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Sample records for embedded characterization technique

  1. Characterizing structural and vibrational properties of nanoparticles embedded in silica with XAS, SAXS and auxiliary techniques

    SciTech Connect

    Araujo, Leandro L.; Kluth, Patrick; Giulian, Raquel; Sprouster, David J.; Ridgway, Mark C.; Johannessen, Bernt; Foran, Garry J.; Cookson, David J.

    2009-01-29

    Synchrotron-based techniques were combined with conventional analysis methods to probe in detail the structural and vibrational properties of nanoparticles grown in a silica matrix by ion implantation and thermal annealing, as well as the evolution of such properties as a function of nanoparticle size. This original approach was successfully applied for several elemental nanoparticles (Au, Co, Cu, Ge, Pt) and the outcomes for Ge are reported here, illustrating the power of this combined methodology. The thorough analysis of XANES, EXAFS, SAXS, TEM and Raman data for Ge nanoparticles with mean diameters between 4 and 9 nm revealed that the peculiar properties of embedded Ge nanoparticles, like the existence of amorphous Ge layers between the silica matrix and the crystalline nanoparticle core, are strongly dependent on particle size and mainly governed by the variation in the surface area-to-volume ratio. Such detailed information provides valuable input for the efficient planning of technological applications.

  2. Dynamic characterization, monitoring and control of rotating flexible beam-mass structures via piezo-embedded techniques

    NASA Technical Reports Server (NTRS)

    Lai, Steven H.-Y.

    1992-01-01

    A variational principle and a finite element discretization technique were used to derive the dynamic equations for a high speed rotating flexible beam-mass system embedded with piezo-electric materials. The dynamic equation thus obtained allows the development of finite element models which accommodate both the original structural element and the piezoelectric element. The solutions of finite element models provide system dynamics needed to design a sensing system. The characterization of gyroscopic effect and damping capacity of smart rotating devices are addressed. Several simulation examples are presented to validate the analytical solution.

  3. A 3-D chimera grid embedding technique

    NASA Technical Reports Server (NTRS)

    Benek, J. A.; Buning, P. G.; Steger, J. L.

    1985-01-01

    A three-dimensional (3-D) chimera grid-embedding technique is described. The technique simplifies the construction of computational grids about complex geometries. The method subdivides the physical domain into regions which can accommodate easily generated grids. Communication among the grids is accomplished by interpolation of the dependent variables at grid boundaries. The procedures for constructing the composite mesh and the associated data structures are described. The method is demonstrated by solution of the Euler equations for the transonic flow about a wing/body, wing/body/tail, and a configuration of three ellipsoidal bodies.

  4. Biometric feature embedding using robust steganography technique

    NASA Astrophysics Data System (ADS)

    Rashid, Rasber D.; Sellahewa, Harin; Jassim, Sabah A.

    2013-05-01

    This paper is concerned with robust steganographic techniques to hide and communicate biometric data in mobile media objects like images, over open networks. More specifically, the aim is to embed binarised features extracted using discrete wavelet transforms and local binary patterns of face images as a secret message in an image. The need for such techniques can arise in law enforcement, forensics, counter terrorism, internet/mobile banking and border control. What differentiates this problem from normal information hiding techniques is the added requirement that there should be minimal effect on face recognition accuracy. We propose an LSB-Witness embedding technique in which the secret message is already present in the LSB plane but instead of changing the cover image LSB values, the second LSB plane will be changed to stand as a witness/informer to the receiver during message recovery. Although this approach may affect the stego quality, it is eliminating the weakness of traditional LSB schemes that is exploited by steganalysis techniques for LSB, such as PoV and RS steganalysis, to detect the existence of secrete message. Experimental results show that the proposed method is robust against PoV and RS attacks compared to other variants of LSB. We also discussed variants of this approach and determine capacity requirements for embedding face biometric feature vectors while maintain accuracy of face recognition.

  5. Constraint Embedding Technique for Multibody System Dynamics

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    Multibody dynamics play a critical role in simulation testbeds for space missions. There has been a considerable interest in the development of efficient computational algorithms for solving the dynamics of multibody systems. Mass matrix factorization and inversion techniques and the O(N) class of forward dynamics algorithms developed using a spatial operator algebra stand out as important breakthrough on this front. Techniques such as these provide the efficient algorithms and methods for the application and implementation of such multibody dynamics models. However, these methods are limited only to tree-topology multibody systems. Closed-chain topology systems require different techniques that are not as efficient or as broad as those for tree-topology systems. The closed-chain forward dynamics approach consists of treating the closed-chain topology as a tree-topology system subject to additional closure constraints. The resulting forward dynamics solution consists of: (a) ignoring the closure constraints and using the O(N) algorithm to solve for the free unconstrained accelerations for the system; (b) using the tree-topology solution to compute a correction force to enforce the closure constraints; and (c) correcting the unconstrained accelerations with correction accelerations resulting from the correction forces. This constraint-embedding technique shows how to use direct embedding to eliminate local closure-loops in the system and effectively convert the system back to a tree-topology system. At this point, standard tree-topology techniques can be brought to bear on the problem. The approach uses a spatial operator algebra approach to formulating the equations of motion. The operators are block-partitioned around the local body subgroups to convert them into aggregate bodies. Mass matrix operator factorization and inversion techniques are applied to the reformulated tree-topology system. Thus in essence, the new technique allows conversion of a system with

  6. Laser Brazing metallic embedding technique for fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Grandal, Tania; Fraga, Sergio; Castro, Gemma; Vazquez, Esteban; Zornoza, Ander

    2017-04-01

    In this paper a fiber optic metallic embedding technique is presented based on laser Brazing manufacturing process. The embedding strategy to follow by the laser Brazing, which consists in three steps, minimizes the thermal stress of the embedded fiber, relaxes microbending strains and reduces damage on the fiber. The minimum embedded fiber optic Ni coating total diameter is 237 μm for a successful process with negligible optical loss on the fiber. Fiber Bragg Gratings were successfully embedded in metallic specimens and their strain response was in accordance with their specifications.

  7. Techniques for characterizing lignin

    Treesearch

    Nicole M. Stark; Daniel J. Yelle; Umesh P. Agarwal

    2016-01-01

    Many techniques are available to characterize lignin. The techniques presented in this chapter are considered nondegradative, which are commonly applied to lignin. A brief discussion of lignin structure is included with this chapter to aid the reader in understanding why the discussed characterization techniques are appropriate for the study of lignin. Because the...

  8. Simple debugging techniques for embedded subsystems

    NASA Astrophysics Data System (ADS)

    MacPherson, Matthew S.; Martin, Kevin S.

    1990-08-01

    This paper describes some of the tools and methods used for developing and debugging embedded subsystems at Fermilab. Specifically, these tools have been used for the Flying Wire project and are currently being employed for the New TECAR upgrade. The Flying Wire is a subsystem that swings a wire through the beam in order to measure luminosity and beam density distribution, and TECAR (Tevatron excitation controller and regulator) controls the power-supply ramp generation for the superconducting Tevatron accelerator at Fermilab. In both instances the subsystem hardware consists of a VME crate with one or more processors, shared memory and a network connection to the accelerator control system. Two real-time-operating systems are currently being used: VRTX for the Flying Wire system, and MTOS for New TECAR. The code which runs in these subsystems is a combination of C and assembler and is developed using the Microtec cross-development tools on a VAX 8650 running VMS. This paper explains how multiple debuggers are used to give the greatest possible flexibility from assembly to high-level debugging. Also discussed is how network debugging and network downloading can make a very effective and efficient means of finding bugs in the subsystem environment. The debuggers used are PROBE1, TRACER and the MTOS debugger.

  9. Strain characterization of embedded aerospace smart materials using shearography

    NASA Astrophysics Data System (ADS)

    Anisimov, Andrei G.; Müller, Bernhard; Sinke, Jos; Groves, Roger M.

    2015-04-01

    The development of smart materials for embedding in aerospace composites provides enhanced functionality for future aircraft structures. Critical flight conditions like icing of the leading edges can affect the aircraft functionality and controllability. Hence, anti-icing and de-icing capabilities are used. In case of leading edges made of fibre metal laminates heater elements can be embedded between composite layers. However this local heating causes strains and stresses in the structure due to the different thermal expansion coefficients of the different laminated materials. In order to characterize the structural behaviour during thermal loading full-field strain and shape measurement can be used. In this research, a shearography instrument with three spatially-distributed shearing cameras is used to measure surface displacement gradients which give a quantitative estimation of the in- and out-of-plane surface strain components. For the experimental part, two GLARE (Glass Laminate Aluminum Reinforced Epoxy) specimens with six different embedded copper heater elements were manufactured: two copper mesh shapes (straight and S-shape), three connection techniques (soldered, spot welded and overlapped) and one straight heater element with delaminations. The surface strain behaviour of the specimens due to thermal loading was measured and analysed. The comparison of the connection techniques of heater element parts showed that the overlapped connection has the smallest effect on the surface strain distribution. Furthermore, the possibility of defect detection and defect depth characterisation close to the heater elements was also investigated.

  10. Synthesis and characterization of embedded germanium nanocrystals

    NASA Astrophysics Data System (ADS)

    Xu, Qing

    Isotopically pure Ge nanocrystals have been synthesized by ion implantation followed by thermal annealing in amorphous silica and crystalline sapphire matrix. The structure, and the mechanical and thermal properties of the two systems are studied and compared. Ge cluster nucleation during implantation is observed in as-implanted silica samples. It results in the wide size distribution observed after thermal annealing. Theoretical calculations predict that if the nucleation during implantation can be suppressed, a much narrower size distribution is achievable. As-grown Ge nanocrystals are under large compressive stress, 1.2GPa for nanocrystals embedded in silica, and 4GPa for those embedded in sapphire. The stress can be gradually relieved by vapor etching, liberating the nanocrystals from the matrix as well as post-growth thermal treatments. One of the main sources of the stress observed in the sapphire system is the volume expansion of Ge clusters in the liquid/solid phase transformation which occurs during the cooling process from annealing temperature to room temperature, as the density of liquid Ge is larger by 4.6% than that of solid Ge. The large stress and damage in the sapphire matrix lead to a unique double-peak size distribution of the Ge nanocrystals. However, the in situ transmission electron microscopy (TEM) experiments indicate that the Ge nanocrystals embedded in silica are already in their solid phase at the annealing temperature. Therefore, the stress originates from other sources. Vapor etching with HF solutions enables a gradual exposure of embedded Ge nanocrystals in SiO2, while the liquid etching in HF solution leaves fully liberated Ge nanocrystals loosely packed on the Si substrate. Transfer of liberated Ge nanocrystals to other surfaces is achieved by solution dispersion and subsequent evaporation. The patterning of nanocrystals has been achieved by a combination of lithography, coimplantation and electron irradiation. The latter one will

  11. Fault tolerance techniques for embedded telemetry system: case study

    NASA Astrophysics Data System (ADS)

    Krosman, Kazimierz; Sosnowski, Janusz

    2016-09-01

    This paper presents software methods of improving fault tolerance in embedded systems. These methods have been adapted to a telemetry system dedicated to tracking vehicles for logistics purposes. The developed telemetry system allows us to monitor vehicle position and some technical parameters via GSM communication. It comprises the capability of remote software reconfiguration. To evaluate dependability of the system we use a fault injection technique based on simulating bit-flip errors within memory cells. For this purpose an original testbed has been developed. It provides not only the capability of disturbing internal state of the tested system (via JTAG interface) but also the possibility of controlling system input states and observing its behavior (in particular output signals) according to specified test scenarios. The whole test process is automatized. The paper presents a case study related to a commercial product but the described methodology and techniques can be extended for other embedded systems.

  12. Structural characterization of copolymer embedded magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Nedelcu, G. G.; Nastro, A.; Filippelli, L.; Cazacu, M.; Iacob, M.; Rossi, C. Oliviero; Popa, A.; Toloman, D.; Dobromir, M.; Iacomi, F.

    2015-10-01

    Small magnetic nanoparticles (Fe3O4) were synthesized by co-precipitation and coated by emulsion polymerization with poly(methyl methacrylate-co-acrylic acid) (PMMA-co-AAc) to create surface functional groups that can attach drug molecules and other biomolecules. The coated and uncoated magnetite nanoparticles were stored for two years in normal closed ships and than characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and electron paramagnetic resonance spectroscopy. The solid phase transformation of magnetite to maghemite, as well as an increase in particle size were evidenced for the uncoated nanoparticles. The coated nanoparticles preserved their magnetite structure and magnetic properties. The influences of monomers and surfactant layers on interactions between the magnetic nanoparticles evidenced that the thickness of the polymer has a significant effect on magnetic properties.

  13. Characterization of rat spermatocytes after plastic embedding.

    PubMed

    Russell, L; Frank, B

    1978-01-01

    Rat testicular tissue, perfused with glutaraldehyde, post-fixed with osmium and stained with toluidine blue, was studied to obtain information which could be used to characterize spermatocytes (also type B gonia and Step 1 spermatids) with the light microscope. Measurements of relative cell, nuclear sizes and absolute nuclear size are presented in graphic form, demonstrating the progressive growth found for spermatocytes. Early prophase spermatocytes (preleptotene, leptotene, zygotene) gradually increased in size. Pachytene cells showed no growth until Stage IV, at which point a dramatic size increase began and continued until the diplotene phase. Guidelines to identify a particular phase of meiosis were established for spermatocytes using primarily nuclear traits. Examination of longitudinal sections through Stages XIII, XIV and I were useful for comparing cells from Meiotic divisions (meta-, ana-, and telophases) I and II and also for differentiating secondary spermatocytes from Step 1 spermatids.

  14. A Flexible Microwave De-Embedding Method for On-Wafer Noise Parameter Characterization of MOSFETs

    NASA Astrophysics Data System (ADS)

    Wang, Yueh-Hua; Cho, Ming-Hsiang; Wu, Lin-Kun

    A flexible noise de-embedding method for on-wafer microwave measurements of silicon MOSFETs is presented in this study. We use the open, short, and thru dummy structures to subtract the parasitic effects from the probe pads and interconnects of a fixtured MOS transistor. The thru standard are used to extract the interconnect parameters for subtracting the interconnect parasitics in gate, drain, and source terminals of the MOSFET. The parasitics of the dangling leg in the source terminal are also modeled and taken into account in the noise de-embedding procedure. The MOS transistors and de-embedding dummy structures were fabricated in a standard CMOS process and characterized up to 20GHz. Compared with the conventional de-embedding methods, the proposed technique is accurate and area-efficient.

  15. Techniques for Embedding Instrumentation in Pressure Vessel Test Articles

    NASA Technical Reports Server (NTRS)

    Cornelius, Michael

    2006-01-01

    Many interesting structural and thermal events occur in materials that are housed within a surrounding pressure vessel. In order to measure the environment during these events and explore their causes instrumentation must be installed on or in the material. Transducers can be selected that are small enough to be embedded within the test material but these instruments must interface with an external system in order to apply excitation voltages and output the desired data. The methods for installing the instrumentation and creating an interface are complicated when the material is located in a case or housing containing high pressures and hot gases. Installation techniques for overcoming some of these difficulties were developed while testing a series of small-scale solid propellant and hybrid rocket motors at Marshall Space Flight Center. These techniques have potential applications in other test articles where data are acquired from materials that require containment due to the severe environment encountered during the test process. This severe environment could include high pressure, hot gases, or ionized atmospheres. The development of these techniques, problems encountered, and the lessons learned from the ongoing testing process are summarized.

  16. Techniques for embedding instrumentation in pressure vessel test articles

    NASA Astrophysics Data System (ADS)

    Cornelius, Michael

    2006-05-01

    Many interesting structural and thermal events occur in materials that are housed within a surrounding pressure vessel. In order to measure the environment during these events and explore their causes instrumentation must be installed on or in the material. Transducers can be selected that are small enough to be embedded within the test material but these instruments must interface with an external system in order to apply excitation voltages and output the desired data. The methods for installing the instrumentation and creating an interface are complicated when the material is located in a case or housing containing high pressures and hot gases. Installation techniques for overcoming some of these difficulties were developed while testing a series of small-scale solid propellant and hybrid rocket motors at Marshall Space Flight Center. These techniques have potential applications in other test articles where data are acquired from materials that require containment due to the severe environment encountered during the test process. This severe environment could include high pressure, hot gases, or ionized atmospheres. The development of these techniques, problems encountered, and the lessons learned from the ongoing testing process are summarized.

  17. A novel embedding technique for dirty paper trellis codes watermarking

    NASA Astrophysics Data System (ADS)

    Chaumont, Marc

    2010-01-01

    Dirty Paper Trellis Codes (DPTC) watermarking, published in 2004, is a very efficient high rate scheme. Nevertheless, it has two strong drawbacks: its security weakness and its CPU computation complexity. We propose an embedding space at least as secure and a faster embedding. The embedding space is built on the projections of some wavelet coefficients onto secret carriers. It keeps a good security level and has also good psycho-visual properties. The embedding is based on a dichotomous rotation in the Cox, Miller and Boom Plane. It gives better performances than previous fast embedding approaches. Four different attacks are performed and revealed good robustness and rapidity performances.

  18. Exactly Embedded Wavefunction Methods for Characterizing Nitrogen Reduction Catalysis

    DTIC Science & Technology

    2015-01-15

    SUBTITLE Exactly Embedded Wavefunction Methods for Characterizing Nitrogen Reduction Catalysis 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA9550... catalysis , such as hydrogen and nitrogen reduction. In a significant methodological advance from the past year, we developed an accurate and...Pasadena, CA 91125 Telephone Number of PI: 626-395-6588 Email of PI: tfm@caltech.edu With AFOSR support in the last funding period ( Grant Number: FA9550-11

  19. Machine learning techniques for energy optimization in mobile embedded systems

    NASA Astrophysics Data System (ADS)

    Donohoo, Brad Kyoshi

    Mobile smartphones and other portable battery operated embedded systems (PDAs, tablets) are pervasive computing devices that have emerged in recent years as essential instruments for communication, business, and social interactions. While performance, capabilities, and design are all important considerations when purchasing a mobile device, a long battery lifetime is one of the most desirable attributes. Battery technology and capacity has improved over the years, but it still cannot keep pace with the power consumption demands of today's mobile devices. This key limiter has led to a strong research emphasis on extending battery lifetime by minimizing energy consumption, primarily using software optimizations. This thesis presents two strategies that attempt to optimize mobile device energy consumption with negligible impact on user perception and quality of service (QoS). The first strategy proposes an application and user interaction aware middleware framework that takes advantage of user idle time between interaction events of the foreground application to optimize CPU and screen backlight energy consumption. The framework dynamically classifies mobile device applications based on their received interaction patterns, then invokes a number of different power management algorithms to adjust processor frequency and screen backlight levels accordingly. The second strategy proposes the usage of machine learning techniques to learn a user's mobile device usage pattern pertaining to spatiotemporal and device contexts, and then predict energy-optimal data and location interface configurations. By learning where and when a mobile device user uses certain power-hungry interfaces (3G, WiFi, and GPS), the techniques, which include variants of linear discriminant analysis, linear logistic regression, non-linear logistic regression, and k-nearest neighbor, are able to dynamically turn off unnecessary interfaces at runtime in order to save energy.

  20. Evaluation of color-embedded wavelet image compression techniques

    NASA Astrophysics Data System (ADS)

    Saenz, Martha; Salama, Paul; Shen, Ke; Delp, Edward J., III

    1998-12-01

    Color embedded image compression is investigated by means of a set of core experiments that seek to evaluate the advantages of various color transformations, spatial orientation trees and the use of monochrome embedded coding schemes such as EZW and SPIHT. In order to take advantage of the interdependencies of the color components for a given color space, two new spatial orientation trees that relate frequency bands and color components are investigated.

  1. An inversion technique for the calculation of embedding potentials

    NASA Astrophysics Data System (ADS)

    Roncero, O.; de Lara-Castells, M. P.; Villarreal, P.; Flores, F.; Ortega, J.; Paniagua, M.; Aguado, A.

    2008-11-01

    A new embedding method to include local correlation in large systems is proposed. In this method the density of the whole system, calculated via density functional theory approaches, is partitioned in two pieces, one corresponding to the subsystem of interest and the rest to the environment. In the second step, an embedding potential is obtained iteratively using as a driving force the self-repulsion due to the density difference, in a similar form as proposed by Zhao et al. [Phys. Rev. A 50, 2138 (1994)], to obtain the "exact" exchange-correlation functional. Such potential is added to the Fock equation to build the localized molecular orbitals which are further used to include the local electronic correlation in the subsystem of interest. This method is an alternative to the previous DFT-based embedding methods first proposed by Wesolowski and Washell [J. Phys. Chem. 97, 8050 (1993)] and after enhanced by Govind et al. [J. Chem. Phys. 110, 7677 (1999)] and adapted to metal extended systems, which use density functionals to describe the kinetic energy contribution to the embedding potential, whose precise form has been largely treated in the literature and its crucial role is discussed here. The method is applied to hydrogen chains and its van der Waals interaction with H2. The results obtained are in very good agreement with exact calculations performed on the whole system, which demonstrates that the method proposed is a very promising route to introduce correlation in large systems.

  2. Computing Flow through Well Screens Using an Embedded Well Technique

    DTIC Science & Technology

    2015-08-01

    can be complex and nonlinear when withdrawal or injection is initiated. To resolve the temporal variation of the well flow pattern accurately, it is... well , a positive total flow represents its withdrawal rate, and a negative total flow represents its injection rate. ADDITIONAL INFORMATION: This...ERDC/CHL CHETN-XI-4 August 2015 Approved for public release; distribution is unlimited. Computing Flow through Well Screens Using an Embedded

  3. Embedded wavelet packet transform technique for texture compression

    NASA Astrophysics Data System (ADS)

    Li, Jin; Cheng, Po-Yuen; Kuo, C.-C. Jay

    1995-09-01

    A highly efficient texture compression scheme is proposed in this research. With this scheme, energy compaction of texture images is first achieved by the wavelet packet transform, and an embedding approach is then adopted for the coding of the wavelet packet transform coefficients. By comparing the proposed algorithm with the JPEG standard, FBI wavelet/scalar quantization standard and the EZW scheme with extensive experimental results, we observe a significant improvement in the rate-distortion performance and visual quality.

  4. 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

  5. Single Cell Electrical Characterization Techniques.

    PubMed

    Mansor, Muhammad Asraf; Ahmad, Mohd Ridzuan

    2015-06-04

    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.

  6. Three embedded techniques for finite element heat flow problem with embedded discontinuities

    NASA Astrophysics Data System (ADS)

    Davari, M.; Rossi, R.; Dadvand, P.

    2017-06-01

    The present paper explores the solution of a heat conduction problem considering discontinuities embedded within the mesh and aligned at arbitrary angles with respect to the mesh edges. Three alternative approaches are proposed as solutions to the problem. The difference between these approaches compared to alternatives, such as the eXtended Finite Element Method (X-FEM), is that the current proposal attempts to preserve the global matrix graph in order to improve performance. The first two alternatives comprise an enrichment of the Finite Element (FE) space obtained through the addition of some new local degrees of freedom to allow capturing discontinuities within the element. The new degrees of freedom are statically condensed prior to assembly, so that the graph of the final system is not changed. The third approach is based on the use of modified FE-shape functions that substitute the standard ones on the cut elements. The imposition of both Neumann and Dirichlet boundary conditions is considered at the embedded interface. The results of all the proposed methods are then compared with a reference solution obtained using the standard FE on a mesh containing the actual discontinuity.

  7. Characterization Techniques for Amorphous Alloys

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 2 http://dx.doi.org/10.1007/9getType="URL"/> 'Systems from B-Be-Fe to Co-W-Zr' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter '2 Characterization Techniques for Amorphous Alloys' with the content:

  8. 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.

  9. 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

  10. Three-dimensional adaptive grid-embedding Euler technique

    NASA Astrophysics Data System (ADS)

    Davis, Roger L.; Dannenhoffer, John F., III

    1994-06-01

    A new three-dimensional adaptive-grid Euler procedure is presented that automatically detects high-gradient regions in the flow and locally subdivides the computational grid in these regions to provide a uniform, high level of accuracy over the entire domain. A tunable, semistructured data system is utilized that provides global topological unstructured-grid flexibility along with the efficiency of a local, structured-grid system. In addition, this structure data allows for the flow solution algorithm to be executed on a wide variety of parallel/vector computing platforms. An explicit, time-marching, control volume procedure is used to integrate the Euler equations to a steady state. In addition, a multiple-grid procedure is used throughout the embedded-grid regions as well as on subgrids coarser than the initial grid to accelerate convergence and properly propagate disturbance waves through refined-grid regions. Upon convergence, high flow gradient regions, where it is assumed that large truncation errors in the solution exist, are detected using a combination of directional refinement vectors that have large components in areas of these gradients. The local computational grid is directionally subdivided in these regions and the flow solution is reinitiated. Overall convergence occurs when a prespecified level of accuracy is reached. Solutions are presented that demonstrate the efficiency and accuracy of the present procedure.

  11. Expansion Techniques of Embedding Audio Watermark Data Rate for Constructing Ubiquitous Acoustic Spaces

    NASA Astrophysics Data System (ADS)

    Modegi, Toshio

    We are proposing “Ubiquitous Acoustic Spaces”, where each sound source can emit some address information with audio signals and make us automatically access to its related cyber space, using handheld devices such as cellphones. In order to realize this concept, we have considered three types of extraction methods, which were an acoustic modulation, an audio fingerprint, and an audio watermark technique. Then we have proposed a novel audio watermarking technique, which enables contactless asynchronous detection of embedded audio watermarks through speaker and microphone devices. However its embedding data rate was around 10 [bps], which was not sufficient for embedding generally used URL address texts. Therefore, we have extended the embedding frequency range and proposed a duplicated embedding algorithm, which uses both previously proposed frequency division method and temporal division method together. By these improvements, possible embedding data rate could be extended to 61.5 [bps], and we could extract watermarks through public telephone networks, even from a cell phone sound source. In this paper, we describe abstracts of our improved watermark embedding and extracting algorithms, and experimental results of watermark extraction precision on several audio signal capturing conditions.

  12. Characterization of heavy metal particles embedded in tire dust.

    PubMed

    Adachi, Kouji; Tainosho, Yoshiaki

    2004-10-01

    Tire dust is a significant pollutant, especially as a source of zinc in the urban environment. This study characterizes the morphology and chemical composition of heavy metal particles embedded in tire dust and traffic-related materials (brake dust, yellow paint, and tire tread) as measured by a field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX). In 60 samples of tire dust, we detected 2288 heavy metal particles, which we classified into four groups using cluster analysis according to the following typical elements: cluster 1: Fe, cluster 2: Cr/Pb, cluster 3: multiple elements (Ti, Cr, Fe, Cu, Zn, Sr, Y, Zr, Sn, Sb, Ba, La, Ce, Pb), cluster 4: ZnO. According to their morphologies and chemical compositions, the possible sources of each cluster were as follows: (1) brake dust (particles rich in Fe and with trace Cu, Sb, and Ba), (2) yellow paint (CrPbO(4) particles), (3) brake dust (particulate Ti, Fe, Cu, Sb, Zr, and Ba) and heavy minerals (Y, Zr, La, and Ce), (4) tire tread (zinc oxide). When the chemical composition of tire dust was compared to that of tire tread, the tire dust was found to have greater concentrations of heavy metal elements as well as mineral or asphalt pavement material characterized by Al, Si, and Ca. We conclude that tire dust consists not only of the debris from tire wear but also of assimilated heavy metal particles emitted from road traffic materials such as brake lining and road paint.

  13. A practical approach for the correction of iatrogenic penile skin loss in children: Scrotal embedding technique

    PubMed Central

    Ziylan, Orhan; Acar, Ömer; Özden, Burcu Celet; Tefik, Tzevat; Dönmez, M. İrfan; Oktar, Tayfun

    2015-01-01

    The aim of this particular study is to determine the efficacy of scrotal embedding technique in children with overly deficient penile shaft skin, which takes advantage of the rich vascular supply of the scrotal layers and provides adequate tissue coverage. We give the operative and clinical details of two consecutive cases for which we preferred scrotal embedding technique to replace deficient penile skin. The mean operative time for the first and second stages was 72.5 and 52.5 min, respectively. Intraoperative and postoperative courses and convalescences were uneventful. The patients were hospitalized for a mean duration of 2 days. After a mean follow-up of 29 months, cosmetic and functional results were satisfactory. Scrotal embedding technique should be considered as a feasible surgical alternative while reconstructing the penile shaft in iatrogenic cases with overly deficient shaft skin. PMID:26623155

  14. Initial experience using the rigid forceps technique to remove wall-embedded IVC filters.

    PubMed

    Avery, Allan; Stephens, Maximilian; Redmond, Kendal; Harper, John

    2015-06-01

    Severely tilted and embedded inferior vena cava (IVC) filters remain the most challenging IVC filters to remove. Heavy endothelialisation over the filter hook can prevent engagement with standard snare and cone recovery techniques. The rigid forceps technique offers a way to dissect the endothelial cap and reliably retrieve severely tilted and embedded filters. By developing this technique, failed IVC retrieval rates can be significantly reduced and the optimum safety profile offered by temporary filters can be achieved. We present our initial experience with the rigid forceps technique described by Stavropoulos et al. for removing wall-embedded IVC filters. We retrospectively reviewed the medical imaging and patient records of all patients who underwent a rigid forceps filter removal over a 22-month period across two tertiary referral institutions. The rigid forceps technique had a success rate of 85% (11/13) for IVC filter removals. All filters in the series showed evidence of filter tilt and embedding of the filter hook into the IVC wall. Average filter tilt from the Z-axis was 19 degrees (range 8-56). Filters observed in the case study were either Bard G2X (n = 6) or Cook Celect (n = 7). Average filter dwell time was 421 days (range 47-1053). There were no major complications observed. The rigid forceps technique can be readily emulated and is a safe and effective technique to remove severely tilted and embedded IVC filters. The development of this technique across both institutions has increased the successful filter removal rate, with perceived benefits to the safety profile of our IVC filter programme. © 2015 The Royal Australian and New Zealand College of Radiologists.

  15. New double embedding technique for specimens of endoscopic submucosal dissection using agarose: comparison with other media.

    PubMed

    Zozumi, Masataka; Nakai, Mayumi; Ito, Takashi; Matsuda, Ikuo; Hao, Hiroyuki; Tsukamoto, Yoshitane; Hirota, Seiichi

    2010-10-01

    Procedure of endoscopic submucosal dissection (ESD) has been introduced widely for treatment of early gastric cancers. For such specimens, accurate pathological diagnosis, especially concerning depth of the invasion and exposure to margins, is essential to decide on the necessity of additional treatment. Therefore, easy and reliable tissue-processing method for multiple cut specimens is needed. The authors report here a new double embedding technique for specimens of ESD. Formalin-fixed whole specimen was superficially wrapped by agarose (the first embedding), and the tissue-agarose block was cut at 2-3 mm intervals. Each cut specimen was laid down with 90° rotation. This procedure permitted 'on edge' embedding of thin tissues in paraffin (the second embedding) and subsequent preparation of perpendicular section to the tissue surface. The authors compared the handleability and stainability among several media including various types of agar, agarose and gelatin for first embedding. A survey by questionnaire was carried out on handleability and/or impression on various tissue-processing steps from pathology technicians. Among the media examined, agarose showed the best solubility in water and the best transparency on several representative stainings. According to the survey, pathology technicians seemed to feel that the present method was better than the usual tissue processing method, especially in shortened time consumption and accuracy of alignment of multiple tissues for ESD specimens. The present new double embedding technique using agarose provides not only an easy and reliable embedding procedure for technicians but also accurate and exact diagnosis for pathologists.

  16. Histology and research at the hard tissue-implant interface using Technovit 9100 New embedding technique.

    PubMed

    Willbold, Elmar; Witte, Frank

    2010-11-01

    Calcified tissues, like bones and teeth, are among the most challenging tissues for histological research. However, especially with respect to dental or orthopaedic research, powerful histological techniques are necessary to study pathological conditions or traumatic injuries, and to investigate the molecular and cellular mechanisms of regeneration processes and functional recovery. The situation is even more complicated in orthopaedic research because here metallic implants or other devices made of various materials are often present, and the hard tissue-implant interface is of crucial interest in both biocompatibility and functional recovery research. After the cutting-grinding technique, embedding in technical resins is the most promising approach. Here we describe an optimized and standardized embedding and cutting technique using Technovit 9100 New. Using this technique, we are able to perform enzyme histochemistry, immunohistochemistry, a great variety of classical histological stains and even in situ hybridization. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. A fiber-optic cure monitoring technique with accuracy improvement of distorted embedded sensors

    NASA Astrophysics Data System (ADS)

    Sampath, Umesh; Kim, Hyunjin; Kim, Dae-gil; Song, Minho

    2015-07-01

    A fiber-optic epoxy cure monitoring technique for efficient wind turbine blade manufacturing and monitoring is presented. To optimize manufacturing cycle, fiber-optic sensors are embedded in composite materials of wind turbine blades. The reflection spectra of the sensors indicate the onset of gelification and the completion of epoxy curing. After manufacturing process, the same sensors are utilized for in-field condition monitoring. Because of residual stresses and strain gradients from the curing process, the embedded sensors may experience distortions in reflection spectra, resulting in measurement errors. We applied a Gaussian curve-fitting algorithm to the distorted spectra, which substantially improved the measurement accuracy.

  18. Channel polymer optical waveguides embedded in glass: Design, fabrication and characterization

    NASA Astrophysics Data System (ADS)

    Fernández Gavela, Adrián; García Granda, Miguel; Rodríguez García, José

    2015-09-01

    In this work, the design, fabrication and experimental evaluation of new channel polymer optical waveguides embedded in glass are reported. We show that high quality microchannels in glass, without roughness on the walls, make possible the fabrication of new channel optical waveguides by filling the microchannels with a polymer. Guided light through those new optical waveguides is demonstrated experimentally. The commercial software OlympIOs was used to design multimode and monomode channel polymer optical waveguides. The microchannels in glass substrate were fabricated by using a laser lithography system and wet-etching procedures. The spin-coating technique was applied to deposit the polymer inside the microchannels. The end-coupling method was implemented for the waveguides characterization. Theoretical and experimental results have confirmed light confinement as well as guided modes propagation by these new channel optical waveguides.

  19. Graph Embedding Techniques for Bounding Condition Numbers of Incomplete Factor Preconditioning

    NASA Technical Reports Server (NTRS)

    Guattery, Stephen

    1997-01-01

    We extend graph embedding techniques for bounding the spectral condition number of preconditioned systems involving symmetric, irreducibly diagonally dominant M-matrices to systems where the preconditioner is not diagonally dominant. In particular, this allows us to bound the spectral condition number when the preconditioner is based on an incomplete factorization. We provide a review of previous techniques, describe our extension, and give examples both of a bound for a model problem, and of ways in which our techniques give intuitive way of looking at incomplete factor preconditioners.

  20. 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

  1. Microwave oven-based technique for immunofluorescent staining of paraffin-embedded tissues

    PubMed Central

    Buggs, Colleen

    2011-01-01

    Immunohistochemical analysis of formalin-fixed paraffin-embedded tissues can be challenging due to potential modifications of protein structure by exposure to formalin. Heat-induced antigen retrieval techniques can reverse reactions between formalin and proteins that block antibody recognition. Interactions between antibodies and antigens are further enhanced by microwave irradiation, which has simplified immunohistochemical staining protocols. In this report, we modify a technique for antigen retrieval and immunofluorescent staining of formalin-fixed paraffin-embedded tissues by showing that it works well with several antibodies and buffers. This microwave-assisted method for antigen retrieval and immunofluorescent staining eliminates the need for blocking reagents and extended washes, which greatly simplifies the protocol allowing one to complete the analysis in less than 3 h. PMID:17653827

  2. Microwave oven-based technique for immunofluorescent staining of paraffin-embedded tissues.

    PubMed

    Long, Delwin J; Buggs, Colleen

    2008-02-01

    Immunohistochemical analysis of formalin-fixed paraffin-embedded tissues can be challenging due to potential modifications of protein structure by exposure to formalin. Heat-induced antigen retrieval techniques can reverse reactions between formalin and proteins that block antibody recognition. Interactions between antibodies and antigens are further enhanced by microwave irradiation, which has simplified immunohistochemical staining protocols. In this report, we modify a technique for antigen retrieval and immunofluorescent staining of formalin-fixed paraffin-embedded tissues by showing that it works well with several antibodies and buffers. This microwave-assisted method for antigen retrieval and immunofluorescent staining eliminates the need for blocking reagents and extended washes, which greatly simplifies the protocol allowing one to complete the analysis in less than 3 h.

  3. 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.

  4. A technique to evaluate the good operation of FBG sensors embedded in a carbon fiber beam

    NASA Astrophysics Data System (ADS)

    Cazzulani, Gabriele; Cinquemani, Simone; Comolli, Lorenzo

    2013-05-01

    Embedding FBG sensors in carbon fiber structures is a very attractive solution, due to the small fiber diameter, and the possibility to manufacture arrays of many gratings into a single optical fiber. These embedding is particularly useful for the manufacturing of smart structures, able to improve their characteristics thanks to embedded sensors and actuators. In this work a carbon fiber beam of 3 m length, with an array of 30 FBG sensors and 3 piezoelectric actuators, is described. The focus of the work is on the evaluation of the good operation of embedded FBG sensors, that is not easy due to the microstructure of woven carbon fiber layers, producing non-homogeneous strain field, a well known problem for the reliability of FBG strain measurements. The proposed technique looks at the standard deviation of the full width at -6 dB of the spectra of each FBG sensors, during a quasi-static motion producing quasi-static strains. 37% of the 30 FBG sensors have been found to produce measurements corrupted by a small error. At the end, vibration control of the described structure is shown.

  5. Atomic-scale characterization of embedded and supported nanostructures by scanning transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Ortalan, Volkan

    Dispersed metal/oxide particles in or on a support matrix are the key structures determining the properties of many scientifically and technologically important materials. Two widely used examples of them which were investigated in this thesis are embedded oxide precipitates in high temperature superconductors (HTS) and supported-metal clusters in heterogeneous catalysis. The superconductive properties of HTS depend on the flux pinning properties of the nanostructures embedded in the host matrix. With the same analogy, the catalytic properties of heterogeneous catalysts, such as the activity and selectivity, strongly depend on the structure parameters. The focus of this thesis is on developing STEM techniques for the characterization of embedded and supported nanostructures. To obtain three-dimensional information for the spatial and size distribution of the nanostructures embedded in the superconductor matrix material, STEM tomography was employed. The effect of various image-processing techniques on the visibility of tomographic reconstructions was investigated. The distribution uniformity, position and size of the particles were observed to be dependent on the interaction of the particles with the twin boundaries. It was observed that the larger particles are generally located on more than one twin boundary, moreover, the particle size is smaller on the twin boundaries shared by several particles. This suggests that the growth of the particles is determined by fast twin boundary diffusion and the formation of the large particles might be prevented by altering the temperature-time parameters of the production processing. Zeolites are prototypical crystalline nanoporous materials that provide supports for transition-metal cations for catalytic applications. As a part of this thesis, aberration-corrected STEM under low-dose imaging conditions was used to image and determine the locations of metal nanoclusters and individual metal atoms within the intra

  6. A comparison of two embedded programming techniques for high rep rate coherent Doppler lidars

    NASA Astrophysics Data System (ADS)

    Arend, Mark F.; Abdelazim, Sameh; Lopez, Miguel; Moshary, Fred

    2013-05-01

    Two FPGA embedded programming approaches are considered and compared for a 20 kHz pulse repetition rate coherent Doppler lidar system which acquires return signals at 400 Msamples/second and operates with signal to noise ratios as low as -20 dB. In the first approach, the acquired return signal is gated in time and the square modulus of the fast Fourier transform is accumulated for each of the range gates, producing a series of power spectra as a function of range. Wind speed decisions based on numerical estimators can then be made after transferring the range gated accumulated power spectra to a host computer, enabling the line of sight wind speed as a function of range gate to be calculated and stored for additional processing. In the second FPGA approach, a digital IQ demodulator and down sampler reduces the data flow requirements so that an autocorrelation matrix representing a pre-selected number of lags can be accumulated, allowing for the process of range gating to be explored on the host computer. The added feature of the second approach is that it allows for an additional capability to adjust the range gate period dynamically as the state of the atmospheric boundary layer (e.g. backscatter coefficient and stability condition) changes. A simple manual beam scanning technique is used to calculate the wind field vector which is graphically displayed on time-height cross section plots. A comparison to other observed and modeled information is presented suggesting the usefulness for the characterization of microscale meteorology.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  8. Characterization of GaAs monolithic circuits by optical techniques

    NASA Astrophysics Data System (ADS)

    Hung, H.-L. A.; Lee, T. T.; Polak-Dingels, P.; Chauchard, E.; Webb, K.

    1989-09-01

    Optical techniques for broadband microwave signal generation and detection have been developed to characterize monolithic microwave integrated circuits (MMICs). Emphasis is on the enhancement of measurement accuracy and the identification of limitations. De-embedded complex S-parameters are derived from time-domain data obtained from both a GaAs photoconductive switch and electro-optic sampling of a Ka-band MMIC power amplifier. These parameters are directly compared with those measured from a network analyzer of the same circuit.

  9. Use of APAAP technique on paraffin wax embedded bone marrow trephines.

    PubMed Central

    Erber, W N; McLachlan, J

    1989-01-01

    The immunoalkaline phosphatase (APAAP) technique was applied to the labelling of decalcified sections of formalin fixed, paraffin wax embedded bone marrow trephine biopsy specimens. A panel of monoclonal antibodies reactive with haemopoietic and epithelial antigens, which survive routine formalin fixation, was assessed on 72 cases of haematological malignancy (including acute and chronic leukaemias and lymphomas) showing bone marrow infiltration. The APAAP method showed clear distinct labelling of antigen positive cells without loss of antigens due to decalcification. Both normal or reactive single cells present in the sample and neoplastic cell populations could be identified morphologically and their antigenic phenotype and cellular origin, whether lymphoid or myeloid, established. The application of the APAAP method to routinely prepared paraffin wax embedded trephines has many advantages over the assessment of specially prepared cryostat sections of bone marrow. Images PMID:2685054

  10. New technique of skin embedded wire double-sided laser beam welding

    NASA Astrophysics Data System (ADS)

    Han, Bing; Tao, Wang; Chen, Yanbin

    2017-06-01

    In the aircraft industry, double-sided laser beam welding is an approved method for producing skin-stringer T-joints on aircraft fuselage panels. As for the welding of new generation aluminum-lithium alloys, however, this technique is limited because of high hot cracking susceptibility and strengthening elements' uneven distributions within weld. In the present study, a new technique of skin embedded wire double-sided laser beam welding (LBW) has been developed to fabricate T-joints consisting of 2.0 mm thick 2060-T8/2099-T83 aluminum-lithium alloys using eutectic alloy AA4047 filler wire. Necessary dimension parameters of the novel groove were reasonably designed for achieving crack-free welds. Comparisons were made between the new technique welded T-joint and conventional T-joint mainly on microstructure, hot crack, elements distribution features and mechanical properties within weld. Excellent crack-free microstructure, uniform distribution of silicon and superior tensile properties within weld were found in the new skin embedded wire double-sided LBW T-joints.

  11. 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.

  12. New approach for structural characterization of planar sets of nanoparticles embedded into a solid matrix

    NASA Astrophysics Data System (ADS)

    Sanchez, Dario F.; Marmitt, Gabriel; Marin, Cristiane; Baptista, Daniel L.; de M. Azevedo, Gustavo; Grande, Pedro L.; Fichtner, Paulo F. P.

    2013-12-01

    In this work we demonstrate that Medium Energy Ion Scattering (MEIS) measurements in combination with Transmission Electron Microscopy (TEM) or Grazing Incidence Small Angle X-Ray Scattering (GISAXS) can provide a complete characterization of nanoparticle (NP) systems embedded into dielectric films. This includes the determination of the nanoparticle characteristics (location, size distribution and number concentration) as well as the depth distribution and concentration of the NP atomic components dispersed in the matrix. Our studies are performed considering a model case system consisting of planar arrangements of Au NPs (size range from 1 to 10 nm) containing three distinct Au concentrations embedded in a SiO2 film.

  13. Virus characterization and discovery in formalin-fixed paraffin-embedded tissues.

    PubMed

    Bodewes, Rogier; van Run, Peter R W A; Schürch, Anita C; Koopmans, Marion P G; Osterhaus, Albert D M E; Baumgärtner, Wolfgang; Kuiken, Thijs; Smits, Saskia L

    2015-03-01

    Detection and characterization of novel viruses is hampered frequently by the lack of properly stored materials. Especially for the retrospective identification of viruses responsible for past disease outbreaks, often only formalin-fixed paraffin-embedded (FFPE) tissue samples are available. Although FFPE tissues can be used to detect known viral sequences, the application of FFPE tissues for detection of novel viruses is currently unclear. In the present study it was shown that sequence-independent amplification in combination with next-generation sequencing can be used to detect sequences of known and unknown viruses, although with relatively low sensitivity. These findings indicate that this technique could be useful for detecting novel viral sequences in FFPE tissues collected from humans and animals with disease of unknown origin, when other samples are not available. In addition, application of this method to FFPE tissues allows to correlate with the presence of histopathological changes in the corresponding tissue sections. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Immersion liquid techniques in solid particle characterization: A review.

    PubMed

    Niskanen, Ilpo; Hibino, Kenichi; Räty, Jukka

    2016-03-01

    Chemical, physical and optical properties of small solid particles are widely utilized in our everyday merchandises. For example, tailored particles embedded in paper or cosmetics improve the visual appearance of the products substantially. As a consequence of the small size of particles, one particle characterization tool is a microscope. It may provide e.g. the particle size, shape and the refractive index. The determination of the refractive index, using the microscope, typically exploited the so-called immersion liquid method. In this review, we provide an overview of non-imaging immersion matching techniques including immersion liquid set, the temperature, the wavelength, the double variation and the liquid evaporation methods. The basic features, benefits and limitations of each technique have been described followed by examples of potential applications in a quality monitoring of particle suspensions and colloids in industry. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  15. Modeling and characterization of embedded electrode performance in transverse electrooptic modulators.

    PubMed

    Title, M A; Lee, S H

    1990-01-01

    A mathematical model with experimental verification is presented to characterize the performance of surface and embedded electrodes in 2-D electrooptic modulators. From the solution of a discretized integral equation for the electrode surface charge, the electrode capacitance and the electric field penetration and uniformity are related to the switching voltage, speed, and uniformity of the electrooptic modulation. Fabricated surface and embedded electrodes in 9/65/35 PLZT are then evaluated with respect to the predictions of the model and the saturated quadratic response of the electrooptic material. These results provide important insight into the design trade-offs of switching speed, halfwave voltage, switching energy, and modulation uniformity of surface and embedded modulator geometries.

  16. Characterization of embedded fiber optic strain sensors into metallic structures via ultrasonic additive manufacturing

    NASA Astrophysics Data System (ADS)

    Schomer, John J.; Hehr, Adam J.; Dapino, Marcelo J.

    2016-04-01

    Fiber Bragg Grating (FBG) sensors measure deviation in a reflected wavelength of light to detect in-situ strain. These sensors are immune to electromagnetic interference, and the inclusion of multiple FBGs on the same fiber allows for a seamlessly integrated sensing network. FBGs are attractive for embedded sensing in aerospace applications due to their small noninvasive size and prospect of constant, real-time nondestructive evaluation. In this study, FBG sensors are embedded in aluminum 6061 via ultrasonic additive manufacturing (UAM), a rapid prototyping process that uses high power ultrasonic vibrations to weld similar and dissimilar metal foils together. UAM was chosen due to the desire to embed FBG sensors at low temperatures, a requirement that excludes other additive processes such as selective laser sintering or fusion deposition modeling. In this paper, the embedded FBGs are characterized in terms of birefringence losses, post embedding strain shifts, consolidation quality, and strain sensing performance. Sensors embedded into an ASTM test piece are compared against an exterior surface mounted foil strain gage at both room and elevated temperatures using cyclic tensile tests.

  17. Composite Characterization Using Ultrasonic Wavefield Techniques

    NASA Technical Reports Server (NTRS)

    Leckey, Cara A. C.; Juarez, Peter D.; Seebo, Jeffrey P.

    2016-01-01

    The large-scale use of composite components in aerospace applications is expected to continue due to the benefits of composite materials, such as reduced weight, increased strength, and tailorability. NASA's Advanced Composites Project (ACP) has the goals of reducing the timeline for certification of composite materials and enabling the expanded use of advanced composite materials. A key technical challenge area for accomplishing these goals is the need for nondestructive evaluation and materials characterization techniques that are optimized for rapid inspection and detailed defect/damage characterization in composite materials. This presentation will discuss ongoing research investigating the use of ultrasonic wavefield techniques for the characterization of defects such as fiber waviness and delamination damage. Ongoing work includes the development of realistic ultrasonic simulation tools for use in predicting the inspectability of composites and optimizing inspection methodologies. Recent studies on detecting/characterizing delamination damage and fiber waviness via wavefield methods will be described.

  18. Revisiting fixation and embedding techniques for optimal detection of dendritic cell subsets in tissues.

    PubMed

    Accart, Nathalie; Sergi, Florinda; Rooke, Ronald

    2014-09-01

    Organ-specific cell types are maintained by tissue homeostasis and may vary in nature and/or frequency in pathological situations. Moreover, within a cell lineage, some sub-populations, defined by combinations of cell-surface markers, may have specific functions. Dendritic cells are the epitome of such a population as they may be subdivided into discrete sub-groups with defined functions in specific compartments of various organs. Technically, to study the distribution of DC sub-populations, it involves performing multiparametric immunofluorescence on well-conserved organ structures. However, immunodetection may be impacted by protein cross-linking and antigenic epitope masking by the use of 10% neutral-buffered formalin. To circumvent this and to preserve a good morphological tissue structure, we evaluated alternative fixatives such as Periodate Lysine Paraformaldehyde or Tris Zinc fixatives in combination with other embedding techniques. The cryosection protocols were adapted for optimal antigen detection but offered a poor morphological preservation. We therefore developed a new methodology based on Tris Zinc fixative, gelatin-sucrose embedding and freezing. Using multiple DC markers, we demonstrate that this treatment is an optimal protocol for cell-surface marker detection on high-quality tissue sections. © The Author(s) 2014.

  19. 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.

  20. Optical characterization of core-shell quantum dots embedded in synthetic saliva: Temporal dynamics.

    PubMed

    de Santana, Juliana F; Pilla, Viviane; Silva, Anielle C A; Dantas, Noelio O; Messias, Djalmir N; Andrade, Acácio A

    2015-10-01

    The present work reports the spectroscopic and thermo-optical properties of CdSe/ZnS and CdSe/CdS core-shell quantum dots (QDs) embedded in synthetic saliva. Spectroscopy studies were performed applying nonfunctionalized CdSe/ZnS QDs (3.4, 3.9 and 5.1 nm cores) and hydroxyl group-functionalized ultrasmall CdSe/CdS core-shell quantum dots (1.6 nm core) suspended in artificial saliva at different potential of hydrogen (pH) values. Saliva was chosen because it is important in a variety of functions such as protecting teeth through the buffering capacity of the formed biofilm, hydration, and dental remineralization. Thermo-optical characterizations using the thermal lens (TL) technique were performed in QD-biofluids for different QD sizes and pH values (3.9-8.3) of the synthetic oral fluids. Transient TL measurements were applied to determine the fluorescence quantum efficiency (η) in QD-biomaterial systems. High η value was obtained for ultrasmall CdSe/CdS QDs. Fluorescence spectral measurements of the biomaterials support the TL results. In addition, for nonfunctionalized (3.4 and 5.1 nm) and hydroxyl group-functionalized QDs, the temporal behavior of the fluorescence spectra was accomplished about approximately 1200 h at two different biofluid pH values (3.9 and 8.3). The temporal fluorescence intensity result is dependent on the pH of the saliva in which the QDs were embedded, QD functionalization and QD sizes. The time for an approximately 50% decrease in the peak intensity fluorescence of CdSe/ZnS QDs (3.4 nm core) and ultrasmall CdSe/CdS QDs is respectively 25 h and 312 h at pH 3.9 and 48 h and 360 h at pH 8.3. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Blind image watermarking technique based on differential embedding in DWT and DCT domains

    NASA Astrophysics Data System (ADS)

    Benoraira, Ali; Benmahammed, Khier; Boucenna, Noureddine

    2015-12-01

    This paper presents a new blind and robust image watermarking scheme based on discrete wavelet transform (DWT) and discrete cosine transform (DCT). Two DCT-transformed sub-vectors are used to embed the bits of the watermark sequence in a differential manner. The original sub-vectors are obtained by the sub-sampling of the approximation coefficients of the DWT transform of the host image. During the extraction stage, the simple difference between the corresponding sub-vectors of the watermarked image, gives directly the embedded watermark sequence. Experimental results demonstrate that the proposed technique successfully fulfills the requirement of imperceptibility and provides high robustness against a number of image-processing attacks, such as JPEG compression, noise adding, low-pass filtering, sharpening, and bit-plane removal. Our scheme exhibits also an acceptable to good performance against some geometrical attacks such as resizing and cropping.

  2. Evaluation of Advanced Signal Processing Techniques to Improve Detection and Identification of Embedded Defects

    SciTech Connect

    Clayton, Dwight A.; Santos-Villalobos, Hector J.; Baba, Justin S.

    2016-09-01

    By the end of 1996, 109 Nuclear Power Plants were operating in the United States, producing 22% of the Nation’s electricity [1]. At present, more than two thirds of these power plants are more than 40 years old. The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [2]. The most important safety structures in an NPP are constructed of concrete. The structures generally do not allow for destructive evaluation and access is limited to one side of the concrete element. Therefore, there is a need for techniques and technologies that can assess the internal health of complex, reinforced concrete structures nondestructively. Previously, we documented the challenges associated with Non-Destructive Evaluation (NDE) of thick, reinforced concrete sections and prioritized conceptual designs of specimens that could be fabricated to represent NPP concrete structures [3]. Consequently, a 7 feet tall, by 7 feet wide, by 3 feet and 4-inch-thick concrete specimen was constructed with 2.257-inch-and 1-inch-diameter rebar every 6 to 12 inches. In addition, defects were embedded the specimen to assess the performance of existing and future NDE techniques. The defects were designed to give a mix of realistic and controlled defects for assessment of the necessary measures needed to overcome the challenges with more heavily reinforced concrete structures. Information on the embedded defects is documented in [4]. We also documented the superiority of Frequency Banded Decomposition (FBD) Synthetic Aperture Focusing Technique (SAFT) over conventional SAFT when probing defects under deep concrete cover. Improvements include seeing an intensity corresponding to a defect that is either not visible at all in regular, full frequency content SAFT

  3. Preparation and characterization of Ag nanoparticle-embedded blank and ligand-anchored silica gels.

    PubMed

    Im, Hee-Jung; Lee, Byung Cheol; Yeon, Jei-Won

    2013-11-01

    Ag nanoparticles, used for halogen (especially iodine) adsorption and an evaluation of halogen behavior, were embedded in synthesized inorganic-organic hybrid gels. In particular, an irradiation method using an electron beam plays a part in introducing Ag nanoparticles to the organofunctionalized silica gels from AgNO3 solutions in a simple way at atmospheric pressure and room temperature. For preparation of the Ag nanoparticle-embedded inorganic-organic hybrid gels, ligands of ethylenediamine (NH2CH2CH2NH-, TMSen) and mercapto (HS-) functionalized three-dimensional porous SiO2 sol-gels were first synthesized through hydrolysis and condensation reactions, and Ag nanoparticles were then embedded into the ethylenediamine- and mercapto-anchored silica gels each, through electron-beam irradiation. The addition of ligands yielded larger average pore sizes than the absence of any ligand. Moreover, the ethylenediamine ligand led to looser structures and better access of the Ag nanoparticles to the ethylenediamine-anchored gel. As a result, more Ag nanoparticles were introduced into the ethylenediamine-anchored gel. The preparation and characterization of Ag nanoparticle-embedded blank and ligand-anchored silica gels are discussed in detail.

  4. Subsurface Synthesis and Characterization of Ag Nanoparticles Embedded in MgO

    SciTech Connect

    Vilayur Ganapathy, Subramanian; Devaraj, Arun; Colby, Robert J.; Pandey, Archana; Varga, Tamas; Shutthanandan, V.; Manandhar, Sandeep; El-Khoury, Patrick Z.; Kayani, Asghar N.; Hess, Wayne P.; Thevuthasan, Suntharampillai

    2013-03-08

    Metal nanoparticles exhibit localized surface plasmon resonance (LSPR) which is very sensitive to the size and shape of the nanoparticle and the dielectric medium surrounding it. LSPR causes field enhancement near the surface of the nanoparticle making them interesting candidates for plasmonic applications. In particular, partially exposed metallic nanoparticles distributed in a dielectric matrix form hotspots which are prime locations for LSPR spectroscopy and sensing. This study involves synthesizing partially buried Ag nanoparticles in MgO and investigating the characteristics of this material system. Ag nanoparticles of different shapes and size distributions were synthesized below the surface of MgO by implanting 200 keV Ag+ ions followed by annealing at 10000C for 10 and 30 hours. A detailed optical and structural characterization was carried out to understand the evolution of Ag nanoparticle microstructure and size distribution inside the MgO matrix. Micro x-ray diffraction (MicroXRD) was employed to investigate the structural properties and estimate the crystallite size. The nanoparticles evolved from a spherical to faceted morphology with annealing time, assuming an octahedral shape truncated at the (001) planes as seen from aberration corrected transmission electron microscopy (TEM) images. The nanoparticles embedded in MgO were shown to be pure metallic Ag using atom probe tomography (APT). The nanoparticles were partially exposed to the surface employing plasma etch techniques to remove the overlaying MgO. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology and obtain a height distribution for the partially exposed nanoparticles.

  5. Fabrication and characterization of polymer gel for MRI phantom with embedded lesion particles

    NASA Astrophysics Data System (ADS)

    In, Eunji; Naguib, Hani E.; Haider, Masoom

    2012-04-01

    Magnetic Resonance Imaging (MRI) is a medical imaging technique used in radiology to visualize the detailed internal structure and body soft tissues in complete 3D image. MRI performs best when optimal imaging parameters such as contrast, signal to noise ratio (SNR), spatial resolution and total scan time are utilized. However, due to a variety of imaging parameters that differ with the manufacturer, a calibration medium that allows the control of these parameters is necessary. Therefore, a phantom that behaves similar to human soft tissue is developed to replace a real human. Polymer gel is novel material that has great potential in the medical imaging. Since very few have focused on examining the behavior of polymer lesions, the motivation of this study is to develop a polymer gel phantom, especially for liver, with embedded lesions. Both the phantom and lesions should be capable of reflecting T1 and T2 relaxation values through various characterization processes. In this paper, phantom and lesion particles were fabricated with carrageenan as a gelling agent by physical aggregation. Agar was used as supplementary gelling agent and T2 modifier and Gd-DTPA as T1 modifier. The polymer gel samples were fabricated by varying the concentrations of the gelling agent, and T1 and T2 modifiers. The lesion particles were obtained by extracting molten polymer gel solution in chilled oil bath to obtain spherical shape. The polymer gel properties including density, elastic modulus, dielectric constant and optical properties were measured to compare with human tissue values for long period of time.

  6. Minimally Invasive Muscle Embedding (MIME) - A Novel Experimental Technique to Facilitate Donor-Cell-Mediated Myogenesis.

    PubMed

    Roche, Joseph A; Begam, Morium; Galen, Sujay S

    2017-08-24

    Skeletal muscle possesses regenerative capacity due to tissue-resident, muscle-fiber-generating (myogenic) satellite cells (SCs), which can form new muscle fibers under the right conditions. Although SCs can be harvested from muscle tissue and cultured in vitro, the resulting myoblast cells are not very effective in promoting myogenesis when transplanted into host muscle. Surgically exposing the host muscle and grafting segments of donor muscle tissue, or the isolated muscle fibers with their SCs onto host muscle, promotes better myogenesis compared to myoblast transplantation. We have developed a novel technique that we call Minimally Invasive Muscle Embedding (MIME). MIME involves passing a surgical needle through the host muscle, drawing a piece of donor muscle tissue through the needle track, and then leaving the donor tissue embedded in the host muscle so that it may act as a source of SCs for the host muscle. Here we describe in detail the steps involved in performing MIME in an immunodeficient mouse model that expresses a green fluorescent protein (GFP) in all of its cells. Immunodeficiency in the host mouse reduces the risk of immune rejection of the donor tissue, and GFP expression enables easy identification of the host muscle fibers (GFP+) and donor-cell-derived muscle fibers (GFP-). Our pilot data suggest that MIME can be used to implant an extensor digitorum longus (EDL) muscle from a donor mouse into the tibialis anterior (TA) muscle of a host mouse. Our data also suggest that when a myotoxin (barium chloride, BaCl2) is injected into the host muscle after MIME, there is evidence of donor-cell-derived myogenesis in the host muscle, with approximately 5%, 26%, 26% and 43% of the fibers in a single host TA muscle showing no host contribution, minimal host contribution, moderate host contribution, and maximal host contribution, respectively.

  7. Retrieval of Tip-embedded Inferior Vena Cava Filters by Using the Endobronchial Forceps Technique: Experience at a Single Institution.

    PubMed

    Stavropoulos, S William; Ge, Benjamin H; Mondschein, Jeffrey I; Shlansky-Goldberg, Richard D; Sudheendra, Deepak; Trerotola, Scott O

    2015-06-01

    To evaluate the use of endobronchial forceps to retrieve tip-embedded inferior vena cava (IVC) filters. This institutional review board-approved, HIPAA-compliant retrospective study included 114 patients who presented with tip-embedded IVC filters for removal from January 2005 to April 2014. The included patients consisted of 77 women and 37 men with a mean age of 43 years (range, 18-79 years). Filters were identified as tip embedded by using rotational venography. Rigid bronchoscopy forceps were used to dissect the tip or hook of the filter from the wall of the IVC. The filter was then removed through the sheath by using the endobronchial forceps. Statistical analysis entailed calculating percentages, ranges, and means. The endobronchial forceps technique was used to successfully retrieve 109 of 114 (96%) tip-embedded IVC filters on an intention-to-treat basis. Five failures occurred in four patients in whom the technique was attempted but failed and one patient in whom retrieval was not attempted. Filters were in place for a mean of 465 days (range, 31-2976 days). The filters in this study included 10 Recovery, 33 G2, eight G2X, 11 Eclipse, one OptEase, six Option, 13 Günther Tulip, one ALN, and 31 Celect filters. Three minor complications and one major complication occurred, with no permanent sequelae. The endobronchial forceps technique can be safely used to remove tip-embedded IVC filters. © RSNA, 2014.

  8. Analytical techniques for characterizing enzymatic biofuel cells.

    PubMed

    Moehlenbrock, Michael J; Arechederra, Robert L; Sjöholm, Kyle H; Minteer, Shelley D

    2009-12-01

    Enzymatic biofuel cells, which replace expensive metal catalysts with enzymes, are still in an early stage of development. This article details the analytical techniques that are often employed for evaluating and characterizing enzymatic biofuel cells and their corresponding bioanodes and biocathodes. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

  9. New characterization techniques for LSST sensors

    DOE PAGES

    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.

  10. New characterization techniques for LSST sensors

    SciTech Connect

    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.

  11. In-situ health monitoring technique for composite structures utilizing embedded thermal fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Stewart, Anna Kristina

    Health monitoring techniques are necessary for the safety, reliability and longevity of structural components. However, dependable, in-situ, and practical damage detection methods are difficult to develop and implement. In this dissertation, a novel health monitoring technique based on thermography that uses optical fiber thermal sensors to detect damage within a laminated graphite epoxy composite specimen is investigated. The concept follows: when an internal defect exists inside a composite panel and an external heat flux is applied, the defect can hinder the heat from propagating through the panel. Consequently, thermal sensors placed near the defect measure a temperature change when compared to a defect-free panel. Fiber optic sensors are permanently embedded within a structure to allow for direct temperature measurement and an in-situ health monitoring technique. Fiber optic sensors are advantageous primarily due to their multiplexing capabilities. Certain fiber optic technologies permit 1000 point sensors on a single fiber, which in turn reduces the cabling sizes by three orders of magnitude. A comprehensive proof-of-concept study involved five sets of composite samples and a numerical model. The first set validated the concept, the second tested two types of fiber optic sensors, the third provided a thorough study using the superior sensor technology, the fourth provided data to develop a numerical model, and the last set validated the model's findings. The numerical model provided a close approximation to the experimental data, and was used to determine proper sensor placement. The first three sets of specimens used a simulated impact system to induce damage of varying degrees into the samples. The last two sets used artificial damage in the form of Teflon inserts in an effort to quantify the size and location of damage. A flash lamp apparatus rapidly heated the samples while the fiber optic sensors and exterior thermocouples recorded temperature changes

  12. Embedding fistulojejunostomy: An easy and secure technique for refractory external pancreatic fistula.

    PubMed

    Luo, Shao-Ciao; Cheng, Shao-Bin; Wu, Cheng-Chung; Huang, Chu-Chun; Lin, Yi-Ling; P'eng, Fang-Ku

    2016-11-02

    Refractory external pancreatic fistula (REPF) is a rare but troublesome event. Fistulojejunostomy with direct suture of the fistula wall to jejunal wall has been demonstrated as a solution. However, it is sometimes technically difficult and some cases of failure were reported. An embedding fistulojejunostomy (EFJ) was designed. The fistula tract was detached from the abdominal wall and impactedly inserted into a Roux-en-Y jejunal lumen without direct suture of the fistula wall to the jejunal wall. Five patients with REPF for > 3 months underwent this procedure in the past 10 years. The preoperatively-placed drainage tubes temporarily exteriorized the pancreatic fluid for 30 days. All fistulojejunostomy procedures were accomplished within 15 minutes. Four patients had uneventful recovery with a postoperative hospital stay ≤ 10 days. One patient had wound infection and needed hospitalization for 23 days. Except for one patient who required pancreatic enzyme supplements for 8 months, no other patient had pancreatic exocrine insufficiency. After follow up for 12-124 months, no patient required pancreatic enzyme supplements, and no patient had recurrent fistula or diabetes mellitus. EFJ makes fistulojejunostomy easier and more secure with a satisfactory early and long-term outcome. It may be a desirable technique for REPF. Copyright © 2016. Published by Elsevier Taiwan.

  13. 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.

  14. Polarization characterization of PZT disks and of embedded PZT plates by thermal wave methods

    SciTech Connect

    Eydam, Agnes Suchaneck, Gunnar Gerlach, Gerald; Esslinger, Sophia; Schönecker, Andreas; Neumeister, Peter

    2014-11-05

    In this work, the thermal wave method was applied to characterize PZT disks and embedded PZT plates with regard to the polarization magnitude and spatial homogeneity. The samples were exposed to periodic heating by means of a laser beam and the pyroelectric response was determined. Thermal relaxation times (single time constants or distributions of time constants) describe the heat losses of the PZT samples to the environment. The resulting pyroelectric current spectrum was fitted to the superposition of thermal relaxation processes. The pyroelectric coefficient gives insight in the polarization distribution. For PZT disks, the polarization distribution in the surface region showed a characteristic decrease towards the electrodes.

  15. Deterministic embedding of a single gold nanoparticle into polymeric microstructures by direct laser writing technique

    NASA Astrophysics Data System (ADS)

    Nguyen, Dam Thuy Trang; Pelissier, Aurélien; Montes, Kevin; Tong, Quang Cong; Ngo, Hoang Minh; Ledoux-Rak, Isabelle; Lai, Ngoc Diep

    2016-04-01

    We have precisely positioned and embedded a single gold nanoparticle (Au NP) into a desired polymeric photonic structure (PS) using a simple and low-cost technique called low one-photon absorption direct laser writing (LOPA DLW), with a two-step process: identification and fabrication. First, the position of the Au NP was identified with a precision of 20 nm by using DLW technique with ultralow excitation laser power (μW). This power did not induce the polymerization of the photoresist (SU8) due to its low absorption at the excitation wavelength (532 nm). Then, the structure containing the NP was fabricated by using the same DLW system with high excitation power (mW). Different 2D photonic structures have been fabricated, which contain a single Au NP at desired position. In particular, we obtained a microsphere instead of a micropillar at the position of the Au NP. The formation of such microsphere was explained by the thermal effect of the Au NP at the wavelength of 532 nm, which induced thermal polymerization of surrounding photoresist. The effect of the post-exposure bake on the quality of structures was taken into account, revealing a more efficient fabrication way by exploiting the local thermal effect of the laser. We studied further the influence of the NP size on the NP/PS coupling by investigating the fabrication and fluorescence measurement of Au NPs of different sizes: 10, 30, 50, 80, and 100 nm. The photon collection enhancements in each case were 12.9 +/- 2.5, 12.6 +/- 5.6, 3.9 +/- 2.7, 5.9 +/- 4.4, and 6.6 +/- 5.1 times, respectively. The gain in fluorescence could reach up to 36.6 times for 10-nm gold NPs.

  16. Compton back scatter imaging for mild steel rebar detection and depth characterization embedded in concrete

    NASA Astrophysics Data System (ADS)

    Margret, M.; Menaka, M.; Venkatraman, B.; Chandrasekaran, S.

    2015-01-01

    A novel non-destructive Compton scattering technique is described to ensure the feasibility, reliability and applicability of detecting the reinforcing steel bar in concrete. The indigenously developed prototype system presented in this paper is capable of detecting the reinforcement of varied diameters embedded in the concrete and as well as up to 60 mm depth, with the aid of Caesium-137(137Cs) radioactive source and a high resolution HPGe detector. The technique could also detect the inhomogeneities present in the test specimen by interpreting the material density variation caused due to the count rate. The experimental results are correlated using established techniques such as radiography and rebar locators. The results obtained from its application to locate the rebars are quite promising and also been successfully used for reinforcement mapping. This method can be applied, especially when the intrusion is located underneath the cover of the concrete or considerably at larger depths and where two sided access is restricted.

  17. 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

  18. 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.

  19. 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.

  20. Surface characterization of InP trenches embedded in oxide using scanning probe microscopy

    SciTech Connect

    Mannarino, Manuel E-mail: manuelmannarino@gmail.com; Chintala, Ravi; Vandervorst, Wilfried; Moussa, Alain; Merckling, Clement; Eyben, Pierre; Paredis, Kristof

    2015-12-14

    Metrology for structural and electrical analyses at device level has been identified as one of the major challenges to be resolved for the sub-14 nm technology nodes. In these advanced nodes, new high mobility semiconductors, such as III–V compounds, are grown in narrow trenches on a Si substrate. Probing the nature of the defects, the defect density, and the role of processing steps on the surface of such structures are prime metrology requirements. In order to enable defect analysis on a (III–V) surface, a proper sample preparation for oxide removal is of primary importance. In this work, the effectiveness of different chemical cleanings and thermal annealing procedures is investigated on both blanket InP and oxide embedded InP trenches by means of scanning probe microscopy techniques. It is found that the most effective approach is a combination of an HCl-based chemical cleaning combined with a low-temperature thermal annealing leading to an oxide free surface with atomically flat areas. Scanning tunneling microscopy (STM) has been the preferred method for such investigations on blanket films due to its intrinsic sub-nm spatial resolution. However, its application on oxide embedded structures is non-trivial. To perform STM on the trenches of interest (generally <20 nm wide), we propose a combination of non-contact atomic force microscopy and STM using the same conductive atomic force microscopy tip Our results prove that with these procedures, it is possible to perform STM in narrow InP trenches showing stacking faults and surface reconstruction. Significant differences in terms of roughness and terrace formation are also observed between the blanket and the oxide embedded InP.

  1. Surface characterization of InP trenches embedded in oxide using scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Mannarino, Manuel; Chintala, Ravi; Moussa, Alain; Merckling, Clement; Eyben, Pierre; Paredis, Kristof; Vandervorst, Wilfried

    2015-12-01

    Metrology for structural and electrical analyses at device level has been identified as one of the major challenges to be resolved for the sub-14 nm technology nodes. In these advanced nodes, new high mobility semiconductors, such as III-V compounds, are grown in narrow trenches on a Si substrate. Probing the nature of the defects, the defect density, and the role of processing steps on the surface of such structures are prime metrology requirements. In order to enable defect analysis on a (III-V) surface, a proper sample preparation for oxide removal is of primary importance. In this work, the effectiveness of different chemical cleanings and thermal annealing procedures is investigated on both blanket InP and oxide embedded InP trenches by means of scanning probe microscopy techniques. It is found that the most effective approach is a combination of an HCl-based chemical cleaning combined with a low-temperature thermal annealing leading to an oxide free surface with atomically flat areas. Scanning tunneling microscopy (STM) has been the preferred method for such investigations on blanket films due to its intrinsic sub-nm spatial resolution. However, its application on oxide embedded structures is non-trivial. To perform STM on the trenches of interest (generally <20 nm wide), we propose a combination of non-contact atomic force microscopy and STM using the same conductive atomic force microscopy tip Our results prove that with these procedures, it is possible to perform STM in narrow InP trenches showing stacking faults and surface reconstruction. Significant differences in terms of roughness and terrace formation are also observed between the blanket and the oxide embedded InP.

  2. Characterization and analysis of carbon fibre-reinforced polymer composite laminates with embedded circular vasculature

    PubMed Central

    Huang, C.-Y.; Trask, R. S.; Bond, I. P.

    2010-01-01

    A study of the influence of embedded circular hollow vascules on structural performance of a fibre-reinforced polymer (FRP) composite laminate is presented. Incorporating such vascules will lead to multi-functional composites by bestowing functions such as self-healing and active thermal management. However, the presence of off-axis vascules leads to localized disruption to the fibre architecture, i.e. resin-rich pockets, which are regarded as internal defects and may cause stress concentrations within the structure. Engineering approaches for creating these simple vascule geometries in conventional FRP laminates are proposed and demonstrated. This study includes development of a manufacturing method for forming vascules, microscopic characterization of their effect on the laminate, finite element (FE) analysis of crack initiation and failure under load, and validation of the FE results via mechanical testing observed using high-speed photography. The failure behaviour predicted by FE modelling is in good agreement with experimental results. The reduction in compressive strength owing to the embedding of circular vascules ranges from 13 to 70 per cent, which correlates with vascule dimension. PMID:20150337

  3. Phenotypic characterization of collagen gel embedded primary human breast epithelial cells in athymic nude mice.

    PubMed

    Yang, J; Guzman, R C; Popnikolov, N; Bandyopadhyay, G K; Christov, K; Collins, G; Nandi, S

    1994-06-30

    We have developed a method to characterize the phenotypes and tumorigenicity of dissociated human breast epithelial cells. The dissociated cells were first embedded in collagen gels and subsequently transplanted subcutaneously in vivo in athymic nude mice. The transplantation of dissociated epithelial cells from reduction mammoplasties, presumed to be normal, always resulted in normal histomorphology. Epithelial cells were arranged as short tubular structures consisting of lumina surrounded by epithelial cells with an occasional more complex branching structure. These outgrowths were surrounded by intact basement membrane and were embedded in collagen gel that, at termination, contained collagenous stroma with fibroblasts and blood vessels. In contrast, transplantation of dissociated breast epithelial cells from breast cancer specimens resulted in outgrowths with an invasive pattern infiltrating the collagen gel as well as frank invasion into vascular space, nerves and muscles. These observations were made long before the subsequent palpable stage which resulted if left in the mouse for a long enough time. The dissociated human breast epithelial cells thus retained their intrinsic property to undergo morphogenesis to reflect their original phenotype when placed in a suitable environment, the collagen gel.

  4. Characterization and analysis of carbon fibre-reinforced polymer composite laminates with embedded circular vasculature.

    PubMed

    Huang, C-Y; Trask, R S; Bond, I P

    2010-08-06

    A study of the influence of embedded circular hollow vascules on structural performance of a fibre-reinforced polymer (FRP) composite laminate is presented. Incorporating such vascules will lead to multi-functional composites by bestowing functions such as self-healing and active thermal management. However, the presence of off-axis vascules leads to localized disruption to the fibre architecture, i.e. resin-rich pockets, which are regarded as internal defects and may cause stress concentrations within the structure. Engineering approaches for creating these simple vascule geometries in conventional FRP laminates are proposed and demonstrated. This study includes development of a manufacturing method for forming vascules, microscopic characterization of their effect on the laminate, finite element (FE) analysis of crack initiation and failure under load, and validation of the FE results via mechanical testing observed using high-speed photography. The failure behaviour predicted by FE modelling is in good agreement with experimental results. The reduction in compressive strength owing to the embedding of circular vascules ranges from 13 to 70 per cent, which correlates with vascule dimension.

  5. Thermomechanical characterization and development of SMA-embedded CFRP composites with self-damage control

    NASA Astrophysics Data System (ADS)

    Jang, Byung-Koog; Xu, Ya; Oishi, Ryutaro; Nagai, Hideki; Yoshida, Hitoshi; Akimune, Yoshio; Otsuka, Kazuhiro; Kishi, Teruo

    2002-07-01

    The focus of this work is the thermomechanical characterization and effect of damage recovery on the pre-strained SMA wire embedded CFRP composites for developing the smart composites with self-damage control. The SMA utilized in this work is a Ni-45at percent Ti wire with a diameter of 0.4 mm. A steel mold was specially designed to embed the pre-strained TiNi wire into CFRP preperg and prevent their recovery during the cure cycle. TiNi/CFRP composites were fabricated by hot-pressing in the temperature range of 150-180 degrees C by controlling the applied pressure. The overall research is divided into four parts: fabrication of SMA wire embedded CFRP composites, experimental characterization of thermomechanical behavior on SMA wire by electrical heating, recovery effect of self-damage control in composites and sensing effect by detecting the electrical resistance at SMA wire. Compressive recovery force induced by thermomechanical actuation of SMA depends on pre-strained level and volume fraction of TiNi. The hot-pressed TiNi/CFRP specimens were loaded under tensile test in order to induce a transverse crack or partial damage. Specially, transverse crack easily happen at 90 degrees stacking CFRP layers. The damage degree due to generation of transverse cracks is quantified by real-time measurements of electrical resistance of SMA in composites during tensile load. After electrical heating, the generated transverse cracks at composites successfully repaired due to compressive force introduced by pre-strained TiNi wires and resulting in the self-damage recovery effect.

  6. Embedded reference electrodes for corrosion potential monitoring, electrochemical characterization, and controlled-potential cathodic protection

    NASA Astrophysics Data System (ADS)

    Merten, Bobbi Jo Elizabeth

    A thin wire Ag/AgCl reference electrode was prepared using 50 mum Ag wire in dilute FeCl3. The wire was embedded beneath the polyurethane topcoat of two sacrificial coating systems to monitor their corrosion potential. This is the first report of a reference electrode embedded between organic coating layers to monitor substrate health. The embedded reference electrode (ERE) successfully monitored the corrosion potential of Mg primer on AA 2024-T3 for 800 days of constant immersion in dilute Harrison's solution. Zn primer on steel had low accuracy in comparison. This is in part due to short circuiting by Zn oxidation products, which are much more conductive than Mg corrosion products. Data interpretation was improved through statistical analysis. On average, ERE corrosion potentials are 0.1 to 0.2 V and 0.2 to 0.3 V more positive than a saturated calomel electrode (SCE) in solution for AA 2024-T3 and steel coating systems, respectively. Further research may confirm that ERE obtains corrosion potential information not possible by an exterior, conventional reference electrode. The ERE is stable under polarization. AA 2024-T3 was polarized to -0.95 V vs ERE to emulate controlled potential cathodic protection (CPCP) applications. Polarizations of -0.75 V vs ERE are recommended for future experiments to minimize cathodic delamination. The ERE was utilized to analyze coating mixtures of lithium carbonate, magnesium nitrate, and Mg metal on AA2024-T3. Corrosion potential, low frequency impedance by electrochemical impedance spectroscopy (EIS), and noise resistance by electrochemical noise method (ENM) were reported. Coating performance ranking is consistent with standard electrochemical characterization and visual analyses. The results suggest anti-corrosion resistance superior to a standard Mg primer following 1600 hours of B117 salt spray. Both lithium carbonate and magnesium nitrate are necessary to achieve corrosion protection. Unique corrosion protective coatings for

  7. A Micro-Computed Tomography Technique to Study the Quality of Fibre Optics Embedded in Composite Materials

    PubMed Central

    Chiesura, Gabriele; Luyckx, Geert; Voet, Eli; Lammens, Nicolas; Van Paepegem, Wim; Degrieck, Joris; Dierick, Manuel; Van Hoorebeke, Luc; Vanderniepen, Pieter; Sulejmani, Sanne; Sonnenfeld, Camille; Geernaert, Thomas; Berghmans, Francis

    2015-01-01

    Quality of embedment of optical fibre sensors in carbon fibre-reinforced polymers plays an important role in the resultant properties of the composite, as well as for the correct monitoring of the structure. Therefore, availability of a tool able to check the optical fibre sensor-composite interaction becomes essential. High-resolution 3D X-ray Micro-Computed Tomography, or Micro-CT, is a relatively new non-destructive inspection technique which enables investigations of the internal structure of a sample without actually compromising its integrity. In this work the feasibility of inspecting the position, the orientation and, more generally, the quality of the embedment of an optical fibre sensor in a carbon fibre reinforced laminate at unit cell level have been proven. PMID:25961383

  8. New Techniques for Improving the Performance of the Lockstep Architecture for SEEs Mitigation in FPGA Embedded Processors

    NASA Astrophysics Data System (ADS)

    Abate, F.; Sterpone, L.; Lisboa, C. A.; Carro, L.; Violante, M.

    2009-08-01

    The growing availability of embedded processors inside FPGAs provides unprecedented flexibility for system designers. The use of such devices for space or mission critical applications, however, is being delayed by the lack of effective low cost techniques to mitigate radiation induced errors. In this paper a non invasive approach for the implementation of fault tolerant systems based on COTS processors embedded in FPGAs, using lockstep in conjunction with checkpoint and rollback recovery, is presented. The proposed approach does not require modifications in the processor architecture or in the application software. The experimental validation of this approach through fault injection is described, the corresponding results are discussed, and the addition of a write history table as a means to reduce the performance overhead imposed by previous implementations is proposed and evaluated.

  9. Fluorescence enhancement from nano-gap embedded plasmonic gratings by a novel fabrication technique with HD-DVD

    NASA Astrophysics Data System (ADS)

    Bhatnagar, K.; Pathak, A.; Menke, D.; Cornish, P. V.; Gangopadhyay, K.; Korampally, V.; Gangopadhyay, S.

    2012-12-01

    We demonstrate strong electromagnetic field enhancement from nano-gaps embedded in silver gratings for visible wavelengths. These structures fabricated using a store-bought HD-DVD worth 10 and conventional micro-contact printing techniques have shown maximum fluorescence enhancement factors of up to 118 times when compared to a glass substrate under epi-fluorescent conditions. The novel fabrication procedure provides for the development of a cost-effective and facile plasmonic substrate for low-level chemical and biological detection. Electromagnetic field simulations were also performed that reveal the strong field confinement in the nano-gap region embedded in the silver grating, which is attributed to the combined effect of localized as well as propagating surface plasmons.

  10. Fluorescence enhancement from nano-gap embedded plasmonic gratings by a novel fabrication technique with HD-DVD.

    PubMed

    Bhatnagar, K; Pathak, A; Menke, D; Cornish, P V; Gangopadhyay, K; Korampally, V; Gangopadhyay, S

    2012-12-14

    We demonstrate strong electromagnetic field enhancement from nano-gaps embedded in silver gratings for visible wavelengths. These structures fabricated using a store-bought HD-DVD worth $10 and conventional micro-contact printing techniques have shown maximum fluorescence enhancement factors of up to 118 times when compared to a glass substrate under epi-fluorescent conditions. The novel fabrication procedure provides for the development of a cost-effective and facile plasmonic substrate for low-level chemical and biological detection. Electromagnetic field simulations were also performed that reveal the strong field confinement in the nano-gap region embedded in the silver grating, which is attributed to the combined effect of localized as well as propagating surface plasmons.

  11. Optical transformation based image encryption and data embedding techniques using MATLAB

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Debalina; Ghosh, Ajay

    2015-06-01

    The proposed work describes optical transformations such as Fourier transformation and Fresnel transformation based encryption and decryption of images using random phase masks (RPMs). The encrypted images have been embedded in some secret cover files of other formats like text files, word files, audio files etc to increase the robustness in the security applications. So, if any one wants to send confidential documents, it will be difficult for the interloper to unhide the secret information. The whole work has been done in MATLAB®

  12. Information-based detection of nonlinear Granger causality in multivariate processes via a nonuniform embedding technique.

    PubMed

    Faes, Luca; Nollo, Giandomenico; Porta, Alberto

    2011-05-01

    We present an approach, framed in information theory, to assess nonlinear causality between the subsystems of a whole stochastic or deterministic dynamical system. The approach follows a sequential procedure for nonuniform embedding of multivariate time series, whereby embedding vectors are built progressively on the basis of a minimization criterion applied to the entropy of the present state of the system conditioned to its past states. A corrected conditional entropy estimator compensating for the biasing effect of single points in the quantized hyperspace is used to guarantee the existence of a minimum entropy rate at which to terminate the procedure. The causal coupling is detected according to the Granger notion of predictability improvement, and is quantified in terms of information transfer. We apply the approach to simulations of deterministic and stochastic systems, showing its superiority over standard uniform embedding. Effects of quantization, data length, and noise contamination are investigated. As practical applications, we consider the assessment of cardiovascular regulatory mechanisms from the analysis of heart period, arterial pressure, and respiration time series, and the investigation of the information flow across brain areas from multichannel scalp electroencephalographic recordings.

  13. Information-based detection of nonlinear Granger causality in multivariate processes via a nonuniform embedding technique

    NASA Astrophysics Data System (ADS)

    Faes, Luca; Nollo, Giandomenico; Porta, Alberto

    2011-05-01

    We present an approach, framed in information theory, to assess nonlinear causality between the subsystems of a whole stochastic or deterministic dynamical system. The approach follows a sequential procedure for nonuniform embedding of multivariate time series, whereby embedding vectors are built progressively on the basis of a minimization criterion applied to the entropy of the present state of the system conditioned to its past states. A corrected conditional entropy estimator compensating for the biasing effect of single points in the quantized hyperspace is used to guarantee the existence of a minimum entropy rate at which to terminate the procedure. The causal coupling is detected according to the Granger notion of predictability improvement, and is quantified in terms of information transfer. We apply the approach to simulations of deterministic and stochastic systems, showing its superiority over standard uniform embedding. Effects of quantization, data length, and noise contamination are investigated. As practical applications, we consider the assessment of cardiovascular regulatory mechanisms from the analysis of heart period, arterial pressure, and respiration time series, and the investigation of the information flow across brain areas from multichannel scalp electroencephalographic recordings.

  14. Characterizing odors from cattle feedlots with different odor techniques

    USDA-ARS?s Scientific Manuscript database

    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...

  15. Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis

    SciTech Connect

    Kuo, William T.; Cupp, John S.; Louie, John D.; Kothary, Nishita; Hofmann, Lawrence V.; Sze, Daniel Y.; Hovsepian, David M.

    2012-06-15

    Purpose: We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation. Methods: We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis. Results: Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Guenther-Tulip (GTF; mean 606 days, range 154-1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196-529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens. Conclusion: Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.

  16. Comparison of histological techniques to visualize iron in paraffin-embedded brain tissue of patients with Alzheimer's disease.

    PubMed

    van Duijn, Sara; Nabuurs, Rob J A; van Duinen, Sjoerd G; Natté, Remco

    2013-11-01

    Better knowledge of the distribution of iron in the brains of Alzheimer's disease (AD) patients may facilitate the development of an in vivo magnetic resonance (MR) marker for AD and may cast light on the role of this potentially toxic molecule in the pathogenesis of AD. Several histological iron staining techniques have been used in the past but they have not been systematically tested for sensitivity and specificity. This article compares three histochemical techniques and ferritin immunohistochemistry to visualize iron in paraffin-embedded human AD brain tissue. The specificity of the histochemical techniques was tested by staining sections after iron extraction. Iron was demonstrated in the white matter, in layers IV/V of the frontal neocortex, in iron containing plaques, and in microglia. In our hands, these structures were best visualized using the Meguro iron stain, a method that has not been described for iron staining in human brain or AD in particular. Ferritin immunohistochemistry stained microglia and iron containing plaques similar to the Meguro method but was less intense in myelin-associated iron. The Meguro method is most suitable for identifying iron-positive structures in paraffin-embedded human AD brain tissue.

  17. Detection of immunoglobulins and complement components in formalin fixed and paraffin embedded renal biopsy material by immunoflourescence technique

    PubMed Central

    Mubarak, Muhammed; Kazi Javed, I; Kulsoom, Umme; Ishaque, Muhammed

    2012-01-01

    Background The technique of direct immunoflourescence (IF) is essential in the accurate diagnosis of renal glomerular diseases. The optimal results are obtained when the procedure is done on fresh frozen tissue (IF-F). However, techniques are available for IF study on formalin fixed and paraffin embedded (FFPE) renal biopsy specimens with variable reported success rates. Objectives We evaluated three such techniques on FFPE tissue and compared the results with those obtained by IF-F from the same patients. Materials and Methods Heat treatment with Tris buffer and citrate buffer, and pronase treatment of the FFPE material was carried out. Direct IF was done for renal panel immunoglobulins and complement components on all biopsies and the results were compared with the historical IF-F study. Results When compared to the IF-F, the immunoflourescence staining on the paraffin sections was less sensitive and less intense in all immune complex-mediated renal diseases, but the diagnostic findings were detected in majority of the cases. Conclusions In conclusion, it is possible to establish the diagnosis in most cases of immune complex-mediated glomerular diseases with IF on paraffin embedded tissue specimens. PMID:24475396

  18. Surface melting of nanometre-sized Pb particles embedded in an Al matrix studied by internal friction technique

    NASA Astrophysics Data System (ADS)

    Chen, X. M.; Fei, G. T.; Cui, P.; Li, Y.; Zhang, L. D.

    2006-08-01

    Nanometre-sized (hereafter n-) Pb particles embedded in an Al matrix were prepared by ball milling, and the surface melting behaviour was studied by the internal friction technique using a dynamic mechanical analyser. There is an internal friction peak appearing around Pb melting point and the height of the internal friction peak decreases with the increase of Pb particle size. Surface melting of n-Pb particles accounts for the internal friction peak. The study may throw light on the nature of surface melting in condensed matter physics. In addition, the present work makes a beneficial attempt at exploring internal friction as an experimental method for studying surface melting.

  19. Histological and genotypical characterization of feline cutaneous mycobacteriosis: a retrospective study of formalin-fixed paraffin-embedded tissues.

    PubMed

    Davies, Jennifer L; Sibley, Jennifer A; Myers, Sherry; Clark, Edward G; Appleyard, Greg D

    2006-06-01

    Twenty-nine cases presumptively diagnosed as feline cutaneous mycobacteriosis were evaluated microscopically with haematoxylin and eosin and modified Fite's stained sections using archived formalin-fixed paraffin-embedded tissue specimens. Lesions were characterized histologically as feline leprosy (7 cases lepromatous and 16 cases tuberculoid) or atypical mycobacteriosis (3 cases); three cases did not fit these criteria and were classified as 'miscellaneous'. Actinomycetales-specific polymerase chain reaction (PCR) of variable regions 1, 2 and 3 of the 16S ribosomal RNA (rRNA) gene and subsequent sequence analysis of the amplicons were performed to identify the species of mycobacteria associated with each case. Together, this study identified 10 different Actinomycetales organisms with greater than 98% nucleotide sequence identity to named species, nine were of the genus Mycobacterium and eight were associated with feline leprosy (both lepromatous and tuberculoid). Based on this study, we conclude that feline cutaneous mycobacteriosis should be considered as a syndrome with varied clinical and histological presentations associated with a variety of different Mycobacterium species, organisms other than Mycobacterium sp. may be associated with feline cutaneous mycobacteriosis lesions, and molecular diagnostic techniques can be an important tool for identifying agents associated with lesions of feline cutaneous mycobacteriosis.

  20. Size dependent optical characterization of semiconductor particle: CdS embedded in polymer matrix

    NASA Astrophysics Data System (ADS)

    Roy, S.; Gogoi, A.; Ahmed, G. A.

    2010-10-01

    We report the optical investigation and analysis of both nano-sized and micrometer size Cadmium Sulphide particles which is embedded in a transparent polyvinyl alcohol (PVOH) dielectric host material. A designed and fabricated laser based light scattering system using a He-Ne laser of wavelength 632.8nm was used for the measurement and study of the scattering properties of the particles as a function of the scattering angle at this wavelength. An attempt was made to experimentally determine the most significant elements of the Mueller scattering matrix using combinations of randomly and linearly polarized incident laser beam and subsequent analyzers in corresponding orientations. The analysis of the experimental data was done by the method of comparison with theoretically generated data. Novel computational technique, involving single scattering for spherical particles using Mie-theory, was developed and applied. The theoretical data was found to be in good agreement with the experimental data within an acceptable margin of error. The results have proved that the combination of the experimental setup and associated computational method is a highly efficient and reliable in-situ system for monitoring size growth of semiconductor particles in the laboratory.

  1. Powering embedded electronics for wind turbine monitoring using multi-source energy harvesting techniques

    NASA Astrophysics Data System (ADS)

    Anton, S. R.; Taylor, S. G.; Raby, E. Y.; Farinholt, K. M.

    2013-03-01

    With a global interest in the development of clean, renewable energy, wind energy has seen steady growth over the past several years. Advances in wind turbine technology bring larger, more complex turbines and wind farms. An important issue in the development of these complex systems is the ability to monitor the state of each turbine in an effort to improve the efficiency and power generation. Wireless sensor nodes can be used to interrogate the current state and health of wind turbine structures; however, a drawback of most current wireless sensor technology is their reliance on batteries for power. Energy harvesting solutions present the ability to create autonomous power sources for small, low-power electronics through the scavenging of ambient energy; however, most conventional energy harvesting systems employ a single mode of energy conversion, and thus are highly susceptible to variations in the ambient energy. In this work, a multi-source energy harvesting system is developed to power embedded electronics for wind turbine applications in which energy can be scavenged simultaneously from several ambient energy sources. Field testing is performed on a full-size, residential scale wind turbine where both vibration and solar energy harvesting systems are utilized to power wireless sensing systems. Two wireless sensors are investigated, including the wireless impedance device (WID) sensor node, developed at Los Alamos National Laboratory (LANL), and an ultra-low power RF system-on-chip board that is the basis for an embedded wireless accelerometer node currently under development at LANL. Results indicate the ability of the multi-source harvester to successfully power both sensors.

  2. An Efficient Algorithm Embedded in an Ultrasonic Visualization Technique for Damage Inspection Using the AE Sensor Excitation Method

    PubMed Central

    Liu, Yaolu; Goda, Riu; Samata, Kiyoshi; Kanda, Atsushi; Hu, Ning; Zhang, Jianyu; Ning, Huiming; Wu, Liangke

    2014-01-01

    To improve the reliability of a Lamb wave visualization technique and to obtain more information about structural damages (e.g., size and shape), we put forward a new signal processing algorithm to identify damage more clearly in an inspection region. Since the kinetic energy of material particles in a damaged area would suddenly change when ultrasonic waves encounter the damage, the new algorithm embedded in the wave visualization technique is aimed at monitoring the kinetic energy variations of all points in an inspection region to construct a damage diagnostic image. To validate the new algorithm, three kinds of surface damages on the center of aluminum plates, including two non-penetrative slits with different depths and a circular dent, were experimentally inspected. From the experimental results, it can be found that the new algorithm can remarkably enhance the quality of the diagnostic image, especially for some minor defects. PMID:25356647

  3. X-ray absorption spectroscopy characterization of embedded and extracted nano-oxides

    DOE PAGES

    Stan, Tiberiu; Sprouster, David J.; Ofan, Avishai; ...

    2016-12-29

    Here, the chemistries and structures of both embedded and extracted Ysingle bondTisingle bondO nanometer-scale oxides in a nanostructured ferritic alloy (NFA) were probed by x-ray absorption spectroscopy (XAS). Y2Ti2O7 is the primary embedded phase, while the slightly larger extracted oxides are primarily Y2TiO5. Analysis of the embedded nano-oxides is difficult partly due to the multiple Ti environments associated with different oxides and those still residing in matrix lattice sites. Thus, bulk extraction followed by selective filtration was used to isolate the larger Y2TiO5 oxides for XAS, while the smaller predominant embedded phase Y2Ti2O7 oxides passed through the filters and weremore » analyzed using the log-ratio method.« less

  4. Fabrication and textural characterization of nanoporous carbon electrodes embedded with CuO nanoparticles for supercapacitors

    PubMed Central

    Prasad, Kumaresa P S; Dhawale, Dattatray S; Sivakumar, Thiripuranthagan; Aldeyab, Salem S; Zaidi, Javaid S M; Ariga, Katsuhiko; Vinu, Ajayan

    2011-01-01

    We introduce a novel strategy of fabricating nanoporous carbons loaded with different amounts of CuO nanoparticles via a hard templating approach, using copper-containing mesoporous silica as the template and sucrose as the carbon source. The nature and dispersion of the CuO nanoparticles on the surface of the nanoporous carbons were investigated by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM) and high-resolution transmission electron microscopy (HRTEM). XRD results reveal that nanoporous carbons with embedded CuO nanoparticles exhibit a well-ordered mesoporous structure, whereas the nitrogen adsorption measurements indicate the presence of excellent textural characteristics such as high surface area, large pore volume and uniform pore size distribution. The amount of CuO nanoparticles in the nanochannels of the nanoporous carbon could be controlled by simply varying the Si/Cu molar ratio of the mesoporous silica template. Morphological characterization by SEM and TEM reveals that high-quality CuO nanoparticles are distributed homogeneously within the nanoporous carbon framework. The supercapacitance behavior of the CuO-loaded nanoporous carbons was investigated. The material with a small amount of CuO in the mesochannels and high surface area affords a maximum specific capacitance of 300 F g-1 at a 20 mV s-1 scan rate in an aqueous electrolyte solution. A supercapacitor containing the CuO-loaded nanoporous carbon is highly stable and exhibits a long cycle life with 91% specific capacitance retained after 1000 cycles. PMID:27877410

  5. Laboratory Techniques in Geology: Embedding Analytical Methods into the Undergraduate Curriculum

    NASA Astrophysics Data System (ADS)

    Baedke, S. J.; Johnson, E. A.; Kearns, L. E.; Mazza, S. E.; Gazel, E.

    2014-12-01

    Paid summer REU experiences successfully engage undergraduate students in research and encourage them to continue to graduate school and scientific careers. However these programs only accommodate a limited number of students due to funding constraints, faculty time commitments, and limited access to needed instrumentation. At JMU, the Department of Geology and Environmental Science has embedded undergraduate research into the curriculum. Each student fulfilling a BS in Geology or a BA in Earth Science completes 3 credits of research, including a 1-credit course on scientific communication, 2 credits of research or internship, followed by a presentation of that research. Our department has successfully acquired many analytical instruments and now has an XRD, SEM/EDS, FTIR, handheld Raman, AA, ion chromatograph, and an IRMS. To give as many students as possible an overview to the scientific uses and operation methods for these instruments, we revived a laboratory methods course that includes theory and practical use of instrumentation at JMU, plus XRF sample preparation and analysis training at Virginia Tech during a 1-day field trip. In addition to practical training, projects included analytical concepts such as evaluating analytical vs. natural uncertainty, determining error on multiple measurements, signal-to-noise ratio, and evaluating data quality. State funding through the 4-VA program helped pay for analytical supplies and support for students to complete research projects over the summer or during the next academic year using instrumentation from the course. This course exemplifies an alternative path to broadening participation in undergraduate research and creating stronger partnerships between PUI's and research universities.

  6. Direct fluorescent antibody technique for the detection of bacterial kidney disease in paraffin-embedded tissues

    USGS Publications Warehouse

    Ochiai, T.; Yasutake, W.T.; Gould, R.W.

    1985-01-01

    The direct fluorescent antibody technique (FAT) was successfully used to detect the causative agent of bacterial kidney disease (BKD), Renibacterium salmoninarum, in Bouin's solution flexed and paraffinembedded egg and tissue sections. This method is superior to gram stain and may be particularly useful in detecting the BKD organism in fish with low-grade infection.

  7. Joint Application Mapping/Interconnect Synthesis Techniques for Embedded Chip-Scale Multiprocessors

    DTIC Science & Technology

    2005-02-01

    information on this or any other computing topic, please visit our Digital Library at www.computer.org/publications/ dlib . 112 IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 16, NO. 2, FEBRUARY 2005 ...is advanta- geous because it allows us to leverage a large library of useful scheduling techniques. The feasibility/flexibility framework, introduced

  8. Industrial Materials Characterization Using Neutron Activation Techniques

    SciTech Connect

    S. Yusuf; W. Rigot; M. Buchmann; T. Quinn

    2000-06-04

    For more than 30 yr now, we have applied neutron activation analysis (NAA) in material characterization by stressing the fundamentals, namely, understanding the nuclear reactions, characterizing the irradiation facility, and establishing a stable counting system. When these three aspects are treated properly, then Eq. (1), A{sub 0} = {lambda}Ce{sup {lambda}t{sub 1}}/(1-e{sup -{lambda}{Delta}})(1-e{sup {lambda}{tau}})={epsilon}{gamma}({theta}mN{sub A}/M){integral}{sub E=0}{sup E={infinity}}{Phi}(E){sigma}(E)dE, is applicable with negligible errors. The quantities in Eq. (1) are all known except for the quantities under the integral and the counting efficiency. It is the treatment of the integral in Eq. (1) that raises a question and is the topic in numerous theses. The object of this paper is to show how the shape-independent approach can be used to cut down time and cost of analysis without compromising accuracy.

  9. Advanced FTIR techniques for photoresist process characterization

    NASA Astrophysics Data System (ADS)

    Carpio, Ronald A.; Byers, Jeff D.; Petersen, John S.; Theiss, Wolfgang

    1997-07-01

    Several applications of Fourier transform IR spectroscopy (FTIR) for the characterization of photoresist thin films are demonstrated. The applications are accurate resist thickness measurements, monitoring of solvent loss during the post-apply-bake, determination of the glass transition temperature, and deprotection reaction kinetics. Model based, spectral analysis is applied for the determination of photoresist thickness from mid-FTIR spectra and is shown to have linear correlation to measurements with UV-visible spectroscopic ellipsometry. Using this capability in conjunction with an external reflection accessory and rapid data acquisition hardware and software, measurements are performed on Shipley SPR-510L photoresist during the post apply bake step, deriving thickness and solvent loss information. The use of this approach is also explored for making glass transition measurements of an environmentally stable chemical amplification positive resist photoresist. Finally, in-situ PEB studies are illustrated for APEX-E photoresist. For off-line analysis, an in-sample compartment mapping accessories is applied to the characterization of multiple open frame exposure matrices on 200 mm double-side polished wafers.

  10. Wafer Stepper Characterization And Process Control Techniques

    NASA Astrophysics Data System (ADS)

    Curry, S. C.; Friedberg, C. B.

    1982-09-01

    A process control vehicle is described which allows the characterization and comparison of wafer steppers with respect to distortion, resolution, uniformity, and misregistration. A block of test structures consisting of optical resolution patterns, verniers, and electrical line width and misalignment resistors is arrayed on an 11 x 11 grid which fills the entire available field of a 10X reticle. Fach block also contains a pair of targets for the THE laser-interferometric auto-alignment system. The ability of the auto-aligner to acquire such targets to within 500 is exploited as a metrology tool whereby the measured coordinates at each site are compared to the ideal (theoretical) coordinates to generate a vector distortion map across the field. Subsequent reduction of misregistration data is accomplished via application of the six parameter model developed by Perloff and co-workers. It is shown that these diagnostic tools permit the rapid characterization of distortion anisotropy for a given stepper and can be used to optimize and monitor level-to-level regis-tration. Further applications are suggested.

  11. The tissue is the issue: improved methylome analysis from paraffin-embedded tissues by application of the HOPE technique.

    PubMed

    Marwitz, Sebastian; Kolarova, Julia; Reck, Martin; Reinmuth, Niels; Kugler, Christian; Schädlich, Ines; Haake, Andrea; Zabel, Peter; Vollmer, Ekkehard; Siebert, Reiner; Goldmann, Torsten; Ammerpohl, Ole

    2014-08-01

    Alterations in the DNA methylome are characteristic for numerous diseases and a typical hallmark of cancer. Therefore, DNA methylation is currently under investigation in research labs and has also entered diagnostics. Recently, protocols like the BeadChip technology have become commercially available to study DNA methylation in an array format and semiquantitative fashion. However, it is known that fixation of the sample material with formalin prior to BeadChip analysis can affect the results. In this study we compared the influence of fixation on the outcome of BeadChip analysis. From six patients each a lung cancer tissue sample and a corresponding tumor-free lung tissue sample were collected. The samples were separated into three pieces. One piece of each sample was fixed with formalin, another one by the non-cross-linking HOPE technique (Hepes-glutamic acid buffer mediated Organic solvent Protection Effect). Subsequently, both became paraffin embedded. As a reference, the remaining third piece was cryopreserved. In addition we used three adenocarcinoma cell lines (H838, A549, and H1650) to validate the results from patient tissues. We show that using the HOPE technique instead of formalin largely prevents the introduction of formalin-fixation related artifacts. An ANOVA analysis significantly separated HOPE- and cryopreserved from formalin-fixed samples (FDR<0.05), while differences in the methylation data obtained from HOPE-fixed and cryopreserved material were minor. Consequently, HOPE fixation is superior to formalin fixation if a subsequent BeadChip analysis of paraffin-embedded sample material is intended.

  12. Certification Aspects in Critical Embedded Software Development with Model Based Techniques: Detection of Unintended Functions

    NASA Astrophysics Data System (ADS)

    Atencia Yepez, A.; Autrán Cerqueira, J.; Urueña, S.; Jurado, R.

    2012-01-01

    This paper, developed under contract with European Aviation Safety Agency (EASA), analyses in detail which may be the certification implications in the aeronautic industry associated to the application of model-level verification and validation techniques. Particularly, this paper focuses on the problematic of detecting unintended functions by applying Model Coverage Criteria at model level. This point is significantly important for the future extensive use of Model Based approaches in safety critical software, since the uncertainty in the system performance introduced by the unintended functions, which may also lead to unacceptable hazardous or catastrophic events, prevents the system to be compliance with certification requirements. The paper provides a definition and a categorization of unintended functions and gives some relevant examples to assess the efficiency of model- coverage techniques in the detection of UF. The paper explains how this analysis is supported by a methodology based on the study of sources for introducing unintended functions. Finally it is analysed the feasibility of using Model-level verification techniques to support the software certification process.

  13. Synthesis Technique and Characterizations of Silver Nanostructures

    NASA Astrophysics Data System (ADS)

    Rajawat, Shweta; Qureshi, M. S.

    2015-06-01

    In this work, we report synthesis of nanostructures of silver nanoparticles using X-ray films. Exposed X-ray films, which consist of silver nanoparticles, are cut into small pieces of size 1 cm × 1 cm. These pieces were heated in distilled water at temperature 70°C. These nanoparticles, separated from heated films, are simultaneously collected through electrolytic deposition using copper and carbon rods. The carbon rod is wrapped over by Low density polyethylene (LDPE) sheet for easy extraction. This process was carried in two different environments (1) in broad daylight and (2) on a cloudy day. Characterization of the two samples was done using X-Ray Diffractometer (XRD), Transmission Electron Microscopy (TEM) and UV-Vis spectroscopy. XRD of the particles gave peaks well in accordance with JCPDS file 04-. This result confirms formation of highly pure silver nanoparticles. TEM revealed that the interaction of silver nanoparticles with sunlight gave chain like structures whereas in the absence of interaction with sunlight, cloudy day, nanoflowers were formed. Nanostructures were more prominent for bigger particles.

  14. Impact of Implantation Technique and Plaque Morphology on Strut Embedment and Scaffold Expansion of Polylactide Bioresorbable Scaffold - Insights From ABSORB Japan Trial.

    PubMed

    Sotomi, Yohei; Onuma, Yoshinobu; Dijkstra, Jouke; Eggermont, Jeroen; Liu, Shengnan; Tenekecioglu, Erhan; Zeng, Yaping; Asano, Taku; de Winter, Robbert J; Popma, Jeffrey J; Kozuma, Ken; Tanabe, Kengo; Serruys, Patrick W; Kimura, Takeshi

    2016-10-25

    The optimal implantation technique for the bioresorbable scaffold (Absorb, Abbott Vascular) is still a matter of debate. The purpose of the present study was to evaluate the effect of implantation technique on strut embedment and scaffold expansion.Methods and Results:Strut embedment depth and scaffold expansion index assessed by optical coherence tomography (OCT) (minimum scaffold area/reference vessel area) were evaluated in the ABSORB Japan trial (OCT subgroup: 87 lesions) with respect to implantation technique using either quantitative coronary angiography (QCA) or OCT. Strut embedment was assessed at the strut level (n=667), while scaffold expansion was assessed at the lesion level (n=81). The mean embedment depth was 63±59 µm. Balloon sizing and inflation pressure had no direct effect on strut embedment. Plaque morphology affected strut embedment [nonatherosclerotic (58.9±54.3 µm), fibroatheroma (73.3±59.6 µm), fibrous plaque (59.7±51.1 µm), and fibrocalcific plaque (-3.1±61.6 µm, negative value means malapposition), P <0.001]. The balloon-artery ratio positively correlated with the expansion index. This relationship was stronger when the OCT-derived reference vessel diameter (RVD) was used as a reference for balloon selection rather than the QCA-derived one [predilatation (Pearson correlation r: QCA: 0.167 vs. OCT: 0.552), postdilatation (QCA: 0.316 vs. OCT: 0.717)]. Underlying plaque morphology influenced strut embedment, whereas implantation technique had no direct effect on it. Optimal balloon sizing based on OCT-derived RVD might be recommended. However, the safety of such a strategy should be investigated in a prospective trial. (Circ J 2016; 80: 2317-2326).

  15. A Vision-Based Driver Nighttime Assistance and Surveillance System Based on Intelligent Image Sensing Techniques and a Heterogamous Dual-Core Embedded System Architecture

    PubMed Central

    Chen, Yen-Lin; Chiang, Hsin-Han; Chiang, Chuan-Yen; Liu, Chuan-Ming; Yuan, Shyan-Ming; Wang, Jenq-Haur

    2012-01-01

    This study proposes a vision-based intelligent nighttime driver assistance and surveillance system (VIDASS system) implemented by a set of embedded software components and modules, and integrates these modules to accomplish a component-based system framework on an embedded heterogamous dual-core platform. Therefore, this study develops and implements computer vision and sensing techniques of nighttime vehicle detection, collision warning determination, and traffic event recording. The proposed system processes the road-scene frames in front of the host car captured from CCD sensors mounted on the host vehicle. These vision-based sensing and processing technologies are integrated and implemented on an ARM-DSP heterogamous dual-core embedded platform. Peripheral devices, including image grabbing devices, communication modules, and other in-vehicle control devices, are also integrated to form an in-vehicle-embedded vision-based nighttime driver assistance and surveillance system. PMID:22736956

  16. A vision-based driver nighttime assistance and surveillance system based on intelligent image sensing techniques and a heterogamous dual-core embedded system architecture.

    PubMed

    Chen, Yen-Lin; Chiang, Hsin-Han; Chiang, Chuan-Yen; Liu, Chuan-Ming; Yuan, Shyan-Ming; Wang, Jenq-Haur

    2012-01-01

    This study proposes a vision-based intelligent nighttime driver assistance and surveillance system (VIDASS system) implemented by a set of embedded software components and modules, and integrates these modules to accomplish a component-based system framework on an embedded heterogamous dual-core platform. Therefore, this study develops and implements computer vision and sensing techniques of nighttime vehicle detection, collision warning determination, and traffic event recording. The proposed system processes the road-scene frames in front of the host car captured from CCD sensors mounted on the host vehicle. These vision-based sensing and processing technologies are integrated and implemented on an ARM-DSP heterogamous dual-core embedded platform. Peripheral devices, including image grabbing devices, communication modules, and other in-vehicle control devices, are also integrated to form an in-vehicle-embedded vision-based nighttime driver assistance and surveillance system.

  17. X-ray absorption spectroscopy characterization of embedded and extracted nano-oxides

    SciTech Connect

    Stan, Tiberiu; Sprouster, David J.; Ofan, Avishai; Odette, G. Robert; Ecker, Lynne E.; Charit, Indrajit

    2016-12-29

    Here, the chemistries and structures of both embedded and extracted Ysingle bondTisingle bondO nanometer-scale oxides in a nanostructured ferritic alloy (NFA) were probed by x-ray absorption spectroscopy (XAS). Y2Ti2O7 is the primary embedded phase, while the slightly larger extracted oxides are primarily Y2TiO5. Analysis of the embedded nano-oxides is difficult partly due to the multiple Ti environments associated with different oxides and those still residing in matrix lattice sites. Thus, bulk extraction followed by selective filtration was used to isolate the larger Y2TiO5 oxides for XAS, while the smaller predominant embedded phase Y2Ti2O7 oxides passed through the filters and were analyzed using the log-ratio method.

  18. Near-infrared photoluminescence and Raman characterization of bismuth-embedded sodalite nanocrystals.

    PubMed

    Sun, Hong-Tao; Fujii, Minoru; Sakka, Yoshio; Bai, Zhenhua; Shirahata, Naoto; Zhang, Liyan; Miwa, Yuji; Gao, Hong

    2010-06-01

    Ultrabroadband near-IR (NIR) emission has been realized in bismuth-embedded sodalite nanocrystals. Steady-state and time-resolved photoluminescence and Raman results suggest that Bi(+) active centers contribute to the NIR emission. This study demonstrates that sodalite nanocrystals can serve as excellent hosts for bismuth NIR active centers, thus paving the way for their wide applications in nanophotonics.

  19. Characterization of embedded fiber optic sensors in advanced composite materials for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Richards, W. L.; Lee, Dong Gun; Piazza, Anthony; Stewart, Anna K.; Carman, Gregory P.

    2004-07-01

    This paper presents comprehensive studies on sensor performance of an embedded Extrinsic Fabry Perot Interferometer (EFPI) fiber optic strain sensor in an aerospace grade composite system to support fiber optic smart structures (FOSS) development for Structural Health Monitoring (SHM) System. A major portion of this study is focused on establishing the accuracy of the embedded EFPI sensors in a graphite epoxy composite material system at different stress levels under quasi-static loading conditions. The NASA Dryden calibrated EFPI's were used for accurate measurements. Two collocated surface-mounted strain gages and a calibrated surface-mounted EFPI sensor are used to validate the calibrated embedded EFPI sensor. Experimental results suggest that once calibrated, the embedded and surface-mounted EFPI sensors provide robust, reliable and accurate measurement for values up to ~5,400 μɛ higher than sensor's durability limit ~3,000 μɛ at 106 cycles. This validation provides evidence that the sensing information emanating from FOSS can be used to monitor accurate health information.

  20. Quantification of DNA Extracted from Formalin Fixed Paraffin-Embeded Tissue Comparison of Three Techniques: Effect on PCR Efficiency

    PubMed Central

    Panigrahi, Manoj Kumar; Suryavanshi, Moushumi; Mehta, Anurag; Saikia, Kandarpa Kumar

    2016-01-01

    Introduction Mutation detection from Formalin Fixed Paraffin-Embedding (FFPE) tissue in molecular lab became a necessary tool for defining potential targeted drug. Accurate quantification of DNA extracted from FFPE tissue is necessary for downstream applications like Polymerase Chain Reaction (PCR), sequencing etc. Aim To check and define which method for FFPE DNA quantification is suitable for downstream processes. Materials and Methods In this experimental experience study Biorad Smartspec Plus spectrophotomery, Qubit Fluorometer, and Qiagen Rotorgene qPCR was used to compare 20 FFPE DNA quantification in Rajiv Gandhi Cancer Institute and Research Centre, in 2015 and quantified amount of DNA used for PCR reaction. Results The average concentration of DNA extracted from FFPE tissue measured using the spectrophotometer was much higher than the concentration measured using the Qubit Fluorometer and qPCR. Conclusion Results varied depending upon the technique used. A fluorometric analysis may be more suitable for quantification of DNA samples extracted from FFPE tissue compared with spectrophotometric analysis. But qPCR is the best technique because it details DNA quantity along with quality of amplifiable DNA from FFPE tissue. PMID:27790419

  1. Synthesis, characterization, UV and dielectric properties of hexagonal disklike ZnO particles embedded in polyimides

    SciTech Connect

    Vural, Sema; Koeytepe, Sueleyman; Seckin, Turgay; Adiguezel, Ibrahim

    2011-10-15

    Graphical abstract: The hexagonal disklike ZnO particles with a diameter of 300-500 nm were synthesized from zinc acetate and NaOH in water with citric acid. ZnO/polyimide composite films with different ZnO contents was prepared. The prepared zinc oxide-polyimide composites were characterized for their structure, morphology and thermal behavior. Composites with ZnO particle contents from 1 to 5 wt% show good transparency in the visible region and luminescent properties. Highlights: {yields} A series of novel ZnO/polyimide composite films with different ZnO contents was prepared. {yields} The ZnO was homogeneously dispersed in the PI matrix. {yields} The composites showed the low dielectric constant of 50 at 10{sup 6} Hz. {yields} Homogenous dispersion and the amount of ZnO particles contributed to the dielectric properties of composites. -- Abstract: A series of novel ZnO/polyimide composite films with different ZnO contents was prepared through incorporation hexagonal disklike ZnO particles into poly(amic acid) of the pre polymer of the polyimide. The hexagonal disklike ZnO particles with a diameter of 300-500 nm were synthesized from zinc acetate and NaOH in water with citric acid. The prepared zinc oxide-polyimide composites were characterized for their structure, morphology, and thermal behavior employing Fourier transform infrared spectroscopy, scanning electron micrograph, X-ray diffraction and thermal analysis techniques. Thermal analyses show that the ZnO particles were successfully incorporated into the polymer matrix and these ZnO/polymer composites have a good thermal stability. Scanning electron microscopy studies indicate the ZnO particles were uniformly dispersed in the polymer and they remained at the original size (300-500 nm) before immobilization. All composite films with ZnO particle contents from 1 to 5 wt% show good transparency in the visible region and luminescent properties.

  2. Hybrid method based on singular value decomposition and embedded zero tree wavelet technique for ECG signal compression.

    PubMed

    Kumar, Ranjeet; Kumar, A; Singh, G K

    2016-06-01

    In the field of biomedical, it becomes necessary to reduce data quantity due to the limitation of storage in real-time ambulatory system and telemedicine system. Research has been underway since very beginning for the development of an efficient and simple technique for longer term benefits. This paper, presents an algorithm based on singular value decomposition (SVD), and embedded zero tree wavelet (EZW) techniques for ECG signal compression which deals with the huge data of ambulatory system. The proposed method utilizes the low rank matrix for initial compression on two dimensional (2-D) ECG data array using SVD, and then EZW is initiated for final compression. Initially, 2-D array construction has key issue for the proposed technique in pre-processing. Here, three different beat segmentation approaches have been exploited for 2-D array construction using segmented beat alignment with exploitation of beat correlation. The proposed algorithm has been tested on MIT-BIH arrhythmia record, and it was found that it is very efficient in compression of different types of ECG signal with lower signal distortion based on different fidelity assessments. The evaluation results illustrate that the proposed algorithm has achieved the compression ratio of 24.25:1 with excellent quality of signal reconstruction in terms of percentage-root-mean square difference (PRD) as 1.89% for ECG signal Rec. 100 and consumes only 162bps data instead of 3960bps uncompressed data. The proposed method is efficient and flexible with different types of ECG signal for compression, and controls quality of reconstruction. Simulated results are clearly illustrate the proposed method can play a big role to save the memory space of health data centres as well as save the bandwidth in telemedicine based healthcare systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. 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.

  4. Thermo-optical characterization of cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots embedded in biocompatible materials.

    PubMed

    Pilla, Viviane; Alves, Leandro P; Iwazaki, Adalberto N; Andrade, Acácio A; Antunes, Andrea; Munin, Egberto

    2013-09-01

    Cadmium selenide/zinc sulfide (CdSe/ZnS) core-shell quantum dots (QDs) embedded in biocompatible materials were thermally and optically characterized with a thermal lens (TL) technique. Transient TL measurements were performed with a mode-mismatched, dual-beam (excitation and probe) configuration. A thermo-optical study of the CdSe/ZnS QDs was performed for different core diameters (3.5, 4.0, 5.2, and 6.6 nm) in aqueous solution and synthetic saliva, and three different core diameters (2.4, 2.9, and 4.1 nm) embedded in restorative dental resin (0.025% by mass). The thermal diffusivity results are characteristic of the biocompatible matrices. The radiative quantum efficiencies for aqueous solution and biofluid materials are dependent on the core size of the CdSe/ZnS core-shell QDs. The results obtained from the fluorescence spectral measurements for the biocompatible materials support the TL results.

  5. Carotid lesion characterization by synthetic-aperture-imaging techniques with multioffset ultrasonic probes

    NASA Astrophysics Data System (ADS)

    Capineri, Lorenzo; Castellini, Guido; Masotti, Leonardo F.; Rocchi, Santina

    1992-06-01

    This paper explores the applications of a high-resolution imaging technique to vascular ultrasound diagnosis, with emphasis on investigation of the carotid vessel. With the present diagnostic systems, it is difficult to measure quantitatively the extension of the lesions and to characterize the tissue; quantitative images require enough spatial resolution and dynamic to reveal fine high-risk pathologies. A broadband synthetic aperture technique with multi-offset probes is developed to improve the lesion characterization by the evaluation of local scattering parameters. This technique works with weak scatterers embedded in a constant velocity medium, large aperture, and isotropic sources and receivers. The features of this technique are: axial and lateral spatial resolution of the order of the wavelength, high dynamic range, quantitative measurements of the size and scattering intensity of the inhomogeneities, and capabilities of investigation of inclined layer. The evaluation of the performances in real condition is carried out by a software simulator in which different experimental situations can be reproduced. Images of simulated anatomic test-objects are presented. The images are obtained with an inversion process of the synthesized ultrasonic signals, collected on the linear aperture by a limited number of finite size transducers.

  6. 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.

  7. 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.

  8. Dielectric characterization of hepatocytes in suspension and embedded into two different polymeric scaffolds.

    PubMed

    Massimi, M; Stampella, A; Devirgiliis, L Conti; Rizzitelli, G; Barbetta, A; Dentini, M; Cametti, C

    2013-02-01

    The dielectric and conductometric properties of hepatocytes in two different environments (in aqueous suspension and embedded into polymeric scaffolds) have been investigated in the frequency range from 1 kHz to 2 GHz, where the interfacial electrical polarization gives rise to marked dielectric relaxation effects. We analyzed the dielectric behavior of hepatocytes in complete medium aqueous suspensions in the light of effective medium approximation for heterogeneous systems and hepatocytes cultured into two different highly porous and interconnected polymeric structures. In the former case, we have evaluated the passive electrical parameters associated with both the plasmatic and nuclear membrane, finding a general agreement with the values reported elsewhere, based on a partially different analysis of the experimental spectra. In the latter case, we have evaluated the cell growth into two different polymeric scaffolds made of alginate and gelatin with a similar pore distribution and similar inter-connectivity. Based on a qualitative analysis of the dielectric spectra, we were able to provide evidence that alginate scaffolds allow an overall survival of cells better than gelatin scaffold can do. These indications, confirmed by biological tests on cell viability, suggest that hepatocytes embedded in alginate scaffolds are able to perform liver specific functions even over on extended period of time.

  9. Analysis and characterization of structurally embedded vascular antennas using liquid metals

    NASA Astrophysics Data System (ADS)

    Hartl, Darren J.; Huff, Gregory H.; Pan, Hong; Smith, Lisa; Bradford, Robyn L.; Frank, Geoffrey J.; Baur, Jeffrey W.

    2016-04-01

    Over the past decade, a large body of research associated with the addition of microvascular networks to structural composites has been generated. The engineering goal is most often the extension of structural utility to include extended functionalities such as self-healing or improved thermal management and resilience. More recently, efforts to design reconfigurable embedded electronics via the incorporation of non-toxic liquid metals have been initiated. A wide range of planar antenna configurations are possible, and the trade-offs between structural effects, other system costs, and increased flexibility in transmitting and receiving frequencies are being explored via the structurally embedded vascular antenna (SEVA) concept. This work describes for the first time the design of a bowtie-like tunable liquid metal-based antenna for integration into a structural composite for electromagnetic use. The design of both the solid/fluid feed structure and fluid transmission lines are described and analysis results regarding the RF performance of the antenna are provided. Fabrication methods for the SEVA are explained in detail and as-fabricated components are described. Challenges associated with both fabrication and system implementation and testing are elucidated. Results from preliminary RF testing indicate that in situ response tuning is feasible in these novel multifunctional composites.

  10. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-03-10

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique is disclosed. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method. 11 figs.

  11. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method.

  12. Signal processing applied to photothermal techniques for materials characterization

    NASA Technical Reports Server (NTRS)

    Rooney, James A.

    1989-01-01

    There is a need to make noncontact measurements of material characteristics in the microgravity environment. Photothermal and photoacoustics techniques offer one approach for attaining this capability since lasers can be used to generate the required thermal or acoustic signals. The perturbations in the materials that can be used for characterization can be detected by optical reflectance, infrared detection or laser detection of photoacoustics. However, some of these laser techniques have disadvantages of either high energy pulsed excitation or low signal-to-noise ratio. Alternative signal processing techniques that have been developed can be applied to photothermal or photoacoustic instrumentation. One fully coherent spread spectrum signal processing technique is called time delay spectrometry (TDS). With TDS the system is excited using a combined frequency-time domain by employing a linear frequency sweep excitation function. The processed received signal can provide either frequency, phase or improved time resolution. This signal processing technique was shown to outperform other time selective techniques with respect to noise rejection and was recently applied to photothermal instrumentation. The technique yields the mathematical equivalent of pulses yet the input irradiances are orders of magnitude less than pulses with the concomitant reduction in perturbation of the sample and can increase the capability of photothermal methods for materials characterization.

  13. Resistance to abrasion of extrinsic porcelain esthetic characterization techniques.

    PubMed

    Chi, Woo J; Browning, William; Looney, Stephen; Mackert, J Rodway; Windhorn, Richard J; Rueggeberg, Frederick

    2017-01-01

    A novel esthetic porcelain characterization technique involves mixing an appropriate amount of ceramic colorants with clear, low-fusing porcelain (LFP), applying the mixture on the external surfaces, and firing the combined components onto the surface of restorations in a porcelain oven. This method may provide better esthetic qualities and toothbrush abrasion resistance compared to the conventional techniques of applying color-corrective porcelain colorants alone, or applying a clear glaze layer over the colorants. However, there is no scientific literature to support this claim. This research evaluated toothbrush abrasion resistance of a novel porcelain esthetic characterization technique by subjecting specimens to various durations of simulated toothbrush abrasion. The results were compared to those obtained using the conventional characterization techniques of colorant application only or colorant followed by placement of a clear over-glaze. Four experimental groups, all of which were a leucite reinforced ceramic of E TC1 (Vita A1) shade, were prepared and fired in a porcelain oven according to the manufacturer's instructions. Group S (stain only) was characterized by application of surface colorants to provide a definitive shade of Vita A3.5. Group GS (glaze over stain) was characterized by application of a layer of glaze over the existing colorant layer as used for Group S. Group SL (stain+LFP) was characterized by application of a mixture of colorants and clear low-fusing add-on porcelain to provide a definitive shade of Vita A3.5. Group C (Control) was used as a control without any surface characterization. The 4 groups were subjected to mechanical toothbrushing using a 1:1 water-to-toothpaste solution for a simulated duration of 32 years of clinical use. The amount of wear was measured at time intervals simulating every 4 years of toothbrushing. These parameters were evaluated longitudinally for all groups as well as compared at similar time points among

  14. 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.

  15. 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.

  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. A new technique for the characterization of chaff elements.

    PubMed

    Scholfield, David; Myat, Maung; Dauby, Jason; Fesler, Jonathon; Bright, Jonathan

    2011-07-01

    A new technique for the experimental characterization of electromagnetic chaff based on Inverse Synthetic Aperture Radar is presented. This technique allows for the characterization of as few as one filament of chaff in a controlled anechoic environment allowing for stability and repeatability of experimental results. This approach allows for a deeper understanding of the fundamental phenomena of electromagnetic scattering from chaff through an incremental analysis approach. Chaff analysis can now begin with a single element and progress through the build-up of particles into pseudo-cloud structures. This controlled incremental approach is supported by an identical incremental modeling and validation process. Additionally, this technique has the potential to produce considerable savings in financial and schedule cost and provides a stable and repeatable experiment to aid model valuation.

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

    PubMed

    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.

  19. Nanostructure Embedded Microchips for Detection, Isolation, and Characterization of Circulating Tumor Cells

    PubMed Central

    2015-01-01

    Conspectus Circulating tumor cells (CTCs) are cancer cells that break away from either a primary tumor or a metastatic site and circulate in the peripheral blood as the cellular origin of metastasis. With their role as a “tumor liquid biopsy”, CTCs provide convenient access to all disease sites, including that of the primary tumor and the site of fatal metastases. It is conceivable that detecting and analyzing CTCs will provide insightful information in assessing the disease status without the flaws and limitations encountered in performing conventional tumor biopsies. However, identifying CTCs in patient blood samples is technically challenging due to the extremely low abundance of CTCs among a large number of hematologic cells. To address this unmet need, there have been significant research endeavors, especially in the fields of chemistry, materials science, and bioengineering, devoted to developing CTC detection, isolation, and characterization technologies. Inspired by the nanoscale interactions observed in the tissue microenvironment, our research team at UCLA pioneered a unique concept of “NanoVelcro” cell-affinity substrates, in which CTC capture agent-coated nanostructured substrates were utilized to immobilize CTCs with high efficiency. The working mechanism of NanoVelcro cell-affinity substrates mimics that of Velcro: when the two fabric strips of a Velcro fastener are pressed together, tangling between the hairy surfaces on two strips leads to strong binding. Through continuous evolution, three generations (gens) of NanoVelcro CTC chips have been established to achieve different clinical utilities. The first-gen NanoVelcro chip, composed of a silicon nanowire substrate (SiNS) and an overlaid microfluidic chaotic mixer, was created for CTC enumeration. Side-by-side analytical validation studies using clinical blood samples suggested that the sensitivity of first-gen NanoVelcro chip outperforms that of FDA-approved CellSearch. In conjunction with

  20. Nanostructure embedded microchips for detection, isolation, and characterization of circulating tumor cells.

    PubMed

    Lin, Millicent; Chen, Jie-Fu; Lu, Yi-Tsung; Zhang, Yang; Song, Jinzhao; Hou, Shuang; Ke, Zunfu; Tseng, Hsian-Rong

    2014-10-21

    Circulating tumor cells (CTCs) are cancer cells that break away from either a primary tumor or a metastatic site and circulate in the peripheral blood as the cellular origin of metastasis. With their role as a "tumor liquid biopsy", CTCs provide convenient access to all disease sites, including that of the primary tumor and the site of fatal metastases. It is conceivable that detecting and analyzing CTCs will provide insightful information in assessing the disease status without the flaws and limitations encountered in performing conventional tumor biopsies. However, identifying CTCs in patient blood samples is technically challenging due to the extremely low abundance of CTCs among a large number of hematologic cells. To address this unmet need, there have been significant research endeavors, especially in the fields of chemistry, materials science, and bioengineering, devoted to developing CTC detection, isolation, and characterization technologies. Inspired by the nanoscale interactions observed in the tissue microenvironment, our research team at UCLA pioneered a unique concept of "NanoVelcro" cell-affinity substrates, in which CTC capture agent-coated nanostructured substrates were utilized to immobilize CTCs with high efficiency. The working mechanism of NanoVelcro cell-affinity substrates mimics that of Velcro: when the two fabric strips of a Velcro fastener are pressed together, tangling between the hairy surfaces on two strips leads to strong binding. Through continuous evolution, three generations (gens) of NanoVelcro CTC chips have been established to achieve different clinical utilities. The first-gen NanoVelcro chip, composed of a silicon nanowire substrate (SiNS) and an overlaid microfluidic chaotic mixer, was created for CTC enumeration. Side-by-side analytical validation studies using clinical blood samples suggested that the sensitivity of first-gen NanoVelcro chip outperforms that of FDA-approved CellSearch. In conjunction with the use of the

  1. Development and Characterization of Embedded Sensory Particles Using Multi-Scale 3D Digital Image Correlation

    NASA Technical Reports Server (NTRS)

    Cornell, Stephen R.; Leser, William P.; Hochhalter, Jacob D.; Newman, John A.; Hartl, Darren J.

    2014-01-01

    A method for detecting fatigue cracks has been explored at NASA Langley Research Center. Microscopic NiTi shape memory alloy (sensory) particles were embedded in a 7050 aluminum alloy matrix to detect the presence of fatigue cracks. Cracks exhibit an elevated stress field near their tip inducing a martensitic phase transformation in nearby sensory particles. Detectable levels of acoustic energy are emitted upon particle phase transformation such that the existence and location of fatigue cracks can be detected. To test this concept, a fatigue crack was grown in a mode-I single-edge notch fatigue crack growth specimen containing sensory particles. As the crack approached the sensory particles, measurements of particle strain, matrix-particle debonding, and phase transformation behavior of the sensory particles were performed. Full-field deformation measurements were performed using a novel multi-scale optical 3D digital image correlation (DIC) system. This information will be used in a finite element-based study to determine optimal sensory material behavior and density.

  2. Development and characterization of silicone embedded distributed piezoelectric sensors for contact detection

    NASA Astrophysics Data System (ADS)

    Acer, Merve; Salerno, Marco; Agbeviade, Kossi; Paik, Jamie

    2015-07-01

    Tactile sensing transfers complex interactive information in a most intuitive sense. Such a populated set of data from the environment and human interactions necessitates various degrees of information from both modular and distributed areas. A sensor design that could provide such types of feedback becomes challenging when the target component has a nonuniform, agile, high resolution, and soft surface. This paper presents an innovative methodology for the manufacture of novel soft sensors that have a high resolution sensing array due to the sensitivity of ceramic piezoelectric (PZT) elements, while uncommonly matched with the high stretchability of the soft substrate and electrode design. Further, they have a low profile and their transfer function is easy to tune by changing the material and thickness of the soft substrate in which the PZTs are embedded. In this manuscript, we present experimental results of the soft sensor prototypes: PZTs arranged in a four by two array form, measuring 1.5-2.3 mm in thickness, with the sensitivity in the range of 0.07-0.12 of the normalized signal change per unit force. We have conducted extensive tests under dynamic loading conditions that include impact, step and cyclic. The presented prototype's mechanical and functional capacities are promising for applications in biomedical systems where soft, wearable and high precision sensors are needed.

  3. Thermooptical properties of gold nanoparticles embedded in ice: characterization of heat generation and melting.

    PubMed

    Richardson, Hugh H; Hickman, Zackary N; Govorov, Alexander O; Thomas, Alyssa C; Zhang, Wei; Kordesch, Martin E

    2006-04-01

    We investigate the system of optically excited gold NPs in an ice matrix aiming to understand heat generation and melting processes at the nanoscale level. Along with the traditional fluorescence method, we introduce thermooptical spectroscopy based on phase transformation of a matrix. With this, we can not only measure optical response but also thermal response, that is, heat generation. After several recrystallization cycles, the nanoparticles are embedded into the ice film where the optical and thermal properties of the nanoparticles are probed. Spatial fluorescence mapping shows the locations of Au nanoparticles, whereas the time-resolved Raman signal of ice reveals the melting process. From the time-dependent Raman signals, we determine the critical light intensities at which the laser beam is able to melt ice around the nanoparticles. The melting intensity depends strongly on temperature and position. The position-dependence is especially strong and reflects a mesoscopic character of heat generation. We think that it comes from the fact that nanoparticles form small complexes of different geometry and each complex has a unique thermal response. Theoretical calculations and experimental data are combined to make a quantitative measure of the amount of heat generated by optically excited Au nanoparticles and agglomerates. The information obtained in this study can be used to design nanoscale heaters and actuators.

  4. Characterization of the embedded micromechanical device approach to the monolithic integration of MEMS with CMOS

    SciTech Connect

    Smith, J.H.; Montague, S.; Sniegowski, J.J.; Murray, J.R.

    1996-10-01

    Recently, a great deal of interest has developed in manufacturing processes that allow the monolithic integration of MicroElectroMechanical Systems (MEMS) with driving, controlling, and signal processing electronics. This integration promises to improve the performance of micromechanical devices as well as lower the cost of manufacturing, packaging, and instrumenting these devices by combining the micromechanical devices with a electronic devices in the same manufacturing and packaging process. In order to maintain modularity and overcome some of the manufacturing challenges of the CMOS-first approach to integration, we have developed a MEMS-first process. This process places the micromechanical devices in a shallow trench, planarizes the wafer, and seals the micromechanical devices in the trench. Then, a high-temperature anneal is performed after the devices are embedded in the trench prior to microelectronics processing. This anneal stress-relieves the micromechanical polysilicon and ensures that the subsequent thermal processing associated with fabrication of the microelectronic processing does not adversely affect the mechanical properties of the polysilicon structures. These wafers with the completed, planarized micromechanical devices are then used as starting material for conventional CMOS processes. The circuit yield for the process has exceeded 98%. A description of the integration technology, the refinements to the technology, and wafer-scale parametric measurements of device characteristics is presented. Additionally, the performance of integrated sensing devices built using this technology is presented.

  5. ZnO nanoparticles embedded in UVM-7-like mesoporous silica materials: Synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Haskouri, Jamal El; Dallali, Lobna; Fernández, Lorenzo; Garro, Nuría; Jaziri, Sihem; Latorre, Julio; Guillem, Carmen; Beltrán, Aurelio; Beltrán, Daniel; Amorós, Pedro

    2009-11-01

    ZnO nanodomains embedded in bimodal mesoporous silica (UVM-7) materials with high Zn content (4≤Si/Zn≤30) have been synthesized by an one-pot surfactant-assisted procedure from a hydro alcoholic medium using a cationic surfactant (CTMABr=cetyltrimethylammonium bromide) as structural directing agent, and starting from molecular atrane complexes of Zn and Si as hydrolytic inorganic precursors. This chemical procedure allows optimizing the dispersion of the ZnO particles in the silica walls. The bimodal mesoporous nature of the final high surface area nano-sized materials is confirmed by XRD, TEM, and N 2 adsorption-desorption isotherms. The small intra-particle mesopore system is due to the supramolecular templating effect of the surfactant, while the large pores have their origin in the packing voids generated by aggregation of the primary nanometric mesoporous particles. A limited pore blocking and a high accessibility to the ZnO active nanoparticles have been achieved. The effects induced by the progressive incorporation of ZnO nanoparticles into the mesostructure have been examined, including a careful optical spectroscopic study (PL and UV-visible).

  6. Freeze substitution followed by low melting point wax embedding preserves histomorphology and allows protein and mRNA localization techniques.

    PubMed

    Durán, Iván; Marí-Beffa, Manuel; Santamaría, Jesús A; Becerra, José; Santos-Ruiz, Leonor

    2011-05-01

    Fixation and embedding are major steps in tissue preservation for histological analysis. However, conventional fixatives like aldehyde-based solutions usually mask tissular epitopes preventing their immunolocalization. Alternative fixation methods used to avoid this drawback, such as cryopreservation, alcohol- or zinc salts-based fixatives do not efficiently preserve tissue and cell morphology. Likewise, paraffin and resin embedding, commonly used for thin sectioning, frequently damage epitopes due to the clearing agents and high temperatures needed along the embedding procedure. Alternatives like cryosectioning avoid the embedding steps but yield sections of poorer quality and are not suitable for all kinds of samples. To overcome these handicaps, we have developed a method that preserves histoarchitecture as well as tissue antigenic properties. This method, which we have named CryoWax, involves freeze substitution of the samples in isopentane and methanol, followed by embedding in low melting point polyester wax. CryoWax has proven efficient in obtaining thin sections of embryos and adult tissues from different species, including amphioxus, zebrafish, and mouse. CryoWax sections displayed optimal preservation of tissue morphology and were successfully immunostained for fixation- and temperature-sensitive antigens. Furthermore, CryoWax has been tested for in situ hybridization application, obtaining positive results. Copyright © 2010 Wiley-Liss, Inc.

  7. High-throughput techniques for compound characterization and purification.

    PubMed

    Kyranos, J N; Cai, H; Zhang, B; Goetzinger, W K

    2001-11-01

    A new paradigm in drug discovery is the synthesis of structurally diverse collections of compounds, so-called libraries, followed by high-throughput biological screening. High-throughput characterization and purification techniques are required to provide high-quality compounds and reliable biological data, which has led to the development of faster methods, system automation and parallel approaches. This review summarizes recent advances in support of analytical characterization and preparative purification technologies. Notably, mass spectrometry (MS) and supercritical fluid chromatography (SFC) are among the areas where new developments have had a major impact on defining these high-throughput applications.

  8. Application of the FICTION technique for the simultaneous detection of immunophenotype and chromosomal abnormalities in routinely fixed, paraffin wax embedded bone marrow trephines.

    PubMed

    Korac, P; Jones, M; Dominis, M; Kusec, R; Mason, D Y; Banham, A H; Ventura, R A

    2005-12-01

    The use of interphase fluorescence in situ hybridisation (FISH) to study cytogenetic abnormalities in routinely fixed paraffin wax embedded tissue has become commonplace over the past decade. However, very few studies have applied FISH to routinely fixed bone marrow trephines (BMTs). This may be because of the acid based decalcification methods that are commonly used during the processing of BMTs, which may adversely affect the suitability of the sample for FISH analysis. For the first time, this report describes the simultaneous application of FISH and immunofluorescent staining (the FICTION technique) to formalin fixed, EDTA decalcified and paraffin wax embedded BMTs. This technique allows the direct correlation of genetic abnormalities to immunophenotype, and therefore will be particularly useful for the identification of genetic abnormalities in specific tumour cells present in BMTs. The application of this to routine clinical practice will assist diagnosis and the detection of minimal residual disease.

  9. Application of the FICTION technique for the simultaneous detection of immunophenotype and chromosomal abnormalities in routinely fixed, paraffin wax embedded bone marrow trephines

    PubMed Central

    Korać, P; Jones, M; Dominis, M; Kušec, R; Mason, D Y; Banham, A H; Ventura, R A

    2005-01-01

    The use of interphase fluorescence in situ hybridisation (FISH) to study cytogenetic abnormalities in routinely fixed paraffin wax embedded tissue has become commonplace over the past decade. However, very few studies have applied FISH to routinely fixed bone marrow trephines (BMTs). This may be because of the acid based decalcification methods that are commonly used during the processing of BMTs, which may adversely affect the suitability of the sample for FISH analysis. For the first time, this report describes the simultaneous application of FISH and immunofluorescent staining (the FICTION technique) to formalin fixed, EDTA decalcified and paraffin wax embedded BMTs. This technique allows the direct correlation of genetic abnormalities to immunophenotype, and therefore will be particularly useful for the identification of genetic abnormalities in specific tumour cells present in BMTs. The application of this to routine clinical practice will assist diagnosis and the detection of minimal residual disease. PMID:16311361

  10. Colorimetry Technique for Scalable Characterization of Suspended Graphene.

    PubMed

    Cartamil-Bueno, Santiago J; Steeneken, Peter G; Centeno, Alba; Zurutuza, Amaia; van der Zant, Herre S J; Houri, Samer

    2016-11-09

    Previous statistical studies on the mechanical properties of chemical-vapor-deposited (CVD) suspended graphene membranes have been performed by means of measuring individual devices or with techniques that affect the material. Here, we present a colorimetry technique as a parallel, noninvasive, and affordable way of characterizing suspended graphene devices. We exploit Newton's rings interference patterns to study the deformation of a double-layer graphene drum 13.2 μm in diameter when a pressure step is applied. By studying the time evolution of the deformation, we find that filling the drum cavity with air is 2-5 times slower than when it is purged.

  11. 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.

  12. Synthesis, characterization and application of Lagerstroemia speciosa embedded magnetic nanoparticle for Cr(VI) adsorption from aqueous solution.

    PubMed

    Srivastava, Shalini; Agrawal, Shashi Bhushan; Mondal, Monoj Kumar

    2017-05-01

    Lagerstroemia speciosa bark (LB) embedded magnetic nanoparticles were prepared by co-precipitation of Fe(2+) and Fe(3+) salt solution with ammonia and LB for Cr(VI) removal from aqueous solution. The native LB, magnetic nanoparticle (MNP), L. speciosa embedded magnetic nanoparticle (MNPLB) and Cr(VI) adsorbed MNPLB particles were characterized by SEM-EDX, TEM, BET-surface area, FT-IR, XRD and TGA methods. TEM analysis confirmed nearly spherical shape of MNP with an average diameter of 8.76nm and the surface modification did not result in the phase change of MNP as established by XRD analysis, while led to the formation of secondary particles of MNPLB with diameter of 18.54nm. Characterization results revealed covalent binding between the hydroxyl group of MNP and carboxyl group of LB particles and further confirmed its physico-chemical nature favorable for Cr(VI) adsorption. The Cr(VI) adsorption on to MNPLB particle as an adsorbent was tested under different contact time, initial Cr(VI) concentration, adsorbent dose, initial pH, temperature and agitation speed. The results of the equilibrium and kinetics of adsorption were well described by Langmuir isotherm and pseudo-second-order model, respectively. The thermodynamic parameters suggest spontaneous and endothermic nature of Cr(VI) adsorption onto MNPLB. The maximum adsorption capacity for MNPLB was calculated to be 434.78mg/g and these particles even after Cr(VI) adsorption were collected effortlessly from the aqueous solution by a magnet. The desorption of Cr(VI)-adsorbed MNPLB was found to be more than 93.72% with spent MNPLB depicting eleven successive adsorption-desorption cycles. Copyright © 2016. Published by Elsevier B.V.

  13. New microarchitectures of (Er,Yb):Lu2O3 nanocrystals embedded in PMMA: synthesis, structural characterization, and luminescent properties

    PubMed Central

    2013-01-01

    We report the formation of two-dimensional disordered arrays of poly(methyl)methacrylate (PMMA) microcolumns with embedded single size distribution of Lu0.990Er0.520Yb0.490 nanocrystals, (Er,Yb):Lu2O3, using a disordered porous silicon template. The cubic (Er,Yb):Lu2O3 nanocrystals, which crystallize into the cubic system with Ia3¯ space group, were synthesized using the modified Pechini method. Electronic microscopic techniques were used to study the distribution of the nanocrystals in the PMMA columns. Cathodoluminescence was used to observe the visible luminescence of the particles. Red emission attributed to 4 F9/2 → 4I15/2 erbium transition is predominant in these new composites. PMID:24034270

  14. Effects of catgut-embedding acupuncture technique on nitric oxide levels and blood pressure in patients with essential hypertension

    NASA Astrophysics Data System (ADS)

    Suhana; Srilestari, A.; Marbun, M. B. H.; Mihardja, H.

    2017-08-01

    Hypertension is common a health problem and its prevalence in Indonesia is quite high (31.7%). Catgut embedding—an acupuncture technique—is known to reduce blood pressure; however, no study has confirmed the underlying mechanism. This study examines the effect of catgut embedding on serum nitric oxide (NO) concentration and blood pressure in patients with essential hypertension. Forty hypertension patients were randomly assigned to two groups: the control group received anti-hypertensive drugs whereas the case group received anti-hypertensive drugs and catgut embedding. Results showed a statistically significant mean difference in NO concentration (p < 0.05) and statistically and clinically significant mean difference in systolic and diastolic blood pressure between the two groups (p < 0.05). The results confirm that catgut embedding can influence serum NO concentration and blood pressure in essential hypertension patients.

  15. Physicochemical characterization techniques for solid lipid nanoparticles: principles and limitations.

    PubMed

    Kathe, Niranjan; Henriksen, Brian; Chauhan, Harsh

    2014-12-01

    Solid lipid nanoparticles (SLNs) are gaining importance due to numerous advantages they offer as a drug delivery system. SLN incorporate poorly soluble drugs, proteins, biologicals, etc. SLN are prepared by techniques like high-pressure homogenization, sonication and employs a wide range of lipids and surfactants. Physicochemical characterization techniques include particle size analysis, zeta potential and determination of crystallinity/polymorphism. Furthermore, drug loading and drug entrapment efficiency are common parameters used to test the efficiency of SLN. Most importantly, the functionality assay of SLN is essential to predict the activity and performance in vivo. The review presented discusses the importance of SLN in drug delivery with emphasis on principles and limitations associated with their physicochemical characterization.

  16. Characterization of Composite Materials Using Millimeter-Wave Techniques (Preprint)

    DTIC Science & Technology

    2011-11-01

    focused on to the sample via an off axis parabolic mirror (f/1.5), which provided high spatial resolution (diffraction limited) and a short depth of...AFRL-RX-WP-TP-2011-4380 CHARACTERIZATION OF COMPOSITE MATERIALS USING MILLIMETER-WAVE TECHNIQUES (PREPRINT) A.T. Cooney Ceramics Branch...Metals, Ceramics & Nondestructive Evaluation Division L. Owens, M. Bischoff, D.T. Petkie, and J.A. Deibel Wright State University

  17. Synthesis and Characterization of Metal Nanoparticle Embedded Conducting Polymer–Polyoxometalate Composites

    PubMed Central

    2008-01-01

    Phosphomolybdate has been employed simultaneously as the oxidizing agent for the monomer polymerization and the reduced polyoxometalate is used as reducing agent for the reduction of metal ions. The composites thus obtained have been characterized and may have many potential applications.

  18. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials.

    PubMed

    Swart, Hendrik C

    2017-08-04

    The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS), time of flight scanning ion mass spectrometry (TOF-SIMS) and High resolution transmission electron microscopy (HRTEM) for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF-SIMS are used for determining the surface chemical composition and valence state of the dopants. The role of XPS to determine the presence of defects in the phosphor matrix is also stated with the different examples. The role of HRTEM in combination with Energy dispersive spectroscopy (EDS) for nanoparticle characterization is also pointed out.

  19. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials

    PubMed Central

    2017-01-01

    The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS), time of flight scanning ion mass spectrometry (TOF-SIMS) and High resolution transmission electron microscopy (HRTEM) for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF-SIMS are used for determining the surface chemical composition and valence state of the dopants. The role of XPS to determine the presence of defects in the phosphor matrix is also stated with the different examples. The role of HRTEM in combination with Energy dispersive spectroscopy (EDS) for nanoparticle characterization is also pointed out. PMID:28777357

  20. 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.

  1. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%.

  2. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-07-07

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.

  3. 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.

  4. Imaging techniques applied to characterize bitumen and bituminous emulsions.

    PubMed

    Rodríguez-Valverde, M A; Ramón-Torregrosa, P; Páez-Dueñas, A; Cabrerizo-Vílchez, M A; Hidalgo-Alvarez, R

    2008-01-15

    The purpose of this article is to present some important advances in the imaging techniques currently used in the characterization of bitumen and bituminous emulsions. Bitumen exhibits some properties, such as a black colour and a reflecting surface at rest, which permit the use of optical techniques to study the macroscopic behaviour of asphalt mixes in the cold mix technology based on emulsion use. Imaging techniques allow monitoring in situ the bitumen thermal sensitivity as well as the complex phenomenon of emulsion breaking. Evaporation-driven breaking was evaluated from the shape of evaporating emulsion drops deposited onto non-porous and hydrophobic substrates. To describe the breaking kinetics, top-view images of a drying emulsion drop placed on an aggregate sheet were acquired and processed properly. We can conclude that computer-aided image analysis in road pavement engineering can elucidate the mechanism of breaking and curing of bituminous emulsion.

  5. Characterizing the nature of embedded young stellar objects through silicate, ice and millimeter observations

    NASA Astrophysics Data System (ADS)

    Crapsi, A.; van Dishoeck, E. F.; Hogerheijde, M. R.; Pontoppidan, K. M.; Dullemond, C. P.

    2008-07-01

    Context: Determining the evolutionary stage of a Young Stellar Object (YSO) is of fundamental importance to test star formation theories. Classification schemes for YSOs are based on evaluating the degree of dissipation of the surrounding envelope, whose main effects are the extinction of the optical radiation from the central YSO and re-emission in the far-infrared to millimeter part of the electromagnetic spectrum. Since extinction is a property of column density along the line of sight, the presence of a protoplanetary disk may lead to a misclassification of pre-main sequence stars with disks when viewed edge-on. Aims: We performed radiative transfer calculations to show the effects of different geometries on the main indicators of YSO evolutionary stage. In particular we tested not only the effects on the infrared colors, like the slope α of the flux between 2.2 and 24 μm, but also on other popular indicators of YSO evolutionary stage, such as the bolometric temperature and the optical depth of silicates and ices. Methods: We used the axisymmetric 3D radiative transfer codes RADMC and RADICAL to calculate the spectral energy distribution including silicates and ice features in a grid of models covering the range of physical properties typical of embedded and pre-main sequence sources. Results: Our set of models compares well with existing observations, supporting the assumed density parametrization and the adopted dust opacities. We show that for systems viewed at intermediate angles (25°-70°) the “classical” indicators of evolution are able to classify the degree of evolution of young stellar objects since they accurately trace the envelope column density, and they all agree with each other. On the other hand, edge-on system are misclassified for inclinations larger than 65° ± 5°, where the spread is mostly due to the range of mass and the flaring degree of the disk. In particular, silicate emission, typical of pre-main sequence stars with disks

  6. New and Evolving Techniques for the Characterization of Peptide Therapeutics.

    PubMed

    D'Addio, Suzanne M; Bothe, Jameson R; Neri, Claudia; Walsh, Paul L; Zhang, Jingtao; Pierson, Elizabeth; Mao, Yun; Gindy, Marian; Leone, Anthony; Templeton, Allen C

    2016-10-01

    Advances in technologies related to the design and manufacture of therapeutic peptides have enabled researchers to overcome the biological and technological challenges that have limited their application in the past. As a result, peptides of increasing complexity have become progressively important against a variety of disease targets. Developing peptide drug products brings with it unique scientific challenges consistent with the unique physicochemical properties of peptide molecules. The identification of the proper characterization tools is required in order to develop peptide formulations with the appropriate stability, manufacturability, and bioperformance characteristics. This knowledge supports the build of critical quality attributes and, ultimately, regulatory specifications. The purpose of this review article is to provide an overview of the techniques that are employed for analytical characterization of peptide drug products. The techniques covered are highlighted in the context of peptide drug product understanding and include chemical and biophysical approaches. Emphasis is placed on summarizing the recent literature experience in the field. Finally, the authors provide regulatory perspective on these characterization approaches and discuss some potential areas for further research in the field. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  7. Wafer hot spot identification through advanced photomask characterization techniques

    NASA Astrophysics Data System (ADS)

    Choi, Yohan; Green, Michael; McMurran, Jeff; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike

    2016-10-01

    As device manufacturers progress through advanced technology nodes, limitations in standard 1-dimensional (1D) mask Critical Dimension (CD) metrics are becoming apparent. Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that the classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on subresolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. These items are not quantifiable with the 1D metrology techniques of today. Likewise, the mask maker needs advanced characterization methods in order to optimize the mask process to meet the wafer lithographer's needs. These advanced characterization metrics are what is needed to harmonize mask and wafer processes for enhanced wafer hot spot analysis. In this paper, we study advanced mask pattern characterization techniques and their correlation with modeled wafer performance.

  8. 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.

  9. Characterization Techniques for Aggregated Nanomaterials in Biological and Environmental Systems

    NASA Astrophysics Data System (ADS)

    Jeon, Seongho

    Nanoparticles, which are defined as objects with characteristic lengths in the 10--9 -- 10--7 m (nanoscale) size range, are used with increasing frequency in a wide of applications, leading to increases in nanomaterial interactions with biological and environmental systems. There is therefore considerable interest in studying the influence nanomaterials can have when inside the human body or dispersed in the ambient environment. However, nanoparticles persist as homo aggregates or heterogeneous mixtures with organic matters, such as proteins, in biological and environmental systems. A large and growing body of research confirm that nanomaterial morphology as well as the degree of aggregation between nanomaterials influences nanomaterial interactions with their surroundings. Specifically, the structures/morphologies of nanoparticles determine their overall surface areas and corresponding surface reactivity (e.g. their catalytic activity). Nanoparticle transport properties (e.g. diffusion coefficient and extent of cellular uptake) are also determined by both their structures and surface properties. Unfortunately, techniques to characterize nanomaterial size and shape quantitatively, when nanomaterials have complex geometries or persist as aggregates, are lacking. Hydrodynamic sizes of nanoparticles and their aggregates can be inferred by dynamic light scattering (DLS) or nanoparticle tracking analysis (NTA). However, since these techniques are relied on the scattering light intensity properties, sizes of polydisperse sub 30 nm particles cannot be effectively measured in those techniques. For structure inference of aggregated nanomaterials, microscopy images have been used for qualitative visual analysis, but the quantitative morphology analysis technique is yet to be developed. Five studies in this dissertation are hence aimed to develop new techniques to provide improved morphology characterization of aggregated nanomaterials in various biological and environmental

  10. Synthesis and characterization of nano Cdo/NiO, nano Ag/ZnO composites & Ag/Zno embedded polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Godasu, Rahul

    Nanoparticles are finest structures whose size composition is within nanometer range. Thus nanoparticles are a collection of atoms bonded together with structural radius less than 100 nm. Nanocomposites are multiphase solid materials where one of the phases has one, two or three dimensions of less than 100 mn. Nano composites are prepared to improve mechanical, electrical, thermal, optical, electrochemical, catalytic properties from its parent materials. For instance, blend of nanoparticles with a polymer are called polymer nanocomposites. Nanostructured composites like Cadmium oxide/Nickel oxide (CdO/NiO) and silver/zinc oxide (Ag/ZnO) were prepared. Characterization of these prepared nanocomposites were carried out using X-ray powder diffraction, Differential scanning calorimetry, Scanning electron microscopy and the average sizes were determined using zeta sizer. Results obtained using characterization methods were in agreement stating that we were successful in synthesizing composites. The prepared Ag/ZnO nano composite was embedded in PCL polymer and we made films of PCL embedded with nano composite. The SEM image of the 5% Ag/ZnO embedded film clearly shows two regions, which indicates that Ag/ZnO nano composite was successfully embedded into the polymer using a non insitu method. SEM results also showed that the Zinc Oxide nano particles were successfully embedded into the polymer .

  11. Detection of Clostridium chauvoei in formalin-fixed, paraffin-embedded tissues of sheep by the peroxidase-antiperoxidase (PAP) technique.

    PubMed

    Giraudo Conesa, L C; Vannelli, S A; Uzal, F A

    1995-01-01

    A peroxidase-antiperoxidase (PAP) technique was used to detect Clostridium chauvoei in tissue sections from sheep inoculated intramuscularly with a pure culture of this microorganism. Samples of various tissues were taken for bacteriology, histopathology and immunohistochemistry. A primary antiserum against C. chauvoei for use in the PAP technique was produced in rabbits. Formalin-fixed, paraffin-embedded sections of muscle samples were positively and specifically stained by the PAP technique. The results were consistent with those obtained by bacteriology, but the PAP test was simpler, quicker and less expensive than the bacteriological procedures. The use of the PAP technique would be appropriate for detecting clostridial infections without the constraints of conventional identification methods, especially where laboratory conditions for anaerobic procedures are not readily available.

  12. Characterization of Tibetan Medicine Zuota by Multiple Techniques

    PubMed Central

    Sun, Mei; Wang, Jing-Xia; Xu, Yun-Zhang; Liu, Yuan; Zhang, Zhi-Feng; Lu, Lu-Yang

    2013-01-01

    Zuota is regarded as the king of Tibetan medicine. However, due to the confidentiality of this precious medicine, the scientific characterization of Zuota is very scarce, which limits the pharmacology and biosafety studies of Zuota. Herein, we collected four different Zuota samples from Tibet, Qinghai, Gansu, and Sichuan and characterized them by multiple techniques. Our results showed that Zuota was mainly an inorganic mixture of HgS, sulfur, and graphite. Morphologically, Zuota samples were composed of nanoparticles, which further aggregated into microsized particles. Chemically, the majorities of Zuota were S and Hg (in the forms of HgS and pure sulfur). All samples contained pure sulfur with orthorhombic crystalline. Zuota from Qinghai province had different HgS crystalline, namely, hexagonal crystalline. The others were all face-centered cubic crystalline. Carbon in Zuota NPs was in the form of graphite. The implication to future studies of Zuota was discussed. PMID:24093005

  13. Speciation and Characterization of E-Waste, Using Analytical Techniques

    NASA Astrophysics Data System (ADS)

    López, C. Cortés; Cruz, V. E. Reyes; Rodríguez, M. A. Veloz; Ávila, J. Hernández; Badillo, J. Flores; Murcia, J. A. Cobos

    Electronic waste (e-waste), have a high potential as a source of precious metals, since they can contain metals like silver, gold, platinum, copper, zinc, nickel, tin and others. In this paper some e-waste were characterized using several analytical techniques as Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and inductively coupled plasma (ICP) in addition to the thermodynamic study by Pourbaix diagrams of silver (Ag), gold (Au), platinum (Pt), copper (Cu), nickel (Ni), tin (Sn) and zinc (Zn); considering an average low concentration of HNO3 (10% v/v). With results of the characterization was determined that the e-waste is an ideal source for the recovery of valuable metals. Similarly, the thermodynamic studies showed that it is possible to obtain all metallic species except Pt, in a potential window of 1.45V to 2.0V vs SCE.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Residual stress characterization with an ultrasonic/magnetic technique

    NASA Technical Reports Server (NTRS)

    Namkung, M.; Heyman, J. S.

    1984-01-01

    A potentially useful new technique for residual stress characterization in ferromagnetic material is described. The unique feature of this technique is the measurement of small changes in ultrasonic wave velocity by the application of external dc magnetic field in the material under various stress conditions. It was found, in steel, that the fractional change in the natural velocity Delta W/W of waves propagating along the external field direction is affected by the uniaxial stress applied in the same axis. External compression lowers the slope of the Delta W/W curve in the low field region, while external tension generally does the opposite. For most cases, the slope in this region falls below zero under external compression. The result of measurements in specimens with residual stress shows exactly the same tendency.

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

    PubMed

    Aguilar, P A; 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 microm.

  20. Interactions Between Antigens and Nanoemulsion Adjuvants: Separation and Characterization Techniques.

    PubMed

    Chan, Michelle Y; Fedor, Dawn M; Phan, Tony; V, Lucien Barnes; Kramer, Ryan M

    2017-01-01

    Determining the association of vaccine components in a formulation is of interest for designing and optimizing well characterized vaccines. Three methods are described to assess interactions between protein antigens and oil-in-water nanoemulsion adjuvants. The methods include (1) ultracentrifugation to measure free versus adjuvant-associated protein, (2) size exclusion chromatography (SEC) to qualitatively assess existing interactions, and (3) Native PAGE as a means to visualize the formulation run in its native state on a polyacrylamide gel. As with many techniques, the methods alone are not definitive, but data from multiple orthogonal assays can provide a more complete picture of protein-adjuvant interactions.

  1. Thermal imaging technique to characterize laser light reflection from thermoplastics

    NASA Astrophysics Data System (ADS)

    Azhikannickal, Elizabeth; Bates, Philip J.; Zak, Gene

    2012-07-01

    Characterization of laser light reflection during the laser transmission welding (LTW) of thermoplastics is especially important for applications in which non-zero laser incidence angles are used. At higher laser incidence angles, reflection increases and has the potential to burn surrounding features of the part to be welded. This study presents and validates a technique for laser reflection measurement. Reflected energy is absorbed by a black plastic plate (containing carbon black, which is the absorber of the reflected energy). The surface temperature of the plate is measured by an infrared (IR) camera. The distribution of reflected power required to generate this temperature profile is estimated using a simple heat transfer model. The technique was validated by irradiating the black plate by the laser directly, while observing the time-varying temperature distribution of the plate by the IR camera. In this case, good agreement was observed between the estimated total power and the actual laser input power. Good agreement also existed between the estimated power distribution and that determined experimentally via a knife edge based beam profiling technique. The thermal imaging technique was subsequently used to measure the magnitude and distribution of laser light reflection from unreinforced nylon 6. Abbreviations: LTW—laser transmission welding, CB—carbon black, IR—infrared, NPFD—normalized power flux distribution

  2. 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.

  3. Synthesis, characterization and electrical property of MWCNT-ZnS nanocomposite embedded in polyaniline

    NASA Astrophysics Data System (ADS)

    Goswami, M.; Mukherjee, A.; Das, A. K.; Ghosh, R.; Meikap, A. K.

    2017-06-01

    PANI/MWCNT-ZnS nanocomposites with different contents of ZnS wt.% have been synthesized by the chemical oxidative in situ polymerization reaction of aniline in the presence of multi-walled carbon nanotube (MWCNT). TEM, XRD, RAMAN and TGA studies have been done for the structural and thermal characterizations of the samples. The particle sizes of ZnS nanoparticles have the values in the range from 3.21 to 5.08 nm. XRD spectrum reveals the co-existence of MWCNT, ZnS in PANI matrix, where ZnS forms a hexagonal structure. TGA result shows that nanocomposite becomes more thermally stable with increase in ZnS content. The dc electrical transport property of PANI/MWCNT-ZnS nanocomposites has been investigated within a temperature range 77 K  ⩽  T  ⩽  300 K. The dc conductivity follows a 3D variable range hopping (VRH) model. A large magnetoconductivity change (23.1%) is observed for 2 wt.% ZnS content in PANI/MWCNT-ZnS, which is explained by the wave function shrinkage model.

  4. Low tip damage AFM technique development for nano structures characterization

    NASA Astrophysics Data System (ADS)

    Liu, Biao; Wang, Charles C.; Huang, Po-Fu; Uritsky, Yuri

    2010-06-01

    Ambient dynamic mode (tapping mode or intermittent-contact mode) AFM imaging has been used extensively for the characterization of the topography of nano structures. However, the results are beset with artifacts, because hard tapping of the AFM tip on sample surface usually causes premature tip damage. Through careful study of the cantilever amplitude and phase signals as functions of tip-to-sample distance, principle of non-contact AFM operation was discovered to enable high resolution and low tip damage AFM image acquisition [1, 2]. However, current study discovers that the conventional way of acquiring amplitude and phase versus distance curves gives erroneous non-contact operating range, because the tip gets damaged during the data acquisition process. A new technique is developed to reliably map the operating parameters of an intact tip that ensures the AFM be operated with the correct non-contact settings. Two examples are given to illustrate the successful applications of this new technique. The first example involves the size characterization of polystyrene latex (PSL) nano particles used for light scattering tool calibration. The second example is the development of robust recipes for the measurement of the depth of phase-shift mask trenches.

  5. Characterization of micro-generators embedded in commercial-off-the-shelf watches for wearable energy harvesting

    NASA Astrophysics Data System (ADS)

    Xue, Tiancheng; Kakkar, Shantnu; Lin, Qianyu; Roundy, Shad

    2016-04-01

    This paper presents the characterization of the micro-generators embedded in Commercial-Off-The-Shelf (COTS) watches based on a generalized rotational energy harvester model which predicts the upper bound on energy generation given certain system constraints and specific inputs. We augment this generalized model to represent the actual micro-generator used in the Seiko Kinetic watch with realistic damping coefficients which allow us to identify optimizations to move the system output towards the upper bound. We have developed a mobile data logging platform which captures 6 DOF inertia data and the voltage output from the micro-generator simultaneously. We have asked 6 subjects to conduct a series of daily activities with the platform worn on different locations of the body. This effort not only serves as the experimental validation of our model but also provides insight into the state of the art in wearable kinetic energy harvesting devices that are commercially available. Finally we identify the opportunity for improvement on energy generation and show that we can increase the power by reducing the mechanical damping in the system, which might require an alternative mechanism with inherent lower friction.

  6. A rapid plastic embedding technique for preparation of three-micron thick sections of decalcified hard tissue.

    PubMed

    Kimmel, D; Jee, W S

    1975-03-01

    A 24 hour start-to-finish method is described for the preparation of three-micron-thick sections of decalcified hard tissues. Following acetone dehydration, the tissue to be embedded is infiltrated under vacuum with a series of graded clearing solutions which approach the content of the final methyl methacrylate mixture. After overnight in a 35 C oven, the plastic is polymerized by four hours heating at 42 C. Three-micron-thick sections are then easily prepared by using a Jung microtome for high resolution histologic or detailed autoradiographic procedures.

  7. Molecular Detection and Genotypic Characterization of Toxoplasma gondii in Paraffin-Embedded Fetoplacental Tissues of Women with Recurrent Spontaneous Abortion

    PubMed Central

    Abdoli, Amir; Dalimi, Abdolhossein; Soltanghoraee, Haleh; Ghaffarifar, Fatemeh

    2017-01-01

    Background Congenital toxoplasmosis is an important cause of spontaneous abortion worldwide. However, there is limited information on detection and genotypic characterization of Toxoplasma gondii (T. gondii) in women with recurrent spontaneous abortion (RSA). The aim of this study is the molecular detection and genotypic characterization of T. gondii in formalin-fixed, paraffin-embedded fetoplacental tissues (FFPTs) of women with RSA that have referred to the Avicenna Research Institute in Tehran, Iran. Materials and Methods This experimental research was undertaken on 210 FFPTs of women with RSA. The information of the patients was collected from the archives of Avicenna Research Institute in Tehran, Iran. After DNA extraction, the presence of T. gondii was examined by nested polymerase chain reaction targeting the GRA6 gene. Genotyping was performed on positive samples using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) that targeted the GRA6 and SAG3 genes. Sequencing was conducted on two GRA6 positive samples. Results T. gondii DNA was detected in 3.8% (8/210) of the samples. Genotyping showed that all positive samples belonged to type III of the T. gondii genotype. Sequencing two genomic DNAs of the GRA6 gene revealed 99% similarity with each other and 99-100% similarity with T. gondii sequences deposited in GenBank. There were six patients with histories of more than three abortions; one patient had a healthy girl and another patient had two previous abortions. Abortions occurred in the first trimester of pregnancy in seven patients and in the second trimester of pregnancy in one patient. Conclusion The results of this study have indicated that genotype III is the predominant type of T. gondii in women with RSA in Tehran, Iran. Also, our findings suggest that toxoplasmosis may play a role in the pathogenesis of RSA. However, further studies are needed to elucidate a clear relationship between T. gondii infection and RSA. PMID

  8. 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. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  9. Advanced techniques for characterization of ion beam modified materials

    DOE PAGES

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; ...

    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

  10. 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.

  11. Application of linear graph embedding as a dimensionality reduction technique and sparse representation classifier as a post classifier for the classification of epilepsy risk levels from EEG signals

    NASA Astrophysics Data System (ADS)

    Prabhakar, Sunil Kumar; Rajaguru, Harikumar

    2015-12-01

    The most common and frequently occurring neurological disorder is epilepsy and the main method useful for the diagnosis of epilepsy is electroencephalogram (EEG) signal analysis. Due to the length of EEG recordings, EEG signal analysis method is quite time-consuming when it is processed manually by an expert. This paper proposes the application of Linear Graph Embedding (LGE) concept as a dimensionality reduction technique for processing the epileptic encephalographic signals and then it is classified using Sparse Representation Classifiers (SRC). SRC is used to analyze the classification of epilepsy risk levels from EEG signals and the parameters such as Sensitivity, Specificity, Time Delay, Quality Value, Performance Index and Accuracy are analyzed.

  12. A new characterization technique for lossy piezoceramic resonators

    NASA Astrophysics Data System (ADS)

    Pastore, Robert Allan, Jr.

    2000-11-01

    Piezoelectricity was discovered by the brothers Curie in 1880. They found that, in certain materials such as zincblende, tourmaline, can sugar, topaz and quartz, mechanical stresses were accompanied by the production of electric surface charges. The piezoelectric effect remained a curiosity until the early 1920s when it was utilized to realize crystal resonators for the stabilization of oscillators, thereby launching the field of frequency control. Piezoelectricity has found many applications as oscillators, filters, and sensors in televisions, cellular phones, radios, ultrasonic imaging, radar and signal processing to name just a few. Most of these applications use high Q single crystal materials such as quartz. These materials can become expensive as the application becomes more specialized. Piezoceramic materials can be used in these applications because it is less expensive, but the Q of the material is low and has very blunt characteristics as compared to quartz. This low Q and blunt resonance is connected to the loss in the material and makes it difficult to characterize the material and to get the maximum performance out of devices made from this material. We have developed a new characterization technique for lossy piezoceramic material based on the use of complex frequencies to stimulate the devices complex resonant point. This technique enables us to find the frequency dependent attenuation constant, and the impedance at the complex resonant point. The material properties of piezoceramics can be described through the use of complex material constants. The solution of the acoustic wave equation leads to complex frequencies as the resonant points for a thickness excited resonator. This leads to the use of complex frequency excitation, which is an exponentially decaying sine wave. The Laplace transform of this type of signal has an imaginary part which is the frequency and the real part which is related to the attenuation of the device. So this type of

  13. Characterization of ultrafast devices using novel optical techniques

    NASA Astrophysics Data System (ADS)

    Ali, Md Ershad

    Optical techniques have been extensively used to examine the high frequency performance of a number of devices including High Electron Mobility Transistors (HEMTs), Heterojunction Bipolar Phototransistors (HPTs) and Low Temperature GaAs (LT-GaAs) Photoconductive Switches. To characterize devices, frequency and time domain techniques, namely optical heterodyning and electro-optic sampling, having measurement bandwidths in excess of 200 GHz, were employed. Optical mixing in three-terminal devices has been extended for the first time to submillimeter wave frequencies. Using a new generation of 50-nm gate pseudomorphic InP-based HEMTs, optically mixed signals were detected to 552 GHz with a signal-to-noise ratio of approximately 5 dB. To the best of our knowledge, this is the highest frequency optical mixing obtained in three- terminal devices to date. A novel harmonic three-wave detection scheme was used for the detection of the optically generated signals. The technique involved downconversion of the signal in the device by the second harmonic of a gate-injected millimeter wave local oscillator. Measurements were also conducted up to 212 GHz using direct optical mixing and up to 382 GHz using a fundamental three-wave detection scheme. New interesting features in the bias dependence of the optically mixed signals have been reported. An exciting novel development from this work is the successful integration of near-field optics with optical heterodyning. The technique, called near-field optical heterodyning (NFOH), allows for extremely localized injection of high-frequency stimulus to any arbitrary point of an ultrafast device or circuit. Scanning the point of injection across the sample provides details of the high frequency operation of the device with high spatial resolution. For the implementation of the technique, fiber-optic probes with 100 nm apertures were fabricated. A feedback controlled positioning system was built for accurate placement and scanning of the

  14. 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.

  15. Nondestructive characterization of prepreg ageing using nuclear magnetic resonance techniques

    SciTech Connect

    Koeller, E.; Dobmann, G.; Kuhn, W. )

    1990-01-01

    Initial results are presented on the application of NMR techniques to prepregs in order to characterize the crosslink state under exposure to room and elevated (50 C) temperature. The experiments were conducted with a MSL-400 Bruker NMR spectrometer and microimaging system which works at 400 MHz. Aside from the sensitive measurement of the cross-link density there is also the potential to separate the influence of moisture content as a further parameter contributing to the aging process. It is shown that these experimental results correlate with results of destructive tests and document the potential of NMR as a NDT tool. An NMR-image of the moisture distribution in a glassfiber reinforced expoxy resin sample is shown. 17 refs.

  16. 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.

  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. 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.

  19. Different techniques for characterizing single-walled carbon nanotube purity

    NASA Astrophysics Data System (ADS)

    Yuca, Neslihan; Camtakan, Zeyneb; Karatepe, Nilgün

    2013-09-01

    Transition-metal catalysts, fullerenes, graphitic carbon, amorphous carbon, and graphite flakes are the main impurities in carbon nanotubes. In this study, we demonstrate an easy and optimum method of cleaning SWCNTs and evaluating their purity. The purification method, which employed oxidative heat treatment followed by 6M HNO3, H2SO4, HNO3:H2SO4 and HCl acid reflux for 6h at 120°C and microwave digestion with 1.5M HNO3 for 0.5h at 210°C which was straightforward, inexpensive, and fairly effective. The purified materials were characterized by thermogravimetric analysis and nuclear techniques such as INAA, XRF and XRD.

  20. Technique for the estimation of surface temperatures from embedded temperature sensing for rapid, high energy surface deposition.

    SciTech Connect

    Watkins, Tyson R.; Schunk, Peter Randall; Roberts, Scott Alan

    2014-07-01

    Temperature histories on the surface of a body that has been subjected to a rapid, highenergy surface deposition process can be di cult to determine, especially if it is impossible to directly observe the surface or attach a temperature sensor to it. In this report, we explore two methods for estimating the temperature history of the surface through the use of a sensor embedded within the body very near to the surface. First, the maximum sensor temperature is directly correlated with the peak surface temperature. However, it is observed that the sensor data is both delayed in time and greatly attenuated in magnitude, making this approach unfeasible. Secondly, we propose an algorithm that involves tting the solution to a one-dimensional instantaneous energy solution problem to both the sensor data and to the results of a one-dimensional CVFEM code. This algorithm is shown to be able to estimate the surface temperature 20 C.

  1. Scanning microwave microscopy technique for nanoscale characterization of magnetic materials

    NASA Astrophysics Data System (ADS)

    Joseph, C. H.; Sardi, G. M.; Tuca, S. S.; Gramse, G.; Lucibello, A.; Proietti, E.; Kienberger, F.; Marcelli, R.

    2016-12-01

    In this work, microwave characterization of magnetic materials using the scanning microwave microscopy (SMM) technique is presented. The capabilities of the SMM are employed for analyzing and imaging local magnetic properties of the materials under test at the nanoscale. The analyses are performed by acquiring both amplitude and phase of the reflected microwave signal. The changes in the reflection coefficient S11 are related to the local properties of the material under investigation, and the changes in its magnetic properties have been studied as a function of an external DC magnetic bias. Yttrium iron garnet (YIG) films deposited by RF sputtering and grown by liquid phase epitaxial (LPE) on gadolinium gallium garnet (GGG) substrates and permalloy samples have been characterized. An equivalent electromagnetic transmission line model is discussed for the quantitative analysis of the local magnetic properties. We also observed the hysteretic behavior of the reflection coefficient S11 with an external bias field. The imaging and spectroscopy analysis on the experimental results are evidently indicating the possibilities of measuring local changes in the intrinsic magnetic properties on the surface of the material.

  2. Quantitative characterization of diesel sprays using digital imaging techniques

    NASA Astrophysics Data System (ADS)

    Shao, J.; Yan, Y.; Greeves, G.; Smith, S.

    2003-07-01

    This paper presents the application of digital imaging and image processing techniques for the quantitative characterization of diesel sprays. An optically accessible, constant volume chamber was configured to allow direct photographic imaging of diesel sprays, which were generated from a six-hole nozzle in a non-evaporating and pressurized environment. A high-resolution CCD camera and a flash light source were used to capture the images of the sprays. Dedicated image processing software has been developed to quantify a set of macroscopic, characteristic parameters of the sprays including tip penetration, near-and far-field angles. The spray parameters produced using this software are compared with those obtained using manual methods. The results obtained under typical spray conditions demonstrate that the software is capable of producing more accurate, consistent and efficient results than the manual methods. An application of the imaging processing software to the characterization of diesel sprays for a valve covered orifice nozzle is also presented and discussed.

  3. A new and improved "quick-hot Gram-chromotrope" technique that differentially stains microsporidian spores in clinical samples, including paraffin-embedded tissue sections.

    PubMed

    Moura, H; Schwartz, D A; Bornay-Llinares, F; Sodré, F C; Wallace, S; Visvesvara, G S

    1997-08-01

    This report describes a new and improved "quick-hot Gram-chromotrope" staining technique that detects microsporidian spores in clinical specimens, such as stool, urine, saliva, nasopharyngeal fluid, and bronchoalveolar lavage samples, as well as in formalin-fixed and paraffin-embedded tissue sections. In this procedure, the samples are stained in heated (50 degrees C to 55 degrees C) solutions of crystal violet and iodine used in Gram's stain, followed by a modified chromotrope solution (heated to 50 degrees C to 55 degrees C). The modified stain is composed of chromotrope 2R (1%), fast green (0.15%), and phosphotungstic acid (0.25%). With this stain and the new protocol, microsporidian spores are stained dark violet against a pale green background, and the total staining time is shortened to 5 minutes. This new technique is fast, reliable, and simple. It can be easily adapted for use in clinical laboratories.

  4. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models.

    PubMed

    Mondon, J A; Howitt, J; Tosiano, M; Kwok, K W H; Hinton, D E

    2011-01-01

    Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  5. Metal-Organic Frameworks to Metal/Metal Oxide Embedded Carbon Matrix: Synthesis, Characterization and Gas Sorption Properties.

    PubMed

    Chen, Jiun-Jen; Chen, Ya-Ting; Raja, Duraisamy Senthil; Kang, Yu-Hao; Tseng, Pen-Chang; Lin, Chia-Her

    2015-08-19

    Three isostructural metal-organic frameworks, (MOFs), [Fe(OH)(1,4-NDC)] (1), [Al(OH)(1,4-NDC)] (2), and [In(OH)(1,4-NDC)] (3) have been synthesized hydrothermally by using 1,4-naphthalene dicarboxylate (1,4-NDC) as a linker. The MOFs were characterized using various techniques and further used as precursor materials for the synthesis of metal/metal oxide nanoparticles inserted in a carbon matrix through a simple thermal conversion method. The newly synthesized carbon materials were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, powder X-ray diffraction and BET analysis. The results showed that the MOF-derived carbon composite materials maintained the morphology of the original MOF upon carbonization, and confirmed the insertion of metal/metal oxide particles in the carbon matrix.

  6. Ultrastructure of hyaline cartilage. I. A comparative study of cartilage from different species and locations, using cryofixation, freeze-substitution and low-temperature embedding techniques.

    PubMed

    Engfeldt, B; Hultenby, K; Müller, M

    1986-09-01

    Important progress in the cryofixation of tissues has recently been made with the introduction of a new technique which permits a great reduction in the rates of ice-crystal growth and nucleation by rapid freezing under a pressure of 2 100 bar. Tissue pieces up to 0.5 mm in thickness can now be processed at a freezing rate sufficient to prevent the formation of detectable ice crystals at the ultrastructural level. In the present investigation this technique, in combination with freeze substitution and low temperature embedding was applied for ultrastructural and immunocytochemical studies of hyaline cartilage. No extraction of matrix proteoglycans was observed during the substitution procedure, and there are good reasons to believe that in preparations obtained by this technique the native state of the matrix components is preserved, since, for example, the collapse temperature of the macromolecules is not exceeded. Furthermore, no chemical fixatives or cryoprotectants are required. Ultrastructural differences in the hyaline cartilage of the growth-plate between normal rats and mice were observed, and also differences between cartilage at different locations, such as tracheal cartilage and growth-plate. Using this technique, further comparative ultrastructural studies enable us to obtain information about the macromolecular organisation of cartilage matrix under various normal and pathological conditions in vivo. In addition, using monoclonal antibodies to the main macromolecules of the matrix, it was found that this technique not only provides excellent tissue preservation but is also well suited for immunocytochemistry with colloidal gold as a marker.

  7. Noncontact thermoacoustic detection of targets embedded in dispersive media

    NASA Astrophysics Data System (ADS)

    Boyle, Kevin C.; Nan, Hao; Khuri-Yakub, Butrus T.; Arbabian, Amin

    2016-10-01

    A microwave-induced thermoacoustic detection system for embedded targets in lossy media is presented. The system achieves reliable detection of 5 cm × 5 cm × 2 cm targets embedded in a large Agarose sample at a 20 cm acoustic standoff. Repeated measurements across different target and sample configurations confirm the system's ability to distinguish between a target signal and a baseline control signal generated by the package without embedded targets. Post-processing techniques including filtering and baseline signal characterization further improve detection performance.

  8. Characterization of a laser-beam spinning technique

    SciTech Connect

    Brandon, E.

    1990-06-01

    The objective of this study was to evaluate the beam spinning technique for bridging gaps in butt joints that are CO{sub 2} laser-welded. A device was designed and built to circularly oscillate a CO{sub 2} laser beam on the plant of a work surface. A series of welds was made using a continuous-wave output power of 805 watts, and the resultant weld bead profile was characterized as a function of three process parameters. From the experimental results, predictor equations were derived for laser-beam spinning speed and amplitude of the beam spinning pattern on the work surface. The data collected in this experiment indicate that the width of the weld bead is increased by oscillating the beam and that this increase may be made without significantly reducing the weld penetration. The increased width of the weld may offer a solution to variable gaps in weld joints, which has been a recurring production problem. 13 figs., 1 tab.

  9. 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.

  10. Nanocrystalline materials: recent advances in crystallographic characterization techniques.

    PubMed

    Ringe, Emilie

    2014-11-01

    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.

  11. Microstructural characterization of ferromagnetic materials using magnetic NDE techniques

    SciTech Connect

    Ranjan, R.

    1987-01-01

    Magnetic NDE techniques, namely, the acoustic Barkhausen noise, the magnetic Barkhausen noise, and the magnetic hysteresis curves were simultaneously used for microstructural characterization of nickel and steels. Results showed that, in nickel, the non-180/sup 0/ domain walls interact more strongly with dislocations than the 180/sup 0/ domain walls. A study of the grain-size effect on the magnetic and acoustic Barkhausen noises showed a great potential as a NDE grain-size-measurement tool. Moreover, the Barkhausen signals indicate that the 180/sup 0/ domain walls in nickel seem to have a stronger interaction with grain boundaries than the non-180/sup 0/ domain walls, as indicated by the acoustic Barkhausen signal. Based on the experimental observations, a theoretical model is being proposed to explain the grain size effect on the Barkhausen signals. The model takes into account the density of magnetic domain walls and their initial velocity, with both quantities being strongly dependent on microstructure. The acoustic and magnetic Barkhausen noises were also found to be very sensitive to the change in carbide morphology. It is proposed that the magnetic Barkhausen peak signal is caused by mainly domain nucleation and the acoustic Barkhausen peak signal due to domain growth.

  12. Microstructural characterization of ferromagnetic materials using magnetic NDE techniques

    SciTech Connect

    Ranjan, R.

    1987-06-01

    Magnetic NDE techniques, namely, the acoustic Barkhausen noise, the magnetic Barkhausen noise and the magnetic hysteresis curves, were simultaneously used for microstructural characterization of nickel and steels. Results showed that, in nickel, the non-180/sup 0/ domain walls interact more strongly with dislocations than the 180/sup 0/ domain walls. A study of the grain size effect on the magnetic and acoustic Barkhausen noises showed a great potential as a NDE grain size measurement tool. Moreover, the Barkhausen signals indicate that the 180/sup 0/ domain walls in nickel seem to have a stronger interaction with grain boundaries than the non-180/sup 0/ domain walls, as indicated by the acoustic Barkhausen signal. A theoretical model is being proposed to explain the grain size effect on the Barkhausen signals. The model takes into account the density of magnetic domain walls and their initial velocity, with both quantities being strongly dependent on microstructure. The acoustic and magnetic Barkhausen noises were also found to be very sensitive to the change in carbide morphology. It is proposed that the magnetic Barkhausen peak signal is caused by mainly domain nucleation and the acoustic Barkhausen peak signal due to domain growth.

  13. 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.

  14. Characterization of Lavandula spp. Honey Using Multivariate Techniques

    PubMed Central

    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

  15. 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

  16. 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.

  17. Characterization of a derivative chromosome 17 by fish-technique.

    PubMed

    Ramesh, K H; Shah, H O; Sherman, J; Lin, J H; Verma, R S

    1996-01-01

    We report a case with derivative chromosome 17 which could not be characterized by routine G-banding, since the additional material on 17q overlapped with chromosome bands 2q35 -->qter, 3p25-->pter, 4p15-->pter, 5q33-->qter, 7p15-->pter, 12p11.2-->pter, 14q24-->qter and 16q22-->qter. Therefore, whole chromosome paint and region specific probes were used to identify the abnormality by FISH-technique which revealed a 46,XY, der (17) t (4;17) (p15.2;q25) karyotype. The proband was partially trisomic for 4p15.2-->pter and monosomic for the distal 17q25-->qter regions. The major clinical features included: anti-mongoloid slanted palpebrae, coloboma of right iris, depressed nasal bridge, high arched palate, protruding tongue, micrognathia and small penis. The MRI of the brain revealed midly hypoplastic cerebellar vermis, and a normal septum pellucidum. The infant responded to therapy for hypoglycemia and was discharged under stable condition. Prior to cytogenetic evaluation the infant was not recognized as either "trisomy 4p syndrome" or "monosomy 17q syndrome".

  18. An ultrasonic array technique for material characterization of plate samples.

    PubMed

    Titov, Sergey; Maev, Roman Gr

    2013-07-01

    An ultrasonic system with a linear array for characterization of a layered specimen placed in immersion liquid parallel to the aperture of the array is considered. To estimate the longitudinal and transverse wave velocities as well as the thickness and density of the specimen, it is proposed to decompose the spatio-temporal data recorded by the array in a spectrum of plane pulse waves. Based on fitting the developed wave model of the system to the experimental data, it is shown that the relative delays and amplitudes of the spectral responses can be used for the estimation of the velocities and thickness of the layer and its density. The distortions of the plane wave spectrum caused by the spatial discretization of the array data are considered. It is proposed to suppress these distortions using individual interpolating processing of the received pulses separated in the spatio-temporal domain. The developed technique is experimentally verified on a fused quartz plate evaluated with a 17-MHz linear array. The relative reproducibility of the estimation is found to be 0.11% in the longitudinal wave velocity and thickness of the plate, and 0.5% and 5% in the transverse wave velocity and the density, respectively.

  19. Combining frozen-density embedding with the conductor-like screening model using Lagrangian techniques for response properties.

    PubMed

    Schieschke, Nils; Di Remigio, Roberto; Frediani, Luca; Heuser, Johannes; Höfener, Sebastian

    2017-07-15

    We present the explicit derivation of an approach to the multiscale description of molecules in complex environments that combines frozen-density embedding (FDE) with continuum solvation models, in particular the conductor-like screening model (COSMO). FDE provides an explicit atomistic description of molecule-environment interactions at reduced computational cost, while the outer continuum layer accounts for the effect of long-range isotropic electrostatic interactions. Our treatment is based on a variational Lagrangian framework, enabling rigorous derivations of ground- and excited-state response properties. As an example of the flexibility of the theoretical framework, we derive and discuss FDE + COSMO analytical molecular gradients for excited states within the Tamm-Dancoff approximation (TDA) and for ground states within second-order Møller-Plesset perturbation theory (MP2) and a second-order approximate coupled cluster with singles and doubles (CC2). It is shown how this method can be used to describe vertical electronic excitation (VEE) energies and Stokes shifts for uracil in water and carbostyril in dimethyl sulfoxide (DMSO), respectively. In addition, VEEs for some simplified protein models are computed, illustrating the performance of this method when applied to larger systems. The interaction terms between the FDE subsystem densities and the continuum can influence excitation energies up to 0.3 eV and, thus, cannot be neglected for general applications. We find that the net influence of the continuum in presence of the first FDE shell on the excitation energy amounts to about 0.05 eV for the cases investigated. The present work is an important step toward rigorously derived ab initio multilayer and multiscale modeling approaches. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor

    SciTech Connect

    Ravelo Arias, S. I.; Ramírez Muñoz, D.; Ferreira, R.; Freitas, P.

    2015-06-15

    The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially when the bridge is micro-fabricated and there is no physical way to separate one resistive element from the others.

  1. Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor.

    PubMed

    Ravelo Arias, S I; Ramírez Muñoz, D; Cardoso, S; Ferreira, R; Freitas, P

    2015-06-01

    The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially when the bridge is micro-fabricated and there is no physical way to separate one resistive element from the others.

  2. Quantum Embedding Theories.

    PubMed

    Sun, Qiming; Chan, Garnet Kin-Lic

    2016-12-20

    In complex systems, it is often the case that the region of interest forms only one part of a much larger system. The idea of joining two different quantum simulations-a high level calculation on the active region of interest, and a low level calculation on its environment-formally defines a quantum embedding. While any combination of techniques constitutes an embedding, several rigorous formalisms have emerged that provide for exact feedback between the embedded system and its environment. These three formulations: density functional embedding, Green's function embedding, and density matrix embedding, respectively, use the single-particle density, single-particle Green's function, and single-particle density matrix as the quantum variables of interest. Many excellent reviews exist covering these methods individually. However, a unified presentation of the different formalisms is so far lacking. Indeed, the various languages commonly used, functional equations for density functional embedding, diagrammatics for Green's function embedding, and entanglement arguments for density matrix embedding, make the three formulations appear vastly different. In this Account, we introduce the basic equations of all three formulations in such a way as to highlight their many common intellectual strands. While we focus primarily on a straightforward theoretical perspective, we also give a brief overview of recent applications and possible future developments. The first section starts with density functional embedding, where we introduce the key embedding potential via the Euler equation. We then discuss recent work concerning the treatment of the nonadditive kinetic potential, before describing mean-field density functional embedding and wave function in density functional embedding. We finish the section with extensions to time-dependence and excited states. The second section is devoted to Green's function embedding. Here, we use the Dyson equation to obtain equations that

  3. Overview of Characterization Techniques for High Speed Crystal Growth

    NASA Technical Reports Server (NTRS)

    Ravi, K. V.

    1984-01-01

    Features of characterization requirements for crystals, devices and completed products are discussed. Key parameters of interest in semiconductor processing are presented. Characterization as it applies to process control, diagnostics and research needs is discussed with appropriate examples.

  4. 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...

  5. Data embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.

    1997-08-19

    A method is disclosed for embedding auxiliary information into a set of host data, such as a photograph, television signal, facsimile transmission, or identification card. All such host data contain intrinsic noise, allowing pixels in the host data which are nearly identical and which have values differing by less than the noise value to be manipulated and replaced with auxiliary data. As the embedding method does not change the elemental values of the host data, the auxiliary data do not noticeably affect the appearance or interpretation of the host data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. 19 figs.

  6. Data embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.

    1997-01-01

    A method of embedding auxiliary information into a set of host data, such as a photograph, television signal, facsimile transmission, or identification card. All such host data contain intrinsic noise, allowing pixels in the host data which are nearly identical and which have values differing by less than the noise value to be manipulated and replaced with auxiliary data. As the embedding method does not change the elemental values of the host data, the auxiliary data do not noticeably affect the appearance or interpretation of the host data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user.

  7. 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

  8. 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

  9. The Use of Electrochemical Techniques to Characterize Wet Steam Environments

    SciTech Connect

    Bruce W. Bussert; John A. Crowley; Kenneth J. Kimball; Brian J. Lashway

    2003-04-30

    The composition of a steam phase in equilibrium with a water phase at high temperature is remarkably affected by the varying capabilities of the water phase constituents to partition into the steam. Ionic impurities (sodium, chloride, sulfate, etc.) tend to remain in the water phase, while weakly ionic or gaseous species (oxygen) partition into the steam. Analysis of the water phase can provide misleading results concerning the steam phase composition or environment. This paper describes efforts that were made to use novel electrochemical probes and sampling techniques to directly characterize a wet steam phase environment in equilibrium with high temperature water. Probes were designed to make electrochemical measurements in the thin film of water existing on exposed surfaces in steam over a water phase. Some of these probes were referenced against a conventional high temperature electrode located in the water phase. Others used two different materials (typically tungsten and platinum) to make measurements without a true reference electrode. The novel probes were also deployed in a steam space removed from the water phase. It was necessary to construct a reservoir and an external, air-cooled condenser to automatically keep the reservoir full of condensed steam. Conventional reference and working electrodes were placed in the water phase of the reservoir and the novel probes protruded into the vapor space above it. Finally, water phase probes (both reference and working electrodes) were added to the hot condensed steam in the external condenser. Since the condensing action collapsed the volatiles back into the water phase, these electrodes proved to be extremely sensitive at detecting oxygen, which is one of the species of highest concern in high temperature power systems. Although the novel steam phase probes provided encouraging initial results, the tendency for tungsten to completely corrode away in the steam phase limited their usefulness. However, the

  10. 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

  11. Characterization of ferromagnetic or conductive properties of metallic foreign objects embedded within the human body with magnetic iron detector (MID): Screening patients for MRI.

    PubMed

    Gianesin, Barbara; Zefiro, Daniele; Paparo, Francesco; Caminata, Alessio; Balocco, Manuela; Carrara, Paola; Quintino, Sabrina; Pinto, Valeria; Bacigalupo, Lorenzo; Rollandi, Gian Andrea; Marinelli, Mauro; Forni, Gian Luca

    2015-05-01

    A preliminary assessment of the MRI-compatibility of metallic object possibly embedded within the patient is required before conducting the MRI examination. The Magnetic Iron Detector (MID) is a highly sensitive susceptometer that uses a weak magnetic field to measure iron overload in the liver. MID might be used to perform a screening procedure for MRI by determining the ferromagnetic/conductive properties of embedded metallic objects. The study was composed by: (i) definition of MID sensitivity threshold; (ii) application of MID in a procedure to characterize the ferromagnetic/conductive properties of metallic foreign objects in 958 patients scheduled for MID examination. The detection threshold for ferromagnetic objects was found to be the equivalent of a piece of wire of length 2 mm and gauge 0.8 mm(2) and, representing purely conductive objects, an aluminum sheet of area 2 × 2 cm(2) . Of 958 patients, 165 had foreign bodies of unknown nature. MID was able to detect those with ferromagnetic and/or conducting properties based on fluctuations in the magnetic and eddy current signals versus control. The high sensitivity of MID makes it suitable for assessing the ferromagnetic/conductive properties of metallic foreign objects embedded within the body of patients scheduled for MRI. © 2015 Wiley Periodicals, Inc.

  12. 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.

  13. 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.

  14. Detection and characterization of Newcastle disease virus in formalin-fixed, paraffin-embedded tissues from commercial broilers in Egypt.

    PubMed

    Abdel-Glil, Mostafa Y; Mor, Sunil K; Sharafeldin, Tamer A; Porter, Robert E; Goyal, Sagar M

    2014-03-01

    Newcastle disease (ND) is highly contagious and causes severe economic losses to the poultry industry due to high morbidity and mortality. In this report, we describe the detection of Newcastle disease virus (NDV) in formalin-fixed tissues from an outbreak of ND on broiler farms in Egypt. The affected birds experienced respiratory and/or nervous signs and a 75% mortality rate. Tissue samples were collected and placed in 10% neutral buffered formalin followed by embedding in paraffin. RNA was extracted from 80-microm formalin-fixed paraffin-embedded tissue blocks and recovered in 60 microl of elution buffer. All samples were negative for influenza virus by real-time reverse-transcription (RT)-PCR but positive for NDV. These flocks were known to have been vaccinated with a live NDV vaccine (LaSota strain). The nucleic acid sequences of the virus detected in this study were similar to those of a velogenic virus at its cleavage site 111GRRQKR*F117 and clustered with class II genogroup VII lineage of NDV, with a nucleotide sequence identity of 94%-99%. Although extraction and amplification of NDV from paraffin-embedded tissues from experimentally infected birds has been reported previously, this study reports on the use of RT-PCR on formalin-fixed tissues from actual field samples.

  15. 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.

  16. Characterization of the electronic properties of magnetic and semiconductor devices using scanning probe techniques

    NASA Astrophysics Data System (ADS)

    Schaadt, Daniel Maria

    In the first part of this dissertation, scanning probe techniques are used in the study of localized charge deposition and subsequent transport in Co nanoclusters embedded in a SiO2 matrix are presented, and the application of this material in a hybrid magneto-electronic device for magnetic field sensing is described. Co nanoclusters are charged by applying a bias voltage pulse between a conductive tip and the sample, and electrostatic force microscopy is used to image charged areas. An exponential decay in the peak charge density is observed with decay times dependent on the nominal Co film thickness and on the sign of the deposited charge. The results are interpreted as a consequence of Coulomb-blockade effects. This study leads to the design of a hybrid magneto-electronic device, in which Co nanoclusters embedded in SiO2 are incorporated into the gate of a Si metal-oxide-semiconductor field-effect transistor. Current flow through the Co nanoclusters leads to a buildup of electronic charge within the gate, and consequently to a transistor threshold voltage shift that varies with applied external magnetic field. The shift in threshold voltage results in an exponential change in subthreshold current and a quadratic change in saturation current. A detailed analysis of the device operation is presented. The second part of this dissertation focuses on the characterization of electronic properties of GaN-based heterostructure devices. Scanning capacitance microscopy (SCM) and spectroscopy (SCS) are used to investigate lateral variations in the transistor threshold voltage and the frequency-dependent response of surface charges and of charge in the two-dimensional electron gas (2DEG). The technique is described in detail, electrostatic simulations performed to study the influence of the probe tip geometry on the measured dC/dV spectra are presented, and the limitations of the SCS technique in a variety of applications are evaluated. Features in SCM images and maps of

  17. Fabrication and static characterization of carbon-fiber-reinforced polymers with embedded NiTi shape memory wire actuators

    NASA Astrophysics Data System (ADS)

    de Araújo, C. J.; Rodrigues, L. F. A.; Coutinho Neto, J. F.; Reis, R. P. B.

    2008-12-01

    In this work, unidirectional carbon-fiber-reinforced polymers (CFRP) with embedded NiTi shape memory alloy (SMA) wire actuators were manufactured using a universal testing machine equipped with a thermally controlled chamber. Beam specimens containing cold-worked, annealed and trained NiTi SMA wires distributed along their neutral plane were fabricated. Several tests in a three-point bending mode at different constant temperatures were performed. To verify thermal buckling effects, electrical activation of the specimens was realized in a cantilevered beam mode and the influence of the SMA wire actuators on the tip deflection of the composite is demonstrated.

  18. Testing techniques for mechanical characterization of rapidly solidified materials

    NASA Technical Reports Server (NTRS)

    Koch, C. C.

    1986-01-01

    Mechanical property testing techniques are reviewed for rapidly solidified materials. Mechanical testing of rapidly solidified materials is complicated by the fact that in most cases at least one dimension of the material is very small (less than 100 microns). For some geometries, i.e., powder or thin surface layers, microhardness is the only feasible mechanical test. The ribbon geometry which is obtained by the melt-spinning method, however, has been used for a variety of mechanical property measurements including elastic properties, tensile properties, fracture toughness, creep, and fatigue. These techniques are described with emphasis placed on the precautions required by the restricted geometry of rapidly solidified specimens.

  19. A modification of the chronic tartrate silver impregnation technique for block impregnation of the central nervous system and paraffin wax embedding.

    PubMed

    Abadía-Fenoll, F; Ostos Garrido, M V; López-Lendínez, J L; Carmona Martos, R

    1985-03-01

    This paper describes a block silver impregnation technique for the CNS. The procedure, which is quite simple, yields highly consistent and reproducible results. After fixation during 6-10 days in 10% saline formaldehyde, 4 mm thick blocks of brain are treated with chromic anhydride and sodium potassium tartrate solution for 4 days. After this period the specimens are rinsed in 0.75% silver nitrate solution to which 8-10 drops of pyridine per 100 ml of solution have been added. This is followed by impregnation for 4 days at 37 degrees C in silver nitrate-pyridine solution identical to that used in the previous rinsing step. The impregnated blocks are reduced during 20-26 h in 1% pyrogallol to which 6 ml commercial formaldehyde per 100 ml of solution have been added, followed by dehydration in dioxan and paraffin embedding. Sections no thicker than 30 microns are then cut for histological study. This fundamentally neurofibrillar method reveals: neuronal somata and their processes; synaptic structures; fibre bundles; and cell nuclei and nucleoli.

  20. 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,…

  1. 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,…

  2. 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.

  3. 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.

  4. 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.

  5. Analytical techniques for mechanistic characterization of EUV photoresists

    NASA Astrophysics Data System (ADS)

    Grzeskowiak, Steven; Narasimhan, Amrit; Murphy, Michael; Ackerman, Christian; Kaminsky, Jake; Brainard, Robert L.; Denbeaux, Greg

    2017-03-01

    Extreme ultraviolet (EUV, 13.5 nm) lithography is the prospective technology for high volume manufacturing by the microelectronics industry. Significant strides towards achieving adequate EUV source power and availability have been made recently, but a limited rate of improvement in photoresist performance still delays the implementation of EUV. Many fundamental questions remain to be answered about the exposure mechanisms of even the relatively well understood chemically amplified EUV photoresists. Moreover, several groups around the world are developing revolutionary metal-based resists whose EUV exposure mechanisms are even less understood. Here, we describe several evaluation techniques to help elucidate mechanistic details of EUV exposure mechanisms of chemically amplified and metal-based resists. EUV absorption coefficients are determined experimentally by measuring the transmission through a resist coated on a silicon nitride membrane. Photochemistry can be evaluated by monitoring small outgassing reaction products to provide insight into photoacid generator or metal-based resist reactivity. Spectroscopic techniques such as thin-film Fourier transform infrared (FTIR) spectroscopy can measure the chemical state of a photoresist system pre- and post-EUV exposure. Additionally, electrolysis can be used to study the interaction between photoresist components and low energy electrons. Collectively, these techniques improve our current understanding of photomechanisms for several EUV photoresist systems, which is needed to develop new, better performing materials needed for high volume manufacturing.

  6. Techniques to develop and characterize nanosized formulation for salbutamol sulfate.

    PubMed

    Bhavna; Ahmad, F J; Khar, R K; Sultana, S; Bhatnagar, A

    2009-12-01

    The present study relates to enhancing the dosing efficiency of pharmaceutical dry powder formulations administered by pulmonary inhalation. In particular, the study relates to the provision of dry powder inhalers (DPI) by forming nanosized particles of salbutamol sulfate (SBM) in order to augment the drug penetrability and deposition in the lungs. SBM, an antiasthmatic was selected to be developed into a nanosized formulation by different techniques like solvation, high-pressure homogenization, and spray drying, which were then compared on the basis of particle shape, particle size, and particle size distribution. In case of solvation method the nanosuspension was prepared by dispersing SBM into a nonsolvent and adding Tween-80 as a surfactant to prevent the agglomeration, the particles obtained therein were in the range of 2-10 mu. The second attempt was made by passing the suspension of SBM through high-pressure homogenizer at 10,000-15,000 psi. A treatment of six cycles of homogenization in presence of a Tween-80 as surfactant was found to give a nanosuspension within a size range 50-100 nm. The only drawback seemed with this technique was the low-product yield and high-processing time (3-4 h). In order to overcome this drawback spray-drying technique was further explored; the solution of SBM containing Tween-80 was stirred on magnetic stirrer at 1,200 rpm and finally dried by using spray dryer at an inlet and outlet temperature of 75 degrees C and 56 degrees C, respectively. The feed rate for spray dryer was kept to be 91 ml/h. The sample was collected and analyzed for particle size distribution which was found to be in the range of 50-100 nm. Keeping in view the positive outcomes in terms of higher yield and lower processing time, the spray-drying technique was taken to give the optimized formulation. Nanosized particles, thus obtained were evaluated for particle size, surface topology and particles size distribution, by Transmission Electron Microscopy (TEM

  7. Advanced characterization of microscopic kidney biopsies utilizing image analysis techniques.

    PubMed

    Goudas, Theodosios; Doukas, Charalampos; Chatziioannou, Aristotle; Maglogiannis, Ilias

    2012-01-01

    Correct annotation and identification of salient regions in Kidney biopsy images can provide an estimation of pathogenesis in obstructive nephropathy. This paper presents a tool for the automatic or manual segmentation of such regions along with methodology for their characterization in terms of the exhibited pathology. The proposed implementation is based on custom code written in Java and the utilization of open source tools (i.e. RapidMiner, ImageJ). The corresponding implementation details along with the initial evaluation of the proposed integrated system are also presented in the paper.

  8. Using data mining techniques to characterize participation in observational studies.

    PubMed

    Linden, Ariel; Yarnold, Paul R

    2016-12-01

    Data mining techniques are gaining in popularity among health researchers for an array of purposes, such as improving diagnostic accuracy, identifying high-risk patients and extracting concepts from unstructured data. In this paper, we describe how these techniques can be applied to another area in the health research domain: identifying characteristics of individuals who do and do not choose to participate in observational studies. In contrast to randomized studies where individuals have no control over their treatment assignment, participants in observational studies self-select into the treatment arm and therefore have the potential to differ in their characteristics from those who elect not to participate. These differences may explain part, or all, of the difference in the observed outcome, making it crucial to assess whether there is differential participation based on observed characteristics. As compared to traditional approaches to this assessment, data mining offers a more precise understanding of these differences. To describe and illustrate the application of data mining in this domain, we use data from a primary care-based medical home pilot programme and compare the performance of commonly used classification approaches - logistic regression, support vector machines, random forests and classification tree analysis (CTA) - in correctly classifying participants and non-participants. We find that CTA is substantially more accurate than the other models. Moreover, unlike the other models, CTA offers transparency in its computational approach, ease of interpretation via the decision rules produced and provides statistical results familiar to health researchers. Beyond their application to research, data mining techniques could help administrators to identify new candidates for participation who may most benefit from the intervention.

  9. Optical characterization of hydrogenated silicon thin films using interference technique

    NASA Astrophysics Data System (ADS)

    Globus, Tatiana; Ganguly, Gautam; Roca i Cabarrocas, Pere

    2000-08-01

    This work introduces an application of an "interference spectroscopy technique" (IST) for determination of absorption coefficient and refractive index spectra of amorphous silicon (a-Si:H) and related thin film materials. The technique is based on computer analysis of measurements of optical transmission and specular reflection (T & R) of thin films (including the films on substrates) over a wide range of the incident photon energies (0.5-2.8 eV) using carefully controlled spectrometer conditions. IST is used to investigate the absorption spectrum in the sub-gap energy range (0.8-1.6 eV) of intrinsic and phosphorous-doped a-Si:H, "polymorphous-Si:H," and microcrystalline silicon films. The enhanced sensitivity of the technique over conventional analysis of T & R data results from utilization of interference to obtain absorption coefficient values at the maxima of transmission. The factors limiting the accuracy of the calculated absorption coefficient are discussed in detail. Measurement on films of thickness ranging from 0.1 to 5 μm identifies that the sub-gap absorption in these films arises from the bulk rather than the surface. A set of samples prepared under widely different conditions that appear to have overlapping (α=20 cm-1) sub-gap absorption spectra measured using photo-thermal deflection spectroscopy (PDS), reveal significant differences (α=10 to 100 cm-1) using IST. Changes (factor of 2) in sub-gap absorption spectra due to light soaking are also clearly observable using IST.

  10. Simultaneous electronic and lattice characterization using coupled femtosecond spectroscopic techniques.

    SciTech Connect

    Beechem Iii, Thomas Edwin; Serrano, Justin Raymond; Hopkins, Patrick E

    2009-09-01

    High-power electronics are central in the development of radar, solid-state lighting, and laser systems. Large powers, however, necessitate improved heat dissipation as heightened temperatures deleteriously affect both performance and reliability. Heat dissipation, in turn, is determined by the cascade of energy from the electronic to lattice system. Full characterization of the transport then requires analysis of each. In response, this four-month late start effort has developed a transient thermoreflectance (TTR) capability that probes the thermal response of electronic carriers with 100 fs resolution. Simultaneous characterization of the lattice carriers with this electronic assessment was then investigated by equipping the optical arrangement to acquire a Raman signal from radiation discarded during the TTR experiment. Initial results show only tentative acquisition of a Raman response at these timescales. Using simulations of the response, challenges responsible for these difficulties are then examined and indicate that with outlined refinements simultaneous acquisition of TTR/Raman signals remains attainable in the near term.

  11. 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.

  12. Characterization of a Viking Blade Fabricated by Traditional Forging Techniques

    NASA Astrophysics Data System (ADS)

    Vo, H.; Frazer, D.; Bailey, N.; Traylor, R.; Austin, J.; Pringle, J.; Bickel, J.; Connick, R.; Connick, W.; Hosemann, P.

    2016-12-01

    A team of students from the University of California, Berkeley, participated in a blade-smithing competition hosted by the Minerals, Metals, and Materials Society at the TMS 2015 144th annual meeting and exhibition. Motivated by ancient forging methods, the UC Berkeley team chose to fabricate our blade from historical smithing techniques utilizing naturally-occurring deposits of iron ore. This approach resulted in receiving the "Best Example of a Traditional Blade Process/Ore Smelting Technique" award for our blade named "Berkelium." First, iron-enriched sand was collected from local beaches. Magnetite (Fe3O4) was then extracted from the sand and smelted into individual high- and low-carbon steel ingots. Layers of high- and low-carbon steels were forge-welded together, predominantly by hand, to form a composite material. Optical microscopy, energy dispersive spectroscopy, and Vickers hardness mechanical testing were conducted at different stages throughout the blade-making process to evaluate the microstructure and hardness evolution during formation. It was found that the pre-heat-treated blade microstructure was composed of ferrite and pearlite, and contained many nonmetallic inclusions. A final heat treatment was performed, which caused the average hardness of the blade edge to increase by more than a factor of two, indicating a martensitic transformation.

  13. 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.

  14. Rapid identification and characterization of Penicillium marneffei using multiplex ligation-dependent probe amplification (MLPA) in paraffin-embedded tissue samples.

    PubMed

    Zhang, Jun-Min; Sun, Jiu-Feng; Feng, Pei-Ying; Li, Xi-Qing; Lu, Chang-Ming; Lu, Sha; Cai, Wen-Ying; Xi, Li-Yan; de Hoog, G S

    2011-04-01

    Penicillium marneffei infection is a deadly disease and early diagnosis leads to prompt and appropriate antifungal therapy. To develop a sensitive method to diagnose P. marneffei infection, a multiplex ligation-dependent probe amplification (MLPA) assay was adapted. This method can rapidly and specifically detect P. marneffei DNA in cultured cells and paraffin-embedded tissue samples. Three pairs of probes were designed for amplifying the internally (intergenic) transcribed spacer (ITS) region of P. marneffei rRNA using a systematic phylogenetic analysis. These three probe sets produced three amplicons of 198, 166, and 152 bp, respectively, specific for P. marneffei. In contrast, there was only one 198 bp amplicon produced for Talaromyces stipitatus, and one 152 bp amplicon for P. funiculosum, T. intermedius and T. derxii. The probes did not amplify any other reference strains. An array of 40 P. marneffei strains isolated from human patients, bamboo rat, and the local environment was tested by using MLPA, and all were positively identified. Most importantly, P. marneffei in paraffin-embedded tissue specimens from infected human patients was positively amplified by MLPA. The sensitivity and specificity of the MLPA assay could be a useful tool for prompt diagnosis, pathogen characterization, and epidemiological studies of fungal infections.

  15. Genetic Characterization of Echinococcus granulosus from a Large Number of Formalin-Fixed, Paraffin-Embedded Tissue Samples of Human Isolates in Iran

    PubMed Central

    Rostami, Sima; Torbaghan, Shams Shariat; Dabiri, Shahriar; Babaei, Zahra; Mohammadi, Mohammad Ali; Sharbatkhori, Mitra; Harandi, Majid Fasihi

    2015-01-01

    Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, presents an important medical and veterinary problem globally, including that in Iran. Different genotypes of E. granulosus have been reported from human isolates worldwide. This study identifies the genotype of the parasite responsible for human hydatidosis in three provinces of Iran using formalin-fixed paraffin-embedded tissue samples. In this study, 200 formalin-fixed paraffin-embedded tissue samples from human CE cases were collected from Alborz, Tehran, and Kerman provinces. Polymerase chain reaction amplification and sequencing of the partial mitochondrial cytochrome c oxidase subunit 1 gene were performed for genetic characterization of the samples. Phylogenetic analysis of the isolates from this study and reference sequences of different genotypes was done using a maximum likelihood method. In total, 54.4%, 0.8%, 1%, and 40.8% of the samples were identified as the G1, G2, G3, and G6 genotypes, respectively. The findings of the current study confirm the G1 genotype (sheep strain) to be the most prevalent genotype involved in human CE cases in Iran and indicates the high prevalence of the G6 genotype with a high infectivity for humans. Furthermore, this study illustrates the first documented human CE case in Iran infected with the G2 genotype. PMID:25535316

  16. Characterization of intrinsic subgap density-of-states in exfoliated MoS2 FETs using a multi-frequency capacitance-conductance technique

    NASA Astrophysics Data System (ADS)

    Bae, Hagyoul; Kim, Choong-Ki; Choi, Yang-Kyu

    2017-07-01

    A multi-frequency capacitance-conductance technique is proposed for characterizing the intrinsic density-of-states (DOS: gint(E)) inside an energy bandgap range (EV < E < EC) by de-embedding the structure-dependent parameters such as parasitic capacitance and resistance in a fabricated exfoliated molybdenum disulfide (MoS2) field effect transistor (EM-FET). The proposed technique uses the measured frequency-dispersive capacitance (Cm) and conductance (Gm=1/Rm=ωCmDm) data with the measured dissipation factor Dm(=Gm/ωCm) at a frequency range of 0.3 kHz to 10 kHz. To extract gint(E), an equivalent circuit model of the MoS2 FET converted from a two-element model for the parallel-mode (Cm-Dm) measurement was developed with this technique.

  17. In Situ Synthesis and Characterization of Ge Embedded Electrospun Carbon Nanostructures as High Performance Anode Material for Lithium-Ion Batteries.

    PubMed

    Lee, Young-Woo; Kim, Da-Mi; Kim, Si-Jin; Kim, Min-Cheol; Choe, Hui-Seon; Lee, Kyu-Ho; Sohn, Jung Inn; Cha, Seung Nam; Kim, Jong Min; Park, Kyung-Won

    2016-03-23

    While active materials based on germanium (Ge) are considered as a promising alternative anodic electrode due to their relatively high reversible capacity and excellent lithium-ion diffusivity, the quite unstable structural/electrochemical stability and severe volume expansion or pulverization problems of Ge electrodes remain a considerable challenge in lithium ion batteries (LIBs). Here, we present the development of Ge embedded in one-dimensional carbon nanostructures (Ge/CNs) synthesized by the modified in situ electrospinning technique using a mixed electrospun solution consisting of a Ge precursor as an active material source and polyacrylonitrile (PAN) as a carbon source. The as-prepared Ge/CNs exhibit superior lithium ion behavior properties, i.e., highly reversible specific capacity, rate performance, Li ion diffusion coefficient, and superior cyclic stability (capacity retention: 85% at 200 mA g(-1)) during Li alloying/dealloying processes. These properties are due to the high electrical conductivity and unique structures containing well-embedded Ge nanoparticles (NPs) and a one-dimensional carbon nanostructure as a buffer medium, which is related to the volume expansion of Ge NPs. Thus, it is expected that the Ge/CNs can be utilized as a promising alternative anodic material in LIBs.

  18. 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.

  19. 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.

  20. 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

  1. Characterization of a Mycobacterium intracellulare variant strain by molecular techniques.

    PubMed

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

    2001-12-01

    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.

  2. 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

  3. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Synthesis and spectral characterization of silver embedded chitosan matrix nanocomposite for the selective colorimetric sensing of toxic mercury

    NASA Astrophysics Data System (ADS)

    Nivethaa, E. A. K.; Narayanan, V.; Stephen, A.

    2015-05-01

    Polymer matrix type chitosan-silver nanocomposite containing different weight percentage of silver was synthesized by the chemical method. HRTEM images confirm the embedment of silver in the chitosan matrix. The binding of silver to the NH2 and OH groups of chitosan is evident from XPS and FTIR studies. An increase in the absorbance observed from UV-Vis analysis on raising the weight percentage of silver showed the increase in the amount of silver in the nanocomposite. The face centered cubic structure of silver and the semi-crystalline nature of chitosan are evident from the XRD studies. On interaction with mercury the UV-Vis spectra of the composite showed a decrease in intensity and a blue shift confirming the use of the composite as a colorimetric sensor for the detection of mercury. The limit of detection was found to be about 7.2 × 10-8 M. High specificity and the sensitivity of the environmental friendly and non-toxic nanocomposite to detect very low concentrations of mercury make the system a perspective one.

  5. Synthesis and spectral characterization of silver embedded chitosan matrix nanocomposite for the selective colorimetric sensing of toxic mercury.

    PubMed

    Nivethaa, E A K; Narayanan, V; Stephen, A

    2015-05-15

    Polymer matrix type chitosan-silver nanocomposite containing different weight percentage of silver was synthesized by the chemical method. HRTEM images confirm the embedment of silver in the chitosan matrix. The binding of silver to the NH2 and OH groups of chitosan is evident from XPS and FTIR studies. An increase in the absorbance observed from UV-Vis analysis on raising the weight percentage of silver showed the increase in the amount of silver in the nanocomposite. The face centered cubic structure of silver and the semi-crystalline nature of chitosan are evident from the XRD studies. On interaction with mercury the UV-Vis spectra of the composite showed a decrease in intensity and a blue shift confirming the use of the composite as a colorimetric sensor for the detection of mercury. The limit of detection was found to be about 7.2×10(-8)M. High specificity and the sensitivity of the environmental friendly and non-toxic nanocomposite to detect very low concentrations of mercury make the system a perspective one. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Fabrication and characterization of a rapid prototyped tissue engineering scaffold with embedded multicomponent matrix for controlled drug release.

    PubMed

    Chen, Muwan; Le, Dang Q S; Hein, San; Li, Pengcheng; Nygaard, Jens V; Kassem, Moustapha; Kjems, Jørgen; Besenbacher, Flemming; Bünger, Cody

    2012-01-01

    Bone tissue engineering implants with sustained local drug delivery provide an opportunity for better postoperative care for bone tumor patients because these implants offer sustained drug release at the tumor site and reduce systemic side effects. A rapid prototyped macroporous polycaprolactone scaffold was embedded with a porous matrix composed of chitosan, nanoclay, and β-tricalcium phosphate by freeze-drying. This composite scaffold was evaluated on its ability to deliver an anthracycline antibiotic and to promote formation of mineralized matrix in vitro. Scanning electronic microscopy, confocal imaging, and DNA quantification confirmed that immortalized human bone marrow-derived mesenchymal stem cells (hMSC-TERT) cultured in the scaffold showed high cell viability and growth, and good cell infiltration to the pores of the scaffold. Alkaline phosphatase activity and osteocalcin staining showed that the scaffold was osteoinductive. The drug-release kinetics was investigated by loading doxorubicin into the scaffold. The scaffolds comprising nanoclay released up to 45% of the drug for up to 2 months, while the scaffold without nanoclay released 95% of the drug within 4 days. Therefore, this scaffold can fulfill the requirements for both bone tissue engineering and local sustained release of an anticancer drug in vitro. These results suggest that the scaffold can be used clinically in reconstructive surgery after bone tumor resection. Moreover, by changing the composition and amount of individual components, the scaffold can find application in other tissue engineering areas that need local sustained release of drug.

  7. Fabrication and characterization of a rapid prototyped tissue engineering scaffold with embedded multicomponent matrix for controlled drug release

    PubMed Central

    Chen, Muwan; Le, Dang QS; Hein, San; Li, Pengcheng; Nygaard, Jens V; Kassem, Moustapha; Kjems, Jørgen; Besenbacher, Flemming; Bünger, Cody

    2012-01-01

    Bone tissue engineering implants with sustained local drug delivery provide an opportunity for better postoperative care for bone tumor patients because these implants offer sustained drug release at the tumor site and reduce systemic side effects. A rapid prototyped macroporous polycaprolactone scaffold was embedded with a porous matrix composed of chitosan, nanoclay, and β-tricalcium phosphate by freeze-drying. This composite scaffold was evaluated on its ability to deliver an anthracycline antibiotic and to promote formation of mineralized matrix in vitro. Scanning electronic microscopy, confocal imaging, and DNA quantification confirmed that immortalized human bone marrow-derived mesenchymal stem cells (hMSC-TERT) cultured in the scaffold showed high cell viability and growth, and good cell infiltration to the pores of the scaffold. Alkaline phosphatase activity and osteocalcin staining showed that the scaffold was osteoinductive. The drug-release kinetics was investigated by loading doxorubicin into the scaffold. The scaffolds comprising nanoclay released up to 45% of the drug for up to 2 months, while the scaffold without nanoclay released 95% of the drug within 4 days. Therefore, this scaffold can fulfill the requirements for both bone tissue engineering and local sustained release of an anticancer drug in vitro. These results suggest that the scaffold can be used clinically in reconstructive surgery after bone tumor resection. Moreover, by changing the composition and amount of individual components, the scaffold can find application in other tissue engineering areas that need local sustained release of drug. PMID:22904634

  8. Hyperspectral imaging based techniques in ornamental stone characterization

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia; Menesatti, Paolo

    2005-11-01

    Ornamental stones are usually utilized for many purposes, ranging from structural to aesthetic ones. In this wide range of utilization, many different industrial sectors are involved. For all of them it is very important, at a different level, that these materials satisfy not only specific physical-chemical-mechanical requirements, but also some attributes that are much more difficult to quantify, that is those attributes strictly related to the final pictorial aspect of the stone manufactured goods. Stone pictorial-aesthetic characteristics are strongly influenced by stone surface status, that is by the surfaces reflectance properties. Such a property depends from stone compositional-textural characteristics and from the working procedures applied. The first set of attributes are related to stone mineral composition and their micro/macro arrangement, the others are related to the tools utilized and the actions applied in terms of operation sequence and workers knowledge-expertise. Each stone and each macro-operation carried out lead to a stone product whose finishing has to follow a specific rule: "optimal" polishing procedures for a stone can lead to very poor results for others. The study was addressed to evaluate the possibility to introduce a new hyperspectral imaging based approach to quantify the level of polishing of stone products and, at the same time, trying to perform also a pictorial-aesthetic characterization trough the identification of natural and/or working defects.

  9. 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

  10. Review of Potential Characterization Techniques in Approaching Energy and Sustainability

    SciTech Connect

    LePoire, David

    2014-03-20

    Societal prosperity is linked to sustainable energy and a healthy environment. But, tough global challenges include increased demand for fossil fuels, while approaching peak oil production and uncertainty in the environmental impacts of energy generation. Recently, energy use was identified as a major component of economic productivity, along with capital and labor. Furthermore, other environmental resources and impacts may be nearing environmental thresholds as indicated by nine planetary environmental boundaries, many of which are linked to energy production and use. Foresight techniques could be applied to guide future actions which include emphasis on (1) energy efficiency to bridge the transition to a renewable energy economy, (2) continued research, development, and assessment of new technologies, (3) improved understanding of environment impacts including natural capital use and degradation, (4) exploration of GDP alternative measures that include both economic production and environmental impacts, and (5) international cooperation and awareness of longer-term opportunities and their associated potential scenarios. Examples from the U.S. and the international community illustrate challenges and potential.

  11. Review of Potential Characterization Techniques in Approaching Energy and Sustainability

    DOE PAGES

    LePoire, David

    2014-03-20

    Societal prosperity is linked to sustainable energy and a healthy environment. But, tough global challenges include increased demand for fossil fuels, while approaching peak oil production and uncertainty in the environmental impacts of energy generation. Recently, energy use was identified as a major component of economic productivity, along with capital and labor. Furthermore, other environmental resources and impacts may be nearing environmental thresholds as indicated by nine planetary environmental boundaries, many of which are linked to energy production and use. Foresight techniques could be applied to guide future actions which include emphasis on (1) energy efficiency to bridge the transitionmore » to a renewable energy economy, (2) continued research, development, and assessment of new technologies, (3) improved understanding of environment impacts including natural capital use and degradation, (4) exploration of GDP alternative measures that include both economic production and environmental impacts, and (5) international cooperation and awareness of longer-term opportunities and their associated potential scenarios. Examples from the U.S. and the international community illustrate challenges and potential.« less

  12. 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.

  13. 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.

  14. Characterization of Hardening by Design Techniques on Commercial, Small Feature Sized Field-Programmable Gate Arrays

    DTIC Science & Technology

    2009-03-01

    AFIT/GE/ENG/09-43 CHARACTERIZATION OF HARDENING BY DESIGN TECHNIQUES ON COMMERCIAL, SMALL FEATURE SIZED FIELD-PROGRAMMABLE GATE ARRAYS THESIS...The purpose of which is to determine the radiation effects and characterize the improvements of various hardening by design techniques. The...Distributed RAM memory elements that are loaded both with ECC and non-error corrected data. The circuit is designed to check for errors in memory data, stuck

  15. Efficient light harvesting within a C153@Zr-based MOF embedded in a polymeric film: spectral and dynamical characterization.

    PubMed

    Gutiérrez, M; López-González, M; Sánchez, F; Douhal, A

    2017-07-21

    Light harvesting is a natural phenomenon that scientists try to mimic in artificial systems. Having this in mind, attention has been focused on using new smart-materials for photonics. Herein, we report on the photobehaviour of a Zr-NDC MOF (NDC = dimethyl 2,6-naphthalenedicarboxylate) and its composite material, Coumarin153@Zr-NDC, embedded within a polymeric membrane of poly[bisphenol A carbonate-co-4,4'-(3,3,5-trimethylcyclohexylidene)diphenol carbonate] (PC). For the mixed matrix membrane (MMM) Zr-NDC/PC, we observed interparticle excimer-like formation, taking place in times shorter than 15 ps and giving rise to a red-shifted broad emission band. The interparticle interactions are supported by the SEM images, as they reflect the contact between the MOF crystals. The C153@Zr-NDC/PC material presents an energy transfer (ET) process from the excited MOF to the trapped C153 molecules in 820 ps, with a 35 nm red-shifted emission band corresponding to C153 in PC. The fluorescence quantum yield, as a result of this ET from the MOF, is high enough (25%) to explore the possibility of using this new composite material in a LED device. To elucidate the observed photobehavior, we compared it with those of C153/PC and (2,6-NDC + C153)/PC films. These results shed light on the spectroscopic and dynamical properties of these new composite materials formed by a highly fluorescent molecule, and easily synthesized MOFs and polymeric matrices, opening the way for more research based on these mixed inorganic and organic compounds for possible applications in the fields of luminescence sensing and emitting devices.

  16. 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.

  17. HOPE--a new fixing technique enables preservation and extraction of high molecular weight DNA and RNA of > 20 kb from paraffin-embedded tissues. Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect.

    PubMed

    Wiedorn, Klaus Hermann; Olert, Jürgen; Stacy, Robin A P; Goldmann, Torsten; Kühl, Heike; Matthus, Jutta; Vollmer, Ekkehard; Bosse, Alexander

    2002-01-01

    The growing number of molecular pathologic tools that are currently available require material with good long term preservation of morphology, nucleic acids, and antigenic structures. However, pathologic investigations of tissues done at a molecular level are often hampered by the fixatives in use. We thus endeavored to design a new fixing system, including subsequent paraffin-embedding and sectioning, that makes complete pathologic analyses possible, with special consideration of immunohistochemistry (IHC), in situ hybridization (ISH), and molecular pathology. The optimized HOPE (Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect) fixing technique allows us to preserve and extract high molecular weight DNA and RNA of > 20 kbp suitable for downstream applications, such as PCR and RT-PCR from HOPE-fixed, paraffin-embedded tissues that are up to 5 years old. This technique will most probably lead to new impacts on molecular pathology.

  18. High-resolution optical spectrum characterization using optical channel estimation and spectrum stitching technique.

    PubMed

    Jin, Chao; Bao, Yuan; Li, Zhaohui; Gui, Tao; Shang, Haiyan; Feng, Xinhuan; Li, Jianping; Yi, Xingwen; Yu, Changyuan; Li, Guifang; Lu, Chao

    2013-07-01

    A technique is proposed to measure the high-resolution and wide-band characterization of amplitude, phase responses, and polarization property of optical components. This technique combines the optical spectrum stitching and optical channel estimation methods. Two kinds of fiber Bragg grating based Fabry-Perot cavities with ultrafine structures have been characterized based on this technique. By using 1024 point fast Fourier transform and a narrow linewidth, wavelength-tunable laser source, a frequency resolution of ~10 MHz is realized with an optical measurement range beyond 250 GHz.

  19. 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.

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

    PubMed

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

    2002-04-01

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

  1. Techniques used for the isolation and characterization of extracellular vesicles: results of a worldwide survey

    PubMed Central

    Gardiner, Chris; Vizio, Dolores Di; Sahoo, Susmita; Théry, Clotilde; Witwer, Kenneth W.; Wauben, Marca; Hill, Andrew F.

    2016-01-01

    Extracellular vesicles (EVs) represent an important mode of intercellular communication. Research in this field has grown rapidly in the last few years, and there is a plethora of techniques for the isolation and characterization of EVs, many of which are poorly standardized. EVs are heterogeneous in size, origin and molecular constituents, with considerable overlap in size and phenotype between different populations of EVs. Little is known about current practices for the isolation, purification and characterization of EVs. We report here the first large, detailed survey of current worldwide practices for the isolation and characterization of EVs. Conditioned cell culture media was the most widely used material (83%). Ultracentrifugation remains the most commonly used isolation method (81%) with 59% of respondents use a combination of methods. Only 9% of respondents used only 1 characterization method, with others using 2 or more methods. Sample volume, sample type and downstream application all influenced the isolation and characterization techniques employed. PMID:27802845

  2. Techniques used for the isolation and characterization of extracellular vesicles: results of a worldwide survey.

    PubMed

    Gardiner, Chris; Di Vizio, Dolores; Sahoo, Susmita; Théry, Clotilde; Witwer, Kenneth W; Wauben, Marca; Hill, Andrew F

    2016-01-01

    Extracellular vesicles (EVs) represent an important mode of intercellular communication. Research in this field has grown rapidly in the last few years, and there is a plethora of techniques for the isolation and characterization of EVs, many of which are poorly standardized. EVs are heterogeneous in size, origin and molecular constituents, with considerable overlap in size and phenotype between different populations of EVs. Little is known about current practices for the isolation, purification and characterization of EVs. We report here the first large, detailed survey of current worldwide practices for the isolation and characterization of EVs. Conditioned cell culture media was the most widely used material (83%). Ultracentrifugation remains the most commonly used isolation method (81%) with 59% of respondents use a combination of methods. Only 9% of respondents used only 1 characterization method, with others using 2 or more methods. Sample volume, sample type and downstream application all influenced the isolation and characterization techniques employed.

  3. 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.

  4. 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.

  5. Contemporary nucleic acid-based molecular techniques for detection, identification, and characterization of Bifidobacterium.

    PubMed

    Mianzhi, Yao; Shah, Nagendra P

    2017-03-24

    Bifidobacteria are one of the most important bacterial groups found in the gastrointestinal tract of humans. Medical and food industry researchers have focused on bifidobacteria because of their health-promoting properties. Researchers have historically relied on classic phenotypic approaches (culture and biochemical tests) for detection and identification of bifidobacteria. Those approaches still have values for the identification and detection of some bifidobacterial species, but they are often labor-intensive and time-consuming and can be problematic in differentiating closely related species. Rapid, accurate, and reliable methods for detection, identification, and characterization of bifidobacteria in a mixed bacterial population have become a major challenge. The advent of nucleic acid-based molecular techniques has significantly advanced isolation and detection of bifidobacteria. Diverse nucleic acid-based molecular techniques have been employed, including hybridization, target amplification, and fingerprinting. Certain techniques enable the detection, characterization, and identification at genus-, species-, and strains-levels, whereas others allow typing of species or strains of bifidobacteria. In this review, an overview of methodological principle, technique complexity, and application of various nucleic acid-based molecular techniques for detection, identification, and characterization of bifidobacteria is presented. Advantages and limitations of each technique are discussed, and significant findings based on particular techniques are also highlighted.

  6. Gel-embedded niosomes: preparation, characterization and release studies of a new system for topical drug delivery.

    PubMed

    Coviello, T; Trotta, A M; Marianecci, C; Carafa, M; Di Marzio, L; Rinaldi, F; Di Meo, C; Alhaique, F; Matricardi, P

    2015-01-01

    In the present paper physical gels, prepared with two polysaccharides, Xanthan and Locust Bean Gum, and loaded with non-ionic surfactant vesicles, are described. The vesicles, composed by Tween20 and cholesterol or by Tween85 and Span20, were loaded with Monoammonium glycyrrhizinate for release experiments. Size and zeta (ζ)-potential of the vesicles were evaluated and the new systems were characterized by rheological and dynamo-mechanical measurements. For an appropriate comparison, a Carbopol gel and a commercial gel for topical applications were also tested. The new formulations showed mechanical properties comparable with those of the commercial product indicating their suitability for topical applications. In vitro release experiments showed that the polysaccharide network protects the integrity of the vesicles and leads to their slow release without disruption of the aggregated structures. Furthermore, being the vesicles composed of molecules possessing enhancing properties, the permeation of the loaded drugs topically delivered can be improved. Thus, the new systems combine the advantages of matrices for a modified release (polymeric component) and those of an easier permeability across the skin (vesicle components). Finally, shelf live experiments indicated that the tested gel/vesicle formulations were stable over 1 year with no need of preservatives.

  7. Shape deposition manufacturing of smart metallic structures with embedded sensors

    NASA Astrophysics Data System (ADS)

    Li, Xiaochun; Golnas, Anastasios; Prinz, Fritz B.

    2000-06-01

    The need to obtain information on the performance and lifetime of a tool in service is of prime importance to many industries. It calls for on-line acquisition of information such as temperature and strain values from tools and structures. With embedded sensors, structures are capable of monitoring parameters at critical locations not accessible to ordinary sensors. To embed sensors in the functional structures, especially structures, Shape Deposition Manufacturing (SDM) is a methodology capable of integrating sensors during the production of tooling or structural components. Thin film sensors and fiber optic sensors have been identified as two promising candidates to be integrated in metallic structures. Embedded thin film strain gages have been characterized in a four-point bending test and the results, showing linearity and no hysteresis, match with those from the theoretical model and commercially available strain gages. Fiber optic sensors have been successfully embedded in nickel and stainless steel structures. The embedded fiber optic sensors have been used to measure temperatures and strains. They provide higher sensitivity, good accuracy, and high temperature capacity. Based on fiber optic sensor embedding techniques, a remote temperature/strain sensing system suitable rotating objects, such as turbine blades, has been developed. The developed techniques can be harnessed for rapid prototyping of smart metallic structures.

  8. Characterization of a sulfadiazine-induced lithiasis calculus by physicochemical techniques.

    PubMed

    Cuervo, C; González, J; Rives, V; Vicente, M A

    2013-03-01

    Currently available information on drug lithiasis usually describes the calculi based on the prescriptions given to the patient, but without a physicochemical characterization of the calculi themselves. We here have applied different, complementary, physicochemical techniques for a complete characterization of an unusual urolithiasis calculus. The calculus was characterized using powder X-ray diffraction, infrared spectroscopy, mass spectrometry, 1H-NMR spectroscopy, and scanning electron microscopy. The precise nature of the calculus was identified, being formed by N4-acetylsulfadiazine, so being related to the drugs prescribed to the patient. Analytical techniques widely used in laboratories of Materials Chemistry have proven to be useful tools for characterizing the chemical nature of unusual urolithiasis.

  9. Characterizing the dealumination of environmentally relevant zeolites using IR, NMR and neutron diffraction techniques

    SciTech Connect

    Paffett, M.T.; Szanyi, J.; Jacubinas, R.M.; Ott, K.C.; VonDreele, R.; Hughes, C.D.; Earl, W.L.

    1997-07-01

    Results of characterization studies monitoring the sequential chemical bond breaking events, local site symmetry, and long range structural modifications of specific zeolites (H-ZSM-5, TS-1) during hydrothermal treatment of these catalyst materials are described. These characterization techniques include infrared spectroscopy of selected probe molecules, magic angle spinning NMR spectroscopy, and powder neutron diffraction. Information regarding selected examples from each of these techniques is presented and the inherent strengths of each is discussed. The experimental insight into the chemical and structural modifications of high surface area microporous catalyst materials as a function of deactivation conditions (hydrothermal conditioning) is highlighted.

  10. 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.

  11. 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.

  12. White-light continuum Z-scan technique for nonlinear materials characterization.

    PubMed

    Balu, Mihaela; Hales, Joel; Hagan, David; Van Stryland, Eric

    2004-08-09

    We present a technique for rapid characterization of degenerate nonlinear absorption and refraction spectra using a femtosecond white-light continuum (WLC) pulse to perform Z-scans. The spectral components of the WLC source are temporally and spatially dispersed to minimize nondegenerate two-photon absorption (2PA) processes. We demonstrate the validity of the method by measuring the 2PA spectrum of a well-characterized semiconductor, ZnSe.

  13. Characterization of rock populations on planetary surfaces - Techniques and a preliminary analysis of Mars and Venus

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Mouginis-Mark, P. J.; Head, J. W.

    1981-01-01

    A data collection and analysis scheme developed for the interpretation of rock morphology from lander images is reviewed with emphasis on rock population characterization techniques. Data analysis techniques are also discussed in the context of identifying key characteristics of a rock that place it in a single category with similar rocks. Actual rock characteristics observed from Viking and Venera lander imagery are summarized. Finally, some speculations regarding the block fields on Mars and Venus are presented.

  14. Technical textiles with embedded fibre Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Bilro, L.; Cunha, H.; Pinto, J. L.; Nogueira, R. N.

    2009-10-01

    The characterization of fiber Bragg grating (FBG) sensors integrated on 2D and 3D mesh structures is presented. Several materials and configurations were tested, namely cork, foams, PVC, hexagonal 3D. Sensors were embedded between two substrates using textile lamination technique. Every sample was subjected to temperature variations and mechanical deformations. Through Bragg wavelength monitoring, thermal, deformation and pressure performance were evaluated. These results provide significant information to the conception of smart textiles.

  15. Characterization Techniques Employed to Determine the Energy Release of Reactive Materials

    DTIC Science & Technology

    2010-03-01

    high speed imaging, and radiography , data can be collected and processed to characterize the energy...the event consist of high speed imaging, emission spectroscopy, pyrometry, pressure measurements and radiography . Due to limited space, a series of... process . Three distinct high speed imaging techniques are incorporated into the testing process ; regular high speed , ultra high speed , and high

  16. A rapid feedback characterization technique for polymeric hollow fiber membranes using disperse dyes

    SciTech Connect

    Clausi, D.T.; Koros, W.J.

    1996-12-31

    The morphologies of advanced asymmetric gas separation membranes can be described in terms of porosity, pore size distribution, and pore connectivity. These complex morphologies are generated via a rapid non-solvent induced phase separation process to yield hollow fiber membranes. Manipulation and control of these microscopic features are accomplished through adjustment of an array of spinning process parameters. A serious limitation to research in hollow fiber membrane formation is the lengthy time lag between fiber spinning and the collection of characteristic data for process optimization. This lag time is due to the intensive downstream processing required before gas based permeation measurements can be conducted. A rapid feedback characterization technique will be discussed for use in polymeric hollow fiber membrane spinning applications utilizing commercially available disperse dyes. This technique involves dyeing wet hollow fibers immediately after spinning in an aqueous dye bath. In the present work, polysulfone fibers have been characterized using this method before lengthy downstream processing (i.e. solvent exchange, drying, and post-treatment). Dye uptake in the hollow fibers appears to be a function of skin porosity, thereby allowing quick evaluation of permeation characteristics. Dye uptake was measured both visually and using UV-visible spectrophotometry. Examples of fibers characterized using this technique and relationships between dye uptake and post-treated selectivity are shown and discussed. This technique allows characterization during the fiber spinning process, making on-line optimization of spinning parameters possible.

  17. 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…

  18. The maturing of high contrast imaging and starlight suppression techniques for future NASA exoplanet characterization missions

    NASA Astrophysics Data System (ADS)

    Coulter, Daniel R.; Gallagher, David B.; Siegler, Nicholas; Shaklan, Stuart; Stapelfeldt, Karl; Traub, Wesley A.

    2016-07-01

    Over 3000 exoplanets and hundreds of exoplanetary systems have been detected to date and we are now rapidly moving toward an era where the focus is shifting from detection to direct imaging and spectroscopic characterization of these new worlds and their atmospheres. NASA is currently studying several exoplanet characterization mission concepts for the 2020 Decadal Survey ranging from probe class to flagships. Detailed and comprehensive exoplanet characterization, particularly of exo-Earths, leading to assessment of habitability, or indeed detection of life, will require significant advances beyond the current state-of-the-art in high contrast imaging and starlight suppression techniques which utilize specially shaped precision optical elements to block the light from the parent star while controlling scattering and diffraction thus revealing and enabling spectroscopic study of the orbiting exoplanets in reflected light. In this paper we describe the two primary high contrast starlight suppression techniques currently being pursued by NASA: 1) coronagraphs (including several design variations) and 2) free-flying starshades. These techniques are rapidly moving from the technology development phase to the design and engineering phase and we discuss the prospects and projected performance for future exoplanet characterization missions utilizing these techniques coupled with large aperture telescopes in space.

  19. 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.

  20. 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.

  1. 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.

  2. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria.

    PubMed

    Asfahani, Jamal

    2011-03-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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.

  5. Multilayer tissue phantoms with embedded capillary system for OCT and DOCT imaging

    NASA Astrophysics Data System (ADS)

    Bykov, Alexander V.; Popov, Alexey P.; Priezzhev, Alexander V.; Myllyla, Risto

    2011-06-01

    We report about manufacturing of fully functional capillary network embedded into the multilayer tissue phantom. Polyvinyl chloride-plastisol was used as a host transparent medium. Scattering was introduced by adding the TiO2submicron particles. OCT technique was used to characterize the manufactured phantoms and to monitor the vessels filling with different liquids.

  6. Embedding Optical Fibers In Cast Metal Parts

    NASA Technical Reports Server (NTRS)

    Gibler, William N.; Atkins, Robert A.; Lee, Chung E.; Taylor, Henry F.

    1995-01-01

    Use of metal strain reliefs eliminates breakage of fibers during casting process. Technique for embedding fused silica optical fibers in cast metal parts devised. Optical fiber embedded in flange, fitting, or wall of vacuum or pressure chamber, to provide hermetically sealed feedthrough for optical transmission of measurement or control signals. Another example, optical-fiber temperature sensor embedded in metal structural component to measure strain or temperature inside component.

  7. Embedding Optical Fibers In Cast Metal Parts

    NASA Technical Reports Server (NTRS)

    Gibler, William N.; Atkins, Robert A.; Lee, Chung E.; Taylor, Henry F.

    1995-01-01

    Use of metal strain reliefs eliminates breakage of fibers during casting process. Technique for embedding fused silica optical fibers in cast metal parts devised. Optical fiber embedded in flange, fitting, or wall of vacuum or pressure chamber, to provide hermetically sealed feedthrough for optical transmission of measurement or control signals. Another example, optical-fiber temperature sensor embedded in metal structural component to measure strain or temperature inside component.

  8. 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.

  9. 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

  10. General approach of the photothermoelectric technique for thermal characterization of solid thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Touati, Karim; Depriester, Michael; Guilmeau, Emmanuel; Sotelo, Andrés; Madre, Maria A.; Gascoin, Franck; Sahraoui, Abdelhak Hadj

    2017-07-01

    This work focuses on the photothermoelectric (PTE) technique allowing the thermal characterization of solid-state thermoelectric (TE) materials. Previously, this technique was restricted to TE materials having low electrical conductivities. Here, the PTE technique is extended and generalized to all solid-state TE materials with low or high electrical conductivities. This is achieved by taking into account the Gaussian shape of the thermal excitation source. The formalism of this new methodology is developed and the procedure for extracting thermal parameters is proposed. For illustration, two different TE materials are studied: with relatively high electrical conductivity (Bi2Te2.4Se0.6) and relatively low electrical conductivity (Bi2Ca2Co1.7O x ). The thermal properties of these two materials (thermal diffusivity, effusivity and conductivity) are found and compared to those obtained by the photothermal radiometry which is a well established technique. The good concordance between the results obtained by these two techniques demonstrates the relevance of the generalized PTE technique. One of the main advantages of this technique is its non use of an external sensor.

  11. The development of a shock-tube based characterization technique for air-coupled ultrasonic probes.

    PubMed

    Revel, G M; Pandarese, G; Cavuto, A

    2014-08-01

    The present paper proposes a new characterization technique for air-coupled ultrasound probes. The technique is based on a shock tube to generate a controlled pressure wave to calibrate transducers within their operating frequency range. The aim is to generate a high frequency pressure wave (at least up to 200 kHz) with the low energy levels typical of commonly used air-coupled ultrasound probes. A dedicated shock-tube has been designed and tested to assess calibration performances. The sensor transfer function has been measured by using a pressure transducer as reference. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Embedded Thermal Control for Subsystems for Next Generation Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Didion, Jeffrey R.

    2015-01-01

    Thermal Fluids and Analysis Workshop, Silver Spring MD NCTS 21070-15. NASA, the Defense Department and commercial interests are actively engaged in developing miniaturized spacecraft systems and scientific instruments to leverage smaller cheaper spacecraft form factors such as CubeSats. This paper outlines research and development efforts among Goddard Space Flight Center personnel and its several partners to develop innovative embedded thermal control subsystems. Embedded thermal control subsystems is a cross cutting enabling technology integrating advanced manufacturing techniques to develop multifunctional intelligent structures to reduce Size, Weight and Power (SWaP) consumption of both the thermal control subsystem and overall spacecraft. Embedded thermal control subsystems permit heat acquisition and rejection at higher temperatures than state of the art systems by employing both advanced heat transfer equipment (integrated heat exchangers) and high heat transfer phenomena. The Goddard Space Flight Center Thermal Engineering Branch has active investigations seeking to characterize advanced thermal control systems for near term spacecraft missions. The embedded thermal control subsystem development effort consists of fundamental research as well as development of breadboard and prototype hardware and spaceflight validation efforts. This paper will outline relevant fundamental investigations of micro-scale heat transfer and electrically driven liquid film boiling. The hardware development efforts focus upon silicon based high heat flux applications (electronic chips, power electronics etc.) and multifunctional structures. Flight validation efforts include variable gravity campaigns and a proposed CubeSat based flight demonstration of a breadboard embedded thermal control system. The CubeSat investigation is technology demonstration will characterize in long-term low earth orbit a breadboard embedded thermal subsystem and its individual components to develop

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

    DOE PAGES

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

    2016-03-03

    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 revealmore » salient microstructural features that cannot be observed from conventional metallographic techniques. As a result, examples are shown to demonstrate the benefit of FIB-SEM in improving microstructural characterization of microscopic inclusions, particularly with respect to nuclear forensics.« less

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

    SciTech Connect

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

    2016-03-03

    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. As a result, examples are shown to demonstrate the benefit of FIB-SEM in improving microstructural characterization of microscopic inclusions, particularly with respect to nuclear forensics.

  15. Characterization of aquifer relationships by using geochemical techniques for plume delineation

    SciTech Connect

    Aggarwal, P.K.; Burton, J.C.; Rose, C.M.

    1994-04-01

    Conventional approaches to characterize aquifers at hazardous waste sites rely heavily on the installation of monitoring wells, hydraulic testing, and sampling and analysis of groundwater for contaminant concentrations. The use of geochemical techniques to determine relationships among aquifers in environmental investigations is limited, in part, because of a generally held view that these techniques may not be useful for shallow aquifers. In this paper, the authors discuss the use of (a) major ion compositions, (b) stable isotope ratios of oxygen, hydrogen, and carbon, and (c) the abundance of tritium to identify multiple aquifers, to establish the lateral extent of aquitards, and to determine hydraulic interconnections among aquifers at two hazardous waste sites. Experience with these and ongoing investigations at several other sites demonstrates that carefully conducted geochemical sampling and analysis of limited samples of groundwater provide an effective tool for hydrogeologic characterization in a variety of geologic settings.

  16. 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.

  17. Linear optical characterization of transparent thin films by the Z-scan technique.

    PubMed

    Boudebs, Georges; Fedus, Kamil

    2009-07-20

    We report experimental characterization of a very small rectangular phase shift (<0.3 rad) obtained from the far-field diffraction patterns using a closed aperture Z-scan technique. The numerical simulations as well as the experimental results reveal a peak-valley configuration in the far-field normalized transmittance, allowing us to determine the sign of the dephasing. The conditions necessary to obtain useful Z-scan traces are discussed. We provide simple linear expressions relating the measured signal to the phase shift. A very good agreement between calculated and experimental Z-scan profiles validates our approach. We show that a very well known nonlinear characterization technique can be extended for linear optical parameter estimation (as refractive index or thickness).

  18. Learning for VMM + WTA Embedded Classifiers

    DTIC Science & Technology

    2016-03-31

    training, less than 30μW of operational power and lower with additional fabrication. Keywords: Embedded Machine Learning ICs, Neuromorphic... Learning for VMM + WTA Embedded Classifiers Jennifer Hasler and Sahil Shah Electrical and Computer Engineering Georgia Institute of Technology...infinite resources). Foundations of VMM+WTA Learning The fundamental question is enabling a working supervised learning technique for these systems

  19. 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.

  20. Metal embedded Fiber Brag Grating Sensors

    NASA Astrophysics Data System (ADS)

    Khanal, Chooda; Vargas, Garman; Balani, Kantesh; Keshri, Anup; Barbosa, Carmen; Agarwal, Arvind; Panepucci, Roberto

    2009-03-01

    A novel method of embedding optical fibers and optical fiber sensors, inside metallic structures will be discussed. We specifically report results for embedding fiber bragg grating sensors in an aluminum coating onto a steel plate. Characterization of an embedded FBG sensor and its effects on the sensor operation are also presented. Temperature sensitivity and the strain sensitivity will be discussed. The novel high throughput deposition method show the potential of embedding optical sensors onto metallic structures which make it suitable for many engineering applications in biomedical, civil, mechanical and aeronautical, among other fields.

  1. Characterization of nanomaterial dispersion in solution prior to in vitro exposure using dynamic light scattering technique.

    PubMed

    Murdock, Richard C; Braydich-Stolle, Laura; Schrand, Amanda M; Schlager, John J; Hussain, Saber M

    2008-02-01

    The need to characterize nanoparticles in solution before assessing the in vitro toxicity is a high priority. Particle size, size distribution, particle morphology, particle composition, surface area, surface chemistry, and particle reactivity in solution are important factors which need to be defined to accurately assess nanoparticle toxicity. Currently, there are no well-defined techniques for characterization of wet nanomaterials in aqueous or biological solutions. Previously reported nanoparticle characterization techniques in aqueous or biological solutions have consisted of the use of ultra-high illumination light microscopy and disc centrifuge sedimentation; however, these techniques are limited by the measurement size range. The current study focuses on characterizing a wide range of nanomaterials using dynamic light scattering (DLS) and transmission electron microscopy, including metals, metal oxides, and carbon-based materials, in water and cell culture media, with and without serum. Cell viability and cell morphology studies were conducted in conjunction with DLS experiments to evaluate toxicological effects from observed agglomeration changes in the presence or absence of serum in cell culture media. Observations of material-specific surface properties were also recorded. It was also necessary to characterize the impact of sonication, which is implemented to aid in particle dispersion and solution mixture. Additionally, a stock solution of nanomaterials used for toxicology studies was analyzed for changes in agglomeration and zeta potential of the material over time. In summary, our results demonstrate that many metal and metal oxide nanomaterials agglomerate in solution and that depending upon the solution particle agglomeration is either agitated or mitigated. Corresponding toxicity data revealed that the addition of serum to cell culture media can, in some cases, have a significant effect on particle toxicity possibly due to changes in agglomeration

  2. 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.

  3. Characterization of ultrafast hard x-ray pulses for LCLS using gas phase techniques

    NASA Astrophysics Data System (ADS)

    Hertlein, Marcus P.; Kienberger, Reinhard; Adaniya, Hidehito

    2005-05-01

    The availability of ultrafast (sub-100 fs) hard x-ray pulses (E > 1000 eV) promises new experimental opportunities, but also requires new techniques for their use. The Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC) is such a source that is expected to provide a high flux of 230 fs monochromatic x-ray photons with energy between 0.8 and 8 keV. Characterization methods for beams with such characteristics still need to be developed. We are presenting several techniques that show promise for the spatial and temporal characterization of ultrafast hard x-rays. They were developed and used at the Advanced Light Source (ALS), and will undergo further testing at the Sub-Picosecond Photon Source (SPPS) at SLAC. Our methods exploit effects such as ultrafast core-hole binding energy changes in atoms after laser excitation, and creation of energy sidebands on Auger electrons that are emitted in a laser field. We have demonstrated the usefulness of these effects on a picosecond time scale, but their use can be extended well into the femtosecond domain. We will also discuss time-of-flight techniques which offer the possibility of nondestructive x-ray spatial mode characterization. Our focus is on gas phase experiments, since they offer the possibility of nondestructive, transparent monitoring of the x-rays, leaving the main beam nearly undisturbed and available for experiments.

  4. Research Techniques Made Simple: Identification and Characterization of Long Noncoding RNA in Dermatological Research.

    PubMed

    Antonini, Dario; Mollo, Maria Rosaria; Missero, Caterina

    2017-03-01

    Long noncoding RNAs (lncRNAs) are a functionally heterogeneous and abundant class of RNAs acting in all cellular compartments that can form complexes with DNA, RNA, and proteins. Recent advances in high-throughput sequencing and techniques leading to the identification of DNA-RNA, RNA-RNA, and RNA-protein complexes have allowed the functional characterization of a small set of lncRNAs. However, characterization of the full repertoire of lncRNAs playing essential roles in a number of normal and dysfunctional cellular processes remains an important goal for future studies. Here we describe the most commonly used techniques to identify lncRNAs, and to characterize their biological functions. In addition, we provide examples of these techniques applied to cutaneous research in healthy skin, that is, epidermal differentiation, and in diseases such as cutaneous squamous cell carcinomas and psoriasis. As with protein-coding RNA transcripts, lncRNAs are differentially regulated in disease, and can serve as novel biomarkers for the diagnosis and prognosis of skin diseases.

  5. State-of-the-art characterization techniques for advanced lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Wu, Tianpin; Amine, Khalil

    2017-03-01

    To meet future needs for industries from personal devices to automobiles, state-of-the-art rechargeable lithium-ion batteries will require both improved durability and lowered costs. To enhance battery performance and lifetime, understanding electrode degradation mechanisms is of critical importance. Various advanced in situ and operando characterization tools developed during the past few years have proven indispensable for optimizing battery materials, understanding cell degradation mechanisms, and ultimately improving the overall battery performance. Here we review recent progress in the development and application of advanced characterization techniques such as in situ transmission electron microscopy for high-performance lithium-ion batteries. Using three representative electrode systems—layered metal oxides, Li-rich layered oxides and Si-based or Sn-based alloys—we discuss how these tools help researchers understand the battery process and design better battery systems. We also summarize the application of the characterization techniques to lithium-sulfur and lithium-air batteries and highlight the importance of those techniques in the development of next-generation batteries.

  6. Characterization techniques for gas diffusion layers for proton exchange membrane fuel cells - A review

    NASA Astrophysics Data System (ADS)

    Arvay, A.; Yli-Rantala, E.; Liu, C.-H.; Peng, X.-H.; Koski, P.; Cindrella, L.; Kauranen, P.; Wilde, P. M.; Kannan, A. M.

    2012-09-01

    The gas diffusion layer (GDL) in a proton exchange membrane fuel cell (PEMFC) is one of the functional components that provide a support structure for gas and water transport. The GDL plays a crucial role when the oxidant is air, especially when the fuel cell operates in the higher current density region. There has been an exponential growth in research and development because the PEMFC has the potential to become the future energy source for automotive applications. In order to serve in this capacity, the GDL requires due innovative analysis and characterization toward performance and durability. It is possible to achieve the optimum fuel cell performance only by understanding the characteristics of GDLs such as structure, pore size, porosity, gas permeability, wettability, thermal and electrical conductivities, surface morphology and water management. This review attempts to bring together the characterization techniques for the essential properties of the GDLs as handy tools for R&D institutions. Topics are categorized based on the ex-situ and in-situ characterization techniques of GDLs along with related modeling and simulation. Recently reported techniques used for accelerated durability evaluation of the GDLs are also consolidated within the ex-situ and in-situ methods.

  7. A new surface characterization technique: RIMAPS (Rotated Image with Maximum Average Power Spectrum).

    PubMed

    Fuentes, N O; Favret, E A

    2002-04-01

    This work introduces a new imaging technique, Rotated Image with Maximum Average Power Spectrum (RIMAPS), for use in determining orientation and characteristics of surface topography. It consists of computing the maximum value of the averaged power spectrum, given by one step of the two-dimensional Fourier transform, for each angle of rotation of a digitized image. The basic measurement science of this technique is described and different cases are studied. The characterization of simple geometrical figures explains the meaning of peaks and their angular positions given by RIMAPS analysis. A known surface pattern made on a sample of pure copper, mechanically ground, is used to study reproducibility, dependence on image quality and topography scale relative to pixel size and magnification. Samples of pure zinc, mechanically ground and chemically etched, were used to show the main features of RIMAPS analysis when characterizing a more complicated pattern on a real surface. All the studies performed under different conditions for observation and acquisition of images give strong evidence of the stability and robustness of RIMAPS as a technique for the characterization of topography.

  8. 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

  9. Clinical decision support systems for brain tumor characterization using advanced magnetic resonance imaging techniques.

    PubMed

    Tsolaki, Evangelia; Kousi, Evanthia; Svolos, Patricia; Kapsalaki, Efthychia; Theodorou, Kyriaki; Kappas, Constastine; Tsougos, Ioannis

    2014-04-28

    In recent years, advanced magnetic resonance imaging (MRI) techniques, such as magnetic resonance spectroscopy, diffusion weighted imaging, diffusion tensor imaging and perfusion weighted imaging have been used in order to resolve demanding diagnostic problems such as brain tumor characterization and grading, as these techniques offer a more detailed and non-invasive evaluation of the area under study. In the last decade a great effort has been made to import and utilize intelligent systems in the so-called clinical decision support systems (CDSS) for automatic processing, classification, evaluation and representation of MRI data in order for advanced MRI techniques to become a part of the clinical routine, since the amount of data from the aforementioned techniques has gradually increased. Hence, the purpose of the current review article is two-fold. The first is to review and evaluate the progress that has been made towards the utilization of CDSS based on data from advanced MRI techniques. The second is to analyze and propose the future work that has to be done, based on the existing problems and challenges, especially taking into account the new imaging techniques and parameters that can be introduced into intelligent systems to significantly improve their diagnostic specificity and clinical application.

  10. A model identification technique to characterize the low frequency behaviour of surrogate explosive materials

    NASA Astrophysics Data System (ADS)

    Paripovic, Jelena; Davies, Patricia

    2016-09-01

    The mechanical response of energetic materials, especially those used in improvised explosive devices, is of great interest to improve understanding of how mechanical excitations may lead to improved detection or detonation. The materials are comprised of crystals embedded into a binder. Microstructural modelling can give insight into the interactions between the binder and the crystals and thus the mechanisms that may lead to material heating and but there needs to be validation of these models and they also require estimates of constituent material properties. Addressing these issues, nonlinear viscoelastic models of the low frequency behavior of a surrogate material-mass system undergoing base excitation have been constructed, and experimental data have been collected and used to estimate the order of components in the system model and the parameters in the model. The estimation technique is described and examples of its application to both simulated and experimental data are given. From the estimated system model the material properties are extracted. Material properties are estimated for a variety of materials and the effect of aging on the estimated material properties is shown.

  11. Gaseous tracer techniques for pore structure characterization of granular materials. [Freon as tracer

    SciTech Connect

    Erickson, K L

    1988-01-01

    The pore structure of granular materials influences several physical and chemical phenomena, including: 1) heat and mass transfer rates, 2) fluid dynamics, 3) mechanical response, and 4) heterogeneous chemical reaction rates. In many systems, these phenomena are coupled, and accurate pore structure characterization is important to developing reliable predictive models. Gaseous tracer techniques show promise as a rapid nondestructive method for characterizing pore structures. To provide a basis for developing a theoretical and experimental approach involving multiple tracer techniques, five characteristic parameters were defined to describe the major features of a macroscopically uniform pore structure. Those parameters are the following: 1) the portion of the total pore space that forms flow paths (flow porosity), 2) the fraction that forms relatively stagnant paths (stagnant porosity), 3) the tortuosity of the flow porosity, 4) the specific surface area of the pore space, and 5) the fraction of the specific surface area that is associated with the flow porosity. Initial experiments with samples having simple, known pore structures were conducted to evaluate the theory and experimental techniques. Agreement between known and experimentally determined parameter values was good. Furthermore, it appears that the tracer techniques can have broad application as nondestructive diagnostic tools for examining granular materials.

  12. 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.

  13. 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. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  14. 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).

  15. 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.

  16. Evolution and enabling capabilities of spatially resolved techniques for the characterization of heterogeneously catalyzed reactions

    DOE PAGES

    Morgan, Kevin; Touitou, Jamal; Choi, Jae -Soon; ...

    2016-01-15

    The development and optimization of catalysts and catalytic processes requires knowledge of reaction kinetics and mechanisms. In traditional catalyst kinetic characterization, the gas composition is known at the inlet, and the exit flow is measured to determine changes in concentration. As such, the progression of the chemistry within the catalyst is not known. Technological advances in electromagnetic and physical probes have made visualizing the evolution of the chemistry within catalyst samples a reality, as part of a methodology commonly known as spatial resolution. Herein, we discuss and evaluate the development of spatially resolved techniques, including the evolutions and achievements ofmore » this growing area of catalytic research. The impact of such techniques is discussed in terms of the invasiveness of physical probes on catalytic systems, as well as how experimentally obtained spatial profiles can be used in conjunction with kinetic modeling. Moreover, some aims and aspirations for further evolution of spatially resolved techniques are considered.« less

  17. 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.

  18. Frequency-domain Harman technique for rapid characterization of bulk and thin film thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Moran, Samuel

    Nanostructured thermoelectrics, often in the form of thin films, may potentially improve the generally poor efficiency of bulk thermoelectric power generators and coolers. In order to characterize the efficiency of these new materials it is necessary to measure their thermoelectric figure of merit, ZT. The only direct measurement of ZT is based on the Harman technique and relies on measuring the voltage drop across a sample subjected to a passing continuous current. Application of this technique to thin films is currently carried out as a time-domain measurement of the voltage as the thermal component decays after switching off an applied voltage. This work develops a technique for direct simultaneous measurement of figure of merit and Seebeck coefficient from the harmonic response of a thermoelectric material under alternating current excitation. A thermocouple mounted on the top surface measures voltage across the device as the frequency of the applied voltage is varied. A thermal model allows the sample thermal conductivity to also be determined and shows good agreement with measurements. This technique provides improved signal-to-noise ratio and accuracy compared to time-domain ZT measurements for comparable conditions while simultaneously measuring Seebeck coefficient. The technique is applied to both bulk and thin film thermoelectric samples.

  19. 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.

  20. 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

  1. Steering charge kinetics in photocatalysis: intersection of materials syntheses, characterization techniques and theoretical simulations.

    PubMed

    Bai, Song; Jiang, Jun; Zhang, Qun; Xiong, Yujie

    2015-05-21

    Charge kinetics is highly critical in determining the quantum efficiency of solar-to-chemical conversion in photocatalysis, and this includes, but is not limited to, the separation of photoexcited electron-hole pairs, utilization of plasmonic hot carriers and delivery of photo-induced charges to reaction sites, as well as activation of reactants by energized charges. In this review, we highlight the recent progress on probing and steering charge kinetics toward designing highly efficient photocatalysts and elucidate the fundamentals behind the combinative use of controlled synthesis, characterization techniques (with a focus on spectroscopic characterizations) and theoretical simulations in photocatalysis studies. We first introduce the principles of various processes associated with charge kinetics that account for or may affect photocatalysis, from which a set of parameters that are critical to photocatalyst design can be summarized. We then outline the design rules for photocatalyst structures and their corresponding synthetic approaches. The implementation of characterization techniques and theoretical simulations in different steps of photocatalysis, together with the associated fundamentals and working mechanisms, are also presented. Finally, we discuss the challenges and opportunities for photocatalysis research at this unique intersection as well as the potential impact on other research fields.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

    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.

  4. Characterization and separation of ash from CANMET coprocessing residue by oil phase agglomeration techniques

    SciTech Connect

    Majid, A.; Coleman, R.D.; Toll, R.; Pleizier, G.; Deslandes, Y.; Sparks, B.D.; Ikura, M.

    1993-12-31

    CANMET`s coal/heavy oil coprocessing unit yields a solid residue that contains most of the ash originally associated with the feed coal as well as reacted catalyst solids. Removal of these ash solids would make it possible to recycle the material to extinction, thereby increasing production of lighter oils. In this investigation the authors have used surface characterization techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and X-ray Photoelectron Spectroscopy (XPS) to characterize toluene insoluble solids associated with the pitch residue, in order to evaluate the separation potential using oil phase agglomeration techniques. Washability studies using float-sink tests were also carried out to determine empirically the level of ash separation attainable. Based on the results of these studies several tests were carried out to beneficiate the organic matter in the residue pitch, by using liquid phase agglomeration techniques. Levels of ash rejection in these tests ranged from 20% to 40%. SEM and EDXA analysis of the agglomerated product and the reject material and Inductively Coupled Plasma (ICP) analysis of the ash from both materials suggest that most of the iron from added catalyst is retained in the agglomerates.

  5. A review of the different techniques for solid surface acid-base characterization.

    PubMed

    Sun, Chenhang; Berg, John C

    2003-09-18

    In this work, various techniques for solid surface acid-base (AB) characterization are reviewed. Different techniques employ different scales to rank acid-base properties. Based on the results from literature and the authors' own investigations for mineral oxides, these scales are compared. The comparison shows that Isoelectric Point (IEP), the most commonly used AB scale, is not a description of the absolute basicity or acidity of a surface, but a description of their relative strength. That is, a high IEP surface shows more basic functionality comparing with its acidic functionality, whereas a low IEP surface shows less basic functionality comparing with its acidic functionality. The choice of technique and scale for AB characterization depends on the specific application. For the cases in which the overall AB property is of interest, IEP (by electrokinetic titration) and H(0,max) (by indicator dye adsorption) are appropriate. For the cases in which the absolute AB property is of interest such as in the study of adhesion, it is more pertinent to use chemical shift (by XPS) and the heat of adsorption of probe gases (by calorimetry or IGC).

  6. 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.

  7. Secure Embedded Systems

    DTIC Science & Technology

    2016-02-26

    computing. An embedded computer system is designed for a dedicated function, in contrast to a general-purpose computer system , e.g., a desktop... embedded system is challenging because security requirements are rarely accurately identified at the start of the design process, and embedded ...architecture that will seamlessly work with various OSA components is a challenge. 3    Design Process (heading level 1) Embedded system CONOPS are

  8. Application of microwave 3D SAR imaging technique for evaluation of corrosion in steel rebars embedded in cement-based structures

    NASA Astrophysics Data System (ADS)

    Kharkovsky, S.; Case, J. T.; Ghasr, M. T.; Zoughi, R.; Bae, S. W.; Belarbi, A.

    2012-05-01

    This paper presents and discusses the attributes and results of using wideband microwave 3D SAR-based imaging technique for evaluation of reinforced cement-based structures. The technique was used to detect corrosion and thinning of reinforcing steel bars and its potential was demonstrated through experiments for different bar sizes, depth of rebar locations, and spacing between rebars. The results of a limited and preliminary investigation in which thinning of rebars with and without rust in two mortar samples were obtained at three frequency bands covering the frequency range from 8.2 GHz-26.5 GHz.

  9. Embedding of copper sulfate and copper oxide on multipurpose paper

    NASA Astrophysics Data System (ADS)

    Almanza, D. L. V.; de Luna, J. L. A.; Herrera, M. U.

    2017-05-01

    Copper sulfate salts were embedded on multipurpose paper using simple soaking technique while copper oxide particles were embedded using in-situ technique. In simple soaking technique, the papers were simply soaked in copper sulfate solution in order for the copper salts to be incorporated in the paper. In the in-situ technique, the copper sulfate-embedded papers were soaked in sodium hydroxide solution for reactions to occur that will lead to the formation of copper oxide. Copper sulfate-embedded papers have blue green color while copper oxide-embedded papers have brown color. The copper sulfate-embedded paper shows excellent antimicrobial property against Staphylococcus aureus. Meanwhile, the copper oxide-embedded paper shows small zone of inhibition against Escherichia coli and Staphylococcus aureus.

  10. 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.

  11. 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.

  12. Characterization of the histone methyltransferase PRDM9 using biochemical, biophysical and chemical biology techniques.

    PubMed

    Koh-Stenta, Xiaoying; Joy, Joma; Poulsen, Anders; Li, Rong; Tan, Yvonne; Shim, Yoonjung; Min, Jung-Hyun; Wu, Liling; Ngo, Anna; Peng, Jianhe; Seetoh, Wei Guang; Cao, Jing; Wee, John Liang Kuan; Kwek, Perlyn Zekui; Hung, Alvin; Lakshmanan, Umayal; Flotow, Horst; Guccione, Ernesto; Hill, Jeffrey

    2014-07-15

    PRDM proteins have emerged as important regulators of disease and developmental processes. To gain insight into the mechanistic actions of the PRDM family, we have performed comprehensive characterization of a prototype member protein, the histone methyltransferase PRDM9, using biochemical, biophysical and chemical biology techniques. In the present paper we report the first known molecular characterization of a PRDM9-methylated recombinant histone octamer and the identification of new histone substrates for the enzyme. A single C321P mutant of the PR/SET domain was demonstrated to significantly weaken PRDM9 activity. Additionally, we have optimized a robust biochemical assay amenable to high-throughput screening to facilitate the generation of small-molecule chemical probes for this protein family. The present study has provided valuable insight into the enzymology of an intrinsically active PRDM protein.

  13. 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.

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

    PubMed

    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.

  16. Novel techniques for detection and characterization of nanomaterials based on aerosol science supporting environmental applications.

    PubMed

    Mugica, Iñaki; Fito, Carlos; Domat, Maidá; Dohányosová, Pavla; Gutierrez-Cañas, Cristina; López-Vidal, Silvia

    2017-12-31

    The number of people exposed to nanoparticles is growing accordingly to the production and development of new nanomaterials. Moreover, this increase is expected to continue in the future. However, there is a lack of standardized sampling and metric methods to measure the level of exposure to nanoparticles, and the information related to possible adverse health effects is scarce. Aerosol technology has been detecting and characterizing nanoparticles for decades and some of their developments can be of use in nanotechnology characterization. We present here two current developments based on used principles in aerosol science, which can widen its application to the characterization of nanomaterials. On the one hand, a sample preparation technique for nanoparticle analysis by electron microscopy based on electrospray atomization technology. Several samples prepared in this way have been analysed and compared to more traditional sample preparation strategies like the "drop on grid" method. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and the number of single particles increases substantially. On the other hand, it is presented an electrical mobility classification system, DMA, with enormous possibilities for the quick and economic size characterization of suspensions of nanoparticles, thanks to its injection system by electrospray and to its high resolution in the lower range of the nanoscale. The first assessment of the abovementioned devices highlights its potential applications in exposure assessment and nanotechnological contexts. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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.

  19. 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.

  20. Characterization of Zirconium Hydride Orientations in Zircaloy Cladding Tubes with a Laser Ultrasound Technique

    NASA Astrophysics Data System (ADS)

    Yeh, Cheng-Hung; Yang, Che-Hua

    2010-02-01

    This research is focused on characterizing Zircaloy cladding tubes with different concentration ratios between radially(R) orientated hydrides and circumferential(C) ones. A procedure corporate with an experimental technique and an inversion algorism is used to investigate the effects of R/C ratio on the dispersion spectra of GW. A laser ultrasound technique (LUT) is used to measure the dispersions of circumferentially guided waves (CGW) propagating along the circumferential direction of the cladding tubes. An inversion algorism based on simplex method is used to extract interested properties from the measured GW dispersion spectra. It is shown that the procedure introduced in the current research is able to relate the phase velocities with hydrogen concentration. In the meanwhile, this procedure is able to distinguish the R/C ratio in a quantitative way as well. It is also found out that the bulk elastic modulus increases as the R/C ratio increases.

  1. PDMS droplet formation and characterization by hydrodynamic flow focusing technique in a PDMS square microchannel

    NASA Astrophysics Data System (ADS)

    Carneiro, J.; Doutel, E.; Campos, J. B. L. M.; Miranda, J. M.

    2016-10-01

    This study reports the generation of polydimethylsiloxane (PDMS) droplets by hydrodynamic flow focusing technique in a PDMS square microchannel. The droplet generation was characterized and a flow regime map addressed by the capillary numbers of each phase was assembled. Different flow regimes were found—dripping, jetting, threading and viscous displacement and the respective boundaries were sketched. Droplet size, breakup distance and formation frequency were analysed and quantified for the jetting and dripping regimes. The dripping regime showed better results for droplet formation, leading to the highest throughput of monodisperse droplets: formation frequency of  ≈12 Hz and droplets almost uniform in size (2.8% the coefficient of variance). The qualitative analysis and quantitative measurement of the different variables and their correlation within a capillary dependent regime map proved to be an invaluable tool to study droplet formation by hydrodynamic flow focusing technique in a PDMS square microchannel.

  2. Doping characterization for germanium-based microelectronics and photovoltaics using the differential Hall technique

    NASA Astrophysics Data System (ADS)

    Bennett, N. S.; Cowern, N. E. B.

    2012-04-01

    In this coming decade, complementary metal-oxide-semiconductor microelectronic devices may undergo a major change with the implementation of germanium channels. Likewise, the performance of photovoltaic cells based on elemental semiconductors will continue to be optimized. Both technologies will rely on a detailed and thorough understanding of electrical properties, and here, precise doping characterization will play a key role. The differential Hall technique combines resistivity and Hall-effect measurements with successive surface layer removal, allowing one to measure independent carrier concentration and mobility depth profiles. In this Letter, we apply the technique for both microelectronic- and photovoltaic-relevant doping structures in germanium. Controllable and uniform layer removal is achieved with tailored depth resolution (<1-20 nm) for a range of doping structures (30-600 nm).

  3. Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

    SciTech Connect

    Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A; Villafana, R J; Wade, J T; Weber, S R; Wong, B M; Souers, P C

    2008-01-16

    The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.

  4. Characterization of copper selenide thin films deposited by chemical bath deposition technique

    NASA Astrophysics Data System (ADS)

    Al-Mamun; Islam, A. B. M. O.

    2004-11-01

    A low-cost chemical bath deposition (CBD) technique has been used for the preparation of Cu2-xSe thin films onto glass substrates and deposited films were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV-vis spectrophotometry. Good quality thin films of smooth surface of copper selenide thin films were deposited using sodium selenosulfate as a source of selenide ions. The structural and optical behaviour of the films are discussed in the light of the observed data.

  5. Characterization of a seeded pulsed molecular beam using the velocity map imaging technique

    NASA Astrophysics Data System (ADS)

    Lietard, Aude; Poisson, Lionel; Mestdagh, Jean-Michel; Gaveau, Marc-André

    2016-11-01

    An experimental study has been performed to characterize the density and the velocity distribution in a pulsed molecular beam generated by a source associating a pulsed valve and an oven placed just downstream. In its operating mode, the flow is alternatively in a supersonic and effusive regime. The Velocity Map Imaging (VMI) technique associated with laser ionization allows measuring the velocity distribution and the density of molecules as a function of time during the expansion. It gives us a very precise insight into the structure of the molecule bunch, and therefore into the nature of the expansion from which the molecular beam is extracted.

  6. Combined application of imaging techniques for the characterization and authentication of ancient weapons

    NASA Astrophysics Data System (ADS)

    Salvemini, Filomena; Grazzi, Francesco; Kardjilov, Nikolay; Wieder, Frank; Manke, Ingo; Edge, David; Williams, Alan; Zoppi, Marco

    2017-05-01

    Non-invasive experimental methods play an important role in the field of cultural heritage. Benefiting from the technical progress in recent years, neutron imaging has been demonstrated to complement effectively studies based on surface analysis, allowing for a non-invasive characterization of the whole three-dimensional volume. This study focuses on a kris and a kanjar, two weapons from ancient Asia, to show the potential of the combined use of X-ray and neutron imaging techniques for the characterisation of the manufacturing methods and the authentication of objects of cultural and historical interest.

  7. A review of electrical characterization techniques for ultrathin FDSOI materials and devices

    NASA Astrophysics Data System (ADS)

    Cristoloveanu, Sorin; Bawedin, Maryline; Ionica, Irina

    2016-03-01

    The characterization of nanosize SOI materials and devices is challenging because multiple oxides, interfaces and channels coexist. Conventional measurement methods need to be replaced, or at least updated. We review the routine techniques that proved efficient for the evaluation of bare SOI wafers (essentially the pseudo-MOSFET) and of MOS structures (transistors and gated diodes). Informative examples are selected to illustrate the typical properties of advanced SOI wafers and MOSFETs. We will show how the ultrathin film and short-channel effects affect the interpretation of the experimental data.

  8. Experimental characterization of 3D localization techniques for particle-tracking and super-resolution microscopy.

    PubMed

    Mlodzianoski, Michael J; Juette, Manuel F; Beane, Glen L; Bewersdorf, Joerg

    2009-05-11

    Three-dimensional (3D) particle localization at the nanometer scale plays a central role in 3D particle tracking and 3D localization-based super-resolution microscopy. Here we introduce a localization algorithm that is independent of theoretical models and therefore generally applicable to a large number of experimental realizations. Applying this algorithm and a convertible experimental setup we compare the performance of the two major 3D techniques based on astigmatic distortions and on multiplane detection. In both methods we obtain experimental 3D localization accuracies in agreement with theoretical predictions and characterize the depth dependence of the localization accuracy in detail.

  9. X-ray microscopy: An emerging technique for semiconductor microstructure characterization

    SciTech Connect

    Padmore, H.A.

    1998-05-01

    The advent of third generation synchrotron radiation x-ray sources, such as the Advanced Light Source (ALS) at Berkeley have enabled the practical realization of a wide range of new techniques in which mature chemical or structural probes such as x-ray photoelectron spectroscopy (XPS) and x-ray diffraction are used in conjunction with microfocused x-ray beams. In this paper the characteristics of some of these new microscopes are described, particularly in reference to their applicability to the characterization of semiconductor microstructures.

  10. Cell adhesion to silicon substrata: characterization by means of optical and acoustic cytometric techniques.

    PubMed

    Grattarola, M; Tedesco, M; Cambiaso, A; Perlo, G; Giannetti, G; Sanguineti, A

    1988-01-01

    The adhesion and growth of cells on silicon dioxide substrata are analysed. The adhesion of human red blood cells to silicon dioxide layers of different depth and doping compares well with that to glass. Rat pheochromocytoma cells also grow on the same substrata. The adhesion of these two biological systems is characterized at the microscopic level by using the quite new technique of scanning reflection acoustic microscopy. Possible future developments towards the functional coupling of living cells to microelectronic integrated circuits are briefly discussed.

  11. 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.

  12. 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.

  13. 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.

  14. Technique for the Characterization of Phospholipid Microbubbles Coatings by Transmission Electron Microscopy.

    PubMed

    Owen, Joshua; Stride, Eleanor

    2015-12-01

    Gas microbubbles stabilized by a surfactant or polymer coating are of considerable clinical interest because of their imaging and drug delivery potential under ultrasound exposure. The utility of microbubbles for a given application is intrinsically linked to their structure and stability. These in turn are highly sensitive to coating composition and fabrication techniques. Various methods including fluorescence and atomic force microscopy have been applied to characterize microbubble properties, but direct observation of coating structure at the nanoscale still poses a considerable challenge. Here we describe a transmission electron microscopy (TEM) technique to observe the surface of microbubbles. Images from a series of phospholipid-coated microbubble systems, including those decorated with nanoparticles, are presented. They indicate that the technique enables visualization of the coating structure, in particular lipid discontinuities and nanoparticle distribution. This information can be used to better understand how microbubble surface structure relates to formulation and/or processing technique and ultimately to functionality. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. 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.

  16. 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

  17. Profile and Instrumentation Driven Methods for Embedded Signal Processing

    DTIC Science & Technology

    2015-01-01

    instrumentation-based tech- niques that facilitate design and maintenance of embedded signal processing systems : 1. We propose and develop a novel, translation...several profile- and instrumentation-based techniques that facilitate design and maintenance of embedded signal processing systems 1. We propose and...9 2.2 Embedded System Design Strategies . . . . . . . . . . . . . . . . . . . . 12 2.3 Dataflow Modeling

  18. 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

  19. RF characterization of monolithic microwave and mm-wave ICs

    NASA Technical Reports Server (NTRS)

    Romanofsky, R. R.; Ponchak, G. E.; Shalkhauser, K. A.; Bhasin, K. B.

    1986-01-01

    A number of fixturing techniques compatible with automatic network analysis are presented. The fixtures are capable of characterizing GaAs Monolithic Microwave Integrated Circuits (MMICs) at K and Ka band. Several different transitions are used to couple the RF test port to microstrip. Fixtures which provide chip level de-embedding are included. In addition, two advanced characterization techniques are assessed.

  20. Upset Characterization of the PowerPC405 Hard-core Processor Embedded in Virtex-II Pro Field Programmable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Swift, Gary M.; Allen, Gregory S.; Farmanesh, Farhad; George, Jeffrey; Petrick, David J.; Chayab, Fayez

    2006-01-01

    Shown in this presentation are recent results for the upset susceptibility of the various types of memory elements in the embedded PowerPC405 in the Xilinx V2P40 FPGA. For critical flight designs where configuration upsets are mitigated effectively through appropriate design triplication and configuration scrubbing, these upsets of processor elements can dominate the system error rate. Data from irradiations with both protons and heavy ions are given and compared using available models.

  1. Upset Characterization of the PowerPC405 Hard-core Processor Embedded in Virtex-II Pro Field Programmable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Swift, Gary M.; Allen, Gregory S.; Farmanesh, Farhad; George, Jeffrey; Petrick, David J.; Chayab, Fayez

    2006-01-01

    Shown in this presentation are recent results for the upset susceptibility of the various types of memory elements in the embedded PowerPC405 in the Xilinx V2P40 FPGA. For critical flight designs where configuration upsets are mitigated effectively through appropriate design triplication and configuration scrubbing, these upsets of processor elements can dominate the system error rate. Data from irradiations with both protons and heavy ions are given and compared using available models.

  2. 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.

  3. Development of techniques to characterize particulates emitted from gas turbine exhausts

    NASA Astrophysics Data System (ADS)

    Johnson, M. P.; Hilton, M.; Waterman, D. R.; Black, J. D.

    2003-07-01

    Particles emitted from aircraft play a role in the formation of contrails and it is essential to characterize them to understand the physical and chemical processes that are happening. Current methods for measuring aircraft particulate emissions study the reflectance of samples collected in filter papers. A series of experiments to more fully characterize particulates has been performed on a small-scale gas turbine engine. An intrusive sampling system conforming to current ICAO regulations for aircraft emissions was used with a scanning mobility particle sizer (SMPS). Non-intrusive measurements were made using laser induced incandescence (LII) and samples were taken from the exhaust to analyse using a transmission electron microscope. Results obtained from different techniques showed good agreement with each other. As engine power conditions increased, both the SMPS and LII indicated that the mass of soot had decreased. Differences were observed between measurements of diluted and undiluted samples. The mean particle size decreased with dilution but the size distribution became bi-modal. The study has shown how significant the sampling environment is for measuring particulates and careful techniques need to be used to ensure that accurate, consistent results can be obtained.

  4. Instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue: A review.

    PubMed

    Mitić, Žarko; Stolić, Aleksandra; Stojanović, Sanja; Najman, Stevo; Ignjatović, Nenad; Nikolić, Goran; Trajanović, Miroslav

    2017-10-01

    A review of recent advances in instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue is presented in this paper. In recent years, biomaterials attracted great attention primarily because of the wide range of biomedical applications. This paper focuses on the practical aspects of instrumental methods and techniques that were most often applied (X-ray methods, vibrational spectroscopy (IR and Raman), magnetic-resonance spectroscopy (NMR and ESR), mass spectrometry (MS), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES), thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM)) in the structural investigation and physicochemical characterization of biomaterials and bone tissue. The application of some other physicochemical methods was also discussed. Hands-on information is provided about these valuable research tools, emphasizing practical aspects such as typical measurement conditions, their limitations and advantages, interpretation of results and practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    SciTech Connect

    Foster, Andrew J.; Lobo, Raul F

    2010-01-01

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

  6. Isolation and characterization of anti ROR1 single chain fragment variable antibodies using phage display technique.

    PubMed

    Aghebati-Maleki, Leili; Younesi, Vahid; Jadidi-Niaragh, Farhad; Baradaran, Behzad; Majidi, Jafar; Yousefi, Mehdi

    2017-01-01

    Receptor tyrosine kinase-like orphan receptor (ROR1) belongs to one of the families of receptor tyrosine kinases (RTKs). RTKs are involved in the various physiologic cellular functions including proliferation, migration, survival, signaling and differentiation. Several RTKs are deregulated in various cancers implying the targeting potential of these molecules in cancer therapy. ROR1 has recently been shown to be expressed in various types of cancer cells but not in normal adult cells. Hence a molecular inhibitor of extracellular domain of ROR1 that inhibits ROR1-cell surface interaction is of great therapeutic importance. In an attempt to develop molecular inhibitors of ROR1, we screened single chain variable fragment (scFv) phage display libraries, Tomlinson I + J, against one specific synthetic oligopeptide from extracellular domain of ROR1 and selected scFvs were characterized using various immunological techniques. Several ROR1 specific scFvs were selected following five rounds of panning procedure. The scFvs showed specific binding to ROR1 using immunological techniques. Our results demonstrate successful isolation and characterization of specific ROR1 scFvs that may have great therapeutic potential in cancer immunotherapy.

  7. Development, implementation, and characterization of a standalone embedded viscosity measurement system based on the impedance spectroscopy of a vibrating wire sensor

    NASA Astrophysics Data System (ADS)

    Santos, José; Janeiro, Fernando M.; Ramos, Pedro M.

    2015-10-01

    This paper presents an embedded liquid viscosity measurement system based on a vibrating wire sensor. Although multiple viscometers based on different working principles are commercially available, there is still a market demand for a dedicated measurement system capable of performing accurate, fast measurements and requiring little or no operator training for simple systems and solution monitoring. The developed embedded system is based on a vibrating wire sensor that works by measuring the impedance response of the sensor, which depends on the viscosity and density of the liquid in which the sensor is immersed. The core of the embedded system is a digital signal processor (DSP) which controls the waveform generation and acquisitions for the measurement of the impedance frequency response. The DSP also processes the acquired waveforms and estimates the liquid viscosity. The user can interact with the measurement system through a keypad and an LCD or through a computer with a USB connection for data logging and processing. The presented system is tested on a set of viscosity standards and the estimated values are compared with the standard manufacturer specified viscosity values. A stability study of the measurement system is also performed.

  8. Synthesis and characterization of β-Ni(OH)2 embedded with MgO and ZnO nanoparticles as nanohybrids for energy storage devices

    NASA Astrophysics Data System (ADS)

    Kumar, C. R. Ravi; Santosh, M. S.; Nagaswarupa, H. P.; Prashantha, S. C.; Yallappa, S.; Kumar, M. R. Anil

    2017-06-01

    In this study, the electrode material (nickel hydroxide powder) has been synthesized by a co-precipitation method using sodium hydroxide and nickel sulphate as precipitator and nickel source, respectively. The obtained nickel hydroxide powder has been subsequently embedded with biosynthesized MgO and ZnO nanoparticles as nanohybrids, which have been investigated as a novel hybrid electrode material for power-storage applications. The powder x-ray diffraction pattern of nickel hydroxide (Ni(OH)2)-based nanohybrid materials reveals a typical β-phase. Fourier transform infrared spectroscopy confirms the embedded structures of nanohybrids and thermal stability by thermogravimetry and differential thermal) analysis. The electrochemical properties of these materials have been studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The specific capacitance values are found to be 439, 1076, and 622 F g-1 for bare β-Ni(OH)2, and for β-Ni(OH)2 embedded with ZnO and MgO nanohybrids, respectively, at a scan rate of 10 mVs-1. The enhanced capacitance of nanohybrids is also evident from EIS measurements. Galvanostatic charge-discharge tests for these designed nanohybrids show excellent capacitance performance in battery and supercapacitor applications. These innovative results could be considered for the expansion of novel resources to scale for power-storage applications and may contribute to the development of this niche area at large.

  9. 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

    2013-09-06

    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.

  10. A study of undulator magnets characterization using the vibrating wire technique

    NASA Astrophysics Data System (ADS)

    Temnykh, Alexander; Levashov, Yurii; Wolf, Zachary

    2010-10-01

    The vibrating wire (VW) technique employs a stretched wire as a magnetic field sensor. Because of the wire's small diameter (˜0.1 mm 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 3.8 m 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 0.9 mm precision in localizing of the field distortion at a distance up to a few meters as well as 0.37 G cm sensitivity to the variation of the local field and 2 G cm sensitivity to the total 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 good agreement.

  11. 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

  12. 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

  13. Characterization and source identification of hydrocarbons in water samples using multiple analytical techniques.

    PubMed

    Wang, Zhendi; Li, K; Fingas, M; Sigouin, L; Ménard, L

    2002-09-20

    This paper describes a case study in which multiple analytical techniques were used to identify and characterize trace petroleum-related hydrocarbons and other volatile organic compounds in groundwater samples collected in a bedrock aquifer exploited for drinking water purposes. The objective of the study was to confirm the presence of gasoline and other petroleum products or other volatile organic pollutants in those samples in order to assess the respective implication of each of the potentially responsible parties to the contamination of the aquifer. In addition, the degree of contamination at different depths in the aquifer was also of interest. The analytical techniques used for analyses of water samples included gas chromatography-mass spectrometry (GC-MS) and capillary GC with flame-ionization detection, solid-phase microextraction and headspace GC-MS techniques. Chemical characterization results revealed the following: (1) The hydrocarbons in sample A (near-surface groundwater, 0-5 m) were clearly of two types, one being gasoline and the other a heavy petroleum product. The significant distribution of five target petroleum-characteristic alkylkated polycyclic aromatic hydrocarbon homologues and biomarkers confirmed the presence of another heavy petroleum product. The concentrations of the TPHs (total petroleum hydrocarbons) and BTEX (collective name of benzene, toluene, ethylbenzene, and p-, m-, and o-xylenes) were determined to be 1070 and 155 microg/kg of water for sample A, respectively. (2) The deepest groundwater (sample B, collected at a depth ranging between 15 and 60 m) was also contaminated, but to a much lesser degree. The concentrations of the TPH and BTEX were determined to be only 130 and 2.6 microg/kg of water for sample B, respectively. (3) The presence of a variety of volatile chlorinated compounds to the groundwater was also clearly identified.

  14. 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.

  15. Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique.

    PubMed

    Anuar, Nor Khaizan; Wui, Wong Tin; Ghodgaonkar, Deepak K; Taib, Mohd Nasir

    2007-01-17

    The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug

  16. Evaluation of Characterization Techniques for Iron Pipe Corrosion Products and Iron Oxide Thin Films

    SciTech Connect

    Borch, Thomas; Camper, Anne K.; Biederman, Joel A.; Butterfield, Phillip; Gerlach, Robin; Amonette, James E.

    2008-10-01

    A common problem faced by drinking water studies is that of properly characterizing the corrosion products (CP) in iron pipescor synthetic Fe (hydr)oxides used to simulate the iron pipe used in municipal drinking-water systems. The present work compares the relative applicability of a suite of imaging and analytical techniques for the characterization of CPs and synthetic Fe oxide thin films and provide an overview of the type of data that each instrument can provide as well as their limitations to help researchers and consultants choose the best technique for a given task. Crushed CP from a water distribution system and synthetic Fe oxide thin films formed on glass surfaces were chosen as test samples for this evaluation. The CP and synthetic Fe oxide thin films were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray powder diffractometry (XRD), grazing incident diffractometry (GID), transmission electron microscopy (TEM), selected area electron diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared, Mössbauer spectroscopy, Brunauer-Emmett-Teller N2 adsorption and Fe concentration was determined by the ferrozine method. XRD and GID were found to be the most suitable techniques for identification of the mineralogical composition of CP and synthetic Fe oxide thin films, respectively. AFM and a combined ToF-SIMS-AFM approach proved excellent for roughness and depth profiling analysis of synthetic Fe oxide thin films, respectively. Corrosion products were difficult to study by AFM due to their surface roughness, while synthetic Fe oxide thin films resisted most spectroscopic methods due to their limited thickness (118 nm). XPS analysis is not recommended for mixtures of Fe (hydr)oxides due to their spectral similarities. SEM and TEM provided great detail on mineralogical morphology.

  17. 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.

  18. Phenotypic and Genetic Characterization of Circulating Tumor Cells by Combining Immunomagnetic Selection and FICTION Techniques

    PubMed Central

    Campos, María; Prior, Celia; Warleta, Fernando; Zudaire, Isabel; Ruíz-Mora, Jesús; Catena, Raúl; Calvo, Alfonso; Gaforio, José J.

    2008-01-01

    The presence of circulating tumor cells (CTCs) in breast cancer patients has been proven to have clinical relevance. Cytogenetic characterization of these cells could have crucial relevance for targeted cancer therapies. We developed a method that combines an immunomagnetic selection of CTCs from peripheral blood with the fluorescence immunophenotyping and interphase cytogenetics as a tool for investigation of neoplasm (FICTION) technique. Briefly, peripheral blood (10 ml) from healthy donors was spiked with a predetermined number of human breast cancer cells. Nucleated cells were separated by double density gradient centrifugation of blood samples. Tumor cells (TCs) were immunomagnetically isolated with an anti-cytokeratin antibody and placed onto slides for FICTION analysis. For immunophenotyping and genetic characterization of TCs, a mixture of primary monoclonal anti-pancytokeratin antibodies was used, followed by fluorescent secondary antibodies, and finally hybridized with a TOP2A/HER-2/CEP17 multicolor probe. Our results show that TCs can be efficiently isolated from peripheral blood and characterized by FICTION. Because genetic amplification of TOP2A and ErbB2 (HER-2) in breast cancer correlates with response to anthracyclines and herceptin therapies, respectively, this novel methodology could be useful for a better classification of patients according to the genetic alterations of CTCs and for the application of targeted therapies. (J Histochem Cytochem 56:667–675, 2008) PMID:18413646

  19. A characterization technique for nanosecond gated CMOS x-ray cameras

    NASA Astrophysics Data System (ADS)

    Dayton, M.; Carpenter, A.; Chen, H.; Palmer, N.; Datte, P.; Bell, P.; Sanchez, M.; Claus, L.; Robertson, G.; Porter, J.

    2016-09-01

    We present a characterization technique for nanosecond gated CMOS cameras designed and built by Sandia National Laboratory under their Ultra-Fast X-ray Imager program. The cameras have been used to record images during HED physics experiments at Sandia's Z Facility and at LLNL's National Ignition Facility. The behavior of the camera's fast shutters was not expected to be ideal since they propagate over a large pixel array of 25 mm x 12 mm, which could result in shutter timing skew, variations in the FWHM, and variations in the shutter's peak response. Consequently, a detailed characterization of the camera at the pixel level was critical for interpreting the images. Assuming the pixel's photo-response was linear, the shutter profiles for each pixel were simplified to a pair of sigmoid functions using standard non-linear fitting methods to make the subsequent analysis less computationally intensive. A pixel-level characterization of a "Furi" camera showed frame-to-frame gain variations that could be normalized with a gain mask and significant timing skew at the sensor's center column that could not be corrected. The shutter profiles for Furi were then convolved with data generated from computational models to forward fit images collected with the camera.

  20. Multi and hyperspectral digital-imaging-based techniques for agricultural soil characterization

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Menesatti, Paolo; Millozza, Mario

    2004-11-01

    Soil characterization and monitoring in agriculture represent the primary key-factors influencing its productivity and the quality of the produced products. A correct and continuous knowledge of agricultural soil characteristics can help to optimize its use and its degree of exploitation both in absolute terms and with reference to specific cultivations. Soil characterization is conventionally performed adopting integrated physical-chemical analyses based on soil portion (samples), properly sampled, classified and then delivered to specialized laboratories. Such an approach obviously requires a chain of actions and it is time consuming. In this work it is examined the possibility offered by multi and hyperspectral digital imaging based spectrophotometric techniques in order to perform fast, reliable and low cost "in situ" analyses to identify and quantify specific soil attributes, of primary importance in agriculture, as: water, basic nutrients and organic matter content. The proposed hardware and software (HW&SW) integrated architecture have been specifically developed, and their response investigated, with the specific aim to contribute to study a set of "flexible", and very simple, procedures to apply in order to be utilized to operate, not only in agricultural soil characterization, but also in other fields as the environmental monitoring and polluted soils reclamation.

  1. Cross-linking thin film characterization technique for data storage, semiconductor, and flat panel display devices

    NASA Astrophysics Data System (ADS)

    Bloomer, Iris; Harrison, Dale A.; Prakash, Shiva; Zhang, Kai; Lian, Sean

    1999-03-01

    In manufacturing devices used in the data storage, semiconductor, and flat panel display industries, thin layers of materials are deposited on a particular substrate. These films may consist of semiconductors, dielectrics, polymers, dyes, (photoresist, resin, etc.), color filters, and metal films. In addition to silicon, substrates may consist of glass, quartz, poly-carbonate, or PET. In order to optimize the performance of these devices, an effective thin film characterization method is needed that can measure these thin film structures. We will present a technique that determines, thickness, spectra of n and k from 190 to 900 nm, Eg, and interface roughness of the 'film/substrate' combinations used in the aforementioned industries. This technique is based on wide-band spectrophotometry, combined with spectral analysis incorporating the Forouhi-Bloomer dispersion equations for n and k. The technique offers an excellent signal to noise ratio even in the deep UV wavelength range (below 350 nm) and takes 1 second for the entire measurement.

  2. 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.

  3. 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.

  4. Thermal-lens study of semiconductor nanoparticles embedded in restorative dental resin

    NASA Astrophysics Data System (ADS)

    Alves, Leandro P.; Pilla, Viviane; Iwazaki, Adalberto N.; Barja, Paulo R.; Munin, Egberto

    2013-02-01

    Thermal Lens (TL) and spectroscopic characterizations were performed in CdSe/ZnS core-shell quantum dots (QDs) embedded into two commercial dental resin composites. The thermal-optical studies were performed in CdSe/ZnS QDs (core size Φ= 4.1 nm) and PMMA-encapsulated CdSe/ZnS (Φ= 3.7 nm) embedded in restorative dental resins at concentration of 0.025 and 0.42 % in mass, respectively. The thermal diffusivity (D) results are characteristics of the dental resin composites studied. Photoacoustic (PA) technique results for the dental resin composites support the TL results.

  5. Characterization of Defects on MOCVD Grown Gallium Nitride Using Transient Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Kasani, Sujan Phani Kumar

    Since the invention of the first visible spectrum (red) LED by Holonyak in 1962, there has been a need for more efficient, more reliable and less expensive LEDs. The III-nitrides revolutionized semiconductor technology with their applications in the blue LED's. However the internal quantum efficiency of LED's are limited by the deep level traps in GaN substrate. Traps are defects in the crystal lattice, which depends on growth parameters. These traps act as non-radiative centers where non-radiative recombination occurs without conversion of available energy into light. Characterization of these traps in a material is necessary for better understanding of the material growth quality and resulting device performance. In this work Capacitance-Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) are conducted which provide electronic properties of trap centers like activation energy, doping concentration and capture cross-section. In n-GaN grown by Metalorganic Chemical Vapor Deposition (MOCVD) on Sapphire two defects types are detected and are characterized by Capacitance-Voltage and Deep Level Transient Spectroscopy. Two deep levels E1 and E2 are typically observed in n-GaN with the activation energies of 0.21eV and 0.53eV at 125°K and 325°K, respectively. The deep level E1 is caused by linear line defects along dislocation cores while deep level E2 is related to point defects. The characterization techniques, experimental systems and preliminary characterization results are discussed in detail.

  6. An osmium-free method of epon embedment that preserves both ultrastructure and antigenicity for post-embedding immunocytochemistry.

    PubMed

    Phend, K D; Rustioni, A; Weinberg, R J

    1995-03-01

    Immunocytochemistry for amino acids with post-embedding gold is compatible with glutaraldehyde fixation, osmication, and embedding in epoxy-based plastics, but immunogold detection of larger molecules in the central nervous system commonly requires special procedures, e.g. minimizing exposure to glutaraldehyde, eliminating osmium, cryosectioning, and/or embedding in acrylic plastics. These make samples more difficult to prepare and view and may compromise structural preservation. We report a new technique, fixing with high levels of glutaraldehyde, replacing osmium with tannic acid followed by other heavy metals and p-phenylenediamine, and embedding in Epon. This method optimizes antigenicity while retaining the structural preservation and convenient handling of standard embedding techniques. Compared to standard Epon embedment, labeling for neuropeptides in brain and spinal cord is improved. Moreover, the present method yields excellent labeling of glutamate receptors (difficult to identify with traditional post-embedding techniques) and enables simultaneous visualization of associated neurotransmitters.

  7. An Optical Characterization Technique for Parabolic Trough Solar Collectors Using Images of the Absorber Reflection

    NASA Astrophysics Data System (ADS)

    Owkes, Jeanmarie Kathleen

    As the concentrating solar power industry competes to develop a less-expensive parabolic trough collector, assurance is needed that new parabolic trough collectors maintain accurate optical alignment. Previous optical characterization techniques are either too slow, ill-suited for field testing, or do not allow the collector to be tested in realistic orientations. The Observer method presented here enables the rapid optical characterization of parabolic trough collectors in any orientation in the field. The Observer method directly measures the combined optical angular errors in the reflector surface shape and the absorber position, which can be separated into its two components: reflector surface slope and absorber misalignment. The data acquisition requires the placement of photogrammetry targets on and around the collector. Multiple photographs of the absorber and its reflection are taken with a digital camera from different angles with respect to the collector. The images are processed to determine the camera location of each image using photogrammetry bundle analysis. The absorber and its reflection are found in the photographs using image-processing techniques. A Monte Carlo uncertainty model was developed to determine the uncertainty in the Observer measurements. The uncertainty was estimated for a wide array of measurement test scenarios to demonstrate the user's control over the measurement uncertainty. To validate the Observer method, the absorber alignment technique was compared to traditional photogrammetry; the absorber position measured with the two methods compared with a root-mean-square difference of 1.5 mm in the transverse direction and 0.86 mm along the optical axis. The reflector surface slope error measurement was compared to both VSHOT and SOFAST, two well-established optical characterization tools, by measuring a single reflector panel in the laboratory. The VSHOT and SOFAST measurements agreed with the Observer with a root

  8. 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

  9. 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.

  10. Characterization of protein N-glycosylation by tandem mass spectrometry using complementary fragmentation techniques

    DOE PAGES

    Ford, Kristina L.; Zeng, Wei; Heazlewood, Joshua L.; ...

    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

  11. 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.

  12. 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.

  13. New white-light spectral interferometric techniques for dispersion characterization of optical samples and fibers

    NASA Astrophysics Data System (ADS)

    Hlubina, Petr

    2003-04-01

    The application of white-light spectral interferometry with the equalization wavelength determination is extended to propose new techniques for dispersion characterization of optical samples and fibers. First, a configuration of a non-dispersive Michelson interferometer and an optical sample of known thickness is proposed and realized to measure the differential group refractive index dispersion and the group velocity dispersion in the optical sample. Second, a tandem configuration of a non-dispersive Michelson interferometer and a birefringent optical sample of known thickness is proposed to measure the differential group refractive index dispersion in the birefringent optical sample. The latter experimental setup can be effectively modified to measure dispersion in both birefringent and polarization maintaining optical fibers.

  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. Characterization of nonlinear ultrasonic effects using the dynamic wavelet fingerprint technique

    NASA Astrophysics Data System (ADS)

    Lv, Hongtao; Jiao, Jingpin; Meng, Xiangji; He, Cunfu; Wu, Bin

    2017-02-01

    An improved dynamic wavelet fingerprint (DWFP) technique was developed to characterize nonlinear ultrasonic effects. The white area in the fingerprint was used as the nonlinear feature to quantify the degree of damage. The performance of different wavelet functions, the effect of scale factor and white subslice ratio on the nonlinear feature extraction were investigated, and the optimal wavelet function, scale factor and white subslice ratio for maximum damage sensitivity were determined. The proposed DWFP method was applied to the analysis of experimental signals obtained from nonlinear ultrasonic harmonic and wave-mixing experiments. It was demonstrated that the proposed DWFP method can be used to effectively extract nonlinear features from the experimental signals. Moreover, the proposed nonlinear fingerprint coefficient was sensitive to micro cracks and correlated well with the degree of damage.

  16. 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.

  17. Characterization of Polysulfone Membranes Prepared with Thermally Induced Phase Separation Technique

    NASA Astrophysics Data System (ADS)

    Tiron, L. G.; Pintilie, Ș C.; Vlad, M.; Birsan, I. G.; Baltă, Ș

    2017-06-01

    Abstract Membrane technology is one of the most used water treatment technology because of its high removal efficiency and cost effectiveness. Preparation techniques for polymer membranes show an important aspect of membrane properties. Generally, polysulfone (PSf) and polyethersulfone (PES) are used for the preparation of ultrafiltration (UF) membranes. Polysulfone (PSf) membranes have been widely used for separation and purification of different solutions because of their excellent chemical and thermal stability. Polymeric membranes were obtained by phase inversion method. The polymer solution introduced in the nonsolvent bath (distilled water) initiate the evaporation of the solvent from the solution, this phenomenon has a strong influence on the transport properties. The effect of the coagulation bath temperature on the membrane properties is of interest for this study. Membranes are characterized by pure water flux, permeability, porosity and retention of methylene blue. The low temperature of coagulation bath improve the membrane’s rejection and its influence was most notable.

  18. 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.

  19. Iterative techniques for characterizing marine bird habitats with time-series of satellite images

    USGS Publications Warehouse

    Haney, J. Christopher

    1989-01-01

    Demonstrating long-term habitat use of marine habitats by seabirds is often complicated by short-term changes in habitat locations, persistence, and age. This paper describes iterative techniques for characterizing non-static habitats, such as meso-scale (10-100 km) ocean eddies and fronts, using time-series of satellite images that define sea surface conditions. Seabird use of satellite-detected habitats was compared using survey data and imagery from the Gulf of Alaska and southeastern United States. Time-series examination of satellite images combined with long-term seabird censuses allow 1) estimation of the successional state (age) of some marine habitats, 2) detection of recurring habitats, 3) geographically-referenced measurement of habitat location and areal extent, 4) identification of consistently-used habitats, and 5) demonstration of time-dependent use by seabirds associated with seasonal or annual variation in habitat availability.

  20. Efficient high-capacity steganography technique

    NASA Astrophysics Data System (ADS)

    Abdulla, Alan A.; Jassim, Sabah A.; Sellahewa, Harin

    2013-05-01

    Performance indicators characterizing modern steganographic techniques include capacity (i.e. the quantity of data that can be hidden in the cover medium), stego quality (i.e. artifacts visibility), security (i.e. undetectability), and strength or robustness (intended as the resistance against active attacks aimed to destroy the secret message). Fibonacci based embedding techniques have been researched and proposed in the literature to achieve efficient steganography in terms of capacity with respect to stego quality. In this paper, we investigated an innovative idea that extends Fibonacci-like steganography by bit-plane(s) mapping instead of bit-plane(s) replacement. Our proposed algorithm increases embedding capacity using bit-plane mapping to embed two bits of the secret message in three bits of a pixel of the cover, at the expense of a marginal loss in stego quality. While existing Fibonacci embedding algorithms do not use certain intensities of the cover for embedding due to the limitation imposed by the Zeckendorf theorem, our proposal solve this problem and make all intensity values candidates for embedding. Experimental results demonstrate that the proposed technique double the embedding capacity when compared to existing Fibonacci methods, and it is secure against statistical attacks such as RS, POV, and difference image histogram (DIH).

  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. Wafer hot spot identification through advanced photomask characterization techniques: part 2

    NASA Astrophysics Data System (ADS)

    Choi, Yohan; Green, Michael; Cho, Young; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike

    2017-03-01

    Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for mask end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on sub-resolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. To overcome the limitation of 1D metrics, there are numerous on-going industry efforts to better define wafer-predictive metrics through both standard mask metrology and aerial CD methods. Even with these improvements, the industry continues to struggle to define useful correlative metrics that link the mask to final device performance. In part 1 of this work, we utilized advanced mask pattern characterization techniques to extract potential hot spots on the mask and link them, theoretically, to issues with final wafer performance. In this paper, part 2, we complete the work by verifying these techniques at wafer level. The test vehicle (TV) that was used for hot spot detection on the mask in part 1 will be used to expose wafers. The results will be used to verify the mask-level predictions. Finally, wafer performance with predicted and verified mask/wafer condition will be shown as the result of advanced mask characterization. The goal is to maximize mask end user yield through mask-wafer technology harmonization. This harmonization will provide the necessary feedback to determine optimum design, mask specifications, and mask-making conditions for optimal wafer process margin.

  3. Characterization of ion-induced radiation effects in nuclear materials using synchrotron x-ray techniques

    DOE PAGES

    Lang, Maik; Tracy, Cameron L.; Palomares, Raul I.; ...

    2015-05-01

    Recent efforts to characterize the nanoscale structural and chemical modifications induced by energetic ion irradiation in nuclear materials have greatly benefited from the application of synchrotron-based x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) techniques. Key to the study of actinide-bearing materials has been the use of small sample volumes, which are particularly advantageous, as the small quantities minimize the level of radiation exposure at the ion-beam and synchrotron user facility. This approach utilizes energetic heavy ions (energy range: 100 MeV–3 GeV) that pass completely through the sample thickness and deposit an almost constant energy per unit length along theirmore » trajectory. High energy x-rays (25–65 keV) from intense synchrotron light sources are then used in transmission geometry to analyze ion-induced structural and chemical modifications throughout the ion tracks. We describe in detail the experimental approach for utilizing synchrotron radiation (SR) to study the radiation response of a range of nuclear materials (e.g., ThO2 and Gd2TixZr2–xO7). Also addressed is the use of high-pressure techniques, such as the heatable diamond anvil cell, as a new means to expose irradiated materials to well-controlled high-temperature (up to 1000 °C) and/or high-pressure (up to 50 GPa) conditions. Furthermore, this is particularly useful for characterizing the annealing kinetics of irradiation-induced material modifications.« less

  4. Characterization of ion-induced radiation effects in nuclear materials using synchrotron x-ray techniques

    SciTech Connect

    Lang, Maik; Tracy, Cameron L.; Palomares, Raul I.; Zhang, Fuxiang; Severin, Daniel; Bender, Markus; Trautmann, Christina; Park, Changyong; Prakapenka, Vitali B.; Skuratov, Vladimir A.; Ewing, Rodney C.

    2015-05-01

    Recent efforts to characterize the nanoscale structural and chemical modifications induced by energetic ion irradiation in nuclear materials have greatly benefited from the application of synchrotron-based x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) techniques. Key to the study of actinide-bearing materials has been the use of small sample volumes, which are particularly advantageous, as the small quantities minimize the level of radiation exposure at the ion-beam and synchrotron user facility. This approach utilizes energetic heavy ions (energy range: 100 MeV–3 GeV) that pass completely through the sample thickness and deposit an almost constant energy per unit length along their trajectory. High energy x-rays (25–65 keV) from intense synchrotron light sources are then used in transmission geometry to analyze ion-induced structural and chemical modifications throughout the ion tracks. We describe in detail the experimental approach for utilizing synchrotron radiation (SR) to study the radiation response of a range of nuclear materials (e.g., ThO2 and Gd2TixZr2–xO7). Also addressed is the use of high-pressure techniques, such as the heatable diamond anvil cell, as a new means to expose irradiated materials to well-controlled high-temperature (up to 1000 °C) and/or high-pressure (up to 50 GPa) conditions. Furthermore, this is particularly useful for characterizing the annealing kinetics of irradiation-induced material modifications.

  5. Microwave non-destructive testing technique for characterization of HPMC-PEG 3000 films.

    PubMed

    Wong, T W; Deepak, K G; Taib, M N; Anuar, N K

    2007-10-01

    The capacity of microwave non-destructive testing (NDT) technique to characterize the matrix property of binary polymeric films for use as transdermal drug delivery system was investigated. Hydroxypropylmethylcellulose (HPMC) and polyethylene glycol (PEG) 3000 were the choice of polymeric matrix and plasticizer, respectively with loratadine as the model drug. Both blank and drug loaded HPMC-PEG 3000 films were prepared using the solvent-evaporation method. These films were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using the established methods of ultra-violet spectrophotometry, differential scanning calorimetry and Fourier transform infrared spectroscopy methods, as well as, novel microwave NDT technique. Blank films exhibited a greater propensity of polymer-polymer interaction at the O-H domain upon storage at a lower level of relative humidity, whereas drug loaded films exhibited a greater propensity of polymer-polymer, polymer-plasticizer and/or drug-polymer interaction via the O-H, C-H and/or aromatic C=C functional groups when they were stored at a lower or moderate level of relative humidity. The absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer, polymer-plasticizer, and/or drug-polymer interaction of the matrix. The measurements of microwave NDT test at 8 and 12 GHz were sensitive to the polar fraction of film involving functional group such as O-H moiety and the less polar environment of matrix consisting of functional groups such as C-H and aromatic C=C moieties. The state of interaction between polymer, plasticizer and/or drug of a binary polymeric film can be elucidated through its absorption and transmission profiles of microwave.

  6. Piecewise flat embeddings for hyperspectral image analysis

    NASA Astrophysics Data System (ADS)

    Hayes, Tyler L.; Meinhold, Renee T.; Hamilton, John F.; Cahill, Nathan D.

    2017-05-01

    Graph-based dimensionality reduction techniques such as Laplacian Eigenmaps (LE), Local Linear Embedding (LLE), Isometric Feature Mapping (ISOMAP), and Kernel Principal Components Analysis (KPCA) have been used in a variety of hyperspectral image analysis applications for generating smooth data embeddings. Recently, Piecewise Flat Embeddings (PFE) were introduced in the computer vision community as a technique for generating piecewise constant embeddings that make data clustering / image segmentation a straightforward process. In this paper, we show how PFE arises by modifying LE, yielding a constrained ℓ1-minimization problem that can be solved iteratively. Using publicly available data, we carry out experiments to illustrate the implications of applying PFE to pixel-based hyperspectral image clustering and classification.

  7. Characterization of plant food allergens: an overview on physicochemical and immunological techniques.

    PubMed

    Harrer, Andrea; Egger, Matthias; Gadermaier, Gabriele; Erler, Anja; Hauser, Michael; Ferreira, Fátima; Himly, Martin

    2010-01-01

    Allergy to plant-derived foods is a highly complex disorder with clinical manifestations ranging from mild oral, gastrointestinal, and cutaneous symptoms to life-threatening systemic conditions. This heterogeneity in clinical manifestations has been attributed to different properties of allergenic molecules. Based on this fact, symptom elicitors were grouped into class I and pollinosis-associated class II food allergens, but clear distinction is rather ambiguous. Moreover, mechanisms underlying food sensitization are not fully understood yet, and food allergy management most often relies on patient's compliance to avoid suspected foods. Therefore, recent efforts aim at the investigation of plant food allergies at the molecular level. This review provides an overview on currently available techniques for allergen characterization and discusses their application for investigation of plant food allergens. Data obtained by an array of physicochemical analyses, such as allergen structure, integrity, aggregation, and stability, need to be linked to results from immunological methods at the level of IgE and T-cell reactivity. Such knowledge allows the development of computational algorithms to predict allergenicity of novel foods being introduced by biotechnological industry. Furthermore, molecular characterization is an indispensable tool for molecule-based diagnosis and future development of safer patient-tailored specific immunotherapy in plant food allergy.

  8. Characterization of Nanocellulose Using Small-Angle Neutron, X-ray, and Dynamic Light Scattering Techniques.

    PubMed

    Mao, Yimin; Liu, Kai; Zhan, Chengbo; Geng, Lihong; Chu, Benjamin; Hsiao, Benjamin S

    2017-02-16

    Nanocellulose extracted from wood pulps using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and sulfuric acid hydrolysis methods was characterized by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) techniques. The dimensions of this nanocellulose (TEMPO-oxidized cellulose nanofiber (TOCN) and sulfuric acid hydrolyzed cellulose nanocrystal (SACN)) revealed by the different scattering methods were compared with those characterized by transmission electron microscopy (TEM). The SANS and SAXS data were analyzed using a parallelepiped-based form factor. The width and thickness of the nanocellulose cross section were ∼8 and ∼2 nm for TOCN and ∼20 and ∼3 nm for SACN, respectively, where the fitting results from SANS and SAXS profiles were consistent with each other. DLS was carried out under both the VV mode with the polarizer and analyzer parallel to each other and the HV mode having them perpendicular to each other. Using rotational and translational diffusion coefficients obtained under the HV mode yielded a nanocellulose length qualitatively consistent with that observed by TEM, whereas the length derived by the translational diffusion coefficient under the VV mode appeared to be overestimated.

  9. In vitro characterization of the technique of portal vein embolization by injection of a surgical glue

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Sandulache, Mihai-Cristinel; Lancon, Oceane; El Kadri Benkara, Khadija

    2012-11-01

    Partial embolization of the portal trunk by glue injection is a minimally invasive technique used in the case of malignant liver tumors. It is conducted few weeks prior to partial liver ablation, when the volume of the remnant liver section is too small to allow hepatectomy. The limitation of glue embolotherapy is that its clinical practice is based on empirical knowledge. The present objective is to study glue injection in a confined blood flow and investigate how the injection dynamics is coupled with glue polymerization. We first characterize polymerization under static conditions for various glue concentrations and then consider the influence of injection. An experimental setup reproduces the co-flow of two immiscible fluids. The glue mixture is injected through a capillary tube into a saline solution with the same ionic concentration, pH and viscosity as blood, flowing steadily in a straight cylindrical tube. The injected phase is visualized with a high-speed imaging system and results are compared with those obtained for non-reacting fluids. These experiments have enabled us to characterize the characteristic times of polymerization of the glue mixtures under static and dynamic conditions and understand how they affect the flow topology of the glue once injected. Biomechanics and Bioengineering Laboratory (UMR CNRS 7338).

  10. Nanotribological and nanomechanical characterization of human hair using a nanoscratch technique.

    PubMed

    Wei, Guohua; Bhushan, Bharat

    2006-01-01

    Human hair ( approximately 50-100 microm in diameter) is a nanocomposite biological fiber with well-characterized microstructures, and is of great interest for both cosmetic science and materials science. Characterization of nanotribological and nanomechanical properties of human hair including the coefficient of friction and scratch resistance is essential to develop better shampoo and conditioner products and advance biological and cosmetic science. In this paper, the coefficient of friction and scratch resistance of Caucasian and Asian hair at virgin, chemo-mechanically damaged, and conditioner-treated conditions are measured using a nanoscratch technique with a Nano Indenter II system. The scratch tests were performed on both the single cuticle cell and multiple cuticle cells of each hair sample, and the scratch wear tracks were studied using scanning electron microscopy (SEM) after the scratch tests. The effect of soaking on the coefficient of friction, scratch resistance, hardness and Young's modulus of hair surface were also studied by performing experiments on hair samples which had been soaked in de-ionized water for 5 min. The nanotribological and nanomechanical properties of human hair as a function of hair structure (hair of different ethnicity), damage, treatment and soaking are discussed.

  11. Characterization of Dickeya and Pectobacterium species by capillary electrophoretic techniques and MALDI-TOF MS.

    PubMed

    Šalplachta, Jiří; Kubesová, Anna; Horký, Jaroslav; Matoušková, Hana; Tesařová, Marie; Horká, Marie

    2015-10-01

    Dickeya and Pectobacterium species represent an important group of broad-host-range phytopathogens responsible for blackleg and soft rot diseases on numerous plants including many economically important plants. Although these species are commonly detected using cultural, serological, and molecular methods, these methods are sometimes insufficient to classify the bacteria correctly. On that account, this study was undertaken to investigate the feasibility of three individual analytical techniques, capillary zone electrophoresis (CZE), capillary isoelectric focusing (CIEF), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), for reliable classification of Dickeya and Pectobacterium species. Forty-three strains, representing different Dickeya and Pectobacterium species, namely Dickeya dianthicola, Dickeya dadantii, Dickeya dieffenbachiae, Dickeya chrysanthemi, Dickeya zeae, Dickeya paradisiaca, Dickeya solani, Pectobacterium carotovorum, and Pectobacterium atrosepticum, were selected for this purpose. Furthermore, the selected bacteria included one strain which could not be classified using traditional microbiological methods. Characterization of the bacteria was based on different pI values (CIEF), migration velocities (CZE), or specific mass fingerprints (MALDI-TOF MS) of intact cells. All the examined strains, including the undetermined bacterium, were characterized and classified correctly into respective species. MALDI-TOF MS provided the most reliable results in this respect.

  12. 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.

  13. 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. © 2015 SETAC.

  14. NATALIE: a 32 detector integrated acquisition system to characterize laser produced energetic particles with nuclear techniques.

    PubMed

    Tarisien, M; Plaisir, C; Gobet, F; Hannachi, F; Aléonard, M M; Rebii, A

    2011-02-01

    We present a stand-alone system to characterize the high-energy particles emitted in the interaction of ultrahigh intensity laser pulses with matter. According to the laser and target characteristics, electrons or protons are produced with energies higher than a few mega electron volts. Selected material samples can, therefore, be activated via nuclear reactions. A multidetector, named NATALIE, has been developed to count the β(+) activity of these irradiated samples. The coincidence technique used, designed in an integrated system, results in very low background in the data, which is required for low activity measurements. It, therefore, allows a good precision on the nuclear activation yields of the produced radionuclides. The system allows high counting rates and online correction of the dead time. It also provides, online, a quick control of the experiment. Geant4 simulations are used at different steps of the data analysis to deduce, from the measured activities, the energy and angular distributions of the laser-induced particle beams. Two applications are presented to illustrate the characterization of electrons and protons.

  15. NATALIE: A 32 detector integrated acquisition system to characterize laser produced energetic particles with nuclear techniques

    SciTech Connect

    Tarisien, M.; Plaisir, C.; Gobet, F.; Hannachi, F.; Aleonard, M. M.; Rebii, A.

    2011-02-15

    We present a stand-alone system to characterize the high-energy particles emitted in the interaction of ultrahigh intensity laser pulses with matter. According to the laser and target characteristics, electrons or protons are produced with energies higher than a few mega electron volts. Selected material samples can, therefore, be activated via nuclear reactions. A multidetector, named NATALIE, has been developed to count the {beta}{sup +} activity of these irradiated samples. The coincidence technique used, designed in an integrated system, results in very low background in the data, which is required for low activity measurements. It, therefore, allows a good precision on the nuclear activation yields of the produced radionuclides. The system allows high counting rates and online correction of the dead time. It also provides, online, a quick control of the experiment. Geant4 simulations are used at different steps of the data analysis to deduce, from the measured activities, the energy and angular distributions of the laser-induced particle beams. Two applications are presented to illustrate the characterization of electrons and protons.

  16. Polymer blend microspheres for controlled drug release: the techniques for preparation and characterization: a review article.

    PubMed

    Dasan, K Priya; Rekha, C

    2012-11-01

    The use of polymers and their microspheres in drug delivery is well known for they are being widely used in the field of drug delivery. The polymer entraps a drug which is to be released in a predesigned manner in the body through biodegradation. The blending of polymers is one way of modifying and enhancing the properties of polymer- based products which is also a cost effective procedure rather than developing a new product. The molecular weight of the polymer, the composition of the blend, the sphere porosity and size, and drug distribution are found to be controllable factors on which drug delivery depends. Polymer blends are obtained by allowing two polymers to combine as one material which has the advantage of two or more polymers. Polymer microspheres are small spherical particles with diameters in the micrometer range between 1μm to 1000μm which are manufactured from various natural and synthetic materials. Microspheres are used to administer medication in a rate- controlled manner and sometimes in a targeted manner. This review presents various polymer blend- combinations in different ratios, the different processing techniques adopted and the details of their characterization through examples found in a literature survey. The characterization of the different polymer blends or microspheres showed changes in structure, increase in drug loading, encapsulation efficiency, biocompatibility and low cytotoxicity.

  17. Biomechanical characterization of double-bundle femoral press-fit fixation techniques.

    PubMed

    Ettinger, M; Haasper, C; Hankemeier, S; Hurschler, C; Breitmeier, D; Krettek, C; Jagodzinski, M

    2011-03-01

    Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. To date, no biomechanical data exist describing an implant-free double-bundle press-fit procedure. The purpose of this study was to characterize the biomechanical properties of three double-bundle press-fit fixations. In a controlled laboratory study, the patellar-, quadriceps- and hamstring tendons of 10 human cadavers (age: 49.2 ± 18.5 years) were used. An inside out press-fit fixation with a knot in the semitendinosus and gracilis tendons (SG) combined with an additional bone block, with two quadriceps tendon bone block grafts (QU) was compared with press-fit fixation of two bone patellar tendon bone block (PT) grafts in 30 porcine femora. Constructs were cyclically stretched and then loaded until failure. Maximum load to failure, stiffness and elongation during failure testing and cyclical loading were investigated. The maximum load to failure was 703 ± 136 N for SG fixation, 632 ± 130 N for QU and 656 ± 127 N for PT fixation. Stiffness of the constructs averaged 138 ± 26 N/mm for SG, 159 ± 74 N/mm for QU, and 154 ± 50 N/mm for PT fixation. Elongation during initial cyclical loading was 1.2 ± 1.4 mm for SG, 2.0 ± 1.4 mm for QU, and 1.0 ± 0.6 mm for PT (significantly larger for PT and QU between the first 5 cycles compared with cycles 15-20th, P < 0.01). All investigated double-bundle fixation techniques were equal in terms of maximum load to failure, stiffness, and elongation. Unlike with single-bundle press-fit fixation techniques that have been published, no difference was observed between pure tendon combined with an additional bone block and tendon bone grafts. All techniques exhibited larger elongation during initial cyclical loading. All three press-fit fixation techniques that were investigated exhibit comparable biomechanical properties. Preconditioning of the constructs

  18. Development and Optimization of Dynamic Atomic Force Microscopy Techniques with Applications in Soft Matter Characterization

    NASA Astrophysics Data System (ADS)

    Eslami, Babak

    The overall goals of this project are (i) to improve the current dynamic modes of atomic force microscopy (AFM) with the focus of multifrequency AFM measurements on soft matters in ambient air and liquid environments and (ii) to develop a new methodology for mechanically characterizing the subsurface of soft samples, allowing users to gradually, controllably and reversibly reveal features that are buried under the surface. This dissertation includes a wide range of studies on multifrequency atomic force microscopy. Firstly, the imaging parameters (drive amplitude and frequency) of each eigenmode is studied, optimized based on the observables. Secondly, a new mutltifrequency AFM technique with capability of imaging subsurface features has been developed and verified through experiments. Based on the first goal of the project, an experimental protocol to select excitation frequency in air for single tapping mode and bimodal AFM are provided. Additionally, a rigorous guideline for the selection of drive frequency in ambient air, liquid environment based on the energy quantities and slope of the cantilever's phase response is established. Finally, an advantage of using higher and stiffer eigenmodes for imaging soft matters has been proposed and verified experimentally. By this technique, subsurface imaging capabilities of AFM are expanded.

  19. 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.

  20. A Novel In-Beam Delayed Neutron Counting Technique for Characterization of Special Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Bentoumi, G.; Rogge, R. B.; Andrews, M. T.; Corcoran, E. C.; Dimayuga, I.; Kelly, D. G.; Li, L.; Sur, B.

    2016-12-01

    A delayed neutron counting (DNC) system, where the sample to be analyzed remains stationary in a thermal neutron beam outside of the reactor, has been developed at the National Research Universal (NRU) reactor of the Canadian Nuclear Laboratories (CNL) at Chalk River. The new in-beam DNC is a novel approach for non-destructive characterization of special nuclear materials (SNM) that could enable identification and quantification of fissile isotopes within a large and shielded sample. Despite the orders of magnitude reduction in neutron flux, the in-beam DNC method can be as informative as the conventional in-core DNC for most cases while offering practical advantages and mitigated risk when dealing with large radioactive samples of unknown origin. This paper addresses (1) the qualification of in-beam DNC using a monochromatic thermal neutron beam in conjunction with a proven counting apparatus designed originally for in-core DNC, and (2) application of in-beam DNC to an examination of large sealed capsules containing unknown radioactive materials. Initial results showed that the in-beam DNC setup permits non-destructive analysis of bulky and gamma shielded samples. The method does not lend itself to trace analysis, and at best could only reveal the presence of a few milligrams of 235U via the assay of in-beam DNC total counts. Through analysis of DNC count rates, the technique could be used in combination with other neutron or gamma techniques to quantify isotopes present within samples.

  1. Structural characterization of bacterial lipopolysaccharides with mass spectrometry and on- and off-line separation techniques.

    PubMed

    Kilár, Anikó; Dörnyei, Ágnes; Kocsis, Béla

    2013-01-01

    The focus of this review is the application of mass spectrometry to the structural characterization of bacterial lipopolysaccharides (LPSs), also referred to as "endotoxins," because they elicit the strong immune response in infected organisms. Recently, a wide variety of MS-based applications have been implemented to the structure elucidation of LPS. Methodological improvements, as well as on- and off-line separation procedures, proved the versatility of mass spectrometry to study complex LPS mixtures. Special attention is given in the review to the tandem mass spectrometric methods and protocols for the analyses of lipid A, the endotoxic principle of LPS. We compare and evaluate the different ionization techniques (MALDI, ESI) in view of their use in intact R- and S-type LPS and lipid A studies. Methods for sample preparation of LPS prior to mass spectrometric analysis are also described. The direct identification of intrinsic heterogeneities of most intact LPS and lipid A preparations is a particular challenge, for which separation techniques (e.g., TLC, slab-PAGE, CE, GC, HPLC) combined with mass spectrometry are often necessary. A brief summary of these combined methodologies to profile LPS molecular species is provided.

  2. Experimental characterization of sulfate damage of concrete based on the harmonic wave modulation technique

    NASA Astrophysics Data System (ADS)

    Yin, Tingyuan; Meng, Wanlin; Talebzadeh, Neda; Chen, Jun

    2017-02-01

    The objective of this paper is to characterize cracking progression of concrete samples subjected to sulfate attack cycles by employment of a nonlinear wave modulation technique. The sidebands in frequency domain (f1±f2) are produced due to the modulation of two ultrasonic waves (high frequency f1 and low frequency f2) and the relative amplitude of sidebands is defined as the nonlinear parameter considered as a caliber for structural damage. Different from previous work where the low frequency signal was generated by the instrumented hammer, the low frequency signal in this research is a harmonic wave produced by an electromagnetic exciter to avoid the uncertainty of man-made influence. Experimental results show that the nonlinear parameter presents an excellent correlation with the progress of material deterioration, indicating that the wave modulation method is capable of discriminating different states of damage. The work validates the feasibility and sensitivity of nonlinear wave modulation technique based on harmonic signals for the damage detection of concrete materials suffered from typical durability problems.

  3. 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.

  4. 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.

  5. 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.

  6. Novel technique for ST-T interval characterization in patients with acute myocardial ischemia.

    PubMed

    Correa, Raúl; Arini, Pedro David; Correa, Lorena Sabrina; Valentinuzzi, Max; Laciar, Eric

    2014-07-01

    The novel signal processing techniques have allowed and improved the use of vectorcardiography (VCG) to diagnose and characterize myocardial ischemia. Herein, we studied vectorcardiographic dynamic changes of ventricular repolarization in 80 patients before (control) and during Percutaneous Transluminal Coronary Angioplasty (PTCA). We propose four vectorcardiographic ST-T parameters, i.e., (a) ST Vector Magnitude Area (aSTVM); (b) T-wave Vector Magnitude Area (aTVM); (c) ST-T Vector Magnitude Difference (ST-TVD), and (d) T-wave Vector Magnitude Difference (TVD). For comparison, the conventional ST-Change Vector Magnitude (STCVM) and Spatial Ventricular Gradient (SVG) were also calculated. Our results indicate that several vectorcardiographic parameters show significant differences (p-value<0.05) before starting and during PTCA. Statistical minute-by-minute PTCA comparison against the control situation showed that ischemic monitoring reached a sensitivity=90.5% and a specificity=92.6% at the 5th minute of the PTCA, when aSTVM and ST-TVD were used as classifiers. We conclude that the sensitivity and specificity for acute ischemia monitoring could be increased with the use of only two vectorcardiographic parameters. Hence, the proposed technique based on vectorcardiography could be used in addition to the conventional ST-T analysis for better monitoring of ischemic patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Analytical model for Transient Current Technique (TCT) signal prediction and analysis for thin interface characterization

    NASA Astrophysics Data System (ADS)

    Bronuzzi, J.; Mapelli, A.; Sallese, J. M.

    2016-12-01

    A silicon wafer bonding technique has been recently proposed for the fabrication of monolithic silicon radiation detectors. This new process would enable direct bonding of a read-out electronic chip wafer on a highly resistive silicon substrate wafer. Therefore, monolithic silicon detectors could be fabricated in this way which would allow the free choice of electronic chips and high resistive silicon bulk, even from different providers. Moreover, a monolithic detector with a high resistive bulk would also be available. Electrical properties of the bonded interface are then critical for this application. Indeed, mobile charges generated by radiation inside the bonded bulk are expected to transit through the interface to be collected by the read-out electronics. In order to characterize this interface, the concept of Transient Current Technique (TCT) has been explored by means of numerical simulations combined with a physics based analytical model. In this work, the analytical model giving insight into the physics behind the TCT dependence upon interface traps is validated using both TCAD simulations and experimental measurements.

  8. Nonlinear optical characterization of graphite oxide thin film by open aperture Z-scan technique

    SciTech Connect

    Sreeja, V. G.; Reshmi, R.; Devasia, Sebin; Anila, E. I.; Cheruvalathu, Ajina

    2016-05-23

    In this paper we explore the structural characterization of graphite oxide powder prepared from graphite powder by oxidation via modified Hummers method. The nonlinear optical properties of the spin coated graphite oxide thin film is also explored by open aperture Z-Scan technique. Structural and physiochemical properties of the samples were investigated with the help of Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy (Raman).The results of FT-IR and Raman spectroscopy showed that the graphite is oxidized by strong oxidants and the oxygen atoms are introduced into the graphite layers forming C=C, O-H and –C-H groups. The synthesized sample has good crystalline nature with lesser defects. The nonlinear optical property of GO thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532 nm. The Z-scan plot showed that the investigated GO thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated to explore its applications in Q switched mode locking laser systems.

  9. 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.

  10. Numerical characterization of landing gear aeroacoustics using advanced simulation and analysis techniques

    NASA Astrophysics Data System (ADS)

    Redonnet, S.; Ben Khelil, S.; Bulté, J.; Cunha, G.

    2017-09-01

    With the objective of aircraft noise mitigation, we here address the numerical characterization of the aeroacoustics by a simplified nose landing gear (NLG), through the use of advanced simulation and signal processing techniques. To this end, the NLG noise physics is first simulated through an advanced hybrid approach, which relies on Computational Fluid Dynamics (CFD) and Computational AeroAcoustics (CAA) calculations. Compared to more traditional hybrid methods (e.g. those relying on the use of an Acoustic Analogy), and although it is used here with some approximations made (e.g. design of the CFD-CAA interface), the present approach does not rely on restrictive assumptions (e.g. equivalent noise source, homogeneous propagation medium), which allows to incorporate more realism into the prediction. In a second step, the outputs coming from such CFD-CAA hybrid calculations are processed through both traditional and advanced post-processing techniques, thus offering to further investigate the NLG's noise source mechanisms. Among other things, this work highlights how advanced computational methodologies are now mature enough to not only simulate realistic problems of airframe noise emission, but also to investigate their underlying physics.

  11. Dimensional characterization of a quasispherical resonator by microwave and coordinate measurement techniques

    NASA Astrophysics Data System (ADS)

    Underwood, R.; Flack, D.; Morantz, P.; Sutton, G.; Shore, P.; de Podesta, M.

    2011-02-01

    We describe the dimensional characterization of copper quasisphere NPL-Cranfield 2. The quasisphere is assembled from two hemispheres such that the internal shape is a triaxial ellipsoid, the major axes of which have nominal radii 62.000 mm, 62.031 mm and 62.062 mm. The artefact has been manufactured using diamond-turning technology and shows a deviation from design form of less than ±1 µm over most of its surface. Our characterization involves both coordinate measuring machine (CMM) experiments and microwave resonance spectroscopy. We have sought to reduce the dimensional uncertainty below the maximum permissible error of the CMM by comparative measurements with silicon and Zerodur spheres of known volume. Using this technique we determined the equivalent radius with an uncertainty of u(k = 1) = 114 nm, a fractional uncertainty of 1.8 parts in 106. Due to anisotropy of the probe response, we could only determine the eccentricities of the quasihemispheres with a fractional uncertainty of approximately 2%. Our microwave characterization uses the TM11 to TM18 resonances. We find the equivalent radius inferred from analysis of these modes to be consistent within ±4 nm with an overall uncertainty u(k = 1) = 11 nm. We discuss corrections for surface conductivity, waveguide perturbations and dielectric surface layers. We find that the CMM radius estimates derived from each hemisphere cannot be used to accurately predict the equivalent radius of the assembled resonator for two reasons. Firstly, the equatorial flanges are flat only to within ±1 µm, leading to an equatorial 'gap' whose dimension cannot be reliably estimated. Secondly, the resonator undergoes significant elastic distortion when the bolts connecting the hemispheres are tightened. We provide CMM and microwave measurements to support these conclusions in addition to finite-element modelling. Finally, we consider the implications of this work on a forthcoming experiment to determine the Boltzmann constant

  12. The data embedding method

    SciTech Connect

    Sandford, M.T. II; Bradley, J.N.; Handel, T.G.

    1996-06-01

    Data embedding is a new steganographic method for combining digital information sets. This paper describes the data embedding method and gives examples of its application using software written in the C-programming language. Sandford and Handel produced a computer program (BMPEMBED, Ver. 1.51 written for IBM PC/AT or compatible, MS/DOS Ver. 3.3 or later) that implements data embedding in an application for digital imagery. Information is embedded into, and extracted from, Truecolor or color-pallet images in Microsoft{reg_sign} bitmap (.BMP) format. Hiding data in the noise component of a host, by means of an algorithm that modifies or replaces the noise bits, is termed {open_quote}steganography.{close_quote} Data embedding differs markedly from conventional steganography, because it uses the noise component of the host to insert information with few or no modifications to the host data values or their statistical properties. Consequently, the entropy of the host data is affected little by using data embedding to add information. The data embedding method applies to host data compressed with transform, or {open_quote}lossy{close_quote} compression algorithms, as for example ones based on discrete cosine transform and wavelet functions. Analysis of the host noise generates a key required for embedding and extracting the auxiliary data from the combined data. The key is stored easily in the combined data. Images without the key cannot be processed to extract the embedded information. To provide security for the embedded data, one can remove the key from the combined data and manage it separately. The image key can be encrypted and stored in the combined data or transmitted separately as a ciphertext much smaller in size than the embedded data. The key size is typically ten to one-hundred bytes, and it is in data an analysis algorithm.

  13. 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

  14. 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

  15. Application of digital image analysis techniques to antimisting fuel spray characterization

    SciTech Connect

    Fleeter, R.; Sarohia, V.; Toaz, R.

    1983-01-01

    A system for fuel mist characterization using digital image analysis and processing techniques has been developed and applied to research on aviation safety fuels. Pulsed ruby laser sheet illumination of the spray is used for initial data recording on very high resolution photographic film. Digitization of mosaic elements is accomplished with a vidicon and video digitizer whose output is stored in computer RAM (Random Access Memory) memory for processing. Highly non-spherical elements and a wide range of drop diameters (8-2000 ..mu..m) resulting from the unusual rheological properties of the fuel-additive system are accomodated by the device configuration and algorithms. Generation of two-dimensional images via scattered light also eliminates errors resulting from variations in the index of refraction and from the presence of submicron scattering sites often present within the modified fuel. No a priori information on the drop size distribution nor on system response to various drop sizes is required. This wide dynamic range, insensitivity to drop optical properties and the lack of a priori assumptions concerning drop shape are some of the unique features of the present analysis technique which are not available in single currently available drop counting methods. A drop histogram is generated for any portion of a spray or for an entire spray field along with local and global spray Sauter mean diameter (SMD) and density information. The technique is applied to analysis of sprays formed in a simulation of an aircraft crash with fuel spillage. Measurements of spray SMD and density are correlated with the results of flammability tests.

  16. Bio-impedance characterization technique with implantable neural stimulator using biphasic current stimulus.

    PubMed

    Lo, Yi-Kai; Chang, Chih-Wei; Liu, Wentai

    2014-01-01

    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.

  17. 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

  18. 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

  19. 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

  20. Embedded human computer interaction.

    PubMed

    Baber, Christopher; Baumann, Konrad

    2002-05-01

    In this paper, human interaction with embedded or ubiquitous technology is considered. The techniques focus on the use of what might be termed "everyday" objects and actions as a means of controlling (or otherwise interacting with) technology. While this paper is not intended to be an exhaustive review, it does present a view of the immediate future of human-computer interaction (HCI) in which users move beyond the desktop to where interacting with technology becomes merged with other activity. At one level this places HCI in the context of other forms of personal and domestic technologies. At another level, this raises questions as to how people will interact with technologies of the future. Until now, HCI had often relied on people learning obscure command sets or learning to recognise words and objects on their computer screen. The most significant advance in HCI (the invention of the WIMP interface) is already some 40 years old. Thus, the future of HCI might be one in which people are encouraged (or at least allowed) to employ the skills that they have developed during their lives in order to interact with technology, rather than being forced to learn and perfect new skills.

  1. Quality Control and Nondestructive Evaluation Techniques for Composites. Part 1. Overview of Characterization Techniques for Composite Reliability

    DTIC Science & Technology

    1982-05-01

    and service life prediction. The concepts of characterization are reviewed in several general references.^ ’ Billmeyer ’ ^ presents the general...34 Cordura Publications, San Diego (1980). 3. F. W. Billmeyer , Textbook of Polymer Science, Interscience, New York, 1962. 4. D. H. Kaelble... Billmeyer , "Textbook of Polymer Science" 5 F. Wehrli and T. Wirthlin, "Interpretation of Carbon 13 NMR Spectra" 5 L. E. Nielsen

  2. Fabrication and characterization of microelectromechanical systems-based gas chromatography column with embedded micro-posts for separation of environmental carcinogens.

    PubMed

    Sun, Jianhai; Cui, Dafu; Chen, Xing; Zhang, Lulu; Cai, Haoyuan; Li, Hui

    2013-05-24

    In this paper, a micro gas chromatography (μGC) column with embedded micro-posts was developed for increasing overall surface area of the columns which is able to support more of the stationary phase and reducing the effective width of the column, leading to higher separation efficiency. The proposed columns have a higher sample capacity as the overall surface area is about 3 times larger than that of open columns with the same dimensions. In order to achieve an even flow velocity in the channels, the location of the micro-posts in the linear channels and the configuration of curved channels were optimized by numerical simulation. The results have indicated that the proposed column separated 5 environmental carcinogens in less than 50s, achieved a separation efficiency of about 9500plates/m and eluted highly symmetrical Gaussian peaks. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Meso-scale characterization of lithium distribution in lithium-ion batteries using ion beam analysis techniques

    NASA Astrophysics Data System (ADS)

    Gonzalez-Arrabal, R.; Panizo-Laiz, M.; Fujita, K.; Mima, K.; Yamazaki, A.; Kamiya, T.; Orikasa, Y.; Uchimoto, Y.; Sawada, H.; Okuda, C.; Kato, Y.; Perlado, J. M.

    2015-12-01

    The performance of a Li-ion battery (LIB) is mainly governed by the diffusion capabilities of lithium in the electrodes. Thus, for LIB improvement it is essential to characterize the lithium distribution. Most of the traditionally used techniques for lithium characterization give information about the local scale or in the macroscopic scale. However, the lithium behavior at the local scale is not mirrored at the macroscopic scale. Therefore, the lithium characterization in the mesoscopic scale would be of help to understand and to connect the mechanisms taking place in the two spatial scales. In this paper, we show a general description of the capabilities and limitations of ion beam analysis techniques to study the distributions of lithium and other elements present in the electrodes in the mesoscopic scale. The potential of the 7Li(p,α0)4He nuclear reaction to non-invasively examine the lithium distribution as a function of depth is illustrated. The lithium spatial distribution is characterized using particle induced γ-ray (μ-PIGE) spectroscopy. This technique allows estimating the density of the active particles in the electrode effectively contributing to the Li intercalation and/or de-intercalation. The advantages of the use of ion beam analysis techniques in comparison to more traditional techniques for electrode characterization are discussed.

  4. 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

  5. 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

  6. 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

  7. Electrical characterization of dislocations in gallium nitride using advanced scanning probe techniques

    NASA Astrophysics Data System (ADS)

    Simpkins, Blake Shelley Ginsberg

    GaN-based materials are promising for high speed and power applications such as amplifier and communications circuits. Ga, In, and AIN-based alloys span a wide optical range (2--6.1 eV) and exhibit strong polarizations making them useful in many devices; however, films are highly defective (˜10 8 dislocations cm-2) due to lack of suitable substrates. Thus, nanoscale electronic characterization of these dislocations is critical for device and growth optimization. Scanning probe techniques enable characterization at length-scales unattainable by conventional techniques. First, scanning Kelvin probe microscopy (SKPM) was used to image surface potential variations due to charged dislocations in HVPE-grown GaN. The film's structural evolution "with thickness was monitored showing a decrease in dislocation density, likely through dislocation reaction. Numerical simulations were used to investigate tip-size effects when imaging highly localized (tens of nm) potential variations indicating that measured dislocation induced potential features in GaN can be much smaller (˜80%) than true variations. Next, capacitance variations in MBE-grown HFETs, due to dislocations-induced carrier depletion, were imaged with scanning capacitance microscopy (SCM). The distribution of these charged centers was correlated with buffer schemes showing that an AIN buffer leads to pseudomorphic (2D) nucleation and randomly distributed misfit dislocations while deposition directly on SiC results in island (3D) nucleation and a domain structure with dislocations grouped at domain boundaries. Hall measurements and numerical simulations were also carried out to further study the implications of these microstructures. Numerical results indicated that randomly distributed dislocations deplete a larger fraction of free carriers than the same density of grouped dislocations and correlated favorably with Hall results. Correlated SKPM and conductive AFM (C-AFM) measurements were then used to study

  8. 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

  9. 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.

  10. Analytical characterization of cyclodextrins: History, official methods and recommended new techniques.

    PubMed

    Szente, Lajos; Szemán, Julianna; Sohajda, Tamás

    2016-10-25

    The main goal of this review is to provide a comprehensive overview on the methods used for analysis of cyclodextrins (CDs) and CD-derivatives. The paper intends to act as a guide for the readers in looking around the classical and modern instrumental analytical methods suitable for identification, characterization and determination of CDs themselves, CDs in finished products or even in biological samples. At present, in the European and United States Pharmacopoeias, the three parent CDs and two synthetic derivatives, namely the (2-hydroxypropyl)-beta-CD and sulfobutylether-beta-CD Na salt are official. Besides these modified CDs, two other derivatives are approved as excipients in human pharmaceutical products: the (2-hydroxypropyl)-gamma-CD and the randomly methylated-beta-CD. Although most of the official analysis methods in the pharmacopoeias have been well used for decades, new aspects of the functional excipient CD characterization suggest a need to revisit compendial methods. Comparison of strengths and weaknesses of current official methods with new improved techniques intends to help analysts to decide on changing traditional analytical methods with improved new ones. This review also deals with the analytical aspects of the first single isomer CD derivative approved as a drug active (Sugammadex/Bridion(®)) as well as analytical considerations of using CDs themselves as active pharmaceutical ingredients. Stability-indicating instrumental methods suitable to adequately follow chemical- and enzymatic degradation of CDs will also be discussed. Challenges in the determination of CDs in different biological matrices will be illustrated on real pharmaco- and toxicokinetic studies of CD-enabled drug formulations.

  11. Extraction techniques using isopropanol and Tenax to characterize polycyclic aromatic hydrocarbons bioavailability in sediment.

    PubMed

    Wang, Bin; Xu, Xiaoyi; Chen, Xi; Ji, Fangying; Hu, Bibo

    2017-02-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacterium strain J1-q (Sphingomonas pseudosanguinis strain J1-q) was isolated from Yangtze River surface sediment in the downtown area of Chongqing in a previous study. Isopropanol and Tenax extraction techniques were used to characterize the bioavailability of target PAH compounds. Phenanthrene (Phe) and fluoranthene (Fluo) were the target PAHs due to their significant background concentrations in surface sediment samples. Isopropanol solutions at concentrations of 50-100% and residual Phe and Fluo concentrations in sediment were correlated, with R(2) values of 0.9846 and 0.9649, respectively. The quantities of the Phe and Fluo fractions extracted for 3days with isopropanol from sediment were closely related with the corresponding quantities of PAHs degraded by bacterial strain J1-q when the extracting concentrations were 55% and 80%, respectively. The quantity of Phe extracted by Tenax agreed with the total quantity biodegraded when the Tenax: sediment mass ratio was 0.25 and the target PAHs were degraded for 30d, whereas the extracted quantity of Fluo accounted for 93.30% of the total quantity biodegraded by the bacterium. The triphasic model was appropriate to simulate the consecutive Phe and Fluo extraction process using Tenax at various Tenax: sediment ratios, and all simulated correlation coefficients were >0.9151. A 24-h extraction period was adequate to estimate the rapidly desorbing fractions when they were extracted with Tenax. Isopropanol extraction was preferable to characterize Phe and Fluo bioavailability under the experimental conditions, whereas Tenax extraction was useful to predict bioavailability of the two target PAHs with particular selectivity.

  12. 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.

  13. Global Material Characterization of Composite Structures Using Lamb Wave Stmr Array Technique

    NASA Astrophysics Data System (ADS)

    Vepakomma, Rajesh; Janapati, Vishu Vardhan; Balasubramaniam, Krishnan; Krishnamurthy, C. V.

    2010-02-01

    Structural health monitoring of plate like structures, using transducer arrays located suitably on the structure, finds applications in monitoring aerospace structures. These plates are anisotropic, with wave propagation properties varying with direction. Single Transmitter Multiple Receiver (STMR) arrays have been shown before to have the ability to locally characterize the stiffness properties of a composite material with anisotropy. The STMR arrays have also been demonstrated for SHM applications using phase reconstruction techniques. The guided ultrasonic Lamb waves are used where the central piezoelectric wafer-active sensor (PWAS) emits the guided waves, and the other PWAS sensors receive the Lamb wave signals. In the current work, this technique has been extended to the determination of global elastic moduli using the Lamb wave S0 and A0 mode signals that are reflected from features in the structure such as edge of the plate, bolt holes, etc. that are known apriori using STMR array and then reconstruct the unknown defects present on the structure using the same sensor array. The reconstruction of elastic moduli is accomplished using a Genetic Algorithm (GA) based inversion algorithm that optimizes an objective function for a particular configuration of the STMR array and the elastic moduli of the component. The solution to this inversion is the global elastic moduli of the composite which is then used to determine the unknown defects in the test component. Simulations were carried out using S0 and A0 mode velocity data for composite layups such as unidirectional, cross-ply, and quasi-isotropic graphite-epoxy composite layups. The inversion algorithm was tested using the simulated edge reflector data and found to agree well with the expected values. Experimental validation has been performed on 3.15 mm quasi-isotropic graphite-epoxy composite.

  14. Synthesis and Thermal Characterization of Hydroxyapatite Powders Obtained by Sol-Gel Technique

    NASA Astrophysics Data System (ADS)

    Jiménez-Flores, Y.; Camacho, N.; Rojas-Trigos, J. B.; Suárez, M.

    The development of bioactive materials presents an interesting and an extremely relevant problem to solve, in the development of customized cranial and maxillofacial prosthesis, bioactive coating, and cements, for example. In such areas, one of the more employed materials is the synthetic hydroxyapatite, due to its proved biocompatibility with the human body; however, there are few studies about the thermal affinity with the biological surroundings, and most of them are centered in the thermal stability of the hydroxyapatite instead of its transient thermal response. In the present paper, the synthesis and physical-chemical characterization of hydroxyapatite samples, obtained by the sol-gel technique employing ultrasonic mixing, are reported. Employing X-ray diffraction patterns, XEDS and FTIR spectra, the crystal symmetry, chemical elements, and the present functional groups of the studied samples were determined and found to correspond to those reported in the literature, with a stoichiometry close to the ideal for biological applications. Additionally, by means of the photoacoustic detection and infrared photothermal radiometry (IPTR) techniques, the thermal response of the samples was obtained. Analyzing the photoacoustic data, the synthetized samples show photoacoustic opaqueness, responding in the thermally thick regime in the measurement range, and their thermal effusivity was also determined, having values of 1.47 folds the thermal effusivity of the mandibular human bone. Finally, from the IPTR measurements, the thermal diffusivity and thermal conductivity of the samples were also determined, having good agreement with the reported values for synthetic hydroxyapatite. The structural and thermophysical properties of the here reported samples show that the synthesized samples have good thermal affinity with the mandibular human bone tissue, and are suitable for biomedical applications.

  15. Characterization of laser damage performance of fused silica using photothermal absorption technique

    NASA Astrophysics Data System (ADS)

    Wan, Wen; Shi, Feng; Dai, Yifan; Peng, Xiaoqiang

    2017-06-01

    The subsurface damage and metal impurities have been the main laser damage precursors of fused silica while subjected to high power laser irradiation. Light field enhancement and thermal absorption were used to explain the appearance of damage pits while the laser energy is far smaller than the energy that can reach the intrinsic threshold of fused silica. For fused silica optics manufactured by magnetorheological finishing or advanced mitigation process, no scratch-related damage site occurs can be found on the surface. In this work, we implemented a photothermal absorption technique based on thermal lens method to characterize the subsurface defects of fused silica optics. The pump beam is CW 532 nm wavelength laser. The probe beam is a He-Ne laser. They are collinear and focused through the same objective. When pump beam pass through the sample, optical absorption induces the local temperature rise. The lowest absorptance that we can detect is about the order of magnitude of 0.01 ppm. When pump beam pass through the sample, optical absorption induces the local temperature rise. The photothermal absorption value of fused silica samples range from 0.5 to 10 ppm. The damage densities of the samples were plotted. The damage threshold of samples at 8J/cm2 were gived to show laser damage performance of fused silica.The results show that there is a strong correlation between the thermal absorption and laser damage density. The photothermal absorption technique can be used to predict and evaluate the laser damage performance of fused silica optics.

  16. A technique for characterizing the time course of odor adaptation in mice.

    PubMed

    Yoder, Wendy M; Munizza, Olivia; Lyman, Michelle; Smith, David W

    2014-09-01

    Although numerous studies have analyzed the temporal characteristics underlying olfactory adaptation at the level of the olfactory receptor neuron, to date, there have been no comparable behavioral measures in an animal model. In this study, odor adaptation was estimated in a group of mice employing a psychophysical technique recently developed for use in humans. The premise of this technique is that extended presentation of an odorant will produce odor adaptation, decreasing the sensitivity of the receptors and increasing thresholds for a brief, simultaneous target odorant presented at different time points on the adaptation contour; adaptation is estimated as the increase in threshold for a target odorant presented simultaneously with an adapting odorant, across varying adapting-to-target odorant onset delays. Previous research from our laboratory suggests that this method provides a reliable estimate of the onset time course of rapid adaptation in human subjects. Consistent with physiological and behavioral data from human subjects, the present findings demonstrate that measurable olfactory adaptive effects can be observed for odorant exposures as brief as 50-100ms, with asymptotic levels evident 400-600ms following adapting odorant onset. When compared with the adaptation contour in humans using the same odorant and stimulus paradigm, some differences in the onset characteristics are evident and may be related to sniffing behavior and to relative differences in thresholds. These data show that this psychophysical paradigm can be adapted for use in animal models, where experimental and genetic manipulations can be used to characterize the different mechanisms underlying odor adaptation. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Optomechatronic Techniques to Characterize the Topography of a MW Satellite Antenna

    NASA Astrophysics Data System (ADS)

    Hölck, Daniel; Molina, Alejandro R. Roldán; Fluxá, Patricio E.; Zerbino, Lía M.; Bava, José A.; Cortizo, Eduardo C.; Garavaglia, Mario

    2008-04-01

    We describe several optomecatronic techniques to characterize the topographic changes due to thermomechanical deformations of models of an off-set MW satellite antenna. The surface of the antennas is a paraboloidal torus. This type of antenna will be installed in the SAC-D/AQUARIUS Satellite Mission; this mission is a collaboration between the NASA from the USA and the Comisión Nacional de Actividades Espaciales (CONAE), Argentina. Two antennas will serve at 23.8 GHz and 36.5 GHz radiometers to study the global water cycle by analyzing various geophysical parameters. The used optomecatronic techniques were Structured illumination (SI), Differential Structured Illumination (DSI), Moiré Profilometry (MP), and Fourier Transform Profilometry (FTP). The temporal changes of temperature and the spatial thermal gradients were recorded by using Infrared Thermography (IRT). Optical measurements were compared with those obtained by a mechanical dial indicator. The quality of the mechanical measurements is of the order of λ/100, where λ is the wavelength of the MW radiation at 23.8 GHz and 36.5 GHz, that is, λ/100 is of the order of 80 μm. This figure of merit is enough for this type of antennas. On the other hand, the quality of the present optical measurement reached a value of λ/30, that is, 270 μm. In spite of the fact that mechanical measurements look better than photomechanical measurements, it was decided to carry on with the application of the SI, DSI, MP and FTP, because they are non contacting procedures which will be used in testing the antennas along warm-up and warm-down cycles in a vacuum, to experimentally simulate their space environment behavior.

  18. 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.

  19. 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.

  20. Chimera. A Grid-Embedding Technique

    DTIC Science & Technology

    1986-04-01

    NASA Langley Research Center, Hampton, Virginia, October 6-7, 1980. 2. Thompson , J . F . and Warsi, Z.U.A. "Boundary-Fitted Coordinate System for...Numerical Solution of Partial Differential Equations: A Review." Journal oj Computational Physics, Vol. 47, No.1, 1982, pp. 1-108. 3. Thompson , J . F ., ed

  1. 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

  2. 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

  3. 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

  4. Characterization of Microstructure and Molecular Dynamics with High Frequency Oscillatory Techniques

    NASA Astrophysics Data System (ADS)

    Remmler, Torsten; Amin, Samiul; Ferrante, Andrea; Pechhold, Wolfgang

    2009-07-01

    To characterize the rheological behaviour of complex viscoelastic fluids, polymer melts and other soft materials, motor-drive controlled rheometers are mainly used, either at constant stress or strain rate, or in the oscillatory mode. The latter has proved advantageous to discover the viscoelastic functions G*, η*, J* as fingerprints of the material under investigation, it's composition, molecular modelling and applicability. A conclusive analysis of such a viscoelastic spectrum can only be achieved if the amplitudes chosen guarantee linearity and if the frequency range covers more than 6 decades to reach the low kHz-domain. Investigations of many materials with motor-drive controlled rheometers are limited at higher frequencies and reach the above mentioned goal by applying the time-temperature superposition principle, i.e. the mastercurve technique. Since this method is restricted to rheologically simple materials (e.g. some polymer melts), but exclude those of small activation energies and others with temperature-sensitive chemical/physical structures including phase transitions, oscillating rheometry should be extended into higher real-frequency ranges, to establish useful linear viscoelastic spectroscopy. Since complex fluids can have structural arrangement over a wide range of lengthscales and their relaxation mechanisms can impact the dynamics over a wide range of timescales, multiple techniques need to be employed in order to accurately and fully establish the links between rheology, microstructure & dynamics. This is also critical information, required for fully validating developed theory and models. In this talk, advantages and limits of classical oscillatory rheometry will be covered, handling and principle of operation of two high frequency options are introduced and typical examples for real frequency spectra on soft matter, such as polymer melts, polymer solutions and weak gels will be shown. A xanthum gum based system has been investigated not only

  5. Production of luster glaze on opal tableware using zarinfam technique and characterization of its structure and color

    NASA Astrophysics Data System (ADS)

    Razavi, Fahime; Rashidi Huyeh, Majid; Ghahari, Mahdi

    2016-05-01

    Lusters are potters that have attracted much attention due to their specific optical features, one of the most important of which is their sparkle that appears in various colors at different angles. This effect linked to the multilayer structure of luster and the presence of metallic nanoparticles in enamel layer. In this research, luster glaze was produced on Opal tableware, manufactured in Mahfam Jam Co., using Zarinfam technique. SEM micrograph image of the samples indicated that the glaze forms a multilayer structure, on the Opal tableware surface, consisting of a glassy superficial layer of some tens of nanometers and a composite layer of some hundreds of nanometers. The enamel composite layer contains silver nanoparticles embedded in a silica medium. Employing a multilayer model, we studied the influence of different parameters such as luster enamel thickness, nanoparticles volume fraction in enamel, nanoparticle size, observe angle, and glass layer thickness on luster color.

  6. Silica Embedded Metal Hydrides

    SciTech Connect

    Heung, L.K.; Wicks, G.G.

    1998-08-01

    A method to produce silica embedded metal hydride was developed. The product is a composite in which metal hydride particles are embedded in a matrix of silica. The silica matrix is highly porous. Hydrogen gas can easily reach the embedded metal hydride particles. The pores are small so that the metal hydride particles cannot leave the matrix. The porous matrix also protects the metal hydride particles from larger and reactive molecules such as oxygen, since the larger gas molecules cannot pass through the small pores easily. Tests show that granules of this composite can absorb hydrogen readily and withstand many cycles without making fines.

  7. Secure Embedded Systems

    DTIC Science & Technology

    2015-08-24

    embedded  12   systems ,  which   consists  of   an  architecture   that  decouples   secure  and   functional   design ...confidentiality   and  14   integrity  of  an   embedded   system  being   designed .    The  development  of  a  hypothetical...secure   embedded  15   system  for  an  unmanned

  8. 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

  9. A plume capture technique for the remote characterization of aircraft engine emissions.

    PubMed

    Johnson, G R; Mazaheri, M; Ristovski, Z D; Morawska, L

    2008-07-01

    A technique for capturing and analyzing plumes from unmodified aircraft or other combustion sources under real world conditions is described and applied to the task of characterizing plumes from commercial aircraft during the taxiing phase of the Landing/Take-Off (LTO) cycle. The method utilizes a Plume Capture and Analysis System (PCAS) mounted in a four-wheel drive vehicle which is positioned in the airfield 60 to 180 m downwind of aircraft operations. The approach offers low test turnaround times with the ability to complete careful measurements of particle and gaseous emission factors and sequentially scanned particle size distributions without distortion due to plume concentration fluctuations. These measurements can be performed for individual aircraft movements at five minute intervals. A Plume Capture Device (PCD) collected samples of the naturally diluted plume in a 200 L conductive membrane conforming to a defined shape. Samples from over 60 aircraft movements were collected and analyzed in situ for particulate and gaseous concentrations and for particle size distribution using a Scanning Particle Mobility Sizer (SMPS). Emission factors are derived for particle number, NO(x), and PM2.5 for a widely used commercial aircraft type, Boeing 737 airframes with predominantly CFM56 class engines, during taxiing. The practical advantages of the PCAS include the capacity to perform well targeted and controlled emission factor and size distribution measurements using instrumentation with varying response times within an airport facility, in close proximity to aircraft during their normal operations.

  10. Single crystal growth by gel technique and characterization of lithium hydrogen tartrate

    NASA Astrophysics Data System (ADS)

    Ahmad, Nazir; Ahmad, M. M.; Kotru, P. N.

    2015-02-01

    Single crystal growth of lithium hydrogen tartrate by gel encapsulation technique is reported. Dependence of crystal count on gel density, gel pH, reactant concentration and temperature are studied and the optimum conditions for these crystals are worked out. The stoichiometric composition of the grown crystals is determined using EDAX/AES and CH analysis. The grown crystals are characterized by X-ray diffraction, FTIR and Uv-Visible spectroscopy. It is established that crystal falls under orthorhombic system and space group P222 with the cell parameters as: a=10.971 Å, b=13.125 Å and c=5.101 Å; α=90.5o, β=γ=90°. The morphology of the crystals as revealed by SEM is illustrated. Crystallite size, micro strain, dislocation density and distortion parameters are calculated from the powder XRD results of the crystal. UV-vis spectroscopy shows indirect allowed transition with an optical band gap of~4.83 eV. The crystals are also shown to have high transmittance in the entire visible region. Dependence of dielectric constant, dielectric loss and conductivity on frequency of the applied ac field is analyzed. The frequency-dependent real part of the complex ac conductivity is found to follow the universal dielectric response: σac (ω)~ωs. The trend in the variation of frequency exponent with frequency corroborates the fact that correlated barrier hopping is the dominant charge-transport mechanism in the present system.

  11. Characterization of a bonding-in-liquid technique for liquid encapsulation into MEMS devices

    NASA Astrophysics Data System (ADS)

    Okayama, Yoshiyuki; Nakahara, Keijiro; Arouette, Xavier; Ninomiya, Takeshi; Matsumoto, Yasuaki; Orimo, Yoshinori; Hotta, Atsushi; Omiya, Masaki; Miki, Norihisa

    2010-09-01

    We demonstrate and characterize a new bonding-in-liquid technique (BiLT) for the encapsulation of liquids in MEMS devices. Liquid encapsulation enables innovative MEMS devices with various functions exploiting the unique characteristics of liquids, such as high deformation and spherical shape due to surface tension. Interfusion of air bubbles, variation of the liquid quantity and leakage of the encapsulated liquid must be avoided, or device performance will deteriorate. In BiLT, two structural layers are passively aligned and brought into contact in a solution, and the encapsulation cavities are filled uniformly with liquid, without air bubbles. A UV-curable resin is used as an adhesive that does not require heat or vacuum to bond the layers, but UV irradiation. DI water, glycerin and phosphate buffer saline were successfully encapsulated in silicon structural layers with PDMS membranes. We experimentally evaluated the bond strengths and alignment accuracy of BiLT in order to provide crucial information for the application of this process to the packaging and/or manufacturing of MEMS devices. Since conventional aligners are not applicable to BiLT, we experimentally evaluated the accuracy of an in-solution passive alignment process, which made use of matching concave and convex structures.

  12. Mechanical characterization of hyperelastic materials with fringe projection and optimization techniques

    NASA Astrophysics Data System (ADS)

    Genovese, Katia; Lamberti, Luciano; Pappalettere, Carmine

    2006-05-01

    This paper presents a new hybrid technique for mechanical characterization of hyperelastic materials. The research is motivated by the fact that standard identification procedures based on the fitting of strain-stress curves determined experimentally from planar biaxial tests may be inaccurate for non-uniform states of deformation. Therefore, we propose an alternative approach where the difference Ω between the displacement field measured with Projection Moiré and its counterpart predicted by FEM is minimized using non-linear optimization algorithms that finally find unknown material properties. In order to check the feasibility of the new procedure, we considered a thin latex membrane modelling it as a two-parameter Mooney-Rivlin (MR) hyperelastic material. The Ω function is minimized either using optimization routines available in a commercial finite element package and by implementing a global optimizer able to deal with non-linearity and non-convexity included in the identification process. In order to check accuracy of optimization results, target values of MR constants for the latex specimen tested have previously been determined by fitting experimental stress-strain data gathered from a standard planar biaxial tension test. Results indicate that the present hybrid identification procedure can determine accurately properties of the hyperelastic material under investigation. In fact, the average residual error on displacements was less than 1% while the difference between the MR constants found with optimization and their target values was less than 3.5%.

  13. A Review of the Principles and Applications of the NMR Technique for Near-Surface Characterization

    NASA Astrophysics Data System (ADS)

    Behroozmand, Ahmad A.; Keating, Kristina; Auken, Esben

    2015-01-01

    This paper presents a comprehensive review of the recent advances in nuclear magnetic resonance (NMR) measurements for near-surface characterization using laboratory, borehole, and field technologies. During the last decade, NMR has become increasingly popular in near-surface geophysics due to substantial improvements in instrumentation, data processing, forward modeling, inversion, and measurement techniques. This paper starts with a description of the principal theory and applications of NMR. It presents a basic overview of near-surface NMR theory in terms of its physical background and discusses how NMR relaxation times are related to different relaxation processes occurring in porous media. As a next step, the recent and seminal near-surface NMR developments at each scale are discussed, and the limitations and challenges of the measurement are examined. To represent the growth of applications of near-surface NMR, case studies in a variety of different near-surface environments are reviewed and, as examples, two recent case studies are discussed in detail. Finally, this review demonstrates that there is a need for continued research in near-surface NMR and highlights necessary directions for future research. These recommendations include improving the signal-to-noise ratio, reducing the effective measurement dead time, and improving production rate of surface NMR (SNMR), reducing the minimum echo time of borehole NMR (BNMR) measurements, improving petrophysical NMR models of hydraulic conductivity and vadose zone parameters, and understanding the scale dependency of NMR properties.

  14. Detailed characterization of lithium diffusion mechanisms in crystalline silicon using the kinetic Activation-Relaxation Technique

    NASA Astrophysics Data System (ADS)

    Trochet, Mickaël; Restrepo Gutierrez, Oscar Antonio; Mousseau, Normand

    Silicon displays a potential for high-capacity anode material for lithium-ion batteries as it can absorb large quantities of this metal. Yet, very little is understood about the evolution of diffusion mechanisms and migration barriers as the concentration of lithium increases. Until now, for example, simulations studies were limited by the time scale over which diffusion takes place. Here, we use the kinetic activation relaxation technique (kART), an unbiased off-lattice Monte Carlo method with on-the fly catalog building, coupled with the ReaxFF forcefield to follow diffusion of Li in c - Si over timescale of seconds and more at room temperature, obtaining detailed information about the whole set of possible diffusion mechanisms as the local environment evolves. We first present a detailed characterization of Li diffusion in the presence of 1 to 3 impurities and then show the evolution of systems with a higher concentration of solute as Li aggregate. These results provide a first detailed picture of the onset of Li aggregating into this high-capacity material, as it modifies the structure through local rearrangements and long-range elastic deformations, crucial information for the development of the next generation of high-capacity anode. ∖pard ∖pard.

  15. 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.

  16. 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.

  17. Experimental techniques for the characterization of carbon nanoparticles – a brief overview

    PubMed Central

    Łoś, Szymon; Kempiński, Mateusz; Markowski, Damian

    2014-01-01

    Summary The review of four experimental methods: X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance and four-point electrical conductivity measurements is presented to characterize carbon nanoparticles. Two types of carbon nanoparticle systems are discussed: one comprising the powder of individual carbon nanoparticles and the second as a structurally interconnected nanoparticle matrix in the form of a fiber. X-ray diffraction and Raman spectroscopy reveal the atomic structure of the carbon nanoparticles and allow for observation of the changes in the quasi-graphitic ordering induced by ultrasonic irradiation and with the so-called quasi-high pressure effect under adsorption conditions. Structural changes have strong influence on the electronic properties, especially the localization of charge carriers within the nanoparticles, which can be observed with the EPR technique. This in turn can be well-correlated with the four-point electrical conductivity measurements which directly show the character of the charge carrier transport within the examined structures. PMID:25383287

  18. Microchannels created by sugar and metal microneedles: characterization by microscopy, macromolecular flux and other techniques.

    PubMed

    Li, Guohua; Badkar, Advait; Kalluri, Haripriya; Banga, Ajay K

    2010-04-01

    The objective of this study was to investigate the feasibility of using microneedle technology to enhance transcutaneous permeation of human immunoglobulin G (IgG) across hairless rat skin. Microchannels created by maltose and metal (DermaRoller) microneedles were characterized by techniques such as methylene blue staining, histological examination, and calcein imaging. Methylene blue staining and histological sections of treated skin showed that maltose microneedles and DermaRoller breached the skin barrier by creating microchannels in the skin with an average depth of approximately 150 microm, as imaged by confocal microscopy. Calcein imaging and pore permeability index values suggested the uniformity of the created pores in microneedle-treated skin. Transdermal studies with IgG indicated a flux rate of 45.96 ng/cm(2)/h, in vitro, and a C(max) of 7.27 ng/mL, in vivo, for maltose microneedles-treated skin while a flux rate of 353.17 ng/cm(2)/h, in vitro, and a C(max) of 9.33 ng/mL, in vivo, was achieved for DermaRoller-treated skin. Transepidermal water loss measurements and methylene blue staining, in vivo, indicated the presence of microchannels for upto 24 h, when occluded. In conclusion, the microchannels created by maltose microneedles and DermaRoller resulted in the percutaneous enhancement of a macromolecule, human IgG.

  19. Formulation, Characterization and Evaluation of Paclitaxel loaded Solid Lipid Nanoparticles Prepared by Temperature Modulated Solidification Technique

    NASA Astrophysics Data System (ADS)

    Deshpande, Ameya Abhay

    The aim of this research was to formulate, characterize, and evaluate the paclitaxel loaded solid lipid nanoparticles (SLNs) prepared by a temperature modulated solidification technique developed and optimized in our laboratory. The particle size analysis through dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed and confirmed the spherical shape and nanometer size range of the formulated nanoparticles. Zeta potential measurements confirmed the physical stability of the SLNs with a negative surface charge. Atomic force microscopy (AFM) studies were done to study the surface topography and particle size and shape. AFM data showed minimal aggregation and more or less spherical SLNs. Differential scanning calorimetry (DSC), powder X-ray diffraction (P-XRD) and Fourier transform infrared spectroscopy (ATR-FTIR) confirmed the conversion of bulk lipid into SLNs and high entrapment of paclitaxel into the lipid matrix. The optimized formulation had an entrapment efficiency of approximately 62%. The in-vitro drug release depicted a sustained release of paclitaxel from the SLNs over duration of one week. The drug release data was found to best fit and hence followed the Higuchi drug-release model.

  20. 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.