobile method for non-destructive mineral and provenance analyses of sandstones. IR spectroscopy is based on activating chemical bonds. By irradiating a mineral mixture, special bonds are activated to vibrate depending on the bond energy (resonance vibration). Accordingly, the energy of the IR spectrum will be reduced thereby generating an absorption spectrum. The positions of the absorption maxima within the spectral region indicate the type of the bonds and in many cases identify minerals containing these bonds. The non-destructive reflection spectroscopy operates in the near infrared region (NIR) and can detect all common clay minerals as well as sulfates, hydroxides and carbonates. The spectra produced have been interpreted by computer using digital mineral libraries that have been especially collected for sandstones. The comparison of all results with XRD, RFA and interpretations of thin sections demonstrates impressively the accuracy and reliability of this method. Not only are different minerals detectable, but also differently ordered kaolinites and varieties of illites can be identified by the shape and size of the absorption bands. Especially clay minerals and their varieties in combination with their relative contents form the characteristic spectra of sandstones. Other components such as limonite, hematite and amorphous silica also influence the spectra. Sandstones, similar in colour and texture, often can be identified by their characteristic reflectance spectra. Reference libraries with more than 60 spectra of important German sandstones have been created to enable entirely computerized interpretations and identifications of these dimension stones. The analysis of infrared spectroscopy results is demonstrated with examples of different sandstones

  6. The microenvironmental modelling approach to assess children's exposure to air pollution - A review.

    PubMed

    Branco, P T B S; Alvim-Ferraz, M C M; Martins, F G; Sousa, S I V

    2014-11-01

    Exposures to a wide spectrum of air pollutants were associated to several effects on children's health. Exposure assessment can be used to establish where and how air pollutants' exposures occur. However, a realistic estimation of children's exposures to air pollution is usually a great ethics challenge, especially for young children, because they cannot intentionally be exposed to contaminants and according to Helsinki declaration, they are not old enough to make a decision on their participation. Additionally, using adult surrogates introduces bias, since time-space-activity patterns are different from those of children. From all the different available approaches for exposure assessment, the microenvironmental (ME) modelling (indirect approach, where personal exposures are estimated or predicted from microenvironment measurements combined with time-activity data) seemed to be the best to assess children's exposure to air pollution as it takes into account the varying levels of pollution to which an individual is exposed during the course of the day, it is faster and less expensive. Thus, this review aimed to explore the use of the ME modelling approach methodology to assess children's exposure to air pollution. To meet this goal, a total of 152 articles, published since 2002, were identified and titles and abstracts were scanned for relevance. After exclusions, 26 articles were fully reviewed and main characteristics were detailed, namely: (i) study design and outcomes, including location, study population, calendar time, pollutants analysed and purpose; and (ii) data collection, including time-activity patterns (methods of collection, record time and key elements) and pollution measurements (microenvironments, methods of collection and duration and time resolution). The reviewed studies were from different parts of the world, confirming the worldwide application, and mostly cross-sectional. Longitudinal studies were also found enhancing the applicability of

  7. Correlation-based imaging technique using ultrasonic transmit-receive array for Non-Destructive Evaluation.

    PubMed

    Quaegebeur, Nicolas; Masson, Patrice

    2012-12-01

    This paper describes a novel array post-processing method for Non-Destructive Evaluation (NDE) using phased-array ultrasonic probes. The approach uses the capture and processing of the full matrix of all transmit-receive time-domain signals from a transducer array as in the case of the Total Focusing Method (TFM), referred as the standard of imaging algorithms. The proposed technique is based on correlation of measured signals with theoretical propagated signals computed over a given grid of points. In that case, real-time imaging can be simply implemented using discrete signal product. The advantage of the present technique is to take into account transducer directivity, dynamics and complex propagation patterns, such that the number of required array elements for a given imaging performance can be greatly reduced. Numerical and experimental application to contact inspection of isotropic structure is presented and real-time implementation issues are discussed.

  8. MCNP ESTIMATE OF THE SAMPLED VOLUME IN A NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS.

    SciTech Connect

    WIELOPOLSKI, L.; DIOSZEGI, I.; MITRA, S.

    2004-05-03

    Global warming, promoted by anthropogenic CO{sub 2} emission into the atmosphere, is partially mitigated by the photosynthesis processes of the terrestrial echo systems that act as atmospheric CO{sub 2} scrubbers and sequester carbon in soil. Switching from till to no till soils management practices in agriculture further augments this process. Carbon sequestration is also advanced by putting forward a carbon ''credit'' system whereby these can be traded between CO{sub 2} producers and sequesters. Implementation of carbon ''credit'' trade will be further promulgated by recent development of a non-destructive in situ carbon monitoring system based on inelastic neutron scattering (INS). Volumes and depth distributions defined by the 0.1, 1.0, 10, 50, and 90 percent neutron isofluxes, from a point source located at either 5 or 30 cm above the surface, were estimated using Monte Carlo calculations.

  9. Non-destructive electron microscopy imaging and analysis of biological samples with graphene coating

    NASA Astrophysics Data System (ADS)

    Park, Jong Bo; Kim, Yong-Jin; Kim, Seong-Min; Yoo, Je Min; Kim, Youngsoo; Gorbachev, Roman; Barbolina, I. I.; Kim, Sang Jin; Kang, Sangmin; Yoon, Myung-Han; Cho, Sung-Pyo; Novoselov, Konstantin S.; Hong, Byung Hee

    2016-12-01

    In electron microscopy (EM), charging of non-conductive biological samples by focused electron beams hinders their high-resolution imaging. Gold or platinum coatings have been commonly used to prevent such sample charging, but it disables further quantitative and qualitative chemical analyses such as energy dispersive spectroscopy (EDS). Here we report that graphene-coating on biological samples enables non-destructive high-resolution imaging by EM as well as chemical analysis by EDS, utilizing graphene’s transparency to electron beams, high conductivity, outstanding mechanical strength and flexibility. We believe that the graphene-coated imaging and analysis would provide us a new opportunity to explore various biological phenomena unseen before due to the limitation in sample preparation and image resolution, which will broaden our understanding on the life mechanism of various living organisms.

  10. A modified positron lifetime spectrometer as method of non-destructive testing in materials

    NASA Astrophysics Data System (ADS)

    Chen, Z. Q.; Shi, J. J.; Jiang, J.; Liu, X. B.; Wang, R. S.; Wu, Y. C.

    2015-02-01

    This paper aims to develop a new non-destructive testing (NDT) method using positron annihilation spectroscopy, a powerful tool to detect vacancy-type defects and defect's chemical environment. A positron NDT system was designed and constructed by modifying the "sandwich" structure of sample-source-sample in the conventional positron lifetime spectrometer. The positron lifetime spectra of one single sample can be measured and analyzed by subtracting the contribution of a reference sample. The feasibility and reliability of the positron NDT system have been tested by analyzing nondestructively deformation damage caused by mechanical treatment in metals and steels. This system can be used for detecting defects and damage in thick or large-size samples without cutting off the sample materials, as well as for detecting two-dimensional distribution of defects.

  11. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality By Eddy Current Method

    SciTech Connect

    B. Mi; G. Zhao; R. Bayles

    2006-08-10

    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.

  12. Portable generator-based XRF instrument for non-destructive analysis at crime scenes

    NASA Astrophysics Data System (ADS)

    Schweitzer, Jeffrey S.; Trombka, Jacob I.; Floyd, Samuel; Selavka, Carl; Zeosky, Gerald; Gahn, Norman; McClanahan, Timothy; Burbine, Thomas

    2005-12-01

    Unattended and remote detection systems find applications in space exploration, telemedicine, teleforensics, homeland security and nuclear non-proliferation programs. The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals investigate crimes. The objective of the program is to produce instruments and communication networks that have application within both NASA's space program and NIJ, together with state and local forensic laboratories. A general-purpose X-ray fluorescence system has been built for non-destructive analyses of trace and invisible material at crime scenes. This portable instrument is based on a generator that can operate to 60 kV and a Schottky CdTe detector. The instrument has been shown to be successful for the analysis of gunshot residue and a number of bodily fluids at crime scenes.

  13. Non-destructive fraud detection in rosehip oil by MIR spectroscopy and chemometrics.

    PubMed

    Santana, Felipe Bachion de; Gontijo, Lucas Caixeta; Mitsutake, Hery; Mazivila, Sarmento Júnior; Souza, Leticia Maria de; Borges Neto, Waldomiro

    2016-10-15

    Rosehip oil (Rosa eglanteria L.) is an important oil in the food, pharmaceutical and cosmetic industries. However, due to its high added value, it is liable to adulteration with other cheaper or lower quality oils. With this perspective, this work provides a new simple, fast and accurate methodology using mid-infrared (MIR) spectroscopy and partial least squares discriminant analysis (PLS-DA) as a means to discriminate authentic rosehip oil from adulterated rosehip oil containing soybean, corn and sunflower oils in different proportions. The model showed excellent sensitivity and specificity with 100% correct classification. Therefore, the developed methodology is a viable alternative for use in the laboratory and industry for standard quality analysis of rosehip oil since it is fast, accurate and non-destructive.

  14. NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS: PRINCIPLE AND RESULTS.

    SciTech Connect

    WIELOPOLSKI, L.; MITRA, S.; HENDREY, G.; ROGERS, H.; TORBERT, A.; PRIOR, S.

    2003-05-05

    Global warming is promoted by anthropogenic CO{sub 2} emissions into the atmosphere, while at the same time it is partially mitigated by carbon sequestration by terrestrial ecosystems. However, improvement in the understanding and monitoring of below ground carbon processes is essential for evaluating strategies for carbon sequestration including quantification of carbon stores for credits. A system for non-destructive in situ carbon monitoring in soil, based on inelastic neutron scattering (INS), is described. The system can be operated in stationary or scanning mode and measures soil to depth of approximately 30 cm. There is a good agreement between results obtained from INS and standard chemical analysis of soil cores collected from the same study site.

  15. Rapid, non-destructive evaluation of ultrathin WSe{sub 2} using spectroscopic ellipsometry

    SciTech Connect

    Eichfeld, Sarah M.; Lin, Yu-Chuan; Hossain, Lorraine; Eichfeld, Chad M.; Robinson, Joshua A.

    2014-09-01

    The utilization of tungsten diselenide (WSe{sub 2}) in electronic and optoelectronic devices depends on the ability to understand and control the process-property relationship during synthesis. We demonstrate that spectroscopic ellipsometry is an excellent technique for accurate, non-destructive determination of ultra-thin (<30 nm) WSe{sub 2} properties. The refractive index (n) and extinction coefficient (k) were found to be independent of thickness down to 1.3 nm, and were used to determine film thickness, which was confirmed to be within 9% of values found via atomic force microscopy. Finally, the optical bandgap was found to closely correlate with thickness, ranging from 1.2 to 1.55 eV as the WSe{sub 2} is thinned to the equivalent of 2 atomic layers.

  16. A robust approach to optimal matched filter design in ultrasonic non-destructive evaluation (NDE)

    NASA Astrophysics Data System (ADS)

    Li, Minghui; Hayward, Gordon

    2017-02-01

    The matched filter was demonstrated to be a powerful yet efficient technique to enhance defect detection and imaging in ultrasonic non-destructive evaluation (NDE) of coarse grain materials, provided that the filter was properly designed and optimized. In the literature, in order to accurately approximate the defect echoes, the design utilized the real excitation signals, which made it time consuming and less straightforward to implement in practice. In this paper, we present a more robust and flexible approach to optimal matched filter design using the simulated excitation signals, and the control parameters are chosen and optimized based on the real scenario of array transducer, transmitter-receiver system response, and the test sample, as a result, the filter response is optimized and depends on the material characteristics. Experiments on industrial samples are conducted and the results confirm the great benefits of the method.

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

    SciTech Connect

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

    2011-10-03

    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.

  18. Template synthesis of test tube nanoparticles using non-destructive replication.

    PubMed

    Wagner, Jonathan; Yao, Jingyuan; Rodgers, David; Hinds, Bruce

    2013-03-01

    Nano test tubes are a promising delivery vehicle for a range of therapeutics, including small molecule drugs and biologics. However, current template synthesis methods of producing nano test tubes are prohibitively expensive and time consuming. Here, non-destructive template replication was used to increase nano test tube yield from porous alumina by more than a hundredfold. We demonstrate how to produce nano test tubes of several sizes and compositions, including hybrid tubes with different inner and outer surfaces for targeted surface chemistry. Nano test tubes were readily suspended and stored in aqueous solutions without the need for chemical treatment. These nano test tubes should find application as delivery vehicles for therapeutics, particularly for processive 'bionanoreactors' loaded with enzymes.

  19. Non-Destructive Evaluation of Depth of Surface Cracks Using Ultrasonic Frequency Analysis

    PubMed Central

    Her, Shiuh-Chuan; Lin, Sheng-Tung

    2014-01-01

    Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted. The ultrasonic frequency spectrum was obtained by Fourier transform technique. A series of test specimens with various depths of surface crack ranging from 1 mm to 8 mm was fabricated. The depth of the surface crack was evaluated using the pulse-echo technique. In this work, three different longitudinal waves with frequencies of 2.25 MHz, 5 MHz and 10 MHz were employed to investigate the effect of frequency on the sizing detection of surface cracks. Reasonable accuracies were achieved with measurement errors less than 7%. PMID:25225875

  20. High-Tc planar SQUID gradiometer for eddy current non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Ming-Jian; Lang, Pei-Lin; Peng, Zhi-Hui; Chen, Ying-Fei; Chen, Ke; Zheng, Dong-Ning

    2006-08-01

    This paper reports the fabrication and test of a high-Tc SQUID planar gradiometer which is patterned from YBCO thin film deposited on a SrTiO3 bicrystal substrate. The measurement of noise spectrum at 77K shows that the white noise at 200 Hz is about 1×10-4Φ0/(Hz)1/2. The minimal magnetic gradient is measured and the results suggest that the minimal magnetic gradient is 94 pT/m. The planar gradiometer is used in non-destructive evaluation (NDE) experiments to detect the artifacts in conducting aluminium plates by performing eddy current testing in an unshielded environment. The effect of the exciting coil dimension on the NDE results is investigated. By mapping out the induced field distribution, flaws about 10mm below the plate surface can be clearly identified.

  1. Research on high-Tc SQUID based non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Wang, Hui-Wu; Kong, Xiang-Yan; Ren, Yu-Feng; Yu, Hong-Wei; Ding, Hong-Sheng; Zhao, Shi-Ping; Chen, Geng-Hua; Zhou, Yue-Liang; Zhang, Li-Hua; He, Yu-Sheng; Yang, Qian-Sheng

    2004-01-01

    A non-destructive evaluation system based on high-Tc dc-SQUID (superconducting quantum interference device) incorporating a gradient field excitation has been built. By using this system a 1mm-diameter hole at a depth of 2mm inside an aluminium plate at room temperature can be easily detected and imaged in an unshielded environment. The relation between the spatial resolution, or the smallest detectable flaw size and experimental parameters is briefly analysed in terms of a simple metal ring model. The result shows that the spatial resolution depends strongly on the sensor-sample separation as well as on some other parameters, such as signal-to-noise ratio of excitation, excitation frequency and material conductivity.

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

    DOEpatents

    Jiles, David C.; Sipahi, Levent B.

    1994-05-17

    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.

  3. Barkhausen spectroscopy: Non-destructive characterization of magnetic materials as a function of depth

    NASA Astrophysics Data System (ADS)

    Kypris, O.; Nlebedim, I. C.; Jiles, D. C.

    2014-05-01

    In this study, we conceptually divided a ferromagnetic specimen into layers along its depth. For each layer, we derived a non-linear integral equation that describes the attenuation with frequency and distance of magnetic Barkhausen emissions coming from that layer. We postulate that the Barkhausen spectrum measured at the surface by an induction coil can be expressed as the sum of the individual layer spectra. We show how a non-linear least squares algorithm can be used to recover the properties in individual layers. These are related to stress using an extension to the theory of ferromagnetic hysteresis. We found that the quality of the fit is influenced by the sensitivity of the ferromagnetic material to strain, as well as by the sensor-specimen coupling. The proposed method can be used for the non-destructive characterization of stress as a function of depth in magnetic materials.

  4. Model-based non-destructive investigation methods in semiconductor industry

    NASA Astrophysics Data System (ADS)

    Bilski, B.; Paz, V. Ferreras; Frenner, K.; Osten, W.

    2013-05-01

    Scatterometry is an investigation method that is gaining in importance in semiconductor industry. As an optical method it has distinct advantages that its competitor-methods do not possess: the ability for a quick and non-destructive measurement of fine features fabricated by modern generations of lithography machines. Scatterometry is very distinct from other measurement techniques also in this respect that it is a model-based method. As such it relies heavily on simulation and is essentially solving an inverse problem. In a forward optical measurement an imaging system processes the object information losing some fraction of information in the process. The measurement process in scatterometry follows the same pattern. The measurement result however is now compared against multiple simulated direct problems. The best fit between the simulation and the measurement is assumed to reconstruct the measured object.

  5. Measurements of aerospace materials and their interpretation for non-destructive testing

    NASA Astrophysics Data System (ADS)

    Salmon, Neil A.; Mason, Ian; Price, Sean; Beale, John

    2009-09-01

    Millimetre and terahertz radiation penetration into materials enables non-destructive testing capabilities for the aerospace industry, either remotely using imaging technology or locally using microscope type diagnostics. This paper presents measurements made on Norcoat and Prosial, used in the aerospace industry for thermal insulation and on carbon fibre, used for its high strength weight ratio. Michelson interferometer measurements over the band 100 GHz to 1 THz, with a 30 GHz spectral resolution, are presented, together with images of a range of samples taken using a 35 GHz real-time imaging system. The measured optical properties of these materials are examined and used in modelling to predict signatures of failure modes in these materials when they are attached to cryogenic fuel tanks.

  6. Characterization and comparison of defects detection limits of three ultrasonic non destructive methods

    NASA Astrophysics Data System (ADS)

    Péronnet, E.; Eyma, F.; Welemane, H.; Pescay, C.

    2010-06-01

    This work deals with the Liquid Resin Infusion (LRI) process developed within the research program “FUSelage COMPosite” of DAHER SOCATA. This manufacturing process enables the realization of complex composite structures or fuselage elements in a single phase (mono-material), which considerably reduce connections and relative difficulties. The concern here is the investigation of non destructive testing (NDT) methods that can be applied to LRI-structures in order to define their capacities for defect detection, and especially their associated critical defect size. In aviation industry, the AITM standards require the ultrasonic testing as NDT for composite materials. Therefore the aim of this work is to characterize and compare three different and complementary ultrasonic techniques on composite specimens. Such analysis allows to define the NDT application field of each method in term of defect detection.

  7. Non-destructive testing of mid-IR optical fiber using infrared imaging

    NASA Astrophysics Data System (ADS)

    Gagnon, Marc-André; Fortin, Vincent; Vallée, Réal; Farley, Vincent; Lagueux, Philippe; Guyot, Éric; Marcotte, Frédérick

    2016-10-01

    Optical fiber lasers offers the advantage of being relatively compact and efficient. However, the materials such as fluoride and chalcogenide glasses used for their fabrication must be exempt of defects in order to make efficient laser systems. However, most existing quality control techniques are not compatible with chalcogenide fibers because of their limited transparency in the visible spectral range. For this reason, the Université Laval's Centre d'optique, photonique et laser (COPL), in Quebec City, Canada, has developed a novel non-destructive testing (NDT) methodology based on infrared imaging to address this problem. The results show how this simple screening technique eases the selection of high-quality fibers for the design of high-power mid-IR lasers.

  8. Could non-destructive methodologies enhance the microbiologically influenced corrosion (MIC) in pipeline systems?

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    Stringent corrosion management programs are being deployed by oil and gas industry to ensure the integrity of pipeline systems. Parts of this program are the corrosion protection systems and inspection detection methods included non-destructive techniques. Those measures induce remnant magnetic field (RMF) in the pipeline steel. Potentially the RMF could affect the corrosion process in the pipeline including microbiologically influenced corrosion (MIC). Microorganisms in pipelines have surface charges and produce a wide variety of metabolic products. Consequently, when they are exposed to RMF generated at the linepipe steel surface by the aforementioned sources there will be potential effects. This sequentially will increase the likelihood of biofilm formation and hence enhance/promote MIC. This study investigates the potential effects of RFM on the MIC by sulfate reducing bacteria (SRB).

  9. Contribution to the improvement of heritage mural painting non-destructive testing by stimulated infrared thermography

    NASA Astrophysics Data System (ADS)

    Bodnar, Jean-Luc; Mouhoubi, Kamel; Di Pallo, Luigi; Detalle, Vincent; Vallet, Jean-Marc; Duvaut, Thierry

    2013-10-01

    Non-destructive testing of heritage mural paintings by means of stimulated infrared thermography has now become rather efficient [1-14]. However, pigments, which form a pictorial layer, have contrasting radiative properties possibly leading to artifact detection. In this paper, attempts to alleviate this difficulty are presented. Based on the spectroscopic study of different paint layers, one can argue that, in the medium infrared field, this radiative disparity decreases significantly. Then, with similar settings, it can be shown that ceramic radiative sources allow reaching this wavelength band. Finally, on the basis of a study carried out on an academic sample and a partial copy of a fresco from the cathedral of Angers, combining ceramic heat sources with a laboratory SAMMTHIR experimental setup enables to make real headway in terms of defects' detection.

  10. Monitoring ground anchor using non-destructive ground anchor integrity test (NDT-GRANIT)

    SciTech Connect

    Robbany, Z. Handayani, G.

    2015-09-30

    Monitoring at ground anchor commonly uses a pull out test method, therefor we developing a non-destructive ground anchor integrity testing (NDT-GRANIT). NDT-GRANIT using the principle of seismic waves that have been modified into form of sweep signal, the signal will be demodulated, filtered, and Fourier transformation (inverse discrete Fourier transform) so the data can be interpreted reflected wave from the ground anchor. The method was applied to determine whether the ground anchor still gripped in the subsurface by looking the attenuation of the wave generated sources. From the result we can see that ground anchor does not grip. To validate the results of the comparison method of measurement used pile integrity test.

  11. Design of ERL Spoke Cavity For Non-Destructive Assay Research

    NASA Astrophysics Data System (ADS)

    Sawamura, M.; Nagai, R.; Nishimori, N.; Hajima, R.

    2015-10-01

    We are proposing non-destructive assay system of nuclear materials with laser Compton scattering combined with an energy-recovery linac (ERL) and a laser. Since constructing accelerator system for nuclear safe guard and security requires small cavities, spoke cavities have many advantages such as shortening the distance between cavities, small frequency detune due to micro-phonics and easy adjustment of field distribution for strong cell coupling. Calculations of optimized cavity shape and HOM coupler shape have been performed and rf properties with aluminum spoke cavity model have been also measured. Considering refrigerator system required for superconducting accelerator, we are planning to develop 325MHz spoke cavity which can be practically operated with 4K liquid helium. We have started to fabricate the niobium one-spoke cavity.

  12. Non-destructive testing of mid-IR optical fiber using infrared imaging

    NASA Astrophysics Data System (ADS)

    Gagnon, Marc-André; Fortin, Vincent; Vallée, Réal; Farley, Vincent; Lagueux, Philippe; Guyot, Éric; Marcotte, Frédérick

    2016-05-01

    Optical fiber lasers offers the advantage of being relatively compact and efficient. However, the materials such as fluoride and chalcogenide glasses used for their fabrication must be exempt of defects in order to make efficient laser systems. However, most existing quality control techniques are not compatible with chalcogenide fibers because of their limited transparency in the visible spectral range. For this reason, the Université Laval's Centre d'optique, photonique et laser (COPL), in Quebec City, Canada, has developed a novel non-destructive testing (NDT) methodology based on infrared imaging to address this problem. The results show how this simple screening technique eases the selection of high-quality fibers for the design of high-power mid-IR lasers.

  13. Main geophysical techniques used for non-destructive evaluation in cultural built heritage: a review

    NASA Astrophysics Data System (ADS)

    Martinho, E.; Dionísio, A.

    2014-10-01

    Geophysical methodologies have been implemented, tested and validated as diagnostic and /or monitoring tools in artworks or historical monuments. They are non-destructive and can give an image of internal structure of investigated medium. This paper is a review about the main geophysical techniques applied to the study of cultural built heritage (excluding the archaeology field). A brief description of the used methodologies is presented, the main investigations done in this field are showed, the method or methods most appropriate to answer each problem (moisture detection, characterization of the materials, study of the structural continuity of the material, assessment of intervention’s effectiveness) are indicated and the main advances and gaps and future developments are also pointed out.

  14. Prediction of Service Life of Cordierite-Mullite Refractory Materials by Non-Destructive Methods

    SciTech Connect

    Boccaccini, D. N.; Kamseu, Elie; Cannio, M.; Romagnoli, M.; Veronesi, P.; Leonelli, C.; Volkov-Husoviae, T. D.; Dlouhy, I.; Boccaccini, A. R.

    2008-02-15

    Ultrasonic pulse velocity testing was used to perform non-destructive quality control of refractory plates used as substrates in fast firing of porcelain whitewares. The measurement of the ultrasonic velocity was used to asses the presence of internal voids or cracks originated from the manufacturing procedure. Image analysis was used to predict thermal stability of the refractory materials. Two cordierite-mullite compositions were investigated that are characterized by different microstructure morphologies and crack propagation behaviour. A brief discussion about the correlation between microstructure, crack propagation behaviour and thermal shock resistance is presented. Moreover, empirical models were developed to predict the service life of refractory plates from measured values of ultrasonic velocities in plates in the as-received state.

  15. Gigahertz time-domain spectroscopy and imaging for non-destructive materials research and evaluation

    PubMed Central

    Bulgarevich, Dmitry S.; Shiwa, Mitsuharu; Furuya, Takashi; Tani, Masahiko

    2016-01-01

    By using optical sampling with repetition frequency modulation of pump/probe laser pulses on photoconductive emitter/detector antennas, the high-speed time/frequency domain gigahertz imaging is reported due to the absence of opto-mechanical delay line in this optical scheme. The clear contrast for a 3-cm wide metal plate, which was placed behind a 5-cm thick concrete block, was observed with a 1 × 1 mm image pixilation. On average, it took only ~0.75 s per pixel/waveform acquisition/assignment with a 675 ps time-domain window. This could become a valuable non-destructive evaluation technique in gigahertz spectral range with all benefits of time-domain spectroscopy. PMID:27302877

  16. Portable 1,5 MeV X-Band Linac For Non-destructive Radiography

    NASA Astrophysics Data System (ADS)

    Saversky, A. J.; Rodionov, A. E.; Shaltyrev, A. P.; Shchedrin, I. S.

    1997-05-01

    Portable linear electron accelerator Y-34 developed in Small Accelerator Laboratory of MEPhI for non-destructive industrial radiography. This Linac is a fully self-contained device with the exception of external electric power 220Vx50Gz, 1 phase, 5 kVA. Full mass of Linac Y-34 - less than 300 kg. The Radiographic parameters: Nominal Energy - 1,5 MeV; Energy Range - 0,7...1,8 MeV; Maximum pulse current - 100 mA; Maximum Intensity - 15 R/min@m; Focal spot size - less than 2 mm. The Linac is comprised of 4 subassemblies. The X-ray head with weight less than 100 kg, dimensions: 0,7x0,7x1,0 m contains the traveling-wave accelerating structure with lens 0,4 m, electron gun, vacuum pump, tungsten target and RF-system with 500-kW magnetron. The permanent magnets focusing system provides focal spot less than 2 mm. The high voltage power unit consist of a line-type magnetron/electron gun modulator 2 kW power supply, the weight is equal 70 kg. The self-contained cooling water supply provides temperature controlled water for accelerator structure and magnetron. The control console allows convenient monitoring of critical system and Linac parameters by manual or remote computer. Portable X-band Linac Y-34 is the effective X - ray and/or electron beam source for such applications as non-destructive examination of nuclear reactor systems, solid rocket motors, technology research.

  17. Non-destructive ripeness sensing by using proton NMR (Nuclear Magnetic Resonance)

    SciTech Connect

    Cho, Seong In; Krutz, G.W.; Stroshine, R.L. . Dept. of Agricultural Engineering); Bellon, V. , 34 - Montpellier )

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz). 7 refs., 4 figs.

  18. Fatigue damage evolution study with non-destructive magnetic properties measurement method using scanning SQUID microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Tae-Kyu

    The fatigue process can be precisely defined in the crack propagation stage, where the fatigue damage can be evaluated by observed cracks and where an increase of the dislocation density occurs at the first 10% of the fatigue life. But for the stages between dislocation saturation and prior to nucleation, no definition can be given due to the relative difficulty in quantifying the damage. Especially, detecting a high-cycle fatigue damage is a particularly important yet an unsolved problem in non-destructive testing. There are no reliable techniques to measure the progress of fatigue in the intermediate fatigue regime, the second stage of fatigue, where the overall dislocation density is approximately constant and the microstructural changes are subtle include about 80% of the fatigue life in high-cycle fatigue. In this study, a non-destructive evaluation method is established by continuously measuring the magnetic properties, which interact with the developing fatigue damage during cyclic loading. Dislocations and microcracks which are initiated during the fatigue act as pinning sites which impede the motion of magnetic domain walls under the applied magnetic field, thereby influencing the bulk magnetic properties. The remanence field of various fatigued steel specimens are detected using a scanning microscope based on a high transition temperature Superconducting Quantum Interference Device (SQUID). The results show the development of localized peaks in remanent magnetization prior to the formation of visible fatigue cracks. Even in the second stage of fatigue, where the macroscopic state of the sample is relatively constant, the results show that a scanning SQUID microscope is capable of detecting regions of fatigue damage both on surface and in sub-surface regions.

  19. Monitoring fungal growth on brown rice grains using rapid and non-destructive hyperspectral imaging.

    PubMed

    Siripatrawan, U; Makino, Y

    2015-04-16

    This research aimed to develop a rapid, non-destructive, and accurate method based on hyperspectral imaging (HSI) for monitoring spoilage fungal growth on stored brown rice. Brown rice was inoculated with a non-pathogenic strain of Aspergillus oryzae and stored at 30 °C and 85% RH. Growth of A. oryzae on rice was monitored using viable colony counts, expressed as colony forming units per gram (CFU/g). The fungal development was observed using scanning electron microscopy. The HSI system was used to acquire reflectance images of the samples covering the visible and near-infrared (NIR) wavelength range of 400-1000 nm. Unsupervised self-organizing map (SOM) was used to visualize data classification of different levels of fungal infection. Partial least squares (PLS) regression was used to predict fungal growth on rice grains from the HSI reflectance spectra. The HSI spectral signals decreased with increasing colony counts, while conserving similar spectral pattern during the fungal growth. When integrated with SOM, the proposed HSI method could be used to classify rice samples with different levels of fungal infection without sample manipulation. Moreover, HSI was able to rapidly identify infected rice although the samples showed no symptoms of fungal infection. Based on PLS regression, the coefficient of determination was 0.97 and root mean square error of prediction was 0.39 log (CFU/g), demonstrating that the HSI technique was effective for prediction of fungal infection in rice grains. The ability of HSI to detect fungal infection at early stage would help to prevent contaminated rice grains from entering the food chain. This research provides scientific information on the rapid, non-destructive, and effective fungal detection system for rice grains.

  20. A Monte Carlo approach applied to ultrasonic non-destructive testing

    NASA Astrophysics Data System (ADS)

    Mosca, I.; Bilgili, F.; Meier, T. M.; Sigloch, K.

    2011-12-01

    Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and engineering structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to analyze ultrasonic waveforms measured at the surface of Plexiglas and rock samples, and to define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface waves in typical materials tested with a non-destructive technique (e.g., marble, unweathered and weathered concrete and natural stone).

  1. Wave field features of shallow vertical discontinuity and their application in non-destructive detection

    USGS Publications Warehouse

    Liu, J.; Xia, J.; Luo, Y.; Chen, C.; Li, X.; Huang, Y.

    2007-01-01

    The geotechnical integrity of critical infrastructure can be seriously compromised by the presence of fractures or crevices. Non-destructive techniques to accurately detect fractures in critical infrastructure such as dams and highways could be of significant benefit to the geotechnical industry. This paper investigates the application of shallow seismic and georadar methods to the detection of a vertical discontinuity using numerical simulations. The objective is to address the kinematical analysis of a vertical discontinuity, determine the resulting wave field characteristics, and provide the basis for determining the existence of vertical discontinuities based on the recorded signals. Simulation results demonstrate that: (1) A reflection from a vertical discontinuity produces a hyperbolic feature on a seismic or georadar profile; (2) In order for a reflection from a vertical discontinuity to be produced, a reflecting horizon below the discontinuity must exist, the offset between source and receiver (x0) must be non-zero, on the same side of the vertical discontinuity; (3) The range of distances from the vertical discontinuity where a reflection event is observed is proportional to its length and to x0; (4) Should the vertical crevice (or fracture) pass through a reflecting horizon, dual hyperbolic features can be observed on the records, and this can be used as a determining factor that the vertical crevice passes through the interface; and (5) diffractions from the edges of the discontinuity can be recorded with relatively smaller amplitude than reflections and their ranges are not constrained by the length of discontinuity. If the length of discontinuity is short enough, diffractions are the dominant feature. Real-world examples show that the shallow seismic reflection method and the georadar method are capable of recording the hyperbolic feature, which can be interpreted as vertical discontinuity. Thus, these methods show some promise as effective non-destructive

  2. Variation in gymnemic acid content and non-destructive harvesting of Gymnema sylvestre (Gudmar)

    PubMed Central

    Pandey, Ashok Kumar; Yadav, Swati

    2010-01-01

    Background: Madhunashini (Gymnema sylvestre R. Br.) commonly known as ‘Gudmar’ in Hindi is an important medicinal climber and extensively used in almost all Indian System of Medicine as a remedy for diabetes, rheumatism, cough, ulcer, jaundice, dyspepsia, constipation, eyes pain and also in snakebite. In India, it is found growing in Andhra Pradesh, Bihar, Chhattisgarh, Karnataka, Kerala, Madhya Pradesh, Maharastra, Orissa, Tamil Nadu, Uttar Pradesh and West Bengal. The major phytoconstituents are gymnemic acids, gudmarin and saponins. Methods: In the present study, Gymnema germplasm collected from various regions of Madhya Pradesh was evaluated on the basis of their morphological characteristics and gymnemic acid content. Gymnemic acid content in the leaves was estimated by HPLC. We have also standardized the non-destructive harvesting practices of Gudmar. Selective harvesting was done without harming the main plant. Only mature leaves (60%) were hand plucked in the month of October. Second harvest was done in the month of June. Results: Data revealed that gymnemic acid content varied between 0.96% ± 0.03 (Seoni) to 1.58% ±0.03 (Amarkantak). It was also observed that the leaves left at the time of 1st harvest during October matured in June at the time of 2nd harvest. Conclusion: Non destructive harvesting practice did not have any negative impact on overall development of the plant. It is evident that there is wide variation in the morphological characteristics and gymnemic acid content in G. sylvestre collected from various locations, which can be exploited for further crop improvement programmes. PMID:21589758

  3. Magnetic Microcalorimeter Gamma Detectors for High-Precision Non-Destructive Analysis

    SciTech Connect

    Friedrich, Stephan; Bates, Cameron; Pereverzev, Sergey

    2014-10-03

    Cryogenic gamma (γ) detectors with operating temperatures of ~0.1 K offer 10× better energy resolution than conventional high-purity germanium detectors that are currently used for non-destructive analysis (NDA) of nuclear materials. This can greatly increase the accuracy of NDA, especially at low-energies where gamma rays often have similar energies and cannot be resolved by Ge detectors. Among the different cryogenic detector types, Magnetic Micro-Calorimeters (MMCs) have the potential of faster count rates and better linearity. High linearity is essential to add spectra from different pixels in detector arrays that are needed for high sensitivity. MMC gamma detectors measure the energy of absorbed gamma rays form the resulting change in magnetization of an erbium-doped gold (Au:Er) sensor. The signal is read out with a SQUID preamplifier and processed digitally with room temperature electronics (see inset figure 2). The objective of this project is to develop ultra-high energy resolution γ-detectors based on magnetic micro-calorimeters (MMCs) for accurate non-destructive isotope analysis (NDA). Since MMCs, like other cryogenic γ-detector technologies with operating temperatures <0.1 K, are intrinsically slow and have to be small for high resolution, special emphasis will be placed on questions that determine sensitivity and the potential for scaling to arrays. Objectives for FY14 were therefore to fabricate an improved version of MMC γ-detectors and test their energy resolution, maximum count rate, readout noise, crosstalk between pixels and linearity.

  4. Non-destructive in situ mapping of macroholes, cracks and inhomogeneities of stalagmites in cave environments

    NASA Astrophysics Data System (ADS)

    Hegymegi, Erika; Gyöngy, Miklós; Bodolai, Tamás; Divós, Ferenc; Barta, Edit; Gribovszki, Katalin; Bokelmann, Götz; Hegymegi, Csaba; Lednická, Markéta; Kovács, Károly

    2016-04-01

    Intact and vulnerable, candle-stick type stalagmites can be used as prehistoric-earthquake indicators during seismic-hazard analysis of a given region, because they are old enough to survive several earthquakes. The continued intactness of the stalagmites indicates a lack of earthquakes that had the strength to destroy them. To make sure that the stalagmites are intact, we have to image their internal structure in order to estimate the steadiness more accurate and potential failure in the last few thousand years, during their evolution. These stalagmites play an important indicator role and carry fundamental information; however, legally they are strictly protected natural objects in Europe. Therefore it is impossible to examine them in the laboratory by conventional equipment such as computer tomography (CT) or X-ray, because this would require taking samples. With the presented non-destructive methods (ultrasound and acoustic tomography) we tried to detect macroholes, cracks and velocity anomalies inside the stalagmites on the mm scale in situ, in the cave. The acoustic tomography applied in the current work is an existing method in forest research. Forest researchers use it to non-destructively detect the size and location of decayed or hollow parts in the trunk and this technique is able to detect the velocity changing of wave propagation and anomalies in the stalagmites as well. The other method that we use is ultrasound imaging, which uses (and is able to calculate) the velocity of sound propagation. Here, the frequency used is much higher (typically 250 kHz to 5 MHz), which increases resolution but at the same time decreases penetration depth compared to acoustic tomography. In this latter work, through transmission and TOFD (time-of-flight-diffraction) ultrasound methods are using thickness-mode ultrasound transducers (Panametrics, Olympus). Such equipment is well-adapted to the cave environment and this is the first time that it has been used for these

  5. Non-destructive Ripeness Sensing by Using Proton NMR [Nuclear Magnetic Resonance

    DOE R&D Accomplishments Database

    Cho, Seong In; Krutz, G. W.; Stroshine, R. L.; Bellon, V.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz).

  6. Ambient air pollution exposure, residential mobility and term birth weight in Oslo, Norway.

    PubMed

    Madsen, Christian; Gehring, Ulrike; Walker, Sam Erik; Brunekreef, Bert; Stigum, Hein; Naess, Oyvind; Nafstad, Per

    2010-05-01

    Environmental exposure during pregnancy may have lifelong health consequences for the offspring and some studies have association between maternal exposure to air pollution during pregnancy and offspring's birth weight. However, many of these studies do not take into account small-scale variations in exposure, residential mobility, and work addresses during pregnancy. We used information from the National Birth Registry of Norway to examine associations between ambient environmental exposure such as air pollution and temperature, and offspring's birth weight taking advantage of information on migration history and work address in a large population-based cohort. A dispersion model was used to estimate ambient air pollution levels at all residential addresses and work addresses for a total of 25,229 pregnancies between 1999 and 2002 in Oslo, Norway. Ambient exposure to traffic pollution for the entire pregnancy was associated with a reduction in term birth weight in crude analyzes when comparing children of the highest and lowest exposed mothers. No evidence for an association between exposure to traffic pollution at home and work addresses and term birth weight after adjustment for covariates known to influence birth weight during pregnancy. After stratification, small statistically non-significant reductions were present but only for multiparious mothers. This group also had less residential mobility and less employment during pregnancy. The overall findings suggest no clear association between term birth weight and traffic pollution exposure during pregnancy. However, mobility patterns could introduce possible confounding when examining small-scale variations in exposure by using addresses. This could be of importance in future studies.

  7. Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models

    PubMed Central

    Ragettli, Martina S.; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E.; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C.

    2014-01-01

    We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland), and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2) as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD) NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m−3, range: 21–61) than with a dispersion model with a lower resolution (39 ± 5 µg m−3; range: 24–51), and a land use regression model (41 ± 5 µg m−3; range: 24–54). Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas. PMID:24823664

  8. Modelling of human exposure to air pollution in the urban environment: a GPS-based approach.

    PubMed

    Dias, Daniela; Tchepel, Oxana

    2014-03-01

    The main objective of this work was the development of a new modelling tool for quantification of human exposure to traffic-related air pollution within distinct microenvironments by using a novel approach for trajectory analysis of the individuals. For this purpose, mobile phones with Global Positioning System technology have been used to collect daily trajectories of the individuals with higher temporal resolution and a trajectory data mining, and geo-spatial analysis algorithm was developed and implemented within a Geographical Information System to obtain time-activity patterns. These data were combined with air pollutant concentrations estimated for several microenvironments. In addition to outdoor, pollutant concentrations in distinct indoor microenvironments are characterised using a probabilistic approach. An example of the application for PM2.5 is presented and discussed. The results obtained for daily average individual exposure correspond to a mean value of 10.6 and 6.0-16.4 μg m(-3) in terms of 5th-95th percentiles. Analysis of the results shows that the use of point air quality measurements for exposure assessment will not explain the intra- and inter-variability of individuals' exposure levels. The methodology developed and implemented in this work provides time-sequence of the exposure events thus making possible association of the exposure with the individual activities and delivers main statistics on individual's air pollution exposure with high spatio-temporal resolution.

  9. Simulation of population-based commuter exposure to NO₂ using different air pollution models.

    PubMed

    Ragettli, Martina S; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C

    2014-05-12

    We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland), and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2) as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD) NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m(-3), range: 21-61) than with a dispersion model with a lower resolution (39 ± 5 µg m(-3); range: 24-51), and a land use regression model (41 ± 5 µg m(-3); range: 24-54). Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas.

  10. A simulation study to determine the attenuation and bias in health risk estimates due to exposure measurement error in bi-pollutant models

    EPA Science Inventory

    To understand the combined health effects of exposure to ambient air pollutant mixtures, it is becoming more common to include multiple pollutants in epidemiologic models. However, the complex spatial and temporal pattern of ambient pollutant concentrations and related exposures ...

  11. Arsenic pesticides and environmental pollution: exposure, poisoning, hazards and recommendations.

    PubMed

    El-Bahnasawy, Mamdouh M; Mohammad, Amina El-Hosini; Morsy, Tosson A

    2013-08-01

    Arsenic is a metalloid element. Acute high-dose exposure to arsenic can cause severe systemic toxicity and death. Lower dose chronic arsenic exposure can result in subacute toxicity that can include peripheral sensorimotor neuropathy, skin eruptions, and hepatotoxicity. Long-term effects of arsenic exposure include an in Due to the physiologic effects of the arsenic on all body systems, thus, chronic arsenic-poisoned patient is a major nursing challenge. The critical care nurse provides valuable assessment and interventions that prevent major multisystem complications from arsenic toxicity.

  12. Climate change impacts on human exposures to air pollution

    EPA Science Inventory

    This is an abstract for a presentations at the Annual Conference of the International Society on Exposure Science and Environmental Epidemiology. This presentation will serve as an introduction to the symposium.

  13. Heterogeneity of passenger exposure to air pollutants in public transport microenvironments

    NASA Astrophysics Data System (ADS)

    Yang, Fenhuan; Kaul, Daya; Wong, Ka Chun; Westerdahl, Dane; Sun, Li; Ho, Kin-fai; Tian, Linwei; Brimblecombe, Peter; Ning, Zhi

    2015-05-01

    Epidemiologic studies have linked human exposure to pollutants with adverse health effects. Passenger exposure in public transport systems contributes an important fraction of daily burden of air pollutants. While there is extensive literature reporting the concentrations of pollutants in public transport systems in different cities, there are few studies systematically addressing the heterogeneity of passenger exposure in different transit microenvironments, in cabins of different transit vehicles and in areas with different characteristics. The present study investigated PM2.5 (particulate matter with aerodynamic diameters smaller than 2.5 μm), black carbon (BC), ultrafine particles (UFP) and carbon monoxide (CO) pollutant concentrations in various public road transport systems in highly urbanized city of Hong Kong. Using a trolley case housing numerous portable air monitors, we conducted a total of 119 trips during the campaign. Transit microenvironments, classified as 1). busy and secondary roadside bus stops; 2). open and enclosed termini; 3). above- and under-ground Motor Rail Transport (MTR) platforms, were investigated and compared to identify the factors that may affect passenger exposures. The pollutants inside bus and MTR cabins were also investigated together with a comparison of time integrated exposure between the transit modes. Busy roadside and enclosed termini demonstrated the highest average particle concentrations while the lowest was found on the MTR platforms. Traffic-related pollutants BC, UFP and CO showed larger variations than PM2.5 across different microenvironments and areas confirming their heterogeneity in urban environments. In-cabin pollutant concentrations showed distinct patterns with BC and UFP high in diesel bus cabins and CO high in LPG bus cabins, suggesting possible self-pollution issues and/or penetration of on-road pollutants inside cabins during bus transit. The total passenger exposure along selected routes, showed bus

  14. Methods for assessing the extent of exposure and effects of air pollution.

    PubMed Central

    Krzyzanowski, M

    1997-01-01

    BACKGROUND AND OBJECTIVES: In many places in Europe, the ambient air pollution exceeds the levels considered to be safe for health. The objective of the paper is to review and summarise the methods of assessment of its impact on health, and to indicate the contributions of various research disciplines, particularly environmental epidemiology. METHODS: The framework for assessment of impact is based on a four stage model: assessment of release of pollutant; assessment of exposure; assessment of the consequence; and risk estimation. RESULTS: Epidemiology is crucial in providing the data for the assessment of consequence. The criteria that determine the use of epidemiological studies for this task include lack of bias, correct control of confounding, and measured estimates of exposure. At present, those criteria are easier to satisfy for studies of short term effects on health than for the delayed consequences of exposure, or exposure accumulated over a prolonged period. Combinations of results from various populations through meta-analysis of existing studies or conducting multicentre studies is often necessary to increase the reliability of the consequence assessment stage. CONCLUSION: To assess the impact on health systematically helps to focus on actions to limit air pollutants with the greatest impacts on human health and on the most affected populations. This method allows identification of the most pertinent questions which have to be answered by studies on relations between pollution and health and on exposure of populations to air pollutants. Epidemiology has considerable potential to contribute to this research. PMID:9155775

  15. Effects of Exposure Measurement Error in the Analysis of Health Effects from Traffic-Related Air Pollution

    EPA Science Inventory

    In large epidemiological studies, many researchers use surrogates of air pollution exposure such as geographic information system (GIS)-based characterizations of traffic or simple housing characteristics. It is important to validate these surrogates against measured pollutant co...

  16. Spatial-temporal modeling of the association between air pollution exposure and preterm birth: identifying critical windows of exposure.

    PubMed

    Warren, Joshua; Fuentes, Montserrat; Herring, Amy; Langlois, Peter

    2012-12-01

    Exposure to high levels of air pollution during the pregnancy is associated with increased probability of preterm birth (PTB), a major cause of infant morbidity and mortality. New statistical methodology is required to specifically determine when a particular pollutant impacts the PTB outcome, to determine the role of different pollutants, and to characterize the spatial variability in these results. We develop a new Bayesian spatial model for PTB which identifies susceptible windows throughout the pregnancy jointly for multiple pollutants (PM(2.5) , ozone) while allowing these windows to vary continuously across space and time. We geo-code vital record birth data from Texas (2002-2004) and link them with standard pollution monitoring data and a newly introduced EPA product of calibrated air pollution model output. We apply the fully spatial model to a region of 13 counties in eastern Texas consisting of highly urban as well as rural areas. Our results indicate significant signal in the first two trimesters of pregnancy with different pollutants leading to different critical windows. Introducing the spatial aspect uncovers critical windows previously unidentified when space is ignored. A proper inference procedure is introduced to correctly analyze these windows.

  17. In situ non-destructive measurement of biofilm thickness and topology in an interferometric optical microscope

    SciTech Connect

    Larimer, Curtis; Suter, Jonathan D.; Bonheyo, George; Addleman, Raymond Shane

    2016-03-15

    Biofilms are ubiquitous and deleteriously impact a wide range of industrial processes, medical and dental health issues, and environmental problems such as transport of invasive species and the fuel efficiency of ocean going vessels. Biofilms are difficult to characterize when fully hydrated, especially in a non-destructive manner, because of their soft structure and water-like bulk properties. Herein we describe a non-destructive high resolution method of measuring and monitoring the thickness and topology of live biofilms of using white light interferometric optical microscopy. Using this technique, surface morphology, surface roughness, and biofilm thickness can be measured non-destructively and with high resolution as a function of time without disruption of the biofilm activity and processes. The thickness and surface topology of a P. putida biofilm were monitored growing from initial colonization to a mature biofilm. Typical bacterial growth curves were observed. Increase in surface roughness was a leading indicator of biofilm growth.

  18. Pre-processing of data coming from a laser-EMAT system for non-destructive testing of steel slabs.

    PubMed

    Sgarbi, Mirko; Colla, Valentina; Cateni, Sivia; Higson, Stuart

    2012-01-01

    Non destructive test systems are increasingly applied in the industrial context for their strong potentialities in improving and standardizing quality control. Especially in the intermediate manufacturing stages, early detection of defects on semi-finished products allow their direction towards later production processes according to their quality, with consequent considerable savings in time, energy, materials and work. However, the raw data coming from non destructive test systems are not always immediately suitable for sophisticated defect detection algorithms, due to noise and disturbances which are unavoidable, especially in harsh operating conditions, such as the ones which are typical of the steelmaking cycle. The paper describes some pre-processing operations which are required in order to exploit the data coming from a non destructive test system. Such a system is based on the joint exploitation of Laser and Electro-Magnetic Acoustic Transducer technologies and is applied to the detection of surface and sub-surface cracks in cold and hot steel slabs.

  19. Traffic, air pollution, minority and socio-economic status: addressing inequities in exposure and risk.

    PubMed

    Pratt, Gregory C; Vadali, Monika L; Kvale, Dorian L; Ellickson, Kristie M

    2015-05-19

    Higher levels of nearby traffic increase exposure to air pollution and adversely affect health outcomes. Populations with lower socio-economic status (SES) are particularly vulnerable to stressors like air pollution. We investigated cumulative exposures and risks from traffic and from MNRiskS-modeled air pollution in multiple source categories across demographic groups. Exposures and risks, especially from on-road sources, were higher than the mean for minorities and low SES populations and lower than the mean for white and high SES populations. Owning multiple vehicles and driving alone were linked to lower household exposures and risks. Those not owning a vehicle and walking or using transit had higher household exposures and risks. These results confirm for our study location that populations on the lower end of the socio-economic spectrum and minorities are disproportionately exposed to traffic and air pollution and at higher risk for adverse health outcomes. A major source of disparities appears to be the transportation infrastructure. Those outside the urban core had lower risks but drove more, while those living nearer the urban core tended to drive less but had higher exposures and risks from on-road sources. We suggest policy considerations for addressing these inequities.

  20. Air Pollution Exposure During Pregnancy and Fetal Markers of Metabolic function: The MIREC Study.

    PubMed

    Lavigne, Eric; Ashley-Martin, Jillian; Dodds, Linda; Arbuckle, Tye E; Hystad, Perry; Johnson, Markey; Crouse, Dan L; Ettinger, Adrienne S; Shapiro, Gabriel D; Fisher, Mandy; Morisset, Anne-Sophie; Taback, Shayne; Bouchard, Maryse F; Sun, Liu; Monnier, Patricia; Dallaire, Renée; Fraser, William D

    2016-05-01

    Previous evidence suggests that exposure to outdoor air pollution during pregnancy could alter fetal metabolic function, which could increase the risk of obesity in childhood. However, to our knowledge, no epidemiologic study has investigated the association between prenatal exposure to air pollution and indicators of fetal metabolic function. We investigated the association between maternal exposure to nitrogen dioxide and fine particulate matter (aerodynamic diameter ≤2.5 µm) and umbilical cord blood leptin and adiponectin levels with mixed-effects linear regression models among 1,257 mother-infant pairs from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, conducted in Canada (2008-2011). We observed that an interquartile-range increase in average exposure to fine particulate matter (3.2 µg/m(3)) during pregnancy was associated with an 11% (95% confidence interval: 4, 17) increase in adiponectin levels. We also observed 13% (95% confidence interval: 6, 20) higher adiponectin levels per interquartile-range increase in average exposure to nitrogen dioxide (13.6 parts per billion) during pregnancy. Significant associations were seen between air pollution markers and cord blood leptin levels in models that adjusted for birth weight z score but not in models that did not adjust for birth weight z score. The roles of prenatal exposure to air pollution and fetal metabolic function in the potential development of childhood obesity should be further explored.

  1. [Applying temporally-adjusted land use regression models to estimate ambient air pollution exposure during pregnancy].

    PubMed

    Zhang, Y J; Xue, F X; Bai, Z P

    2017-03-06

    The impact of maternal air pollution exposure on offspring health has received much attention. Precise and feasible exposure estimation is particularly important for clarifying exposure-response relationships and reducing heterogeneity among studies. Temporally-adjusted land use regression (LUR) models are exposure assessment methods developed in recent years that have the advantage of having high spatial-temporal resolution. Studies on the health effects of outdoor air pollution exposure during pregnancy have been increasingly carried out using this model. In China, research applying LUR models was done mostly at the model construction stage, and findings from related epidemiological studies were rarely reported. In this paper, the sources of heterogeneity and research progress of meta-analysis research on the associations between air pollution and adverse pregnancy outcomes were analyzed. The methods of the characteristics of temporally-adjusted LUR models were introduced. The current epidemiological studies on adverse pregnancy outcomes that applied this model were systematically summarized. Recommendations for the development and application of LUR models in China are presented. This will encourage the implementation of more valid exposure predictions during pregnancy in large-scale epidemiological studies on the health effects of air pollution in China.

  2. Exposure and measurement contributions to estimates of acute air pollution effects.

    PubMed

    Sheppard, Lianne; Slaughter, James C; Schildcrout, Jonathan; Liu, L-J Sally; Lumley, Thomas

    2005-07-01

    Air pollution health effect studies are intended to estimate the effect of a pollutant on a health outcome. The definition of this effect depends upon the study design, disease model parameterization, and the type of analysis. Further limitations are imposed by the nature of exposure and our ability to measure it. We define a plausible exposure model for air pollutants that are relatively nonreactive and discuss how exposure varies. We discuss plausible disease models and show how their parameterizations are affected by different exposure partitions and by different study designs. We then discuss a measurement model conditional on ambient concentrations and incorporate this into the disease model. We use simulation studies to show the impact of a range of exposure model assumptions on estimation of the health effect in the ecologic time series design. This design only uses information from the time-varying ambient source exposure. When ambient and nonambient sources are independent, exposure variation due to nonambient source exposures behaves like Berkson measurement error and does not bias the effect estimates. Variation in the population attenuation of ambient concentrations over time does bias the estimates with the bias being either positive or negative depending upon the association of this parameter with ambient pollution. It is not realistic to substitute measured average personal exposures into time series studies because so much of the variation in personal exposures comes from nonambient sources that do not contribute information in the time series design. We conclude that general statements about the implications of measurement error need to be conditioned on the health effect study design and the health effect parameter to be estimated.

  3. Destructive and non-destructive determination of the transport current density radial distribution: Application to Bi-2212 textured rods

    NASA Astrophysics Data System (ADS)

    Martínez, E.; Natividad, E.; Angurel, L. A.; Navarro, R.; Yang, Y.; Beduz, C.

    2003-03-01

    Destructive and non-destructive methods to estimate the radial distribution of the transport critical current, Jc( r), of long cylindrical superconductors are presented. The non-destructive method is based on the measurement of self-field AC losses as a function of the current amplitude, Q( I0) and takes into account the E- J characteristics of the material. Both methods have been used to derive the Jc( r) profiles of long and thin Bi-2212 rods textured by laser-induced zone melting techniques. The obtained results have been correlated with the microstructure of the samples and their critical temperature.

  4. Reduced exposure to air pollution on the boardwalk in Dublin, Ireland. Measurement and prediction.

    PubMed

    McNabola, A; Broderick, B M; Gill, L W

    2008-01-01

    This paper outlines an air pollution study carried out on Dublin city's recently completed boardwalk along the side of and overhanging the River Liffey. Air quality samples were taken along the length of the boardwalk to investigate whether pedestrians using the boardwalk would have a lower air pollution exposure than those using the adjoining footpath along the road. The results of the study show significant reductions in pedestrian exposure to both traffic derived particulates and hydrocarbons along the boardwalk as opposed to the footpath. Computational fluid dynamics was also used to model the outcome of these field measurements and shows the importance of the boundary wall between the footpath and boardwalk in reducing air pollution exposure for the pedestrian, the results of which are also presented herein.

  5. NEUROBEHAVIORAL EFFECTS OF EXPOSURE TO ENVIRONMENTAL POLLUTANTS IN CZECH CHILDREN

    EPA Science Inventory

    Ambient levels of SO2, NOx, PAHs and heavy metals are elevated in Northern Bohemia as a result of intensive mining and combustion of brown coal. To assess the neurotoxicological effects of exposure to these chemicals, tests from the Neurobehavioral Evaluation System (NES2) we...

  6. Traffic pollution exposure is associated with altered brain connectivity in school children.

    PubMed

    Pujol, Jesus; Martínez-Vilavella, Gerard; Macià, Dídac; Fenoll, Raquel; Alvarez-Pedrerol, Mar; Rivas, Ioar; Forns, Joan; Blanco-Hinojo, Laura; Capellades, Jaume; Querol, Xavier; Deus, Joan; Sunyer, Jordi

    2016-04-01

    Children are more vulnerable to the effects of environmental elements due to their active developmental processes. Exposure to urban air pollution has been associated with poorer cognitive performance, which is thought to be a result of direct interference with brain maturation. We aimed to assess the extent of such potential effects of urban pollution on child brain maturation using general indicators of vehicle exhaust measured in the school environment and a comprehensive imaging evaluation. A group of 263 children, aged 8 to 12 years, underwent MRI to quantify regional brain volumes, tissue composition, myelination, cortical thickness, neural tract architecture, membrane metabolites, functional connectivity in major neural networks and activation/deactivation dynamics during a sensory task. A combined measurement of elemental carbon and NO2 was used as a putative marker of vehicle exhaust. Air pollution exposure was associated with brain changes of a functional nature, with no evident effect on brain anatomy, structure or membrane metabolites. Specifically, a higher content of pollutants was associated with lower functional integration and segregation in key brain networks relevant to both inner mental processes (the default mode network) and stimulus-driven mental operations. Age and performance (motor response speed) both showed the opposite effect to that of pollution, thus indicating that higher exposure is associated with slower brain maturation. In conclusion, urban air pollution appears to adversely affect brain maturation in a critical age with changes specifically concerning the functional domain.

  7. Selection of native plants with phytoremediation potential for highly contaminated Mediterranean soil restoration: Tools for a non-destructive and integrative approach.

    PubMed

    Heckenroth, Alma; Rabier, Jacques; Dutoit, Thierry; Torre, Franck; Prudent, Pascale; Laffont-Schwob, Isabelle

    2016-12-01

    The aim of this study was to develop an effective and non-destructive method for the selection of native Mediterranean plants with phytoremediation potential based on their spontaneous recovery capacities. The study site consisted in a mixed contaminated soils (As, Cu, Pb, Sb, Zn) in the vicinity of a former lead smelting factory abandoned since 1925 in the Calanques National Park (Marseille, southeastern France). We developed an integrated characterization approach that takes into account topsoil metal(loid)s (MM) contamination, plant community composition and structure and mesologic parameters without using destructive methods. From a statistical selection of significant environmental descriptors, plant communities were described and interpreted as the result of spontaneous recovery under multiple stresses and local conditions (both natural and anthropogenic). We collected phytoecological and MM topsoil data using field monitoring and geographic information system (GIS) on a pollution hotspot where natural plant communities occur. The results of the multivariate analysis performed between species and descriptors indicated that a century of MM pollution pressure produced a significant correlation with plant community dynamics in terms of composition, diversity and structure, leading to the co-occurrence of different plant succession stages. Thus, these successions seemed linked to the variability of anthropogenic disturbance regimes within the study site. We recorded high topsoil contamination heterogeneity at the scale both of the plot and of the whole study area that suggested a heterogeneous MM distribution pattern dependent on the source of contaminants and site environmental variability. We identified 4 spontaneous plant communities co-occurring through a MM contamination gradient that could be used later from degraded to reference communities to define ecological restoration target combined to phytoremediation applications with respect to local conditions

  8. Racial Differences in Perceptions of Air Pollution Health Risk: Does Environmental Exposure Matter?

    PubMed

    Chakraborty, Jayajit; Collins, Timothy W; Grineski, Sara E; Maldonado, Alejandra

    2017-01-25

    This article extends environmental risk perception research by exploring how potential health risk from exposure to industrial and vehicular air pollutants, as well as other contextual and socio-demographic factors, influence racial/ethnic differences in air pollution health risk perception. Our study site is the Greater Houston metropolitan area, Texas, USA-a racially/ethnically diverse area facing high levels of exposure to pollutants from both industrial and transportation sources. We integrate primary household-level survey data with estimates of excess cancer risk from ambient exposure to industrial and on-road mobile source emissions of air toxics obtained from the U.S. Environmental Protection Agency. Statistical analysis is based on multivariate generalized estimation equation models which account for geographic clustering of surveyed households. Our results reveal significantly higher risk perceptions for non-Hispanic Black residents and those exposed to greater cancer risk from industrial pollutants, and also indicate that gender influences the relationship between race/ethnicity and air pollution risk perception. These findings highlight the need to incorporate measures of environmental health risk exposure in future analysis of social disparities in risk perception.

  9. Diablo/SMAC: a novel biomarker of pollutant exposure in European flounder (Platichthys flesus).

    PubMed

    Zacchino, Valentina; Minghetti, Matteo; Centoducati, Gerardo; Leaver, Michael J

    2012-05-01

    Diablo (or SMAC) is a protein released from mitochondria following apoptotic stimuli and inhibits the actions of Inhibitors of Apoptosis (IAP) proteins. IAPs regulate the activity of caspases and NFkB, the primary executioners of apoptosis and of inflammation, respectively. Thus, Diablo is important for the regulation of cellular responses to damage. In Northern Europe, statutory governmental marine monitoring programs measure various biomarkers in flounder to indicate biological effects of pollutant exposure. More recently transcriptomic techniques have been applied in flounder to gain a more comprehensive understanding of pollutant effects, and to discover novel biomarkers. In most of these studies utilising flounder, Diablo was amongst the most highly increased transcripts identified. The aim of this study was to further examine piscine Diablo, at the gene level and mRNA level, after exposure to prototypical pollutants, and in flounder caught from polluted environments. The results show that two genes encoding Diablo exist in fish species, and in flounder one of these genes is increased in liver after exposure to polyaromatic hydrocarbons and polychlorinated biphenyls, and also in livers from fish living on contaminated estuarine sediments. Therefore, Diablo measurement has potential as a biomarker of pollutant exposure, and could indicate damaging effects of chemical contaminants.

  10. Racial Differences in Perceptions of Air Pollution Health Risk: Does Environmental Exposure Matter?

    PubMed Central

    Chakraborty, Jayajit; Collins, Timothy W.; Grineski, Sara E.; Maldonado, Alejandra

    2017-01-01

    This article extends environmental risk perception research by exploring how potential health risk from exposure to industrial and vehicular air pollutants, as well as other contextual and socio-demographic factors, influence racial/ethnic differences in air pollution health risk perception. Our study site is the Greater Houston metropolitan area, Texas, USA—a racially/ethnically diverse area facing high levels of exposure to pollutants from both industrial and transportation sources. We integrate primary household-level survey data with estimates of excess cancer risk from ambient exposure to industrial and on-road mobile source emissions of air toxics obtained from the U.S. Environmental Protection Agency. Statistical analysis is based on multivariate generalized estimation equation models which account for geographic clustering of surveyed households. Our results reveal significantly higher risk perceptions for non-Hispanic Black residents and those exposed to greater cancer risk from industrial pollutants, and also indicate that gender influences the relationship between race/ethnicity and air pollution risk perception. These findings highlight the need to incorporate measures of environmental health risk exposure in future analysis of social disparities in risk perception. PMID:28125059

  11. Prenatal exposure to traffic-related air pollution and risk of early childhood cancers.

    PubMed

    Ghosh, Jo Kay C; Heck, Julia E; Cockburn, Myles; Su, Jason; Jerrett, Michael; Ritz, Beate

    2013-10-15

    Exposure to air pollution during pregnancy has been linked to the risk of childhood cancer, but the evidence remains inconclusive. In the present study, we used land use regression modeling to estimate prenatal exposures to traffic exhaust and evaluate the associations with cancer risk in very young children. Participants in the Air Pollution and Childhood Cancers Study who were 5 years of age or younger and diagnosed with cancer between 1988 and 2008 were had their records linked to California birth certificates, and controls were selected from birth certificates. Land use regression-based estimates of exposures to nitric oxide, nitrogen dioxide, and nitrogen oxides were assigned based on birthplace residence and temporally adjusted using routine monitoring station data to evaluate air pollution exposures during specific pregnancy periods. Logistic regression models were adjusted for maternal age, race/ethnicity, educational level, parity, insurance type, and Census-based socioeconomic status, as well as child's sex and birth year. The odds of acute lymphoblastic leukemia increased by 9%, 23%, and 8% for each 25-ppb increase in average nitric oxide, nitrogen dioxide, and nitrogen oxide levels, respectively, over the entire pregnancy. Second- and third-trimester exposures increased the odds of bilateral retinoblastoma. No associations were found for annual average exposures without temporal components or for any other cancer type. These results lend support to a link between prenatal exposure to traffic exhaust and the risk of acute lymphoblastic leukemia and bilateral retinoblastoma.

  12. Prenatal Exposure to Traffic-related Air Pollution and Risk of Early Childhood Cancers

    PubMed Central

    Ghosh, Jo Kay C.; Heck, Julia E.; Cockburn, Myles; Su, Jason; Jerrett, Michael; Ritz, Beate

    2013-01-01

    Exposure to air pollution during pregnancy has been linked to the risk of childhood cancer, but the evidence remains inconclusive. In the present study, we used land use regression modeling to estimate prenatal exposures to traffic exhaust and evaluate the associations with cancer risk in very young children. Participants in the Air Pollution and Childhood Cancers Study who were 5 years of age or younger and diagnosed with cancer between 1988 and 2008 were had their records linked to California birth certificates, and controls were selected from birth certificates. Land use regression–based estimates of exposures to nitric oxide, nitrogen dioxide, and nitrogen oxides were assigned based on birthplace residence and temporally adjusted using routine monitoring station data to evaluate air pollution exposures during specific pregnancy periods. Logistic regression models were adjusted for maternal age, race/ethnicity, educational level, parity, insurance type, and Census-based socioeconomic status, as well as child's sex and birth year. The odds of acute lymphoblastic leukemia increased by 9%, 23%, and 8% for each 25-ppb increase in average nitric oxide, nitrogen dioxide, and nitrogen oxide levels, respectively, over the entire pregnancy. Second- and third-trimester exposures increased the odds of bilateral retinoblastoma. No associations were found for annual average exposures without temporal components or for any other cancer type. These results lend support to a link between prenatal exposure to traffic exhaust and the risk of acute lymphoblastic leukemia and bilateral retinoblastoma. PMID:23989198

  13. Accuracy of Non-Destructive Testing of PBRs to Estimate Fragilities

    NASA Astrophysics Data System (ADS)

    Brune, J. N.; Brune, R.; Biasi, G. P.; Anooshehpoor, R.; Purvance, M.

    2011-12-01

    Prior studies of Precariously Balanced Rocks (PBRs) have involved various methods of documenting rock shapes and fragilities. These have included non-destructive testing (NDT) methods such as photomodeling, and potentially destructive testing (PDT) such as forced tilt tests. PDT methods usually have the potential of damaging or disturbing the rock or its pedestal so that the PBR usefulness for future generations is compromised. To date we have force-tilt tested approximately 28 PBRs, and of these we believe 7 have been compromised. We suggest here that given other inherent uncertainties in the current methodologies, NDT methods are now sufficiently advanced as to be adequate for the current state of the art use for comparison with Ground Motion Prediction Equations (GMPEs) and seismic hazard maps (SHMs). Here we compare tilt-test static toppling estimates to three non-destructive methods: (1) 3-D photographic modeling (2) profile analysis assuming the rock is 2-D, and (3) expert judgments from photographs. 3-D modeling uses the commercial Photomodeler program and photographs in the field taken from numerous directions around the rock. The output polyhedral shape is analyzed in Matlab determine the center of mass and in Autocad to estimate the static overturning angle alpha. For the 2-D method we chose the photograph in profile looking perpendicular to the estimated direction of toppling. The rock is outlined as a 2-D object in Matlab. Rock dimensions, rocking points, and a vertical reference are supplied by the photo analyst to estimate the center of gravity and static force overturning angles. For the expert opinion method we used additional photographs taken from different directions to improve the estimates of the center of mass and the rocking points. We used 7 rocks for comparisons. The error in estimating tan alpha from 3-D modeling is about 0.05. For 2-D estimates an average error is about 0.1 (?). For expert opinion estimates the error is about 0.06. For

  14. Non-destructive evaluation of containment walls in nuclear power plants

    NASA Astrophysics Data System (ADS)

    Garnier, V.; Payan, C.; Lott, M.; Ranaivomanana, N.; Balayssac, J. P.; Verdier, J.; Larose, E.; Zhang, Y.; Saliba, J.; Boniface, A.; Sbartai, Z. M.; Piwakowski, B.; Ciccarone, C.; Hafid, H.; Henault, J. M.; Buffet, F. Ouvrier

    2017-02-01

    Two functions are regularly tested on containment walls in order to anticipate a possible accident. The first is mechanical to resist a possible internal over-pressure and the second is to prevent leakage. The AAPR reference accident is the rupture of a pipe in the primary circuit of a nuclear plant. In this case, the pressure and temperature can reach 5 bar and 180°C in 20 seconds. The national project `Non-destructive testing of the containment structures of nuclear plants' aims at studying the non-destructive techniques capable to evaluate the concrete properties and its damaging and cracks. This 4-year-project is segmented into two parts. The first consists in developing and selecting the most relevant NDEs in the laboratory to reach these goals. These evaluations are developed in conditions representing the real conditions of the stresses generated during ten-yearly visits of the plants or those related to an accident. The second part consists in applying the selected techniques to two containment structures under pressure. The first structure is proposed by ONERA and the second is a mockup of a containment wall on a 1/3 scale made by EDF within the VeRCoRs project. Communication is focused on the part of the project that concerns the damage and crack process characterization by means of NDT. The tests are done in 3 or 4 points bending in order to study the cracks' generation, their propagation, as well as their opening and closing. The main ultrasonic techniques developed concern linear or non-linear acoustic: acoustic emission [1], Locadiff [2], energy diffusion, surface wave's velocity and attenuation, DAET [3]. The recorded data contribute to providing the mapping of the investigated parameters, either in volume, in surface or globally. Digital image correlation is an important additional asset to validate the coherence of the data. The spatial normalization of the data in the specimen space allows proposing algorithms on the combination of the

  15. Non-destructive Assessment of Plant Nitrogen Parameters Using Leaf Chlorophyll Measurements in Rice.

    PubMed

    Ata-Ul-Karim, Syed Tahir; Cao, Qiang; Zhu, Yan; Tang, Liang; Rehmani, Muhammad Ishaq Asif; Cao, Weixing

    2016-01-01

    Non-destructive assessment of plant nitrogen (N) status is essential for efficient crop production and N management in intensive rice (Oryza sativa L.) cropping systems. Chlorophyll meter (SPAD-502) has been widely used as a rapid, non-destructive and cost-effective diagnostic tool for in-season assessment of crop N status. The present study was intended to establish the quantitative relationships between chlorophyll meters readings, plant N concentration (PNC), N nutrition index (NNI), accumulated N deficit (AND), and N requirement (NR), as well as to compare the stability of these relationships at different vegetative growth stages in Japonica and Indica rice cultivars. Seven multi-locational field experiments using varied N rates and seven rice cultivars were conducted in east China. The results showed that the PNC and chlorophyll meters readings increased with increasing N application rates across the cultivars, growing seasons, and sites. The PNC and chlorophyll meters readings under varied N rates ranged from 2.29 to 3.21, 1.06 to 1.82 and 37.10 to 45.4 and 37.30 to 46.6, respectively, at TL and HD stages for Japonica rice cultivars, while they ranged from 2.25 to 3.23, 1.34 to 1.91 and 35.6 to 43.3 and 37.3 to 45.5 for Indica rice cultivars, respectively. The quantitative relationships between chlorophyll meters readings, PNC, NNI, AND, and NR established at different crop growth stages in two rice ecotypes, were highly significant with R(2) values ranging from 0.69 to 0.93 and 0.71 to 0.86 for Japonica and Indica rice, respectively. The strongest relationships were observed for AND and NR at panicle initiation and booting stages in both rice ecotypes. The validation of the relationships developed in the present study with an independent data exhibited a solid model performance and confirmed their robustness as a reliable and rapid diagnostic tool for in-season estimation of plant N parameters for sustainable N management in rice. The results of this study

  16. Non-destructive Phenotyping of Lettuce Plants in Early Stages of Development with Optical Sensors.

    PubMed

    Simko, Ivan; Hayes, Ryan J; Furbank, Robert T

    2016-01-01

    Rapid development of plants is important for the production of 'baby-leaf' lettuce that is harvested when plants reach the four- to eight-leaf stage of growth. However, environmental factors, such as high or low temperature, or elevated concentrations of salt, inhibit lettuce growth. Therefore, non-destructive evaluations of plants can provide valuable information to breeders and growers. The objective of the present study was to test the feasibility of using non-destructive phenotyping with optical sensors for the evaluations of lettuce plants in early stages of development. We performed the series of experiments to determine if hyperspectral imaging and chlorophyll fluorescence imaging can determine phenotypic changes manifested on lettuce plants subjected to the extreme temperature and salinity stress treatments. Our results indicate that top view optical sensors alone can accurately determine plant size to approximately 7 g fresh weight. Hyperspectral imaging analysis was able to detect changes in the total chlorophyll (RCC) and anthocyanin (RAC) content, while chlorophyll fluorescence imaging revealed photoinhibition and reduction of plant growth caused by the extreme growing temperatures (3 and 39°C) and salinity (100 mM NaCl). Though no significant correlation was found between Fv/Fm and decrease in plant growth due to stress when comparisons were made across multiple accessions, our results indicate that lettuce plants have a high adaptability to both low (3°C) and high (39°C) temperatures, with no permanent damage to photosynthetic apparatus and fast recovery of plants after moving them to the optimal (21°C) temperature. We have also detected a strong relationship between visual rating of the green- and red-leaf color intensity and RCC and RAC, respectively. Differences in RAC among accessions suggest that the selection for intense red color may be easier to perform at somewhat lower than the optimal temperature. This study serves as a proof of concept

  17. Non-destructive testing for the structures and civil infrastructures characterization

    NASA Astrophysics Data System (ADS)

    Capozzoli, L.; Rizzo, E.

    2012-04-01

    infrared thermography and sonic testing. Finally, we investigated a radiant floor by GPR (900 MHz to 2000 MHz antennas) and long-wave infrared camera. Non-destructive diagnostic techniques allow to investigate a building structure in reinforced concrete or masonry without altering the characteristics of the element investigated. For this reason, geo-electrical and electromagnetic surveys of masonry are a suitable non-destructive tool for the diagnosis of a deteriorated concrete structure. Moreover, the integration of different NDT techniques (conventional and no-conventional) is a very powerful to maximize the capabilities and to compensate for the limitations of each method.

  18. Non-destructive Phenotyping of Lettuce Plants in Early Stages of Development with Optical Sensors

    PubMed Central

    Simko, Ivan; Hayes, Ryan J.; Furbank, Robert T.

    2016-01-01

    Rapid development of plants is important for the production of ‘baby-leaf’ lettuce that is harvested when plants reach the four- to eight-leaf stage of growth. However, environmental factors, such as high or low temperature, or elevated concentrations of salt, inhibit lettuce growth. Therefore, non-destructive evaluations of plants can provide valuable information to breeders and growers. The objective of the present study was to test the feasibility of using non-destructive phenotyping with optical sensors for the evaluations of lettuce plants in early stages of development. We performed the series of experiments to determine if hyperspectral imaging and chlorophyll fluorescence imaging can determine phenotypic changes manifested on lettuce plants subjected to the extreme temperature and salinity stress treatments. Our results indicate that top view optical sensors alone can accurately determine plant size to approximately 7 g fresh weight. Hyperspectral imaging analysis was able to detect changes in the total chlorophyll (RCC) and anthocyanin (RAC) content, while chlorophyll fluorescence imaging revealed photoinhibition and reduction of plant growth caused by the extreme growing temperatures (3 and 39°C) and salinity (100 mM NaCl). Though no significant correlation was found between Fv/Fm and decrease in plant growth due to stress when comparisons were made across multiple accessions, our results indicate that lettuce plants have a high adaptability to both low (3°C) and high (39°C) temperatures, with no permanent damage to photosynthetic apparatus and fast recovery of plants after moving them to the optimal (21°C) temperature. We have also detected a strong relationship between visual rating of the green- and red-leaf color intensity and RCC and RAC, respectively. Differences in RAC among accessions suggest that the selection for intense red color may be easier to perform at somewhat lower than the optimal temperature. This study serves as a proof of

  19. Non-destructive Assessment of Plant Nitrogen Parameters Using Leaf Chlorophyll Measurements in Rice

    PubMed Central

    Ata-Ul-Karim, Syed Tahir; Cao, Qiang; Zhu, Yan; Tang, Liang; Rehmani, Muhammad Ishaq Asif; Cao, Weixing

    2016-01-01

    Non-destructive assessment of plant nitrogen (N) status is essential for efficient crop production and N management in intensive rice (Oryza sativa L.) cropping systems. Chlorophyll meter (SPAD-502) has been widely used as a rapid, non-destructive and cost-effective diagnostic tool for in-season assessment of crop N status. The present study was intended to establish the quantitative relationships between chlorophyll meters readings, plant N concentration (PNC), N nutrition index (NNI), accumulated N deficit (AND), and N requirement (NR), as well as to compare the stability of these relationships at different vegetative growth stages in Japonica and Indica rice cultivars. Seven multi-locational field experiments using varied N rates and seven rice cultivars were conducted in east China. The results showed that the PNC and chlorophyll meters readings increased with increasing N application rates across the cultivars, growing seasons, and sites. The PNC and chlorophyll meters readings under varied N rates ranged from 2.29 to 3.21, 1.06 to 1.82 and 37.10 to 45.4 and 37.30 to 46.6, respectively, at TL and HD stages for Japonica rice cultivars, while they ranged from 2.25 to 3.23, 1.34 to 1.91 and 35.6 to 43.3 and 37.3 to 45.5 for Indica rice cultivars, respectively. The quantitative relationships between chlorophyll meters readings, PNC, NNI, AND, and NR established at different crop growth stages in two rice ecotypes, were highly significant with R2 values ranging from 0.69 to 0.93 and 0.71 to 0.86 for Japonica and Indica rice, respectively. The strongest relationships were observed for AND and NR at panicle initiation and booting stages in both rice ecotypes. The validation of the relationships developed in the present study with an independent data exhibited a solid model performance and confirmed their robustness as a reliable and rapid diagnostic tool for in-season estimation of plant N parameters for sustainable N management in rice. The results of this study

  20. A review of air exchange rate models for air pollution exposure assessments.

    PubMed

    Breen, Michael S; Schultz, Bradley D; Sohn, Michael D; Long, Thomas; Langstaff, John; Williams, Ronald; Isaacs, Kristin; Meng, Qing Yu; Stallings, Casson; Smith, Luther

    2014-11-01

    A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.

  1. Traffic-related air pollution exposure and incidence of stroke in four cohorts from Stockholm.

    PubMed

    Korek, Michal J; Bellander, Tom D; Lind, Tomas; Bottai, Matteo; Eneroth, Kristina M; Caracciolo, Barbara; de Faire, Ulf H; Fratiglioni, Laura; Hilding, Agneta; Leander, Karin; Magnusson, Patrik K E; Pedersen, Nancy L; Östenson, Claes-Göran; Pershagen, Göran; Penell, Johanna C

    2015-01-01

    We investigated the risk of stroke related to long-term ambient air pollution exposure, in particular the role of various exposure time windows, using four cohorts from Stockholm County, Sweden. In total, 22,587 individuals were recruited from 1992 to 2004 and followed until 2011. Yearly air pollution levels resulting from local road traffic emissions were assessed at participant residences using dispersion models for particulate matter (PM10) and nitrogen oxides (NOX). Cohort-specific hazard ratios were estimated for time-weighted air pollution exposure during different time windows and the incidence of stroke, adjusted for common risk factors, and then meta-analysed. Overall, 868 subjects suffered a non-fatal or fatal stroke during 238,731 person-years of follow-up. An increment of 20 μg/m(3) in estimated annual mean of road-traffic related NOX exposure at recruitment was associated with a hazard ratio of 1.16 (95% CI 0.83-1.61), with evidence of heterogeneity between the cohorts. For PM10, an increment of 10 μg/m(3) corresponded to a hazard ratio of 1.14 (95% CI 0.68-1.90). Time-window analyses did not reveal any clear induction-latency pattern. In conclusion, we found suggestive evidence of an association between long-term exposure to NOX and PM10 from local traffic and stroke at comparatively low levels of air pollution.

  2. Integrating Human Indoor Air Pollutant Exposure within Life Cycle Impact Assessment

    SciTech Connect

    Hellweg, Stefanie; Demou, Evangelia; Bruzzi, Raffaella; Meijer, Arjen; Rosenbaum, Ralph K.; Huijbregts, Mark A.J.; McKone, Thomas E.

    2008-12-21

    Neglecting health effects from indoor pollutant emissions and exposure, as currently done in Life Cycle Assessment (LCA), may result in product or process optimizations at the expense of workers? or consumers? health. To close this gap, methods for considering indoor exposure to chemicals are needed to complement the methods for outdoor human exposure assessment already in use. This paper summarizes the work of an international expert group on the integration of human indoor and outdoor exposure in LCA, within the UNEP/SETAC Life Cycle Initiative. A new methodological framework is proposed for a general procedure to include human-health effects from indoor exposure in LCA. Exposure models from occupational hygiene and household indoor air quality studies and practices are critically reviewed and recommendations are provided on the appropriateness of various model alternatives in the context of LCA. A single-compartment box model is recommended for use as a default in LCA, enabling one to screen occupational and household exposures consistent with the existing models to assess outdoor emission in a multimedia environment. An initial set of model parameter values was collected. The comparison between indoor and outdoor human exposure per unit of emission shows that for many pollutants, intake per unit of indoor emission may be several orders of magnitude higher than for outdoor emissions. It is concluded that indoor exposure should be routinely addressed within LCA.

  3. In-situ observation of self-cleansing phenomena during ultra-high vacuum anneal of transition metal nitride thin films: Prospects for non-destructive photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Greczynski, G.; Hultman, L.

    2016-11-01

    Self-cleansing of transition metal nitrides is discovered to take place during ultra-high vacuum annealing of TiN, NbN, and VN thin films. Native oxide layers from air exposure disappear after isothermal anneal at 1000 °C. Also, for TiN, the Ti 2p and N 1s X-ray photoelectron spectra (XPS) recorded after the anneal are identical to those obtained from in-situ grown and analyzed epitaxial TiN(001). These unexpected effects are explained by oxide decomposition in combination with N-replenishing of the nitride during recrystallization. The finding opens up new possibilities for true bonding assignments through non-destructive XPS analyses, thus avoiding artefacts from Ar etching.

  4. ADDRESSING HUMAN EXPOSURE TO AIR POLLUTANTS AROUND BUILDINGS IN URBAN AREAS WITH COMPUTATIONAL FLUID DYNAMICS (CFD) MODELS

    EPA Science Inventory

    Computational Fluid Dynamics (CFD) simulations provide a number of unique opportunities for expanding and improving capabilities for modeling exposures to environmental pollutants. The US Environmental Protection Agency's National Exposure Research Laboratory (NERL) has been c...

  5. Maternal air pollution exposure induces fetal neuroinflammation and predisposes offspring to obesity in aduthood in a sex-specific manner

    EPA Science Inventory

    Emerging evidence suggests environmental chemical exposures during critical windows of development may contribute to the escalating prevalence of obesity. We tested the hypothesis that prenatal air pollution exposure would predispose the offspring to weight gain in adulthood. Pre...

  6. #2 - An Empirical Assessment of Exposure Measurement Error and Effect Attenuation in Bi-Pollutant Epidemiologic Models

    EPA Science Inventory

    Background• Differing degrees of exposure error acrosspollutants• Previous focus on quantifying and accounting forexposure error in single-pollutant models• Examine exposure errors for multiple pollutantsand provide insights on the potential for bias andattenuation...

  7. Hypoxia Stress Test Reveals Exaggerated Cardiovascular Effects in Hypertensive Rats after Exposure to the Air Pollutant Acrolein

    EPA Science Inventory

    Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in susceptible populations with cardiovascular disease. Stress tests are useful in assessing cardiovascular risk and manifesting latent effects of exposure. The goal of this study w...

  8. Non-destructive testing for combined stresses using high-resolution thermal infrared remote sensing and ''three-temperature model'': A case study on mangrove plant Kandelia obovata

    NASA Astrophysics Data System (ADS)

    Shen, X.; LI, R.; Li, Y. H.; Chai, M. W.; Qiu, G. Y.

    2015-12-01

    Mangrove forests are currently facing serious heavy metal pollution and eutrophication problems. Remote sensing of vegetation is a non-invasive methodology to monitor physiological characteristics of plants. The potential of high-resolution thermal infrared remote sensing and the three-temperature model (3T model) for monitoring the effects of combined stresses on mangrove plant Kandelia obovata was assessed. The experiment consists of four levels of CdCl2 stress (0, 1, 5 and 10 mg·L-1) in each of four NH4Cl stress levels: 0, 10, 50 and 100 mg·L-1, respectively. The non-destructive testing indices, including plant transpiration transfer coefficient (hat) and estimated instant transpiration rate, were calculated from thermal images and the 3T model. The photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) were also tested to validate the results of non-destructive testing. The results showed that: (1) The plant transpiration transfer coefficients (hat) were changed from 0.246 to 0.928 and the estimated instant transpiration rates ranged from 0.590 to 6.119 mmol H2O m-2s-1 among different combined stresses. With increasing stress, there were significant decreases for estimated instant transpiration rate and increases for hat (P < 0.05). (2) The photosynthetic characteristics, including Pn, Gs and Tr, were significantly decreased with the increasing combined stresses (P < 0.05). (3) The effects of Cd, N, and their interaction on non-destructive indices and photosynthetic parameters were significant (P < 0.05). (4) The hat was significantly negatively correlated with photosynthetic parameters and the T-3T was significantly positively correlated with photosynthetic parameters (P < 0.05). Therefore, the transpiration transfer coefficient (hat) andestimated instant transpiration rate detecting by infrared thermography device could be indicators to reflect the stress conditions. Based on high-resolution thermal infrared remote sensing, we

  9. Participatory measurements of individual exposure to air pollution in urban areas

    NASA Astrophysics Data System (ADS)

    Madelin, Malika; Duché, Sarah; Dupuis, Vincent

    2016-04-01

    Air pollution is a major environmental issue in urban areas. Chronic and high concentration exposure presents a health risk with cardiovascular and respiratory problems and longer term nervous, carcinogenic and endocrine problems. In addition to the estimations based on simulations of both background and regional pollution and of the pollution induced by the traffic, knowing exposure of each individual is a key issue. This exposure reflects the high variability of pollution at fine spatial and time scales, according to the proximity of emission sources and the urban morphology outside. The emergence of citizen science and the progress of miniaturized electronics, low-cost and accessible to (almost) everyone, offers new opportunities for the monitoring of air pollution, but also for the citizens' awareness of their individual exposure to air pollution. In this communication, we propose to present a participatory research project 'What is your air?' (project funded by the Île-de-France region), which aims at raising awareness on the theme of air quality, its monitoring with sensors assembled in a FabLab workshop and an online participatory mapping. Beyond the discussion on technical choices, the stages of manufacture or the sensor calibration procedures, we discuss the measurements made, in this case the fine particle concentration measurements, which are dated and georeferenced (communication via a mobile phone). They show high variability between the measurements (in part linked to the substrates, land use, traffic) and low daily contrasts. In addition to the analysis of the measurements and their comparison with the official data, we also discuss the choice of representation of information, including mapping, and therefore the message about pollution to communicate.

  10. Measuring combined exposure to environmental pressures in urban areas: an air quality and noise pollution assessment approach.

    PubMed

    Vlachokostas, Ch; Achillas, Ch; Michailidou, A V; Moussiopoulos, Nu

    2012-02-01

    This study presents a methodological scheme developed to provide a combined air and noise pollution exposure assessment based on measurements from personal portable monitors. Provided that air and noise pollution are considered in a co-exposure approach, they represent a significant environmental hazard to public health. The methodology is demonstrated for the city of Thessaloniki, Greece. The results of an extensive field campaign are presented and the variations in personal exposure between modes of transport, routes, streets and transport microenvironments are evaluated. Air pollution and noise measurements were performed simultaneously along several commuting routes, during the morning and evening rush hours. Combined exposure to environmental pollutants is highlighted based on the Combined Exposure Factor (CEF) and Combined Dose and Exposure Factor (CDEF). The CDEF takes into account the potential relative uptake of each pollutant by considering the physical activities of each citizen. Rather than viewing environmental pollutants separately for planning and environmental sustainability considerations, the possibility of an easy-to-comprehend co-exposure approach based on these two indices is demonstrated. Furthermore, they provide for the first time a combined exposure assessment to these environmental pollutants for Thessaloniki and in this sense they could be of importance for local public authorities and decision makers. A considerable environmental burden for the citizens of Thessaloniki, especially for VOCs and noise pollution levels is observed. The material herein points out the importance of measuring public health stressors and the necessity of considering urban environmental pollution in a holistic way.

  11. Predicting personal exposure of pregnant women to traffic-related air pollutants.

    PubMed

    Nethery, Elizabeth; Teschke, Kay; Brauer, Michael

    2008-05-20

    As epidemiological studies report associations between ambient air pollution and adverse birth outcomes, it is important to understand determinants of exposures among pregnant women. We measured (48-h, personal exposure) and modeled (using outdoor ambient monitors and a traffic-based land-use regression model) NO, NO(2), fine particle mass and absorbance in 62 non-smoking pregnant women in Vancouver, Canada on 1-3 occasions during pregnancy (total N=127). We developed predictive models for personal measurements using modeled ambient concentrations and individual determinants of exposure. Geometric mean exposures of personal samples were relatively low (GM (GSD) NO=37 ppb (2.0); NO(2)=17 ppb (1.6); 'soot', as filter absorbance=0.8 10(-5) m(-1) (1.5); PM(2.2)=10 microg m(-3) (1.6)). Having a gas stove (vs. electric stove) in the home was associated with exposure increases of 89% (NO), 44% (NO(2)), 20% (absorbance) and 35% (fine PM). Interpolated concentrations from outdoor fixed-site monitors were associated with all personal exposures except NO(2). Land-use regression model estimates of outdoor air pollution were associated with personal NO and NO(2) only. The effects of outdoor air pollution on personal samples were consistent, with and without adjustment for other individual determinants (e.g. gas stove). These findings improve our understanding of sources of exposure to air pollutants among pregnant women and support the use of outdoor concentration estimates as proxies for exposure in epidemiologic studies.

  12. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    NASA Astrophysics Data System (ADS)

    Kiefel, Denis; Stoessel, Rainer; Grosse, Christian

    2015-03-01

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  13. Ultrasonic non-destructive testing of pieces of complex geometry with a flexible phased array transducer

    PubMed

    Chatillon; Cattiaux; Serre; Roy

    2000-03-01

    Ultrasonic non-destructive testing of components of complex geometry in the nuclear industry faces several difficulties: sensitivity variations due to unmatched contact, inaccurate localization of defects due to variations of transducer orientation, and uncovered area of the component. To improve the performances of such testing and defect characterization, we propose a new concept of ultrasonic contact phased array transducer. The phased array transducer has a flexible radiating surface able to fit the actual surface of the piece to optimize the contact and thus the sensitivity of the test. To control the transmitted field, and therefore to improve the defect characterization, a delay law optimizing algorithm is developed. To assess the capability of such a transducer, the Champ-Sons model, developed at the French Atomic Energy Commission for predicting field radiated by arbitrary transducers into pieces, has to be extended to sources directly in contact with pieces of complex geometry. The good behavior of this new type of probe predicted by computations is experimentally validated with a jointed transducer positioned on pieces of various profiles.

  14. Robotic path planning for non-destructive testing of complex shaped surfaces

    NASA Astrophysics Data System (ADS)

    Mineo, Carmelo; Pierce, Stephen Gareth; Wright, Ben; Nicholson, Pascual Ian; Cooper, Ian

    2015-03-01

    The requirement to increase inspection speeds for non-destructive testing (NDT) of composite aerospace parts is common to many manufacturers. The prevalence of complex curved surfaces in the industry provides significant motivation for the use of 6 axis robots for deployment of NDT probes in these inspections. A new system for robot deployed ultrasonic inspection of composite aerospace components is presented. The key novelty of the approach is through the accommodation of flexible robotic trajectory planning, coordinated with the NDT data acquisition. Using a flexible approach in MATLAB, the authors have developed a high level custom toolbox that utilizes external control of an industrial 6 axis manipulator to achieve complex path planning and provide synchronization of the employed ultrasonic phase array inspection system. The developed software maintains a high level approach to the robot programming, in order to ease the programming complexity for an NDT inspection operator. Crucially the approach provides a pathway for a conditional programming approach and the capability for multiple robot control (a significant limitation in many current off-line programming applications). Ultrasonic and experimental data has been collected for the validation of the inspection technique. The path trajectory generation for a large, curved carbon-fiber-reinforced polymer (CFRP) aerofoil component has been proven and is presented. The path error relative to a raster-scan tool-path, suitable for ultrasonic phased array inspection, has been measured to be within + 2mm over the 1.6 m2 area of the component surface.

  15. Neutron tomography of particulate filters: a non-destructive investigation tool for applied and industrial research

    NASA Astrophysics Data System (ADS)

    Toops, Todd J.; Bilheux, Hassina Z.; Voisin, Sophie; Gregor, Jens; Walker, Lakeisha; Strzelec, Andrea; Finney, Charles E. A.; Pihl, Josh A.

    2013-11-01

    This research describes the development and implementation of high-fidelity neutron imaging and the associated analysis of the images. This advanced capability allows the non-destructive, non-invasive imaging of particulate filters (PFs) and how the deposition of particulate and catalytic washcoat occurs within the filter. The majority of the efforts described here were performed at the High Flux Isotope Reactor (HFIR) CG-1D neutron imaging beamline at Oak Ridge National Laboratory; the current spatial resolution is approximately 50 μm. The sample holder is equipped with a high-precision rotation stage that allows 3D imaging (i.e., computed tomography) of the sample when combined with computerized reconstruction tools. What enables the neutron-based image is the ability of some elements to absorb or scatter neutrons where other elements allow the neutron to pass through them with negligible interaction. Of particular interest in this study is the scattering of neutrons by hydrogen-containing molecules, such as hydrocarbons (HCs) and/or water, which are adsorbed to the surface of soot, ash and catalytic washcoat. Even so, the interactions with this adsorbed water/HC is low and computational techniques were required to enhance the contrast, primarily a modified simultaneous iterative reconstruction technique (SIRT). This effort describes the following systems: particulate randomly distributed in a PF, ash deposition in PFs, a catalyzed washcoat layer in a PF, and three particulate loadings in a SiC PF.

  16. Non-Destructive Current Sensing for Energy Efficiency Monitoring in Buildings with Environmental Certification.

    PubMed

    Mota, Lia Toledo Moreira; Mota, Alexandre de Assis; Coiado, Lorenzo Campos

    2015-07-10

    Nowadays, buildings environmental certifications encourage the implementation of initiatives aiming to increase energy efficiency in buildings. In these certification systems, increased energy efficiency arising from such initiatives must be demonstrated. Thus, a challenge to be faced is how to check the increase in energy efficiency related to each of the employed initiatives without a considerable building retrofit. In this context, this work presents a non-destructive method for electric current sensing to assess implemented initiatives to increase energy efficiency in buildings with environmental certification. This method proposes the use of a sensor that can be installed directly in the low voltage electrical circuit conductors that are powering the initiative under evaluation, without the need for reforms that result in significant costs, repair, and maintenance. The proposed sensor consists of three elements: an air-core transformer current sensor, an amplifying/filtering stage, and a microprocessor. A prototype of the proposed sensor was developed and tests were performed to validate this sensor. Based on laboratory tests, it was possible to characterize the proposed current sensor with respect to the number of turns and cross-sectional area of the primary and secondary coils. Furthermore, using the Least Squares Method, it was possible to determine the efficiency of the air core transformer current sensor (the best efficiency found, considering different test conditions, was 2%), which leads to a linear output response.

  17. Non-destructive mobile monitoring of microbial contaminations on meat surfaces using porphyrin fluorescence intensities.

    PubMed

    Durek, J; Fröhling, A; Bolling, J; Thomasius, R; Durek, P; Schlüter, O K

    2016-05-01

    A non-destructive mobile system for meat quality monitoring was developed and investigated for the possible application along the whole production chain of fresh meat. Pork and lamb meat was stored at 5 °C for up to 20 days post mortem and measured with a fluorescence spectrometer. Additionally, the bacterial influence on the fluorescence signals was evaluated by different experimental procedures. Fluorescence of NADH and different porphyrins could be correlated to the growth of diverse bacteria and hence used for contamination monitoring. The increase of porphyrin fluorescence started after 9 days p.m. for pork and after 2 days p.m. for lamb meat. Based on the results, a mobile fluorescence system was built and compared with the laboratory system. The corrected function of the meat slices showed a root mean square error of 1156.97 r.u. and a mean absolute percentage error of 12.59%; for lamb the values were 470.81 r.u. and 15.55%, respectively. A mobile and non-invasive measurement system would improve the microbial security of fresh meat.

  18. PHOTOACOUSTIC NON-DESTRUCTIVE EVALUATION AND IMAGING OF CARIES IN DENTAL SAMPLES

    SciTech Connect

    Li, T.; Dewhurst, R. J.

    2010-02-22

    Dental caries is a disease wherein bacterial processes damage hard tooth structure. Traditional dental radiography has its limitations for detecting early stage caries. In this study, a photoacoustic (PA) imaging system with the near-infrared light source has been applied to postmortem dental samples to obtain 2-D and 3-D images. Imaging results showed that the PA technique can be used to image human teeth caries. For non-destructive photoacoustic evaluation and imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. For example, temperature rises above 5 deg. C within live human teeth will cause pulpal necrosis. Therefore, several simulations based on the thermoelastic effect have been applied to predict temperature and pressure fields within samples. Predicted temperature levels are below corresponding safety limits, but care is required to avoid nonlinear absorption phenomena. Furthermore, PA imaging results from the phantom provide evidence for high sensitivity, which shows the imaging potential of the PA technique for detecting early stage disease.

  19. Non-Destructive Characterization of Activated Ion-Implanted Doping Profiles Based on Photomodulated Optical Reflectance

    NASA Astrophysics Data System (ADS)

    Bogdanowicz, Janusz; Clarysse, Trudo; Moussa, Alain; Mody, Jay; Eyben, Pierre; Vandervorst, Wilfried; Rosseel, Erik

    2011-01-01

    The accurate characterization of free carrier profiles in ultra-shallow junctions, such as the source and drain extension regions, is one of the major challenges of metrology in modern silicon Complementary Metal-Oxide-Semiconductor technology. Currently, only destructive and time-consuming techniques, such as Scanning Spreading Resistance Microscopy, have shown the ability to solve this need. However, there is still a clear absence of an accurate, fast, non-destructive technique. For this purpose, we study the capabilities of the Photomodulated Optical Reflectance (PMOR) technique, such as implemented in the Therma-Probe® (TP) tool. PMOR is a pump-probe technique, wherein the probe laser measures, through reflection, the modulated pump-laser-induced change in refractive index. In this paper, we investigate PMOR measurements on sub-20 nm activated implantation profiles. By combining the PMOR signal with the simultaneously measured DC probe reflectance, we show that it is possible to reconstruct the underlying free carrier profile. Except for an overestimated depth (˜25%), the results are in good agreement with Secondary Ion Mass Spectrometry and Scanning Spreading Resistance Microscopy measurements.

  20. Static characterization of a soft elastomeric capacitor for non destructive evaluation applications

    SciTech Connect

    Saleem, Hussam; Laflamme, Simon; Zhang, Huanhuan; Geiger, Randall; Kessler, Michael; Rajan, Krishna

    2014-02-18

    A large and flexible strain transducer consisting of a soft elastomeric capacitor (SEC) has been proposed by the authors. Arranged in a network setup, the sensing strategy offers tremendous potential at conducting non-destructive evaluation of large-scale surfaces. In prior work, the authors have demonstrated the performance of the sensor at tracking strain history, localizing cracks, and detecting vibration signatures. In this paper, we characterize the static performance of the proposed SEC. The characterization includes sensitivity of the signal, and temperature and humidity dependences. Tests are conducted on a simply supported aluminum beam subjected to bending as well as on a free standing sensor. The performance of the SEC is compared against off-the-shelf resistance-based strain gauges with resolution of 1 με. A sensitivity of 1190 pF/ε is obtained experimentally, in agreement with theory. Results also show the sensor linearity over the given level of strain, showing the promise of the SEC at monitoring of surface strain.

  1. Non-Destructive Micro-Chemical and Micro-Luminescence Characterization of Jadeite.

    PubMed

    Mitrani Viggiano, Alejandro; Ruvalcaba Sil, José Luis; Manrique Ortega, Mayra D; Corregidor Berdasco, Victoria

    2016-12-01

    Jadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its importance, knowledge of its mining sources was lost after the Spanish conquest. In the 1950s the only confirmed jadeite deposits in Mesoamerica were found in the Motagua River Fault (MRF), Guatemala. The aim of this study is to present a methodology that is appropriate for the study of archeological jadeite objects using non-destructive spectroscopic and micro-ion beam analysis techniques. This methodology has been applied to perform mineral, elemental, and luminescence characterization of five jadeite samples from the MRF, with white, lilac, and green colors. Fourier-transformed infrared spectroscopy and X-ray diffraction analysis confirmed the presence of jadeite, albite, and omphacite as the main mineral phases in the samples. Elemental maps using particle-induced X-ray emission (PIXE) with a nuclear microprobe and elemental concentration analysis from individual mineral grains using micro-PIXE coupled with micro-ionoluminescence (IL) allowed the detection of minor feldspar, titanite, and grossular mineral contents. Distinctive features from the mineral, elemental, and luminescence characterization have been found that allow the identification of these five jadeite samples.

  2. On oxidative degradation of parchment and its non-destructive characterisation and dating

    NASA Astrophysics Data System (ADS)

    Možir, Alenka; Strlič, Matija; Trafela, Tanja; Cigić, Irena Kralj; Kolar, Jana; Deselnicu, Viorica; de Bruin, Gerrit

    2011-07-01

    Historic parchment is an extremely complex material, not only due to the various methods of production used and various past environmental histories of objects, but also due to its inhomogeneous structure. Many traditional methods of characterisation are empirical, but useful since they have gained recognition by the end-users. In this paper, we investigated the shrinkage temperature of collagen and the influence of lipids contained in parchment on the measurements. While the content of lipids does not seem to significantly affect shrinkage temperature measurements themselves, it strongly affects the decrease of shrinkage temperature of collagen during degradation, and thus its thermomechanical properties. This confirms the high importance of lipid peroxidation during degradation of parchment. While shrinkage temperature determination is a micro-destructive method, we also demonstrated that it is possible to determine this property using near infrared (NIR) spectroscopy based on partial least squares calibration. The root-mean square error of validation (RMSEV), obtained on a set of variously delipidised and degraded samples, was 7°C, so the method could be used for condition assessment or classification of historic objects. Using a set of 185 historic objects dating from 1200-1800, we also developed a method for non-destructive dating of parchment based on NIR spectroscopy using partial least squares regression (RMSEV=72 years), and successfully determined the correct age of a historic charter from the collection of Nationaal Archief, The Netherlands.

  3. Non-destructive inspection of drilled holes in reinforced honeycomb sandwich panels using active thermography

    NASA Astrophysics Data System (ADS)

    Usamentiaga, R.; Venegas, P.; Guerediaga, J.; Vega, L.; López, I.

    2012-11-01

    The aerospace industry is in constant need of ever-more efficient inspection methods for quality control. Product inspection is also essential to maintain the safe operation of aircraft components designed to perform for decades. This paper proposes a method for non-destructive inspection of drilled holes in reinforced honeycomb sandwich panels. Honeycomb sandwich panels are extensively employed in the aerospace industry due to their high strength and stiffness to weight ratios. In order to attach additional structures to them, panels are reinforced by filling honeycomb cells and drilling holes into the reinforced areas. The proposed procedure is designed to detect the position of the holes within the reinforced area and to provide a robust measurement of the distance between each hole and the boundary of the reinforced area. The result is a fast, safe and clean inspection method for drilled holes in reinforced honeycomb sandwich panels that can be used to robustly assess a possible displacement of the hole from the center of the reinforced area, which could have serious consequences. The proposed method is based on active infrared thermography, and uses state of the art methods for infrared image processing, including signal-to-nose ratio enhancement, hole detection and segmentation. Tests and comparison with X-ray inspections indicate that the proposed system meets production needs.

  4. Laser ultrasound and simulated time reversal on bulk waves for non destructive control

    NASA Astrophysics Data System (ADS)

    Diot, G.; Walaszek, H.; Kouadri-David, A.; Guégan, S.; Flifla, J.

    2014-06-01

    Laser welding of aluminium generally creates embedded welding defects, such as porosities or cracks. Non Destructive Inspection (NDI) after processing may ensure an acceptable weld quality by defect detection. Nowadays, NDI techniques used to control the inside of a weld are mainly limited to X-Rays or ultrasonics. The current paper describes the use of a Laser Ultrasound (LU) technique to inspect porosities in 2 and 4-mm thick sheet lap welds. First experimentations resulted in the detection of 0.5-mm drilled holes in bulk aluminium sheets. The measurement of the depth of these defects is demonstrated too. Further experimentations shows the applicability of the LU technique to detect porosities in aluminium laser welds. However, as the interpretation of raw measures is limiting the detection capacity of this technique, we developed a signal processing using Time-Reversal capabilities to enhance detection capacities. Furthermore, the signal processing output is a geometrical image of the material's inner state, increasing the ease of interpretation. It is based on a mass-spring simulation which enables the back-propagation of the acquired ultrasound signal. The spring-mass simulation allows the natural generation of all the different sound waves and thus enables the back-propagation of a raw signal without any need of filtering or wave identification and extraction. Therefore the signal processing uses the information contained in the compression wave as well as in the shear wave.

  5. Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189

    SciTech Connect

    Simpson, A.; Pitts, M.; Ludowise, J.D.; Valentinelli, P.; Grando, C.J.; Haggard, D.L.

    2013-07-01

    The Hanford burial grounds contains a broad spectrum of low activity radioactive wastes, transuranic (TRU) wastes, and hazardous wastes including fission products, byproduct material (thorium and uranium), plutonium and laboratory chemicals. A passive neutron non-destructive assay technique has been developed for characterization of shielded concreted drums exhumed from the burial grounds. This method facilitates the separation of low activity radiological waste containers from TRU waste containers exhumed from the burial grounds. Two identical total neutron counting systems have been deployed, each consisting of He-3 detectors surrounded by a polyethylene moderator. The counts are processed through a statistical filter that removes outliers in order to suppress cosmic spallation events and electronic noise. Upon completion of processing, a 'GO / NO GO' signal is provided to the operator based on a threshold level equivalent to 0.5 grams of weapons grade plutonium in the container being evaluated. This approach allows instantaneous decisions to be made on how to proceed with the waste. The counting systems have been set up using initial on-site measurements (neutron emitting standards loaded into surrogate waste containers) combined with Monte Carlo modeling techniques. The benefit of this approach is to allow the systems to extend their measurement ranges, in terms of applicable matrix types and container sizes, with minimal interruption to the operations at the burial grounds. (authors)

  6. METAPHIX-1 non destructive post irradiation examinations in the irradiated elements cell at Phenix

    SciTech Connect

    Breton, Laurent; Masson, M.; Garces, E.; Desjardins, S.; Fontaine, B.; Lacroix, B.; Martella, T.; Loubet, L.; Ohta, H.; Yokoo, T.; Ougier, M.; Glatz, J.P.

    2007-07-01

    Central Research Institute of Electric Power Industry (CRIEPI) has been developing minor actinide (MA) transmutation technology in homogeneous loading mode by use of metal fuel fast reactors in cooperation with Institute for Transuranium Elements (ITU) and Commissariat a l'Energie Atomique (CEA). Fast reactor metal fuel pins of Uranium- Plutonium-Zirconium (U-Pu-Zr) alloy containing 2 wt% MAs and 2 wt% rare earth elements (REs), 5 wt% MAs, and 5 wt% MAs and 5 wt% REs were irradiated in the PHENIX French fast reactor as METAPHIX experiments. In these METAPHIX experiments, three rigs each consisting of three metal fuel experimental pins and sixteen oxide fuel driver pins were irradiated. The target burnup of the three rigs is 2.4 at%, 7 at% and 11 at% which corresponds to 120, 360 and 600 equivalent full power days (EFPD) in terms of irradiation periods, respectively. The low burnup rig of 2.4 at%, METAPHIX-1, was discharged from the core in August 2004. After cooling, the non-destructive post irradiation examinations (PIEs) of the rig (visual examination, measurement of rig length and deformation) and of the metal fuel pins (visual examination, measurement of pin length and deformation, {gamma}-spectrometry and neutron radiography) were conducted in the Irradiated Elements Cell (IEC) at PHENIX. (authors)

  7. Unmanned Ground Vehicle for Autonomous Non-Destructive Testing of FRP Bridge Decks

    NASA Astrophysics Data System (ADS)

    Klinkhachorn, P.; Mercer, A. Scott; Halabe, Udaya B.; GangaRao, Hota V. S.

    2007-03-01

    Current non-destructive techniques for defect analysis of FRP bridge decks have a narrow scope. These techniques are very good at detecting certain types of defects but are not robust enough to detect all defects by themselves. For example, infrared thermography (IRT) can detect air filled defects and Ground Penetrating Radar (GPR) is good at detecting water filled ones. These technologies can be combined to create a more robust defect detection scheme. To accomplish this, an Unmanned Ground Vehicle (UGV) has been designed that incorporates both IR and GPR analysis to create a comprehensive defect map of a bridge deck. The UGV autonomously surveys the deck surface and acquires data. The UGV has two 1.5 GHz ground coupled GPR antennas that are mounted on the front of the UGV to collect GPR data. It also incorporates an active heating source and a radiometric IR camera to capture IR images of the deck, even in less than ideal weather scenarios such as cold cloudy days. The UGV is designed so that it can collect data in an assembly line fashion. It moves in 1 foot increments. When moving, it collects GPR data from the two antennas. When it stops it heats a section of the deck. The next time it stops to heat a section, the IR camera is analyzing the preheated deck section while preparing for the next section. Because the data is being continually collected using this method, the UGV can survey the entire deck in an efficient and timely manner.

  8. Thermal Wave Imaging for Non-Destructive Evaluation of Subsurface Cracks in Opaque Materials

    NASA Astrophysics Data System (ADS)

    Grice, Kenneth Russell

    The technique of thermal wave imaging has been applied using two approaches to detect subsurface cracks in opaque materials. These two approaches are (1) the scanning photoacoustic microscopy (SPAM) and (2) the optical deflection of laser probes (MIRAGE). These two approaches have been examined and compared in terms of signal magnitude and phase both theoretically and experimentally. The effects of sample crack size, orientation and closure on the thermal wave signal has been considered and discussed. Cracks as small as 40 (mu)m in length have been detected. Also nearly vertical closed cracks have been detected using the MIRAGE technique. As a more difficult test of the thermal wave technique, we examined the feasibility of detecting a fatigue crack on the inner surface of a bolt hole. This experiment represents the first time that a crack on the interior wall of a bolt hole has been detected using thermal wave imaging. These results emphatically demonstrate the versatility of the SPAM approach when applied to complex geometries. Thermal wave imaging has been shown to have considerable potential for non-destructive evaluation (NDE) of solids for science and industry.

  9. Enhancing the bandwidth of piezoelectric composite transducers for air-coupled non-destructive evaluation.

    PubMed

    Banks, Robert; O'Leary, Richard L; Hayward, Gordon

    2017-03-01

    This paper details the development of a novel method for increasing the operational bandwidth of piezocomposites without the need for lossy backing material, the aim being to increase fractional bandwith by geometrical design. Removing the need for lossy backing materials, should in turn increase the transmit efficiency in the desired direction of propagation. Finite element analysis has been employed to determine the mode of operation of the new piezocomposite devices and shows good correlation with that derived experimentally. Through a series of practical and analytical methods it has been shown that additional thickness mode resonances can be introduced into the structure by a simple machining process. The shaped composites described in this paper offer increased operational bandwidth. A simple example of a two step thickness design is described to validate and illustrate the principle. A more complex conical design is presented that illustrates a possible tenfold increase in bandwidth from 30kHz to 300kHz, operating in air without backing. An illustration of the applicability of this type of transducer technology for frequency agile guided mode non-destructive evaluation is then presented.

  10. Non-destructive quantification of alignment of nanorods embedded in uniaxially stretched polymer films

    SciTech Connect

    Stoenescu, Stefan Packirisamy, Muthukumaran; Truong, Vo-Van

    2014-03-21

    Among several methods developed for uniaxial alignment of metallic nanorods for optical applications, alignment by film stretching consists in embedding the rods in a transparent thin film of thermoplastic polymer, followed by simultaneous heating and uniaxial stretching of the composite film. As to the quantification of the resulting alignment, it has been limited to statistical calculations based on microscopic examination, which is incomplete, subject to errors due to geometric distortions of the scanning electron microscope images and destructive, since it involves cutting of samples. In contrast, we present in this paper a non-destructive quantification of the average orientation of the rods, based on a probabilistic approach combined with numerical simulations of absorbance spectra and spectrometric characterization of the composite film. Assuming electromagnetically non-interacting rods, we consider the longitudinal absorbance peak of their ensemble to consist of the superposition of their individual spectra that we obtain by numerical simulation using the size and shape adapted dielectric function of the metal and the finite difference time domain method. The accuracy of the solution depends on the number of discretization intervals, the accuracy of the numerical simulations, and the accurate knowledge of the polydispersity of the rods. For the sake of concreteness, we used nanorods to describe the quantification steps but the method is equally valid for any dichroic particles.

  11. Non-destructive state detection for quantum logic spectroscopy of molecular ions.

    PubMed

    Wolf, Fabian; Wan, Yong; Heip, Jan C; Gebert, Florian; Shi, Chunyan; Schmidt, Piet O

    2016-02-25

    Precision laser spectroscopy of cold and trapped molecular ions is a powerful tool in fundamental physics--used, for example, in determining fundamental constants, testing for their possible variation in the laboratory, and searching for a possible electric dipole moment of the electron. However, the absence of cycling transitions in molecules poses a challenge for direct laser cooling of the ions, and for controlling and detecting their quantum states. Previously used state-detection techniques based on photodissociation or chemical reactions are destructive and therefore inefficient, restricting the achievable resolution in laser spectroscopy. Here, we experimentally demonstrate non-destructive detection of the quantum state of a single trapped molecular ion through its strong Coulomb coupling to a well controlled, co-trapped atomic ion. An algorithm based on a state-dependent optical dipole force changes the internal state of the atom according to the internal state of the molecule. We show that individual quantum states in the molecular ion can be distinguished by the strength of their coupling to the optical dipole force. We also observe quantum jumps (induced by black-body radiation) between rotational states of a single molecular ion. Using the detuning dependence of the state-detection signal, we implement a variant of quantum logic spectroscopy of a molecular resonance. Our state-detection technique is relevant to a wide range of molecular ions, and could be applied to state-controlled quantum chemistry and to spectroscopic investigations of molecules that serve as probes for interstellar clouds.

  12. High-resolution non-destructive three-dimensional imaging of integrated circuits.

    PubMed

    Holler, Mirko; Guizar-Sicairos, Manuel; Tsai, Esther H R; Dinapoli, Roberto; Müller, Elisabeth; Bunk, Oliver; Raabe, Jörg; Aeppli, Gabriel

    2017-03-15

    Modern nanoelectronics has advanced to a point at which it is impossible to image entire devices and their interconnections non-destructively because of their small feature sizes and the complex three-dimensional structures resulting from their integration on a chip. This metrology gap implies a lack of direct feedback between design and manufacturing processes, and hampers quality control during production, shipment and use. Here we demonstrate that X-ray ptychography-a high-resolution coherent diffractive imaging technique-can create three-dimensional images of integrated circuits of known and unknown designs with a lateral resolution in all directions down to 14.6 nanometres. We obtained detailed device geometries and corresponding elemental maps, and show how the devices are integrated with each other to form the chip. Our experiments represent a major advance in chip inspection and reverse engineering over the traditional destructive electron microscopy and ion milling techniques. Foreseeable developments in X-ray sources, optics and detectors, as well as adoption of an instrument geometry optimized for planar rather than cylindrical samples, could lead to a thousand-fold increase in efficiency, with concomitant reductions in scan times and voxel sizes.

  13. Non-destructive Assay Measurements Using the RPI Lead Slowing Down Spectrometer

    SciTech Connect

    Becker, Bjorn; Weltz, Adam; Kulisek, Jonathan A.; Thompson, J. T.; Thompson, N.; Danon, Yaron

    2013-10-01

    The use of a Lead Slowing-Down Spectrometer (LSDS) is consid- ered as a possible option for non-destructive assay of fissile material of used nuclear fuel. The primary objective is to quantify the 239Pu and 235U fissile content via a direct measurement, distinguishing them through their characteristic fission spectra in the LSDS. In this pa- per, we present several assay measurements performed at the Rensse- laer Polytechnic Institute (RPI) to demonstrate the feasibility of such a method and to provide benchmark experiments for Monte Carlo cal- culations of the assay system. A fresh UOX fuel rod from the RPI Criticality Research Facility, a 239PuBe source and several highly en- riched 235U discs were assayed in the LSDS. The characteristic fission spectra were measured with 238U and 232Th threshold fission cham- bers, which are only sensitive to fission neutron with energy above the threshold. Despite the constant neutron and gamma background from the PuBe source and the intense interrogation neutron flux, the LSDS system was able to measure the characteristic 235U and 239Pu responses. All measurements were compared to Monte Carlo simula- tions. It was shown that the available simulation tools and models are well suited to simulate the assay, and that it is possible to calculate the absolute count rate in all investigated cases.

  14. Ultra-portable, wireless smartphone spectrometer for rapid, non-destructive testing of fruit ripeness.

    PubMed

    Das, Anshuman J; Wahi, Akshat; Kothari, Ishan; Raskar, Ramesh

    2016-09-08

    We demonstrate a smartphone based spectrometer design that is standalone and supported on a wireless platform. The device is inherently low-cost and the power consumption is minimal making it portable to carry out a range of studies in the field. All essential components of the device like the light source, spectrometer, filters, microcontroller and wireless circuits have been assembled in a housing of dimensions 88 mm × 37 mm × 22 mm and the entire device weighs 48 g. The resolution of the spectrometer is 15 nm, delivering accurate and repeatable measurements. The device has a dedicated app interface on the smartphone to communicate, receive, plot and analyze spectral data. The performance of the smartphone spectrometer is comparable to existing bench-top spectrometers in terms of stability and wavelength resolution. Validations of the device were carried out by demonstrating non-destructive ripeness testing in fruit samples. Ultra-Violet (UV) fluorescence from Chlorophyll present in the skin was measured across various apple varieties during the ripening process and correlated with destructive firmness tests. A satisfactory agreement was observed between ripeness and fluorescence signals. This demonstration is a step towards possible consumer, bio-sensing and diagnostic applications that can be carried out in a rapid manner.

  15. Non-destructive detection of defects in artificial skin tissue by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Schmitt, R.; Marx, U.; Heymer, A.; Kaufmann, M.

    2009-07-01

    The application of optical coherence tomography OCT in tissue engineering facilities offers great potential for the automated detection of defects or inhomogeneities in tissue products. This non-invasive and non-destructive measurement technique enables the high speed generation of two dimensional cross sections of tissue with micron resolution. The integration of an OCT device into a tissue production facility allows the monitoring and quality control of tissue engineering products. By the selective exclusion of tissue products with insufficient quality features a high degree in production standard is guaranteed. In a first study, OCT tomograms of artificial skin equivalents were acquired and compared with microscopic images of associated histologies. As a result, a well-defined analogy of the obtained images is presented. The most common defect in terms of hole structures that occurs due to a procedural steps could be detected. Further characteristics like the topography, homogeneity and layer structure was analysed. Hence, OCT provides a powerful measurement technique to monitor the quality of tissue products in automated tissue engineering facilities.

  16. Photoacoustic Non-Destructive Evaluation and Imaging of Caries in Dental Samples

    NASA Astrophysics Data System (ADS)

    Li, T.; Dewhurst, R. J.

    2010-02-01

    Dental caries is a disease wherein bacterial processes damage hard tooth structure. Traditional dental radiography has its limitations for detecting early stage caries. In this study, a photoacoustic (PA) imaging system with the near-infrared light source has been applied to postmortem dental samples to obtain 2-D and 3-D images. Imaging results showed that the PA technique can be used to image human teeth caries. For non-destructive photoacoustic evaluation and imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. For example, temperature rises above 5 °C within live human teeth will cause pulpal necrosis. Therefore, several simulations based on the thermoelastic effect have been applied to predict temperature and pressure fields within samples. Predicted temperature levels are below corresponding safety limits, but care is required to avoid nonlinear absorption phenomena. Furthermore, PA imaging results from the phantom provide evidence for high sensitivity, which shows the imaging potential of the PA technique for detecting early stage disease.

  17. Non-destructive analysis of DU content in the NIF hohlraums

    SciTech Connect

    Gharibyan, Narek; Moody, Ken J.; Shaughnessy, Dawn A.

    2015-12-16

    The advantage of using depleted uranium (DU) hohlraums in high-yield deuterium-tritium (DT) shots at the National Ignition Facility (NIF) is addressed by Döppner, et al., in great detail [1]. This DU based hohlraum incorporates a thin layer of DU, ~7 μm thick, on the inner surface along with a thin layer of a gold coating, ~0.7 μm thick, while the outer layer is ~22 μm thick gold. A thickness measurement of the DU layer can be performed using an optical microscope where the total DU weight can be computed provided a uniform DU layer. However, the uniformity of the thickness is not constant throughout the hohlraum since CAD drawing calculations of the DU weight do not agree with the computed values from optical measurements [2]. Therefore, a non-destructive method for quantifying the DU content in hohlraums has been established by utilizing gamma-ray spectroscopy. The details of this method, along with results from several hohlraums, are presented in this report.

  18. Research Based on Optical Non-Destructive Testing of Pigment Identification.

    PubMed

    Wang, Jigang; Hao, Shengcai; Zhou, Wenhua; Qi, Xiaokun; Shi, Jilong

    2016-04-01

    Optical Non-Destructive Testing (ONDT) can be applied as penetrating elemental and structure analysis technology in the Pigments identification field. Three-dimensional video microscopy, Raman microscopy and energy dispersive X-ray fluorescence spectroscopy are employed to measure the materials based on a Qing Dynasty meticulous painting. The results revealed that the dark yellow area within the decorative patterns was presented due to the interaction of Emerald green and hematite, and the bright yellow edge area was delineated by Cu-Zn-Pb composition. The interesting thing is that an artificial synthetic ultramarine blue was checked in the painting. According to the first synthesized time of ultramarine blue and Paris green, the time limit of the painting completion can be identified. The principle of Pigment subtractive colorant and nitikaset method were employed to interpreting the results. Optical testing combined with the area of cultural relic identification can be a potential method to build an expert identification system successfully. This work also help lay the optical method groundwork for further cultural relic identification, sterilization, and preservation.

  19. Spectral algorithm for non-destructive damage localisation: Application to an ancient masonry arch model

    NASA Astrophysics Data System (ADS)

    Masciotta, Maria-Giovanna; Ramos, Luís F.; Lourenço, Paulo B.; Vasta, Marcello

    2017-02-01

    Structural monitoring and vibration-based damage identification methods are fundamental tools for condition assessment and early-stage damage identification, especially when dealing with the conservation of historical constructions and the maintenance of strategic civil structures. However, although the substantial advances in the field, several issues must still be addressed to broaden the application range of such tools and to assert their reliability. This study deals with the experimental validation of a novel method for non-destructive damage identification purposes. This method is based on the use of spectral output signals and has been recently validated by the authors through a numerical simulation. After a brief insight into the basic principles of the proposed approach, the spectral-based technique is applied to identify the experimental damage induced on a masonry arch through statically increasing loading. Once the direct and cross spectral density functions of the nodal response processes are estimated, the system's output power spectrum matrix is built and decomposed in eigenvalues and eigenvectors. The present study points out how the extracted spectral eigenparameters contribute to the damage analysis allowing to detect the occurrence of damage and to locate the target points where the cracks appear during the experimental tests. The sensitivity of the spectral formulation to the level of noise in the modal data is investigated and discussed. As a final evaluation criterion, the results from the spectrum-driven method are compared with the ones obtained from existing non-model based damage identification methods.

  20. Quantifying tetrodotoxin levels in the California newt using a non-destructive sampling method.

    PubMed

    Bucciarelli, Gary M; Li, Amy; Zimmer, Richard K; Kats, Lee B; Green, David B

    2014-03-01

    Toxic or noxious substances often serve as a means of chemical defense for numerous taxa. However, such compounds may also facilitate ecological or evolutionary processes. The neurotoxin, tetrodotoxin (TTX), which is found in newts of the genus Taricha, acts as a selection pressure upon predatory garter snakes, is a chemical cue to conspecific larvae, which elicits antipredator behavior, and may also affect macroinvertebrate foraging behavior. To understand selection patterns and how potential variation might affect ecological and evolutionary processes, it is necessary to quantify TTX levels within individuals and populations. To do so has often required that animals be destructively sampled or removed from breeding habitats and brought into the laboratory. Here we demonstrate a non-destructive method of sampling adult Taricha that obviates the need to capture and collect individuals. We also show that embryos from oviposited California newt (Taricha torosa) egg masses can be individually sampled and TTX quantified from embryos. We employed three different extraction techniques to isolate TTX. Using a custom fabricated high performance liquid chromatography (HPLC) system we quantified recovery of TTX. We found that a newly developed micro-extraction technique significantly improved recovery compared to previously used methods. Results also indicate our improvements to the HPLC method have high repeatability and increased sensitivity, with a detection limit of 48 pg (0.15 pmol) TTX. The quantified amounts of TTX in adult newts suggest fine geographic variation in toxin levels between sampling localities isolated by as little as 3 km.

  1. Plane Wave Imaging for ultrasonic non-destructive testing: Generalization to multimodal imaging.

    PubMed

    Le Jeune, Léonard; Robert, Sébastien; Lopez Villaverde, Eduardo; Prada, Claire

    2016-01-01

    This paper describes a new ultrasonic array imaging method for Non-Destructive Testing (NDT) which is derived from the medical Plane Wave Imaging (PWI) technique. The objective is to perform fast ultrasound imaging with high image quality. The approach is to transmit plane waves at several angles and to record the back-scattered signals with all the array elements. Focusing in receive is then achieved by coherent summations of the signals in every point of a region of interest. The medical PWI is generalized to immersion setups where water acts as a coupling medium and to multimodal (direct, half-skip modes) imaging in order to detect different types of defects (inclusions, porosities, cracks). This method is compared to the Total Focusing Method (TFM) which is the reference imaging technique in NDT. First, the two post-processing algorithms are described. Then experimental results with the array probe either in contact or in immersion are presented. A good agreement between the TFM and the PWI is observed, with three to ten times less transmissions required for the PWI.

  2. NON-DESTRUCTIVE RADIOCARBON DATING: NATURALLY MUMMIFIED INFANT BUNDLE FROM SW TEXAS

    SciTech Connect

    Steelman, K L; Rowe, M W; Turpin, S A; Guilderson, T P; Nightengale, L

    2004-09-07

    Plasma oxidation was used to obtain radiocarbon dates on six different materials from a naturally mummified baby bundle from the Lower Pecos River region of southwest Texas. This bundle was selected because it was thought to represent a single event and would illustrate the accuracy and precision of the plasma oxidation method. Five of the materials were clearly components of the original bundle with 13 dates combined to yield a weighted average of 2135 {+-} 11 B.P. Six dates from a wooden stick of Desert Ash averaged 939 {+-} 14 B.P., indicating that this artifact was not part of the original burial. Plasma oxidation is shown to be a virtually non-destructive alternative to combustion. Because only sub-milligram amounts of material are removed from an artifact over its exposed surface, no visible change in fragile materials has been observed, even under magnification. The method is best applied when natural organic contamination is unlikely and serious consideration of this issue is needed in all cases. If organic contamination is present, it will have to be removed before plasma oxidation to obtain accurate radiocarbon dates.

  3. Application of coupled electric field method for eddy current non-destructive inspection of multilayer structures

    NASA Astrophysics Data System (ADS)

    Bouchala, T.; Abdelhadi, B.; Benoudjit, A.

    2015-04-01

    The development of fast and accurate method describing the electromagnetic phenomena intervening in eddy current non-destructive systems is very interesting, since it permits the design of reliable systems permitting the detection and the characterisation of defect in conductive materials. The coupled electric field method presented in this article can assume a large part of these objectives, because it is fast in comparison to the finite element method and easily invertible since the sensor impedance variation is an explicit function of target physical and geometrical characteristics. These advantages have motivated us to extend this method for multilayered structures, very interesting in aeronautic industry, by superposing the inductive effects in different layers. The impedance of an absolute sensor operating above three conducting layers will be calculated and compared to those obtained with finite element method. Afterwards, we shall exploit the model to study the effect of defect characteristics on the sensor impedance. Furthermore, regarding to the depth penetration effect, we shall make into evidence the necessity of accomplishing an optimal choice of the exciting field frequency during the inspection of multilayered materials. The essential importance of this method, besides of its rapidity, resides in its possibility to be extended to 2D irregular and 3D asymmetric configurations.

  4. Non-destructive evaluation of spiral-welded pipes using flexural guided waves

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaowei; Tang, Zhifeng; Lü, Fuzai; Pan, Xiaohong

    2016-02-01

    Millions of miles of pipes are being used in both civil and industrial fields. Spiral-welded pipes, which are widely applied in fields such as drainage, architecture as well as oil and gas storage and transportation, are difficult to inspect due to their complex geometry. Guided waves have shown a great potential in Non-Destructive Evaluation (NDE) and Structural Health Monitoring (SHM) for such cases. Flexural guided waves that propagate at a helix angle relative to the axial direction of pipe, are the most appropriate modes for inspecting spiral-welded pipes. The classical Normal Mode Expansion method (NME) is adopted to disseminate the forced response and perturbation analysis of a steel pipe with respect to a time delay circular loading. A time delay circular array transducer (TDCAT) is proposed for the purpose of exciting pure flexural mode in pipes. Pure flexural mode can be excited when the time delay parameter is specifically designed. The theoretical prediction is verified by finite element numerical evaluation and spiral-welded pipe inspection experiment.

  5. Non-destructive characterisation of iron gall ink drawings: not such a galling problem.

    PubMed

    Strlic, Matija; Cséfalvayová, Linda; Kolar, Jana; Menart, Eva; Kosek, Joanna; Barry, Caroline; Higgitt, Catherine; Cassar, May

    2010-04-15

    Iron gall inks are of extraordinary historical significance considering their widespread use for over a millennium. Due to their corrosiveness, which is a consequence of their acidity and content of transition metals, iron gall inks accelerate the degradation of the writing or drawing support, which in this study is rag paper. Characterisation of acidity (pH) and degree of polymerisation (DP) of cellulose in paper is thus of high interest as it enables the estimation of material stability and assessment of risks associated with its handling. Based on a well-characterised set of samples with iron gall ink from the 18th and 19th centuries, we developed a near infrared spectroscopic method with partial least squares calibration for non-destructive determination of pH and DP of both inked areas and paper. Using this method, 27 18th and 19th century iron gall ink drawings from the British Museum collection were analysed and in all cases, inked areas turned out to be more acidic and degraded than the surrounding paper. Based on the obtained DP data, we were able to estimate the time needed for the inked areas to degrade to the point when they become at risk of damage due to handling. Using the average uncertainty of the calculated lifetime, we propose a quantitative stability classification method which could contribute to the curatorial and conservation decision-making process.

  6. From local to global analysis of defect detectability in infrared non-destructive testing

    NASA Astrophysics Data System (ADS)

    Florez-Ospina, J. F.; Benitez, H. D.

    2014-03-01

    Several image processing techniques are employed in Infrared Non-Destructive Testing (IRNDT) to enhance defect detectability. To date, there is no adequate global measurement that objectively assesses defect visibility in processed frames. In this work, a Global Signal to Noise Ratio (GSNR) that comprehensively evaluates defect detectability in processed infrared (IR) images is proposed, as well as a defect visibility measure named Infrared Image Quality Index (IRIQI) that compares the structural information of defective and sound areas. In addition, GSNR and IRIQI are validated by using the area under ROC curve (AUC). AUC quantitatively assesses defect visibility by comparing the outcomes of processing techniques to human judgements. The remarkable benefit of this global approach is that it allows one to determine the frame at which processing techniques reveals the majority of the defects by evaluating the times at which AUC curves reach their maxima. The test pieces were a Carbon-Fiber Reinforced Plastic (CFRP) sample containing delaminations and a honeycomb specimen with delaminations, skin unbonds, excessive adhesive, and crushed core.

  7. Non-destructive analysis of museum objects by fibre-optic Raman spectroscopy

    PubMed Central

    Tate, Jim; Moens, Luc

    2006-01-01

    Raman spectroscopy is a versatile technique that has frequently been applied for the investigation of art objects. By using mobile Raman instrumentation it is possible to investigate the artworks without the need for sampling. This work evaluates the use of a dedicated mobile spectrometer for the investigation of a range of museum objects in museums in Scotland, including antique Egyptian sarcophagi, a panel painting, painted surfaces on paper and textile, and the painted lid and soundboard of an early keyboard instrument. The investigations of these artefacts illustrate some analytical challenges that arise when analysing museum objects, including fluorescing varnish layers, ambient sunlight, large dimensions of artefacts and the need to handle fragile objects with care. Analysis of the musical instrument (the Mar virginals) was undertaken in the exhibition gallery, while on display, which meant that interaction with the public and health and safety issues had to be taken into account. Experimental set-up for the non-destructive Raman spectroscopic investigation of a textile banner in the National Museums of Scotland PMID:16953310

  8. Non-destructive analysis of museum objects by fibre-optic Raman spectroscopy.

    PubMed

    Vandenabeele, Peter; Tate, Jim; Moens, Luc

    2007-02-01

    Raman spectroscopy is a versatile technique that has frequently been applied for the investigation of art objects. By using mobile Raman instrumentation it is possible to investigate the artworks without the need for sampling. This work evaluates the use of a dedicated mobile spectrometer for the investigation of a range of museum objects in museums in Scotland, including antique Egyptian sarcophagi, a panel painting, painted surfaces on paper and textile, and the painted lid and soundboard of an early keyboard instrument. The investigations of these artefacts illustrate some analytical challenges that arise when analysing museum objects, including fluorescing varnish layers, ambient sunlight, large dimensions of artefacts and the need to handle fragile objects with care. Analysis of the musical instrument (the Mar virginals) was undertaken in the exhibition gallery, while on display, which meant that interaction with the public and health and safety issues had to be taken into account. Experimental set-up for the non-destructive Raman spectroscopic investigation of a textile banner in the National Museums of Scotland.

  9. Non-destructive X-ray examination of weft knitted wire structures

    NASA Astrophysics Data System (ADS)

    Obermann, M.; Ellouz, M.; Aumann, S.; Martens, Y.; Bartelt, P.; Klöcker, M.; Kordisch, T.; Ehrmann, A.; Weber, M. O.

    2016-07-01

    Conductive yarns or wires are often integrated in smart textiles to enable data or energy transmission. In woven fabrics, these conductive parts are fixed at defined positions and thus protected from external loads. Knitted fabrics, however, have relatively loose structures, resulting in higher impacts of possible mechanical forces on the individual yarns. Hence, metallic wires with smaller diameters in particular are prone to break when integrated in knitted fabrics. In a recent project, wires of various materials including copper, silver and nickel with diameters varying between 0.05 mm and 0.23 mm were knitted in combination with textile yarns. Hand flat knitting machines of appropriate gauges were used to produce different structures. On these samples, non-destructive examinations, using an industrial X-ray system Seifert x|cube (225 kV) equipped with a minifocus X-ray tube, were carried out, directly after knitting as well as after different mechanical treatments (tensile, burst, and washing tests). In this way, structural changes of the stitch geometry could be visualized before failure. In this paper, the loop geometries in the knitted fabrics are depicted depending on knitted structures, wire properties and the applied mechanical load. Consequently, it is shown which metallic wires and yarns are most suitable to be integrated into knitted smart textiles.

  10. Non-destructive in-situ method and apparatus for determining radionuclide depth in media

    DOEpatents

    Xu, X. George; Naessens, Edward P.

    2003-01-01

    A non-destructive method and apparatus which is based on in-situ gamma spectroscopy is used to determine the depth of radiological contamination in media such as concrete. An algorithm, Gamma Penetration Depth Unfolding Algorithm (GPDUA), uses point kernel techniques to predict the depth of contamination based on the results of uncollided peak information from the in-situ gamma spectroscopy. The invention is better, faster, safer, and/cheaper than the current practice in decontamination and decommissioning of facilities that are slow, rough and unsafe. The invention uses a priori knowledge of the contaminant source distribution. The applicable radiological contaminants of interest are any isotopes that emit two or more gamma rays per disintegration or isotopes that emit a single gamma ray but have gamma-emitting progeny in secular equilibrium with its parent (e.g., .sup.60 Co, .sup.235 U, and .sup.137 Cs to name a few). The predicted depths from the GPDUA algorithm using Monte Carlo N-Particle Transport Code (MCNP) simulations and laboratory experiments using .sup.60 Co have consistently produced predicted depths within 20% of the actual or known depth.

  11. Non-destructive testing of ceramic balls using high frequency ultrasonic resonance spectroscopy.

    PubMed

    Petit, S; Duquennoy, M; Ouaftouh, M; Deneuville, F; Ourak, M; Desvaux, S

    2005-12-01

    Although ceramic balls are used more and more for bearings in the aerospace and space industries, defects in this type of ceramic material could be dangerous, particularly if such defects are located close to the surface. In this paper, we propose a non-destructive testing method for silicon nitride balls, based on ultrasonic resonance spectroscopy. Through the theoretical study of their elastic vibrations, it is possible to characterize the balls using a vibration mode that is similar to surface wave propagation. The proposed methodology can both excite spheroidal vibrations in the ceramic balls and detect such vibrations over a large frequency range. Studying their resonance spectrums allows the balls' elastic parameters be characterized. Ours is an original method that can quickly estimate the velocity of surface waves using high frequency resonances, which permits surface and sub-surface areas to be tested specifically. Two applications are described in this paper. Both use velocity measurements to achieve their different goals, the first to differentiate between flawless balls from different manufacturing processes, and the second to detect small defects, such as cracks. Our method is rapid and permits the entire ceramic ball to be tested in an industrial context.

  12. Potential for non-destructive astrochemistry using the ExoMars PanCam

    NASA Astrophysics Data System (ADS)

    Storrie-Lombardi, Michael C.; Muller, J.-P.; Fisk, M. R.; Griffiths, A. D.; Coates, A. J.

    2008-06-01

    We investigate the utility of adding a 365 nm ultraviolet (UV) light source to the ExoMars panoramic camera (PanCam) scheduled for launch in 2013. The modification makes it feasible to monitor rover drill cuttings for aromatic organic molecules and provide constraints on polycyclic aromatic hydrocarbons (PAH) as a function of depth to the 2-meter limit of the ExoMars drill. This non-destructive triage allows prioritized deployment of organic detection experiments requiring sample destruction and/or expenditure of non-replaceable resources. Utilizing the Beagle 2 PanCam backup filter wheel fitted with original blue (440 nm), green (530 nm), and red (670 nm) filters we captured fluorescent images following 365 nm excitation of 3-, 4- and 5-ring PAH species doped on Mars analog peridotite grains. We demonstrate a detection limit for pyrene of 1.5 μg in granular peridotite doped at pyrene levels of 50 +/- 5 ppm for camera-to-target distance of 1 meter.

  13. Non-destructive methods of control of thermo-physical properties of fuel rods

    NASA Astrophysics Data System (ADS)

    Kruglov, A. B.; Kruglov, V. B.; Kharitonov, V. S.; Struchalin, P. G.; Galkin, A. G.

    2017-01-01

    Information about the change of thermal properties of the fuel elements needed for a successful and safe operation of the nuclear power plant. At present, the existing amount of information on the fuel thermal conductivity change and “fuel-shell” thermal resistance is insufficient. Also, there is no technique that would allow for the measurement of these properties on the non-destructive way of irradiated fuel elements. We propose a method of measuring the thermal conductivity of the fuel in the fuel element and the contact thermal resistance between the fuel and the shell without damaging the integrity of the fuel element, which is based on laser flash method. The description of the experimental setup, implementing methodology, experiments scheme. The results of test experiments on mock-ups of the fuel elements and their comparison with reference data, as well as the results of numerical modeling of thermal processes that occur during the measurement. Displaying harmonization of numerical calculation with the experimental thermograms layout shell portions of the fuel cell, confirming the correctness of the calculation model.

  14. First-time observation of Mastro Giorgio masterpieces by means of non-destructive techniques

    NASA Astrophysics Data System (ADS)

    Padeletti, G.; Ingo, G. M.; Bouquillon, A.; Pages-Camagna, S.; Aucouturier, M.; Roehrs, S.; Fermo, P.

    2006-06-01

    For the first time some excellent pieces belonging to the majolica production of the great master Giorgio Andreoli from Gubbio (Central Italy) have been characterized from a chemical and structural point of view with the aim to identify the composition of both pigments and lustres. A series of particle-induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and Raman analyses have been performed on some plates coming from Museo del Palazzo dei Consoli (Gubbio) and several French museums (Louvre, Musée National de la Céramique, Musée National de la Renaissance) lustred by Giorgio Andreoli and decorated by famous majolica painters such as Francesco Xanto Avelli. The three techniques are complementary and useful in the investigation of art objects since they are non-destructive. Furthermore, the low detection limits allow the identification of all elements and compounds present, and RBS allows concentration profiling, too. It is worth noticing that the examined objects are characterized by the presence of both gold and ruby-red lustres, a peculiarity of Mastro Giorgio’s technique. The measurements by PIXE and RBS have been carried out on the AGLAE accelerator at C2RMF, Louvre Palace.

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

    SciTech Connect

    Beattie, A.G.; Rumsey, M.

    1998-12-17

    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.

  16. An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    1993-01-01

    A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples.

  17. Recent advances in rapid and non-destructive assessment of meat quality using hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Tao, Feifei; Ngadi, Michael

    2016-05-01

    Meat is an important food item in human diet. Its production and consumption has greatly increased in the last decades with the development of economies and improvement of peoples' living standards. However, most of the traditional methods for evaluation of meat quality are time-consuming, laborious, inconsistent and destructive to samples, which make them not appropriate for a fast-paced production and processing environment. Development of innovative and non-destructive optical sensing techniques to facilitate simple, fast, and accurate evaluation of quality are attracting increasing attention in the food industry. Hyperspectral imaging is one of the promising techniques. It integrates the combined merits of imaging and spectroscopic techniques. This paper provides a comprehensive review on recent advances in evaluation of the important quality attributes of meat including color, marbling, tenderness, pH, water holding capacity, and also chemical composition attributes such as moisture content, protein content and fat content in pork, beef and lamb. In addition, the future potential applications and trends of hyperspectral imaging are also discussed in this paper.

  18. Non-destructive diagnosis of relativistic electron beams using a short undulator

    SciTech Connect

    Ponds, M.L.; Madey, J.M.J.; O`Shea, P.G.

    1995-12-31

    The performance of an FEL depends critically on the characteristics of the electron beam used to drive it. In the past it has been very difficult to measure the details of the transverse and longitudinal phase-space distributions of high-energy electron beams with the precision required to predict FEL performance. Furthermore, the available diagnostics were generally pertubative, and could not be used simultaneously with lasing. We investigate the potential use of a short undulator insertion device for non-destructive diagnosis of relativistic electron beams. Incoherent visible to near-infrared synchrotron radiation from a single magnet in the diagnostic undulator will be used to obtain information on beam position and transverse phase-space. Coherent off-axis undulator radiation in the millimeter to sub-millimeter range will be used to measure longitudinal phase-space characteristics of the beam. These two types of radiation can be analyzed simultaneously, while the FEL is lasing; thus giving a complete picture of relevant electron beam characteristics. In this paper we analyze the theoretical and practical design issues associated with such a diagnostic undulator.

  19. Analysis of non-destructive current simulators of flux compression generators

    NASA Astrophysics Data System (ADS)

    O'Connor, K. A.; Curry, R. D.

    2014-06-01

    Development and evaluation of power conditioning systems and high power microwave components often used with flux compression generators (FCGs) requires repeated testing and characterization. In an effort to minimize the cost and time required for testing with explosive generators, non-destructive simulators of an FCG's output current have been developed. Flux compression generators and simulators of FCGs are unique pulsed power sources in that the current waveform exhibits a quasi-exponential increasing rate at which the current rises. Accurately reproducing the quasi-exponential current waveform of a FCG can be important in designing electroexplosive opening switches and other power conditioning components that are dependent on the integral of current action and the rate of energy dissipation. Three versions of FCG simulators have been developed that include an inductive network with decreasing impedance in time. A primary difference between these simulators is the voltage source driving them. It is shown that a capacitor-inductor-capacitor network driving a constant or decreasing inductive load can produce the desired high-order derivatives of the load current to replicate a quasi-exponential waveform. The operation of the FCG simulators is reviewed and described mathematically for the first time to aid in the design of new simulators. Experimental and calculated results of two recent simulators are reported with recommendations for future designs.

  20. Autofluorescence microscopy: a non-destructive tool to monitor mitochondrial toxicity.

    PubMed

    Rodrigues, Robim M; Macko, Peter; Palosaari, Taina; Whelan, Maurice P

    2011-10-30

    Visualization of NADH by fluorescence microscopy makes it possible to distinguish mitochondria inside living cells, allowing structure analysis of these organelles in a non-invasive way. Mitochondrial morphology is determined by the occurrence of mitochondrial fission and fusion. During normal cell function mitochondria appear as elongated tubular structures. However, cellular malfunction induces mitochondria to fragment into punctiform, vesicular structures. This change in morphology is associated with the generation of reactive oxygen species (ROS) and early apoptosis. The aim of this study is to demonstrate that autofluorescence imaging of mitochondria in living eukaryotic cells provides structural and morphological information that can be used to assess mitochondrial health. We firstly established the illumination conditions that do not affect mitochondrial structure and calculated the maximum safe light dose to which the cells can be exposed. Subsequently, sequential recording of mitochondrial fluorescence was performed and changes in mitochondrial morphology were monitored in a continuous non-destructive way. This approach was then used to assess mitochondrial toxicity induced by potential toxicants exposed to mammalian cells. Both mouse and human cells were used to evaluate mitochondrial toxicity of different compounds with different toxicities. This technique constitutes a novel and promising approach to explore chemical induced toxicity because of its reliability to monitor mitochondrial morphology changes and corresponding toxicity in a non-invasive way.

  1. Non-Destructive Current Sensing for Energy Efficiency Monitoring in Buildings with Environmental Certification

    PubMed Central

    Mota, Lia Toledo Moreira; Mota, Alexandre de Assis; Coiado, Lorenzo Campos

    2015-01-01

    Nowadays, buildings environmental certifications encourage the implementation of initiatives aiming to increase energy efficiency in buildings. In these certification systems, increased energy efficiency arising from such initiatives must be demonstrated. Thus, a challenge to be faced is how to check the increase in energy efficiency related to each of the employed initiatives without a considerable building retrofit. In this context, this work presents a non-destructive method for electric current sensing to assess implemented initiatives to increase energy efficiency in buildings with environmental certification. This method proposes the use of a sensor that can be installed directly in the low voltage electrical circuit conductors that are powering the initiative under evaluation, without the need for reforms that result in significant costs, repair, and maintenance. The proposed sensor consists of three elements: an air-core transformer current sensor, an amplifying/filtering stage, and a microprocessor. A prototype of the proposed sensor was developed and tests were performed to validate this sensor. Based on laboratory tests, it was possible to characterize the proposed current sensor with respect to the number of turns and cross-sectional area of the primary and secondary coils. Furthermore, using the Least Squares Method, it was possible to determine the efficiency of the air core transformer current sensor (the best efficiency found, considering different test conditions, was 2%), which leads to a linear output response. PMID:26184208

  2. Non-destructive quantification of alignment of nanorods embedded in uniaxially stretched polymer films

    NASA Astrophysics Data System (ADS)

    Stoenescu, Stefan; Truong, Vo-Van; Packirisamy, Muthukumaran

    2014-03-01

    Among several methods developed for uniaxial alignment of metallic nanorods for optical applications, alignment by film stretching consists in embedding the rods in a transparent thin film of thermoplastic polymer, followed by simultaneous heating and uniaxial stretching of the composite film. As to the quantification of the resulting alignment, it has been limited to statistical calculations based on microscopic examination, which is incomplete, subject to errors due to geometric distortions of the scanning electron microscope images and destructive, since it involves cutting of samples. In contrast, we present in this paper a non-destructive quantification of the average orientation of the rods, based on a probabilistic approach combined with numerical simulations of absorbance spectra and spectrometric characterization of the composite film. Assuming electromagnetically non-interacting rods, we consider the longitudinal absorbance peak of their ensemble to consist of the superposition of their individual spectra that we obtain by numerical simulation using the size and shape adapted dielectric function of the metal and the finite difference time domain method. The accuracy of the solution depends on the number of discretization intervals, the accuracy of the numerical simulations, and the accurate knowledge of the polydispersity of the rods. For the sake of concreteness, we used nanorods to describe the quantification steps but the method is equally valid for any dichroic particles.

  3. Rapid and non-destructive identification of water-injected beef samples using multispectral imaging analysis.

    PubMed

    Liu, Jinxia; Cao, Yue; Wang, Qiu; Pan, Wenjuan; Ma, Fei; Liu, Changhong; Chen, Wei; Yang, Jianbo; Zheng, Lei

    2016-01-01

    Water-injected beef has aroused public concern as a major food-safety issue in meat products. In the study, the potential of multispectral imaging analysis in the visible and near-infrared (405-970 nm) regions was evaluated for identifying water-injected beef. A multispectral vision system was used to acquire images of beef injected with up to 21% content of water, and partial least squares regression (PLSR) algorithm was employed to establish prediction model, leading to quantitative estimations of actual water increase with a correlation coefficient (r) of 0.923. Subsequently, an optimized model was achieved by integrating spectral data with feature information extracted from ordinary RGB data, yielding better predictions (r = 0.946). Moreover, the prediction equation was transferred to each pixel within the images for visualizing the distribution of actual water increase. These results demonstrate the capability of multispectral imaging technology as a rapid and non-destructive tool for the identification of water-injected beef.

  4. Non-destructive determination of anisotropic mechanical properties of pharmaceutical solid dosage forms.

    PubMed

    Akseli, I; Hancock, B C; Cetinkaya, C

    2009-07-30

    The mechanical property anisotropy of compacts made from four commercially available pharmaceutical excipient powders (microcrystalline cellulose, lactose monohydrate, ascorbic acid, and aspartame) was evaluated. The speed of pressure (longitudinal) waves in the uni-axially compressed cubic compacts of each excipient in the three principle directions was determined using a contact ultrasonic method. Average Young's moduli of each compact in the axial (x) and radial (y and z) directions were characterized. The contact ultrasonic measurements revealed that average Young's modulus values vary with different testing orientations which indicate Young's modulus anisotropy in the compacts. The extent of Young's modulus anisotropy was quantified by using a dimensionless ratio and was found to be significantly different for each material (microcrystalline cellulose>lactose>aspartame>ascorbic acid). It is also observed that using the presented contact method, compacts at high solid fraction (0.857-0.859) could be differentiated than those at the solid fraction of 0.85 in their groups. The presented contact ultrasonic method is an attractive tool since it has the advantages of being sensitive to solid fraction ratio, non-destructive, requiring small amount of material and rapid. It is noteworthy that, since the approach provides insight into the performance of common pharmaceutical materials and fosters increased process knowledge, it can be applied to broaden the understanding of the effect of the mechanical properties on the performance (e.g., disintegration profiles) of solid oral dosage forms.

  5. Ultra-portable, wireless smartphone spectrometer for rapid, non-destructive testing of fruit ripeness

    PubMed Central

    Das, Anshuman J.; Wahi, Akshat; Kothari, Ishan; Raskar, Ramesh

    2016-01-01

    We demonstrate a smartphone based spectrometer design that is standalone and supported on a wireless platform. The device is inherently low-cost and the power consumption is minimal making it portable to carry out a range of studies in the field. All essential components of the device like the light source, spectrometer, filters, microcontroller and wireless circuits have been assembled in a housing of dimensions 88 mm × 37 mm × 22 mm and the entire device weighs 48 g. The resolution of the spectrometer is 15 nm, delivering accurate and repeatable measurements. The device has a dedicated app interface on the smartphone to communicate, receive, plot and analyze spectral data. The performance of the smartphone spectrometer is comparable to existing bench-top spectrometers in terms of stability and wavelength resolution. Validations of the device were carried out by demonstrating non-destructive ripeness testing in fruit samples. Ultra-Violet (UV) fluorescence from Chlorophyll present in the skin was measured across various apple varieties during the ripening process and correlated with destructive firmness tests. A satisfactory agreement was observed between ripeness and fluorescence signals. This demonstration is a step towards possible consumer, bio-sensing and diagnostic applications that can be carried out in a rapid manner. PMID:27606927

  6. High-resolution non-destructive three-dimensional imaging of integrated circuits

    NASA Astrophysics Data System (ADS)

    Holler, Mirko; Guizar-Sicairos, Manuel; Tsai, Esther H. R.; Dinapoli, Roberto; Müller, Elisabeth; Bunk, Oliver; Raabe, Jörg; Aeppli, Gabriel

    2017-03-01

    Modern nanoelectronics has advanced to a point at which it is impossible to image entire devices and their interconnections non-destructively because of their small feature sizes and the complex three-dimensional structures resulting from their integration on a chip. This metrology gap implies a lack of direct feedback between design and manufacturing processes, and hampers quality control during production, shipment and use. Here we demonstrate that X-ray ptychography—a high-resolution coherent diffractive imaging technique—can create three-dimensional images of integrated circuits of known and unknown designs with a lateral resolution in all directions down to 14.6 nanometres. We obtained detailed device geometries and corresponding elemental maps, and show how the devices are integrated with each other to form the chip. Our experiments represent a major advance in chip inspection and reverse engineering over the traditional destructive electron microscopy and ion milling techniques. Foreseeable developments in X-ray sources, optics and detectors, as well as adoption of an instrument geometry optimized for planar rather than cylindrical samples, could lead to a thousand-fold increase in efficiency, with concomitant reductions in scan times and voxel sizes.

  7. Metal composite as backing for ultrasonic transducers dedicated to non-destructive measurements in hostile

    NASA Astrophysics Data System (ADS)

    Boubenia, R.; Rosenkrantz, E.; Despetis, F.; P, P.; Ferrandis, J.-Y.

    2016-03-01

    Our team is specialized in ultrasonic measurements in hostile environment especially under high temperatures. There is a need for acoustic transducers capable of continuous measurement at temperatures up to 700°C. To improve the performances of acoustic sensors we focus our works on the realisation and characterisation of transducer backings able to operate under very high temperature. Commercially, they are produced by the incorporation of tungsten powder in a plastic matrix, which limits the working temperature. The realisation of ultrasonic transducers for non-destructive measures at high temperatures requires adequate materials, manufacturing and assembly processes. To produce the backings, composites were made using very ductile metals such as tin and tungsten. These composites are manufactured by uniaxial hot pressing. First, we studied the influence of temperature and pressure on the densification of tin pellets. Then, several specimens made of tin/W were made and characterised by measuring the specific weight, speed and attenuation of sound. The acoustic measures were realised by ultrasonic spectroscopy. This test-bench was designed and tested on control samples of PMMA and on standard backings (epoxy / tungsten).

  8. X-ray based methods for non-destructive testing and material characterization

    NASA Astrophysics Data System (ADS)

    Hanke, Randolf; Fuchs, Theobald; Uhlmann, Norman

    2008-06-01

    The increasing complexity and miniaturization in the field of new materials as well as in micro-production requires in the same way improvements and technical advances in the field of micro-NDT to provide better quality data and more detailed knowledge about the internal structures of micro-components. Therefore, non-destructive methods like radioscopy, ultrasound, optical or thermal imaging increasingly gain in importance with respect to ongoing product and material development in the different phases like material characterization, production control or module reliability testing. Because of the manifold different application fields, i.e., certain physical NDT methods applied to material inspection, characterization or reliability testing, this contribution will focus on the radioscopic-based methods related to their most important applications. Today, in modern industrial quality control, X-ray transmission is used in two different ways: Two-dimensional radioscopic transmission imaging (projection technique), usually applied to inline inspection tasks in application fields like lightweight material production, electronic component soldering or food production. Computed tomography (CT) for generation of three-dimensional data, representing spatial information and density distribution of objects. CT application fields are on the one hand the understanding of production process failure or component and module inspection (completeness) and on the other hand the dimensional measuring of hidden geometrical outlines (metrology). This paper demonstrates the methods including technical set-ups (X-ray source and detector), imaging and reconstruction results and the methods for high speed and high-resolution volume data generation and evaluation.

  9. Numerical study of light propagation in agricultural products for non-destructive assessment of food quality

    NASA Astrophysics Data System (ADS)

    Hattori, Kiyohito; Fujii, Hiroyuki; Tatekura, Yuki; Kobayashi, Kazumichi; Watanabe, Masao

    2015-12-01

    An accurate determination of optical properties of agricultural products is crucial for non-destructive assessment of food quality. For the determination, light intensity is measured at the surface of the product; then, inverse analysis is employed based on a light propagation model such as the radiative transfer equation (RTE). The inverse analysis requires high computational loads because the light intensity is numerically calculated using the model every time the optical properties are changed. For the calculation, we propose an efficient technique by combining a numerical solution with an analytical solution of the RTE, and investigate the validity of the technique in a two-dimensional homogeneous circular medium which is regarded as a light propagation model with optical properties of kiwifruit. The proposed technique can provide accurate results of the light intensity in change of the optical properties, and the accuracy is less dependent on the boundary conditions and source-detector angles. In addition, the technique can reduce computation time compared with that for numerical calculation of the RTE. These results indicate usefulness of the proposed technique for the inverse analysis.

  10. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    SciTech Connect

    Kiefel, Denis E-mail: Rainer.Stoessel@airbus.com; Stoessel, Rainer E-mail: Rainer.Stoessel@airbus.com; Grosse, Christian

    2015-03-31

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  11. Ultra-portable, wireless smartphone spectrometer for rapid, non-destructive testing of fruit ripeness

    NASA Astrophysics Data System (ADS)

    Das, Anshuman J.; Wahi, Akshat; Kothari, Ishan; Raskar, Ramesh

    2016-09-01

    We demonstrate a smartphone based spectrometer design that is standalone and supported on a wireless platform. The device is inherently low-cost and the power consumption is minimal making it portable to carry out a range of studies in the field. All essential components of the device like the light source, spectrometer, filters, microcontroller and wireless circuits have been assembled in a housing of dimensions 88 mm × 37 mm × 22 mm and the entire device weighs 48 g. The resolution of the spectrometer is 15 nm, delivering accurate and repeatable measurements. The device has a dedicated app interface on the smartphone to communicate, receive, plot and analyze spectral data. The performance of the smartphone spectrometer is comparable to existing bench-top spectrometers in terms of stability and wavelength resolution. Validations of the device were carried out by demonstrating non-destructive ripeness testing in fruit samples. Ultra-Violet (UV) fluorescence from Chlorophyll present in the skin was measured across various apple varieties during the ripening process and correlated with destructive firmness tests. A satisfactory agreement was observed between ripeness and fluorescence signals. This demonstration is a step towards possible consumer, bio-sensing and diagnostic applications that can be carried out in a rapid manner.

  12. Feasibility for non-destructive discrimination of natural and beryllium-diffused sapphires using Raman spectroscopy.

    PubMed

    Chang, Kyeol; Lee, Sanguk; Park, Jimin; Chung, Hoeil

    2016-03-01

    Raman spectroscopy based non-destructive discrimination between natural and beryllium-diffused (Be-diffused) sapphires has been attempted. The initial examination of Raman image acquired on a sapphire revealed that microscopic structural and compositional heterogeneity was apparent in the sample, so acquisition of spectra able to represent a whole body of sapphire rather than a localized area was necessary for a reliable discrimination. For this purpose, a wide area illumination (WAI) scheme (illumination area: 28.3mm(2)) providing a large sampling volume was employed to collect representative Raman spectra of sapphires. Upon the diffusion of Be into a sapphire, the band shift originated from varied lattice structure by substitution of Be at cation sites was observed and utilized as a valuable spectral signature for the discrimination. In the domain of principal component (PC) scores, the groups of natural and Be-diffused sapphires were identifiable with minor overlapping and the cross-validated discrimination error was 7.3% when k-Nearest Neighbor (k-NN) was used as a classifier.

  13. Imaging air volume fraction in sea ice using non-destructive X-ray tomography

    NASA Astrophysics Data System (ADS)

    Crabeck, O.; Galley, R. J.; Delille, B.; Else, B. G. T.; Geilfus, N.-X.; Lemes, M.; Des Roches, M.; Francus, P.; Tison, J.-L.; Rysgaard, S.

    2015-09-01

    Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate 3-D images of air-volume inclusions in sea ice. The technique was performed on relatively thin (4-22 cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air-volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the size of the brine channel. We differentiate micro bubbles (∅ < 1 mm), large bubbles (1 < ∅ < 5 mm) and macro bubbles (∅ > 5 mm). While micro bubbles were the most abundant type of air inclusions, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice microstructure (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration and can help considerably improving parameterization of these processes in sea ice biogeochemical models.

  14. Imaging air volume fraction in sea ice using non-destructive X-ray tomography

    NASA Astrophysics Data System (ADS)

    Crabeck, Odile; Galley, Ryan; Delille, Bruno; Else, Brent; Geilfus, Nicolas-Xavier; Lemes, Marcos; Des Roches, Mathieu; Francus, Pierre; Tison, Jean-Louis; Rysgaard, Søren

    2016-05-01

    Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate images of air volume inclusions in sea ice. The technique was performed on relatively thin (4-22 cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the brine volume fraction. We differentiate micro bubbles (Ø < 1 mm), large bubbles (1 mm < Ø < 5 mm) and macro bubbles (Ø > 5 mm). While micro bubbles were the most abundant type of gas bubbles, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice texture (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration.

  15. Non-destructive assessment of mechanical properties of microcrystalline cellulose compacts.

    PubMed

    Palomäki, Emmi; Ehlers, Henrik; Antikainen, Osmo; Sandler, Niklas; Yliruusi, Jouko

    2015-11-30

    In the present study the mechanical properties of microcrystalline cellulose compacts compressed were studied. The resistance to crushing was tested using diametral compression testing and apparent Young's modulus was determined using consecutive uniaxial compression of the full cross-sectional area of single tablets. As non-elastic deformation during the first compression cycle and reverse plasticity were discovered, the loading phase of the second compression cycle was used to determine Young's modulus. The relative standard deviation of 10 consecutive measurements was 3.6%. The results indicate a direct correlation between crushing strength and Young's modulus, which found further support when comparing surface roughness data and radial recovery of the tablets to Young's modulus. The extrapolated elastic modulus at zero-porosity was found to be 1.80±0.08 GPa, which is slightly lower than previously reported values, confirming the complexity of measuring the elastic properties of microcrystalline cellulose compacts. The method can be used for non-destructive assessment of mechanical properties of powder compacts for example during storage studies.

  16. Non-destructive optical monitoring of grape maturation by proximal sensing.

    PubMed

    Ben Ghozlen, Naïma; Cerovic, Zoran G; Germain, Claire; Toutain, Sandrine; Latouche, Gwendal

    2010-01-01

    A new, commercial, fluorescence-based optical sensor for plant constituent assessment was recently introduced. This sensor, called the Multiplex(®) (FORCE-A, Orsay, France), was used to monitor grape maturation by specifically monitoring anthocyanin accumulation. We derived the empirical anthocyanin content calibration curves for Champagne red grape cultivars, and we also propose a general model for the influence of the proportion of red berries, skin anthocyanin content and berry size on Multiplex(®) indices. The Multiplex(®) was used on both berry samples in the laboratory and on intact clusters in the vineyard. We found that the inverted and log-transformed far-red fluorescence signal called the FERARI index, although sensitive to sample size and distance, is potentially the most widely applicable. The more robust indices, based on chlorophyll fluorescence excitation ratios, showed three ranges of dependence on anthocyanin content. We found that up to 0.16 mg cm(-2), equivalent to approximately 0.6 mg g(-1), all indices increase with accumulation of skin anthocyanin content. Excitation ratio-based indices decrease with anthocyanin accumulation beyond 0.27 mg cm(-2). We showed that the Multiplex(®) can be advantageously used in vineyards on intact clusters for the non-destructive assessment of anthocyanin content of vine blocks and can now be tested on other fruits and vegetables based on the same model.

  17. The use of digital image correlation for non-destructive and multi-scale damage quantification

    NASA Astrophysics Data System (ADS)

    Schwartz, Eric; Saralaya, Raghavendra; Cuadra, Jefferson; Hazeli, Kavan; Vanniamparambil, Prashanth A.; Carmi, Rami; Bartoli, Ivan; Kontsos, Antonios

    2013-04-01

    This research demonstrates the use of Digital Image Correlation (DIC) as a non-contact, non-destructive testing and evaluation (NDT and E) technique by presenting experimental results pertinent to damage monitoring and quantification in several material systems at different length scales of interest. At the microstructural level compact tension aluminum alloy specimens were tested under Mode I loading conditions using an appropriate field of view to track grain scale crack initiation and growth. The results permitted the quantification of the strain accumulation near the tip of the fatigue pre-crack, as well as the computation of the relevant crack opening displacement as a function of crack length. At the mesoscale level, damage quantification in fiber reinforced composites subject to both tensile and fatigue loading conditions was achieved by using the DIC as part of a novel integrated NDT approach combining both acoustic and thermal methods. DIC in these experiments provided spatially resolved and high accuracy strain measurements capable to track the formation of damage "hot spots" that corresponded to the sites of the ultimately visible fracture pattern, while it further allowed the correlation of mechanical parameters to thermal and acoustic features. Finally, at the macrostructural level DIC measurements were also performed and compared to traditional displacement gauges mounted on a steel deck model subject to both static and dynamic loads, as well as on masonry structures including hollow and grouted concrete walls.

  18. Non-destructive Evaluation of Bonds Between Fiberglass Composite and Metal

    NASA Technical Reports Server (NTRS)

    Zhao, Selina; Sonta, Kestutis; Perey, Daniel F.; Cramer, K. E.; Berger, Libby

    2015-01-01

    To assess the integrity and reliability of an adhesive joint in an automotive composite component, several non-destructive evaluation (NDE) methodologies are correlated to lap shear bond strengths. A glass-fabric-reinforced composite structure was bonded to a metallic structure with a two-part epoxy adhesive. Samples were subsequently cut and tested in shear, and flaws were found in some areas. This study aims to develop a reliable and portable NDE system for service-level adhesive inspection in the automotive industry. The results of the experimental investigation using several NDE methods are presented and discussed. Fiberglass-to-metal bonding is the ideal configuration for NDE via thermography using excitation with induction heating, due to the conductive metal and non-conductive glass-fiber-reinforced composites. Excitation can be either by a research-grade induction heater of highly defined frequency and intensity, or by a service-level heater, such as would be used for sealing windshields in a body shop. The thermographs thus produced can be captured via a high-resolution infrared camera, with principal component analysis and 2D spatial Laplacian processing. Alternatively, the thermographs can be captured by low resolution thermochromic microencapsulated liquid crystal film imaging, which needs no post-processing and can be very inexpensive. These samples were also examined with phased-array ultrasound. The NDE methods are compared to the lap shear values and to each other for approximate cost, accuracy, and time and level of expertise needed.

  19. Combined non-destructive XRF and SR-XAS study of archaeological artefacts.

    PubMed

    Bardelli, Fabrizio; Barone, Germana; Crupi, Vincenza; Longo, Francesca; Majolino, Domenico; Mazzoleni, Paolo; Venuti, Valentina

    2011-03-01

    We report on a non-destructive study of Sicilian ceramic fragments of cultural heritage interest, classified as "proto-majolica" pottery and dating back to the twelfth to thirteen centuries AD. The analytical approach used is based on the employment of two totally non-invasive spectroscopic techniques: X-ray fluorescence (XRF), using a portable energy-dispersive XRF analyser, and X-ray absorption spectroscopy, using synchrotron radiation as a probe (SR-XAS). XRF measurements allowed us to collect elemental and spatially resolved information on major and minor constituents of the decorated coating of archaeological pottery fragments, so providing preliminary results on the main components characterizing the surface. In particular, we assigned to Fe and Mn the role of key elements of the colouring agent. With the aim of obtaining more detailed information, we performed SR-XAS measurements at the Fe and Mn K-edges at the Italian BM08 beamline at the European Synchrotron Radiation Facility (Grenoble, France). The experimental data were analysed by applying principal component analysis and least-squares fitting to the near-edge part of the spectra (X-ray absorption near-edge structure) to determine the samples' speciation. From the overall results, umber, a class of brownish pigments characterized by a mixture of hydrated iron and manganese oxides, has been ascribed as a pigmenting agent.

  20. Development of vibrational spectroscopic methods to rapidly and non-destructively assess quality of chicken breast meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of Vibrational Spectroscopic Methods to Rapidly and Non-Destructively Assess Quality of Chicken Breast Meat H. Zhuang1, M. Sohn2, S. Trabelsi1 and K. Lawrence1 1Quality and Safety Assessment Research Unit, ARS-USDA, 950 College Station Road, Athens, GA 30605 2University of Georgia, De...

  1. Non-destructive detection and quantification of blueberry bruising using near-infrared (NIR) hyperspectral reflectance imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, blueberry bruising is evaluated by either human visual/tactile inspection or firmness measurement instruments. These methods are destructive and time-consuming. The goal of this paper was to develop a non-destructive approach for blueberry bruising detection and quantification. The spe...

  2. Direct, non-destructive, and rapid evaluation of developmental cotton fibers by ATR FT-IR spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical, compositional, and structural differences within the fibers at different growth stages have been investigated considerably through a number of methodologies. Due to its direct, non-destructive, and rapid attribute, this study reports the utilization of attenuated total reflection Fourier t...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. A new facility for Non-Destructive Assay with a time-tagged {sup 252}Cf source

    SciTech Connect

    Stevanato, L.; Caldogno, M.; Hao Xin; Dima, R.; Fabris, D.; Nebbia, G.; Lunardon, M.; Moretto, S.; Pesente, S.; Viesti, G.; Sajo-Bohus, L.

    2010-08-04

    A new facility for non-destructive assay using a time-tagged {sup 252}Cf source is presented. The system is designed to analyze samples having maximum size of about 15x20 cm{sup 2}, the material recognition being obtained by measuring simultaneously transmission of neutrons and gamma rays.

  5. Long-term selection using a single trait criterion, non-destructive deformation, in White Leghorns: Effect over time on genetic parameters for traits related to egg production.

    PubMed

    Gervais, Olivier; Nirasawa, Keijiro; Vincenot, Christian E; Nagamine, Yoshitaka; Moriya, Kazuyuki

    2017-02-01

    Although non-destructive deformation is relevant for assessing eggshell strength, few long-term selection experiments are documented which use non-destructive deformation as a selection criterion. This study used restricted maximum likelihood-based methods with a four-trait animal model to analyze the effect of non-destructive deformation on egg production, egg weight and sexual maturity in a two-way selection experiment involving 17 generations of White Leghorns. In the strong shell line, corresponding to the line selected for low non-destructive deformation values, the heritability estimates were 0.496 for non-destructive deformation, 0.253 for egg production, 0.660 for egg weight and 0.446 for sexual maturity. In the weak shell line, corresponding to the line selected for high non-destructive deformation values, the heritabilities were 0.372, 0.162, 0.703 and 0.404, respectively. An asymmetric response to selection was observed for non-destructive deformation, egg production and sexual maturity, whereas egg weight decreased for both lines. Using non-destructive deformation to select for stronger eggshell had a small negative effect on egg production and sexual maturity, suggesting the need for breeding programs to balance selection between eggshell traits and egg production traits. However, the analysis of the genetic correlation between non-destructive deformation and egg weight revealed that large eggs are not associated with poor eggshell quality.

  6. In-vehicle exposures to particulate air pollution in Canadian metropolitan areas: the urban transportation exposure study.

    PubMed

    Weichenthal, Scott; Van Ryswyk, Keith; Kulka, Ryan; Sun, Liu; Wallace, Lance; Joseph, Lawrence

    2015-01-06

    Commuters may be exposed to increased levels of traffic-related air pollution owing to close proximity to traffic-emissions. We collected in-vehicle and roof-top air pollution measurements over 238 commutes in Montreal, Toronto, and Vancouver, Canada between 2010 and 2013. Voice recordings were used to collect real-time information on traffic density and the presence of diesel vehicles and multivariable linear regression models were used to estimate the impact of these factors on in-vehicle pollutant concentrations (and indoor/outdoor ratios) along with parameters for road type, land use, and meteorology. In-vehicle PM2.5 and NO2 concentrations consistently exceeded regional outdoor levels and each unit increase in the rate of encountering diesel vehicles (count/min) was associated with substantial increases (>100%) in in-vehicle concentrations of ultrafine particles (UFPs), black carbon, and PM2.5 as well as strong increases (>15%) in indoor/outdoor ratios. A model based on meteorology and the length of highway roads within a 500 m buffer explained 53% of the variation in in-vehicle UFPs; however, models for PM2.5 (R(2) = 0.24) and black carbon (R(2) = 0.30) did not perform as well. Our findings suggest that vehicle commuters experience increased exposure to air pollutants and that traffic characteristics, land use, road types, and meteorology are important determinants of these exposures.

  7. Road-traffic pollution and asthma – using modelled exposure assessment for routine public health surveillance

    PubMed Central

    Ferguson, Elspeth C; Maheswaran, Ravi; Daly, Mark

    2004-01-01

    Asthma is a common disease and appears to be increasing in prevalence. There is evidence linking air pollution, including that from road-traffic, with asthma. Road traffic is also on the increase. Routine surveillance of the impact of road-traffic pollution on asthma, and other diseases, would be useful in informing local and national government policy in terms of managing the environmental health risk. Several methods for exposure assessment have been used in studies examining the association between asthma and road traffic pollution. These include comparing asthma prevalence in areas designated as high and low pollution areas, using distance from main roads as a proxy for exposure to road traffic pollution, using traffic counts to estimate exposure, using vehicular miles travelled and using modelling techniques. Although there are limitations to all these methods, the modelling approach has the advantage of incorporating several variables and may be used for prospective health impact assessment. The modelling approach is already in routine use in the United Kingdom in support of the government's strategy for air quality management. Combining information from such models with routinely collected health data would form the basis of a routine public health surveillance system. Such a system would facilitate prospective health impact assessment, enabling policy decisions concerned with road-traffic to be made with knowledge of the potential implications. It would also allow systematic monitoring of the health impacts when the policy decisions and plans have been implemented. PMID:15485575

  8. Changes in Gene Expression due to Chronic Exposure to Environmental Pollutants

    PubMed Central

    Oleksiak, Marjorie F.

    2008-01-01

    Populations of the teleost fish Fundulus heteroclitus inhabit and have adapted to highly polluted Superfund sites that are contaminated with persistent toxic chemicals. Populations inhabiting different Superfund sites provide independent contrasts for studying mechanisms of toxicity and resistance due to exposure to environmental pollutants. To identify both shared and unique responses to chronic pollutant exposure, liver, metabolic gene expression in F. heteroclitus populations from each of three Superfund sites (New Bedford Harbor, MA, Newark Bay, NJ, and Elizabeth River, VA) were compared to two flanking reference site populations (9 populations in total). In comparisons to their two clean reference sites, the three Superfund sites had 8 to 32% of genes with altered expression patterns. Between any two Superfund populations, up to 9 genes (4%) show a conserved response, yet among all three populations, there was no gene which had a conserved, altered pattern of expression. Across all three Superfund sites in comparison to all six reference populations, the most significant gene was fatty acid synthase. Fatty acid synthase is involved in the storage of excess energy as fat, and its lesser expression in the polluted populations suggests that the polluted populations may have limited energy stores. In contrast to previous studies of metabolic gene expression in F. heteroclitus, body weight was a significant covariate for many of the genes which could reflect accumulation and different body burdens of pollutants. Overall, the altered gene expression in these populations likely represents both induced and adaptive changes in gene expression. PMID:18929415

  9. Health and Household Air Pollution from Solid Fuel Use: The Needfor Improved Exposure Assessment

    EPA Science Inventory

    Background: Nearly half the world’s population relies on solid fuel combustion to meet basic household energy needs (e.g., cooking and heating). Resulting air pollution exposures are estimated to cause 3% of the global burden of disease. Large variability and a lack of resource...

  10. Comparison of modeled traffic exposure zones using on-road air pollution measurements

    EPA Science Inventory

    Modeled traffic data were used to develop traffic exposure zones (TEZs) such as traffic delay, high volume, and transit routes in the Research Triangle area of North Carolina (USA). On-road air pollution measurements of nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxid...

  11. Review of Air Exchange Rate Models for Air Pollution Exposure Assessments

    EPA Science Inventory

    A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings, where people spend their time. The AER, which is rate the exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pol...

  12. LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION

    EPA Science Inventory

    LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION. J. Rubes*, D. Zudova*, Veterinary Research Institute, Brno, CR, S.G. Selevan*, US EPA/ORD/NCEA, Washington, DC, D.P. Evenson, South Dakota State University, Brookings, SD, and S.D. Perreault, US ...

  13. Exposure to concentrated coarse air pollution particles causes mild cardiopulmonary effects in young healthy adults

    EPA Science Inventory

    Rationale: There is ample epidemiological and toxicological evidence that exposure to fme air pollution particles (PM2.5), which are primarily derived from combustion processes, can result in increased mortality and morbidity. There is less certainty as to the contribution of coa...

  14. AGGREGATE EXPOSURES OF NINE PRESCHOOL CHILDREN TO PERSISTENT ORGANIC POLLUTANTS AT DAY CARE AND AT HOME

    EPA Science Inventory

    In the summer of 1997, we measured the aggregate exposures of nine preschool children, ages two to five years, to a suite of organic pesticides and other persistent organic pollutants that are commonly found in the home and school environment. The children attended either of t...

  15. AIR PARTICULATE POLLUTION EXPOSURE INDUCES SYSTEMIC OXIDATIVE STRESS IN HEALTHY MICE

    EPA Science Inventory

    Air particulate pollution exposure induces systemic oxidative stress in healthy mice

    Elizabeth S Roberts1 and Kevin L Dreher2. 1 College or Veterinary Medicine, NC State University, Raleigh, NC , 2US Environmental Protection Agency, NHEERL, RTP, NC

    Epidemiological s...

  16. Exposure of Mammalian Cells to Air-Pollutant Mixtures at the Air-Liquid Interface

    EPA Science Inventory

    It has been widely accepted that exposure of mammalian cells to air-pollutant mixtures at the air-liquid interface is a more realistic approach than exposing cell under submerged conditions. The VITROCELL systems, are commercially available systems for air-liquid interface expo...

  17. GST M1 GENOTYPE INFLUENCES SPERM DNA DAMAGE ASSOCIATED WITH EXPOSURE TO AIR POLLUTION

    EPA Science Inventory

    For Society for Epidemiologic Research Meeting, June 15-18, 2004, Salt Lake City, Utah.

    Presenter: Sherry G. Selevan

    GSTM1 GENOTYPE INFLUENCES SPERM DNA DAMAGE ASSOCIATED WITH EXPOSURE TO AIR POLLUTION. J Rubes, SG Selevan*, R. Sram, DPEvenson, SD Perreault. VRI, ...

  18. Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal

    PubMed Central

    Devakumar, D.; Semple, S.; Osrin, D.; Yadav, S.K.; Kurmi, O.P.; Saville, N.M.; Shrestha, B.; Manandhar, D.S.; Costello, A.; Ayres, J.G.

    2014-01-01

    The exposure of children to air pollution in low resource settings is believed to be high because of the common use of biomass fuels for cooking. We used microenvironment sampling to estimate the respirable fraction of air pollution (particles with median diameter less than 4 μm) to which 7–9 year old children in southern Nepal were exposed. Sampling was conducted for a total 2649 h in 55 households, 8 schools and 8 outdoor locations of rural Dhanusha. We conducted gravimetric and photometric sampling in a subsample of the children in our study in the locations in which they usually resided (bedroom/living room, kitchen, veranda, in school and outdoors), repeated three times over one year. Using time activity information, a 24-hour time weighted average was modeled for all the children in the study. Approximately two-thirds of homes used biomass fuels, with the remainder mostly using gas. The exposure of children to air pollution was very high. The 24-hour time weighted average over the whole year was 168 μg/m3. The non-kitchen related samples tended to show approximately double the concentration in winter than spring/autumn, and four times that of the monsoon season. There was no difference between the exposure of boys and girls. Air pollution in rural households was much higher than the World Health Organization and the National Ambient Air Quality Standards for Nepal recommendations for particulate exposure. PMID:24533994

  19. What Doesn't Kill You Makes You Weaker: Prenatal Pollution Exposure and Educational Outcomes

    ERIC Educational Resources Information Center

    Sanders, Nicholas J.

    2012-01-01

    I examine the impact of prenatal total suspended particulate (TSP) exposure on educational outcomes using county-level variation in the timing and severity of the industrial recession of the early 1980s as a shock to ambient TSPs (similar to Chay and Greenstone 2003b). I then instrument for pollution levels using county-level changes in relative…

  20. Summary and Findings of the EPA and CDC Symposium on Air Pollution Exposure and Health

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) and the U.S. Centers for Disease Control (CDC) co-organized a symposium on "Air Pollution Exposure and Health" at Research Triangle Park, North Carolina on September 19–20, 2006. The symposium brought together health and environmenta...

  1. Pollutant exposures from unvented gas cooking burners: A Simulation-based Assessment for Southern California

    SciTech Connect

    Logue, Jennifer M.; Klepeis, Neil E.; Lobscheid, Agnes B.; Singer, Brett C.

    2014-01-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. In this study, LBNL researchers quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes.The simulation model estimated that—in homes using NGCBs without coincident use of venting range hoods -- 62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. The study recommends that reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

  2. Long-term exposure to traffic pollution and hospital admissions in London.

    PubMed

    Halonen, Jaana I; Blangiardo, Marta; Toledano, Mireille B; Fecht, Daniela; Gulliver, John; Anderson, H Ross; Beevers, Sean D; Dajnak, David; Kelly, Frank J; Tonne, Cathryn

    2016-01-01

    Evidence on the effects of long-term exposure to traffic pollution on health is inconsistent. In Greater London we examined associations between traffic pollution and emergency hospital admissions for cardio-respiratory diseases by applying linear and piecewise linear Poisson regression models in a small-area analysis. For both models the results for children and adults were close to unity. In the elderly, linear models found negative associations whereas piecewise models found non-linear associations characterized by positive risks in the lowest and negative risks in the highest exposure category. An increased risk was observed among those living in areas with the highest socioeconomic deprivation. Estimates were not affected by adjustment for traffic noise. The lack of convincing positive linear associations between primary traffic pollution and hospital admissions agrees with a number of other reports, but may reflect residual confounding. The relatively greater vulnerability of the most deprived populations has important implications for public health.

  3. Surrounding Greenness and Exposure to Air Pollution During Pregnancy: An Analysis of Personal Monitoring Data

    PubMed Central

    de Nazelle, Audrey; Triguero-Mas, Margarita; Schembari, Anna; Cirach, Marta; Amoly, Elmira; Figueras, Francesc; Basagaña, Xavier; Ostro, Bart; Nieuwenhuijsen, Mark

    2012-01-01

    Background: Green spaces are reported to improve health status, including beneficial effects on pregnancy outcomes. Despite the suggestions of air pollution–related health benefits of green spaces, there is no available evidence on the impact of greenness on personal exposure to air pollution. Objectives: We investigated the association between surrounding greenness and personal exposure to air pollution among pregnant women and to explore the potential mechanisms, if any, behind this association. Methods: In total, 65 rounds of sampling were carried out for 54 pregnant women who resided in Barcelona during 2008–2009. Each round consisted of a 2-day measurement of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) and a 1-week measurement of nitric oxides collected simultaneously at both the personal and microenvironmental levels. The study participants were also asked to fill out a time–microenvironment–activity diary during the sampling period. We used satellite retrievals to determine the surrounding greenness as the average of Normalized Difference Vegetation Index (NDVI) in a buffer of 100 m around each maternal residential address. We estimated the impact of surrounding greenness on personal exposure levels, home-outdoor and home-indoor pollutant levels, and maternal time-activity. Results: Higher residential surrounding greenness was associated with lower personal, home-indoor, and home-outdoor PM2.5 levels, and more time spent at home-outdoor. Conclusions: We found lower levels of personal exposure to air pollution among pregnant women residing in greener areas. This finding may be partly explained by lower home-indoor pollutant levels and more time spent in less polluted home-outdoor environment by pregnant women in greener areas. PMID:22647671

  4. ANALYTICAL METHODS DEVELOPED FOR THE CHILDREN'S TOTAL EXPOSURES TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP) STUDY

    EPA Science Inventory

    The Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study was designed by the U.S. EPA to collect data on young children's exposures to pesticides and other pollutants in their everyday environments in support of the Food Quality...

  5. The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): Study Design and Methods

    EPA Science Inventory

    The Near-road EXposures and effects of urban air pollutants Study (NEXUS) was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children who live close to major roadways in Detroit, Michigan USA...

  6. Exposure to Severe Urban Air Pollution Influences Cognitive Outcomes, Brain Volume and Systemic Inflammation in Clinically Healthy Children

    ERIC Educational Resources Information Center

    Calderon-Garciduenas, Lilian; Engle, Randall; Mora-Tiscareno, Antonieta; Styner, Martin; Gomez-Garza, Gilberto; Zhu, Hongtu; Jewells, Valerie; Torres-Jardon, Ricardo; Romero, Lina; Monroy-Acosta, Maria E.; Bryant, Christopher; Gonzalez-Gonzalez, Luis Oscar; Medina-Cortina, Humberto; D'Angiulli, Amedeo

    2011-01-01

    Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes,…

  7. IN VIVO EVIDENCE OF FREE RADICAL FORMATION IN THE RAT LUNG AFTER EXPOSURE TO AN EMISSION SOURCE AIR POLLUTION PARTICLE

    EPA Science Inventory

    Exposure to air pollution particles can be associated with increased human morbidity and mortality. The mechanism(s) of lung injury remains unknown. We tested the hypothesis that lung exposure to oil fly ash (an emission source air pollution particle) causes in vivo free radical ...

  8. Modeling exposures to traffic-related air pollutants for the NEXUS respiratory health study of asthmatic children in Detroit, MI

    EPA Science Inventory

    The Near-Road EXposures and Effects of Urban Air Pollutants Study (NEXUS) was designed to investigate associations between exposure to traffic-related air pollution and the respiratory health of asthmatic children living near major roadways in Detroit, MI. A combination of modeli...

  9. Air Pollution Exposure in Relation to the Commute to School: A Bradford UK Case Study

    PubMed Central

    Dirks, Kim N.; Wang, Judith Y. T.; Khan, Amirul; Rushton, Christopher

    2016-01-01

    Walking School Buses (WSBs) provide a safe alternative to being driven to school. Children benefit from the contribution the exercise provides towards their daily exercise target, it gives children practical experience with respect to road safety and it helps to relieve traffic congestion around the entrance to their school. Walking routes are designed largely based in road safety considerations, catchment need and the availability of parent support. However, little attention is given to the air pollution exposure experienced by children during their journey to school, despite the commuting microenvironment being an important contributor to a child’s daily air pollution exposure. This study aims to quantify the air pollution exposure experienced by children walking to school and those being driven by car. A school was chosen in Bradford, UK. Three adult participants carried out the journey to and from school, each carrying a P-Trak ultrafine particle (UFP) count monitor. One participant travelled the journey to school by car while the other two walked, each on opposite sides of the road for the majority of the journey. Data collection was carried out over a period of two weeks, for a total of five journeys to school in the morning and five on the way home at the end of the school day. Results of the study suggest that car commuters experience lower levels of air pollution dose due to lower exposure and reduced commute times. The largest reductions in exposure for pedestrians can be achieved by avoiding close proximity to traffic queuing up at intersections, and, where possible, walking on the side of the road opposite the traffic, especially during the morning commuting period. Major intersections should also be avoided as they were associated with peak exposures. Steps to ensure that the phasing of lights is optimised to minimise pedestrian waiting time would also help reduce exposure. If possible, busy roads should be avoided altogether. By the careful design

  10. Air Pollution Exposure in Relation to the Commute to School: A Bradford UK Case Study.

    PubMed

    Dirks, Kim N; Wang, Judith Y T; Khan, Amirul; Rushton, Christopher

    2016-10-29

    Walking School Buses (WSBs) provide a safe alternative to being driven to school. Children benefit from the contribution the exercise provides towards their daily exercise target, it gives children practical experience with respect to road safety and it helps to relieve traffic congestion around the entrance to their school. Walking routes are designed largely based in road safety considerations, catchment need and the availability of parent support. However, little attention is given to the air pollution exposure experienced by children during their journey to school, despite the commuting microenvironment being an important contributor to a child's daily air pollution exposure. This study aims to quantify the air pollution exposure experienced by children walking to school and those being driven by car. A school was chosen in Bradford, UK. Three adult participants carried out the journey to and from school, each carrying a P-Trak ultrafine particle (UFP) count monitor. One participant travelled the journey to school by car while the other two walked, each on opposite sides of the road for the majority of the journey. Data collection was carried out over a period of two weeks, for a total of five journeys to school in the morning and five on the way home at the end of the school day. Results of the study suggest that car commuters experience lower levels of air pollution dose due to lower exposure and reduced commute times. The largest reductions in exposure for pedestrians can be achieved by avoiding close proximity to traffic queuing up at intersections, and, where possible, walking on the side of the road opposite the traffic, especially during the morning commuting period. Major intersections should also be avoided as they were associated with peak exposures. Steps to ensure that the phasing of lights is optimised to minimise pedestrian waiting time would also help reduce exposure. If possible, busy roads should be avoided altogether. By the careful design of

  11. Effect of geocoding errors on traffic-related air pollutant exposure and concentration estimates

    PubMed Central

    Ganguly, Rajiv; Batterman, Stuart; Isakov, Vlad; Snyder, Michelle; Breen, Michael; Brakefield-Caldwell, Wilma

    2015-01-01

    Exposure to traffic-related air pollutants is highest very near roads, and thus exposure estimates are sensitive to positional errors. This study evaluates positional and PM2.5 concentration errors that result from the use of automated geocoding methods and from linearized approximations of roads in link-based emission inventories. Two automated geocoders (Bing Map and ArcGIS) along with handheld GPS instruments were used to geocode 160 home locations of children enrolled in an air pollution study investigating effects of traffic-related pollutants in Detroit, Michigan. The average and maximum positional errors using the automated geocoders were 35 and 196 m, respectively. Comparing road edge and road centerline, differences in house-to-highway distances averaged 23 m and reached 82 m. These differences were attributable to road curvature, road width and the presence of ramps, factors that should be considered in proximity measures used either directly as an exposure metric or as inputs to dispersion or other models. Effects of positional errors for the 160 homes on PM2.5 concentrations resulting from traffic-related emissions were predicted using a detailed road network and the RLINE dispersion model. Concentration errors averaged only 9%, but maximum errors reached 54% for annual averages and 87% for maximum 24-h averages. Whereas most geocoding errors appear modest in magnitude, 5% to 20% of residences are expected to have positional errors exceeding 100 m. Such errors can substantially alter exposure estimates near roads because of the dramatic spatial gradients of traffic-related pollutant concentrations. To ensure the accuracy of exposure estimates for traffic-related air pollutants, especially near roads, confirmation of geocoordinates is recommended. PMID:25670023

  12. Effect of geocoding errors on traffic-related air pollutant exposure and concentration estimates.

    PubMed

    Ganguly, Rajiv; Batterman, Stuart; Isakov, Vlad; Snyder, Michelle; Breen, Michael; Brakefield-Caldwell, Wilma

    2015-01-01

    Exposure to traffic-related air pollutants is highest very near roads, and thus exposure estimates are sensitive to positional errors. This study evaluates positional and PM2.5 concentration errors that result from the use of automated geocoding methods and from linearized approximations of roads in link-based emission inventories. Two automated geocoders (Bing Map and ArcGIS) along with handheld GPS instruments were used to geocode 160 home locations of children enrolled in an air pollution study investigating effects of traffic-related pollutants in Detroit, Michigan. The average and maximum positional errors using the automated geocoders were 35 and 196 m, respectively. Comparing road edge and road centerline, differences in house-to-highway distances averaged 23 m and reached 82 m. These differences were attributable to road curvature, road width and the presence of ramps, factors that should be considered in proximity measures used either directly as an exposure metric or as inputs to dispersion or other models. Effects of positional errors for the 160 homes on PM2.5 concentrations resulting from traffic-related emissions were predicted using a detailed road network and the RLINE dispersion model. Concentration errors averaged only 9%, but maximum errors reached 54% for annual averages and 87% for maximum 24-h averages. Whereas most geocoding errors appear modest in magnitude, 5% to 20% of residences are expected to have positional errors exceeding 100 m. Such errors can substantially alter exposure estimates near roads because of the dramatic spatial gradients of traffic-related pollutant concentrations. To ensure the accuracy of exposure estimates for traffic-related air pollutants, especially near roads, confirmation of geocoordinates is recommended.

  13. Prenatal Air Pollution Exposure and Ultrasound Measures of Fetal Growth in Los Angeles, California

    PubMed Central

    Ritz, Beate; Qiu, Jiaheng; Lee, Pei-Chen; Lurmann, Fred; Penfold, Bryan; Weiss, Robert Erin; McConnell, Rob; Arora, Chander; Hobel, Calvin; Wilhelm, Michelle

    2014-01-01

    Background Few previous studies examined the impact of prenatal air pollution exposures on fetal development based on ultrasound measures during pregnancy. Methods In a prospective birth cohort of more than 500 women followed during 1993-1996 in Los Angeles, California, we examined how air pollution impacts fetal growth during pregnancy. Exposure to traffic related air pollution was estimated using CALINE4 air dispersion modeling for nitrogen oxides (NOx) and a land use regression (LUR) model for nitrogen monoxide (NO), nitrogen dioxide (NO2) and NOx. Exposures to carbon monoxide (CO), NO2, ozone (O3) and particles <10 μm in aerodynamic diameter (PM10) were estimated using government monitoring data. We employed a linear mixed effects model to estimate changes in fetal size at approximately 19, 29 and 37 weeks gestation based on ultrasound. Results Exposure to traffic-derived air pollution during 29 to 37 weeks was negatively associated with biparietal diameter at 37 weeks gestation. For each interquartile range (IQR) increase in LUR-based estimates of NO, NO2 and NOx, or freeway CALINE4 NOx we estimated a reduction in biparietal diameter of 0.2-0.3 mm. For women residing within 5 km of a monitoring station, we estimated biparietal diameter reductions of 0.9-1.0 mm per IQR increase in CO and NO2. Effect estimates were robust to adjustment for a number of potential confounders. We did not observe consistent patterns for other growth endpoints we examined. Conclusions Prenatal exposure to traffic-derived pollution was negatively associated with fetal head size measured as biparietal diameter in late pregnancy. PMID:24517884

  14. Exposure to Indoor Pollutants and Wheeze and Asthma Development during Early Childhood

    PubMed Central

    Patelarou, Evridiki; Tzanakis, Nikolaos; Kelly, Frank J.

    2015-01-01

    Background: This review aimed to summarize existing epidemiological evidence of the association between quantitative estimates of indoor air pollution with early childhood respiratory disease. Methods: We carried out a systematic literature search of peer-reviewed epidemiological studies undertaken in “westernized” countries that have assessed exposure to indoor pollutants and asthma and wheeze from infancy up to the age of 5. Results: The search, between January 2004 and February 2014 yielded 1840 studies for consideration. Following application of eligibility criteria to titles and abstracts 22 independent studies were deemed relevant for further review. Two additional studies were next identified through examination of the references’ lists of these studies. Of these 24 selected studies, 16 adopted a prospective cohort design and 8 were case-control studies. Fourteen studies assessed exposure to bio-aerosols, 8 studies assessed exposure to specific air chemicals and two studies assessed exposure to bio-aerosols and air chemicals. Furthermore, 11 studies examined the association of exposure with asthma and 16 with wheeze. Findings indicate that existing studies have reported contradictory effects of indoor pollutants levels and occurrence of asthma/wheeze. Conclusion: Additional research to establish causality and evaluate interventions to prevent disease onset is needed. PMID:25872014

  15. Bayesian modeling of air pollution health effects with missing exposure data.

    PubMed

    Molitor, John; Molitor, Nuoo-Ting; Jerrett, Michael; McConnell, Rob; Gauderman, Jim; Berhane, Kiros; Thomas, Duncan

    2006-07-01

    The authors propose a new statistical procedure that utilizes measurement error models to estimate missing exposure data in health effects assessment. The method detailed in this paper follows a Bayesian framework that allows estimation of various parameters of the model in the presence of missing covariates in an informative way. The authors apply this methodology to study the effect of household-level long-term air pollution exposures on lung function for subjects from the Southern California Children's Health Study pilot project, conducted in the year 2000. Specifically, they propose techniques to examine the long-term effects of nitrogen dioxide (NO2) exposure on children's lung function for persons living in 11 southern California communities. The effect of nitrogen dioxide exposure on various measures of lung function was examined, but, similar to many air pollution studies, no completely accurate measure of household-level long-term nitrogen dioxide exposure was available. Rather, community-level nitrogen dioxide was measured continuously over many years, but household-level nitrogen dioxide exposure was measured only during two 2-week periods, one period in the summer and one period in the winter. From these incomplete measures, long-term nitrogen dioxide exposure and its effect on health must be inferred. Results show that the method improves estimates when compared with standard frequentist approaches.

  16. [Exposure to pollutants and allergens in the asthmatic child compared with the healthy child].

    PubMed

    Sarrazola Sanjuan, D M; Salas Ramírez, M; Segura Méndez, N H; Medrano, S; Martínez Cairo Cueto, S

    1997-01-01

    To assess the frequency of exposure to allergens and indoor pollutants of school age asthmatic children at the time of their first visit to the specialist, we studied 14 cases with the diagnosis of asthma according to international criteria, and 21 healthy controls. The parents of the children filed a questionnaire asking about socio-economic level, family history of asthma, exposure to allergens or indoor pollutants, and clinical severity of the disease. Questionnaires with less than 80% of the responses were excluded from analysis. Asthmatic patients had higher frequency of exposure to tobacco smoke (42.8% vs 38%), moisture in the home walls (42.9% vs 19%), and to dust reservoirs (71.4% vs 52.4%). A high proportion of the asthmatic patients did not apply adequate environmental control measures. Education for the patients and their primary care physicians must be increased, to reduce the morbidity of the diseases.

  17. Assessment of different route choice on commuters' exposure to air pollution in Taipei, Taiwan.

    PubMed

    Li, Hsien-Chih; Chiueh, Pei-Te; Liu, Shi-Ping; Huang, Yu-Yang

    2017-01-01

    The purposes of this study are to develop a healthy commute map indicating cleanest route in Taipei metropolitan area for any given journey and to evaluate the pollutant doses exposed in different commuting modes. In Taiwan, there are more than 13.6 million motorcycles and 7.7 million vehicles among the 23 million people. Exposure to traffic-related air pollutants can thus cause adverse health effects. Moreover, increasing the level of physical activity during commuting and longer distances will result in inhalation of more polluted air. In this study, we utilized air pollution monitoring data (CO, SO2, NO2, PM10, and PM2.5) from Taiwan EPA's air quality monitoring stations in Taipei metropolitan area to estimate each pollutant exposure while commuting by different modes (motorcycling, bicycling, and walking). Spatial interpolation methods such as inverse distance weighting (IDW) were used to estimate each pollutant's distribution in Taipei metropolitan area. Three routes were selected to represent the variety of different daily commuting pathways. The cleanest route choice was based upon Dijkstra's algorithm to find the lowest cumulative pollutant exposure. The IDW interpolated values of CO, SO2, NO2, PM10, and PM2.5 ranged from 0.42-2.2 (ppm), 2.6-4.8 (ppb), 17.8-42.9 (ppb), 32.4-65.6 (μg/m(3)), and 14.2-38.9 (μg/m(3)), respectively. To compare with the IDW results, concentration of particulate matter (PM10, PM2.5, and PM1) along the motorcycle route was measured in real time. In conclusion, the results showed that the shortest commuting route for motorcyclists resulted in a much higher cumulative dose (PM2.5 3340.8 μg/m(3)) than the cleanest route (PM2.5 912.5 μg/m(3)). The mobile personal monitoring indicated that the motorcyclists inhaled significant high pollutants during commuting as a result of high-concentration exposure and short-duration peaks. The study could effectively present less polluted commuting routes for citizen health benefits.

  18. The effect of variation in phased array element performance for Non-Destructive Evaluation (NDE).

    PubMed

    Duxbury, David; Russell, Jonathan; Lowe, Michael

    2013-08-01

    This paper reports the results of an investigation into the effects of phased array element performance on ultrasonic beam integrity. This investigation has been performed using an array beam model based on Huygens' principle to independently investigate the effects of element sensitivity and phase, and non-functioning elements via Monte Carlo simulation. The purpose of this work is to allow a new method of array calibration for Non-Destructive Evaluation (NDE) to be adopted that focuses on probe integrity rather than beam integrity. This approach is better suited to component inspections that utilise Full Matrix Capture (FMC) to record data as the calibration routine is uncoupled from the beams that the array is required to produce. For this approach to be adopted specifications must be placed on element performance that guarantee beam quality without carrying out any beam forming. The principal result of this investigation is that the dominant outcome following variations in array element performance is the introduction of beam artefacts such as main beam broadening, raising of the noise floor of the ultrasonic field, and the enlargement or creation of side lobes. Specifications for practical allowable limits of element sensitivity, element phase, and the number of non-functioning elements have been suggested based on a minimum amplitude difference between beam artefacts and the main beam peak of 8 dB. Simulation at a number of centre frequencies has led to a recommendation that the product of transducer bandwidth and maximum phase error should be kept below 0.051 and 0.035 for focused and plane beams respectively. Element sensitivity should be within 50% of mean value of the aperture, and no more than 9% of the elements should be non-functioning.

  19. Crime scene investigations using portable, non-destructive space exploration technology.

    PubMed

    Trombka, Jacob I; Schweitzer, Jeffrey; Selavka, Carl; Dale, Mark; Gahn, Norman; Floyd, Samuel; Marie, James; Hobson, Maritza; Zeosky, Jerry; Martin, Ken; McClannahan, Timothy; Solomon, Pamela; Gottschang, Elyse

    2002-09-10

    The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASAs) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals solve crimes. The objective of the program is to produce instruments and communication networks that have application within both NASA's space program and NIJ programs with state and local forensic laboratories. A working group of NASA scientists and law enforcement professionals has been established to develop and implement a feasibility demonstration program. Specifically, the group has focused its efforts on identifying gunpowder and primer residue, blood, and semen at crime scenes. Non-destructive elemental composition identification methods are carried out using portable X-ray fluorescence (XRF) systems. These systems are similar to those being developed for planetary exploration programs. A breadboard model of a portable XRF system has been constructed for these tests using room temperature silicon and cadmium-zinc telluride (CZT) detectors. Preliminary tests have been completed with gunshot residue (GSR), blood-spatter and semen samples. Many of the element composition lines have been identified. Studies to determine the minimum detectable limits needed for the analyses of GSR, blood and semen in the crime scene environment have been initiated and preliminary results obtained. Furthermore, a database made up of the inorganic composition of GSR is being developed. Using data obtained from the open literature of the elemental composition of barium (Ba) and antimony (Sb) in handswipes of GSR, we believe that there may be a unique GSR signature based on the Sb to Ba ratio.

  20. Non destructive technique for cracks detection by an eddy current in differential mode for steel frames

    NASA Astrophysics Data System (ADS)

    Harzalla, S.; Belgacem, F. Bin Muhammad; Chabaat, M.

    2014-12-01

    In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing results for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented.

  1. Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique.

    PubMed

    Anuar, Nor Khaizan; Wui, Wong Tin; Ghodgaonkar, Deepak K; Taib, Mohd Nasir

    2007-01-17

    The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug

  2. Crime scene investigations using portable, non-destructive space exploration technology

    NASA Technical Reports Server (NTRS)

    Trombka, Jacob I.; Schweitzer, Jeffrey; Selavka, Carl; Dale, Mark; Gahn, Norman; Floyd, Samuel; Marie, James; Hobson, Maritza; Zeosky, Jerry; Martin, Ken; McClannahan, Timothy; Solomon, Pamela; Gottschang, Elyse

    2002-01-01

    The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASAs) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals solve crimes. The objective of the program is to produce instruments and communication networks that have application within both NASA's space program and NIJ programs with state and local forensic laboratories. A working group of NASA scientists and law enforcement professionals has been established to develop and implement a feasibility demonstration program. Specifically, the group has focused its efforts on identifying gunpowder and primer residue, blood, and semen at crime scenes. Non-destructive elemental composition identification methods are carried out using portable X-ray fluorescence (XRF) systems. These systems are similar to those being developed for planetary exploration programs. A breadboard model of a portable XRF system has been constructed for these tests using room temperature silicon and cadmium-zinc telluride (CZT) detectors. Preliminary tests have been completed with gunshot residue (GSR), blood-spatter and semen samples. Many of the element composition lines have been identified. Studies to determine the minimum detectable limits needed for the analyses of GSR, blood and semen in the crime scene environment have been initiated and preliminary results obtained. Furthermore, a database made up of the inorganic composition of GSR is being developed. Using data obtained from the open literature of the elemental composition of barium (Ba) and antimony (Sb) in handswipes of GSR, we believe that there may be a unique GSR signature based on the Sb to Ba ratio.

  3. Non destructive technique for cracks detection by an eddy current in differential mode for steel frames

    SciTech Connect

    Harzalla, S. Chabaat, M.; Belgacem, F. Bin Muhammad

    2014-12-10

    In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing results for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented.

  4. Microwave non-destructive testing technique for characterization of HPMC-PEG 3000 films.

    PubMed

    Wong, T W; Deepak, K G; Taib, M N; Anuar, N K

    2007-10-01

    The capacity of microwave non-destructive testing (NDT) technique to characterize the matrix property of binary polymeric films for use as transdermal drug delivery system was investigated. Hydroxypropylmethylcellulose (HPMC) and polyethylene glycol (PEG) 3000 were the choice of polymeric matrix and plasticizer, respectively with loratadine as the model drug. Both blank and drug loaded HPMC-PEG 3000 films were prepared using the solvent-evaporation method. These films were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using the established methods of ultra-violet spectrophotometry, differential scanning calorimetry and Fourier transform infrared spectroscopy methods, as well as, novel microwave NDT technique. Blank films exhibited a greater propensity of polymer-polymer interaction at the O-H domain upon storage at a lower level of relative humidity, whereas drug loaded films exhibited a greater propensity of polymer-polymer, polymer-plasticizer and/or drug-polymer interaction via the O-H, C-H and/or aromatic C=C functional groups when they were stored at a lower or moderate level of relative humidity. The absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer, polymer-plasticizer, and/or drug-polymer interaction of the matrix. The measurements of microwave NDT test at 8 and 12 GHz were sensitive to the polar fraction of film involving functional group such as O-H moiety and the less polar environment of matrix consisting of functional groups such as C-H and aromatic C=C moieties. The state of interaction between polymer, plasticizer and/or drug of a binary polymeric film can be elucidated through its absorption and transmission profiles of microwave.

  5. A rapid and non-destructive screenable marker, FAST, for identifying transformed seeds of Arabidopsis thaliana.

    PubMed

    Shimada, Takashi L; Shimada, Tomoo; Hara-Nishimura, Ikuko

    2010-02-01

    The creation of transgenic plants has contributed extensively to the advancement of plant science. Establishing homozygous transgenic lines is time-consuming and laborious, and using antibiotics or herbicides to select transformed plants may adversely affect the growth of some transgenic plants. Here we describe a novel technology, which we have named FAST (fluorescence-accumulating seed technology), that overcomes these difficulties. Although this technology was designed for use in Arabidopsis thaliana, it may be adapted for use in other plants. The technology is based on the expression of a fluorescent co-dominant screenable marker FAST, under the control of a seed-specific promoter, on the oil body membrane. The FAST marker harbors a fusion gene encoding either GFP or RFP with an oil body membrane protein that is prominent in seeds. The marker protein was only expressed in a specific organ (i.e. in dry seeds) and at a specific time (i.e. during dormancy), which are desirable features of selectable and/or screenable markers. This technique provides an immediate and non-destructive method for identifying transformed dry seeds. It identified the heterozygous transformed seeds among the T(1) population and the homozygous seeds among the T(2) population with a false-discovery rate of <1%. The FAST marker reduces the length of time required to produce homozygous transgenic lines from 7.5 to 4 months. Furthermore, it does not require sterilization, clean-bench protocols or the handling of large numbers of plants. This technology should greatly facilitate the generation of transgenic Arabidopsis plants.

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

    NASA Astrophysics Data System (ADS)

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

    2007-01-01

    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

  7. Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

    NASA Astrophysics Data System (ADS)

    Chintakunta, Satish R.; Boone, Shane D.

    2014-02-01

    Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

  8. The use of non-destructive passive neutron measurement methods in dismantling and radioactive waste characterization

    SciTech Connect

    Jallu, F.; Allinei, P. G.; Bernard, P.; Loridon, J.; Soyer, P.; Pouyat, D.; Torreblanca, L.; Reneleau, A.

    2011-07-01

    The cleaning up and dismantling of nuclear facilities lead to a great volume of technological radioactive wastes which need to be characterized in order to be sent to the adequate final disposal or interim storage. The control and characterization can be performed with non-destructive nuclear measurements such as gamma-ray spectrometry. Passive neutron counting is an alternative when the alpha-gamma emitters cannot be detected due to the presence of a high gamma emission resulting from fission or activation products, or when the waste matrix is too absorbing for the gamma rays of interest (too dense and/or made of high atomic number elements). It can also be a complement to gamma-ray spectrometry when two measurement results must be confronted to improve the confidence in the activity assessment. Passive neutron assays involve the detection of spontaneous fission neutrons emitted by even nuclides ({sup 238}Pu, {sup 240}Pu, {sup 242}Pu, {sup 242}Cm, {sup 244}Cm...) and neutrons resulting from ({alpha}, n) reactions with light nuclides (O, F, Be...). The latter is conditioned by the presence of high {alpha}-activity radionuclides ({sup 234}U, {sup 238}Pu, {sup 240}Pu, {sup 241}Am...) and low-Z elements, which depends on the chemical form (metallic, oxide or fluorine) of the plutonium or uranium contaminant. This paper presents the recent application of passive neutron methods to the cleaning up of a nuclear facility located at CEA Cadarache (France), which concerns the Pu mass assessment of 2714 historic, 100 litre radioactive waste drums produced between 1980 and 1997. Another application is the dismantling and decommissioning of an uranium enrichment facility for military purposes, which involves the {sup 235}U and total uranium quantifications in about a thousand, large compressors employed in the gaseous diffusion enrichment process. (authors)

  9. Infrared thermography non-destructive evaluation of lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Wang, Zi-jun; Li, Zhi-qiang; Liu, Qiang

    2011-08-01

    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.

  10. Stress Corrosion Cracking and Non-Destructive Examination of Dissimilar Metal Welds and Alloy 600

    SciTech Connect

    Jackson, Deborah A.

    2002-07-01

    The United States Nuclear Regulatory Commission (USNRC) has conducted research since 1977 in the areas of environmentally assisted cracking and assessment and reliability of non-destructive examination (NDE). Recent occurrences of cracking in Alloy 82/182 welds and Alloy 600 base metal at several domestic and overseas plants have raised several issues relating to both of these areas of NRC research. The occurrences of cracking were identified by the discovery of boric acid deposits resulting from through-wall cracking in the primary system pressure boundary. Analyses indicate that the cracking has occurred due to primary water stress corrosion cracking (PWSCC) in Alloy 82/182 welds. This cracking has occurred in two different locations: in hot leg nozzle-to-safe end welds and in control rod drive mechanism (CRDM) nozzle welds. The cracking associated with safe-end welds is important due to the potential for a large loss of reactor coolant inventory, and the cracking of CRDM nozzle base metal and welds, particularly circumferential cracking of CRDM nozzle base metal, is important due to the potential for a control rod to eject resulting in a loss of coolant accident. The industry response in the U.S. to this cracking is being coordinated through the Electric Power Research Institute's Materials Reliability Project (EPRI-MRP) in a comprehensive, multifaceted effort. Although the industry program is addressing many of the issues raised by these cracking occurrences, confirmatory research is necessary for the staff to evaluate the work conducted by industry groups. Several issues requiring additional consideration regarding the generic implications of these isolated events have been identified. This paper will discuss the recent events of significant cracking in domestic and foreign plants, discuss the limitations of NDE in detecting SCC, identify deficiencies in information available in this area, discuss the USNRC approach to address these issues, and discuss the

  11. Pallasite formation after a non-destructive impact. An experimental- and image analyses-based study

    NASA Astrophysics Data System (ADS)

    Solferino, Giulio; Golabek, Gregor J.; Nimmo, Francis; Schmidt, Max W.

    2015-04-01

    The formation conditions of pallasite meteorites in the interior of terrestrial planetesimals have been matter of debate over the last 40 years. Among other characteristics, the simple mineralogical composition (i.e., olivine, FeNi, FeS +/- pyroxene) and the dualism between fragmental and rounded olivine-bearing pallasites must be successfully reproduced by a potential formation scenario. This study incorporates a series of annealing experiments with olivine plus Fe-S, and digital image analyses of slabs from Brenham, Brahin, Seymchan, and Springwater pallasites. Additionally a 1D finite-difference numerical model was employed to show that a non-destructive collision followed by mixing of the impactor's core with the target body silicate mantle could lead to the formation of both fragmental and rounded pallasite types. Specifically, an impact occurring right after the accomplishment of the target body differentiation and up to several millions of years afterwards allows for (i) average grain sizes consistent with the observed rounded olivine-bearing pallasites, (ii) a remnant magnetization of Fe-Ni olivine inclusions as measured in natural pallasites and (iii) for the metallographic cooling rates derived from Fe-Ni in pallasites. An important result of this investigation is the definition of the grain growth rate of olivine in molten Fe-S as follows: dn - d0n = k0 exp(-Ea/RT) t, where, d0 is the starting grain size, d the grain size at time t, n = 2.42(46) the growth exponent, k0 = 9.43•E06 μm n s-1 a characteristic constant, Ea = 289 kJ/mol the activation energy for a specific growth process, R the gas constant, and T the absolute temperature. The computed olivine coarsening rate is markedly faster than in olivine-FeNi and olivine-Ni systems.

  12. Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

    SciTech Connect

    Chintakunta, Satish R.; Boone, Shane D.

    2014-02-18

    Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  14. Preconception and early pregnancy air pollution exposures and risk of gestational diabetes mellitus

    SciTech Connect

    Robledo, Candace A.; Mendola, Pauline; Yeung, Edwina; Männistö, Tuija; Sundaram, Rajeshwari; Liu, Danping; Ying, Qi; Sherman, Seth; Grantz, Katherine L.

    2015-02-15

    Background: Air pollution has been linked to gestational diabetes mellitus (GDM) but no studies have evaluated impact of preconception and early pregnancy air pollution exposures on GDM risk. Methods: Electronic medical records provided data on 219,952 singleton deliveries to mothers with (n=11,334) and without GDM (n=208,618). Average maternal exposures to particulate matter (PM) ≤ 2.5 μm (PM{sub 2.5}) and PM{sub 2.5} constituents, PM ≤ 10 μm (PM{sub 10}), nitrogen oxides (NO{sub x}), carbon monoxide, sulfur dioxide (SO{sub 2}) and ozone (O{sub 3}) were estimated for the 3-month preconception window, first trimester, and gestational weeks 1–24 based on modified Community Multiscale Air Quality models for delivery hospital referral regions. Binary regression models with robust standard errors estimated relative risks (RR) for GDM per interquartile range (IQR) increase in pollutant concentrations adjusted for study site, maternal age and race/ethnicity. Results: Preconception maternal exposure to NO{sub X} (RR=1.09, 95% CI: 1.04, 1.13) and SO{sub 2} (RR=1.05, 1.01, 1.09) were associated with increased risk of subsequent GDM and risk estimates remained elevated for first trimester exposure. Preconception O{sub 3} was associated with lower risk of subsequent GDM (RR=0.93, 0.90, 0.96) but risks increased later in pregnancy. Conclusion: Maternal exposures to NO{sub x} and SO{sub 2} preconception and during the first few weeks of pregnancy were associated with increased GDM risk. O{sub 3} appeared to increase GDM risk in association with mid-pregnancy exposure but not in earlier time windows. These common exposures merit further investigation. - Highlights: • Air pollution may be related to gestational diabetes (GDM). • No prior studies have examined preconception exposure. • Maternal exposure to NO{sub x} and SO{sub 2} before conception increased subsequent GDM risk. • NO{sub x} and SO{sub 2} exposure in the first seven weeks of pregnancy also increased

  15. Spatial associations between socioeconomic groups and NO2 air pollution exposure within three large Canadian cities.

    PubMed

    Pinault, Lauren; Crouse, Daniel; Jerrett, Michael; Brauer, Michael; Tjepkema, Michael

    2016-05-01

    Previous studies of environmental justice in Canadian cities have linked lower socioeconomic status to greater air pollution exposures at coarse geographic scales, (i.e., Census Tracts). However, studies that examine these associations at finer scales are less common, as are comparisons among cities. To assess differences in exposure to air pollution among socioeconomic groups, we assigned estimates of exposure to ambient nitrogen dioxide (NO2), a marker for traffic-related pollution, from city-wide land use regression models to respondents of the 2006 Canadian census long-form questionnaire in Toronto, Montreal, and Vancouver. Data were aggregated at a finer scale than in most previous studies (i.e., by Dissemination Area (DA), which includes approximately 400-700 persons). We developed simultaneous autoregressive (SAR) models, which account for spatial autocorrelation, to identify associations between NO2 exposure and indicators of social and material deprivation. In Canada's three largest cities, DAs with greater proportions of tenants and residents who do not speak either English or French were characterised by greater exposures to ambient NO2. We also observed positive associations between NO2 concentrations and indicators of social deprivation, including the proportion of persons living alone (in Toronto), and the proportion of persons who were unmarried/not in a common-law relationship (in Vancouver). Other common measures of deprivation (e.g., lone-parent families, unemployment) were not associated with NO2 exposures. DAs characterised by selected indicators of deprivation were associated with higher concentrations of ambient NO2 air pollution in the three largest cities in Canada.

  16. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    SciTech Connect

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  17. Exposure information in environmental health research: current opportunities and future directions for particulate matter, ozone, and toxic air pollutants.

    PubMed

    McKone, Thomas E; Ryan, P Barry; Ozkaynak, Halûk

    2009-01-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health effect studies for air pollution. Air pollution epidemiology, risk assessment, health tracking, and accountability assessments are examples of health effect studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factor data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency and the Centers for Disease Control and Prevention along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges, and recommendations identified by the exposure working group, who used case studies of particulate matter, ozone, and toxic air-pollutant exposure to evaluate health effects for air pollution. One of the overarching lessons of this workshop is that obtaining better exposure information for these different health effect studies requires both goal setting for what is needed and mapping out the transition pathway from current capabilities for meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another overarching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure-assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media monitoring, and/or personal

  18. The association of annual air pollution exposure with blood pressure among patients with sleep-disordered breathing.

    PubMed

    Liu, Wen-Te; Lee, Kang-Yun; Lee, Hsin-Chien; Chuang, Hsiao-Chi; Wu, Dean; Juang, Jer-Nan; Chuang, Kai-Jen

    2016-02-01

    While sleep-disordered breathing (SDB), high blood pressure (BP) and air pollution exposure have separately been associated with increased risk of cardiopulmonary mortality, the association linking air pollution exposure to BP among patients with sleep-disordered breathing is still unclear. We collected 3762 participants' data from the Taipei Medical University Hospital's Sleep Center and air pollution data from the Taiwan Environmental Protection Administration. Associations of 1-year mean criteria air pollutants [particulate matter with aerodynamic diameters ≤10 μm (PM10), particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5), nitrogen dioxide (NO2) and ozone (O3)] with systolic BP (SBP) and diastolic BP (DBP) were investigated by generalized additive models. After controlling for age, sex, body mass index (BMI), temperature and relative humidity, we observed that increases in air pollution levels were associated with decreased SBP and increased DBP. We also found that patients with apnea-hypopnea index (AHI) ≥30 showed a stronger BP response to increased levels of air pollution exposure than those with AHI<30. Stronger effects of air pollution exposure on BP were found in overweight participants than in participants with normal BMI. We concluded that annual exposure to air pollution was associated with change of BP among patients with sleep-disordered breathing. The association between annual air pollution exposure and BP could be modified by AHI and BMI.

  19. Indoor metallic pollution and children exposure in a mining city.

    PubMed

    Barbieri, Enio; Fontúrbel, Francisco E; Herbas, Cristian; Barbieri, Flavia L; Gardon, Jacques

    2014-07-15

    Mining industries are known for causing strong environmental contamination. In most developing countries, the management of mining wastes is not adequate, usually contaminating soil, water and air. This situation is a source of concern for human settlements located near mining centers, especially for vulnerable populations such as children. The aim of this study was to assess the correlations of the metallic concentrations between household dust and children hair, comparing these associations in two different contamination contexts: a mining district and a suburban non-mining area. We collected 113 hair samples from children between 7 and 12 years of age in elementary schools in the mining city of Oruro, Bolivia. We collected 97 indoor dust samples from their households, as well as information about the children's behavior. Analyses of hair and dust samples were conducted to measure As, Cd, Pb, Sb, Sn, Cu and Zn contents. In the mining district, there were significant correlations between non-essential metallic elements (As, Cd, Pb, Sb and Sn) in dust and hair, but not for essential elements (Cu and Zn), which remained after adjusting for children habits. Children who played with dirt had higher dust-hair correlations for Pb, Sb, and Cu (P=0.006; 0.022 and 0.001 respectively) and children who put hands or toys in their mouths had higher dust-hair correlations of Cd (P=0.011). On the contrary, in the suburban area, no significant correlations were found between metallic elements in dust and children hair and neither children behavior nor gender modified this lack of associations. Our results suggest that, in a context of high metallic contamination, indoor dust becomes an important exposure pathway for children, modulated by their playing behavior.

  20. Exposure to occupational air pollution and cardiac function in workers of the Esfahan Steel Industry, Iran.

    PubMed

    Golshahi, Jafar; Sadeghi, Masoumeh; Saqira, Mohammad; Zavar, Reihaneh; Sadeghifar, Mostafa; Roohafza, Hamidreza

    2016-06-01

    Air pollution is recognized as an important risk factor for cardiovascular disease. We investigated association of exposure to occupational air pollution and cardiac function in the workers of the steel industry. Fifty male workers of the agglomeration and coke-making parts of the Esfahan Steel Company were randomly selected (n = 50). Workers in the administrative parts were studied as controls (n = 50). Those with known history of hypertension, dyslipidemia, or diabetes, and active smokers were not included. Data of age, body mass index, employment duration, blood pressure, fasting blood sugar, and lipid profile were gathered. Echocardiography was performed to evaluate cardiac function. Left ventricular ejection fraction was lower in workers of the agglomeration/coke-making parts than in controls (mean difference = 5 to 5.5 %, P < 0.001). Mild right ventricular dilatation and grade I pulmonary hypertension were present in three (12 %) workers of the coke-making part, but none of the controls (P = 0.010). According to these results, occupational air pollution exposure in workers of the steel industry is associated with left heart systolic dysfunction. Possible right heart insults due to air pollution exposure warrant further investigations.

  1. An analysis of numerical models of air pollutant exposure and vegetation response.

    PubMed

    Krupa, S; Kickert, R N

    1987-01-01

    A number of empirical (statistical, regression oriented) and mechanistic (process oriented) models are presently available to examine the relationship between air pollution stress and plant response. These models have their strengths and weaknesses. In all these models, a major concern is the numerical definition of the pollutant exposure kinetics (dose). At present there are no numerical definitions of dose which make satisfactory biological sense. A key issue is the existence of a biological time clock where plants respond differently to the pollutant stress at different stages of their growth. On the other hand, policy makers and regulatory personnel prefer a simple approach which would facilitate implementation and administration of ambient air quality standards. Long-term air pollutant averaging techniques create artifacts due to the non-normal distribution of ambient concentrations. A more appropriate approach may be the use of 'median' and 'percentiles' computed from short duration pollutant concentrations. Such an approach would be free of the influence of the non-normal distribution, but would require the development of appropriate exposure-response models. Any transfer of results from unit level models to regional level leads to 'scaling error'. There is no general agreement among researchers on how to deal with the scale problem. While this situation persists, any policy formulated on regional impact assessment must acknowledge the uncertainty.

  2. The influence from synoptic weather on the variation of air pollution and pollen exposure

    NASA Astrophysics Data System (ADS)

    Grundström, Maria; Dahl, Åslög; Chen, Deliang; Pleijel, Håkan

    2014-05-01

    Exposure to elevated air pollution levels can make people more susceptible to allergies or result in more severe allergic reactions for people with an already pronounced sensitivity to pollen. The aim of this study was to investigate the relationships between urban air pollution (nitrogen oxides, ozone and particles) and airborne Betula pollen in Gothenburg, Sweden, during the pollen seasons for the years 2001-2012. Further, the influence from atmospheric weather pattern on pollen/pollution related risk, using Lamb Weather Types (LWT), was also considered. Daily LWTs were obtained by comparing the variation in atmospheric pressure from a 16 point grid over a given region on earth (scale ~1000km) and essentially describe the air mass movement for the region. They include two non-directional types, cyclonic (C) and anticyclonic (A) and eight directional types depending on the wind direction (N, NE, E... etc.). LWTs with dry and calm meteorological character e.g. limited precipitation and low to moderate wind speeds (A, NE, E, SE) were associated with strongly elevated air pollution and pollen levels where Betula was exceptionally high in LWTs NE and E. The co-variation between Betula pollen and ozone was strong and significant during situations with LWTs A, NE, E and SE. The most important conclusion from this study was that LWTs A, NE, E and SE were associated with high pollen and air pollution levels and can therefore be classified as high risk weather situations for combined air pollution and pollen exposure. Our study shows that LWTs have the potential to be developed into an objective tool for integrated air quality forecasting and a warning system for risk of high exposure situations.

  3. Pollutant Exposures from Natural Gas Cooking Burners: A Simulation-Based Assessment for Southern California

    SciTech Connect

    Logue, Jennifer M.; Klepeis, Neil E.; Lobscheid, Agnes B.; Singer, Brett C.

    2014-06-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants and they are typically used without venting. The objective of this study is to quantify pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass balance model was applied to estimate time-dependent pollutant concentrations throughout homes and the "exposure concentrations" experienced by individual occupants. The model was applied to estimate nitrogen dioxide (NO{sub 2}), carbon monoxide (CO), and formaldehyde (HCHO) concentrations for one week each in summer and winter for a representative sample of Southern California homes. The model simulated pollutant emissions from NGCBs, NO{sub 2} and CO entry from outdoors, dilution throughout the home, and removal by ventilation and deposition. Residence characteristics and outdoor concentrations of CO and NO{sub 2} were obtained from available databases. Ventilation rates, occupancy patterns, and burner use were inferred from household characteristics. Proximity to the burner(s) and the benefits of using venting range hoods were also explored. Replicate model executions using independently generated sets of stochastic variable values yielded estimated pollutant concentration distributions with geometric means varying less than 10%. The simulation model estimates that in homes using NGCBs without coincident use of venting range hoods, 62%, 9%, and 53% of occupants are routinely exposed to NO{sub 2}, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3000, and 20 ppb for NO{sub 2}, CO, and HCHO, respectively. Reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health

  4. Modeling population exposure to community noise and air pollution in a large metropolitan area.

    PubMed

    Gan, Wen Qi; McLean, Kathleen; Brauer, Michael; Chiarello, Sarah A; Davies, Hugh W

    2012-07-01

    Epidemiologic studies have shown that both air pollution and community noise are associated with cardiovascular disease mortality. Because road traffic is a major contributor to these environmental pollutants in metropolitan areas, it is plausible that the observed associations may be confounded by coexistent pollutants. As part of a large population-based cohort study to address this concern, we used a noise prediction model to assess annual average community noise levels from transportation sources in metropolitan Vancouver, Canada. The modeled annual average noise level was 64 (inter quartile range 60-68) dB(A) for the region. This model was evaluated by comparing modeled annual daytime A-weighted equivalent continuous noise levels (L(day)) with measured 5-min daytime A-weighted equivalent continuous noise levels (L(eq,day,5 min)) at 103 selected roadside sites in the study region. On average, L(day) was 6.2 (95% CI, 6.0-7.9) dB(A) higher than, but highly correlated (r=0.62; 95% CI, 0.48-0.72) with, L(eq,day,5 min). These results suggest that our model-based noise exposure assessment could approximately reflect actual noise exposure in the study region. Overall, modeled noise levels were not strongly correlated with land use regression estimates of traffic-related air pollutants including black carbon, particulate matter with aerodynamic diameter ≤2.5 μm (PM(2.5)), NO(2) and NO; the highest correlation was with black carbon (r=0.48), whereas the lowest correlation was with PM(2.5) (r=0.18). There was no consistent effect of traffic proximity on the correlations between community noise levels and traffic-related air pollutant concentrations. These results, consistent with previous studies, suggest that it is possible to assess potential adverse cardiovascular effects from long-term exposures to community noise and traffic-related air pollution in prospective epidemiologic studies.

  5. Occupational exposure to particulate air pollution and mortality due to ischaemic heart disease and cerebrovascular disease

    PubMed Central

    Torén, Kjell; Bergdahl, Ingvar A; Nilsson, Tohr; Järvholm, Bengt

    2007-01-01

    Objectives A growing number of epidemiological studies are showing that ambient exposure to particulate matter air pollution is a risk factor for cardiovascular disease; however, whether occupational exposure increases this risk is not clear. The aim of the present study was to examine whether occupational exposure to particulate air pollution increases the risk for ischaemic heart disease and cerebrovascular disease. Methods The study population was a cohort of 176 309 occupationally exposed Swedish male construction workers and 71 778 unexposed male construction workers. The definition of exposure to inorganic dust (asbestos, man‐made mineral fibres, dust from cement, concrete and quartz), wood dust, fumes (metal fumes, asphalt fumes and diesel exhaust) and gases and irritants (organic solvents and reactive chemicals) was based on a job‐exposure matrix with focus on exposure in the mid‐1970s. The cohort was followed from 1971 to 2002 with regard to mortality to ischaemic heart disease and cerebrovascular disease. Relative risks (RR) were obtained by the person‐years method and from Poisson regression models adjusting for baseline values of blood pressure, body mass index, age and smoking habits. Results Any occupational particulate air pollution was associated with an increased risk for ischemic heart disease (RR 1.13, 95% CI 1.07 to 1.19), but there was no increased risk for cerebrovascular disease (RR 0.97, 95% CI 0.88 to 1.07). There was an increased risk for ischaemic heart disease and exposure to inorganic dust (RR 1.07, 95% CI 1.03 to 1.12) and exposure to fumes (RR 1.05, 95% CI 1.00 to 1.10), especially diesel exhaust (RR 1.18, 95% CI 1.13 to 1.24). There was no significantly increased risk for cerebrovascular disease and exposure to inorganic dust, fumes or wood dust. Conclusions Occupational exposure to particulate air pollution, especially diesel exhaust, among construction workers increases the risk for ischaemic heart disease. PMID

  6. Long-term exposure to air pollution is associated with biological aging

    PubMed Central

    Ward-Caviness, Cavin K.; Nwanaji-Enwerem, Jamaji C.; Wolf, Kathrin; Wahl, Simone; Colicino, Elena; Trevisi, Letizia; Kloog, Itai; Just, Allan C.; Vokonas, Pantel; Cyrys, Josef; Gieger, Christian; Schwartz, Joel; Baccarelli, Andrea A.; Schneider, Alexandra; Peters, Annette

    2016-01-01

    Long-term exposure to air pollution is associated with age-related diseases. We explored the association between accelerated biological aging and air pollution, a potential mechanism linking air pollution and health. We estimated long-term exposure to PM10, PM2.5, PM2.5 absorbance/black carbon (BC), and NOx via land-use regression models in individuals from the KORA F4 cohort. Accelerated biological aging was assessed using telomere length (TeloAA) and three epigenetic measures: DNA methylation age acceleration (DNAmAA), extrinsic epigenetic age acceleration (correlated with immune cell counts, EEAA), and intrinsic epigenetic age acceleration (independent of immune cell counts, IEAA). We also investigated sex-specific associations between air pollution and biological aging, given the published association between sex and aging measures. In KORA an interquartile range (0.97 μg/m3) increase in PM2.5 was associated with a 0.33 y increase in EEAA (CI = 0.01, 0.64; P = 0.04). BC and NOx (indicators or traffic exposure) were associated with DNAmAA and IEAA in women, while TeloAA was inversely associated with BC in men. We replicated this inverse BC-TeloAA association in the Normative Aging Study, a male cohort based in the USA. A multiple phenotype analysis in KORA F4 combining all aging measures showed that BC and PM10 were broadly associated with biological aging in men. Thus, we conclude that long-term exposure to air pollution is associated with biological aging measures, potentially in a sex-specific manner. However, many of the associations were relatively weak and further replication of overall and sex-specific associations is warranted. PMID:27793020

  7. Measurement error in mobile source air pollution exposure estimates due to residential mobility during pregnancy.

    PubMed

    Pennington, Audrey Flak; Strickland, Matthew J; Klein, Mitchel; Zhai, Xinxin; Russell, Armistead G; Hansen, Craig; Darrow, Lyndsey A

    2016-12-14

    Prenatal air pollution exposure is frequently estimated using maternal residential location at the time of delivery as a proxy for residence during pregnancy. We describe residential mobility during pregnancy among 19,951 children from the Kaiser Air Pollution and Pediatric Asthma Study, quantify measurement error in spatially resolved estimates of prenatal exposure to mobile source fine particulate matter (PM2.5) due to ignoring this mobility, and simulate the impact of this error on estimates of epidemiologic associations. Two exposure estimates were compared, one calculated using complete residential histories during pregnancy (weighted average based on time spent at each address) and the second calculated using only residence at birth. Estimates were computed using annual averages of primary PM2.5 from traffic emissions modeled using a Research LINE-source dispersion model for near-surface releases (RLINE) at 250 m resolution. In this cohort, 18.6% of children were born to mothers who moved at least once during pregnancy. Mobile source PM2.5 exposure estimates calculated using complete residential histories during pregnancy and only residence at birth were highly correlated (rS>0.9). Simulations indicated that ignoring residential mobility resulted in modest bias of epidemiologic associations toward the null, but varied by maternal characteristics and prenatal exposure windows of interest (ranging from -2% to -10% bias).Journal of Exposure Science and Environmental Epidemiology advance online publication, 14 December 2016; doi:10.1038/jes.2016.66.

  8. Evaluating the neurotoxic effects of lactational exposure to persistent organic pollutants (POPs) in Spanish children.

    PubMed

    Gascon, Mireia; Verner, Marc-André; Guxens, Mònica; Grimalt, Joan O; Forns, Joan; Ibarluzea, Jesús; Lertxundi, Nerea; Ballester, Ferran; Llop, Sabrina; Haddad, Sami; Sunyer, Jordi; Vrijheid, Martine

    2013-01-01

    Although the brain continues developing in the postnatal period, epidemiological studies on the effects of postnatal exposure to neurotoxic POPs through breast-feeding remain mostly inconclusive. Failure to detect associations between postnatal exposure and health outcomes may stem from the limitations of commonly employed approaches to assess lactational exposure. The aim of the present study was to assess whether lactational exposure to polychlorinated biphenyl-153 (PCB-153), dichlorodiphenyldichloroethylene (DDE), or hexachlorobenzene (HCB) as estimated with a physiologically based pharmacokinetic (PBPK) model, is associated with decrements in mental and psychomotor development scores of the Bayley Scales of Infant Development (BSID) test in children aged around 14-months of a subsample (N=1175) of the Spanish INMA birth cohort, and to compare this with the effects of prenatal exposure. Although in the present study population PCB-153, DDE and HCB exposure increased within the first months of postnatal life, no associations were found between different periods of postnatal exposure to these compounds and mental or psychomotor scores. Increasing prenatal PCB-153 concentrations were associated with worse mental and psychomotor scores, although significance was only reached for psychomotor development (β [95%CI]=-1.36 [-2.61, -0.11]). Indeed, the association between exposure and effects observed during prenatal life weakened gradually across periods of postnatal life. Results of the present study suggest that, although breastfeeding increases children's blood persistent organic pollutants (POPs) levels during postnatal life, deleterious effects of PCB-153 on neuropsychological development are mainly attributable to prenatal exposure.

  9. Cleaning products and air fresheners: exposure to primary and secondary air pollutants

    NASA Astrophysics Data System (ADS)

    Nazaroff, William W.; Weschler, Charles J.

    Building occupants, including cleaning personnel, are exposed to a wide variety of airborne chemicals when cleaning agents and air fresheners are used in buildings. Certain of these chemicals are listed by the state of California as toxic air contaminants (TACs) and a subset of these are regulated by the US federal government as hazardous air pollutants (HAPs). California's Proposition 65 list of species recognized as carcinogens or reproductive toxicants also includes constituents of certain cleaning products and air fresheners. In addition, many cleaning agents and air fresheners contain chemicals that can react with other air contaminants to yield potentially harmful secondary products. For example, terpenes can react rapidly with ozone in indoor air generating many secondary pollutants, including TACs such as formaldehyde. Furthermore, ozone-terpene reactions produce the hydroxyl radical, which reacts rapidly with organics, leading to the formation of other potentially toxic air pollutants. Indoor reactive chemistry involving the nitrate radical and cleaning-product constituents is also of concern, since it produces organic nitrates as well as some of the same oxidation products generated by ozone and hydroxyl radicals. Few studies have directly addressed the indoor concentrations of TACs that might result from primary emissions or secondary pollutant formation following the use of cleaning agents and air fresheners. In this paper, we combine direct empirical evidence with the basic principles of indoor pollutant behavior and with information from relevant studies, to analyze and critically assess air pollutant exposures resulting from the use of cleaning products and air fresheners. Attention is focused on compounds that are listed as HAPs, TACs or Proposition 65 carcinogens/reproductive toxicants and compounds that can readily react to generate secondary pollutants. The toxicity of many of these secondary pollutants has yet to be evaluated. The inhalation

  10. Maternal ambient air pollution exposure preconception and during early gestation and offspring congenital orofacial defects

    PubMed Central

    Zhu, Yeyi; Zhang, Cuilin; Liu, Danping; Grantz, Katherine L.; Wallace, Maeve; Mendola, Pauline

    2015-01-01

    Background Maternal air pollution exposure has been related to orofacial clefts but the literature is equivocal. Potential chronic preconception effects have not been studied. Objectives Criteria air pollutant exposure during three months preconception and gestational weeks 3–8 was studied in relation to orofacial defects. Methods Among 188,102 live births and fetal deaths from the Consortium on Safe Labor (2002–2008), 63 had isolated cleft palate (CP) and 159 had isolated cleft lip with or without cleft palate (CL ± CP). Exposures were estimated using a modified Community Multiscale Air Quality model. Logistic regression with generalized estimating equations adjusted for site/region and maternal demographic, lifestyle and clinical factors calculated the odds ratio (OR) and 95% CI per interquartile increase in each pollutant. Results Preconception, carbon monoxide (CO; OR = 2.24; CI: 1.21, 4.16) and particulate matter (PM) ≤10 μm (OR = 1.72; CI: 1.12, 2.66) were significantly associated with CP, while sulfur dioxide (SO2) was associated with CL ± CP (OR = 1.93; CI: 1.16, 3.21). During gestational weeks 3–8, CO remained a significant risk for CP (OR = 2.74; CI: 1.62, 4.62) and nitrogen oxides (NOx; OR = 3.64; CI: 1.73, 7.66) and PM ≤2.5 μm (PM2.5; OR = 1.74; CI: 1.15, 2.64) were also related to the risk. Analyses by individual week revealed that positive associations of NOx and PM2.5 with CP were most prominent from weeks 3–6 and 3–5, respectively. Conclusions Exposure to several criteria air pollutants preconception and during early gestation was associated with elevated odds for CP, while CL ± CP was only associated with preconception SO2 exposure. PMID:26099933

  11. Short-Term Exposure to Air Pollution and Lung Function in the Framingham Heart Study

    PubMed Central

    Ljungman, Petter L.; Wilker, Elissa H.; Gold, Diane R.; Schwartz, Joel D.; Koutrakis, Petros; Washko, George R.; O’Connor, George T.; Mittleman, Murray A.

    2013-01-01

    Rationale: Short-term exposure to ambient air pollution has been associated with lower lung function. Few studies have examined whether these associations are detectable at relatively low levels of pollution within current U.S. Environmental Protection Agency (EPA) standards. Objectives: To examine exposure to ambient air pollutants within EPA standards and lung function in a large cohort study. Methods: We included 3,262 participants of the Framingham Offspring and Third Generation cohorts living within 40 km of the Harvard Supersite monitor in Boston, Massachusetts (5,358 examinations, 1995–2011) who were not current smokers, with previous-day pollutant levels in compliance with EPA standards. We compared lung function (FEV1 and FVC) after previous-day exposure to particulate matter less than 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in the “moderate” range of the EPA Air Quality Index to exposure in the “good” range. We also examined linear relationships between moving averages of pollutant concentrations 1, 2, 3, 5, and 7 days before spirometry and lung function. Measurements and Main Results: Exposure to pollutant concentrations in the “moderate” range of the EPA Air Quality Index was associated with a 20.1-ml lower FEV1 for PM2.5 (95% confidence interval [CI], −33.4, −6.9), a 30.6-ml lower FEV1 for NO2 (95% CI, −60.9, −0.2), and a 55.7-ml lower FEV1 for O3 (95% CI, −100.7, −10.8) compared with the “good” range. The 1- and 2-day moving averages of PM2.5, NO2, and O3 before testing were negatively associated with FEV1 and FVC. Conclusions: Short-term exposure to PM2.5, NO2, and O3 within current EPA standards was associated with lower lung function in this cohort of adults. PMID:24200465

  12. Impacts of Mercury Pollution Controls on Atmospheric Mercury Concentration and Occupational Mercury Exposure in a Hospital.

    PubMed

    Li, Ping; Yang, Yan; Xiong, Wuyan

    2015-12-01

    Mercury (Hg) and Hg-containing products are used in a wide range of settings in hospitals. Hg pollution control measures were carried out in the pediatric ward of a hospital to decrease the possibility of Hg pollution occurring and to decrease occupational Hg exposure. Total gaseous Hg (TGM) concentrations in the pediatric ward and hair and urine Hg concentrations for the pediatric staff were determined before and after the Hg pollution control measures had been implemented. A questionnaire survey performed indicated that the pediatric staff had little understanding of Hg pollution and that appropriate disposal techniques were not always used after Hg leakage. TGM concentrations in the pediatric ward and urine Hg (UHg) concentrations for the pediatric staff were 25.7 and 22.2% lower, respectively, after the Hg pollution control measures had been implemented than before, which indicated that the control measures were effective. However, TGM concentrations in the pediatric ward remained significantly higher than background concentrations and UHg concentrations for the pediatric staff were remained significantly higher than the concentrations in control group, indicating continued existence of certain Hg pollution.

  13. Evaluation of the quality of commercial silicon carbide wafers by an optical non-destructive inspection technique

    NASA Astrophysics Data System (ADS)

    Hatakeyama, T.; Ichinoseki, K.; Fukuda, K.; Higuchi, N.; Arai, K.

    2008-03-01

    There is a great need for an in-line, high-speed and non-destructive inspection system capable of evaluating and analyzing the quality SiC wafers for SiC power devices. We have examined whether the laser-based optical non-destructive inspection system by KLA-Tencor meets these requirements. By optimizing the optical setup and improving the defect recognition and classification recipe, we have successfully mapped classified defects on a SiC wafer. Using this system, incoming inspection of purchased SiC wafers has been performed. The obtained inspection data show that micropipe density is sufficiently low in a device-grade wafer and, therefore, micropipes are not the main cause of device failure. The next challenges for a device-grade SiC wafer are reduction of epitaxial defects and relatively small defects classified as "particles".

  14. Non-invasive and non-destructive characterization of tissue engineered constructs using ultrasound imaging technologies: a review

    PubMed Central

    Kim, Kang; Wagner, William R.

    2015-01-01

    With the rapid expansion of biomaterial development and coupled efforts to translate such advances toward the clinic, non-invasive and non-destructive imaging tools to evaluate implants in situ in a timely manner are critically needed. The required multilevel information is comprehensive, including structural, mechanical, and biological changes such as scaffold degradation, mechanical strength, cell infiltration, extracellular matrix formation and vascularization to name a few. With its inherent advantages of non-invasiveness and non-destructiveness, ultrasound imaging can be an ideal tool for both preclinical and clinical uses. In this review, currently available ultrasound imaging technologies that have been applied in vitro and in vivo for tissue engineering and regenerative medicine are discussed and some new emerging ultrasound technologies and multi-modality approaches utilizing ultrasound are introduced. PMID:26518412