Science.gov

Sample records for innovative characterization techniques

  1. Preparation and Characterization of SnO Nanoplatelets by Microwave Innovative Technique

    SciTech Connect

    Krishnakumar, T.; Perumal, K.; Jayaprakash, R.; Pinna, Nicola

    2008-04-23

    Tin oxide (SnO) nanoplatelets have been synthesized by a Microwave innovative technique with an operating frequency of 2.45 GHz in just few minutes. The crystalline size and structure was evaluated from XRD pattern. The SEM and TEM analysis showed the single crystal platelets together with many small particles attached to its surface. The FT-IR and the electrical conductivity of the samples have also been investigated.

  2. Characterization of Electronic Materials HgZnSe and HgZnTe Using Innovative and Conventional Techniques

    NASA Technical Reports Server (NTRS)

    Tanton, George; Kesmodel, Roy; Burden, Judy; Su, Ching-Hua; Cobb, Sharon D.; Lehoczky, S. L.

    2000-01-01

    HgZnSe and HgZnTe are electronic materials of interest for potential IR detector and focal plane array applications due to their improved strength and compositional stability over HgCdTe, but they are difficult to grow on Earth and to fully characterize. Conventional contact methods of characterization, such as Hall and van der Paw, although adequate for many situations are typically labor intensive and not entirely suitable where only very small samples are available. To adequately characterize and compare properties of electronic materials grown in low earth orbit with those grown on Earth, innovative techniques are needed that complement existing methods. This paper describes the implementation and test results of a unique non-contact method of characterizing uniformity, mobility, and carrier concentration together with results from conventional methods applied to HgZnSe and HgZnTe. The innovative method has advantages over conventional contact methods since it circumvents problems of possible contamination from alloying electrical contacts to a sample and also has the capability to map a sample. Non- destructive mapping, the determination of the carrier concentration and mobility at each place on a sample, provides a means to quantitatively compare, at high spatial resolution, effects of microgravity on electronic properties and uniformity of electronic materials grown in low-Earth orbit with Earth grown materials. The mapping technique described here uses a 1mm diameter polarized beam of radiation to probe the sample. Activation of a magnetic field, in which the sample is placed, causes the plane of polarization of the probe beam to rotate. This Faraday rotation is a function of the free carrier concentration and the band parameters of the material. Maps of carrier concentration, mobility, and transmission generated from measurements of the Faraday rotation angles over the temperature range from 300K to 77K will be presented. New information on band parameters

  3. Innovative hyperspectral imaging (HSI) based techniques applied to end-of-life concrete drill core characterization for optimal dismantling and materials recovery

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Picone, Nicoletta; Serranti, Silvia

    2015-02-01

    The reduction of EOL concrete disposal in landfills, together with a lower exploitation of primary raw materials, generates a strong interest to develop, set-up and apply innovative technologies to maximize Construction and Demolition Waste (C&DW) conversion into useful secondary raw materials. Such a goal can be reached starting from a punctual in-situ efficient characterization of the objects to dismantle in order to develop demolition actions aimed to set up innovative mechanical-physical processes to recover the different materials and products to recycle. In this paper an innovative recycling-oriented characterization strategy based on HyperSpectral Imaging (HSI) is described in order to identify aggregates and mortar in drill core samples from end-of-life concrete. To reach this goal, concrete drill cores from a demolition site were systematically investigated by HSI in the short wave infrared field (1000-2500 nm). Results obtained by the adoption of the HSI approach showed as this technology can be successfully applied to analyze quality and characteristics of C&DW before dismantling and as final product to reutilise after demolition-milling-classification actions. The proposed technique and the related recognition logics, through the spectral signature detection of finite physical domains (i.e. concrete slice and/or particle) of different nature and composition, allows; i) to develop characterization procedures able to quantitatively assess end-of-life concrete compositional/textural characteristics and ii) to set up innovative sorting strategies to qualify the different materials constituting drill core samples.

  4. Innovative Techniques Simplify Vibration Analysis

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the early years of development, Marshall Space Flight Center engineers encountered challenges related to components in the space shuttle main engine. To assess the problems, they evaluated the effects of vibration and oscillation. To enhance the method of vibration signal analysis, Marshall awarded Small Business Innovation Research (SBIR) contracts to AI Signal Research, Inc. (ASRI), in Huntsville, Alabama. ASRI developed a software package called PC-SIGNAL that NASA now employs on a daily basis, and in 2009, the PKP-Module won Marshall s Software of the Year award. The technology is also used in many industries: aircraft and helicopter, rocket engine manufacturing, transportation, and nuclear power."

  5. Innovative Techniques for Teaching Research Methods.

    ERIC Educational Resources Information Center

    Babbie, Earl

    An explanation of three innovative techniques the author has used successfully to introduce undergraduate and graduate students to sociological methodology. The three methods are: (1) body-learning, which involves moving students around physically in ways analogous to the data manipulations being taught; (2) experimental learning, which involves…

  6. Electronic Creativity Techniques for Organizational Innovation.

    ERIC Educational Resources Information Center

    Siau, Keng L.

    1996-01-01

    Discusses using advanced electronic and communication technology to improve organizational innovation. Group creativity techniques, such as electronic brainstorming, PMI (a brainstorming approach involving plus, minus, and interesting points), synectics, and their verbal counterparts are compared. Electronic PMI and synectics are found to be…

  7. Innovative application of classic and newer techniques for the characterization of haemocytes in the New Zealand black-footed abalone (Haliotis iris).

    PubMed

    Grandiosa, Roffi; Mérien, Fabrice; Pillay, Krish; Alfaro, Andrea

    2016-01-01

    Haemocytes play an important role in innate immune responses within invertebrate organisms. However, identification and quantification of different types of haemocytes can be extremely challenging, and has led to numerous inconsistencies and misinterpretations within the literature. As a step to rectify this issue, we present a comprehensive and detailed approach to characterize haemocytes using a combination of classical (cytochemical and phagocytosis assays with optical microscopy) and novel (flow cytometry with Sysmex XN-1000 and Muse(®) Cell analyser) techniques. The Sysmex XN-1000 is an innovative fluorescent flow cytometric analyser that can effectively detect, identify and count haemocytes, while the Muse(®) Cell analyser provides accurate and rapid haemocyte cell counts and viability. To illustrate this approach, we present the first report on morphological and functional features of New Zealand black-footed abalone (Haliotis iris) haemocyte cells. Two types of haemocytes were identified in this study, including type I (monocyte-like) and type II (lymphocyte-like) cells. Granular cells, which have been reported in other molluscan species, were not detected in H. iris. Cell types were categorized based on shape, size, internal structures and function. The lymphocyte-like haemocytes were the most abundant hemocytes in the haemolymph samples, and they had large nuclei and basic cytoplasms. Monocyte-like cells generally were larger cells compared to lymphocyte-like cells, and had low nucleus-cytoplasm ratios. Monocyte-like cells showed higher phagocytic activity when encountering Zymosan A particles compared to lymphocyte-like cells. The present study provides a comprehensive and accurate new approach to identify and quantify haemocyte cells for future comparative studies on the immune system of abalone and other molluscan species. PMID:26672903

  8. Site characterization techniques

    USGS Publications Warehouse

    U.S. Geological Survey

    1995-01-01

    Geoelectrical methods have been used since the 1920's to search for metallic ore deposits. During the last decade, traditional mining geophysical techniques have been adapted for environmental site characterization. Geoelectrical geophysics is now a well developed engineering specialty, with different methods to focus both on a range of targets and on depths below the surface. Most methods have also been adapted to borehole measurements.

  9. Using Innovative Information Systems Techniques To Teach Information Systems.

    ERIC Educational Resources Information Center

    Chimi, Carl J.; Gordon, Gene M.

    This paper discusses a number of innovative techniques that were used to teach courses in Information Systems to undergraduate and graduate students. While none of these techniques is individually innovative, the combination of techniques provides a true "hands-on" environment for students; because of the way that the components of the courses are…

  10. Innovative Tools Advance Revolutionary Weld Technique

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The iconic, orange external tank of the space shuttle launch system not only contains the fuel used by the shuttle s main engines during liftoff but also comprises the shuttle s backbone, supporting the space shuttle orbiter and solid rocket boosters. Given the tank s structural importance and the extreme forces (7.8 million pounds of thrust load) and temperatures it encounters during launch, the welds used to construct the tank must be highly reliable. Variable polarity plasma arc welding, developed for manufacturing the external tank and later employed for building the International Space Station, was until 1994 the best process for joining the aluminum alloys used during construction. That year, Marshall Space Flight Center engineers began experimenting with a relatively new welding technique called friction stir welding (FSW), developed in 1991 by The Welding Institute, of Cambridge, England. FSW differs from traditional fusion welding in that it is a solid-state welding technique, using frictional heat and motion to join structural components without actually melting any of the material. The weld is created by a shouldered pin tool that is plunged into the seam of the materials to be joined. The tool traverses the line while rotating at high speeds, generating friction that heats and softens but does not melt the metal. (The heat produced approaches about 80 percent of the metal s melting temperature.) The pin tool s rotation crushes and stirs the plasticized metal, extruding it along the seam as the tool moves forward. The material cools and consolidates, resulting in a weld with superior mechanical properties as compared to those weld properties of fusion welds. The innovative FSW technology promises a number of attractive benefits. Because the welded materials are not melted, many of the undesirables associated with fusion welding porosity, cracking, shrinkage, and distortion of the weld are minimized or avoided. The process is more energy efficient, safe

  11. Single Cell Electrical Characterization Techniques

    PubMed Central

    Mansor, Muhammad Asraf; Ahmad, Mohd Ridzuan

    2015-01-01

    Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell’s electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell’s electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed. PMID:26053399

  12. Innovative measurement techniques in surface science.

    PubMed

    Freund, Hans-Joachim; Nilius, Niklas; Risse, Thomas; Schauermann, Swetlana; Schmidt, Thomas

    2011-01-17

    We describe four new experimental techniques advanced during the last decade in the authors' laboratory. The techniques include photon scanning tunneling microscopy; aberration-corrected low-energy electron microscopy in combination with photoelectron emission microscopy, microcalorimetry, and electron-spin resonance spectroscopy. It is demonstrated how those techniques may be applied to solve fundamental problems in surface science with growing demands to tackle complex nanoscopic systems, and, in particular in catalysis science, which, without the availability of those techniques, would be difficult if not impossible to address. PMID:21226183

  13. [Innovative techniques in atrial fibrillation therapy].

    PubMed

    Metzner, A; Wissner, E; Fink, T; Ouyang, F; Kuck, K-H

    2015-02-01

    Pulmonary vein isolation (PVI) is the established cornerstone in most catheter-based ablation treatment strategies for atrial fibrillation (AF); however, it is still a challenge to create contiguous, transmural and permanent ablation lesions using radiofrequency current in combination with three-dimensional mapping systems. To overcome these limitations, innovative spiral mapping and ablation catheters as well as balloon-based ablation catheters incorporating alternative energy sources, such as cryoenergy and laser were developed and evaluated and have proved their potential for safe and clinically effective PVI. In addition, novel ablation strategies, such as identification and ablation of AF-inducing foci and/or AF-perpetuating rotors using either endocardial or epicardial mapping systems were introduced and are currently under clinical evaluation. The identification and modulation of atrial ganglionic plexi (GP) and, therefore, of the autonomous nervous system is another additive ablation approach which requires further clinical evaluation. PMID:25585587

  14. Interpersonal Process Recall: An Innovative Technique

    ERIC Educational Resources Information Center

    Benedek, Elissa P.; Bieniek, Christine M.

    1977-01-01

    Three specific skills are described that the novice psychiatric resident must begin to learn: interviewing techniques, self-observation, and empathy. Curriculum effective in accelerating the learning process, i.e., interpersonal process recall, is also discussed. (Author/LBH)

  15. Innovative optical alignment technique for CMP wafers

    NASA Astrophysics Data System (ADS)

    Sugaya, Ayako; Kanaya, Yuho; Nakajima, Shinichi; Nagayama, Tadashi; Shiraishi, Naomasa

    2002-07-01

    Detecting position of the wafers such as after CMP process is critical theme of current and forthcoming IC manufacturing. The alignment system must be with high accuracy for any process. To satisfy such requirements, we have studied and analyzed factors that have made alignment difficult. From the result of the studies, we have developed new optical alignment techniques which improve the accuracy of FIA (alignment sensor of Nikon's NSR series) and examined them. The approaches are optimizing the focus position, developing an advanced algorithm for position detection, and selecting a suitable mark design. For experiment, we have developed the special wafers that make it possible to evaluate the influence of CMP processes. The experimental results show that the overlay errors decrease dramatically with the new alignment techniques. FIA with these new techniques will be much accurate and suitable alignment sensor for CMP and other processes of future generation ULSI production.

  16. Surface Characterization Techniques: An Overview

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2002-01-01

    To understand the benefits that surface modifications provide, and ultimately to devise better ones, it is necessary to study the physical, mechanical, and chemical changes they cause. This chapter surveys classical and leading-edge developments in surface structure and property characterization methodologies. The primary emphases are on the use of these techniques as they relate to surface modifications, thin films and coatings, and tribological engineering surfaces and on the implications rather than the instrumentation.

  17. Innovative production technique for PEFC electrodes

    SciTech Connect

    Bevers, D.; Guelzow, E.; Helmbold, A.; Mueller, B.

    1996-12-31

    Fuel cells are high efficient and low polluting energy conversation devices. Using hydrogen as a fuel gas they are applicable to solve environmental problems e.g. CO{sub 2} impact on the climate. Thus international research efforts have been increased in recent years. Low temperature fuel cells e.g. the PEFC are specially applicable for future transportation and stationary energy supply systems. Application and economics success of his technology is obstructed by the high investment costs with respect to conventional energy conversion devices. The intent of our activities is the improvement of electrodes and membrane-electrode-assemblies as used in PEFC. Commercial and technical aspects of electrode manufacturing have been considered in early stages of the development of the production procedure. Two different techniques are developed at DLR. The first is a rolling procedure as used for production for batteries and alkaline fuel cells which has been modified and adapted to the specific demand of PEFC electrodes. The second technique is a new printing process to produce ultra thin layers of catalyst directly on the electrolyte. In this paper we will show the first results of the first electrode technique which have been tested in fuel cells and a short description of the second very new method.

  18. Innovative Balloon Buoyancy Techniques for Atmospheric Exploration

    NASA Technical Reports Server (NTRS)

    Jones, J.

    2000-01-01

    Until quite recently, the only practical means to control balloon buoyancy, and thus altitude, required consuming large amounts of fuel or the limited venting of helium balloons and/or dropping of ballast. With recent discoveries at JPL, novel long-life, balloon buoyancy techniques have been discovered that for the first time allow balloons to float in the primarily hydrogen atmospheres of Jupiter, Saturn, Uranus, and Neptune (using ambient fill-gas), and by using renewable energy sources, allow multiple controlled landings on Venus (using atmospheric temperature differences), Mars (solar heat), Titan (RTG heat), and Earth (planet radiant heat).

  19. Comparison of Traditional and Innovative Techniques to Solve Technical Challenges

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele

    2011-01-01

    This slide presentation reviews the use of traditional and innovative techniques to solve technical challenges in food storage technology. The planning for a mission to Mars is underway, and the food storage technology improvements requires that improvements be made. This new technology is required, because current food storage technology is inadequate,refrigerators or freezers are not available for food preservation, and that a shelf life of 5 years is expected. A 10 year effort to improve food packaging technology has not enhanced significantly food packaging capabilities. Two innovation techniques were attempted InnoCentive and Yet2.com and have provided good results, and are still under due diligence for solver verification.

  20. Electrical characterization of a Mapham inverter using pulse testing techniques

    NASA Technical Reports Server (NTRS)

    Baumann, E. D.; Myers, I. T.; Hammoud, A. N.

    1990-01-01

    The use of a multiple pulse testing technique to determine the electrical characteristics of large megawatt-level power systems for aerospace missions is proposed. An innovative test method based on the multiple pulse technique is demonstrated on a 2-kW Mapham inverter. The concept of this technique shows that characterization of large power systems under electrical equilibrium at rated power can be accomplished without large costly power supplies. The heat generation that occurs in systems when tested in a continuous mode is eliminated. The results indicate that there is a good agreement between this testing technique and that of steady state testing.

  1. Electrical characterization of a Mapham inverter using pulse testing techniques

    NASA Astrophysics Data System (ADS)

    Baumann, E. D.; Myers, I. T.; Hammoud, A. N.

    The use of a multiple pulse testing technique to determine the electrical characteristics of large megawatt-level power systems for aerospace missions is proposed. An innovative test method based on the multiple pulse technique is demonstrated on a 2-kW Mapham inverter. The concept of this technique shows that characterization of large power systems under electrical equilibrium at rated power can be accomplished without large costly power supplies. The heat generation that occurs in systems when tested in a continuous mode is eliminated. The results indicate that there is a good agreement between this testing technique and that of steady state testing.

  2. Hair transplantation update: procedural techniques, innovations, and applications.

    PubMed

    Bunagan, M J Kristine; Banka, Nusrat; Shapiro, Jerry

    2013-01-01

    The advances in hair transplantation, particularly the advent of follicular unit transplantation, have greatly elevated the outcome of this procedure. Various modifications to the basic technique as well as innovations focused on the different aspects of the hair transplantation procedure have further enhanced this type of hair restoration surgery. In addition, there is ongoing expansion of the indications and applications of this procedure beyond the usual male pattern hair loss. PMID:23159183

  3. Innovative techniques for the description of reservoir heterogeneity using tracers

    SciTech Connect

    Pope, G.; Sepehrnoori, K.

    1991-09-01

    The objective of this research is to develop an advanced, innovative technique for the description of reservoir heterogeneity. This proposed method consists of using tracers in single-well backflow tests. The general idea is to make use of fluid drift in the reservoir either due to naturally occurring pressure gradients in the reservoir, or by deliberately imposed pressure gradients using adjacent injection and production wells in the same reservoir. The analytical tool that will be used to design and interpret these tests is a compositional reservoir simulator with special features added and tested specifically for this purpose. 2 refs., 5 figs.

  4. Ambient air contamination: Characterization and detection techniques

    NASA Technical Reports Server (NTRS)

    Nulton, C. P.; Silvus, H. S.

    1985-01-01

    Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

  5. An innovative technique to probe the middle and upper atmosphere

    NASA Astrophysics Data System (ADS)

    Assink, Jelle; Smets, Pieter; Le Pichon, Alexis; Evers, Läslo

    2016-04-01

    The middle atmosphere has gained more and more importance for the purpose of weather and climate prediction, since increasing evidence has indicated that the troposphere and stratosphere are more closely coupled than assumed before. Significant effort has been made towards a more comprehensive representation of the atmosphere to better capture the stratospheric variability as well as the stratospheric-tropospheric interactions, for example during Sudden Stratospheric Warming (SSW) events. Despite these advances, it remains difficult to measure in the upper layers of the atmosphere. Over recent years, new developments in the field of low-frequency inaudible sound (infrasound) have lead to an innovative method for evaluating numerical weather prediction models. In this presentation, the general technique is described and a case study is presented in which stratospheric forecasts of the European Centre for Medium-range Weather Forecasts (ECMWF) of the 2013 major SSW are evaluated.

  6. Expedited site characterization. Innovative technology summary report

    SciTech Connect

    1998-12-01

    Expedited Site Characterization (ESC) has been developed, demonstrated, and deployed as a new time-saving, cost-effective approach for hazardous waste site investigations. ESC is an alternative approach that effectively shortens the length of the assessment period and may significantly reduce costs at many sites. It is not a specific technology or system but is a methodology for most effectively conducting a site characterization. The principal elements of ESC are: a field investigation conducted by an integrated team of experienced professionals working in the field at the same time, analysis, integration and initial validation of the characterization data as they are obtained in the field, and a dynamic work plan that enables the team to take advantage of new insights from recent data to adjust the work plan in the field. This report covers demonstrations that took place between 1989 and 1996. This paper gives a description of the technology and discusses its performance, applications, cost, regulatory and policy issues, and lessons learned.

  7. Characterization techniques for surface-micromachined devices

    SciTech Connect

    Eaton, W.P.; Smith, N.F.; Irwin, L.; Tanner, D.M.

    1998-08-01

    Using a microengine as the primary test vehicle, the authors have examined several aspects of characterization. Parametric measurements provide fabrication process information. Drive signal optimization is necessary for increased microengine performance. Finally, electrical characterization of resonant frequency and quality factor can be more accurate than visual techniques.

  8. Pleiades-Hr Innovative Techniques for Radiometric Image Quality Commissioning

    NASA Astrophysics Data System (ADS)

    Blanchet, G.; Lebeque, L.; Fourest, S.; Latry, C.; Porez-Nadal, F.; Lacherade, S.; Thiebaut, C.

    2012-07-01

    The first Pleiades-HR satellite, part of a constellation of two, has been launched on December 17, 2011. This satellite produces high resolution optical images. In order to achieve good image quality, Pleiades-HR should first undergo an important 6 month commissioning phase period. This phase consists in calibrating and assessing the radiometric and geometric image quality to offer the best images to end users. This new satellite has benefited from technology improvements in various fields which make it stand out from other Earth observation satellites. In particular, its best-in-class agility performance enables new calibration and assessment techniques. This paper is dedicated to presenting these innovative techniques that have been tested for the first time for the Pleiades- HR radiometric commissioning. Radiometric activities concern compression, absolute calibration, detector normalization, and refocusing operations, MTF (Modulation Transfer Function) assessment, signal-to-noise ratio (SNR) estimation, and tuning of the ground processing parameters. The radiometric performances of each activity are summarized in this paper.

  9. Halstedian technique revisited. Innovations in teaching surgical skills.

    PubMed Central

    Barnes, R W; Lang, N P; Whiteside, M F

    1989-01-01

    This paper reviews the laboratory models used to teach fundamental surgical skills in our general surgery residency. The laboratory modules allow supervision and self-instruction, practice, and videotape monitoring of the following techniques: skin incision, suturing, knot tying, hemostasis, vascular anastomosis, and intestinal anastomosis. Pigs' feet simulate human skin for exercises in skin incision, lesion excision, suturing, and basic plastic surgical techniques. Latex tubing and penrose drains allow experience in suturing, knot tying, and hemostasis. Polytetrafluoroethylene vascular prostheses permit quantification of the precision of needle passage and suturing by measurement of leakage of water through a vascular anastomosis. Reconstituted, lyophilized, irradiated bovine arteries and ileum provide models of biologic tissue for creating handsewn vascular anastomoses and sutured or stapled gastrointestinal anastomoses. A headlamp videocamera allows unobstructive recording of the resident's technical performance and provides subsequent visual feedback for self-improvement when compared to reference instructional videotapes. We feel that these innovations may enhance surgical dexterity of residents without the need for animal sacrifice. Our goal is to foreshorten the learning curve for basic surgical skills and improve performance in the clinical operating room. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2742408

  10. AN INNOVATIVE TECHNIQUE FOR THIN FILM INTERFACE TOUGHNESS RESEARCH

    SciTech Connect

    Wang, J.J.

    2004-11-01

    scale and MA956 substrate is 3.7 N-m/m{sup 2}, and the estimated equivalent Mode I fracture toughness is 1.1 MPa {radical}m. This innovative technique is expected to greatly assist the development of coating materials with improved protective capabilities and provide a reliable method for use in assessing material performance.

  11. Using Innovative Techniques for Manufacturing Rocket Engine Hardware

    NASA Technical Reports Server (NTRS)

    Betts, Erin M.; Reynolds, David C.; Eddleman, David E.; Hardin, Andy

    2011-01-01

    Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using the Workhorse Gas Generator (WHGG) test setup at MSFC?s East Test Area test stand 116, the duct was subject to extreme J-2X gas generator environments and endured a total of 538 seconds of hot-fire time. The duct survived the testing and was inspected after the test. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

  12. Electrical characterization of a Mapham inverter using pulse testing techniques

    NASA Technical Reports Server (NTRS)

    Baumann, E. D.; Myers, I. T.; Hammond, A. N.

    1990-01-01

    Electric power requirements for aerospace missions have reached megawatt power levels. Within the next few decades, it is anticipated that a manned lunar base, interplanetary travel, and surface exploration of the Martian surface will become reality. Several research and development projects aimed at demonstrating megawatt power level converters for space applications are currently underway at the NASA Lewis Research Center. Innovative testing techniques will be required to evaluate the components and converters, when developed, at their rated power in the absence of costly power sources, loads, and cooling systems. Facilities capable of testing these components and systems at full power are available, but their use may be cost prohibitive. The use of a multiple pulse testing technique is proposed to determine the electrical characteristics of large megawatt level power systems. Characterization of a Mapham inverter is made using the proposed technique and conclusions are drawn concerning its suitability as an experimental tool to evaluate megawatt level power systems.

  13. Arc Plasma Synthesis of Nanostructured Materials: Techniques and Innovations

    SciTech Connect

    Das, A. K.; Bhoraskar, S. V.; Kakati, M.; Karmakar, Soumen

    2008-10-23

    Arc plasma aided synthesis of nanostructured materials has the potential of producing complex nano phase structures in bulk quantities. Successful implementation of this potential capability to industrial scale nano generation needs establishment of a plasma parameter control regime in terms of plasma gas, flow pattern, pressure, local temperature and the plasma fields to obtain the desired nano phase structures. However, there is a need to design innovative in situ experiments for generation of an extensive database and subsequently to correlate plasma parameters to the size, shape and phase of the generated nanostructures. The present paper reviews the various approaches utilized in the field of arc plasma nanosynthesis in general and in the authors' laboratories in particular. Simple plasma diagnostics and monitoring schemes have been used in conjunction with nano materials characterization tools to explore the possibility of controlling the size, shape, yield and phase composition of the arc generated nanostructures through plasma control. Case studies related to synthesis of AlN, Al2O3, TiO2, ZrO2, ZnO), magnetic (e.g. {gamma}-Fe2O3, Fe3O4) and single elemental materials (e.g. carbon nanotubes) are presented.

  14. SITE PROGRAM CURRENT AND FUTURE INNOVATIVE TECHNIQUES FOR GROUNDWATER TREATMENT

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) conducts research related to the demonstration and evaluation of innovative cleanup technologies. One of the mechanisms for the evaluation of innovative field-scale technologies for hazardous ...

  15. Optical Measurement Technique for Space Column Characterization

    NASA Technical Reports Server (NTRS)

    Barrows, Danny A.; Watson, Judith J.; Burner, Alpheus W.; Phelps, James E.

    2004-01-01

    A simple optical technique for the structural characterization of lightweight space columns is presented. The technique is useful for determining the coefficient of thermal expansion during cool down as well as the induced strain during tension and compression testing. The technique is based upon object-to-image plane scaling and does not require any photogrammetric calibrations or computations. Examples of the measurement of the coefficient of thermal expansion are presented for several lightweight space columns. Examples of strain measured during tension and compression testing are presented along with comparisons to results obtained with Linear Variable Differential Transformer (LVDT) position transducers.

  16. Techniques for Characterizing Microwave Printed Antennas

    NASA Technical Reports Server (NTRS)

    Simons, Rainee; Lee, Richard Q.

    2003-01-01

    The combination of a de-embedding technique and a direct on-substrate measurement technique has been devised to enable measurement of the electrical characteristics (impedances, scattering parameters, and gains) of microwave printed antennas that may be formed integrally with feed networks that include slot lines, coplanar striplines, and/or coplanar waveguides. The combination of techniques eliminates the need for custom test fixtures, including transitions between (1) coaxial or waveguide feed lines in typical test equipment and (2) the planar waveguide structures of the printed circuits under test. The combination of techniques can be expected to be especially useful for rapid, inexpensive, and accurate characterization of antennas for miniature wireless communication units that operate at frequencies from a few to tens of gigahertz.

  17. New characterization techniques for LSST sensors

    DOE PAGESBeta

    Nomerotski, A.

    2015-06-18

    Fully depleted, thick CCDs with extended infra-red response have become the sensor of choice for modern sky surveys. The charge transport effects in the silicon and associated astrometric distortions could make mapping between the sky coordinates and sensor coordinates non-trivial, and limit the ultimate precision achievable with these sensors. Two new characterization techniques for the CCDs, which both could probe these issues, are discussed: x-ray flat fielding and imaging of pinhole arrays.

  18. Enhanced Landfill Mining case study: Innovative separation techniques

    NASA Astrophysics Data System (ADS)

    Cuyvers, Lars; Moerenhout, Tim; Helsen, Stefan; Van de Wiele, Katrien; Behets, Tom; Umans, Luk; Wille, Eddy

    2014-05-01

    In 2011, a corporate vision on Enhanced Landfill Mining (ELFM)1 was approved by the OVAM Board of directors, which resulted in an operational programme over the period 2011-2015. OVAM (Public Waste Agency of Flanders) is the competent authority in charge of waste, Sustainable Materials Management (SMM) and contaminated soil management in Flanders. The introduction of the ELFM concept needs to be related with the concept of SMM and the broader shift to a circular economy. Within the concept of ELFM, landfills are no longer considered to be a final and static situation, but a dynamic part of the materials cycle. The main goal of this research programme is to develop a comprehensive policy on resource management to deal with the issue of former landfills. In order to investigate the opportunities of ELFM, the OVAM is applying a three step approach including mapping, surveying and mining of these former landfills. As a result of the mapping part over 2,000 landfill sites, that will need to be dealt with, were revealed. The valorisation potential of ELFM could be assigned to different goals, according to the R³P-concept : Recycling of Materials, Recovery of Energy, Reclamation of Land and Protection of drinking water supply. . On behalf of the OVAM, ECOREM was assigned to follow-up a pilot case executed on a former landfill, located in Zuienkerke, Flanders. Within this case study some technical tests were carried out on the excavated waste material to investigate the possibilities for a waste to resource conversion. The performance of both on site and off site techniques were evaluated. These testings also contribute to the mapping part of OVAM's research programme on ELFM and reveal more information on the composition of former landfills dating from different era's. In order to recover as many materials as possible, five contractors were assigned to perform separation tests on the bulk material from the Zuienkerke landfill. All used techniques were described

  19. UTILITY EXPERIENCE WITH INNOVATIVE WATER MAIN REHAB TECHNIQUES

    EPA Science Inventory

    All utilities are motivated to renew their aging infrastructure in the most efficient manner with respect to cost and minimal disruption to the community. American Water was given an opportunity to participate in an EPA funded project to demonstrate innovative water (and wastewa...

  20. Innovative green technique for preparing of flame retardant cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to its environmentally benign character, microwave-assisted or supercritical carbon dioxide high pressure reactors are considered in green chemistry as a substitute for organic solvents in chemical reactions. In this paper, an innovative approach for preparation of flame retardant cotton fabric ...

  1. The NLP Swish Pattern: An Innovative Visualizing Technique.

    ERIC Educational Resources Information Center

    Masters, Betsy J.; And Others

    1991-01-01

    Describes swish pattern, one of many innovative therapeutic interventions that developers of neurolinguistic programing (NLP) have contributed to counseling profession. Presents brief overview of NLP followed by an explanation of the basic theory and expected outcomes of the swish. Presents description of the intervention process and case studies…

  2. Distributive Marketing Education: Innovative Instructional Techniques in Distributive Marketing Education.

    ERIC Educational Resources Information Center

    Office of Education (DHEW), Washington, DC.

    The conference featured more than 40 presentations representing existing and planned innovative programs in all levels of distributive marketing education in six States. In addition to the presentations (not reproduced in their entirety in the report), there were sessions and workshops for secondary, post secondary, and adult levels and for city…

  3. INNOVATIONS IN EQUIPMENT AND TECHNIQUES FOR THE BIOLOGY TEACHING LABORATORY.

    ERIC Educational Resources Information Center

    BARTHELEMY, RICHARD E.; AND OTHERS

    LABORATORY TECHNIQUES AND EQUIPMENT APPROPRIATE FOR TEACHING BIOLOGICAL SCIENCE CURRICULUM STUDY BIOLOGY ARE EMPHASIZED. MAJOR CATEGORIES INCLUDE (1) LABORATORY FACILITIES, (2) EQUIPMENT AND TECHNIQUES FOR CULTURE OF MICRO-ORGANISMS, (3) LABORATORY ANIMALS AND THEIR HOUSING, (4) TECHNIQUES FOR STUDYING PLANT GROWTH, (5) TECHNIQUES FOR STUDYING…

  4. New Techniques in Characterization of Ferroelectric Materials

    NASA Technical Reports Server (NTRS)

    Sehirlioglu, Alp

    2008-01-01

    Two new techniques have been developed to characterize Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) based ferroelectric single crystals: (i) electro-thermal imaging, and (ii) single crystal x-ray diffraction in the transmission mode. (i) Electro-thermal imaging is a remote sensing technique that can detect the polarization direction and poling state of a whole crystal slice. This imaging technique utilizes an IR camera to determine the field induced temperature change and does not require any special or destructive sample preparation. In the resulting images it is possible to distinguish regions of 180 deg domains. This powerful technique can be used remotely during poling to determine the poling state of the crystal to avoid over-poling that can result in inferior properties and/or cracking of the crystals. Electro-thermal imaging produced the first direct observations of polarization rotation. Under bipolar field, the domains near the corners were the first to switch direction. As the field increased above the coercive field, domains at the center part of the crystals switched direction. (ii) X-ray diffraction in the transmission mode has long been used in structure determination of organic crystals and proteins; however, it is not used much to characterize inorganic systems. 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystals were examined by this XRD technique for the first time, and a never-before-seen super-lattice was revealed with a doubling of the unit cell in all three directions, giving a cell volume eight times that of a traditional perovskite unit cell. The significance of the super-lattice peaks increased with poling, indicating a structural contribution to ordering. Lack of such observations by electron diffraction in the transmission electron microscope examinations suggests the presence of a bulk effect.

  5. Techniques for physicochemical characterization of nanomaterials

    PubMed Central

    Lin, Ping-Chang; Lin, Stephen; Wang, Paul C.; Sridhar, Rajagopalan

    2014-01-01

    Advances in nanotechnology have opened up a new era of diagnosis, prevention and treatment of diseases and traumatic injuries. Nanomaterials, including those with potential for clinical applications, possess novel physicochemical properties that have an impact on their physiological interactions, from the molecular level to the systemic level. There is a lack of standardized methodologies or regulatory protocols for detection or characterization of nanomaterials. This review summarizes the techniques that are commonly used to study the size, shape, surface properties, composition, purity and stability of nanomaterials, along with their advantages and disadvantages. At present there are no FDA guidelines that have been developed specifically for nanomaterial based formulations for diagnostic or therapeutic use. There is an urgent need for standardized protocols and procedures for the characterization of nanoparticles, especially those that are intended for use as theranostics. PMID:24252561

  6. Measurement and characterization techniques for thermoelectric materials

    SciTech Connect

    Tritt, T.M.

    1997-07-01

    Characterization of thermoelectric materials can pose many problems. A temperature difference can be established across these materials as an electrical current is passed due to the Peltier effect. The thermopower of these materials is quite large and thus large thermal voltages can contribute to many of the measurements necessary to investigate these materials. This paper will discuss the chracterization techniques necessary to investigate these materials and provide an overview of some of the potential systematic errors which can arise. It will also discuss some of the corrections one needs to consider. This should provide an introduction to the characterization and measurement of thermoelectric materials and provide references for a more in depth discussion of the concepts. It should also serve as an indication of the care that must be taken while working with thermoelectric materials.

  7. Characterization techniques for incorporating backgrounds into DIRSIG

    NASA Astrophysics Data System (ADS)

    Brown, Scott D.; Schott, John R.

    2000-07-01

    The appearance of operation hyperspectral imaging spectrometers in both solar and thermal regions has lead to the development of a variety of spectral detection algorithms. The development and testing of these algorithms requires well characterized field collection campaigns that can be time and cost prohibitive. Radiometrically robust synthetic image generation (SIG) environments that can generate appropriate images under a variety of atmospheric conditions and with a variety of sensors offers an excellent supplement to reduce the scope of the expensive field collections. In addition, SIG image products provide the algorithm developer with per-pixel truth, allowing for improved characterization of the algorithm performance. To meet the needs of the algorithm development community, the image modeling community needs to supply synthetic image products that contain all the spatial and spectral variability present in real world scenes, and that provide the large area coverage typically acquired with actual sensors. This places a heavy burden on synthetic scene builders to construct well characterized scenes that span large areas. Several SIG models have demonstrated the ability to accurately model targets (vehicles, buildings, etc.) Using well constructed target geometry (from CAD packages) and robust thermal and radiometry models. However, background objects (vegetation, infrastructure, etc.) dominate the percentage of real world scene pixels and utilizing target building techniques is time and resource prohibitive. This paper discusses new methods that have been integrated into the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model to characterize backgrounds. The new suite of scene construct types allows the user to incorporate both terrain and surface properties to obtain wide area coverage. The terrain can be incorporated using a triangular irregular network (TIN) derived from elevation data or digital elevation model (DEM) data from actual

  8. Geologic flow characterization using tracer techniques

    SciTech Connect

    Klett, R. D.; Tyner, C. E.; Hertel, Jr., E. S.

    1981-04-01

    A new tracer flow-test system has been developed for in situ characterization of geologic formations. This report describes two sets of test equipment: one portable and one for testing in deep formations. Equations are derived for in situ detector calibration, raw data reduction, and flow logging. Data analysis techniques are presented for computing porosity and permeability in unconfined isotropic media, and porosity, permeability and fracture characteristics in media with confined or unconfined two-dimensional flow. The effects of tracer pulse spreading due to divergence, dispersion, and porous formations are also included.

  9. Waste minimization in analytical chemistry through innovative sample preparation techniques.

    SciTech Connect

    Smith, L. L.

    1998-05-28

    Because toxic solvents and other hazardous materials are commonly used in analytical methods, characterization procedures result in significant and costly amount of waste. We are developing alternative analytical methods in the radiological and organic areas to reduce the volume or form of the hazardous waste produced during sample analysis. For the radiological area, we have examined high-pressure, closed-vessel microwave digestion as a way to minimize waste from sample preparation operations. Heated solutions of strong mineral acids can be avoided for sample digestion by using the microwave approach. Because reactivity increases with pressure, we examined the use of less hazardous solvents to leach selected contaminants from soil for subsequent analysis. We demonstrated the feasibility of this approach by extracting plutonium from a NET reference material using citric and tartaric acids with microwave digestion. Analytical results were comparable to traditional digestion methods, while hazardous waste was reduced by a factor often. We also evaluated the suitability of other natural acids, determined the extraction performance on a wider variety of soil types, and examined the extraction efficiency of other contaminants. For the organic area, we examined ways to minimize the wastes associated with the determination of polychlorinated biphenyls (PCBs) in environmental samples. Conventional methods for analyzing semivolatile organic compounds are labor intensive and require copious amounts of hazardous solvents. For soil and sediment samples, we have a method to analyze PCBs that is based on microscale extraction using benign solvents (e.g., water or hexane). The extraction is performed at elevated temperatures in stainless steel cells containing the sample and solvent. Gas chromatography-mass spectrometry (GC/MS) was used to quantitate the analytes in the isolated extract. More recently, we developed a method utilizing solid-phase microextraction (SPME) for natural

  10. Photographic techniques for characterizing streambed particle sizes

    USGS Publications Warehouse

    Whitman, M.S.; Moran, E.H.; Ourso, R.T.

    2003-01-01

    We developed photographic techniques to characterize coarse (>2-mm) and fine (???2-mm) streambed particle sizes in 12 streams in Anchorage, Alaska. Results were compared with current sampling techniques to assess which provided greater sampling efficiency and accuracy. The streams sampled were wade-able and contained gravel - cobble streambeds. Gradients ranged from about 5% at the upstream sites to about 0.25% at the downstream sites. Mean particle sizes and size-frequency distributions resulting from digitized photographs differed significantly from those resulting from Wolman pebble counts for five sites in the analysis. Wolman counts were biased toward selecting larger particles. Photographic analysis also yielded a greater number of measured particles (mean = 989) than did the Wolman counts (mean = 328). Stream embeddedness ratings assigned from field and photographic observations were significantly different at 5 of the 12 sites, although both types of ratings showed a positive relationship with digitized surface fines. Visual estimates of embeddedness and digitized surface fines may both be useful indicators of benthic conditions, but digitizing surface fines produces quantitative rather than qualitative data. Benefits of the photographic techniques include reduced field time, minimal streambed disturbance, convenience of postfield processing, easy sample archiving, and improved accuracy and replication potential.

  11. Innovative Techniques for Teaching about Landslides and Triggered Landslide Events

    NASA Astrophysics Data System (ADS)

    Taylor, F. E.; Malamud, B. D.

    2014-12-01

    When we think of a landslide (mass wasting), both the public and scientists often envisage an individual movement of earth material down a slope. Yet, landslides often occur not as individuals, but as parts of a triggered landslide event. This is where a trigger (e.g., an earthquake or heavy rainfall) results in up to tens of thousands of landslides in a region in the minutes to days after the trigger. In this paper, we will present ideas for innovative demonstrations, teaching practicals and projects, ranging from low-cost low-tech to more advanced digital methods, to communicate the ideas of landslides and triggered landslide events to the public and students. This paper is aimed at those in secondary school/university education and the public sector looking for examples to interest and inform their respective audiences about landslides, triggered landslide events, and the importance and implications of considering landslides not just as individuals, but as populations.

  12. Innovative techniques to analyze time series of geomagnetic activity indices

    NASA Astrophysics Data System (ADS)

    Balasis, Georgios; Papadimitriou, Constantinos; Daglis, Ioannis A.; Potirakis, Stelios M.; Eftaxias, Konstantinos

    2016-04-01

    Magnetic storms are undoubtedly among the most important phenomena in space physics and also a central subject of space weather. The non-extensive Tsallis entropy has been recently introduced, as an effective complexity measure for the analysis of the geomagnetic activity Dst index. The Tsallis entropy sensitively shows the complexity dissimilarity among different "physiological" (normal) and "pathological" states (intense magnetic storms). More precisely, the Tsallis entropy implies the emergence of two distinct patterns: (i) a pattern associated with the intense magnetic storms, which is characterized by a higher degree of organization, and (ii) a pattern associated with normal periods, which is characterized by a lower degree of organization. Other entropy measures such as Block Entropy, T-Complexity, Approximate Entropy, Sample Entropy and Fuzzy Entropy verify the above mentioned result. Importantly, the wavelet spectral analysis in terms of Hurst exponent, H, also shows the existence of two different patterns: (i) a pattern associated with the intense magnetic storms, which is characterized by a fractional Brownian persistent behavior (ii) a pattern associated with normal periods, which is characterized by a fractional Brownian anti-persistent behavior. Finally, we observe universality in the magnetic storm and earthquake dynamics, on a basis of a modified form of the Gutenberg-Richter law for the Tsallis statistics. This finding suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism. Signatures of discrete scale invariance in Dst time series further supports the aforementioned proposal.

  13. Denture bar-coding: An innovative technique in forensic dentistry

    PubMed Central

    Dineshshankar, Janardhanam; Venkateshwaran, Rajendran; Vidhya, J.; Anuradha, R.; Mary, Gold Pealin; Pradeep, R.; Senthileagappan, A. R.

    2015-01-01

    Denture markers play an important role in forensic odontology and also in identifying a person. A number of methods are there for identifying dentures from a less expensive technique to a more expensive technique. Out of different denture markers, the bar-coding system is a way of collecting data from the mobile. Even a huge amount of data can be stored in that. It can be easily incorporated during acrylization of the denture and thus could be helpful in identification. This article reviews the strengths of bar-coding and how easily it can be used in the routine procedure. PMID:26538876

  14. Current Trends and Innovations in Bioanalytical Techniques of Metabolomics.

    PubMed

    Zhang, Tianlei; Zhang, Aihua; Qiu, Shi; Yang, Suqing; Wang, Xijun

    2016-07-01

    The advancement of omics technology has vigorously promoted the development of the life sciences; metabolomics in particular has emerged as a powerful tool that has a promising future in scientific research and clinical practice. As terminal products of complex biochemical networks, endogenous low-molecular-weight metabolites contain rich information about the physiological status of an individual or group of people. Also, this information has more practical significance in that we know "what happened" instead of "what might happen" to some degree. Rapid and accurate screening of metabolites on a large scale was beyond imagining in the past; however, benefiting from high-throughput technical means, the overall disturbance of metabolites induced by environmental stimulus or treatments can now be well analyzed. After appropriate bioinformatic analysis, clinically relevant biomarkers of a disease can be found, and an accurate and dynamic picture of metabolic disturbance that contributes to a phenotype of a certain organism can be constructed. Biomarkers can also reveal the general metabolic condition by pathways that correlate with disease progression, or even with the risk of certain diseases. Thus, as an indispensable part of the framework of systems biology, metabolomics has been widely used in, but not limited to, the fields of medical science, pharmaceuticals, botany, and microbiology. In this article, we focus on metabolomics' mainstream research content and technical innovations such as determination methods for biologically active compounds; further, we pay more attention to the future trends and various possibilities for metabolomics study. PMID:26337255

  15. Comparison of Traditional and Innovative Techniques to Solve Technical Challenges

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele

    2010-01-01

    Although NASA has an adequate food system for current missions, research is required to accommodate new requirements for future NASA exploration missions. The Inadequate Food System risk reflects the need to develop requirements and technologies that will enable NASA to provide the crew with a safe, nutritious and acceptable food system while effectively balancing appropriate resources such as mass, volume, and crew time in exploratory missions. As we go deeper into space or spend more time on the International Space Station (ISS), there will be requirements for packaged food to be stored for 3 5 years. New food packaging technologies are needed that have adequate oxygen and water barrier properties to maintain the foods' quality over this extended shelf life. NASA has been unsuccessful in identify packaging materials that meet the necessary requirements when using several traditional routes including literature reviews, workshops, and internal shelf life studies on foods packaged in various packaging materials. Small Business Innovative Research grants were used for accelerating food packaging materials research with limited success. In order to accelerate the process, a theoretical challenge was submitted to InnoCentive resulting in a partial award. A similar food packaging challenge was submitted to Yet2.com and several potential commercial packaging material suppliers were identified that, at least partially, met the requirements. Comparisons and results of these challenges will be discussed.

  16. Filtrates and Residues: Gel Filtration--An Innovative Separation Technique.

    ERIC Educational Resources Information Center

    Blumenfeld, Fred; Gardner, James

    1985-01-01

    Gel filtration is a form of liquid chromatography that separates molecules primarily on the basis of their size. Advantages of using this technique, theoretical aspects, and experiments (including procedures used) are discussed. Several questions for students to answer (with answers) are also provided. (JN)

  17. INNOVATIVE TECHNIQUE TO EVALUATE LINT CLEANER GRID BAR DESIGNS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Photographic techniques were used to show the path that fibers attached to a gin saw take as they are drawn over a lint cleaner cleaning grid bar. A 1979 study showed that fibers were swept backwards, closer to the saw, as saw speed increased. The angle between the tip of the saw tooth and the fib...

  18. Innovative Reactive and Proactive Graduate Student Recruiting Techniques.

    ERIC Educational Resources Information Center

    Laird, Hugh E., II

    1989-01-01

    The evolution of the recruiting techniques used by the University of Arizona's pharmacology and toxicology graduate program are described, considerations in the development of recruitment efforts are discussed, and issues for the profession to examine in developing a long-term strategy for recruiting students are outlined. (MSE)

  19. X-ray techniques for innovation in industry

    PubMed Central

    Lawniczak-Jablonska, Krystyna; Cutler, Jeffrey

    2014-01-01

    The smart specialization declared in the European program Horizon 2020, and the increasing cooperation between research and development found in companies and researchers at universities and research institutions have created a new paradigm where many calls for proposals require participation and funding from public and private entities. This has created a unique opportunity for large-scale facilities, such as synchrotron research laboratories, to participate in and support applied research programs. Scientific staff at synchrotron facilities have developed many advanced tools that make optimal use of the characteristics of the light generated by the storage ring. These tools have been exceptionally valuable for materials characterization including X-ray absorption spectroscopy, diffraction, tomography and scattering, and have been key in solving many research and development issues. Progress in optics and detectors, as well as a large effort put into the improvement of data analysis codes, have resulted in the development of reliable and reproducible procedures for materials characterization. Research with photons has contributed to the development of a wide variety of products such as plastics, cosmetics, chemicals, building materials, packaging materials and pharma. In this review, a few examples are highlighted of successful cooperation leading to solutions of a variety of industrial technological problems which have been exploited by industry including lessons learned from the Science Link project, supported by the European Commission, as a new approach to increase the number of commercial users at large-scale research infrastructures. PMID:25485139

  20. Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques

    NASA Technical Reports Server (NTRS)

    Goodman, John L.; Walker, Stephen R.

    2009-01-01

    Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.

  1. Innovative, Inexpensive Etching Technique Developed for Polymer Electro- Optical Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.

    1999-01-01

    Electro-optic, polymer-based integrated optic devices for high-speed communication and computing applications offer potentially significant advantages over conventional inorganic electro-optic crystals. One key area of integrated optical technology--primary processing and fabrication--may particularly benefit from the use of polymer materials. However, as efforts concentrate on the miniaturization of electro-integrated circuit pattern geometries, the ability to etch fine features and smoothly sloped sidewalls is essential to make polymers useful for electro-integrated circuit applications. There are many existing processes available to etch polymer materials, but they all yield nearly vertical sidewalls. Vertical sidewalls are too difficult to reliably cover with a metal layer, and incomplete metalization degrades microwave performance, particularly at high frequency. However, obtaining a very sloped sidewall greatly improves the deposition of metal on the sidewall, leading to low-loss characteristics, which are essential to integrating these devices in highspeed electro-optic modulators. The NASA Lewis Research Center has developed in-house an inexpensive etching technique that uses a photolithography method followed by a simple, wet chemical etching process to etch through polymer layers. In addition to being simpler and inexpensive, this process can be used to fabricate smoothly sloped sidewalls by using a commercial none rodible mask: Spin-On-Glass. A commercial transparent material, Spin-On-Glass, uses processes and equipment similar to that for photoresist techniques.

  2. Innovative Seismological Techniques for Investigating the Interior Structure of Venus

    NASA Astrophysics Data System (ADS)

    Stevenson, D. J.; Cutts, J. A.; Mimoun, D.

    2014-12-01

    The formation, evolution and structure of Venus remain a mystery more than fifty years after the first visit by a robotic spacecraft. Radar images have revealed a surface that is much younger than those of the Moon, Mercury and Mars as well as a variety of enigmatic volcanic and tectonic features quite unlike those generated by plate tectonics on Earth. To understand how Venus works as a planet it is necessary to probe the interior of Venus. To accomplish this seismology must play a key role. Conventional seismology employs sensors in contact with the planetary surface but for Venus theses sensors must tolerate the Venus environment (460oC and 90 bars) for up to a year. The dense atmosphere of Venus, which efficiently couples seismic energy into the atmosphere as infrasonic waves, enables an alternative: detection of infrasonic waves in the upper atmosphere using either high altitude balloons or orbiting spacecraft. In June 2014, the Keck Institute for Space Studies (KISS) at the California Institute of Technology sponsored a one week workshop with 30 specialists in the key techniques and technologies that can bring these technique to readiness. In this paper, we describe the key synergies with earth science drawing on methods from terrestrial seismology and oceanography and identify key technical issues that need to be solved as well as important precursor measurements that should be made.

  3. DEPLOYMENT OF INNOVATIVE CHARACTERIZATION TECHNOLOGIES AND IMPLEMENTATION OF THE MARSSIM PROCESS AT RADIOLOGICALLY CONTAMINATED SITES.

    SciTech Connect

    KALB,P.D.; MILIAN,L.; LUCKETT,L.; WATTERS,D.; MILLER,K.M.; GOGOLAK,C.

    2001-05-01

    The success of this Accelerated Site Technology Deployment (ASTD) project is measured on several levels. First, the deployment of this innovative approach using in situ characterization, portable field laboratory measurements, and implementation of MARSSIM was successfully established for all three phases of D and D characterization, i.e., pre-job scoping, on-going disposition of waste, and final status surveys upon completion of the activity. Unlike traditional D and D projects, since the Brookhaven Graphite Research Reactor Decommissioning Project (BGRR-DP) is operating on an accelerated schedule, much of the work is being carried out simultaneously. Rather than complete a full characterization of the facility before D and D work begins, specific removal actions require characterization as the activity progresses. Thus, the need for rapid and cost-effective techniques for characterization is heightened. Secondly, since the approach used for this ASTD project was not thoroughly proven prior to deployment, a large effort was devoted to demonstrating technical comparability to project managers, regulators and stakeholders. During the initial phases, large numbers of replicate samples were taken and analyzed by conventional baseline techniques to ensure that BGRR-DP quality assurance standards were met. ASTD project staff prepared comparisons of data gathered using ISOCS and BetaScint with traditional laboratory methods and presented this information to BGRR-DP staff and regulators from EPA Region II, NYS Department of Environmental Conservation, and the Suffolk County Board of Health. As the results of comparability evaluations became available, approval for these methods was received and the techniques associated with in situ characterization, portable field laboratory measurements, and implementation of MARSSIM were gradually integrated into BGRR-DP procedures.

  4. Innovative Visualization Techniques applied to a Flood Scenario

    NASA Astrophysics Data System (ADS)

    Falcão, António; Ho, Quan; Lopes, Pedro; Malamud, Bruce D.; Ribeiro, Rita; Jern, Mikael

    2013-04-01

    The large and ever-increasing amounts of multi-dimensional, time-varying and geospatial digital information from multiple sources represent a major challenge for today's analysts. We present a set of visualization techniques that can be used for the interactive analysis of geo-referenced and time sampled data sets, providing an integrated mechanism and that aids the user to collaboratively explore, present and communicate visually complex and dynamic data. Here we present these concepts in the context of a 4 hour flood scenario from Lisbon in 2010, with data that includes measures of water column (flood height) every 10 minutes at a 4.5 m x 4.5 m resolution, topography, building damage, building information, and online base maps. Techniques we use include web-based linked views, multiple charts, map layers and storytelling. We explain two of these in more detail that are not currently in common use for visualization of data: storytelling and web-based linked views. Visual storytelling is a method for providing a guided but interactive process of visualizing data, allowing more engaging data exploration through interactive web-enabled visualizations. Within storytelling, a snapshot mechanism helps the author of a story to highlight data views of particular interest and subsequently share or guide others within the data analysis process. This allows a particular person to select relevant attributes for a snapshot, such as highlighted regions for comparisons, time step, class values for colour legend, etc. and provide a snapshot of the current application state, which can then be provided as a hyperlink and recreated by someone else. Since data can be embedded within this snapshot, it is possible to interactively visualize and manipulate it. The second technique, web-based linked views, includes multiple windows which interactively respond to the user selections, so that when selecting an object and changing it one window, it will automatically update in all the other

  5. The Elnady Technique: An innovative, new method for tissue preservation.

    PubMed

    Elnady, Fawzy A

    2016-01-01

    At the Faculty of Veterinary Medicine, Cairo University, there is an increasing number of students but a limited availability of animal cadavers used for dissection, and student exposure to formalin is a known hazard. In order to address these challenges, a new method for tissue preservation was developed, the "Elnady Technique." This method is a modified form of plastination, where the chemicals used are not patented, are inexpensive and locally available, and the process is performed at room temperature. The produced specimens are realistic, durable, have no offensive odor, and are dry, soft and flexible. They can be used to replace the use of animals killed for teaching basic anatomy, embryology, pathology, parasitology and forensic medicine. They have great potential to support training in clinical skills and surgery, including for clinical examination, endoscopy, surgical sutures, and obstetrics simulation. PMID:26821550

  6. Innovative techniques for sampling stream-inhabiting salamanders

    SciTech Connect

    T.M. Luhring; C.A. Young

    2006-01-01

    Although salamanders are excellent indicators of environmental health, the ability to catch them efficiently without substantially disrupting their habitat is not always practical or even possible with current techniques. Ripping open logs and raking leaf packs onto shore (Bruce 1972) are examples of such practices that are disruptive but widely used by herpetologists who have no other means of efficient collection. Drift fences with pitfall traps are effective in catching animals moving within or between habitats but are time consuming and require an initial financial investment and constant upkeep to maintain functionality and prevent animal fatalities (Gibbons and Semlitsch 1981). One current alternative to drift fences is the use of coverboards (Grant et al. 1992), which require less maintenance and sampling effort than drift fences. However, coverboards do not integrate captures over a long time period and often result in a lower number of captures per trap (Grant et al. 1992).

  7. The innovative application of surface geophysical techniques for remedial investigations

    SciTech Connect

    Saunders, W.R.; Smith, S.; Gilmore, P.; Cox, S.

    1993-03-01

    When researchers are investigating potential subsurface contamination at hazardous waste landfills, the surface geophysical techniques they may use are often limited. Many geophysical surveys are concerned with areas next to and not directly within the landfill units. The highly variable properties of the materials within the landfill may result in geophysical data that are either difficult or impossible to interpret. Therefore, contamination at these sites may not be detected until substantial lateral migration away from the unit has occurred. In addition, because of the poor resolution of some techniques, the landfill as a whole must be considered as a source, where discrete disposal areas within landfill units may be the actual point sources of contaminants. In theory, if specific sources within the landfill are identified and isolated, then reduced time, effort, and expenditures will be required for remediation activities. In the summer of 1989, the Idaho National Engineering Laboratory (INEL) investigated a small potentially hazardous waste landfill to determine if contaminant hot spots could be identified within the landfill and to determine if significant vertical and lateral migration of contaminants was occurring away from these locations. Based on the present hydrogeologic conditions, researchers anticipated that subsurface flow would be primarily vertical, with the zone of saturation at a depth greater than 150 meters. This necessitated that the survey be performed, for the most part, directly on the capped portion of the landfill. Focused geophysical surveys conducted off the landfill would not have provided useful information concerning conditions directly beneath the landfill. This paper discusses the planning, application, and analysis of four combined sensing methods: two methods of electromagnetic induction [low induction (Em) and time domain (TEM)], ground penetrating radar (GPR), and soil gas.

  8. Innovative technology summary report: mobile automated characterization system

    SciTech Connect

    1999-04-01

    The Mobile Automated Characterization System (MACS) has been developed by Oak Ridge National Laboratory (ORNL) and the Savannah River Technology Center (SRTC) for the U.S. Department of Energy's (DOE) Robotics Technology Development Program as an automated floor surface contamination characterization system. MACS was designed for use by Health Physics (HP) personnel in the performance of floor surveys of known or suspected contaminated areas, to be used during any floor characterization task which has significant open areas requiring radiological surveys. MACS was designed to automate the collection, storage and analysis of large, open floor areas, relieving the HP personnel of this portion of the floor characterization task. MACS does not require a dedicated full time operator and can be setup by the normal HP staff to survey the open areas while other techniques are used on the more constrained areas. The HP personnel performing the other characterization activities can monitor the MACS progress and address any problems encountered by MACS during survey operations. MACS is designed for unattended operation and has safety and operational monitoring functions which will safely shut the system down if any difficulties are encountered. During survey operations, MACS generates a map of surveyed areas with color-coding indicating radiation levels. This map is displayed on the control console monitor during operation and can be printed for survey result documentation. MACS produces data files containing data for all sensors used during a survey, providing a complete record of samples taken and contamination levels found for all areas traversed during a survey. This data can be processed to produce tabular output of the survey results.

  9. Characterizing odors from cattle feedlots with different odor techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odors from cattle feedlots negatively affect local communities. The purpose of this study was to characterize odors and odorants using different odor sampling techniques. Odors were characterized with field olfactometers (Nasal Ranger®), sensory techniques (GC-O) and analytical techniques (sorbent t...

  10. Innovative site characterization demonstration saves time and money

    SciTech Connect

    Floran, R.J.; Bujewski, G.E.; Johnson, R.L.

    1995-02-01

    A technology demonstration that optimizes sampling strategies and real-time data collection was carried out at the Kirtland Air Force Base RB-11 Radioactive Burial Site, Albuquerque, New Mexico in August 1994. The project, which was funded by the Strategic Environmental Research and Development Program (SERDP), involved the application of a geostatistical-based {open_quotes}smart sampling{close_quotes} methodology and software with on-site field screening of soils for radiation, organic compounds and metals. The software, known as Plume{trademark}, was developed at Argonne National Laboratory as part of the DOE/OTD-funded Mixed Waste Landfill Integrated Demonstration (MWLID). The objective of the investigation was to compare an innovative Adaptive Sampling approach that stressed real-time decision-making with a conventional RCRA-driven site characterization carried out by the Air Force. The latter investigation used a standard drilling and sampling plan as mandated by the EPA. To make the comparison realistic, the same contractors and sampling equipment (Geoprobe{reg_sign} soil samplers) were used. In both investigations, soil samples were collected at several depths at numerous locations adjacent to burial trenches that contain low-level radioactive waste and animal carcasses. Neither study revealed the presence of contaminants appreciably above risk based action levels, indicating that minimal to no migration has occurred away from the trenches. The combination of Adaptive Sampling with field screening achieved a similar level of confidence compared to the RCRA investigation regarding the potential migration of contaminants at the site. By comparison, the Adaptive Sampling program drilled 28 locations (vs. 36 for the conventional investigation), collected 81 samples (vs. 163), and sent 15 samples (vs. 163) off-site for laboratory analysis. In addition, the field work took 3 1/2 days compared to 13 days for the RCRA investigation.

  11. Innovative directional and position specific sampling technique (POLO). Innovative technology summary report

    SciTech Connect

    Not Available

    1999-06-01

    The UTD Inc. Position Location (POLO) device is used for identifying the position of characterization sensors in the subsurface. POLO fits within a cone penetrometer rod to quickly and cost-effectively identify sample location, rod tip location, and track the rod path. UTD demonstrated the POLO device at a private site in Virginia and at the DOE Savannah River Site in South Carolina. Results show POLO as accurate as any alternative approach at less than 0.50% error, and at a fraction of the cost. POLO can be used in close proximity to tanks, pipelines, and buildings with greatly reduced risk of puncture and resulting spills--a major improvement over current approaches. POLO only adds about 4% to cost of penetrometer use.

  12. Photogrammetric detection technique for rotor blades structural characterization

    NASA Astrophysics Data System (ADS)

    Enei, C.; Bernardini, G.; Serafini, J.; Mattioni, L.; Ficuciello, C.; Vezzari, V.

    2015-11-01

    This paper describes an innovative use of photogrammetric detection techniques to experimentally estimate structural/inertial properties of helicopter rotor blades. The identification algorithms for the evaluation of mass and flexural stiffness distributions are an extension of the ones proposed by Larsen, whereas the procedure for torsional properties determination (stiffness and shear center position) is based on the Euler-Prandtl beam theory. These algorithms rely on measurements performed through photogrammetric detection, which requires the collection of digital photos allowing the identification of 3D coordinates of labeled points (markers) on the structure through the correlation of 2D pictures. The displacements are evaluated by comparing the positions of markers in loaded and reference configuration. Being the applied loads known, the structural characteristics can be directly obtained from the measured displacements. The accuracy of the proposed identification algorithms has been firstly verified by comparison with numerical and experimental data, and then applied to the structural characterization of two main rotor blades, designed for ultra-light helicopter applications.

  13. Innovative techniques for the description of reservoir heterogeneity using tracers. Final report, October 1992--December 1993

    SciTech Connect

    Pope, G.A.; Sepehrnoori, K.; Delshad, M.; Ferreira, L.; Gupta, A.; Maroongroge, V.

    1994-11-01

    This is the final report of a three year research project on the use of tracers for reservoir characterization. The objective of this research was to develop advanced, innovative techniques for the description of reservoir characteristics using both single-well backflow and interwell tracer tests. (1) The authors implemented and validated tracer modeling features in a compositional simulator (UTCOMP). (2) They developed and applied a new single well tracer test for estimating reservoir heterogeneity. (3) They developed and applied a new single well tracer test for estimating reservoir wettability in-situ. (4) They developed a new, simple and efficient method to analyze two well tracer tests based upon type curve matching and illustrated its use with actual field tracer data. (5) They developed a new method for deriving an integrated reservoir description based upon combinatorial optimization schemes. (6) They developed a new, interwell tracer test for reservoir heterogeneity called vertical tracer profiling (VTP) and demonstrated its advantages over conventional interwell tracer testing. (7) They developed a simple and easy analytical method to estimate swept pore volume from interwell tracer data and showed both the theoretical basis for this method and its practical utility. (8) They made numerous enhancements to our compositional reservoir simulator such as including the full permeability tensor, adding faster solvers, improving its speed and robustness and making it easier to use (better I/0) for tracer simulation problems. (9) They applied the enhanced version of UTCOMP to the analysis of interwell tracer data using perfluorocarbons at Elks Hill Naval Petroleum Reserve. All of these accomplishments taken together have significantly improved the state of reservoir tracer technology and have demonstrated that it is a far more powerful and useful tool for quantitative reservoir characterization than previously realized or practiced by the industry.

  14. SUPERFUND INNOVATIVE TECHNOLOGIES EVALUATION (SITE) PROGRAM FOR MONITORING AND CHARACTERIZATION TECHNOLOGIES

    EPA Science Inventory

    This task seeks to identify high priority needs of the Regions and Program Offices for innovative field sampling, characterization, monitoring, and measurement technologies. When an appropriate solution to a specific problem is identified, a field demonstration is conducted to d...

  15. Innovators.

    ERIC Educational Resources Information Center

    NEA Today, 2001

    2001-01-01

    Describes various innovations that have been developed to enhance education. These innovations include: helping educators help at-risk students succeed; promoting high school journalism; ensuring quality online learning experiences; developing a student performing group that uses theater to address social issues; and having students design their…

  16. Electrokinetic characterization techniques for contaminated soils

    SciTech Connect

    Eykholt, G.R.; Hung, H.

    1995-12-31

    One important element to the success of electrokinetic remediation of contaminated soils may be the assessment and control of the soil surface chemistry. This is usually reflected by an operative zeta-potential or electroosmotic coefficient, k{sub eo}, found by an electroosmosis test on a plug of contaminated soil. However, several researchers have shown that both the magnitude and uniformity of k{sub eo} change over the course of testing, as does the electric field intensity and zeta-potential, two basic parameters of the fundamental driving force. The electric field intensity can be measured during the test, but it is more difficult to assess the zeta potential. Independent techniques are needed. A conventional technique is dilute electrophoresis, but this test may not be truly representative or convenient. In this research summary, alternative techniques based on electroacoustic phenomena are presented in conjunction with other electrokinetic tests on reference and contaminated soils.

  17. Characterizing Hyperspectral Imagery (AVIRIS) Using Fractal Technique

    NASA Technical Reports Server (NTRS)

    Qiu, Hong-Lie; Lam, Nina Siu-Ngan; Quattrochi, Dale

    1997-01-01

    With the rapid increase in hyperspectral data acquired by various experimental hyperspectral imaging sensors, it is necessary to develop efficient and innovative tools to handle and analyze these data. The objective of this study is to seek effective spatial analytical tools for summarizing the spatial patterns of hyperspectral imaging data. In this paper, we (1) examine how fractal dimension D changes across spectral bands of hyperspectral imaging data and (2) determine the relationships between fractal dimension and image content. It has been documented that fractal dimension changes across spectral bands for the Landsat-TM data and its value [(D)] is largely a function of the complexity of the landscape under study. The newly available hyperspectral imaging data such as that from the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) which has 224 bands, covers a wider spectral range with a much finer spectral resolution. Our preliminary result shows that fractal dimension values of AVIRIS scenes from the Santa Monica Mountains in California vary between 2.25 and 2.99. However, high fractal dimension values (D > 2.8) are found only from spectral bands with high noise level and bands with good image quality have a fairly stable dimension value (D = 2.5 - 2.6). This suggests that D can also be used as a summary statistics to represent the image quality or content of spectral bands.

  18. Development of innovative techniques and principles that may be used as models to improve plant performance

    SciTech Connect

    Hanna, W.W.; Burton, G.W.

    1989-06-01

    Plant breeding has made possible a large portion of the record yields of our major food crops, and can claim credit for at least half of their increased yield. It can continue to do this but the population explosion demands that it be done in less time. Innovative techniques must be developed. The purpose of this research is: to develop techniques and principles of transferring germplasm from the primary, secondary, and tertiary gene pools of the wild species to cultivated species and evaluate the transferred germplasm; to evaluate diverse cytoplasms from wild species in isogenic lines to detect cytoplasmic effects on agronomic characteristics; and to develop an obligate apomictic pearl millet. 32 refs.

  19. Innovative analytical tools to characterize prebiotic carbohydrates of functional food interest.

    PubMed

    Corradini, Claudio; Lantano, Claudia; Cavazza, Antonella

    2013-05-01

    Functional foods are one of the most interesting areas of research and innovation in the food industry. A functional food or functional ingredient is considered to be any food or food component that provides health benefits beyond basic nutrition. Recently, consumers have shown interest in natural bioactive compounds as functional ingredients in the diet owing to their various beneficial effects for health. Water-soluble fibers and nondigestible oligosaccharides and polysaccharides can be defined as functional food ingredients. Fructooligosaccharides (FOS) and inulin are resistant to direct metabolism by the host and reach the caecocolon, where they are used by selected groups of beneficial bacteria. Furthermore, they are able to improve physical and structural properties of food, such as hydration, oil-holding capacity, viscosity, texture, sensory characteristics, and shelf-life. This article reviews major innovative analytical developments to screen and identify FOS, inulins, and the most employed nonstarch carbohydrates added or naturally present in functional food formulations. High-performance anion-exchange chromatography with pulsed electrochemical detection (HPAEC-PED) is one of the most employed analytical techniques for the characterization of those molecules. Mass spectrometry is also of great help, in particularly matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), which is able to provide extensive information regarding the molecular weight and length profiles of oligosaccharides and polysaccharides. Moreover, MALDI-TOF-MS in combination with HPAEC-PED has been shown to be of great value for the complementary information it can provide. Some other techniques, such as NMR spectroscopy, are also discussed, with relevant examples of recent applications. A number of articles have appeared in the literature in recent years regarding the analysis of inulin, FOS, and other carbohydrates of interest in the field and

  20. Female stress urinary incontinence: standard techniques revisited and critical evaluation of innovative techniques

    NASA Astrophysics Data System (ADS)

    de Riese, Cornelia; de Riese, Werner T. W.

    2003-06-01

    Objectives: The treatment of female urinary incontinence (UI) is a growing health care concern in our aging society. Publications of recent innovations and modifications are creating expectations. This brief review provides some insight and structure regarding indications and expected outcomes for the different approaches. Materials: Data extraction is part of a Medline data base search, which was performed for "female stress incontinence" from 1960 until 2000. Additional literature search was performed to cover 2001 and 2002. Outcome data were extracted. Results: (1) INJECTION OF BULKING AGENTS (collagen, synthetic agents): The indication for mucosal coaptation was more clearly defined and in the majority of articles limited to ISD. (2) OPEN COLPOSUSPENSION (Burch, MMK): Best long-term results of all operative procedures, to date considered the gold standard. (3) LAPAROSCOPIC COLPOSUSPENSION (different modifications): Long-term success rates appear dependent on operator skills. There are few long-term data. (4) NEEDLE SUSPENSION: (Stamey, Pareyra and modifications): Initial results were equal to Burch with less morbidity, but long-term success rates are worse. (5) SLING PROCEDURES (autologous, synthetic, allogenic graft materials, different modes of support and anchoring, free tapes): The suburethral sling has traditionally been considered a procedure for those in whom suspension had failed and for those with severe ISD. The most current trend shows its use as a primary procedure for SUI. Long-term data beyond 5 years are insufficient. (6) EXTERNAL OCCLUSIVE DEVICES (vaginal sponges and pessaries, urethral insert): Both vaginal and urethral insert devices can be effective in selected patients. (7) IMPLANTABLE ARTEFICIAL URETHRAL SPHINCTERS: Modifications and improvements of the devices resulted in improved clinical results regarding durability and efficacy. CONCLUSION: (1) The Burch colposuspension is still considered the gold standard in the treatment of female

  1. Remote Underwater Characterization System - Innovative Technology Summary Report

    SciTech Connect

    Willis, W D

    1999-04-01

    Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available "Scallop" vehicle 1 , but has been modified by the Department of Energy's Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a "head-to-head" fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations.

  2. Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases

    PubMed Central

    Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis

    2016-01-01

    India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease. PMID:27284221

  3. Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases.

    PubMed

    Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis

    2016-05-01

    India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease. PMID:27284221

  4. Remote Underwater Characterization System - Innovative Technology Summary Report

    SciTech Connect

    Willis, Walter David

    1999-04-01

    Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The underwater characterization equipment is often required to operate at depths exceeding 20 ft (6.1 m) and in relatively confined or congested spaces. The typical baseline approach has been the use of radiation detectors and underwater cameras mounted on long poles, or stationary cameras with pan and tilt features mounted on the sides of the underwater facility. There is a perceived need for an inexpensive, more mobile method of performing close-up inspection and radiation measurements in confined spaces underwater. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available “Scallop” vehicle1, but has been modified by Department of Energy’s Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at Idaho National Engineering and environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a “head-tohead” fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations.

  5. Innovative sputtering techniques for CIS and CdTe submodule fabrication

    SciTech Connect

    Armstrong, J.M.; Misra, M.S.; Lanning, B. . Astronautics Group)

    1993-03-01

    This report describes work done during Phase 1 of the subject subcontract. The subcontract was designed to study innovative deposition techniques, such as the rotating cylindrical magnetron sputtering system and electrodeposition for large-area, low-cost copper indium diselenide (CIS) and cadmium telluride (CdTe) devices. A key issue for photovoltaics (PV) in terrestrial and future space applications is producibility, particularly for applications using a large quantity of PV. Among the concerns for fabrication of polycrystalline thin-film PV, such as CIS and CdTe, are production volume, cost, and minimization of waste. Both rotating cylindrical magnetron (C-Mag[trademark]) sputtering and electrodeposition have tremendous potential for the fabrication of polycrystalline thin-film PV due to scaleability, efficient utilization of source materials, and inherently higher deposition rates. In the case of sputtering, the unique geometry of the C-Mae facilitates innovative cosputtering and reactive sputtering that could lead to greater throughput reduced health and safety risks, and, ultimately, lower fabrication cost. Electrodeposited films appear to be adherent and comparable with low-cost fabrication techniques. Phase I involved the initial film and device fabrication using the two techniques mentioned herein. Devices were tested by both internal facilities, as well as NREL and ISET.

  6. Innovative techniques in preventing and salvaging neurovascular pedicle flaps in reconstructive foot and ankle surgery.

    PubMed

    Zgonis, Thomas; Stapleton, John J

    2008-04-01

    Pedicle flaps to cover soft tissue defects of the foot, ankle, and lower extremity are invaluable. However, venous congestion and flap necrosis, a common complication, poses greater morbidity to the patient as few remaining options for attempted limb salvage remain. The authors discuss how to prevent flap failure by allowing close observation and strict offloading of the pedicle flap through current external fixation designs. This article also discusses the role of medicinal leeches in reestablishing blood flow through the pedicle flap to prevent tissue necrosis. In addition, the use of hydrosurgery as an innovative technique offers the surgeon another option if faced with pedicle flap necrosis. PMID:19825700

  7. An Innovative Application for SMOS: Characterization of Seasonal Soil Freezing

    NASA Astrophysics Data System (ADS)

    Rautiainen, Kimmo; Lemmetyinen, Juha; Schwank, Mike; Pulliainen, Jouni; Mätzler, Christian; Kontu, Anna; Wiesmann, Andreas

    2013-04-01

    Soil freezing and thawing, including the winter-time evolution of soil frost, are important characteristics influencing hydrological and climate processes at the regions of seasonal frost and permafrost, which include major land areas of North America and northern Eurasia. Changes in the seasonal behaviour of soil frost have a major effect on the surface energy balance, as well as on the intensity of CO2 and CH4 fluxes. The monitoring of seasonal frost and the permafrost active layer is currently based mostly on sparse in-situ observations. Some research using satellite observations for global and continuous coverage has been conducted in the past using active and passive microwave data. The European Space Agency's (ESA) SMOS satellite (Soil Moisture and Ocean Salinity) is the first passive instrument using a low microwave frequency band (1.403 - 1.424 GHz) for Earth remote sensing. The output signal of the SMOS payload instrument MIRAS (Microwave Imaging Radiometer with Aperture Synthesis) is highly sensitive to changes in soil permittivity (i.e. soil liquid water content), with relatively low influence of surface vegetation. Due to the instrument's low operating frequency, information on the soil processes can be achieved from deeper layers than from previously available satellite instruments. SMOS sensitivity to changes in soil permittivity and the deeper soil layer monitoring capabilities ensure new possibilities for soil freeze/thaw cycle monitoring. Within the frame of SMOS programme, ESA has initialized several innovation projects to extend the applicability of SMOS data. One such project is SMOS+ Innovation Permafrost, coordinated by the Finnish Meteorological Institute (FMI) with GAMMA Remote Sensing as a Swiss partner. The main objectives of the project are (1) to develop methods and algorithms for detection and monitoring of soil freezing/thawing processes using L-band passive microwave data and (2) to demonstrate the developed methods with soil frost

  8. Innovative methods for optimization and characterization of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Pelizzo, M. G.; Suman, M.; Monaco, G.; Windt, D. L.; Nicolosi, P.

    2009-05-01

    A numerical method to design multilayer coating (ML) is presented. The mathematical tool is based on an "evolutive strategy" algorithm which provides aperiodic solutions by maximizing input merit functions. It allows the optimization of any kind of structures, comprising interlayers and capping layers, and modelling also inter-diffusion and interface roughness. It has been applied to the design of MLs for different applications, as photolithography, space instrumentation and short pulse preservation/compression. The optimization allows the control of the standing wave distribution inside the ML. When the EUV radiation interacts with the structure, the superposition of the incident and reflected electromagnetic wave generates a standing wave field distribution in the ML. An aperiodic design allows the regulation of the distribution of this field, attributing specific properties to the ML. An experimental technique to recover standing wave intensity on top of the ML is also cited. The technique is based on electron photoemission measurements, which allow to determine both reflectivity as well as phase on top of ML. Thanks to this technique, both tests of the ML performances compliance with expected theoretical ones and of degradation through time can be carried on.

  9. Statistical techniques for the characterization of partially observed epidemics.

    SciTech Connect

    Safta, Cosmin; Ray, Jaideep; Crary, David; Cheng, Karen

    2010-11-01

    Techniques appear promising to construct and integrate automated detect-and-characterize technique for epidemics - Working off biosurveillance data, and provides information on the particular/ongoing outbreak. Potential use - in crisis management and planning, resource allocation - Parameter estimation capability ideal for providing the input parameters into an agent-based model, Index Cases, Time of Infection, infection rate. Non-communicable diseases are easier than communicable ones - Small anthrax can be characterized well with 7-10 days of data, post-detection; plague takes longer, Large attacks are very easy.

  10. Application of Material Characterization Techniques to Electrical Forensic Analysis

    SciTech Connect

    Mills, T.D.

    2003-03-11

    The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component failure event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion.

  11. Combined No Dig techniques for the characterization of historical buildings' structural elements in Abruzzo

    NASA Astrophysics Data System (ADS)

    Ranalli, Danilo; Santacroce, Cristina

    2013-04-01

    Non destructive investigation techniques, No Dig Techniques, have been applied in engineering field since over fifty years, and their employment innovations increase proportionally to the technological development. Actually, for existing buildings, is possible to employ several non destructive investigation techniques, according to current national and local regulations. The application of an indirect survey campaign, enable to extend the result obtained by a confined e/o local destructive investigation method to the whole studied object. It offers a more complete structure knowledge, in terms of physics, chemistry and mechanical characterization, in despite of using less invasive investigation methods. In this paper the attention is pointed on structures characterization, belonging to historic and architectonic Italian heritage, using minimal impact investigation methods. The proposed method consists of the combined employing of Georadar technique, using high frequencies antennas unit, and sonic method, setting an impulsive mass centred on low frequencies. The result of this combined method, employed in the Abruzzi Region post seismic context (6th april 2009 Earthquake), are exposed treating two case-studies of masonry pillars characterization in the "De Amicis" school courtyard (L'Aquila old town centre), and in the naves of Valvense Basilica di San Pelino (Corfinio).

  12. Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures

    NASA Astrophysics Data System (ADS)

    Wiggenhauser, H.; Niederleithinger, E.

    2013-07-01

    Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented.

  13. Polarized light scattering technique for morphological characterization of waterborne pathogens

    NASA Astrophysics Data System (ADS)

    Devarakonda, Venkat V.; Manickavasagam, Sivakumar

    2009-05-01

    We have recently developed an elliptically polarized light scattering (EPLS) technique to characterize the morphology of fine particles suspended in an optically non-absorbing medium such as water. This technique provides the size distribution, shape and agglomeration characteristics of suspended particles. This technique can be used to detect various types of biological pathogens such as bacteria, protozoa and viruses in potable water systems. Here we report results obtained from EPLS measurements on two strains of Bacillus spores suspended in water along with comparison with electron microscopy.

  14. Analytical technique characterizes all trace contaminants in water

    NASA Technical Reports Server (NTRS)

    Foster, J. N.; Lysyj, I.; Nelson, K. H.

    1967-01-01

    Properly programmed combination of advanced chemical and physical analytical techniques characterize critically all trace contaminants in both the potable and waste water from the Apollo Command Module. This methodology can also be applied to the investigation of the source of water pollution.

  15. Physical and chemical characterization techniques for metallic powders

    SciTech Connect

    Slotwinski, J. A.; Stutzman, P. E.; Ferraris, C. F.; Watson, S. S.; Peltz, M. A.; Garboczi, E. J.

    2014-02-18

    Systematic studies have been carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. An extensive array of characterization techniques were applied to these two powders. The physical techniques included laser-diffraction particle-size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to chemistry included X-ray diffraction and energy-dispersive analytical X-ray analysis. The background of these techniques will be summarized and some typical findings comparing different samples of virgin additive manufacturing powders, taken from the same lot, will be given. The techniques were used to confirm that different samples of powder from the same lot were essentially identical, within the uncertainty of the measurements.

  16. Characterization of microstructure with low frequency electromagnetic techniques

    SciTech Connect

    Cherry, Matthew R.; Sathish, Shamachary; Pilchak, Adam L.; Blodgett, Mark P.; Cherry, Aaron J.

    2014-02-18

    A new computational method for characterizing the relationship between surface crystallography and electrical conductivity in anisotropic materials with low frequency electromagnetic techniques is presented. The method is discussed from the standpoint of characterizing the orientation of a single grain, as well as characterizing statistical information about grain ensembles in the microstructure. Large-area electron backscatter diffraction (EBSD) data was obtained and used in conjunction with a synthetic aperture approach to simulate the eddy current response of beta annealed Ti-6Al-4V. Experimental eddy current results are compared to the computed eddy current approximations based on electron backscatter diffraction (EBSD) data, demonstrating good agreement. The detectability of notches in the presence of noise from microstructure is analyzed with the described simulation method and advantages and limitations of this method are discussed relative to other NDE techniques for such analysis.

  17. Plant cell wall characterization using scanning probe microscopy techniques

    PubMed Central

    Yarbrough, John M; Himmel, Michael E; Ding, Shi-You

    2009-01-01

    Lignocellulosic biomass is today considered a promising renewable resource for bioenergy production. A combined chemical and biological process is currently under consideration for the conversion of polysaccharides from plant cell wall materials, mainly cellulose and hemicelluloses, to simple sugars that can be fermented to biofuels. Native plant cellulose forms nanometer-scale microfibrils that are embedded in a polymeric network of hemicelluloses, pectins, and lignins; this explains, in part, the recalcitrance of biomass to deconstruction. The chemical and structural characteristics of these plant cell wall constituents remain largely unknown today. Scanning probe microscopy techniques, particularly atomic force microscopy and its application in characterizing plant cell wall structure, are reviewed here. We also further discuss future developments based on scanning probe microscopy techniques that combine linear and nonlinear optical techniques to characterize plant cell wall nanometer-scale structures, specifically apertureless near-field scanning optical microscopy and coherent anti-Stokes Raman scattering microscopy. PMID:19703302

  18. An innovative technique to restore velopharyngeal incompetency for a patient with cleft lip and palate.

    PubMed

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2013-01-01

    Treatment of cleft lip and palate patients often demand well-coordinated work of medical and dental specialists. In spite of surgical and orthodontic therapy, prosthetic rehabilitation is always necessary because of partial anadontia, maxillary hypoplasia and velopharyngeal dysfuction. The aim of the prosthetic treatment is to improve aesthetics, function and speech of the patients; however, factors like underdeveloped and collapsed maxillary arch, retrognathic maxilla and reduced alveolar ridge height make the treatment challenging. This clinical report describes an interdisciplinary approach for the management of cleft lip and palate patient associated with mutilated dentition. The prosthetic phase began along with orthodontic treatment to achieve sufficient space distribution, which was restored with fixed dental prosthesis to stabilise the achieved status of occlusion. Palatal lift prosthesis was fabricated to restore the velopharyngeal incompetency with an innovative technique using 'standard orthodontic expansion screw' to eliminate hypernasality, decrease intelligibility of speech and to aid in deglutition. PMID:23821635

  19. In-situ characterization technique for screening contaminated soils

    SciTech Connect

    Jaselskis, E.J.; Anderson, M.S.; D`Silva, A.P.; Baldwin, D.P.; Zamzow, D.S.

    1995-07-01

    An innovative field sampling system for screening contaminated soils has been developed using laser ablation coupled with inductively coupled plasma-atomic emission spectrometry (LA-ICP-AES) technology. This sampling approach provides in-situ real-time analysis of trace inorganic elements and is conducted through a mobile testing facility that consists of an instrumentation vehicle called the Mobile Demonstration Laboratory for Environmental Screening Technologies (MDLEST) and an attached trailer called the Robotic Sampling Accessory (RSA). The RSA provides automated sampling capabilities through an attached three-degree-of-freedom robot that is equipped with a surface-sampling probe. The MDLEST-RSA was successfully tested at a Department of Energy (DOE) site in Fernald, Ohio, during the fall of 1992. This paper provides a description of the analysis technique, the MDLEST and RSA, and results of the field demonstration. In addition, benefits, limitations, and future plans are also discussed.

  20. Techniques for nonlinear optical characterization of materials: a review

    NASA Astrophysics Data System (ADS)

    de Araújo, Cid B.; Gomes, Anderson S. L.; Boudebs, Georges

    2016-03-01

    Various techniques to characterize the nonlinear (NL) optical response of centro-symmetric materials are presented and evaluated with emphasis on the relationship between the macroscopic measurable quantities and the microscopic properties of photonic materials. NL refraction and NL absorption of the materials are the phenomena of major interest. The dependence of the NL refraction and NL absorption coefficients on the nature of the materials was studied as well as on the laser excitation characteristics of wavelength, intensity, spatial profile, pulse duration and pulses repetition rate. Selected experimental results are discussed and illustrated. The various techniques currently available were compared and their relative advantages and drawbacks were evaluated. Critical comparisons among established techniques provided elements to evaluate their accuracies and sensitivities with respect to novel methods that present improvements with respect to the conventional techniques.

  1. Materials characterization in petroleum pipeline using Compton Scattering technique

    NASA Astrophysics Data System (ADS)

    Gouveia, M. A. G.; Lopes, R. T.; de Jesus, E. F. O.; Camerini, C. S.

    2003-06-01

    In this paper Compton Scattering technique is analyzed as a possible tool for the characterization of materials inside draining petroleum pipelines. The study was accomplished in laboratory scale, so the results should be analyzed to conclude if the system could be used in the field. The system used was composed of two detectors aligned by a Ce-137 source forming an angle of 90° with the detectors line (662 keV—direct beam, and 288 keV—scattered beam). The results obtained show the capability of the system for the characterization of materials like sand, paraffin and water inside pipelines.

  2. Preparation and characterization of mesh membranes using electrospinning technique

    NASA Astrophysics Data System (ADS)

    Russo, Giuseppina; Peters, Gerrit W. M.; Solberg, Ramon H. M.

    2012-07-01

    This paper is focused on the formulation and characterization of membranes that can act as biomedical devices with a mesh sample structure to reduce local inflammation and improve the tissue regeneration. These systems were realized homogenously dispersing lamellar Hydrotalcite loaded with Diclofenac Sodium (HTLc-DIK) in a polymeric matrix of Poly-caprolactone (PCL). Membranes were obtained through the electrospinning technique that has shown many advantages with respect to other techniques. Experiments carried out on the manufactured samples highlight the no- toxicity of the samples and very good interactions between cells and device.

  3. Innovative Techniques for Estimating Illegal Activities in a Human-Wildlife-Management Conflict

    PubMed Central

    Cross, Paul; St. John, Freya A. V.; Khan, Saira; Petroczi, Andrea

    2013-01-01

    Effective management of biological resources is contingent upon stakeholder compliance with rules. With respect to disease management, partial compliance can undermine attempts to control diseases within human and wildlife populations. Estimating non-compliance is notoriously problematic as rule-breakers may be disinclined to admit to transgressions. However, reliable estimates of rule-breaking are critical to policy design. The European badger (Meles meles) is considered an important vector in the transmission and maintenance of bovine tuberculosis (bTB) in cattle herds. Land managers in high bTB prevalence areas of the UK can cull badgers under license. However, badgers are also known to be killed illegally. The extent of illegal badger killing is currently unknown. Herein we report on the application of three innovative techniques (Randomized Response Technique (RRT); projective questioning (PQ); brief implicit association test (BIAT)) for investigating illegal badger killing by livestock farmers across Wales. RRT estimated that 10.4% of farmers killed badgers in the 12 months preceding the study. Projective questioning responses and implicit associations relate to farmers' badger killing behavior reported via RRT. Studies evaluating the efficacy of mammal vector culling and vaccination programs should incorporate estimates of non-compliance. Mitigating the conflict concerning badgers as a vector of bTB requires cross-disciplinary scientific research, departure from deep-rooted positions, and the political will to implement evidence-based management. PMID:23341973

  4. Innovative techniques for estimating illegal activities in a human-wildlife-management conflict.

    PubMed

    Cross, Paul; St John, Freya A V; Khan, Saira; Petroczi, Andrea

    2013-01-01

    Effective management of biological resources is contingent upon stakeholder compliance with rules. With respect to disease management, partial compliance can undermine attempts to control diseases within human and wildlife populations. Estimating non-compliance is notoriously problematic as rule-breakers may be disinclined to admit to transgressions. However, reliable estimates of rule-breaking are critical to policy design. The European badger (Meles meles) is considered an important vector in the transmission and maintenance of bovine tuberculosis (bTB) in cattle herds. Land managers in high bTB prevalence areas of the UK can cull badgers under license. However, badgers are also known to be killed illegally. The extent of illegal badger killing is currently unknown. Herein we report on the application of three innovative techniques (Randomized Response Technique (RRT); projective questioning (PQ); brief implicit association test (BIAT)) for investigating illegal badger killing by livestock farmers across Wales. RRT estimated that 10.4% of farmers killed badgers in the 12 months preceding the study. Projective questioning responses and implicit associations relate to farmers' badger killing behavior reported via RRT. Studies evaluating the efficacy of mammal vector culling and vaccination programs should incorporate estimates of non-compliance. Mitigating the conflict concerning badgers as a vector of bTB requires cross-disciplinary scientific research, departure from deep-rooted positions, and the political will to implement evidence-based management. PMID:23341973

  5. Phase-modulated beams technique for thin photorefractive films characterization

    NASA Astrophysics Data System (ADS)

    Barmenkov, Yu. O.; Kir'yanov, A. V.; Starodumov, A. N.; Kozhevnikov, N. M.; Lemmetyinen, H.

    2000-04-01

    The phase-modulated beams technique is developed for nonlinear thin photorefractive films characterization. In the Raman-Nath diffraction approximation, the formulas are deduced, allowing us to measure the amplitude of phase grating recorded in a film and its nonlinear refractive index n2. The method is applied for studying Langmuir-Blodgett multilayer thin (˜0.6 μm) films of Bacteriorhodopsin at wavelength 633 nm.

  6. Vadose Zone Characterization Techniques Developed by EMSP Research

    SciTech Connect

    Guillen, Donna P.

    2003-02-24

    This paper discusses research contributions made by Environmental Management Science Program (EMSP) research in the area of geophysical characterization of the subsurface. The goal of these EMSP research projects is to develop combined high-resolution measurement and interpretation packages that provide accurate, timely information needed to characterize the vadose zone. Various types of geophysical imaging techniques can be used to characterize the shallow subsurface. Since individual geophysical characterization tools all have specific limitations, many different techniques are being explored to provide more widespread applicability over a range of hydrogeologic settings. A combination of laboratory, field, theoretical, and computational studies are necessary to develop our understanding of how contaminants move through the vadose zone. This entails field tests with field-hardened systems, packaging and calibration of instrumentation, data processing and analysis algorithms, forward and inverse modeling, and so forth. DOE sites are seeking to team with EMSP researchers to leverage the basic science research investment and apply these advances to address subsurface contamination issues that plague many U.S. Department of Energy (DOE) sites.

  7. Characterization of European sword blades through neutron imaging techniques

    NASA Astrophysics Data System (ADS)

    Salvemini, F.; Grazzi, F.; Peetermans, S.; Gener, M.; Lehmann, E. H.; Zoppi, M.

    2014-09-01

    In the present work, we have studied two European rapier blades, dating back to the period ranging from the Late Renaissance to the Early Modern Age (about 17th to 18th century). In order to determine variation in quality and differences in technology, a study was undertaken with the purpose to observe variations in the blade microstructure (and consequently in the construction processes). The samples, which in the present case were expendable, have been investigated, preliminarily, through standard metallography and then by means of white beam and energy-selective neutron imaging. The comparison of the results, using the two techniques, turned out to be satisfactory, with a substantial quantitative agreement of the results obtained with the two techniques, and show the complementarity of the two methods. Metallography has been considered up to now the method of choice for metal material characterization. The correspondence between the two methods, as well as the non-invasive character of the neutron-based techniques and its possibility to obtain 3D reconstruction, candidate neutron imaging as an important and quantitatively reliable technique for metal characterization.

  8. Characterization of patinas by means of microscopic techniques

    SciTech Connect

    Vazquez-Calvo, C.

    2007-11-15

    Many stone-made historic buildings have a yellowish layer called 'patina' on their external surface. In some cases, it is due to the natural ageing of the stone caused by chemical-physical reactions between the surface of the stone and the environment, and in other cases it is the result of biological activity. The origin of these patinas can be also be due to ancient protective treatments. The use of organic additives, such as protein-based compounds, in lime or gypsum-based patinas is a traditional technique, which has been used in past centuries for the conservation and protection of stone materials. The thinness of the patinas ensures that microscopic techniques are irreplaceable for their analysis. Optical Microscopy, Fluorescence Microscopy, Scanning Electron Microscopy together with an Energy Dispersive X-ray Spectrometer, and Electron Microprobe are the microscopic techniques used for the characterization of these coverings, providing very useful information on their composition, texture and structure.

  9. Characterization of burns using hyperspectral imaging technique - a preliminary study.

    PubMed

    Calin, Mihaela Antonina; Parasca, Sorin Viorel; Savastru, Roxana; Manea, Dragos

    2015-02-01

    Surgical burn treatment depends on accurate estimation of burn depth. Many methods have been used to asses burns, but none has gained wide acceptance. Hyperspectral imaging technique has recently entered the medical research field with encouraging results. In this paper we present a preliminary study (case presentation) that aims to point out the value of this optical method in burn wound characterization and to set up future lines of investigation. A hyperspectral image of a leg and foot with partial thickness burns was obtained in the fifth postburn day. The image was analyzed using linear spectral unmixing model as a tool for mapping the investigated areas. The article gives details on the mathematical bases of the interpretation model and correlations with clinical examination pointing out the advantages of hyperspectral imaging technique. While the results were encouraging, further more extended and better founded studies are being prepared before recognizing hyperspectral imaging technique as an applicable method of burn wound assessment. PMID:24997530

  10. Demonstration of innovative techniques used for real-time closed-loop infrared scene generation

    NASA Astrophysics Data System (ADS)

    Olson, Eric M.; Coker, Charles F.; Coker, Jason S.; Garbo, Dennis L.

    1998-07-01

    Real-time infrared (IR) scene generation for Hardware-in-the- Loop (HWIL) testing of IR seeker systems is a complex operation. High frame rates and high image fidelity are required to properly evaluate a seeker system's designation, identification, tracking, and aim-point selection tasks. Rapidly improving Commercial-off-the-Shelf (COTS) scene generation hardware has become a viable solution for HWIL test activities conducted at the Kinetic Kill Vehicle Hardware-in- the-Loop Simulator (KHILS) facility at Eglin AFB, Florida. A real-time IR scene generation implementation for a complete closed-loop guided missile simulation test entry was accomplished at KHILS. The scenarios used for the simulation were Theater Missile Defense (TMD) exo-atmospheric hit-to-kill intercepts of a re-entry target. Innovative scene generation techniques were devised to resolve issues concerning scene content and rendering accuracy while maintaining the required imaging frame rate. This paper focuses on the real-time scene generation requirements, issues, and solutions used for KHILS test entries.

  11. Scientific Tools and Techniques: An Innovative Introduction to Planetary Science / Astronomy for 9th Grade Students

    NASA Astrophysics Data System (ADS)

    Albin, Edward F.

    2014-11-01

    Fernbank Science Center in Atlanta, GA (USA) offers instruction in planetary science and astronomy to gifted 9th grade students within a program called "Scientific Tools and Techniques" (STT). Although STT provides a semester long overview of all sciences, the planetary science / astronomy section is innovative since students have access to instruction in the Center's Zeiss planetarium and observatory, which includes a 0.9 m cassegrain telescope. The curriculum includes charting the positions of planets in planetarium the sky; telescopic observations of the Moon and planets; hands-on access to meteorites and tektites; and an introduction to planetary spectroscopy utilizing LPI furnished ALTA reflectance spectrometers. In addition, students have the opportunity to watch several full dome planetary themed planetarium presentations, including "Back to the Moon for Good" and "Ring World: Cassini at Saturn." An overview of NASA's planetary exploration efforts is also considered, with special emphasis on the new Orion / Space Launch System for human exploration of the solar system. A primary goal of our STT program is to not only engage but encourage students to pursue careers in the field of science, with the hope of inspiring future scientists / leaders in the field of planetary science.

  12. Reverse engineering and rapid prototyping techniques to innovate prosthesis socket design

    NASA Astrophysics Data System (ADS)

    Colombo, Giorgio; Bertetti, Massimiliano; Bonacini, Daniele; Magrassi, Grazia

    2006-02-01

    The paper presents an innovative approach totally based on digital data to optimize lower limb socket prosthesis design. This approach is based on a stump's detailed geometric model and provides a substitute to plaster cast obtained through the traditional manual methodology with a physical model, realized with Rapid Prototyping technologies; this physical model will be used for the socket lamination. The paper discusses a methodology to reconstruct a 3D geometric model of the stump able to describe with high accuracy and detail the complete structure subdivided into bones, soft tissues, muscular masses and dermis. Some different technologies are used for stump acquisition: non contact laser technique for external geometry, CT and MRI imaging technologies for the internal structure, the first one dedicated to bones geometrical model, the last for soft tissues and muscles. We discuss problems related to 3D geometric reconstruction: the patient and stump positioning for the different acquisitions, markers' definition on the stump to identify landmarks, alignment's strategies for the different digital models, in order to define a protocol procedure with a requested accuracy for socket's realization. Some case-studies illustrate the methodology and the results obtained.

  13. Application of physical and chemical characterization techniques to metallic powders

    SciTech Connect

    Slotwinski, J. A.; Watson, S. S.; Stutzman, P. E.; Ferraris, C. F.; Peltz, M. A.; Garboczi, E. J.

    2014-02-18

    Systematic studies have been carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to chemistry, including X-ray diffraction and energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, were also employed. Results of these analyses will be used to shed light on the question: how does virgin powder change after being exposed to and recycled from one or more additive manufacturing build cycles? In addition, these findings can give insight into the actual additive manufacturing process.

  14. Closing the gap: accelerating the translational process in nanomedicine by proposing standardized characterization techniques

    PubMed Central

    Khorasani, Ali A; Weaver, James L; Salvador-Morales, Carolina

    2014-01-01

    On the cusp of widespread permeation of nanomedicine, academia, industry, and government have invested substantial financial resources in developing new ways to better treat diseases. Materials have unique physical and chemical properties at the nanoscale compared with their bulk or small-molecule analogs. These unique properties have been greatly advantageous in providing innovative solutions for medical treatments at the bench level. However, nanomedicine research has not yet fully permeated the clinical setting because of several limitations. Among these limitations are the lack of universal standards for characterizing nanomaterials and the limited knowledge that we possess regarding the interactions between nanomaterials and biological entities such as proteins. In this review, we report on recent developments in the characterization of nanomaterials as well as the newest information about the interactions between nanomaterials and proteins in the human body. We propose a standard set of techniques for universal characterization of nanomaterials. We also address relevant regulatory issues involved in the translational process for the development of drug molecules and drug delivery systems. Adherence and refinement of a universal standard in nanomaterial characterization as well as the acquisition of a deeper understanding of nanomaterials and proteins will likely accelerate the use of nanomedicine in common practice to a great extent. PMID:25525356

  15. An Innovative Method for Dynamic Characterization of Fan FilterUnit Operation.

    SciTech Connect

    Xu, Tengfang

    2006-12-21

    Fan filter units (FFU) are widely used to deliver re-circulated air while providing filtration control of particle concentration in controlled environments such as cleanrooms, minienvironments, and operating rooms in hospitals. The objective of this paper is to document an innovative method for characterizing operation and control of an individual fan filter unit within its operable conditions. Built upon the draft laboratory method previously published [1] , this paper presents an updated method including a testing procedure to characterize dynamic operation of fan filter units, i.e., steady-state operation conditions determined by varied control schemes, airflow rates, and pressure differential across the units. The parameters for dynamic characterization include total electric power demand, total pressure efficiency, airflow rate, pressure differential across fan filter units, and airflow uniformity.

  16. Fluorescent techniques for discovery and characterization of phosphopantetheinyl transferase inhibitors

    PubMed Central

    Kosa, Nicolas M.; Foley, Timothy L.; Burkart, Michael D.

    2016-01-01

    Phosphopantetheinyl transferase (E.C. 2.7.8.-) activates biosynthetic pathways that synthesize both primary and secondary metabolites in bacteria. Inhibitors of these enzymes have the potential to serve as antibiotic compounds that function through a unique mode of action and possess clinical utility. Here we report a direct and continuous assay for this enzyme class based upon monitoring polarization of a fluorescent phosphopantetheine analog as it is transferred from a low molecular weight coenzyme A substrate to higher molecular weight protein acceptor. We demonstrate the utility of this method for the biochemical characterization of phosphopantetheinyl transferase Sfp, a canonical representative from this class. We also establish the portability of this technique to other homologs by adapting the assay to function with the human phosphopantetheinyl transferase, a target for which a microplate detection method does not currently exist. Comparison of these targets provides a basis to predict therapeutic index of inhibitor candidates and offers a valuable characterization of enzyme activity. PMID:24192555

  17. Exploring Characterizations of Learning Object Repositories Using Data Mining Techniques

    NASA Astrophysics Data System (ADS)

    Segura, Alejandra; Vidal, Christian; Menendez, Victor; Zapata, Alfredo; Prieto, Manuel

    Learning object repositories provide a platform for the sharing of Web-based educational resources. As these repositories evolve independently, it is difficult for users to have a clear picture of the kind of contents they give access to. Metadata can be used to automatically extract a characterization of these resources by using machine learning techniques. This paper presents an exploratory study carried out in the contents of four public repositories that uses clustering and association rule mining algorithms to extract characterizations of repository contents. The results of the analysis include potential relationships between different attributes of learning objects that may be useful to gain an understanding of the kind of resources available and eventually develop search mechanisms that consider repository descriptions as a criteria in federated search.

  18. Innovation, Innovation, Innovation

    ERIC Educational Resources Information Center

    Schuller, Tom

    2007-01-01

    Innovation, Universities and Skills. The new title of the department offers much food for thought. The title is indeed an intriguing and important one. Bringing the idea of innovation right to the fore is, to use an overworked term, challenging. Pinning down what innovation means is not at all easy. There are three different lines of argument. The…

  19. Structured Problem-Solving Techniques to Stimulate Innovation in New Product Development in UK SMEs

    ERIC Educational Resources Information Center

    Hall, D. M.; McKinna, A.; Thake, G.

    2003-01-01

    "Innovation" is an often used, yet much misunderstood term. Often innovation is left to chance or, at best, approached by relatively unstructured hard work and hard thinking. This paper describes a research programme known as the "Futures Project", which provides a "virtual" body of expertise that small and medium-sized enterprises (SMEs) can…

  20. A High-speed Characterization Technique for Solar Silicon

    NASA Technical Reports Server (NTRS)

    Lehmann, V.; Foell, H.; Bernewitz, L.; Grabmaier, J. G.

    1984-01-01

    High-speed crystal growth techniques demand high-speed characterization techniques to allow a timely feed-back of information to the crystal growers. The unique properties of the Si electrolyte-contact (SEC) provide for an extremely fast and simple measurement of the light-induced photo-current for any piece of Si without lengthy preparation of the specimen. Electropolishing at high anodic current densities allows for insitu generation of fresh surfaces whereas preferential etching of defects in various modes is possible at low current densities. In n-type Si a simple estimation of the minority-carrier diffusion length is possible in many cases. Laser-scanning enables local probing of the photocurrent and provides data about the homogeneity of a sample. The experimental realization of the method is described in detail and examples are given and discussed.

  1. Characterization of PTFE Using Advanced Thermal Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Blumm, J.; Lindemann, A.; Meyer, M.; Strasser, C.

    2010-10-01

    Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer used in numerous industrial applications. It is often referred to by its trademark name, Teflon. Thermal characterization of a PTFE material was carried out using various thermal analysis and thermophysical properties test techniques. The transformation energetics and specific heat were measured employing differential scanning calorimetry. The thermal expansion and the density changes were determined employing pushrod dilatometry. The viscoelastic properties (storage and loss modulus) were analyzed using dynamic mechanical analysis. The thermal diffusivity was measured using the laser flash technique. Combining thermal diffusivity data with specific heat and density allows calculation of the thermal conductivity of the polymer. Measurements were carried out from - 125 °C up to 150 °C. Additionally, measurements of the mechanical properties were carried out down to - 170 °C. The specific heat tests were conducted into the fully molten regions up to 370 °C.

  2. Characterizing TPS Microstructure: A Review of Some techniques

    NASA Technical Reports Server (NTRS)

    Gasch, Matthew; Stackpole, Mairead; Agrawal, Parul; Chavez-Garcie, Jose

    2011-01-01

    I. When seeking to understand ablator microstructure and morphology there are several useful techniques A. SEM 1) Visual characteriza3on at various length scales. 2) Chemical mapping by backscatter or x-ray highlights areas of interest. 3) Combined with other techniques (density, weight change, chemical analysis) SEM is a powerful tool to aid in explaining thermo/structural data. B. ASAP. 1) Chemical characteriza3on at various length scales. 2) Chemical mapping of pore structure by gas adsorption. 3) Provides a map of pore size vs. pore volume. 4) Provided surface area of exposed TPS. II. Both methods help characterize and understand how ablators react with other chemical species and provides insight into how they oxidize.

  3. Experimental techniques in ultrasonics for NDE and material characterization

    NASA Astrophysics Data System (ADS)

    Tittmann, B. R.

    A development status evaluation is presented for ultrasonics NDE characterization of aerospace alloys and composites in such application as the Space Shuttle, Space Station Freedom, and hypersonic aircraft. The use of such NDE techniques extends to composite-cure monitoring, postmanufacturing quality assurance, and in-space service inspection of such materials as graphite/epoxy, Ti alloys, and Al honeycomb. Attention is here given to the spectroscopy of elastically scattered wave pulses from flaws, the acoustical imaging of flaws in honeycomb structures, and laser-based ultrasonics for the noncontact inspection of composite structures.

  4. Modulation Z-scan technique for characterization of photorefractive crystals

    NASA Astrophysics Data System (ADS)

    Aguilar, P. A. Marquez; Sanchez-Mondragon, J. J.; Stepanov, S.

    1996-10-01

    We propose a simple single-beam configuration for characterization of the amplitude, speed of growth, and polarization properties of the photoinduced refractive-index change that is due to a drift photorefractive mechanism of nonlinearity in crystals, namely, the modulation Z-scan technique, based on the modulation of an externally applied electric field. The results of a simple theoretical model developed for one-dimensional parabolic photorefractive lens formation in this configuration are illustrated by original experiments with a semi-insulating GaAs crystal at lambda =1.06 mu m .

  5. Ultrasonic wave techniques and characterization of filled elastomers and biodegradable polymers

    NASA Astrophysics Data System (ADS)

    Wu, Hsueh-Chang

    Ultrasonic wave technique is an excellent method for non-destructive testing and for the monitoring of polymer curing, fatigue damage and polymer transition. It is also a potentially effective tool to be applied in the characterization of high frequency viscoelastic properties of polymers. This research represents the effort to improve and further develop ultrasonic wave techniques and extend its applications to new material evaluation areas. The work is presented as followings: In chapter 1, the fundamental wave propagation theories and characterization of the viscoelastic properties of materials by acoustic parameters were briefly reviewed. In chapter 2, the effects of carbon black filler on the elastomers were studied by the longitudinal wave pulse-echo technique. It is found that the enhanced pulse-echo technique is able to characterize the effects of polymer base, filler loading level, type as well as temperature, on the acoustic properties of filled elastomers. In chapter 3, the application of longitudinal wave pulse-echo technique was extended to the monitoring of the degradation process of biodegradable polymers: poly (glycolic acid)(PGA), poly (lactic acid) (PLA) and their copolymer-poly(d,l-lactide-co-glycolide) (PDLLG). It shows that the pulse-echo technique is able to differentiate the effects of polymer structure and preparation method on the degradation behavior of biopolymers. In chapter 4, the Young's modulus, shear modulus, bulk modulus and Poisson ratio of carbon black filled elastomers were determined by the longitudinal wave pulse-echo method and the shear wave through-transmission method. The effects of polymer base, filler loading and dispersion on the elastomers were also studied by the calculated elastic constants. In chapter 5, the effects of carbon black filler on the elastomers were studied by an innovative calibrated longitudinal and shear wave surface impedance technique. The results show that the effects of polymer base, filler loading

  6. Hyperspectral-imaging-based techniques applied to wheat kernels characterization

    NASA Astrophysics Data System (ADS)

    Serranti, Silvia; Cesare, Daniela; Bonifazi, Giuseppe

    2012-05-01

    Single kernels of durum wheat have been analyzed by hyperspectral imaging (HSI). Such an approach is based on the utilization of an integrated hardware and software architecture able to digitally capture and handle spectra as an image sequence, as they results along a pre-defined alignment on a surface sample properly energized. The study was addressed to investigate the possibility to apply HSI techniques for classification of different types of wheat kernels: vitreous, yellow berry and fusarium-damaged. Reflectance spectra of selected wheat kernels of the three typologies have been acquired by a laboratory device equipped with an HSI system working in near infrared field (1000-1700 nm). The hypercubes were analyzed applying principal component analysis (PCA) to reduce the high dimensionality of data and for selecting some effective wavelengths. Partial least squares discriminant analysis (PLS-DA) was applied for classification of the three wheat typologies. The study demonstrated that good classification results were obtained not only considering the entire investigated wavelength range, but also selecting only four optimal wavelengths (1104, 1384, 1454 and 1650 nm) out of 121. The developed procedures based on HSI can be utilized for quality control purposes or for the definition of innovative sorting logics of wheat.

  7. Characterization of Cavities Using the GPR, LIDAR and GNSS Techniques

    NASA Astrophysics Data System (ADS)

    Conejo-Martín, Miguel Angel; Herrero-Tejedor, Tomás Ramón; Lapazaran, Javier; Perez-Martin, Enrique; Otero, Jaime; Prieto, Juan F.; Velasco, Jesús

    2015-11-01

    The study of the many types of natural and manmade cavities in different parts of the world is important to the fields of geology, geophysics, engineering, architectures, agriculture, heritages and landscape. Ground-penetrating radar (GPR) is a noninvasive geodetection and geolocation technique suitable for accurately determining buried structures. This technique requires knowing the propagation velocity of electromagnetic waves (EM velocity) in the medium. We propose a method for calibrating the EM velocity using the integration of laser imaging detection and ranging (LIDAR) and GPR techniques using the Global Navigation Satellite System (GNSS) as support for geolocation. Once the EM velocity is known and the GPR profiles have been properly processed and migrated, they will also show the hidden cavities and the old hidden structures from the cellar. In this article, we present a complete study of the joint use of the GPR, LIDAR and GNSS techniques in the characterization of cavities. We apply this methodology to study underground cavities in a group of wine cellars located in Atauta (Soria, Spain). The results serve to identify construction elements that form the cavity and group of cavities or cellars. The described methodology could be applied to other shallow underground structures with surface connection, where LIDAR and GPR profiles could be joined, as, for example, in archaeological cavities, sewerage systems, drainpipes, etc.

  8. Innovative combination of spectroscopic techniques to reveal nanoparticle fate in a crop plant

    NASA Astrophysics Data System (ADS)

    Larue, Camille; Castillo-Michel, Hiram; Stein, Ricardo J.; Fayard, Barbara; Pouyet, Emeline; Villanova, Julie; Magnin, Valérie; Pradas del Real, Ana-Elena; Trcera, Nicolas; Legros, Samuel; Sorieul, Stéphanie; Sarret, Géraldine

    2016-05-01

    Nanotechnology is the new industrial revolution of our century. Its development leads to an increasing use of nanoparticles and thus to their dissemination. Their fate in the environment is of great concern and especially their possible transfer in trophic chains might be an issue for food safety. However, so far our knowledge on this topic has been restricted by the lack of appropriate techniques to characterize their behavior in complex matrices. Here, we present in detail the use of cutting-edge beam-based techniques for nanoparticle in situ localization, quantification and speciation in a crop plant species (Lactuca sativa). Lettuce seedlings have been exposed to TiO2 and Ag nanoparticles and analyzed by inductively coupled plasma spectrometry, micro-particle induced X-ray emission coupled to Rutherford backscattering spectroscopy on nuclear microprobe, micro-X-ray fluorescence spectroscopy and X-ray absorption near edge structure spectroscopy. The benefits and drawbacks of each technique are discussed, and the types of information that can be drawn, for example on the translocation to edible parts, change of speciation within the plant, detoxification mechanisms, or impact on the plant ionome, are highlighted. Such type of coupled approach would be an asset for nanoparticle risk assessment.

  9. INNOVATIVE ALARA TECHNIQUES & WORK PRACTICES USED AT HANFORD FOR D & D

    SciTech Connect

    WAGGONER, L.O.

    2005-01-05

    The Department of Energy's Hanford Site has several nuclear facilities in the process of decontamination and decommissioning (D&D) with many more to follow. These facilities contain hazardous and highly radioactive materials in plant systems, gloveboxes, hot cells, rooms, collection tanks, ventilation ducts, fuel pools and outside these facilities. Some of the radioactive isotopes are fissile material and have to be closely guarded and require special handling. To safely work in this environment, workers had to learn new skills and develop innovative techniques to decontaminate, remove all equipment and demolish these radioactive work facilities without spreading contamination to the environment. Changing the workscope and worker attitudes involves a culture change for workers, managers, Department of Energy (DOE) and support organizations. D&D involves making different types of risk-based decisions than were made when the plants were operated or sitting dormant. Management involvement, use of the Integrated Safety Management System (ISMS), communications and sharing lessons learned are essential ingredients in developing a successful D&D strategy. New technologies have to be learned including the use of robotic devices and manipulative arms due to high dose rates and amount of radioactive contamination. Minimizing the amount of Transuranic and Mixed radioactive waste and learning how to ship the large quantities of waste are additional skills the Hanford workers have had to learn. D&D work at Hanford is in progress and Hanford Contractors have completed some very difficult and intense D&D work. This presentation will provide information on the best As Low As Reasonably Achievable (ALARA) protective measures, work practices, and the lessons learned to date.

  10. Innovations in high-pressure liquid injection technique for gas chromatography: pressurized liquid injection system.

    PubMed

    Luong, Jim; Gras, Ronda; Tymko, Richard

    2003-01-01

    In gas chromatography (GC), highly volatile liquefied hydrocarbons are commonly injected using devices such as high-pressure syringes, piston valves, liquid rotary sampling valves, or vaporizing regulators. Although these techniques are adequate in some cases, there are known deficiencies. A new generation of sampling valve has been recently innovated and commercialized. Some of the highlights of the pressurized liquid injection system (PLIS) include compact size, the capability to directly couple to an injection port without the need for preinjection vaporization and transfer lines, and sample sizes ranging from 0.2 to 2.0 micro L. Although the valve has a specification of helium leak-free rating of 82.7 bar (1200 psig), the valve passes a hydrostatic pressure test of up to 414 bar (6000 psig). In the unheated version of PLIS, vaporization of solutes occur mainly because of the sheering effect of carrier gas in combination with thermal energy drawn from an injection port or a heated adaptor. This was found to be adequate for solutes with high to medium volatility of up to nC14 hydrocarbon. A higher molecular weight range of up to nC44 hydrocarbon can be achieved with the implementation of a heated version of PLIS, in which the channel of the shaft can be resistively heated at a rate of up to 400 degrees C/s. With its first introduction in May 2002, PLIS has gained acceptance amongst practitioners in GC because it addresses a key unarticulated need in sample introduction/enrichment and by specifically targeting many deficiencies encountered in contemporary high-pressure injection devices. In this paper, the design and performance of the various valve systems of PLIS, as well as industrial chromatographic applications, is presented. PMID:14629794

  11. Advanced techniques for characterization of ion beam modified materials

    DOE PAGESBeta

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; Kluth, Patrick; Tuomisto, Filip

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiationmore » effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.« less

  12. Advanced techniques for characterization of ion beam modified materials

    SciTech Connect

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; Kluth, Patrick; Tuomisto, Filip

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiation effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.

  13. Innovative application of optical techniques to comprehensive study of the etiology of osteoarthritis

    NASA Astrophysics Data System (ADS)

    Ugryumova, Nadya; Matcher, Stephen J.

    2006-08-01

    Osteoarthritis is a painful condition, causing restricted mobility in the articular joints. In this paper we present a review of different optical techniques that might be used to clarify the etiology of degeneration of connective joint tissues, such as bone and articular cartilage. Significant correlation (R2 = 0.8) between bone mineral density and scattering coefficient of cortical bone tissue are found by using Integrating Sphere Technique. Optical Coherence Tomography and Polarization-Sensitive Optical Coherence Tomography images of cartilage tissue are presented. They were performed as series of angle-dependant measurements for different location along the surface. Method for spatial mapping the birefringence of equine articular cartilage is proposed. Variations in band spacing of birefringence obtained from visually healthy and abnormal cartilage samples are compared. Visible osteoarthritic lesions are characterized by a loss of the regular birefringence bands shown by normal cartilage. We discuss the hypothesis that some of these variations may be due to changes in intrinsic structure of tissue.

  14. Innovative Surgical Management of the Synovial Chondromatosis of Temporo-Mandibular Joints: Highly Conservative Surgical Technique.

    PubMed

    Ionna, Franco; Amantea, Massimiliano; Mastrangelo, Filiberto; Ballini, Andrea; Maglione, Maria Grazia; Aversa, Corrado; De Cecio, Rossella; Russo, Daniela; Marrelli, Massimo; Tatullo, Marco

    2016-07-01

    Synovial chondromatosis (SC) is an uncommon disease characterized by a benign nodular cartilaginous proliferation arising from the joint synovium, bursae, or tendon sheaths. Although the temporomandibular joint is rarely affected by neoplastic lesions, SC is the most common neoplastic lesion of this joint. The treatment of this disease consists in the extraoral surgery with a wide removal of the lesion; in this study, the authors described a more conservative intraoral surgical approach. Patient with SC of temporomandibular joint typically refer a limitation in the mouth opening, together with a persistent not physiological mandibular protrusion and an appearance of a neoformation located at the right preauricular region: the authors reported 1 scholar patient. After biopsy of the neoformation, confirming the synovial chondromatosis, the patient underwent thus to the surgical excision of the tumor, via authors' conservative transoral approach, to facilitate the enucleation of the neoformation. The mass fully involved the pterygo-maxillary fossa with involvement of the parotid lodge and of the right TMJ: this multifocal extension suggested for a trans-oral surgical procedure, in the light of the suspicion of a possible malignant nature of the neoplasm. Our intraoral conservative approach to surgery is aimed to reduce the presence of unaesthetic scars in preauricular and facial regions, with surgical results undoubtedly comparable to the traditional surgical techniques much more aggressive. Our technique could be a valid, alternative, and safe approach to treat this rare and complex kind of oncological disease. PMID:27300457

  15. Laser Shockwave Technique For Characterization Of Nuclear Fuel Plate Interfaces

    SciTech Connect

    James A. Smith; Barry H. Rabin; Mathieu Perton; Daniel Lévesque; Jean-Pierre Monchalin; Martin Lord

    2012-07-01

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  16. Laser shockwave technique for characterization of nuclear fuel plate interfaces

    SciTech Connect

    Perton, M.; Levesque, D.; Monchalin, J.-P.; Lord, M.; Smith, J. A.; Rabin, B. H.

    2013-01-25

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  17. Electrical Characterizations of Lightning Strike Protection Techniques for Composite Materials

    NASA Technical Reports Server (NTRS)

    Szatkowski, George N.; Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Mielnik, John J.

    2009-01-01

    The growing application of composite materials in commercial aircraft manufacturing has significantly increased the risk of aircraft damage from lightning strikes. Composite aircraft designs require new mitigation strategies and engineering practices to maintain the same level of safety and protection as achieved by conductive aluminum skinned aircraft. Researchers working under the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project are investigating lightning damage on composite materials to support the development of new mitigation, diagnosis & prognosis techniques to overcome the increased challenges associated with lightning protection on composite aircraft. This paper provides an overview of the electrical characterizations being performed to support IVHM lightning damage diagnosis research on composite materials at the NASA Langley Research Center.

  18. Characterization of Sorolla's gouache pigments by means of spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Roldán, Clodoaldo; Juanes, David; Ferrazza, Livio; Carballo, Jorgelina

    2016-02-01

    This paper presents the characterization of the Joaquín Sorolla's gouache sketches for the oil on canvas series "Vision of Spain" commissioned by A. M. Huntington to decorate the library of the Hispanic Society of America in New York. The analyses were focused on the identification of the elemental composition of the gouache pigments by means of portable EDXRF spectrometry in a non-destructive mode. Additionally, SEM-EDX and FTIR analyses of a selected set of micro-samples were carried out to identify completely the pigments, the paint technique and the binding media. The obtained results have confirmed the identification of lead and zinc white, vermillion, earth pigments, ochre, zinc yellow, chrome yellow, ultramarine, Prussian blue, chromium based and copper-arsenic based green pigments, bone black and carbon based black pigments, and the use of gum arabic as binding media in the gouache pigments.

  19. Therapy ultrasound equipment characterization: Comparison of three techniques.

    PubMed

    Gutierrez, M I; Leija, L; Vera, A

    2008-01-01

    Methods for characterizing ultrasonic therapy equipment rapidly and easily have to be implemented in order to avoid damages to patients; the existent methods measure different parameters in the ultrasonic beam that can be used to determine if the equipment works appropriately. In this paper, a comparison of three methods to characterize the ultrasonic beam is presented. The first one is a C-scan with microprobe which uses a hydrophone for measuring the signal and a positioning system. The second method is the IR-thermography which uses a phantom to absorb the ultrasonic energy and to convert it into heat. Here, the heat distribution is obtained with an IR camera. The third method uses a sheet of thermochromic liquid crystals (TLC) as sensor and a phantom to absorb the energy. The heat distribution is obtained with a normal camera because the TLCs change their color as a function of temperature. The results indicate that each technique has its own benefits, but the most important parameters can be obtained with only one of them. PMID:19163868

  20. Eddy current techniques for super duplex stainless steel characterization

    NASA Astrophysics Data System (ADS)

    Camerini, C.; Sacramento, R.; Areiza, M. C.; Rocha, A.; Santos, R.; Rebello, J. M.; Pereira, G.

    2015-08-01

    Super duplex stainless steel (SDSS) is a two-phase material where the microstructure consists of grains of ferrite (δ) and austenite (γ). SDSS exhibit an attractive combination of properties, such as: strength, toughness and stress corrosion cracking resistance. Nevertheless, SDSS attain these properties after a controlled solution heat treatment, leading to a similar volumetric fraction of δ and γ. Any further heat treatment, welding operation for example, can change the balance of the original phases, or may also lead to precipitation of a deleterious phase, such as sigma (σ). For these situations, the material corrosion resistance is severely impaired. In the present study, several SDSS samples with low σ phase content and non-balanced microstructure were intentionally obtained by thermally treating SDSS specimens. Electromagnetic techniques, conventional Eddy Current Testing (ECT) and Saturated Low Frequency Eddy Current (SLOFEC), were employed to characterize the SDSS samples. The results showed that ECT and SLOFEC are reliable techniques to evaluate σ phase presence in SDSS and can provide an estimation of the δ content.

  1. An innovative approach to the development of a portable unit for analytical flame characterization in a microgravity environment

    NASA Technical Reports Server (NTRS)

    Dubinskiy, Mark A.; Kamal, Mohammed M.; Misra, Prabhaker

    1995-01-01

    The availability of manned laboratory facilities in space offers wonderful opportunities and challenges in microgravity combustion science and technology. In turn, the fundamentals of microgravity combustion science can be studied via spectroscopic characterization of free radicals generated in flames. The laser-induced fluorescence (LIF) technique is a noninvasive method of considerable utility in combustion physics and chemistry suitable for monitoring not only specific species and their kinetics, but it is also important for imaging of flames. This makes LIF one of the most important tools for microgravity combustion science. Flame characterization under microgravity conditions using LIF is expected to be more informative than other methods aimed at searching for effects like pumping phenomenon that can be modeled via ground level experiments. A primary goal of our work consisted in working out an innovative approach to devising an LIF-based analytical unit suitable for in-space flame characterization. It was decided to follow two approaches in tandem: (1) use the existing laboratory (non-portable) equipment and determine the optimal set of parameters for flames that can be used as analytical criteria for flame characterization under microgravity conditions; and (2) use state-of-the-art developments in laser technology and concentrate some effort in devising a layout for the portable analytical equipment. This paper presents an up-to-date summary of the results of our experiments aimed at the creation of the portable device for combustion studies in a microgravity environment, which is based on a portable UV tunable solid-state laser for excitation of free radicals normally present in flames in detectable amounts. A systematic approach has allowed us to make a convenient choice of species under investigation, as well as the proper tunable laser system, and also enabled us to carry out LIF experiments on free radicals using a solid-state laser tunable in the UV.

  2. Structural characterization of sol-gel derived oxide nanostuctures using synchrotron x-ray techniques

    NASA Astrophysics Data System (ADS)

    Sun, Tao

    Ceramic oxides possess extraordinarily rich functionalities. With the advent of nanofabrication techniques, it is now possible to grow nanostructured oxides with precise control of composition, morphology, and microstructure, which has re-vitalized the research in the field of traditional ceramics. The unexpected behavior and enhanced properties of oxide nanostructures have been extensively reported. However, knowledge about the underlying mechanisms as well as structural implications is still quite limited. Therefore, it is imperative to develop and employ sophisticated characterization tools for unraveling the structure-property relationships for oxide nanostructures. The present thesis work aims at addressing the critical issues associated with fabrication, and more importantly, structural characterization of functional oxide nanostructures. The dissertation starts with introducing the strategy for synthesizing phase-pure and highly controlled oxide nanostructures using sol-gel deposition and an innovative approach called "soft" electron beam lithography. Some specific oxides are chosen for the present study, such as BiFeO3, CoFe2O4, and SnO2, because of their scientific and technological significance. Subsequent to fabrication of tailored oxide nanostructures, advanced synchrotron x-ray scattering techniques have been applied for structural characterization. The nucleation and growth behavior of BiFeO3 thin film was investigated using in situ grazing-incidence small-angle x-ray scattering (GISAXS) technique. The results reveal that the kinetics for early-stage nuclei growth are governed by the oriented-attachment model. Moreover, the porous structures of undoped and Pd-doped semiconducting SnOx thin films were quantitatively characterized using GISAXS. By correlating the structural parameters with H2 sensitivity of SnOx films, it is found out that the microstructure of doped film is favorable for gas sensing, but it is not the major reason for the overall

  3. High-resolution accurate mass spectrometry as a technique for characterization of complex lysimeter leachate samples.

    PubMed

    Hand, Laurence H; Marshall, Samantha J; Saeed, Mansoor; Earll, Mark; Hadfield, Stephen T; Richardson, Kevan; Rawlinson, Paul

    2016-06-01

    Lysimeter studies can be used to identify and quantify soil degradates of agrochemicals (metabolites) that have the potential to leach to groundwater. However, the apparent metabolic profile of such lysimeter leachate samples will often be significantly more complex than would be expected in true groundwater samples. This is particularly true for S-metolachlor, which has an extremely complex metabolic pathway. Consequently, it was not practically possible to apply a conventional analytical approach to identify all metabolites in an S-metolachlor lysimeter study, because there was insufficient mass to enable the use of techniques such as nuclear magnetic resonance. Recent advances in high-resolution accurate mass spectrometry, however, allow innovative screening approaches to characterize leachate samples to a greater extent than previously possible. Leachate from the S-metolachlor study was screened for accurate masses (±5 ppm of the nominal mass) corresponding to more than 400 hypothetical metabolite structures. A refined list of plausible metabolites was constructed from these data to provide a comprehensive description of the most likely metabolites present. The properties of these metabolites were then evaluated using a principal component analysis model, based on molecular descriptors, to visualize the entire chemical space and to cluster the metabolites into a number of subclasses. This characterization and principal component analysis evaluation enabled the selection of suitable representative metabolites that were subsequently used as exemplars to assess the toxicological relevance of the leachate as a whole. Environ Toxicol Chem 2016;35:1401-1412. © 2015 SETAC. PMID:26627902

  4. Peer Assessment Learning Sessions (PALS): An Innovative Feedback Technique for Large Engineering Classes

    ERIC Educational Resources Information Center

    O'Moore, Liza; Baldock, Tom

    2007-01-01

    This paper reports the development of innovative assessment sessions within two core technical courses in Civil Engineering at the University of Queensland. Peer Assessment Learning Sessions (PALS) facilitate a student's peer assessment of a colleague's problem-based learning assignment or tutorial within a "traditional" whole-class setting, under…

  5. The Sentence Stem Technique: An Innovative Interaction between Counselor and Client

    ERIC Educational Resources Information Center

    Hodges, Shannon

    2011-01-01

    This column is designed to underscore relationally based creative interventions used by counselors and psychotherapists in their practices. Our intention is to provide examples of novel, innovative ways of working with clients in their efforts to deepen self-awareness and their connections with others. Although the interventions within this column…

  6. Development of Innovative Radioactive Isotope Production Techniques at the Pennsylvania State University Radiation Science and Engineering Center

    SciTech Connect

    Johnsen, Amanda M.; Heidrich, Brenden; Durrant, Chad; Bascom, Andrew; Unlu, Kenan

    2013-08-15

    The Penn State Breazeale Nuclear Reactor (PSBR) at the Radiation Science and Engineering Center (RSEC) has produced radioisotopes for research and commercial purposes since 1956. With the rebirth of the radiochemistry education and research program at the RSEC, the Center stands poised to produce a variety of radioisotopes for research and industrial work that is in line with the mission of the DOE Office of Science, Office of Nuclear Physics, Isotope Development and Production Research and Application Program. The RSEC received funding from the Office of Science in 2010 to improve production techniques and develop new capabilities. Under this program, we improved our existing techniques to provide four radioisotopes (Mn-56, Br-82, Na-24, and Ar-41) to researchers and industry in a safe and efficient manner. The RSEC is also working to develop new innovative techniques to provide isotopes in short supply to researchers and others in the scientific community, specifically Cu-64 and Cu-67. Improving our existing radioisotopes production techniques and investigating new and innovative methods are two of the main initiatives of the radiochemistry research program at the RSEC.

  7. Innovative Field Methods for Characterizing the Hydraulic Properties of a Complex Fractured Rock Aquifer (Ploemeur, Brittany)

    NASA Astrophysics Data System (ADS)

    Bour, O.; Le Borgne, T.; Longuevergne, L.; Lavenant, N.; Jimenez-Martinez, J.; De Dreuzy, J. R.; Schuite, J.; Boudin, F.; Labasque, T.; Aquilina, L.

    2014-12-01

    Characterizing the hydraulic properties of heterogeneous and complex aquifers often requires field scale investigations at multiple space and time scales to better constrain hydraulic property estimates. Here, we present and discuss results from the site of Ploemeur (Brittany, France) where complementary hydrological and geophysical approaches have been combined to characterize the hydrogeological functioning of this highly fractured crystalline rock aquifer. In particular, we show how cross-borehole flowmeter tests, pumping tests and frequency domain analysis of groundwater levels allow quantifying the hydraulic properties of the aquifer at different scales. In complement, we used groundwater temperature as an excellent tracer for characterizing groundwater flow. At the site scale, measurements of ground surface deformation through long-base tiltmeters provide robust estimates of aquifer storage and allow identifying the active structures where groundwater pressure changes occur, including those acting during recharge process. Finally, a numerical model of the site that combines hydraulic data and groundwater ages confirms the geometry of this complex aquifer and the consistency of the different datasets. The Ploemeur site, which has been used for water supply at a rate of about 106 m3 per year since 1991, belongs to the French network of hydrogeological sites H+ and is currently used for monitoring groundwater changes and testing innovative field methods.

  8. Thermal Characterization of Edible Oils by Using Photopyroelectric Technique

    NASA Astrophysics Data System (ADS)

    Lara-Hernández, G.; Suaste-Gómez, E.; Cruz-Orea, A.; Mendoza-Alvarez, J. G.; Sánchez-Sinéncio, F.; Valcárcel, J. P.; García-Quiroz, A.

    2013-05-01

    Thermal properties of several edible oils such as olive, sesame, and grape seed oils were obtained by using the photopyroelectric technique. The inverse photopyroelectric configuration was used in order to obtain the thermal effusivity of the oil samples. The theoretical equation for the photopyroelectric signal in this configuration, as a function of the incident light modulation frequency, was fitted to the experimental data in order to obtain the thermal effusivity of these samples. Also, the back photopyroelectric configuration was used to obtain the thermal diffusivity of these oils; this thermal parameter was obtained by fitting the theoretical equation for this configuration, as a function of the sample thickness (called the thermal wave resonator cavity), to the experimental data. All measurements were done at room temperature. A complete thermal characterization of these edible oils was achieved by the relationship between the obtained thermal diffusivities and thermal effusivities with their thermal conductivities and volumetric heat capacities. The obtained results are in agreement with the thermal properties reported for the case of the olive oil.

  9. Nanocrystalline materials: recent advances in crystallographic characterization techniques

    PubMed Central

    Ringe, Emilie

    2014-01-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask ‘how are nanoshapes created?’, ‘how does the shape relate to the atomic packing and crystallography of the material?’, ‘how can we control and characterize the external shape and crystal structure of such small nanocrystals?’. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed. PMID:25485133

  10. Characterization of Lavandula spp. Honey Using Multivariate Techniques.

    PubMed

    Estevinho, Leticia M; Chambó, Emerson Dechechi; Pereira, Ana Paula Rodrigues; Carvalho, Carlos Alfredo Lopes de; Toledo, Vagner de Alencar Arnaut de

    2016-01-01

    Traditionally, melissopalynological and physicochemical analyses have been the most used to determine the botanical origin of honey. However, when performed individually, these analyses may provide less unambiguous results, making it difficult to discriminate between mono and multifloral honeys. In this context, with the aim of better characterizing this beehive product, a selection of 112 Lavandula spp. monofloral honey samples from several regions were evaluated by association of multivariate statistical techniques with physicochemical, melissopalynological and phenolic compounds analysis. All honey samples fulfilled the quality standards recommended by international legislation, except regarding sucrose content and diastase activity. The content of sucrose and the percentage of Lavandula spp. pollen have a strong positive association. In fact, it was found that higher amounts of sucrose in honey are related with highest percentage of pollen of Lavandula spp.. The samples were very similar for most of the physicochemical parameters, except for proline, flavonoids and phenols (bioactive factors). Concerning the pollen spectrum, the variation of Lavandula spp. pollen percentage in honey had little contribution to the formation of samples groups. The formation of two groups regarding the physicochemical parameters suggests that the presence of other pollen types in small percentages influences the factor termed as "bioactive", which has been linked to diverse beneficial health effects. PMID:27588420

  11. STATE-OF-THE-ART FIELD TECHNIQUES FOR SITE CHARACTERIZATION

    EPA Science Inventory

    Many of the traditional methods for characterizing the hydrogeologic properties and contaminant distribution of subsurface materials were derived from methods developed in the water supply industry. These methods generally result in the characterization of bulk aquifer propert...

  12. Use of non-standardised micro-destructive techniques in the characterization of traditional construction materials

    NASA Astrophysics Data System (ADS)

    Ioannou, Ioannis; Theodoridou, Magdalini; Modestou, Sevasti; Fournari, Revecca; Dagrain, Fabrice

    2013-04-01

    The characterization of material properties and the diagnosis of their state of weathering and conservation are three of the most important steps in the field of cultural heritage preservation. Several standardised experimental methods exist, especially for determining the material properties and their durability. However, they are limited in their application by the required size of test specimens and the controlled laboratory conditions needed to undertake the tests; this is especially true when the materials under study constitute immovable parts of heritage structures. The current use of other advanced methods of analysis, such as imaging techniques, in the aforementioned field of research offers invaluable results. However, these techniques may not always be accessible to the wider research community due to their complex nature and relatively high cost of application. This study presents innovative applications of two recently developed cutting techniques; the portable Drilling Resistance Measuring System (DRMS) and the scratch tool. Both methods are defined as micro-destructive, since they only destroy a very small portion of sample material. The general concept of both methods lies within the forces needed to cut a material by linear (scratch tool) or rotational (DRMS) cutting action; these forces are related to the mechanical properties of the material and the technological parameters applied on the tool. Therefore, for a given testing configuration, the only parameter influencing the forces applied is the strength of the material. These two techniques have been used alongside a series of standardised laboratory tests aiming at the correlation of various stone properties (density, porosity, dynamic elastic modulus and uniaxial compressive strength). The results prove the potential of both techniques in assessing the uniaxial compressive strength of stones. The scratch tool has also been used effectively to estimate the compressive strength of mud bricks. It

  13. Investigating flavour characteristics of British ale yeasts: techniques, resources and opportunities for innovation

    PubMed Central

    Parker, Neva; James, Steve; Dicks, Jo; Bond, Chris; Nueno-Palop, Carmen; White, Chris; Roberts, Ian N

    2015-01-01

    Five British ale yeast strains were subjected to flavour profiling under brewery fermentation conditions in which all other brewing parameters were kept constant. Significant variation was observed in the timing and quantity of flavour-related chemicals produced. Genetic tests showed no evidence of hybrid origins in any of the strains, including one strain previously reported as a possible hybrid of Saccharomyces cerevisiae and S. bayanus. Variation maintained in historical S. cerevisiae ale yeast collections is highlighted as a potential source of novelty in innovative strain improvement for bioflavour production. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25361168

  14. Investigating flavour characteristics of British ale yeasts: techniques, resources and opportunities for innovation.

    PubMed

    Parker, Neva; James, Steve; Dicks, Jo; Bond, Chris; Nueno-Palop, Carmen; White, Chris; Roberts, Ian N

    2015-01-01

    Five British ale yeast strains were subjected to flavour profiling under brewery fermentation conditions in which all other brewing parameters were kept constant. Significant variation was observed in the timing and quantity of flavour-related chemicals produced. Genetic tests showed no evidence of hybrid origins in any of the strains, including one strain previously reported as a possible hybrid of Saccharomyces cerevisiae and S. bayanus. Variation maintained in historical S. cerevisiae ale yeast collections is highlighted as a potential source of novelty in innovative strain improvement for bioflavour production. PMID:25361168

  15. Joint application of non-invasive techniques to characterize the dynamic behaviuor of engineering structures

    NASA Astrophysics Data System (ADS)

    Gallipoli, M. R.; Perrone, A.; Stabile, T. A.; Ponzo, F. C.; Ditommaso, R.

    2012-04-01

    The systematic monitoring of strategic civil infrastructures such as bridges, large dams or high-rise buildings in order to ensure their structural stability is a strategic issue particularly in earthquake-prone regions. Nevertheless, in areas less exposed to seismic hazard, the monitoring is also an important tool for civil engineers, for instance if they have to deal with structures exposed to heavy operational demands for extended periods of time and whose structural integrity might be in question or at risk. A continuous monitoring of such structures allows the identification of their fundamental response characteristics and the changes of these over time, the latter representing indicators for potential structural degradation. The aim of this paper is the estimation of fundamental dynamic parameters of some civil infrastructures by the joint application of fast executable, non-invasive techniques such as the Ambient Noise Standard Spectral Ratio, and Ground-Based microwave Radar Interferometer techniques. The joint approach combine conventional, non-conventional and innovative techniques in order to set up a non destructive evaluation procedure allowing for a multi-sensing monitoring at a multi-scale and multi-depth levels (i.e. with different degrees of spatial resolution and different subsurface depths). In particular, techniques based on ambient vibration recordings have become a popular tool for characterizing the seismic response and state-of-health of strategic civil infrastructure. The primary advantage of these approaches lies in the fact that no transient earthquake signals or even active excitation of the structure under investigation are required. The microwave interferometry radar technology, it has proven to be a powerful remote sensing tool for vibration measurement of structures, such as bridge, heritage architectural structures, vibrating stay cables, and engineering structures. The main advantage of this radar technique is the possibility to

  16. An innovative impression technique for fabrication of a custom made ocular prosthesis

    PubMed Central

    Tripuraneni, Sunil Chandra; Vadapalli, Sriharsha Babu; Ravikiran, P; Nirupama, N

    2015-01-01

    Various impression and fitting techniques have been described in the past for restoring ocular defects. The present article describes a new direct impression technique for recording and rehabilitating ocular defects, by custom-made ocular prosthesis. All the techniques described in the history, mainly concentrated in recording the tissue surface of the defect, which made it difficult to contour the palpebral surface resulting in the poor esthetics of the prosthesis. The present impression technique uses heavy bodied polyvinyl siloxane impression material, which facilitates accurate recording of the tissue surface and the palpebral surface of the defect, resulting in the fabrication of functionally and esthetically acceptable prosthesis. PMID:26265651

  17. An Innovative Ultrasound Technique for Evaluation of Tumor Vascularity in Breast Cancers: Superb Micro-Vascular Imaging

    PubMed Central

    Park, Ah Young; Cha, Sang Hoon; Yeom, Suk Keu; Lee, Seung Wha; Chung, Hwan Hoon

    2016-01-01

    Tumor vascularity is an important indicator for differential diagnosis, tumor growth, and prognosis. Superb micro-vascular imaging (SMI) is an innovative ultrasound technique for vascular examination that uses a multidimensional filter to eliminate clutter and preserve extremely low-velocity flows. Theoretically, SMI could depict more vessels and more detailed vascular morphology, due to the increased sensitivity of slow blood flow. Here, we report the early experience of using SMI in 21 breast cancer patients. We evaluated tumor vascular features in breast cancer and compared SMI and conventional color or power Doppler imaging. SMI was superior to color or power Doppler imaging in detecting tumor vessels, the details of vessel morphology, and both peripheral and central vascular distribution. In conclusion, SMI is a promising ultrasound technique for evaluating microvascular information of breast cancers.

  18. Characterization of soil behavior using electromagnetic wave-based technique

    NASA Astrophysics Data System (ADS)

    Dong, Xiaobo

    samples so that the beta value, i.e., the ratio between the conductivities of the sediment and the fluid, is smaller than 1. The beta value is greater than 1 in the Group B samples owing to an overcompensation of surface conduction. Sedimentation behavior of two kaolinite samples with distinct fabric associations is characterized using mechanical and electromagnetic wave-based techniques. The two different fabric formations, the edge-to-face (EF) flocculated structure (i.e., sample A) and the dispersed and deflocculated structure (i.e., sample B), were regulated by changing the pH of the pore fluid and are produced. The anisotropy of shear wave velocity and DC conductivity was not observed in the sediment of sample A because of EF isotropic fabric associations but it was detected in sample B as a result of face-to-face (FF) aggregation. An open card-house structure of the sample A sediment results in a higher relaxation strength of the bulk water, Deltakappaw owing to a higher water content; the smaller Deltakappaw measured in the sample B sediment indicates denser packing. In both samples, sediment consolidation gives rise to a decrease in the bulk-water relaxation strength but an increase in the bound-water relaxation strength owing to increasing particle content. In response to sediment consolidation, the sediment conductivity of sample A continuously decreases because of the reduced contribution from the fluid conductivity. In sample B, the surface conduction via the overlapped double layer overcompensates such a decreased contribution so that the sediment conductivity increases with increasing particle content. The slim-form open-ended coaxial probe is also used to conduct a local dielectric measurement. The measured results, i.e. dielectric relaxation strength of bulk water, Deltakappaw, and the DC conductivity of the saturated sample, sigmamix, are jointly used to characterize the spatial variability of different specimens including glass beads, sand and mica

  19. Characterizing Subglacial Interfaces With Airborne Radar Sounding Techniques

    NASA Astrophysics Data System (ADS)

    Peters, M. E.; Blankenship, D. D.; Morse, D. L.

    2004-12-01

    Ice sheets are sensitive indicators of global change including sea-level rise. An ice sheet's subglacial interface is an important factor controlling its dynamic behavior. In particular, the grounding zones of ice streams and subglacial lakes are complex systems involving the interaction of the moving ice mass with underlying materials such as liquid water, saturated lubricating tills, and rough or frozen bedrock sticky spots. Imaging and characterizing the subglacial environment of ice sheets is fundamental to understanding these complex systems. Airborne radar sounding is a powerful and well-known technique for studying ice sheets and glaciers and their contiguous underlying environments. We present results from data acquired in 2001 over the ice stream C grounding zone in West Antarctica, as well as over a hypothesized subglacial lake near the South Pole. These data were acquired using a uniquely configured coherent airborne radar system. Our focus has been to characterize the subglacial interface through radar echo analysis based on reflection and scattering theory. The radar system uses a programmable signal source linked to a 10 kW transmitter and a dual-channel coherent down-conversion receiver. The radar operates in chirped pulse mode at 60 MHz with 15 MHz bandwidth. High and low-gain channels allow for recording a wide dynamic range of echoes simultaneously and without range-dependent gain control. Data acquisition includes integrations of 16 returned radar signals about every 15 cm along-track. Pulse compression and synthetic aperture radar (SAR) processing were components of data analysis. Subglacial echoes are influenced by the physical properties of the interface such as the composition and roughness of the materials at the interface. Other important factors include dielectric losses and volumetric scattering losses from propagation through the ice as well as transmission and refraction at the air-ice interface. Unfocussed SAR narrows the along

  20. Microbe-Clay Mineral Reactions and Characterization Techniques

    NASA Astrophysics Data System (ADS)

    Dong, H.; Zhang, G.; Ji, S.; Jaisi, D.; Kim, J.

    2008-12-01

    Clays and clay minerals are ubiquitous in soils, sediments, and sedimentary rocks. They play an important role in environmental processes such as nutrient cycling, plant growth, contaminant migration, organic matter maturation, and petroleum production. The changes in the oxidation state of the structural iron in clay minerals, in part, control their physical and chemical properties in natural environments, such as clay particle flocculation, dispersion, swelling, hydraulic conductivity, surface area, cation and anion exchange capacity, and reactivity towards organic and inorganic contaminants. The structural ferric iron [Fe(III)] in clay minerals can be reduced either chemically or biologically. Many different chemical reductants have been tried, but the most commonly used agent is dithionite. Biological reductants are bacteria, including dissimilatory iron reducing prokaryotes (DIRP) and sulfate-reducing bacteria (SRB). A wide variety of DIRP have been used to reduce ferric iron in clay minerals, including mesophilic, thermophilic, and hyperthermophilic prokaryotes. Multiple clay minerals have been used for microbial reduction studies, including smectite, nontronite (iron-rich smectite variety), illite, illite/smectite, chlorite, and their various mixtures. All these clay minerals are reducible by microorganisms under various conditions with smectite (nontronite) being the most reducible. The reduction extent and rate of ferric iron in clay minerals are measured by wet chemistry, and the reduced clay mineral products are typically characterized with chemical methods, X-ray diffraction, scanning and transmission electron microscopy, Mössbauer spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), UV-vis spectroscopy, and synchrotron-based techniques (such as EXAFS). Microbially reduced smectites (nontronites) have been found to be reactive in reducing a variety of organic and inorganic contaminants. Degradable organic contaminants include pesticides

  1. Advanced NDE techniques for quantitative characterization of aircraft

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Winfree, William P.

    1990-01-01

    Recent advances in nondestructive evaluation (NDE) at NASA Langley Research Center and their applications that have resulted in quantitative assessment of material properties based on thermal and ultrasonic measurements are reviewed. Specific applications include ultrasonic determination of bolt tension, ultrasonic and thermal characterization of bonded layered structures, characterization of composite materials, and disbonds in aircraft skins.

  2. An innovative radio-guided surgery technique for complete resection of tumors

    NASA Astrophysics Data System (ADS)

    Russomando, A.; Collamati, F.; Bellini, F.; Bocci, V.; De Lucia, E.; Faccini, R.; Frallicciardi, P. M.; Marafini, M.; Mattei, I.; Morganti, S.; Patera, V.; Piersanti, L.; Pinci, D.; Recchia, L.; Senzacqua, M.; Sarti, A.; Sciubba, A.; Solfaroli Camillocci, E.; Voena, C.

    2014-12-01

    Finding new ways to fight cancer is essential to increase the patients life expectancy. This paper reports the latest results of the project CHIRONE finalized to increase the potential of the Radio Guided Surgery through the use of β- emitting radio-tracers and β- probes. This innovation could overcome the present main limiting factor represented by a diffuse background due to the high penetration power of the gamma radiation used. We created a prototype of β- probe and in this paper we report measures of photon efficiency, acquired with commercial photons sources. Then we estimated the signal and background rates in realistic cases of meningioma through a simulation. The device is able to detect residuals of 0.1 ml in 1 s with an administered activity less than 3 MBq/kg.

  3. Simulating the Homunculus Nebula of Eta Carinae with an Innovative Multi-mass SPH Technique

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Benedict J. R.; Podsiadlowski, P.

    2010-01-01

    We present a multi-mass, mixed resolution SPH technique which allows greatly reduced particle number while obtaining high resolution in lower density areas. Two sets of SPH particles are used - high mass for high density regions, low mass for low density regions. Hydrodynamic interaction between the sets is performed with the use of 'buffer' or tracer particles for each set. This technique has many applications in high density contrast simulations such as common envelope spin-up and low mass loss winds and mass transfer in binaries. We use this technique to test a common envelope ejection origin for the Homunculus nebula around Eta Carinae.

  4. Characterization of Deep Tunneling Activity through Remote-Sensing Techniques

    SciTech Connect

    R. G. Best, P. J. Etzler, and J. D. Bloom

    1997-10-01

    This work is a case study demonstrating the uses of multispectral and multi-temporal imagery to characterize deep tunneling activity. A drainage tunnel excavation in Quincy, MA is the case locality. Data used are aerial photographs (digitized) and Daedalus 3600 MSS image data that were collected in July and October of 1994. Analysis of the data includes thermal characterization, spectral characterization, multi-temporal analysis, and volume estimation using digital DEM generation. The results demonstrate the type of information that could be generated by multispectral, multi-temporal data if the study locality were a clandestine excavation site with restricted surface access.

  5. Characterization and biological abatement of diffuse methane emissions and odour in an innovative wastewater treatment plant.

    PubMed

    Barcón, Tamara; Hernández, Jerónimo; Gómez-Cuervo, Santiago; Garrido, Juan M; Omil, Francisco

    2015-01-01

    An innovative and patented process for medium-high strength sewage which comprises an anaerobic step followed by a hybrid anoxic-aerobic chamber and a final ultrafiltration stage was characterized in terms of methane fugitive emissions as well as odours. The operation at ambient temperature implies higher methane content in the liquid anaerobic effluent, which finally causes concentrations around 0.01-2.4% in the off-gas released in the anoxic-aerobic chamber (1.25% average). Mass balances indicate that these emissions account for up to 30-35% of the total methane generated in the anaerobic reactor. A conventional biofilter (BF) operated at an empty bed residence time of 4 min was used to treat these emissions for 70 d. In spite of the fluctuations in the methane inlet concentrations derived from the operation of the wastewater treatment plant (WWTP), it was possible to operate at pseudo-steady-state conditions, achieving average removal efficiencies of 76.5% and maximum elimination capacities of 30.1 g m(-3) h(-1). Odour removal was quantified as 99.1%. Fluorescence in situ hybridization probes as well as metabolic activity assays demonstrated the suitability of the biomass developed in the WWTP as inoculum to start up the BF due to the presence of methanotrophic bacteria. PMID:25749282

  6. Manufactured gas plant sites: Characterization of wastes and IGT`s innovative remediation alternatives

    SciTech Connect

    Srivastava, V.J.

    1993-12-31

    Manufactured gas plants (MGP)--often referred to as town gas plants--have existed in many parts of the world, including the United States, during the nineteenth and twentieth centuries. Consequently, many of these plants disposed of process wastes and less valuable by-products onsite, contaminated with coal-tar wastes, light oils, naphthalene, etc. Polynuclear aromatic hydrocarbons (PAHs) are components of coal-tar wastes and other wastes that remain at many of these town gas sites. PAH- containing soils, as a result, represent the largest waste type at most MGP sites. Also, certain PAHs are recognized today as being potential animal and/or human carcinogens and, as such, represent an environmental hazard. The Institute of Gas Technology (IGT) has developed and/or evaluated several techniques/processes to improve the biodegradation of PAHs present at MGP sites. As a result of extensive studies, IGT has successfully developed and demonstrated an integrated Chemical/Biological Treatment (CBT) process that is capable of enhancing the rate as well as the extent of PAH degradation. This process combines two complementary as well as powerful remedial techniques: (1) chemical pretreatment using Fenton`s reagent and (2) a biological system using native aerobic microorganisms. This paper presents the general characteristics of MGP sites and wastes and the innovative IGT processes at various stages of development and demonstration. This paper also discusses the IGT/GRI treatability protocol that can be used to determine the potential of bioremediation for any MGP site soil within a 2 to 3-month period.

  7. An innovative technique for recording picture-in-picture ultrasound videos.

    PubMed

    Rajasekaran, Sathish; Finnoff, Jonathan T

    2013-08-01

    Many ultrasound educational products and ultrasound researchers present diagnostic and interventional ultrasound information using picture-in-picture videos, which simultaneously show the ultrasound image and transducer and patient positions. Traditional techniques for creating picture-in-picture videos are expensive, nonportable, or time-consuming. This article describes an inexpensive, simple, and portable way of creating picture-in-picture ultrasound videos. This technique uses a laptop computer with a video capture device to acquire the ultrasound feed. Simultaneously, a webcam captures a live video feed of the transducer and patient position and live audio. Both sources are streamed onto the computer screen and recorded by screen capture software. This technique makes the process of recording picture-in-picture ultrasound videos more accessible for ultrasound educators and researchers for use in their presentations or publications. PMID:23887962

  8. Innovative vibration technique applied to polyurethane foam as a viable substitute for conventional fatigue testing

    NASA Astrophysics Data System (ADS)

    Peralta, Alexander; Just-Agosto, Frederick; Shafiq, Basir; Serrano, David

    2012-12-01

    Lifetime prediction using three-point bending (TPB) can at times be prohibitively time consuming and costly, whereas vibration testing at higher frequency may potentially save time and revenue. A vibration technique that obtains lifetimes that reasonably match those determined under flexural TPB fatigue is developed. The technique designs the specimen with a procedure based on shape optimization and finite element analysis. When the specimen is vibrated in resonance, a stress pattern that mimics the stress pattern observed under conventional TPB fatigue testing is obtained. The proposed approach was verified with polyurethane foam specimens, resulting in an average error of 4.5% when compared with TPB.

  9. Innovative techniques and tools for public participation in U.S. Department of Energy programs

    SciTech Connect

    McMakin, A.H.; Henrich, D.L.; Kuhlman, C.A.; White, G.W.

    1995-07-01

    In early 1995, Jon Yerxa, Public Involvement Team Leader in the Office of External Affairs at the US Department of Energy (DOE) Richland Operations Office, identified the need to ``provide Hanford`s Public Participation Program with input and advice concerning public involvement issues at Hanford.`` Yerxa identified the following committees: (1) Training, (2) Tri-Party Agreement/NEPA/ Environmental Justice, (3) Program, (4) Performance Evaluation, and (5) Communications Techniques and Technology. These committees were to be staffed by public involvement and communications staff from DOE and its contractors on the Hanford Site. This report describes the activities and recommendations of the Communications Techniques and Technology committee.

  10. New Ways in Content-Based Instruction. New Ways in TESOL Series II. Innovative Classroom Techniques.

    ERIC Educational Resources Information Center

    Brinton, Donna M., Ed.; Master, Peter, Ed.

    A wide variety of techniques and classroom activities, contributed by teachers, for content-based instruction (CBI) in English as a second language (ESL) are presented. CBI is defined to include theme-based second language courses, sheltered content-area courses, and paired or adjunct arrangements in which language and content courses are taught…

  11. Innovative acoustic reflection imaging techniques and application to clinical breast tomography

    NASA Astrophysics Data System (ADS)

    Schmidt, Steve P.

    Conventional ultrasound techniques use beam-formed, constant sound speed ray models for fast image reconstruction. However, these techniques are inadequate for the emerging new field of ultrasound tomography (UST). We present a new technique for reconstruction of reflection images from UST data. We have extended the planar Kirchhoff migration method used in geophysics, and combined it with sound speed and attenuation data obtained from the transmission signals to create reflection ultrasound images that are corrected for refractive and attenuative effects. The resulting techniques were applied to simulated numerical phantom data, physical phantom data and in-vivo breast data obtained with an experimental ring transducer prototype. Additionally, the ring transducer was customized to test compatibility with an existing ultrasound workstation. We were able to obtain independently recorded radio-frequency (RF) data for individual transmit-receive pair combinations for all 128 transducers. The signal data was then successfully reconstructed into reflection data using the Kirchhoff migration techniques. The results from the use of sound speed and attenuation corrections lead to significant improvements in image quality, particularly in dense tissues where the refractive and scattering effects are the greatest. The procedure was applied to a variety of breast densities and masses of different natures. The resulting reflection images successfully resolved boundaries and textures. The reflection characteristics of tomographic ultrasound maintain an indispensible position in the quantification of proper mass identification. The results of this project indicate the clinical significance of the invocation of properly compensated Kirchhoff based reconstruction method with the use of sound speed and attenuation parameters for the visualization and classification of masses and tissue.

  12. Flaw imaging and ultrasonic techniques for characterizing sintered silicon carbide

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Abel, Phillip B.

    1987-01-01

    The capabilities were investigated of projection microfocus x-radiography, ultrasonic velocity and attenuation, and reflection scanning acoustic microscopy for characterizing silicon carbide specimens. Silicon carbide batches covered a range of densities and different microstructural characteristics. Room temperature, four point flexural strength tests were conducted. Fractography was used to identify types, sizes, and locations of fracture origins. Fracture toughness values were calculated from fracture strength and flaw characterization data. Detection capabilities of radiography and acoustic microscopy for fracture-causing flaws were evaluated. Applicability of ultrasonics for verifying material strength and toughness was examined.

  13. Characterization of concrete materials by using stress wave NDE techniques

    NASA Astrophysics Data System (ADS)

    Sadri, Afshin; deWalle, Brian

    1999-12-01

    A new instrument for monitoring the quality of concrete materials has been developed by Andec Mfg. Ltd. This new instrument, the AndeScope, can be used to evaluate concrete materials by measuring the stress wave velocity, dynamic elastic constant, quality factor (Q-factor), signal frequency, and decay coefficient. The AndeScope can be used to estimate the strength gain at the setting time, or it can be used to diagnose problems such as Alkali-Silica Reaction (ASR) or micro fracturing. The three stress wave propagation techniques are used in combination for this evaluation: ultrasonic through-transmission, pulse-echo and impact-echo. The ultrasonic through-transmission technique uses a direct arrangement between the transmitting and receiving transducers, while the pulse-echo and impact-echo technique are used to monitor concrete materials and structures from a single available face. The AndeScope's three stress wave modes can also be used to detect flaws, delamination, thickness, honeycombing, and crack depth measurements. In this paper, the principles of the three stress wave techniques and actual functions of the instrument are described. The advantages and disadvantages of each technique and new methodologies are discussed.

  14. Fricke xylenol gel characterization using a photoacustic technique

    NASA Astrophysics Data System (ADS)

    Caldeira, A. M. F.; de Almeida, A.; Neto, A. M.; Baesso, M. L.; Bento, A. C.; Silva, M. A.

    2007-11-01

    Fricke chemical dosimetry measurements of the absorbed dose of ionizing radiation depend on the quality and characteristics of the system that reads each dosimeter. The final accuracy is significantly dependent on the technique used for measuring the chemical concentration changes in the dosimeters. We have used a photoacoustic technique to detect the Fricke xylenol gel (FXG) optical absorbance. The FXG, a derivation of the aqueous Fricke dosimeter, is made more sensitive and stable with addition of gelatin (300 Bloom) and xylenol orange. The light intensity transmitted through an FXG sample before and after irradiation was measured with an acoustic detector. The incremental optical absorbance is directly proportional to the ionizing radiation absorbed dose. We present the optical absorbance measurements as a function of absorbed dose and of post-irradiation time. We apply our photoacoustic technique to determine absorbed dose profiles. The results show that the photoacoustic technique applied to FXG provides a new dosimetric system, as good as those already established using spectrophotometric techniques.

  15. Shape and Surface: The challenges and advantages of 3D techniques in innovative fashion, knitwear and product design

    NASA Astrophysics Data System (ADS)

    Bendt, E.

    2016-07-01

    The presentation wants to show what kind of problems fashion and textile designers are facing in 3D-knitwear design, especially regarding fashionable flat-knit styles, and how they can use different kinds of techniques and processes to generate new types of 3D-designs and structures. To create really new things we have to overcome standard development methods and traditional thinking and should start to open our minds again for the material itself to generate new advanced textile solutions. This paper mainly introduces different results of research projects worked out in the master program “Textile Produkte” during lectures in “Innovative Product Design” and “Experimental Knitting”.

  16. Spray characterization with a nonintrusive technique using absolute scattered light

    NASA Technical Reports Server (NTRS)

    Hess, C. F.; Espinosa, V. E.

    1984-01-01

    A technique to measure the size and velocity of particles is discussed, and results are presented. In this technique two small laser beams of one color identify the center of a laser beam of a different color. This defines a region of almost uniform intensity where the light scattered by the individual particles can be related to their sizes. A variation of this technique that uses two polarizations of the same color of laser beam is also presented. Results are presented for monodisperse, bimodal, trimodal, and polydisperse sprays produced by the Berglund-Liu droplet generator and a pressure nozzle. Size distributions obtained at three different ranges for the same spray show excellent self-consistency in the overlapping regions. Measurements of a spray of known characteristics exhibit errors in the order of 10 percent.

  17. Critical incident technique: an innovative participatory approach to examine and document racial disparities in breast cancer healthcare services.

    PubMed

    Yonas, Michael A; Aronson, Robert; Schaal, Jennifer; Eng, Eugenia; Hardy, Christina; Jones, Nora

    2013-10-01

    Disproportionate and persistent inequities in quality of healthcare have been observed among persons of color in the United States. To understand and ultimately eliminate such inequities, several public health institutions have issued calls for innovative methods and approaches that examine determinants from the social, organizational and public policy contexts to inform the design of systems change interventions. The authors, including academic and community research partners in a community-based participatory research (CBPR) study, reflected together on the use and value of the critical incident technique (CIT) for exploring racial disparities in healthcare for women with breast cancer. Academic and community partners used initial large group discussion involving a large partnership of 35 academic and community researchers guided by principles of CBPR, followed by the efforts of a smaller interdisciplinary manuscript team of academic and community researchers to reflect, document summarize and translate this participatory research process, lessons learned and value added from using the CIT with principles of CBPR and Undoing Racism. The finding of this article is a discussion of the process, strengths and challenges of utilizing CIT with CBPR. The participation of community members at all levels of the research process including development, collection of the data and analysis of the data was enhanced by the CIT process. As the field of CBPR continues to mature, innovative processes which combine the expertise of community and academic partners can enhance the success of such partnerships. This report contributes to existing literature by illustrating a unique and participatory research application of CIT with principles of CBPR and Undoing Racism. Findings highlight the collaborative process used to identify and implement this novel method and the adaptability of this technique in the interdisciplinary exploration of system-level changes to understand and

  18. Critical incident technique: an innovative participatory approach to examine and document racial disparities in breast cancer healthcare services

    PubMed Central

    Yonas, Michael A.; Aronson, Robert; Schaal, Jennifer; Eng, Eugenia; Hardy, Christina; Jones, Nora

    2013-01-01

    Disproportionate and persistent inequities in quality of healthcare have been observed among persons of color in the United States. To understand and ultimately eliminate such inequities, several public health institutions have issued calls for innovative methods and approaches that examine determinants from the social, organizational and public policy contexts to inform the design of systems change interventions. The authors, including academic and community research partners in a community-based participatory research (CBPR) study, reflected together on the use and value of the critical incident technique (CIT) for exploring racial disparities in healthcare for women with breast cancer. Academic and community partners used initial large group discussion involving a large partnership of 35 academic and community researchers guided by principles of CBPR, followed by the efforts of a smaller interdisciplinary manuscript team of academic and community researchers to reflect, document summarize and translate this participatory research process, lessons learned and value added from using the CIT with principles of CBPR and Undoing Racism. The finding of this article is a discussion of the process, strengths and challenges of utilizing CIT with CBPR. The participation of community members at all levels of the research process including development, collection of the data and analysis of the data was enhanced by the CIT process. As the field of CBPR continues to mature, innovative processes which combine the expertise of community and academic partners can enhance the success of such partnerships. This report contributes to existing literature by illustrating a unique and participatory research application of CIT with principles of CBPR and Undoing Racism. Findings highlight the collaborative process used to identify and implement this novel method and the adaptability of this technique in the interdisciplinary exploration of system-level changes to understand and

  19. Innovative chimney-graft technique for endovascular repair of a pararenal abdominal aortic aneurysm.

    PubMed

    Galiñanes, Edgar Luis; Hernandez-Vila, Eduardo A; Krajcer, Zvonimir

    2015-02-01

    After abdominal aortic aneurysm repair, progressive degeneration of the aneurysm can be challenging to treat. Multiple comorbidities and previous operations place such patients at high risk for repeat surgery. Endovascular repair is a possible alternative; however, challenging anatomy can push the limits of available technology. We describe the case of a 71-year-old man who presented with a 5.3-cm pararenal aneurysm 4 years after undergoing open abdominal aortic aneurysm repair. To avoid reoperation, we excluded the aneurysm by endovascular means, using visceral-artery stenting, a chimney-graft technique. Low-profile balloons on a monorail system enabled the rapid exchange of coronary wires via a buddy-wire technique. This novel approach facilitated stenting and simultaneous angioplasty of multiple visceral vessels and the abdominal aorta. PMID:25873796

  20. Innovative Chimney-Graft Technique for Endovascular Repair of a Pararenal Abdominal Aortic Aneurysm

    PubMed Central

    Galiñanes, Edgar Luis; Hernandez-Vila, Eduardo A.

    2015-01-01

    After abdominal aortic aneurysm repair, progressive degeneration of the aneurysm can be challenging to treat. Multiple comorbidities and previous operations place such patients at high risk for repeat surgery. Endovascular repair is a possible alternative; however, challenging anatomy can push the limits of available technology. We describe the case of a 71-year-old man who presented with a 5.3-cm pararenal aneurysm 4 years after undergoing open abdominal aortic aneurysm repair. To avoid reoperation, we excluded the aneurysm by endovascular means, using visceral-artery stenting, a chimney-graft technique. Low-profile balloons on a monorail system enabled the rapid exchange of coronary wires via a buddy-wire technique. This novel approach facilitated stenting and simultaneous angioplasty of multiple visceral vessels and the abdominal aorta. PMID:25873796

  1. Endoscopic Debridement for Treatment of Chronic Plantar Fasciitis: An Innovative Surgical Technique.

    PubMed

    Cottom, James M; Maker, Jared M

    2016-01-01

    Plantar fasciitis is one the most common pathologies seen by foot and ankle surgeons. When nonoperative therapy fails, surgical intervention is warranted. Various surgical procedures are available for the treatment of recalcitrant plantar fasciitis. The most common surgical management typically consists of open versus endoscopic plantar fascia release. The documented comorbidities associated with the release of the plantar fascia include lateral column overload and metatarsalgia. We present a new technique for this painful condition that is minimally invasive, allows visualization of the plantar fascia, and maintains the integrity of this fascia. Our hypothesis was that the use of endoscopic debridement of the plantar fascia would provide a minimally invasive technique with acceptable patient outcomes. PMID:26952313

  2. Overview of characterization and metrology techniques for microlenses and microlens arrays

    NASA Astrophysics Data System (ADS)

    Kim, Myun-Sik; Allegre, Lisa; Sunarjo, Jonathan; Noell, Wilfried; Voelkel, Reinhard

    2015-05-01

    We review various metrology techniques for the characterization of refractive microlenses and microlens arrays (MLAs). The limitations and strength of each technique are analyzed. The goal is to obtain more stable and repeatable metrology routines for micro-optics manufacturing. This analysis comprises both techniques for the characterization of individual microlenses and the analysis of a very large number of microlenses in array configurations. Metrology of spherical and aspherical lens profiles, surface properties, aberrations, Strehl ratio, and focal properties will be presented.

  3. Recovery Act Validation of Innovative Exploration Techniques Pilgrim Hot Springs, Alaska

    SciTech Connect

    Holdmann, Gwen

    2015-04-30

    Drilling and temperature logging campaigns between the late 1970's and early 1980’s measured temperatures at Pilgrim Hot Springs in excess of 90°C. Between 2010 and 2014 the University of Alaska used a variety of methods including geophysical surveys, remote sensing techniques, heat budget modeling, and additional drilling to better understand the resource and estimate the available geothermal energy.

  4. Innovative technique for tailoring intrinsic stress in reactively sputtered piezoelectric aluminum nitride films

    SciTech Connect

    Felmetsger, V. V.; Laptev, P. N.; Tanner, S. M.

    2009-05-15

    Novel technical and technological solutions enabling effective stress control in highly textured polycrystalline aluminum nitride (AlN) thin films deposited with ac (40 kHz) reactive sputtering processes are discussed. Residual stress in the AlN films deposited by a dual cathode S-Gun magnetron is well controlled by varying Ar gas pressure, however, since deposition rate and film thickness uniformity depend on gas pressure too, an independent stress control technique has been developed. The technique is based on regulation of the flux of the charged particles from ac plasma discharge to the substrate. In the ac powered S-Gun, a special stress adjustment unit (SAU) is employed for reducing compressive stress in the film by means of redistribution of discharge current between electrodes of the S-Gun leading to controllable suppression of bombardment of the growing film. This technique is complementary to AlN deposition with rf substrate bias which increases ion bombardment and shifts stress in the compressive direction, if required. Using SAU and rf bias functions ensures tailoring intrinsic stress in piezoelectric AlN films for a particular application from high compressive -700 MPa to high tensile +300 MPa and allows the gas pressure to be adjusted independently to fine control the film uniformity. The AlN films deposited on Si substrates and Mo electrodes have strong (002) texture with full width at half maximum ranging from 2 degree sign for 200 nm to 1 degree sign for 2000 nm thick films.

  5. Characterizing nonconstant instrumental variance in emerging miniaturized analytical techniques.

    PubMed

    Noblitt, Scott D; Berg, Kathleen E; Cate, David M; Henry, Charles S

    2016-04-01

    Measurement variance is a crucial aspect of quantitative chemical analysis. Variance directly affects important analytical figures of merit, including detection limit, quantitation limit, and confidence intervals. Most reported analyses for emerging analytical techniques implicitly assume constant variance (homoskedasticity) by using unweighted regression calibrations. Despite the assumption of constant variance, it is known that most instruments exhibit heteroskedasticity, where variance changes with signal intensity. Ignoring nonconstant variance results in suboptimal calibrations, invalid uncertainty estimates, and incorrect detection limits. Three techniques where homoskedasticity is often assumed were covered in this work to evaluate if heteroskedasticity had a significant quantitative impact-naked-eye, distance-based detection using paper-based analytical devices (PADs), cathodic stripping voltammetry (CSV) with disposable carbon-ink electrode devices, and microchip electrophoresis (MCE) with conductivity detection. Despite these techniques representing a wide range of chemistries and precision, heteroskedastic behavior was confirmed for each. The general variance forms were analyzed, and recommendations for accounting for nonconstant variance discussed. Monte Carlo simulations of instrument responses were performed to quantify the benefits of weighted regression, and the sensitivity to uncertainty in the variance function was tested. Results show that heteroskedasticity should be considered during development of new techniques; even moderate uncertainty (30%) in the variance function still results in weighted regression outperforming unweighted regressions. We recommend utilizing the power model of variance because it is easy to apply, requires little additional experimentation, and produces higher-precision results and more reliable uncertainty estimates than assuming homoskedasticity. PMID:26995641

  6. Biochemistry and Molecular Biology Techniques for Person Characterization

    ERIC Educational Resources Information Center

    Herrero, Salvador; Ivorra, Jose Luis; Garcia-Sogo, Magdalena; Martinez-Cortina, Carmen

    2008-01-01

    Using the traditional serological tests and the most novel techniques for DNA fingerprinting, forensic scientists scan different traits that vary from person to person and use the data to include or exclude suspects based on matching with the evidence obtained in a criminal case. Although the forensic application of these methods is well known,…

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

    NASA Astrophysics Data System (ADS)

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

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

  8. Application of Acoustic Techniques for Characterization of Biological Samples

    NASA Astrophysics Data System (ADS)

    Tittmann, Bernhard R.; Ebert, Anne

    The atomic force microscope (AFM) is emerging as a powerful tool in cell biology. Originally developed for high-resolution imaging purposes, the AFM also has unique capabilities as a nano-indenter to probe the dynamic viscoelastic material properties of living cells in culture. In particular, AFM elastography combines imaging and indentation modalities to map the spatial distribution of cell mechanical properties, which in turn reflect the structure and function of the underlying cytoskeleton. Such measurements have contributed to our understanding of cell mechanics and cell biology and appear to be sensitive to the presence of disease in individual cells. Examples of applications and considerations on the effective capability of ultrasonic AFM techniques on biological samples (both mammalian and plant) are reported in this chapter. Included in the discussion is scanning near-field ultrasound holography an acoustic technique which has been used to image structure and in particular nanoparticles inside cells. For illustration an example that is discussed in some detail is a technique for rapid in vitro single-cell elastography. The technique is based on atomic force acoustic microscopy (AFAM) but (1) requires only a few minutes of scan time, (2) can be used on live cells briefly removed from most of the nutrient fluid, (3) does negligible harm or damage to the cell, (4) provides semi-quantitative information on the distribution of modulus across the cell, and (5) yields data with 1-10 nm resolution. The technique is shown to enable rapid assessment of physical/biochemical signals on the cell modulus and contributes to current understanding of cell mechanics.

  9. Innovative approaches to exoplanet detection and characterization: Notes from the Nov 10-13 Keck Institute for Space Studies workshop

    NASA Astrophysics Data System (ADS)

    Young, Eliot; Traub, Wesley; Unwin, Stephen; Stapelfeldt, Karl

    2010-05-01

    A four-day workshop was convened on November 10-13, 2009 by the Keck Institute for Space Studies and JPL to consider innovative approaches to detecting and characterizing exoplanets and planetary systems. The program and many of the presentations can be found online: . We present some of the observational strategies discussed in this workshop and summarize some of the issues associated with them. In particular, we will highlight some of the advantages and shortcomings of suborbital and orbital (e.g., ESPA rings) observing platforms in the context of exoplanet detection and characterization.

  10. System and technique for ultrasonic characterization of settling suspensions

    DOEpatents

    Greenwood, Margaret S.; Panetta, Paul D.; Bamberger, Judith A.; Pappas, Richard A.

    2006-11-28

    A system for determining properties of settling suspensions includes a settling container, a mixer, and devices for ultrasonic interrogation transverse to the settling direction. A computer system controls operation of the mixer and the interrogation devices and records the response to the interrogating as a function of settling time, which is then used to determine suspension properties. Attenuation versus settling time for dilute suspensions, such as dilute wood pulp suspension, exhibits a peak at different settling times for suspensions having different properties, and the location of this peak is used as one mechanism for characterizing suspensions. Alternatively or in addition, a plurality of ultrasound receivers are arranged at different angles to a common transmitter to receive scattering responses at a variety of angles during particle settling. Angular differences in scattering as a function of settling time are also used to characterize the suspension.

  11. Innovative Approaches for Rapid Subsurface Characterization Compared at a Rural Megasite

    NASA Astrophysics Data System (ADS)

    Rein, A.; Holm, O.; Popp, S.; Bittens, M.; Rotard, W.; Dietrich, P.

    2008-12-01

    Megasites often are characterized by extended areas which are contaminated in soil and groundwater. In view of sustainable land management, the revitalization of such sites may significantly contribute to the reduction of land consumption. Furthermore, potential external effects need to be assessed, such as contaminant discharge via groundwater and potential impacts to off-site receptors. Due to multiple contaminant sources and high uncertainties concerning the possible distribution of contamination in the subsurface, information on the whole site may be required. Respective site investigation needs to be reliable and cost-effective, facing limited budgets especially for rural or suburban areas, i.e. due to a lower pressure of development compared to urban locations. At a former military site near Berlin, Germany, adaptive strategies and technologies for a risk-based site characterization and monitoring were developed and applied and compared to conventional techniques. Direct-push (DP)-based groundwater screening and tree core sampling, i.e. considering contaminant uptake into trees as an indirect indication of organic pollutions in the subsurface, were performed along a wide- meshed grid covering the whole site of approx. 120 hectares. Tree core sampling also covered the downstream area of the site, which is characterized by wetlands that are not accessible for DP, in order to investigate the plume extension. The DP-based groundwater screening was performed within a short time period, i.e. less than three weeks, at significantly lower costs compared to investigations based upon conventional groundwater wells (which characterized areas of suspected contamination, only). Findings of monitoring at the conventional wells could be confirmed, and new and unexpected areas of groundwater contamination at the site were identified. Results of groundwater sampling were in a good accordance to results of the tree core sampling campaign. Consequently, this novel investigation

  12. Characterization of super smooth surfaces by light scattering techniques

    NASA Astrophysics Data System (ADS)

    Mattsson, Lars H.

    1989-03-01

    A characteristic feature of a supersmooth surface is its low scatter. The scatter is proportional to the square of the rms surface roughness. Therefore, light scattering is a suitable and nondestructive method for characterization of smooth surfaces. It is possible to detect scattering created by height differences of a few atomic layers but the lateral sensitivity is limited to the order of the wavelength, ~0.5μm. The new F 1048-87 ASTM standard test method for measuring the effective surface roughness of optical components is based on total integrated scattering (TIS). The amount of scattering, caused by the surface roughness, is of primary interest for optical applications, while the roughness itself is of greater concern in the fields of microelectronics and magnetic memory storage. This paper will highlight the use of a low noise TIS instrument for characterization of sub-Å roughness on semiconductor wafers, for thin film characterization, and for detection of traces of contamination on silicon surfaces.

  13. Direct Exoplanet Imaging around Sun-like Stars: Beating the Speckle Noise with Innovative Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Marois, Christian; Doyon, R.; Racine, R.; Nadeau, D.; Lafreniere, D.; Vallee, P.; Riopel, M.; Macintosh, B.

    2005-08-01

    Indirect surveys have now uncovered more than 150 exoplanets, but are limited to planets close to the star and measure only the projected mass and orbital parameters. Both photometry and spectroscopy of exoplanets are required to derive their physical characteristics. The star to exoplanet intensity ratio (>108 in the near infrared) and the relative separation (< 0.5 arcseconds) significantly complicate this endeavour. Current ground- and space-based direct imaging surveys achieve an intensity ratio up to 104 at 0.5. separation, a factor 10,000 from the desired goal. These surveys are limited by uncorrected atmospheric turbulence and optical surface imperfections that produce quasi-static speckles that look like exoplanets, but much brighter. Two techniques will be discussed to attenuate this speckle noise. The first is the Simultaneous Spectral Differential Imaging technique (SSDI), acquiring a number of images simultaneously at different adjacent narrowband wavelengths and combining them to attenuate speckles. The second is the Angular Differential Imaging technique (ADI), taking multiple observations while rotating the telescope or waiting for sufficient field rotation to subtract static speckles and to preserve the companion flux. Results from a dedicated SSDI camera "TRIDENT" that was mounted under PUEO/CFHT and from an ongoing ADI survey at Gemini with Altair/NIRI will be presented. Future work involving a new type of detector, the Multi-Color Detector Assembly (MCDA), will also be discussed. Combining these observation strategies and new detectors are of particular interest for specialized exoplanet finder instruments for 10-m telescopes that are currently under study, like ExAOC at Gemini, and future space-based observatories like TPF.

  14. Innovative High-Accuracy Lidar Bathymetric Technique for the Frequent Measurement of River Systems

    NASA Astrophysics Data System (ADS)

    Gisler, A.; Crowley, G.; Thayer, J. P.; Thompson, G. S.; Barton-Grimley, R. A.

    2015-12-01

    Lidar (light detection and ranging) provides absolute depth and topographic mapping capability compared to other remote sensing methods, which is useful for mapping rapidly changing environments such as riverine systems. Effectiveness of current lidar bathymetric systems is limited by the difficulty in unambiguously identifying backscattered lidar signals from the water surface versus the bottom, limiting their depth resolution to 0.3-0.5 m. Additionally these are large, bulky systems that are constrained to expensive aircraft-mounted platforms and use waveform-processing techniques requiring substantial computation time. These restrictions are prohibitive for many potential users. A novel lidar device has been developed that allows for non-contact measurements of water depth down to 1 cm with an accuracy and precision of < 1 cm by exploiting the polarization properties of the light-surface interaction. This system can transition seamlessly from ranging over land to shallow to deep water allowing for shoreline charting, measuring water volume, mapping bottom topology, and identifying submerged objects. The scalability of the technique opens up the ability for handheld or UAS-mounted lidar bathymetric systems, which provides for potential applications currently unavailable to the community. The high laser pulse repetition rate allows for very fine horizontal resolution while the photon-counting technique permits real-time depth measurement and object detection. The enhanced measurement capability, portability, scalability, and relatively low-cost creates the opportunity to perform frequent high-accuracy monitoring and measuring of aquatic environments which is crucial for understanding how rivers evolve over many timescales. Results from recent campaigns measuring water depth in flowing creeks and murky ponds will be presented which demonstrate that the method is not limited by rough water surfaces and can map underwater topology through moderately turbid water.

  15. Innovative non-invasive analysis techniques for cultural heritage using terahertz technology

    NASA Astrophysics Data System (ADS)

    Fukunaga, Kaori; Hosako, I.

    2010-08-01

    Terahertz (THz) spectroscopy and THz imaging techniques are expected to have great potential for carrying out the non-invasive analysis of artworks. THz waves can penetrate opaque materials and they can perform three-dimensional material mapping non-destructively by spectroscopic imaging. Several attempts have been made to analyse artworks. Clear results, such as imaging of hidden art by using model paintings, have been obtained by many institutions. We succeeded to observe the first ever non-invasive cross-sectional image of a tempera masterpiece by Giotto. These results prove that THz technology can yield useful information in art conservation science.

  16. Pulsed photothermal mirror technique: characterization of opaque materials.

    PubMed

    Capeloto, O A; Lukasievicz, G V B; Zanuto, V S; Herculano, L S; Souza Filho, N E; Novatski, A; Malacarne, L C; Bialkowski, S E; Baesso, M L; Astrath, N G C

    2014-11-20

    The time-resolved thermal mirror technique is developed under pulsed laser excitation for quantitative measurement of thermal and mechanical properties of opaque materials. Heat diffusion and thermoelastic equations are solved analytically for pulsed excitation assuming surface absorption and an instantaneous pulse. Analytical results for the temperature change and surface displacement in the sample are compared to all-numerical solutions using finite element method analysis accounting for the laser pulse width and sample geometry. Experiments are performed that validate the theoretical model and regression fitting is performed to obtain the thermal diffusivity and the linear thermal expansion coefficient of the samples. The values obtained for these properties are in agreement with literature data. The technique is shown to be useful for quantitative determinations of the physics properties of metals with high thermal diffusivity. PMID:25607877

  17. Demonstration to characterize watershed runoff potential by microwave techniques

    NASA Technical Reports Server (NTRS)

    Blanchard, B. J.

    1977-01-01

    Characteristics such as storage capacity of the soil, volume of storage in vegetative matter, and volume of storage available in local depressions are expressed in empirical watershed runoff equations as one or more coefficients. Conventional techniques for estimating coefficients representing the spatial distribution of these characteristics over a watershed drainage area are subjective and produce significant errors. Characteristics of the wear surface are described as a single coefficient called the curve number.

  18. An innovative technique in scanning land areas with a multi-FIDLER system.

    PubMed

    Marianno, C M; Higley, K A; Hunter, D

    2001-05-01

    Remediation can be a long and tedious effort. One possible step in this process is the scanning of land to locate elevated areas of radiological contamination. By adapting existing global positioning technology with radiation detection systems, this process can be significantly accelerated. The Field Instrument for Detecting Low Energy Radiation (FIDLER) was used in conjunction with a Global Positioning System (GPS) and Trimble data logger. With this system two different land areas were scanned using two different scanning methods. In the first method, three FIDLERs were attached to a baby jogger and were used to scan a 20-acre site devoid of vegetation. The second technique involved individuals carrying the instruments over a 15-acre site that contained vegetation. Here the FIDLERs were waved in front of the workers in 50-cm arcs. In all cases, radiological and position data were collected by the data loggers. Using these results, accurate maps were generated for each site clearly illustrating areas and spots of elevated activity. By employing this technique over 250,000 data points pertaining to position and count rate were used to map nearly 40 acres of land in under 3 wk. PMID:11316088

  19. Advancing the Frontiers in Nanocatalysis, Biointerfaces, and Renewable Energy Conversion by Innovations of Surface Techniques

    SciTech Connect

    Somorjai, G.A.; Frei, H.; Park, J.Y.

    2009-07-23

    The challenge of chemistry in the 21st century is to achieve 100% selectivity of the desired product molecule in multipath reactions ('green chemistry') and develop renewable energy based processes. Surface chemistry and catalysis play key roles in this enterprise. Development of in situ surface techniques such as high-pressure scanning tunneling microscopy, sum frequency generation (SFG) vibrational spectroscopy, time-resolved Fourier transform infrared methods, and ambient pressure X-ray photoelectron spectroscopy enabled the rapid advancement of three fields: nanocatalysts, biointerfaces, and renewable energy conversion chemistry. In materials nanoscience, synthetic methods have been developed to produce monodisperse metal and oxide nanoparticles (NPs) in the 0.8-10 nm range with controlled shape, oxidation states, and composition; these NPs can be used as selective catalysts since chemical selectivity appears to be dependent on all of these experimental parameters. New spectroscopic and microscopic techniques have been developed that operate under reaction conditions and reveal the dynamic change of molecular structure of catalysts and adsorbed molecules as the reactions proceed with changes in reaction intermediates, catalyst composition, and oxidation states. SFG vibrational spectroscopy detects amino acids, peptides, and proteins adsorbed at hydrophobic and hydrophilic interfaces and monitors the change of surface structure and interactions with coadsorbed water. Exothermic reactions and photons generate hot electrons in metal NPs that may be utilized in chemical energy conversion. The photosplitting of water and carbon dioxide, an important research direction in renewable energy conversion, is discussed.

  20. An innovative privacy preserving technique for incremental datasets on cloud computing.

    PubMed

    Aldeen, Yousra Abdul Alsahib S; Salleh, Mazleena; Aljeroudi, Yazan

    2016-08-01

    Cloud computing (CC) is a magnificent service-based delivery with gigantic computer processing power and data storage across connected communications channels. It imparted overwhelming technological impetus in the internet (web) mediated IT industry, where users can easily share private data for further analysis and mining. Furthermore, user affable CC services enable to deploy sundry applications economically. Meanwhile, simple data sharing impelled various phishing attacks and malware assisted security threats. Some privacy sensitive applications like health services on cloud that are built with several economic and operational benefits necessitate enhanced security. Thus, absolute cyberspace security and mitigation against phishing blitz became mandatory to protect overall data privacy. Typically, diverse applications datasets are anonymized with better privacy to owners without providing all secrecy requirements to the newly added records. Some proposed techniques emphasized this issue by re-anonymizing the datasets from the scratch. The utmost privacy protection over incremental datasets on CC is far from being achieved. Certainly, the distribution of huge datasets volume across multiple storage nodes limits the privacy preservation. In this view, we propose a new anonymization technique to attain better privacy protection with high data utility over distributed and incremental datasets on CC. The proficiency of data privacy preservation and improved confidentiality requirements is demonstrated through performance evaluation. PMID:27369566

  1. An innovative technique to simply fabricate ZrO₂-HA-TiO₂ nanostructured layers.

    PubMed

    Samanipour, F; Bayati, M R; Golestani-Fard, F; Zargar, H R; Troczynski, T; Mirhabibi, A R

    2011-08-01

    For the first time, ZrO₂-HA-TiO₂ layers were synthesized through EPD-Enhanced MAO (EEMAO) technique in only one step where no supplementary treatment was required. SEM, XRD, EDX, and XPS techniques were employed to propose a correlation between the growth parameters and the physical and chemical properties of the layers. The layers revealed a porous structure where applying higher voltages and/or utilizing higher concentrated electrolytes resulted in formation of wider pores and increasing the zirconium concentration in the layers; meanwhile, prolonging the growth time had the same effects. The layers mainly consisted of anatase, hydroxyapatite, monoclinic ZrO₂, and tetragonal ZrO₂ phases. Increasing the voltage, electrolyte concentration, and time, hydroxyapatite as well as tetragonal ZrO₂ was decomposed to α-TCP, monoclinic ZrO₂, and ZrO. The nanosized zirconia particles (d = 20-60 nm) were further accumulated on the vicinity of the layers when thicker electrolytes were utilized or higher voltages were applied. Emphasizing on the chemical and electrochemical foundations, a probable formation mechanism was finally put forward. PMID:21514799

  2. From Brainstorming to C-Sketch to Principles of Historical Innovators: Ideation Techniques to Enhance Student Creativity

    ERIC Educational Resources Information Center

    White, Christina; Wood, Kristin; Jensen, Dan

    2012-01-01

    The heart and soul of engineering is innovation and our ability to improve the human condition through design. To enrich engineering education, it is critical that we advance our teaching in innovation and design processes. This research focuses on the ideation component of innovation through the investigation of a suite of concept generation…

  3. Characterization of Magnetron Sputtered Coatings by Pulsed Eddy Current Techniques

    SciTech Connect

    Mulligan, Chris; Lee Changqing; Danon, Yaron

    2005-04-09

    A method that uses induced pulsed eddy currents for characterization of thick magnetron sputtered Nb coatings on steel is presented in this paper. The objectives of this work are to develop a system for rapid quantitative nondestructive inspection of coatings as well as to determine the correlation between coating properties, such as density and purity, and eddy current measured resistivity of coatings. A two-probe differential system having higher sensitivity and less noise than a one-probe system with 2-D scanning ability was developed.

  4. A Innovative Technique - Modified Feeding Bottle for a Cleft Palate Infant

    PubMed Central

    Lingegowda, Ashwini Budunur; Rayannavar, Sounyala; Kumari, Nirmala

    2016-01-01

    Cleft lip and cleft palate are one of the most common craniofacial anomalies. Infants suffer a lot of difficulty in sucking during the initial few days after birth. There is even psychological stress to the parents due to improper feeding and the infants lose weight and are prone to nutritional insufficiency. Due to recent advancement in the medical field, there is a total repair of cleft lip and cleft palate and these procedures are performed in the later stages of infants. It is the multidisciplinary approach which includes pedodontist, oral surgeon, prosthodontist and speech therapist. In this article, the technique is highlighted to fulfill the feeding problem of infants in the early stages of birth with a modified feeding bottle. PMID:27190971

  5. A Innovative Technique - Modified Feeding Bottle for a Cleft Palate Infant.

    PubMed

    Hiremath, Vinuta Siddayya; Lingegowda, Ashwini Budunur; Rayannavar, Sounyala; Kumari, Nirmala

    2016-04-01

    Cleft lip and cleft palate are one of the most common craniofacial anomalies. Infants suffer a lot of difficulty in sucking during the initial few days after birth. There is even psychological stress to the parents due to improper feeding and the infants lose weight and are prone to nutritional insufficiency. Due to recent advancement in the medical field, there is a total repair of cleft lip and cleft palate and these procedures are performed in the later stages of infants. It is the multidisciplinary approach which includes pedodontist, oral surgeon, prosthodontist and speech therapist. In this article, the technique is highlighted to fulfill the feeding problem of infants in the early stages of birth with a modified feeding bottle. PMID:27190971

  6. Mini-FLOTAC, an Innovative Direct Diagnostic Technique for Intestinal Parasitic Infections: Experience from the Field

    PubMed Central

    Barda, Beatrice Divina; Rinaldi, Laura; Ianniello, Davide; Zepherine, Henry; Salvo, Fulvio; Sadutshang, Tsetan; Cringoli, Giuseppe; Clementi, Massimo; Albonico, Marco

    2013-01-01

    Background Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini–FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings. Methodology/Principal Findings The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC). Conclusion/Significance We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings — particularly for helminth diagnosis. PMID:23936577

  7. Superresolution imaging system on innovative localization microscopy technique with commonly using dyes and CMOS camera

    NASA Astrophysics Data System (ADS)

    Dudenkova, V.; Zakharov, Yu.

    2015-05-01

    Optical methods for study biological tissue and cell at micro- and nanoscale level step now over diffraction limit. Really it is single molecule localization techniques that achieve the highest spatial resolution. One of those techniques, called bleaching/blinking assisted localization microscopy (BaLM) relies on the intrinsic bleaching and blinking behavior characteristic of commonly used fluorescent probes. This feature is the base of BaLM image series acquisition and data analysis. In our work blinking of single fluorescent spot against a background of others comes to light by subtraction of time series successive frames. Then digital estimation gives the center of the spot as a point of fluorescent molecule presence, which transfers to other image with higher resolution according to accuracy of the center localization. It is a part of image with improved resolution. This approach allows overlapping fluorophores and not requires single photon sensitivity, so we use 8,8 megapixel CMOS camera with smallest (1.55 um) pixel size. This instrumentation on the base of Zeiss Axioscope 2 FS MOT allows image transmission from object plane to matrix on a scale less than 100 nm/pixel using 20x-objective, thereafter the same resolution and 5 times more field of view as compared to EMCCD camera with 6 um pixel size. To optimize excitation light power, frame rate and gain of camera we have made appropriate estimations taking into account fluorophores behaviors features and equipment characteristics. Finely we have clearly distinguishable details of the sample in the processed field of view.

  8. Using morphometric and analytical techniques to characterize elephant ivory.

    PubMed

    Singh, Rina Rani; Goyal, Surendra Prakash; Khanna, Param Pal; Mukherjee, Pulok Kumar; Sukumar, Raman

    2006-10-16

    There is a need to characterize Asian elephant ivory and compare with African ivory for controlling illegal trade and implementation of national and international laws. In this paper, we characterize ivory of Asian and African elephants using Schreger angle measurements, elemental analysis {X-ray fluorescence (XRF), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and inductively coupled plasma-mass spectroscopy (ICP-MS)} and isotopic analysis. We recorded Schreger angle characteristics of elephant ivory at three different zones in ivory samples of African (n=12) and Asian (n=28) elephants. The Schreger angle ranged from 32 degrees to 145 degrees and 30 degrees to 153 degrees in Asian and African ivory, respectively. Elemental analysis (for Asian and African ivory) by XRF, ICP-AES and ICP-MS provided preliminary data. We attempted to ascertain source of origin of Asian elephant ivory similarly as in African ivory based on isotopes of carbon, nitrogen and strontium. We determined isotopic ratios of carbon (n=31) and nitrogen (n=31) corresponding to diet and rainfall, respectively. Reference ivory samples from five areas within India were analyzed using collagen and powder sample and the latter was found more suitable for forensic analysis. During our preliminary analysis, the range of delta13C values (-13.6+/-0.15 per thousand and -25.6+/-0.15 per thousand) and delta15N values (10.2+/-0.15 per thousand and 3.5+/-0.15 per thousand) were noted. PMID:16891073

  9. Discovery of naked charm particles and lifetime differences among charm species using nuclear emulsion techniques innovated in Japan

    PubMed Central

    NIU, Kiyoshi

    2008-01-01

    This is a historical review of the discovery of naked charm particles and lifetime differences among charm species. These discoveries in the field of cosmic-ray physics were made by the innovation of nuclear emulsion techniques in Japan. A pair of naked charm particles was discovered in 1971 in a cosmic-ray interaction, three years prior to the discovery of the hidden charm particle, J/Ψ, in western countries. Lifetime differences between charged and neutral charm particles were pointed out in 1975, which were later re-confirmed by the collaborative Experiment E531 at Fermilab. Japanese physicists led by K.Niu made essential contributions to it with improved emulsion techniques, complemented by electronic detectors. This review also discusses the discovery of artificially produced naked charm particles by us in an accelerator experiment at Fermilab in 1975 and of multiple-pair productions of charm particles in a single interaction in 1987 by the collaborative Experiment WA75 at CERN. PMID:18941283

  10. Integration of Scale Invariant Generator Technique and S-A Technique for Characterizing 2-D Patterns for Information Retrieve

    NASA Astrophysics Data System (ADS)

    Cao, L.; Cheng, Q.

    2004-12-01

    The scale invariant generator technique (SIG) and spectrum-area analysis technique (S-A) were developed independently relevant to the concept of the generalized scale invariance (GSI). The former was developed for characterizing the parameters involved in the GSI for characterizing and simulating multifractal measures whereas the latter was for identifying scaling breaks for decomposition of superimposed multifractal measures caused by multiple geophysical processes. A natural integration of these two techniques may yield a new technique to serve two purposes, on the one hand, that can enrich the power of S-A by increasing the interpretability of decomposed patterns in some applications of S-A and, on the other hand, that can provide a mean to test the uniqueness of multifractality of measures which is essential for application of SIG technique in more complicated environment. The implementation of the proposed technique has been done as a Dynamic Link Library (DLL) in Visual C++. The program can be friendly used for method validation and application in different fields.

  11. Characterization of a Mycobacterium intracellulare Variant Strain by Molecular Techniques

    PubMed Central

    Menendez, M. C.; Palenque, E.; Navarro, M. C.; Nuñez, M. C.; Rebollo, M. J.; Garcia, M. J.

    2001-01-01

    This paper describes a Mycobacterium intracellulare variant strain causing an unusual infection. Several isolates obtained from an immunocompromised patient were identified as members of the Mycobacterium avium complex (MAC) by the commercial AccuProbe system and biochemical standard identification. Further molecular approaches were undertaken for a more accurate characterization of the bacteria. Up to seven different genomic sequences were analyzed, ranging from conserved mycobacterial genes such as 16S ribosomal DNA to MAC-specific genes such as mig (macrophage-induced gene). The results obtained identify the isolates as a variant of M. intracellulare, an example of the internal variability described for members of the MAC, particularly within that species. The application of other molecular approaches is recommended for more accurate identification of bacteria described as MAC members. PMID:11724827

  12. Thermal Characterization of Carbon Nanotubes by Photothermal Techniques

    NASA Astrophysics Data System (ADS)

    Leahu, G.; Li Voti, R.; Larciprete, M. C.; Sibilia, C.; Bertolotti, M.; Nefedov, I.; Anoshkin, I. V.

    2015-06-01

    Carbon nanotubes (CNTs) are multifunctional materials commonly used in a large number of applications in electronics, sensors, nanocomposites, thermal management, actuators, energy storage and conversion, and drug delivery. Despite recent important advances in the development of CNT purity assessment tools and atomic resolution imaging of individual nanotubes by scanning tunnelling microscopy and high-resolution transmission electron microscopy, the macroscale assessment of the overall surface qualities of commercial CNT materials remains a great challenge. The lack of quantitative measurement technology to characterize and compare the surface qualities of bulk manufactured and engineered CNT materials has negative impacts on the reliable and consistent nanomanufacturing of CNT products. In this paper it is shown how photoacoustic spectroscopy and photothermal radiometry represent useful non-destructive tools to study the optothermal properties of carbon nanotube thin films.

  13. PIXE as a characterization technique in the cutting tool industry

    NASA Astrophysics Data System (ADS)

    Freemantle, C. S.; Sacks, N.; Topic, M.; Pineda-Vargas, C. A.

    2014-01-01

    Two WC-Co powders have been analyzed using micro-PIXE to identify elemental concentration and distribution. A powder recycled primarily from used mining components and a powder produced exclusively from fresh raw materials was studied. Elemental mapping of major elements as well as impurities, within powder granule cross sections, was performed. Contaminants (e.g. Fe and Ni) from manufacturing processes, as well as trace impurities (e.g. Cr, Cl, Ca and S) from recycling were detected, quantified and compared. The extent of increased concentrations of impurities resulting from recycling were observed, demonstrating the potential for PIXE as a characterization tool for detecting trace elements in cemented carbides, allowing for future improvements in the manufacturing and recycling processes.

  14. Characterization of drug iontophoresis with a fast microassay technique.

    PubMed Central

    Dionne, V E

    1976-01-01

    The iontophoretic release of drugs from micropipettes into free (Ringer's) solution was described using an ion-selective microelectrode assay method. This characterization, with a temporal resolution of 20 ms, showed that the equilibrium rate of drug transport was not linearly proportional to release current; the departure from linearity was increased by backing current and the result was demonstrated with analytically derived drug release functions. The general relation between the drug transport rate and release current was independent of the specific drug or pipette resistance; no functional relation was observed that might quantitatively predict this dependence without prior use of the assay. The diffusion coefficients at 25 degrees C in frog Ringer's of the drugs used in this study, all neuromuscular agonists, were determined: all values X 10(6) cm2/s; acetylcholine 6.11 +/- 0.30; carbamylcholine 7.44 +/- 0.34; 3-(m-hydroxyphenyl) prophyltrimethyl ammonium 5.79 +/- 0.13. PMID:938714

  15. Numerical analysis of radiation propagation in innovative volumetric receivers based on selective laser melting techniques

    NASA Astrophysics Data System (ADS)

    Alberti, Fabrizio; Santiago, Sergio; Roccabruna, Mattia; Luque, Salvador; Gonzalez-Aguilar, Jose; Crema, Luigi; Romero, Manuel

    2016-05-01

    Volumetric absorbers constitute one of the key elements in order to achieve high thermal conversion efficiencies in concentrating solar power plants. Regardless of the working fluid or thermodynamic cycle employed, design trends towards higher absorber output temperatures are widespread, which lead to the general need of components of high solar absorptance, high conduction within the receiver material, high internal convection, low radiative and convective heat losses and high mechanical durability. In this context, the use of advanced manufacturing techniques, such as selective laser melting, has allowed for the fabrication of intricate geometries that are capable of fulfilling the previous requirements. This paper presents a parametric design and analysis of the optical performance of volumetric absorbers of variable porosity conducted by means of detailed numerical ray tracing simulations. Sections of variable macroscopic porosity along the absorber depth were constructed by the fractal growth of single-cell structures. Measures of performance analyzed include optical reflection losses from the absorber front and rear faces, penetration of radiation inside the absorber volume, and radiation absorption as a function of absorber depth. The effects of engineering design parameters such as absorber length and wall thickness, material reflectance and porosity distribution on the optical performance of absorbers are discussed, and general design guidelines are given.

  16. An innovative antisolvent precipitation process as a promising technique to prepare ultrafine rifampicin particles

    NASA Astrophysics Data System (ADS)

    Viçosa, Alessandra; Letourneau, Jean-Jacques; Espitalier, Fabienne; Inês Ré, Maria

    2012-03-01

    Many existing and new drugs fail to be fully utilized because of their limited bioavailability due to poor solubility in aqueous media (BCS drug classes II and IV). In this work, for accelerating dissolution of this kind of poorly water-soluble drugs, an antisolvent precipitation method that does not require the use of conventional volatile organic solvents is proposed. To demonstrate this technique, ultrafine particles of rifampicin were prepared using a room temperature ionic liquid (1-ethyl 3- methyl imidazolium methyl-phosphonate) as an alternative solvent and a phosphate buffer as an antisolvent. Rifampicin solubility was measured in various solvents (1-ethyl 3-methyl imidazolium methylphosphonate, water and phosphate buffer), showing the RTIL good solvency for the model drug: rifampicin solubility was found to be higher than 90 mg/g in RTIL at 30 °C and lower than 1 mg/g in water at 25 °C. Additionally, it was demonstrated that introduction of rifampicin solution in 1-ethyl 3- methyl imidazolium methyl-phosphonate into the aqueous solution antisolvent can produce particles in the submicron range with or without hydroxypropyl methylcellulose as the stabilizer. The ultrafine particles (280-360 nm) are amorphous with enhanced solubility and faster dissolution rate. To our knowledge, this is the first published work examining the suitability of using RTILs for ultrafine drug nanoparticles preparation by an antisolvent precipitation process.

  17. Photothermal laser deflection, an innovative technique to measure particles in exhausts

    NASA Astrophysics Data System (ADS)

    Hess, Cecil F.

    1993-10-01

    Photothermal Laser Deflection (PLD) is an analytical technique to measure in real-time the mass concentration of particles and gaseous exhaust pollutants in a variety of combustion devices (e.g., gas turbine engines and rockets). PLD uses a pump laser to locally heat the particle or gaseous species, thus changing the refractive index of the surrounding gas to form a thermal lens. A probe laser beam travelling through the thermal lens is temporarily deflected, and the amount of deflection is proportional to the species mass concentration. The experiments and analyses conducted during phase 1 demonstrated the feasibility of PLD in measuring the mass concentration of both soot particles and NO2 at a repetition rate of 25 HZ. PLD response was linear at soot concentrations from 0.3 to 10 mg/cubic meters at NO2 concentrations from approximately 6 to 208 ppm. Strategies to measure lower concentrations have been defined and include focusing the probe beam onto the face of the bi-cell detector. The large dynamic range, fast acquisition rate, and ability to measure particulate and gaseous pollutants makes PLD superior to other available methods.

  18. Innovative techniques for analyzing the three-dimensional behavioral results from acoustically tagged fish

    NASA Astrophysics Data System (ADS)

    Steig, Tracey W.; Timko, Mark A.

    2005-04-01

    Acoustic tags were used to monitor the swimming patterns of downstream migrating salmon smolts approaching various dams on the Columbia River, USA. Downstream migrating yearling chinook (Oncorhynchus tshawytscha), steelhead (Oncorhynchus mykiss), sockeye (Oncorhynchus nerka), and sub-yearling chinook smolts were surgically implanted with acoustic tags. Fish were tracked in three-dimensions as they approached and passed into the turbine intakes, spillways, and surface bypass channel entrances at the dams during the 2004 spring and summer outmigrations. A number of advances in the analysis techniques and software have been made over the past few years. Some of these improvements include the development of various fish density algorithms, stream trace modeling analysis, and advances of three-dimensional animation programs. Three-dimensional tracks of fish approaching the turbine intakes, spillways, and surface bypass channel entrances will be presented. Concentrations of fish passage will be presented as three-dimensional fish densities superimposed over dam structures. Stream trace modeling animation will be presented showing predicted fish passage routes.

  19. Ground Penetrating Radar technique for railway track characterization in Portugal

    NASA Astrophysics Data System (ADS)

    De Chiara, Francesca; Fontul, Simona; Fortunato, Eduardo; D'Andrea, Antonio

    2013-04-01

    Maintenance actions are significant for transport infrastructures but, today, costs have to be necessary limited. A proper quality control since the construction phase is a key factor for a long life cycle and for a good economy policy. For this reason, suitable techniques have to be chosen and non-destructive tests represent an efficient solution, as they allow to evaluate infrastructure characteristics in a continuous or quasi-continuous way, saving time and costs, enabling to make changes if tests results do not comply with the project requirements. Ground Penetrating Radar (GPR) is a quick and effective technique to evaluate infrastructure condition in a continuous manner, replacing or reducing the use of traditional drilling method. GPR application to railways infrastructures, during construction and monitoring phase, is relatively recent. It is based on the measuring of layers thicknesses and detection of structural changes. It also enables the assessment of materials properties that constitute the infrastructure and the evaluation of the different types of defects such as ballast pockets, fouled ballast, poor drainage, subgrade settlement and transitions problems. These deteriorations are generally the causes of vertical deviations in track geometry and they cannot be detected by the common monitoring procedures, namely the measurements of track geometry. Moreover, the development of new GPR systems with higher antenna frequencies, better data acquisition systems, more user friendly software and new algorithms for calculation of materials properties can lead to a regular use of GPR. Therefore, it represents a reliable technique to assess track geometry problems and consequently to improve maintenance planning. In Portugal, rail inspection is performed with Plasser & Theurer EM120 equipment and recently 400 MHz IDS antennas were installed on it. GPR tests were performed on the Portuguese rail network and, as case study in this paper, a renewed track was

  20. Thermal characterization of nanofluids using laser induced thermal lens technique

    NASA Astrophysics Data System (ADS)

    Kurian, Achamma; Kumar, Rajesh B.; George, Sajan D.

    2009-08-01

    A laser induced thermal lens technique has been employed to evaluate the dynamic thermal parameter, the thermal diffusivity, of gold nanofluids. Gold nanoparticles were synthesized by citrate reduction of HAuCl4 in water. The UVVIS optical absorption spectra show an absorption peak around 540 nm owing to surface Plasmon resonance band of the gold particles. The thermal diffusivity of gold nanoparticles was evaluated by knowing the time constant of transient thermal lens obtained by fitting the experimental curve to the theoretical model of the mode-matched thermal lens. Analyses of the results show that the nanofluid exhibits lower thermal diffusivity value in comparison to the host medium, water. Further investigations also reveal that the concentration of nanoparticles in the fluid have influence on the measured thermal diffusivity value. Results are interpreted in terms of interfacial thermal resistance around the nanoparticles as well as on the clustering of nanoparticles.

  1. Modulation transfer function technique for real time radioscopic system characterization

    SciTech Connect

    Tobin, K.W. ); Brenizer, J.S. ); Mait, J.N. )

    1989-12-01

    At the University of Virginia neutron radiography facility, a modulation transfer function technique has been developed that can easily predict and compare the resolving characteristics of the real time system and the individual system components. We desired a simple method by which new system components could be analyzed to determine their image transfer characteristics and to estimate how they would affect the composite system during data acquisition. The method employed measures a small set of constant system parameters related to data collected across a cadmium cut-edge aperture. The effects of system noise and spatial variance on the measured data are reduced so that a representation of the true signal can be obtained for analysis. Resolution parameters for the total neutron radiography system and for the individual system components are reported.

  2. Modulation transfer function technique for real time radioscopic system characterization.

    PubMed

    Tobin, K W; Brenizer, J S; Mait, J N

    1989-12-01

    At the University of Virginia neutron radiography facility, a modulation transfer function technique has been developed that can easily predict and compare the resolving characteristics of the real time system and the individual system components. We desired a simple method by which new system components could be analyzed to determine their image transfer characteristics and to estimate how they would affect the composite system during data acquisition. The method employed measures a small set of constant system parameters related to data collected across a cadmium cut-edge aperture. The effects of system noise and spatial variance on the measured data are reduced so that a representation of the true signal can be obtained for analysis. Resolution parameters for the total neutron radiography system and for the individual system components are reported. PMID:20555991

  3. A New Spitzer IRAC Technique to Characterize Exoplanet Atmospheres

    NASA Astrophysics Data System (ADS)

    Krick, Jessica; Ingalls, J.; Carey, S.; von Braun, K.

    2012-05-01

    Spitzer’s extended warm mission gives us the opportunity to contribute to its legacy by performing comparative science on atmospheres of extrasolar planets. Observation of phase curves produce maps of the longitudinal brightness/temperature distributions in the planetary atmospheres, which are then used to calculate energy redistribution efficiencies between the hot dayside and cooler nightside - exoplanetary weather. Recent improvements in the calibration of IRAC make possible a new observing technique which will be much more efficient than standard staring mode observations by using snapshot observations to emulate a full phase curve. The challenge with using snapshot observations is in making sure all observing epochs can be tied together with high enough photometric precision. The dominant source of error in this task is intrapixel gain variations on sub pixel levels. We have effectively removed this source of error by using the Pointing Calibration and Reference Sensor (PCRS) onboard Spitzer for pointing repeatability that is significantly better than random pointing. Because we have achieved this excellent repeatability, we are able to build up a map of the intrapixel gain, which is then used to independently correct IRAC photometry as a function of position on the pixel. We discuss additional sources of noise below the gain variations, at the sub percent level, such as pixel-wise nonlinearities, and our efforts to remove them. We present preliminary 4.5 micron data of HD209458 where we compare staring mode observations to snapshots taken with this new technique, corrected by the gain and residual nonlinearity map, and comment on the scientific implications of the resultant phase curve.

  4. Characterizing a Brazilian sanitary landfill using geophysical seismic techniques.

    PubMed

    Abreu, A E S; Gandolfo, O C B; Vilar, O M

    2016-07-01

    Two different geophysical techniques, namely crosshole and multichannel analysis of surface waves - MASW, were applied to investigate the mechanical response of Municipal Solid Waste buried under humid, subtropical climate. Direct investigations revealed that the buried waste was composed mainly of soil-like material (51%) and plastics (31%) with moisture content average values of 43% near the surface and 53% after around 11m depth. Unit weight varied between 9kN/m(3) and 15kN/m(3). Seismic investigation of the landfill yielded shear wave velocities (VS) estimated from the crosshole tests ranging from 92 to 214m/s, while compression wave velocities (VP) ranged from 197 to 451m/s. Both velocities were influenced by vertical confining stress and thus tended to increase with depth. VS calculated from MASW tests were lower than the ones calculated from the crosshole tests, probably due to the different frequencies used in the tests. The results of both methods tended to configure a lower bound to the values reported in the technical literature in general, as expected for low compaction waste with small amounts of cover soil. Although VS did not show abrupt changes with depth, VP profile distribution combined with direct investigations results, such as temperature, in-place unit weight and moisture content, suggest that the waste body could be divided into two strata. The lower one is poorly drained and shows higher moisture content, as a consequence of the operational techniques used in the first years, while the upper stratum is probably related to a better drained waste stratum, resulting from the improvement of operational standards and increase in drainage facilities throughout the years. PMID:27107707

  5. Innovative frequency measurement technique used in the design of a single channel frequency to digital converter ASIC

    NASA Astrophysics Data System (ADS)

    Ramalingam, Neranjen; Varadan, Vijay K.; Varadan, Vasundara V.

    1996-09-01

    The frequency to digital converter (FDC) is an application specific integrated circuit. The chip has been designed to handle one input channel but can easily be expanded to handle multiple channels of frequencies. The channel is capable of measuring frequencies from 100 Hz to 100 kHz. The power consumption of the chip is very low. The frequency measurement accuracy is better than 0.1 percent. The conversion rate per channel is 100 samples/second which can be carried too. The chip has a built-in test equipment to verify its operation. It is able to generate frequencies like 8 Mhz, 4Mhz, 2Mhz and 1Mhz which can be fed as optional clock frequencies depending on the accuracy desired. The FDC chip can be interfaced to a 16 bit bus. To meet these stringent specifications of the FDC chip an innovative frequency measurement technique has been devised called the hybrid technique of frequency measurement. The technique proves to be very accurate and it is found that by varying the sampling rate the range of input frequencies over which this accuracy can be achieved also changes. The specifications are particularly strict so that it is possible to use the chip for any military application for which a very reliable operation is demanded. The FDC chip is hence ideal for control and guidance purposes. The chip has wide ranging applications. In conjunction with sensors such as accelerometers it can be used to design smart sensors. The chip can play a vital role in engine controllers and in pressure measurements using vibrating type transducers. Sometimes to isolate transducers, the output is converted to frequency and isolation is achieved using opto-isolators; then by measuring the frequency using this chip this can be converted to digital information.

  6. Novel monitoring techniques for characterizing frictional interfaces in the laboratory.

    PubMed

    Selvadurai, Paul A; Glaser, Steven D

    2015-01-01

    A pressure-sensitive film was used to characterize the asperity contacts along a polymethyl methacrylate (PMMA) interface in the laboratory. The film has structural health monitoring (SHM) applications for flanges and other precision fittings and train rail condition monitoring. To calibrate the film, simple spherical indentation tests were performed and validated against a finite element model (FEM) to compare normal stress profiles. Experimental measurements of the normal stress profiles were within -7.7% to 6.6% of the numerical calculations between 12 and 50 MPa asperity normal stress. The film also possessed the capability of quantifying surface roughness, an important parameter when examining wear and attrition in SHM applications. A high definition video camera supplied data for photometric analysis (i.e., the measure of visible light) of asperities along the PMMA-PMMA interface in a direct shear configuration, taking advantage of the transparent nature of the sample material. Normal stress over individual asperities, calculated with the pressure-sensitive film, was compared to the light intensity transmitted through the interface. We found that the luminous intensity transmitted through individual asperities linearly increased 0.05643 ± 0.0012 candelas for an increase of 1 MPa in normal stress between normal stresses ranging from 23 to 33 MPa. PMID:25923930

  7. Novel Monitoring Techniques for Characterizing Frictional Interfaces in the Laboratory

    PubMed Central

    Selvadurai, Paul A.; Glaser, Steven D.

    2015-01-01

    A pressure-sensitive film was used to characterize the asperity contacts along a polymethyl methacrylate (PMMA) interface in the laboratory. The film has structural health monitoring (SHM) applications for flanges and other precision fittings and train rail condition monitoring. To calibrate the film, simple spherical indentation tests were performed and validated against a finite element model (FEM) to compare normal stress profiles. Experimental measurements of the normal stress profiles were within −7.7% to 6.6% of the numerical calculations between 12 and 50 MPa asperity normal stress. The film also possessed the capability of quantifying surface roughness, an important parameter when examining wear and attrition in SHM applications. A high definition video camera supplied data for photometric analysis (i.e., the measure of visible light) of asperities along the PMMA-PMMA interface in a direct shear configuration, taking advantage of the transparent nature of the sample material. Normal stress over individual asperities, calculated with the pressure-sensitive film, was compared to the light intensity transmitted through the interface. We found that the luminous intensity transmitted through individual asperities linearly increased 0.05643 ± 0.0012 candelas for an increase of 1 MPa in normal stress between normal stresses ranging from 23 to 33 MPa. PMID:25923930

  8. An Innovative Technique for Evaluating the Integrity and Durability of Wind Turbine Blade Composites

    SciTech Connect

    Wang, Jy-An John; Ren, Fei

    2010-09-01

    Wind turbine blades are subjected to complex multiaxial stress states during operation. A review of the literature suggests that mixed mode fracture toughness can be significantly less than that of the tensile opening mode (Mode I), implying that fracture failure can occur at a much lower load capacity if the structure is subject to mixed-mode loading. Thus, it will be necessary to identify the mechanisms that might lead to failure in blade materials under mixed-mode loading conditions. Meanwhile, wind turbine blades are typically fabricated from fiber reinforced polymeric materials, e.g. fiber glass composites. Due to the large degree of anisotropy in mechanical properties that is usually associated with laminates, the fracture behavior of these composite materials is likely to be strongly dependent on the loading conditions. This may further strengthen the need to study the effect of mixed-mode loading on the integrity and durability of the wind turbine blade composites. To quantify the fracture behavior of composite structures under mixed mode loading conditions, particularly under combined Mode I (flexural or normal tensile stress) and Mode III (torsional shear stress) loading, a new testing technique is proposed based on the spiral notch torsion test (SNTT). As a 2002 R&D 100 Award winner, SNTT is a novel fracture testing technology. SNTT has many advantages over conventional fracture toughness methods and has been used to determine fracture toughness values on a wide spectrum of materials. The current project is the first attempt to utilize SNTT on polymeric and polymer-based composite materials. It is expected that mixed-mode failure mechanisms of wind turbine blades induced by typical in-service loading conditions, such as delamination, matrix cracking, fiber pull-out and fracture, can be effectively and economically investigated by using this methodology. This project consists of two phases. The Phase I (FY2010) effort includes (1) preparation of testing

  9. Faulted reservoirs characterization by an image processing technique

    SciTech Connect

    Martinez-Angeles, R.

    1994-12-31

    This paper has developed an image processing method for obtaining the discontinuous areal distribution of oil parameters (formation top, porosity, water saturation,...) of faulted heterogeneous oil reservoirs. For its application it requires the previous knowledge of a set of discrete values z(k,l) from well-logs and seismic profiles. Faulted structures were discretized into continuous structures or blocks bounded by faults. The theoretical fundamental assumption of the proposed method establishes that the natural distributions can be considered as the superposition of several elementary brownian distributions, represented by discrete values z(k,l), whose physical model is the diffusion differential equation and its solution associated. This is a technique that allows the representation of a composed brownian distribution as a linear combination of all elementary brownian functions. For illustrating the operational aspect of brownian analysis, two examples are studied. The results are presented as a digital images by means of an image processing software. This method can be applied in mapping, three dimensions interpolation and reserves calculation of faulted reservoirs.

  10. Diagnosis of industrial catalyst deactivation by surface characterization techniques

    SciTech Connect

    Menon, P.G. . Lab. voor Petrochemische Techniek Chalmers Univ. of Technology, Goeteborg . Dept. of Engineering Chemistry)

    1994-06-01

    The exact nature of the catalyst surface and the various ways of catalyst deactivation are subjects of great scientific interest and enormous economic importance. A brief review like the present one has to be very selective, giving only the underlying principles and representative examples. The focus of this review is on industrial catalysts, in particular, on the most commonly used supported metal and mixed-oxide type catalysts. Here again, only typical examples are chosen and cited to illustrate the specific types of problems involved in catalyst deactivation and how these problems wee diagnosed by a judicious application of the experimental techniques available today. Of the types of catalyst deactivation caused by coking, poisoning, and solid-state transformations, the emphasis in this review is on the last type. Changes in the chemical composition of the catalyst surface, restructuring or reconstruction of the surface, phase transformations, gradual enrichment/depletion of a particular catalyst component on/from the catalyst surface, these are the topics of prominence in this review. Even here, emphasis is on normally unexpected or unsuspected types of deactivation and the catalyst metamorphosis produced by the catalytic reaction itself, as distinct from the purely thermal effects at the reaction temperature. This review is aimed to provide some essential background information and possibly to serve as a reference guide for trouble-shooting when a catalyst is deactivated for rather mysterious reasons. 147 refs.

  11. Understanding, promoting and protecting geodiversity and geoheritage of the Piemonte region (Italy) through innovative techniques and public engagement in Earth Science studies

    NASA Astrophysics Data System (ADS)

    Giardino, Marco; Lozar, Francesca; Perotti, Luigi; Palomba, Mauro; Groppo, Chiara; Natalicchio, Marcello; Ghiraldi, Luca; Beltramo, Riccardo; Lombardo, Vincenzo

    2016-04-01

    The onset of Antropocene demonstrates the importance of considering both 1) geodiversity and 2) geoheritage as parts of the landscape "interfaces" where relationships between natural and socio-economic systems can be studied and interpreted. By definition: 1) is the variety, recognizable in nature ("diversity"), of geological features (rocks, minerals, fossils…), of geomorphological environments (and related forms and processes) and of soil characteristics; 2) is an integral part of the global natural heritage focusing on unique, special and representative sites of geological interests (geosites l.s.). In the Antropocene, both 1) and 2) hold a dynamic character, as the result of actions and interactions of natural and/or human factors. Therefore, geodiversity and geoheritage studies are essential for breaking down geological environments and human territories into their main parts and to understand the variables and mechanisms that control their changes. In this perspective, results of the multidisciplinary project PROGEO-Piemonte ("PROactive management of GEOlogical heritage in the Piemonte Region") are presented here: an innovative approach for assessing geodiversity in order to select areas of high potential value of geoheritage to be enhanced by targeted management actions. Since the geodiversity of Piemonte is materialized by elements of high scientific, educational, tourism, etc. value, the geosites where this geoheritage is preserved have been comprehensively analysed and characterized for encompassing both public and private interests. 9 strategic geothematic areas have been selected in the Piemonte Region to test this approach, and to improve social engagement aimed at protecting and promoting geodiversity ad geoheritage. The investigated areas represent the multifaceted geodiversity of Piemonte; each area is characterized by high potential for scientific studies, enhancement of public understanding of science, recreation activities and for economic

  12. A plan for implementation of innovative hazardous waste minimization techniques at an eastern US Naval Plating Shop

    SciTech Connect

    Walker, J.F. Jr.; Villiers-Fisher, J.F.; Brown, C.H. Jr.

    1987-01-01

    Oak Ridge National Laboratory (ORNL) was contracted by the Naval Energy and Environmental Support Activity (NEESA) to analyze the wastewater problems at a Naval Ordnance Station (NOS) plating shop in the eastern United States to recommend innovative wastewater treatment technologies for handling those problems and to implement the recommended treatment technology. Hexavalent chromium was identified as the major problem area at NOS. Water conservation measures were recommended which would reduce the volume of chromium-contaminated wastewater from approximately 300 L/min to approximately 20 L/min. A treatment scheme consisting of RO followed by evaporation of the RO concentrate steam was recommended. Paint-stripping operations at NOS potentially contaminate the wastewater with phenol, trichloroethane, and possibly other organics. However, the need for a treatment unit for removal of organics could not be established due to a lack of organic analytical data. A characterization study was therefore recommended for the NOS plating shop. If treatment for organics is necessary, the treatment unit might include two-stage filtration for removal of paint flakes or other solids, air stripping for removal of volatile organics, and carbon adsorption for removal of residual organics. 7 refs., 6 figs., 3 tabs.

  13. Innovative techniques for the description of reservoir heterogeneity using tracers. Second technical annual progress report, October 1991--September 1992

    SciTech Connect

    Pope, G.A.; Sepehrnoori, K.

    1992-12-31

    This second annual report on innovative uses of tracers for reservoir characterization contains four sections each describing a novel use of oilfield tracers. The first section describes and illustrates the use of a new single-well tracer test to estimate wettability. This test consists of the injection of brine containing tracers followed by oil containing tracers, a shut-in period to allow some of the tracers to react, and then production of the tracers. The inclusion of the oil injection slug with tracers is unique to this test, and this is what makes the test work. We adapted our chemical simulator, UTCHEM, to enable us to study this tracer method and made an extensive simulation study to evaluate the effects of wettability based upon characteristic curves for relative permeability and capillary pressure for differing wetting states typical of oil reservoirs. The second section of this report describes a new method for analyzing interwell tracer data based upon a type-curve approach. Theoretical frequency response functions were used to build type curves of ``transfer function`` and ``phase spectrum`` that have dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. We illustrate this method by analyzing field tracer data. The third section of this report describes a new theory for interpreting interwell tracer data in terms of channeling and dispersive behavior for reservoirs. Once again, a stochastic approach to reservoir description is taken. The fourth section of this report describes our simulation of perfluorocarbon gas tracers. This new tracer technology developed at Brookhaven National Laboratory is being tested at the Elk Hills Naval Petroleum Reserve No. 1 in California. We report preliminary simulations made of these tracers in one of the oil reservoirs under evaluation with these tracers in this field. Our compostional simulator (UTCOMP) was used for this simulation study.

  14. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Frauk; Hughes, Richard G.

    2001-08-15

    Research continues on characterizing and modeling the behavior of naturally fractured reservoir systems. Work has progressed on developing techniques for estimating fracture properties from seismic and well log data, developing naturally fractured wellbore models, and developing a model to characterize the transfer of fluid from the matrix to the fracture system for use in the naturally fractured reservoir simulator.

  15. Adapting of the Background-Oriented Schlieren (BOS) Technique in the Characterization of the Flow Regimes in Thermal Spraying Processes

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Abdulgader, M.; Rademacher, H. G.; Anjami, N.; Hagen, L.

    2014-01-01

    In thermal spraying technique, the changes in the in-flight particle velocities are considered to be only a function of the drag forces caused by the dominating flow regimes in the spray jet. Therefore, the correct understanding of the aerodynamic phenomena occurred at nozzle out let and at the substrate interface is an important task in the targeted improvement in the nozzle and air-cap design as well as in the spraying process in total. The presented work deals with the adapting of an innovative technique for the flow characterization called background-oriented Schlieren. The flow regimes in twin wire arc spraying (TWAS) and high velocity oxygen fuel (HVOF) were analyzed with this technique. The interfering of the atomization gas flow with the intersected wires causes in case of TWAS process a deformation of the jet shape. It leads also to areas with different aero dynamic forces. The configurations of the outlet air-caps in TWAS effect predominantly the outlet flow characteristics. The ratio between fuel and oxygen determine the dominating flow regimes in the HVOF spraying jet. Enhanced understanding of the aerodynamics at outlet and at the substrate interface could lead to a targeted improvement in thermal spraying processes.

  16. The option to abandon: stimulating innovative groundwater remediation technologies characterized by technological uncertainty.

    PubMed

    Compernolle, T; Van Passel, S; Huisman, K; Kort, P

    2014-10-15

    Many studies on technology adoption demonstrate that uncertainty leads to a postponement of investments by integrating a wait option in the economic analysis. The aim of this study however is to demonstrate how the investment in new technologies can be stimulated by integrating an option to abandon. Furthermore, this real option analysis not only considers the ex ante decision analysis of the investment in a new technology under uncertainty, but also allows for an ex post evaluation of the investment. Based on a case study regarding the adoption of an innovative groundwater remediation strategy, it is demonstrated that when the option to abandon the innovative technology is taken into account, the decision maker decides to invest in this technology, while at the same time it determines an optimal timing to abandon the technology if its operation proves to be inefficient. To reduce uncertainty about the effectiveness of groundwater remediation technologies, samples are taken. Our analysis shows that when the initial belief in an effective innovative technology is low, it is important that these samples provide correct information in order to justify the adoption of the innovative technology. PMID:25063916

  17. Mechanism for single-event burnout of power MOSFETs and its characterization technique

    NASA Astrophysics Data System (ADS)

    Kuboyama, S.; Matsuda, S.; Kanno, T.; Ishii, T.

    1992-12-01

    A novel characterization technique for single event burnout (SEB) of power MOSFETs was developed. The technique is based on a pulse-height analyzer system for charge collection measurement with a modified charge-sensitive amplifier which has a very wide dynamic range. The data obtained by this technique give detailed information about the SEB mechanism of power MOSFETs. The experimental data suggested a position-independent charge collection mechanism along an ion track, and a new parameter for SEB hardness was proposed.

  18. Color metallography and electron microscopy techniques applied to the characterization of 413.0 aluminum alloys.

    PubMed

    Vander Voort, George; Asensio-Lozano, Juan; Suárez-Peña, Beatriz

    2013-08-01

    The influence on alloy 413.0 of the refinement and modification of its microstructure was analyzed by means of several microscopy techniques, as well as the effect of the application of high pressure during solidification. For each treatment and solidification pressure condition employed, the most suitable microscopy techniques for identifying and characterizing the phases present were investigated. Color metallography and electron microscopy techniques were applied to the qualitative microstructural analysis. Volume fraction and grain size of the primary α-Al were characterized by quantitative metallographic techniques. The results show that the effect caused by applying high pressure during solidification of the alloy is more pronounced than that caused by modification and refinement of the microstructure when it solidifies at atmospheric pressure. Furthermore, it has been shown that, for Al-Si alloy characterization, when aiming to characterize the primary α-Al phase, optical color metallography observed under crossed polarized light plus a sensitive tint filter is the most suitable technique. When the goal is to characterize the eutectic Si, the use of optical color metallography or electron microscopy is equally valid. The characterization of iron-rich intermetallic compounds should preferably be performed by means of backscattered electron imaging. PMID:23701972

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

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1986-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1985-01-01

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

  1. Recent Experience Using Active Love Wave Techniques to Characterize Seismographic Station Sites

    NASA Astrophysics Data System (ADS)

    Martin, A. J.; Yong, A.; Salomone, L.

    2014-12-01

    Active-source Love waves recorded by the multi-channel analysis of surface wave (MASLW) technique were recently analyzed in two site characterization projects. Between 2010 and 2011, the 2009 American Recovery and Reinvestment Act (ARRA) funded GEOVision to conduct geophysical investigations at 189 seismographic stations—185 in California and 4 in the Central Eastern U.S. (CEUS). The original project plan was to utilize active and passive Rayleigh wave-based techniques to obtain shear-wave velocity (VS) profiles to a minimum depth of 30 m and the time-averaged VS of the upper 30 meters (VS30). Early in the investigation it became evident that Rayleigh wave techniques, such as multi-channel analysis of surface waves (MASRW), were not effective at characterizing all sites. Shear-wave seismic refraction and MASLW techniques were therefore applied. The MASLW technique was deployed at a total of 38 sites, in addition to other methods, and used as the primary technique to characterize 22 sites, 5 of which were also characterized using Rayleigh wave techniques. In 2012, the Electric Power Research Institute funded characterization of 33 CEUS station sites. Based on experience from the ARRA investigation, both MASRW and MASLW data were acquired by GEOVision at 24 CEUS sites—the remaining 9 sites and 2 overlapping sites were characterized by University of Texas, Austin. Of the 24 sites characterized by GEOVision, 16 were characterized using MASLW data, 4 using both MASLW and MASRW data and 4 using MASRW data. Love wave techniques were often found to perform better, or at least yield phase velocity data that could be more readily modeled using the fundamental mode assumption, at shallow rock sites, sites with steep velocity gradients, and, sites with a thin, low velocity, surficial soil layer overlying stiffer sediments. These types of velocity structure often excite dominant higher modes in Rayleigh wave data, but not in Love wave data. At such sites, it may be possible

  2. Ultrasound Imaging Techniques for Spatiotemporal Characterization of Composition, Microstructure, and Mechanical Properties in Tissue Engineering.

    PubMed

    Deng, Cheri X; Hong, Xiaowei; Stegemann, Jan P

    2016-08-01

    Ultrasound techniques are increasingly being used to quantitatively characterize both native and engineered tissues. This review provides an overview and selected examples of the main techniques used in these applications. Grayscale imaging has been used to characterize extracellular matrix deposition, and quantitative ultrasound imaging based on the integrated backscatter coefficient has been applied to estimating cell concentrations and matrix morphology in tissue engineering. Spectral analysis has been employed to characterize the concentration and spatial distribution of mineral particles in a construct, as well as to monitor mineral deposition by cells over time. Ultrasound techniques have also been used to measure the mechanical properties of native and engineered tissues. Conventional ultrasound elasticity imaging and acoustic radiation force imaging have been applied to detect regions of altered stiffness within tissues. Sonorheometry and monitoring of steady-state excitation and recovery have been used to characterize viscoelastic properties of tissue using a single transducer to both deform and image the sample. Dual-mode ultrasound elastography uses separate ultrasound transducers to produce a more potent deformation force to microscale characterization of viscoelasticity of hydrogel constructs. These ultrasound-based techniques have high potential to impact the field of tissue engineering as they are further developed and their range of applications expands. PMID:26771992

  3. TOPICAL REVIEW Organic photovoltaics: principles and techniques for nanometre scale characterization

    NASA Astrophysics Data System (ADS)

    Nicholson, Patrick G.; Castro, Fernando A.

    2010-12-01

    The photoconversion efficiency of state-of-the-art organic solar cells has experienced a remarkable increase in the last few years, with reported certified efficiency values of up to 8.3%. This increase has been due to an improved understanding of the underlying physics, synthetic discovery and the realization of the pivotal role that morphological optimization plays. Advances in nanometre scale characterization have underpinned all three factors. Here we give an overview of the current understanding of the fundamental processes in organic photovoltaic devices, on optimization considerations and on recent developments in nanometre scale measuring techniques. Finally, recommendations for future developments from the perspective of characterization techniques are set forth.

  4. Template Synthesis Of Copper Nanowires Via Electrodeposition Technique And Their Characterization

    SciTech Connect

    Kumar, Narinder; Kumar, Rajesh; Kumar, Sushil; Chakarvarti, S. K.

    2011-12-12

    Copper nanowires have been synthesized successfully using template assisted electrodeposition technique. Commercial polycarbonate membrane (Whatman, Japan) having pore diameter 100 nm, thickness 10 {mu}m and pore density 10{sup 7} pores/cm{sup 2} was used as template. Scanning electron microscopy and X-ray diffraction techniques were used to characterize the synthesized copper nanowires. XRD and SEM results reveal that polycrystalline copper nanowires were obtained with fcc lattice structure having diameter equal to the diameter of the template used.

  5. Characterization techniques for semiconductors and nanostructures: a review of recent advances

    NASA Astrophysics Data System (ADS)

    Acher, Olivier

    2015-01-01

    Optical spectroscopy techniques are widely used for the characterization of semiconductors and nanostructures. Confocal Raman microscopy is useful to retrieve chemical and molecular information at the ultimate submicrometer resolution of optical microscopy. Fast imaging capabilities, 3D confocal ability, and multiple excitation wavelengths, have increased the power of the technique while making it simpler to use for material scientists. Recently, the development of the Tip Enhanced Raman Spectroscopy (TERS) has opened the way to the use of Raman information at nanoscale, by combining the resolution of scanning probe microscopy and chemical selectivity of Raman spectroscopy. Significant advances have been reported in the field of profiling the atomic composition of multilayers, using the Glow Discharge Optical Emission Spectroscopy technique, including real-time determination of etched depth by interferometry. This allows the construction of precise atomic profiles of sophisticated multilayers with a few nm resolution. Ellipsometry is another widely used technique to determine the profile of multilayers, and recent development have provided enhanced spatial resolution useful for the investigation of patterned materials. In addition to the advances of the different characterization techniques, the capability to observe the same regions at micrometer scale at different stages of material elaboration, or with different instrument, is becoming a critical issue. Several advances have been made to allow precise re-localization and co-localization of observation with different complementary characterization techniques.

  6. Towards long lasting zirconia-based composites for dental implants. Part I: innovative synthesis, microstructural characterization and in vitro stability.

    PubMed

    Palmero, Paola; Fornabaio, Marta; Montanaro, Laura; Reveron, Helen; Esnouf, Claude; Chevalier, Jérôme

    2015-05-01

    In order to fulfill the clinical requirements for strong, tough and stable ceramics used in dental applications, we designed and developed innovative zirconia-based composites, in which equiaxial α-Al2O3 and elongated SrAl12O19 phases are dispersed in a ceria-stabilized zirconia matrix. The composite powders were prepared by an innovative surface coating route, in which commercial zirconia powders were coated by inorganic precursors of the second phases, which crystallize on the zirconia particles surface under proper thermal treatment. Samples containing four different ceria contents (in the range 10.0-11.5 mol%) were prepared by carefully tailoring the amount of the cerium precursor during the elaboration process. Slip cast green bodies were sintered at 1450 °C for 1 h, leading to fully dense materials. Characterization of composites by SEM and TEM analyses showed highly homogeneous microstructures with an even distribution of both equiaxial and elongated-shape grains inside a very fine zirconia matrix. Ce content plays a major role on aging kinetics, and should be carefully controlled: sample with 10 mol% of ceria were transformable, whereas above 10.5 mol% there is negligible or no transformation during autoclave treatment. Thus, in this paper we show the potential of the innovative surface coating route, which allows a perfect tailoring of the microstructural, morphological and compositional features of the composites; moreover, its processing costs and environmental impacts are limited, which is beneficial for further scale-up and real use in the biomedical field. PMID:25736494

  7. A Systematic Characterization of Cognitive Techniques for Learning from Textual and Pictorial Representations

    ERIC Educational Resources Information Center

    Ploetzner, Rolf; Lowe, Richard; Schlag, Sabine

    2013-01-01

    Pictorial representations can play a pivotal role in both printed and digital learning material. Although there has been extensive research on cognitive techniques and strategies for learning from text, the same cannot be said for static and dynamic pictorial representations. In this paper we propose a systematic characterization of cognitive…

  8. Analytical techniques for characterization of cyclodextrin complexes in the solid state: A review.

    PubMed

    Mura, Paola

    2015-09-10

    Cyclodextrins are cyclic oligosaccharides able to form inclusion complexes with a variety of hydrophobic guest molecules, positively modifying their physicochemical properties. A thorough analytical characterization of cyclodextrin complexes is of fundamental importance to provide an adequate support in selection of the most suitable cyclodextrin for each guest molecule, and also in view of possible future patenting and marketing of drug-cyclodextrin formulations. The demonstration of the actual formation of a drug-cyclodextrin inclusion complex in solution does not guarantee its existence also in the solid state. Moreover, the technique used to prepare the solid complex can strongly influence the properties of the final product. Therefore, an appropriate characterization of the drug-cyclodextrin solid systems obtained has also a key role in driving in the choice of the most effective preparation method, able to maximize host-guest interactions. The analytical characterization of drug-cyclodextrin solid systems and the assessment of the actual inclusion complex formation is not a simple task and involves the combined use of several analytical techniques, whose results have to be evaluated together. The objective of the present review is to present a general prospect of the principal analytical techniques which can be employed for a suitable characterization of drug-cyclodextrin systems in the solid state, evidencing their respective potential advantages and limits. The applications of each examined technique are described and discussed by pertinent examples from literature. PMID:25743620

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    PubMed

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

    2015-06-01

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies. PMID:26133867

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

    SciTech Connect

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

    2015-06-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  14. Evaluating Local Primary Dendrite Arm Spacing Characterization Techniques Using Synthetic Directionally Solidified Dendritic Microstructures

    NASA Astrophysics Data System (ADS)

    Tschopp, Mark A.; Miller, Jonathan D.; Oppedal, Andrew L.; Solanki, Kiran N.

    2015-10-01

    Microstructure characterization continues to play an important bridge to understanding why particular processing routes or parameters affect the properties of materials. This statement certainly holds true in the case of directionally solidified dendritic microstructures, where characterizing the primary dendrite arm spacing is vital to developing the process-structure-property relationships that can lead to the design and optimization of processing routes for defined properties. In this work, four series of simulations were used to examine the capability of a few Voronoi-based techniques to capture local microstructure statistics (primary dendrite arm spacing and coordination number) in controlled (synthetically generated) microstructures. These simulations used both cubic and hexagonal microstructures with varying degrees of disorder (noise) to study the effects of length scale, base microstructure, microstructure variability, and technique parameters on the local PDAS distribution, local coordination number distribution, bulk PDAS, and bulk coordination number. The Voronoi tesselation technique with a polygon-side-length criterion correctly characterized the known synthetic microstructures. By systematically studying the different techniques for quantifying local primary dendrite arm spacings, we have evaluated their capability to capture this important microstructure feature in different dendritic microstructures, which can be an important step for experimentally correlating with both processing and properties in single crystal nickel-based superalloys.

  15. The deployment of an innovative real-time radiological soil characterization system

    SciTech Connect

    David Allen; Raymond Danahy; Gregory Laird; Dale Seiller; Joan White; Robert Janke

    2000-09-29

    Fluor Fernald Inc., in conjunction with partners from Argonne National Laboratory, the Department of Energy's Environmental Measurements Laboratory, and Idaho National Engineering and Environmental Laboratory, has developed a program for characterizing radiological contaminants in soil in real time. The soil characterization system in use at the Fernald Environmental Management Project (FEMP) for over three years combines gamma ray spectrometry equipment with other technologies to produce a system that can scan large areas of ground and produce color coded maps which display quantitative information regarding isotopic contamination patterns. Software running on a battery powered lap-top computer, is used to control acquisition of gamma spectral data to link the spectral Information with precise detector position measurements from Global Positioning System (GPS) satellites, and to control transmission of data to a central station or van via a wireless Ethernet link where Surfer6 mapping software is used to produce maps showing the position and amount of each target analyte. Either sodium iodide (NaI) gamma ray detectors mounted on three different vehicles for mobile measurements or stationary tripod-mounted hyper-pure germanium (HPGe) detectors can be used in this system to radiologically characterize soil. The operational and performance characteristics, as well as the strengths and limitations of each of these units, will be described. The isotopic information generated by this system can be made available to remediation project mangers within an hour after the completion of a scan to aid in determination of excavation footprints, segregation of contaminated soil and verification of contamination removal. The immediate availability of radiological characterization data made possible by this real-time scanning system has allowed Fluor Fernald to accelerate remediation schedules and reduce costs by avoiding excavation delays and expensive and time consuming

  16. Characterization techniques to validate models of density variations in pressed powder compacts

    SciTech Connect

    Garino, T.; Mahoney, M.; Readey, M.; Ewsuk, K.; Gieske, J.; Stoker, G.; Min, S.

    1995-07-01

    Techniques for characterizing density gradients generated during typical powder compaction processes are reviewed and several are evaluated. The techniques reviewed are ultrasonic velocity measurements, laser ultrasonic velocity measurements, x-ray radiography, autoradiography, computer tomography (CT), magnetic resonance imaging (MRI), and simple image analysis of polished cross-sections. Experimental results are reported for all of these techniques except autoradiography, CT and MRI. The test specimens examined were right circular cylinders of a high length/diameter ratio (to ensure significant density variation) pressed from commercial spray-dried alumina powders. Although the density gradients could be detected with all four techniques, ultrasonic velocity measurements gave the best contour map of gradients and is therefore most suitable for model validation. On the other hand, it was concluded that x-ray radiography is preferable in situations where cost and/or number of samples are more important that high resolution.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  18. Residual stress characterization of welds and post-weld processes using x-ray diffraction techniques

    NASA Astrophysics Data System (ADS)

    Brauss, Michael E.; Pineault, James A.; Eckersley, John S.

    1998-03-01

    This paper illustrates the importance of residual stress characterization in welds and post weld processes. The failure to characterize residual stresses created during welding and/or post weld processes can lead to unexpected occurrences of stress corrosion cracking, distortion, fatigue cracking as well as instances of over design or over processing. The development of automated residual stress mapping and the availability of portable and fast equipment have now made the characterization of residual stresses using x-ray diffraction practical for process control and optimization. The paper presents examples where x-ray diffraction residual stress characterization techniques were applied on various kinds of welds including arc welds, TIG welds, resistance welds, laser welds and electron beam welds. The nondestructive nature of the x-ray diffraction technique has made the residual stress characterization of welds a useful tool for process optimization and failure analysis, particularly since components can be measured before and after welding and post welding processes. Some examples presented show the residual stresses before and after the application of post weld processes such as shot peening, grinding and heat treatment.

  19. CODEHOP-mediated PCR – A powerful technique for the identification and characterization of viral genomes

    PubMed Central

    Rose, Timothy M

    2005-01-01

    Consensus-Degenerate Hybrid Oligonucleotide Primer (CODEHOP) PCR primers derived from amino acid sequence motifs which are highly conserved between members of a protein family have proven to be highly effective in the identification and characterization of distantly related family members. Here, the use of the CODEHOP strategy to identify novel viruses and obtain sequence information for phylogenetic characterization, gene structure determination and genome analysis is reviewed. While this review describes techniques for the identification of members of the herpesvirus family of DNA viruses, the same methodology and approach is applicable to other virus families. PMID:15769292

  20. Characterization of third-degree burned skin by nonlinear microscopy technique

    NASA Astrophysics Data System (ADS)

    dos Santos, Moisés O.; Pelegati, Vitor B.; Cesar, Carlos L.; Correa, Paulo R.; Zorn, Telma Maria T.; Zezell, Denise M.

    2011-03-01

    Nonlinear microscopy imaging technique enable take both images of collagen fibers in dermis through second harmonic generation (SHG) signal and elastic fibers by two-photon emission fluorescence microscopy (TPEFM). These techniques are the most commonly used technique for turbid and thick tissue imaging and also to image biological samples which presents highly ordered structural proteins without any exogenous label. The objective of this study is characterizing dermis of third-degree burned skin by TPEFM and SHG technique. The modelocked laser (Spectra Physics) source used in this study with pulse width of approximately 100 fs at 80 MHz was directed into a multiphoton microscope using a laser scanning unit (Olympus Fluoview 300), mounted on an inverted confocal system microscope (Olympus IX81), with focusing objective (40x, NA = 1.30). The samples were obtained from Wistar rats, male, adult. One dorsum area was submitted to burn caused by vapour exposure. The biopsies obtained were cryosectioned in slices of 20 μm width. Selected area of interface between the injured and healthy subdermal burned skin were imaged by TPEFM and SHG technique. Two different autofluorescence signals are observed as a function of excitation wavelength. The autofluorescence observed at 760 nm and 690 nm suggest components of extracellular matrix at differents depths. In SHG images, collagen fibers are visible. According to the images obtained, these methodologies can be used to characterize dermis of burned tissue as its healing process with reduced out-of-plane photobleaching and phototoxicity.

  1. Developing High-Frequency Quantitative Ultrasound Techniques to Characterize Three-Dimensional Engineered Tissues

    NASA Astrophysics Data System (ADS)

    Mercado, Karla Patricia E.

    Tissue engineering holds great promise for the repair or replacement of native tissues and organs. Further advancements in the fabrication of functional engineered tissues are partly dependent on developing new and improved technologies to monitor the properties of engineered tissues volumetrically, quantitatively, noninvasively, and nondestructively over time. Currently, engineered tissues are evaluated during fabrication using histology, biochemical assays, and direct mechanical tests. However, these techniques destroy tissue samples and, therefore, lack the capability for real-time, longitudinal monitoring. The research reported in this thesis developed nondestructive, noninvasive approaches to characterize the structural, biological, and mechanical properties of 3-D engineered tissues using high-frequency quantitative ultrasound and elastography technologies. A quantitative ultrasound technique, using a system-independent parameter known as the integrated backscatter coefficient (IBC), was employed to visualize and quantify structural properties of engineered tissues. Specifically, the IBC was demonstrated to estimate cell concentration and quantitatively detect differences in the microstructure of 3-D collagen hydrogels. Additionally, the feasibility of an ultrasound elastography technique called Single Tracking Location Acoustic Radiation Force Impulse (STL-ARFI) imaging was demonstrated for estimating the shear moduli of 3-D engineered tissues. High-frequency ultrasound techniques can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, these high-frequency quantitative ultrasound techniques can enable noninvasive, volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation.

  2. Development and application of techniques for the microstructural characterization of hydrogen permeability in zirconium oxides

    NASA Astrophysics Data System (ADS)

    Glavicic, Michael G.

    Equipment and techniques have been developed for the microstructural characterization of Zirconium Oxide films grown on Zr-2.5%Nb pressure tubes. A thin film texture apparatus was constructed and used to measure the texture and stress present in thin zirconium oxide films. The general techniques developed employ a grazing incidence geometry which allows the texture and stress present in thin films (<1mum) of any type to be examined. In addition, a technique for the quantitative phase analysis of textured ZrO2 films grown on zirconium alloys using pole figure data has also been developed. Moreover, equipment was constructed to determine the relative porosity of oxide films grown on a metal substrate using an electrochemical method that measures the effective non-porous oxide thickness. The described equipment and techniques were then used to characterize a test matrix of specimens whose relative hydrogen pick-up was measured by Differential Scanning Calorimetry. The application of beat treatments to the substrates prior to oxide growth was found to have a pronounced effect upon the sharpness of the oxide texture. A correlation between the degree of sharpness of the oxide texture and hydrogen pick-up and corrosion rate of the substrate was also determined. In addition, based upon the new techniques developed it was determined that the tetragonal phase of the oxide is stress stabilized in a region close to the metal/oxide interface.

  3. Characterization of thermal desorption with the Deans-switch technique in gas chromatographic analysis of volatile organic compounds.

    PubMed

    Ou-Yang, Chang-Feng; Huang, Ying-Xue; Huang, Ting-Jyun; Chen, Yong-Shen; Wang, Chieh-Heng; Wang, Jia-Lin

    2016-09-01

    This study presents a novel application based on the Deans-switch cutting technique to characterize the thermal-desorption (TD) properties for gas chromatographic (GC) analysis of ambient volatile organic compounds (VOCs). Flash-heating of the sorbent bed at high temperatures to desorb trapped VOCs to GC may easily produce severe asymmetric or tailing GC peaks affecting resolution and sensitivity if care is not taken to optimize the TD conditions. The TD peak without GC separation was first examined for the quality of the TD peak by analyzing a standard gas mixture from C2 to C12 at ppb level. The Deans switch was later applied in two different stages. First, it was used to cut the trailing tail of the TD peak, which, although significantly improved the GC peak symmetry, led to more loss of the higher boiling compounds than the low boiling ones, thus suggesting compound discrimination. Subsequently, the Deans switch was used to dissect the TD peak into six 30s slices in series, and an uneven distribution in composition between the slices were found. A progressive decrease in low boiling compounds and increase in higher boiling ones across the slices indicated severe inhomogeneity in the TD profile. This finding provided a clear evidence to answer the discrimination problem found with the tail cutting approach to improve peak symmetry. Through the use of the innovated slicing method based on the Deans-switch cutting technique, optimization of TD injection for highly resolved, symmetric and non-discriminated GC peaks can now be more quantitatively assessed and guided. PMID:27492597

  4. Fast Track Characterization of Highly Radioactive Waste Pits Combining Off-the-Shelf Robotics with Innovative Investigation Protocols

    SciTech Connect

    Chabeuf, Jean-Michel; Boya, Didier

    2008-01-15

    The investigation and characterization of radioactive waste pits and effluent storage tanks represents a substantial and challenging step in the overall decommissioning programme launched by AREVA NC in 1998 on the site of Marcoule on behalf of the French Atomic Energy commission. Physical ,radiological and regulatory constraints, combined with a tight schedule, have lead our teams to use proven conventional instrumentation and robotics in innovative configurations . One such investigation, conducted on a particularly challenging radioactive effluent storage pit, is described below. The 'H' pit is a stainless steel clad concrete cavity, located in the second basement of the de-cladding building of Marcoule site. It was used for forty years as buffer storage for high activity effluents and has a length of 5 meters, a width of 3 meters , a height of 2.5 meters, and is topped by lead plates over 5 cm thick and The bottom of the cavity is covered with a layer of mud containing mainly graphite, diatoms and resins. The mud level ranges from about 20 centimeters to over 50 centimeters. The overall mud volume is around 2.4 cubic meters. Ambient dose rates above the lead plates exceed 10 mSv/h. The main purpose of our investigation was to characterize the muds for future recovery and conditioning prior to decontaminating the pit. The history of the pit together with the varying mud altimetry lead us to believe that sedimentation had probably occurred throughout the years. We thus decided to combine dose rate measurements using IF104 probes, gamma spectroscopy with CdTe probes and sample collections at different depths to ensure the representativeness and full characterization of the muds. Poor access, ambient dose rates have lead us to conceive a robotic arm, mounted on an shaft which can be modified to fit a wide range of pits and tanks. Custom built robotic tools with maximum manoeuvrability generally involve costs and delays far exceeding our purposes. SIT, a French

  5. Characterization of Terahertz Single-Photon-Sensitive Bolometric Detectors Using a Pulsed Microwave Technique

    SciTech Connect

    Santavicca, D. F.; Frunzio, L.; Prober, D. E.; Reulet, B.; Karasik, B. S.; Pereverzev, S. V.; Olaya, D.; Gershenson, M. E.

    2009-12-16

    We describe a technique for characterizing bolometric detectors that have sufficient sensitivity to count single terahertz photons. The device is isolated from infrared blackbody radiation and a single terahertz photon is simulated by a fast microwave pulse, where the absorbed energy of the pulse is equal to the photon energy. We have employed this technique to characterize bolometric detectors consisting of a superconducting titanium nanobridge with niobium contacts. Present devices have T{sub c} = 0.3 K and a measured intrinsic energy resolution of approximately 6 terahertz full-width at half-maximum, near the predicted value due to intrinsic thermal fluctuation noise, with a time constant of 2 {mu}s. An intrinsic energy resolution of 1 terahertz should be achievable by reducing the volume of the titanium nanobridge. Such a detector has important applications in future space-based terahertz astronomy missions.

  6. Three-dimensional microstructural characterization of bulk plutonium and uranium metals using focused ion beam technique

    NASA Astrophysics Data System (ADS)

    Chung, Brandon W.; Erler, Robert G.; Teslich, Nick E.

    2016-05-01

    Nuclear forensics requires accurate quantification of discriminating microstructural characteristics of the bulk nuclear material to identify its process history and provenance. Conventional metallographic preparation techniques for bulk plutonium (Pu) and uranium (U) metals are limited to providing information in two-dimension (2D) and do not allow for obtaining depth profile of the material. In this contribution, use of dual-beam focused ion-beam/scanning electron microscopy (FIB-SEM) to investigate the internal microstructure of bulk Pu and U metals is demonstrated. Our results demonstrate that the dual-beam methodology optimally elucidate microstructural features without preparation artifacts, and the three-dimensional (3D) characterization of inner microstructures can reveal salient microstructural features that cannot be observed from conventional metallographic techniques. Examples are shown to demonstrate the benefit of FIB-SEM in improving microstructural characterization of microscopic inclusions, particularly with respect to nuclear forensics.

  7. Innovative sputtering techniques for CIS and CdTe submodule fabrication. Annual subcontract report, 1 September 1991--31 August 1992

    SciTech Connect

    Armstrong, J.M.; Misra, M.S.; Lanning, B.

    1993-03-01

    This report describes work done during Phase 1 of the subject subcontract. The subcontract was designed to study innovative deposition techniques, such as the rotating cylindrical magnetron sputtering system and electrodeposition for large-area, low-cost copper indium diselenide (CIS) and cadmium telluride (CdTe) devices. A key issue for photovoltaics (PV) in terrestrial and future space applications is producibility, particularly for applications using a large quantity of PV. Among the concerns for fabrication of polycrystalline thin-film PV, such as CIS and CdTe, are production volume, cost, and minimization of waste. Both rotating cylindrical magnetron (C-Mag{trademark}) sputtering and electrodeposition have tremendous potential for the fabrication of polycrystalline thin-film PV due to scaleability, efficient utilization of source materials, and inherently higher deposition rates. In the case of sputtering, the unique geometry of the C-Mae facilitates innovative cosputtering and reactive sputtering that could lead to greater throughput reduced health and safety risks, and, ultimately, lower fabrication cost. Electrodeposited films appear to be adherent and comparable with low-cost fabrication techniques. Phase I involved the initial film and device fabrication using the two techniques mentioned herein. Devices were tested by both internal facilities, as well as NREL and ISET.

  8. Thermal characterization and tomography of carbon fiber reinforced plastics using individual identification technique

    SciTech Connect

    Vavilov, V.P.; Grinzato, E.; Bison, P.G.; Marinetti, S.; Bressan, C.

    1996-05-01

    A method for thermal characterization of defect depth and thickness using individual inversion functions is described. Experimental results are obtained with standard carbon fiber reinforced plastic specimens which contained Teflon inserts and impact damage. Accuracy in determining defect dimensions was about 10 percent for defect depth and 33 percent for defect thickness. A technique to synthesize images of defect parameters is proposed. Thermal tomography advantages in analyzing defect in-depth propagation are illustrated.

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

    NASA Astrophysics Data System (ADS)

    Rudolf, Chris; Boesl, Benjamin; Agarwal, Arvind

    2016-01-01

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

  10. Innovative instrumentation for microarray scanning and analysis: application for characterization of oligonucleotide duplexes behavior.

    PubMed

    Khomyakova, E B; Dreval, E V; Tran-Dang, M; Potier, M C; Soussaline, F P

    2004-05-01

    Accuracy in microarray technology requires new approaches to microarray reader development. A microarray reader system (optical scanning array or OSA reader) based on automated microscopy with large field of view, high speed 3 axis scanning at multiple narrow-band spectra of excitation light has been developed. It allows fast capture of high-resolution, multi-fluorescence images and is characterized by a linear dynamic range and sensitivity comparable to commonly used photo-multiplier tube (PMT)-based laser scanner. Controlled by high performance software, the instrument can be used for scanning and quantitative analysis of any type of dry microarray. Studies implying temperature-controlled hybridization chamber containing a microarray can also be performed. This enables the registration of kinetics and melting curves. This feature is required in a wide range of on-chip chemical and enzymatic reactions including on-chip PCR amplification. We used the OSA reader for the characterization of hybridization and melting behaviour of oligonucleotide:oligonucleotide duplexes on three-dimensional Code Link slides. PMID:15209342

  11. JUST in time health emergency interventions: an innovative approach to training the citizen for emergency situations using virtual reality techniques and advanced IT tools (the VR Tool).

    PubMed

    Manganas, A; Tsiknakis, M; Leisch, E; Ponder, M; Molet, T; Herbelin, B; Magnetat-Thalmann, N; Thalmann, D; Fato, M; Schenone, A

    2004-01-01

    This paper reports the results of the second of the two systems developed by JUST, a collaborative project supported by the European Union under the Information Society Technologies (IST) Programme. The most innovative content of the project has been the design and development of a complementary training course for non-professional health emergency operators, which supports the traditional learning phase, and which purports to improve the retention capability of the trainees. This was achieved with the use of advanced information technology techniques, which provide adequate support and can help to overcome the present weaknesses of the existing training mechanisms. PMID:15747937

  12. JUST in time health emergency interventions: an innovative approach to training the citizen for emergency situations using virtual reality techniques and advanced IT tools (the Web-CD).

    PubMed

    Manganas, A; Tsiknakis, M; Leisch, E; Karefilaki, L; Monsieurs, K; Bossaert, L L; Giorgini, F

    2004-01-01

    This paper reports the results of the first of the two systems developed by JUST, a collaborative project supported by the European Union under the Information Society Technologies (IST) Programme. The most innovative content of the project has been the design and development of a complementary training course for non-professional health emergency operators, which supports the traditional learning phase, and which purports to improve the retention capability of the trainees. This was achieved with the use of advanced information technology techniques, which provide adequate support and can help to overcome the present weaknesses of the existing training mechanisms. PMID:15747936

  13. Isolation, Identification, and Characterization of One Degradation Product in Ambroxol by HPLC-Hyphenated Techniques

    PubMed Central

    Thummala, Veera Raghava Raju; Ivaturi, Mrutyunjaya Rao; Nittala, Someswara Rao

    2014-01-01

    This study details the isolation, identification, and characterization of ambroxol’s unknown impurity. One unknown impurity of ambroxol was formed in the formulated drug under stress conditions [40°C /75% relative humidity (RH) for 6 months] with the relative retention time (RRT) 0.68 in RP-HPLC. The impurity was enriched by exposing it to heat and it was isolated by using preparative HPLC. The enriched impurity was purified and characterized using the following sophisticated techniques: 2D NMR (gDQ-COSY, gHSQC, and gHMBC), FTIR, and LC-MS/MS. On the basis of the spectral data, the impurity was characterized as trans-4-(6,8-dibromoquinazolin-3(4H)-yl)cyclohexanol. PMID:24959402

  14. Site and Event Characterization Using the CTBT On-Site Inspection Techniques (Invited)

    NASA Astrophysics Data System (ADS)

    Labak, P.; Gaya Pique, L. R.; Rowlands, A. P.; Arndt, R. H.

    2013-12-01

    One of the four elements of the CTBT verification regime is On-Site Inspection (OSI). The sole purpose of an OSI is to clarify whether a nuclear weapon test explosion or any other nuclear explosion has been conducted in violation of the CTBT. An OSI would be conducted within an area no bigger than 1000 km2 and by no more than 40 inspectors at any one time, applying search logic and inspection techniques with the aim of collecting relevant information that will be the basis for the inspection report. During the course of an OSI less intrusive techniques applied over broad areas (usually with lower spatial resolution) are supplemented with more intrusive techniques applied to more targeted areas (usually at a higher spatial resolution). Environmental setting and the evolution of OSI-relevant observables over time will influence the application of OSI techniques. In the course of the development of OSI methodology and relevant techniques, field tests and exercises have been conducted. While earlier activities mainly focused on progress of individual techniques (such as visual observation, passive seismological monitoring for aftershocks and measurements of radioactivity), recent work covered both technique development (such as multi-spectral imaging including infrared measurements, and environmental sampling and analysis of solids, liquids and gases) as well as the integration of techniques, search logic and data flow. We will highlight examples of application of OSI technologies for site and event characterization from recently conducted field tests and exercises and demonstrate the synthesis of techniques and data necessary for the conduct of an OSI.

  15. Experimental source characterization techniques for studying the acoustic properties of perforates under high level acoustic excitation.

    PubMed

    Bodén, Hans

    2011-11-01

    This paper discusses experimental techniques for obtaining the acoustic properties of in-duct samples with non-linear acoustic characteristic. The methods developed are intended both for studies of non-linear energy transfer to higher harmonics for samples only accessible from one side such as wall treatment in aircraft engine ducts or automotive exhaust systems and for samples accessible from both sides such as perforates or other top sheets. When harmonic sound waves are incident on the sample nonlinear energy transfer results in sound generation at higher harmonics at the sample (perforate) surface. The idea is that these sources can be characterized using linear system identification techniques similar to one-port or two-port techniques which are traditionally used for obtaining source data for in-duct sources such as IC-engines or fans. The starting point will be so called polyharmonic distortion modeling which is used for characterization of nonlinear properties of microwave systems. It will be shown how acoustic source data models can be expressed using this theory. Source models of different complexity are developed and experimentally tested. The results of the experimental tests show that these techniques can give results which are useful for understanding non-linear energy transfer to higher harmonics. PMID:22087890

  16. Characterization of hard coatings produced by laser cladding using laser-induced breakdown spectroscopy technique

    NASA Astrophysics Data System (ADS)

    Varela, J. A.; Amado, J. M.; Tobar, M. J.; Mateo, M. P.; Yañez, A.; Nicolas, G.

    2015-05-01

    Protective coatings with a high abrasive wear resistance can be obtained from powders by laser cladding technique, in order to extend the service life of some industrial components. In this work, laser clad layers of self-fluxing NiCrBSi alloy powder mixed with WC powder have been produced on stainless steel substrates of austenitic type (AISI 304) in a first step and then chemically characterized by laser-induced breakdown spectroscopy (LIBS) technique. With the suitable laser processing parameters (mainly output power, beam scan speed and flow rate) and powders mixture proportions between WC ceramics and NiCrBSi alloys, dense pore free layers have been obtained on single tracks and on large areas with overlapped tracks. The results achieved by LIBS technique and applied for the first time to the analysis of laser clads provided the chemical composition of the tungsten carbides in metal alloy matrix. Different measurement modes (multiple point analyses, depth profiles and chemical maps) have been employed, demonstrating the usefulness of LIBS technique for the characterization of laser clads based on hardfacing alloys. The behavior of hardness can be explained by LIBS maps which evidenced the partial dilution of some WC spheres in the coating.

  17. Damage characterization in engineering materials using a combination of optical, acoustic, and thermal techniques

    NASA Astrophysics Data System (ADS)

    Tragazikis, I. K.; Exarchos, D. A.; Dalla, P. T.; Matikas, T. E.

    2016-04-01

    This paper deals with the use of complimentary nondestructive methods for the evaluation of damage in engineering materials. The application of digital image correlation (DIC) to engineering materials is a useful tool for accurate, noncontact strain measurement. DIC is a 2D, full-field optical analysis technique based on gray-value digital images to measure deformation, vibration and strain a vast variety of materials. In addition, this technique can be applied from very small to large testing areas and can be used for various tests such as tensile, torsion and bending under static or dynamic loading. In this study, DIC results are benchmarked with other nondestructive techniques such as acoustic emission for damage localization and fracture mode evaluation, and IR thermography for stress field visualization and assessment. The combined use of these three nondestructive methods enables the characterization and classification of damage in materials and structures.

  18. A new technique of characterization of intrapixel response dedicated to astronomical detectors

    NASA Astrophysics Data System (ADS)

    Ketchazo, C.; Viale, T.; Boulade, O.; Druart, G.; Moreau, V.; Mugnier, L.; Dubrueil, D.; Derelle, S.; Ronayette, S.; Guérineau, N.; Berthé, M.

    2015-07-01

    This paper is devoted to the presentation of a new technique of characterization of the intra-pixel sensitivity variations (IPSVs) of astronomical detectors. The IPSV is the spatial variation of the pixel response function (PRF). In the case of under-sampled instruments for high quality imaging and accurate photometry, IPSV can contribute to the instrument global error and it should be considered carefully. Our measurement technique is based in the Fourier transform (FT) approach. It consists into the sampling of the pixel transfer function (PTF) by projecting high-resolution periodic patterns onto the whole sensor without classic optics but using the self-imaging property (the Talbot effect) of a continuously self imaging grating (CSIG) illuminated by a plane wave. The PRF is determined by computing the inverse FT. Our measurement technique permits to determine the PRF with a resolution of pixel/10 (10 times Nyquist frequency).

  19. Parametric techniques for characterizing myocardial tissue by magnetic resonance imaging (part 1): T1 mapping.

    PubMed

    Perea Palazón, R J; Ortiz Pérez, J T; Prat González, S; de Caralt Robira, T M; Cibeira López, M T; Solé Arqués, M

    2016-01-01

    The development of myocardial fibrosis is a common process in the appearance of ventricular dysfunction in many heart diseases. Magnetic resonance imaging makes it possible to accurately evaluate the structure and function of the heart, and its role in the macroscopic characterization of myocardial fibrosis by late enhancement techniques has been widely validated clinically. Recent studies have demonstrated that T1-mapping techniques can quantify diffuse myocardial fibrosis and the expansion of the myocardial extracellular space in absolute terms. However, further studies are necessary to validate the usefulness of this technique in the early detection of tissue remodeling at a time when implementing early treatment would improve a patient's prognosis. This article reviews the state of the art for T1 mapping of the myocardium, its clinical applications, and its limitations. PMID:26944850

  20. A novel optical technique to characterize fiberization of textured vegetable proteins under high-moisture extrusion

    NASA Astrophysics Data System (ADS)

    Yao, Gang; Liu, Keshun; Hsieh, Fu-Hung

    2004-11-01

    There have been great interests in using twin-screw extruders under high moisture conditions to produce textured vegetable proteins. Unlike the low moisture extrusion counterpart, a product extruded under high moisture can have well-defined fiber orientation and bears a strong resemblance to muscle meat. The textural properties of such extruded products are important for consumer acceptance. In this study, we developed a novel fluorescence polarization based technique that measures the fiber formation of extruded protein products. The experimental results using our new technique showed good agreements with results obtained from visual inspection and digital imaging of the dissected samples. The new technique provides an in vivo and noninvasive approach to characterize the fiber formation of textured vegetable proteins under high moisture extrusion. It has a potential to be used as a real time monitoring tool in food extrusion studies.

  1. An innovative approach for the characterization of the isoforms of a monoclonal antibody product

    PubMed Central

    Sundaram, Shanmuuga; Matathia, Alice; Qian, Jun; Zhang, Jingming; Hsieh, Ming-Ching; Liu, Tun; Crowley, Richard

    2011-01-01

    Protein biopharmaceuticals, such as monoclonal antibodies (mAbs) are widely used for the prevention and treatment of various diseases. The complex and lengthy upstream and downstream production methods of the antibodies make them susceptible to physical and chemical modifications. Several IgG1 immunoglobulins are used as medical agents for the treatment of colon, breast and head and neck cancers, and at least four to eight isoforms exist in the products. The regulatory agencies understand the complex nature of the antibody molecules and allow the manufactures to set their own specifications for lot release, provided the safety and efficacy of the products are established in animal models prior to clinical trials. During the manufacture of a mAb product, we observed lot-to-lot variability in the isoform content and, although the variability is within the set specifications for lot release, made attempts to gain mechanistic insight by isolating and characterizing the individual isoforms. Matrix-assisted laser desorption/ionization (MALDI) and liquid chromatography (LC)/mass spectrometry (MS)/MS analyses of the isolated isoforms indicate that this variability is caused by sialic acid content, as well as truncation of C-terminal lysine of the individual isoforms. Sialidase and carboxypeptidase treatment of the product confirm the observations made by MALDI and LC/MS/MS. PMID:22123057

  2. Endoscopic Debridement for Treatment of Chronic Plantar Fasciitis: An Innovative Technique and Prospective Study of 46 Consecutive Patients.

    PubMed

    Cottom, James M; Maker, Jared M; Richardson, Phillip; Baker, Joseph S

    2016-01-01

    Plantar fasciitis is one the most common pathologies treated by foot and ankle surgeons. When nonoperative therapy fails, surgical intervention might be warranted. Various surgical procedures are available for the treatment of recalcitrant plantar fasciitis. The most common surgical management typically consists of open versus endoscopic plantar fascia release. Comorbidities associated with the release of the plantar fascia have been documented, including lateral column overload and metatarsalgia. We present an innovative technique for this painful condition that is minimally invasive, allows visualization of the plantar fascia, and maintains the integrity of the fascia. Our hypothesis was that the use of endoscopic debridement of the plantar fascia with or without heel spur resection would provide a minimally invasive technique with acceptable patient outcomes. PMID:27066869

  3. Structural characterization of low level degradants in aztreonam injection and an innovative approach to aid HPLC method validation.

    PubMed

    Ye, Qingmei; Ding, Wei; Rinaldi, Frank; Huang, Yande; Miller, Scott A; Bolgar, Mark

    2016-05-30

    Three new degradants have been identified from drug product and active pharmaceutical ingredient stability samples of aztreonam, a marketed synthetic monocyclic beta-lactam antibiotic. The degradants were detected following the implementation of a new, more selective HPLC method for the determination of impurities and degradants. The new method was developed in response to changes in the regulatory requirement for mature products. Two of the new unknown Degradants (I and II) were observed in chromatograms from stability samples of aztreonam injection. The third new Degradant (III) was observed during a stability study of the aztreonam active pharmaceutical ingredient. These degradants were structurally characterized. A small amount (ca. 1-3mg) of each degradant was isolated via preparative HPLC for structure elucidation using accurate MS, one and two-dimensional NMR spectroscopy. The small amount of each NMR sample was then reused as a standard for HPLC purity/impurity method validation. Their exact concentrations were determined using quantitative NMR which enabled the execution of the quantitative elements of the HPLC method validation. This innovative approach eliminated the need to isolate or synthesize larger quantities of markers for HPLC/UV method validation, thus saving significant time and reducing costs. PMID:26991056

  4. An innovative, easily fabricated, silver nanoparticle-based titanium implant coating: development and analytical characterization.

    PubMed

    De Giglio, E; Cafagna, D; Cometa, S; Allegretta, A; Pedico, A; Giannossa, L C; Sabbatini, L; Mattioli-Belmonte, M; Iatta, R

    2013-01-01

    Microbial colonization and biofilm formation on implanted devices represent an important complication in orthopaedic and dental surgery and may result in implant failure. Controlled release of antibacterial agents directly at the implant site may represent an effective approach to treat these chronic complications. Resistance to conventional antibiotics by pathogenic bacteria has emerged in recent years as a major problem of public health. In order to overcome this problem, non-conventional antimicrobial agents have been under investigation. In this study, polyacrylate-based hydrogel thin coatings have been electrosynthesised on titanium substrates starting from poly(ethylene glycol diacrylate)-co-acrylic acid. Silver nanoparticles (AgNPs) with a narrow size distribution have been synthesized using a "green" procedure and immobilized on Ti implant surfaces exploiting hydrogel coatings' swelling capabilities. The coatings have been characterized by XPS and SEM/EDX, while their silver release performances have been monitored by ICP-MS. The antibacterial activity of these AgNP-modified hydrogel coatings was tested evaluating in vitro inhibition growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, among the most common pathogens in orthopaedic infections. Moreover, a preliminary investigation of the biocompatibility of silver-loaded coatings versus MG63 human osteoblast-like cells has been performed. An important point of strength of this paper, in fact, is the concern about the effect of silver species on the surrounding cell system in implanted medical devices. Silver ion release has been properly tuned in order to assure antibacterial activity while preserving osteoblasts' response at the implant interface. PMID:22926126

  5. X-ray Scattering Techniques for Characterization of Nanosystems in Lifescience

    SciTech Connect

    Saw, C K

    2005-04-11

    The intent of this chapter is to provide the basics of using x-ray diffraction techniques in order to obtain information on the structure and morphology of the nanosystems, and also to point out some of its strengths and weaknesses when compare to other characterization techniques. X-ray scattering examines over a wide range of density domains from a tenth to a thousandth angstrom. Essentially, this covers a whole range of condensed matter, including the structure and morphology of nanosystems, particularly useful for examining nanostructures in lifescience. This range of domain size requires both the wide-angle x-ray scattering (WAXS) and small-angle (SAXS) x-ray scattering techniques. Roughly WAXS covers from 2 nm down, and SAXS covers from .5 nm to 100 nm and possibly 1,000 nm for a finely tuned instrument. Brief theoretical description of both WAXS and SAXS will be given in this chapter. WAXS, by itself is a powerful technique in providing information on the crystallographic structure or lack of structure, atomic positions and sizes in a unit cell, to some extend, chemical compositions and as well as chemical stoichiometry. Examples of such experiments will also be given. In order to be able to describe the technique of x-ray scattering, some historical and theoretical background will be given in the hope of making this subject interesting and simple.

  6. A Study of undulator magnets characterization using the Vibrating Wire technique

    SciTech Connect

    Temnykh, Alexander; Levashov, Yurii; Wolf, Zachary; /SLAC

    2011-02-07

    The vibrating wire (VW) technique employs a stretched wire as a magnetic field sensor. Because of the wire's small diameter ({approx}0.1mm or smaller) and because the wire can be supported from outside the magnet, this technique is very appealing for field measurements in small gap/bore undulators with small good field regions and with limited access to the tested field. In addition, in the case of elliptical undulators in which Hall probe (HP) measurements can be affected by the planar Hall effect, VW technique can be used as an independent method to verify and supplement HP measurements. In this article we studied the potential of the VW technique for measurement of magnetic field errors and for prediction of beam trajectories in undulator magnets using a 3.8m long LCLS undulator as a test bench. Introducing calibrated magnetic field distortion at various locations, we measured the sensitivity and spatial resolution of the method. The method demonstrated 0.9mm spatial resolution at a distance up to a few meters and 0.37Gcm sensitivity to the field integral. To compare Hall probe and Vibrating wire measurements side-by-side, we measured field errors in an LCLS undulator previously characterized by Hall probe measurements. The field errors found with the Vibrating Wire technique appeared to be in good agreement with errors measured with the Hall probe. Beam trajectory distortions calculated from both data sets are also in a good agreement.

  7. Experimental techniques for characterizing the thermo-electro-mechanical shakedown response of SMA wires and tubes

    NASA Astrophysics Data System (ADS)

    Churchill, Christopher B.

    Shape Memory Alloys (SMAs) are a unique and valuable group of active materials. NiTi, the most popular SMA, has a power density orders of magnitude greater than any other known material, making it valuable in the medical and transportation industries where weight and space are at a premium. In the nearly half-century since its discovery, the adoption of NiTi has been slowed primarily by the engineering difficulties associated with its use: strong thermal coupling, material level instabilities, and rapid shakedown of material properties during cycling. Material properties change drastically with minute changes in alloy composition, so it is common to require a variety of experiments to fully characterize a new SMA material, all of which must be performed and interpreted with specialized techniques. This thesis collects many of these techniques into a series of characterization experiments, documenting several new phenomena in the process. First, three different alloys of NiTi wire are characterized through differential scanning calorimetry, isothermal tension, and constant load thermal cycling experiments. New techniques are presented for ER measurement and temperature control of SMA wires and temperature measurement of SMA tubes. It is shown that the shakedown of material properties with thermal cycling is not only dependent on the applied load and number of cycles, but has a large association with the direction of phase transformation. Several of these techniques are then applied to a systematic characterization of NiTi tubes in tension, compression, and bending. Particular attention is given to the nucleation and propagation of transformation fronts in tensile specimens. Compression experiments show dramatic asymmetry in the uniaxial response, with compression characterized by a lower transformation strain, higher transformation stress, and uniform transformations (no fronts). A very simple SMA actuator model is introduced. After identifying the relevant non

  8. A novel and innovative technique of using a disposable syringe and mesh for harvesting fat for structural fat grafting

    PubMed Central

    Ashok, B. C.; Nagaraj, Pradeep Kumar; Ananteshwar, Y. N.; Srikanth, V.

    2015-01-01

    Background: Successful restoration of structure and function using autologous free fat grafts has remained elusive. Review of literature shows that various harvesting and preparation techniques have been suggested. The goal of these techniques is to obtain greater adipocyte cell survival and consequently more reliable clinical results. Materials and Methods: In our technique, a piece of mesh is kept at one end of the lipoaspiration syringe, which is then connected to the Suction pump. As one syringe fills, it is replaced by another one until the required amount of fat is obtained. Results: By using a polypropylene mesh in our technique, we can separate the transfusate from the harvested fat graft during harvesting itself. The fat graft thus obtained is dense and concentrated, with fewer impurities. Conclusion: Hence, we recommend our technique as a reliable method for extracting sterile emulsified fat in an economical way. PMID:25991892

  9. X-ray wavefront characterization using a rotating shearing interferometer technique.

    PubMed

    Wang, Hongchang; Sawhney, Kawal; Berujon, Sébastien; Ziegler, Eric; Rutishauser, Simon; David, Christian

    2011-08-15

    A fast and accurate method to characterize the X-ray wavefront by rotating one of the two gratings of an X-ray shearing interferometer is described and investigated step by step. Such a shearing interferometer consists of a phase grating mounted on a rotation stage, and an absorption grating used as a transmission mask. The mathematical relations for X-ray Moiré fringe analysis when using this device are derived and discussed in the context of the previous literature assumptions. X-ray beam wavefronts without and after X-ray reflective optical elements have been characterized at beamline B16 at Diamond Light Source (DLS) using the presented X-ray rotating shearing interferometer (RSI) technique. It has been demonstrated that this improved method allows accurate calculation of the wavefront radius of curvature and the wavefront distortion, even when one has no previous information on the grating projection pattern period, magnification ratio and the initial grating orientation. As the RSI technique does not require any a priori knowledge of the beam features, it is suitable for routine characterization of wavefronts of a wide range of radii of curvature. PMID:21935019

  10. Characterizing surface features on conducting specimens through an insulation layer using the capacitive imaging technique

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Yin, Xiaokang; Yan, An; Li, Wei; Chen, Guoming

    2016-02-01

    Capacitive imaging (CI) technique is a novel electromagnetic NDE technique. It uses a carefully designed probe with a pair of metal electrodes. Interaction between the Quasi-static electromagnetic field from the electrode pair and the testing material causes changes in signal when the electrical properties of the sample themselves change, leading to the possibility of imaging. Due to its capacitive nature, the CI technique requires single side non-contact access to the testing material and little sample surface preparation. In addition, it provides a very clear and simple defect indication. Previous work [1] has demonstrated the feasibility of the CI technique to the detection of surface features on conducting specimens. It is found that the CI technique is useful to confirm the presence of a defect but cannot further characterize it due to the "blurring effect". The problem caused by the blurring effect is more significant, when trying to image smaller feature though a thicker insulation layer (comparing to the dimensions of the CI probe). This paper aims to tackle this problem using a two dimensional deconvolution method based on the analysis of the measurement sensitivity distribution. In this paper, the trade-offs between penetration depth, signal strength and imaging resolution of the CI technique are discussed. The blurring effect due to the CI probe geometry is explained. The proposed method to retrieve the real shape of the feature is then described in details, and its feasibility is also demonstrated. The results indicated that the CI technique could be useful to detect Corrosion Under Insulation (CUI).

  11. Region-growing technique adapted to precise microcalcification characterization in mammography

    NASA Astrophysics Data System (ADS)

    Darboux, Michel; Dinten, Jean-Marc; Nicolas, Eric

    1996-11-01

    The early detection of breast cancer is essential for increasing the survival rate of the disease. Today, mammography is the only breast screening technique capable of detecting breast cancer at a very early stage. The presence of a breast tumor is indicated by some features on the mammogram. One sign of malignancy is the presence of clusters of fine, granular microcalcifications. We present here a three-step method for detecting and characterizing these microcalcifications. We begin with the detection of potential candidates. The aim of this first step is to detect all the pixels that could be a microcalcification. Then we focus on our specific region growing technique which provides an accurate extraction of the shape of the region corresponding to each detected growing technique which provides an accurate extraction of the shape of the region corresponding to each detected seed. This second step is essential because microcalcifications shape is a very important feature for the diagnosis. It is then possible to determine precise parameters to characterize these microcalcifications. This three-step method has been evaluated on a set of images form the mammographic image analysis society database.

  12. BIOSENSORS RESEARCH FOR DEVELOPMENT OF INNOVATIVE MONITORING TECHNIQUES THAT SUPPORT EXPOSURE ASSESSMENT RELATED TO THE SUPERFUND PROGRAM

    EPA Science Inventory

    One of the approaches for reducing uncertainties in the assessment of human exposure is to better characterize the hazardous wastes that contaminate our environment. A significant limitation to this approach, however, is that sampling and laboratory analysis of contaminated envi...

  13. Off-label innovation: characterization through a case study of rhBMP-2 for spinal fusion.

    PubMed

    Schnurman, Zane; Smith, Michael L; Kondziolka, Douglas

    2016-09-01

    OBJECTIVE Off-label therapies are widely used in clinical practice by spinal surgeons. Some patients and practitioners have advocated for increased regulation of their use, and payers have increasingly questioned reimbursment for off-label therapies. In this study, the authors applied a model that quantifies publication data to analyze the developmental process from initial on-label use to off-label innovation, using as an example recombinant human bone morphogenetic protein 2 (rhBMP-2) because of its wide off-label use. METHODS As a case study of off-label innovation, the developmental patterns of rhBMP-2 from FDA-approved use for anterior lumbar interbody fusion to several of its off-label uses, including posterolateral lumbar fusion, anterior cervical discectomy and fusion, and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion, were evaluated using the "progressive scholarly acceptance" (PSA) model. In this model, PSA is used as an end point indicating acceptance of a therapy or procedure by the relevant scientific community and is reached when the total number of peer-reviewed studies devoted to refinement or improvement of a therapy surpasses the total number assessing initial efficacy. Report characteristics, including the number of patients studied and study design, were assessed in addition to the time to and pattern of community acceptance, and results compared with previous developmental study findings. Disclosures and reported conflicts of interest for all articles were reviewed, and these data were also used in the analysis. RESULTS Publication data indicated that the acceptance of rhBMP-2 off-label therapies occurred more rapidly and with less evidence than previously studied on-label therapies. Additionally, the community appeared to respond more robustly (by rapidly changing publication patterns) to reports of adverse events than to new questions of efficacy. CONCLUSIONS The development of off-label therapies, including the

  14. Secondary side photographic techniques used in characterization of Surry steam generator

    SciTech Connect

    Sinclair, R.B.

    1984-10-01

    Characterization of the generator's secondary side prior to destructive removal of tubing presents a significant challenge. Information must be obtained in a radioactive field (up to 15 R/h) throughout the tightly spaced bundle of steam generator tubes. This report discusses the various techniques employed, along with their respective advantages and disadvantages. The most successful approach to nondestructive secondary side characterization and documentation was through use of in-house developed pinhole cameras. These devices provided accurate photographic documentation of generator condition. They could be fabricated in geometries allowing access to all parts of the generator. Semi-remote operation coupled with large area coverage per investigation and short at-location times resulted in significant personnel exposure advantages. The fabrication and use of pinhole cameras for remote inspection is discussed in detail.

  15. Spatial and vectorial characterization of thermal relaxation using the spin-stand imaging technique

    NASA Astrophysics Data System (ADS)

    Tse, C.; Mircea, D. I.; Mayergoyz, I. D.; Andrei, P.; Krafft, C.

    2002-05-01

    The spatial and vectorial characterization of thermal relaxation of recorded magnetization patterns by using the spin-stand imaging technique [I. D. Mayergoyz et al., J. Appl. Phys. 87, 6824 (2000); 89, 6772 (2001)] is reported. In order to obtain such characterization, a recorded track is scanned at successive instants of time over periods of 70 hours. As a result, the spatial distributions of the read-back voltages (that constitute the "raw" images of the track) are consecutively collected. The images of the vectorial magnetization are then reconstructed and local magnetization relaxation rates are subsequently evaluated. It is demonstrated that the spatially inhomogeneous and vectorial nature of thermal relaxation of recorded patterns may result in temporal track broadening. It is found that this temporal track broadening is more pronounced for disks with higher coercivities.

  16. Spectroscopic techniques applied to the characterization of decorated potteries from Caltagirone (Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Barilaro, D.; Barone, G.; Crupi, V.; Donato, M. G.; Majolino, D.; Messina, G.; Ponterio, R.

    2005-06-01

    The aim of the present work is the characterization of decorated pottery samples from Caltagirone (Sicily, Italy), a renowned production centre of this kind of artwork. These fragments were found during archaeological excavations and were attributed to historical periods extremely far in time from each other (from XVIII century b.C. to XVI a.C.). Therefore, we expect that the manufacture techniques result rather different over so long time. The measurements, performed by Fourier Transform-InfraRed (FT-IR) absorbance and micro-Raman scattering, allowed us a non-destructive study of so precious artefacts. Some pigments were identified, various elements of ceramic paste and glazed layer were characterized.

  17. Materials Characterization Challenges for the Semiconductor Industry: Physical and Chemical Techniques

    NASA Astrophysics Data System (ADS)

    Shaffner, Thomas J.

    2002-03-01

    Materials and device characterization serve the essential role of defining how an integrated circuit differs from its intended design and function. Over the years, a variety of physical and chemical techniques based on probes of electrons, ions and photons have evolved to fill this need. Each has a specialized application for resolving specific problems related to smaller geometry, thin film composition, and shallow junction profiling. As we enter the internet era, demands for higher speed, reliability and performance from both silicon and compound semiconductor materials and circuits is prematurely pushing sophisticated and costly R&D characterization tools closer to the manufacturing environment. This review illustrates how this is happening with emphasis on new developments in electron microscopy, ion backscattering, scanning probe methodologies, and even futuristic methods, such as the position-sensitive atom probe.

  18. Monitoring the stress build-up in dental cements: a novel optical characterization technique

    NASA Astrophysics Data System (ADS)

    Ottevaere, Heidi; Tabak, M.; Bartholomees, F.; de Wilde, Willy P.; Veretennicoff, Irina P.; Thienpont, Hugo

    2001-01-01

    It is well known that during the curing of dental cements, polymerization shrinkage induces unacceptable stresses, which can result into cracks and an over-sensitivity of the teeth. We demonstrate that polarimetric optical fiber sensors can be used to characterize this shrinkage quantitatively. To determine the time evolution and the amount of shrinkage we embed a highly birefringent optical fiber in the dental cement and analyze the change in optical polarization at its output. This change is a measure for the dynamic stress-build up. We also demonstrate the repeatability of our characterization method for these cements. Moreover we given indications that this technique allows for in- vivo monitoring of the stress build-up dynamics between dentine and porcelain facings. This may bring durable all-ceramic restorations closer to reality. In this paper we present the principle of this original optical fiber sensor, its practical implementation and the experimental results we obtained for this application.

  19. The multianalyser system of the three axes neutron spectrometer PUMA: Pilot experiments with the innovative multiplex technique

    NASA Astrophysics Data System (ADS)

    Sobolev, Oleg; Hoffmann, Ron; Gibhardt, Holger; Jünke, Norbert; Knorr, Andreas; Meyer, Volker; Eckold, Götz

    2015-02-01

    A new type of multiplex technique for three axes neutron spectrometers has been realized and successfully commissioned at the PUMA spectrometer at FRM II. Consisting of eleven analyser-detector channels which can be configured individually, this technique is especially suitable for kinetic experiments where a single excitation spectrum is recorded as a function of time without the need to move the spectrometer. On a time-scale of seconds an entire spectrum can be recorded thus allowing users to monitor changes during fast kinetic processes in single shot experiments without the need for stroboscopic techniques. Moreover, the multianalyser system provides an efficient and rapid tool for mapping excitations in (Q,ω)-space. The results of pilot experiments demonstrate the performance of this new technique and a user-friendly software is presented which assists users during their experiments.

  20. Innovations and techniques for balloon-enteroscope-assisted endoscopic retrograde cholangiopancreatography in patients with altered gastrointestinal anatomy.

    PubMed

    Yamauchi, Hiroshi; Kida, Mitsuhiro; Imaizumi, Hiroshi; Okuwaki, Kosuke; Miyazawa, Shiro; Iwai, Tomohisa; Koizumi, Wasaburo

    2015-06-01

    Endoscopic retrograde cholangiopancreatography (ERCP) remains challenging in patients who have undergone surgical reconstruction of the intestine. Recently, many studies have reported that balloon-enteroscope-assisted ERCP (BEA-ERCP) is a safe and effective procedure. However, further improvements in outcomes and the development of simplified procedures are required. Percutaneous treatment, Laparoscopy-assisted ERCP, endoscopic ultrasound-guided anterograde intervention, and open surgery are effective treatments. However, treatment should be noninvasive, effective, and safe. We believe that these procedures should be performed only in difficult-to-treat patients because of many potential complications. BEA-ERCP still requires high expertise-level techniques and is far from a routinely performed procedure. Various techniques have been proposed to facilitate scope insertion (insertion with percutaneous transhepatic biliary drainage (PTBD) rendezvous technique, Short type single-balloon enteroscopes with passive bending section, Intraluminal injection of indigo carmine, CO2 inflation guidance), cannulation (PTBD or percutaneous transgallbladder drainage rendezvous technique, Dilation using screw drill, Rendezvous technique combining DBE with a cholangioscope, endoscopic ultrasound-guided rendezvous technique), and treatment (overtube-assisted technique, Short type balloon enteroscopes) during BEA-ERCP. The use of these techniques may allow treatment to be performed by BEA-ERCP in many patients. A standard procedure for ERCP yet to be established for patients with a reconstructed intestine. At present, BEA-ERCP is considered the safest and most effective procedure and is therefore likely to be recommended as first-line treatment. In this article, we discuss the current status of BEA-ERCP in patients with surgically altered gastrointestinal anatomy. PMID:26074685

  1. Innovations and techniques for balloon-enteroscope-assisted endoscopic retrograde cholangiopancreatography in patients with altered gastrointestinal anatomy

    PubMed Central

    Yamauchi, Hiroshi; Kida, Mitsuhiro; Imaizumi, Hiroshi; Okuwaki, Kosuke; Miyazawa, Shiro; Iwai, Tomohisa; Koizumi, Wasaburo

    2015-01-01

    Endoscopic retrograde cholangiopancreatography (ERCP) remains challenging in patients who have undergone surgical reconstruction of the intestine. Recently, many studies have reported that balloon-enteroscope-assisted ERCP (BEA-ERCP) is a safe and effective procedure. However, further improvements in outcomes and the development of simplified procedures are required. Percutaneous treatment, Laparoscopy-assisted ERCP, endoscopic ultrasound-guided anterograde intervention, and open surgery are effective treatments. However, treatment should be noninvasive, effective, and safe. We believe that these procedures should be performed only in difficult-to-treat patients because of many potential complications. BEA-ERCP still requires high expertise-level techniques and is far from a routinely performed procedure. Various techniques have been proposed to facilitate scope insertion (insertion with percutaneous transhepatic biliary drainage (PTBD) rendezvous technique, Short type single-balloon enteroscopes with passive bending section, Intraluminal injection of indigo carmine, CO2 inflation guidance), cannulation (PTBD or percutaneous transgallbladder drainage rendezvous technique, Dilation using screw drill, Rendezvous technique combining DBE with a cholangioscope, endoscopic ultrasound-guided rendezvous technique), and treatment (overtube-assisted technique, Short type balloon enteroscopes) during BEA-ERCP. The use of these techniques may allow treatment to be performed by BEA-ERCP in many patients. A standard procedure for ERCP yet to be established for patients with a reconstructed intestine. At present, BEA-ERCP is considered the safest and most effective procedure and is therefore likely to be recommended as first-line treatment. In this article, we discuss the current status of BEA-ERCP in patients with surgically altered gastrointestinal anatomy. PMID:26074685

  2. Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.

    SciTech Connect

    Tangyunyong, Paiboon; Miller, Mary A.; Cole, Edward Isaac, Jr.

    2012-03-01

    We present the results of a two-year early career LDRD that focused on defect localization in deep green and deep ultraviolet (UV) light-emitting diodes (LEDs). We describe the laser-based techniques (TIVA/LIVA) used to localize the defects and interpret data acquired. We also describe a defect screening method based on a quick electrical measurement to determine whether defects should be present in the LEDs. We then describe the stress conditions that caused the devices to fail and how the TIVA/LIVA techniques were used to monitor the defect signals as the devices degraded and failed. We also describe the correlation between the initial defects and final degraded or failed state of the devices. Finally we show characterization results of the devices in the failed conditions and present preliminary theories as to why the devices failed for both the InGaN (green) and AlGaN (UV) LEDs.

  3. NanoXCT—A High-Resolution Technique For TSV Characterization

    NASA Astrophysics Data System (ADS)

    Niese, Sven; Krueger, Peter; Zschech, Ehrenfried

    2011-09-01

    Lab-based Transmission X-ray Microscopy and X-ray Computed Tomography (TXM/XCT) with sub-100 nm resolution are evaluated for their application in process and quality control in microelectronics, particularly for TSV characterization. These are the techniques of choice to localize defects in copper TSVs for 3D IC integration. In contrast to other techniques like Focused Ion Beam cross-sectioning and subsequent Scanning Electron Microscopy imaging, the region of interest, i.e. the TSV, is imaged nondestructively and three dimensionally. For flat samples like thinned wafers, the tilted rotational axis tomography is proposed instead of the limited angle tomography since the better in-plane resolution increases the quality of the resulting tomogram. Yield- and reliability-limiting processes in 3D TSV technology like voids and incomplete filled vias can be made visible for an array of adjacent TSVs during one measurement without affecting the TSV.

  4. NanoXCT - A High-Resolution Technique For TSV Characterization

    SciTech Connect

    Niese, Sven; Krueger, Peter; Zschech, Ehrenfried

    2011-09-12

    Lab-based Transmission X-ray Microscopy and X-ray Computed Tomography (TXM/XCT) with sub-100 nm resolution are evaluated for their application in process and quality control in microelectronics, particularly for TSV characterization. These are the techniques of choice to localize defects in copper TSVs for 3D IC integration. In contrast to other techniques like Focused Ion Beam cross-sectioning and subsequent Scanning Electron Microscopy imaging, the region of interest, i.e. the TSV, is imaged nondestructively and three dimensionally. For flat samples like thinned wafers, the tilted rotational axis tomography is proposed instead of the limited angle tomography since the better in-plane resolution increases the quality of the resulting tomogram. Yield- and reliability-limiting processes in 3D TSV technology like voids and incomplete filled vias can be made visible for an array of adjacent TSVs during one measurement without affecting the TSV.

  5. Evaluation of remote sensing and automatic data techniques for characterization of wetlands. [Atchafalaya River Basin, Louisiana

    NASA Technical Reports Server (NTRS)

    Cartmill, R. H.

    1974-01-01

    This investigation has been conducted in the Atchafalaya River Basin of South Central Louisiana. This is a humid area of heavily forested swamps with a large volume of flow mostly from a diversion of the lower Mississippi River. Techniques to obtain enlarged imagery from computer compatible tapes of ERTS data without photographic enlargement is explained and illustrated. Techniques of extraction of environmental information from single bands and multiband pattern recognition procedures are explained and evaluated. A comparison of pattern recognition classifications of the Atchafalaya Basin by aircraft multispectral scanner and ERTS MSS data is made. Data for this comparison were gathered within three weeks of each other in the winter of 1973. Scorecards of the accuracy of the classifications are presented. Recommendations are made concerning the utilization of each sensor platform to perform specific tasks of wetlands characterization.

  6. Design and optimization of stepped austempered ductile iron using characterization techniques

    SciTech Connect

    Hernández-Rivera, J.L.; Garay-Reyes, C.G.; Campos-Cambranis, R.E.; Cruz-Rivera, J.J.

    2013-09-15

    Conventional characterization techniques such as dilatometry, X-ray diffraction and metallography were used to select and optimize temperatures and times for conventional and stepped austempering. Austenitization and conventional austempering time was selected when the dilatometry graphs showed a constant expansion value. A special heat color-etching technique was applied to distinguish between the untransformed austenite and high carbon stabilized austenite which had formed during the treatments. Finally, it was found that carbide precipitation was absent during the stepped austempering in contrast to conventional austempering, on which carbide evidence was found. - Highlights: • Dilatometry helped to establish austenitization and austempering parameters. • Untransformed austenite was present even for longer processing times. • Ausferrite formed during stepped austempering caused important reinforcement effect. • Carbide precipitation was absent during stepped treatment.

  7. A comparison of conventional and advanced ultrasonic inspection techniques in the characterization of TMC materials

    NASA Astrophysics Data System (ADS)

    Holland, Mark R.; Handley, Scott M.; Miller, James G.; Reighard, Mark K.

    Results obtained with a conventional ultrasonic inspection technique as well as those obtained with more advanced ultrasonic NDE methods in the characterization of an 8-ply quasi-isotropic titanium matrix composite (TMC) specimen are presented. Images obtained from a conventional ultrasonic inspection of TMC material are compared with those obtained using more sophisticated ultrasonic inspection methods. It is suggested that the latter techniques are able to provide quantitative images of TMC material. They are able to reveal the same potential defect indications while simultaneously providing more quantitative information concerning the material's inherent properties. Band-limited signal loss and slope-of-attenuation images provide quantitative data on the inherent material characteristics and defects in TMC.

  8. A comparison of conventional and advanced ultrasonic inspection techniques in the characterization of TMC materials

    NASA Technical Reports Server (NTRS)

    Holland, Mark R.; Handley, Scott M.; Miller, James G.; Reighard, Mark K.

    1992-01-01

    Results obtained with a conventional ultrasonic inspection technique as well as those obtained with more advanced ultrasonic NDE methods in the characterization of an 8-ply quasi-isotropic titanium matrix composite (TMC) specimen are presented. Images obtained from a conventional ultrasonic inspection of TMC material are compared with those obtained using more sophisticated ultrasonic inspection methods. It is suggested that the latter techniques are able to provide quantitative images of TMC material. They are able to reveal the same potential defect indications while simultaneously providing more quantitative information concerning the material's inherent properties. Band-limited signal loss and slope-of-attenuation images provide quantitative data on the inherent material characteristics and defects in TMC.

  9. Electrical characterization and modeling of pulse-based forming techniques in RRAM arrays

    NASA Astrophysics Data System (ADS)

    Grossi, Alessandro; Zambelli, Cristian; Olivo, Piero; Miranda, Enrique; Stikanov, Valeriy; Walczyk, Christian; Wenger, Christian

    2016-01-01

    The forming process, which corresponds to the activation of the switching filament in Resistive Random Access Memory (RRAM) arrays, has a strong impact on the cells' performances. In this paper we characterize and compare different pulse forming techniques in terms of forming time, yield and cell-to-cell variability on 4 kbits RRAM arrays. Moreover, post-forming modeling during Reset operation of correctly working and over formed cells has been performed. An incremental form and verify technique, based on a sequence of trapezoidal waveforms with increasing voltages followed by a verify operation that terminates when the expected switching behavior has been achieved, showed the best results. This procedure narrows the post-forming current distribution whereas reducing the Reset switching voltage and the operative current. These advantages materialize in a better control of the cell-to-cell variability and in an overall time and energy saving at the system level.

  10. Characterization of some groups of gram-negative nonfermentative bacteria by the carbon source alkalinization technique.

    PubMed Central

    Martin, R; Riley, P S; Hollis, D G; Weaver, R E; Krichevsky, M I

    1981-01-01

    A total of 541 gram-negative nonfermentative bacterial strains comprising 26 species and unclassified groups were characterized by routine diagnostic and carbon substrate alkalinization techniques. These microorganisms were tested for the ability to cause alkalinization of a basal medium on a total of 217 substrates. We found that 58 carbon substrates had some discriminatory potential. We also performed 30 routine diagnostic tests. The results of these studies were evaluated by numerical taxonomy techniques. A cluster analysis of the results by the Jaccard coefficient method identified 30 clusters at the 45% level. We identified 39 tests that separated most of the groups. Groups of similar organisms or organisms that were difficult to identify were analyzed, and tests that were differential were identified. Because of variability within the clusters, further studies utilizing deoxyribonucleic acid-deoxyribonucleic acid homologies should be undertaken. PMID:7021587

  11. Measurement technique for in situ characterizing aberrations of projection optics in lithographic tools

    SciTech Connect

    Wang Fan; Wang Xiangzhao; Ma Mingying

    2006-08-20

    As the feature size decreases, degradation of image quality caused by wavefront aberrations of projection optics in lithographic tools has become a serious problem in the low-k1 process. We propose a novel measurement technique for in situ characterizing aberrations of projection optics in lithographic tools.Considering the impact of the partial coherence illumination, we introduce a novel algorithm that accurately describes the pattern displacement and focus shift induced by aberrations. Employing the algorithm, the measurement condition is extended from three-beam interference to two-, three-, and hybrid-beam interferences. The experiments are performed to measure the aberrations of projection optics in an ArF scanner.

  12. Application of magnetoacoustic emission technique to temper embrittlement characterization of HY-80 steel

    NASA Technical Reports Server (NTRS)

    Denale, R.; Namkung, M.; Todhunter, R. G.

    1990-01-01

    Magnetoacoustic phenomena associated with the use of the magnetoacoustic emission technique for the temper embrittlement characterization of HY-80 steel are investigated in an attempt to explain some peculiarities observed in highly embrittled HY-80 samples. In particular, attention is given to the effects of the ac magnetic field frequency and shape. The peak amplitude of the magnetoacoustic burst, which is directly related to the width of the pulse height distribution, is shown to be a critical parameter in the determination of the degree of temper embrittlement in the steel.

  13. River embankment characterization: The joint use of geophysical and geotechnical techniques

    NASA Astrophysics Data System (ADS)

    Perri, Maria Teresa; Boaga, Jacopo; Bersan, Silvia; Cassiani, Giorgio; Cola, Simonetta; Deiana, Rita; Simonini, Paolo; Patti, Salvatore

    2014-11-01

    Recent flood events in Northern Italy (particularly in the Veneto Region) have brought river embankments into the focus of public attention. Many of these embankments are more than 100 years old and have been repeatedly repaired, so that detailed information on their current structure is generally missing. The monitoring of these structures is currently based, for the most part, on visual inspection and localized measurements of the embankment material parameters. However, this monitoring is generally insufficient to ensure an adequate safety level against floods. For these reasons there is an increasing demand for fast and accurate investigation methods, such as geophysical techniques. These techniques can provide detailed information on the subsurface structures, are non-invasive, cost-effective, and faster than traditional methods. However, they need verification in order to provide reliable results, particularly in complex and reworked man-made structures such as embankments. In this paper we present a case study in which three different geophysical techniques have been applied: electrical resistivity tomography (ERT), frequency domain electromagnetic induction (FDEM) and Ground Penetrating Radar (GPR). Two test sites have been selected, both located in the Province of Venice (NE Italy) where the Tagliamento River has large embankments. The results obtained with these techniques have been calibrated against evidence resolving from geotechnical investigations. The pros and cons of each technique, as well as their relative merit at identifying the specific features of the embankments in this area, are highlighted. The results demonstrate that geophysical techniques can provide very valuable information for embankment characterization, provided that the data interpretation is constrained via direct evidence, albeit limited in space.

  14. A preliminary evaluation of certain NDA techniques for RH-TRU characterization

    SciTech Connect

    Hartwell, J.K.; Yoon, W.Y.; Peterson, H.K.

    1996-12-31

    This report presents the results of modeling efforts to evaluate selected NDA assay methods for RH-TRU waste characterization. The target waste stream was Content Code 104/107 113-liter waste drums that comprise the majority of the INEL`s RH-TRU waste inventory. Two NDA techniques are treated in detail. One primary NDA technique examined is gamma-ray spectrometry to determine the drum fission and activation product content, and fuel sample inventory calculations using the ORIGEN code to predict the total drum inventory. A heavily shielded and strongly collimated HPGE spectrometer system was designed using MCNP modeling. Detection limits and expected precision of this approach were estimated by a combination of Monte Carlo modeling and synthetic gamma-ray spectrum generation. This technique may allow the radionuclide content of these wastes to be determined with relative standard deviations of 20 to 55% depending on the drum matrix and radionuclide. The INEL Passive/Active Neutron (PAN) assay system is the second primary technique considered. A shielded overpack for the 113-liter CC104/107 RH-TRU drums was designed to shield the PAN detectors from excessive gamma radiation. MCNP modeling suggests PAN detection limits of about 0.06 g {sup 235}U and 0.04 g {sup 239}Pu during active assays.

  15. Whole body MRI: Improved Lesion Detection and Characterization With Diffusion Weighted Techniques

    PubMed Central

    Attariwala, Rajpaul; Picker, Wayne

    2013-01-01

    Diffusion-weighted imaging (DWI) is an established functional imaging technique that interrogates the delicate balance of water movement at the cellular level. Technological advances enable this technique to be applied to whole-body MRI. Theory, b-value selection, common artifacts and target to background for optimized viewing will be reviewed for applications in the neck, chest, abdomen, and pelvis. Whole-body imaging with DWI allows novel applications of MRI to aid in evaluation of conditions such as multiple myeloma, lymphoma, and skeletal metastases, while the quantitative nature of this technique permits evaluation of response to therapy. Persisting signal at high b-values from restricted hypercellular tissue and viscous fluid also permits applications of DWI beyond oncologic imaging. DWI, when used in conjunction with routine imaging, can assist in detecting hemorrhagic degradation products, infection/abscess, and inflammation in colitis, while aiding with discrimination of free fluid and empyema, while limiting the need for intravenous contrast. DWI in conjunction with routine anatomic images provides a platform to improve lesion detection and characterization with findings rivaling other combined anatomic and functional imaging techniques, with the added benefit of no ionizing radiation. PMID:23960006

  16. A preliminary evaluation of certain NDA techniques for RH-TRU characterization

    SciTech Connect

    Hartwell, J.K.; Yoon, W.Y.; Peterson, H.K.

    1997-11-01

    This report presents the results of modeling efforts to evaluate selected NDA assay methods for RH-TRU waste characterization. The target waste stream was Content Code 104/107 113-liter waste drums that comprise the majority of the INEL`s RH-TRU waste inventory. Two NDA techniques are treated in detail. One primary NDA technique examined is gamma-ray spectrometry to determine the drum fission and activation product content, and fuel sample inventory calculations using the ORIGEN code to predict the total drum inventory. A heavily shielded and strongly collimated HPGe spectrometer system was designed using MCNP modeling. Detection limits and expected precision of this approach were estimated by a combination of Monte Carlo modeling and synthetic gamma-ray spectrum generation. This technique may allow the radionuclide content of these wastes to be determined with relative standard deviations of 20 to 50% depending on the drum matrix and radionuclide. The INEL Passive/Active Neutron (PAN) assay system is the second primary technique considered. A shielded overpack for the 113-liter CC104/107 RH-TRU drums was designed to shield the PAN detectors from excessive gamma radiation. MCNP modeling suggests PAN detection limits of about 0.06 g {sup 235}U and 0.04 g {sup 239}Pu during active assays. 12 refs., 2 figs., 6 tabs.

  17. RBS: an analytical technique for elemental characterization of standards; advantages and limits of application

    NASA Astrophysics Data System (ADS)

    Climent-Font, A.; Fernández-Jiménez, M. T.; Wätjen, U.; Perrière, J.

    1994-12-01

    Rutherford backscattering spectrometry (RBS) is an ion beam analytical technique fulfilling unique conditions to give information on the elemental composition of the near surface of materials. Some of the physical processes involved in an RBS experiment are very well understood and are described by analytical formulas allowing for the elaboration of simple computer codes recreating theoretical RBS experiments. Such computer codes are of great help for fast and accurate interpretation of experimental RBS spectra. Under favorable circumstances quantitative composition depth profiles can be obtained. The possibility of doing absolute measurements with RBS makes it very attractive for the characterization of standard samples useful and necessary in other analytical techniques if quantitative analysis is required. In spite of its capabilities, RBS is not free from some flaws that make difficult to reduce the level of uncertainties below 5% in the quantification of the spectra or to make an unambiguous interpretation of the results. In this work we illustrate with a few examples some of the relevant features of RBS which make this analytical technique so useful, and we also discuss situations in which RBS can give only ambiguous information, and where the assistance of a complementary analytical technique is required for a successful interpretation of the results.

  18. The German collaborative project SUGAR Utilization of a natural treasure - Developing innovative techniques for the exploration and production of natural gas from hydrate-bearing sediments

    NASA Astrophysics Data System (ADS)

    Haeckel, M.; Bialas, J.; Wallmann, K. J.

    2009-12-01

    Gas hydrates occur in nature at all active and passive continental margins as well as in permafrost regions, and vast amounts of natural gas are bound in those deposits. Geologists estimate that twice as much carbon is bound in gas hydrates than in any other fossil fuel reservoir, such as gas, oil and coal. Hence, natural gas hydrates represent a huge potential energy resource that, in addition, could be utilized in a CO2-neutral and therefore environmentally friendly manner. However, the utilization of this natural treasure is not as easy as the conventional production of oil or natural gas and calls for new and innovative techniques. In the framework of the large-scale collaborative research project SUGAR (Submarine Deposits of Gas Hydrates - Exploration, Production and Transportation), we aim to produce gas from methane hydrates and to sequester carbon dioxide from power plants and other industrial sources as CO2 hydrates in the same host sediments. Thus, the SUGAR project addresses two of the most pressing and challenging topics of our time: development of alternative energy strategies and greenhouse gas mitigation techniques. The SUGAR project is funded by two federal German ministries and the German industry for an initial period of three years. In the framework of this project new technologies starting from gas hydrate exploration techniques over drilling technologies and innovative gas production methods to CO2 storage in gas hydrates and gas transportation technologies will be developed and tested. Beside the performance of experiments, numerical simulation studies will generate data regarding the methane production and CO2 sequestration in the natural environment. Reservoir modelling with respect to gas hydrate formation and development of migration pathways complete the project. This contribution will give detailed information about the planned project parts and first results with focus on the production methods.

  19. Characterization of radiochromic film scanning techniques used in short-pulse-laser ion acceleration

    SciTech Connect

    Cowan, Joseph S.; Flippo, Kirk A.; Gaillard, Sandrine A.

    2008-10-15

    Radiochromic film (RCF) is increasingly being used as a detector for proton beams from short-pulse laser-matter interaction experiments using the RCF imaging spectroscope technique. The community has traditionally used inexpensive flatbed scanners to digitize and analyze the data, as opposed to more expensive and time-consuming microdensitometers (MicroDs). Often, the RCF densities in some regions exceed an optical density (OD) of 3. Flatbed scanners are generally limited to a maximum OD of {approx}3. Because of the high exposure density, flatbed scanners may yield data that are not reliable due to light scatter and light diffusion from areas of low density to areas of high density. This happens even when the OD is slightly above 1. We will demonstrate the limitations of using flatbed scanners for this type of radiographic media and characterize them compared to measurements made using a MicroD. A technique for cross characterizing both systems using a diffuse densitometer with a NIST wedge will also be presented.

  20. Technique for needle-free drop deposition: Pathway for precise characterization of superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Waghmare, Prashant R.; Das, Siddhartha; Mitra, Sushanta K.

    2013-11-01

    The most important step for characterizing the wettability of a surface is to deposit a water drop on the surface and measure the contact angle made by the drop on the surface. This innocuously simple process relies on bringing a needle holding the water drop in close proximity to the surface, with a ``desire'' that the drop would spontaneously detach from the needle and get deposited on the surface. Problem occurs when the surface is superhydrophobic, expressing an ``unwillingness'' to ``see'' the water drop in preference to a much more ``water-loving'' needle surface. There exists no solution to this problem, and surfaces are invariably characterized where the drop-needle assembly contacts the superhydrophobic surface. Such a configuration will always lead to an incorrect estimation of the contact angle, as there is no certainty of the existence of the drop-surface contact. Here we shall discuss our recently invented technique, where we solve this long-standing problem-we indeed ensure a needle-free drop in contact with the superhydrophobic surface, thereby ascertaining precise determination of the contact angle. The successful application of the technique will address a major headache of the big research community interested in science and technology of superhydrophobic surfaces.

  1. M-BAND IMAGING OF THE HR 8799 PLANETARY SYSTEM USING AN INNOVATIVE LOCI-BASED BACKGROUND SUBTRACTION TECHNIQUE

    SciTech Connect

    Galicher, Raphael; Marois, Christian; Macintosh, Bruce; Konopacky, Quinn; Barman, Travis

    2011-10-01

    Multi-wavelength observations/spectroscopy of exoplanetary atmospheres are the basis of the emerging exciting field of comparative exoplanetology. The HR 8799 planetary system is an ideal laboratory to study our current knowledge gap between massive field brown dwarfs and the cold 5 Gyr old solar system planets. The HR 8799 planets have so far been imaged at J- to L-band, with only upper limits available at M-band. We present here deep high-contrast Keck II adaptive optics M-band observations that show the imaging detection of three of the four currently known HR 8799 planets. Such detections were made possible due to the development of an innovative LOCI-based background subtraction scheme that is three times more efficient than a classical median background subtraction for Keck II AO data, representing a gain in telescope time of up to a factor of nine. These M-band detections extend the broadband photometric coverage out to {approx}5 {mu}m and provide access to the strong CO fundamental absorption band at 4.5 {mu}m. The new M-band photometry shows that the HR 8799 planets are located near the L/T-type dwarf transition, similar to what was found by other studies. We also confirm that the best atmospheric fits are consistent with low surface gravity, dusty, and non-equilibrium CO/CH{sub 4} chemistry models.

  2. Innovative optical scanning technique and device for three-dimensional full-scale measurement of wind-turbine blades

    NASA Astrophysics Data System (ADS)

    Fu, Ho-Ling; Fan, Kuang-Chao; Huang, Yu-Jan; Hu, Ming-Kai

    2014-12-01

    A full-scale three-dimensional profile measurement system with an innovative optical setup for measuring the geometric shape of large wind-turbine blades in high accuracy is developed. A normal full-scale wind blade geometry measurement system can be very expensive. The presented system is low cost, but it can yield a high accuracy for geometric dimensions by error compensation from its measured data. It consists of a low cost long linear stage driven by a direct current motor with linear scale feedback for position and velocity control, and two line-scan optical heads mounted on opposite sides. The line image of the sectional shape profile can be captured by two charge-coupled devices. By scanning the optical head throughout the full length of the blade, the image of the whole profile can be collected. The shape parameters of the wind-turbine blades can thus be determined. A special effort has been employed to improve the straightness and positioning accuracy of the linear stage by error compensation. With system calibration of the stage and the cameras, experimental results show high accuracy of the developed system. This low-cost optical system is expected to measure any full-scale wind blade profile up to several meters in length.

  3. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    SciTech Connect

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for

  4. Dosimetric characterization and optimization of a customized Stanford total skin electron irradiation (TSEI) technique.

    PubMed

    Luĉić, Felipe; Sánchez-Nieto, Beatriz; Caprile, Paola; Zelada, Gabriel; Goset, Karen

    2013-01-01

    Total skin electron irradiation (TSEI) has been used as a treatment for mycosis fungoides. Our center has implemented a modified Stanford technique with six pairs of 6 MeV adjacent electron beams, incident perpendicularly on the patient who remains lying on a translational platform, at 200 cm from the source. The purpose of this study is to perform a dosimetric characterization of this technique and to investigate its optimization in terms of energy characteristics, extension, and uniformity of the treatment field. In order to improve the homogeneity of the distribution, a custom-made polyester filter of variable thickness and a uniform PMMA degrader plate were used. It was found that the characteristics of a 9 MeV beam with an 8 mm thick degrader were similar to those of the 6 MeV beam without filter, but with an increased surface dose. The combination of the degrader and the polyester filter improved the uniformity of the distribution along the dual field (180cm long), increasing the dose at the borders of field by 43%. The optimum angles for the pair of beams were ± 27°. This configuration avoided displacement of the patient, and reduced the treatment time and the positioning problems related to the abutting superior and inferior fields. Dose distributions in the transversal plane were measured for the six incidences of the Stanford technique with film dosimetry in an anthropomorphic pelvic phantom. This was performed for the optimized treatment and compared with the previously implemented technique. The comparison showed an increased superficial dose and improved uniformity of the 85% isodose curve coverage for the optimized technique. PMID:24036877

  5. INNOVATIVE SENSING TECHNIQUES FOR MONITORING AND MEASURING SELECTED DIOXINS, FURANS, AND POLYCYCLIC AROMATIC HYDROCARBONS IN STACK GAS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has determined the need to develop in-situ continuous or semi-continuous emissions monitoring (GEM) techniques for assessing dioxin, furan, and polycyclic aromatic hydrocarbon (PAH) emissions from municipal solid waste (MSW) incinera...

  6. Development of innovative techniques and principles that may be used as models to improve plant performance. Final report

    SciTech Connect

    Hanna, Wayne W.; Burton, Glenn W.

    2000-06-25

    We developed fundamental methods and techniques for transferring germplasm from wild to cultivated species. Germplasm transferred included diverse cytoplasms, new genes for pest resistance, genes controlling dry matter yield and apomixis. Some of the germplasm has been shown to be valuable in plant breeding and has been incorporated into commercial cultivators.

  7. Headspace Theater: An Innovative Method for Experiential Learning of Psychiatric Symptomatology Using Modified Role-Playing and Improvisational Theater Techniques

    ERIC Educational Resources Information Center

    Ballon, Bruce C.; Silver, Ivan; Fidler, Donald

    2007-01-01

    Objective: Headspace Theater has been developed to allow small group learning of psychiatric conditions by creating role-play situations in which participants are placed in a scenario that simulates the experience of the condition. Method: The authors conducted a literature review of role-playing techniques, interactive teaching, and experiential…

  8. Elemental characterization of LL-MA radioactive waste packages with the associated particle technique

    SciTech Connect

    Perot, B.; Carasco, C.; Toure, M.; El Kanawati, W.; Eleon, C.

    2011-07-01

    The French Alternative Energies and Atomic Energy Commission (CEA) and National Radioactive Waste Management Agency (ANDRA) are conducting an R and D program to improve the characterization of long-lived and medium activity (LL-MA) radioactive waste packages with analytical methods and with non-destructive nuclear measurements. This paper concerns fast neutron interrogation with the associated particle technique (APT), which brings 3D information about the waste material composition. The characterization of volume elements filled with iron, water, aluminium, and PVC in bituminized and fibre concrete LL-MA waste packages has been investigated with MCNP [1] and MODAR data analysis software [2]. APT provides usable information about major elements presents in the volumes of interest. However, neutron scattering on hydrogen nuclei spreads the tagged neutron beam out of the targeted volume towards surrounding materials, reducing spatial selectivity. Simulation shows that small less than 1 L targets can be characterised up to the half-radius of a 225 L bituminized drum, the matrix of which is very rich in hydrogen. Deeper characterization in concrete is possible but limited by counting statistics due to photon attenuation in this dense matrix and, unless large inspection volumes are considered, by the lack of spatial selectivity of the tagged neutron beam due to neutron scattering. (authors)

  9. A multi-technique chemical characterization of a Stradivari decorated violin top plate

    NASA Astrophysics Data System (ADS)

    Malagodi, M.; Canevari, C.; Bonizzoni, L.; Galli, A.; Maspero, F.; Martini, M.

    2013-08-01

    This paper focuses on the characterization of the materials of a violin top plate made by Antonio Stradivari (17th century), with different diagnostic techniques and with an integrated and non-destructive analytical methodology to study surface coatings and decorations. The UV-induced visible fluorescence, optical digital microscopy, ED-XRF associated with micro-FTIR spectroscopy analysis, and dendrochronology were performed. The investigations were aimed to identify the presence of original varnish layers and to characterize the composition of the decorations, either the inlaid purflings or the composite false-inlay strip between them. Several results were achieved: (i) evidence of the absence of varnish layers on the surface as a result of extended and inappropriate restoring; (ii) identification of the dye used for the black layers of the purflings; (iii) characterization of the black matrix and the white elements of the decoration. Furthermore, a dendrochronological dating was performed. A copy of the top plate was realized with materials similar to those identified on the Stradivari original; the same analyses performed on the original model were carried out on the same areas of the copy.

  10. Technique for GEO RSO Station-Keeping Characterization and Maneuver Detection

    NASA Astrophysics Data System (ADS)

    Decoto, J.; Loerch, P.

    As the Geosynchronous satellite population increases so too does the importance of accurate catalog maintenance for purpose of conjunction assessment and spacecraft operator situational awareness, particularly for operators in closely spaced regions or in collocated GEO slots. This paper presents the design, results, and limitations of an algorithm developed to aid these efforts by characterizing maneuver histories of geosynchronous satellites using published satellite TLE histories. Central to the algorithm is use of basic signal processing techniques to enhance the ability to detect small orbit changes amongst the noise in the raw data. After filtering out any single point inconsistent outliers the algorithm processes each orbit state with a temporal lead trail window of surrounding orbit states being propagated over a range of common epochs with key metrics being recorded. Potential maneuver events are then declared at any epoch where the comparison metrics between orbit states exceed several checks. Maneuver events are characterized as In-Plane or Out-of-Plane events, referring to the direction of the imparted change in velocity relative to the orbital plane of the satellite. Also characterized is the operational tempo of maneuvers including whether electric or chemical propulsion methods are being used. To illustrate this approach several examples from publicly available catalogs are processed with results provided.

  11. Isolation and characterization of related substances in alogliptin benzoate by LC-QTOF mass spectrometric techniques.

    PubMed

    Lu, Yuting; Yang, Danyi; Li, Zhiyu; Hang, Taijun; Song, Min

    2016-09-01

    A highly specific and efficient LC-QTOF mass spectrometric method was developed for the separation and characterization of process related substances and the major degradation products in alogliptin benzoate and its tablets. The separation was performed on Phenomenex Gemini-NX C18 column (250mm×4.6mm, 5μm) using 0.2% formic acid-0.2% ammonium acetate in water as mobile phase A, acetonitrile and methanol (60:40, v/v) as mobile phase B in linear gradient elution mode. Forced degradation studies were also conducted under ICH prescribed stress conditions. Alogliptin benzoate and its tablets were tending to degrade under acid, alkaline, oxidative and thermal stresses, while relatively stable to photolytic stress. A total of seven related substances were detected and characterized through liquid chromatography-high resolution QTOF mass spectrometry techniques, including process related substances and degradation products, and two of them were further synthesized and characterized by NMR spectroscopy. Based on the related substances elucidation and the plausible formation mechanisms, efficient approaches were proposed to reduce or eliminate related substances, and in consequence the quality of alogliptin benzoate and its tablets have been promoted obviously. Therefore, the impurity profiles obtained are critical to the quality control and manufacturing processes optimization and monitoring of alogliptin benzoate and its tablets. PMID:27281581

  12. Analytical techniques for characterization of cyclodextrin complexes in aqueous solution: a review.

    PubMed

    Mura, Paola

    2014-12-01

    Cyclodextrins are cyclic oligosaccharides endowed with a hydrophilic outer surface and a hydrophobic inner cavity, able to form inclusion complexes with a wide variety of guest molecules, positively affecting their physicochemical properties. In particular, in the pharmaceutical field, cyclodextrin complexation is mainly used to increase the aqueous solubility and dissolution rate of poorly soluble drugs, and to enhance their bioavailability and stability. Analytical characterization of host-guest interactions is of fundamental importance for fully exploiting the potential benefits of complexation, helping in selection of the most appropriate cyclodextrin. The assessment of the actual formation of a drug-cyclodextrin inclusion complex and its full characterization is not a simple task and often requires the use of different analytical methods, whose results have to be combined and examined together. The purpose of the present review is to give, as much as possible, a general overview of the main analytical tools which can be employed for the characterization of drug-cyclodextrin inclusion complexes in solution, with emphasis on their respective potential merits, disadvantages and limits. Further, the applicability of each examined technique is illustrated and discussed by specific examples from literature. PMID:24680374

  13. Characterization of the microbial acid mine drainage microbial community using culturing and direct sequencing techniques.

    PubMed

    Auld, Ryan R; Myre, Maxine; Mykytczuk, Nadia C S; Leduc, Leo G; Merritt, Thomas J S

    2013-05-01

    We characterized the bacterial community from an AMD tailings pond using both classical culturing and modern direct sequencing techniques and compared the two methods. Acid mine drainage (AMD) is produced by the environmental and microbial oxidation of minerals dissolved from mining waste. Surprisingly, we know little about the microbial communities associated with AMD, despite the fundamental ecological roles of these organisms and large-scale economic impact of these waste sites. AMD microbial communities have classically been characterized by laboratory culturing-based techniques and more recently by direct sequencing of marker gene sequences, primarily the 16S rRNA gene. In our comparison of the techniques, we find that their results are complementary, overall indicating very similar community structure with similar dominant species, but with each method identifying some species that were missed by the other. We were able to culture the majority of species that our direct sequencing results indicated were present, primarily species within the Acidithiobacillus and Acidiphilium genera, although estimates of relative species abundance were only obtained from direct sequencing. Interestingly, our culture-based methods recovered four species that had been overlooked from our sequencing results because of the rarity of the marker gene sequences, likely members of the rare biosphere. Further, direct sequencing indicated that a single genus, completely missed in our culture-based study, Legionella, was a dominant member of the microbial community. Our results suggest that while either method does a reasonable job of identifying the dominant members of the AMD microbial community, together the methods combine to give a more complete picture of the true diversity of this environment. PMID:23485423

  14. The Role of Lattice Matching Techniques in the Characterization of Polymorphic Forms

    PubMed Central

    Mighell, Alan D.

    2011-01-01

    An inspection of the recent literature reveals that polymorphism is a frequently encountered phenomenon. The recognition of polymorphic forms plays a vital role in the materials sciences because such structures are characterized by different crystal packing and accordingly have different physical properties. In the pharmaceutical industry, recognition of polymorphic forms can be critical for, in certain cases, a polymorphic form of a drug may be an ineffective therapeutic agent due to its unfavorable physical properties. A check of the recent literature has revealed that in some cases new polymorphic forms are not recognized. In other instances, a supposedly new polymeric form is actually the result of an incorrect structure determination. Fortunately, lattice-matching techniques, which have proved invaluable in the identification and characterization of crystal structures, represent a powerful tool for analyzing polymorphic forms. These lattice-matching methods are based on either of two strategies: (a) the reduced cell strategy–the matching of reduced cells of the respective lattices or (b) the matrix strategy–the determination of a matrix or matrices relating the two lattices coupled with an analysis of the matrix elements. Herein, these techniques are applied to three typical cases–(a) the identification of a new polymorphic form, (b) the demonstration that a substance may not be a new polymorphic form due to missed symmetry, and (c) the evaluation of pseudo polymorphism because of a missed lattice. To identify new polymorphic forms and to prevent errors, it is recommended that these lattice matching techniques become an integral part of the editorial review process of crystallography journals. PMID:26989586

  15. Development of innovative techniques and principles that may be used as models to improve plant performance: Technical progress report, February 1, 1988--January 31, 1989

    SciTech Connect

    Hanna, W.W.

    1988-09-01

    We propose to help develop innovative techniques to improve plant performance. Cytoplasms from wild Pennisetum species have been identified that affect forage yields, days to anthesis, head length, seed weight, and cytoplasmic-genic male sterility (cms). A number of new cytoplasms for cms are being identified. The A' genome from the secondary gene pool in Pennisetum is proving to be a valuable source of genes that can be rapidly used to improve cultivated pearl millet. The discovery and use of this germplasm may have a significant impact on developing pearl millet as a new drought tolerant grain crop for the US. Significant progress is being made in transferring gene(s) controlling apomixis from wild P. squamulatum to cultivated pearl millet for the purpose of producing true-breeding hybrids. 27 refs.

  16. A surface-based technique for mapping homotopic interhemispheric connectivity: Development, characterization, and clinical application.

    PubMed

    Tobyne, Sean M; Boratyn, Daria; Johnson, Jessica A; Greve, Douglas N; Mainero, Caterina; Klawiter, Eric C

    2016-08-01

    The functional organization of the human brain consists of a high degree of connectivity between interhemispheric homologous regions. The degree of homotopic organization is known to vary across the cortex and homotopic connectivity is high in regions that share cross-hemisphere structural connections or are activated by common input streams (e.g., the visual system). Damage to one or both regions, as well as damage to the connections between homotopic regions, could disrupt this functional organization. Here were introduce and test a computationally efficient technique, surface-based homotopic interhermispheric connectivity (sHIC), that leverages surface-based registration and processing techniques in an attempt to improve the spatial specificity and accuracy of cortical interhemispheric connectivity estimated with resting state functional connectivity. This technique is shown to be reliable both within and across subjects. sHIC is also characterized in a dataset of nearly 1000 subjects. We confirm previous results showing increased interhemispheric connectivity in primary sensory regions, and reveal a novel rostro-caudal functionally defined network level pattern of sHIC across the brain. In addition, we demonstrate a structural-functional relationship between sHIC and atrophy of the corpus callosum in multiple sclerosis (r = 0.2979, p = 0.0461). sHIC presents as a sensitive and reliable measure of cortical homotopy that may prove useful as a biomarker in neurologic disease. Hum Brain Mapp 37:2849-2868, 2016. © 2016 Wiley Periodicals, Inc. PMID:27219660

  17. Thermal characterization of a liquid resin for 3D printing using photothermal techniques

    NASA Astrophysics Data System (ADS)

    Jiménez-Pérez, José L.; Pincel, Pavel Vieyra; Cruz-Orea, Alfredo; Correa-Pacheco, Zormy N.

    2016-05-01

    Thermal properties of a liquid resin were studied by thermal lens spectrometry (TLS) and open photoacoustic cell (OPC), respectively. In the case of the TLS technique, the two mismatched mode experimental configuration was used with a He-Ne laser, as a probe beam and an Argon laser was used as the excitation source. The characteristic time constant of the transient thermal lens was obtained by fitting the theoretical expression to the experimental data in order to obtain the thermal diffusivity ( α) of the resin. On the other hand, the sample thermal effusivity ( e) was obtained by using the OPC technique. In this technique, an Argon laser was used as the excitation source and was operated at 514 nm with an output power of 30 mW. From the obtained thermal diffusivity ( α) and thermal effusivity ( e) values, the thermal conductivity ( k) and specific heat capacity per unit volume ( ρc) of resin were calculated through the relationships k = e( α)1/2 and ρc = e/( α)1/2. The obtained thermal parameters were compared with the thermal parameters of the literature. To our knowledge, the thermal characterization of resin has not been reported until now. The present study has applications in laser stereo-lithography to manufacture 3D printing pieces.

  18. Analysis and evaluation of interwell seismic logging techniques for hydrocarbon reservoir characterization. Final report

    SciTech Connect

    Parra, J.O.; Zook, B.J.; Sturdivant, V.R.

    1994-06-01

    The work reported herein represents the third year work in evaluating high-resolution interwell seismic logging techniques for hydrocarbon reservoir characterization. The objective of this project is to investigate interwell seismic logging techniques for indirectly interpreting oil and gas reservoir geology and rock physical properties. The work involves a balanced study of theoretical and numerical modeling of seismic waves transmitted between pairs of wells combined with experimental data acquisition and processing at controlled field conditions. The field applications of this reservoir probing concept are aimed at demonstrating high resolution measurements and detailed interpretation of heterogeneous hydrocarbon-bearing formations. The first part of this third year project efforts was devoted to thoroughly evaluating interwell seismic logging and reverse VSP in a hydrocarbon-bearing formation at the Buckhorn test site in Illinois. Specifically, the data from the experiments conducted in the second year of this project were analyzed to delineate geological structures and to extract rock physical parameters. The second part of this project is devoted to the evaluation of continuity logging techniques for hydrocarbon reservoir continuity. Specifically, this part of the project includes the evaluation of methods of measurements, modeling and data processing to delineate the reservoir architecture and relate dispersion and attenuation measurements to rock physical properties.

  19. Boards and panels aren`t just wood products anymore: Two innovative customer feedback techniques at Duke Power

    SciTech Connect

    Ireland, G.

    1994-11-01

    In their push to become truly customer-driven, utilities have come to require a greater amount of customer input and feedback than ever before. Likewise, in this changing environment, speed and cost-effectiveness have become the name of the game in all that they do. In response to these demands and pressures, Duke Power has developed two methods of getting residential customer feedback and input in a cost-effective and timely way: the Board of Customers (for qualitative feedback) and the Consumer Panel (for quantitative applications). These feedback tools have been used successfully at Duke Power for a variety of applications, including gleaning customer reaction to customer service options, concept-testing product ideas, and assessing corporate image and reputation. With both qualitative and quantitative capabilities in place, Duke Power has the ability to respond quickly to a variety of needs and situations. For example, Duke used the Consumer Panel to implement a lengthy mail survey on image and reputation in a total of 25 days. Likewise, using a regularly scheduled quarterly meeting of the Board of Customers, Duke was able to provide customer reactions to a product concept within 48 hours of the client`s request. As the nature of competition continues to change in the utility industry, the ability to gather cost-effective customer input for quick, concise decision-making will be even more vital to maintaining the competitive edge. This paper describes the design, implementation and applications of the Board of Customers and the Consumer Panel, and how these two innovative tools translate to the bottom line in cost-effective decision-making at Duke Power.

  20. An Innovative Technique for Evaluating the Integrity and Durability of Wind Turbine Blade Composites - Final Project Report

    SciTech Connect

    Wang, Jy-An John; Ren, Fei; Tan, Ting; Mandell, John; Agastra, Pancasatya

    2011-11-01

    To build increasingly larger, lightweight, and robust wind turbine blades for improved power output and cost efficiency, durability of the blade, largely resulting from its structural composites selection and aerodynamic shape design, is of paramount concern. The safe/reliable operation of structural components depends critically on the selection of materials that are resistant to damage and failure in the expected service environment. An effective surveillance program is also necessary to monitor the degradation of the materials in the course of service. Composite materials having high specific strength/stiffness are desirable for the construction of wind turbines. However, most high-strength materials tend to exhibit low fracture toughness. That is why the fracture toughness of the composite materials under consideration for the manufacture of the next generation of wind turbines deserves special attention. In order to achieve the above we have proposed to develop an innovative technology, based on spiral notch torsion test (SNTT) methodology, to effectively investigate the material performance of turbine blade composites. SNTT approach was successfully demonstrated and extended to both epoxy and glass fiber composite materials for wind turbine blades during the performance period. In addition to typical Mode I failure mechanism, the mixed-mode failure mechanism induced by the wind turbine service environments and/or the material mismatch of the composite materials was also effectively investigated using SNTT approach. The SNTT results indicate that the proposed protocol not only provides significant advance in understanding the composite failure mechanism, but also can be readily utilized to assist the development of new turbine blade composites.

  1. PARTITIONING INTERWELL TRACER TEST FOR NAPL SOURCE CHARACTERIZATION: A GENERAL OVERVIEW

    EPA Science Inventory

    Innovative and nondestructive characterization techniques have been developed to locate and quantify nonaqueous phase liquids (NAPLs) in the vadose and saturated zones in the subsurface environment. One such technique is the partitioning interwell tracer test (PITT). The PITT i...

  2. Study to perform preliminary experiments to evaluate particle generation and characterization techniques for zero-gravity cloud physics experiments

    NASA Technical Reports Server (NTRS)

    Katz, U.

    1982-01-01

    Methods of particle generation and characterization with regard to their applicability for experiments requiring cloud condensation nuclei (CCN) of specified properties were investigated. Since aerosol characterization is a prerequisite to assessing performance of particle generation equipment, techniques for characterizing aerosol were evaluated. Aerosol generation is discussed, and atomizer and photolytic generators including preparation of hydrosols (used with atomizers) and the evaluation of a flight version of an atomizer are studied.

  3. An innovative, interdisciplinary, and multi-technique study of gilding and painting techniques in the decoration of the main altarpiece of Miranda do Douro Cathedral (XVII-XVIII(th) centuries, Portugal).

    PubMed

    Sandu, Irina Crina Anca; Murta, Elsa; Veiga, Rita; Muralha, Vânia Solange F; Pereira, Manuel; Kuckova, Stepanka; Busani, Tito

    2013-07-01

    The research results presented in this paper are part of a larger study on the materials and techniques used in polychrome altarpieces of gilded woodcarving decoration ("talha dourada") in Portugal. The paper focuses on a narrative Portuguese Altarpiece from Miranda do Douro, considered one of the masterpieces of "talha dourada" among all the retables of the Iberian Peninsula in XVII(th) and XVIII(th) centuries. Although on the Portuguese territory, the altarpiece was made by artists from the Royal Spanish school of Valladolid, under a mannerist style. Thus the study opens a window on the artists' circulation between Spain and Portugal and influences of the Spanish schools in Baroque epoch on the Portuguese "talha". During its history this altarpiece underwent several transformations and extensive conservation treatments in 1989. On this occasion more than 50 samples were collected and analyzed using an interdisciplinary multi-technique methodology. 27 of these samples are chosen for this study in order to investigate the chromatic palette, the materials and techniques used in the polychromy of the retable. A novel protocol of investigation using different conventional and unconventional analytical techniques (OM + fluorescent staining tests on cross-sections, Raman microscopy, XRD, XRF, X-ray micro-CT, SEM-EDX, MALDI-TOF-MS and LC-MS/MS) was established within an innovative research project (http://sites.fct.unl.pt/gilt-teller/) and applied on these samples. This protocol is necessary to confirm the results obtained in the 1989 campaign and to have further insight into the gilding and polychrome decoration materials and techniques and the additional information reported in the historical documents. The material and technical history of this important altarpiece will be thus re-documented from a scientific perspective, meant to confirm and bring new information on the decorative technique used in the creation of this complex Portuguese monument. PMID:23650028

  4. Innovative techniques for the production of energetic radicals for lunar materials processing including photogeneration via concentrated solar energy

    NASA Technical Reports Server (NTRS)

    Osborn, D. E.; Lynch, D. C.; Fozzolari, R.

    1991-01-01

    A technique for photo generation of radicals is discussed that can be used in the recovery of oxygen and metals from extraterrestrial resources. The concept behind this work was to examine methods whereby radicals can be generated and used in the processing of refractory materials. In that regard, the focus is on the use of sunlight. Sunlight provides useful energy for processing in the forms of both thermal and quantum energy. A number of experiments were conducted in the chlorination of metals with and without the aid of UV and near UV light. The results of some of those experiments are discussed.

  5. Nanogels based on alginic aldehyde and gelatin by inverse miniemulsion technique: synthesis and characterization.

    PubMed

    Sarika, P R; Anil Kumar, P R; Raj, Deepa K; James, Nirmala Rachel

    2015-03-30

    Nanogels were developed from alginic aldehyde and gelatin by an inverse miniemulsion technique. Stable inverse miniemulsions were prepared by sonication of noncontinuous aqueous phase (mixture of alginic aldehyde and gelatin) in a continuous organic phase (Span 20 dissolved in cyclohexane). Cross-linking occurred between alginic aldehyde (AA) and gelatin (gel) in the presence of borax by Schiff's base reaction during the formation of inverse miniemulsion. The effects of surfactant (Span 20) concentration, volume of the aqueous phase and AA/gel weight ratio on the size of the alginic aldehyde-gelatin (AA-gel) nanoparticles were studied. Nanogels were characterized by DLS, FT-IR spectroscopy, TGA, SEM and TEM. DLS, TEM and SEM studies demonstrated nanosize and spherical morphology of the nanogels. Hemocompatibility and in vitro cytocompatibility analyses of the nanogels proved their nontoxicity. The results indicated the potential of the present nanogel system as a candidate for drug- and gene-delivery applications. PMID:25563951

  6. In situ characterization of natural pyrite bioleaching using electrochemical noise technique

    NASA Astrophysics Data System (ADS)

    Chen, Guo-bao; Yang, Hong-ying; Li, Hai-jun

    2016-02-01

    An in situ characterization technique called electrochemical noise (ECN) was used to investigate the bioleaching of natural pyrite. ECN experiments were conducted in four active systems (sulfuric acid, ferric-ion, 9k culture medium, and bioleaching solutions). The ECN data were analyzed in both the time and frequency domains. Spectral noise impedance spectra obtained from power spectral density (PSD) plots for different systems were compared. A reaction mechanism was also proposed on the basis of the experimental data analysis. The bioleaching system exhibits the lowest noise resistance of 0.101 MΩ. The bioleaching of natural pyrite is considered to be a bio-battery reaction, which distinguishes it from chemical oxidation reactions in ferric-ion and culture-medium (9k) solutions. The corrosion of pyrite becomes more severe over time after the long-term testing of bioleaching.

  7. Identification and characterization of colorectal cancer using Raman spectroscopy and feature selection techniques.

    PubMed

    Li, Shaoxin; Chen, Gong; Zhang, Yanjiao; Guo, Zhouyi; Liu, Zhiming; Xu, Junfa; Li, Xueqiang; Lin, Lin

    2014-10-20

    This study aims to detect colorectal cancer with near-infrared Raman spectroscopy and feature selection techniques. A total of 306 Raman spectra of colorectal cancer tissues and normal tissues are acquired from 44 colorectal cancer patients. Five diagnostically important Raman bands in the regions of 815-830, 935-945, 1131-1141, 1447-1457 and 1665-1675 cm(-1) related to proteins, nucleic acids and lipids of tissues are identified with the ant colony optimization (ACO) and support vector machine (SVM). The diagnostic models built with the identified Raman bands provide a diagnostic accuracy of 93.2% for identifying colorectal cancer from normal Raman spectroscopy. The study demonstrates that the Raman spectroscopy associated with ACO-SVM diagnostic algorithms has great potential to characterize and diagnose colorectal cancer. PMID:25401621

  8. Characterization of protein N-glycosylation by tandem mass spectrometry using complementary fragmentation techniques

    DOE PAGESBeta

    Ford, Kristina L.; Zeng, Wei; Heazlewood, Joshua L.; Bacic, Antony

    2015-08-28

    The analysis of post-translational modifications (PTMs) by proteomics is regarded as a technically challenging undertaking. While in recent years approaches to examine and quantify protein phosphorylation have greatly improved, the analysis of many protein modifications, such as glycosylation, are still regarded as problematic. Limitations in the standard proteomics workflow, such as use of suboptimal peptide fragmentation methods, can significantly prevent the identification of glycopeptides. The current generation of tandem mass spectrometers has made available a variety of fragmentation options, many of which are becoming standard features on these instruments. Lastly, we have used three common fragmentation techniques, namely CID, HCD,more » and ETD, to analyze a glycopeptide and highlight how an integrated fragmentation approach can be used to identify the modified residue and characterize the N-glycan on a peptide.« less

  9. Characterization of protein N-glycosylation by tandem mass spectrometry using complementary fragmentation techniques

    SciTech Connect

    Ford, Kristina L.; Zeng, Wei; Heazlewood, Joshua L.; Bacic, Antony

    2015-08-28

    The analysis of post-translational modifications (PTMs) by proteomics is regarded as a technically challenging undertaking. While in recent years approaches to examine and quantify protein phosphorylation have greatly improved, the analysis of many protein modifications, such as glycosylation, are still regarded as problematic. Limitations in the standard proteomics workflow, such as use of suboptimal peptide fragmentation methods, can significantly prevent the identification of glycopeptides. The current generation of tandem mass spectrometers has made available a variety of fragmentation options, many of which are becoming standard features on these instruments. Lastly, we have used three common fragmentation techniques, namely CID, HCD, and ETD, to analyze a glycopeptide and highlight how an integrated fragmentation approach can be used to identify the modified residue and characterize the N-glycan on a peptide.

  10. Stationary phases with special structural properties for high-throughput separation techniques: preparation, characterization and applications.

    PubMed

    Buszewski, Boguslaw; Welerowicz, Tomasz

    2004-06-01

    Stationary phases with specific structural properties for high-throughput liquid chromatographic (LC) techniques are described. Special attention was paid to phases with special structural properties, mainly containing internal functional group (e.g. amide). Such materials are generally called "embedded phases". There are phases created in amidation process of aminopropylated silica gel, especially phases based on biological compounds, like phospholipids and cholesterol, which are called immobilized artificial membranes (IAM's). The synthesis and applications of polar embedded amide LC stationary phases were also reviewed. Methods of characterization of synthesized packing materials were presented, with general focusing on spectroscopic measurements like (13C and 29Si CP/MAS NMR and FT-IR), elemental and thermal analysis as well as chromatographic quantitative structure-retention relationships (QSRR) and extended chemometric tests. The potential applications of various dedicated stationary phases in a high-throughput LC screening procedures were also presented. PMID:15200378

  11. Characterization of a one dimensional focusing compound refractive lens using the rotating shearing interferometer technique

    SciTech Connect

    Wang Hongchang; Berujon, Sebastien; Sawhney, Kawal

    2012-07-31

    A one dimensional (1D) compound refractive lens (CRL) has been characterized using the grating based rotating shearing interferometer technique. The method is based on the calculation of moire fringes orientation to sense wavefront information. The phase shift and the optical aberration introduced by the 1D CRL on an X-ray beam were retrieved from a single moire fringe image. The radius of curvature of the lens at the apex was derived. This physical radius of the CRL, which is also closely related to the focal length of the 1D CRL, was shown to vary with the incident angle of the incoming X-ray beam onto the CRL. The experimental measurement agreed very well with the theoretical expectations.

  12. Impact of advanced microstructural characterization techniques on modeling and analysis of radiation damage

    SciTech Connect

    Garner, F.A.; Odette, G.R.

    1980-01-01

    The evolution of radiation-induced alterations of dimensional and mechanical properties has been shown to be a direct and often predictable consequence of radiation-induced microstructural changes. Recent advances in understanding of the nature and role of each microstructural component in determining the property of interest has led to a reappraisal of the type and priority of data needed for further model development. This paper presents an overview of the types of modeling and analysis activities in progress, the insights that prompted these activities, and specific examples of successful and ongoing efforts. A review is presented of some problem areas that in the authors' opinion are not yet receiving sufficient attention and which may benefit from the application of advanced techniques of microstructural characterization. Guidelines based on experience gained in previous studies are also provided for acquisition of data in a form most applicable to modeling needs.

  13. Self-normalized photoacoustic technique for thermo-optical characterization of samples mounted between transparent media

    NASA Astrophysics Data System (ADS)

    Balderas-López, J. A.; Díaz-Reyes, J.; Jaime-Fonseca, M. R.; Martínez-Pérez, L.; Pescador-Rojas, J. A.

    2016-03-01

    A self-normalized photoacoustic technique for thermo-optical characterization of materials, mounted between transparent media, is presented. It involves a complex ratio of photoacoustic signals in transmission and front configurations, taking the modulation frequency as the only variable. The analytical solutions for the corresponding 1D heat diffusion problems are analyzed to provide suitable methodologies for measuring the optical absorption coefficients and thermal diffusivity of such samples. This methodology was tested by measuring the optical absorption coefficient, at 660 nm, of methylene blue solutions at various concentrations and the thermal diffusivity of a black drawing ink sample. In addition, an approximated range of optical absorption coefficients, where this photoacoustic methodology is adequate, was established.

  14. A study of the stress wave factor technique for the characterization of composite materials

    NASA Technical Reports Server (NTRS)

    Henneke, E. G., II; Duke, J. C., Jr.; Stinchcomb, W. W.; Govada, A.; Lemascon, A.

    1983-01-01

    A testing program was undertaken to provide an independent investigation and evaluation of the stress wave factor for characterizing the mechanical behavior of composite laminates. Some of the data which was obtained after performing a very large number of tests to determine the reproducibility of the SWF measurement is presented. It was determined that, with some optimizing of experimental parameters, the SWF value can be reproduced to within + or - 10%. Results are also given which show that, after careful calibration procedures, the lowest SWF value along the length of a specimen will correlate very closely to the site of final failure when the specimen is loaded in tension. Finally, using a moire interferometry technique, it was found that local regions having the highest in plane strains under tensile loading also had the lowest SWF values.

  15. Forward-Inverse Adaptive Techniques for Reservoir Characterization and Simulation: Theory and Applications

    SciTech Connect

    Doss, S D; Ezzedine, S; Gelinas, R; Chawathe, A

    2001-06-11

    A novel approach called Forward-Inverse Adaptive Techniques (FIAT) for reservoir characterization is developed and applied to three representative exploration cases. Inverse modeling refers to the determination of the entire reservoir permeability under steady state single-phase flow regime, given only field permeability, pressure and production well measurements. FIAT solves the forward and inverse partial differential equations (PDEs) simultaneously by adding a regularization term and filtering pressure gradients. An implicit adaptive-grid, Galerkin, numerical scheme is used to numerically solve the set of PDEs subject to pressure and permeability boundary conditions. Three examples are presented. Results from all three cases demonstrate attainable and reasonably accurate solutions and, more importantly, provide insights into the consequences of data undersampling.

  16. A first look at roadheader construction and estimating techniques for site characterization at Yucca Mountain, Nevada

    SciTech Connect

    Neil, D.M.; Taylor, D.L.

    1991-12-31

    The Yucca Mountain site characterization program will be based on mechanical excavation techniques for the mined repository construction and development. Tunnel Boring Machines (TBM`s), Mobile Miners (MM), Raiseborers (RB), Blind Hole Shaft Boring Machines (BHSB), and Roadheaders (RH) have been selected as the mechanical excavation machines most suited to mine the densely welded and non-welded tuffs of the Topopah Springs and Calico Hills members. Heavy duty RH in the 70 to 100 ton class with 300 Kw cutter motors have been evaluated and formulas developed to predict machine performance based on the rock physical properties and the results of Linear Cutting Machine (LCM) tests done at the Colorado School of Mines (CSM) for Sandia National Labs. (SNL).

  17. Mechanical characterization of TiO{sub 2} nanofibers produced by different electrospinning techniques

    SciTech Connect

    Vahtrus, Mikk; Šutka, Andris; Vlassov, Sergei; Šutka, Anna; Polyakov, Boris; Saar, Rando; Dorogin, Leonid; Lõhmus, Rünno

    2015-02-15

    In this work TiO{sub 2} nanofibers produced by needle and needleless electrospinning processes from the same precursor were characterized and compared using Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and in situ SEM nanomechanical testing. Phase composition, morphology, Young's modulus and bending strength values were found. Weibull statistics was used to evaluate and compare uniformity of mechanical properties of nanofibers produced by two different methods. It is shown that both methods yield nanofibers with very similar properties. - Graphical abstract: Display Omitted - Highlights: • TiO{sub 2} nanofibers were produced by needle and needleless electrospinning processes. • Structure was studied by Raman spectroscopy and electron microscopy methods. • Mechanical properties were measured using advanced in situ SEM cantilevered beam bending technique. • Both methods yield nanofibers with very similar properties.

  18. Characterization of protein N-glycosylation by tandem mass spectrometry using complementary fragmentation techniques

    PubMed Central

    Ford, Kristina L.; Zeng, Wei; Heazlewood, Joshua L.; Bacic, Antony

    2015-01-01

    The analysis of post-translational modifications (PTMs) by proteomics is regarded as a technically challenging undertaking. While in recent years approaches to examine and quantify protein phosphorylation have greatly improved, the analysis of many protein modifications, such as glycosylation, are still regarded as problematic. Limitations in the standard proteomics workflow, such as use of suboptimal peptide fragmentation methods, can significantly prevent the identification of glycopeptides. The current generation of tandem mass spectrometers has made available a variety of fragmentation options, many of which are becoming standard features on these instruments. We have used three common fragmentation techniques, namely CID, HCD, and ETD, to analyze a glycopeptide and highlight how an integrated fragmentation approach can be used to identify the modified residue and characterize the N-glycan on a peptide. PMID:26379696

  19. Diffusion and ideal MRI techniques to characterize limb-girdle muscular dystrophy

    NASA Astrophysics Data System (ADS)

    Hernández-Salazar, G.; Hidalgo-Tobon, S.; Vargas-Cañas, S.; Marrufo-Melendez, O.; Solis-Najera, S.; Taboada-Barajas, J.; Rodríguez, A. O.; Delgado-Hernández, R.

    2012-10-01

    Limb-girdle muscular dystrophies (LGMD) are a group of autosomal dominantly or recessively inherited muscular dystrophies that also present with primary proximal (limb-girdle) muscle weakness. In the thigh, muscles at the back are affected, with a tendency to preserve the tibialis anterior and gastrocnemius. The aim of this study was to compare quantitative MRI measurements from IDEAL-based imaging and DW imaging in the thigh muscles of adults with LGMDs and healthy volunteers(HC). Six women (three patients and three healthy volunteers) were examined. Imaging experiments were conducted on a 1.5T GE scanner (General Electric Medical Systems. Milwaukee). T1 IDEAL 2D images and diffusion images were acquired. Results demonstrated that the use of noninvasive MRI techniques may provide the means to characterize the muscle through quantitative methods to determine the percentage of fat and ADC values.

  20. Characterization of beam dynamics in the APS injector rings using time-resolved imaging techniques

    SciTech Connect

    Yang, B.X.; Lumpkin, A.H.; Borland, M.

    1997-06-01

    Images taken with streak cameras and gated intensified cameras with both time (longitudinal) and spatial (transverse) resolution reveal a wealth of information about circular accelerators. The authors illustrate a novel technique by a sequence of dual-sweep streak camera images taken at a high dispersion location in the booster synchrotron, where the horizontal coordinate is strongly correlated with the particle energy and the {open_quotes}top-view{close_quotes} of the beam gives a good approximation to the particle density distribution in the longitudinal phase space. A sequence of top-view images taken fight after injection clearly shows the beam dynamics in the phase space. We report another example from the positron accumulator ring for the characterization of its beam compression bunching with the 12th harmonic rf.

  1. Optimization of site characterization and remediation methods using 3-D geoscience modeling and visualization techniques

    SciTech Connect

    Hedegaard, R.F.; Ho, J.; Eisert, J.

    1996-12-31

    Three-dimensional (3-D) geoscience volume modeling can be used to improve the efficiency of the environmental investigation and remediation process. At several unsaturated zone spill sites at two Superfund (CERCLA) sites (Military Installations) in California, all aspects of subsurface contamination have been characterized using an integrated computerized approach. With the aide of software such as LYNX GMS{trademark}, Wavefront`s Data Visualizer{trademark} and Gstools (public domain), the authors have created a central platform from which to map a contaminant plume, visualize the same plume three-dimensionally, and calculate volumes of contaminated soil or groundwater above important health risk thresholds. The developed methodology allows rapid data inspection for decisions such that the characterization process and remedial action design are optimized. By using the 3-D geoscience modeling and visualization techniques, the technical staff are able to evaluate the completeness and spatial variability of the data and conduct 3-D geostatistical predictions of contaminant and lithologic distributions. The geometry of each plume is estimated using 3-D variography on raw analyte values and indicator thresholds for the kriged model. Three-dimensional lithologic interpretation is based on either {open_quote}linked{close_quote} parallel cross sections or on kriged grid estimations derived from borehole data coded with permeability indicator thresholds. Investigative borings, as well as soil vapor extraction/injection wells, are sighted and excavation costs are estimated using these results. The principal advantages of the technique are the efficiency and rapidity with which meaningful results are obtained and the enhanced visualization capability which is a desirable medium to communicate with both the technical staff as well as nontechnical audiences.

  2. Application of different molecular techniques for characterization of catalase-positive cocci isolated from sucuk.

    PubMed

    Kesmen, Zülal; Yarimcam, Burcu; Aslan, Hakiye; Ozbekar, Esra; Yetim, Hasan

    2014-02-01

    This study was carried out for the characterization and discrimination of the indigenous Gram positive, catalase-positive cocci (GCC) population in sucuk, a traditional Turkish dry-fermented sausage. Sucuk samples, produced by the traditional method without starter culture were collected from 8 local producers in Kayseri/Turkey and a total of 116 GCC isolates were identified by using different molecular techniques. Two different molecular fingerprinting methods; namely, randomly amplified polymorphic DNA-PCR (RAPD-PCR) and repetitive extragenic palindrome-PCR (rep-PCR), were used for the clustering of isolates and identification at species level was carried out by full length sequencing of 16S rDNA. Combining the results obtained from molecular fingerprinting and 16S rDNA sequencing showed that the dominant GCC species isolated from the sucuk samples was Staphylococcus saprophyticus followed by Staphylococcus succinus and Staphylococcus equorum belonging to the Staphylococcus genus. Real-time PCR DNA melting curve analysis and high-resolution melting (HRM) analysis targeting the V1 + V3 regions of 16S rDNA were also applied for the discrimination of isolates belonging to different species. It was observed statistically different Tm values and species-specific HRM profiles for all except 2 species (S. saprophyticus and Staphylococcus xylosus) that have high 16S rDNA sequence similarity. The combination of rep-PCR and/or PCR-RAPD with 16S rRNA gene sequencing was an efficient approach for the characterization and identification of the GCC population in spontaneously fermented sucuk. On the other hand, intercalating dye assays were found to be a simple and very promising technique for the differentiation of the GCC population at species level. PMID:24410408

  3. Characterization of itraconazole semisolid dosage forms prepared by hot melt technique.

    PubMed

    Shim, Sang-Young; Ji, Chang-Won; Sah, Hongkee; Park, Eun-Seok; Lee, Beom-Jin

    2006-11-01

    The objective of this study was to formulate itraconazole semisolid dosage forms and characterize their physicochemical properties. Itraconazole and excipients such as polysorbate 80, fatty acids, fatty alcohols, oils and organic acids were melted at 160 degrees C. The fused solution was then cooled immediately at -10 degrees C to make wax-like semisolid preparations. Their physicochemical attributes were first characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometry. The solubility of itraconazole in semisolid preparations and their dispersability in the simulated gastric fluid were also determined. Our semisolid preparations did not show any distinct endothermic peak of a crystalline form of itraconazole around 160-163 degrees C. This suggested that it was changed into amorphous one, when it was formulated into semisolid preparations. In addition, the distinctive functional peaks and chemical shifts of itraconazole were well retained after processing into semisolid preparations. It could be inferred from the data that itraconazole was stable during incorporation into semisolid preparations by the hot melt technique. In particular, itraconazole semisolid preparations composed of polysorbate 80, fatty acids and organic acids showed good solubility and dissolution when dispersed in an aqueous medium. It was anticipated that the semisolid dosage forms would be industrially applicable to improving the bioavailability of poorly water-soluble drugs. PMID:17146976

  4. Chemical and mineralogical characterizations of LD converter steel slags: A multi-analytical techniques approach

    SciTech Connect

    Waligora, J.; Bulteel, D.; Degrugilliers, P.; Damidot, D.; Potdevin, J.L.; Measson, M.

    2010-01-15

    The use of LD converter steel slags (coming from Linz-Donawitz steelmaking process) as aggregates in road construction can in certain cases lead to dimensional damage due to a macroscopic swelling that is the consequence of chemical reactions. The aim of this study was to couple several analytical techniques in order to carefully undertake chemical and mineralogical characterizations of LD steel slags and identify the phases that are expected to be responsible for their instability. Optical microscopy, scanning electron microscopy and electron probe microanalyses revealed that LD steel slags mainly contain calcium silicates, dicalcium ferrites, iron oxides and lime. However, as a calcium silicate phase is heterogeneous, Raman microspectrometry and transmitted electron microscopy had to be used to characterize it more precisely. Results showed that lime is present under two forms in slag grains: some nodules observed in the matrix whose size ranges from 20 to 100 {mu}m and some micro-inclusions, enclosed in the heterogeneous calcium silicate phase whose size ranges from 1 to 3 {mu}m. It was also established that without the presence of magnesia, lime is expected to be the only phase responsible for LD steel slags instability. Nevertheless, the distribution of lime between nodules and micro-inclusions may play a major role and could explain that similar amounts of lime can induce different instabilities. Thus, it appears that lime content of LD steel slags is not the only parameter to explain their instability.

  5. Karst characterization in a semi-arid region using gravity, seismic, and resistivity geophysical techniques.

    SciTech Connect

    Barnhart, Kevin Scott

    2013-10-01

    We proposed to customize emerging in situ geophysical monitoring technology to generate time-series data during sporadic rain events in a semi-arid region. Electrodes were to be connected to wireless %5Cnodes%22 which can be left in the eld for many months. Embedded software would then increase sampling frequency during periods of rainfall. We hypothesized that this contrast between no-volume ow in karst passageways dur- ing dry periods and partial- or saturated-volume ow during a rain event is detectable by these Wireless Sensor Network (WSN) geophysical nodes, we call this a Wireless Resistivity Network (WRN). The development of new methodologies to characterize semi-arid karst hydrology is intended to augment Sandia National Laboratorys mission to lead e orts in energy technologies, waste disposal and climate security by helping to identify safe and secure regions and those that are at risk. Development and initial eld testing identi ed technological barriers to using WRNs for identifying semi-arid karst, exposing R&D which can be targeted in the future. Gravity, seismic, and resis- tivity surveys elucidated how each technique might e ectively be used to characterize semi-arid karst. This research brings to light the importance and challenges with char- acterizing semi-arid karst through a multi-method geophysical study. As there have been very few studies with this emphasis, this study has expanded the body of practical experience needed to protect the nations water and energy security interests.

  6. Laser ultrasound technique applied in material characterization of thermally sprayed nickel aluminum coatings

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Yang, C. H.; Hsiao, W. T.; Su, C.-Y.

    2012-05-01

    Thermal spraying processing usually uses a nickel-aluminum alloy system as the major powder due to its strong adhesion to substrates. The contents of powder material and the processing parameters used in the spraying process cause material properties of coatings exhibiting a wide variation. This research aims at nondestructive characterization of thermal spraying coatings. A laser-generation/laser-detection laser ultrasound technique (LUT) is used for the measurements of dispersion spectra of surface waves propagating along the coated surfaces. Theoretical model for surface waves propagating along a multi-layered structure with coating and substrate is used to model the sprayed coatings. An inversion algorithm based on Shuffled Complex Evolution (SCE-UA) is used to extract mechanical properties from the measured dispersion spectra cooperating with theoretical model. Three coatings with different sprayed powders and powder processing are investigated. Results indicate that substantial linear scatterings are observed for the inverted properties due to the measured dispersion spectra with limited bandwidth inherited from the relatively high attenuations. The slope of linear scattering can be used to distinguish the coating properties. The ANiBNb sample with ball-milled coating has the best properties based on its highest velocity and least attenuation. This method is potentially useful to characterize the mechanical properties of thermally spraying coating in a nondestructive way.

  7. Preparation and characterization of hydroxyapatite-coated iron oxide particles by spray-drying technique.

    PubMed

    Donadel, Karina; Felisberto, Marcos D V; Laranjeira, Mauro C M

    2009-06-01

    Magnetic particles of iron oxide have been increasingly used in medical diagnosis by magnetic resonance imaging and in cancer therapies involving targeted drug delivery and magnetic hyperthermia. In this study we report the preparation and characterization of iron oxide particles coated with bioceramic hydroxyapatite by spray-drying. The iron oxide magnetic particles (IOMP) were coated with hydroxyapatite (HAp) by spray-drying using two IOMP/HAp ratios (0.7 and 3.2). The magnetic particles were characterized by way of scanning electronic microscopy, energy dispersive X-ray, X-ray diffraction, Fourier transformed infrared spectroscopy, flame atomic absorption spectrometry,vibrating sample magnetometry and particle size distribution (laser diffraction). The surface morphology of the coated samples is different from that of the iron oxide due to formation of hydroxyapatite coating. From an EDX analysis, it was verified that the surface of the coated magnetic particles is composed only of HAp, while the interior containsiron oxide and a few layers of HAp as expected. The results showed that spray-drying technique is an efficient and relatively inexpensive method for forming spherical particles with a core/shell structure. PMID:19488622

  8. Electrical characterization of grain boundaries of CZTS thin films using conductive atomic force microscopy techniques

    SciTech Connect

    Muhunthan, N.; Singh, Om Pal; Toutam, Vijaykumar; Singh, V.N.

    2015-10-15

    Graphical abstract: Experimental setup for conducting AFM (C-AFM). - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) thin film was grown by reactive co-sputtering. • The electronic properties were probed using conducting atomic force microscope, scanning Kelvin probe microscopy and scanning capacitance microscopy. • C-AFM current flow mainly through grain boundaries rather than grain interiors. • SKPM indicated higher potential along the GBs compared to grain interiors. • The SCM explains that charge separation takes place at the interface of grain and grain boundary. - Abstract: Electrical characterization of grain boundaries (GB) of Cu-deficient CZTS (Copper Zinc Tin Sulfide) thin films was done using atomic force microscopic (AFM) techniques like Conductive atomic force microscopy (CAFM), Kelvin probe force microscopy (KPFM) and scanning capacitance microscopy (SCM). Absorbance spectroscopy was done for optical band gap calculations and Raman, XRD and EDS for structural and compositional characterization. Hall measurements were done for estimation of carrier mobility. CAFM and KPFM measurements showed that the currents flow mainly through grain boundaries (GB) rather than grain interiors. SCM results showed that charge separation mainly occurs at the interface of grain and grain boundaries and not all along the grain boundaries.

  9. Innovative techniques for the production of energetic radicals for lunar materials processing including photogeneration via concentrated solar energy

    NASA Technical Reports Server (NTRS)

    Osborn, D. E.; Lynch, D. C.; Fazzolari, R.

    1990-01-01

    The Department of Materials Science and Engineering (MSE) is investigating the use of monatomic chlorine produced in a cold plasma to recover oxygen and metallurgically significant metals from lunar materials. Development of techniques for the production of the chlorine radical (and other energetic radicals for these processes) using local planetary resources is a key step for a successful approach. It was demonstrated terrestrially that the use of UV light to energize the photogeneration of OH radicals from ozone or hydrogen peroxide in aqueous solutions can lead to rapid reaction rates for the breakdown of toxic organic compounds in water. A key question is how to use the expanded solar resource at the lunar surface to generate process-useful radicals. This project is aimed at investigating that question.

  10. Fundamental characterization of shrink techniques on negative tone development based dense contact holes

    NASA Astrophysics Data System (ADS)

    Jain, Kaveri; Light, Scott L.

    2016-03-01

    Enormous advances have been made in recent years to design sub 40nm dense contact hole pattern with local CD uniformity (CDU) that the process can tolerate. Negative tone development process (NTD) on 193nm photoresists has achieved this to a large extent without the requirement of additional processing steps on the patterned layer. With further shrinking of size of the subsequent nodes, the demand to produce smaller patterns with wider process window, low defectivity, and improved CDU is increasing, and reaching beyond what can be achieved through NTD alone. A number of techniques are in practice today to achieve this, most notably, implementation of a collar of Atomic Layer Deposited SiO2 (ALD) on photoresist or substrate. However, in recent years, various material suppliers have also proposed shrink chemistries to achieve this. In this paper, we have provided fundamental characterization of shrink via application of spin-on agents (organic as well as aqueous) on the post-imaged pattern. We have also compared them for their shrink capacity, defect tendency, dry etch capability and ease of implementation in the process flow. In addition, we have provided recommendations on which technique is suitable for a given set of process prerequisites.

  11. Operando characterization of nanocatalysts via spectroscopy, scattering and imaging techniques in the same micro-reactor

    NASA Astrophysics Data System (ADS)

    Li, Yuanyuan; Frenkel, Anatoly; Baumann, Philipp; Tappero, Ryan; Zakharov, Dmitri; Stach, Eric; Elsen, Annika; Jung, Ulrich; Nuzzo, Ralph

    2014-03-01

    The increasing demand to rationally design new catalysts for energy generation/conversion calls for improvements in research methodology which enables multi-technique investigations of working catalysts in reaction conditions. Using the operando approach is necessary to establish structure activity/selectivity relationship. However, this approach is hindered by many challenges, e.g., the incompatibility of different characterization methods with respect to the sample concentration and environment, and, hence, the need to use multiple in situ reactor designs. We report on the development and tests of the single, portable reactor compatible with most useful techniques for operando studies of nanocatalysts: X-ray absorption, transmission electron microscopy, infrared and Raman spectroscopies. The test system was Pt/SiO2 nanocatalyst and the reaction was the ethylene hydrogenation. The reactor was a closed cell with SiN windows enabled catalytic reactions under atmospheric pressure. Both XAFS and TEM experiments were conducted in identical conditions, while monitoring the product formation using mass spectrometry. Comparison of TEM and XAFS results provided new information on the structure-activity relationship of these catalysts.

  12. Characterization and bioactivity study of nanohydroxyapatite on superhydrophilic vertically aligned carbon nanotubes using optical techniques

    NASA Astrophysics Data System (ADS)

    Ferreira Irineu, Joao Anderson; Marsi, Teresa C.; Santos, Tiago G.; Santo, Ana Maria E.; Rangel, Joao L.; Mengui, Ursula A.; Martin, Airton A.; Corat, Evaldo J.; Marciano, Fernanda R.; Lobo, Anderson O.

    2012-03-01

    Vertically-aligned multi-walled carbon nanotubes (VACNT) is of particular interest in regenerative medicine. Templateinduced hydroxyapatite (HA) has broad prospects in applied fields of bone regenerative medicine. Thus, it becomes very attractive a combination these two excellent materials to bone tissue engineering applications. In this study the HA/VACNT nanocomposites were used as scaffolds to Human osteoblast cells culture. Superhydrophilic VACNT films were obtained by CVD method and funcionalized by oxygen plasma. The fabrication of HA/VACNT nanocomposites was performed with a direct electrodeposition of the thin HA films on the VACNT films. The bioactivity and biomineralization in vitro process of superhydrophilic HA/VACNT nanocomposites were investigated using simulated body fluid (SBF) and optical techniques. The characterization of of HA/VACNT nanocomposites was performed before and after soaking 21 days in SBF and compared to superydrophilic VACNT films. Fourier transform infrared spectroscopy, micro X-ray fluorescence spectrometer by energy-dispersive and X-ray difractogram were employed to investigate the structural and chemical properties. The morphology was investigated by FEG-SEM analysis. After 21 days was identified that others biological apatites were formed only on HA/VACNT nanocomposites. Optical techniques showing a powerful tool to characterizated and investigated the bioactivity in vitro process. These findings were very atractive to application of this new nanocomposite to bone tissue regeneration.

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1998-01-01

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

  14. Development of DNA affinity techniques for the functional characterization of purified RNA polymerase II transcription factors

    SciTech Connect

    Garfinkel, S.; Thompson, J.A.; Cohen, R.B.; Brendler, T.; Safer, B.

    1987-05-01

    Affinity adsorption, precipitation, and partitioning techniques have been developed to purify and characterize RNA Pol II transcription components from whole cell extracts (WCE) (HeLa) and nuclear extracts (K562). The titration of these extracts with multicopy constructs of the Ad2 MLP but not pUC8, inhibits transcriptional activity. DNA-binding factors precipitated by this technique are greatly enriched by centrifugation. Using this approach, factors binding to the upstream promoter sequence (UPS) of the Ad2 MLP have been rapidly isolated by Mono Q, Mono S, and DNA affinity chromatography. By U.V. crosslinking to nucleotides containing specific TSP-phosphodiester bonds within the recognition sequence, this factor is identified as a M/sub r/ = 45,000 polypeptide. To generate an assay system for the functional evaluation of single transcription components, a similar approach using synthetic oligonucleotide sequences spanning single promoter binding sites has been developed. The addition of a synthetic 63-mer containing the UPS element of the Ad2 MLP to HeLa WCE inhibited transcription by 60%. The addition of partially purified UPS binding protein, but not RNA Pol II, restored transcriptional activity. The addition of synthetic oligonucleotides containing other regulatory sequences not present in the Ad2 MLP was without effect.

  15. Characterization of (Th,U)O 2 fuel pellets made by impregnation technique

    NASA Astrophysics Data System (ADS)

    Kutty, T. R. G.; Nair, M. R.; Sengupta, P.; Basak, U.; Kumar, Arun; Kamath, H. S.

    2008-02-01

    Impregnation technique is an attractive alternative for manufacturing highly radiotoxic 233U bearing thoria based mixed oxide fuel pellets, which are remotely treated in hot cell or shielded glove-box facilities. This technique is being investigated to fabricate the fuel for the forthcoming Indian Advanced Heavy Water Reactor (AHWR). In the impregnation process, porous ThO 2 pellets are prepared in an unshielded facility which are then impregnated with 1.5 molar uranyl nitrate solution in a shielded facility. The resulting composites are dried and denitrated at 500 °C and then sintered in reducing/oxidizing atmosphere to obtain high density (Th,U)O 2 pellets. In this work, the densification behaviour of ThO 2-2% UO 2 and ThO 2-4% UO 2 pellets was studied in reducing and oxidizing atmospheres using a high temperature dilatometer. Densification was found to be larger in air than in Ar-8% H 2. The characterization of the sintered pellets was made by optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The grain structure of ThO 2-2% UO 2 and ThO 2-4% UO 2 pellets was uniform. The EPMA data confirmed that the uranium concentration was slightly higher at the periphery of the pellet than that at the centre.

  16. Comparative analysis of different measurement techniques for characterizing soil surface roughness in agricultural soils

    NASA Astrophysics Data System (ADS)

    Martinez-Agirre, Alex; Álvarez-Mozos, Jesús; Valle, José Manuel; Rodríguez, Álvaro; Giménez, Rafael

    2016-04-01

    analysis was threefold: (1) comparison of raw data (point clouds), (2) comparison of interpolated DEMs considering different resolutions (2.5mm, 5mm and 10mm) and (3) comparison of roughness parameters. In all cases the profilometer was used as a reference because of its vertical accuracy and nadiral viewing geometry. Thus point clouds and interpolated DEMs were compared to the height profiles. The results showed that in most cases surface height discrepancies were below 10 mm for raw data and increased slightly when increasing the pixel size of DEMs. Finally, a thorough analysis of different roughness parameters proposed in the literature was carried out to find the most appropriate technique and parameter for the characterization of roughness in each case. Although still preliminary, results offer practical recommendations on the usefulness of each technique.

  17. Innovation in san francisco.

    PubMed

    Travis, J

    1992-08-01

    In San Francisco 2 weeks ago, AAAS and Science sponsored a new meeting, Science Innovation '92. The unusual gathering focused not on research results but on new techniques and instruments, particularly for biomedical science. As seen in the stories below, some of the most eye-catching innovations emerged at the intersection of physics and biology. PMID:17736460

  18. Applied Protein and Molecular Techniques for Characterization of B Cell Neoplasms in Horses

    PubMed Central

    Badial, Peres R.; Tallmadge, Rebecca L.; Miller, Steven; Stokol, Tracy; Richards, Kristy; Borges, Alexandre S.

    2015-01-01

    Mature B cell neoplasms cover a spectrum of diseases involving lymphoid tissues (lymphoma) or blood (leukemia), with an overlap between these two presentations. Previous studies describing equine lymphoid neoplasias have not included analyses of clonality using molecular techniques. The objective of this study was to use molecular techniques to advance the classification of B cell lymphoproliferative diseases in five adult equine patients with a rare condition of monoclonal gammopathy, B cell leukemia, and concurrent lymphadenopathy (lymphoma/leukemia). The B cell neoplasms were phenotypically characterized by gene and cell surface molecule expression, secreted immunoglobulin (Ig) isotype concentrations, Ig heavy-chain variable (IGHV) region domain sequencing, and spectratyping. All five patients had hyperglobulinemia due to IgG1 or IgG4/7 monoclonal gammopathy. Peripheral blood leukocyte immunophenotyping revealed high proportions of IgG1- or IgG4/7-positive cells and relative T cell lymphopenia. Most leukemic cells lacked the surface B cell markers CD19 and CD21. IGHG1 or IGHG4/7 gene expression was consistent with surface protein expression, and secreted isotype and Ig spectratyping revealed one dominant monoclonal peak. The mRNA expression of the B cell-associated developmental genes EBF1, PAX5, and CD19 was high compared to that of the plasma cell-associated marker CD38. Sequence analysis of the IGHV domain of leukemic cells revealed mutated Igs. In conclusion, the protein and molecular techniques used in this study identified neoplastic cells compatible with a developmental transition between B cell and plasma cell stages, and they can be used for the classification of equine B cell lymphoproliferative disease. PMID:26311245

  19. Use of microfocus computerized tomography as a new technique for characterizing bone tissue around oral implants.

    PubMed

    Van Oossterwyck, H; Duyck, J; Vander Sloten, J; Van der Perre, G; Jansen, J; Wevers, M; Naert, I

    2000-01-01

    Qualitative and quantitative analysis of peri-implant tissues around retrieved oral implants is typically done by means of light microscopy on thin histological sections containing the metal surface and the undecalcified bone. It remains, however, a labor-intensive and thus time-consuming job. Moreover, it is a destructive technique that allows tissue quantification in only a limited number of two-dimensional sections. As an alternative, we evaluated the bone structure around screw-shaped titanium implants by means of microfocus computerized tomography (micro-CT) because it presents a number of advantages compared to conventional sectioning techniques: micro-CT is nondestructive, fast, and allows a fully three-dimensional characterization of the bone structure around the implant. Images can be reconstructed in an arbitrary plane, and three-dimensional reconstructions are also possible. Because of its high resolution, individual trabeculae can be visualized. The accuracy of micro-CT was qualitatively evaluated by comparing histological sections with the corresponding CT slices for the same specimen. The overall trabecular structure is very similar according to both techniques. Even very close to the interface, the titanium implant does not seem to produce significant artifacts. Furthermore, because the complete digital data on the trabecular bone structure around the implant is available, it is possible to create finite-element models of the bone-implant system that model the trabeculae in detail so that mechanical stress transfer at the interface can be studied at the level of individual trabeculae. Therefore, micro-CT seems to be very promising for the in vitro assessment of the three-dimensional bone structure around oral implants. Further research will be needed to evaluate its accuracy in a more quantitative way. PMID:11831302

  20. Threading Dislocation Characterization and Stress Mapping Depth Profiling via Ray Tracing Technique

    NASA Astrophysics Data System (ADS)

    Zhou, Tianyi

    Zinc oxide (ZnO) has been well known as a transparent, dielectric, piezoelectric and wide band gap material. The potential capabilities have been demonstrated for a wide range of applications such as piezoelectric transducer, gas sensor, optical waveguides and transparent electrode. It could also be applied as a substrate material for GaN-based devices. However, while some applications have already been realized, issues relating to crystalline defects remain a barrier to the successful realization of several others. In this thesis, the central focus of Chapter II is to characterize threading dislocations in hydrothermal grown ZnO substrates through simulation work as well as other techniques. The goal of this study is to find the origin of threading dislocations and design strategies to mitigate their negative effects by either reducing their densities or completely eliminating them. In Chapter III, the technique of SMART (stress mapping analysis via ray tracing) is discussed in detail to measure residue stress in packaged silicon circuits. Residual stress plays an important role in the performance and lifetime of single crystal device material. There are mainly two advantages of SMART compared with other techniques: (a) all six components of the stress tensor could be evaluated; (b) it is non-destructive and no damaging trace will be left on the sample. In this study, our goal is to build a relationship between stress distribution and depth. The concept of penetration depth is critically important in this study and its value may cause great changes for real space stress distribution. A new function is applied to get better fitting curves. Data in this study is obtained from various penetration depth, which represents exponentially decaying weighted average of actual stress value or in other words this stress profile is Laplace transform of real stress profile. Mathematical procedure is described to determine real stress profile from Laplace profile. Experiment

  1. Bio-Impedance Characterization Technique with Implantable Neural Stimulator Using Biphasic Current Stimulus

    PubMed Central

    Lo, Yi-Kai; Chang, Chih-Wei; Liu, Wentai

    2016-01-01

    Knowledge of the bio-impedance and its equivalent circuit model at the electrode-electrolyte/tissue interface is important in the application of functional electrical stimulation. Impedance can be used as a merit to evaluate the proximity between electrodes and targeted tissues. Understanding the equivalent circuit parameters of the electrode can further be leveraged to set a safe boundary for stimulus parameters in order not to exceed the water window of electrodes. In this paper, we present an impedance characterization technique and implement a proof-of-concept system using an implantable neural stimulator and an off-the-shelf microcontroller. The proposed technique yields the parameters of the equivalent circuit of an electrode through large signal analysis by injecting a single low-intensity biphasic current stimulus with deliberately inserted inter-pulse delay and by acquiring the transient electrode voltage at three well-specified timings. Using low-intensity stimulus allows the derivation of electrode double layer capacitance since capacitive charge-injection dominates when electrode overpotential is small. Insertion of the inter-pulse delay creates a controlled discharge time to estimate the Faradic resistance. The proposed method has been validated by measuring the impedance of a) an emulated Randles cells made of discrete circuit components and b) a custom-made platinum electrode array in-vitro, and comparing estimated parameters with the results derived from an impedance analyzer. The proposed technique can be integrated into implantable or commercial neural stimulator system at low extra power consumption, low extra-hardware cost, and light computation. PMID:25569999

  2. Characterization of corrosion pit initiation in aluminum using advanced electron microscopy techniques

    NASA Astrophysics Data System (ADS)

    Elswick, Danielle S.

    The resistance to pitting corrosion in aluminum is due to the presence of a compact thin, approximately 5 nm, oxide. Certain conditions locally attack this protective oxide layer leading to its breakdown and resulting in the formation of corrosion pits. Numerous studies have investigated the growth and propagation stages of pitting corrosion yet the initiation stage remains not clearly defined nor well understood. The presence of aggressive chemical species, such as chloride, plays a critical role in the pitting phenomenon and is explored in this investigation. This dissertation focuses on the localization of pitting corrosion in high purity aluminum in order to accurately predict where and when the pit initiation process will occur so that microstructural changes associated with pit initiation can be easily identified and characterized using electron microscopy. A comprehensive investigation into the corrosion initiation process was attempted utilizing advanced characterization techniques in the transmission electron microscope (TEM) coupled with high-resolution microanalysis. Localization of pitting was successful through use of different sample geometries that reduced the length scale for which pitting events occurred. Three geometries were investigated, each with unique features for pitting corrosion. Electropolished Al needles localized pitting to a sharp tip due to a geometric field enhancement effect, while other experiments employed an Al wire micro-electrode geometry. Both geometries minimized the area where corrosion pits initiated and were electrochemically tested using a solution that contained the chloride species. A third geometry included electron beam evaporated Al films implanted with chloride, which induced pitting corrosion in an otherwise chloride-free environment. Localization of pitting was successfully achieved using novel sample geometries that isolated the desired stages of pitting corrosion, i.e. metastable pitting, through controlled

  3. Characterization of Deficiencies in the Frequency Domain Forced Response Analysis Technique for Supersonic Turbine Bladed Disks

    NASA Technical Reports Server (NTRS)

    Brown, Andrew M.; Schmauch, Preston

    2011-01-01

    Turbine blades in rocket and jet engine turbomachinery experience enormous harmonic loading conditions. These loads result from the integer number of upstream and downstream stator vanes as well as the other turbine stages. Assessing the blade structural integrity is a complex task requiring an initial characterization of whether resonance is possible and then performing a forced response analysis if that condition is met. The standard technique for forced response analysis in rocket engines is to decompose a CFD-generated flow field into its harmonic components, and to then perform a frequency response analysis at the problematic natural frequencies. Recent CFD analysis and water-flow testing at NASA/MSFC, though, indicates that this technique may miss substantial harmonic and non-harmonic excitation sources that become present in complex flows. A substantial effort has been made to account for this denser spatial Fourier content in frequency response analysis (described in another paper by the author), but the question still remains whether the frequency response analysis itself is capable of capturing the excitation content sufficiently. Two studies comparing frequency response analysis with transient response analysis, therefore, of bladed-disks undergoing this complex flow environment have been performed. The first is of a bladed disk with each blade modeled by simple beam elements. Six loading cases were generated by varying a baseline harmonic excitation in different ways based upon cold-flow testing from Heritage Fuel Air Turbine Test. It was hypothesized that the randomness and other variation from the standard harmonic excitation would reduce the blade structural response, but the results showed little reduction. The second study was of a realistic model of a bladed-disk excited by the same CFD used in the J2X engine program. It was hypothesized that enforcing periodicity in the CFD (inherent in the frequency response technique) would overestimate the

  4. Traditional and innovative methods applied to a crystalline aquifer for characterizing fault zone hydrology at different scales

    NASA Astrophysics Data System (ADS)

    Bour, O.; Ruelleu, S.; Le Borgne, T.; Boudin, F.; Moreau, F.; Durand, S.; Longuevergne, L.

    2011-12-01

    confined aquifer is relatively high, in agreement with ground-surface deformation measurements that suggest a relativity high compressibility of the fault zone. At larger scale, we show through a high-resolution gravimetric survey that the highly fractured contact between granite and micaschists, which constitutes the main path for groundwater flow, is a gently dipping structure. A 3D gravimetric model confirms also the presence of sub-vertical faults that may constitute important drains for the aquifer recharge. In addition, groundwater temperature monitoring allows to shows that the main water supply comes from a depth of at least 300 meters. Such a depth in a low relief region involves relatively deep groundwater circulation that can be achieved only thanks to major permeable fault zone. This field example shows the advantages and limitations of some traditional and innovative methods to characterize fault zone hydrology in crystalline bedrock aquifers.

  5. Laboratory instrumentation and techniques for characterizing multi-junction solar cells for space applications

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.

    1995-01-01

    Multi-junction solar cells are attractive for space applications because they can be designed to convert a larger fraction of AMO into electrical power at a lower cost than single-junction cells. The performance of multi-junction cells is much more sensitive to the spectral irradiance of the illuminating source than single-junction cells. The design of high efficiency multi-junction cells for space applications requires matching the optoelectronic properties of the junctions to AMO spectral irradiance. Unlike single-junction cells, it is not possible to carry out quantum efficiency measurements using only a monochromatic probe beam and determining the cell short-circuit current assuming linearity of the quantum efficiency. Additionally, current-voltage characteristics can not be calculated from measurements under non-AMO light sources using spectral-correction methods. There are reports in the literature on characterizing the performance of multi junction cells by measuring and convoluting the quantum efficiency of each junction with the spectral irradiance; the technique is of limited value for the characterization of cell performance under AMO power-generating conditions. We report the results of research to develop instrumentation and techniques for characterizing multi junction solar cells for space . An integrated system is described which consists of a standard lamp, spectral radiometer, dual-source solar simulator, and personal computer based current-voltage and quantum efficiency equipment. The spectral radiometer is calibrated regularly using the tungsten-halogen standard lamp which has a calibration based on NIST scales. The solar simulator produces the light bias beam for current-voltage and cell quantum efficiency measurements. The calibrated spectral radiometer is used to 'fit' the spectral irradiance of the dual-source solar simulator to WRL AMO data. The quantum efficiency apparatus includes a monochromatic probe beam for measuring the absolute cell

  6. Phytochemical fingerprint and chemometrics for natural food preparation pattern recognition: an innovative technique in food supplement quality control.

    PubMed

    Donno, D; Boggia, R; Zunin, P; Cerutti, A K; Guido, M; Mellano, M G; Prgomet, Z; Beccaro, G L

    2016-02-01

    Recently, the fingerprint approach using chromatography has become one of the most effective tools for quality assessment of herbal medicines and food supplements: due to the complexity of the chromatographic fingerprint and the irreproducibility of chromatographic instruments and experimental conditions, chemometric approach is employed to deal with the chromatographic fingerprint. The study was aimed at developing new analytical methods for the multivariate phytochemical fingerprinting of bioactive compounds in eight tree-species bud-preparations, commonly used in phytotherapy. Methods was used to identify and quantify the main bioactive compounds (polyphenols, organic acids and vitamins), and obtain a specific botanical profile in order to assess the contribution of each single bioactive class to the total bud preparation phytocomplex. A chemometric approach was used to distinguish among different genotypes assuring the identity, safety and quality of the botanical raw materials. The established protocol was simple, sensitive and reliable and it could be used for the evaluation and quality control of bud-extracts and natural food supplements: the proposed method was successfully applied to the characterization of commercial bud-preparations, demonstrating to be an effective tool for the fingerprinting of this plant material. The new approach developed in this study represents a good alternative for improving the classification results of herbal materials with complex chromatograms. It should be necessary to develop a "multivariate chromatographic fingerprint", in order to differentiate the herbal preparations according to their genotype, avoiding substitutions, changes or adulterations with other species or synthetic drugs. PMID:27162387

  7. Innovative technique of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration: A comparative study

    PubMed Central

    Kim, Say-June; Kim, Kee-Hwan; An, Chang-Hyeok; Kim, Jeong-Soo

    2015-01-01

    AIM: To investigate the safety and feasibility of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration (nSIL-CBDE) by comparing the surgical outcomes of this technique with those of conventional laparoscopic CBDE (CL-CBDE). METHODS: We retrospectively analyzed the clinical data of patients who underwent CL-CBDE or nSIL-CBDE for the treatment of common bile duct (CBD) stones between January 2000 and December 2014. For performing nSIL-CBDE, a needlescopic grasper was also inserted through a direct puncture below the right subcostal line after introducing a single-port through the umbilicus. The needlescopic grasper helped obtain the critical view of safety by retracting the gallbladder laterally and by preventing crossing or conflict between laparoscopic instruments. The gallbladder was then partially dissected from the liver bed and used for retraction. CBD stones were usually extracted through a longitudinal supraduodenal choledochotomy, mostly using flushing a copious amount of normal saline through a ureteral catheter. Afterward, for the certification of CBD clearance, CBDE was performed mostly using a flexible choledochoscope. The choledochotomy site was primarily closed without using a T-tube, and simultaneous cholecystectomies were performed. RESULTS: During the study period, 40 patients underwent laparoscopic CBDE. Of these patients, 20 underwent CL-CBDE and 20 underwent nSIL-CBDE. The operative time for nSIL-CBDE was significantly longer than that for CL-CBDE (238 ± 76 min vs 192 ± 39 min, P = 0.007). The stone clearance rate was 100% (40/40) in both groups. Postoperatively, the nSIL-CBDE group required less intravenous analgesic (pethidine) (46.5 ± 63.5 mg/kg vs 92.5 ± 120.1 mg/kg, P = 0.010) and had a shorter hospital stay than the CL-CBDE group (3.8 ± 2.0 d vs 5.1 ± 1.7 d, P = 0.010). There was no significant difference in the incidence of postoperative complications between the two groups. CONCLUSION: The

  8. Technical note: Modifying Atlantic salmon (Salmo salar) jumping behavior to facilitate innovation of parasitic sea lice control techniques.

    PubMed

    Dempster, T; Kristiansen, T S; Korsøen, Ø J; Fosseidengen, J E; Oppedal, F

    2011-12-01

    Industrial salmon farms are reservoirs of parasitic sea lice (Lepeophtheirus salmonis and Caligus spp.), which causes both production inefficiencies and contributes to population-level declines of wild salmon and trout. Current control methods vary in effect and stimulate controversy by the discharge of chemicals into the environment. An alternate control method uses a thin, chemical-infused oil layer on the sea surface. As farmed salmon jump through the surface, the treatment makes contact with the lipophilic carapace of sea lice and kills them. To enhance the effectiveness of this method, we tested whether the natural jumping behavior of salmon could be increased and directed. In a 2,000-m(3) experimental sea-cage, we removed the ability of groups of salmon to access the surface for different periods (0 to 48 h) and measured their surface behaviors after the surface became accessible again. Surface removal for 24 and 48 h induced 93% of salmon to jump in the 2 h after surface access was reinstated, a result that differed (P < 0.001) from the shorter duration (0 to 12 h) treatments. Salmon without surface access for 24 and 48 h jumped 2 to 3 times more often (P < 0.001), and made their first jump 2 to 3 times sooner (P = 0.003) on average after surface access became available than salmon in the shorter duration treatments. Our results indicate that removal of surface access for short periods may lead to loss of air from the physostomous swim bladder and cause negative buoyancy. This creates a behavioral drive for salmon to jump, swallow air and fill their swim bladders once surface access is reinstated. By combining the increased jumping behavior induced by this technique with a floating, oil-infused treatment, efficiency of sea lice treatments may be improved and treatment chemicals can be re-collected, thus decreasing environmental pollution. PMID:21821806

  9. Climatology of Vertical Air Motion During Rainfall in Niamey, Niger and Black Forest, Germany using an Innovative Cloud Radar Retrieval Technique

    NASA Astrophysics Data System (ADS)

    Luke, E. P.; Giangrande, S. E.; Kollias, P.

    2008-12-01

    In recent years, the DOE Atmospheric Radiation Measurement (ARM) program has deployed its ARM Mobile Facility (AMF) to collect continuous measurements in several climatologically distinct locations, including a year-long stay in Niamey, Niger and eight months in Germany's Black Forest. The AMF includes a vertically pointing 95 GHz cloud radar, a tool of choice for profiling non-precipitating clouds at high spatial and temporal resolutions, but commonly considered poorly suited to the quantitative study of precipitation, due in large part to attenuation. However, an innovative technique first explored by Lhermitte in the late 1980s, and subsequently by others, sidesteps much of the quantitative uncertainty imposed by attenuation by exploiting non-Rayleigh resonance effects of scattering from raindrops at 95 GHz. Given a modest range of suitable drop sizes, non-Rayleigh resonances appear as distinct peaks and valleys in Doppler spectra, which once identified, can be directly mapped to known drop sizes by Mie theory. Although attenuation in rain at 95 GHz is substantial, key to the technique is that all non-Rayleigh peaks and valleys in a given Doppler spectrum are affected equally, preserving their relative positions and magnitudes (barring feature extinction). Vertical air motion is retrieved very accurately by taking the difference between the measured Doppler velocity of a resonance feature (usually the first valley) and the known terminal velocity of its associated drop size. We have achieved promising retrieval accuracies at spatial and temporal resolutions of 30 meters and 2 seconds. Here we present lessons learned when the retrieval technique is automated and applied to measurements taken in rain over the full durations of the Niamey and Black Forest AMF deployments, comparing vertical air velocity patterns of monsoonal precipitation over the African desert with those of the orographically influenced precipitation in Germany's mountains.

  10. Characterization and Processing of Organic Nonlinear Optical Materials using Ellipsometric, Waveguiding, and Absorption Spectroscopy Techniques

    NASA Astrophysics Data System (ADS)

    Olbricht, Benjamin C.

    The first focus of this work is to describe methods for characterizing organic electro-optic materials. Teng-Man Ellipsometry and Attenuated Total Internal Reflection are reviewed. Experimental techniques for these instruments are described and the calculation of an electro-optic activity is derived. The two techniques are compared; it has been found that in Situ Teng-Man ellipsometry is useful to determine poling conditions but not for reliably evaluating electro-optic activity. Attenuated Total Internal Reflection is found to provide very reliable and precise measurements of electro-optic activity and linear optical constants. As a reference, many materials systems have been evaluated and their electro-optic activities are recorded herein. Methods for fabricating devices for test by Teng-Man ellipsometry and Attenuated Total Internal Reflection are presented. A process for inducing Pockel's response via contact-geometry electric field poling is also described, along with modifications to the simple slab dielectric device to enhance the efficacy of poling. An additional method for enhancing the efficiency of poling is presented. This technique relies on the photoisomerization of azobenzene dyes under 532nm radiation to reduce the dimensionality accessible to chromophores doped into the azobenzene matrix. This effect is known as "Laser Assisted Poling" and is shown to increase poling efficiency by more than two fold. The second purpose of this work is to present an experimental technique to measure the order parameter = 3cos 2q -12 . This method is known as Variable-Angle Polarization-Referenced Absorption Spectroscopy (VAPRAS). The experimental apparatus used for VAPRAS introduces small alterations to a UV/Vis Spectrophotometer and an order parameter is derived by exclusively using classical models for transmittance. VAPRAS provides an effective refractive index for the electro-optic material film which is used to calculate the order of absorbers in the film

  11. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Second quarter 1992

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  12. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No[sub x]) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO[sub x] combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO[sub x] reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO[sub x] burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO[sub x] reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  13. Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets.

    PubMed

    Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Rashidi, Ali Morad; Shirkhanloo, Hamid; Rahighi, Reza

    2016-01-01

    A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL(-1)), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL(-1)). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L(-1) for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24-15.6, 0.015-0.95 and 0.039-2.33 µg L(-1) for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned metal ions in river water, human urine and

  14. Innovative 3D and 4D geological interpretation, modelling and visualisation techniques for subsurface characterisation of complex industrial sites - examples in the UK nuclear industry

    NASA Astrophysics Data System (ADS)

    Smith, Nicholas; Shevelan, John; Hodgetts, David; Head, William

    2013-04-01

    Industrial sites are typically complex, with numerous plants within their (often) relatively small footprint. The 'cramped' nature of these sites means that the geological characterisation that is essential to the development of environmental safety cases may be hampered by a lack of access to exposures, if they exist at all. Due to access limitations and potential for ground vibration affecting key plants, geophysical data are typically limited to those gathered from lower resolution surveys (e.g. electrical resistivity tomography) rather than those gathered from more informative vibroseis seismic reflection surveys. Thus, whilst many industrial sites may possess numerous intrusive boreholes (Sellafield, perhaps the UK's most complex industrial site, has over 3000), there is a lack of ties to either high resolution geophysical data, or important regional lithostratigraphic data provided by exposure of key sequences. This poses a conundrum: the hydrogeological 3D and 4D numerical models required to show the predicted migration paths of potential contamination within the subsurface require the best geological understanding possible, yet without high resolution geophysical data or geological exposure within the sites themselves geological interpretation is often restricted to attempting to correlate between boreholes that may be tens to hundreds of metres apart and only a few metres deep, which one could assume may not provide a good geological understanding. In this paper, using examples from the nuclear industry, we describe how the use of outcrop analogues and innovative GIS-based, 3D/4D geological interpretation, characterisation, modelling and visualisation techniques goes some way to addressing these issues. Regional outcrops of Triassic sandstone and unconsolidated Quaternary sequences are ideal analogues for unexposed sequences underlying key nuclear sites in West Cumbria (UK), providing important sedimentological (and depositional), lithostratigraphic and

  15. Potential and limitations of microanalysis SEM techniques to characterize borides in brazed Ni-based superalloys

    SciTech Connect

    Ruiz-Vargas, J.; Siredey-Schwaller, N.; Noyrez, P.; Mathieu, S.; Bocher, P.; and others

    2014-08-15

    Brazed Ni-based superalloys containing complex phases of different Boron contents remain difficult to characterize at the micrometer scale. Indeed Boron is a light element difficult to measure precisely. The state-of-the-art microanalysis systems have been tested on a single crystal MC2 based metal brazed with BNi-2 alloy to identify boride precipitates. Effort has been made to evaluate the accuracy in Boron quantitation. Energy-dispersive and wavelength-dispersive X-ray spectroscopy attached to a Scanning Electron Microscope have first been used to determine the elemental composition of Boron-free phases, and then applied to various types of borides. Results have been compared to the ones obtained using a dedicated electron probe microanalysis, considered here as the reference technique. The most accurate method to quantify Boron using EDS is definitely by composition difference. A precision of 5 at.% could be achieved with optimized data acquisition and post-processing schemes. Attempts that aimed at directly quantifying Boron with various standards using EDS or coupled EDS/WDS gave less accurate results. Ultimately, Electron Backscatter Diffraction combined with localized EDS analysis has proved invaluable in conclusively identifying micrometer sized boride precipitates; thus further improving the characterization of brazed Ni-based superalloys. - Highlights: • We attempt to accurately identify Boron-rich phases in Ni-based superalloys. • EDS, WDS, EBSD systems are tested for accurate identification of these borides. • Results are compared with those obtained by electron probe microanalysis. • Boron was measured with EDS by composition difference with a precision of 5 at. %. • Additional EBSD in phase identification mode conclusively identifies the borides.

  16. Hydrogeologic facies characterization of an alluvial fan near Fresno, California, using geophysical techniques

    USGS Publications Warehouse

    Burow, Karen R.; Weissmann, G.S.; Miller, R.D.; Placzek, Gary

    1997-01-01

    DBCP (1,2-dibromo-3-chloropropane) contamination in the sole source aquifer near Fresno, California, has significantly affected drinking-water supplies. Borehole and surface geophysical data were integrated with borehole textural data to characterize the Kings River alluvial fan sediments and to provide a framework for computer modeling of pesticide transport in ground water. Primary hydrogeologic facies units, such as gravel, coarse sand or gravel, fine sand, and silt and clay, were identified in cores collected from three borings located on a 4.6-kilometer transect of multilevel monitoring wells. Borehole geophysical logs collected from seven wells and surface geophysical surveys were used to extrapolate hydrogeologic facies to depths of about 82meters and to correlate the facies units with neighboring drilling sites. Thickness ranged from 0.3to 13 meters for sand and gravel units, and from 0.3 to 17 meters for silt and clay. The lateral extent of distinct silt and clay layers was mapped using shallow seismic reflection and ground-penetrating radar techniques. About 3.6 kilometers of seismic reflection data were collected; at least three distinct fine-grained layers were mapped. The depth of investigation of the seismic survey ranged from 34 to 107 meters below land surface, and vertical resolution was about 3.5 meters. The ground-penetrating radar survey covered 3.6kilometers and imaged a 1.5-meters thick, continuous fine-grained layer located at a depth of about 8 meters. Integrated results from the borehole sediment descriptions and geophysical surveys provided a detailed characterization over a larger areal extent than traditional hydrogeologic methods alone.

  17. Zone wise local characterization of welds using digital image correlation technique

    NASA Astrophysics Data System (ADS)

    Saranath, K. M.; Sharma, Abhay; Ramji, M.

    2014-12-01

    The process of welding is associated with high and varying thermal gradients across the weld, resulting in inhomogeneous material properties surrounding the weldment. A proper understanding of the varying mechanical properties of the weld and surrounding materials is important in designing and modelling of components with weld. In the present study the characterization of different zones such as fusion zone, heat affected zones and unaffected base material of a deposited weld is carried out using digital image correlation (DIC) technique. A methodology using the micrographic observation and image processing is proposed for accurate identification of various weld zones. The response of welded samples in the elastic and plastic region is compared with the virgin sample. Full range stress-strain curves are obtained for each zone using the whole field strain measurement involving DIC. The parameters investigated are Young's modulus, Poisson's ratio, yield stress, strain hardening exponent and strength coefficient. A study regarding the variation of properties with respect to varying weld currents of 100 A, 130 A and 150 A is carried out. The Vickers microhardness measurement is also conducted to obtain the variation in hardness across weldment. Fusion zone of all the welded samples have reported lower Young's modulus and higher yield strength compared to virgin samples. The Vickers hardness values obtained for fusion and heat affected zones are in line with the yield stress variation obtained zone wise. Proposed zone wise local characterization of welds using digital image correlation. Weld zones are identified using a strain based method coupled with micrographs. Full range stress-strain curves are extracted for each local weld zones. Local elastic, plastic properties and microhardness across the weld are extracted. Local properties of welds produced using different current ratings are compared.

  18. Imaging as characterization techniques for thin-film cadmium telluride photovoltaics

    NASA Astrophysics Data System (ADS)

    Zaunbrecher, Katherine

    The goal of increasing the efficiency of solar cell devices is a universal one. Increased photovoltaic (PV) performance means an increase in competition with other energy technologies. One way to improve PV technologies is to develop rapid, accurate characterization tools for quality control. Imaging techniques developed over the past decade are beginning to fill that role. Electroluminescence (EL), photoluminescence (PL), and lock-in thermography are three types of imaging implemented in this study to provide a multifaceted approach to studying imaging as applied to thin-film CdTe solar cells. Images provide spatial information about cell operation, which in turn can be used to identify defects that limit performance. This study began with developing EL, PL, and dark lock-in thermography (DLIT) for CdTe. Once imaging data were acquired, luminescence and thermography signatures of non-uniformities that disrupt the generation and collection of carriers were identified and cataloged. Additional data acquisition and analysis were used to determine luminescence response to varying operating conditions. This includes acquiring spectral data, varying excitation conditions, and correlating luminescence to device performance. EL measurements show variations in a cell's local voltage, which include inhomogeneities in the transparent-conductive oxide (TCO) front contact, CdS window layer, and CdTe absorber layer. EL signatures include large gradients, local reduction of luminescence, and local increases in luminescence on the interior of the device as well as bright spots located on the cell edges. The voltage bias and spectral response were analyzed to determine the response of these non-uniformities and surrounding areas. PL images of CdTe have not shown the same level of detail and features compared to their EL counterparts. Many of the signatures arise from reflections and severe inhomogeneities, but the technique is limited by the external illumination source used to

  19. Characterization of a constrained paired-view technique in iterative reconstruction for breast tomosynthesis

    SciTech Connect

    Wu, Gang; Yaffe, Martin J.; Mainprize, James G.

    2013-10-15

    Purpose: The order in which the projection views are employed in the reconstruction of tomosynthesis by iterative algorithms, such as simultaneous algebraic reconstruction technique and maximum likelihood, has a strong effect on the rate of convergence, accuracy, and the edge-blurring artifacts in the reconstructed image. The purpose of this investigation was to characterize and evaluate the effects of ordering schemes on image quality for breast tomosynthesis reconstruction and to explore a new constrained paired-view technique that could provide reduction of reconstruction artifacts. In this work, the authors compared several different ordering schemes and characterized the image quality and the formation of out-of-plane artifacts. Furthermore, a new normalization method is presented. It produces more accurate reconstructions with reduced artifacts comparing to the standard method of sequential ordering.Methods: In addition to visual assessment of image quality, several indices such as the signal-difference-to-noise ratio, the artifact-spread function, and the lesion detectability (d{sup ′}) were computed to quantitatively evaluate the effect of ordering scheme. The sets of breast tomosynthesis projection images were simulated for reconstruction; one set had uniform background (white noise only) and the other two contained both anatomic background and quantum noise. Clinical breast images were also studied for comparison.Results: The authors have quantified the image quality in reconstructed slices for a range of tumor sizes. The authors’ proposed method provides better performance for all of the metrics tested (contrast, d{sup ′}, and the level of artifacts) both for the uniform phantom case and in the presence of anatomical structure.Conclusions: The paired projection normalization provides better performance in the image quality of the reconstructed slices, and results in a lower level of artifacts in the Z direction. This implies that even a relatively

  20. Dynamic tensile characterization of a 4330-V steel with kolsky bar techniques.

    SciTech Connect

    Song, Bo; Antoun, Bonnie R.; Connelly, Kevin

    2010-09-01

    There has been increasing demand to understand the stress-strain response as well as damage and failure mechanisms of materials under impact loading condition. Dynamic tensile characterization has been an efficient approach to acquire satisfactory information of mechanical properties including damage and failure of the materials under investigation. However, in order to obtain valid experimental data, reliable tensile experimental techniques at high strain rates are required. This includes not only precise experimental apparatus but also reliable experimental procedures and comprehensive data interpretation. Kolsky bar, originally developed by Kolsky in 1949 [1] for high-rate compressive characterization of materials, has been extended for dynamic tensile testing since 1960 [2]. In comparison to Kolsky compression bar, the experimental design of Kolsky tension bar has been much more diversified, particularly in producing high speed tensile pulses in the bars. Moreover, instead of directly sandwiching the cylindrical specimen between the bars in Kolsky bar compression bar experiments, the specimen must be firmly attached to the bar ends in Kolsky tensile bar experiments. A common method is to thread a dumbbell specimen into the ends of the incident and transmission bars. The relatively complicated striking and specimen gripping systems in Kolsky tension bar techniques often lead to disturbance in stress wave propagation in the bars, requiring appropriate interpretation of experimental data. In this study, we employed a modified Kolsky tension bar, newly developed at Sandia National Laboratories, Livermore, CA, to explore the dynamic tensile response of a 4330-V steel. The design of the new Kolsky tension bar has been presented at 2010 SEM Annual Conference [3]. Figures 1 and 2 show the actual photograph and schematic of the Kolsky tension bar, respectively. As shown in Fig. 2, the gun barrel is directly connected to the incident bar with a coupler. The cylindrical

  1. Dynamic tensile characterization of a 4330 steel with kolsky bar techniques.

    SciTech Connect

    Song, Bo; Antoun, Bonnie R.; Connelly, Kevin

    2010-08-01

    There has been increasing demand to understand the stress-strain response as well as damage and failure mechanisms of materials under impact loading condition. Dynamic tensile characterization has been an efficient approach to acquire satisfactory information of mechanical properties including damage and failure of the materials under investigation. However, in order to obtain valid experimental data, reliable tensile experimental techniques at high strain rates are required. This includes not only precise experimental apparatus but also reliable experimental procedures and comprehensive data interpretation. Kolsky bar, originally developed by Kolsky in 1949 [1] for high-rate compressive characterization of materials, has been extended for dynamic tensile testing since 1960 [2]. In comparison to Kolsky compression bar, the experimental design of Kolsky tension bar has been much more diversified, particularly in producing high speed tensile pulses in the bars. Moreover, instead of directly sandwiching the cylindrical specimen between the bars in Kolsky bar compression bar experiments, the specimen must be firmly attached to the bar ends in Kolsky tensile bar experiments. A common method is to thread a dumbbell specimen into the ends of the incident and transmission bars. The relatively complicated striking and specimen gripping systems in Kolsky tension bar techniques often lead to disturbance in stress wave propagation in the bars, requiring appropriate interpretation of experimental data. In this study, we employed a modified Kolsky tension bar, newly developed at Sandia National Laboratories, Livermore, CA, to explore the dynamic tensile response of a 4330-V steel. The design of the new Kolsky tension bar has been presented at 2010 SEM Annual Conference [3]. Figures 1 and 2 show the actual photograph and schematic of the Kolsky tension bar, respectively. As shown in Fig. 2, the gun barrel is directly connected to the incident bar with a coupler. The cylindrical

  2. Influence of nanostructure composition on its morphometric characterization by different techniques.

    PubMed

    Carvalho Silva, Renata; Alexandre Muehlmann, Luis; Rodrigues Da Silva, Jaqueline; de Bentes Azevedo, Ricardo; Madeira Lucci, Carolina

    2014-09-01

    Morphometric characterization of nanoparticles is crucial to determine their biological effects and to obtain a formulation pattern. Determining the best technique requires knowledge of the particles being analyzed, the intended application of the particles, and the limitations of the techniques being considered. The aim of this article was to present transmission (TEM) and scanning (SEM) electron microscopy protocols for the analysis of two different nanostructures, namely polymeric nanoemulsion and poly(lactic-co-glycolic acid) (PLGA) nanoparticles, and to compare these results with conventional dynamic light scattering (DLS) measurements. The mean hydrodynamic diameter, the polydispersity index, and zeta potential of the nanostructures of polymeric nanoemulsion were 370.5 ± 0.8 nm, 0.133 ± 0.01, and -36.1 ± 0.15 mV, respectively, and for PLGA nanoparticles were 246.79 ± 5.03 nm, 0.096 ± 0.025, and -4.94 ± 0.86 mV, respectively. TEM analysis of polymeric nanoemulsion revealed a mean diameter of 374 ± 117 nm. SEM analysis showed a mean diameter of 368 ± 69 nm prior to gold coating and 448 ± 70 nm after gold coating. PLGA nanoparticles had a diameter of 131 ± 41.18 nm in TEM and 193 ± 101 nm in SEM. Morphologically, in TEM analysis, the polymeric nanoemulsions were spherical, with variable electron density, very few showing an electron-dense core and others an electron-dense surface. PLGA nanoparticles were round, with an electron-lucent core and electron-dense surface. In SEM, polymeric nanoemulsions were also spherical with a rough surface, and PLGA nanoparticles were round with a smooth surface. The results show that the "gold standards" for morphometric characterization of polymeric nanoemulsion and PLGA nanoparticles were, respectively, SEM without gold coating and TEM with negative staining. PMID:24919585

  3. Characterizing local traffic contributions to particulate air pollution in street canyons using mobile monitoring techniques

    NASA Astrophysics Data System (ADS)

    Zwack, Leonard M.; Paciorek, Christopher J.; Spengler, John D.; Levy, Jonathan I.

    2011-05-01

    Traffic within urban street canyons can contribute significantly to ambient concentrations of particulate air pollution. In these settings, it is challenging to separate within-canyon source contributions from urban and regional background concentrations given the highly variable and complex emissions and dispersion characteristics. In this study, we used continuous mobile monitoring of traffic-related particulate air pollutants to assess the contribution to concentrations, above background, of traffic in the street canyons of midtown Manhattan. Concentrations of both ultrafine particles (UFP) and fine particles (PM 2.5) were measured at street level using portable instruments. Statistical modeling techniques accounting for autocorrelation were used to investigate the presence of spatial heterogeneity of pollutant concentrations as well as to quantify the contribution of within-canyon traffic sources. Measurements were also made within Central Park, to examine the impact of offsets from major roadways in this urban environment. On average, an approximate 11% increase in concentrations of UFP and 8% increase in concentrations of PM 2.5 over urban background was estimated during high-traffic periods in street canyons as opposed to low traffic periods. Estimates were 8% and 5%, respectively, after accounting for temporal autocorrelation. Within Central Park, concentrations were 40% higher than background (5% after accounting for temporal autocorrelation) within the first 100 m from the nearest roadway for UFP, with a smaller but statistically significant increase for PM 2.5. Our findings demonstrate the viability of a mobile monitoring protocol coupled with spatiotemporal modeling techniques in characterizing local source contributions in a setting with street canyons.

  4. Characterization of water movement in a reconstructed slope in Keokuk, Iowa, using advanced geophysical techniques

    NASA Astrophysics Data System (ADS)

    Schettler, Megan Elizabeth

    This project addresses the topic of evaluating water movement inside a hillslope using a combination of conventional and advanced geophysical techniques. While slope dynamics have been widely studied, ground water movement in hills is still poorly understood. A combination of piezometers, ground-penetrating radar (GPR), and electrical resistivity (ER) surveys were used in an effort to monitor fluctuations in the subsurface water level in a reengineered slope near Keokuk, Iowa. This information, integrated with rainfall data, formed a picture of rainfall-groundwater response dynamics. There were two hypotheses: 1) that the depth and fluctuation of the water table could be accurately sensed using a combination of monitoring wells, ground-penetrating radar and resistivity surveys; and 2) that the integration of data from the instrumentation array and the geophysical surveys would enable the characterization of water movement in the slope in response to rainfall events. This project also sought to evaluate the utility and limitations of using these techniques in landslide and hydrology studies, advance our understanding of hillslope hydrology, and improve our capacity to better determine when slope failure may occur. Results from monitoring wells, stratigraphy, and resistivity surveys at the study site indicated the presence of a buried swale, channelizing subsurface storm flow and creating variations in groundwater. Although there was some success in defining hydrologic characteristics and response of the slope using this integrated approach, it was determined that GPR was ultimately not well suited to this site. However, the use of GPR as part of an integrated approach to study hillslope hydrology still appears to hold potential, and future work to further evaluate the applicability and potential of this approach would be warranted.

  5. Characterization of Porosity Development in Oxidized Graphite using Automated Image Analysis Techniques

    SciTech Connect

    Contescu, Cristian I; Burchell, Timothy D

    2009-09-01

    This document reports on initial activities at ORNL aimed at quantitative characterization of porosity development in oxidized graphite specimens using automated image analysis (AIA) techniques. A series of cylindrical shape specimens were machined from nuclear-grade graphite (type PCEA, from GrafTech International). The specimens were oxidized in air to various levels of weight loss (between 5 and 20 %) and at three oxidation temperatures (between 600 and 750 oC). The procedure used for specimen preparation and oxidation was based on ASTM D-7542-09. Oxidized specimens were sectioned, resin-mounted and polished for optical microscopy examination. Mosaic pictures of rectangular stripes (25 mm x 0.4 mm) along a diameter of sectioned specimens were recorded. A commercial software (ImagePro) was evaluated for automated analysis of images. Because oxidized zones in graphite are less reflective in visible light than the pristine, unoxidized material, the microstructural changes induced by oxidation can easily be identified and analyzed. Oxidation at low temperatures contributes to development of numerous fine pores (< 100 m2) distributed more or less uniformly over a certain depth (5-6 mm) from the surface of graphite specimens, while causing no apparent external damage to the specimens. In contrast, oxidation at high temperatures causes dimensional changes and substantial surface damage within a narrow band (< 1 mm) near the exposed graphite surface, but leaves the interior of specimens with little or no changes in the pore structure. Based on these results it appears that weakening and degradation of mechanical properties of graphite materials produced by uniform oxidation at low temperatures is related to the massive development of fine pores in the oxidized zone. It was demonstrated that optical microscopy enhanced by AIA techniques allows accurate determination of oxidant penetration depth and of distribution of porosity in oxidized graphite materials.

  6. Routine characterization of 3-D profiles of SRF cavity defects using replica techniques

    SciTech Connect

    Ge, M.; Wu, G.; Burk, D.; Ozelis, J.; Harms, E.; Sergatskov, D.; Hicks, D.; Cooley, L.D.; /Fermilab

    2010-09-01

    Recent coordination of thermometry with optical images has shown that obvious defects at specific locations produce heat or even quench superconducting radio frequency (SRF) cavities, imposing a significant limit on the overall accelerating gradient produced by the cavity. Characterization of the topography at such locations provides clues about how the defects originated, from which schemes for their prevention might be devised. Topographic analyses also provide understanding of the electromagnetic mechanism by which defects limit cavity performance, from which viability of repair techniques might be assessed. In this article we discuss how a variety of two-component silicone-based room-temperature vulcanizing agents can be routinely used to make replicas of the cavity surface and extract topographic details of cavity defects. Previously, this level of detail could only be obtained by cutting suspect regions from the cavity, thus destroying the cavity. We show 3-D profiles extracted from several different 1.3 GHz cavities. The defect locations, which were all near cavity welds, compelled us to develop extraction techniques for both equator and iris welds as well as from deep inside long 9-cell cavities. Profilometry scans of the replicas yield micrometer-scale information, and we describe various curious features, such as small peaks at the bottom of pits, which were not apparent in previous optical inspections. We also discuss contour information in terms of electromagnetic mechanisms proposed by others for local cavity heating. We show that production of the replica followed by high-pressure rinsing dose not adversely affect the cavity RF performance.

  7. Characterization and performance evaluation of an innovative mesoporous activated carbon used for drinking water purification in comparison with commercial carbons.

    PubMed

    Gong, Xu-Jin; Li, Wei-Guang; Wang, Guang-Zhi; Zhang, Duo-Ying; Fan, Wen-Biao; Yin, Zhao-Dong

    2015-09-01

    The preparation, characterization, and performance evaluation of an innovative mesoporous activated carbon (C-XHIT) were conducted in this study. Comparative evaluation with commercial carbons (C-PS and C-ZJ15) and long-term performance evaluation of C-XHIT were conducted in small-scale system-A (S-A) and pilot-scale system-B (S-B-1 and S-B-2 in series), respectively, for treating water from Songhua River. The cumulative uptake of micropollutants varied with KBV (water volume fed to columns divided by the mass of carbons, m(3) H2O/kg carbon) was employed in the performance evaluation. The results identified that mesoporous and microporous volumes were simultaneously well-developed in C-XHIT. Higher mesoporosity (63.94 %) and average pore width (37.91 Å) of C-XHIT ensured a higher adsorption capacity for humic acid compared to C-PS and C-ZJ15. When the KBV of S-A reached 12.58 m(3) H2O/kg carbon, cumulative uptake of organic pollutants achieved by C-XHIT increased by 32.82 and 156.29 % for DOC (QC) and 22.53 and 112.48 % for UV254 (QUV) compared to C-PS and C-ZJ15, respectively; in contrast, the adsorption capacity of NH4 (+)-N did not improve significantly. C-XHIT achieved high average removal efficiencies for DOC (77.43 ± 16.54 %) and UV254 (83.18 ± 13.88 %) in S-B over 253 days of operation (KBV = 62 m(3) H2O/kg carbon). Adsorption dominated the removal of DOC and UV254 in the initial phases of KBV (0-15 m(3) H2O/kg carbon), and simultaneous biodegradation and adsorption were identified as the mechanisms for organic pollutant uptake at KBV above 25 m(3) H2O/kg carbon. The average rates contributed by S-B-1 and S-B-2 for QC and QUV were approximately 0.75 and 0.25, respectively. Good linear and exponential correlations were observed between S-A and S-B in terms of QC and QUV obtained by C-XHIT, respectively, for the same KBV ranges, indicating a rapid and cost-saving evaluation method. The linear correlation between mesoporosity and QC

  8. Novel Techniques for Optical Characterization of Single-Walled Carbon Nanotube Samples

    NASA Astrophysics Data System (ADS)

    Streit, Jason K.

    Photoluminescence spectroscopy has emerged as a powerful tool for characterizing the structure and optical properties of single-walled carbon nanotube (SWCNT) samples. This thesis will discuss the development and application of new fluorescence-based methods designed to fully characterize bulk SWCNT suspensions by length and structural composition. An efficient new method is demonstrated to measure length distributions of aqueous SWCNT samples by analyzing the diffusional motions of many individual nanotubes captured in sequences of short-wave infrared (SWIR) fluorescence images. This method, termed length analysis by nanotube diffusion (LAND), provides distributions in very good agreement with those obtained by conventional atomic force microscopy analysis. A novel microscopy technique is described to measure the peak emission wavelengths of many individual nanotubes without the use of a spectrometer. We exploit the chromatic aberration of an objective lens to deduce emission wavelength from focal depth. Spectral measurements successfully reproduce bulk emission spectra and also provide relative abundances of specific SWCNT structures. A new approach is applied to find nanotube concentrations by directly counting SWCNTs in SWIR fluorescence images. Concentrations are used to rigorously determine absolute absorption cross sections for the E11 and E22 electronic transitions of the (6,5), (7,5), (7,6), (8,6), (8,7) and (9,7) SWCNT species. It is found that the absorption cross section per carbon atom decreases with increasing nanotube diameter. Finally, the spectral analysis of fluorescence fluctuations (SAFF) method is developed and used to characterize SWCNT samples by structural composition, sample quality, and aggregation state. Fluorescence spectra are sequentially measured from small volumes of slowly flowing dilute samples and the intensity fluctuations resulting from small statistical variations in nanotube concentration are analyzed. The ratio of the squared

  9. Novel techniques for characterization of hydrocarbon emission sources in the Barnett Shale

    NASA Astrophysics Data System (ADS)

    Nathan, Brian Joseph

    Changes in ambient atmospheric hydrocarbon concentrations can have both short-term and long-term effects on the atmosphere and on human health. Thus, accurate characterization of emissions sources is critically important. The recent boom in shale gas production has led to an increase in hydrocarbon emissions from associated processes, though the exact extent is uncertain. As an original quantification technique, a model airplane equipped with a specially-designed, open-path methane sensor was flown multiple times over a natural gas compressor station in the Barnett Shale in October 2013. A linear optimization was introduced to a standard Gaussian plume model in an effort to determine the most probable emission rate coming from the station. This is shown to be a suitable approach given an ideal source with a single, central plume. Separately, an analysis was performed to characterize the nonmethane hydrocarbons in the Barnett during the same period. Starting with ambient hourly concentration measurements of forty-six hydrocarbon species, Lagrangian air parcel trajectories were implemented in a meteorological model to extend the resolution of these measurements and achieve domain-fillings of the region for the period of interest. A self-organizing map (a type of unsupervised classification) was then utilized to reduce the dimensionality of the total multivariate set of grids into characteristic one-dimensional signatures. By also introducing a self-organizing map classification of the contemporary wind measurements, the spatial hydrocarbon characterizations are analyzed for periods with similar wind conditions. The accuracy of the classification is verified through assessment of observed spatial mixing ratio enhancements of key species, through site-comparisons with a related long-term study, and through a random forest analysis (an ensemble learning method of supervised classification) to determine the most important species for defining key classes. The hydrocarbon

  10. Phase topography-based characterization of thermal effects on materials and joining techniques.

    PubMed

    Lorenz, Hagen; Beckert, Erik; Schödel, René

    2015-03-10

    There are growing demands to characterize the stability of assemblies of optical components for ultrahigh-precision instruments. In this paper we demonstrate how absolute length measurements by interferometry can be applied to measure the thermal and dimensional stability of connections. In order to enable investigation of common joining techniques, including wringing, screwing, and gluing, as well as specialized, inorganic joining techniques such as silicatic bonding, thin-film soldering, and solderjet bumping, representative connections were fabricated. By using gage blocks or prismatic bodies as joining parts, parallelism and flatness were provided which are needed for precision interferometric length measurements. The stability of connection elements used in ultrahigh-precision instruments was investigated longitudinally and laterally to the connection interface, and also mutual tilting of the parts was detected by analysis of the phase topographies. The measurements have an accuracy level of about 1 nm, and the traditional wringing method was also considered as a reference joining technique. The long-term behavior was studied within a period of about 1 year under constant temperature. Further, the thermal dilatation and the reaction of connections to thermal stress were measured. Results show that screwed connections do not exhibit a significant drift of length or orientation. They also did not show response to temperature variations of ±10°C. This is different for adhesive connections, where dimensional changes of up to 100 nm were observed. The specimens produced by using thin-film soldering as well as silicatic bonding revealed stability of length better than 5 nm per year and angular stability within ±0.1   arcsec. Furthermore, these specimens were shown to be insensitive to a temporary temperature variation in a range from 10°C to 40°C. This situation is slightly different for the sample connections produced by solderjet bumping, which show a

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

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Chen, Jianwei; Zhang, Zhenzhen

    2015-09-01

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

  12. Multi-technique characterization of poly-L-lysine dendrigrafts-Cu(II) complexes for biocatalysis.

    PubMed

    Rossi, Jean-Christophe; Maret, Barbara; Vidot, Kevin; Francoia, Jean-Patrick; Cangiotti, Michela; Lucchi, Susanna; Coppola, Concetta; Ottaviani, Maria Francesca

    2015-02-01

    Poly-L-lysine is a biocompatible polymer used for drug or gene delivery, for transport through cellular membranes, and as nanosized magnetic resonance imaging contrast agents. Cu(II)-poly-L-lysine complexes are of particular interest for their role in biocatalysis. In this study, poly-L-lysine dendrigrafts (DGLs) at different generations (G2, G3, and G4) are synthesized and characterized in absence and presence of Cu(II) by means of electron paramagnetic resonance (EPR), UV-Vis, potentiometric titration and circular dichroism (CD). The analysis is performed as a function of the [Cu(II)]/[Lys] (=R) molar ratio, pH and generation by identifying differently flexible complexes in different dendrimer regions. The amine sites in the lateral chains become increasingly involved with the increase of pH. The good agreement and complementarity of the results from the different techniques provide an integrate view of the structural and dynamic properties of Cu(II)-DGL complexes implementing their use as biocatalysts. PMID:25330467

  13. Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

    SciTech Connect

    Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

    1992-12-31

    Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site`s microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog {reg_sign} evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog{reg_sign} activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

  14. Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

    SciTech Connect

    Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

    1992-01-01

    Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site's microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog [reg sign] evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog[reg sign] activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

  15. Collection and characterization of aerosols from metal cutting techniques typically used in decommissioning nuclear facilities.

    PubMed

    Newton, G J; Hoover, M D; Barr, E B; Wong, B A; Ritter, P D

    1987-11-01

    This study was designed to collect and characterize aerosols released during metal cutting activities typically used in decommissioning radioactively contaminated facilities. Such information can guide in the selection of appropriate control technologies for these airborne materials. Mechanical cutting tools evaluated included a multi-wheel pipe cutter, reciprocating saw, band saw, chop saw, and large and small grinding wheels. Melting-vaporization cutting techniques included an oxy-acetylene torch, electric arc cut rod and plasma torch. With the exception of the multi-wheel pipe cutter, all devices created aerosols in the respirable size range (less than 10 micron aerodynamic diameter). Time required to cut 2-in. (5-cm) Schedule 40, Type 304L, stainless steel ranged from about 0.6 min for the plasma torch to about 3.0 min for the reciprocating saw. Aerosol production rate ranged from less than 10 mg/min for the reciprocating saw to more than 3000 mg/min for the electric arc cut rod. Particles from mechanical tools were irregular in shape, whereas particles from vaporization tools were spheres and ultrafine branched-chain aggregates. PMID:3425551

  16. The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

    NASA Astrophysics Data System (ADS)

    Nicolas, G.; Mateo, M. P.; Yañez, A.

    2007-12-01

    The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits.

  17. Characterization and analysis of surface notches on Ti-alloy plates fabricated by additive manufacturing techniques

    NASA Astrophysics Data System (ADS)

    Chan, Kwai S.

    2015-12-01

    Rectangular plates of Ti-6Al-4V with extra low interstitial (ELI) were fabricated by layer-by-layer deposition techniques that included electron beam melting (EBM) and laser beam melting (LBM). The surface conditions of these plates were characterized using x-ray micro-computed tomography. The depth and radius of surface notch-like features on the LBM and EBM plates were measured from sectional images of individual virtual slices of the rectangular plates. The stress concentration factors of individual surface notches were computed and analyzed statistically to determine the appropriate distributions for the notch depth, notch radius, and stress concentration factor. These results were correlated with the fatigue life of the Ti-6Al-4V ELI alloys from an earlier investigation. A surface notch analysis was performed to assess the debit in the fatigue strength due to the surface notches. The assessment revealed that the fatigue lives of the additively manufactured plates with rough surface topographies and notch-like features are dominated by the fatigue crack growth of large cracks for both the LBM and EBM materials. The fatigue strength reduction due to the surface notches can be as large as 60%-75%. It is concluded that for better fatigue performance, the surface notches on EBM and LBM materials need to be removed by machining and the surface roughness be improved to a surface finish of about 1 μm.

  18. Synthesis and Characterization of Cholesterol Nano Particles by Using w/o Microemulsion Technique

    NASA Astrophysics Data System (ADS)

    Vyas, Poorvesh M.; Vasant, Sonal R.; Hajiyani, Rakesh R.; Joshi, Mihir J.

    2010-10-01

    Cholesterol is one of the most abundant and well known steroids in the animal kingdom. Cholesterol rich micro-emulsions and nano-emulsions are useful for the treatment of breast cancer and gynecologic cancers. The nano particles of cholesterol and other pharmaceutically important materials have been reported. In the present investigation, the nano particles of cholesterol were synthesized by direct precipitation technique using triton X-100/water/n-butanol micro-emulsion. The average particle size of cholesterol nano particles was estimated by applying Scherrer's formula to the powder X-ray diffraction pattern, which was found to be 22 nm. The nanoparticles of cholesterol were observed by using TEM and the particle size was found within the range from 15 nm-31 nm. The distribution of particle size was studied through DLS. The nanoparticles of cholesterol were characterized by using FT-IR spectroscopy and the force constant was also calculated for O-H, C-H and C-O bonds. The thermal response of nanoparticles of cholesterol was studied by TGA, which showed that the nanoparticles were stable up to 200 °C and then decomposed. Kinetic and thermodynamic parameters of decomposition process were also calculated by applying Coats and Redfern formula to thermo-gram.

  19. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Bekdash, O.; Norcross, J.; Meginnis, I.

    2016-01-01

    Providing adequate carbon dioxide (CO2) washout is essential to the reduction of risk in performing suited operations. Long term CO2 exposure can lead to symptoms such as headache, lethargy, and dizziness. Thus maintaining adequate CO2 washout in both ground testing and during in flight EVAs is a requirement of current and future suit designs. It is necessary to understand the inspired CO2 of suit wearers such that future requirements for space suits appropriately address the risk of inadequate washout. Testing conducted by the EVA Physiology Laboratory at the NASA Johnson Space Center aimed to characterize a method for noninvasively measuring inspired oronasal CO2 under pressurized suited conditions in order to better inform requirements definition and verification techniques for future CO2 washout limits in space suits. Based on a meta-analysis of those studies it was decided to test a nasal cannula as it is a commercially available device, would not impede suit ventilation delivery, and is placed directly in the breathing path of the user.

  20. Collection and characterization of aerosols from metal cutting techniques typically used in decommissioning nuclear facilities

    SciTech Connect

    Newton, G.J.; Hoover, M.D.; Barr, E.B.; Wong, B.A.; Ritter, P.D.

    1987-11-01

    This study was designed to collect and characterize aerosols released during metal cutting activities typically used in decommissioning radioactively contaminated facilities. Such information can guide in the selection of appropriate control technologies for these airborne materials. Mechanical cutting tools evaluated included a multi-wheel pipe cutter, reciprocating saw, band saw, chop saw, and large and small grinding wheels. Melting-vaporization cutting techniques included an oxy-acetylene torch, electric arc cut rod and plasma torch. With the exception of the multi-wheel pipe cutter, all devices created aerosols in the respirable size range (less than 10 micron aerodynamic diameter). Time required to cut 2-in. (5-cm) Schedule 40, Type 304L, stainless steel ranged from about 0.6 min for the plasma torch to about 3.0 min for the reciprocating saw. Aerosol production rate ranged from less than 10 mg/min for the reciprocating saw to more than 3000 mg/min for the electric arc cut rod. Particles from mechanical tools were irregular in shape, whereas particles from vaporization tools were spheres and ultrafine branched-chain aggregates.

  1. Generalized 1D photopyroelectric technique for optical and thermal characterization of liquids

    NASA Astrophysics Data System (ADS)

    Balderas-López, J. A.

    2012-06-01

    The analytical solution for the one-dimensional heat diffusion problem for a three-layer system, in the Beer-Lambert model for light absorption, is used for the implementation of a photopyroelectric (PPE) methodology for thermal and optical characterization of pigments in liquid solution, even for those ones potentially harmful to the pyroelectric sensor, taking the liquid sample's thickness as the only variable. Exponential decay of the PPE amplitude followed by a constant PPE phase for solutions at low pigment concentration, and exponential decay of the PPE amplitude but a linear decrease of the PPE phase for the concentrated ones are theoretically shown, allowing measurements of the optical absorption coefficient (at the wavelength used for the analysis) and the thermal diffusivity for the liquid sample, respectively. This PPE methodology was tested by measuring the thermal diffusivity of a concentrated solution of methylene blue in distilled water and the optical absorption coefficient, at two wavelengths (658 and 785 nm), of water solutions of copper sulfate at various concentrations. These optical parameters were used for measuring the molar absorption coefficient of this last pigment in water solution at these two wavelengths. This last optical property was also measured using a commercial spectrometer, finding very good agreement with the corresponding ones using this PPE technique.

  2. Characterization of Air Plane Soot Surrogates using Raman spectroscopy and laser ablation techniques

    NASA Astrophysics Data System (ADS)

    Chazallon, Bertrand; Ortega, Ismael Kenneth; Ikhenazene, Raouf; Pirim, Claire; Carpentier, Yvain; Irimiea, Cornelia; Focsa, Cristian; Ouf, François-Xavier

    2016-04-01

    Aviation alters the composition of the atmosphere globally and can thus drive climate change and ozone depletion [1]. Aircraft exhaust plumes contain species (gases and soot particles) produced by the combustion of kerosene with ambient air in the combustion chamber of the engine. Soot particles emitted by air-planes produce persistent contrails in the upper troposphere in ice-supersaturated air masses that contribute to cloudiness and impact the radiative properties of the atmosphere. These aerosol-cloud interactions represent one of the largest sources of uncertainty in global climate models [2]. Though the formation of atmospheric ice particles has been studied for many years [3], there are still numerous opened questions on nucleation properties of soot particles [4], as the ice nucleation experiments showed a large spread in results depending on the nucleation mode chosen and origin of the soot produced. The reasons behind these discrepancies reside in the different physico-chemical properties (composition, structure) of soot particles produced in different conditions, e.g., with respect to fuel or combustion techniques. In this work, we use Raman microscopy (514 and 785 nm excitation wavelengths) and ablation techniques (Secondary Ions Mass Spectrometry, and Laser Desorption Mass Spectrometry) to characterize soot particle surrogates produced from a CAST generator (propane fuel, four different global equivalence ratios). They are produced as analogues of air-plane soot collected at different engine regimes (PowerJet SaM-146 turbofan) simulating a landing and take-off (LTO) cycle (MERMOSE project (http://mermose.onera.fr/)) [6]. The spectral parameters of the first-order Raman bands of these soot samples are analyzed using a de-convolution approach described by Sadezky et al. (2005) [5]. A systematic Raman analysis is carried out to select a number of parameters (laser wavelength, irradiance at sample, exposure time) that will alter the sample and the

  3. Development of ICP-MS based nanometrology techniques for characterization of silver nanoparticles in environmental systems

    NASA Astrophysics Data System (ADS)

    Mitrano, Denise Marie

    The ubiquitous use of goods containing nanoparticles (NPs) will lead inevitably to environmental release and interaction with biota. Methods to detect, quantify, and characterize NPs in environmental matrices are highlighted as one of the areas of highest priority research in understanding potential environmental and health risks. Specifically, techniques are needed to determine the size and concentration of NPs in complex matrices. Particular analytical challenges include distinguishing NPs from other constituents of the matrix (i.e. natural particles, humic substances, and debris), method detection limits are often higher than exposure concentrations, and differentiating dissolved metal and NPs. This work focuses on the development and optimization of two methods that address a number of challenges for nanometrology: single particle (sp)ICP-MS and asymmetrical flow field flow fractionation (AF4)-ICP-MS. Advancements in the spICP-MS method included systematic studies on distinction between ionic and NP fractions, resolution of polydisperse NP samples, and defining the techniques' dynamic range (in terms of both particle size and concentration). Upon application of the technique, silver (Ag) NPs were discovered in raw wastewater treatment plant influent and effluent. Furthermore, methodical Ag NP stability studies determined the influence of particle capping agents and water chemistry parameters in a variety of synthetic, natural and processed waters. Method development for AF4-ICP-MS revolved around optimizing run conditions (i.e. operational flows, carrier fluid, membrane choice) to study detection limits, sample recovery, and resolution of polydisperse samples. Practical studies included sizing Ag NP in a sediment-dwelling, freshwater oligochaete (Lumbriculus variegatus) and the kinetics of accumulation of protein bound Ag+. In direct comparison, spICP-MS was found to be more versatile with less sample preparation and lower total analyte detection limit (ng/L vs

  4. Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

    PubMed Central

    2015-01-01

    Summary The performance of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC) is critically dependent on the selection of materials and optimization of individual components. A conventional high-temperature membrane electrode assembly (HT-MEA) primarily consists of a polybenzimidazole (PBI)-type membrane containing phosphoric acid and two gas diffusion electrodes (GDE), the anode and the cathode, attached to the two surfaces of the membrane. This review article provides a survey on the materials implemented in state-of-the-art HT-MEAs. These materials must meet extremely demanding requirements because of the severe operating conditions of HT-PEMFCs. They need to be electrochemically and thermally stable in highly acidic environment. The polymer membranes should exhibit high proton conductivity in low-hydration and even anhydrous states. Of special concern for phosphoric-acid-doped PBI-type membranes is the acid loss and management during operation. The slow oxygen reduction reaction in HT-PEMFCs remains a challenge. Phosphoric acid tends to adsorb onto the surface of the platinum catalyst and therefore hampers the reaction kinetics. Additionally, the binder material plays a key role in regulating the hydrophobicity and hydrophilicity of the catalyst layer. Subsequently, the binder controls the electrode–membrane interface that establishes the triple phase boundary between proton conductive electrolyte, electron conductive catalyst, and reactant gases. Moreover, the elevated operating temperatures promote carbon corrosion and therefore degrade the integrity of the catalyst support. These are only some examples how materials properties affect the stability and performance of HT-PEMFCs. For this reason, materials characterization techniques for HT-PEMFCs, either in situ or ex situ, are highly beneficial. Significant progress has recently been made in this field, which enables us to gain a better understanding of underlying processes occurring during

  5. Characterization of Mineral Assemblages in Ancient Roman Maritime Concrete with Synchrotron X-ray Techniques

    NASA Astrophysics Data System (ADS)

    Meral, C.; Jackson, M. D.; Monteiro, P. J.; Wenk, H.

    2012-12-01

    Romans used lime and aluminosilicate-rich volcanic ash to bind tuff aggregates in concrete structures that have remained durable for 2000 years. A major accomplishment of Roman engineers was to construct enduring coastal underwater structures in seawater, which were important to long-distance trade and military endeavors. Two millennia later, the reasons for the extraordinary durability of the maritime structures remain enigmatic. The concretes are highly complex composites composed of relict lime, tuff and pumice clasts and pozzolanic reaction products. Calcium-chloroaluminates and sulfoaluminates occur in certain relict voids. Further understanding of their mineralogical components would provide guidelines in designing future structures. Here, we use synchroton radiation applications to characterize certain phases within a Roman maritime mortar specimen from a breakwater in Pozzuoli Bay, Baianus Sinus, near Naples. We performed X-ray computed micro-tomography (μ-XCT) at beamline 8.3.2 of the Advanced Light Source (ALS) at Lawrence Berkeley Laboratories to segment the complex composite without damaging the specimen. We isolated certain relict sub-spherical voids and illustrated crystal morphologies with 3-D reconstructions. We then used beamline 12.3.2 at the ALS to provide highly accurate identifications of diverse crystal phases in various mortar components - relict lime clasts, tuff or pumice clasts, cementitious matrix and relict voids - in sites previously identified and characterized with petrogaphic techniques. X-ray micro-fluorescence (μ-XRF) mapping provided calcium and iron maps of the sites, which were useful in selecting fine-scale areas for scanning transmission X-ray micro-diffraction (μ-XRD) mapping at high spatial resolution, about 1 micron. The μ-XRD analyses utilized both monochromatic and polychromatic light measurements. Polychromatic light was more appropriate for phases with grain sizes larger than the doubly focused X-ray beam, about 1 x

  6. Preparation, characterization and optoelectronic properties of nanodiamonds doped zinc oxide nanomaterials by a ball milling technique

    NASA Astrophysics Data System (ADS)

    Ullah, Hameed; Sohail, Muhammad; Malik, Uzma; Ali, Naveed; Bangash, Masroor Ahmad; Nawaz, Mohsan

    2016-07-01

    Zinc oxide (ZnO) is one of the very important metal oxides (MOs) for applications in optoelectronic devices which work in the blue and UV regions. However, to meet the challenges of obtaining ZnO nanomaterials suitable for practical applications, various modifications in physico-chemical properties are highly desirable. One of the ways adopted for altering the properties is to synthesize composite(s) of ZnO with various reinforcements. Here we report on the tuning of optoelectronic properties of ZnO upon doping by nanodiamonds (NDs) using the ball milling technique. A varying weight percent (wt.%) of NDs were ball milled for 2 h with ZnO nanoparticles prepared by a simple precipitation method. The effects of different parameters, the calcination temperature of ZnO, wt.% of NDs and mechanical milling upon the optoelectronic properties of the resulting ZnO–NDs nanocomposites have been investigated. The ZnO–NDs nanocomposites were characterized by IR spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The UV-vis spectroscopy revealed the alteration in the bandgap energy (Eg ) of ZnO as a function of the calcination temperature of ZnO, changing the concentration of NDs, and mechanical milling of the resulting nanocomposites. The photoluminescence (PL) spectroscopy showed a decrease in the deep level emission (DLE) peaks and an increase in near-band-edge transition peaks as a result of the increasing concentration of NDs. The decrease in DLE and increase in band to band transition peaks were due to the strong interaction between the NDs and the Zn+; consequently, the Zn+ concentration decreased on the interstitial sites.

  7. Surface acoustic wave technique for the characterization of porous properties of microporous silicate thin films

    NASA Astrophysics Data System (ADS)

    Hietala, Susan Leslie

    1997-12-01

    Features of gas adsorption onto sol-gel derived microporous silicate thin films, for characterization of porous properties, are detailed using a surface acoustic wave (SAW) technique. Mass uptake and film effective modulus changes calculated from the SAW data are investigated in detail. The effects of stress and surface tension on the SAW sensor are calculated and found to be negligible in these experiments. Transient behavior recorded during nitrogen adsorption at 77 K is discussed in the context of mass uptake and effective modulus contributions. The time constant associated with the effective modulus calculation is consistent with that of diffusivity of nitrogen into a 5A zeolite. Further calculations indicate that the transient behavior is not due to thermal effects. A unique dual sensor SAW experiment to decouple the mass and effective modulus contributions to the frequency response was performed in conjunction with a Silicon beam-bending experiment. The beam-bending experiment results in a calculation of stress induced during adsorption of methanol on a microporous silicate thin film. The decoupled mass and effective modulus calculated from the SAW data have similar shaped isotherms, and are quite different from that of the stress developed in the Silicon beam. The total effective modulus change calculated from the SAW data is consistent with that calculated using Gassmann's equation. The SAW system developed for this work included unique electronics and customized hardware which is suitable for work under vacuum and at temperatures from 77K to 473K. This unique setup is suitable for running thin film samples on a Micromeritics ASAP 2000 Gas Adsorption unit in automatic mode. This setup is also general enough to be compatible with a custom gas adsorption unit and the beam bending apparatus, both using standard vacuum assemblies.

  8. Isolation and characterization of Mycobacterium bovis strains from indigenous Zambian cattle using Spacer oligonucleotide typing technique

    PubMed Central

    2009-01-01

    Background Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has remained a major source of concern to public health officials in Zambia. Previous investigations have used traditional epidemiological methods that are unable to identify the causative agent and from which dynamics of disease dispersion is difficult to discern. The objective of this study was to isolate, characterize and determine the genetic diversity and relatedness of M. bovis from major cattle rearing districts in Zambia by spoligotyping. A total of 695 carcasses were examined and 98 tissues had gross post-mortem lesions compatible with BTB. Results Forty-two out of the ninety-eight suspected tissues examined had culture properties characteristic of mycobacteria from which 31 isolates yielded interpretable spoligotypes. This technique showed good discriminatory power (HGDI = 0.98), revealing 10 different spoligotype patterns. Twenty-seven isolates belonged to one cluster with more than 95% similarity and inside the cluster, one predominant spoligotype was found in 20 (64.5%) of the isolates tested. The highest number of spoligotypes was observed among samples from Namwala district. Spoligotypes from 26 (83.9%) of the isolates belonged to five spoligotypes that have been reported before while the remaining 5 (16.1%) isolates had unique spoligotypes that are being reported for the first time; these have been assigned numbers SB1763 to SB1767. Five of the 6 districts had the predominant spoligotype (SB0120). Conclusion The study has described the dispersion patterns of M. bovis in Zambian cattle for the first time and has identified 5 spoligotype patterns specific to Zambia. The observation of an overlap in the spoligotype pattern SB0120 in 5 of the 6 districts suggests the probability of sharing a common source of infection. PMID:19619309

  9. Mechanical Characterization of Copper-Copper Wires Joined by Friction Welding Using Instrumented Indentation Technique

    NASA Astrophysics Data System (ADS)

    Morales, M.; Xuriguera, E.; Martínez, M.; Padilla, J. A.; Molera, J.; Ferrer, N.; Segarra, M.; Espiell, F.

    2014-11-01

    Friction welding samples of both the fire-refined high-conductivity (FRHC) and electrolytically tough pitch (ETP) copper alloy wires have been mechanically characterized by instrumented indentation technique and tensile test. Hardness profiles in the perpendicular direction to the weld interface, in both the central and peripheral zones, of the as-welded FRHC-FRHC and ETP-ETP samples have been investigated at nano-/micrometric scale. The microstructures of welds have been observed using both the optical microscopy and scanning electronic microscopy. The results show the typical friction welding zones: the interface zone, the thermo-mechanically affected zone (TMAZ), and the transition zone between the TMAZ and the base metal zone (BMZ) that present a microstructure and hardness close to the base metal. No presence of a heat-affected zone is observed. Although both welds show the same tendency in hardness distribution, FHRC-FHRC weld presents a TMAZ narrower than ETP-ETP one, which produces a stronger drop in hardness with increasing of the distance from welding central line, and a higher difference in hardness between the central and peripheral zones. The tensile tests of ETP-ETP welds showed that all samples broke by the BMZ that is far away from the interface of the welded joint, while the most of the FRHC-FRHC welds are broken at the TMAZ region at low strengths. These appreciable differences in mechanical properties for the FHRC-FHRC welds are probably generated by a stronger variation in their microstructural properties. Therefore, it may justify the welding failures in the FHRC-FHRC weld at the typical tensile stress for an industrial cold-drawn process of wires.

  10. Characterization of nitrogen-rich silicon nitride films grown by the electron cyclotron resonance plasma technique

    NASA Astrophysics Data System (ADS)

    Wang, L.; Reehal, H. S.; Martínez, F. L.; San Andrés, E.; del Prado, A.

    2003-07-01

    Amorphous hydrogenated silicon nitride films have been deposited by the electron cyclotron resonance plasma technique, using N2 and SiH4 as precursor gases. The gas flow ratio, deposition temperature and microwave power have been varied in order to study their effect on the properties of the films, which were characterized by Rutherford back-scattering spectrometry, elastic recoil detection analysis (ERDA), Fourier transform infrared spectroscopy and ellipsometry. All samples show N/Si ratios near or above the stoichiometric value (N/Si = 1.33). The hydrogen content determined from ERDA measurements is significantly higher than the amount detected by infrared spectroscopy, evidencing the presence of non-bonded H. As the N2/SiH4 gas flow ratio is increased (by decreasing the SiH4 partial pressure), the Si content decreases and the N-H concentration increases, while the N content remains constant, resulting in an increase of the N/Si ratio. The decrease of the Si content causes a decrease of the refractive index and the density of the film, while the growth ratio also decreases due to the limiting factor of the SiH4 partial pressure. The infrared Si-N stretching band shifts to higher wavenumbers as the N-H concentration increases. The increase of deposition temperature promotes the release of H, resulting in a higher incorporation of N and Si into the film and a decrease of the N/Si ratio. The effect of increasing the microwave power is analogous to increasing the N2/SiH4 ratio, due to the increase in the proportion of nitrogen activated species.

  11. Investigation of new devices and characterization techniques in the III-V semiconductor system

    NASA Astrophysics Data System (ADS)

    Cheng, Xiao-Chang

    This thesis concerns the investigation of novel devices and material characterization techniques in the III-V semiconductor system. In the first part of the thesis, we demonstrate that novel devices, such as avalanche photodiodes and tunnel switch diodes, can be fabricated from InAs/GaSb/AlSb heterostructures by molecular beam epitaxy (MBE). In the second part of the thesis, ballistic electron emission microscopy (BEEM) is employed to examine the local band offset in these heterostructures, which is often found to be crucial in device design. In the avalanche photodiode study, devices with near infrared response out to 1.74 mum were demonstrated. Two types of devices were investigated: those with a bulk Al0.04Ga0.96Sb multiplication region and those with a GaSb/AlSb superlattice multiplication region. Both types of devices were implemented in a MBE grown p-n + structure that uses a selectively doped InAs/AlSb superlattice as the n-type layer. This particular structure was optimized through several design, fabrication, characterization cycles. It was found that the photodiode dark current depended critically on the InAs/AlSb superlattice period and the resulting band offset at the p-n+ heterojunction. The InAs/AlSb superlattice was henceforth optimized by using a three stage design. The ionization rates in bulk multiplication layer devices were measured and found to be consistent with hole impact ionization enhancement in Al0.04Ga0.96Sb. However, direct comparison with superlattice multiplication layer devices revealed the latter to be more promising due to more effective dark current suppression from the larger band gap of the superlattice multiplication layer. The second device studied is the tunnel switch diode. We have fabricated the first such device in the antimonide material system and obtained characteristic "S" shaped I-V curves from these devices. The epilayer and barrier dependence of tunnel diode switching were studied and found to deviate significantly

  12. Characterization of Deficiencies in the Frequency Domain Forced Response Analysis Technique for Supersonic Turbine Bladed Disks

    NASA Technical Reports Server (NTRS)

    Brown, Andrew M.; Schmauch, Preston

    2012-01-01

    Turbine blades in rocket and jet engine turbomachinery experience enormous harmonic loading conditions. These loads result from the integer number of upstream and downstream stator vanes as well as the other turbine stages. Assessing the blade structural integrity is a complex task requiring an initial characterization of whether resonance is possible and then performing a forced response analysis if that condition is met. The standard technique for forced response analysis in rocket engine turbines is to decompose a computational fluid dynamics (CFD).generated flow field into its harmonic components, and to then perform a frequency response analysis at the problematic natural frequencies using cyclically symmetric structural dynamic models. Recent CFD analysis and water-flow testing at NASA/MSFC, though, indicates that this technique may miss substantial harmonic and non ]harmonic excitation sources that become present in complex flows. This complex content can only be captured by a CFD flow field encompassing at least an entire revolution. A substantial development effort to create a series of software programs to enable application of the 360 degree forcing function in a frequency response analysis on cyclic symmetric models has been completed (to be described in a future paper), but the question still remains whether the frequency response analysis itself is capable of capturing the excitation content sufficiently. Two studies comparing frequency response analysis with transient response analysis, therefore, of bladed-disks undergoing this complex flow environment have been performed. The first is of a bladed disk with each blade modeled by simple beam elements and the disk modeled with plates (using the finite element code MSC/NASTRAN). The focus of this model is to be representative of response of realistic bladed disks, and so the dimensions are roughly equivalent to the new J2X rocket engine 1st stage fuel pump turbine. The simplicity of the model allows

  13. Split-tip scanning capacitance microscopy (SSCM): Special techniques in surface characterization and measurements

    NASA Astrophysics Data System (ADS)

    Clark, Beverly Andrew, III

    Hallen). This work invents and develops a new technique for electrical, electro-optical, and topographical characterization at the nanoscale. Split-tip scanning capacitance microscopy (SSCM) offers advantages over other scanning probe methods. The dependence of the measurements on sample characteristics is reduced, and analysis is simplified by having both electrodes secured to the probe. This feature allows non-conducting, as well as conducting surfaces to be imaged without loss of optical or capacitance resolution. SSCM allows surface measurements without destroying the sample of interest and does not require special surface preparation. To develop this new technique, the project focused on the following: (1) shear-force feedback as an accurate tip-sample distance controller; (2) imaging techniques for irregular sample surfaces; (3) development of computational model for simulating split-tip measurements; (4) split-tip integration into a conventional near-field scanning optical microscope; (5) contrast modeling for surface structures; (6) tip-sample approach capacitance measurements as a stringent test of SSCM. We show that a non-linear tip sample interaction dominates the shear force feedback signal evidenced by a change in the resonance frequency as the tip approaches the sample. Shear force feedback relies on a decrease in the signal amplitude at the operating frequency. We present data and a numerical model describing the time response and how this nonlinear interaction can be used to speed up the response. We demonstrate the imaging of irregular surfaces such as paint samples and show the distribution of pigment quantified by the peak in the histogram of optical signal versus separation at the nano- to micron scale illuminates the length-scale of failure in paint samples. We compare a high quality paint sample with one that fails a standard quality control test based upon visual inspection. Features such as pigment clumping and pigment density fluctuations

  14. Rock surface roughness measurement using CSI technique and analysis of surface characterization by qualitative and quantitative results

    NASA Astrophysics Data System (ADS)

    Mukhtar, Husneni; Montgomery, Paul; Gianto; Susanto, K.

    2016-01-01

    In order to develop image processing that is widely used in geo-processing and analysis, we introduce an alternative technique for the characterization of rock samples. The technique that we have used for characterizing inhomogeneous surfaces is based on Coherence Scanning Interferometry (CSI). An optical probe is first used to scan over the depth of the surface roughness of the sample. Then, to analyse the measured fringe data, we use the Five Sample Adaptive method to obtain quantitative results of the surface shape. To analyse the surface roughness parameters, Hmm and Rq, a new window resizing analysis technique is employed. The results of the morphology and surface roughness analysis show micron and nano-scale information which is characteristic of each rock type and its history. These could be used for mineral identification and studies in rock movement on different surfaces. Image processing is thus used to define the physical parameters of the rock surface.

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

    PubMed

    Safinia, Laleh; Mantalaris, Athanasios; Bismarck, Alexander

    2006-03-28

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

  16. A fast and innovative microextraction technique, μSPEed, followed by ultrahigh performance liquid chromatography for the analysis of phenolic compounds in teas.

    PubMed

    Porto-Figueira, Priscilla; Figueira, José A; Pereira, Jorge A M; Câmara, José S

    2015-12-11

    The objective of this study was to evaluate the efficiency of a promising solid phase microextraction technique, μSPEed, in the analysis of selected phenolic compounds from teas by ultrahigh performance liquid chromatography with photodiode array detection (μSPEed/UHPLC-PDA). The innovative μSPEed configuration uses 3-μm sorbent particles tightly packed in a disposable needle equipped with a pressure-driven valve to withdraw samples in a single direction. The system was operated by the electronic pipette eVol® and different parameters influencing the extraction efficiency, as the nature of sorbent, pH, loading and elution conditions, and solvents were optimized. The best extracting conditions were obtained by loading twice 100μL of tea samples through the PS/DVB-RP sorbent and eluting with 50μL of acidified MeOH 95%. The following chromatographic separation was carried out in an Acquity C18 BEH capillary column using a gradient of 0.1% FA and acetonitrile. The optimized μSPEed/UHPLC-PDA methodology is selective and specific and was properly validated for 8 phenolic compounds widely reported in different teas. Overall, an excellent analytical performance was obtained in the 0.2-20μg/L linear dynamic range (LDR), with very low limits of detection (LODs) and quantification (LOQs), ranging between 3.5-16.8ng/mL and 10.6-50.6ng/mL, respectively, high recoveries (89.3-103.3%), good precision (RSD<5%) and negligible matrix effect. The methodology was used to assess the target polyphenols concentration in several tea samples. Rutin and quercetin-3-glucoside were the most abundant phenolics in all tea samples analysed and, with exception of naringenin and cinnamic acid, which are present in high amounts in the investigated citric teas, remain phenolic compounds are present in trace levels. PMID:26585207

  17. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Norcross, J.; Bekdash, O.; Meginnis, I.

    2016-01-01

    Providing adequate carbon dioxide (CO2) washout is essential to the reduction of risk in performing suited operations. Long term CO2 exposure can lead to symptoms such as headache, lethargy, dizziness, and in severe cases can lead to unconsciousness and death. Thus maintaining adequate CO2 washout in both ground testing and during in flight EVAs is a requirement of current and future suit designs. It is necessary to understand the inspired CO2 of suit wearers such that future requirements for space suits appropriately address the risk of inadequate washout. Testing conducted by the EVA Physiology Laboratory at the NASA Johnson Space Center aimed to characterize a method for noninvasively measuring inspired oronasal CO2 under pressurized suited conditions in order to better inform requirements definition and verification techniques for future CO2 washout limits in space suits. Prior work conducted by the EPL examined several different wearable, respirator style, masks that could be used to sample air from the vicinity surround the nose and mouth of a suited test subject. Previously published studies utilized these masks, some being commercial products and some novel designs, to monitor CO2 under various exercise and flow conditions with mixed results for repeatability and/or consistency between subjects. Based on a meta-analysis of those studies it was decided to test a nasal cannula as it is a commercially available device that is placed directly in the flow path of the user as they breathe. A nasal cannula was used to sample air inhaled by the test subjects during both rest and exercise conditions. Eight subjects were tasked with walking on a treadmill or operating an arm ergometer to reach target metabolic rates of 1000, 2000, and 3000 BTU/hr. Suit pressure was maintained at 4.3 psid for all tests, with supply flow rates of 6, 4, and 2 actual cubic feet per minute depending on the test condition. Each test configuration was conducted twice with subjects breathing

  18. Characterization of synthetic hematite (α-Fe2O3) nanoparticles using a multi-technique approach.

    PubMed

    Colombo, Claudio; Palumbo, Giuseppe; Ceglie, Andrea; Angelico, Ruggero

    2012-05-15

    The aim of this work was to investigate the surface structure of aqueous hematite dispersions characterized by a large variability of morphology and particle size combining structural investigations obtained from Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) techniques with in vitro particle size distributions and zeta potential measurements from Dynamic Light Scattering (DLS) technique, and we achieved a self-consistent and detailed characterization of hematite particles whose sizes and morphologies could be correlated to the synthesis conditions (type of added anion, Al substitution and pH). Surface AFM characterization provided an accurate analysis of particle microstructure and also indicated that the growth of microcrystals followed different surface roughness. DLS, AFM, and TEM techniques furnished complementary information on the average particle dimensions, whose variation could be attributed to the morphological difference of hematites, ranging from platy to regular or irregular hexagonal or ellipsoidal shape. Finally, a correlation between the average particle dimensions and the measured zeta potential was also been found in aqueous dilute suspensions characterized by neither pH nor-ionic-strength-control, for which a drop of zeta potential from positive to negative values was detected for hematite particle dimensions larger than a threshold size of ~150 nm. PMID:22381942

  19. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Meginnis, I; Norcross, J.; Bekdash, O.

    2016-01-01

    It is essential to provide adequate carbon dioxide (CO2) washout in a space suit to reduce the risks associated with manned operations in space suits. Symptoms of elevated CO2 levels range from reduced cognitive performance and headache to unconsciousness and death at high levels of CO2. Because of this, NASA imposes limits on inspired CO2 levels for space suits when they are used in space and for ground testing. Testing and/or analysis must be performed to verify that a space suit meets CO2 washout requirements. Testing for developmental space suits has traditionally used an oronasal mask that collects CO2 samples at the left and rights sides of the mouth. Testing with this mask resulted in artificially elevated CO2 concentration measurements, which is most likely due to the dead space volume at the front of the mask. The mask also extends outward and into the supply gas stream, which may disrupt the washout effect of the suit supply gas. To mitigate these problems, a nasal cannula was investigated as a method for measuring inspired CO2 based on the assumptions that it is low profile and would not interfere with the designed suit gas flow path, and it has reduced dead space. This test series compared the performance of a nasal cannula to the oronasal mask in the Mark III space suit. Inspired CO2 levels were measured with subjects at rest and at metabolic workloads of 1000, 2000, and 3000 BTU/hr. Workloads were achieved by use of an arm ergometer or treadmill. Test points were conducted at air flow rates of 2, 4, and 6 actual cubic feet per minute, with a suit pressure of 4.3 psid. Results from this test series will evaluate the accuracy and repeatability across subjects of the nasal cannula collection method, which will provide rationale for using a nasal cannula as the new method for measuring inspired CO2 in a space suit. Proper characterization of sampling methods and of suit CO2 washout capability will better inform requirements definition and verification

  20. Characterization of a unique technique for culturing primary adult human epithelial progenitor/“stem cells”

    PubMed Central

    2012-01-01

    Background Primary keratinocytes derived from epidermis, oral mucosa, and urothelium are used in construction of cell based wound healing devices and in regenerative medicine. This study presents in vitro technology that rapidly expands keratinocytes in culture by growing monolayers under large volumes of serum-free, essential fatty acid free, low calcium medium that is replaced every 24 hrs. Methods Primary cell cultures were produced from epidermal skin, oral mucosa and ureter by trypsinization of tissue. Cells were grown using Epilife medium with growth factors under high medium volumes. Once densely confluent, the keratinocyte monolayer produced cells in suspension in the overlying medium that can be harvested every 24 hrs. over a 7–10 day period. The cell suspension (approximately 8 X 105 cells/ml) is poured into a new flask to form another confluent monolayer over 2–4 days. This new culture, in turn produced additional cell suspensions that when serially passed expand the cell strain over 2–3 months, without the use of enzymes to split the cultures. The cell suspension, called epithelial Pop Up Keratinocytes (ePUKs) were analyzed for culture expansion, cell size and glucose utilization, attachment to carrier beads, micro-spheroid formation, induction of keratinocyte differentiation, and characterized by immunohistochemistry. Results The ePUKs expanded greatly in culture, attached to carrier beads, did not form micro-spheroids, used approximately 50% of medium glucose over 24 hrs., contained a greater portion of smaller diameter cells (8–10 microns), reverted to classical appearing cultures when returned to routine feeding schedules (48 hrs. and 15 ml/T-75 flask) and can be differentiated by either adding 1.2 mM medium calcium, or essential fatty acids. The ePUK cells are identified as cycling (Ki67 expressing) basal cells (p63, K14 expressing). Conclusions Using this primary culture technique, large quantities of epithelial cells can

  1. Development of nanoindentation techniques for characterizing local mechanical properties of soft materials

    NASA Astrophysics Data System (ADS)

    Wood, Charles David

    Indentation has become a popular mechanical characterization technique due to the promise of high-resolution maps of material stiffness. Due to the far-reaching nature of the testing framework, indentation tests can occur on nearly any material type and on any length scale. In this dissertation, we will look at three different materials systems and demonstrate new and unique uses for the indentation framework. These results will provide information not available by other methodologies, thereby proving its universal value. Two different indentation schemes are employed, either probing the top surface of cross-section samples or by probing into the thickness of a thin film. The differences between each of the studies highlight the importance of sample geometry/orientation, contact conditions, material response, etc. First, we will use indentation to probe local regions near carbon nanotube/glass fiber hybrid composites in an epoxy matrix. Indentations were performed to determine the radial gradient of modulus enhancements from the glass fiber surface. The results from indentation demonstrated that spatial reinforcement due to the presence of nanotubes was tied to fiber morphology and not the local morphology of carbon nanotubes. Secondly, we look at rubber and filler interaction on two different levels; macroscale and nanoscale. On the nanoscale, we show that interactions at the filler/polymer interface create regions of altered polymer mobility. These regions are influenced by geometric and chemical confinement, which increase the stiffness of these small regions (< 200nm). We employ two different indentation methods to highlight how contact orientation determines the nature of our results. Ultra-soft materials, such as hydrogels and tissues, pose rather unique challenges when they are tested mechanically. However, with tissues and gels, the sensitivity of the machines is challenged and therefore protocols must be developed to produce accurate results. We validate

  2. Common Practice Lightning Strike Protection Characterization Technique to Quantify Damage Mechanisms on Composite Substrates

    NASA Technical Reports Server (NTRS)

    Szatkowski, George N.; Dudley, Kenneth L.; Koppen, Sandra V.; Ely, Jay J.; Nguyen, Truong X.; Ticatch, Larry A.; Mielnik, John J.; Mcneill, Patrick A.

    2013-01-01

    heating parameters which occur during lightning attachment. Following guidance defined in the universal common practice LSP test documents, protected and unprotected CFRP panels were evaluated at 20, 40 and 100KAmps. This report presents analyzed data demonstrating the scientific usefulness of the common practice approach. Descriptions of the common practice CFRP test articles, LSP test bed fixture, and monitoring techniques to capture the electrical, mechanical and thermal parameters during lightning attachment are presented here. Two methods of measuring the electrical currents were evaluated, inductive current probes and a newly developed fiberoptic sensor. Two mechanical displacement methods were also examined, optical laser measurement sensors and a digital imaging correlation camera system. Recommendations are provided to help users implement the common practice test approach and obtain LSP test characterizations comparable across data sets.

  3. Advanced analytical techniques for the extraction and characterization of plant-derived essential oils by gas chromatography with mass spectrometry.

    PubMed

    Waseem, Rabia; Low, Kah Hin

    2015-02-01

    In recent years, essential oils have received a growing interest because of the positive health effects of their novel characteristics such as antibacterial, antifungal, and antioxidant activities. For the extraction of plant-derived essential oils, there is the need of advanced analytical techniques and innovative methodologies. An exhaustive study of hydrodistillation, supercritical fluid extraction, ultrasound- and microwave-assisted extraction, solid-phase microextraction, pressurized liquid extraction, pressurized hot water extraction, liquid-liquid extraction, liquid-phase microextraction, matrix solid-phase dispersion, and gas chromatography (one- and two-dimensional) hyphenated with mass spectrometry for the extraction through various plant species and analysis of essential oils has been provided in this review. Essential oils are composed of mainly terpenes and terpenoids with low-molecular-weight aromatic and aliphatic constituents that are particularly important for public health. PMID:25403494

  4. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Fourth quarter 1992

    SciTech Connect

    Not Available

    1992-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x } reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB tong-term data collected show the full load NO{sub x} emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO{sub x} emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term, full load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stack particulate emissions issue is resolved.

  5. Electromagnetic diagnostic techniques for hypervelocity projectile detection, velocity measurement, and size characterization: Theoretical concept and first experimental test

    SciTech Connect

    Uhlig, W. Casey; Heine, Andreas

    2015-11-14

    A new measurement technique is suggested to augment the characterization and understanding of hypervelocity projectiles before impact. The electromagnetic technique utilizes magnetic diffusion principles to detect particles, measure velocity, and indicate relative particle dimensions. It is particularly suited for detection of small particles that may be difficult to track utilizing current characterization methods, such as high-speed video or flash radiography but can be readily used for large particle detection, where particle spacing or location is not practical for other measurement systems. In this work, particles down to 2 mm in diameter have been characterized while focusing on confining the detection signal to enable multi-particle characterization with limited particle-to-particle spacing. The focus of the paper is on the theoretical concept and the analysis of its applicability based on analytical and numerical calculation. First proof-of-principle experimental tests serve to further validate the method. Some potential applications are the characterization of particles from a shaped-charge jet after its break-up and investigating debris in impact experiments to test theoretical models for the distribution of particles size, number, and velocity.

  6. Electromagnetic diagnostic techniques for hypervelocity projectile detection, velocity measurement, and size characterization: Theoretical concept and first experimental test

    NASA Astrophysics Data System (ADS)

    Uhlig, W. Casey; Heine, Andreas

    2015-11-01

    A new measurement technique is suggested to augment the characterization and understanding of hypervelocity projectiles before impact. The electromagnetic technique utilizes magnetic diffusion principles to detect particles, measure velocity, and indicate relative particle dimensions. It is particularly suited for detection of small particles that may be difficult to track utilizing current characterization methods, such as high-speed video or flash radiography but can be readily used for large particle detection, where particle spacing or location is not practical for other measurement systems. In this work, particles down to 2 mm in diameter have been characterized while focusing on confining the detection signal to enable multi-particle characterization with limited particle-to-particle spacing. The focus of the paper is on the theoretical concept and the analysis of its applicability based on analytical and numerical calculation. First proof-of-principle experimental tests serve to further validate the method. Some potential applications are the characterization of particles from a shaped-charge jet after its break-up and investigating debris in impact experiments to test theoretical models for the distribution of particles size, number, and velocity.

  7. Innovative Universities.

    ERIC Educational Resources Information Center

    Barsi, Louis M.; Kaebnick, Gweneth W.

    1989-01-01

    The phenomenon of innovation within the university is examined, noting the possibility of innovation as a key to college vitality. A study was conducted using a group of institutions that demonstrated recent innovative spirit. Members of the American Association of State Colleges and Universities (AASCU), each has been recognized in an annual…

  8. Observational and Data Reduction Techniques to Optimize Mineralogical Characterizations of Asteroid Surface Materials

    NASA Technical Reports Server (NTRS)

    Gaffey, M. J.

    2003-01-01

    Mineralogy is the key to determining the compositional history of the asteroids and to determining the genetic relationships between the asteroids and meteorites. The most sophisticated remote mineralogical characterizations involve the quantitative extraction of specific diagnostic parameters from reflectance spectra and the use of quantitative interpretive calibrations to determine the presence, abundance and/or composition of mineral phases in a surface material. Although this approach is potentially subject to systematic errors, it provides the only consistent set of asteroid surface material characterizations.

  9. Real-time technique for the characterization of tunable single-frequency lasers

    SciTech Connect

    Strzelecki, E.M.; Cohen, D.A.; Corzine, S.W.; Karin, J.R.; Coldren, L.A.

    1988-06-27

    An all-fiber Mach--Zehnder interferometric system has been developed for characterization of tunable semiconductor lasers. The tuning rate, range, and linearity of directly frequency-modulated lasers as well as laser linewidth are measured using the same system. To investigate the features of the system and demonstrate its usefulness, 1.3 ..mu..m coupled-cavity lasers, tunable with constant amplitude, were characterized. The effects of optical feedback on laser parameters have also been investigated.

  10. Surface-Enhanced Raman Scattering as an Emerging Characterization and Detection Technique

    SciTech Connect

    Culha, Mustafa; Cullum, Brian; Lavrik, Nickolay; Klutse, Charles K.

    2012-01-01

    While surface-enhanced Raman spectroscopy (SERS) has been attracting a continuously increasing interest of scientific community since its discovery, it has enjoyed a particularly rapid growth in the last decade. Most notable recent advances in SERS include novel technological approaches to SERS substrates and innovative applications of SERS in medicine and molecular biology. While a number of excellent reviews devoted to SERS appeared in the literature over the last two decades, we will focus this paper more specifically on several promising trends that have been highlighted less frequently. In particular, we will briefly overview strategies in designing and fabricating SERS substrates using deterministic patterning and then cover most recent biological applications of SERS.

  11. Characterization of Apollo Regolith by X-Ray and Electron Microbeam Techniques: An Analog for Future Sample Return Missions

    NASA Technical Reports Server (NTRS)

    Zeigler, Ryan A.

    2015-01-01

    The Apollo missions collected 382 kg of rock and regolith from the Moon; approximately 1/3 of the sample mass collected was regolith. Lunar regolith consists of well mixed rocks, minerals, and glasses less than 1-centimeter n size. The majority of most surface regolith samples were sieved into less than 1, 1-2, 2-4, and 4-10- millimiter size fractions; a portion of most samples was re-served unsieved. The initial characterization and classification of most Apollo regolith particles was done primarily by binocular microscopy. Optical classification of regolith is difficult because (1) the finest fraction of the regolith coats and obscures the textures of the larger particles, and (b) not all lithologies or minerals are uniquely identifiable optically. In recent years, we have begun to use more modern x-ray beam techniques [1-3], coupled with high resolution 3D optical imaging techniques [4] to characterize Apollo and meteorite samples as part of the curation process. These techniques, particularly in concert with SEM imaging of less than 1-millimeter regolith grain mounts, allow for the rapid characterization of the components within a regolith.

  12. MULTIPOLE EXPANSION TECHNIQUES FOR THE CALCULATION AND CHARACTERIZATION OF MOLECULAR ELECTROSTATIC POTENTIALS

    EPA Science Inventory

    The electrostatic interaction between a chemical and its site of biological action is often important in determining biological activity. In order to include this interaction in methods to assess the potential biological activity of large molecules, rapid and reliable techniques ...

  13. Industrial fouling: problem characterization, economic assessment, and review of prevention, mitigation, and accommodation techniques

    SciTech Connect

    Garrett-Price, B.A.; Smith, S.A.; Watts, R.L.

    1984-02-01

    A comprehensive overview of heat exchanger fouling in the manufacturing industries is provided. Specifically, this overview addresses: the characteristics of industrial fouling problems; the mitigation and accommodation techniques currently used by industry; and the types and magnitude of costs associated with industrial fouling. A detailed review of the fouling problems, costs and mitigation techniques is provided for the food, textile, pulp and paper, chemical, petroleum, cement, glass and primary metals industries.

  14. Characterizing the intrinsic bioremediation potential of 1,4-dioxane and trichloroethene using innovative environmental diagnostic tools.

    PubMed

    Chiang, Sheau-Yun Dora; Mora, Rebecca; Diguiseppi, William H; Davis, Greg; Sublette, Kerry; Gedalanga, Phillip; Mahendra, Shaily

    2012-09-01

    An intrinsic biodegradation study involving the design and implementation of innovative environmental diagnostic tools was conducted to evaluate whether monitored natural attenuation (MNA) could be considered as part of the remedial strategy to treat an aerobic aquifer contaminated with 1,4-dioxane and trichloroethene (TCE). In this study, advanced molecular biological and stable isotopic tools were applied to confirm in situ intrinsic biodegradation of 1,4-dioxane and TCE. Analyses of Bio-Trap® samplers and groundwater samples collected from monitoring wells verified the abundance of bacteria and enzymes capable of aerobically degrading TCE and 1,4-dioxane. Furthermore, phospholipid fatty acid analysis with stable isotope probes (PLFA-SIP) of the microbial community validated the ability for microbial degradation of TCE and 1,4-dioxane. Compound specific isotope analysis (CSIA) of groundwater samples for TCE resulted in δ(13)C values that indicated likely biodegradation of TCE in three of the four monitoring wells sampled. Results of the MNA evaluation showed that enzymes capable of aerobically degrading TCE and 1,4-dioxane were present, abundant, and active in the aquifer. Taken together, these results provide direct evidence of the occurrence of TCE and 1,4-dioxane biodegradation at the study site, supporting the selection of MNA as part of the final remedy at some point in the future. PMID:22825917

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

    PubMed

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

    2007-11-01

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

  16. Use of Iba Techniques to Characterize High Velocity Thermal Spray Coatings

    NASA Astrophysics Data System (ADS)

    Trompetter, W.; Markwitz, A.; Hyland, M.

    Spray coatings are being used in an increasingly wide range of industries to improve the abrasive, erosive and sliding wear of machine components. Over the past decade industries have moved to the application of supersonic high velocity thermal spray techniques. These coating techniques produce superior coating quality in comparison to other traditional techniques such as plasma spraying. To date the knowledge of the bonding processes and the structure of the particles within thermal spray coatings is very subjective. The aim of this research is to improve our understanding of these materials through the use of IBA techniques in conjunction with other materials analysis techniques. Samples were prepared by spraying a widely used commercial NiCr powder onto substrates using a HVAF (high velocity air fuel) thermal spraying technique. Detailed analysis of the composition and structure of the power particles revealed two distinct types of particles. The majority was NiCr particles with a significant minority of particles composing of SiO2/CrO3. When the particles were investigated both as raw powder and in the sprayed coating, it was surprising to find that the composition of the coating meterial remained unchanged during the coating process despite the high velocity application.

  17. An X-band waveguide measurement technique for the accurate characterization of materials with low dielectric loss permittivity.

    PubMed

    Allen, Kenneth W; Scott, Mark M; Reid, David R; Bean, Jeffrey A; Ellis, Jeremy D; Morris, Andrew P; Marsh, Jeramy M

    2016-05-01

    In this work, we present a new X-band waveguide (WR90) measurement method that permits the broadband characterization of the complex permittivity for low dielectric loss tangent material specimens with improved accuracy. An electrically long polypropylene specimen that partially fills the cross-section is inserted into the waveguide and the transmitted scattering parameter (S21) is measured. The extraction method relies on computational electromagnetic simulations, coupled with a genetic algorithm, to match the experimental S21 measurement. The sensitivity of the technique to sample length was explored by simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments. Analysis of our simulated data predicts the technique will have the sensitivity to measure loss tangent values on the order of 10(-3) for materials such as polymers with relatively low real permittivity values. The ability to accurately characterize low-loss dielectric material specimens of polypropylene is demonstrated experimentally. The method was validated by excellent agreement with a free-space focused-beam system measurement of a polypropylene sheet. This technique provides the material measurement community with the ability to accurately extract material properties of low-loss material specimen over the entire X-band range. This technique could easily be extended to other frequency bands. PMID:27250447

  18. Characterization of biocatalysts prepared with Thermomyces lanuginosus lipase and different silica precursors, dried using aerogel and xerogel techniques.

    PubMed

    Barão, Carlos Eduardo; Daniel de Paris, Leandro; Dantas, João Henrique; Pereira, Matheus Mendonça; Filho, Lucio Cardozo; Ferreira de Castro, Heizir; Zanin, Gisella Maria; Faria de Moraes, Flavio; Faria Soares, Cleide Mara

    2014-01-01

    The use of lipases in industrial processes can result in products with high levels of purity and at the same time reduce pollutant generation and improve both selectivity and yields. In this work, lipase from Thermomyces lanuginosus was immobilized using two different techniques. The first involves the hydrolysis/polycondensation of a silica precursor (tetramethoxysilane (TMOS)) at neutral pH and ambient temperature, and the second one uses tetraethoxysilane (TEOS) as the silica precursor, involving the hydrolysis and polycondensation of the alkoxide in appropriate solvents. After immobilization, the enzymatic preparations were dried using the aerogel and xerogel techniques and then characterized in terms of their hydrolytic activities using a titrimetric method with olive oil and by the formation of 2-phenylethyl acetate in a transesterification reaction. The morphological properties of the materials were characterized using scanning electron microscopy, measurements of the surface area and pore size and volume, thermogravimetric analysis, and exploratory differential calorimetry. The results of the work indicate that the use of different silica precursors (TEOS or TMOS) and different drying techniques (aerogel or xerogel) can significantly affect the properties of the resulting biocatalyst. Drying with supercritical CO2 provided higher enzymatic activities and pore sizes and was therefore preferable to drying, using the xerogel technique. Thermogravimetric analysis and differential scanning calorimetry analyses revealed differences in behavior between the two biocatalyst preparations due to the compounds present. PMID:24078188

  19. Complementary use of flow and sedimentation field-flow fractionation techniques for size characterizing biodegradable poly(lactic acid) nanospheres

    PubMed Central

    Contado, Catia; Dalpiaz, Alessandro; Leo, Eliana; Zborowski, Maciej; Williams, P. Stephen

    2009-01-01

    Poly(lactic acid) nanoparticles were synthesized using a modified evaporation method, testing two different surfactants (sodium cholate and Pluronic F68) for the process. During their formulation the prodrug 5′-octanoyl-CPA (Oct-CPA) of the antiischemic N6-cyclopentyladenosine (CPA) was encapsulated. Three different purification methods were compared with respect to the influence of surfactant on the size characteristics of the final nanoparticle product. Flow and sedimentation field-flow fractionation techniques (FlFFF and SdFFF, respectively) were used to size characterize the five poly(lactic acid) particle samples. Two different combinations of carrier solution (mobile phase) were employed in the FlFFF analyses, while a solution of poly(vinyl alcohol) was used as mobile phase for the SdFFF runs. The separation performances of the two techniques were compared and the particle size distributions, derived from the fractograms, were interpreted with the support of observations by scanning electron microscopy. Some critical aspects, such as the carrier choice and the channel thickness determination for the FlFFF, have been investigated. This is the first comprehensive comparison of the two FFF techniques for characterizing non standard particulate materials. The two FFF techniques proved to be complementary and gave good, congruent and very useful information on the size distributions of the five poly(lactic acid) particle samples. PMID:17482199

  20. An X-band waveguide measurement technique for the accurate characterization of materials with low dielectric loss permittivity

    NASA Astrophysics Data System (ADS)

    Allen, Kenneth W.; Scott, Mark M.; Reid, David R.; Bean, Jeffrey A.; Ellis, Jeremy D.; Morris, Andrew P.; Marsh, Jeramy M.

    2016-05-01

    In this work, we present a new X-band waveguide (WR90) measurement method that permits the broadband characterization of the complex permittivity for low dielectric loss tangent material specimens with improved accuracy. An electrically long polypropylene specimen that partially fills the cross-section is inserted into the waveguide and the transmitted scattering parameter (S21) is measured. The extraction method relies on computational electromagnetic simulations, coupled with a genetic algorithm, to match the experimental S21 measurement. The sensitivity of the technique to sample length was explored by simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments. Analysis of our simulated data predicts the technique will have the sensitivity to measure loss tangent values on the order of 10-3 for materials such as polymers with relatively low real permittivity values. The ability to accurately characterize low-loss dielectric material specimens of polypropylene is demonstrated experimentally. The method was validated by excellent agreement with a free-space focused-beam system measurement of a polypropylene sheet. This technique provides the material measurement community with the ability to accurately extract material properties of low-loss material specimen over the entire X-band range. This technique could easily be extended to other frequency bands.

  1. Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): part 2--morphological and mineralogical features.

    PubMed

    Calabrese, S; D'Alessandro, W

    2015-01-01

    Volcanic emissions were studied at Mount Etna (Italy) by using moss-bags technique. Mosses were exposed around the volcano at different distances from the active vents to evaluate the impact of volcanic emissions in the atmosphere. Morphology and mineralogy of volcanic particulate intercepted by mosses were investigated using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). Particles emitted during passive degassing activity from the two active vents, Bocca Nuova and North East Crater (BNC and NEC), were identified as silicates, sulfates and halide compounds. In addition to volcanic particles, we found evidences also of geogenic, anthropogenic and marine spray input. The study has shown the robustness of this active biomonitoring technique to collect particles, very useful in active volcanic areas characterized by continuous degassing and often not easily accessible to apply conventional sampling techniques. PMID:25311770

  2. Statistical factor analysis technique for characterizing basalt through interpreting nuclear and electrical well logging data (case study from Southern Syria).

    PubMed

    Asfahani, Jamal

    2014-02-01

    Factor analysis technique is proposed in this research for interpreting the combination of nuclear well logging, including natural gamma ray, density and neutron-porosity, and the electrical well logging of long and short normal, in order to characterize the large extended basaltic areas in southern Syria. Kodana well logging data are used for testing and applying the proposed technique. The four resulting score logs enable to establish the lithological score cross-section of the studied well. The established cross-section clearly shows the distribution and the identification of four kinds of basalt which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The factor analysis technique is successfully applied on the Kodana well logging data in southern Syria, and can be used efficiently when several wells and huge well logging data with high number of variables are required to be interpreted. PMID:24296157

  3. The use of synchrotron radiation techniques in the characterization of strained semiconductor heterostructures and thin films [review article

    NASA Astrophysics Data System (ADS)

    Lamberti, C.

    2004-05-01

    In the last couple of decades, high-performance electronic and optoelectronic devices based on semiconductor heterostructures have been required to obtain increasingly strict and well-defined performances, needing a detailed control, at the atomic level, of the structural composition of the buried interfaces. This goal has been achieved by an improvement of the epitaxial growth techniques and by the parallel use of increasingly sophisticated characterization techniques. Among them, a leading role has been certainly played by those exploiting synchrotron radiation (SR) sources. In fact synchrotron radiation has distinct advantages as a photon source, notably high brilliance and continuous energy spectrum; by using the latter characteristic atomic selectivity can be obtained and this is of fundamental help to investigate the structural environment of atoms present only in a few angstrom (Å) thick interface layers of heterostructures. The third generation synchrotron radiation sources have allowed to reach the limit of measuring a monolayer of material, corresponding to about 10 14 atoms/cm 2. Since, in the last decade, the use of intentionally strained heterostructures has greatly enhanced the performance of electrical and electro-optical semiconductor, a particular attention will be devoted to intentionally strained superlattices. First the effect of strain on the band lineups alignments in strained heterostructures will be discussed deeply. Then the attention will be focused on to review the most important results obtained by several groups in the characterization of semiconductor heterostructures using the following structural SR techniques: (i) X-ray absorption-based techniques such as EXAFS, polarization-dependent EXAFS, surface EXAFS and NEXAFS (or XANES); (ii) X-ray diffraction-based techniques such as high-resolution XRD, grazing incidence XRD, XRD reciprocal space maps, X-ray standing waves and diffraction anomalous fine structure (DAFS); (iii

  4. Rapid Identification and Characterization of Francisella by Molecular Biology and Other Techniques

    PubMed Central

    Lai, Xin-He; Zhao, Long-Fei; Chen, Xiao-Ming; Ren, Yi

    2016-01-01

    Francisella tularensis is the causative pathogen of tularemia and a Tier 1 bioterror agent on the CDC list. Considering the fact that some subpopulation of the F. tularensis strains is more virulent, more significantly associated with mortality, and therefore poses more threat to humans, rapid identification and characterization of this subpopulation strains is of invaluable importance. This review summarizes the up-to-date developments of assays for mainly detecting and characterizing F. tularensis and a touch of caveats of some of the assays. PMID:27335619

  5. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2003-02-11

    This research was directed toward developing a systematic reservoir characterization methodology which can be used by the petroleum industry to implement infill drilling programs and/or enhanced oil recovery projects in naturally fractured reservoir systems in an environmentally safe and cost effective manner. It was anticipated that the results of this research program will provide geoscientists and engineers with a systematic procedure for properly characterizing a fractured reservoir system and a reservoir/horizontal wellbore simulator model which can be used to select well locations and an effective EOR process to optimize the recovery of the oil and gas reserves from such complex reservoir systems.

  6. Characterization of high resolution MR images reconstructed by a GRAPPA based parallel technique

    NASA Astrophysics Data System (ADS)

    Banerjee, Suchandrima; Majumdar, Sharmila

    2006-03-01

    This work implemented an auto-calibrating parallel imaging technique and applied it to in vivo magnetic resonance imaging (MRI) of trabecular bone micro-architecture. A Generalized auto-calibrating partially parallel acquisition (GRAPPA) based reconstruction technique using modified robust data fitting was developed. The MR data was acquired with an eight channel phased array receiver on three normal volunteers on a General Electric 3 Tesla scanner. Microstructures comprising the trabecular bone architecture are of the order of 100 microns and hence their depiction requires very high imaging resolution. This work examined the effects of GRAPPA based parallel imaging on signal and noise characteristics and effective spatial resolution in high resolution (HR) images, for the range of undersampling or reduction factors 2-4. Additionally quantitative analysis was performed to obtain structural measures of trabecular bone from the images. Image quality in terms of contrast and depiction of structures was maintained in parallel images for reduction factors up to 3. Comparison between regular and parallel images suggested similar spatial resolution for both. However differences in noise characteristics in parallel images compared to regular images affected the threshholding based quantification. This suggested that GRAPPA based parallel images might require different analysis techniques. In conclusion, the study showed the feasibility of using parallel imaging techniques in HR-MRI of trabecular bone, although quantification strategies will have to be further investigated. Reduction of acquisition time using parallel techniques can improve the clinical feasibility of MRI of trabecular bone for prognosis and staging of the skeletal disorder osteoporosis.

  7. Innovative automatic resonant mode identification for nano-scale dynamic full-field characterization of MEMS using interferometric fringe analysis

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Huang, Yao-Ting; Lai, Huang-Wen; Chen, Jin-Liang; Chang, Calvin C.

    2008-12-01

    A dynamic 3D nano-scale surface profilometer was successfully developed for novel automatic resonant frequency identification using stroboscopic interferometric principle. With rapid increase in the application of micro electromechanical systems (MEMS) to industries, the needs of accurate dynamic characterization have become a major challenge in design and fabrication. In view of such, an interferometric microscopy was developed using LED stroboscopic interferometry to achieve dynamic full-field profilometry and characterization of MEMS with a measurement bandwidth exceeding 1 MHz. Most importantly, a novel detection algorithm was also developed employing interferogram fringe density measure for automatic resonant frequency identification. Natural resonant modes of a series of microstructures can be accurately detected, giving values consistent with theoretical ones. To verify the effectiveness of the developed methodology, an AFM cantilever microbeam and a cross-bridge microbeam were measured to analyze their full-field resonant vibratory shapes. Our experimental results confirmed that the resonant vibration of the tested beams can be fully characterized while achieving an accuracy in vertical measurement of 3-5 nm with a vertical measurement range of tens of micrometers.

  8. Synthesis and characterization of nanoporous silica film via non-surfactant template sol-gel technique

    NASA Astrophysics Data System (ADS)

    Al-Harbi, T.; Al-Hazmi, F.; Mahmoud, Waleed E.

    2012-10-01

    Nanoporous silicon dioxide has received growing interests owing to their peculiar application potentials in conservation and storage energy. Therefore, the development of novel and simple techniques is required for raising these nanoporous materials to industrial level. In this research, we report novel strategy for the synthesis of nanoporous SiO2 via non-surfactant template sol-gel technique for the first time. The morphology and structure of the as prepared and annealed nanoporous silica films were studied using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy and nitrogen absorption/desorption technique. The results showed that highly order nanoporous silica film has been obtained at annealing temperature 600 °C with average diameter 5.1 nm and average pore volume 3.6 cm3 g-1.

  9. Geostatistical characterization of the soil of Aguascalientes, México, by using spatial estimation techniques.

    PubMed

    Magdaleno-Márquez, Ricardo; de la Luz Pérez-Rea, María; Castaño, Víctor M

    2016-01-01

    Four spatial estimation techniques available in commercial computational packages are evaluated and compared, namely: regularized splines interpolation, tension splines interpolation, inverse distance weighted interpolation, and ordinary Kriging estimation, in order to establish the best representation for the shallow stratigraphic configuration in the city of Aguascalientes, in Central Mexico. Data from 478 sample points along with the software ArcGIS (Environmental Systems Research Institute, Inc. (ESRI), ArcGIS, ver. 9.3, Redlands, California 2008) to calculate the spatial estimates. Each technique was evaluated based on the root mean square error, calculated from a validation between the generated estimates and measured data from 64 sample points which were not used in the spatial estimation process. The present study shows that, for the estimation of the hard-soil layer, ordinary Kriging offered the best performance among the evaluated techniques. PMID:27386362

  10. Advanced, time-resolved imaging techniques for electron-beam characterizations

    SciTech Connect

    Lumpkin, A.H.

    1990-01-01

    Several unique time-resolved imaging techniques have been developed to address radio frequency (RF)-linac generated electron beams and the free-electron lasers (FEL) driven by such systems. The time structures of these beams involve a series of micropulses with 10 to 15-ps duration, separated by tens of nanoseconds. Mechanisms to convert the e-beam information to optical radiation include optical transition radiation (OTR), Cherenkov radiation, spontaneous emission radiation (SER), and the FEL mechanism itself. The use of gated, intensified television cameras and synchroscan and dual-sweep streak cameras to time-resolve these signals has greatly enhanced the power of these techniques. A brief review of the less familiar conversion mechanisms and electro-optic techniques is followed by a series of specific experimental examples from the RF linac FEL facilities at Los Alamos and Boeing (Seattle, WA). 23 refs., 35 figs., 3 tabs.

  11. Thermal characterization of starch-water system by photopyroelectric technique and adiabatic scanning calorimetry

    NASA Astrophysics Data System (ADS)

    Cruz-Orea, A.; Bentefour, E. H.; Jamée, P.; Chirtoc, M.; Glorieux, C.; Pitsi, G.; Thoen, J.

    2003-01-01

    Starch is one of the most important carbohydrate sources in human nutrition. For the thermal analysis of starch, techniques such as differential scanning calorimetry have been extensively used. As an alternative, we have applied a photopyroelectric (PPE) configuration and adiabatic scanning calorimetry (ASC) to study the thermal properties of starch-water systems. For this study we used nixtamalized corn flour and potato starch with different quantities of distilled water, in order to obtain samples with different moisture content. By using PPE and ASC methods we have measured, for each technique separately, the heat capacity by unit volume (ρcp) at room temperature for a corn flour sample at 90% moisture. The obtained values agree within experimental uncertainty. By using these techniques we also studied the thermal behavior of potato starch, at 80% moisture, in the temperature range where phase transitions occur. In this case the PPE signal phase could be used as a sensitive and versatile monitor for phase transitions.

  12. Advanced atomic force microscopy techniques for characterizing the properties of cellulosic nanomaterials

    NASA Astrophysics Data System (ADS)

    Wagner, Ryan Bradley

    The measurement of nanomechanical properties is of great interest to science and industry. Key to progress in this area is the development of new techniques and analysis methods to identify, measure, and quantify these properties. In this dissertation, new data analysis methods and experimental techniques for measuring nanomechanical properties with the atomic force microscope (AFM) are considered. These techniques are then applied to the study of cellulose nanoparticles, an abundant, plant derived nanomaterial. Quantifying uncertainty is a prerequisite for the manufacture of reliable nano-engineered materials and products. However, rigorous uncertainty quantification is rarely applied for material property measurements with the AFM. A framework is presented to ascribe uncertainty to local nanomechanical properties of any nanoparticle or surface measured with the AFM by taking into account the main uncertainty sources inherent in such measurements. This method is demonstrated by quantifying uncertainty in force displacement AFM based measurements of the transverse elastic modulus of tunicate cellulose nanocrystals. Next, a more comprehensive study of different types of cellulose nanoparticles is undertaken with contact resonance (CR) AFM. CR-AFM is a dynamic AFM technique that exploits the resonance frequency of the AFM cantilever while it is permanent contact with the sample surface to predict nanomechanical properties. This technique offers improved measurement sensitivity over static AFM methods for some material systems. The effects of cellulose source material and processing technique on the properties of cellulose nanoparticles are compared. Finally, dynamic AFM cantilever vibration shapes are studied. Many AFM modes exploit the dynamic response of a cantilever in permanent contact with a sample to extract local material properties. A common challenge to these modes is that they assume a certain shape of cantilever vibration, which is not accessible in

  13. CHARACTERIZATION OF FUNGI FROM HYPERSALINE ENVIRONMENTS OF SOLAR SALTERNS USING MORPHOLOGICAL AND MOLECULAR TECHNIQUES

    EPA Science Inventory

    The Cabo Rojo Solar Salterns located on the southwest coast of Puerto Rico are composed of two main ecosystems (i.e., salt ponds and microbial mats). Even though these locations are characterized by high solar radiation (mean light intensity of 39 mol photons m-2d-1) they harbor ...

  14. Nuclear Microscopy for Air-Pollutant Characterization and Its Advantages over Traditional Techniques

    NASA Astrophysics Data System (ADS)

    Ram, S. S.; Kumar, R. V.; Chaudhuri, P.; Chanda, S.; Santra, S. C.; Deary, M.; Sudarshan, M.; Chakraborty, A.

    2014-03-01

    In the present study we establish the use of the proton induced X-ray emission (PIXE) technique coupled with Rutherford backscattering as a sensitive technique for air-pollution monitoring. Several elements such as Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and As were detected in the ppm level of concentration. Comparisons show the advantages of micro-PIXE over scanning microscope-based energy-dispersive X-ray spectrometry (SEM-EDX) and energy-dispersive X-ray fluorescence spectrometry (EDXRF).

  15. Micro-structural characterization of materials using synchrotron hard X-ray imaging techniques

    SciTech Connect

    Agrawal, Ashish Singh, Balwant; Kashyap, Yogesh; Sarkar, P. S.; Shukla, Mayank; Sinha, Amar

    2015-06-24

    X-ray imaging has been an important tool to study the materials microstructure with the laboratory based sources however the advent of third generation synchrotron sources has introduced new concepts in X-ray imaging such as phase contrast imaging, micro-tomography, fluorescence imaging and diffraction enhance imaging. These techniques are being used to provide information of materials about their density distribution, porosity, geometrical and morphological characteristics at sub-micron scalewith improved contrast. This paper discusses the development of various imaging techniques at synchrotron based imaging beamline Indus-2 and few recent experiments carried out at this facility.

  16. Innovative Classroom Techniques for Teaching Personal Economics: A Summary of Winning Entries in the 1973-74 Personal Economics Competence Awards Program.

    ERIC Educational Resources Information Center

    Illinois Council on Economic Education, DeKalb.

    The purpose of the awards program is to initiate a new merger between economics and education by sharing innovative methods with all Illinois teachers for the teaching of personal economics. Personal economics is defined as the study of the individual's decision-making process and his/her participation in economic life in the roles of consumer,…

  17. INVESTIGATING ULTRASONIC DIFFRACTION GRATING SPECTROSCOPY AND REFLECTION TECHNIQUES FOR CHARACTERIZING SLURRY PROPERTIES

    EPA Science Inventory

    The objectives of the project are to investigate the use of (1) ultrasonic diffraction grating spectroscopy (UDGS) for measuring the particle size of a slurry and (2) shear wave reflection techniques to measure the viscosity of a slurry. For the first topic, the basic principle...

  18. Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries using Synchrotron Radiation Techniques

    SciTech Connect

    Mehta, Apurva; Stanford Synchrotron Radiation Lightsource; Doeff, Marca M.; Chen, Guoying; Cabana, Jordi; Richardson, Thomas J.; Mehta, Apurva; Shirpour, Mona; Duncan, Hugues; Kim, Chunjoong; Kam, Kinson C.; Conry, Thomas

    2013-04-30

    We describe the use of synchrotron X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques to probe details of intercalation/deintercalation processes in electrode materials for Li ion and Na ion batteries. Both in situ and ex situ experiments are used to understand structural behavior relevant to the operation of devices.

  19. 11-Isopropylcryptolepine: A novel alkaloid isolated from cryptolepis sanguinolenta characterized using submicro NMR techniques

    PubMed

    Hadden; Sharaf; Guido; Robins; Tackie; Phoebe; Schiff; Martin

    1999-02-01

    A new alkaloid has been isolated from extracts of the West African plant Cryptolepis sanguinolenta and identified by submicro NMR techniques as 11-isopropylcryptolepine (1). The unusual incorporation of the isopropyl group at the 11-position of the indolo[3,2-b]quinoline nucleus is suggestive of a mixed biosynthetic origin for the alkaloid. PMID:10075749

  20. Advance development of a technique for characterizing the thermomechanical properties of thermally stable polymers

    NASA Technical Reports Server (NTRS)

    Gillham, J. K.; Stadnicki, S. J.; Hazony, Y.

    1974-01-01

    The torsional braid experiment has been interfaced with a centralized hierarchical computing system for data acquisition and data processing. Such a system, when matched by the appropriate upgrading of the monitoring techniques, provides high resolution thermomechanical spectra of rigidity and damping, and their derivatives with respect to temperature.

  1. A methodological intercomparison of topographic survey techniques for characterizing wadeable streams and rivers

    NASA Astrophysics Data System (ADS)

    Bangen, Sara G.; Wheaton, Joseph M.; Bouwes, Nicolaas; Bouwes, Boyd; Jordan, Chris

    2014-02-01

    Fine-scale (submeter) resolution digital elevation models (DEMs) created from high precision (subcentimeter) instruments (e.g., total station, rtkGPS, and laser scanning) have become ubiquitous in the field of fluvial geomorphology. They permit a diverse range of spatially explicit analyses including hydraulic modeling, habitat modeling, and geomorphic change detection. While previous studies have assessed the quality of specific topographic survey methods at individual sites or across a limited number of sites, an intercomparison of survey technologies across a diverse range of wadeable streams could help clarify which techniques are feasible, as well as which work best under what circumstances and for what purposes. Although a wealth of existing studies and protocols explain how to undertake each individual technique, in this study we seek to provide guidance on what techniques to use in which circumstances. We quantified the relative quality and the amount of effort spent collecting data to derive bare earth topography from an array of ground-based and airborne survey techniques. We used topographic survey data collected over the summer of 2010 from six sample reaches of varying complexity in the Lemhi River basin, Idaho, USA. We attempted to conduct complete, replicate surveys at each site using total station (TS), real-time kinematic (rtk) GPS, discrete return terrestrial laser scanner (TLS), and airborne LiDaR surveys (ALS). We evaluated the precision and accuracy of derived bare earth DEMs relative to the higher precision total station point data. Discrepancies between pairwise techniques were calculated using propagated DEM errors thresholded at a 95% confidence interval. Mean discrepancies between total station and rtkGPS DEMs were relatively low (≤ 0.05 m), yet TS data collection time was up to 2.4 times longer than rtkGPS. The ALS DEMs had lower accuracy than TS or rtkGPS DEMs, but the aerial coverage and floodplain context of the ALS data set was

  2. Mechanical characterization of thin film structures using a laser spallation technique

    NASA Astrophysics Data System (ADS)

    Wu, Jianxin

    The laser spallation technique has been developed to measure the interface strength between different materials, especially thin film structures. In this work, it is refined and applied to various material systems. With these advances, the laser spallation technique is now fully mature for applications not only to measurement of material interface strength, but also to the study of laser-material interaction, dynamic fracture mechanics, as well as to the measurement of material bulk properties. In the first part of this work, the laser spallation technique was examined quantitatively for signal processing and stress wavefield recovery. It is shown that the short time Fourier transformation is another appropriate means for recovering the free surface displacement from the acquired optical signal. Two methods have been chosen to recover the stress field inside the sample. When the displacement of the coating's free surface is recorded directly, it is convenient to use a special finite difference strategy. When the free surface displacement is recorded on the bare substrate surface, it is more convenient to use the finite element method to calculate the interface strength. The application work includes several topics. The first one was the evaluation of the effect of substrate orientation and deposition mode on the interface strength of Nb-sapphire interfaces. The interface strength is higher for the sapphire substrate with prismatic orientation, and RF deposition mode yields higher interface strength than the DC mode. The second application estimated the effect of substrate roughness on the interface strength of Nb-alumina system. The effect of chemical composition of thin films on the interface strength was also investigated. The final application investigated the dynamic fracture mechanics of thin film structures. The purpose of this chapter is to clarify the controversial topic regarding the limit speed of bimaterial interface crack propagation. We were successful

  3. Synchrotron Techniques for in-situ Characterization of Hydrogen Storage Materials and Their Applications to NaAlH4

    NASA Astrophysics Data System (ADS)

    Gao, Yan; Rijssenbeek, Job T.; Morris, William; Heward, William; Smentkowski, Vincent; Hanson, Jon; Wang, Xianqin; Chupas, Peter; Lee, Peter; Srinivasan, Sesha S.; Jensen, Craig M.

    2004-03-01

    Several synchrotron techniques, including time-resolved powder diffraction (XRD), X-ray Absorption Fine Structure (XAFS) and Rapid Acquisition Pair-Distribution Function (RA-PDF) analysis, for in-situ characterization of hydrogen storage materials will be discussed. Studies on NaAlH4 will be used as an example but these techniques are useful for hydrogen storage materials in general. We will demonstrate the capabilities of powder diffraction with high speed data acquisition (3 seconds per pattern) and under high-pressure (2000 psi) recently achieved using synchrotron sources, which are of importance for studying fast kinetics and high-pressure charging reactions. The superior angular resolution of synchrotron radiation allows the detection of subtle changes in crystallite size (such as the Al phase in the case of NaAlH_4) during cycling of these materials, which often is not possible with in-house sources. We will also describe in-situ XAFS at high-temperatures for studying the oxidation state and chemical environment of low level catalysts (such as Ti) commonly used in these materials. Finally, we will discuss the time-resolved RA-PDF technique, which follows the change of interatomic distances in the course of phase transformation. These techniques are complementary and each probes the microstructure of these materials from a unique perspective; the combined use of these techniques will open an unprecedented opportunity for improving our understanding of hydrogen storage materials.

  4. Innovation @ NASA

    NASA Technical Reports Server (NTRS)

    Roman, Juan A.

    2014-01-01

    This presentation provides an overview of the activities National Aeronautics and Space Administration (NASA) is doing to encourage innovation across the agency. All information provided is available publicly.

  5. Novel elastomers, characterization techniques, and improvements in the mechanical properties of some thermoplastic biodegradable polymers and their nanocomposites

    NASA Astrophysics Data System (ADS)

    Hassan, Mohamed Korany Ibrahim

    This work focused in its first part on the preparation and characterization of novel elastomers based on poly(tetrahydrofuran) (PTHF) networks. Elastomers were prepared by a hydrolysis-condensation reaction which has been followed up by FTIR spectroscopic techniques. The elastomers thus obtained were studied with regard to their equilibrium swelling in toluene at 25°C, and their stress-strain isotherms in elongation. For some of the samples, high elongations seemed to bring about highly desirable strain-induced crystallization, as evidenced by upturns in the modulus. Swelling of these samples with increasing amounts of the non-volatile diluent dibutyl phthalate caused the upturns to gradually disappear. The second part of this work was focused on diversifying the newly developed sound wave propagation technique to characterize elastomeric polymer networks. The technique was applied to characterize polybutadiene (PBD) networks. The speed of wave propagation in PBD networks was found to be strongly dependent on the network structural parameters such as average molecular weight of chain between crosslinks and entanglement molecular weight. Also, for the swollen networks, pulse speeds decreased with increase in degree of swelling. Upturns due to strain-induced crystallization at higher elongations were clearly evidenced in the pulse speeds. The third part of this work presented improvements in the mechanical properties of thermoplastic biodegradable poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (Nodax(TM)) using a pre-orientation technique. This simple approach involved heating the polymer film to a temperature above its glass transition temperature, stretching it to the desired extension (%), and then quenching it to room temperature while in the stretched state. As expected, pre-orientation resulted in substantial improvements in the mechanical properties of the films. The pre-oriented films had higher values of the modulus, toughness, yield stress, and tensile

  6. Material and energy recovery in integrated waste management systems: an innovative approach for the characterization of the gaseous emissions from residual MSW bio-drying.

    PubMed

    Ragazzi, M; Rada, E C; Antolini, D

    2011-01-01

    In the sector of residual municipal solid waste management an increasing attention is put towards the role of biological treatments like bio-drying and bio-stabilization in order to decrease the need of landfilling volumes. The literature shows a lack of information concerning the emission factor of pollutants released from these processes. The available data are generally spot characterizations of concentration and air flow-rate that are used together in order to assess the emission factors. This approach caused significant differences among the available data as the release of pollutants is not steady. This paper belongs to a group of six papers concerning a research on material and energy recovery in integrated waste management systems, developed by a network of five universities. The contribution of the University of Trento, focuses on the bio-drying process with the following targets: (a) developing an innovative low cost method of sampling/measurement able to take into account the dynamics of release of pollutants; (b) checking the efficiency of a bio-filter; (c) verifying the variability of generation of some pollutants; (d) generating emission factors. The research was developed using a bio-drying pilot plant. As a treatment of the process air, the bio-reactor was coupled with a bio-filter. The emissions were characterized using an original approach based on the adoption of two measurement chambers suitable for hosting passive samplers. The passive samplers allowed the characterization of VOCs, N(2)O, NH(3) and H(2)S. A bio-chemical model, useful for energy and mass balances, supported the interpretation of the presented bio-drying run. PMID:21482095

  7. Material and energy recovery in integrated waste management systems: An innovative approach for the characterization of the gaseous emissions from residual MSW bio-drying

    SciTech Connect

    Ragazzi, M.; Rada, E.C.; Antolini, D.

    2011-09-15

    In the sector of residual municipal solid waste management an increasing attention is put towards the role of biological treatments like bio-drying and bio-stabilization in order to decrease the need of landfilling volumes. The literature shows a lack of information concerning the emission factor of pollutants released from these processes. The available data are generally spot characterizations of concentration and air flow-rate that are used together in order to assess the emission factors. This approach caused significant differences among the available data as the release of pollutants is not steady. This paper belongs to a group of six papers concerning a research on material and energy recovery in integrated waste management systems, developed by a network of five universities. The contribution of the University of Trento, focuses on the bio-drying process with the following targets: (a) developing an innovative low cost method of sampling/measurement able to take into account the dynamics of release of pollutants; (b) checking the efficiency of a bio-filter; (c) verifying the variability of generation of some pollutants; (d) generating emission factors. The research was developed using a bio-drying pilot plant. As a treatment of the process air, the bio-reactor was coupled with a bio-filter. The emissions were characterized using an original approach based on the adoption of two measurement chambers suitable for hosting passive samplers. The passive samplers allowed the characterization of VOCs, N{sub 2}O, NH{sub 3} and H{sub 2}S. A bio-chemical model, useful for energy and mass balances, supported the interpretation of the presented bio-drying run.

  8. Structural characterization of MG and pre-MG states of proteins by MD simulations, NMR, and other techniques.

    PubMed

    Naiyer, Abdullah; Hassan, Md Imtaiyaz; Islam, Asimul; Sundd, Monica; Ahmad, Faizan

    2015-01-01

    Almost all proteins fold via a number of partially structured intermediates such as molten globule (MG) and pre-molten globule states. Understanding the structure of these intermediates at atomic level is often a challenge, as these states are observed under extreme conditions of pH, temperature, and chemical denaturants. Furthermore, several other processes such as chemical modification, site-directed mutagenesis (or point mutation), and cleavage of covalent bond of natural proteins often lead to MG like partially unfolded conformation. However, the dynamic nature of proteins in these states makes them unsuitable for most structure determination at atomic level. Intermediate states studied so far have been characterized mostly by circular dichroism, fluorescence, viscosity, dynamic light scattering measurements, dye binding, infrared techniques, molecular dynamics simulations, etc. There is a limited amount of structural data available on these intermediate states by nuclear magnetic resonance (NMR) and hence there is a need to characterize these states at the molecular level. In this review, we present characterization of equilibrium intermediates by biophysical techniques with special reference to NMR. PMID:25586676

  9. Design Concepts, Fabrication and Advanced Characterization Methods of Innovative Piezoelectric Sensors Based on ZnO Nanowires.

    PubMed

    Araneo, Rodolfo; Rinaldi, Antonio; Notargiacomo, Andrea; Bini, Fabiano; Pea, Marialilia; Celozzi, Salvatore; Marinozzi, Franco; Lovat, Giampiero

    2014-01-01

    Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct bandgap, piezoelectricity, pyroelectricity and biocompatibility. Most applications are based on the cooperative and average response of a large number of ZnO micro/nanostructures. However, in order to assess the quality of the materials and their performance, it is fundamental to characterize and then accurately model the specific electrical and piezoelectric properties of single ZnO structures. In this paper, we report on focused ion beam machined high aspect ratio nanowires and their mechanical and electrical (by means of conductive atomic force microscopy) characterization. Then, we investigate the suitability of new power-law design concepts to accurately model the relevant electrical and mechanical size-effects, whose existence has been emphasized in recent reviews. PMID:25494351

  10. Design Concepts, Fabrication and Advanced Characterization Methods of Innovative Piezoelectric Sensors Based on ZnO Nanowires

    PubMed Central

    Araneo, Rodolfo; Rinaldi, Antonio; Notargiacomo, Andrea; Bini, Fabiano; Pea, Marialilia; Celozzi, Salvatore; Marinozzi, Franco; Lovat, Giampiero

    2014-01-01

    Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct bandgap, piezoelectricity, pyroelectricity and biocompatibility. Most applications are based on the cooperative and average response of a large number of ZnO micro/nanostructures. However, in order to assess the quality of the materials and their performance, it is fundamental to characterize and then accurately model the specific electrical and piezoelectric properties of single ZnO structures. In this paper, we report on focused ion beam machined high aspect ratio nanowires and their mechanical and electrical (by means of conductive atomic force microscopy) characterization. Then, we investigate the suitability of new power-law design concepts to accurately model the relevant electrical and mechanical size-effects, whose existence has been emphasized in recent reviews. PMID:25494351

  11. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2002-10-08

    During this reporting period, research was continued on characterizing and modeling the behavior of naturally fractured reservoir systems. This report proposed a model to relate the seismic response to production data to determine crack spacing and aperture, provided details of tests of proposed models to obtain fracture properties from conventional well logs with actual field data, and verification of the naturally fractured reservoir simulator developed in this project.

  12. New techniques for the characterization of refuse-derived fuels and solid recovered fuels.

    PubMed

    Rotter, Vera Susanne; Lehmann, Annekatrin; Marzi, Thomas; Möhle, Edda; Schingnitz, Daniel; Hoffmann, Gaston

    2011-02-01

    Solid recovered fuel (SRF) today refers to a waste-derived fuel meeting defined quality specifications, in terms of both origin (produced from non-hazardous waste) and levels of certain fuel properties. Refuse-derived fuel (RDF) nowadays is more used for unspecified waste after a basic processing to increase the calorific value and therefore this term usually refers to the segregated, high calorific fraction of municipal solid waste (MSW), commercial or industrial wastes. In comparison with conventional fuels, both types of secondary fuel show waste of inherently varying quality and an increased level of waste-specific contaminants.The transition from RDF to SRF in the emerging national and European market requires a quality assurance system with defined quality parameters and analytical methods to ensure reliable fuel characterization. However, due to the quality requirements for RDF and SRF, the current standardized analysis methods often do not meet these practical demands. Fast test methods, which minimize personnel, financial and time efforts and which are applicable for producers as well as users can be an important supporting tool for RDF- and SRF-characterization. Currently, a fast test system based on incineration and correlation analyses which enable the determination of relevant fuel parameters is under development. Fast test methods are not aimed at replacing current standardized test methods, but have to be considered as practical supporting tools for the characterization of RDF and SRF. PMID:20392788

  13. Development and characterization of an automatic technique for the alignment of fMRI time series.

    PubMed

    Ciulla, C; Deek, F P

    2001-01-01

    An automatic technique for the registration of fMRI time series has been developed, implemented and tested. The method assumes the human brain to be a rigid body and computes a head coordinate system on the basis of three reference points that lies on the directions corresponding to two of the principal axes of the volume at the intersections with the head boundary. Such directions are found computing the eigenvectors of the symmetric inertia matrix of the image. The inertia components were extracted weighting pixels' coordinates with their intensity values. The three reference points were found in the same position, relative to the head, in both the test and the reference images. The technique has been tested using T2*-weighted Magnetic Resonance (MR) images in which known rigid body transformations have been applied. The results obtained indicate that the method offers subvoxel accuracy in correcting misalignment among time points in fMRI time series. PMID:11599532

  14. Characterizing Si:P quantum dot qubits with spin resonance techniques.

    PubMed

    Wang, Yu; Chen, Chin-Yi; Klimeck, Gerhard; Simmons, Michelle Y; Rahman, Rajib

    2016-01-01

    Quantum dots patterned by atomically precise placement of phosphorus donors in single crystal silicon have long spin lifetimes, advantages in addressability, large exchange tunability, and are readily available few-electron systems. To be utilized as quantum bits, it is important to non-invasively characterise these donor quantum dots post fabrication and extract the number of bound electron and nuclear spins as well as their locations. Here, we propose a metrology technique based on electron spin resonance (ESR) measurements with the on-chip circuitry already needed for qubit manipulation to obtain atomic scale information about donor quantum dots and their spin configurations. Using atomistic tight-binding technique and Hartree self-consistent field approximation, we show that the ESR transition frequencies are directly related to the number of donors, electrons, and their locations through the electron-nuclear hyperfine interaction. PMID:27550779

  15. Dual-sensor technique for characterization of carrier lifetime decay transients in semiconductors

    SciTech Connect

    Ahrenkiel, R. K.; Johnston, S. W.; Kuciauskas, D.; Tynan, Jerry

    2014-12-07

    This work addresses the frequent discrepancy between transient photoconductive (PC) decay and transient photoluminescence (PL) decay. With this dual- sensor technique, one measures the transient PC and PL decay simultaneously with the same incident light pulse, removing injection-level uncertainty. Photoconductive decay measures the transient photoconductivity, Δσ(t). PCD senses carriers released from shallow traps as well as the photo-generated electron-hole pairs. In addition, variations in carrier mobility with injection level (and time) contribute to the decay time. PL decay senses only electron-hole recombination via photon emission. Theory and experiment will show that the time dependence of the two techniques can be quite different at high injection.

  16. An Approximate Numerical Technique for Characterizing Optical Pulse Propagation in Inhomogeneous Biological Tissue

    PubMed Central

    Handapangoda, Chintha C.; Premaratne, Malin

    2008-01-01

    An approximate numerical technique for modeling optical pulse propagation through weakly scattering biological tissue is developed by solving the photon transport equation in biological tissue that includes varying refractive index and varying scattering/absorption coefficients. The proposed technique involves first tracing the ray paths defined by the refractive index profile of the medium by solving the eikonal equation using a Runge-Kutta integration algorithm. The photon transport equation is solved only along these ray paths, minimizing the overall computational burden of the resulting algorithm. The main advantage of the current algorithm is that it enables to discretise the pulse propagation space adaptively by taking optical depth into account. Therefore, computational efficiency can be increased without compromising the accuracy of the algorithm. PMID:18317526

  17. Quantitative characterization of lignocellulosic biomass using surrogate mixtures and multivariate techniques.

    PubMed

    Krasznai, Daniel J; Champagne, Pascale; Cunningham, Michael F

    2012-04-01

    PLS regression models were developed using mixtures of cellulose, xylan, and lignin in a ternary mixture experimental design for multivariate model calibration. Mid-infrared spectra of these representative samples were recorded using Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FT-IR) spectroscopy and regressed against their known composition using Partial Least Squares (PLSs) multivariate techniques. The regression models were cross-validated and then used to predict the unknown compositions of two Arabidopsis cultivars, B10 and C10. The effect of various data preprocessing techniques on the final predictive ability of the PLS regression models was also evaluated. The predicted compositions of B10 and C10 by the PLS regression model after second derivative data preprocessing were similar to the results provided by a third-party analysis. This study suggests that mixture designs could be used as calibration standards in PLS regression for the compositional analysis of lignocellulosic materials if the infrared data is appropriately preprocessed. PMID:22342087

  18. Techniques for improving the Si-SiO2 interface characterization

    NASA Technical Reports Server (NTRS)

    Sher, A.; Hoffman, H. J.; Su, P.; Tsuo, Y. H.

    1983-01-01

    The two techniques which have provided most of the information on interface states in MIS-C (metal-insulator-semiconductor-capacitor) structures are the 'quasi-static method' and the 'conductance method'. Sher et al. (1979) and Su et al. (1980) have suggested a number of improvements concerning these methods. The present investigation has the objective to extend the earlier results and to offer a new tentative interpretation of the data. A critical review is conducted of the data collection and reduction techniques for the quasi-static method, taking into account the sample, the quasi-static capacitance, and the surface potential. In connection with a discussion of the conductance method, attention is given to parallel conductance and capacitance measurements, interface-state densities, time constants, and measurements on a (110) surface orientation.

  19. Characterizing Si:P quantum dot qubits with spin resonance techniques

    PubMed Central

    Wang, Yu; Chen, Chin-Yi; Klimeck, Gerhard; Simmons, Michelle Y.; Rahman, Rajib

    2016-01-01

    Quantum dots patterned by atomically precise placement of phosphorus donors in single crystal silicon have long spin lifetimes, advantages in addressability, large exchange tunability, and are readily available few-electron systems. To be utilized as quantum bits, it is important to non-invasively characterise these donor quantum dots post fabrication and extract the number of bound electron and nuclear spins as well as their locations. Here, we propose a metrology technique based on electron spin resonance (ESR) measurements with the on-chip circuitry already needed for qubit manipulation to obtain atomic scale information about donor quantum dots and their spin configurations. Using atomistic tight-binding technique and Hartree self-consistent field approximation, we show that the ESR transition frequencies are directly related to the number of donors, electrons, and their locations through the electron-nuclear hyperfine interaction. PMID:27550779

  20. Growth and characterization of 4-chloro-3-nitrobenzophenone single crystals using vertical Bridgman technique

    SciTech Connect

    Aravinth, K. Babu, G. Anandha Ramasamy, P.

    2014-04-24

    4-chloro-3-nitrobenzophenone (4C3N) has been grown by using vertical Bridgman technique. The grown crystal was confirmed by Powder X-ray diffraction analysis. The crystalline perfection of the grown crystal was examined by high-resolution X-ray diffraction study. The fluorescence spectra of grown 4C3N single crystals exhibit emission peak at 575 nm. The micro hardness measurements were used to analyze the mechanical property of the grown crystal.