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Sample records for advanced spectroscopic techniques

  1. Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: introduction to the special section.

    PubMed

    Lombi, Enzo; Hettiarachchi, Ganga M; Scheckel, Kirk G

    2011-01-01

    Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describe the complexity of environmental biogeochemical reaction mechanisms relies on our analytical ability through the application and developmemnt of advanced spectroscopic techniques. Accompanying this introductory article are nine papers that either review advanced in situ spectroscopic methods or present original research utilizing these techniques. This collection of articles summarizes the challenges facing environmental biogeochemistry, highlights the recent advances and scientific gaps, and provides an outlook into future research that may benefit from the use of in situ spectroscopic approaches. The use of synchrotron-based techniques and other methods are discussed in detail, as is the importance to integrate multiple analytical approaches to confirm results of complementary procedures or to fill data gaps. We also argue that future direction in research will be driven, in addition to recent analytical developments, by emerging factors such as the need for risk assessment of new materials (i.e., nanotechnologies) and the realization that biogeochemical processes need to be investigated in situ under environmentally relevant conditions.

  2. Use of Advanced Spectroscopic Techniques for Predicting the Mechanical Properties of Wood Composites

    Treesearch

    Timothy G. Rials; Stephen S. Kelley; Chi-Leung So

    2002-01-01

    Near infrared (NIR) spectroscopy was used to characterize a set of medium-density fiberboard (MDF) samples. This spectroscopic technique, in combination with projection to latent structures (PLS) modeling, effectively predicted the mechanical strength of MDF samples with a wide range of physical properties. The stiffness, strength, and internal bond properties of the...

  3. Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.; Pelling, M. R.; Peterson, L. E.; Lin, R. P.; Anderson, K. A.; Pehl, R. H.; Hurley, K. C.; Vedrenne, G.; Sniel, M.; Durouchoux, P.

    1985-01-01

    An advanced gamma-ray spectrometer that is currently in development is described. It will obtain a sensitivity of 0.0001 ph/sq cm./sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging.

  4. Advances in Understanding the Molecular Structures and Functionalities of Biodegradable Zein-Based Materials Using Spectroscopic Techniques: A Review.

    PubMed

    Turasan, Hazal; Kokini, Jozef L

    2017-02-13

    Zein's amphiphilic properties, film forming capability, and biodegradability make it a highly demanded polymer for fabrication of packaging materials, production of drug carrier nanoparticles, scaffolds in tissue engineering, and formation of biodegradable platforms for biosensors including microfluidic devices. Zein properties can be improved by chemical modifications, which are often analyzed with spectroscopic techniques. However, there is not a consensus on the structure of zein. For this reason, in this Review the aim is to compile the recent studies conducted on zein-based products and compare them under five main spectroscopic techniques: Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, circular dichroism (CD), X-ray diffraction (XRD) and atomic force microscopy (AFM). This Review serves as a library of recent zein studies and helps readers to have a better perception of contradictions in the literature to take their studies one step further.

  5. Advanced Spectroscopic Synchrotron Techniques to Unravel the Intrinsic Properties of Dilute Magnetic Oxides: The Case of Co:ZnO

    SciTech Connect

    Ney, A; Opel, M; Kaspar, Tiffany C; Ney, V; Ye, S; Ollefs, K; Kammermeier, T; Bauer, S; Nielsen, K W; Goennenwein, S Tb; Engelhard, Mark H; Zhou, S; Potzger, K; Simon, J; Mader, W; Heald, Steve M; Cezar, J C; Wilhelm, F; Rogalev, A; Gross, R; Chambers, Scott A

    2010-01-22

    The use of synchrotron-based spectroscopy has revolutionized the way we look at matter. X-ray absorption spectroscopy (XAS) using linear and circular polarized light offers a powerful toolbox of element-specific structural, electronic, and magnetic probes that is especially well suited for complex materials containing several elements. We use the specific example of Zn1-xCoxO (Co:ZnO) to demonstrate the usefulness of combining these XAS techniques to unravel its intrinsic properties. We are able to demonstrate, that as long as phase separation or excessive defect formation is absent Co:ZnO is paramagnetic and we can establish independent quality indicators based on XAS. Samples which show long-range magnetic order fail to meet the quality indicators and complementary experimental techniques such as x-ray diffraction and transmission electron microscopy indeed prove phase separation. By deconvoluting the XAS spectra, the characteristic spectral features of the phase separated materials are derived.

  6. Advanced spectroscopic synchrotron techniques to unravel the intrinsic properties of dilute magnetic oxides : the case of Co:ZnO.

    SciTech Connect

    Ney, A.; Opel, M.; Kaspar, T. C.; Ney, V.; Ye, S.; Ollefs, K.; Kammermeier, T.; Bauer, S.; Nielsen, K.-W.; Goennenwein, S. T. B.; Engelhard, M. H.; Zhou, S.; Potzger, K.; Simon, J.; Mader, W.; Heald, S. M.; Cezar, C.; Wilhelm, F.; Rogalev, A.; Gross, R.; Chambers, S. A.; X-Ray Science Division; Univ. at Duisburg-Essen; Walther-Meibner-Inst.; PNNL; Inst.fur Ionenstrahlphysik und Materialforschung; European Synchrotron Radiation Facility; Friedrich-Wilhelms-Univ.

    2010-02-01

    The use of synchrotron-based spectroscopy has revolutionized the way we look at matter. X-ray absorption spectroscopy (XAS) using linear and circular polarized light offers a powerful toolbox of element-specific structural, electronic and magnetic probes that is especially well suited for complex materials containing several elements. We use the specific example of Zn{sub 1-x}Co{sub x}O (Co:ZnO) to demonstrate the usefulness of combining these XAS techniques to unravel its intrinsic properties. We demonstrate that as long as phase separation or excessive defect formation is absent, Co:ZnO is paramagnetic. We can establish quantitative thresholds based on four reliable quality indicators using XAS; samples that show ferromagnet-like behaviour fail to meet these quality indicators, and complementary experimental techniques indeed prove phase separation. Careful analysis of XAS spectra is shown to provide quantitative information on the presence and type of dilute secondary phases in a highly sensitive, non-destructive manner.

  7. Advanced echocardiographic techniques

    PubMed Central

    Perry, Rebecca

    2015-01-01

    Abstract Echocardiography has advanced significantly since its first clinical use. The move towards more accurate imaging and quantification has driven this advancement. In this review, we will briefly focus on three distinct but important recent advances, three‐dimensional (3D) echocardiography, contrast echocardiography and myocardial tissue imaging. The basic principles of these techniques will be discussed as well as current and future clinical applications. PMID:28191159

  8. Imaging spectroscopic analysis at the Advanced Light Source

    SciTech Connect

    MacDowell, A. A.; Warwick, T.; Anders, S.; Lamble, G.M.; Martin, M.C.; McKinney, W.R.; Padmore, H.A.

    1999-05-12

    One of the major advances at the high brightness third generation synchrotrons is the dramatic improvement of imaging capability. There is a large multi-disciplinary effort underway at the ALS to develop imaging X-ray, UV and Infra-red spectroscopic analysis on a spatial scale from. a few microns to 10nm. These developments make use of light that varies in energy from 6meV to 15KeV. Imaging and spectroscopy are finding applications in surface science, bulk materials analysis, semiconductor structures, particulate contaminants, magnetic thin films, biology and environmental science. This article is an overview and status report from the developers of some of these techniques at the ALS. The following table lists all the currently available microscopes at the. ALS. This article will describe some of the microscopes and some of the early applications.

  9. Application of optical spectroscopic techniques for disease diagnosis

    NASA Astrophysics Data System (ADS)

    Saha, Anushree

    Optical spectroscopy, a truly non-invasive tool for remote diagnostics, is capable of providing valuable information on the structure and function of molecules. However, most spectroscopic techniques suffer from drawbacks, which limit their application. As a part of my dissertation work, I have developed theoretical and experimental methods to address the above mentioned issues. I have successfully applied these methods for monitoring the physical, chemical and biochemical parameters of biomolecules involved in some specific life threatening diseases like lead poisoning and age-related macular degeneration (AMD). I presented optical studies of melanosomes, which are one of the vital organelles in the human eye, also known to be responsible for a disease called age-related macular degeneration (AMD), a condition of advanced degeneration which causes progressive blindness. I used Raman spectroscopy, to first chemically identify the composition of melanosome, and then monitor the changes in its functional and chemical behavior due to long term exposure to visible light. The above study, apart from explaining the role of melanosomes in AMD, also sets the threshold power for lasers used in surgeries and other clinical applications. In the second part of my dissertation, a battery of spectroscopic techniques was successfully applied to explore the different binding sites of lead ions with the most abundant carrier protein molecule in our circulatory system, human serum albumin. I applied optical spectroscopic tools for ultrasensitive detection of heavy metal ions in solution which can also be used for lead detection at a very early stage of lead poisoning. Apart from this, I used Raman microspectroscopy to study the chemical alteration occurring inside a prostate cancer cell as a result of a treatment with a low concentrated aqueous extract of a prospective drug, Nerium Oleander. The experimental methods used in this study has tremendous potential for clinical

  10. Advancement on Visualization Techniques

    DTIC Science & Technology

    1980-10-01

    Aeroa and As ronautics Massachusetts Institute of Technology Cambridge, MA 02139 USA I !ii 1 I This AGARDograph was prepared at the request of the...the fields of science § and technology relating to aerospace for the following purposes: - Exchanging of scientific and technical information...Techniques for providing the pilot visualization have grown rapidly. Technology has developed fron mechanical gauges through electro-mechanical

  11. A Comparison of Galaxy Counting Techniques in Spectroscopically Undersampled Regions

    NASA Astrophysics Data System (ADS)

    Specian, Mike A.; Szalay, Alex S.

    2016-11-01

    Accurate measures of galactic overdensities are invaluable for precision cosmology. Obtaining these measurements is complicated when members of one’s galaxy sample lack radial depths, most commonly derived via spectroscopic redshifts. In this paper, we utilize the Sloan Digital Sky Survey’s Main Galaxy Sample to compare seven methods of counting galaxies in cells when many of those galaxies lack redshifts. These methods fall into three categories: assigning galaxies discrete redshifts, scaling the numbers counted using regions’ spectroscopic completeness properties, and employing probabilistic techniques. We split spectroscopically undersampled regions into three types—those inside the spectroscopic footprint, those outside but adjacent to it, and those distant from it. Through Monte Carlo simulations, we demonstrate that the preferred counting techniques are a function of region type, cell size, and redshift. We conclude by reporting optimal counting strategies under a variety of conditions.

  12. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  13. Advanced Planarization Techniques

    NASA Astrophysics Data System (ADS)

    Basol, Bulent M.

    As the integrated circuit technology nodes reach 45 nm and beyondgrowing requirement for reduced propagation delay dictates inclusion of low-k materials in the interconnect metallization structures. Unfortunately, mechanical properties, such as hardness and Young's modulus of the dielectric materials, deteriorate as their porosity is increased and the k value is reduced to 2.5 and below [1]. Reliability issues such as electromigration, stress migration, and time-dependent dielectric breakdown (TDDB) lifetimes are also becoming more challenging for multi-stack low-k structures. The low-k and ultra low-k materials are prone to delamination [2] and cracking [3] during CMP; risk of damage rising as the polishing pressure and time increases [4]. It has been demonstrated that delamination in low-k stacks was driven by the work done against the friction force during the CMP process [5]. Therefore, it is becoming more and more difficult to polish and planarize topographic copper layers, deposited on low-k dielectric materials, at low stress and high rate while maintaining the mechanical integrity of the overall interconnect structure. Furthermore as feature widths and depths shrink, tolerances for metal loss and line resistance variation over the wafer surface are also reduced. In advanced interconnects, adding sacrificial thickness to the dielectric layer which can then be removed during CMP overpolish step is not a good option to minimize topography because hard cap layers are often used to protect the low-k dielectric materials from the negative effects of CMP [6, 7] and thickness of these layers is kept to a minimum to reduce their contribution to the effective dielectric constant of the stack. Therefore, as technology nodes move beyond 45 nm, planarization steps of the interconnect manufacturing process flow are expected to offer reduced stress, higher planarization efficiency, reduced copper dishing, less dielectric erosion, better global line resistance uniformity

  14. Advanced Wavefront Control Techniques

    SciTech Connect

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    this project, work was performed in four areas (1) advanced modeling tools for deformable mirrors (2) low-order wavefront correctors with Alvarez lenses, (3) a direct phase measuring heterdyne wavefront sensor, and (4) high-spatial-frequency wavefront control using spatial light modulators.

  15. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M.

    1993-12-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ``builds in`` the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ``process capability`` is illustrated and a comparison of 10-keV x-ray and Co{sup 60} gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe`s Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  16. Techniques in Advanced Language Teaching.

    ERIC Educational Resources Information Center

    Ager, D. E.

    1967-01-01

    For ease of presentation, advanced grammar teaching techniques are briefly considered under the headings of structuralism (belief in the effectiveness of presenting grammar rules) and contextualism (belief in the maximum use by students of what they know in the target language). The structuralist's problem of establishing a syllabus is discussed…

  17. Spectroscopic Measurement Techniques for Aerospace Flows

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Bathel, Brett F.; Johansen, Craig T.; Cutler, Andrew D.; Hurley, Samantha

    2014-01-01

    The conditions that characterize aerospace flows are so varied, that a single diagnostic technique is not sufficient for its measurement. Fluid dynamists use knowledge of similarity to help categorize and focus on different flow conditions. For example, the Reynolds number represents the ratio of inertial to viscous forces in a flow. When the velocity scales, length scales, and gas density are large and the magnitude of the molecular viscosity is low, the Reynolds number becomes large. This corresponds to large scale vehicles (e.g Airbus A380), fast moving objects (e.g. artillery projectiles), vehicles in dense fluids (e.g. submarine in water), or flows with low dynamic viscosity (e.g. skydiver in air). In each of these cases, the inertial forces dominate viscous forces, and unsteady turbulent fluctuations in the flow variables are observed. In contrast, flows with small length scales (e.g. dispersion of micro-particles in a solid rocket nozzle), slow moving objects (e.g. micro aerial vehicles), flows with low density gases (e.g. atmospheric re-entry), or fluids with a large magnitude of viscosity (e.g. engine coolant flow), all have low Reynolds numbers. In these cases, viscous forces become very important and often the flows can be steady and laminar. The Mach number, which is the ratio of the velocity to the speed of sound in the medium, also helps to differentiate types of flows. At very low Mach numbers, acoustic waves travel much faster than the object, and the flow can be assumed to be incompressible (e.g. Cessna 172 aircraft). As the object speed approaches the speed of sound, the gas density can become variable (e.g. flow over wing of Learjet 85). When the object speed is higher than the speed of sound (Ma > 1), the presences of shock waves and other gas dynamic features can become important to the vehicle performance (e.g. SR-71 Blackbird). In the hypersonic flow regime (Ma > 5), large changes in temperature begin to affect flow properties, causing real

  18. LHC Olympics: Advanced Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Armour, Kyle; Larkoski, Andrew; Gray, Amanda; Ventura, Dan; Walsh, Jon; Schabinger, Rob

    2006-05-01

    The LHC Olympics is a series of workshop aimed at encouraging theorists and experimentalists to prepare for the soon-to-be-online Large Hadron Collider in Geneva, Switzerland. One aspect of the LHC Olympics program consists of the study of simulated data sets which represent various possible new physics signals as they would be seen in LHC detectors. Through this exercise, LHC Olympians learn the phenomenology of possible new physics models and gain experience in analyzing LHC data. Additionally, the LHC Olympics encourages discussion between theorists and experimentalists, and through this collaboration new techniques could be developed. The University of Washington LHC Olympics group consists of several first-year graduate and senior undergraduate students, in both theoretical and experimental particle physics. Presented here is a discussion of some of the more advanced techniques used and the recent results of one such LHC Olympics study.

  19. Breath Analysis Using Laser Spectroscopic Techniques: Breath Biomarkers, Spectral Fingerprints, and Detection Limits

    PubMed Central

    Wang, Chuji; Sahay, Peeyush

    2009-01-01

    Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), cavity enhanced absorption spectroscopy (CEAS), cavity leak-out spectroscopy (CALOS), photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS). Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis. PMID:22408503

  20. Breath analysis using laser spectroscopic techniques: breath biomarkers, spectral fingerprints, and detection limits.

    PubMed

    Wang, Chuji; Sahay, Peeyush

    2009-01-01

    Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), cavity enhanced absorption spectroscopy (CEAS), cavity leak-out spectroscopy (CALOS), photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS). Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.

  1. Evaluation of Her2 status using photoacoustic spectroscopic CT techniques

    NASA Astrophysics Data System (ADS)

    Shaffer, Michael; Kruger, Robert; Reinecke, Daniel; Chin-Sinex, Helen; Mendonca, Marc; Stantz, Keith M.

    2010-02-01

    Purpose: The purpose of this study is to determine the feasibility of using photacoustic CT spectroscopy(PCT-s) to track a near infrared dye conjugated with trastuzumab in vivo. Materials and Methods: An animal model was developed which contained both high and low Her2 expression tumor xenografts on the same mouse. The tumors were imaged at multiple wavelengths (680- 950nm) in the PCT scanner one day prior to injection of the near infrared conjugated probe. Baseline optical imaging data was acquired and the probe was then injected via the tail vein. Fluorescence data was acquired over the next week, PCT spectroscopic data was also acquired during this timeframe. The mice were sacrificed and tumors were extirpated and sent to pathology for IHC staining to verify Her2 expression levels. The optical fluorescence images were analyzed to determine probe uptake dynamics. Reconstructed PCT spectroscopic data was analyzed using IDL routines to deconvolve the probe signal from endogenous background signals, and to determine oxygen saturation. Results: The location of the NIR conjugate was able to be identified within the tumor utilizing IDL fitting routines, in addition oxygen saturation, and hemoglobin concentrations were discernible from the spectroscopic data. Conclusion: Photacoustic spectroscopy allows for the determination of in vivo tumor drug delivery at greater depths than can be determined from optical imaging techniques.

  2. Advances in information extraction techniques

    NASA Technical Reports Server (NTRS)

    Nagy, G.

    1982-01-01

    Sundry recent developments are presented which show some potential for affecting the automatic extraction of information from remotely sensed data. Pattern representations more abstract than Euclidean vector spaces offer some hope of unifying structural and decision theoretical approaches. The estimation of expected classification error rates is becoming more sophisticated and rigorous, but useful finite-sample results for nonparametric distributions appear unobtainable. Focus on computational complexity allows comparison of algorithms, while software engineering techniques reduce the effort necessary to develop and maintain complex image processing systems. Advances in computer systems architecture, commercial database technology, and man-machine communications should be closely monitored by the remote sensing community. A NASA-sponsored recommendation for research directions in mathematical pattern recognition are offered.

  3. Vibration/Acoustic Isolation Techniques for spectroscopic mapping STS

    NASA Astrophysics Data System (ADS)

    Alldredge, Jacob; Hoskinson, Emile; Hoffmann, Joan; Harrd, Thomas; Packard, Richard; Davis, J. C.

    2004-03-01

    Previous studies of spectroscopic mapping STS systems indicate that the coupling of mechanical, acoustic, and electrical building noise to experiments can be the limiting noise factor when making measurements. With this in mind we have set out to construct new labs that reduce or eliminate noise from the building. Here we describe the design considerations and techniques used in the construction of new, extremely low vibration lab space, to be used initially for scanning tunneling spectroscopy experiments. The lab space is decoupled from the building by placing it upon 25 ton inertial blocks (30 tons including sound room and equipment) resting on air springs. The experimental apparatus itself rests on another set of air springs. The entire space is surrounded by two nested acoustic rooms. We report on the degree of isolation achieved by these techniques.

  4. New Developments of Broadband Cavity Enhanced Spectroscopic Techniques

    NASA Astrophysics Data System (ADS)

    Walsh, A.; Zhao, D.; Linnartz, H.; Ubachs, W.

    2013-06-01

    In recent years, cavity enhanced spectroscopic techniques, such as cavity ring-down spectroscopy (CRDS), cavity enhanced absorption spectroscopy (CEAS), and broadband cavity enhanced absorption spectroscopy (BBCEAS), have been widely employed as ultra-sensitive methods for the measurement of weak absorptions and in the real-time detection of trace species. In this contribution, we introduce two new cavity enhanced spectroscopic concepts: a) Optomechanical shutter modulated BBCEAS, a variant of BBCEAS capable of measuring optical absorption in pulsed systems with typically low duty cycles. In conventional BBCEAS applications, the latter substantially reduces the signal-to-noise ratio (S/N), consequently also reducing the detection sensitivity. To overcome this, we incorporate a fast optomechanical shutter as a time gate, modulating the detection scheme of BBCEAS and increasing the effective duty cycle reaches a value close to unity. This extends the applications of BBCEAS into pulsed samples and also in time-resolved studies. b) Cavity enhanced self-absorption spectroscopy (CESAS), a new spectroscopic concept capable of studying light emitting matter (plasma, flames, combustion samples) simultaneously in absorption and emission. In CESAS, a sample (plasma, flame or combustion source) is located in an optically stable cavity consisting of two high reflectivity mirrors, and here it acts both as light source and absorbing medium. A high detection sensitivity of weak absorption is reached without the need of an external light source, such as a laser or broadband lamp. The performance is illustrated by the first CESAS result on a supersonically expanding hydrocarbon plasma. We expect CESAS to become a generally applicable analytical tool for real time and in situ diagnostics. A. Walsh, D. Zhao, W. Ubachs, H. Linnartz, J. Phys. Chem. A, {dx.doi.org/10.1021/jp310392n}, in press, 2013. A. Walsh, D. Zhao, H. Linnartz Rev. Sci. Instrum. {84}(2), 021608 2013. A. Walsh, D. Zhao

  5. Rapid identification of single microbes by various Raman spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Rösch, Petra; Harz, Michaela; Schmitt, Michael; Peschke, Klaus-Dieter; Ronneberger, Olaf; Burkhardt, Hans; Motzkus, Hans-Walter; Lankers, Markus; Hofer, Stefan; Thiele, Hans; Popp, Jürgen

    2006-02-01

    A fast and unambiguous identification of microorganisms is necessary not only for medical purposes but also in technical processes such as the production of pharmaceuticals. Conventional microbiological identification methods are based on the morphology and the ability of microbes to grow under different conditions on various cultivation media depending on their biochemical properties. These methods require pure cultures which need cultivation of at least 6 h but normally much longer. Recently also additional methods to identify bacteria are established e.g. mass spectroscopy, polymerase chain reaction (PCR), flow cytometry or fluorescence spectroscopy. Alternative approaches for the identification of microorganisms are vibrational spectroscopic techniques. With Raman spectroscopy a spectroscopic fingerprint of the microorganisms can be achieved. Using UV-resonance Raman spectroscopy (UVRR) macromolecules like DNA/RNA and proteins are resonantly enhanced. With an excitation wavelength of e.g. 244 nm it is possible to determine the ratio of guanine/cytosine to all DNA bases which allows a genotypic identification of microorganisms. The application of UVRR requires a large amount of microorganisms (> 10 6 cells) e.g. at least a micro colony. For the analysis of single cells micro-Raman spectroscopy with an excitation wavelength of 532 nm can be used. Here, the obtained information is from all type of molecules inside the cells which lead to a chemotaxonomic identification. In this contribution we show how wavelength dependent Raman spectroscopy yields significant molecular information applicable for the identification of microorganisms on a single cell level.

  6. Advanced techniques for microwave reflectometry

    SciTech Connect

    Sanchez, J.; Branas, B.; Luna, E. de la; Estrada, T.; Zhuravlev, V. |; Hartfuss, H.J.; Hirsch, M.; Geist, T.; Segovia, J.; Oramas, J.L.

    1994-12-31

    Microwave reflectometry has been applied during the last years as a plasma diagnostic of increasing interest, mainly due to its simplicity, no need for large access ports and low radiation damage of exposed components. Those characteristics make reflectometry an attractive diagnostic for the next generation devices. Systems used either for density profile or density fluctuations have also shown great development, from the original single channel heterodyne to the multichannel homodyne receivers. In the present work we discuss three different advanced reflectometer systems developed by CIEMAT members in collaboration with different institutions. The first one is the broadband heterodyne reflectometer installed on W7AS for density fluctuations measurements. The decoupling of the phase and amplitude of the reflected beam allows for quantitative analysis of the fluctuations. Recent results showing the behavior of the density turbulence during the L-H transition on W7AS are shown. The second system shows how the effect of the turbulence can be used for density profile measurements by reflectometry in situations where the complicated geometry of the waveguides cannot avoid many parasitic reflections. Experiments from the TJ-I tokamak will be shown. Finally, a reflectometer system based on the Amplitude Modulation (AM) technique for density profile measurements is discussed and experimental results from the TJ-I tokamak are shown. The AM system offers the advantage of being almost insensitive to the effect of fluctuations. It is able to take a direct measurement of the time delay of the microwave pulse which propagates to the reflecting layer and is reflected back. In order to achieve fast reconstruction for real time monitoring of the density profile application of Neural Networks algorithms will be presented the method can reduce the computing times by about three orders of magnitude. 10 refs., 10 figs.

  7. Advances in Procedural Techniques - Antegrade

    PubMed Central

    Wilson, William; Spratt, James C.

    2014-01-01

    There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the “hybrid’ approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited “interventional” collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

  8. Advances of vibrational spectroscopic methods in phytomics and bioanalysis.

    PubMed

    Huck, Christian W

    2014-01-01

    During the last couple of years great advances in vibrational spectroscopy including near-infrared (NIR), mid-infrared (MIR), attenuated total reflection (ATR) and imaging and also mapping techniques could be achieved. On the other hand spectral treatment features have improved dramatically allowing filtering out relevant information from spectral data much more efficiently and providing new insights into the biochemical composition. These advances offer new possible quality control strategies in phytomics and enable to get deeper insights into biochemical background in terms of medicinal relevant questions. It is the aim of the present article pointing out the technical and methodological advancements in the NIR and MIR field and to demonstrate the individual methods efficiency by discussing distinct selected applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Advanced spectroscopic analysis of coal surfaces during beneficiation

    SciTech Connect

    McClelland, J.F.; Oh, J.S.

    1989-01-01

    Development work advanced on two new FTIR spectroscopic approaches for measuring coal surface oxidation and on-line infrared spectra of coal. The former FTIR/UV approach used UV induced oxidation to gauge the level of carbonyl forming species present in coal. The latter approach is called Transient Infrared Emission Spectroscopy (TIRES) and uses pulsed surface heating of coal to obtain an emission spectrum which is not distorted by excessive self absorption. In FTIR/UV work oven-oxidized coals were analyzed after 1, 3, and 6 days of exposure to oxygen at 100{degree}C. Spectra of the oven and U induced carbonyl formation overlapped but had somewhat different band shapes indicative of some differences in the two oxidation processes. A TIRES apparatus was constructed using an argon ion laser, rotating sample stage, and FTIR spectrometer. A spectrum was measured of Illinois {number sign}6 coal moving at a velocity of 60 ft/min. which compared favorably with photoacoustic spectrum of the same coal. 4 figs.

  10. The Advanced X-ray Spectroscopic Imaging Observatory

    NASA Astrophysics Data System (ADS)

    Bookbinder, Jay A.; Smith, R.; Garcia, M.; Tananbaum, H.; White, N.; Petre, R.; Ptak, A.; Hornschemeier, A.; Zhang, W.; Bandler, S.; Daelemans, G.; Bautz, M.; Hielmann, R.; McEntaffer, R.; Bregman, J.; Reid, P.

    2012-01-01

    The Advanced X-ray Spectroscopic Imaging Observatory (AXSIO) is a NASA facility class X-ray observatory which can carry out many of the science goals of the International X-ray Observatory as outlined in the NWNH Astro2010 Decadal Survey. Studies of the mission configuration and science reach will inform NASA technology investments over the next several years. The primary science goals will be directly observing the effects of strong gravity in black holes; mapping temperatures, abundances and dynamics in hot gas on scales ranging from the local ISM to galaxy clusters; observing feedback from AGN and star formation in galaxies; finding the missing baryonic matter; and studying the structure of neutron stars. The mission configuration required to achieve these goals builds on the IXO segmented glass optics technology, but with a (shorter)10m focal length. These optics provide 10 arcsec HPD (5 arcsec goal) images and 1m2 of area at 1.25keV and 0.2m2 at 6keV. A new micro-calorimeter configuration provides 2 eV spectral resolution over a central 0.6 arcmin area, and < 5eV over a 4.8 arcmin square extended region. A grating spectrometer provides the low-energy spectroscopy (from 0.3keV to 1.0keV) with spectral resolution of>3000 and an effective area of>1000cm2.

  11. Advanced techniques for ladar sensors

    NASA Astrophysics Data System (ADS)

    Schwartz, William C.; Wangler, Richard J.; Condatore, Lawrence A., Jr.

    1995-06-01

    This paper discusses new techniques for providing a `FLIR like', multi-pixel range receiver for applications of control and guidance by an active LADAR system. The major tradeoffs in developing a LADAR sensor with multi-pixel high resolution capabilities using conventional techniques are large size, high cost, or a slow frame rate. SEO has conceived and is currently developing a new receiver technique using a Charge Coupled Device array element that shows great promise for overcoming all of these drawbacks. Although this technique is a new approach for LADAR sensors, it is a concept that has been used for decades in the receivers of common-module FLIR systems.

  12. Terahertz imaging of metastatic lymph nodes using spectroscopic integration technique

    PubMed Central

    Park, Jae Yeon; Choi, Hyuck Jae; Cheon, Hwayeong; Cho, Seong Whi; Lee, Seungkoo; Son, Joo-Hiuk

    2017-01-01

    Terahertz (THz) imaging was used to differentiate the metastatic states of frozen lymph nodes (LNs) by using spectroscopic integration technique (SIT). The metastatic states were classified into three groups: healthy LNs, completely metastatic LNs, and partially metastatic LNs, which were obtained from three mice without infection and six mice infected with murine melanoma cells for 30 days and 15 days, respectively. Under histological examination, the healthy LNs and completely metastatic LNs were found to have a homogeneous cellular structure but the partially metastatic LNs had interfaces of the melanoma and healthy tissue. THz signals between the experimental groups were not distinguished at room temperature due to high attenuation by water in the tissues. However, a signal gap between the healthy and completely metastatic LNs was detected at freezing temperature. The signal gap could be enhanced by using SIT that is a signal processing method dichotomizing the signal difference between the healthy cells and melanoma cells with their normalized spectral integration. This technique clearly imaged the interfaces in the partially metastatic LNs, which could not be achieved by existing methods using a peak point or spectral value. The image resolution was high enough to recognize a metastatic area of about 0.7 mm size in the partially metastatic LNs. Therefore, this pilot study demonstrated that THz imaging of the frozen specimen using SIT can be used to diagnose the metastatic state of LNs for clinical application. PMID:28271007

  13. Time-resolved infrared spectroscopic techniques as applied to channelrhodopsin

    PubMed Central

    Ritter, Eglof; Puskar, Ljiljana; Bartl, Franz J.; Aziz, Emad F.; Hegemann, Peter; Schade, Ulrich

    2015-01-01

    Among optogenetic tools, channelrhodopsins, the light gated ion channels of the plasma membrane from green algae, play the most important role. Properties like channel selectivity, timing parameters or color can be influenced by the exchange of selected amino acids. Although widely used, in the field of neurosciences for example, there is still little known about their photocycles and the mechanism of ion channel gating and conductance. One of the preferred methods for these studies is infrared spectroscopy since it allows observation of proteins and their function at a molecular level and in near-native environment. The absorption of a photon in channelrhodopsin leads to retinal isomerization within femtoseconds, the conductive states are reached in the microsecond time scale and the return into the fully dark-adapted state may take more than minutes. To be able to cover all these time regimes, a range of different spectroscopical approaches are necessary. This mini-review focuses on time-resolved applications of the infrared technique to study channelrhodopsins and other light triggered proteins. We will discuss the approaches with respect to their suitability to the investigation of channelrhodopsin and related proteins. PMID:26217670

  14. Advanced Spectroscopy Technique for Biomedicine

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Zeng, Haishan

    This chapter presents an overview of the applications of optical spectroscopy in biomedicine. We focus on the optical design aspects of advanced biomedical spectroscopy systems, Raman spectroscopy system in particular. Detailed components and system integration are provided. As examples, two real-time in vivo Raman spectroscopy systems, one for skin cancer detection and the other for endoscopic lung cancer detection, and an in vivo confocal Raman spectroscopy system for skin assessment are presented. The applications of Raman spectroscopy in cancer diagnosis of the skin, lung, colon, oral cavity, gastrointestinal tract, breast, and cervix are summarized.

  15. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  16. Advanced Geophysical Environmental Simulation Techniques

    DTIC Science & Technology

    2007-11-02

    cloud property retrieval algorithms for processing of large multiple-satellite data sets; development and application of improved cloud -phase and... cloud optical property retrieval algorithms; investigation of techniques potentially applicable for retrieval of cloud spatial properties from very...14. SUBJECT TERMS cirrus cloud retrieval satellite meteorology polar-orbiting geostationary 15. NUMBER OF PAGES 16. PRICE CODE 17. SECURITY

  17. Advanced Intellect-Augmentation Techniques.

    ERIC Educational Resources Information Center

    Engelbart, D. C.

    This progress report covers a two-year project which is part of a program that is exploring the value of computer aids in augmenting human intellectual capability. The background and nature of the program, its resources, and the activities it has undertaken are outlined. User experience in applying augmentation tools and techniques to various…

  18. Advanced intellect-augmentation techniques

    NASA Technical Reports Server (NTRS)

    Engelbart, D. C.

    1972-01-01

    User experience in applying our augmentation tools and techniques to various normal working tasks within our center is described so as to convey a subjective impression of what it is like to work in an augmented environment. It is concluded that working-support, computer-aid systems for augmenting individuals and teams, are undoubtedly going to be widely developed and used. A very special role in this development is seen for multi-access computer networks.

  19. Advanced measurement techniques, part 1

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.; Carraway, Debra L.; Manuel, Gregory S.; Croom, Cynthia C.

    1987-01-01

    In modern laminar flow flight and wind tunnel research, it is important to understand the specific cause(s) of laminar to turbulent boundary layer transition. Such information is crucial to the exploration of the limits of practical application of laminar flow for drag reduction on aircraft. The process of transition involves both the possible modes of disturbance growth, and the environmental conditioning of the instabilities by freestream or surface conditions. The possible modes of disturbance growth include viscous, inviscid, and modes which may bypass these natural ones. Theory provides information on the possible modes of disturbance amplification, but experimentation must be relied upon to determine which of those modes actually dominates the transition process in a given environment. The results to date of research on advanced devices and methods used for the study of transition phenomena in the subsonic and transonic flight and wind tunnel environments are presented.

  20. Septoplasty: Basic and Advanced Techniques.

    PubMed

    Most, Sam P; Rudy, Shannon F

    2017-05-01

    Nasal septal deviation is a prevalent problem that can have significant quality of life ramifications. Septoplasty is commonly performed to provide qualitative and quantitative benefit to those with nasal obstruction owing to septal deviation. Although a standard, basic technique is often adequate for individuals with mild to moderate mid to posterior septal deviation, unique challenges arise with caudal septal deviation. Herein, multiple strategies that attempt to address anterior septal deviation are discussed. Anterior septal reconstruction has been shown to be a safe and effective means by which to address severe caudal septal deviation and long-term reduction in preoperative symptoms.

  1. New Techniques for the Next Far Ultraviolet Spectroscopic Mission

    NASA Technical Reports Server (NTRS)

    Green, James C.; Wilkinson, Erik

    2005-01-01

    The Far Ultraviolet Spectroscopic Explorer (FUSE) has been a great success, and has addressed many critical scientific questions (Moos, et al, 2000). However, it has also highlighted the need for even more powerful instrumentation in the 900- 1200 A, regime. In particular, significantly increased effective area will permit the pursuit of additional scientific programs currently impractical or impossible with FUSE. It is unlikely that FUSE will last more than a few more years. Nor is it likely that any large scale UV-optical follow-on to HST (such as SUVO) will include the 900-1200 A, bandpass. However, FUSE remains well oversubscribed and continues to perform excellent science. Therefore, a MIDEX class mission in the next 4-6 years that could significantly improve on the FUSE capabilities would be a powerful scientific tool that would be of great utility to the astronomical community. It would open up new scientific programs if it can improve on the sensitivity of FUSE by an order of magnitude. We have identified a powerful technique for efficient, high-resolution spectroscopy in the FUV (and possibly the EUV) that may provide exactly what is needed for such a mission To achieve a factor of 10 improvement in effective area, we propose using a large (meter class), low-cost, grazing incidence metal optics. This would produced in a manner similar to the EUVE mirrors (Green, et al, 1986), using diamond turning to create the optical figure followed by uncontrolled polishing to achieve a high quality surface. This process will introduce significant figure errors that will degrade the image quality. However, if a holographic grating is employed, which has utilized the actual telescope in the recording geometry, all wavefront errors will be automatically corrected in the end-to-end spectrometer, and high quality spectroscopy will be possible with low quality (and low-cost) optics. In this way a MIDEX class FUSE can be proposed with 10 times the effective area of the

  2. Advanced techniques to prepare seed to sow

    Treesearch

    Robert P. Karrfalt

    2013-01-01

    This paper reviews research on improving the basic technique of cold stratification for tree and shrub seeds. Advanced stratification techniques include long stratification, stratification re-dry, or multiple cycles of warm-cold stratification. Research demonstrates that careful regulation of moisture levels and lengthening the stratification period have produced a...

  3. Advanced sialoendoscopy techniques, rare findings, and complications.

    PubMed

    Nahlieli, Oded

    2009-12-01

    This article presents and discusses advanced minimally invasive sialoendoscopy and combined methods: endoscopy, endoscopic-assisted techniques, and external-lithotripsy combined procedures. It also presents rare situations and complications encountered during sialoendoscopic procedures. Sialoendoscopy is a relatively novel technique, which adds significant new dimensions to the surgeon's armamentarium for management of inflammatory salivary gland diseases. Because of the rapid development in minimally invasive surgical techniques, surgeons are capable of more facilely treating complicated inflammatory and obstructive conditions of the salivary glands.

  4. Hybrid mesh generation using advancing reduction technique

    USDA-ARS?s Scientific Manuscript database

    This study presents an extension of the application of the advancing reduction technique to the hybrid mesh generation. The proposed algorithm is based on a pre-generated rectangle mesh (RM) with a certain orientation. The intersection points between the two sets of perpendicular mesh lines in RM an...

  5. Advanced Techniques Using Contrast Media in Neuroimaging

    PubMed Central

    Ferré, Jean-Christophe; Shiroishi, Mark S.; Law, Meng

    2012-01-01

    This article presents an overview of advanced MRI techniques using contrast media in neuroimaging, focusing on T2*-weighted dynamic susceptibility contrast MR imaging (DSC-MRI) and T1-weighted dynamic contrast-enhanced MR imaging (DCE-MRI). Image acquisition and data processing methods as well as their clinical application in brain tumors, stroke, dementia and multiple sclerosis are discussed. PMID:23088946

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

    PubMed

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

    2015-01-01

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

  7. Advances in spectroscopic methods for quantifying soil carbon

    USGS Publications Warehouse

    Liebig, Mark; Franzluebbers, Alan J.; Follett, Ronald F.; Hively, W. Dean; Reeves, James B.; McCarty, Gregory W.; Calderon, Francisco

    2012-01-01

    The gold standard for soil C determination is combustion. However, this method requires expensive consumables, is limited to the determination of the total carbon and in the number of samples which can be processed (~100/d). With increased interest in soil C sequestration, faster methods are needed. Thus, interest in methods based on diffuse reflectance spectroscopy in the visible, near-infrared or mid-infrared ranges using either proximal or remote sensing. These methods have the ability to analyze more samples (2 to 3X/d) or huge areas (imagery) and do multiple analytes simultaneously, but require calibrations relating spectral and reference data and have specific problems, i.e., remote sensing is capable of scanning entire watersheds, thus reducing the sampling needed, but is limiting to the surface layer of tilled soils and by difficulty in obtaining proper calibration reference values. The objective of this discussion is the present state of spectroscopic methods for soil C determination.

  8. Advances in spectroscopic methods for quantifying soil carbon

    USGS Publications Warehouse

    Reeves, James B.; McCarty, Gregory W.; Calderon, Francisco; Hively, W. Dean

    2012-01-01

    The current gold standard for soil carbon (C) determination is elemental C analysis using dry combustion. However, this method requires expensive consumables, is limited by the number of samples that can be processed (~100/d), and is restricted to the determination of total carbon. With increased interest in soil C sequestration, faster methods of analysis are needed, and there is growing interest in methods based on diffuse reflectance spectroscopy in the visible, near-infrared or mid-infrared spectral ranges. These spectral methods can decrease analytical requirements and speed sample processing, be applied to large landscape areas using remote sensing imagery, and be used to predict multiple analytes simultaneously. However, the methods require localized calibrations to establish the relationship between spectral data and reference analytical data, and also have additional, specific problems. For example, remote sensing is capable of scanning entire watersheds for soil carbon content but is limited to the surface layer of tilled soils and may require difficult and extensive field sampling to obtain proper localized calibration reference values. The objective of this chapter is to discuss the present state of spectroscopic methods for determination of soil carbon.

  9. Investigation into Spectroscopic Techniques for Thermal Barrier Coating Spall Detection

    NASA Technical Reports Server (NTRS)

    deGroot, Wim; Opila, Beth

    2001-01-01

    Spectroscopic methods are proposed for detection of thermal barrier coating (TBC) spallation from engine hot zone components. These methods include absorption and emission of airborne marker species originally embedded in the TBC bond coat. In this study, candidate marker materials for this application were evaluated. Thermochemical analysis of candidate marker materials combined with additional constraints such as toxicity and uniqueness to engine environment, provided a short list of four potential species: platinum, copper oxide, zinc oxide. and indium. The melting point of indium was considered to be too low for serious consideration. The other three candidate marker materials, platinum, copper oxide, and zinc oxide were placed in a high temperature furnace and emission and absorption properties were measured over a temperature range from 800-1400 C and a spectral range from 250 to 18000 nm. Platinum did not provide the desired response, likely due to the low vapor Pressure of the metallic species and the low absorption of the oxide species. It was also found, however. that platinum caused a broadening of the carbon dioxide absorption at 4300 nm. The nature of this effect is not known. Absorption and emission caused by sodium and potassium impurities in the platinum were found in the platinum tests. Zinc oxide did not provide the desired response, again, most likely due to the low vapor pressure of the metallic species and the low absorption of the oxide species. Copper oxide generated two strongly temperature dependent absorption peaks at 324.8 and 327.4 nm. The melting point of copper oxide was determined to be too low for serious consideration as marker material.

  10. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  11. Advanced techniques in echocardiography in small animals.

    PubMed

    Chetboul, Valérie

    2010-07-01

    Transthoracic echocardiography has become a major imaging tool for the diagnosis and management of canine and feline cardiovascular diseases. During the last decade, more recent advances in ultrasound technology with the introduction of newer imaging modalities, such as tissue Doppler imaging, strain and strain rate imaging, and 2-dimensional speckle tracking echocardiography, have provided new parameters to assess myocardial performance, including regional myocardial velocities and deformation, ventricular twist, and mechanical synchrony. An outline of these 4 recent ultrasound techniques, their impact on the understanding of right and left ventricular function in small animals, and their application in research and clinical settings are given in this article.

  12. Basic concepts of advanced MRI techniques.

    PubMed

    Pagani, Elisabetta; Bizzi, Alberto; Di Salle, Francesco; De Stefano, Nicola; Filippi, Massimo

    2008-10-01

    An overview is given of magnetic resonance (MR) techniques sensitized to diffusion, flow, magnetization transfer effect, and local field inhomogeneities induced by physiological changes, that can be viewed, in the clinical practice, as advanced because of their challenging implementation and interpretation. These techniques are known as diffusion-weighted, perfusion, magnetization transfer, functional MRI and MR spectroscopy. An important issue is that they can provide quantitative estimates of structural and functional characteristics that are below the voxel resolution. This review does not deal with the basic concepts of the MR physics and the description of the available acquisition and postprocessing methods, but hopefully provides an adequate background to readers and hence facilitate the understanding of the following clinical contributions.

  13. Optical Emission Spectroscopic Techniques for Low Electron Density Diagnostics

    SciTech Connect

    Ivkovic, M.

    2006-12-01

    This paper comprises an analysis of optical emission spectroscopy (OES) techniques and results of their application for diagnostics of middle and low electron densities in low temperature plasmas. The following OES diagnostic techniques based on: 1) line merging along spectral line series, 2) use of line shapes and Stark halfwidths of hydrogen Balmer lines, 3) line shape of helium lines with forbidden components and 4) use of molecular nitrogen bandhead intensities are studied, discussed, tested and applied and in some cases ugraded for electron density measurements. The overall comparative analysis is performed also.

  14. Advanced flow MRI: emerging techniques and applications.

    PubMed

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented.

  15. Advanced flow MRI: emerging techniques and applications

    PubMed Central

    Markl, M.; Schnell, S.; Wu, C.; Bollache, E.; Jarvis, K.; Barker, A. J.; Robinson, J. D.; Rigsby, C. K.

    2016-01-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented. PMID:26944696

  16. Advanced Bode Plot Techniques for Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The Bode plot, displayed as either impedance or admittance versus frequency, is the most basic test used by ultrasonic transducer designers. With simplicity and ease-of-use, Bode plots are ideal for baseline comparisons such as spacing of parasitic modes or impedance, but quite often the subtleties that manifest as poor process control are hard to interpret or are nonexistence. In-process testing of transducers is time consuming for quantifying statistical aberrations, and assessments made indirectly via the workpiece are difficult. This research investigates the use of advanced Bode plot techniques to compare ultrasonic transducers with known "good" and known "bad" process performance, with the goal of a-priori process assessment. These advanced techniques expand from the basic constant voltage versus frequency sweep to include constant current and constant velocity interrogated locally on transducer or tool; they also include up and down directional frequency sweeps to quantify hysteresis effects like jumping and dropping phenomena. The investigation focuses solely on the common PZT8 piezoelectric material used with welding transducers for semiconductor wire bonding. Several metrics are investigated such as impedance, displacement/current gain, velocity/current gain, displacement/voltage gain and velocity/voltage gain. The experimental and theoretical research methods include Bode plots, admittance loops, laser vibrometry and coupled-field finite element analysis.

  17. Advanced sperm selection techniques for assisted reproduction.

    PubMed

    McDowell, Simon; Kroon, Ben; Ford, Emily; Hook, Ysanne; Glujovsky, Demián; Yazdani, Anusch

    2014-10-28

    Assisted reproductive technologies (ART) such as in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) bring together gametes outside of the body to enhance the probability of fertilisation and pregnancy. Advanced sperm selection techniques are increasingly being employed in ART, most commonly in cycles utilising ICSI. Advanced sperm selection techniques are thought to improve the chance that structurally intact and mature sperm with high DNA integrity are selected for fertilisation. Advanced sperm selection strategies include selection according to surface charge; sperm apoptosis; sperm birefringence; ability to bind to hyaluronic acid; and sperm morphology under ultra-high magnification. These techniques theoretically improve ART outcomes. To evaluate the impact of advanced sperm selection techniques on ART outcomes. Systematic search of electronic databases (Cochrane Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Latin American and Caribbean Health Science Information Database (LILACS)), trials registers (ClinicalTrials.gov, Current Controlled Trials, World Health Organization International Clinical Trials Registry Platform), conference abstracts (Web of Knowledge) and grey literature (OpenGrey) for relevant randomised controlled trials. We handsearched the reference lists of included studies and similar reviews. The search was conducted in May 2014. We included randomised controlled trials (RCTs) comparing an advanced sperm selection technique versus standard IVF or ICSI or versus another advanced sperm selection technique. We excluded studies of sperm selection using ultra-high magnification (intracytoplasmic morphologically selected sperm injection, or IMSI), as they are the subject of a separate Cochrane review. Quasi-randomised and pseudo-randomised trials were

  18. Use of different spectroscopic techniques in the analysis of Roman age wall paintings.

    PubMed

    Agnoli, Francesca; Calliari, Irene; Mazzocchin, Gian-Antonio

    2007-01-01

    In this paper the analysis of samples of Roman age wall paintings coming from: Pordenone, Vicenza and Verona is carried out by using three different techniques: energy dispersive x-rays spectroscopy (EDS), x-rays fluorescence (XRF) and proton induced x-rays emission (PIXE). The features of the three spectroscopic techniques in the analysis of samples of archaeological interest are discussed. The studied pigments were: cinnabar, yellow ochre, green earth, Egyptian blue and carbon black.

  19. 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.

  20. Studies of tropical fruit ripening using three different spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Huang, Jing; Li, Tianqi; Wu, Xiuxiang; Svanberg, Sune; Svanberg, Katarina

    2014-06-01

    We present a noninvasive method to study fruit ripening. The method is based on the combination of reflectance and fluorescence spectroscopies, as well as gas in scattering media absorption spectroscopy (GASMAS). Chlorophyll and oxygen are two of the most important constituents in the fruit ripening process. Reflectance and fluorescence spectroscopies were used to quantify the changes of chlorophyll and other chromophores. GASMAS, based on tunable diode laser absorption spectroscopy, was used to measure free molecular oxygen in the fruit tissue at 760 nm, based on the fact that the free gases have much narrower spectral imprints than those of solid materials. The fruit maturation and ripening processes can be followed by studying the changes of chlorophyll and oxygen contents with these three techniques.

  1. Fast magnetic resonance spectroscopic imaging techniques in human brain- applications in multiple sclerosis.

    PubMed

    Al-Iedani, Oun; Lechner-Scott, Jeannette; Ribbons, Karen; Ramadan, Saadallah

    2017-02-28

    Multi voxel magnetic resonance spectroscopic imaging (MRSI) is an important imaging tool that combines imaging and spectroscopic techniques. MRSI of the human brain has been beneficially applied to different clinical applications in neurology, particularly in neurooncology but also in multiple sclerosis, stroke and epilepsy. However, a major challenge in conventional MRSI is the longer acquisition time required for adequate signal to be collected. Fast MRSI of the brain in vivo is an alternative approach to reduce scanning time and make MRSI more clinically suitable.Fast MRSI can be categorised into spiral, echo-planar, parallel and turbo imaging techniques, each with its own strengths. After a brief introduction on the basics of non-invasive examination ((1)H-MRS) and localization techniques principles, different fast MRSI techniques will be discussed from their initial development to the recent innovations with particular emphasis on their capacity to record neurochemical changes in the brain in a variety of pathologies.The clinical applications of whole brain fast spectroscopic techniques, can assist in the assessment of neurochemical changes in the human brain and help in understanding the roles they play in disease. To give a good example of the utilities of these techniques in clinical context, MRSI application in multiple sclerosis was chosen. The available up to date and relevant literature is discussed and an outline of future research is presented.

  2. Advanced techniques in current signature analysis

    NASA Astrophysics Data System (ADS)

    Smith, S. F.; Castleberry, K. N.

    1992-02-01

    In general, both ac and dc motors can be characterized as weakly nonlinear systems, in which both linear and nonlinear effects occur simultaneously. Fortunately, the nonlinearities are generally well behaved and understood and can be handled via several standard mathematical techniques already well developed in the systems modeling area; examples are piecewise linear approximations and Volterra series representations. Field measurements of numerous motors and motor-driven systems confirm the rather complex nature of motor current spectra and illustrate both linear and nonlinear effects (including line harmonics and modulation components). Although previous current signature analysis (CSA) work at Oak Ridge and other sites has principally focused on the modulation mechanisms and detection methods (AM, PM, and FM), more recent studies have been conducted on linear spectral components (those appearing in the electric current at their actual frequencies and not as modulation sidebands). For example, large axial-flow compressors (approximately 3300 hp) in the US gaseous diffusion uranium enrichment plants exhibit running-speed (approximately 20 Hz) and high-frequency vibrational information (greater than 1 kHz) in their motor current spectra. Several signal-processing techniques developed to facilitate analysis of these components, including specialized filtering schemes, are presented. Finally, concepts for the designs of advanced digitally based CSA units are offered, which should serve to foster the development of much more computationally capable 'smart' CSA instrumentation in the next several years.

  3. Advanced techniques for computer-controlled polishing

    NASA Astrophysics Data System (ADS)

    Schinhaerl, Markus; Stamp, Richard; Pitschke, Elmar; Rascher, Rolf; Smith, Lyndon; Smith, Gordon; Geiss, Andreas; Sperber, Peter

    2008-08-01

    Computer-controlled polishing has introduced determinism into the finishing of high-quality surfaces, for example those used as optical interfaces. Computer-controlled polishing may overcome many of the disadvantages of traditional polishing techniques. The polishing procedure is computed in terms of the surface error-profile and the material removal characteristic of the polishing tool, the influence function. Determinism and predictability not only enable more economical manufacture but also facilitate considerably increased processing accuracy. However, there are several disadvantages that serve to limit the capabilities of computer-controlled polishing, many of these are considered to be issues associated with determination of the influence function. Magnetorheological finishing has been investigated and various new techniques and approaches that dramatically enhance the potential as well as the economics of computer-controlled polishing have been developed and verified experimentally. Recent developments and advancements in computer-controlled polishing are discussed. The generic results of this research may be used in a wide variety of alternative applications in which controlled material removal is employed to achieve a desired surface specification, ranging from surface treatment processes in technical disciplines, to manipulation of biological surface textures in medical technologies.

  4. Inverse lithography technique for advanced CMOS nodes

    NASA Astrophysics Data System (ADS)

    Villaret, Alexandre; Tritchkov, Alexander; Entradas, Jorge; Yesilada, Emek

    2013-04-01

    Resolution Enhancement Techniques have continuously improved over the last decade, driven by the ever growing constraints of lithography process. Despite the large number of RET applied, some hotspot configurations remain challenging for advanced nodes due to aggressive design rules. Inverse Lithography Technique (ILT) is evaluated here as a substitute to the dense OPC baseline. Indeed ILT has been known for several years for its near-to-ideal mask quality, while also being potentially more time consuming in terms of OPC run and mask processing. We chose to evaluate Mentor Graphics' ILT engine "pxOPCTM" on both lines and via hotspot configurations. These hotspots were extracted from real 28nm test cases where the dense OPC solution is not satisfactory. For both layer types, the reference OPC consists of a dense OPC engine coupled to rule-based and/or model-based assist generation method. The same CM1 model is used for the reference and the ILT OPC. ILT quality improvement is presented through Optical Rule Check (ORC) results with various adequate detectors. Several mask manufacturing rule constraints (MRC) are considered for the ILT solution and their impact on process ability is checked after mask processing. A hybrid OPC approach allowing localized ILT usage is presented in order to optimize both quality and runtime. A real mask is prepared and fabricated with this method. Finally, results analyzed on silicon are presented to compare localized ILT to reference dense OPC.

  5. Advanced Imaging Techniques for Multiphase Flows Analysis

    NASA Astrophysics Data System (ADS)

    Amoresano, A.; Langella, G.; Di Santo, M.; Iodice, P.

    2017-08-01

    Advanced numerical techniques, such as fuzzy logic and neural networks have been applied in this work to digital images acquired on two applications, a centrifugal pump and a stationary spray in order to define, in a stochastic way, the gas-liquid interface evolution. Starting from the numeric matrix representing the image it is possible to characterize geometrical parameters and the time evolution of the jet. The algorithm used works with the fuzzy logic concept to binarize the chromatist of the pixels, depending them, by using the difference of the light scattering for the gas and the liquid phase.. Starting from a primary fixed threshold, the applied technique, can select the ‘gas’ pixel from the ‘liquid’ pixel and so it is possible define the first most probably boundary lines of the spray. Acquiring continuously the images, fixing a frame rate, a most fine threshold can be select and, at the limit, the most probably geometrical parameters of the jet can be detected.

  6. Advanced techniques in current signature analysis

    SciTech Connect

    Smith, S.F.; Castleberry, K.N.

    1992-03-01

    In general, both ac and dc motors can be characterized as weakly nonlinear systems, in which both linear and nonlinear effects occur simultaneously. Fortunately, the nonlinearities are generally well behaved and understood and an be handled via several standard mathematical techniques already well developed in the systems modeling area; examples are piecewise linear approximations and Volterra series representations. Field measurements of numerous motors and motor-driven systems confirm the rather complex nature of motor current spectra and illustrate both linear and nonlinear effects (including line harmonics and modulation components). Although previous current signature analysis (CSA) work at Oak Ridge and other sites has principally focused on the modulation mechanisms and detection methods (AM, PM, and FM), more recent studies have been conducted on linear spectral components (those appearing in the electric current at their actual frequencies and not as modulation sidebands). For example, large axial-flow compressors ({approximately}3300 hp) in the US gaseous diffusion uranium enrichment plants exhibit running-speed ({approximately}20 Hz) and high-frequency vibrational information (>1 kHz) in their motor current spectra. Several signal-processing techniques developed to facilitate analysis of these components, including specialized filtering schemes, are presented. Finally, concepts for the designs of advanced digitally based CSA units are offered, which should serve to foster the development of much more computationally capable ``smart`` CSA instrumentation in the next several years. 3 refs.

  7. Advanced Synchrotron Techniques at High Pressure Collaborative Access Team (HPCAT)

    NASA Astrophysics Data System (ADS)

    Shen, G.; Sinogeikin, S. V.; Chow, P.; Kono, Y.; Meng, Y.; Park, C.; Popov, D.; Rod, E.; Smith, J.; Xiao, Y.; Mao, H.

    2012-12-01

    High Pressure Collaborative Access Team (HPCAT) is dedicated to advancing cutting-edge, multidisciplinary, high-pressure science and technology using synchrotron radiation at Sector 16 of the Advanced Photon Source (APS) of Argonne National Laboratory. At HPCAT an array of novel x-ray diffraction and spectroscopic techniques has been integrated with high pressure and extreme temperature instrumentation for studies of structure and materials properties at extreme conditions.. HPCAT consists of four active independent beamlines performing a large range of various experiments at extreme conditions. 16BM-B beamline is dedicated to energy dispersive and white Laue X-ray diffraction. The majority of experiments are performed with a Paris-Edinburgh large volume press (to 7GPa and 2500K) and include amorphous and liquid structure measurement, white beam radiography, elastic sound wave velocity measurement of amorphous solid materials, with viscosity and density measurement of liquid being under development. 16BM-D is a monochromatic diffraction beamline for powder and single crystal diffraction at high pressure and high (resistive heating) / low (cryostats) temperature. The additional capabilities include high-resolution powder diffraction and x-ray absorption near edge structure (XANES) spectroscopy. The insertion device beamline of HPCAT has two undulators in canted mode (operating independently) and LN cooled Si monochromators capable of providing a large range of energies. 16IDB is a microdiffraction beamline mainly focusing on high-pressure powder and single crystal diffraction in DAC at high temperatures (double-sided laser heating and resistive heating) and low temperature (various cryostats). The modern instrumentation allows high-quality diffraction at megabar pressures from light element, fast experiments with pulsed laser heating, fast dynamic experiments with Pilatus detector, and so on. 16ID-D beamline is dedicated to x-ray scattering and spectroscopy research

  8. Non-Destructive and rapid evaluation of staple foods quality by using spectroscopic techniques: A review.

    PubMed

    Su, Wen-Hao; He, Hong-Ju; Sun, Da-Wen

    2017-03-24

    Staple foods, including cereals, legumes, and root/tuber crops, dominate the daily diet of humans by providing valuable proteins, starch, oils, minerals, and vitamins. Quality evaluation of staple foods is primarily carried out on sensory (e.g. external defect, color), adulteration (e.g. species, origin), chemical (e.g. starch, proteins), mycotoxin (e.g. Fusarium toxin, aflatoxin), parasitic infection (e.g. weevil, beetle), and internal physiological (e.g. hollow heart, black heart) aspects. Conventional methods for the quality assessment of staple foods are always laborious, destructive, and time-consuming. Requirements for online monitoring of staple foods have been proposed to encourage the development of rapid, reagentless, and noninvasive techniques. Spectroscopic techniques, such as visible-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance spectroscopy, and spectral imaging, have been introduced as promising analytical tools and applied for the quality evaluation of staple foods. This review summarizes the recent applications and progress of such spectroscopic techniques in determining various qualities of staple foods. Besides, challenges and future trends of these spectroscopic techniques are also presented.

  9. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

  10. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

  11. Application of spectroscopic techniques for the study of paper documents: A survey

    NASA Astrophysics Data System (ADS)

    Manso, M.; Carvalho, M. L.

    2009-06-01

    For many centuries paper was the main material for recording cultural achievements all over the world. Paper is mostly made from cellulose with small amounts of organic and inorganic additives, which allow its identification and characterization and may also contribute to its degradation. Prior to 1850, paper was made entirely from rags, using hemp, flax and cotton fibres. After this period, due to the enormous increase in demand, wood pulp began to be commonly used as raw material, resulting in rapid degradation of paper. Spectroscopic techniques represent one of the most powerful tools to investigate the constituents of paper documents in order to establish its identification and its state of degradation. This review describes the application of selected spectroscopic techniques used for paper characterization and conservation. The spectroscopic techniques that have been used and will be reviewed include: Fourier-Transform Infrared spectroscopy, Raman spectroscopy, Nuclear Magnetic Resonance spectroscopy, X-Ray spectroscopy, Laser-based Spectroscopy, Inductively Coupled Mass Spectroscopy, Laser ablation, Atomic Absorption Spectroscopy and X-Ray Photoelectron Spectroscopy.

  12. Measurement of optical nonlinearity by antiresonant ring interferometric nonlinear spectroscopic (ARINS) technique

    NASA Astrophysics Data System (ADS)

    Bhushan, B.

    2016-08-01

    We have reported the measurement of third-order optical nonlinearity by antiresonant ring interferometric nonlinear spectroscopic (ARINS) technique and discussed its usefulness over other popular measuring techniques such as Z-scan, degenerate four wave mixing (DFWM) and third harmonic generation (THG). The measurement has been simulated theoretically by taking different numerical values as well as sign of δ, which is a key parameter of ARINS. The technique has been benchmarked using toluene and the theoretical simulation has been substantiated experimentally by measuring the nonlinear optical coefficients ( n 2 and β) of two different samples. The disadvantages of the technique have also been discussed. However, a number of advantages of ARINS override its disadvantages and therefore, ARINS may be preferred over other measuring techniques for the measurement of nonlinear optical parameters.

  13. Novel Infrared Coherent Sources and Techniques for Spectroscopic Test of Fundamental Physics Principles

    NASA Astrophysics Data System (ADS)

    Pastor, P. Cancio; Galli, I.; Giusfredi, G.; Mazzotti, D.; De Natale, P.

    2013-06-01

    Recent achievements in high sensitivity and precision molecular spectroscopy in the mid-IR open new perspectives for experiments looking for possible violations of the basic postulates in quantum mechanics or quantum electro-dynamics in simple molecular systems. A new generation of hybrid infrared sources, including a direct link to optical frequency comb synthesizers (OFCSs) is under development. They provide metrological frequency precision and sensitivities that have achieved record levels of tens of parts-per-quadrillion when appropriate spectroscopic techniques are implemented. Such very recent developments will be reviewed. An example of possible application to the test of fundamental principles is attacking the symmetrization postulate (SP). Actually, the requirement of symmetry of the wave function under exchange of identical particles has a striking demonstration in the spectra of molecules including identical nuclei. The basic idea of the spectroscopic tests is to search with extremely high sensitivity for (weak) molecular lines involving the forbidden states. Since the early test of SP violation in bosonic particles, ^{12}C^{16}O_2 molecule has been considered a playground system. An upper limit of 10^{-11} to such violation was measured more than one decade ago by our group. The recent developed spectroscopic technique^{d,e} measured a minimum detected CO_2 gas pressures, in a 1-Hz bandwidth, of a few tens of femtobar, which could improve the previous test by more than two orders of magnitude. Progress in high sensitivity spectroscopic measurements in view of new violation tests will be reviewed, to investigate molecules with two and also three identical nuclei, like SO_3 and NH_3. I. Galli et al., Opt. Lett. 35, 3616 (2010). I. Ricciardi et al., Opt. Express 20, 9178 (2012). S. Borri, et al., Opt. Lett. 37, 1011 (2012). G. Giusfredi et al., Phys. Rev. Lett. 104, 110801(2010). I. Galli et al., Phys. Rev. Lett. 107, 270802 (2011). D. Mazzotti et al

  14. The role of simulation chambers in the development of spectroscopic techniques: campaigns at EUPHORE

    NASA Astrophysics Data System (ADS)

    Ródenas, Milagros; Muñoz, Amalia; Euphore Team

    2016-04-01

    Simulation chambers represent a very useful tool for the study of chemical reactions and their products, but also to characterize instruments. The development of spectroscopic techniques throughout the last decades has benefited from tests and intercomparison exercises carried out in chambers. In fact, instruments can be exposed to various controlled atmospheric scenarios that account for different environmental conditions, eliminating the uncertainties associated to fluctuations of the air mass, which must be taken into account when extrapolating results to the real conditions. Hence, a given instrument can be characterized by assessing its precision, accuracy, detection limits, time response and potential interferences in the presence of other chemical compounds, aerosols, etc. This implies that the instrument can be calibrated and validated, which allows to enhance the features of the instrument. Moreover, chambers are also the scenario of intercomparison trials, permitting multiple instruments to sample from the same well-mixed air mass simultaneously. An overview of different campaigns to characterize and/or intercompare spectroscopic techniques that have taken place in simulation chambers will be given; in particular, those carried out at EUPHORE (two twin domes, 200 m3 each, Spain), where various intercomparison exercises have been deployed under the frame of European projects (e.g. TOXIC, FIONA, PSOA campaigns supported by EUROCHAMP-II). With the common aim of measuring given compounds (e.g. HONO, NO2, OH, glyoxal, m-glyoxal, etc), an important number of spectroscopic instruments and institutions have been involved in chamber experiments, having the chance to intercompare among them and also with other non-spectroscopic systems (e.g. monitors, cromatographs, etc) or model simulations.

  15. Bringing Advanced Computational Techniques to Energy Research

    SciTech Connect

    Mitchell, Julie C

    2012-11-17

    Please find attached our final technical report for the BACTER Institute award. BACTER was created as a graduate and postdoctoral training program for the advancement of computational biology applied to questions of relevance to bioenergy research.

  16. Glucose Oxidase Adsorption on Sequential Adsorbed Polyelectrolyte Films Studied by Spectroscopic Techniques

    NASA Astrophysics Data System (ADS)

    Tristán, Ferdinando; Solís, Araceli; Palestino, Gabriela; Gergely, Csilla; Cuisinier, Frédéric; Pérez, Elías

    2005-04-01

    The adsorption of Glucose Oxidase (GOX) on layers of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) deposited on Sequentially Adsorbed Polyelectrolyte Films (SAPFs) were studied by three different spectroscopic techniques. These techniques are: Optical Wave Light Spectroscopy (OWLS) to measure surface density; Fluorescence Resonance Energy Transfer (FRET) to verify the adsorption of GOX on the surface; and Fourier Transform Infrared Spectroscopy in Attenuated Total Reflection mode (FTIR-HATR) to inspect local structure of polyelectrolytes and GOX. Two positive and two negative polyelectrolytes are used: Cationic poly(ethyleneimine) (PEI) and poly(allylamine hydrochloride) (PAH) and anionic poly(sodium 4-styrene sulfonate) (PSS) and poly(acrylic acid) (PAA). These spectroscopic techniques do not require any labeling for GOX or SAPFs, specifically GOX and PSS are naturally fluorescent and are used as a couple donor-acceptor for the FRET technique. The SAPFs are formed by a (PEI)-(PSS/PAH)2 film followed by (PAA/PAH)n bilayers. GOX is finally deposited on top of SAPFs at different values of n (n=1..5). Our results show that GOX is adsorbed on positive ended SAPFs forming a monolayer. Contrary, GOX adsorption is not observed on negative ended film polyelectrolyte. GOX stability was tested adding a positive and a negative polyelectrolyte after GOX adsorption. Protein is partially removed by PAH and PAA, with lesser force by PAA.

  17. Noninvasive Intracranial Pressure Monitoring Using Advanced Machine Learning Techniques

    DTIC Science & Technology

    2013-11-01

    This project explored the use of advanced machine learning techniques to noninvasively estimate real-time intracranial pressure (ICP) in traumatic...brain injury patients from continuous electronic physiological monitoring data. We hypothesized that advanced machine learning techniques could process...provide a valid analytic platform for the noninvasive monitoring of ICP for defined periods and clinical needs. We developed a machine learning algorithm

  18. Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control

    SciTech Connect

    Czerwinski, Kenneth; Weck, Phil

    2013-09-13

    Ultraviolet–visible spectroscopy (UV–Visible) and time-resolved laser fluorescence spectroscopy (TRLFS) optical techniques can permit on-line analysis of actinide elements in a solvent extraction process in real time. These techniques have been used for measuring actinide speciation and concentration under laboratory conditions and are easily adaptable to multiple sampling geometries, such as dip probes, fiber-optic sample cells, and flow-through cell geometries. To fully exploit these techniques, researchers must determine the fundamental speciation of target actinides and the resulting influence on spectroscopic properties. Detection limits, process conditions, and speciation of key actinide components can be established and utilized in a range of areas, particularly those related to materials accountability and process control. Through this project, researchers will develop tools and spectroscopic techniques to evaluate solution extraction conditions and concentrations of U, Pu, and Cm in extraction processes, addressing areas of process control and materials accountability. The team will evaluate UV– Visible and TRLFS for use in solvent extraction-based separations. Ongoing research is examining efficacy of UV-Visible spectroscopy to evaluate uranium and plutonium speciation under conditions found in the UREX process and using TRLFS to evaluate Cm speciation and concentration in the TALSPEAK process. A uranyl and plutonium nitrate UV–Visible spectroscopy study met with success, which supports the utility and continued exploration of spectroscopic methods for evaluation of actinide concentrations and solution conditions for other aspects of the UREX+ solvent extraction scheme. This project will examine U and Pu absorbance in TRUEX and TALSPEAK, perform detailed examination of Cm in TRUEX and TALSPEAK, study U laser fluorescence, and apply project data to contactors. The team will also determine peak ratios as a function of solution concentrations for the

  19. A COMPARISON OF SPECTROSCOPIC VERSUS IMAGING TECHNIQUES FOR DETECTING CLOSE COMPANIONS TO KEPLER OBJECTS OF INTEREST

    SciTech Connect

    Teske, Johanna K.; Everett, Mark E.; Hirsch, Lea; Furlan, Elise; Ciardi, David R.; Horch, Elliott P.; Howell, Steve B.; Gonzales, Erica; Crepp, Justin R.

    2015-11-15

    Kepler planet candidates require both spectroscopic and imaging follow-up observations to rule out false positives and detect blended stars. Traditionally, spectroscopy and high-resolution imaging have probed different host star companion parameter spaces, the former detecting tight binaries and the latter detecting wider bound companions as well as chance background stars. In this paper, we examine a sample of 11 Kepler host stars with companions detected by two techniques—near-infrared adaptive optics and/or optical speckle interferometry imaging, and a new spectroscopic deblending method. We compare the companion effective temperatures (T{sub eff}) and flux ratios (F{sub B}/F{sub A}, where A is the primary and B is the companion) derived from each technique and find no cases where both companion parameters agree within 1σ errors. In 3/11 cases the companion T{sub eff} values agree within 1σ errors, and in 2/11 cases the companion F{sub B}/F{sub A} values agree within 1σ errors. Examining each Kepler system individually considering multiple avenues (isochrone mapping, contrast curves, probability of being bound), we suggest two cases for which the techniques most likely agree in their companion detections (detect the same companion star). Overall, our results support the advantage that the spectroscopic deblending technique has for finding very close-in companions (θ ≲ 0.″02–0.″05) that are not easily detectable with imaging. However, we also specifically show how high-contrast AO and speckle imaging observations detect companions at larger separations (θ ≥ 0.″02–0.″05) that are missed by the spectroscopic technique, provide additional information for characterizing the companion and its potential contamination (e.g., position angle, separation, magnitude differences), and cover a wider range of primary star effective temperatures. The investigation presented here illustrates the utility of combining the two techniques to reveal higher

  20. Vibrational Spectroscopic Microscopy: Raman, Near-Infrared and Mid-Infrared Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Lewis, E. Neil; Levin, Ira W.

    1995-02-01

    New instrumental approaches for performing vibrational Raman, near-infrared and mid-infrared spectroscopic imaging microscopy are described. The instruments integrate imaging quality filters such as acousto-optic tunable filters (AOTFs), with visible charge-coupled device (CCD) and infrared focal-plane array detectors. These systems are used in conjunction with infinity-corrected, refractive microscopes for operation in the visible and near-infrared spectral regions and with Cassegrainian reflective optics for operation in the mid-infrared spectral interval. Chemically specific images at moderate spectral resolution (2 nm) and high spatial resolution (1 [mu]m) can be collected rapidly and noninvasively. Image data are presented containing 128 × 128 pixels, although significantly larger format images can be collected in approximately the same time. The instruments can be readily configured for both absorption and reflectance spectroscopies. We present Raman emission images of polystyrene microspheres and a lipid/amino acid mixture and near-infrared images of onion epidermis and a hydrated phospholipid dispersion. Images generated from mid-infrared spectral data are presented for a KBr disk containing nonhomogeneous domains of lipid and for 50-[mu]m slices of monkey cerebellum. These are the first results illustrating the use of infrared focal-plane array detectors as chemically specific spectroscopic imaging devices and demonstrating their application in biomolecular areas. Extensions and future applications of the various vibrational spectroscopic imaging techniques are discussed.

  1. Optical detection of middle ear infection using spectroscopic techniques: phantom experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Huang, Jing; Li, Tianqi; Svanberg, Sune; Svanberg, Katarina

    2015-05-01

    A noninvasive optical technique, which is based on a combination of reflectance spectroscopy and gas in scattering media absorption spectroscopy, is demonstrated. It has the potential to improve diagnostics of middle ear infections. An ear phantom prepared with a tissue cavity, which was covered with scattering material, was used for spectroscopic measurements. Diffuse reflectance spectra of the phantom eardrum were measured with a reflectance probe. The presence of oxygen and water vapor as well as gas exchange in the phantom cavity were studied with a specially designed fiber-optic probe for backscattering detection geometry. The results suggest that this method can be developed for improved clinical detection of middle ear infection.

  2. Optical detection of middle ear infection using spectroscopic techniques: phantom experiments.

    PubMed

    Zhang, Hao; Huang, Jing; Li, Tianqi; Svanberg, Sune; Svanberg, Katarina

    2015-05-01

    A noninvasive optical technique, which is based on a combination of reflectance spectroscopy and gas in scattering media absorption spectroscopy, is demonstrated. It has the potential to improve diagnostics of middle ear infections. An ear phantom prepared with a tissue cavity, which was covered with scattering material, was used for spectroscopic measurements. Diffuse reflectance spectra of the phantom eardrum were measured with a reflectance probe. The presence of oxygen and water vapor as well as gas exchange in the phantom cavity were studied with a specially designed fiber-optic probe for backscattering detection geometry. The results suggest that this method can be developed for improved clinical detection of middle ear infection.

  3. A versatile setup using femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering

    SciTech Connect

    Shen, Yujie; Voronine, Dmitri V.; Sokolov, Alexei V.; Scully, Marlan O.

    2015-08-15

    We report a versatile setup based on the femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering. The setup uses a femtosecond Ti:Sapphire oscillator source and a folded 4f pulse shaper, in which the pulse shaping is carried out through conventional optical elements and does not require a spatial light modulator. Our setup is simple in alignment, and can be easily switched between the collinear single-beam and the noncollinear two-beam configurations. We demonstrate the capability for investigating both transparent and highly scattering samples by detecting transmitted and reflected signals, respectively.

  4. A versatile setup using femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering.

    PubMed

    Shen, Yujie; Voronine, Dmitri V; Sokolov, Alexei V; Scully, Marlan O

    2015-08-01

    We report a versatile setup based on the femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering. The setup uses a femtosecond Ti:Sapphire oscillator source and a folded 4f pulse shaper, in which the pulse shaping is carried out through conventional optical elements and does not require a spatial light modulator. Our setup is simple in alignment, and can be easily switched between the collinear single-beam and the noncollinear two-beam configurations. We demonstrate the capability for investigating both transparent and highly scattering samples by detecting transmitted and reflected signals, respectively.

  5. FAST CARS: Engineering a laser spectroscopic technique for rapid identification of bacterial spores

    PubMed Central

    Scully, M. O.; Kattawar, G. W.; Lucht, R. P.; Opatrný, T.; Pilloff, H.; Rebane, A.; Sokolov, A. V.; Zubairy, M. S.

    2002-01-01

    Airborne contaminants, e.g., bacterial spores, are usually analyzed by time-consuming microscopic, chemical, and biological assays. Current research into real-time laser spectroscopic detectors of such contaminants is based on e.g., resonance fluorescence. The present approach derives from recent experiments in which atoms and molecules are prepared by one (or more) coherent laser(s) and probed by another set of lasers. However, generating and using maximally coherent oscillation in macromolecules having an enormous number of degrees of freedom is challenging. In particular, the short dephasing times and rapid internal conversion rates are major obstacles. However, adiabatic fast passage techniques and the ability to generate combs of phase-coherent femtosecond pulses provide tools for the generation and utilization of maximal quantum coherence in large molecules and biopolymers. We call this technique FAST CARS (femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman spectroscopy), and the present article proposes and analyses ways in which it could be used to rapidly identify preselected molecules in real time. PMID:12177405

  6. 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.

  7. Advanced Techniques for MIMO Broadband Communications

    DTIC Science & Technology

    2005-12-01

    Multiple input multiple output ( MIMO ) systems can provide high...Approved for Public Release Distribution Unlimited 20060614025 Abstract Multiple input multiple output ( MIMO ) systems can provide high diversity, high... multiple transmit/receive antennas are referred to as multiple input multiple output ( MIMO ) systems. As studies advance, it is shown that MIMO

  8. Advancements in IR spectroscopic approaches for the determination of fungal derived contaminations in food crops.

    PubMed

    McMullin, David; Mizaikoff, Boris; Krska, Rudolf

    2015-01-01

    Infrared spectroscopy is a rapid, nondestructive analytical technique that can be applied to the authentication and characterization of food samples in high throughput. In particular, near infrared spectroscopy is commonly utilized in the food quality control industry to monitor the physical attributes of numerous cereal grains for protein, carbohydrate, and lipid content. IR-based methods require little sample preparation, labor, or technical competence if multivariate data mining techniques are implemented; however, they do require extensive calibration. Economically important crops are infected by fungi that can severely reduce crop yields and quality and, in addition, produce mycotoxins. Owing to the health risks associated with mycotoxins in the food chain, regulatory limits have been set by both national and international institutions for specific mycotoxins and mycotoxin classes. This article discusses the progress and potential of IR-based methods as an alternative to existing chemical methods for the determination of fungal contamination in crops, as well as emerging spectroscopic methods.

  9. Studies on Nephrite and Jadeite Jades by Fourier Transform Infrared (ftir) and Raman Spectroscopic Techniques

    NASA Astrophysics Data System (ADS)

    Tan, T. L.; Ng, L. L.; Lim, L. C.

    2013-10-01

    The mineralogical properties of black nephrite jade from Western Australia are studied by Fourier transform infrared (FTIR) spectroscopy using both transmission and specular reflectance techniques in the 4000-400 cm-1 wavenumber region. The infrared absorption peaks in the 3700-3600 cm-1 region which are due to the O-H stretching mode provides a quantitative analysis of the Fe/(Fe+Mg) ratio in the mineral composition of jade samples. The Fe/(Fe+Mg) percentage in black nephrite is found to be higher than that in green nephrite, but comparable to that of actinolite (iron-rich nephrite). This implies that the mineralogy of black nephrite is closer to actinolite than tremolite. The jade is also characterized using Raman spectroscopy in the 1200-200 cm-1 region. Results from FTIR and Raman spectroscopic data of black nephrite jade are compared with those of green nephrite jade from New Zealand and jadeite jade from Myanmar. Black nephrite appears to have a slightly different chemical composition from green nephrite. Spectra from FTIR and Raman spectroscopic techniques were found to be useful in differentiating black nephrite, green nephrite, and green jadeite jades. Furthermore, data on refractive index, specific gravity, and hardness of black nephrite jade are measured and compared with those of green nephrite and of jadeite jade.

  10. Spectroscopic investigation on cocrystal formation between adenine and fumaric acid based on infrared and Raman techniques.

    PubMed

    Du, Yong; Fang, Hong Xia; Zhang, Qi; Zhang, Hui Li; Hong, Zhi

    2016-01-15

    As an important component of double-stranded DNA, adenine has powerful hydrogen-bond capability, due to rich hydrogen bond donors and acceptors existing within its molecular structure. Therefore, it is easy to form cocrystal between adenine and other small molecules with intermolecular hydrogen-bond effect. In this work, cocrystal of adenine and fumaric acid has been characterized as model system by FT-IR and FT-Raman spectral techniques. The experimental results show that the cocrystal formed between adenine and fumaric acid possesses unique spectroscopical characteristic compared with that of starting materials. Density functional theory (DFT) calculation has been performed to optimize the molecular structures and simulate vibrational modes of adenine, fumaric acid and the corresponding cocrystal. Combining the theoretical and experimental vibrational results, the characteristic bands corresponding to bending and stretching vibrations of amino and carbonyl groups within cocrystal are shifted into lower frequencies upon cocrystal formation, and the corresponding bond lengths show some increase due to the effect of intermolecular hydrogen bonding. Different vibrational modes shown in the experimental spectra have been assigned based on the simulation DFT results. The study could provide experimental and theoretical benchmarks to characterize cocrystal formed between active ingredients and cocrystal formers and also the intermolecular hydrogen-bond effect within cocrystal formation process by vibrational spectroscopic techniques.

  11. Spectroscopic investigation on cocrystal formation between adenine and fumaric acid based on infrared and Raman techniques

    NASA Astrophysics Data System (ADS)

    Du, Yong; Fang, Hong Xia; Zhang, Qi; Zhang, Hui Li; Hong, Zhi

    2016-01-01

    As an important component of double-stranded DNA, adenine has powerful hydrogen-bond capability, due to rich hydrogen bond donors and acceptors existing within its molecular structure. Therefore, it is easy to form cocrystal between adenine and other small molecules with intermolecular hydrogen-bond effect. In this work, cocrystal of adenine and fumaric acid has been characterized as model system by FT-IR and FT-Raman spectral techniques. The experimental results show that the cocrystal formed between adenine and fumaric acid possesses unique spectroscopical characteristic compared with that of starting materials. Density functional theory (DFT) calculation has been performed to optimize the molecular structures and simulate vibrational modes of adenine, fumaric acid and the corresponding cocrystal. Combining the theoretical and experimental vibrational results, the characteristic bands corresponding to bending and stretching vibrations of amino and carbonyl groups within cocrystal are shifted into lower frequencies upon cocrystal formation, and the corresponding bond lengths show some increase due to the effect of intermolecular hydrogen bonding. Different vibrational modes shown in the experimental spectra have been assigned based on the simulation DFT results. The study could provide experimental and theoretical benchmarks to characterize cocrystal formed between active ingredients and cocrystal formers and also the intermolecular hydrogen-bond effect within cocrystal formation process by vibrational spectroscopic techniques.

  12. Advanced crystallization techniques of 'solar grade' silicon

    NASA Astrophysics Data System (ADS)

    Gasparini, M.; Calligarich, C.; Rava, P.; Sardi, L.; Alessandri, M.; Redaelli, F.; Pizzini, S.

    Microstructural, electrical and photo-voltaic characteristics of polycrystal line silicon solar cells fabricated with silicon ingots containing 5, 100 and 500 ppmw iron are reported and discussed. All silicon ingots were grown by the directional solidification technique in graphite or special quartz molds and doped intentionally with iron, in order to evaluate the potentiality of the D.S. technique when employed with solar silicon feedstocks. Results indicate that structural breakdown limits the amount of the ingot which is usable for solar cells fabrication, but also that efficiencies in excess of 10 percent are obtained using the 'good' region of the ingot.

  13. [Advanced MRI techniques of the fetal brain].

    PubMed

    Schöpf, V; Dittrich, E; Berger-Kulemann, V; Kasprian, G; Kollndorfer, K; Prayer, D

    2013-02-01

    Evaluation of the normal and pathological fetal brain. Magnetic resonance imaging (MRI). Advanced MRI of the fetal brain. Diffusion tensor imaging (DTI) is used in clinical practice, all other methods are used at a research level. Serving as standard methods in the future. Combined structural and functional data for all gestational ages will allow more specific insight into the developmental processes of the fetal brain. This gain of information will help provide a common understanding of complex spatial and temporal procedures of early morphological features and their impact on cognitive and sensory abilities.

  14. Investigation of effect of annealing on thermally evaporated ZnSe thin films through spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Mahesha, M. G.; Rashmitha; Meghana, N.; Padiyar, Meghavarsha

    2017-09-01

    ZnSe thin films have been grown on clean glass substrates by thermal evaporation technique and deposited films have been annealed at 473 K. William-Hall method has been adopted to extract information on crystallite size and internal strain in the film from X-ray diffractogram. Effect of annealing on ZnSe films has been analyzed by spectroscopic techniques which include optical absorption, Raman, and photoluminescence spectroscopy. From optical absorption, band gap has been estimated along with other optical parameters like refractive index and extinction coefficient. Also, Urbach tail, which originates near bad edge due to structural disorders, has been characterized. Raman spectra have been analyzed to get the information on the influence of crystallite size and strain effect on peak position, intensity and width. Photoluminescence spectra have been recorded and analyzed to get an insight on defect levels induced due to vacancies, interstadials, and impurity complexes.

  15. Implementation of Multiple Spectroscopic Techniques to Simultaneously Observe Native and Mutated Protein Unfolding

    NASA Astrophysics Data System (ADS)

    Cull, Brennan; Ben, Kelty; Link, Justin

    A protein's natural, correctly folded structure can determine the protein's ability to carry out its function. If the unfolding process of proteins can be observed, then the relative stability can be better understood between native and mutated proteins. A global picture of the unfolding process may be completed through the studies of strategically mutated proteins using tryptophan as a probe. Horse heart cytochrome c, a thoroughly studied, model protein was used in our investigation to explore this idea. Various spectroscopic techniques such as circular dichroism (CD), absorbance, and fluorescence were simultaneously applied while slowly unfolding our protein by increasing the concentration of a chemical denaturant, guanidine hydrochloride. This provided us information about the thermodynamic properties of the protein and several mutants which can then be interpreted to gain relative stability information among mutations. Efforts to utilize these techniques on native and mutated proteins in comparison to current scientific unfolding theories will be presented in this session.

  16. Selective spectroscopic imaging of hyperpolarized pyruvate and its metabolites using a single-echo variable phase advance method in balanced SSFP

    PubMed Central

    Varma, Gopal; Wang, Xiaoen; Vinogradov, Elena; Bhatt, Rupal S.; Sukhatme, Vikas; Seth, Pankaj; Lenkinski, Robert E.; Alsop, David C.; Grant, Aaron K.

    2015-01-01

    Purpose In balanced steady state free precession (bSSFP), the signal intensity has a well-known dependence on the off-resonance frequency, or, equivalently, the phase advance between successive radiofrequency (RF) pulses. The signal profile can be used to resolve the contributions from the spectrally separated metabolites. This work describes a method based on use of a variable RF phase advance to acquire spatial and spectral data in a time-efficient manner for hyperpolarized 13C MRI. Theory and Methods The technique relies on the frequency response from a bSSFP acquisition to acquire relatively rapid, high-resolution images that may be reconstructed to separate contributions from different metabolites. The ability to produce images from spectrally separated metabolites was demonstrated in-vitro, as well as in-vivo following administration of hyperpolarized 1-13C pyruvate in mice with xenograft tumors. Results In-vivo images of pyruvate, alanine, pyruvate hydrate and lactate were reconstructed from 4 images acquired in 2 seconds with an in-plane resolution of 1.25 × 1.25mm2 and 5mm slice thickness. Conclusions The phase advance method allowed acquisition of spectroscopically selective images with high spatial and temporal resolution. This method provides an alternative approach to hyperpolarized 13C spectroscopic MRI that can be combined with other techniques such as multi-echo or fluctuating equilibrium bSSFP. PMID:26507361

  17. Assessment of amsacrine binding with DNA using UV-visible, circular dichroism and Raman spectroscopic techniques.

    PubMed

    Jangir, Deepak Kumar; Dey, Sanjay Kumar; Kundu, Suman; Mehrotra, Ranjana

    2012-09-03

    Proper understanding of the mechanism of binding of drugs to their targets in cell is a fundamental requirement to develop new drug therapy regimen. Amsacrine is a rationally designed anticancer drug, used to treat leukemia and lymphoma. Binding with cellular DNA is a crucial step in its mechanism of cytotoxicity. Despite numerous studies, DNA binding properties of amsacrine are poorly understood. Its reversible binding with DNA does not permit X-ray crystallography or NMR spectroscopic evaluation of amsacrine-DNA complexes. In the present work, interaction of amsacrine with calf thymus DNA is investigated at physiological conditions. UV-visible, FT-Raman and circular dichroism spectroscopic techniques were employed to determine the binding mode, binding constant, sequence specificity and conformational effects of amsacrine binding to native calf thymus DNA. Our results illustrate that amsacrine interacts with DNA by and large through intercalation between base pairs. Binding constant of the amsacrine-DNA complex was found to be K=1.2±0.1×10(4) M(-1) which is indicative of moderate type of binding of amsacrine to DNA. Raman spectroscopic results suggest that amsacrine has a binding preference of intercalation between AT base pairs of DNA. Minor groove binding is also observed in amsacrine-DNA complexes. These results are in good agreement with in silico investigation of amsacrine binding to DNA and thus provide detailed insight into DNA binding properties of amsacrine, which could ultimately, renders its cytotoxic efficacy. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. [Advanced online search techniques and dedicated search engines for physicians].

    PubMed

    Nahum, Yoav

    2008-02-01

    In recent years search engines have become an essential tool in the work of physicians. This article will review advanced search techniques from the world of information specialists, as well as some advanced search engine operators that may help physicians improve their online search capabilities, and maximize the yield of their searches. This article also reviews popular dedicated scientific and biomedical literature search engines.

  19. Advanced automated char image analysis techniques

    SciTech Connect

    Tao Wu; Edward Lester; Michael Cloke

    2006-05-15

    Char morphology is an important characteristic when attempting to understand coal behavior and coal burnout. In this study, an augmented algorithm has been proposed to identify char types using image analysis. On the basis of a series of image processing steps, a char image is singled out from the whole image, which then allows the important major features of the char particle to be measured, including size, porosity, and wall thickness. The techniques for automated char image analysis have been tested against char images taken from ICCP Char Atlas as well as actual char particles derived from pyrolyzed char samples. Thirty different chars were prepared in a drop tube furnace operating at 1300{sup o}C, 1% oxygen, and 100 ms from 15 different world coals sieved into two size fractions (53-75 and 106-125 {mu}m). The results from this automated technique are comparable with those from manual analysis, and the additional detail from the automated sytem has potential use in applications such as combustion modeling systems. Obtaining highly detailed char information with automated methods has traditionally been hampered by the difficulty of automatic recognition of individual char particles. 20 refs., 10 figs., 3 tabs.

  20. Advanced analysis techniques for uranium assay

    SciTech Connect

    Geist, W. H.; Ensslin, Norbert; Carrillo, L. A.; Beard, C. A.

    2001-01-01

    Uranium has a negligible passive neutron emission rate making its assay practicable only with an active interrogation method. The active interrogation uses external neutron sources to induce fission events in the uranium in order to determine the mass. This technique requires careful calibration with standards that are representative of the items to be assayed. The samples to be measured are not always well represented by the available standards which often leads to large biases. A technique of active multiplicity counting is being developed to reduce some of these assay difficulties. Active multiplicity counting uses the measured doubles and triples count rates to determine the neutron multiplication (f4) and the product of the source-sample coupling ( C ) and the 235U mass (m). Since the 35U mass always appears in the multiplicity equations as the product of Cm, the coupling needs to be determined before the mass can be known. A relationship has been developed that relates the coupling to the neutron multiplication. The relationship is based on both an analytical derivation and also on empirical observations. To determine a scaling constant present in this relationship, known standards must be used. Evaluation of experimental data revealed an improvement over the traditional calibration curve analysis method of fitting the doubles count rate to the 235Um ass. Active multiplicity assay appears to relax the requirement that the calibration standards and unknown items have the same chemical form and geometry.

  1. ADVANCE: An effective and feasible technique in acute stroke treatment.

    PubMed

    Gurkas, Erdem; Akpinar, Cetin Kursad; Aytac, Emrah

    2017-04-01

    Background and purpose Different techniques regarding efficient utilization of thrombectomy devices have been reported. Here, we described a novel technique named ADVANCE that is based on advancing a distal access catheter over the stent retriever. In this study, we aimed to report our initial results with this novel thrombectomy technique. Methods and results Sixty-seven consecutive acute anterior circulation ischemic stroke patients (35 male, 32 female) between January 2015 and January 2016 who were treated by mechanical thrombectomy were included in this prospective study. Patients were classified randomly into two groups: patients treated with either the ADVANCE technique or standard technique. Patients had a mean age of 61.1 ± 12.9 years. The average NIHSS score was 15.8 ± 3.8. In the ADVANCE group, the successful revascularization (mTICI 2b-3) rate was 87.1% and the 90-day good functional outcome rate (mRS 0-2) was 74.1%. The revascularization rate in the ADVANCE group was significantly ( p = 0.005) better than the standard technique group and good functional outcome at 90 days in the ADVANCE group was non-significantly better than the standard technique group ( p = 0.052). Conclusions ADVANCE is the first comparison of this technique to standard stent retriever thrombectomy with a higher rate of revascularization with no emboli to new territory and fewer distal emboli to target territory. This safe and efficient technique needs to be validated in large patient series in new thrombectomy trials.

  2. Unravel the interaction of protoporphyrin IX with reduced graphene oxide by vital spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Jhonsi, Mariadoss Asha; Nithya, Chandrasekaran; Kathiravan, Arunkumar

    2017-05-01

    Probing interaction between dyes and reduced graphene oxide (rGO) is of contemporary research interest. Since, rGO is widely used as electron acceptor in photovoltaic and optoelectronic devices. Hence, we have investigated the interaction between protoporphyrin IX (PPIX) and rGO by vital spectroscopic techniques. The adsorption of PPIX on rGO is studied by Attenuated total reflection-Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopic (XPS) measurements. The fluorescence quenching measurements are also performed and the fluorescence intensity of PPIX is quenched by rGO. The quenching of PPIX with rGO is evaluated by the Stern-Volmer equation and time-resolved fluorescence lifetime studies. The results revealed that the fluorescence quenching of PPIX with rGO is due to the static quenching mechanism. The dominant process for this quenching has been attributed to the process of electron transfer from excited state PPIX to rGO. Fluorescence lifetime measurements were used to calculate the rate of electron transfer process between excited state of PPIX and rGO. Transient absorption studies demonstrated the formation of PPIX cation radical for the evidence of electron transfer between PPIX and rGO.

  3. Recent advances in DNA sequencing techniques

    NASA Astrophysics Data System (ADS)

    Singh, Rama Shankar

    2013-06-01

    Successful mapping of the draft human genome in 2001 and more recent mapping of the human microbiome genome in 2012 have relied heavily on the parallel processing of the second generation/Next Generation Sequencing (NGS) DNA machines at a cost of several millions dollars and long computer processing times. These have been mainly biochemical approaches. Here a system analysis approach is used to review these techniques by identifying the requirements, specifications, test methods, error estimates, repeatability, reliability and trends in the cost reduction. The first generation, NGS and the Third Generation Single Molecule Real Time (SMART) detection sequencing methods are reviewed. Based on the National Human Genome Research Institute (NHGRI) data, the achieved cost reduction of 1.5 times per yr. from Sep. 2001 to July 2007; 7 times per yr., from Oct. 2007 to Apr. 2010; and 2.5 times per yr. from July 2010 to Jan 2012 are discussed.

  4. Diagnostics of nonlocal plasmas: advanced techniques

    NASA Astrophysics Data System (ADS)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  5. Pectoralis major turnover versus advancement technique for sternal wound reconstruction.

    PubMed

    Zahiri, Hamid R; Lumpkins, Kimberly; Kelishadi, Shahrooz; Stromberg, Jeffrey A; Silverman, Ronald P; Slezak, Sheri; Goldberg, Nelson H; Holton, Luther; Singh, Devinder P

    2013-02-01

    We compared the efficacy of pectoralis turnover versus advancement technique for sternal wound reconstruction. A retrospective chart review was performed, December 1989 to December 2010, to compare postoperative complication rates between pectoralis major turnover versus pectoralis major advancement reconstruction techniques. Complications included hematomas, wound infections, tissue necrosis, dehiscence, and need for reoperation. Pearson χ and logistic regression were used and significance was P < 0.05. Sixty-seven patients received 91 tissue flaps. Eleven patients (16%) required reoperation due to complications, including recurrent wound infection, tissue necrosis, wound dehiscence, mediastinitis, and hematoma formation. Four patients (6%) were treated conservatively for minor complications. Overall, complication rates were significantly higher after pectoralis major advancement reconstruction (32.5% vs. 3.7%, P = 0.004). When feasible, pectoralis major turnover flap offers a superior reconstructive technique for complex sternal wounds, with diminished complications compared with the pectoralis advancement flap.

  6. Spectroscopic studies of UV irradiated erythrosine B thin films prepared by spin coating technique

    NASA Astrophysics Data System (ADS)

    Zeyada, H. M.; El-Mallah, H. M.; Atwee, T.; El-Damhogi, D. G.

    2017-05-01

    The spectroscopic studies of erythrosine B thin films manufactured by the spin coating technique have been presented. The spectra of infrared absorption allow characterization of vibrational modes for erythrosine B in powder form, pristine and UV irradiated thin films. The absorption spectra recorded in UV-vis-NIR for pristine films of erythrosine B display two main bands. UV irradiation on erythrosine B films decreased absorbance over the spectra. Indirect allowed transition with optical energy gap of 2.57 eV is observed in pristine films. UV irradiation introduced structural defects and decreased optical band gap. Some of the optical absorption parameters and their relation to UV irradiation times, namely molar extinction coefficient (ε), electronic dipole strength (q2), and oscillator strength (f), of the principal optical transitions have also been evaluated.

  7. Spectroscopic studies of UV irradiated erythrosine B thin films prepared by spin coating technique.

    PubMed

    Zeyada, H M; El-Mallah, H M; Atwee, T; El-Damhogi, D G

    2017-05-15

    The spectroscopic studies of erythrosine B thin films manufactured by the spin coating technique have been presented. The spectra of infrared absorption allow characterization of vibrational modes for erythrosine B in powder form, pristine and UV irradiated thin films. The absorption spectra recorded in UV-vis-NIR for pristine films of erythrosine B display two main bands. UV irradiation on erythrosine B films decreased absorbance over the spectra. Indirect allowed transition with optical energy gap of 2.57eV is observed in pristine films. UV irradiation introduced structural defects and decreased optical band gap. Some of the optical absorption parameters and their relation to UV irradiation times, namely molar extinction coefficient (ε), electronic dipole strength (q(2)), and oscillator strength (f), of the principal optical transitions have also been evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Study on the interaction between Besifloxacin and bovine serum albumin by spectroscopic techniques.

    PubMed

    Yu, Xianyong; Jiang, Bingfei; Liao, Zhixi; Jiao, Yue; Yi, Pinggui

    2015-01-01

    The interaction between Besifloxacin (BFLX) and bovine serum albumin (BSA) was investigated by spectroscopic (fluorescence, UV-Vis absorption and circular dichroism) techniques under imitated physiological conditions. The experiments were conducted at different temperatures (298, 304 and 310 K) and the results showed that the BFLX caused the fluorescence quenching of BSA through a static quenching procedure. The binding constant (Ka), binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated at different temperatures. The results revealed that the binding process was spontaneous and the acting force between BFLX and BSA were mainly electrostatic forces. According to Förster non-radiation energy transfer theory, the binding distance between BFLX and BSA was calculated to be 4.96 nm. What is more, both synchronous fluorescence and circular dichroism spectra confirmed conformational changes of BSA.

  9. Dielectric studies of boron sub phthalocyanine chloride thin films by admittance spectroscopic techniques

    SciTech Connect

    Kalia, Sameer; Neerja; Mahajan, Aman Sharma, Anshul Kumar; Kumar, Sanjeev; Bedi, R. K.

    2016-05-06

    The dielectric properties of Boron Sub Phthalocyanine Chloride (Cl-SubPc) thermally deposited on ITO substrate have been studied using admittance spectroscopic techniques. The I-V and capacitance –frequency (C-F) studies at various bias voltages reveal that the mobility of charge carriers decrease with bias voltage, however the conduction phenomenon still remain hopping in nature. From the differential susceptance curve, the contribution of the Schottky barrier contact in the charge carrier concentration was found to be absent. The mobility of charge carriers have been determined using differential susceptance variation and from the phase of admittance curve. The values obtained in two cases have been found to be in agreement with each other.

  10. Systematic toxicological analysis of drugs and poisons in biosamples by hyphenated chromatographic and spectroscopic techniques.

    PubMed

    Polettini, A

    1999-10-15

    The introduction of hyphenated chromatographic-spectroscopic techniques represented a substantial step-forward for Systematic Toxicological Analysis (STA), increasing the amount and quality of information obtainable from the analysis of a biological sample, and enhancing the possibilities of identifying unknown drugs and poisons. STA methods based either on GC-MS or on HPLC-UV published in the last decade are reviewed in this paper. The different analytical phases, i.e. sample preparation (pretreatment, extraction, derivatisation), chromatographic separation and detection/identification are examined in detail in order to emphasise the complementarity of the two approaches. In addition, the first STA method based on HPLC-MS is illustrated and some applications of TLC-UV to drug screening are also described. Finally, an overview of semi- and fully-automated STA methods is given.

  11. Spectroscopic study of floating zone technique-grown Nd3+-doped CaMoO4

    NASA Astrophysics Data System (ADS)

    Andrade, L. H. C.; Reyes Ardila, D.; Barbosa, L. B.; Andreeta, J. P.; Li, M. Siu; Brenier, A.; Guyot, Y.; Boulon, G.

    2005-01-01

    Optical spectroscopy studies of Nd3+-doped scheelite calcium molybdate (CaMoO{4}) single crystal grown by a floating zone-like technique was performed using Judd-Ofelt analysis, besides luminescence data and lifetime measurements in the visible and near infrared domains. The excited state absorption in cross section units of this material was measured by two different methods for all expected infrared emission. By using calculated intensity parameters Ω t (t=2, 4, 6), it were determined branching ratios, emission cross-sections, and lifetimes for all related transitions. The observed single excited state absorption calibrated in absorption cross-section units was found too small to disturb the laser efficiency in the 1030 1100 nm spectral range. A comparison of main spectroscopic parameters of this material with those of other Nd3+-doped crystals is presented.

  12. Thiourea recognition by 2,6-bis(2-benzimidazolyl)pyridine using spectroscopic techniques and DFT

    NASA Astrophysics Data System (ADS)

    Chetia, Bolin; Goutam, Prasanta J.; Chipem, Francis A. S.; Iyer, Parameswar K.

    2013-06-01

    Recognition of thiourea by 2,6-bis(2-benzimidazolyl)pyridine, bbp, a neutral tridentate ligand was studied by UV visible and fluorescence spectroscopic techniques. FTIR spectroscopy and supportive DFT calculations established that, thiourea molecule, while bound to the binding site of bbp took up a near perpendicular orientation to the plane of the receptor. While forming the complex, the two imidazole H atoms present in the binding site of bbp formed two weak interactions with S atom of thiourea, which has low electronegativity. Moreover, bigger size of S atom restricted approach of thiourea inside the binding site. Stability of the bbp:thiourea complex basically increased as one of the imine H atom of thiourea is involved in a hydrogen bond with the pyridine N atom of bbp, which forced the near perpendicular orientation of thiourea on the plane of bbp. This binding mode is significantly different from the binding mode of urea with bbp as reported earlier.

  13. Evaluation of Advanced Retrieval Techniques in an Experimental Online Catalog.

    ERIC Educational Resources Information Center

    Larson, Ray R.

    1992-01-01

    Discusses subject searching problems in online library catalogs; explains advanced information retrieval (IR) techniques; and describes experiments conducted on a test collection database, CHESHIRE (California Hybrid Extended SMART for Hypertext and Information Retrieval Experimentation), which was created to evaluate IR techniques in online…

  14. Innovative Tools Advance Revolutionary Weld Technique

    NASA Technical Reports Server (NTRS)

    2009-01-01

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

  15. Recent developments in spectroscopic imaging techniques for historical paintings - A review

    NASA Astrophysics Data System (ADS)

    Alfeld, M.; de Viguerie, L.

    2017-10-01

    This paper provides an overview over the application of scanning macro-XRF with mobile instruments for the investigation of historical paintings. The method is compared to synchrotron based macro-XRF imaging and Neutron Activation Auto-Radiography. Full-Field XRF imaging instruments, a potential future alternative to scanning macro-XRF, and confocal XRF, providing complementary depth profiles and developing into a 3D imaging technique itself, are described with the focus on investigations of historical paintings. Recent developments of X-ray radiography are presented and the investigation of cultural heritage objects other than paintings by MA-XRF is summarized. In parallel to XRF, hyperspectral imaging in the visible and range has developed into a technique with comparable capabilities, providing insight in chemical compounds, where XRF imaging identifies the distribution of elements. Due to the complementary nature of these techniques the latter is summarized. Further, progress and state of the art in data evaluation for spectroscopic imaging is discussed. In general it could be observed that technical capabilities in MA-XRF and hyperspectral imaging have reached a plateau and that with the availability of commercial instruments the focus of recent studies has shifted from the development of methods to applications of the instruments. Further, that while simple instruments are easily available with medium budgets only few groups have high-end instrumentation available, bought or in-house built.

  16. Development of an ultrahigh-performance infrared detector platform for advanced spectroscopic sensing systems

    NASA Astrophysics Data System (ADS)

    Jain, Manish; Wicks, Gary; Marshall, Andrew; Craig, Adam; Golding, Terry; Hossain, Khalid; McEwan, Ken; Howle, Chris

    2014-05-01

    Laser-based stand-off sensing of threat agents (e.g. explosives, toxic industrial chemicals or chemical warfare agents), by detection of distinct infrared spectral absorption signature of these materials, has made significant advances recently. This is due in part to the availability of infrared and terahertz laser sources with significantly improved power and tunability. However, there is a pressing need for a versatile, high performance infrared sensor that can complement and enhance the recent advances achieved in laser technology. This work presents new, high performance infrared detectors based on III-V barrier diodes. Unipolar barrier diodes, such as the nBn, have been very successful in the MWIR using InAs(Sb)-based materials, and in the MWIR and LWIR using type-II InAsSb/InAs superlattice-based materials. This work addresses the extension of the barrier diode architecture into the SWIR region, using GaSb-based and InAs-based materials. The program has resulted in detectors with unmatched performance in the 2-3 μm spectral range. Temperature dependent characterization has shown dark currents to be diffusion limited and equal to, or within a factor of 5, of the Rule 07 expression for Auger-limited HgCdTe detectors. Furthermore, D* values are superior to those of existing detectors in the 2-3 μm band. Of particular significance to spectroscopic sensing systems is the ability to have near-background limited performance at operation temperatures compatible with robust and reliable solid state thermoelectric coolers.

  17. Advances in gamma titanium aluminides and their manufacturing techniques

    NASA Astrophysics Data System (ADS)

    Kothari, Kunal; Radhakrishnan, Ramachandran; Wereley, Norman M.

    2012-11-01

    Gamma titanium aluminides display attractive properties for high temperature applications. For over a decade in the 1990s, the attractive properties of titanium aluminides were outweighed by difficulties encountered in processing and machining at room temperature. But advances in manufacturing technologies, deeper understanding of titanium aluminides microstructure, deformation mechanisms, and advances in micro-alloying, has led to the production of gamma titanium aluminide sheets. An in-depth review of key advances in gamma titanium aluminides is presented, including microstructure, deformation mechanisms, and alloy development. Traditional manufacturing techniques such as ingot metallurgy and investment casting are reviewed and advances via powder metallurgy based manufacturing techniques are discussed. Finally, manufacturing challenges facing gamma titanium aluminides, as well as avenues to overcome them, are discussed.

  18. Study on the interaction of catechins with human serum albumin using spectroscopic and electrophoretic techniques

    NASA Astrophysics Data System (ADS)

    Trnková, Lucie; Boušová, Iva; Staňková, Veronika; Dršata, Jaroslav

    2011-01-01

    The interaction between eight naturally occurring flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate) and human serum albumin (HSA) has been investigated by spectroscopic (fluorescence quenching and UV-Vis absorption) and electrophoretic (native and SDS PAGE) techniques under simulated physiological conditions (pH 7.40, 37 °C). The spectroscopic results confirmed the complex formation for the tested systems. The binding constants and the number of binding sites were obtained by analysis of fluorescence data. The strongest binding affinity to HSA was found for epicatechin gallate and decreased in the order epicatechin gallate ⩾ catechin gallate > epigallocatechin gallate > gallocatechin gallate ≫ epicatechin ⩾ catechin > gallocatechin ⩾ epigallocatechin. All free energy changes possessed negative sign indicating the spontaneity of catechin-HSA systems formation. The binding distances between the donor (HSA) and the acceptors (catechins) estimated by the Förster theory revealed that non-radiation energy transfer from HSA to catechins occurred with high possibility. According to results obtained by native PAGE, the galloylated catechins increased the electrophoretic mobility of HSA, which indicated the change in the molecular charge of HSA, whilst the non-galloylated catechins caused no changes. The ability of aggregation and cross-linking of tested catechins with HSA was not proved by SDS-PAGE. The relationship between the structure characteristics of all tested catechins (e.g. presence of the galloyl moiety on the C-ring, the number of hydroxyl groups on the B-ring, and the spatial arrangement of the substituents on the C-ring) and their binding properties to HSA is discussed. The presented study contributes to the current knowledge in the area of protein-ligand binding, particularly catechin-HSA interactions.

  19. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... COMMISSION Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing... importation of certain semiconductor products made by advanced lithography techniques and products containing... certain semiconductor products made by advanced lithography techniques or products containing same...

  20. Advanced liner-cooling techniques for gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Riddlebaugh, S. M.

    1985-01-01

    Component research for advanced small gas turbine engines is currently underway at the NASA Lewis Research Center. As part of this program, a basic reverse-flow combustor geometry was being maintained while different advanced liner wall cooling techniques were investigated. Performance and liner cooling effectiveness of the experimental combustor configuration featuring counter-flow film-cooled panels is presented and compared with two previously reported combustors featuring: splash film-cooled liner walls; and transpiration cooled liner walls (Lamilloy).

  1. Advanced regenerative-cooling techniques for future space transportation systems

    NASA Technical Reports Server (NTRS)

    Wagner, W. R.; Shoji, J. M.

    1975-01-01

    A review of regenerative-cooling techniques applicable to advanced planned engine designs for space booster and orbit transportation systems has developed the status of the key elements of this cooling mode. This work is presented in terms of gas side, coolant side, wall conduction heat transfer, and chamber life fatigue margin considerations. Described are preliminary heat transfer and trade analyses performed using developed techniques combining channel wall construction with advanced, high-strength, high-thermal-conductivity materials (NARloy-Z or Zr-Cu alloys) in high heat flux regions, combined with lightweight steel tubular nozzle wall construction. Advanced cooling techniques such as oxygen cooling and dual-mode hydrocarbon/hydrogen fuel operation and their limitations are indicated for the regenerative cooling approach.

  2. Application of spectroscopic techniques for the analysis of kidney stones: a pilot study

    NASA Astrophysics Data System (ADS)

    Shameem, K. M., Muhammed; Chawla, Arun; Bankapur, Aseefhali; Unnikrishnan, V. K.; Santhosh, C.

    2016-03-01

    Identification and characterization of kidney stone remains one of the important analytical tasks in the medical field. Kidney stone is a common health complication throughout the world, which may cause severe pain, obstruction and infection of urinary tract, and can lead to complete renal damage. It commonly occurs in both sexes regardless of age. Kidney stones have different composition, although each stones have a major single characteristic component. A complete understanding of a sample properties and their function can only be feasible by utilizing elemental and molecular information simultaneously. Two laser based analytical techniques; Laser Induced Breakdown spectroscopy (LIBS) and Raman spectroscopy have been used to study different types of kidney stones from different patients. LIBS and Raman spectroscopy are highly complementary spectroscopic techniques, which provide elemental and molecular information of a sample. Q-switched Nd:YAG laser at 355 nm laser having energy 17mJ per pulse at 10 Hz repetition rate was used for getting LIBS spectra. Raman measurements were carried out using a home assembled micro-Raman spectrometer. Using the recorded Raman spectra of kidney stones, we were able to differentiate different kinds of kidney stones. LIBS spectra of the same stones are showing the evidence of C, Ca, H, and O and also suggest the presence of certain pigments.

  3. A RAPID SPECTROSCOPIC TECHNIQUE FOR DETERMINING THE POTENTIAL ALPHA ENERGY CONCENTRATION OF RADON DECAY PRODUCTS

    SciTech Connect

    Revzan, K. L.; Nazaroff, W. W.

    1981-07-01

    We consider the application of alpha spectroscopy to the rapid determination of the potential alpha energy concentration (PAEC) of radon decay products indoors. Two count totals are obtained after a single counting period. The PAEC is then estimated by a linear combination of the count totals, the two coefficients being determined by analysis of the dependence of the statistical and procedural errors on the equilibrium conditions and the sampling, delay, and counting times. For a total measurement time of 11 min, the procedural error is unlikely to exceed 20% for equilibrium conditions commonly found indoors; the statistical error is less than 20% at a PAEC of 0.005 WL, assuming a product of detector efficiency and flow rate of at least 1.0 l/min. An analysis is made of techniques based on a total alpha count, and the results are compared with those obtained with the rapid spectroscopic technique; the latter is clearly preferable when the measurement time does not exceed 15 min.

  4. DNA-binding study of anticancer drug cytarabine by spectroscopic and molecular docking techniques.

    PubMed

    Shahabadi, Nahid; Falsafi, Monireh; Maghsudi, Maryam

    2017-01-02

    The interaction of anticancer drug cytarabine with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multispectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove-binding mode, while the binding constant of UV-vis and the number of binding sites were 4.0 ± 0.2 × 10(4) L mol(-1) and 1.39, respectively. The fluorimetric studies showed that the reaction between the drugs with CT-DNA is exothermic. Circular dichroism spectroscopy was employed to measure the conformational change of DNA in the presence of cytarabine. Furthermore, the drug induces detectable changes in its viscosity for DNA interaction. The molecular modeling results illustrated that cytarabine strongly binds to groove of DNA by relative binding energy of docked structure -20.61 KJ mol(-1). This combination of multiple spectroscopic techniques and molecular modeling methods can be widely used in the investigation on the interaction of small molecular pollutants and drugs with biomacromolecules for clarifying the molecular mechanism of toxicity or side effect in vivo.

  5. Mineralogical Characterization Studies on Unburnt Ceramic Product Made from Rock Residue Additives by Ft-Ir Spectroscopic Technique

    NASA Astrophysics Data System (ADS)

    Vijayaragavan, R.; Mullainathan, S.; Balachandramohan, M.; Krishnamoorthy, N.; Nithiyanantham, S.; Murugesan, S.; Vanathi, V.

    2013-10-01

    The usability of waste rock (rock residue) powder as an additive material in ceramic samples was investigated. Qualitative analysis was carried out to determine the major and minor constituent minerals present in ceramic bodies made from rock residue powder by using FT-IR spectroscopic technique. Further, the representative ceramic bodies are analyzed by FT-IR technique to yield more information about the functional groups and also to estimate the order or disorder of kaolinite structure.

  6. Planetary Surface Analysis Using Fast Laser Spectroscopic Techniques: Combined Microscopic Raman, LIBS, and Fluorescence Spectroscopy

    NASA Astrophysics Data System (ADS)

    Blacksberg, J.; Rossman, G. R.; Maruyama, Y.; Charbon, E.

    2011-12-01

    In situ exploration of planetary surfaces has to date required multiple techniques that, when used together, yield important information about their formation histories and evolution. We present a time-resolved laser spectroscopic technique that could potentially collect complementary sets of data providing information on mineral structure, composition, and hydration state. Using a picosecond-scale pulsed laser and a fast time-resolved detector we can simultaneously collect spectra from Raman, Laser Induced Breakdown Spectroscopy (LIBS), and fluorescence emissions that are separated in time due to the unique decay times of each process. The use of a laser with high rep rate (40 KHz) and low pulse energy (1 μJ/pulse) allows us to rapidly collect high signal to noise Raman spectra while minimizing sample damage. Increasing the pulse energy by about an order of magnitude creates a microscopic plasma near the surface and enables the collection of LIBS spectra at an unusually high rep rate and low pulse energy. Simultaneously, broader fluorescence peaks can be detected with lifetimes varying from nanosecond to microsecond. We will present Raman, LIBS, and fluorescence spectra obtained on natural mineral samples such as sulfates, clays, pyroxenes and carbonates that are of interest for Mars mineralogy. We demonstrate this technique using a photocathode-based streak camera detector as well as a newly-developed solid state Single Photon Avalanche Diode (SPAD) sensor array based on Complementary Metal-Oxide Semiconductor (CMOS) technology. We will discuss the impact of system design and detector choice on science return of a potential planetary surface mission, with a specific focus on size, weight, power, and complexity. The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

  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. Advanced Marketing Core Curriculum. Test Items and Assessment Techniques.

    ERIC Educational Resources Information Center

    Smith, Clifton L.; And Others

    This document contains duties and tasks, multiple-choice test items, and other assessment techniques for Missouri's advanced marketing core curriculum. The core curriculum begins with a list of 13 suggested textbook resources. Next, nine duties with their associated tasks are given. Under each task appears one or more citations to appropriate…

  9. Advanced alloy design technique: High temperature cobalt base superalloy

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Freche, J. C.; Sandrock, G. D.

    1972-01-01

    Advanced alloy design technique was developed for treating alloys that will have extended life in service at high temperature and intermediate temperatures. Process stabilizes microstructure of the alloy by designing it so that compound identified with embrittlement is eliminated or minimized. Design process is being used to develop both nickel and cobalt-base superalloys.

  10. Bringing The Web Down to Size: Advanced Search Techniques.

    ERIC Educational Resources Information Center

    Huber, Joe; Miley, Donna

    1997-01-01

    Examines advanced Internet search techniques, focusing on six search engines. Includes a chart comparison of nine search features: "include two words,""exclude one of two words,""exclude mature audience content,""two adjacent words,""exact match,""contains first and neither of two following…

  11. Bringing The Web Down to Size: Advanced Search Techniques.

    ERIC Educational Resources Information Center

    Huber, Joe; Miley, Donna

    1997-01-01

    Examines advanced Internet search techniques, focusing on six search engines. Includes a chart comparison of nine search features: "include two words,""exclude one of two words,""exclude mature audience content,""two adjacent words,""exact match,""contains first and neither of two following…

  12. Spectroscopic technique with wide range of wavelength information improves near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Eda, Hideo; Aoki, Hiromichi; Eura, Shigeru; Ebe, Kazutoshi

    2009-02-01

    Near-infrared spectroscopy (NIRS) calculates hemoglobin parameters, such as oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) using the near-infrared light around the wavelength of 800nm. This is based on the modified-Lambert-Beer's law that changes in absorbance are proportional to changes in hemoglobin parameters. Many conventional measurement methods uses only a few wavelengths, however, in this research, basic examination of NIRS measurement was approached by acquiring wide range of wavelength information. Venous occlusion test was performed by using the blood pressure cuff around the upper arm. Pressure of 100mmHg was then applied for about 3 minutes. During the venous occlusion, the spectrum of the lower arm muscles was measured every 15 seconds, within the range of 600 to 1100nm. It was found that other wavelength bands hold information correlating to this venous occlusion task. Technique of improving the performance of NIRS measurement using the Spectroscopic Method is very important for Brain science.

  13. Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in animal depression model

    NASA Astrophysics Data System (ADS)

    Depciuch, J.; Sowa-Kucma, M.; Nowak, G.; Papp, M.; Gruca, P.; Misztak, P.; Parlinska-Wojtan, M.

    2017-04-01

    Depression becomes nowadays a high mortality civilization disease with one of the major causes being chronic stress. Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of rats subjected to chronic mild stress, which is a common animal depression model. Moreover, the efficiency of the imipramine treatment was evaluated. It was found that chronic mild stress not only damages the structure of the phospholipids and proteins, but also decreases their level in the blood serum. A 5 weeks imipramine treatment did increase slightly the quantity of proteins, leaving the damaged phospholipids unchanged. Structural information from phospholipids and proteins was obtained by UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of stressed rats was normalized after imipramine therapy, while the impaired structure of phospholipids remained unaffected. These findings strongly suggest that the depression factor, which is chronic mild stress, may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression.

  14. Soil examination for a forensic trace evidence laboratory--Part 1: Spectroscopic techniques.

    PubMed

    Woods, Brenda; Lennard, Chris; Kirkbride, K Paul; Robertson, James

    2014-12-01

    In the past, forensic soil examination was a routine aspect of trace evidence examination in forensic science. However, in Australia, the apparent need for soil examinations has diminished and with it the capability of forensic science laboratories to carry out soil examination has been eroded. In recent years, due to soil examinations contributing to some high profile investigations, interest in soil examinations has been renewed. Routine soil examinations conducted in a forensic science laboratory by trace evidence scientists can be facilitated if the examinations are conducted using the instrumentation routinely used by these examiners. Spectroscopic techniques such as visible microspectrophotometry (MSP) and Attenuated Total Reflectance (ATR) Fourier Transform Infrared spectroscopy (FTIR) are routinely used by trace evidence analysts for the colour and compositional analysis, respectively, of forensic items, including paints, fibres, inks and toners, tapes, adhesives and other miscellaneous examinations. This article presents an examination of the feasibility of using MSP and ATR-FTIR as a first step in the forensic comparison of soils with particular reference to Australian soil samples. This initial study demonstrates MSP and ATR-FTIR can effectively be used as a screening test for the discrimination of "forensic-sized" soil samples prior to submission for more detailed analyses by a soil expert. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Investigation of fungal deterioration of synthetic paint binders using vibrational spectroscopic techniques.

    PubMed

    Cappitelli, Francesca; Vicini, Silvia; Piaggio, Paolo; Abbruscato, Pamela; Princi, Elisabetta; Casadevall, Arturo; Nosanchuk, Joshua D; Zanardini, Elisabetta

    2005-01-14

    The deterioration of synthetic polymers caused by biological process is usually evaluated by visual inspection and measuring physical effects. In contrast to this approach, we have applied vibrational spectroscopies to study the biodegradation of the synthetic resins. 29 synthetic resins used as paint binding media, including acrylic, alkyd and poly(vinyl acetate) polymers, were examined for potential susceptibility to fungal degradation using the standard method ASTM G21-96(2002). In addition, the degraded resins were analysed by Raman spectroscopy, FT-IR and FT-IR photoacoustic spectroscopy. Almost all the acrylic resins studied proved to be resistant to microbial attack, while all alkyd resins and some poly(vinyl acetates) turned out to be biodegradable. Within a few days of inoculation Aspergillus niger was the most copious fungus on the biodegraded resins. A comparison of the IR and Raman spectra of control and biodegraded resins did not show any differences, but photoacoustic spectroscopy revealed additional bands for the fungal-degraded resins, consistent with the presence of fungal-derived substances. The additional bands in the photoacoustic spectra were due to the presence of Aspergillus niger and melanin, a fungal pigment. Since IR photoacoustic spectroscopy can be also a suitable technique for the chemical characterisation of binding media, the same spectroscopic analysis can be employed to both characterise the material and obtain evidence for fungal colonization. Microbial growth on Sobral 1241ML (alkyd resin) after 28 d (growth rating 4) compared with the non-inoculated resin.

  16. Characterization of the binding of nevadensin to bovine serum albumin by optical spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Yu, Zhaolian; Li, Daojin; Ji, Baoming; Chen, Jianjun

    2008-10-01

    Binding of nevadensin to bovine serum albumin (BSA) has been studied in detail at 298 and 310 K using spectrophotometric technique. The intrinsic fluorescence of BSA was strongly quenched by the addition of nevadensin and spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of nevadensin ( Cdrug/ CBSA < 1) and a combined quenching process at higher concentration of nevadensin ( Cdrug/ CBSA > 1). The binding parameters for the reaction at a pH above (7.40) or below (3.40) the isoelectric point have been calculated according to the double logarithm regression curve. The thermodynamic parameters Δ H0, Δ G0, Δ S0 at different temperatures and binding mechanism of nevadensin to BSA at pH 7.40 and 3.40 were evaluated. The binding ability of nevadensin to BSA at pH 7.40 was stronger than that at pH 3.40. Steady fluorescence, synchronous fluorescence and circular dichroism (CD) were applied to investigate protein conformation. A value of 2.15 nm for the average distance r between nevadensin (acceptor) and tryptophan residues (Trp) of BSA (donor) was derived from the fluorescence resonance energy transfer. Moreover, influence of pH on the interaction nevadensin with BSA was investigated.

  17. Integrated Analysis of the Wood Oil from Xanthocyparis vietnamensis Farjon & Hiep. by Chromatographic and Spectroscopic Techniques.

    PubMed

    Bazzali, Ophélie; Thai, Tran Huy; Hoi, Tran Minh; Khang, Nguyen Sinh; Hien, Nguyen Thi; Casanova, Joseph; Bighelli, Ange; Tomi, Félix

    2016-06-27

    In order to get better knowledge about the volatiles produced by Xanthocyparis vietnamensis, a species recently discovered in Vietnam, its wood oil has been analyzed by a combination of chromatographic (GC, CC) and spectroscopic (GC-MS, (13)C-NMR) techniques. Forty components that accounted for 87.9% of the oil composition have been identified. The composition is dominated by nootkatene (20.7%), 11,12,13-tri-nor-eremophil-1(10)-en-7-one (17.2%), γ-eudesmol (5.1%), nootkatone (4.7%), valencene (3.5%) and 13-nor-eremophil-1(10)-en-11-one (2.6%). The structure of two new compounds-10-epi-nor-γ-eudesmen-11-one and 12-hydroxy-isodihydroagarofuran-has been elucidated, while 11,12,13-tri-nor-eremophil-1(10)-en-7-ol is reported as a natural product for the first time. The composition of X. vietnamensis wood oil varied drastically from those of leaf oils, dominated by hedycaryol (34.4%), phyllocladene (37.8%) or by pimara-6(14)-15-diene (19.4%).

  18. Studies on the interaction of salvianolic acid B with human hemoglobin by multi-spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Chen, Tingting; Zhu, Shajun; Cao, Hui; Shang, Yanfang; Wang, Miao; Jiang, Guoqing; Shi, Yujun; Lu, Tianhong

    2011-04-01

    The interaction between salvianolic acid B (Sal B) and human hemoglobin (HHb) under physiological conditions was investigated by UV-vis absorption, fluorescence, synchronous fluorescence and circular dichroism spectroscopic techniques. The experimental results indicate that the quenching mechanism of fluorescence of HHb by Sal B is a static quenching procedure, the binding reaction is spontaneous, and the hydrophobic interactions play a major role in binding of Sal B to HHb. Based on Förster's theory of non-radiative energy transfer, the binding distance between Sal B and the inner tryptophan residues of HHb was determined to be 2.64 nm. The synchronous fluorescence experiment revealed that Sal B can not lead to the microenvironmental changes around the Tyr and Trp residues of HHb, and the binding site of Sal B on HHb is located at α 1β 2 interface of HHb. Furthermore, the CD spectroscopy indicated the secondary structure of HHb is not changed in the presence of Sal B.

  19. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in radio frequency plasmas

    NASA Astrophysics Data System (ADS)

    Daksha, M.; Berger, B.; Schuengel, E.; Korolov, I.; Derzsi, A.; Koepke, M.; Donkó, Z.; Schulze, J.

    2016-06-01

    A computationally assisted spectroscopic technique to measure secondary electron emission coefficients (γ-CAST) in capacitively-coupled radio-frequency plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of phase resolved optical emission spectroscopy and particle-based kinetic simulations. In such plasmas (under most conditions in electropositive gases) the spatio-temporally resolved electron-impact excitation/ionization rate features two distinct maxima adjacent to each electrode at different times within each RF period. While one maximum is the consequence of the energy gain of electrons due to sheath expansion, the second maximum is produced by secondary electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the adjacent sheath. Due to these different excitation/ionization mechanisms, the ratio of the intensities of these maxima is very sensitive to the secondary electron emission coefficient γ. This sensitvity, in turn, allows γ to be determined by comparing experimental excitation profiles and simulation data obtained with various γ-coefficients. The diagnostic, tested here in a geometrically symmetric argon discharge, yields an effective secondary electron emission coefficient of γ =0.066+/- 0.01 for stainless steel electrodes.

  20. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in technological rf plasmas

    NASA Astrophysics Data System (ADS)

    Berger, Birk; Schulze, Julian; Daksha, Manaswi; Schuengel, Edmund; Koepke, Mark; Korolov, Ihor; Derzsi, Aranka; Donko, Zoltan

    2016-09-01

    A Computationally Assisted Spectroscopic Technique to measure secondary electron emission coefficients (y-CAST) in capacitive rf plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of Phase Resolved Optical Emission Spectroscopy and PIC simulations. Under most conditions in electropositive plasmas the spatio-temporally resolved electron-impact excitation rate features two distinct maxima adjacent to each electrode at different times within one rf period. One maximum is the consequence of an energy gain of the electrons due to sheath expansion. The second maximum is produced by electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the sheath. Due to the different excitation mechanisms the ratio of the intensities of these maxima is very sensitive to y, which allows for its determination via comparing the experimentally measured excitation profiles with corresponding simulation data obtained with various y-coefficients. This diagnostic is tested here in a geometrically symmetric reactor, for stainless steel electrodes and argon gas. An effective secondary electron emission coefficient of y = 0.067+-0.010 is obtained, which is in excellent agreement with previous experimental results.

  1. Advanced techniques in safeguarding a conditioning facility for spent fuel

    SciTech Connect

    Rudolf, K.; Weh, R. )

    1992-01-01

    Although reprocessing continues to be the main factor in the waste management of nuclear reactors, the alternative of direct final disposal is currently being developed to the level of industrial applications, based on an agreement between the heads of the federal government and the federal states of Germany. Thus, the Konrad and Gorleben sites are being studied as potential final repositories as is the pilot conditioning facility (PKA) under construction. Discussions on the application of safeguards measures have led to the drafting of an approach that will cover the entire back end of the fuel cycle. The conditioning of fuel prior to direct final disposal represents one element in the overall approach. A modern facility equipped with advanced technology, PKA is a pilot plant with regard to conditioning techniques as well as to safeguards. Therefore, the PKA safeguards approach is expected to facilitate future industrial applications of the conditioning procedure. This cannot be satisfactorily implemented without advanced safeguards techniques. The level of development of the safeguards techniques varies. While advanced camera and seal systems are basically available, the other techniques and methods still require research and development. Feasibility studies and equipment development are geared to providing applicable safeguards techniques in time for commissioning of the PKA.

  2. Novel infrared spectroscopic techniques for the study of adsorbed proteins on photoactive thin films

    NASA Astrophysics Data System (ADS)

    Angle, Taylor Allan

    Through the development of attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopic techniques, as well as biocompatible nanoporous gold film confining layers and photoactive nanocrystal cadmium telluride (CdTe) thin films, a system capable of in situ study of adsorbed protein films on photoactive layers was created. Due to the oxygen intolerance of the enzyme of interest for this work (a [FeFe]-hydrogenase from Clostridium acetobutylicum), techniques were developed in a manner conducive to anaerobic environments. Solid-state ligand exchange processes were shown to have no detrimental effect on the continued ability of nanocrystal CdTe layers to reduce species via the transfer of photogenerated electrons. Nanoporous gold films were shown to effectively confine poorly bound surface species including nanocrystal CdTe layers and adsorbed protein films. An ATR "stack'' structure, consisting of a silicon wafer coupled to a zinc selenide ATR crystal by a high index optical coupling fluid, was designed and implemented, leading to a tunable optical structure for use with existing ATR setups. This ATR stack was shown to maintain resolution and signal intensity of traditional ATR configurations for both aqueous and solid-state samples. Through the use of coupled silicon wafers, we significantly increased both sample throughput and the number of available chemical processes by replacing the expensive ATR crystals as the default sample substrate. Shown herein to function as initially intended, these novel methods provide the groundwork for more complex experiments, such as an in situ monitoring of the photooxidation of surface-bound hydrogenases.

  3. [Application of Raman spectroscopic technique to the identification and investigation of Chinese ancient jades and jade artifacts].

    PubMed

    Zhao, Hong-Xia; Gan, Fu-Xi

    2009-11-01

    Laser Raman spectroscopic technique is one of the essential methods in scientific archaeological research, which belongs to the nondestructive analysis. As a very good nondestructive analysis approach, it has not been widely applied in the research of the Chinese ancient jade artifacts. First of all in the present paper the fundamentals of laser Raman spectroscopic technique and the new research progress in this field were reviewed. Secondly, the Raman spectra of five familiar jades including nephrite (mainly composed of tremolite), Xiuyan Jade (mainly composed of serpentine), Dushan Jade (mainly composed of anorthite and Zoisite), turquoise and lapis lazuli were summarized respectively. As for an example, the Raman spectra of the four Chinese ancient jade artifacts excavated from Liangzhu Site of Zhejiang Province and Yinxu Site of Anyang in Henan Province were compared with that of the nephrite sample in Hetian of Xinjiang Province. It was shown that the Raman spectroscopic technique is a good nondestructive approach to the identification and investigation of the structures and mineral composition of Chinese ancient jade artifacts. Finally, the limitations and the foreground of this technique were discussed.

  4. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  5. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  6. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    DOE PAGES

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; ...

    2014-09-10

    In this paper, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insightsmore » gained from these studies are described and future directions of this field are also discussed.« less

  7. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    SciTech Connect

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey; Lu, Yi

    2014-09-10

    In this paper, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed.

  8. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    PubMed Central

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey

    2014-01-01

    In this review, we summarize recent progresses in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed. PMID:25205057

  9. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials.

    PubMed

    Wu, Peiwen; Yu, Yang; McGhee, Claire E; Tan, Li Huey; Lu, Yi

    2014-12-10

    In this review, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed.

  10. Electric field measurements of the LH wave and ICRF near-field utilizing non-perturbative spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Martin, E. H.; Caughman, J. B. O.; Klepper, C. C.; Goniche, M.; Isler, R. C.; Hillairet, J.; Bottereau, C.

    2015-12-01

    The physics of wave heating and current drive processes in the bulk hot plasma are generally well identified. However, details of the wave-plasma interaction in the cold plasma edge are still not fully understood. In this paper a spectroscopic technique allowing for measurements of the electric field driving wave-plasma interactions in the edge region for LH current drive and ICRH systems will be discussed. Experimental results obtained in Tore Supra near the LH C3 antenna and in the magnetized capacitively coupled RF sheath from an experiment designed to mimic the ICRF near-field are presented. In conclusion, future plans to implement a laser-based spectroscopic technique to acquire the high resolution measurements needed for model validation is discussed.

  11. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high-quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  12. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  13. Determination of lipid content of oleaginous microalgal biomass by NMR spectroscopic and GC-MS techniques.

    PubMed

    Sarpal, Amarijt S; Teixeira, Claudia M L L; Silva, Paulo R M; Lima, Gustavo M; Silva, Samantha R; Monteiro, Thays V; Cunha, Valnei S; Daroda, Romeu J

    2015-05-01

    Direct methods based on (1)H NMR spectroscopic techniques have been developed for the determination of neutral lipids (triglycerides and free fatty acids) and polar lipids (glyceroglycolipids/phospholipids) in the solvent extracts of oleaginous microalgal biomasses cultivated on a laboratory scale with two species in different media. The chemical shift assignments observed in the (1)H and (13)C NMR spectra corresponding to unsaturated (C18:N, N = 1-3, C20:3, C20:5, C22:6, epoxy) and saturated (C14-C18) fatty acid ester components in a complex matrix involving overlapped resonances have been unambiguously confirmed by the application of 2D NMR spectroscopy (total correlation spectroscopy and heteronuclear single quantum coherence-total correlation spectroscopy). The study of the effect of a polar lipid matrix on the determination of neutral lipids by an internal reference blending process by a systematic designed experimental protocol has provided absolute quantification. The fatty acid composition of algal extracts was found to be similar to that of vegetable oils containing saturated (C16-C18:0) and unsaturated (C18:N, N = 1-3, C20:N, N = 3-4, C22:6) fatty acids as confirmed by NMR spectroscopy and gas chromatography-mass spectrometry analyses. The NMR methods developed offer great potential for rapid screening of algal strains for generation of algal biomass with the desired lipid content, quality, and potential for biodiesel and value-added polyunsaturated fatty acids in view of the cost economics of the overall cost of generation of the biomass.

  14. Data Compression Techniques for Advanced Space Transportation Systems

    NASA Technical Reports Server (NTRS)

    Bradley, William G.

    1998-01-01

    Advanced space transportation systems, including vehicle state of health systems, will produce large amounts of data which must be stored on board the vehicle and or transmitted to the ground and stored. The cost of storage or transmission of the data could be reduced if the number of bits required to represent the data is reduced by the use of data compression techniques. Most of the work done in this study was rather generic and could apply to many data compression systems, but the first application area to be considered was launch vehicle state of health telemetry systems. Both lossless and lossy compression techniques were considered in this study.

  15. Advanced thermal management techniques for space power electronics

    NASA Astrophysics Data System (ADS)

    Reyes, Angel Samuel

    1992-01-01

    Modern electronic systems used in space must be reliable and efficient with thermal management unaffected by outer space constraints. Current thermal management techniques are not sufficient for the increasing waste heat dissipation of novel electronic technologies. Many advanced thermal management techniques have been developed in recent years that have application in high power electronic systems. The benefits and limitations of emerging cooling technologies are discussed. These technologies include: liquid pumped devices, mechanically pumped two-phase cooling, capillary pumped evaporative cooling, and thermoelectric devices. Currently, liquid pumped devices offer the most promising alternative for electronics thermal control.

  16. Advance techniques for monitoring human tolerance to positive Gz accelerations

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Sandler, H.; Rositano, S.; Skrettingland, K.; Mancini, R.

    1973-01-01

    Tolerance to positive g accelerations was measured in ten normal male subjects using both standard and advanced techniques. In addition to routine electrocardiogram, heart rate, respiratory rate, and infrared television, monitoring techniques during acceleration exposure included measurement of peripheral vision loss, noninvasive temporal, brachial, and/or radial arterial blood flow, and automatic measurement of indirect systolic and diastolic blood pressure at 60-sec intervals. Although brachial and radial arterial flow measurements reflected significant cardiovascular changes during and after acceleration, they were inconsistent indices of the onset of grayout or blackout. Temporal arterial blood flow, however, showed a high correlation with subjective peripheral light loss.

  17. Advanced computer graphic techniques for laser range finder (LRF) simulation

    NASA Astrophysics Data System (ADS)

    Bedkowski, Janusz; Jankowski, Stanislaw

    2008-11-01

    This paper show an advanced computer graphic techniques for laser range finder (LRF) simulation. The LRF is the common sensor for unmanned ground vehicle, autonomous mobile robot and security applications. The cost of the measurement system is extremely high, therefore the simulation tool is designed. The simulation gives an opportunity to execute algorithm such as the obstacle avoidance[1], slam for robot localization[2], detection of vegetation and water obstacles in surroundings of the robot chassis[3], LRF measurement in crowd of people[1]. The Axis Aligned Bounding Box (AABB) and alternative technique based on CUDA (NVIDIA Compute Unified Device Architecture) is presented.

  18. The Advanced Space Plant Culture Device with Live Imaging Technique

    NASA Astrophysics Data System (ADS)

    Zheng, Weibo; Zhang, Tao; Tong, Guanghui

    The live imaging techniques, including the color and fluorescent imags, are very important and useful for space life science. The advanced space plant culture Device (ASPCD) with live imaging Technique, developed for Chinese Spacecraft, would be introduced in this paper. The ASPCD had two plant experimental chambers. Three cameras (two color cameras and one fluorescent camera) were installed in the two chambers. The fluorescent camera could observe flowering genes, which were labeled by GFP. The lighting, nutrient, temperature controling and water recycling were all independent in each chamber. The ASPCD would beed applied to investigate for the growth and development of the high plant under microgravity conditions on board the Chinese Spacecraft.

  19. Three-dimensional hybrid grid generation using advancing front techniques

    NASA Technical Reports Server (NTRS)

    Steinbrenner, John P.; Noack, Ralph W.

    1995-01-01

    A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.

  20. Strategies and advanced techniques for marine pollution studies

    SciTech Connect

    Giam, C.S.; Dou, H.J.M.

    1986-01-01

    Here is a review of strategies and techniques for evaluating marine pollution by hazardous organic compounds. Geo-chemical considerations such as the relationship between the inputs, atmospheric and estuarine transport, and the outputs, sedimentation and degradation, guide the decision on appropriate approaches to pollution monitoring in the marine environment. The latest instrumental methods and standard protocols for analysis of organic compounds are presented, as well as advances in interpretation and correlation of data made possible by the accessibility of commercial data bases.

  1. Advanced endoscopic ultrasound management techniques for preneoplastic pancreatic cystic lesions

    PubMed Central

    Arshad, Hafiz Muhammad Sharjeel; Bharmal, Sheila; Duman, Deniz Guney; Liangpunsakul, Suthat; Turner, Brian G

    2017-01-01

    Pancreatic cystic lesions can be benign, premalignant or malignant. The recent increase in detection and tremendous clinical variability of pancreatic cysts has presented a significant therapeutic challenge to physicians. Mucinous cystic neoplasms are of particular interest given their known malignant potential. This review article provides a brief but comprehensive review of premalignant pancreatic cystic lesions with advanced endoscopic ultrasound (EUS) management approaches. A comprehensive literature search was performed using PubMed, Cochrane, OVID and EMBASE databases. Preneoplastic pancreatic cystic lesions include mucinous cystadenoma and intraductal papillary mucinous neoplasm. The 2012 International Sendai Guidelines guide physicians in their management of pancreatic cystic lesions. Some of the advanced EUS management techniques include ethanol ablation, chemotherapeutic (paclitaxel) ablation, radiofrequency ablation and cryotherapy. In future, EUS-guided injections of drug-eluting beads and neodymium:yttrium aluminum agent laser ablation is predicted to be an integral part of EUS-guided management techniques. In summary, International Sendai Consensus Guidelines should be used to make a decision regarding management of pancreatic cystic lesions. Advanced EUS techniques are proving extremely beneficial in management, especially in those patients who are at high surgical risk. PMID:27574295

  2. Angular-divergence calculation for Experimental Advanced Superconducting Tokamak neutral beam injection ion source based on spectroscopic measurements

    SciTech Connect

    Chi, Yuan; Hu, Chundong; Zhuang, Ge

    2014-02-15

    Calorimetric method has been primarily applied for several experimental campaigns to determine the angular divergence of high-current ion source for the neutral beam injection system on the Experimental Advanced Superconducting Tokamak (EAST). A Doppler shift spectroscopy has been developed to provide the secondary measurement of the angular divergence to improve the divergence measurement accuracy and for real-time and non-perturbing measurement. The modified calculation model based on the W7AS neutral beam injectors is adopted to accommodate the slot-type accelerating grids used in the EAST's ion source. Preliminary spectroscopic experimental results are presented comparable to the calorimetrically determined value of theoretical calculation.

  3. Teaching advanced wound closure techniques using cattle digits.

    PubMed

    Khalil, Philipe N; Kanz, Karl-Georg; Siebeck, Matthias; Mutschler, Wolf

    2011-03-01

    To evaluate a model used to impart advanced wound closure skills because available models do not meet the necessary requirements to a substantial degree. Seventy-one residents were asked to evaluate a 75-minute-long skills course using cadaveric cattle digits to learn Z-plasty, V-Y-plasty, and oval-shaped rotational flaps. A short film and the course instructor demonstrated each technique first. A Likert rating scale ranging from 1 to 6 was used for questions in the survey given to the residents. There was strong agreement among residents (1.65 ± 1.17 years of experience) that advanced wound closure training courses are necessary (5.73 ± 0.73), which corresponded to the residents' low level of knowledge and self-assessment of practical skills and present experience (2.84 ± 1.01). The course was evaluated with high acceptance, even though it was found to be demanding for the trainees (5.84 ± 0.40). This might also be related to the high rating of the model itself, which was found to be a suitable method for teaching advanced wound closure techniques (5.50 ± 0.71) that was easily comprehensible (5.73 ± 0.53). Skills training courses for young trainees are warranted to impart advanced wound closure techniques. The curriculum using cattle digits presented here is recommended. The authors have indicated no significant interest with commercial supporters. © 2011 by the American Society for Dermatologic Surgery, Inc.

  4. The fusion of MIR absorbance and NIR Raman spectroscopic techniques for identification of improvised explosive materials in multiple scenarios

    NASA Astrophysics Data System (ADS)

    Stokes, Robert J.; Normand, Erwan L.; Lindley, Ruth; Black, Paul; McCulloch, Michael; Middleton, David N.; Smith, W. Ewen; Foulger, Brian; Lewis, Colin

    2009-09-01

    We demonstrate how molecular spectroscopy methods using NIR and MIR lasers can provide rapid detection and identification of many threat materials. It is increasingly recognised that one spectroscopic method will not be suited to every target in every scenario, both in terms of spectroscopic selectivity and the context e.g. vapour phase or within a sealed container. The orthogonal selection rules and capabilities of IR and Raman in combination allow the identification of a very broad range of targets, both in liquid and vapour phase. Therefore, we introduce the benefits of the combining infra-red absorbance based on Quantum Cascade lasers (QC-IR) and NIR Raman spectroscopy for nitrogenous and peroxide based materials. Rapid scan rates up to 10Hz for QC-IR and Raman and are demonstrated using current technology. However, understanding of the chemistry and spectroscopic signatures behind such materials is necessary for accurate fast fitting algorithms to benefit of the full advantage with advances in hardware. This is especially true as future users requirements move towards rapid multiplexed analysis and data fusion from a variety of sensors.

  5. Advanced computer modeling techniques expand belt conveyor technology

    SciTech Connect

    Alspaugh, M.

    1998-07-01

    Increased mining production is continuing to challenge engineers and manufacturers to keep up. The pressure to produce larger and more versatile equipment is increasing. This paper will show some recent major projects in the belt conveyor industry that have pushed the limits of design and engineering technology. Also, it will discuss the systems engineering discipline and advanced computer modeling tools that have helped make these achievements possible. Several examples of technologically advanced designs will be reviewed. However, new technology can sometimes produce increased problems with equipment availability and reliability if not carefully developed. Computer modeling techniques that help one design larger equipment can also compound operational headaches if engineering processes and algorithms are not carefully analyzed every step of the way.

  6. Advanced aeroservoelastic stabilization techniques for hypersonic flight vehicles

    NASA Technical Reports Server (NTRS)

    Chan, Samuel Y.; Cheng, Peter Y.; Myers, Thomas T.; Klyde, David H.; Magdaleno, Raymond E.; Mcruer, Duane T.

    1992-01-01

    Advanced high performance vehicles, including Single-Stage-To-Orbit (SSTO) hypersonic flight vehicles, that are statically unstable, require higher bandwidth flight control systems to compensate for the instability resulting in interactions between the flight control system, the engine/propulsion dynamics, and the low frequency structural modes. Military specifications, such as MIL-F-9490D and MIL-F-87242, tend to limit treatment of structural modes to conventional gain stabilization techniques. The conventional gain stabilization techniques, however, introduce low frequency effective time delays which can be troublesome from a flying qualities standpoint. These time delays can be alleviated by appropriate blending of gain and phase stabilization techniques (referred to as Hybrid Phase Stabilization or HPS) for the low frequency structural modes. The potential of using HPS for compensating structural mode interaction was previously explored. It was shown that effective time delay was significantly reduced with the use of HPS; however, the HPS design was seen to have greater residual response than a conventional gain stablized design. Additional work performed to advance and refine the HPS design procedure, to further develop residual response metrics as a basis for alternative structural stability specifications, and to develop strategies for validating HPS design and specification concepts in manned simulation is presented. Stabilization design sensitivity to structural uncertainties and aircraft-centered requirements are also assessed.

  7. Advances in Testing Techniques for Digital Microfluidic Biochips

    PubMed Central

    Shukla, Vineeta; Hussin, Fawnizu Azmadi; Hamid, Nor Hisham; Zain Ali, Noohul Basheer

    2017-01-01

    With the advancement of digital microfluidics technology, applications such as on-chip DNA analysis, point of care diagnosis and automated drug discovery are common nowadays. The use of Digital Microfluidics Biochips (DMFBs) in disease assessment and recognition of target molecules had become popular during the past few years. The reliability of these DMFBs is crucial when they are used in various medical applications. Errors found in these biochips are mainly due to the defects developed during droplet manipulation, chip degradation and inaccuracies in the bio-assay experiments. The recently proposed Micro-electrode-dot Array (MEDA)-based DMFBs involve both fluidic and electronic domains in the micro-electrode cell. Thus, the testing techniques for these biochips should be revised in order to ensure proper functionality. This paper describes recent advances in the testing technologies for digital microfluidics biochips, which would serve as a useful platform for developing revised/new testing techniques for MEDA-based biochips. Therefore, the relevancy of these techniques with respect to testing of MEDA-based biochips is analyzed in order to exploit the full potential of these biochips. PMID:28749411

  8. Application of advanced techniques for the assessment of bio-stability of biowaste-derived residues: A minireview.

    PubMed

    Lü, Fan; Shao, Li-Ming; Zhang, Hua; Fu, Wen-Ding; Feng, Shi-Jin; Zhan, Liang-Tong; Chen, Yun-Min; He, Pin-Jing

    2017-06-12

    Bio-stability is a key feature for the utilization and final disposal of biowaste-derived residues, such as aerobic compost or vermicompost of food waste, bio-dried waste, anaerobic digestate or landfilled waste. The present paper reviews conventional methods and advanced techniques used for the assessment of bio-stability. The conventional methods are reclassified into two categories. Advanced techniques, including spectroscopic (fluorescent, ultraviolet-visible, infrared, Raman, nuclear magnetic resonance), thermogravimetric and thermochemolysis analysis, are emphasized for their application in bio-stability assessment in recent years. Their principles, pros and cons are critically discussed. These advanced techniques are found to be convenient in sample preparation and to supply diversified information. However, the viability of these techniques as potential indicators for bio-stability assessment ultimately lies in the establishment of the relationship of advanced ones with the conventional methods, especially with the methods based on biotic response. Furthermore, some misuses in data explanation should be noted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Testing aspects of advanced coherent electron cooling technique

    SciTech Connect

    Litvinenko, V.; Jing, Y.; Pinayev, I.; Wang, G.; Samulyak, R.; Ratner, D.

    2015-05-03

    An advanced version of the Coherent-electron Cooling (CeC) based on the micro-bunching instability was proposed. This approach promises significant increase in the bandwidth of the CeC system and, therefore, significant shortening of cooling time in high-energy hadron colliders. In this paper we present our plans of simulating and testing the key aspects of this proposed technique using the set-up of the coherent-electron-cooling proof-of-principle experiment at BNL.

  10. Recent advances in UHV techniques for particle accelerators

    SciTech Connect

    M. G. Rao

    1995-01-01

    The ultrahigh vacuum (UHV) requirements for storage rings and accelerators, and the development of the science and technology of UHV for particle accelerators and magnetic fusion devices have been recently reviewed by N.B. Mistry and H.F. Dylla respectively. In this paper, the latest developments in the advancement of UHV techniques for the vacuum integrity of Continuous Electron Beam Accelerator Facility (CEBAF) and for successfully dealing with the synchrotron radiation related beam line vacuum problem encountered in the design of the SSC are reviewed: the review includes developments in extreme sensitivity He leak detection technique based on the dynamic adsorption and desorption of He, operation of ionization gauges at Lhe temperatures, metal sponges for the effective cryopumping of H{sup 2} and He to pressures better than 10{sup -14} torr, and low cost and high He sensitivity RGA's. The details of a new extreme sensitivity He leak detector system are also discussed here.

  11. Nasal base narrowing: the alar flap advancement technique.

    PubMed

    Ismail, Ahmed Soliman

    2011-01-01

    To evaluate the role of creating an alar-based advancement flap in narrowing the nasal base and correcting excessive alar flare. Case series with chart review. This is a retrospective record review study. The study included 35 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined the alar base reduction with alar flare excision by creating a single laterally based alar flap. Any caudal septal deformities and any nasal tip modification procedures were corrected before the nasal base narrowing. The mean follow-up period was 23 months. The mean alar flap narrowing was 6.3 mm, whereas the mean width of sill narrowing was 2.9 mm. This single laterally based advancement alar flap resulted in a more conservative external resection, thus avoiding alar wedge overresection or blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid were encountered, and the external alar wedge excision healed with no apparent scar that was hidden in the depth of the alar-facial crease. The risk of notching of the alar rim at the sill incision is reduced by adopting a 2-layer closure of the vestibular floor. The alar base advancement flap is an effective technique in narrowing both the nasal base and excessive alar flare. It adopts a single skin excision to correct the 2 deformities while commonly feared complications were avoided.

  12. Recent Advances in Techniques for Hyperspectral Image Processing

    NASA Technical Reports Server (NTRS)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; Marconcini, Mattia; Tilton, James C.; Trianni, Giovanna

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  13. Recent Advances in Techniques for Hyperspectral Image Processing

    NASA Technical Reports Server (NTRS)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; hide

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  14. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  15. Aesthetic Lateral Canthoplasty Using Tarso-Conjunctival Advancement Technique.

    PubMed

    Lee, Eun Jung; Lew, Dae Hyun; Song, Seung Han; Lee, Myung Chul

    2017-01-01

    Reduced horizontal length of the palpebral fissure is a distinctive characteristic of Asian eyelids, and aesthetic lateral canthal lengthening techniques have been performed for a refinement. The aim of this study is to describe a novel lateral canthoplasty using tarso-conjunctival advancement with a lid margin splitting procedure on the upper eyelids and to report the postoperative results. From December 2011 to June 2014, patients who underwent lateral canthoplasty using the tarso-conjunctival advancement procedure for aesthetic purposes were reviewed retrospectively. The predictor variables were grouped into demographic and operative categories. The primary outcome variables were the distances from the mid-pupillary line to the lateral canthus and the horizontal length of the palpebral aperture (distance from the medial to lateral canthus). Data analyses were performed using descriptive and univariate statistics. Patients who showed increment in objective measurements were considered significant. Aesthetic appearance was also evaluated based on pre- and postoperative clinical photographs. A total of 45 patients were enrolled in this study. Both the distance from the mid-pupil to the lateral canthus (ΔDpupil-lateral; 2.78 ± 0.54 mm, P <0.05) and the palpebral aperture horizontal length (ΔDmedial-lateral 2.93 ± 0.81 mm, P <0.05) increased significantly from pre- to postoperative state. All the patients demonstrated satisfactory results aesthetically during the follow-up. The tarso-conjunctival advancement technique for lateral canthoplasty produced satisfactory aesthetic results with an enlarged palpebral aperture. Future research is required to fully delineate the risk of possible complications, including injury to the eyelashes and meibomian glands.

  16. Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques. Master's thesis

    SciTech Connect

    Shaffer, B.L.

    1990-12-01

    Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques. The M0006 semiconductor samples were placed into a 28.5 degree inclination, 480 km altitude, near-circular orbit aboard the Long Duration Exposure Facility satellite and exposed to direct space environment for a period of 11 months, and were shielded by 0.313 inches of aluminum for another 58 months. The samples were examined for changes using cathodoluminescence and photoluminescence in various wavelength regions from 0.5 to 1.8 micrometers. Samples were cooled to approximately 10 degrees Kelvin in a vacuum of 10-8. (JS)

  17. Adjunctive techniques to traditional advancement procedures for treating severe blepharoptosis.

    PubMed

    Baik, Bong Soo; Ha, Won; Lee, Ji Won; Ji, So Young; Yang, Wan Suk; Park, Daeun; Kim, Kenneth K

    2014-04-01

    To create a more physiologic eyelid opening in patients with severe blepharoptosis, the authors used lamina propria mucosa of conjunctiva, which continues to the check ligament of the superior fornix, in addition to levator aponeurosis and Müller's muscle as a composite flap. In patients with epicanthal folds with associated telecanthus, the authors also performed epicanthoplasty with medial canthal tendon shortening. Fifty blepharoptosis patients (85 eyelids) with a degree of ptosis of greater than 4 mm underwent the advancement technique using the levator aponeurosis-Müller's muscle-lamina propria mucosa of conjunctiva as a composite flap. Twenty-one (42 percent) of those patients also underwent split V-W epicanthoplasty and plication of the medial canthal tendon for epicanthal folds with associated telecanthus. Degree of ptosis and levator function were measured preoperatively and postoperatively. Complete or near-complete correction of ptosis (degree of ptosis, <1 mm) was achieved in 54 eyelids (63.5 percent) and mild residual ptosis (degree of ptosis, 1 to 2 mm) was observed in 22 eyelids (25.9 percent) in postoperative follow-up after 6 months. The most common complication was reoperation, which was done in 15 eyelids (17.6 percent) because of incomplete correction. The advancement technique using the levator aponeurosis- Müller's muscle-lamina propria mucosa of conjunctiva composite was effective in the treatment of severe blepharoptosis with levator function of 2 to 7 mm. The technique produced elevating motion of the physiologic eyelid in a superior-posterior direction. There were no serious complications, such as long-term lagophthalmos or lid lag. Therapeutic, IV.

  18. Development and Quantification of UV-Visible and Laser Spectroscopic Techniques for Materials Accountability and Process Control

    SciTech Connect

    Ken Czerwinski; Phil Weck; Frederic Poineau

    2010-12-29

    Ultraviolet-Visible Spectroscopy (UV-Visible) and Time Resolved Laser Fluorescence Spectroscopy (TRLFS) optical techniques can permit on-line, real-time analysis of the actinide elements in a solvent extraction process. UV-Visible and TRLFS techniques have been used for measuring the speciation and concentration of the actinides under laboratory conditions. These methods are easily adaptable to multiple sampling geometries, such as dip probes, fiber-optic sample cells, and flow-through cell geometries. To fully exploit these techniques for GNEP applications, the fundamental speciation of the target actinides and the resulting influence on 3 spectroscopic properties must be determined. Through this effort detection limits, process conditions, and speciation of key actinide components can be establish and utilized in a range of areas of interest to GNEP, especially in areas related to materials accountability and process control.

  19. Advancing the frontiers in nanocatalysis, biointerfaces, and renewable energy conversion by innovations of surface techniques.

    PubMed

    Somorjai, Gabor A; Frei, Heinz; Park, Jeong Y

    2009-11-25

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

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

    SciTech Connect

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

    2009-07-23

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

  1. Advanced Techniques for Removal of Retrievable Inferior Vena Cava Filters

    SciTech Connect

    Iliescu, Bogdan; Haskal, Ziv J.

    2012-08-15

    Inferior vena cava (IVC) filters have proven valuable for the prevention of primary or recurrent pulmonary embolism in selected patients with or at high risk for venous thromboembolic disease. Their use has become commonplace, and the numbers implanted increase annually. During the last 3 years, in the United States, the percentage of annually placed optional filters, i.e., filters than can remain as permanent filters or potentially be retrieved, has consistently exceeded that of permanent filters. In parallel, the complications of long- or short-term filtration have become increasingly evident to physicians, regulatory agencies, and the public. Most filter removals are uneventful, with a high degree of success. When routine filter-retrieval techniques prove unsuccessful, progressively more advanced tools and skill sets must be used to enhance filter-retrieval success. These techniques should be used with caution to avoid damage to the filter or cava during IVC retrieval. This review describes the complex techniques for filter retrieval, including use of additional snares, guidewires, angioplasty balloons, and mechanical and thermal approaches as well as illustrates their specific application.

  2. Recent advances in biosynthetic modeling of nitric oxide reductases and insights gained from nuclear resonance vibrational and other spectroscopic studies

    SciTech Connect

    Chakraborty, Saumen; Reed, Julian; Sage, Timothy; Branagan, Nicole C.; Petrik, Igor D.; Miner, Kyle D.; Hu, Michael Y.; Zhao, Jiyong; Alp, E. Ercan; Lu, Yi

    2015-10-05

    This Forum Article focuses on recent advances in structural and spectroscopic studies of biosynthetic models of nitric oxide reductases (NORs). NORs are complex metalloenzymes found in the denitrification pathway of Earth's nitrogen cycle where they catalyze the proton-dependent twoelectron reduction of nitric oxide (NO) to nitrous oxide (N2O). While much progress has been made in biochemical and biophysical studies of native NORs and their variants, a. clear mechanistic understanding of this important metalloenzyme related to its function is still elusive. We report herein UV vis and nuclear resonance vibrational spectroscopy (NRVS) studies of mononitrosylated intermediates of the NOR reaction of a biosynthetic model. The ability to selectively substitute metals at either heme or nonheme metal sites allows the introduction of independent 57Fe probe atoms at either site, as well as allowing the preparation of analogues of stable reaction intermediates by replacing either metal with a redox inactive metal. Together with previous structural and spectroscopic results, we summarize insights gained from studying these biosynthetic models toward understanding structural features responsible for the NOR activity and its mechanism. As a result, the outlook on NOR modeling is also discussed, with an emphasis on the design of models capable of catalytic turnovers designed based on close mimics of the secondary coordination sphere of native NORs.

  3. Recent advances in biosynthetic modeling of nitric oxide reductases and insights gained from nuclear resonance vibrational and other spectroscopic studies.

    PubMed

    Chakraborty, Saumen; Reed, Julian; Sage, J Timothy; Branagan, Nicole C; Petrik, Igor D; Miner, Kyle D; Hu, Michael Y; Zhao, Jiyong; Alp, E Ercan; Lu, Yi

    2015-10-05

    This Forum Article focuses on recent advances in structural and spectroscopic studies of biosynthetic models of nitric oxide reductases (NORs). NORs are complex metalloenzymes found in the denitrification pathway of Earth's nitrogen cycle where they catalyze the proton-dependent two-electron reduction of nitric oxide (NO) to nitrous oxide (N2O). While much progress has been made in biochemical and biophysical studies of native NORs and their variants, a clear mechanistic understanding of this important metalloenzyme related to its function is still elusive. We report herein UV-vis and nuclear resonance vibrational spectroscopy (NRVS) studies of mononitrosylated intermediates of the NOR reaction of a biosynthetic model. The ability to selectively substitute metals at either heme or nonheme metal sites allows the introduction of independent (57)Fe probe atoms at either site, as well as allowing the preparation of analogues of stable reaction intermediates by replacing either metal with a redox inactive metal. Together with previous structural and spectroscopic results, we summarize insights gained from studying these biosynthetic models toward understanding structural features responsible for the NOR activity and its mechanism. The outlook on NOR modeling is also discussed, with an emphasis on the design of models capable of catalytic turnovers designed based on close mimics of the secondary coordination sphere of native NORs.

  4. Laser-spectroscopic measurement techniques for hypersonic, turbulent wind tunnel flows

    NASA Technical Reports Server (NTRS)

    Mckenzie, Robert L.; Fletcher, Douglas G.

    1992-01-01

    A review is given of the nature, present status, and capabilities of two laser spectroscopic methods for the simultaneous measurement of temperature, density, and their fluctuations owing to turbulence in high speed wind tunnel flows. One method is based on the two frequency excitation of nitric oxide seeded into a nitrogen flow, using tunable dye lasers. The second, more recent method relies on the excitation of oxygen in air flows using a tunable, ArF excimer laser. Signal are obtained from both the laser induced fluorescence and from Raman scattering of the same laser pulse. Measurements are demonstrated in the turbulent boundary layer of a Mach-2 channel flow.

  5. Advances in image-guided intratumoral drug delivery techniques

    PubMed Central

    Solorio, Luis; Patel, Ravi B; Wu, Hanping; Krupka, Tianyi; Exner, Agata A

    2017-01-01

    Image-guided drug delivery provides a means for treating a variety of diseases with minimal systemic involvement while concurrently monitoring treatment efficacy. These therapies are particularly useful to the field of interventional oncology, where elevation of tumor drug levels, reduction of systemic side effects and post-therapy assessment are essential. This review highlights three such image-guided procedures: transarterial chemoembolization, drug-eluting implants and convection-enhanced delivery. Advancements in medical imaging technology have resulted in a growing number of new applications, including image-guided drug delivery. This minimally invasive approach provides a comprehensive answer to many challenges with local drug delivery. Future evolution of imaging devices, image-acquisition techniques and multifunctional delivery agents will lead to a paradigm shift in patient care. PMID:22816134

  6. COAL AND CHAR STUDIES BY ADVANCED EMR TECHNIQUES

    SciTech Connect

    R. Linn Belford; Robert B. Clarkson; Mark J. Nilges; Boris M. Odintsov; Alex I. Smirnov

    2001-04-30

    Advanced electronic magnetic resonance (EMR) as well as nuclear magnetic resonance (NMR) methods have been used to examine properties of coals, chars, and molecular species related to constituents of coal. During the span of this grant, progress was made on construction and applications to coals and chars of two high frequency EMR systems particularly appropriate for such studies--48 GHz and 95 GHz electron magnetic resonance spectrometer, on new low-frequency dynamic nuclear polarization (DNP) experiments to examine the interaction between water and the surfaces of suspended char particulates in slurries, and on a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water directly in contact with the surfaces and pore spaces of carbonaceous particulates.

  7. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one

  8. Robotic suturing: technique and benefit in advanced laparoscopic surgery.

    PubMed

    Kenngott, Hannes G; Muller-Stich, Beat P; Reiter, Michael A; Rassweiler, Jens; Gutt, Carsten N

    2008-01-01

    Suturing is one of the main tasks in advanced laparoscopic surgery, but limited degrees of freedom, 2D vision, fulcrum and pivoting effect make it difficult to perform. Robotic systems provide corresponding solutions as three-dimensional (3D) view, intuitive motion and additional degrees of freedom. This review evaluates these benefits for their impact on suturing in experimental and clinical studies. The Medline database was searched for "robot*, telemanipulat* and laparoscop*". A total of 1150 references were found and further limited to "suturing" for experimental evaluation, finding 89 references. All references were considered for information on robotic suturing in advanced laparoscopy. Further references were obtained through cross-referencing the bibliography cited in each work. In experimental studies current robotic systems have proven their superior suturing capabilities compared to conventional laparoscopic techniques, mainly attributed to 3D visualization and full seven degrees of freedom. In clinical studies these benefits have not yet been sufficiently reproduced. Robotic systems have to prove the benefits shown in experimental studies for suturing tasks in clinical applications. Robotic devices shorten the learning curve of laparoscopic procedures. Further clinical trials focusing on anastomosis time are needed to assess this question.

  9. Microcomposition of Human Urinary Calculi Using Advanced Imaging Techniques

    PubMed Central

    Blaschko, Sarah D.; Miller, Joe; Chi, Thomas; Flechner, Lawrence; Fakra, Sirine; Kahn, Arnold; Kapahi, Pankaj; Stoller, Marshall L.

    2013-01-01

    Purpose Common methods of commercial urolithiasis analysis, such as light microscopy and Fourier transform infrared spectroscopy, provide limited or no information on the molecular composition of stones, which is vital when studying early stone pathogenesis. We used synchrotron radiation based microfocused x-ray fluorescence, x-ray absorption and x-ray diffraction advanced imaging techniques to identify and map the elemental composition, including trace elements, of urinary calculi on a μm (0.0001 cm) scale. Materials and Methods Human stone samples were obtained during serial percutaneous nephrolithotomy and ureteroscopy procedures. A portion of each sample was sent for commercial stone analysis and a portion was retained for synchrotron radiation based advanced imaging analysis. Results Synchrotron radiation based methods of stone analysis correctly identified stone composition and provided additional molecular detail on elemental components and spatial distribution in uroliths. Resolution was on the order of a few μm. Conclusions Knowledge of all elements present in lithogenesis at this detail allows for better understanding of early stone formation events, which may provide additional insight to prevent and treat stone formation. PMID:23021997

  10. Microcomposition of human urinary calculi using advanced imaging techniques.

    PubMed

    Blaschko, Sarah D; Miller, Joe; Chi, Thomas; Flechner, Lawrence; Fakra, Sirine; Kahn, Arnold; Kapahi, Pankaj; Stoller, Marshall L

    2013-02-01

    Common methods of commercial urolithiasis analysis, such as light microscopy and Fourier transform infrared spectroscopy, provide limited or no information on the molecular composition of stones, which is vital when studying early stone pathogenesis. We used synchrotron radiation based microfocused x-ray fluorescence, x-ray absorption and x-ray diffraction advanced imaging techniques to identify and map the elemental composition, including trace elements, of urinary calculi on a μm (0.0001 cm) scale. Human stone samples were obtained during serial percutaneous nephrolithotomy and ureteroscopy procedures. A portion of each sample was sent for commercial stone analysis and a portion was retained for synchrotron radiation based advanced imaging analysis. Synchrotron radiation based methods of stone analysis correctly identified stone composition and provided additional molecular detail on elemental components and spatial distribution in uroliths. Resolution was on the order of a few μm. Knowledge of all elements present in lithogenesis at this detail allows for better understanding of early stone formation events, which may provide additional insight to prevent and treat stone formation. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  11. Liver MRI: From basic protocol to advanced techniques.

    PubMed

    Donato, Henrique; França, Manuela; Candelária, Isabel; Caseiro-Alves, Filipe

    2017-08-01

    Liver MR is a well-established modality with multiparametric capabilities. However, to take advantage of its full capacity, it is mandatory to master the technique and optimize imaging protocols, apply advanced imaging concepts and understand the use of different contrast media. Physiologic artefacts although inherent to upper abdominal studies can be minimized using triggering techniques and new strategies for motion control. For standardization, the liver MR protocol should include motion-resistant T2-w sequences, in-op phase GRE T1 and T2-w fast spin echo sequences with fat suppression. Diffusion-weighted imaging (DWI) is mandatory, especially for detection of sub-centimetre metastases. Contrast-enhanced MR is the cornerstone of liver MR, especially for lesion characterization. Although extracellular agents are the most extensively used contrast agents, hepatobiliary contrast media can provide an extra-layer of functional diagnostic information adding to the diagnostic value of liver MR. The use of high field strength (3T) increases SNR but is more challenging especially concerning artefact control. Quantitative MR belongs to the new and evolving field of radiomics where the use of emerging biomarkers such as perfusion or DWI can derive new information regarding disease detection, prognostication and evaluation of tumour response. This information can overcome some of the limitations of current tests, especially when using vascular disruptive agents for oncologic treatment assessment. MR is, today, a robust, mature, multiparametric imaging modality where clinical applications have greatly expanded from morphology to advanced imaging. This new concept should be acknowledged by all those involved in producing high quality, high-end liver MR studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Advances in the Rising Bubble Technique for discharge measurement

    NASA Astrophysics Data System (ADS)

    Hilgersom, Koen; Luxemburg, Willem; Willemsen, Geert; Bussmann, Luuk

    2014-05-01

    Already in the 19th century, d'Auria described a discharge measurement technique that applies floats to find the depth-integrated velocity (d'Auria, 1882). The basis of this technique was that the horizontal distance that the float travels on its way to the surface is the image of the integrated velocity profile over depth. Viol and Semenov (1964) improved this method by using air bubbles as floats, but still distances were measured manually until Sargent (1981) introduced a technique that could derive the distances from two photographs simultaneously taken from each side of the river bank. Recently, modern image processing techniques proved to further improve the applicability of the method (Hilgersom and Luxemburg, 2012). In the 2012 article, controlling and determining the rising velocity of an air bubble still appeared a major challenge for the application of this method. Ever since, laboratory experiments with different nozzle and tube sizes lead to advances in our self-made equipment enabling us to produce individual air bubbles with a more constant rising velocity. Also, we introduced an underwater camera to on-site determine the rising velocity, which is dependent on the water temperature and contamination, and therefore is site-specific. Camera measurements of the rising velocity proved successful in a laboratory and field setting, although some improvements to the setup are necessary to capture the air bubbles also at depths where little daylight penetrates. References D'Auria, L.: Velocity of streams; A new method to determine correctly the mean velocity of any perpendicular in rivers and canals, (The) American Engineers, 3, 1882. Hilgersom, K.P. and Luxemburg, W.M.J.: Technical Note: How image processing facilitates the rising bubble technique for discharge measurement, Hydrology and Earth System Sciences, 16(2), 345-356, 2012. Sargent, D.: Development of a viable method of stream flow measurement using the integrating float technique, Proceedings of

  13. Advanced Cytologic Techniques for the Detection of Malignant Pancreatobiliary Strictures

    PubMed Central

    Moreno Luna, Laura E.; Kipp, Benjamin; Halling, Kevin C.; Sebo, Thomas J.; Kremers., Walter K.; Roberts, Lewis R.; Barr Fritcher, Emily G.; Levy, Michael J.; Gores, Gregory J.

    2006-01-01

    Background & Aims Two advanced cytologic techniques for detecting aneuploidy, digital image analysis (DIA) and fluorescence in situ hybridization (FISH) have recently been developed to help identify malignant pancreatobiliary strictures. The aim of this study was to assess the clinical utility of cytology, DIA, and FISH for the identification of malignant pancreatobiliary strictures. Methods Brush cytologic specimens from 233 consecutive patients undergoing ERCP for pancreatobiliary strictures were examined by all three techniques. Strictures were stratified as proximal (n=33) or distal (n=114) based on whether they occurred above or below the cystic duct, respectively. Strictures in patients with PSC (n=86) were analyzed separately. Results Despite the stratification, the performances of the tests were similar. Routine cytology has a low sensitivity (5–20%) but 100% specificity. Because of the high specificity for cytology, we assessed the performance of the other tests when routine cytology was negative. In this clinical context, FISH had an increased sensitivity (35–60%) when assessing for chromosomal gains (polysomy) while preserving the specificity of cytology. The sensitivity and specificity of DIA was intermediate as compared to routine cytology and FISH, but was additive to FISH values demonstrating only trisomy of chromosome 7 or chromosome 3. Conclusions These findings suggest that FISH and DIA increase the sensitivity for the diagnosis of malignant pancreatobiliary tract strictures over that obtained by conventional cytology while maintaining an acceptable specificity. PMID:17030177

  14. Combined external lithotripsy and endoscopic techniques for advanced sialolithiasis cases.

    PubMed

    Nahlieli, Oded; Shacham, Rachel; Zaguri, Ami

    2010-02-01

    To assess a combined external lithotripsy-sialoendoscopy method developed for advanced salivary gland sialolithiasis. A total of 94 patients (43 males and 51 females) underwent these treatment methods. Of these 94 patients, 60 had pathologic features in the submandibular gland and 34 in the parotid gland. A miniature external lithotripter was used, combined with multifunctional sialoendoscopes and endoscopic-assisted techniques, to achieve effective removal/elimination of the stones in these difficult cases. Total elimination of the stone using lithotripsy alone was achieved in 32% of the cases; in 29%, intraductal endoscopic assistance was needed. In the remaining 39%, the removal of a stone was achieved with the help of an endoscopy-assisted extraductal approach (37 cases). At 6 months of follow-up, all patients who had undergone lithotripsy or lithotripsy plus intraductal endoscopy had an absence of symptoms. Of the 37 patients who had undergone an endoscopy-assisted extraductal approach, 35 (95%) remained asymptomatic. Lithotripsy plus intraductal or extraductal endoscopic treatment of sialolithiasis is a highly effective surgical method of eliminating/removing salivary stones, especially those attached to the surrounding tissue and in the secondary ducts. This method helps to avoid resection of the salivary glands and represents an additional development of minimal invasive surgical techniques. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  15. New Spectroscopic Technique Based on Coaddition of Surface Brightness Fluctuations: NGC 4449 and its Stellar Tidal Stream

    NASA Astrophysics Data System (ADS)

    Toloba, Elisa; Guhathakurta, Puragra; Romanowsky, Aaron J.; Brodie, Jean P.; Martínez-Delgado, David; Arnold, Jacob A.; Ramachandran, Neel; Theakanath, Kuriakose

    2016-06-01

    We present a new spectroscopic technique based in part on targeting the upward fluctuations of the surface brightness for studying the internal stellar kinematics and metallicities of galaxies of low surface brightness effects both to galaxies and streams beyond the Local Group. The distance to these systems makes them unsuitable for targeting individual red giant branch (RGB) stars (tip of RGB at I≳ 24 mag) and their surface brightness is too low ({μ }r≳ 25 mag arcsec-2) for integrated light spectroscopic measurements. This technique overcomes these two problems by targeting individual objects that are brighter than the tip of the RGB. We apply this technique to the star-forming dwarf galaxy NGC 4449 and its stellar stream. We use Keck/DEIMOS data to measure the line-of-sight radial velocity out to ˜7 kpc in the east side of the galaxy and ˜8 kpc along the stream. We find that the two systems are likely gravitationally bound to each other and have heliocentric radial velocities of 227.3 ± 10.7 km s-1 and 225.8 ± 16.0 km s-1, respectively. Neither the stream nor the near half of the galaxy shows a significant velocity gradient. We estimate the stellar metallicity of the stream based on the equivalent width of its calcium triplet lines and find [Fe/H] =\\quad -1.37+/- 0.41, which is consistent with the metallicity-luminosity relation for dwarf galaxies in the Local Group. Whether the stream's progenitor was moderately or severely stripped cannot be constrained with this uncertainty in metallicity. We demonstrate that this new technique can be used to measure the kinematics and (possibly) the metallicity of the numerous faint satellites and stellar streams in the halos of nearby (˜4 Mpc) galaxies.

  16. Recent Advances in Seismic Wavefront Tracking Techniques and Their Applications

    NASA Astrophysics Data System (ADS)

    Sambridge, M.; Rawlinson, N.; Hauser, J.

    2007-12-01

    In observational seismology, wavefront tracking techniques are becoming increasingly popular as a means of predicting two point traveltimes and their associated paths. Possible applications include reflection migration, earthquake relocation and seismic tomography at a wide variety of scales. Compared with traditional ray based techniques such as shooting and bending, wavefront tracking has the advantage of locating traveltimes between the source and every point in the medium; in many cases, improved efficiency and robustness; and greater potential for tracking multiple arrivals. In this presentation, two wavefront tracking techniques will be considered: the so-called Fast Marching Method (FMM), and a wavefront construction (WFC) scheme. Over the last several years, FMM has become a mature technique in seismology, with a number of improvements to the underlying theory and the release of software tools that allow it to be used in a variety of applications. At its core, FMM is a grid based solver that implicitly tracks a propagating wavefront by seeking finite difference solutions to the eikonal equation along an evolving narrow band. Recent developments include the use of source grid refinement to improve accuracy, the introduction of a multi-stage scheme to allow reflections and refractions to be tracked in layered media, and extension to spherical coordinates. Implementation of these ideas has led to a number of different applications, including teleseismic tomography, wide-angle reflection and refraction tomography, earthquake relocation, and ambient noise imaging using surface waves. The WFC scheme represents the wavefront surface as a set of points in 6-D phase space; these points are advanced in time using local initial value ray tracing in order to form a sequence of wavefront surfaces that fill the model volume. Surface refinement and simplification techniques inspired by recent developments in computer graphics are used to maintain a fixed density of nodes

  17. Analysis of leading edge and trailing edge cover glass samples before and after treatment with advanced satellite contamination removal techniques

    NASA Technical Reports Server (NTRS)

    Hotaling, S. P.

    1993-01-01

    Two samples from Long Duration Exposure Facility (LDEF) experiment M0003-4 were analyzed for molecular and particulate contamination prior to and following treatment with advanced satellite contamination removal techniques (CO2 gas/solid jet spray and oxygen ion beam). The pre- and post-cleaning measurements and analyses are presented. The jet spray removed particulates in seconds. The low energy reactive oxygen ion beam removed 5,000 A of photo polymerized organic hydrocarbon contamination in less than 1 hour. Spectroscopic analytical techniques were applied to the analysis of cleaning efficiency including: Fourier transform infrared, Auger, x ray photoemissions, energy dispersive x ray, and ultraviolet/visible. The results of this work suggest that the contamination studied here was due to spacecraft self-contamination enhanced by atomic oxygen plasma dynamics and solar UV radiation. These results also suggest the efficacy for the jet spray and ion beam contamination control technologies for spacecraft optical surfaces.

  18. Nanocasting technique to prepare lotus-leaf-like superhydrophobic electroactive polyimide as advanced anticorrosive coatings.

    PubMed

    Chang, Kung-Chin; Lu, Hsin-I; Peng, Chih-Wei; Lai, Mei-Chun; Hsu, Sheng-Chieh; Hsu, Min-Hsiang; Tsai, Yuan-Kai; Chang, Chi-Hao; Hung, Wei-I; Wei, Yen; Yeh, Jui-Ming

    2013-02-01

    Nanocasting technique was used to obtain a biomimetic superhydrophobic electroactive polyimide (SEPI) surface structure from a natural Xanthosoma sagittifolium leaf. An electroactive polyimide (EPI) was first synthesized through thermal imidization. An impression of the superhydrophobic Xanthosoma sagittifolium leaf was then nanocasted onto the surface of the EPI so that the resulting EPI was superhydrophobic and would prevent corrosion. Polydimethylsiloxane (PDMS) was then used as a negative template to transfer the impression of the superhydrophobic surface of the biomimetic EPI onto a cold-rolled steel (CRS) electrode. The superhydrophobic electroactive material could be used as advanced coatings that protect metals against corrosion. The morphology of the surface of the as-synthesized SEPI coating was investigated using scanning electron microscopy (SEM). The surface showed numerous micromastoids, each decorated with many nanowrinkles. The water contact angle (CA) for the SEPI coating was 155°, which was significantly larger than that for the EPI coating (i.e., CA = 87°). The significant increase in the contact angle indicated that the biomimetic morphology effectively repelled water. Potentiodynamic and electrochemical impedance spectroscopic measurements indicated that the SEPI coating offered better protection against corrosion than the EPI coating did.

  19. Binding studies of lophirone B with bovine serum albumin (BSA): Combination of spectroscopic and molecular docking techniques

    NASA Astrophysics Data System (ADS)

    Chaves, Otávio Augusto; da Silva, Veridiana A.; Sant'Anna, Carlos Maurício R.; Ferreira, Aurélio B. B.; Ribeiro, Tereza Auxiliadora N.; de Carvalho, Mário G.; Cesarin-Sobrinho, Dari; Netto-Ferreira, José Carlos

    2017-01-01

    The interaction between the transport protein bovine serum albumin (BSA) and the natural product lophirone B, was investigated by spectroscopic techniques combined with a computational method (molecular docking). From the KSV and kq values it was concluded that lophirone B quenches the fluorescence of BSA by dynamic and static mechanisms. The Ka values, of the order of 104 M-1, and the number of binding sites (n ≈ 1), indicate that the binding is moderate and there is just one main binding site in BSA for lophirone B. The negative ΔG° values are in accordance with the spontaneity of the process and the positive ΔH° and ΔS° values indicate that the binding is entropically driven; the main binding forces for the association BSA:lophirone B are probably lipophilic interactions. Circular dichroism (CD) studies show there is not a significant perturbation on the secondary structure of the albumin upon the binding process. In order to better understand the spectroscopic results, a computational method was applied: molecular docking suggests Trp-213 site, as the main binding site for the ligand. Lophirone B seems to be exposed to the aqueous media as well as accommodated inside the protein cavity, resulting in a moderate affinity for the albumin. The Arg-198, His-287, Lys-294 and Lys-439 residues are interacting via hydrogen bonding with lophirone B, whereas the interaction with Trp-213 residue occurs through a lipophilic interaction.

  20. CB7 as a drug vehicle and controlled release of drug through non ionic surfactant: Spectroscopic technique.

    PubMed

    Singharoy, Dipti; Mati, Soumya Sundar; Ghosh, Swadesh; Bhattacharya, Subhash Chandra

    2017-09-06

    A study of the comparative drug carrier properties of cucurbituril[7] (CB7) and β-cyclodextrin (β-CD) with a naphthalimide derivative, [2-(2-aminoethyl)-1H-benzo[deisoquinoline-1,3(2H)-dione] (NAP) and its release in aqueous solution using micellar environment, is the key research interest of this work. The profound changes in the different spectroscopic behavior have been attributed to the formation of a 1:1 inclusion complex for NAP:CB7 system. Several experimental outcomes clearly interpreted that CB7 has better drug carrier properties for NAP compared to β-CD. It has been also focused on the systematic release of NAP molecule from CB7 by using different ionic and non ionic surfactants. Before releasing the drug molecules from CB7 the interaction between NAP and the three different types of surfactants has also been investigated separately. The selectivity of drug carrier and releaser has been monitored, using different spectroscopic techniques like absorbance, fluorescence, fluorescence decay life time and (1)H NMR spectroscopy. Besides, a theoretical approach has been followed for a proper geometrical optimized structure of NAP molecule and molecular arrangement of NAP:CB7 inclusion complex. From Density Functional Theory (DFT) it has been seen that NAP molecule is oriented as a t-bone like structure in its optimized form. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Use of advanced modeling techniques to optimize thermal packaging designs.

    PubMed

    Formato, Richard M; Potami, Raffaele; Ahmed, Iftekhar

    2010-01-01

    Through a detailed case study the authors demonstrate, for the first time, the capability of using advanced modeling techniques to correctly simulate the transient temperature response of a convective flow-based thermal shipper design. The objective of this case study was to demonstrate that simulation could be utilized to design a 2-inch-wall polyurethane (PUR) shipper to hold its product box temperature between 2 and 8 °C over the prescribed 96-h summer profile (product box is the portion of the shipper that is occupied by the payload). Results obtained from numerical simulation are in excellent agreement with empirical chamber data (within ±1 °C at all times), and geometrical locations of simulation maximum and minimum temperature match well with the corresponding chamber temperature measurements. Furthermore, a control simulation test case was run (results taken from identical product box locations) to compare the coupled conduction-convection model with a conduction-only model, which to date has been the state-of-the-art method. For the conduction-only simulation, all fluid elements were replaced with "solid" elements of identical size and assigned thermal properties of air. While results from the coupled thermal/fluid model closely correlated with the empirical data (±1 °C), the conduction-only model was unable to correctly capture the payload temperature trends, showing a sizeable error compared to empirical values (ΔT > 6 °C). A modeling technique capable of correctly capturing the thermal behavior of passively refrigerated shippers can be used to quickly evaluate and optimize new packaging designs. Such a capability provides a means to reduce the cost and required design time of shippers while simultaneously improving their performance. Another advantage comes from using thermal modeling (assuming a validated model is available) to predict the temperature distribution in a shipper that is exposed to ambient temperatures which were not bracketed

  2. A review of hemorheology: Measuring techniques and recent advances

    NASA Astrophysics Data System (ADS)

    Sousa, Patrícia C.; Pinho, Fernando T.; Alves, Manuel A.; Oliveira, Mónica S. N.

    2016-02-01

    Significant progress has been made over the years on the topic of hemorheology, not only in terms of the development of more accurate and sophisticated techniques, but also in terms of understanding the phenomena associated with blood components, their interactions and impact upon blood properties. The rheological properties of blood are strongly dependent on the interactions and mechanical properties of red blood cells, and a variation of these properties can bring further insight into the human health state and can be an important parameter in clinical diagnosis. In this article, we provide both a reference for hemorheological research and a resource regarding the fundamental concepts in hemorheology. This review is aimed at those starting in the field of hemodynamics, where blood rheology plays a significant role, but also at those in search of the most up-to-date findings (both qualitative and quantitative) in hemorheological measurements and novel techniques used in this context, including technical advances under more extreme conditions such as in large amplitude oscillatory shear flow or under extensional flow, which impose large deformations comparable to those found in the microcirculatory system and in diseased vessels. Given the impressive rate of increase in the available knowledge on blood flow, this review is also intended to identify areas where current knowledge is still incomplete, and which have the potential for new, exciting and useful research. We also discuss the most important parameters that can lead to an alteration of blood rheology, and which as a consequence can have a significant impact on the normal physiological behavior of blood.

  3. Advances in Poly(4-aminodiphenylaniline) Nanofibers Preparation by Electrospinning Technique.

    PubMed

    Della Pina, C; Busacca, C; Frontera, P; Antonucci, P L; Scarpino, L A; Sironi, A; Falletta, E

    2016-05-01

    Polyaniline (PANI) nanofibers are drawing a great deal of interest from academia and industry due to their multiple applications, especially in biomedical field. PANI nanofibers were successfully electrospun for the first time by MacDiarmid and co-workers at the beginning of the millennium and since then many efforts have been addressed to improve their quality. However, traditional PANI prepared from aniline monomer shows some drawbacks, such as presence of toxic (i.e., benzidine) and inorganic (salts and metals) co-products, that complicate polymer post-treatment, and low solubility in common organic solvents, making hard its processing by electrospinning technique. Some industrial sectors, such as medical and biomedical, need to employ materials free from toxic and polluting species. In this regard, the oxidative polymerization of N-(4-aminophenyl)aniline, aniline dimer, to produce poly(4-aminodiphenylaniline), P4ADA, a kind of PANI, represents an innovative alternative to the traditional synthesis because the obtained polymer results free from carcinogenic and/or polluting co-products, and, moreover, more soluble than traditional PANI. This latter feature can be exploited to obtain P4ADA nanofibers by electrospinning technique. In this paper we report the advances obtained in the P4ADA nanofibers electrospinnig. A comparison among polyethylene oxide (PEO), polymethyl methacrylate (PMMA) and polystyrene (PS), as the second polymer to facilitate the electrospinning process, is shown. In order to increase the conductivity of P4ADA nanofibers, two strategies were adopted and compared: selective insulating binder removal from electrospun nanofibers by a rinsing tratment, afterwards optimizing the minimum amount of binder necessary for the electrospinning process. Moreover, the effect of PEO/P4ADA weight ratio on the fibers morphology and conductivity was highlighted.

  4. Advanced Techniques for Power System Identification from Measured Data

    SciTech Connect

    Pierre, John W.; Wies, Richard; Trudnowski, Daniel

    2008-11-25

    Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing

  5. 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.

  6. Dissecting cell adhesion architecture using advanced imaging techniques

    PubMed Central

    Morton, Penny E

    2011-01-01

    Cell adhesion to extracellular matrix proteins or to other cells is essential for the control of embryonic development, tissue integrity, immune function and wound healing. Adhesions are tightly spatially regulated structures containing over one hundred different proteins that coordinate both dynamics and signaling events at these sites. Extensive biochemical and morphological analysis of adhesion types over the past three decades has greatly improved understanding of individual protein contributions to adhesion signaling and, in some cases, dynamics. However, it is becoming increasingly clear that these diverse macromolecular complexes contain a variety of protein sub-networks, as well as distinct sub-domains that likely play important roles in regulating adhesion behavior. Until recently, resolving these structures, which are often less than a micron in size, was hampered by the limitations of conventional light microscopy. However, recent advances in optical techniques and imaging methods have revealed exciting insight into the intricate control of adhesion structure and assembly. Here we provide an overview of the recent data arising from such studies of cell:matrix and cell:cell contact and an overview of the imaging strategies that have been applied to study the intricacies and hierarchy of proteins within adhesions. PMID:21785274

  7. 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

  8. Pediatric Cardiopulmonary Resuscitation: Advances in Science, Techniques, and Outcomes

    PubMed Central

    Topjian, Alexis A.; Berg, Robert A.; Nadkarni, Vinay M.

    2009-01-01

    More than 25% of children survive to hospital discharge after in-hospital cardiac arrests, and 5% to 10% survive after out-of-hospital cardiac arrests. This review of pediatric cardiopulmonary resuscitation addresses the epidemiology of pediatric cardiac arrests, mechanisms of coronary blood flow during cardiopulmonary resuscitation, the 4 phases of cardiac arrest resuscitation, appropriate interventions during each phase, special resuscitation circumstances, extracorporeal membrane oxygenation cardiopulmonary resuscitation, and quality of cardiopulmonary resuscitation. The key elements of pathophysiology that impact and match the timing, intensity, duration, and variability of the hypoxic-ischemic insult to evidence-based interventions are reviewed. Exciting discoveries in basic and applied-science laboratories are now relevant for specific subpopulations of pediatric cardiac arrest victims and circumstances (eg, ventricular fibrillation, neonates, congenital heart disease, extracorporeal cardiopulmonary resuscitation). Improving the quality of interventions is increasingly recognized as a key factor for improving outcomes. Evolving training strategies include simulation training, just-in-time and just-in-place training, and crisis-team training. The difficult issue of when to discontinue resuscitative efforts is addressed. Outcomes from pediatric cardiac arrests are improving. Advances in resuscitation science and state-of-the-art implementation techniques provide the opportunity for further improvement in outcomes among children after cardiac arrest. PMID:18977991

  9. Achieving miniature sensor systems via advanced packaging techniques

    NASA Astrophysics Data System (ADS)

    Hartup, David C.; Bobier, Kevin; Demmin, Jeffrey

    2005-05-01

    Demands for miniaturized networked sensors that can be deployed in large quantities dictate that the packages be small and cost effective. In order to accomplish these objectives, system developers generally apply advanced packaging techniques to proven systems. A partnership of Nova Engineering and Tessera begins with a baseline of Nova's Unattended Ground Sensors (UGS) technology and utilizes Tessera's three-dimensional (3D) Chip-Scale Packaging (CSP), Multi-Chip Packaging (MCP), and System-in-Package (SIP) innovations to enable novel methods for fabricating compact, vertically integrated sensors utilizing digital, RF, and micro-electromechanical systems (MEMS) devices. These technologies, applied to a variety of sensors and integrated radio architectures, enable diverse multi-modal sensing networks with wireless communication capabilities. Sensors including imaging, accelerometers, acoustical, inertial measurement units, and gas and pressure sensors can be utilized. The greatest challenge to high density, multi-modal sensor networks is the ability to test each component prior to integration, commonly called Known Good Die (KGD) testing. In addition, the mix of multi-sourcing and high technology magnifies the challenge of testing at the die level. Utilizing Tessera proprietary CSP, MCP, and SIP interconnection methods enables fully testable, low profile stacking to create multi-modal sensor radios with high yield.

  10. Recommended advanced techniques for waterborne pathogen detection in developing countries.

    PubMed

    Alhamlan, Fatimah S; Al-Qahtani, Ahmed A; Al-Ahdal, Mohammed N

    2015-02-19

    The effect of human activities on water resources has expanded dramatically during the past few decades, leading to the spread of waterborne microbial pathogens. The total global health impact of human infectious diseases associated with pathogenic microorganisms from land-based wastewater pollution was estimated to be approximately three million disability-adjusted life years (DALY), with an estimated economic loss of nearly 12 billion US dollars per year. Although clean water is essential for healthy living, it is not equally granted to all humans. Indeed, people who live in developing countries are challenged every day by an inadequate supply of clean water. Polluted water can lead to health crises that in turn spread waterborne pathogens. Taking measures to assess the water quality can prevent these potential risks. Thus, a pressing need has emerged in developing countries for comprehensive and accurate assessments of water quality. This review presents current and emerging advanced techniques for assessing water quality that can be adopted by authorities in developing countries.

  11. REVIEW ARTICLE: Emission measurement techniques for advanced powertrains

    NASA Astrophysics Data System (ADS)

    Adachi, Masayuki

    2000-10-01

    Recent developments in high-efficiency low-emission powertrains require the emission measurement technologies to be able to detect regulated and unregulated compounds with very high sensitivity and a fast response. For example, levels of a variety of nitrogen compounds and sulphur compounds should be analysed in real time in order to develop aftertreatment systems to decrease emission of NOx for the lean burning powertrains. Also, real-time information on the emission of particulate matter for the transient operation of diesel engines and direct injection gasoline engines is invaluable. The present paper reviews newly introduced instrumentation for such emission measurement that is demanded for the developments in advanced powertrain systems. They include Fourier transform infrared spectroscopy, mass spectrometry and fast response flame ionization detection. In addition, demands and applications of the fuel reformer developments for fuel cell electric vehicles are discussed. Besides the detection methodologies, sample handling techniques for the measurement of concentrations emitted from low emission vehicles for which the concentrations of the pollutants are significantly lower than the concentrations present in ambient air, are also described.

  12. Development of advanced strain diagnostic techniques for reactor environments.

    SciTech Connect

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Miller, Timothy J.; Hall, Aaron Christopher; Urrea, David Anthony,; Parma, Edward J.,

    2013-02-01

    The following research is operated as a Laboratory Directed Research and Development (LDRD) initiative at Sandia National Laboratories. The long-term goals of the program include sophisticated diagnostics of advanced fuels testing for nuclear reactors for the Department of Energy (DOE) Gen IV program, with the future capability to provide real-time measurement of strain in fuel rod cladding during operation in situ at any research or power reactor in the United States. By quantifying the stress and strain in fuel rods, it is possible to significantly improve fuel rod design, and consequently, to improve the performance and lifetime of the cladding. During the past year of this program, two sets of experiments were performed: small-scale tests to ensure reliability of the gages, and reactor pulse experiments involving the most viable samples in the Annulated Core Research Reactor (ACRR), located onsite at Sandia. Strain measurement techniques that can provide useful data in the extreme environment of a nuclear reactor core are needed to characterize nuclear fuel rods. This report documents the progression of solutions to this issue that were explored for feasibility in FY12 at Sandia National Laboratories, Albuquerque, NM.

  13. Nonintrusive spectroscopic techniques for supersonic/hypersonic aerodynamics and combustion diagnostics

    NASA Technical Reports Server (NTRS)

    Exton, R. J.

    1992-01-01

    This paper presents an overview of the primary nonintrusive diagnostic techniques being developed by the NASA Langley Research Center to address the validation needs of Computational Fluid Dynamic (CFD) codes. The techniques include absorption in the UV and IR, Laser Induced Fluorescence, electron beam fluorescence, and a number of scattering techniques including Rayleigh, spontaneous Raman, and several coherent Raman spectroscopies. Most of the techniques are highly specialized, require complex data interpretation, and can satisfy only a few of the CFD needs. For these reasons, the evolving trend in flowfield diagnostics appears to favor a mode in which the diagnostic researcher, the experimental aerodynamicist, and the CFD community jointly define experiments based on the aeronautical requirements and on available diagnostic techniques.

  14. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques

    NASA Astrophysics Data System (ADS)

    Singh, Gurpreet; Mohanty, B. P.; Saini, G. S. S.

    2016-02-01

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide.

  15. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques.

    PubMed

    Singh, Gurpreet; Mohanty, B P; Saini, G S S

    2016-02-15

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Study on the interaction characteristics of cefamandole with bovine serum albumin by spectroscopic technique.

    PubMed

    Wang, Qian; Liu, Xuyang; Su, Ming; Shi, Zhihong; Sun, Hanwen

    2015-02-05

    The interaction of cefamandole with bovine serum albumin (BSA) was studied by fluorescence quenching in combination with UV-Vis spectroscopic method under near physiological conditions. The fluorescence quenching rate constants and binding constants for BSA-cefamandole system were determined at different temperatures. The fluorescence quenching of BSA by cefamandole is due to static quenching and energy transfer. The results of thermodynamic parameters, ΔH (-268.0 kJ mol(-1)), ΔS (-810.0 J mol(-1) K(-1)) and ΔG (-26.62 to -8.52 kJ mol(-1)), indicated that van der Waals interaction and hydrogen bonding played a major role for cefamandole-BSA association. The competitive experiments demonstrated that the primary binding site of cefamandole on BSA was located at site III in sub-domain IIIA of BSA. The distance between cefamandole and a tryptophane unit was estimated to be 1.18 nm based on the Förster resonance energy transfer theory. The binding constant (KA) of BSA-cefamandole at 298 K was 2.239×10(4) L mol(-1). Circular dichroism spectra, synchronous fluorescence and three-dimensional fluorescence studies showed that the presence of cefamandole could change the conformation of BSA during the binding process.

  17. Molecular structure and spectroscopic characterization of Carbamazepine with experimental techniques and DFT quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Suhasini, M.; Sailatha, E.; Gunasekaran, S.; Ramkumaar, G. R.

    2015-04-01

    A systematic vibrational spectroscopic assignment and analysis of Carbamazepine has been carried out by using FT-IR, FT-Raman and UV spectral data. The vibrational analysis were aided by electronic structure calculations - ab initio (RHF) and hybrid density functional methods (B3LYP) performed with standard basis set 6-31G(d,p). Molecular equilibrium geometries, electronic energies, natural bond order analysis, harmonic vibrational frequencies and IR intensities have been computed. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED) by VEDA program. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λmax were determined by HF/6-311++G(d,p) Time-Dependent method. The thermodynamic functions of the title molecule were also performed using the RHF and DFT methods. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of Carbamazepine.

  18. Molecular structure and spectroscopic characterization of Carbamazepine with experimental techniques and DFT quantum chemical calculations.

    PubMed

    Suhasini, M; Sailatha, E; Gunasekaran, S; Ramkumaar, G R

    2015-04-15

    A systematic vibrational spectroscopic assignment and analysis of Carbamazepine has been carried out by using FT-IR, FT-Raman and UV spectral data. The vibrational analysis were aided by electronic structure calculations - ab initio (RHF) and hybrid density functional methods (B3LYP) performed with standard basis set 6-31G(d,p). Molecular equilibrium geometries, electronic energies, natural bond order analysis, harmonic vibrational frequencies and IR intensities have been computed. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED) by VEDA program. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λmax were determined by HF/6-311++G(d,p) Time-Dependent method. The thermodynamic functions of the title molecule were also performed using the RHF and DFT methods. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the (13)C and (1)H NMR chemical shifts of Carbamazepine. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    SciTech Connect

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore

  20. Monitoring PDT effects in murine tumors by spectroscopic and imaging techniques

    NASA Astrophysics Data System (ADS)

    Ramaprasad, Subbaraya; Rzepka, Elzbieta; Pi, Jiaxiong; Joshi, Shantaram S.; Dobhal, Mahabeer; Missert, Joseph; Pandey, Ravindra K.

    2004-04-01

    The changes in the tumor that occur following photodynamic therapy (PDT) were studied using a small animal MR imager operating at 7Tesla. The animal model used in these studies was mice bearing radiation induced fibrosarcoma (RIF) tumor on the foot dorsum. The mice were injected with 10μM/kg of one of the photosensitizers: (1) Photofrin, (2) Non-fluorinated porphyrin photosensitizer (DOD-1), (3) Fluorinated porphyrin photosensitizer (DOD-2) and, (4) Fluorinated chlorin photosensitizer (DOD-6). Laser light at 630 or 650 nm (150 mW/cm2, 270 joules/cm2) was delivered to the tumor at 2-24 hours of photosensitizer administration. The MR spectroscopic and imaging examination of the tumors involved both the 1H and 31P nuclei. The tumor bioenergetics was measured by 31P spectroscopy. The water proton relaxivity and diffusion measurements were used to obtain local changes in different regions of the tumor. Changes in 31P MR spectra were observed following PDT using Photofrin and fluorinated chlorin sensitizer (DOD-6). However, no significant changes were observed when the fluorinated porphyrin and its nonfluorinated analog were used. The PDT induced changes in tumor volumes showed significant tumor regression with Photofrin, fluorinated porphyrin and chlorin sensitizers. No tumor regression was observed with the non labeled porphyrin sensitizer and the growth profile followed the general pattern of unperturbed tumors. Serial noninvasive measurements of tumor response to PDT are measurable by both MRI and MRS. The MR derived parameters that are characteristic of the tumor status before and after the therapy are discussed here.

  1. Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations

    NASA Astrophysics Data System (ADS)

    Zellweger, Christoph; Emmenegger, Lukas; Firdaus, Mohd; Hatakka, Juha; Heimann, Martin; Kozlova, Elena; Spain, T. Gerard; Steinbacher, Martin; van der Schoot, Marcel V.; Buchmann, Brigitte

    2016-09-01

    Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements.

  2. Development of a spectroscopic technique for simultaneous magnetic field, electron density, and temperature measurements in ICF-relevant plasmas

    NASA Astrophysics Data System (ADS)

    Dutra, E. C.; Koch, J. A.; Presura, R.; Angermeier, W. A.; Darling, T.; Haque, S.; Mancini, R. C.; Covington, A. M.

    2016-11-01

    Spectroscopic techniques in the visible range are often used in plasma experiments to measure B-field induced Zeeman splitting, electron densities via Stark broadening, and temperatures from Doppler broadening. However, when electron densities and temperatures are sufficiently high, the broadening of the Stark and Doppler components can dominate the emission spectra and obscure the Zeeman component. In this research, we are developing a time-resolved multi-axial technique for measuring the Zeeman, Stark, and Doppler broadened line emission of dense magnetized plasmas for Z-pinch and Dense Plasma Focus (DPF) accelerators. The line emission is used to calculate the electron densities, temperatures, and B-fields. In parallel, we are developing a line-shape modeling code that incorporates the broadening effects due to Stark, Doppler, and Zeeman effects for dense magnetized plasma. This manuscript presents the details of the experimental setup and line shape code, along with the results obtained from an Al iii doublet at the University of Nevada, Reno at Nevada Terawatt Facility. Future tests are planned to further evaluate the technique and modeling on other material wire array, gas puff, and DPF platforms.

  3. Coupling spectroscopic and chromatographic techniques for evaluation of the depositional history of hydrocarbons in a subtropical estuary.

    PubMed

    Martins, César C; Doumer, Marta E; Gallice, Wellington C; Dauner, Ana Lúcia L; Cabral, Ana Caroline; Cardoso, Fernanda D; Dolci, Natiely N; Camargo, Luana M; Ferreira, Paulo A L; Figueira, Rubens C L; Mangrich, Antonio S

    2015-10-01

    Spectroscopic and chromatographic techniques can be used together to evaluate hydrocarbon inputs to coastal environments such as the Paranaguá estuarine system (PES), located in the SW Atlantic, Brazil. Historical inputs of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed using two sediment cores from the PES. The AHs were related to the presence of biogenic organic matter and degraded oil residues. The PAHs were associated with mixed sources. The highest hydrocarbon concentrations were related to oil spills, while relatively low levels could be attributed to the decrease in oil usage during the global oil crisis. The results of electron paramagnetic resonance were in agreement with the absolute AHs and PAHs concentrations measured by chromatographic techniques, while near-infrared spectroscopy results were consistent with unresolved complex mixture (UCM)/total n-alkanes ratios. These findings suggest that the use of a combination of techniques can increase the accuracy of assessment of contamination in sediments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Weldability and joining techniques for advanced fossil energy system alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M.

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  5. Advanced in situ Spectroscopic Techniques And Their Applications In Environmental Biogeochemistry: Introduction To The Special Section

    EPA Science Inventory

    Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describ...

  6. Advanced in situ Spectroscopic Techniques And Their Applications In Environmental Biogeochemistry: Introduction To The Special Section

    EPA Science Inventory

    Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describ...

  7. Development of Laser Spectroscopic Diagnostics to Support Advanced Compound Semiconductor Deposition Techniques

    DTIC Science & Technology

    1990-07-30

    Spectra of High Concentrations of TBA. Large Lower Arrows Indicate AsH Line Positions, while Light Arrows Denote Lines which Increase in Intensity in...Derived from Spectra of Higher Concentrations of TBA. Large Lower Arrows Indicate AsH Line Positions, while Light Arrows Denote Lines which Increase...from studies in which the residence time was varied while the pressure remained constant that th’e plasmas studied have reached a steady state, with

  8. Characterization of organic and inorganic optoelectronic semiconductor devices using advanced spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Schroeder, Raoul

    In this thesis, advanced spectroscopy methods are discussed and applied to gain understanding of the physical properties of organic conjugated molecules, II-VI thin film semiconductors, and vertical cavity surface emitting lasers (VCSEL). Experiments include single photon and two-photon excitation with lasers, with subsequent measurements of the absorption and photoluminescence, as well as photocurrent measurements using tungsten and xenon lamps, measuring the direct current and the alternating current of the devices. The materials are investigated in dissolved form (conjugated polymers), thin films (polymers, II-VI semiconductors), and complex layer structures (hybrid device, VCSEL). The experiments are analyzed and interpreted by newly developed or applied theories for two-photon saturation processes in semiconductors, bandgap shrinkage due to optically induced electron hole pairs, and the principle of detailed balance to describe the photoluminescence in thin film cadmium sulfide.

  9. Advanced solid-state carbon-13 nuclear magnetic resonance spectroscopic studies of sewage sludge organic matter: detection of organic "domains".

    PubMed

    Smernik, Ronald J; Oliver, Ian W; Merrington, Graham

    2003-01-01

    Two novel solid-state 13C nuclear magnetic resonance (NMR) spectroscopic techniques, PSRE (proton spin relaxation editing) and RESTORE [Restoration of Spectra via T(CH) and T(1rho)H (T One Rho H) Editing], were used to provide detailed chemical characterization of the organic matter from six Australian sewage sludges. These methods were used to probe the submicrometer heterogeneity of sludge organic matter, and identify and quantify spatially distinct components. Analysis of the T1H relaxation behavior of the sludges indicated that each sludge contained two types of organic domains. Carbon-13 PSRE NMR subspectra were generated to determine the chemical nature of these domains. The rapidly relaxing component of each sludge was rich in protein and alkyl carbon, and was identified as dead bacterial material. The slowly relaxing component of each sludge was rich in carbohydrate and lignin structures, and was identified as partly degraded plant material. The bacterial domains were shown, using the RESTORE technique, to also have characteristically rapid T(1rho)H relaxation rates. This rapid T(1rho)H relaxation was identified as the main cause of underrepresentation of these domains in standard 13C cross polarization (CP) NMR spectra of sludges. The heterogeneous nature of sewage sludge organic matter has implications for land application of sewage sludge, since the two components are likely to have different capacities for sorbing organic and inorganic toxicants present in sewage sludge, and will decompose at different rates.

  10. Investigation of joining techniques for advanced austenitic alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Kikuchi, Y.; Shi, C.; Gill, T.P.S.

    1991-05-01

    Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.

  11. Spatially-resolved spectroscopic technique for measuring optical properties of food

    USDA-ARS?s Scientific Manuscript database

    Quantification of optical properties is important to understand light interaction with biological materials, and to develop effective optical sensing techniques for property characterization and quality measurement of food products. This chapter reviews spatially-resolved method, with the focus on f...

  12. Reflective and photoacoustic infrared spectroscopic techniques in assessment of binding media in paintings

    NASA Astrophysics Data System (ADS)

    Łojewski, Tomasz; Bagniuk, Jacek; Kołodziej, Andrzej; Łojewska, Joanna

    2011-11-01

    This study proposes a method to estimate the lipid content in binding media in paintings that can be used at any laboratory equipped with an infrared spectrometer. The lipid content estimator, termed greasiness index (GI), is defined as a ratio of lipid ν(C=O) and protein amide I bands at 1743 and 1635 cm-1, respectively. Three Fourier transform infrared (FTIR) sampling techniques were evaluated for GI determination: reflective attenuated total reflection—ATR, specular reflection microscopy— μSR and photoacoustic—PAS. A set of model painting samples containing three tempera binding media (casein, egg, egg + oil), seven pigments and one varnish type were used in the study. Multivariate analysis was used to evaluate the resulting data. A good reproducibility of GI was obtained by ATR and PAS but not with μSR. The discriminative power of the technique is higher for unvarnished samples, but, generally, the GI estimator can be used for the categorisation of binding media in large populations of painting samples analysed with the same FTIR technique (sampling technique, detection, etc.).

  13. New spectroscopic tools and techniques for characterizing M dwarfs and discovering their planets in the near-infrared

    NASA Astrophysics Data System (ADS)

    Terrien, Ryan C.

    M dwarfs are the least massive and most common stars in the Galaxy. Due to their prevalence and long lifetimes, these diminutive stars play an outsize role in several fields of astronomical study. In particular, it is now known that they commonly host planetary systems, and may be the most common hosts of Earth-size, rocky planets in the habitable zone. A comprehensive understanding of M dwarfs is crucial for understanding the origins and conditions of their planetary systems, including their potential habitability. Such an understanding depends on methods for precisely and accurately measuring their properties. These tools have broader applicability as well, underlying the use of M dwarfs as fossils of Galactic evolution, and helping to constrain the structures and interiors of these stars. The measurement of the fundamental parameters of M dwarfs is encumbered by their spectral complexity. Unlike stars of spectral type F, G, or K that are similar to our G type Sun, whose spectra are dominated by continuum emission and atomic features, the cool atmospheres of M dwarfs are dominated by complex molecular absorption. Another challenge for studies of M dwarfs is that these stars are optically faint, emitting much of their radiation in the near-infrared (NIR). The availability and performance of NIR spectrographs have lagged behind those of optical spectrographs due to the challenges of producing low-noise, high-sensitivity NIR detector arrays, which have only recently become available. This thesis discusses two related lines of work that address these challenges, motivated by the development of the Habitable Zone Planet Finder (HPF), a NIR radial velocity (RV) spectrograph under development at Penn State that will search for and confirm planets around nearby M dwarfs. This work includes the development and application of new NIR spectroscopic techniques for characterizing M dwarfs, and the development and optimization of new NIR instrumentation for HPF. The first line

  14. Murillo's paintings revealed by spectroscopic techniques and dedicated laboratory-made micro X-ray diffraction.

    PubMed

    Duran, A; Siguenza, M B; Franquelo, M L; Jimenez de Haro, M C; Justo, A; Perez-Rodriguez, J L

    2010-06-25

    This paper describes one of the first case studies using micro-diffraction laboratory-made systems to analyse painting cross-sections. Pigments, such as lead white, vermilion, red ochre, red lac, lapis lazuli, smalt, lead tin yellow type I, massicot, ivory black, lamp black and malachite, were detected in cross-sections prepared from six Bartolomé Esteban Murillo paintings by micro-Raman and micro-XRD combined with complementary techniques (optical microscopy, SEM-EDS, and FT-IR). The use of micro-XRD was necessary due to the poor results obtained with conventional XRD. In some cases, pigment identification was only possible by combining results from the different analytical techniques utilised in this study. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Neutron Stimulated Emission Computed Tomography: A New Technique for Spectroscopic Medical Imaging

    NASA Astrophysics Data System (ADS)

    Kapadia, A. J.

    Neutron stimulated emission computed tomography (NSECT) is being developed as a new medical-imaging technique to quantify spatial distributions of elements in a sample through inelastic scattering of fast neutrons and detection of the resulting gamma rays. It has the potential to diagnose several disorders in the human body that are characterized by changes in element concentration in the diseased tissue. NSECT is sensitive to several naturally occurring elements in the human body that demonstrate concentration changes in the presence of diseases. NSECT, therefore, has the potential to noninvasively diagnose such disorders with radiation dose that is comparable to other ionizing imaging modalities. This chapter discusses the development and progress of NSECT and presents an overview of the current status of the imaging technique.

  16. Microsampling techniques for infrared spectroscopic analysis of lunar and terrestrial minerals

    NASA Technical Reports Server (NTRS)

    Estep, P. A.; Kovach, J. J.; Karr, C.

    1973-01-01

    Microsampling techniques have been developed for infrared analysis of single mineral grains from lunar rocks and dusts, allowing a detailed molecular structure characterization of these complex fine-grained samples. The methods include special devices for isolating single grains, preparing micropellets from the grains, and obtaining in situ microspecular reflectance spectra from grains in polished rock samples. Although specifically developed for the work on lunar samples, the special techniques for single grain infrared analysis were found to be equally useful in studies of complex terrestrial mineral samples. For example, infrared microanalysis has contributed substantially in solving problems concerned with our natural resources, such as the structural characterization of minerals from commercial iron ores, marine deposits, coal, and fly ash derived from coal.

  17. Microsampling techniques for infrared spectroscopic analysis of lunar and terrestrial minerals

    NASA Technical Reports Server (NTRS)

    Estep, P. A.; Kovach, J. J.; Karr, C.

    1973-01-01

    Microsampling techniques have been developed for infrared analysis of single mineral grains from lunar rocks and dusts, allowing a detailed molecular structure characterization of these complex fine-grained samples. The methods include special devices for isolating single grains, preparing micropellets from the grains, and obtaining in situ microspecular reflectance spectra from grains in polished rock samples. Although specifically developed for the work on lunar samples, the special techniques for single grain infrared analysis were found to be equally useful in studies of complex terrestrial mineral samples. For example, infrared microanalysis has contributed substantially in solving problems concerned with our natural resources, such as the structural characterization of minerals from commercial iron ores, marine deposits, coal, and fly ash derived from coal.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  19. Development of a spectroscopic technique for simultaneous magnetic field, electron density, and temperature measurements in Z-pinch plasmas

    NASA Astrophysics Data System (ADS)

    Dutra, Eric; Presura, Radu; Covington, Aaron; Mancini, Roberto; Darling, Timothy; Angermeier, William

    2016-10-01

    Visible spectroscopic techniques are often used in plasma experiments to measure B-field induced Zeeman splitting, electron densities via Stark broadening, and temperatures from Doppler broadening. However, when electron densities and temperatures are sufficiently high, the broadening of the Stark and Doppler components can dominate the emission spectra and obscure the Zeeman component. In this research, we are developing a time-resolved multi-axial technique for measuring the Zeeman, Stark, and Doppler broadened line emission of dense magnetized plasmas for Z-pinch. In parallel, we are developing a line-shape modeling code that incorporates the broadening effects due to Stark, Doppler, and Zeeman effects for dense magnetized plasma. Experiments were conducted at the University of Nevada (Reno) at the Nevada Terawatt Facility (NTF) using the 1 MA Z-pinch (Zebra). The research explored the optical emission of Al III doublet, 4P 2P3/2 to 4S 2S1/2 and 4P 2P1/2 to 4s 2S1/2 transitions and used it to measure Zeeman, Stark, and Doppler broadened emission. The initial parameters for the line shape code are varied to simulate emission spectra. The simulated spectra are compared to experimental results. These results are used to infer temperature, electron density, and B-fields in the magnetized plasma.

  20. Frequency-scanned ultrafast spectroscopic techniques applied to infrared four-wave mixing spectroscopy

    NASA Astrophysics Data System (ADS)

    Meyer, Kent Albert

    Frequency-scanned techniques of ultrafast spectroscopy were applied to infrared four-wave mixing (IRFWM) in order to determine their effectiveness in the detection and quantification of vibrationally coupled modes. Frequency-scanned ultrafast techniques are a mixed version of frequency and time domain approaches with some advantages of each domain. The frequency domain advantages include the ability to select individual components from a mixture; time domain advantages include the ability to temporally discriminate many non-linear pathways that can congest spectra and interpretation. These advantages have been experimentally verified with doubly vibrationally enhanced (DOVE) and triply vibrationally enhanced (TRIVE) FWM using dilute carbon disulfide as a model system. DOVE and TRIVE are multi-dimensional vibrational coupling techniques analogous to multi-dimensional NMR spin coupling techniques. They differ from NMR in that DOVE and TRIVE spectroscopy occur on the ultrafast (<1 ps) timescale and can provide new chemical dynamics information. Quantification of DOVE signal has been performed computationally of dilute carbon disulfide and agrees with values extracted from linear infrared spectra. Additional parameters from computational models show population dephasing contributions of dilute carbon disulfide's major combination band and strongly absorbing fundamental to be values not far from expected ones. An advantage of TRIVE over the standard IR-IR pump-probe methods is in the possible reduction of the total number of interfering pathways. Pathways not typically explored in the pump-probe paths may be useful in their line narrowing of correlated vibrational modes. The issue of broadening of spectral lines in mixed domain spectra due to the breadth of the electric fields has been addressed with the concept of gated line narrowing. Shaped input pulses can narrow homogeneously broadened lines when gated at a far time. In TRIVE, gating can take place in the form of

  1. Development and applications of laser spectroscopic techniques related to combustion diagnostics

    NASA Astrophysics Data System (ADS)

    Aldén, Marcus

    2006-07-01

    Thanks to features as non-intrusiveness combined with high spatial and temporal resolution, various laser diagnostic techniques have during the last decades become of utmost importance for characterization of combustion related phenomena. In the following presentation some further development of the techniques will be highlighted aiming at a) surface temperatures using Thermographic Phosphors, TP, b) species specific, spatially and temporally resolved detection of species absorbing in the IR spectral region using polarization spectroscopy and Laser-induced fluorescence, and finally c) high speed visualization using a special designed laser system in combination with a framing camera. In terms of surface thermometry, Thermographic Phosphors have been used for many years for temperature measurements on solid surfaces. We have during the last years further developed and applied this technique for temperature measurements on burning surfaces and on materials going through phase shifts, e.g. pyrolysis and droplets. The basic principle behind this technique is to apply micron size particles to the surface of interest. By exciting the TP with a short pulse UV laser (ns), the phosphorescence will exhibit a behaviour where the spectral emission as well as the temporal decay are dependent on the temperature. It is thus possible to measure the temperature both in one and two dimensions. The presentation will include basic description of the technique as well as various applications, e.g in fire science, IC engines and gasturbines. Several of the species of interest for combustion/flow diagnostics exhibit a molecular structure which inhibits the use of conventional laser-induced fluorescence for spatially and spectrally resolved measurements. We have during the last years investigated the use of excitation and detection in the infrared region of the spectrum. Here, it is possible to detect both carbonmono/dioxide, water as well as species specific hydrocarbons. The techniques

  2. THz spectroscopic studies of materials using the FTIR technique: experiment and simulation

    NASA Astrophysics Data System (ADS)

    Lepodise, Lucia Malebogo

    2014-04-01

    Terahertz (THz) radiation has remained the least developed part of the electromagnetic spectrum for quite a long time and thus it was traditionally known as the 'terahertz gap'. The progress of research in this field has been hindered by lack of powerful sources and detectors as compared to both the sources and detectors for the electronic and optical sides of the terahertz radiation region. However, the research on the THz field has intensified in recent years due to a number of emerging interesting technologies and owing to its unique properties. It has several advantages over its counterparts like X-ray and hence it has attracted much interest in a variety of applications scientifically and commercially. THz work has been recently focused in the low frequency region (0.1-3 THz). This is the region where most of the THz spectral features of many materials lie. Studies in this frequency range have been seen revolutionizing the THz field giving it a pool of potential applications which are still yet to be realized. The low frequency THz region (0.1-3 THz) is accessible through the use of the THz-TDS technique and this technique is the mostly used to date. The value of this method is evident throughout the work published in terahertz research and thus its use prevails over other techniques. Many materials show some spectral features in the much higher frequency region (up to 21 THz), but however this frequency range has not attracted much attention in comparison to the low frequency range which of course is more rich in THz spectral features. Furthermore, although the low frequency THz region has been quite extensively studied, the concentration has been at room temperature with a few temperature-dependence studies mostly done at particular temperatures rather than over a wide range.

  3. Raman spectroscopic studies of thin film carbon nanostructures deposited using electro deposition technique

    NASA Astrophysics Data System (ADS)

    Dayal, Saurabh; Sasi, Arshali; Jhariya, Sapna; Sasikumar, C.

    2016-05-01

    In the present work our focus is to synthesize carbon nanostructures (CNS) by electro deposition technique without using any surface pretreatment or catalyst preparation before CNS formation. The process were carried out at significantly low voltage and at low temperature as reported elsewhere. Further the samples were characterized using different characterization tools such as SEM and Raman spectroscopy. The SEM results showed the fibres or tubular like morphology. Raman spectra shows strong finger print at 1600 cm-1 (G peak), 1350 cm-1 (D peak) along with the radial breathing mode (RBM) between 150cm-1 to 300 cm-1. This confirms the formation of tubular carbon nanostructures.

  4. The analytical investigations of ancient pottery from Kaveripakkam, Vellore dist, Tamilnadu by spectroscopic techniques.

    PubMed

    Ravisankar, R; Naseerutheen, A; Annamalai, G Raja; Chandrasekaran, A; Rajalakshmi, A; Kanagasabapathy, K V; Prasad, M V R; Satpathy, K K

    2014-01-01

    Analytical investigations using Fourier Transform infrared spectroscopy (FT-IR), Powder X-ray Diffraction (PXRD), Thermal Analysis (TG-DTA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) were carried out on ancient pottery fragments from Kaveripakkam, in order to outline manufacturing skills, technology information, firing condition and temperature of potteries. The whole set of data showed the firing temperature in the range of 800-900°C. The analytical characterization of the potsherds, by different complimentary techniques has allowed to identifying the raw materials and technology applied by the ancient artisans.

  5. The analytical investigations of ancient pottery from Kaveripakkam, Vellore dist, Tamilnadu by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Ravisankar, R.; Naseerutheen, A.; Raja Annamalai, G.; Chandrasekaran, A.; Rajalakshmi, A.; Kanagasabapathy, K. V.; Prasad, M. V. R.; Satpathy, K. K.

    2014-03-01

    Analytical investigations using Fourier Transform infrared spectroscopy (FT-IR), Powder X-ray Diffraction (PXRD), Thermal Analysis (TG-DTA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) were carried out on ancient pottery fragments from Kaveripakkam, in order to outline manufacturing skills, technology information, firing condition and temperature of potteries. The whole set of data showed the firing temperature in the range of 800-900 °C. The analytical characterization of the potsherds, by different complimentary techniques has allowed to identifying the raw materials and technology applied by the ancient artisans.

  6. Micro-spectroscopic techniques applied to characterization of varnished archeological findings

    NASA Astrophysics Data System (ADS)

    Barone, G.; Ioppolo, S.; Majolino, D.; Migliardo, P.; Ponterio, R.

    2000-04-01

    This work reports an analysis on terracotta varnished finding recovered in east Sicily area (Messina). We have performed FTIR micro-spectroscopy and electronic microscopy (SEM)measurements in order to recognize the elemental constituents of the varnished surfaces. Furthermore, for all the samples, a study on the bulk has been performed by Fourier Transform Infrared Absorption. The analyzed samples consist of a number of pottery fragments belonging to archaic and classical ages, varnished in black and red colors. The obtained data furnished useful information about composition of decorated surfaces and bulk matrixes, about baking temperature, manufacture techniques and alteration mechanisms of findings due to the long burial.

  7. In-situ Spectroscopic and Structural Studies of Electrode Materials for Advanced Battery Applications

    SciTech Connect

    Daniel A Scherson

    2013-03-14

    Techniques have been developed and implemented to gain insight into fundamental factors that affect the performance of electrodes in Li and Li-ion batteries and other energy storage devices. These include experimental strategies for monitoring the Raman scattering spectra of single microparticles of carbon and transition metal oxides as a function of their state of charge. Measurements were performed in electrolytes of direct relevance to Li and Li-Ion batteries both in the static and dynamic modes. In addition, novel strategies were devised for performing conventional experiments in ultrahigh vacuum environments under conditions which eliminate effects associated with presence of impurities, using ultrapure electrolytes, both of the polymeric and ionic liquid type that display no measurable vapor pressure. Also examined was the reactivity of conventional non aqueous solvent toward ultrapure Li films as monitored in ultrahigh vacuum with external reflection Fourier transform infrared spectroscopy. Also pursued were efforts toward developing applying Raman-scattering for monitoring the flow of charge of a real Li ion battery. Such time-resolved, spatially-resolved measurements are key to validating the results of theoretical simulations involving real electrode structures.

  8. Refining Techniques for the Spectroscopic Detection of Reflected Light from Exoplanets

    NASA Astrophysics Data System (ADS)

    Roy, Arpita; Bender, Chad; Mahadevan, Suvrath

    2015-12-01

    The detection of reflected light from exoplanets provides a direct measure of planetary mass as well as a powerful probe of atmospheric composition and albedo. However, close-in giant planets which provide the largest planet-to-star flux ratios are dim in the optical. With contrasts at the level of 10^-5, the direct detection of these present a severe technical challenge to current instruments, and require both large aperture telescopes for high signal-to-noise ratio observations, and a stabilized spectrograph for stable instrument profiles. Leveraging the heritage and stability of the HARPS spectrograph, Martins et al (2015) recently published evidence of a direct detection of the historic exoplanet 51 Peg b, using the stellar mask cross-correlation technique. We attempt to expand upon their results with independent spectral and CCF reductions, using a two-template cross-correlation technique that can potentially be tuned to match the planetary signal and probe models of the albedo. By cross-correlating against a spectrum rather than a mask, we access the full information content in the lines, but must ensure proper telluric correction to mitigate the possibility of overwhelming the small planetary signal with terrestrial features. We are on the verge of confidently recovering planetary albedos for close-in giant planets, while also refining predictive and analytical tools that will come into their full capability with the arrival of the next generation of planet characterizing instruments, such as ESPRESSO on VLT and HIRES on E-ELT.

  9. Analysis of the binding interaction in uric acid - Human hemoglobin system by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Makarska-Bialokoz, Magdalena

    2017-05-01

    The binding interaction between human hemoglobin and uric acid has been studied for the first time, by UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence techniques. Characteristic effects observed for human hemoglobin intrinsic fluorescence during interaction with uric acid at neutral pH point at the formation of stacking non-covalent and non-fluorescent complexes. All the calculated parameters, the binding, fluorescence quenching and bimolecular quenching rate constants, as well as Förster resonance energy transfer parameters confirm the existence of static quenching. The results of synchronous fluorescence measurements indicate that the fluorescence quenching of human hemoglobin originates both from Trp and Tyr residues and that the addition of uric acid could significantly hinder the physiological functions of human hemoglobin.

  10. Study on the interaction of silver(I) complex with bovine serum albumin by spectroscopic techniques.

    PubMed

    Shahabadi, Nahid; Maghsudi, Maryam; Ahmadipour, Zeinab

    2012-06-15

    The interaction of silver(I) complex, [Ag (2,9-dimethyl-1,10-phenanthroline)(2)](NO(3))·H(2)O, and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorimetry and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the complex was a static procedure. Various binding parameters were evaluated. The negative value of ΔH, negative value of ΔS and the negative value of ΔG indicated that van der Waals force and hydrogen bonding play major roles in the binding of the complex and BSA. Based on Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (Ag(I) complex) was evaluated. The results of CD and UV-vis spectroscopy showed that the binding of this complex could bind to BSA and be effectively transported and eliminated in the body.

  11. 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.

  12. Characterization of ceramic films and interfaces by electron microscopic and spectroscopic techniques

    SciTech Connect

    Erdemir, A.; Cheng, C.C.

    1988-01-01

    In this study, Auger electron spectroscopy (AES) in combination with inert gas ion milling and cross-sectional transmission electron microscopy (XTEM) were employed to investigate the chemical and microstructural characteristics of a TiN film on a M50 steel and the film-substrate interfaces formed during ion plating at 100 C and 500 C deposition temperatures. The results of both analytical techniques indicated that the coating produced at 100 C was composed of a thin Ti layer (approximately 1000 A) and a thick TiN layer. Upon vacuum annealing at 500 C for 45 minutes, it was found that the Ti rich interlayer was transformed into a TiC phase. The coating produced at 500 C consisted of a thin TiC and a relatively thick TiN layers. Ion plating as well as post vacuum annealing at 500 C resulted in grain growth and reduced defect density. 11 refs., 8 figs.

  13. Analysis of the binding interaction in uric acid - Human hemoglobin system by spectroscopic techniques.

    PubMed

    Makarska-Bialokoz, Magdalena

    2017-01-31

    The binding interaction between human hemoglobin and uric acid has been studied for the first time, by UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence techniques. Characteristic effects observed for human hemoglobin intrinsic fluorescence during interaction with uric acid at neutral pH point at the formation of stacking non-covalent and non-fluorescent complexes. All the calculated parameters, the binding, fluorescence quenching and bimolecular quenching rate constants, as well as Förster resonance energy transfer parameters confirm the existence of static quenching. The results of synchronous fluorescence measurements indicate that the fluorescence quenching of human hemoglobin originates both from Trp and Tyr residues and that the addition of uric acid could significantly hinder the physiological functions of human hemoglobin.

  14. Comparison of spectroscopic techniques for the determination of Kjeldahl and ammoniacal nitrogen content of farmyard manure.

    PubMed

    Kemsley, E K; Tapp, H S; Scarlett, A J; Miles, S J; Hammond, R; Wilson, R H

    2001-02-01

    The feasibility of determining the nitrogen content of farmyard manure using infrared spectroscopy was investigated. Fifteen samples each of cattle, pig, and turkey manure were analyzed by three infrared techniques: Fourier transform mid-infrared (MIR), using attenuated total reflection (ATR); near-infrared reflectance (NIR-R); and near-infrared optothermal photoacoustic (NIR-OT). The near-infrared measurements were made at wavelengths determined respectively by four (NIR-OT) and five (NIR-R) band-pass filters. The total nitrogen (using the Kjeldahl method) and volatile (ammoniacal) nitrogen contents of all samples were measured by wet chemistry. Internally cross-validated (ICV) partial least-squares (PLS) regression was then used to obtain calibrations for the nitrogen content. The data sets obtained by each technique were treated separately. Within these sets, data from each manure type were treated both separately and combined: the best predictive ability was obtained by combining data from all three manure types. From the combined data set, the residual standard deviations and correlation coefficients for the ICV-predicted versus actual Kjeldahl nitrogen content were, respectively, 6772 mg/kg dry wt, 0.862 (MIR); 9434 mg/kg dry wt, 0.771 (NIR-OT); and 8943 mg/kg dry wt, 0.865 (NIR-R). For the ammoniacal nitrogen content, the residual standard deviations and correlation coefficients were 3869 mg/kg dry wt, 0.899 (MIR); 6079 mg/kg dry wt, 0.820 (NIR-OT); and 3498 mg/kg dry wt, 0.961 (NIR-R).

  15. Recent advances in sample preparation techniques for effective bioanalytical methods.

    PubMed

    Kole, Prashant Laxman; Venkatesh, Gantala; Kotecha, Jignesh; Sheshala, Ravi

    2011-01-01

    This paper reviews the recent developments in bioanalysis sample preparation techniques and gives an update on basic principles, theory, applications and possibilities for automation, and a comparative discussion on the advantages and limitation of each technique. Conventional liquid-liquid extraction (LLE), protein precipitation (PP) and solid-phase extraction (SPE) techniques are now been considered as methods of the past. The last decade has witnessed a rapid development of novel sample preparation techniques in bioanalysis. Developments in SPE techniques such as selective sorbents and in the overall approach to SPE, such as hybrid SPE and molecularly imprinted polymer SPE, have been addressed. Considerable literature has been published in the area of solid-phase micro-extraction and its different versions, e.g. stir bar sorptive extraction, and their application in the development of selective and sensitive bioanalytical methods. Techniques such as dispersive solid-phase extraction, disposable pipette extraction and micro-extraction by packed sorbent offer a variety of extraction phases and provide unique advantages to bioanalytical methods. On-line SPE utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications. PP sample preparation techniques such as PP filter plates/tubes offer many advantages like removal of phospholipids and proteins in plasma/serum. Newer approaches to conventional LLE techniques (salting-out LLE) are also covered in this review article.

  16. Advanced rehabilitation techniques for the multi-limb amputee.

    PubMed

    Harvey, Zach T; Loomis, Gregory A; Mitsch, Sarah; Murphy, Ian C; Griffin, Sarah C; Potter, Benjamin K; Pasquina, Paul

    2012-01-01

    Advances in combat casualty care have contributed to unprecedented survival rates of battlefield injuries, challenging the field of rehabilitation to help injured service members achieve maximal functional recovery and independence. Nowhere is this better illustrated than in the care of the multiple-limb amputee. Specialized medical, surgical, and rehabilitative interventions are needed to optimize the care of this unique patient population. This article describes lessons learned at Walter Reed National Military Medical Center Bethesda in providing advanced therapy and prosthetics for combat casualties, but provides guidelines for all providers involved in the care of individuals with amputation.

  17. Advanced radiation measurement techniques in diagnostic radiology and molecular imaging.

    PubMed

    Del Guerra, Alberto; Belcari, Nicola; Llacer, Gabriela Llosa; Marcatili, Sara; Moehrs, Sascha; Panetta, Daniele

    2008-01-01

    This paper reports some technological advances recently achieved in the fields of micro-CT and small animal PET instrumentation. It highlights a balance between image-quality improvement and dose reduction. Most of the recent accomplishments in these fields are due to the use of novel imaging sensors such as CMOS-based X-ray detectors and silicon photomultipliers (SiPM). Some of the research projects carried out at the University of Pisa for the development of such advanced radiation imaging technology are also described.

  18. Analytic Syntax: A Technique for Advanced Level Reading

    ERIC Educational Resources Information Center

    Berman, Ruth

    1975-01-01

    The technique explained here can increase a foreign student's awareness of English grammatical and rhetorical structures. Structural paraphrase is a syntactic reformulation of difficult phrases with minimal vocabulary changes. The technique is illustrated and suggestions are given for class presentation. (CHK)

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  20. The Book of Kells: A non-invasive MOLAB investigation by complementary spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Doherty, B.; Daveri, A.; Clementi, C.; Romani, A.; Bioletti, S.; Brunetti, B.; Sgamellotti, A.; Miliani, C.

    2013-11-01

    This paper highlights the efficacy of non-invasive portable spectroscopy for assessing the execution technique and constituent materials in one of the most important medieval manuscripts, the Book of Kells. An aimed campaign of in situ measurements by the MObile LABoratory (MOLAB) has analyzed its elemental composition and vibrational and electronic molecular properties. The ample analytical toolbox has afforded complementary diagnostic information of the pigment palette permitting the characterization of both inorganic and organic materials as pigments and dyes in the white, purple, blue, red, orange, green and black areas. In particular, the novel widespread use of calcinated gypsum (anhydrite) as both a white pigment and in correlation to the organic dyes in this manuscript has been noted. The non-invasive identification of the organic dye orchil is significant considering its rare non invasive detection in medieval manuscripts. Finally the occurrence of particular alterations of the organic black areas giving rise to calcium carboxylate and calcium oxalate has been specifically highlighted. Importantly, this work elaborates complex aspects of the employed painting materials which have given rise to numerous significant points of interest for a more elaborate understanding of this Irish treasure.

  1. In vitro DNA binding studies of anticancer drug idarubicin using spectroscopic techniques.

    PubMed

    Ozluer, Can; Kara, Hayriye Eda Satana

    2014-09-05

    The interaction between idarubicin and double stranded deoxyribonucleic acid (ds-DNA) was investigated by UV-VIS spectrophotometry, fluorescence and Raman spectroscopy techniques. The absorption spectra of idarubicin with ds-DNA showed a slight red shift and hypochromic effect. In the fluorescence experiments, emission peaks were decreased by adding ds-DNA. Using ethidium bromide (ETB) as a fluorescence probe, fluorescence quenching of the emission peak was observed in the ETB-DNA system when idarubicin was added. Moreover, similar results were obtained in Raman spectroscopy. Binding constants of idarubicin with ds-DNA were determined as 5.14×10(5) M(-1) and 5.8×10(5) M(-1) for UV-VIS spectrophotometry and fluorescence spectroscopy, respectively. The large binding constant indicated that idarubicin has a high affinity with ds-DNA. All the evidences indicated that the binding mode of idarubicin with DNA was an intercalative binding. Furthermore, quantitative determination of idarubicin in pharmaceutical formulation was done. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The Book of Kells: a non-invasive MOLAB investigation by complementary spectroscopic techniques.

    PubMed

    Doherty, B; Daveri, A; Clementi, C; Romani, A; Bioletti, S; Brunetti, B; Sgamellotti, A; Miliani, C

    2013-11-01

    This paper highlights the efficacy of non-invasive portable spectroscopy for assessing the execution technique and constituent materials in one of the most important medieval manuscripts, the Book of Kells. An aimed campaign of in situ measurements by the MObile LABoratory (MOLAB) has analyzed its elemental composition and vibrational and electronic molecular properties. The ample analytical toolbox has afforded complementary diagnostic information of the pigment palette permitting the characterization of both inorganic and organic materials as pigments and dyes in the white, purple, blue, red, orange, green and black areas. In particular, the novel widespread use of calcinated gypsum (anhydrite) as both a white pigment and in correlation to the organic dyes in this manuscript has been noted. The non-invasive identification of the organic dye orchil is significant considering its rare non invasive detection in medieval manuscripts. Finally the occurrence of particular alterations of the organic black areas giving rise to calcium carboxylate and calcium oxalate has been specifically highlighted. Importantly, this work elaborates complex aspects of the employed painting materials which have given rise to numerous significant points of interest for a more elaborate understanding of this Irish treasure. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. 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.

  4. 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.

  5. Bricklaying Curriculum: Advanced Bricklaying Techniques. Instructional Materials. Revised.

    ERIC Educational Resources Information Center

    Turcotte, Raymond J.; Hendrix, Laborn J.

    This curriculum guide is designed to assist bricklaying instructors in providing performance-based instruction in advanced bricklaying. Included in the first section of the guide are units on customized or architectural masonry units; glass block; sills, lintels, and copings; and control (expansion) joints. The next two units deal with cut,…

  6. Recent advances in microscopic techniques for visualizing leukocytes in vivo

    PubMed Central

    Jain, Rohit; Tikoo, Shweta; Weninger, Wolfgang

    2016-01-01

    Leukocytes are inherently motile and interactive cells. Recent advances in intravital microscopy approaches have enabled a new vista of their behavior within intact tissues in real time. This brief review summarizes the developments enabling the tracking of immune responses in vivo. PMID:27239292

  7. Bricklaying Curriculum: Advanced Bricklaying Techniques. Instructional Materials. Revised.

    ERIC Educational Resources Information Center

    Turcotte, Raymond J.; Hendrix, Laborn J.

    This curriculum guide is designed to assist bricklaying instructors in providing performance-based instruction in advanced bricklaying. Included in the first section of the guide are units on customized or architectural masonry units; glass block; sills, lintels, and copings; and control (expansion) joints. The next two units deal with cut,…

  8. Classical Raman spectroscopic studies of NADH and NAD+ bound to liver alcohol dehydrogenase by difference techniques

    SciTech Connect

    Chen, D.; Yue, K.T.; Martin, C.; Rhee, K.W.; Sloan, D.; Callender, R.

    1987-07-28

    We report the Raman spectra of reduced and oxidized nicotinamide adenine dinucleotide (NADH and NAD+, respectively) and adenosine 5'-diphosphate ribose (ADPR) when bound to the coenzyme site of liver alcohol dehydrogenase (LADH). The bound NADH spectrum is calculated by taking the classical Raman difference spectrum of the binary complex, LADH/NADH, with that of LADH. We have investigated how the bound NADH spectrum is affected when the ternary complexes with inhibitors are formed with dimethyl sulfoxide (Me2SO) or isobutyramide (IBA), i.e., LADH/NADH/Me2SO or LADH/NADH/IBA. Similarly, the difference spectra of LADH/NAD+/pyrazole or LADH/ADPR with LADH are calculated. The magnitude of these difference spectra is on the order of a few percent of the protein Raman spectrum. We report and discuss the experimental configuration and control procedures we use in reliably calculating such small difference signals. These sensitive difference techniques could be applied to a large number of problems where the classical Raman spectrum of a ''small'' molecule, like adenine, bound to the active site of a protein is of interest. The spectrum of bound ADPR allows an assignment of the bands of the bound NADH and NAD+ spectra to normal coordinates located primarily on either the nicotinamide or the adenine moiety. By comparing the spectra of the bound coenzymes with model compound data and through the use of deuterated compounds, we confirm and characterize how the adenine moiety is involved in coenzyme binding and discuss the validity of the suggestion that the adenine ring is protonated upon binding. The nicotinamide moiety of NADH shows significant molecular changes upon binding.

  9. Classical Raman spectroscopic studies of NADH and NAD+ bound to liver alcohol dehydrogenase by difference techniques.

    PubMed

    Chen, D; Yue, K T; Martin, C; Rhee, K W; Sloan, D; Callender, R

    1987-07-28

    We report the Raman spectra of reduced and oxidized nicotinamide adenine dinucleotide (NADH and NAD+, respectively) and adenosine 5'-diphosphate ribose (ADPR) when bound to the coenzyme site of liver alcohol dehydrogenase (LADH). The bound NADH spectrum is calculated by taking the classical Raman difference spectrum of the binary complex, LADH/NADH, with that of LADH. We have investigated how the bound NADH spectrum is affected when the ternary complexes with inhibitors are formed with dimethyl sulfoxide (Me2SO) or isobutyramide (IBA), i.e., LADH/NADH/Me2SO or LADH/NADH/IBA. Similarly, the difference spectra of LADH/NAD+/pyrazole or LADH/ADPR with LADH are calculated. The magnitude of these difference spectra is on the order of a few percent of the protein Raman spectrum. We report and discuss the experimental configuration and control procedures we use in reliably calculating such small difference signals. These sensitive difference techniques could be applied to a large number of problems where the classical Raman spectrum of a "small" molecule, like adenine, bound to the active site of a protein is of interest. The spectrum of bound ADPR allows an assignment of the bands of the bound NADH and NAD+ spectra to normal coordinates located primarily on either the nicotinamide or the adenine moiety. By comparing the spectra of the bound coenzymes with model compound data and through the use of deuterated compounds, we confirm and characterize how the adenine moiety is involved in coenzyme binding and discuss the validity of the suggestion that the adenine ring is protonated upon binding. The nicotinamide moiety of NADH shows significant molecular changes upon binding.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Surface analysis of all elements with isotopic resolution at high ambient pressures using ion spectroscopic techniques

    SciTech Connect

    Smentkowski, V.S.; Krauss, A.R.; Gruen, D.M.; Holecek, J.C.; Schultz, J.A.

    1997-09-01

    The authors have developed a mass spectrometer capable of surface analysis using the techniques of secondary ion mass spectroscopy (SIMS) and mass spectroscopy of recoiled ions (MSRI). For SIMS, an energetic ion beam creates a collision cascade which results in the ejection of low kinetic energy secondary ions from the surface being analyzed. The low kinetic energy SIMS ions are very susceptible to charge neutralization with the surface, and as a result, the SIMS ion yield varies by orders of magnitude depending on the chemical state of the surface. SIM spectra contain elemental ions, and molecular ions. For MSRI, a pulsed ion beam induces a binary collision with the surface being analyzed and the surface species are recoiled into the forward scattering direction with a large kinetic energy. The violence of the binary collision results in complete molecular decomposition, and only elemental ions are detected. The high kinetic energy MSRI ions are much less susceptible to charge neutralization with the surface than the low kinetic energy SIMS ions. In MSRI, the ion yield typically varies by less than a factor of ten as the chemical state of the surface changes--simplifying quantitative analysis vs. SIMS. In this paper, they authors will demonstrate that the high kinetic energy MSRI ions are able to transverse high pressure paths with only a reduction in peak intensity--making MSRI an ideal tool for real-time, in-situ film growth studies. The use of a single analyzer for both MSRI and SIMS is unique and provides complimentary information.

  11. Measurement of the optical properties of skin using terahertz time-domain spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Wilmink, Gerald J.; Ibey, Bennett L.; Tongue, Thomas; Schulkin, Brian; Peralta, Xomalin; Rivest, Benjamin D.; Haywood, Eric C.; Roach, William P.

    2010-02-01

    Terahertz (THz) radiation is increasingly being used in biomedical imaging and spectroscopy applications. These techniques show tremendous promise to provide new sophisticated tools for the improved detection of skin cancer. However, despite recent efforts to develop these applications, few studies have been conducted to characterize the optical properties of skin at THz frequencies. Such information is required to better understand THz-tissue interactions, and is critical for determining the feasibility of proposed applications. In this study, we have developed and tested a THz time-domain spectroscopy system. We used this system to acquire the optical properties for fresh and frozen/thawed excised porcine skin from 0.1 to 2.0 THz. Results show that the index of refraction (n) for both frozen and fresh skin decreases with frequency. For frozen skin, n equals 2.5 at 0.1 THz and 2.0 at 2.0 THz, and for fresh skin equals 2.0 at 0.1 THz and 1.7 at 2.0 THz. Values for the absorption coefficient (μa) increase with frequency for both frozen and fresh skin. Frozen skin exhibits μa values equal to 56 cm-1 at 0.1 THz and 550 cm-1 at 2.0 THz, whereas fresh skin exhibits values of 56 cm-1 at 0.1 THz and 300 cm-1 at 2.0 THz. Assuming the optical penetration depth (δ) is inversely proportional to μa (absorption-dominated interactions), THz radiation has limited δ in skin (200 μm at 0.1 THz to 40 μm at 2.0 THz). These results suggest that applications exploiting THz radiation show the most promise for investigating superficial tissues.

  12. Development and experimental testing of an optical micro-spectroscopic technique incorporating true line-scan excitation.

    PubMed

    Biener, Gabriel; Stoneman, Michael R; Acbas, Gheorghe; Holz, Jessica D; Orlova, Marianna; Komarova, Liudmila; Kuchin, Sergei; Raicu, Valerică

    2013-12-27

    Multiphoton micro-spectroscopy, employing diffraction optics and electron-multiplying CCD (EMCCD) cameras, is a suitable method for determining protein complex stoichiometry, quaternary structure, and spatial distribution in living cells using Förster resonance energy transfer (FRET) imaging. The method provides highly resolved spectra of molecules or molecular complexes at each image pixel, and it does so on a timescale shorter than that of molecular diffusion, which scrambles the spectral information. Acquisition of an entire spectrally resolved image, however, is slower than that of broad-bandwidth microscopes because it takes longer times to collect the same number of photons at each emission wavelength as in a broad bandwidth. Here, we demonstrate an optical micro-spectroscopic scheme that employs a laser beam shaped into a line to excite in parallel multiple sample voxels. The method presents dramatically increased sensitivity and/or acquisition speed and, at the same time, has excellent spatial and spectral resolution, similar to point-scan configurations. When applied to FRET imaging using an oligomeric FRET construct expressed in living cells and consisting of a FRET acceptor linked to three donors, the technique based on line-shaped excitation provides higher accuracy compared to the point-scan approach, and it reduces artifacts caused by photobleaching and other undesired photophysical effects.

  13. Study on the interaction between histidine-capped Au nanoclusters and bovine serum albumin with spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Zheng, Chengzhi; Wang, Huiping; Xu, Wei; Xu, Chaoyong; Liang, Jiangong; Han, Heyou

    2014-01-01

    The understanding of the protein-nanoclusters interaction has significant implications for biological applications of nanoclusters (NCs). In this manuscript, the interaction of histidine-capped Au nanoclusters (NCs) with bovine serum albumin (BSA) has been investigated by fluorescence, UV-vis, circular dichroism (CD) and Raman spectroscopic techniques under simulative physiological conditions. The results showed that the fluorescence of BSA was quenched by Au NCs. The quenching mechanism was discussed to be a dynamic quenching style, which was proved by the fluorescence spectra and UV-vis absorption spectra. According to modified Stern-Volmer equations at different temperatures, corresponding thermodynamic parameters, ΔHθ, ΔSθ and ΔGθ were observed to be 35.97 kJ mol-1, 199.53 J mol-1 K-1 and -23.49 kJ mol-1, respectively. The hydrophobic force played a key role in the interaction process. Further results from the CD spectra and Raman spectra demonstrated that the α-helical content in BSA was reduced upon interaction with Au NCs which induced a partial protein destabilization. This study contributes to a better understanding of the biology toxicity of Au NCs to biomolecular, which is very essential for the development of safe and functional Au NCs.

  14. Binding of caffeine with caffeic acid and chlorogenic acid using fluorescence quenching, UV/vis and FTIR spectroscopic techniques.

    PubMed

    Belay, Abebe; Kim, Hyung Kook; Hwang, Yoon-Hwae

    2016-03-01

    The interactions of caffeine (CF) with chlorogenic acid (CGA) and caffeic acid (CFA) were investigated by fluorescence quenching, UV/vis and Fourier transform infrared (FTIR) spectroscopic techniques. The results of the study indicated that the fluorescence quenching between caffeine and hydroxycinnamic acids could be rationalized in terms of static quenching or the formation of non-fluorescent CF-CFA and CF-CGA complexes. From fluorescence quenching spectral analysis, the quenching constant (KSV), quenching rate constant (kq), number of binding sites (n), thermodynamic properties and conformational changes of the interaction were determined. The quenching constants (KSV) between CF and CGA, CFA are 1.84 × 10(4) and 1.04 × 10(4) L/mol at 298 K and their binding site n is ~ 1. Thermodynamic parameters determined using the Van't Hoff equation indicated that hydrogen bonds and van der Waal's forces have a major role in the reaction of caffeine with caffeic acid and chlorogenic acid. The 3D fluorescence, UV/vis and FTIR spectra also showed that the binding of CF with CFA and CGA induces conformational changes in CFA and CGA. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Interaction of an antiepileptic drug, lamotrigine with human serum albumin (HSA): Application of spectroscopic techniques and molecular modeling methods.

    PubMed

    Poureshghi, Fatemeh; Ghandforoushan, Parisa; Safarnejad, Azam; Soltani, Somaieh

    2017-01-01

    Lamotrigine (an epileptic drug) interaction with human serum albumin (HSA) was investigated by fluorescence, UV-Vis, FTIR, CD spectroscopic techniques, and molecular modeling methods. Binding constant (Kb) of 5.74×10(3) and number of binding site of 0.97 showed that there is a slight interaction between lamotrigine and HSA. Thermodynamic studies was constructed using the flourimetric titrations in three different temperatures and the resulted data used to calculate the parameters using Vant Hoff equation. Decreased Stern Volmer quenching constant by enhanced temperature revealed the static quenching mechanism. Negative standard enthalpy (ΔH) and standard entropy (ΔS) changes indicated that van der Waals interactions and hydrogen bonds were dominant forces which facilitate the binding of Lamotrigine to HSA, the results were confirmed by molecular docking studies which showed no hydrogen binding. The FRET studies showed that there is a possibility of energy transfer between Trp214 and lamotrigine. Also the binding of lamotrigine to HSA in the studied concentrations was not as much as many other drugs, but the secondary structure of the HSA was significantly changed following the interaction in a way that α-helix percentage was reduced from 67% to 57% after the addition of lamotrigine in the molar ratio of 4:1 to HSA. According to the docking studies, lamotrigine binds to IB site preferably.

  16. Conformers of β-aminoisobutyric acid probed by jet-cooled microwave and matrix isolation infrared spectroscopic techniques.

    PubMed

    Kuş, N; Sharma, A; Peña, I; Bermúdez, M C; Cabezas, C; Alonso, J L; Fausto, R

    2013-04-14

    β-aminoisobutyric acid (BAIBA) has been studied in isolation conditions: in the gas phase and trapped into a cryogenic N2 matrix. A solid sample of the compound was vaporized by laser ablation and investigated through their rotational spectra in a supersonic expansion using two different spectroscopic techniques: broadband chirped pulse Fourier transform microwave spectroscopy and conventional molecular beam Fourier transform microwave spectroscopy. Four conformers with structures of two types could be successfully identified by comparison of the experimental rotational and (14)N nuclear quadruple coupling constants with those predicted theoretically: type A, bearing an OH⋯N intramolecular hydrogen bond and its carboxylic group in the trans geometry (H-O-C=O dihedral ∼180°), and type B, having an NH⋯O bond and the cis arrangement of the carboxylic group. These two types of conformers could also be trapped from the gas phase into a cryogenic N2 matrix and probed by Fourier transform infrared (IR) spectroscopy. In situ irradiation of BAIBA isolated in N2 matrix of type B conformers using near-IR radiation tuned at the frequency of the O-H stretching 1st overtone (∼6930 cm(-1)) of these forms allowed to selectively convert them into type A conformers and into a new type of conformers of higher energy (type D) bearing an NH⋯O=C bond and a O-H "free" trans carboxylic group.

  17. Conformers of β-aminoisobutyric acid probed by jet-cooled microwave and matrix isolation infrared spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Kuş, N.; Sharma, A.; Peña, I.; Bermúdez, M. C.; Cabezas, C.; Alonso, J. L.; Fausto, R.

    2013-04-01

    β-aminoisobutyric acid (BAIBA) has been studied in isolation conditions: in the gas phase and trapped into a cryogenic N2 matrix. A solid sample of the compound was vaporized by laser ablation and investigated through their rotational spectra in a supersonic expansion using two different spectroscopic techniques: broadband chirped pulse Fourier transform microwave spectroscopy and conventional molecular beam Fourier transform microwave spectroscopy. Four conformers with structures of two types could be successfully identified by comparison of the experimental rotational and 14N nuclear quadruple coupling constants with those predicted theoretically: type A, bearing an OH⋯N intramolecular hydrogen bond and its carboxylic group in the trans geometry (H-O-C=O dihedral ˜180°), and type B, having an NH⋯O bond and the cis arrangement of the carboxylic group. These two types of conformers could also be trapped from the gas phase into a cryogenic N2 matrix and probed by Fourier transform infrared (IR) spectroscopy. In situ irradiation of BAIBA isolated in N2 matrix of type B conformers using near-IR radiation tuned at the frequency of the O-H stretching 1st overtone (˜6930 cm-1) of these forms allowed to selectively convert them into type A conformers and into a new type of conformers of higher energy (type D) bearing an NH⋯O=C bond and a O-H "free" trans carboxylic group.

  18. Study on the interaction between bovine serum albumin and CdTe quantum dots with spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Liang, Jiangong; Cheng, Yanping; Han, Heyou

    2008-12-01

    The interaction between bovine serum albumin (BSA) and CdTe quantum dots (QDs) was studied by fluorescence, UV-vis and Raman spectroscopic techniques. The results showed that the fluorescence of BSA was strongly quenched by CdTe QDs. The quenching mechanism was discussed to be a static quenching procedure, which was proved by the quenching rate constant ( Kq) and UV-vis absorption spectra. According to Lineweaver-Burk equations at different temperatures, the thermodynamic parameters, Δ H θ, Δ S θ and Δ G θ were observed to be -23.69 kJ mol -1, 48.39 J mol -1 K -1 and -38.04 kJ mol -1, respectively. The binding constant ( KA) and the number of binding sites ( n) were obtained by Scatchard equation. It was found that hydrophobic force and sulfhydryl group played a key role in the interaction process. Further results from Raman spectra indicated that the α-helical content in BSA reduced after binding with CdTe QDs.

  19. Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilde, S.; Zhang, Y.; Dall'Osto, M.

    2014-04-01

    The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterized by a less dense urbanization. We present here the results obtained in San Pietro Capofiume, which is located in a sparsely inhabited sector of the Po Valley, Italy. The experiment was carried out in summer 2009 in the framework of the EUCAARI project ("European Integrated Project on Aerosol, Cloud Climate Aerosol Interaction"). For the first time in Europe, six state-of-the-art techniques were used in parallel: (1) on-line TSI aerosol time-of-flight mass spectrometer (ATOFMS), (2) on-line Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS), (3) soot particle aerosol mass spectrometer (SP-AMS), (4) on-line high resolution time-of-flight mass spectrometer-thermal desorption aerosol gas chromatograph (HR-ToFMS-TAG), (5) off-line twelve-hour resolution proton nuclear magnetic resonance (H-NMR) spectroscopy, and (6) chemical ionization mass spectrometry (CIMS) for the analysis of gas-phase precursors of secondary aerosol. Data from each aerosol spectroscopic method were analysed individually following ad-hoc tools (i.e. PMF for AMS, Art-2a for ATOFMS). The results obtained from each techniques are herein presented and compared. This allows us to clearly link the modifications in aerosol chemical composition to transitions in air mass origin and meteorological regimes. Under stagnant conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC

  20. Backscattered Electron Microscopy as an Advanced Technique in Petrography.

    ERIC Educational Resources Information Center

    Krinsley, David Henry; Manley, Curtis Robert

    1989-01-01

    Three uses of this method with sandstone, desert varnish, and granite weathering are described. Background information on this technique is provided. Advantages of this type of microscopy are stressed. (CW)

  1. Backscattered Electron Microscopy as an Advanced Technique in Petrography.

    ERIC Educational Resources Information Center

    Krinsley, David Henry; Manley, Curtis Robert

    1989-01-01

    Three uses of this method with sandstone, desert varnish, and granite weathering are described. Background information on this technique is provided. Advantages of this type of microscopy are stressed. (CW)

  2. Recent Advances in Fluorescent Labeling Techniques for Fluorescence Microscopy

    PubMed Central

    Suzuki, Takeshi; Matsuzaki, Toshiyuki; Hagiwara, Haruo; Aoki, Takeo; Takata, Kuniaki

    2007-01-01

    Tremendous progress in recent computer-controlled systems for fluorescence and laser-confocal microscopy has provided us with powerful tools to visualize and analyze molecular events in the cells. Various fluorescent staining and labeling techniques have also been developed to be used with these powerful instruments. Fluorescent proteins such as green fluorescent protein (GFP) allow us to directly label particular proteins of interest in living cells. This technique has been extended over a large area of cell biology, and a variety of fluorescent protein-derived techniques have been developed to visualize the functions and conditions of the molecules within living cells. In this review, we summarize the techniques for fluorescent staining and labeling for recent fluorescence microscopy. PMID:18224244

  3. Stable carbon dioxide isotopes for partitioning grassland fluxes: a comparison of Mass Spectrometric and Spectroscopic (FTIR and QCL) techniques.

    NASA Astrophysics Data System (ADS)

    Zeeman, M. J.; Mohn, J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Emmenegger, L.; Buchmann, N.

    2006-12-01

    Three research sites on elevations covering the relevant stages of the Swiss agricultural system (400, 1000, and 2000 m a.s.l.) have been established. This allows for in-situ investigation of the processes involved in green-house gas exchanges of grassland. A first assessment of stable carbon dioxide isotope analysis has provided valuable information on CO2 flux partitioning. For the first time a comparison of three independent measurement techniques for stable isotope ratios (13C/12C) and (18O/16O) and green-house gas concentrations of carbon dioxide, methane and nitrous oxide was performed. During a three week period, air samples were collected at four height profiles (z = 0.055; 0.14; 0.40; 1.90 m) and in a regular two hours interval by automated air samplers connected to a switching inlet system. The isotopic ratios (13C/12C) and (18O/16O) of carbon dioxide were measured in the laboratory with Isotope Ratio Mass Spectrometry (IRMS). Simultaneously, two additional optical techniques were used to continuously measure these stable isotope ratios in the field: (1) Fourier Transform Infrared (FTIR) and (2) Quantum Cascade Laser (QCL) spectroscopy. The time resolution was one minute and one second, respectively. Furthermore, the greenhouse gas concentrations were continuously monitored with an open path IR gas analyser for carbon dioxide and a photo-acoustic gas analyser for carbon dioxide, methane, and nitrous oxide. The FTIR spectrometer also measured the concentrations of carbon dioxide, carbon monoxide, methane and nitrous oxide. The preliminary results show the added value of high time resolution measurements for the investigation of flux partitioning, with use of new spectroscopic technologies. The FTIR instrument achieved accuracy in δ13C ratios of +/- 0.4 %0. The achieved temporal resolution of 1 second of the QCL system has significant potential in computation of eddy covariance isotopic fluxes.

  4. Advanced Statistical Signal Processing Techniques for Landmine Detection Using GPR

    DTIC Science & Technology

    2014-07-12

    based ground penetrating radars for the detection of subsurface objects that are low in metal content and hard to detect. The derived techniques...penetrating radars for the detection of subsurface objects that are low in metal content and hard to detect. The derived techniques include the exploitation...5.00 4.00 3.00 9.00 T. Glenn, J. Wilson, D. Ho. A MULTIMODAL MATCHING PURSUITS DISSIMILARITY MEASURE APPLIED TO LANDMINE/CLUTTER DISCRIMINATION

  5. Advanced millimeter-wave security portal imaging techniques

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Bernacki, Bruce E.; McMakin, Douglas L.

    2012-03-01

    Millimeter-wave (mm-wave) imaging is rapidly gaining acceptance as a security tool to augment conventional metal detectors and baggage x-ray systems for passenger screening at airports and other secured facilities. This acceptance indicates that the technology has matured; however, many potential improvements can yet be realized. The authors have developed a number of techniques over the last several years including novel image reconstruction and display techniques, polarimetric imaging techniques, array switching schemes, and high-frequency high-bandwidth techniques. All of these may improve the performance of new systems; however, some of these techniques will increase the cost and complexity of the mm-wave security portal imaging systems. Reducing this cost may require the development of novel array designs. In particular, RF photonic methods may provide new solutions to the design and development of the sequentially switched linear mm-wave arrays that are the key element in the mm-wave portal imaging systems. Highfrequency, high-bandwidth designs are difficult to achieve with conventional mm-wave electronic devices, and RF photonic devices may be a practical alternative. In this paper, the mm-wave imaging techniques developed at PNNL are reviewed and the potential for implementing RF photonic mm-wave array designs is explored.

  6. Electroextraction and electromembrane extraction: Advances in hyphenation to analytical techniques

    PubMed Central

    Oedit, Amar; Ramautar, Rawi; Hankemeier, Thomas

    2016-01-01

    Electroextraction (EE) and electromembrane extraction (EME) are sample preparation techniques that both require an electric field that is applied over a liquid‐liquid system, which enables the migration of charged analytes. Furthermore, both techniques are often used to pre‐concentrate analytes prior to analysis. In this review an overview is provided of the body of literature spanning April 2012–November 2015 concerning EE and EME, focused on hyphenation to analytical techniques. First, the theoretical aspects of concentration enhancement in EE and EME are discussed to explain extraction recovery and enrichment factor. Next, overviews are provided of the techniques based on their hyphenation to LC, GC, CE, and direct detection. These overviews cover the compounds and matrices, experimental aspects (i.e. donor volume, acceptor volume, extraction time, extraction voltage, and separation time) and the analytical aspects (i.e. limit of detection, enrichment factor, and extraction recovery). Techniques that were either hyphenated online to analytical techniques or show high potential with respect to online hyphenation are highlighted. Finally, the potential future directions of EE and EME are discussed. PMID:26864699

  7. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1999-03-31

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size and type on water nuclear spin relaxation, T2, were measured and modeled.

  8. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1998-09-30

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size on water nuclear spin relaxation, T2, were measured.

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

    SciTech Connect

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

    2015-09-01

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

  10. Application of Active Learning Techniques to an Advanced Course

    NASA Astrophysics Data System (ADS)

    Knop, R. A.

    2004-05-01

    The New Faculty Workshop provided a wealth of techniques as well as an overriding philosophy for the teaching of undergraduate Physics and Astronomy courses. The focus of the workshop was active learning, summarized in ``Learner-Centered Astronomy Teaching" by Slater & Adams: it's not what you do in class that matters, it's what the students do. Much of the specific focus of the New Faculty Workshop is on teaching the large, introductory Physics classes that many of the faculty present are sure to teach, both algebra-based and calculus-based. Many of these techniques apply directly and with little modification to introductory Astronomy courses. However, little direct attention is given to upper-division undergraduate, or even graduate, courses. In this presentation, I will share my experience in attempting to apply some of the techniques discussed at the New Faculty Workshop to an upper-division course in Galactic Astrophysics at Vanderbilt University during the Spring semester of 2004.

  11. The bumper technique for advancing a large profile microcatheter.

    PubMed

    Kellner, Christopher P; Chartrain, Alexander G; Schwegel, Claire; Oxley, Thomas J; Shoirah, Hazem; Mocco, J

    2017-03-09

    Operators commonly encounter difficulty maneuvering a microcatheter beyond the distal lip of wide neck aneurysms and aneurysms in challenging locations. Few techniques have been described to guide operators in these particular situations. In this case report of a 56-year-old woman with a 16 mm ophthalmic artery aneurysm, the microcatheter continually snagged the distal aneurysm lip, preventing delivery of a flow diverter into the distal parent vessel. In troubleshooting this obstacle, a second microguidewire was introduced alongside the microcatheter and was used to cover the distal lip of the aneurysm to prevent further snagging. The second guidewire successfully deflected the microcatheter into the distal vessel, a technique that we have aptly dubbed the 'bumper technique'.

  12. Application of advanced coating techniques to rocket engine components

    NASA Technical Reports Server (NTRS)

    Verma, S. K.

    1988-01-01

    The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.

  13. Transcranial Doppler: Techniques and advanced applications: Part 2

    PubMed Central

    Sharma, Arvind K.; Bathala, Lokesh; Batra, Amit; Mehndiratta, Man Mohan; Sharma, Vijay K.

    2016-01-01

    Transcranial Doppler (TCD) is the only diagnostic tool that can provide continuous information about cerebral hemodynamics in real time and over extended periods. In the previous paper (Part 1), we have already presented the basic ultrasound physics pertaining to TCD, insonation methods, and various flow patterns. This article describes various advanced applications of TCD such as detection of right-to-left shunt, emboli monitoring, vasomotor reactivity (VMR), monitoring of vasospasm in subarachnoid hemorrhage (SAH), monitoring of intracranial pressure, its role in stoke prevention in sickle cell disease, and as a supplementary test for confirmation of brain death. PMID:27011639

  14. New Synthetic Techniques for Advanced Propellant Ingredients: Trifluoromethanesulfonate Derivitive Intermediates

    DTIC Science & Technology

    1987-04-01

    Advanced Propellant Ingredients: Trifluoromethanesulfonate Derivitive Intermediates April 1987 Authors: R . D. Chapman J. L. Andreshak S. A. Shackelford...31 Sun«. P. J.. Hanack, M.. Subraroanian. L. R . Hvnthau 1982, 8M26 (4) Ho»ella. R D; McCown. J D Chrm Rrv 1177. 77. 69-92 (5) Sung. P J.; Whit«, M R ...Brr l»gl lit. 810-813 (8) Beard, C D . Baum, K. J Urf Vht-m l»74. J9. 3875 ;W77 (9) Shone. R 1. Tttrahtdron Ltll 1977. »93 996. (10) Hildreth

  15. Advances in High-Fidelity Multi-Physics Simulation Techniques

    DTIC Science & Technology

    2008-01-01

    fluid dynamics with other disciplines also yield a large and typically stiff equation set whose numerical solution mandates the development and...and Electromagnetics . . . . . 3 2.1 Governing Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Numerical Technique...discrete equivalent of the governing equations . Thus, the values of the solution vector are localized in a pointwise sense at each node of the mesh. This

  16. Benefits of advanced software techniques for mission planning systems

    NASA Technical Reports Server (NTRS)

    Gasquet, A.; Parrod, Y.; Desaintvincent, A.

    1994-01-01

    The increasing complexity of modern spacecraft, and the stringent requirement for maximizing their mission return, call for a new generation of Mission Planning Systems (MPS). In this paper, we discuss the requirements for the Space Mission Planning and the benefits which can be expected from Artificial Intelligence techniques through examples of applications developed by Matra Marconi Space.

  17. Advances in reduction techniques for tire contact problems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1995-01-01

    Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

  18. Advances in reduction techniques for tire contact problems

    NASA Astrophysics Data System (ADS)

    Noor, Ahmed K.

    1995-08-01

    Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

  19. Single Molecule Techniques for Advanced in situ Hybridization

    SciTech Connect

    Hollars, C W; Stubbs, L; Carlson, K; Lu, X; Wehri, E

    2003-02-03

    One of the most significant achievements of modern science is completion of the human genome sequence, completed in the year 2000. Despite this monumental accomplishment, researchers have only begun to understand the relationships between this three-billion-nucleotide genetic code and the regulation and control of gene and protein expression within each of the millions of different types of highly specialized cells. Several methodologies have been developed for the analysis of gene and protein expression in situ, yet despite these advancements, the pace of such analyses is extremely limited. Because information regarding the precise timing and location of gene expression is a crucial component in the discovery of new pharmacological agents for the treatment of disease, there is an enormous incentive to develop technologies that accelerate the analytical process. Here we report on the use of plasmon resonant particles as advanced probes for in situ hybridization. These probes are used for the detection of low levels of gene-probe response and demonstrate a detection method that enables precise, simultaneous localization within a cell of the points of expression of multiple genes or proteins in a single sample.

  20. Task 7: Image Enhancement and Advanced Information Extraction Techniques, 1385

    NASA Technical Reports Server (NTRS)

    Malila, W. A.; Nalepka, R. F. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Atmospheric effects in satellite multispectral scanner data can influence results obtained with either manual image interpretation or computer information extraction techniques. The atmosphere attenuates radiation arriving from the surface and adds an extraneous path radiance component. Initial results of an investigation of atmospheric effects in ERTS-1 data are presented. Empirical analyses of ERTS-1 MSS data and simultaneous airborne MSS underflight data for one frame, along with theoretical calculations of atmospheric effects, are discussed. The effect of limited spatial resolution on the accuracy of information extracted from ERTS-1 data also is important. Problems occur when individual resolution elements contain two or more materials. Results from an initial application of Environmental Research Institute of Michigan techniques for estimating proportions of materials within individual elements are presented and discussed. Very accurate determination of surface areas of small lakes is achieved.

  1. Advanced optical techniques for monitoring dosimetric parameters in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Li, Buhong; Qiu, Zhihai; Huang, Zheng

    2012-12-01

    Photodynamic therapy (PDT) is based on the generation of highly reactive singlet oxygen through interactions of photosensitizer, light and molecular oxygen. PDT has become a clinically approved, minimally invasive therapeutic modality for a wide variety of malignant and nonmalignant diseases. The main dosimetric parameters for predicting the PDT efficacy include the delivered light dose, the quantification and photobleaching of the administrated photosensitizer, the tissue oxygen concentration, the amount of singlet oxygen generation and the resulting biological responses. This review article presents the emerging optical techniques that in use or under development for monitoring dosimetric parameters during PDT treatment. Moreover, the main challenges in developing real-time and noninvasive optical techniques for monitoring dosimetric parameters in PDT will be described.

  2. 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.

  3. Computational ghost imaging: advanced compressive sensing (CS) technique

    NASA Astrophysics Data System (ADS)

    Katkovnik, Vladimir; Astola, Jaakko

    2012-10-01

    A novel efficient variational technique for speckle imaging is discussed. It is developed with the main motivation to filter noise, to wipe out the typical diffraction artifacts and to achieve crisp imaging. A sparse modeling is used for the wave field at the object plane in order to overcome the loss of information due to the ill-posedness of forward propagation image formation operators. This flexible and data adaptive modeling relies on the recent progress in sparse imaging and compressive sensing (CS). Being in line with the general formalism of CS, we develop an original approach to wave field reconstruction.7 In this paper we demonstrate this technique in its application for computational amplitude ghost imaging (GI), where a spatial light modulator (SLM) is used in order to generate a speckle wave field sensing a transmitted mask object.

  4. A comparison investigation of DNP-binding effects to HSA and HTF by spectroscopic and molecular modeling techniques.

    PubMed

    Zolfagharzadeh, Mahboobeh; Pirouzi, Maliheh; Asoodeh, Ahmad; Saberi, Mohammad Reza; Chamani, Jamshidkhan

    2014-12-01

    This paper describes the interaction between 2,4-dinitrophenol (DNP) with the two drug carrier proteins - human serum albumin (HSA) and human holo transferrin (HTF). Hence, binding characteristics of DNP to HSA and HTF were analyzed by spectroscopic and molecular modeling techniques. Based on results obtained from fluorescence spectroscopy, DNP had a strong ability to quench the intrinsic fluorescence of HSA and HTF through a static quenching procedure. The binding constant and the number of binding sites were calculated as 2.3 × 10(11) M(-1) and .98 for HSA, and 1.7 × 10(11) M(-1) and 1.06 for HTF, respectively. In addition, synchronous fluorescence results showed that the microenvironment of Trp had a slight tendency of increasing its hydrophobicity, whereas the microenvironment of the Tyr residues of HSA did not change and that of HTF showed a significant trend (red shift of about 4 nm) of an increase in polarity. The distance between donor and acceptor was obtained by the Förster energy according to fluorescence resonance energy transfer, and was found to be 3.99 and 3.72 nm for HSA and HTF, respectively. The critical induced aggregation concentration (CCIAC) of the drug on both proteins was determined and confirmed by an inflection point of the zeta potential behavior. Circular dichroism data revealed that the presence of DNP caused a decrease of the α-helical content of HSA and HTF, and induced a remarkable mild denaturation of both proteins. The molecular modeling data confirmed our experimental results. This study is deemed useful for determining drug dosage.

  5. Application of phosphorus-31 and aluminum-27 NMR spectroscopic techniques to study aqueous and methanolic solutions of tetraphenylammonium aluminophosphate

    NASA Astrophysics Data System (ADS)

    Goudarzi, Nasser; Amin, Amir H.

    2017-01-01

    In this work, aluminum-27 and phosphorus-31 NMR spectroscopic techniques were used to investigate and characterize the distribution of aluminophosphate (AlPO) species soluble in the aqueous and methanolic solutions of tetraphenylammonium (TPhA) chloride. The reaction between hexaaquaaluminum cations, [A1(H2O)6]3+, and different phosphate ligands such as H3PO4, H2PO4-, and the acidic dimers H6P2O8 and H5P2O8- resulted in the formation of the soluble AlPO cations. The effective aluminum-27 and phosphorous-31 NMR spectroscopies can be employed to characterize the species present in a solution. Assignment of the peaks present in the aluminum-27 NMR spectra to the aluminate species or aluminate connectivities was done to acquire information about different AlPO complexes. Some resonance lines were observed in the phosphorus-31 {1H} NMR spectra, indicating the existence of different complexes in the AlPO solutions. Some peaks were observed in the methanolic solutions of AlPO at the chemical shifts of -0.41, -6.4, -7.5, -7.9, -13.1, -13.9, -16.6, -18.1, and -20.6 ppm. Four additional peaks were also observed in the phosphorus-31 {1H} NMR spectra of the methanolic solutions of AlPO, whose intensities changed with changes in the methanol:water volume ratio; they were observed in methanol but not in aqueous AlPO.

  6. Advance techniques for monitoring human tolerance to +Gz accelerations.

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Sandler, H.; Rositano, S.; Skrettingland, K.; Mancini, R.

    1972-01-01

    Standard techniques for monitoring the acceleration-stressed human subject have been augmented by measuring (1) temporal, brachial and/or radial arterial blood flow, and (2) indirect systolic and diastolic blood pressure at 60-sec intervals. Results show that the response of blood pressure to positive accelerations is complex and dependent on an interplay of hydrostatic forces, diminishing venous return, redistribution of blood, and other poorly defined compensatory reflexes.

  7. 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

  8. 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.

  9. Brain development in preterm infants assessed using advanced MRI techniques.

    PubMed

    Tusor, Nora; Arichi, Tomoki; Counsell, Serena J; Edwards, A David

    2014-03-01

    Infants who are born preterm have a high incidence of neurocognitive and neurobehavioral abnormalities, which may be associated with impaired brain development. Advanced magnetic resonance imaging (MRI) approaches, such as diffusion MRI (d-MRI) and functional MRI (fMRI), provide objective and reproducible measures of brain development. Indices derived from d-MRI can be used to provide quantitative measures of preterm brain injury. Although fMRI of the neonatal brain is currently a research tool, future studies combining d-MRI and fMRI have the potential to assess the structural and functional properties of the developing brain and its response to injury. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Development of processing techniques for advanced thermal protection materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna S.

    1994-01-01

    The effort, which was focused on the research and development of advanced materials for use in Thermal Protection Systems (TPS), has involved chemical and physical testing of refractory ceramic tiles, fabrics, threads and fibers. This testing has included determination of the optical properties, thermal shock resistance, high temperature dimensional stability, and tolerance to environmental stresses. Materials have also been tested in the Arc Jet 2 x 9 Turbulent Duct Facility (TDF), the 1 atmosphere Radiant Heat Cycler, and the Mini-Wind Tunnel Facility (MWTF). A significant part of the effort hitherto has gone towards modifying and upgrading the test facilities so that meaningful tests can be carried out. Another important effort during this period has been the creation of a materials database. Computer systems administration and support have also been provided. These are described in greater detail below.

  11. Recent advances in bioprinting techniques: approaches, applications and future prospects.

    PubMed

    Li, Jipeng; Chen, Mingjiao; Fan, Xianqun; Zhou, Huifang

    2016-09-20

    Bioprinting technology shows potential in tissue engineering for the fabrication of scaffolds, cells, tissues and organs reproducibly and with high accuracy. Bioprinting technologies are mainly divided into three categories, inkjet-based bioprinting, pressure-assisted bioprinting and laser-assisted bioprinting, based on their underlying printing principles. These various printing technologies have their advantages and limitations. Bioprinting utilizes biomaterials, cells or cell factors as a "bioink" to fabricate prospective tissue structures. Biomaterial parameters such as biocompatibility, cell viability and the cellular microenvironment strongly influence the printed product. Various printing technologies have been investigated, and great progress has been made in printing various types of tissue, including vasculature, heart, bone, cartilage, skin and liver. This review introduces basic principles and key aspects of some frequently used printing technologies. We focus on recent advances in three-dimensional printing applications, current challenges and future directions.

  12. Advanced materials and techniques for fibre-optic sensing

    NASA Astrophysics Data System (ADS)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  13. Advanced techniques for constrained internal coordinate molecular dynamics.

    PubMed

    Wagner, Jeffrey R; Balaraman, Gouthaman S; Niesen, Michiel J M; Larsen, Adrien B; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-04-30

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle, and torsional coordinates instead of a Cartesian coordinate representation. Freezing high-frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed to make the CICMD method robust and widely usable. In this article, we have designed a new framework for (1) initializing velocities for nonindependent CICMD coordinates, (2) efficient computation of center of mass velocity during CICMD simulations, (3) using advanced integrators such as Runge-Kutta, Lobatto, and adaptive CVODE for CICMD simulations, and (4) cancelling out the "flying ice cube effect" that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this article, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse-graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided "freezing and thawing" of degrees of freedom in the molecule on the fly during molecular dynamics simulations and is shown to fold four proteins to their native topologies. With these advancements, we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. Copyright © 2013 Wiley Periodicals, Inc.

  14. Advanced Techniques for Constrained Internal Coordinate Molecular Dynamics

    PubMed Central

    Wagner, Jeffrey R.; Balaraman, Gouthaman S.; Niesen, Michiel J. M.; Larsen, Adrien B.; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-01-01

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle and torsional coordinates instead of a Cartesian coordinate representation. Freezing high frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed in order to make the CICMD method robust and widely usable. In this paper we have designed a new framework for 1) initializing velocities for non-independent CICMD coordinates, 2) efficient computation of center of mass velocity during CICMD simulations, 3) using advanced integrators such as Runge-Kutta, Lobatto and adaptive CVODE for CICMD simulations, and 4) cancelling out the “flying ice cube effect” that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this paper, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided “freezing and thawing” of degrees of freedom in the molecule on the fly during MD simulations, and is shown to fold four proteins to their native topologies. With these advancements we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. PMID:23345138

  15. Advances in dental veneers: materials, applications, and techniques

    PubMed Central

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers. PMID:23674920

  16. Advances in parameter estimation techniques applied to flexible structures

    NASA Technical Reports Server (NTRS)

    Maben, Egbert; Zimmerman, David C.

    1994-01-01

    In this work, various parameter estimation techniques are investigated in the context of structural system identification utilizing distributed parameter models and 'measured' time-domain data. Distributed parameter models are formulated using the PDEMOD software developed by Taylor. Enhancements made to PDEMOD for this work include the following: (1) a Wittrick-Williams based root solving algorithm; (2) a time simulation capability; and (3) various parameter estimation algorithms. The parameter estimations schemes will be contrasted using the NASA Mini-Mast as the focus structure.

  17. The emerging role of advanced neuroimaging techniques for brain metastases.

    PubMed

    Nowosielski, Martha; Radbruch, Alexander

    2015-06-01

    Brain metastases are an increasingly encountered and frightening manifestation of systemic cancer. More effective therapeutic strategies for the primary tumor are resulting in longer patient survival on the one hand while on the other, better brain tumor detection has resulted from increased availability and development of more precise brain imaging methods. This review focuses on the emerging role of functional neuroimaging techniques; magnetic resonance imaging (MRI) as well as positron emission tomography (PET), in establishing diagnosis, for monitoring treatment response with an emphasis on new targeted as well as immunomodulatory therapies and for predicting prognosis in patients with brain metastases.

  18. Recent Advances in Cardiovascular Magnetic Resonance: Techniques and Applications.

    PubMed

    Salerno, Michael; Sharif, Behzad; Arheden, Håkan; Kumar, Andreas; Axel, Leon; Li, Debiao; Neubauer, Stefan

    2017-06-01

    Cardiovascular magnetic resonance imaging has become the gold standard for evaluating myocardial function, volumes, and scarring. Additionally, cardiovascular magnetic resonance imaging is unique in its comprehensive tissue characterization, including assessment of myocardial edema, myocardial siderosis, myocardial perfusion, and diffuse myocardial fibrosis. Cardiovascular magnetic resonance imaging has become an indispensable tool in the evaluation of congenital heart disease, heart failure, cardiac masses, pericardial disease, and coronary artery disease. This review will highlight some recent novel cardiovascular magnetic resonance imaging techniques, concepts, and applications. © 2017 American Heart Association, Inc.

  19. Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilge, S.; Zhang, Y.; Dall'Osto, M.

    2014-11-01

    The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterised by a less dense urbanisation. We present here the results obtained at a background site in the Po Valley, Italy, in summer 2009. For the first time in Europe, six state-of-the-art spectrometric techniques were used in parallel: aerosol time-of-flight mass spectrometer (ATOFMS), two aerosol mass spectrometers (high-resolution time-of-flight aerosol mass spectrometer - HR-ToF-AMS and soot particle aerosol mass spectrometer - SP-AMS), thermal desorption aerosol gas chromatography (TAG), chemical ionisation mass spectrometry (CIMS) and (offline) proton nuclear magnetic resonance (1H-NMR) spectroscopy. The results indicate that, under high-pressure conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC), secondary semivolatile compounds such as ammonium nitrate and amines and a class of monocarboxylic acids which correspond to the AMS cooking organic aerosol (COA) already identified in urban areas. In daytime, the entrainment of aged air masses in the mixing layer is responsible for the accumulation of low-volatility oxygenated organic aerosol (LV-OOA) and also for the recycling of non-volatile primary species such as black carbon. According to organic aerosol source apportionment, anthropogenic aerosols accumulating in the lower layers overnight accounted for 38% of organic aerosol mass on average, another 21% was accounted for by aerosols recirculated in

  20. Comparison of three advanced chromatographic techniques for cannabis identification.

    PubMed

    Debruyne, D; Albessard, F; Bigot, M C; Moulin, M

    1994-01-01

    The development of chromatography technology, with the increasing availability of easier-to-use mass spectrometers combined with gas chromatography (GC), the use of diode-array or programmable variable-wavelength ultraviolet absorption detectors in conjunction with high-performance liquid chromatography (HPLC), and the availability of scanners capable of reading thin-layer chromatography (TLC) plates in the ultraviolet and visible regions, has made for easier, quicker and more positive identification of cannabis samples that standard analytical laboratories are occasionally required to undertake in the effort to combat drug addiction. At laboratories that do not possess the technique of GC combined with mass spectrometry, which provides an irrefutable identification, the following procedure involving HPLC or TLC techniques may be used: identification of the chromatographic peaks corresponding to each of the three main cannabis constituents-cannabidiol (CBD), delta-9-tetrahydrocannabinol (delta-9-THC) and cannabinol (CBN)-by comparison with published data in conjunction with a specific absorption spectrum for each of those constituents obtained between 200 and 300 nm. The collection of the fractions corresponding to the three major cannabinoids at the HPLC system outlet and the cross-checking of their identity in the GC process with flame ionization detection can further corroborate the identification and minimize possible errors due to interference.

  1. Advanced terahertz techniques for quality control and counterfeit detection

    NASA Astrophysics Data System (ADS)

    Ahi, Kiarash; Anwar, Mehdi

    2016-04-01

    This paper reports our invented methods for detection of counterfeit electronic. These versatile techniques are also handy in quality control applications. Terahertz pulsed laser systems are capable of giving the material characteristics and thus make it possible to distinguish between the materials used in authentic components and their counterfeit clones. Components with material defects can also be distinguished in section in this manner. In this work different refractive indices and absorption coefficients were observed for counterfeit components compared to their authentic counterparts. Existence of unexpected ingredient materials was detected in counterfeit components by Fourier Transform analysis of the transmitted terahertz pulse. Thicknesses of different layers are obtainable by analyzing the reflected terahertz pulse. Existence of unexpected layers is also detectable in this manner. Recycled, sanded and blacktopped counterfeit electronic components were detected as a result of these analyses. Counterfeit ICs with die dislocations were detected by depicting the terahertz raster scanning data in a coordinate plane which gives terahertz images. In the same manner, raster scanning of the reflected pulse gives terahertz images of the surfaces of the components which were used to investigate contaminant materials and sanded points on the surfaces. The results of the later technique, reveals the recycled counterfeit components.

  2. Advanced techniques in reliability model representation and solution

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.; Nicol, David M.

    1992-01-01

    The current tendency of flight control system designs is towards increased integration of applications and increased distribution of computational elements. The reliability analysis of such systems is difficult because subsystem interactions are increasingly interdependent. Researchers at NASA Langley Research Center have been working for several years to extend the capability of Markov modeling techniques to address these problems. This effort has been focused in the areas of increased model abstraction and increased computational capability. The reliability model generator (RMG) is a software tool that uses as input a graphical object-oriented block diagram of the system. RMG uses a failure-effects algorithm to produce the reliability model from the graphical description. The ASSURE software tool is a parallel processing program that uses the semi-Markov unreliability range evaluator (SURE) solution technique and the abstract semi-Markov specification interface to the SURE tool (ASSIST) modeling language. A failure modes-effects simulation is used by ASSURE. These tools were used to analyze a significant portion of a complex flight control system. The successful combination of the power of graphical representation, automated model generation, and parallel computation leads to the conclusion that distributed fault-tolerant system architectures can now be analyzed.

  3. Advanced cell culture techniques for cancer drug discovery.

    PubMed

    Lovitt, Carrie J; Shelper, Todd B; Avery, Vicky M

    2014-05-30

    Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor.

  4. Recent Advances in Spaceborne Precipitation Radar Measurement Techniques and Technology

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Durden, Stephen L.; Tanelli, Simone

    2006-01-01

    NASA is currently developing advanced instrument concepts and technologies for future spaceborne atmospheric radars, with an over-arching objective of making such instruments more capable in supporting future science needs and more cost effective. Two such examples are the Second-Generation Precipitation Radar (PR-2) and the Nexrad-In-Space (NIS). PR-2 is a 14/35-GHz dual-frequency rain radar with a deployable 5-meter, wide-swath scanned membrane antenna, a dual-polarized/dual-frequency receiver, and a realtime digital signal processor. It is intended for Low Earth Orbit (LEO) operations to provide greatly enhanced rainfall profile retrieval accuracy while consuming only a fraction of the mass of the current TRMM Precipitation Radar (PR). NIS is designed to be a 35-GHz Geostationary Earth Orbiting (GEO) radar for providing hourly monitoring of the life cycle of hurricanes and tropical storms. It uses a 35-m, spherical, lightweight membrane antenna and Doppler processing to acquire 3-dimensional information on the intensity and vertical motion of hurricane rainfall.

  5. Advanced Cell Culture Techniques for Cancer Drug Discovery

    PubMed Central

    Lovitt, Carrie J.; Shelper, Todd B.; Avery, Vicky M.

    2014-01-01

    Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor. PMID:24887773

  6. XII Advanced Computing and Analysis Techniques in Physics Research

    NASA Astrophysics Data System (ADS)

    Speer, Thomas; Carminati, Federico; Werlen, Monique

    November 2008 will be a few months after the official start of LHC when the highest quantum energy ever produced by mankind will be observed by the most complex piece of scientific equipment ever built. LHC will open a new era in physics research and push further the frontier of Knowledge This achievement has been made possible by new technological developments in many fields, but computing is certainly the technology that has made possible this whole enterprise. Accelerator and detector design, construction management, data acquisition, detectors monitoring, data analysis, event simulation and theoretical interpretation are all computing based HEP activities but also occurring many other research fields. Computing is everywhere and forms the common link between all involved scientists and engineers. The ACAT workshop series, created back in 1990 as AIHENP (Artificial Intelligence in High Energy and Nuclear Research) has been covering the tremendous evolution of computing in its most advanced topics, trying to setup bridges between computer science, experimental and theoretical physics. Conference web-site: http://acat2008.cern.ch/ Programme and presentations: http://indico.cern.ch/conferenceDisplay.py?confId=34666

  7. Coal and Coal Constituent Studies by Advanced EMR Techniques

    SciTech Connect

    Alex I. Smirnov; Mark J. Nilges; R. Linn Belford; Robert B. Clarkson

    1998-03-31

    Advanced electronic magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. We have achieved substantial progress on upgrading the high field (HF) EMR (W-band, 95 GHz) spectrometers that are especially advantageous for such studies. Particularly, we have built a new second W-band instrument (Mark II) in addition to our Mark I. Briefly, Mark II features: (i) an Oxford custom-built 7 T superconducting magnet which is scannable from 0 to 7 T at up to 0.5 T/min; (ii) water-cooled coaxial solenoid with up to ±550 G scan under digital (15 bits resolution) computer control; (iii) custom-engineered precision feed-back circuit, which is used to drive this solenoid, is based on an Ultrastab 860R sensor that has linearity better than 5 ppm and resolution of 0.05 ppm; (iv) an Oxford CF 1200 cryostat for variable temperature studies from 1.8 to 340 K. During this grant period we have completed several key upgrades of both Mark I and II, particularly microwave bridge, W-band probehead, and computer interfaces. We utilize these improved instruments for HF EMR studies of spin-spin interaction and existence of different paramagnetic species in carbonaceous solids.

  8. 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.

  9. Advanced fabrication techniques for hydrogen-cooled engine structures

    NASA Technical Reports Server (NTRS)

    Buchmann, O. A.; Arefian, V. V.; Warren, H. A.; Vuigner, A. A.; Pohlman, M. J.

    1985-01-01

    Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

  10. Advanced Techniques in Musculoskeletal Oncology: Perfusion, Diffusion, and Spectroscopy.

    PubMed

    Teixeira, Pedro A Gondim; Beaumont, Marine; Gabriela, Hossu; Bailiang, Chen; Verhaeghe, Jean-luc; Sirveaux, François; Blum, Alain

    2015-12-01

    The imaging characterization of musculoskeletal tumors can be challenging, and a significant number of lesions remain indeterminate when conventional imaging protocols are used. In recent years, clinical availability of functional imaging methods has increased. Functional imaging has the potential to improve tumor detection, characterization, and follow-up. The most frequently used functional methods are perfusion imaging, diffusion-weighted imaging (DWI), and MR proton spectroscopy (MRS). Each of these techniques has specific protocol requirements and diagnostic pitfalls that need to be acknowledged to avoid misdiagnoses. Additionally, the application of functional methods in the MSK system has various technical issues that need to be addressed to ensure data quality and comparability. In this article, the application of contrast-enhanced perfusion imaging, DWI, and MRS for the evaluation of bone and soft tissue tumors is discussed, with emphasis on acquisition protocols, technical difficulties, and current clinical indications.

  11. Bioactive glass thin films synthesized by advanced pulsed laser techniques

    NASA Astrophysics Data System (ADS)

    Mihailescu, N.; Stan, George E.; Ristoscu, C.; Sopronyi, M.; Mihailescu, Ion N.

    2016-10-01

    Bioactive materials play an increasingly important role in the biomaterials industry, and are extensively used in a range of applications, including biodegradable metallic implants. We report on Bioactive Glasses (BG) films deposition by pulsed laser techniques onto biodegradable substrates. The BG coatings were obtained using a KrF* excimer laser source (λ= 248 nm, τFWHM ≤ 25 ns).Their thickness has been determined by Profilometry measurements, whilst their morphology has been analysed by Scanning Electron Microscopy (SEM). The obtained coatings fairly preserved the targets composition and structure, as revealed by Energy Dispersive X-Ray Spectroscopy, Grazing Incidence X-Ray Diffraction, and Fourier Transform Infra-Red Spectroscopy analyses.

  12. Advanced experimental techniques for transonic wind tunnels - Final lecture

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    A philosophy of experimental techniques is presented, suggesting that in order to be successful, one should like what one does, have the right tools, stick to the job, avoid diversions, work hard, interact with people, be informed, keep it simple, be self sufficient, and strive for perfection. Sources of information, such as bibliographies, newsletters, technical reports, and technical contacts and meetings are recommended. It is pointed out that adaptive-wall test sections eliminate or reduce wall interference effects, and magnetic suspension and balance systems eliminate support-interference effects, while the problem of flow quality remains with all wind tunnels. It is predicted that in the future it will be possible to obtain wind tunnel results at the proper Reynolds number, and the effects of flow unsteadiness, wall interference, and support interference will be eliminated or greatly reduced.

  13. Advanced Doppler radar physiological sensing technique for drone detection

    NASA Astrophysics Data System (ADS)

    Yoon, Ji Hwan; Xu, Hao; Garcia Carrillo, Luis R.

    2017-05-01

    A 24 GHz medium-range human detecting sensor, using the Doppler Radar Physiological Sensing (DRPS) technique, which can also detect unmanned aerial vehicles (UAVs or drones), is currently under development for potential rescue and anti-drone applications. DRPS systems are specifically designed to remotely monitor small movements of non-metallic human tissues such as cardiopulmonary activity and respiration. Once optimized, the unique capabilities of DRPS could be used to detect UAVs. Initial measurements have shown that DRPS technology is able to detect moving and stationary humans, as well as largely non-metallic multi-rotor drone helicopters. Further data processing will incorporate pattern recognition to detect multiple signatures (motor vibration and hovering patterns) of UAVs.

  14. 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

  15. Advances in techniques for assessment of microalgal lipids.

    PubMed

    Challagulla, Vineela; Nayar, Sasi; Walsh, Kerry; Fabbro, Larelle

    2016-07-15

    Microalgae are a varied group of organisms with considerable commercial potential as sources of various biochemicals, storage molecules and metabolites such as lipids, sugars, amino acids, pigments and toxins. Algal lipids can be processed to bio-oils and biodiesel. The conventional method to estimate algal lipids is based on extraction using solvents and quantification by gravimetry or chromatography. Such methods are time consuming, use hazardous chemicals and are labor intensive. For rapid screening of prospective algae or for management decisions (e.g. decision on timing of harvest), a rapid, high throughput, reliable, accurate, cost effective and preferably nondestructive analytical technique is desirable. This manuscript reviews the application of fluorescent lipid soluble dyes (Nile Red and BODIPY 505/515), nuclear magnetic resonance (NMR), Raman, Fourier transform infrared (FTIR) and near infrared (NIR) spectroscopy for the assessment of lipids in microalgae.

  16. Advanced Infusion Techniques with 3-D Printed Tooling

    SciTech Connect

    Nuttall, David; Elliott, Amy; Post, Brian K.; Love, Lonnie J.

    2016-05-10

    The manufacturing of tooling for large, contoured surfaces for fiber-layup applications requires significant effort to understand the geometry and then to subtractively manufacture the tool. Traditional methods for the auto industry use clay that is hand sculpted. In the marine pleasure craft industry, the exterior of the model is formed from a foam lay-up that is either hand cut or machined to create smooth lines. Engineers and researchers at Oak Ridge National Laboratory s Manufacturing Demonstration Facility (ORNL MDF) collaborated with Magnum Venus Products (MVP) in the development of a process for reproducing legacy whitewater adventure craft via digital scanning and large scale 3-D printed layup molds. The process entailed 3D scanning a legacy canoe form, converting that form to a CAD model, additively manufacturing (3-D Print) the mold tool, and subtractively finishing the mold s transfer surfaces. Future work will include applying a gelcoat to the mold transfer surface and infusing using vacuum assisted resin transfer molding, or VARTM principles, to create a watertight vessel. The outlined steps were performed on a specific canoe geometry found by MVP s principal participant. The intent of utilizing this geometry is to develop an energy efficient and marketable process for replicating complex shapes, specifically focusing on this particular watercraft, and provide a finished product for demonstration to the composites industry. The culminating part produced through this agreement has been slated for public presentation and potential demonstration at the 2016 CAMX (Composites and Advanced Materials eXpo) exposition in Anaheim, CA. Phase I of this collaborative research and development agreement (MDF-15-68) was conducted under CRADA NFE-15-05575 and was initiated on May 7, 2015, with an introduction to the MVP product line, and concluded in March of 2016 with the printing of and processing of a canoe mold. The project partner Magnum Venous Products (MVP) is

  17. Nondestructive and rapid concurrent estimation of paracetamol and nimesulide in their combined dosage form using Raman spectroscopic technique.

    PubMed

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

    2013-03-01

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

  18. Application of a new non-linear least squares velocity curve analysis technique for spectroscopic binary stars

    NASA Astrophysics Data System (ADS)

    Karami, K.; Mohebi, R.; Soltanzadeh, M. M.

    2008-11-01

    Using measured radial velocity data of nine double lined spectroscopic binary systems NSV 223, AB And, V2082 Cyg, HS Her, V918 Her, BV Dra, BW Dra, V2357 Oph, and YZ Cas, we find corresponding orbital and spectroscopic elements via the method introduced by Karami and Mohebi (Chin. J. Astron. Astrophys. 7:558, 2007a) and Karami and Teimoorinia (Astrophys. Space Sci. 311:435, 2007). Our numerical results are in good agreement with those obtained by others using more traditional methods.

  19. Preventing Advanced Carious Lesions with Caries Atraumatic Restorative Technique.

    PubMed

    Byrd, Tammi O

    2016-06-01

    An alternative approach to controlling dental caries and preventing the associated pain, called atraumatic restorative technique (ART), is described for populations in need, where dental hygienists restore decayed teeth with glass ionomer restorations without prior removal of all decayed tooth structure. There are populations whose decay needs are not adequately being met within the current oral health care delivery system. These include those in poverty conditions, vulnerable children, and the elderly who are often in long-term care facilities without adequate resources or opportunities for traditional dentistry. ART provides a viable option for controlling caries and relieving the pain of untreated decay. The purpose of this article is to suggest that the evidence surrounding ART be viewed objectively and that dental hygienists, with additional education in this approach, can contribute to relieving the pain of untreated dental decay. Evidence suggests that teeth can be effectively restored with ART. Dental hygienists represent an appropriate workforce to provide ART with their current background and education combined plus a brief training program; it is suggested that dental hygiene educational programs include ART within the curriculum. Along with dental sealants and fluoride varnish application, ART can be an important component of a comprehensive preventive program to address the unmet needs of vulnerable populations. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Advances in Current Rating Techniques for Flexible Printed Circuits

    NASA Technical Reports Server (NTRS)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  1. Advanced Manufacturing Techniques Demonstrated for Fabricating Developmental Hardware

    NASA Technical Reports Server (NTRS)

    Redding, Chip

    2004-01-01

    NASA Glenn Research Center's Engineering Development Division has been working in support of innovative gas turbine engine systems under development by Glenn's Combustion Branch. These one-of-a-kind components require operation under extreme conditions. High-temperature ceramics were chosen for fabrication was because of the hostile operating environment. During the designing process, it became apparent that traditional machining techniques would not be adequate to produce the small, intricate features for the conceptual design, which was to be produced by stacking over a dozen thin layers with many small features that would then be aligned and bonded together into a one-piece unit. Instead of using traditional machining, we produced computer models in Pro/ENGINEER (Parametric Technology Corporation (PTC), Needham, MA) to the specifications of the research engineer. The computer models were exported in stereolithography standard (STL) format and used to produce full-size rapid prototype polymer models. These semi-opaque plastic models were used for visualization and design verification. The computer models also were exported in International Graphics Exchange Specification (IGES) format and sent to Glenn's Thermal/Fluids Design & Analysis Branch and Applied Structural Mechanics Branch for profiling heat transfer and mechanical strength analysis.

  2. Recent advances on ionic liquid uses in separation techniques.

    PubMed

    Berthod, A; Ruiz-Ángel, M J; Carda-Broch, S

    2017-09-22

    The molten organic salts with melting point below 100°C, commonly called ionic liquids (ILs) have found numerous uses in separation sciences due to their exceptional properties as non molecular solvents, namely, a negligible vapor pressure, a high thermal stability, and unique solvating properties due to polarity and their ionic character of molten salts. Other properties, such as viscosity, boiling point, water solubility, and electrochemical window, are adjustable playing with which anion is associated with which cation. This review focuses on recent development of the uses of ILs in separation techniques actualizing our 2008 article (same authors, J. Chromatogr. A, 1184 (2008) 6-18) focusing on alkyl methylimidazolium salts. These developments include the use of ILs in nuclear waste reprocessing, highly thermally stable ILs that allowed for the introduction of polar gas chromatography capillary columns able to work at temperature never seen before (passing 300°C), the use of ILs in liquid chromatography and capillary electrophoresis, and the introduction of tailor-made ILs for mass spectrometry detection of trace anions at the few femtogram level. The recently introduced deep eutectic solvents are not exactly ILs, they are related enough so that their properties and uses in countercurrent chromatography are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Advances in low energy neutral atom imaging techniques

    SciTech Connect

    Scime, E.E.; Funsten, H.O.; McComas, D.J.; Moore, K.R. ); Gruntman, M. . Space Sciences Center)

    1993-01-01

    Recently proposed low energy neutral atom (LENA) imaging techniques use a collisional process to convert the low energy neutrals into ions before detection. At low energies, collisional processes limit the angular resolution and conversion efficiencies of these devices. However, if the intense ultraviolet light background can be suppressed, direct LENA detection is possible. We present results from a series of experiments designed to develop a novel filtering structure based on free-standing transmission gratings. If the grating period is sufficiently small, free standing transmission gratings can be employed to substantially polarize ultraviolet (UV) light in the wavelength range 300 [Angstrom] to 1500 [Angstrom]. If a second grating is placed behind the first grating with its axis of polarization oriented at a right angle to the first's, a substantial attenuation of UV radiation is achievable. ne neutrals will pass through the remaining open area of two gratings and be detected without UV background complications. We have obtained nominal 2000 [Angstrom] period (1000 [Angstrom] bars with 1000 [Angstrom] slits) free standing, gold transmission gratings and measured their UV and atomic transmission characteristics. The geometric factor of a LENA imager based on this technology is comparable to that of other proposed LENA imagers. In addition, this of imager does not distort the neutral trajectories, allowing for high angular resolution.

  4. Simulation of an advanced techniques of ion propulsion Rocket system

    NASA Astrophysics Data System (ADS)

    Bakkiyaraj, R.

    2016-07-01

    The ion propulsion rocket system is expected to become popular with the development of Deuterium,Argon gas and Hexagonal shape Magneto hydrodynamic(MHD) techniques because of the stimulation indirectly generated the power from ionization chamber,design of thrust range is 1.2 N with 40 KW of electric power and high efficiency.The proposed work is the study of MHD power generation through ionization level of Deuterium gas and combination of two gaseous ions(Deuterium gas ions + Argon gas ions) at acceleration stage.IPR consists of three parts 1.Hexagonal shape MHD based power generator through ionization chamber 2.ion accelerator 3.Exhaust of Nozzle.Initially the required energy around 1312 KJ/mol is carrying out the purpose of deuterium gas which is changed to ionization level.The ionized Deuterium gas comes out from RF ionization chamber to nozzle through MHD generator with enhanced velocity then after voltage is generated across the two pairs of electrode in MHD.it will produce thrust value with the help of mixing of Deuterium ion and Argon ion at acceleration position.The simulation of the IPR system has been carried out by MATLAB.By comparing the simulation results with the theoretical and previous results,if reaches that the proposed method is achieved of thrust value with 40KW power for simulating the IPR system.

  5. Recent advances in techniques for tsetse-fly control*

    PubMed Central

    MacLennan, K. J. R.

    1967-01-01

    With the advent of modern persistent insecticides, it has become possible to utilize some of the knowledge that has accumulated on the ecology and bionomics of Glossina and to devise more effective techniques for the control and eventual extermination of these species. The present article, based on experience of the tsetse fly problem in Northern Nigeria, points out that the disadvantages of control techniques—heavy expenditure of money and manpower and undue damage to the biosystem—can now largely be overcome by basing the application of insecticides on knowledge of the habits of the particular species of Glossina in a particular environment. Two factors are essential to the success of a control project: the proper selection of sites for spraying (the concept of restricted application) and the degree of persistence of the insecticide used. Reinfestation from within or outside the project area must also be taken into account. These and other aspects are discussed in relation to experience gained from a successful extermination project carried out in the Sudan vegetation zone and from present control activities in the Northern Guinea vegetation zone. PMID:5301739

  6. Advanced Manufacturing Techniques Demonstrated for Fabricating Developmental Hardware

    NASA Technical Reports Server (NTRS)

    Redding, Chip

    2004-01-01

    NASA Glenn Research Center's Engineering Development Division has been working in support of innovative gas turbine engine systems under development by Glenn's Combustion Branch. These one-of-a-kind components require operation under extreme conditions. High-temperature ceramics were chosen for fabrication was because of the hostile operating environment. During the designing process, it became apparent that traditional machining techniques would not be adequate to produce the small, intricate features for the conceptual design, which was to be produced by stacking over a dozen thin layers with many small features that would then be aligned and bonded together into a one-piece unit. Instead of using traditional machining, we produced computer models in Pro/ENGINEER (Parametric Technology Corporation (PTC), Needham, MA) to the specifications of the research engineer. The computer models were exported in stereolithography standard (STL) format and used to produce full-size rapid prototype polymer models. These semi-opaque plastic models were used for visualization and design verification. The computer models also were exported in International Graphics Exchange Specification (IGES) format and sent to Glenn's Thermal/Fluids Design & Analysis Branch and Applied Structural Mechanics Branch for profiling heat transfer and mechanical strength analysis.

  7. Advanced signal processing technique for damage detection in steel tubes

    NASA Astrophysics Data System (ADS)

    Amjad, Umar; Yadav, Susheel Kumar; Dao, Cac Minh; Dao, Kiet; Kundu, Tribikram

    2016-04-01

    In recent years, ultrasonic guided waves gained attention for reliable testing and characterization of metals and composites. Guided wave modes are excited and detected by PZT (Lead Zirconate Titanate) transducers either in transmission or reflection mode. In this study guided waves are excited and detected in the transmission mode and the phase change of the propagating wave modes are recorded. In most of the other studies reported in the literature, the change in the received signal strength (amplitude) is investigated with varying degrees of damage while in this study the change in phase is correlated with the extent of damage. Feature extraction techniques are used for extracting phase and time-frequency information. The main advantage of this approach is that the bonding condition between the transducer and the specimen does not affect the phase while it can affect the strength of recorded signal. Therefore, if the specimen is not damaged but the transducer-specimen bonding is deteriorated then the received signal strength is altered but the phase remains same and thus false positive predictions for damage can be avoided.

  8. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    SciTech Connect

    Durlofsky, Louis J.

    2000-08-28

    This project targets the development of (1) advanced reservoir simulation techniques for modeling non-conventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and well index (for use in simulation models), including the effects of wellbore flow; and (3) accurate approaches to account for heterogeneity in the near-well region.

  9. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  10. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  11. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  12. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.; Stebbins, J. P.; Smith, A. W.; Pullen, K. E.

    1973-01-01

    A method for the prediction of propellant-material compatibility for periods of time up to ten years is presented. Advanced sensitive measurement techniques used in the prediction method are described. These include: neutron activation analysis, radioactive tracer technique, and atomic absorption spectroscopy with a graphite tube furnace sampler. The results of laboratory tests performed to verify the prediction method are presented.

  13. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  14. Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

    PubMed Central

    Kume, Keiichiro

    2014-01-01

    The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks. PMID:24914364

  15. Spectroscopic analysis of solar and cosmic X-ray spectra. 1: The nature of cosmic X-ray spectra and proposed analytical techniques

    NASA Technical Reports Server (NTRS)

    Walker, A. B. C., Jr.

    1975-01-01

    Techniques for the study of the solar corona are reviewed as an introduction to a discussion of modifications required for the study of cosmic sources. Spectroscopic analysis of individual sources and the interstellar medium is considered. The latter was studied via analysis of its effect on the spectra of selected individual sources. The effects of various characteristics of the ISM, including the presence of grains, molecules, and ionization, are first discussed, and the development of ISM models is described. The expected spectral structure of individual cosmic sources is then reviewed with emphasis on supernovae remnants and binary X-ray sources. The observational and analytical requirements imposed by the characteristics of these sources are identified, and prospects for the analysis of abundances and the study of physical parameters within them are assessed. Prospects for the spectroscopic study of other classes of X-ray sources are also discussed.

  16. The Acquisition of Development of Advanced Processing Techniques for CCD Arrays.

    DTIC Science & Technology

    1981-01-01

    pressure oxidation ( HIPOX ) techniques as a viable alternative to standard (atmospheric pressure) oxidation techniques in our buried channel CCD process. If...work performed may be summarized as follows: (1) Modelling of high pressure oxidation and anneal cycles. Subsitution of the new HIPOX cycles in the...NANP L I I "I lii-..D -- I The Acquisition of Develoment of Advanced ProcessinR Techniques for CCD Arrays ca- C-., Prepared by Bell-Northern Research

  17. Inferior vena cava filter retrieval: effectiveness and complications of routine and advanced techniques.

    PubMed

    Al-Hakim, Ramsey; Kee, Stephen T; Olinger, Kristen; Lee, Edward W; Moriarty, John M; McWilliams, Justin P

    2014-06-01

    To investigate the success and safety of routine versus advanced inferior vena cava (IVC) filter retrieval techniques. A retrospective review was performed of patients who underwent IVC filter placement and/or a retrieval attempt over a 10-year period. Retrieval technique(s), preretrieval computed tomography, preretrieval venography, and clinical/imaging follow-up for 30 days after retrieval were analyzed. Mean filter dwell time was 134 days (range, 0-2,475 d). Filter retrieval was attempted 231 times in 217 patients (39% female, 61% male; mean age, 50.7 y), with success rates of 73.2% (169 of 231) and 94.7% (54 of 57) for routine and advanced filter retrieval techniques, respectively. The overall filter retrieval complication rate was 1.7% (four of 231); complications in four patients (with multiple complications in some cases) included IVC dissection, IVC intussusception, IVC thrombus/stenosis, filter fracture with embedded strut, IVC injury with hemorrhage, and vascular injury from complicated venous access. The rate of complications associated with filter retrievals that required advanced technique was significantly higher than seen with routine technique (5.3% vs 0.4%; P < .05). Longer dwell time, more transverse tilt, and presence of an embedded hook were associated with significantly increased rates of failed retrieval via routine technique (P < .05). IVC filters can be retrieved with a high overall success rate (98.2%) and a low complication rate (1.7%) by using advanced techniques when the routine approach has failed; however, the use of advanced techniques is associated with a significantly higher complication rate. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  18. A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

    NASA Technical Reports Server (NTRS)

    Garmestai, H.; Harris, K.; Lourenco, L.

    1997-01-01

    Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

  19. Using non-invasive molecular spectroscopic techniques to detect unique aspects of protein Amide functional groups and chemical properties of modeled forage from different sourced-origins

    NASA Astrophysics Data System (ADS)

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-01

    The non-invasive molecular spectroscopic technique-FT/IR is capable to detect the molecular structure spectral features that are associated with biological, nutritional and biodegradation functions. However, to date, few researches have been conducted to use these non-invasive molecular spectroscopic techniques to study forage internal protein structures associated with biodegradation and biological functions. The objectives of this study were to detect unique aspects and association of protein Amide functional groups in terms of protein Amide I and II spectral profiles and chemical properties in the alfalfa forage (Medicago sativa L.) from different sourced-origins. In this study, alfalfa hay with two different origins was used as modeled forage for molecular structure and chemical property study. In each forage origin, five to seven sources were analyzed. The molecular spectral profiles were determined using FT/IR non-invasive molecular spectroscopy. The parameters of protein spectral profiles included functional groups of Amide I, Amide II and Amide I to II ratio. The results show that the modeled forage Amide I and Amide II were centered at 1653 cm- 1 and 1545 cm- 1, respectively. The Amide I spectral height and area intensities were from 0.02 to 0.03 and 2.67 to 3.36 AI, respectively. The Amide II spectral height and area intensities were from 0.01 to 0.02 and 0.71 to 0.93 AI, respectively. The Amide I to II spectral peak height and area ratios were from 1.86 to 1.88 and 3.68 to 3.79, respectively. Our results show that the non-invasive molecular spectroscopic techniques are capable to detect forage internal protein structure features which are associated with forage chemical properties.

  20. Using non-invasive molecular spectroscopic techniques to detect unique aspects of protein Amide functional groups and chemical properties of modeled forage from different sourced-origins.

    PubMed

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-05

    The non-invasive molecular spectroscopic technique-FT/IR is capable to detect the molecular structure spectral features that are associated with biological, nutritional and biodegradation functions. However, to date, few researches have been conducted to use these non-invasive molecular spectroscopic techniques to study forage internal protein structures associated with biodegradation and biological functions. The objectives of this study were to detect unique aspects and association of protein Amide functional groups in terms of protein Amide I and II spectral profiles and chemical properties in the alfalfa forage (Medicago sativa L.) from different sourced-origins. In this study, alfalfa hay with two different origins was used as modeled forage for molecular structure and chemical property study. In each forage origin, five to seven sources were analyzed. The molecular spectral profiles were determined using FT/IR non-invasive molecular spectroscopy. The parameters of protein spectral profiles included functional groups of Amide I, Amide II and Amide I to II ratio. The results show that the modeled forage Amide I and Amide II were centered at 1653 cm(-1) and 1545 cm(-1), respectively. The Amide I spectral height and area intensities were from 0.02 to 0.03 and 2.67 to 3.36 AI, respectively. The Amide II spectral height and area intensities were from 0.01 to 0.02 and 0.71 to 0.93 AI, respectively. The Amide I to II spectral peak height and area ratios were from 1.86 to 1.88 and 3.68 to 3.79, respectively. Our results show that the non-invasive molecular spectroscopic techniques are capable to detect forage internal protein structure features which are associated with forage chemical properties.

  1. Modulation/demodulation techniques for satellite communications. Part 2: Advanced techniques. The linear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory is presented for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the linear satellite channel. The underlying principle used is the development of receiver structures based on the maximum-likelihood decision rule. The application of the performance prediction tools, e.g., channel cutoff rate and bit error probability transfer function bounds to these modulation/demodulation techniques.

  2. Advanced combustion techniques for controlling NO sub x emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments designed to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere was discussed. Of particular concern are the oxides of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  3. POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique

    SciTech Connect

    Karekh, B K; Tao, D; Groppo, J G

    1998-08-28

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy's program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 45 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 - March 31, 1998.

  4. Modulation/demodulation techniques for satellite communications. Part 3: Advanced techniques. The nonlinear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the nonlinear satellite channel is presented. The underlying principle used throughout is the development of receiver structures based on the maximum likelihood decision rule and aproximations to it. The bit error probability transfer function bounds developed in great detail in Part 4 is applied to these modulation/demodulation techniques. The effects of the various degrees of receiver mismatch are considered both theoretically and by numerous illustrative examples.

  5. Advances in neutron radiographic techniques and applications: a method for nondestructive testing.

    PubMed

    Berger, Harold

    2004-10-01

    A brief history of neutron radiography is presented to set the stage for a discussion of significant neutron radiographic developments and an assessment of future directions for neutron radiography. Specific advances are seen in the use of modern, high dynamic range imaging methods (image plates and flat panels) and for high contrast techniques such as phase contrast, and phase-sensitive imaging. Competition for neutron radiographic inspection may develop as these techniques offer application prospects for X-ray methods.

  6. Application of Advanced Magnetic Resonance Imaging Techniques in Evaluation of the Lower Extremity

    PubMed Central

    Braun, Hillary J.; Dragoo, Jason L.; Hargreaves, Brian A.; Levenston, Marc E.; Gold, Garry E.

    2012-01-01

    Synopsis This article reviews current magnetic resonance imaging techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MRI include imaging at 7 Tesla, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphological changes within articular cartilage, and imaging around orthopedic hardware. PMID:23622097

  7. Parental Attitudes Toward Advanced Behavior Guidance Techniques Used in Pediatric Dentistry.

    PubMed

    Patel, Monica; McTigue, Dennis J; Thikkurissy, Sarat; Fields, Henry W

    2016-01-01

    To re-examine parental attitudes toward advanced behavior management techniques in pediatric dentistry and determine whether cost, urgency, and amount of treatment influence parental preferences. Parents viewed previously validated videotaped clinical vignettes of four advanced behavior guidance techniques: (1) passive immobilization; (2) active immobilization; (3) general anesthesia; and (4) oral sedation. The study was conducted in a children's hospital dental clinic and a suburban private pediatric dentistry office. Parents rated overall acceptance of the techniques, and acceptance under specified conditions using an anchored visual analogue scale. One hundred five parents completed the survey; 55 from the children's hospital and 50 from private practice. Oral sedation was rated as the most acceptable technique, followed by general anesthesia, active immobilization, and passive immobilization. As urgency, convenience, and previous experience increased, parental acceptance of the technique increased. As cost of treatment increased, parental acceptance decreased. Ratings between the children's hospital group and private practice group differed, as did the demographic variables of insurance, income, and race. The hierarchy of parental acceptance of advanced behavior guidance techniques is changing with increasing approval of pharmacological management and decreasing approval of physical management. The health care delivery system, urgency, convenience, previous experience, and cost all influence parental acceptance.

  8. 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.

  9. Recognizing and Managing Complexity: Teaching Advanced Programming Concepts and Techniques Using the Zebra Puzzle

    ERIC Educational Resources Information Center

    Crabtree, John; Zhang, Xihui

    2015-01-01

    Teaching advanced programming can be a challenge, especially when the students are pursuing different majors with diverse analytical and problem-solving capabilities. The purpose of this paper is to explore the efficacy of using a particular problem as a vehicle for imparting a broad set of programming concepts and problem-solving techniques. We…

  10. Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation

    NASA Technical Reports Server (NTRS)

    Davis, Steven B.

    1990-01-01

    Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

  11. Recognizing and Managing Complexity: Teaching Advanced Programming Concepts and Techniques Using the Zebra Puzzle

    ERIC Educational Resources Information Center

    Crabtree, John; Zhang, Xihui

    2015-01-01

    Teaching advanced programming can be a challenge, especially when the students are pursuing different majors with diverse analytical and problem-solving capabilities. The purpose of this paper is to explore the efficacy of using a particular problem as a vehicle for imparting a broad set of programming concepts and problem-solving techniques. We…

  12. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  13. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  14. Assessment of natural radioactivity and function of minerals in soils of Yelagiri hills, Tamilnadu, India by Gamma Ray spectroscopic and Fourier Transform Infrared (FTIR) techniques with statistical approach.

    PubMed

    Chandrasekaran, A; Ravisankar, R; Rajalakshmi, A; Eswaran, P; Vijayagopal, P; Venkatraman, B

    2015-02-05

    Gamma Ray and Fourier Transform Infrared (FTIR) spectroscopic techniques were used to evaluate the natural radioactivity due to natural radionuclides and mineralogical characterization in soils of Yelagiri hills, Tamilnadu, India. Various radiological parameters were calculated to assess the radiation hazards associated with the soil. The distribution pattern of activity due to natural radionuclides is explained by Kriging method of mapping. Using FTIR spectroscopic technique the minerals such as quartz, microcline feldspar, orthoclase feldspar, kaolinite, montmorillonite, illite, and organic carbon were identified and characterized. The extinction coefficient values were calculated to know the relative distribution of major minerals such as quartz, microcline feldspar, orthoclase feldspar and kaolinite. The calculated values indicate that the amount of quartz is higher than orthoclase feldspar, microcline feldspar and much higher than kaolinite. Crystallinity index was calculated to know the crystalline nature of quartz. The result indicates that the presence of disordered crystalline quartz in soils. The relation between minerals and radioactivity was assessed by multivariate statistical analysis (Pearson's correlation and cluster analysis). The statistical analysis confirms that the clay mineral kaolinite and non-clay mineral quartz is the major factor than other major minerals to induce the important radioactivity variables and concentrations of uranium and thorium. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Assessment of natural radioactivity and function of minerals in soils of Yelagiri hills, Tamilnadu, India by Gamma Ray spectroscopic and Fourier Transform Infrared (FTIR) techniques with statistical approach

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, A.; Ravisankar, R.; Rajalakshmi, A.; Eswaran, P.; Vijayagopal, P.; Venkatraman, B.

    2015-02-01

    Gamma Ray and Fourier Transform Infrared (FTIR) spectroscopic techniques were used to evaluate the natural radioactivity due to natural radionuclides and mineralogical characterization in soils of Yelagiri hills, Tamilnadu, India. Various radiological parameters were calculated to assess the radiation hazards associated with the soil. The distribution pattern of activity due to natural radionuclides is explained by Kriging method of mapping. Using FTIR spectroscopic technique the minerals such as quartz, microcline feldspar, orthoclase feldspar, kaolinite, montmorillonite, illite, and organic carbon were identified and characterized. The extinction coefficient values were calculated to know the relative distribution of major minerals such as quartz, microcline feldspar, orthoclase feldspar and kaolinite. The calculated values indicate that the amount of quartz is higher than orthoclase feldspar, microcline feldspar and much higher than kaolinite. Crystallinity index was calculated to know the crystalline nature of quartz. The result indicates that the presence of disordered crystalline quartz in soils. The relation between minerals and radioactivity was assessed by multivariate statistical analysis (Pearson's correlation and cluster analysis). The statistical analysis confirms that the clay mineral kaolinite and non-clay mineral quartz is the major factor than other major minerals to induce the important radioactivity variables and concentrations of uranium and thorium.

  16. Advances in surgical techniques in non-small cell lung cancer.

    PubMed

    Kim, Anthony W; Detterbeck, Frank C

    2013-12-01

    Thoracic surgery is a dynamic field, and many scientific, technological, technical, and organizational changes are occurring. A prominent example is the use of less invasive approaches to major resection of non-small cell lung cancer (NSCLC), both thoracoscopic and robotic. Sophisticated technology corroborated by clinical data has led to these approaches becoming accepted additions to the armamentarium. Additionally, improvements in perioperative pain management have also contributed to dramatically changing the experience of patients who undergo modern thoracic surgery. Lung cancer is being detected more often at an early stage. At the same time, advances in techniques, patient care, clinical science, and multidisciplinary treatment support an increased role for aggressive resection in the face of larger locally advanced tumors or for those with limited metastatic disease. These advances, conducted in the setting of multidisciplinary decision making, have resulted in real and palpable advancements for patients with lung cancer. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  17. Explaining the Cyclic Voltammetry of a Poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene) Copolymer upon Oxidation by using Spectroscopic Techniques.

    PubMed

    Enengl, Christina; Enengl, Sandra; Bouguerra, Nassima; Havlicek, Marek; Neugebauer, Helmut; Egbe, Daniel A M

    2017-01-04

    Poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene) (PPE-PPV) copolymers have attracted quite a lot of attention in the last few years for electronic device applications owing to their enhanced fluorescence. In this work, we focus on one particular PPE-PPV copolymer with dissymmetrically substituted 1,4-phenylene-ethynylene and symmetrically substituted 1,4-phenylene-vinylene building units. Six successively performed cyclic voltammograms are presented, measured during the oxidation reactions. As the oxidation onset of the electrochemical reaction shifts to lower potentials in each cycle, this behavior is elucidated by using spectroscopic techniques ranging from UV/Vis/near-IR to mid-IR including spin-resonance techniques. Hence, these findings help to explain some of the copolymer's most advantageous properties in terms of possible oxidation products. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.

    1972-01-01

    The search for advanced measurement techniques for determining long term compatibility of materials with propellants was conducted in several parts. A comprehensive survey of the existing measurement and testing technology for determining material-propellant interactions was performed. Selections were made from those existing techniques which were determined could meet or be made to meet the requirements. Areas of refinement or changes were recommended for improvement of others. Investigations were also performed to determine the feasibility and advantages of developing and using new techniques to achieve significant improvements over existing ones. The most interesting demonstration was that of the new technique, the volatile metal chelate analysis. Rivaling the neutron activation analysis in terms of sensitivity and specificity, the volatile metal chelate technique was fully demonstrated.

  19. Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering.

    PubMed

    Ehn, Andreas; Zhu, Jiajian; Li, Xuesong; Kiefer, Johannes

    2017-03-01

    Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities. The aim of this article is to present selected important laser-based techniques for gas-phase diagnostics focusing on their applications in combustion and aerospace engineering. Applicable laser-based techniques for investigations of turbulent flows and combustion such as planar laser-induced fluorescence, Raman and Rayleigh scattering, coherent anti-Stokes Raman scattering, laser-induced grating scattering, particle image velocimetry, laser Doppler anemometry, and tomographic imaging are reviewed and described with some background physics. In addition, demands on instrumentation are further discussed to give insight in the possibilities that are offered by laser flow diagnostics.

  20. Examination of optimum carrier materials and quantum dots for a quantum dot solar concentrator using spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Gallagher, S. J.; Rowan, B. C.; Doran, J.; Norton, B.

    2005-08-01

    Spectroscopic measurements have been undertaken for a range of different quantum dot (QD) types and transparent host materials for use in a novel solar energy-concentrating device, a Quantum Dot Solar Concentrator1 (QDSC). A QDSC comprises QDs seeded in materials such as plastics and glasses that are suitable for incorporation into buildings where photovoltaic cells attached to the edges convert direct and diffuse solar energy into electricity for use in the building. High transparency in the matrix material and QDs with a large Stokes shift are essential for an efficient QDSC. An optimum matrix material for a QDSC has been determined based on absorption characteristics and an optimum commercially available QD type has been chosen using steady-state absorption, photoluminescence and photoluminescence excitation spectroscopy of QDs in solution and solid matrices.

  1. Identification of vegetable oil botanical speciation in refined vegetable oil blends using an innovative combination of chromatographic and spectroscopic techniques.

    PubMed

    Osorio, Maria Teresa; Haughey, Simon A; Elliott, Christopher T; Koidis, Anastasios

    2015-12-15

    European Regulation 1169/2011 requires producers of foods that contain refined vegetable oils to label the oil types. A novel rapid and staged methodology has been developed for the first time to identify common oil species in oil blends. The qualitative method consists of a combination of a Fourier Transform Infrared (FTIR) spectroscopy to profile the oils and fatty acid chromatographic analysis to confirm the composition of the oils when required. Calibration models and specific classification criteria were developed and all data were fused into a simple decision-making system. The single lab validation of the method demonstrated the very good performance (96% correct classification, 100% specificity, 4% false positive rate). Only a small fraction of the samples needed to be confirmed with the majority of oils identified rapidly using only the spectroscopic procedure. The results demonstrate the huge potential of the methodology for a wide range of oil authenticity work. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Recent advances in 3D computed tomography techniques for simulation and navigation in hepatobiliary pancreatic surgery.

    PubMed

    Uchida, Masafumi

    2014-04-01

    A few years ago it could take several hours to complete a 3D image using a 3D workstation. Thanks to advances in computer science, obtaining results of interest now requires only a few minutes. Many recent 3D workstations or multimedia computers are equipped with onboard 3D virtual patient modeling software, which enables patient-specific preoperative assessment and virtual planning, navigation, and tool positioning. Although medical 3D imaging can now be conducted using various modalities, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography (US) among others, the highest quality images are obtained using CT data, and CT images are now the most commonly used source of data for 3D simulation and navigation image. If the 2D source image is bad, no amount of 3D image manipulation in software will provide a quality 3D image. In this exhibition, the recent advances in CT imaging technique and 3D visualization of the hepatobiliary and pancreatic abnormalities are featured, including scan and image reconstruction technique, contrast-enhanced techniques, new application of advanced CT scan techniques, and new virtual reality simulation and navigation imaging.

  3. Complementary Spectroscopic Assays for Investigating Protein-Ligand Binding Activity: A Project for the Advanced Chemistry Laboratory

    ERIC Educational Resources Information Center

    Mascotti, David P.; Waner, Mark J.

    2010-01-01

    A protein-ligand binding, guided-inquiry laboratory project with potential application across the advanced undergraduate curriculum is described. At the heart of the project are fluorescence and spectrophotometric assays utilizing biotin-4-fluorescein and streptavidin. The use of the same stock solutions for an assay that may be examined by two…

  4. Complementary Spectroscopic Assays for Investigating Protein-Ligand Binding Activity: A Project for the Advanced Chemistry Laboratory

    ERIC Educational Resources Information Center

    Mascotti, David P.; Waner, Mark J.

    2010-01-01

    A protein-ligand binding, guided-inquiry laboratory project with potential application across the advanced undergraduate curriculum is described. At the heart of the project are fluorescence and spectrophotometric assays utilizing biotin-4-fluorescein and streptavidin. The use of the same stock solutions for an assay that may be examined by two…

  5. Frontofacial osteotomies, advancement, and remodeling by distraction: an extended application of the technique.

    PubMed

    Talisman, R; Hemmy, D C; Denny, A D

    1997-07-01

    The purpose of this clinical report is to present the distraction technique for advancement of the frontofacial skeleton as a unit. Our 14-year-old patient was diagnosed with Carpenter's syndrome and kleblattschädel deformity at birth. At other centers the patient underwent corrective surgeries, including repeated fronto-orbital advancement in an attempt to correct the residual deformity. This has resulted in bony malunion and recurrent deformity, and it has left the patient with no available donor sites for harvesting of bone graft. The patient had class III malocclusion, severe midfacial and frontal deficiency, and relative turricephaly. We performed frontofacial osteotomies and placement of the distraction devices. Distraction of 20 mm was accomplished, correcting the exophthalmos and midface retrusion and producing class I dental occlusion. We conclude that distraction is an optional surgical method that can be applied in selected cases for advancement of the entire frontofacial skeleton.

  6. Advances in the surface modification techniques of bone-related implants for last 10 years

    PubMed Central

    Qiu, Zhi-Ye; Chen, Cen; Wang, Xiu-Mei; Lee, In-Seop

    2014-01-01

    At the time of implanting bone-related implants into human body, a variety of biological responses to the material surface occur with respect to surface chemistry and physical state. The commonly used biomaterials (e.g. titanium and its alloy, Co–Cr alloy, stainless steel, polyetheretherketone, ultra-high molecular weight polyethylene and various calcium phosphates) have many drawbacks such as lack of biocompatibility and improper mechanical properties. As surface modification is very promising technology to overcome such problems, a variety of surface modification techniques have been being investigated. This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating, radiation grafting, plasma surface engineering, ion beam processing and surface patterning techniques. The contents are organized with different types of techniques to applicable materials, and typical examples are also described. PMID:26816626

  7. Unified Instrumentation: Examining the Simultaneous Application of Advanced Measurement Techniques for Increased Wind Tunnel Testing Capability

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A. (Editor); Bartram, Scott M.; Humphreys, William M., Jr.; Jenkins, Luther N.; Jordan, Jeffrey D.; Lee, Joseph W.; Leighty, Bradley D.; Meyers, James F.; South, Bruce W.; Cavone, Angelo A.; Ingram, JoAnne L.

    2002-01-01

    A Unified Instrumentation Test examining the combined application of Pressure Sensitive Paint, Projection Moire Interferometry, Digital Particle Image Velocimetry, Doppler Global Velocimetry, and Acoustic Microphone Array has been conducted at the NASA Langley Research Center. The fundamental purposes of conducting the test were to: (a) identify and solve compatibility issues among the techniques that would inhibit their simultaneous application in a wind tunnel, and (b) demonstrate that simultaneous use of advanced instrumentation techniques is feasible for increasing tunnel efficiency and identifying control surface actuation / aerodynamic reaction phenomena. This paper provides summary descriptions of each measurement technique used during the Unified Instrumentation Test, their implementation for testing in a unified fashion, and example results identifying areas of instrument compatibility and incompatibility. Conclusions are drawn regarding the conditions under which the measurement techniques can be operated simultaneously on a non-interference basis. Finally, areas requiring improvement for successfully applying unified instrumentation in future wind tunnel tests are addressed.

  8. Recent Advances in Techniques for Starch Esters and the Applications: A Review

    PubMed Central

    Hong, Jing; Zeng, Xin-An; Brennan, Charles S.; Brennan, Margaret; Han, Zhong

    2016-01-01

    Esterification is one of the most important methods to alter the structure of starch granules and improve its applications. Conventionally, starch esters are prepared by conventional or dual modification techniques, which have the disadvantages of being expensive, have regent overdoses, and are time-consuming. In addition, the degree of substitution (DS) is often considered as the primary factor in view of its contribution to estimate substituted groups of starch esters. In order to improve the detection accuracy and production efficiency, different detection techniques, including titration, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis/infrared spectroscopy (TGA/IR) and headspace gas chromatography (HS-GC), have been developed for DS. This paper gives a comprehensive overview on the recent advances in DS analysis and starch esterification techniques. Additionally, the advantages, limitations, some perspectives on future trends of these techniques and the applications of their derivatives in the food industry are also presented. PMID:28231145

  9. Recent Advances in Techniques for Starch Esters and the Applications: A Review.

    PubMed

    Hong, Jing; Zeng, Xin-An; Brennan, Charles S; Brennan, Margaret; Han, Zhong

    2016-07-09

    Esterification is one of the most important methods to alter the structure of starch granules and improve its applications. Conventionally, starch esters are prepared by conventional or dual modification techniques, which have the disadvantages of being expensive, have regent overdoses, and are time-consuming. In addition, the degree of substitution (DS) is often considered as the primary factor in view of its contribution to estimate substituted groups of starch esters. In order to improve the detection accuracy and production efficiency, different detection techniques, including titration, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis/infrared spectroscopy (TGA/IR) and headspace gas chromatography (HS-GC), have been developed for DS. This paper gives a comprehensive overview on the recent advances in DS analysis and starch esterification techniques. Additionally, the advantages, limitations, some perspectives on future trends of these techniques and the applications of their derivatives in the food industry are also presented.

  10. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    1998-09-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 pm) clean coal. Economical dewatering of an ultra-fine clean-coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

  11. Advanced combustion techniques for controlling NO/x/ emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments have been and continue to be sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere. Of particular concern are the oxides of nitrogen (NO/x/) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NO/x/ emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  12. Imaging of skull base pathologies: Role of advanced magnetic resonance imaging techniques

    PubMed Central

    Mathur, Ankit; Kesavadas, C; Thomas, Bejoy; Kapilamoorthy, TR

    2015-01-01

    Imaging plays a vital role in evaluation of skull base pathologies as this region is not directly accessible for clinical evaluation. Computerized tomography (CT) and magnetic resonance imaging (MRI) have played complementary roles in the diagnosis of the various neoplastic and non-neoplastic lesions of the skull base. However, CT and conventional MRI may at times be insufficient to correctly pinpoint the accurate diagnosis. Advanced MRI techniques, though difficult to apply in the skull base region, in conjunction with CT and conventional MRI can however help in improving the diagnostic accuracy. This article aims to highlight the importance of advanced MRI techniques like diffusion-weighted imaging, susceptibility-weighted imaging, perfusion-weighted imaging, and MR spectroscopy in differentiation of various lesions involving the skull base. PMID:26427895

  13. The investigation of advanced remote sensing techniques for the measurement of aerosol characteristics

    NASA Technical Reports Server (NTRS)

    Deepak, A.; Becher, J.

    1979-01-01

    Advanced remote sensing techniques and inversion methods for the measurement of characteristics of aerosol and gaseous species in the atmosphere were investigated. Of particular interest were the physical and chemical properties of aerosols, such as their size distribution, number concentration, and complex refractive index, and the vertical distribution of these properties on a local as well as global scale. Remote sensing techniques for monitoring of tropospheric aerosols were developed as well as satellite monitoring of upper tropospheric and stratospheric aerosols. Computer programs were developed for solving multiple scattering and radiative transfer problems, as well as inversion/retrieval problems. A necessary aspect of these efforts was to develop models of aerosol properties.

  14. [Principles and advanced techniques for better internetpresentations in obstetrics and gynecology].

    PubMed

    Seufert, R; Molitor, N; Pollow, K; Woernle, F; Hawighorst-Knapstein, S

    2001-08-01

    Internet presentations are common tools for better medical communication and better scientific work. Meanwhile a great number of gynecological and obstetrical institutions present data via the world wide web within a wide range of quality and performance. Specific HTML editors offer quick and easy presentations, but only advanced internet techniques enable interesting multimedia presentations. N-tier applications are the future standard and we must integrate them in general informatical systems. New Concepts, actual tools and general problems will be discussed and new principles similar to actual E commerce techniques are able to solve our special medical demands.

  15. Combined preputial advancement and phallopexy as a revision technique for treating paraphimosis in a dog.

    PubMed

    Wasik, S M; Wallace, A M

    2014-11-01

    A 7-year-old neutered male Jack Russell terrier-cross was presented for signs of recurrent paraphimosis, despite previous surgical enlargement of the preputial ostium. Revision surgery was performed using a combination of preputial advancement and phallopexy, which resulted in complete and permanent coverage of the glans penis by the prepuce, and at 1 year postoperatively, no recurrence of paraphimosis had been observed. The combined techniques allow preservation of the normal penile anatomy, are relatively simple to perform and provide a cosmetic result. We recommend this combination for the treatment of paraphimosis in the dog, particularly when other techniques have failed.

  16. Advanced digital modulation: Communication techniques and monolithic GaAs technology

    NASA Technical Reports Server (NTRS)

    Wilson, S. G.; Oliver, J. D., Jr.; Kot, R. C.; Richards, C. R.

    1983-01-01

    Communications theory and practice are merged with state-of-the-art technology in IC fabrication, especially monolithic GaAs technology, to examine the general feasibility of a number of advanced technology digital transmission systems. Satellite-channel models with (1) superior throughput, perhaps 2 Gbps; (2) attractive weight and cost; and (3) high RF power and spectrum efficiency are discussed. Transmission techniques possessing reasonably simple architectures capable of monolithic fabrication at high speeds were surveyed. This included a review of amplitude/phase shift keying (APSK) techniques and the continuous-phase-modulation (CPM) methods, of which MSK represents the simplest case.

  17. Noncompaction cardiomyopathy: The role of advanced multimodality imaging techniques in diagnosis and assessment.

    PubMed

    Chebrolu, Lakshmi H; Mehta, Anjlee M; Nanda, Navin C

    2017-02-01

    Noncompaction cardiomyopathy (NCCM) is a unique cardiomyopathy with a diverse array of genotypic and phenotypic manifestations. Its hallmark morphology consists of a bilayered myocardium with a compact epicardial layer and prominent trabeculations that comprise the noncompacted endocardial layer. The controversial diagnostic criteria for NCCM have been frequently discussed in the literature. This review touches on those diagnostic criteria, delves further into the evolving use of advanced imaging techniques within the major imaging modalities (echocardiography, computed tomography, and cardiac magnetic resonance imaging), and proposes an alternative algorithm incorporating these techniques for aiding with the diagnosis of NCCM.

  18. Development of advanced electron holographic techniques and application to industrial materials and devices.

    PubMed

    Yamamoto, Kazuo; Hirayama, Tsukasa; Tanji, Takayoshi

    2013-06-01

    The development of a transmission electron microscope equipped with a field emission gun paved the way for electron holography to be put to practical use in various fields. In this paper, we review three advanced electron holography techniques: on-line real-time electron holography, three-dimensional (3D) tomographic holography and phase-shifting electron holography, which are becoming important techniques for materials science and device engineering. We also describe some applications of electron holography to the analysis of industrial materials and devices: GaAs compound semiconductors, solid oxide fuel cells and all-solid-state lithium ion batteries.

  19. New test techniques and analytical procedures for understanding the behavior of advanced propellers

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Bober, L. J.; Neumann, H. E.

    1983-01-01

    Analytical procedures and experimental techniques were developed to improve the capability to design advanced high speed propellers. Some results from the propeller lifting line and lifting surface aerodynamic analysis codes are compared with propeller force data, probe data and laser velocimeter data. In general, the code comparisons with data indicate good qualitative agreement. A rotating propeller force balance demonstrated good accuracy and reduced test time by 50 percent. Results from three propeller flow visualization techniques are shown which illustrate some of the physical phenomena occurring on these propellers.

  20. Advanced techniques for all-electrical spectroscopy on spin caloric phenomena

    NASA Astrophysics Data System (ADS)

    Huber, R.; Klemm, P.; Neusser, S.; Botters, B.; Wittmann, A.; Weiler, M.; Goennenwein, S. T. B.; Heyn, C.; Schneider, M.; Böni, P.; Grundler, D.

    2010-04-01

    Spin-dependent properties of nanomagnets and magnetic/nonmagnetic hybrid systems have gained a renewed interest after the discovery of spin caloric transport phenomena. To explore such properties in detail, advanced techniques need to be developed. In this paper we report novel approaches to study both the magneto-thermal and magneto-mechanical characteristics of hybrid systems. These techniques involve in particular broadband spectroscopy of spin dynamics and surface acoustic waves in the GHz frequency regime. By these means we investigate ferromagnet/semiconductor hybrid systems to explore spin pumping and the Seebeck effect as well as ferromagnet/piezoelectric hybrid systems to address magneto-mechanical coupling at high frequencies.

  1. An example of requirements for Advanced Subsonic Civil Transport (ASCT) flight control system using structured techniques

    NASA Technical Reports Server (NTRS)

    Mclees, Robert E.; Cohen, Gerald C.

    1991-01-01

    The requirements are presented for an Advanced Subsonic Civil Transport (ASCT) flight control system generated using structured techniques. The requirements definition starts from initially performing a mission analysis to identify the high level control system requirements and functions necessary to satisfy the mission flight. The result of the study is an example set of control system requirements partially represented using a derivative of Yourdon's structured techniques. Also provided is a research focus for studying structured design methodologies and in particular design-for-validation philosophies.

  2. ADVANCING THE FUNDAMENTAL UNDERSTANDING AND SCALE-UP OF TRISO FUEL COATERS VIA ADVANCED MEASUREMENT AND COMPUTATIONAL TECHNIQUES

    SciTech Connect

    Biswas, Pratim; Al-Dahhan, Muthanna

    2012-11-01

    to advance the fundamental understanding of the hydrodynamics by systematically investigating the effect of design and operating variables, to evaluate the reported dimensionless groups as scaling factors, and to establish a reliable scale-up methodology for the TRISO fuel particle spouted bed coaters based on hydrodynamic similarity via advanced measurement and computational techniques. An additional objective is to develop an on-line non-invasive measurement technique based on gamma ray densitometry (i.e. Nuclear Gauge Densitometry) that can be installed and used for coater process monitoring to ensure proper performance and operation and to facilitate the developed scale-up methodology. To achieve the objectives set for the project, the work will use optical probes and gamma ray computed tomography (CT) (for the measurements of solids/voidage holdup cross-sectional distribution and radial profiles along the bed height, spouted diameter, and fountain height) and radioactive particle tracking (RPT) (for the measurements of the 3D solids flow field, velocity, turbulent parameters, circulation time, solids lagrangian trajectories, and many other of spouted bed related hydrodynamic parameters). In addition, gas dynamic measurement techniques and pressure transducers will be utilized to complement the obtained information. The measurements obtained by these techniques will be used as benchmark data to evaluate and validate the computational fluid dynamic (CFD) models (two fluid model or discrete particle model) and their closures. The validated CFD models and closures will be used to facilitate the developed methodology for scale-up, design and hydrodynamic similarity. Successful execution of this work and the proposed tasks will advance the fundamental understanding of the coater flow field and quantify it for proper and safe design, scale-up, and performance. Such achievements will overcome the barriers to AGR applications and will help assure that the US maintains

  3. 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.

  4. Study of advanced techniques for determining the long term performance of components

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The application of existing and new technology to the problem of determining the long-term performance capability of liquid rocket propulsion feed systems is discussed. The long term performance of metal to metal valve seats in a liquid propellant fuel system is stressed. The approaches taken in conducting the analysis are: (1) advancing the technology of characterizing components through the development of new or more sensitive techniques and (2) improving the understanding of the physical of degradation.

  5. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    Groppo, J.G.; Parekh, B.K.; Rawls, P.

    1995-11-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

  6. [Application value of core needle biopsy technique in the pathological diagnosis of locally advanced pancreatic cancer].

    PubMed

    Che, Xu; Zhang, Jianwei; Chen, Yingtai; Sun, Yuemin; Wang, Chengfeng

    2015-04-14

    To explore the application value of core needle biopsy technique in the pathological diagnosis of locally advanced pancreatic cancer patients. During April 2007 to April 2014, retrospective analysis was conducted for 36 patients of locally advanced pancreatic cancer to summarize the clinical data of core needle biopsy technique. And the relevant data included clinical features, pathological findings and puncture-related complications. Regular postoperative follow-ups were conducted. All received pathological examination of core needle biopsy. And the pathological diagnoses were pancreatic cancer (n=29), pancreatic neuroendocrine tumors (n=2) and chronic pancreatitis (n=5). During the follow-ups, liver metastasis was pathologically confirmed postoperatively at Months 4 and 6 months among 5 chronic pancreatitis patients. The remainder was followed up for over 12 months. There was neither change in size nor metastasis. One case was diagnosed at Peking Union Hospital as autoimmune pancreatitis while another 2 cases had a clinical diagnosis of chronic pancreatitis. The accuracy of core needle puncture was 94.4%. There were 2 cases of postoperative pancreatic fistula in class A. Bleeding complication was absent. The application of core needle biopsy technique is both safe and effective in the pathological diagnosis of locally advanced pancreatic cancer.

  7. A new surgical technique for concealed penis using an advanced musculocutaneous scrotal flap.

    PubMed

    Han, Dong-Seok; Jang, Hoon; Youn, Chang-Shik; Yuk, Seung-Mo

    2015-06-19

    Until recently, no single, universally accepted surgical method has existed for all types of concealed penis repairs. We describe a new surgical technique for repairing concealed penis by using an advanced musculocutaneous scrotal flap. From January 2010 to June 2014, we evaluated 12 patients (12-40 years old) with concealed penises who were surgically treated with an advanced musculocutaneous scrotal flap technique after degloving through a ventral approach. All the patients were scheduled for regular follow-up at 6, 12, and 24 weeks postoperatively. The satisfaction grade for penile size, morphology, and voiding status were evaluated using a questionnaire preoperatively and at all of the follow-ups. Information regarding complications was obtained during the postoperative hospital stay and at all follow-ups. The patients' satisfaction grades, which included the penile size, morphology, and voiding status, improved postoperatively compared to those preoperatively. All patients had penile lymphedema postoperatively; however, this disappeared within 6 weeks. There were no complications such as skin necrosis and contracture, voiding difficulty, or erectile dysfunction. Our advanced musculocutaneous scrotal flap technique for concealed penis repair is technically easy and safe. In addition, it provides a good cosmetic appearance, functional outcomes and excellent postoperative satisfaction grades. Lastly, it seems applicable in any type of concealed penis, including cases in which the ventral skin defect is difficult to cover.

  8. Integrating Organic Matter Structure with Ecosystem Function using Advanced Analytical Chemistry Techniques

    NASA Astrophysics Data System (ADS)

    Boot, C. M.

    2012-12-01

    Microorganisms are the primary transformers of organic matter in terrestrial and aquatic ecosystems. The structure of organic matter controls its bioavailability and researchers have long sought to link the chemical characteristics of the organic matter pool to its lability. To date this effort has been primarily attempted using low resolution descriptive characteristics (e.g. organic matter content, carbon to nitrogen ratio, aromaticity, etc .). However, recent progress in linking these two important ecosystem components has been advanced using advanced high resolution tools (e.g. nuclear magnetic resonance (NMR) spectroscopy, and mass spectroscopy (MS)-based techniques). A series of experiments will be presented that highlight the application of high resolution techniques in a variety of terrestrial and aquatic ecosystems with the focus on how these data explicitly provide the foundation for integrating organic matter structure into our concept of ecosystem function. The talk will highlight results from a series of experiments including: an MS-based metabolomics and fluorescence excitation emission matrix approach evaluating seasonal and vegetation based changes in dissolved organic matter (DOM) composition from arctic soils; Fourier transform ion cyclotron resonance (FTICR) MS and MS metabolomics analysis of DOM from three lakes in an alpine watershed; and the transformation of 13C labeled glucose track with NMR during a rewetting experiment from Colorado grassland soils. These data will be synthesized to illustrate how the application of advanced analytical techniques provides novel insight into our understanding of organic matter processing in a wide range of ecosystems.

  9. Potential of advanced MR imaging techniques in the differential diagnosis of parkinsonism.

    PubMed

    Hotter, Anna; Esterhammer, Regina; Schocke, Michael F H; Seppi, Klaus

    2009-01-01

    The clinical differentiation of parkinsonian syndromes remains challenging not only for neurologists but also for movement disorder specialists. Conventional magnetic resonance imaging (cMRI) with the visual assessment of T2- and T1-weighted imaging as well as different advanced MRI techniques offer objective measures, which may be a useful tool in the diagnostic work-up of Parkinson's disease and atypical parkinsonian disorders (APDs). In clinical practice, cMRI is a well-established method for the exclusion of symptomatic parkinsonism due to other pathologies. Over the past two decades, abnormalities in the basal ganglia and infratentorial structures have been shown especially in APDs not only by cMRI but also by different advanced MRI techniques, including methods to assess regional cerebral atrophy quantitatively such as magnetic resonance volumetry, proton magnetic resonance spectroscopy, diffusion-weighted imaging, and magnetization transfer imaging. This article aims to review recent research findings on the role of advanced MRI techniques in the differential diagnosis of neurodegenerative parkinsonian disorders.

  10. Investigation into the interaction of losartan with human serum albumin and glycated human serum albumin by spectroscopic and molecular dynamics simulation techniques: A comparison study.

    PubMed

    Moeinpour, Farid; Mohseni-Shahri, Fatemeh S; Malaekeh-Nikouei, Bizhan; Nassirli, Hooriyeh

    2016-09-25

    The interaction between losartan and human serum albumin (HSA), as well as its glycated form (gHSA) was studied by multiple spectroscopic techniques and molecular dynamics simulation under physiological conditions. The binding information, including the binding constants, effective quenching constant and number of binding sites showed that the binding partiality of losartan to HSA was higher than to gHSA. The findings of three-dimensional fluorescence spectra demonstrated that the binding of losartan to HSA and gHSA would alter the protein conformation. The distances between Trp residue and the binding sites of the drug were evaluated on the basis of the Förster theory, and it was indicated that non-radiative energy transfer from HSA and gHSA to the losartan happened with a high possibility. According to molecular dynamics simulation, the protein secondary and tertiary structure changes were compared in HSA and gHSA for clarifying the obtained results.

  11. Investigation on the interaction between isorhamnetin and bovine liver catalase by spectroscopic techniques under different pH conditions.

    PubMed

    Yang, Yumin; Li, Daojin

    2016-08-01

    The binding of isorhamnetin to bovine liver catalase (BLC) was first investigated at 302, 310 and 318 K at pH 7.4 using spectroscopic methods including fluorescence spectra, circular dichroism (CD) and UV-vis absorption. Spectrophotometric observations are rationalized mainly in terms of a static quenching process. The binding constants and binding sites were evaluated by fluorescence quenching methods. Enzymatic activity of BLC in the absence and presence of isorhamnetin was measured using a UV/vis spectrophotometer. The result revealed that the binding of isorhamnetin to BLC led to a reduction in the activity of BLC. The positive entropy change and enthalpy change indicated that the interaction of isorhamnetin with BLC was mainly driven by hydrophobic forces. The distance r between the donor (BLC) and acceptor (isorhamnetin) was estimated to be 2.99 nm according to fluorescence resonance energy transfer. Fluorescence, synchronous fluorescence, and CD spectra showed no obvious change in the conformation of BLC upon the binding of isorhamnetin. In addition, the influence of pH on the binding of isorhamnetin to BLC was investigated and the binding ability of the drug to BLC deceased under other pH conditions (pH 9.0, 6.5, 5.0, 3.5, or 2.0) as compared with that at pH 7.4. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Analytical performance of different X-ray spectroscopic techniques for the environmental monitoring of the recultivated uranium mine site

    NASA Astrophysics Data System (ADS)

    Alsecz, A.; Osán, J.; Kurunczi, S.; Alföldy, B.; Várhegyi, A.; Török, S.

    2007-08-01

    One uranium deposit exists in Hungary, with continuous radiological monitoring of the site. Nuclear spectroscopical methods are well established in order to study the problem concerning radionuclides. However, very limited information is available on the distribution and chemical form of uranium in the tailings sludge. In order to solve this complex analytical problem, a combination of different analytical methods is necessary. One of the most applied methods for studying the major elemental composition of particulate samples is electron probe microanalysis (EPMA). However, uranium and its daughter elements are often present only at trace amounts in the particles, below detection limit of EPMA. For most actinides that are long-lived radionuclides, microbeam X-ray fluorescence (μ-XRF) has superior sensitivity to determine elements in microparticles. Detection limits and applicability of EPMA and laboratory μ-XRF are discussed for localization of uranium-rich particles in the inhomogeneous tailings material. Laboratory μ-XRF provided an efficient way to identify these particles that can be easily relocated for further non-destructive microchemical investigations. Finally, for water analysis a simple and reliable method for U analysis is presented using total reflection X-ray fluorescence spectrometry (TXRF) that can be applied for on-site analysis in situations of accidental uranium contamination.

  13. Determination of photocarrier density under continuous photoirradiation using spectroscopic techniques as applied to polymer: Fullerene blend films

    NASA Astrophysics Data System (ADS)

    Kanemoto, Katsuichi; Nakatani, Hitomi; Domoto, Shinya

    2014-10-01

    We propose a method to determine the density of photocarrier under continuous photoirradiation in conjugated polymers using spectroscopic signals obtained by photoinduced absorption (PIA) measurements. The bleaching signals in the PIA measurements of polymer films and the steady-state absorption signals of oxidized polymer solution are employed to determine the photocarrier density. The method is applied to photocarriers of poly (3-hexylthiophene) (P3HT) in a blended film consisting of P3HT and [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The photocarrier density under continuous photoirradiation of 580 mW/cm2 is determined to be 3.5 × 1016 cm-3. Using a trend of the carrier density increasing in proportion to the square root of photo-excitation intensity, we provide a general formula to estimate the photocarrier density under simulated 1 sun solar irradiation for the P3HT: PCBM film of an arbitrary thickness. We emphasize that the method proposed in this study enables an estimate of carrier density without measuring a current and can be applied to films with no electrodes as well as to devices.

  14. Determination of photocarrier density under continuous photoirradiation using spectroscopic techniques as applied to polymer: Fullerene blend films

    SciTech Connect

    Kanemoto, Katsuichi Nakatani, Hitomi; Domoto, Shinya

    2014-10-28

    We propose a method to determine the density of photocarrier under continuous photoirradiation in conjugated polymers using spectroscopic signals obtained by photoinduced absorption (PIA) measurements. The bleaching signals in the PIA measurements of polymer films and the steady-state absorption signals of oxidized polymer solution are employed to determine the photocarrier density. The method is applied to photocarriers of poly (3-hexylthiophene) (P3HT) in a blended film consisting of P3HT and [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The photocarrier density under continuous photoirradiation of 580 mW/cm{sup 2} is determined to be 3.5 × 10{sup 16 }cm{sup −3}. Using a trend of the carrier density increasing in proportion to the square root of photo-excitation intensity, we provide a general formula to estimate the photocarrier density under simulated 1 sun solar irradiation for the P3HT: PCBM film of an arbitrary thickness. We emphasize that the method proposed in this study enables an estimate of carrier density without measuring a current and can be applied to films with no electrodes as well as to devices.

  15. A novel technique for advancing the inferior labrum in a bankart repair.

    PubMed

    Adams, Brook A; Garrett, William H; Wright, Garth B; Khan, Maher W; Taylor, Jonathon B; Nord, Keith D

    2013-05-01

    Passing suture during a Bankart repair can be a difficult task. A key component of a Bankart repair involves shifting the anteroinferior capsule and labrum superiorly. This technical note describes a new technique of reaching the inferior aspect of the Bankart lesion from posterior. Typical suture passers push the tissue further away. Using a SutureLasso through the low posterolateral portal allows one to push the tissue from inferior toward the suture anchor, making it simpler to advance the capsulolabral complex. Three suture anchors are used in the anteroinferior quadrant. The lowest suture anchor is the critical anchor for advancing the capsule and labrum. The SutureLasso is placed into the axillary recess through the low posterolateral portal, and the nitinol wire is advanced through the capsule and labrum, retrieving the suture and pulling it back through the tissue for tying with a sliding locking knot. This ensures good superior advancement of the tissue and helps obtain an optimal arthroscopic result in Bankart repair. Additional anchors are placed, and suture passage for the middle and superior anchors is then completed from anterior. The advancement and restoration of the tissue tightness provide the optimal components for an excellent result.

  16. Response to the Letter to the Editor by D. Richardson: Analysis of the Interaction of Dp44mT with Human Serum Albumin and Calf Thymus DNA Using Molecular Docking and Spectroscopic Techniques

    PubMed Central

    Xu, Zhongjie; Liu, Youxun; Zhou, Sufeng; Fu, Yun; Li, Changzheng

    2016-01-01

    This response refers to: Xu, Z.; Liu, Y.; Zhou, S.; Fu, Y.; Li, C. Analysis of the Interaction of Dp44mT with Human Serum Albumin and Calf Thymus DNA Using Molecular Docking and Spectroscopic Techniques. Int. J. Mol. Sci. 2016, 17, 1042. Merlot, A.M.; Sahni, S.; Lane, D.J.R.; Richardson, V.; Huang, M.L.H.; Kalinowski, D.S.; Richardson, D.R. Letter to the Editor: Analysis of the Interaction of Dp44mT with Human Serum Albumin and Calf Thymus DNA Using Molecular Docking and Spectroscopic Techniques and. Int. J. Mol. Sci. 2016, 17, 1916. PMID:27854349

  17. Advanced Time-Resolved Fluorescence Microscopy Techniques for the Investigation of Peptide Self-Assembly

    NASA Astrophysics Data System (ADS)

    Anthony, Neil R.

    The ubiquitous cross beta sheet peptide motif is implicated in numerous neurodegenerative diseases while at the same time offers remarkable potential for constructing isomorphic high-performance bionanomaterials. Despite an emerging understanding of the complex folding landscape of cross beta structures in determining disease etiology and final structure, we lack knowledge of the critical initial stages of nucleation and growth. In this dissertation, I advance our understanding of these key stages in the cross-beta nucleation and growth pathways using cutting-edge microscopy techniques. In addition, I present a new combined time-resolved fluorescence analysis technique with the potential to advance our current understanding of subtle molecular level interactions that play a pivotal role in peptide self-assembly. Using the central nucleating core of Alzheimer's Amyloid-beta protein, Abeta(16 22), as a model system, utilizing electron, time-resolved, and non-linear microscopy, I capture the initial and transient nucleation stages of peptide assembly into the cross beta motif. In addition, I have characterized the nucleation pathway, from monomer to paracrystalline nanotubes in terms of morphology and fluorescence lifetime, corroborating the predicted desolvation process that occurs prior to cross-beta nucleation. Concurrently, I have identified unique heterogeneous cross beta domains contained within individual nanotube structures, which have potential bionanomaterials applications. Finally, I describe a combined fluorescence theory and analysis technique that dramatically increases the sensitivity of current time-resolved techniques. Together these studies demonstrate the potential for advanced microscopy techniques in the identification and characterization of the cross-beta folding pathway, which will further our understanding of both amyloidogenesis and bionanomaterials.

  18. Advanced nuclear analytical and related techniques for the growing challenges in nanotoxicology.

    PubMed

    Chen, Chunying; Li, Yu-Feng; Qu, Ying; Chai, Zhifang; Zhao, Yuliang

    2013-11-07

    Manufactured nanomaterials with novel physicochemical properties are an important basis for nanosciences and related technologies. Nanotoxicology, aiming to understand the principles of interactions at the nano-bio interface and the relationship between the physicochemical properties of nanomaterials and their toxicological profiles, has become a new frontier in nanoscience. Nearly one decade of nanotoxicology research has shown that the interactions between nanomaterials and proteins, cells, animals, humans and the environment as well as the underlying mechanisms of toxicity for nanomaterials are remarkably complicated, requiring dedicated analytical methodology and tools. Because of their advantages of absolute quantification, high sensitivity, excellent accuracy and precision, low matrix effects and non-destructiveness, nuclear analytical techniques have been playing important roles in the study of nanotoxicology. A systematic summary and comprehensive review of the advanced nuclear analytical and related techniques in nanotoxicology is greatly needed. In this review article, we present a comprehensive overview of nuclear analytical techniques applied to the physicochemical characterization of nanomaterials, structural analysis of bio-nano interactions, visualization of nanomaterials in vitro, quantification of bio-distribution, bio-accumulation, and transformation of nanomaterials in vivo. As important complementary tools, optical imaging technologies are also highlighted. Future directions regarding advanced nuclear analytical approaches for nanotoxicology are also discussed. The rapid development of advanced light source-based techniques will enable new high-throughput screening techniques and provide high sensitivity with low detection limits, which are required for the distribution, imaging, and structural analysis of nanomaterials, and the molecular information of biomarkers for all aspects of nanotoxicology.

  19. LIBS spectroscopic classification relative to compressive sensing

    NASA Astrophysics Data System (ADS)

    Griffin, Steven T.; Jacobs, Eddie; Furxhi, Orges

    2011-05-01

    Laser Induced Breakdown Spectroscopy (LIBS) utilizes a diversity of standard spectroscopic techniques for classification of materials present in the sample. Pre-excitation processing sometimes limits the analyte to a short list of candidates. Prior art demonstrates that sparsity is present in the data. This is sometimes characterized as identification by components. Traditionally, spectroscopic identification has been accomplished by an expert reader in a manner typical for MRI images in the medicine. In an effort to automate this process, more recent art has emphasized the use of customized variations to standard classification algorithms. In addition, formal mathematical proofs for compressive sensing have been advanced. Recently the University of Memphis has been contracted by the Spectroscopic Materials Identification Center to advance and characterize the sensor research and development related to LIBS. Applications include portable standoff sensing for improvised explosive device detection and related law enforcement and military applications. Reduction of the mass, power consumption and other portability parameters is seen as dependent on classification choices for a LIBS system. This paper presents results for the comparison of standard LIBS classification techniques to those implied by Compressive Sensing mathematics. Optimization results and implications for portable LIBS design are presented.

  20. Study of hydrogen-bonding, vibrational dynamics and structure-activity relationship of genistein using spectroscopic techniques coupled with DFT

    NASA Astrophysics Data System (ADS)

    Singh, Harshita; Singh, Swapnil; Srivastava, Anubha; Tandon, Poonam; Bharti, Purnima; Kumar, Sudhir; Dev, Kapil; Maurya, Rakesh

    2017-02-01

    The conformational and hydrogen bonding studies of genistein have been performed by combined spectroscopic and quantum chemical approach. The vibrational spectra (FT-IR and FT-Raman), UV-visible and 1H and 13C NMR absorption spectra of genistein have been recorded and examined. The vibrational wavenumbers of optimized geometry and total energy for isolated molecule and hydrogen-bonded dimers of genistein have been determined using the quantum chemical calculation (DFT/B3LYP) with extended 6-311++G (d,p) basis set. The vibrational assignments for the observed FT-IR and FT-Raman spectra of genistein are provided by calculations on monomer and hydrogen-bonded dimer. The quantum theory of atoms in molecules (QTAIM) is used for investigating the nature and strength of hydrogen-bonds. UV-visible spectrum of the genistein was recorded in methanol solvent and the electronic properties were calculated by using time-dependent density functional theory (TD-DFT). The computed HOMO and LUMO energies predicted the type of transition as π → π*. The 1H and 13C NMR signals of the genistein were computed by the Gauge including atomic orbital (GIAO) approach. Natural bond orbital (NBO) analysis predicted the stability of molecules due to charge delocalization and hyper conjugative interactions. NBO analysis shows that there is an Osbnd H⋯O inter and intramolecular hydrogen bond, and π → π* transition in the monomer and dimer, which is consistent with the conclusion obtained by the investigation of molecular structure and assignment of UV-visible spectra.

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

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

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

  2. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate ('dynamic fatigue') testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rate in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  3. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate ('dynamic fatigue') testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rate in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  4. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  5. Advanced spatio-temporal filtering techniques for photogrammetric image sequence analysis in civil engineering material testing

    NASA Astrophysics Data System (ADS)

    Liebold, F.; Maas, H.-G.

    2016-01-01

    The paper shows advanced spatial, temporal and spatio-temporal filtering techniques which may be used to reduce noise effects in photogrammetric image sequence analysis tasks and tools. As a practical example, the techniques are validated in a photogrammetric spatio-temporal crack detection and analysis tool applied in load tests in civil engineering material testing. The load test technique is based on monocular image sequences of a test object under varying load conditions. The first image of a sequence is defined as a reference image under zero load, wherein interest points are determined and connected in a triangular irregular network structure. For each epoch, these triangles are compared to the reference image triangles to search for deformations. The result of the feature point tracking and triangle comparison process is a spatio-temporally resolved strain value field, wherein cracks can be detected, located and measured via local discrepancies. The strains can be visualized as a color-coded map. In order to improve the measuring system and to reduce noise, the strain values of each triangle must be treated in a filtering process. The paper shows the results of various filter techniques in the spatial and in the temporal domain as well as spatio-temporal filtering techniques applied to these data. The best results were obtained by a bilateral filter in the spatial domain and by a spatio-temporal EOF (empirical orthogonal function) filtering technique.

  6. Multidisciplinary approach for the study of an Egyptian coffin (late 22nd/early 25th dynasty): Combining imaging and spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Bracci, S.; Caruso, O.; Galeotti, M.; Iannaccone, R.; Magrini, D.; Picchi, D.; Pinna, D.; Porcinai, S.

    2015-06-01

    This paper demonstrates that an educated methodology based on both non-invasive and micro invasive techniques in a two-step approach is a powerful tool to characterize the materials and stratigraphies of an Egyptian coffin, which was restored several times. This coffin, belonging to a certain Mesiset, is now located at the Museo Civico Archeologico of Bologna (inventory number MCABo EG 1963). Scholars attributed it to the late 22nd/early 25th dynasty by stylistic comparison. The first step of the diagnostic approach applied imaging techniques on the whole surface in order to select measurements spots and to unveil both original and restored areas. Images and close microscopic examination of the polychrome surface allowed selecting representative areas to be investigated in situ by portable spectroscopic techniques: X-ray Fluorescence (XRF), Fiber Optic Reflectance Spectroscopy (FORS) and Fourier Transform Infrared spectroscopy (FTIR). After the analysis of the results coming from the first step, very few selected samples were taken to clarify the stratigraphy of the polychrome layers. The first step, based on the combination of imaging and spectroscopic techniques in a totally non-invasive modality, is quite unique in the literature on Egyptian coffins and enabled us to reveal many differences in the ground layer's composition and to identify a remarkable number of pigments in the original and restored areas. This work offered also a chance to check the limitations of the non-invasive approach applied on a complex case, namely the right localization of different materials in the stratigraphy and the identification of binding media. Indeed, to dissolve any remaining doubts on superimposed layers belonging to different interventions, it was necessary to sample few micro-fragments in some selected areas and analyze them prepared as cross-sections. The original ground layer is made of calcite, while the restored areas show the presence of either a mixture of calcite

  7. Multidisciplinary approach for the study of an Egyptian coffin (late 22nd/early 25th dynasty): combining imaging and spectroscopic techniques.

    PubMed

    Bracci, S; Caruso, O; Galeotti, M; Iannaccone, R; Magrini, D; Picchi, D; Pinna, D; Porcinai, S

    2015-06-15

    This paper demonstrates that an educated methodology based on both non-invasive and micro invasive techniques in a two-step approach is a powerful tool to characterize the materials and stratigraphies of an Egyptian coffin, which was restored several times. This coffin, belonging to a certain Mesiset, is now located at the Museo Civico Archeologico of Bologna (inventory number MCABo EG 1963). Scholars attributed it to the late 22nd/early 25th dynasty by stylistic comparison. The first step of the diagnostic approach applied imaging techniques on the whole surface in order to select measurements spots and to unveil both original and restored areas. Images and close microscopic examination of the polychrome surface allowed selecting representative areas to be investigated in situ by portable spectroscopic techniques: X-ray Fluorescence (XRF), Fiber Optic Reflectance Spectroscopy (FORS) and Fourier Transform Infrared spectroscopy (FTIR). After the analysis of the results coming from the first step, very few selected samples were taken to clarify the stratigraphy of the polychrome layers. The first step, based on the combination of imaging and spectroscopic techniques in a totally non-invasive modality, is quite unique in the literature on Egyptian coffins and enabled us to reveal many differences in the ground layer's composition and to identify a remarkable number of pigments in the original and restored areas. This work offered also a chance to check the limitations of the non-invasive approach applied on a complex case, namely the right localization of different materials in the stratigraphy and the identification of binding media. Indeed, to dissolve any remaining doubts on superimposed layers belonging to different interventions, it was necessary to sample few micro-fragments in some selected areas and analyze them prepared as cross-sections. The original ground layer is made of calcite, while the restored areas show the presence of either a mixture of calcite

  8. Evaluate the usage of different advanced endodontic instruments and techniques in pediatric dentistry.

    PubMed

    Kathariya, Mitesh D; Patil, Swapnil; Patil, Anil; Jadav, Rutiga H; Mandlik, Jyoti; Sharma, Anupam S

    2013-01-01

    The purpose of study is to find the prevalence of usage of different advanced endodontic instruments and techniques in pediatric dentistry. A self-administered, structured questionnaire written in English validated through a pretested survey was randomly mailed to the postgraduate students in different dental colleges. A total of 182 of the complete filled questionnaires were returned with response rate of 68.2%. The data were analyzed using the SPSS version 15.0. The Student's t-test and ANOVA test were used as test of significance. Karl Pearson's correlation test was used to assess years of education and usage of endodontic instruments. There was a limited use of new endodontic technologies in the present study. The highest positive response to the usage of advanced endodontic instruments was related to NiTi rotary files with highest number seen among 3rd year students. A linear relationship was found between years of postgraduation and usage of advanced endodontic instruments using Karl Pearson's correlation coefficient. Based on the results of the present study, it seems that the usage of advanced endodontic instruments is not up to the level. Also we found increased use of new technologies with years of postgraduation.

  9. Review of recent advances in analytical techniques for the determination of neurotransmitters

    PubMed Central

    Perry, Maura; Li, Qiang; Kennedy, Robert T.

    2009-01-01

    Methods and advances for monitoring neurotransmitters in vivo or for tissue analysis of neurotransmitters over the last five years are reviewed. The review is organized primarily by neurotransmitter type. Transmitter and related compounds may be monitored by either in vivo sampling coupled to analytical methods or implanted sensors. Sampling is primarily performed using microdialysis, but low-flow push-pull perfusion may offer advantages of spatial resolution while minimizing the tissue disruption associated with higher flow rates. Analytical techniques coupled to these sampling methods include liquid chromatography, capillary electrophoresis, enzyme assays, sensors, and mass spectrometry. Methods for the detection of amino acid, monoamine, neuropeptide, acetylcholine, nucleoside, and soluable gas neurotransmitters have been developed and improved upon. Advances in the speed and sensitivity of these methods have enabled improvements in temporal resolution and increased the number of compounds detectable. Similar advances have enabled improved detection at tissue samples, with a substantial emphasis on single cell and other small samples. Sensors provide excellent temporal and spatial resolution for in vivo monitoring. Advances in application to catecholamines, indoleamines, and amino acids have been prominent. Improvements in stability, sensitivity, and selectivity of the sensors have been of paramount interest. PMID:19800472

  10. Determination of Two-Photon Absorption Cross-Section of Noble Gases for Calibration of Laser Spectroscopic Techniques

    SciTech Connect

    Rosa, M. I. de la; Perez, C.; Gruetzmacher, K.; Fuentes, L. M.

    2008-10-22

    The objective of our work is to apply two-photon polarization spectroscopy as a new calibration method for the determination of two-photon excitation cross-sections of noble gases, like Xe and Kr, which are commonly used for calibrations of MP-LIF techniques in other laboratories.

  11. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  12. Advanced Molecular Diagnostic Techniques for Detection of Food-borne Pathogens; Current Applications and Future Challenges.

    PubMed

    Umesha, S; Manukumar, H M

    2016-01-08

    The elimination of disease-causing microbes from the food supply is a primary goal and this review deals with the overall techniques availavle for detection of food-borne pathogens. Now-a-days conventional methods are replaced by advanced methods like Biosensors, Nucleic Acid-based Tests (NAT) and different PCR based techniques used in molecular biology to identify specific pathogens. Bacillus cereus, Staphylococcus aureus, Proteus vulgaris, Escherichia coli, Campylobacter, Listeria monocytogenes, Salmonella spp, Aspergillus spp. Fusarium spp. Penicillium spp., and pathogens are detected in contaminated food items which cause always diseases in human in any one or the other way. Identification of food-borne pathogens in a short period of time is still a challenge to the scientific field in general and food technology in particular. The low level of food contamination by major pathogens requires specific sensitive detection platforms and the present area of hot research looking forward to new nanomolecular techniques for nanomaterials, make them suitable for the development of assays with high sensitivity, response time and portability. With the sound of these we attemet to highlight a comprehensive overview about food-borne pathogen detection by rapid, sensitive, accurate and cost affordable in situ analytical methods from conventional methods to recent molecular approaches for advanced food and microbiology research.

  13. 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.

  14. Mini-dental implant insertion with the auto-advance technique for ongoing applications.

    PubMed

    Balkin, B E; Steflik, D E; Naval, F

    2001-01-01

    The clinical and histological results of two cases demonstrating retrieved Sendax mini-dental implants in two different patients is the focus of this report. The mini-dental implants were inserted using the auto-advance technique and loaded immediately. The implants were retrieved at 4 months following insertion and at 5 months following insertion and were prepared and reviewed histologically. Clinically, the implants had no mobility, with no apparent exudate or bleeding upon probing, prior to removal. At the time explant procedures were performed, the mini-dental implants had provided immediate support for prostheses during the integration of traditional root-form endosteal implants. Upon explantation, the mini-dental implants were in a state of health and functioning in their intended purpose. Histologically, the bone appeared to be integrated to the surface of the implant at the light microscope level, and the bone appeared to be relatively mature and healthy in the areas observed, more so than one would expect in this amount of time from insertion of mini-dental implants with immediate loading. A discussion of the purposes and technique used for insertion and removal of these mini-dental implants is discussed. This is the first human histological report on the auto-advance technique with immediate loading of mini-dental implants, demonstrating feasibility in ongoing applications.

  15. Advanced MRI techniques to improve our understanding of experience-induced neuroplasticity.

    PubMed

    Tardif, Christine Lucas; Gauthier, Claudine Joëlle; Steele, Christopher John; Bazin, Pierre-Louis; Schäfer, Andreas; Schaefer, Alexander; Turner, Robert; Villringer, Arno

    2016-05-01

    Over the last two decades, numerous human MRI studies of neuroplasticity have shown compelling evidence for extensive and rapid experience-induced brain plasticity in vivo. To date, most of these studies have consisted of simply detecting a difference in structural or functional images with little concern for their lack of biological specificity. Recent reviews and public debates have stressed the need for advanced imaging techniques to gain a better understanding of the nature of these differences - characterizing their extent in time and space, their underlying biological and network dynamics. The purpose of this article is to give an overview of advanced imaging techniques for an audience of cognitive neuroscientists that can assist them in the design and interpretation of future MRI studies of neuroplasticity. The review encompasses MRI methods that probe the morphology, microstructure, function, and connectivity of the brain with improved specificity. We underline the possible physiological underpinnings of these techniques and their recent applications within the framework of learning- and experience-induced plasticity in healthy adults. Finally, we discuss the advantages of a multi-modal approach to gain a more nuanced and comprehensive description of the process of learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 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.

  17. Comprehensive analysis of TEM methods for LiFePO4/FePO4 phase mapping: spectroscopic techniques (EFTEM, STEM-EELS) and STEM diffraction techniques (ACOM-TEM).

    PubMed

    Mu, X; Kobler, A; Wang, D; Chakravadhanula, V S K; Schlabach, S; Szabó, D V; Norby, P; Kübel, C

    2016-11-01

    Transmission electron microscopy (TEM) has been used intensively in investigating battery materials, e.g. to obtain phase maps of partially (dis)charged (lithium) iron phosphate (LFP/FP), which is one of the most promising cathode material for next generation lithium ion (Li-ion) batteries. Due to the weak interaction between Li atoms and fast electrons, mapping of the Li distribution is not straightforward. In this work, we revisited the issue of TEM measurements of Li distribution maps for LFP/FP. Different TEM techniques, including spectroscopic techniques (energy filtered (EF)TEM in the energy range from low-loss to core-loss) and a STEM diffraction technique (automated crystal orientation mapping (ACOM)), were applied to map the lithiation of the same location in the same sample. This enabled a direct comparison of the results. The maps obtained by all methods showed excellent agreement with each other. Because of the strong difference in the imaging mechanisms, it proves the reliability of both the spectroscopic and STEM diffraction phase mapping. A comprehensive comparison of all methods is given in terms of information content, dose level, acquisition time and signal quality. The latter three are crucial for the design of in-situ experiments with beam sensitive Li-ion battery materials. Furthermore, we demonstrated the power of STEM diffraction (ACOM-STEM) providing additional crystallographic information, which can be analyzed to gain a deeper understanding of the LFP/FP interface properties such as statistical information on phase boundary orientation and misorientation between domains.

  18. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Obland, M. D.; Ismail, S.; Meadows, B.; Browell, E. V.

    2014-12-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper.

  19. Advanced techniques and technology for efficient data storage, access, and transfer

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Miller, Warner

    1991-01-01

    Advanced techniques for efficiently representing most forms of data are being implemented in practical hardware and software form through the joint efforts of three NASA centers. These techniques adapt to local statistical variations to continually provide near optimum code efficiency when representing data without error. Demonstrated in several earlier space applications, these techniques are the basis of initial NASA data compression standards specifications. Since the techniques clearly apply to most NASA science data, NASA invested in the development of both hardware and software implementations for general use. This investment includes high-speed single-chip very large scale integration (VLSI) coding and decoding modules as well as machine-transferrable software routines. The hardware chips were tested in the laboratory at data rates as high as 700 Mbits/s. A coding module's definition includes a predictive preprocessing stage and a powerful adaptive coding stage. The function of the preprocessor is to optimally process incoming data into a standard form data source that the second stage can handle.The built-in preprocessor of the VLSI coder chips is ideal for high-speed sampled data applications such as imaging and high-quality audio, but additionally, the second stage adaptive coder can be used separately with any source that can be externally preprocessed into the 'standard form'. This generic functionality assures that the applicability of these techniques and their recent high-speed implementations should be equally broad outside of NASA.

  20. Extrusion based rapid prototyping technique: an advanced platform for tissue engineering scaffold fabrication.

    PubMed

    Hoque, M Enamul; Chuan, Y Leng; Pashby, Ian

    2012-02-01

    Advances in scaffold design and fabrication technology have brought the tissue engineering field stepping into a new era. Conventional techniques used to develop scaffolds inherit limitations, such as lack of control over the pore morphology and architecture as well as reproducibility. Rapid prototyping (RP) technology, a layer-by-layer additive approach offers a unique opportunity to build complex 3D architectures overcoming those limitations that could ultimately be tailored to cater for patient-specific applications. Using RP methods, researchers have been able to customize scaffolds to mimic the biomechanical properties (in terms of structural integrity, strength, and microenvironment) of the organ or tissue to be repaired/replaced quite closely. This article provides intensive description on various extrusion based scaffold fabrication techniques and review their potential utility for TE applications. The extrusion-based technique extrudes the molten polymer as a thin filament through a nozzle onto a platform layer-by-layer and thus building 3D scaffold. The technique allows full control over pore architecture and dimension in the x- and y- planes. However, the pore height in z-direction is predetermined by the extruding nozzle diameter rather than the technique itself. This review attempts to assess the current state and future prospects of this technology.

  1. On-line preferential solvation studies of polymers by coupled chromatographic-Fourier transform infrared spectroscopic flow-cell technique.

    PubMed

    Malanin, M; Eichhorn, K-J; Lederer, A; Treppe, P; Adam, G; Fischer, D; Voigt, D

    2009-12-18

    Qualitative and quantitative comparison between liquid chromatography (LC) and LC coupled with Fourier transform infrared spectroscopy (LC-FTIR) to evaluate preferential solvation phenomenon of polymers in a mixed solvent has been performed. These studies show that LC-FTIR technique leads to detailed structural information without the requirement for determination of additional parameters for quantitative analysis except calibration. Appropriate experimental conditions for preferential solvation study have been established by variation of polymer concentration, molar mass and eluent content.

  2. One-step Multiple Component Isolation from the Oil of Crinitaria tatarica (Less.) Sojak by Preparative Capillary Gas Chromatography with Characterization by Spectroscopic and Spectrometric Techniques and Evaluation of Biological Activity

    DTIC Science & Technology

    2012-01-01

    20] Adams, R. P., Identification of Essential Oil Components by Gas Chromatography /Mass Spectrometry, Allured Publishing Corporation, Carol Stream... chromatography with characterization by spectroscopic and spectrometric techniques and evaluation of biological activity Gas chromatographic analysis revealed...step multiple fractionation of the oil and separation of two unknown constituents were performed using preparative capillary gas chromatography

  3. Development of a low resolution (1)H NMR spectroscopic technique for the study of matrix mobility in fresh and freeze-thawed hen egg yolk.

    PubMed

    Au, Carmen; Wang, Tong; Acevedo, Nuria C

    2016-08-01

    Three experiments were conducted in developing a low resolution proton nuclear magnetic resonance ((1)H NMR) spectroscopic technique to study matrix mobility in fresh and freeze-thawed gelled yolk. The Carr-Purcell-Meiboom-Gill (CPMG) sequence was used to measure spin-spin relaxation times of proton pools representing major yolk constituents. A component identification test distinguished 3-4 pools. The least mobile pool was assigned to proteins, protein-lipid and protein-water interactions, and the most mobile to unbound water. The remaining pools were assigned to lipids, lipid-protein and lipid-water interactions. A stability test indicated that yolk had varied matrix mobility within the same sample across five days of refrigeration storage. A reproducibility test demonstrated high repeatability of fresh yolk measurements, but significant differences (p<0.05) were found within gelled yolk samples. This research determined that (1)H NMR spectroscopy, a non-destructive technique, can identify yolk components and detect changes in the matrix. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Evaluation of structure-reactivity descriptors and biological activity spectra of 4-(6-methoxy-2-naphthyl)-2-butanone using spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Agrawal, Megha; Deval, Vipin; Gupta, Archana; Sangala, Bagvanth Reddy; Prabhu, S. S.

    2016-10-01

    The structure and several spectroscopic features along with reactivity parameters of the compound 4-(6-methoxy-2-naphthyl)-2-butanone (Nabumetone) have been studied using experimental techniques and tools derived from quantum chemical calculations. Structure optimization is followed by force field calculations based on density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory. The vibrational spectra have been interpreted with the aid of normal coordinate analysis. UV-visible spectrum and the effect of solvent have been discussed. The electronic properties such as HOMO and LUMO energies have been determined by TD-DFT approach. In order to understand various aspects of pharmacological sciences several new chemical reactivity descriptors - chemical potential, global hardness and electrophilicity have been evaluated. Local reactivity descriptors - Fukui functions and local softnesses have also been calculated to find out the reactive sites within molecule. Aqueous solubility and lipophilicity have been calculated which are crucial for estimating transport properties of organic molecules in drug development. Estimation of biological effects, toxic/side effects has been made on the basis of prediction of activity spectra for substances (PASS) prediction results and their analysis by Pharma Expert software. Using the THz-TDS technique, the frequency-dependent absorptions of NBM have been measured in the frequency range up to 3 THz.

  5. Reliable Welding of HSLA Steels by Square Wave Pulsing Using an Advanced Sensing (EDAP) Technique.

    DTIC Science & Technology

    1986-04-30

    situation is the result of welding on A710 steel . (A similar effect on welding on HY80 ?) The following is offered by Woods and Milner (Ref. 12): "The...AD-R69 762 RELIABLE MELDING OF HSLA STEELS BY SQUARE MAVE PULSING 1/2 USING AN ADV NCED.. (U) APPLIED FUSION TECHNOLOGIES INC FORT COLLINS CO C...6 p . 0 Report 0001 AZ AD-A 168 762 I "RELIABLE WELDING OF HSLA STEELS BY SQUARE WAVE PULSING USING AN ADVANCED SENSING (EDAP) TECHNIQUE- Preliminary

  6. Techniques for measurement of the thermal expansion of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Tompkins, Stephen S.

    1989-01-01

    Techniques available to measure small thermal displacements in flat laminates and structural tubular elements of advanced composite materials are described. Emphasis is placed on laser interferometry and the laser interferometric dilatometer system used at the National Aeronautics and Space Administration (NASA) Langley Research Center. Thermal expansion data are presented for graphite-fiber reinforced 6061 and 2024 aluminum laminates and for graphite fiber reinforced AZ91 C and QH21 A magnesium laminates before and after processing to minimize or eliminate thermal strain hysteresis. Data are also presented on the effects of reinforcement volume content on thermal expansion of silicon-carbide whisker and particulate reinforced aluminum.

  7. Measuring the microbiome: perspectives on advances in DNA-based techniques for exploring microbial life

    PubMed Central

    Bunge, John; Gilbert, Jack A.; Moore, Jason H.

    2012-01-01

    This article reviews recent advances in ‘microbiome studies’: molecular, statistical and graphical techniques to explore and quantify how microbial organisms affect our environments and ourselves given recent increases in sequencing technology. Microbiome studies are moving beyond mere inventories of specific ecosystems to quantifications of community diversity and descriptions of their ecological function. We review the last 24 months of progress in this sort of research, and anticipate where the next 2 years will take us. We hope that bioinformaticians will find this a helpful springboard for new collaborations with microbiologists. PMID:22308073

  8. Advanced techniques in IR thermography as a tool for the pest management professional

    NASA Astrophysics Data System (ADS)

    Grossman, Jon L.

    2006-04-01

    Within the past five years, the Pest Management industry has become aware that IR thermography can aid in the detection of pest infestations and locate other conditions that are within the purview of the industry. This paper will review the applications that can be utilized by the pest management professional and discuss the advanced techniques that may be required in conjunction with thermal imaging to locate insect and other pest infestations, moisture within structures, the verification of data and the special challenges associated with the inspection process.

  9. Techniques for measurement of the thermal expansion of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Tompkins, Stephen S.

    1989-01-01

    Techniques available to measure small thermal displacements in flat laminates and structural tubular elements of advanced composite materials are described. Emphasis is placed on laser interferometry and the laser interferometric dilatometer system used at the National Aeronautics and Space Administration (NASA) Langley Research Center. Thermal expansion data are presented for graphite-fiber reinforced 6061 and 2024 aluminum laminates and for graphite fiber reinforced AZ91 C and QH21 A magnesium laminates before and after processing to minimize or eliminate thermal strain hysteresis. Data are also presented on the effects of reinforcement volume content on thermal expansion of silicon-carbide whisker and particulate reinforced aluminum.

  10. Defining Prolonged Dwell Time: When Are Advanced Inferior Vena Cava Filter Retrieval Techniques Necessary? An Analysis in 762 Procedures.

    PubMed

    Desai, Kush R; Laws, James L; Salem, Riad; Mouli, Samdeep K; Errea, Martin F; Karp, Jennifer K; Yang, Yihe; Ryu, Robert K; Lewandowski, Robert J

    2017-06-01

    Despite growth in placement of retrievable inferior vena cava filters, retrieval rates remain low. Filters with extended implantation times present a challenge to retrieval, where standard techniques often fail. The development of advanced retrieval techniques has positively impacted retrieval of retrievable inferior vena cava filters with prolonged dwell times; however, there is no precise definition of the time point when advanced techniques become necessary. We aim to define prolonged retrievable inferior vena cava filters dwell time by determining the inflection point when the risk of standard retrieval technique failure increases significantly, necessitating advanced retrieval techniques to maintain overall technical success of retrieval. From January 2009 to April 2015, 762 retrieval procedures were identified from a prospectively acquired database. We assessed patient age/sex, filter dwell time, procedural technical success, the use of advanced techniques, and procedure-related adverse events. Overall retrieval success rate was 98% (n=745). When standard retrieval techniques failed, advanced techniques were used; this was necessary 18% of the time (n=138). Logistic regression identified that dwell time was the only risk factor for failure of standard retrieval technique (odds ratio, 1.08; 95% confidence interval, 1.05-1.10; P<0.001). Spline function regression analysis demonstrated that if dwell time exceeded 7 months, the risk of standard technique failure was 40.9%. Adverse events occurred at a rate of 2% (n=18; 15 minor and 3 major). The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time. Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval. © 2017 American Heart Association, Inc.

  11. Advancing IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements from Space

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Chen, S.; Obland, M. D.

    2013-12-01

    Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) decadal survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, time shifted PN, sine wave modulated PN, and sine wave pulsed PN. Different PN code techniques are presented that are appropriate for different types of lidar hardware, including our current ASCENDS IM-CW concept space hardware. These techniques have excellent auto-correlation properties without sidelobes while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space.

  12. Arthroscopically assisted Sauvé-Kapandji procedure: an advanced technique for distal radioulnar joint arthritis.

    PubMed

    Luchetti, Riccardo; Khanchandani, Prakash; Da Rin, Ferdinando; Borelli, Pierpaolo P; Mathoulin, Christophe; Atzei, Andrea

    2008-12-01

    Osteoarthritis of distal radioulnar joint (DRUJ) leads to chronic wrist pain, weakness of grip strength, and limitation of motion, all of which affect the quality of life of the patient. Over the years, several procedures have been used for the treatment of this condition; however, this condition still remains a therapeutic challenge for the hand surgeons. Many procedures such as Darrach procedure, Bower procedure, Sauvé-Kapandji procedure, and ulnar head replacement have been used. Despite many advances in wrist arthroscopy, arthroscopy has not been used for the treatment of arthritis of the DRUJ. We describe a novel technique of arthroscopically assisted Sauvé-Kapandji procedure for the arthritis of the DRUJ. The advantages of this technique are its less invasive nature, preservation of the extensor retinaculum, more anatomical position of the DRUJ, faster rehabilitation, and a better cosmesis.

  13. The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques.

    PubMed

    Li, Tie-Qiang; Wahlund, Lars-Olof

    2011-03-01

    The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel-based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS).

  14. Benign Spine Lesions: Advances in Techniques for Minimally Invasive Percutaneous Treatment.

    PubMed

    Tomasian, A; Wallace, A N; Jennings, J W

    2017-02-09

    Minimally invasive percutaneous imaging-guided techniques have been shown to be safe and effective for the treatment of benign tumors of the spine. Techniques available include a variety of tumor ablation technologies, including radiofrequency ablation, cryoablation, microwave ablation, alcohol ablation, and laser photocoagulation. Vertebral augmentation may be performed after ablation as part of the same procedure for fracture stabilization or prevention. Typically, the treatment goal in benign spine lesions is definitive cure. Painful benign spine lesions commonly encountered in daily practice include osteoid osteoma, osteoblastoma, vertebral hemangioma, aneurysmal bone cyst, Paget disease, and subacute/chronic Schmorl node. This review discusses the most recent advancement and use of minimally invasive percutaneous therapeutic options for the management of benign spine lesions.

  15. Clinical applications of advanced magnetic resonance imaging techniques for arthritis evaluation

    PubMed Central

    Martín Noguerol, Teodoro; Luna, Antonio; Gómez Cabrera, Marta; Riofrio, Alexie D

    2017-01-01

    Magnetic resonance imaging (MRI) has allowed a comprehensive evaluation of articular disease, increasing the detection of early cartilage involvement, bone erosions, and edema in soft tissue and bone marrow compared to other imaging techniques. In the era of functional imaging, new advanced MRI sequences are being successfully applied for articular evaluation in cases of inflammatory, infectious, and degenerative arthropathies. Diffusion weighted imaging, new fat suppression techniques such as DIXON, dynamic contrast enhanced-MRI, and specific T2 mapping cartilage sequences allow a better understanding of the physiopathological processes that underlie these different arthropathies. They provide valuable quantitative information that aids in their differentiation and can be used as potential biomarkers of articular disease course and treatment response. PMID:28979849

  16. The role of alternative (advanced) conscious sedation techniques in dentistry for adult patients: a series of cases.

    PubMed

    Robb, N

    2014-03-01

    The basic techniques of conscious sedation have been found to be safe and effective for the management of anxiety in adult dental patients requiring sedation to allow them to undergo dental treatment. There remains great debate within the profession as to the role of the so called advanced sedation techniques. This paper presents a series of nine patients who were managed with advanced sedation techniques where the basic techniques were either inappropriate or had previously failed to provide adequate relief of anxiety. In these cases, had there not been the availability of advanced sedation techniques, the most likely recourse would have been general anaesthesia--a treatment modality that current guidance indicates should not be used where there is an appropriate alternative. The sedation techniques used have provided that appropriate alternative management strategy.

  17. In vivo optical analysis of pancreatic cancer tissue in living model mice using fluorescence and Raman spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshiaki; Hattori, Yusuke; Katagiri, Takashi; Mitsuoka, Hiroki; Sato, Ken-ichi; Asakura, Toru; Shimosegawa, Toru; Sato, Hidetoshi

    2009-02-01

    Living pancreatic cancer tissues grown subcutaneously in nude mice are studied by in vivo Raman spectroscopy and autofluorescence imaging. Comparing the same point spectra of alive pancreatic cancer tissue to that of the dead tissue, it is found that they are different each other. The results suggest that the spectral changes reflect the protein conformational changes in the tumor tissue with death of the host animal. From the result of autofluorescence study, in vivo autofluorescence imaging has potential as a method to assign the histological elements of the pancreatic cancer tissue without any staining. These results strongly suggest that combination of these techniques is very important to study biological tissue.

  18. Determining the mode of interaction of calf thymus DNA with the drug sumatriptan using voltammetric and spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Moghadam, Neda Hosseinpour

    2012-12-01

    The interaction of native calf thymus DNA with sumatriptan(1-[3-(2-dimethylaminoethyl)-1H-indol-5-yl]-N-methyl-methanesulfonamide) at physiological pH was studied by spectrophotometry, circular dichroism, voltammetry and viscosimetric techniques. Sumatriptan molecule intercalated between base pairs of DNA, showed by a sharp increase in specific viscosity of DNA. In cyclic voltammetry, decrease of the peak current and positive shift indicated that this drug is able to intercalate between the DNA base pairs. In addition, the drug induced changes in the CD spectrum of CT-DNA, as well as hypochromism changes in its UV-vis spectrum.

  19. Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches

    SciTech Connect

    Xiang, Dao; /SLAC

    2012-06-05

    Ultrashort electron bunches with rms length of {approx} 1 femtosecond (fs) can be used to generate ultrashort x-ray pulses in FELs that may open up many new regimes in ultrafast sciences. It is also envisioned that ultrashort electron bunches may excite {approx}TeV/m wake fields for plasma wake field acceleration and high field physics studies. Recent success of using 20 pC electron beam to drive an x-ray FEL at LCLS has stimulated world-wide interests in using low charge beam (1 {approx} 20 pC) to generate ultrashort x-ray pulses (0.1 fs {approx} 10 fs) in FELs. Accurate measurement of the length (preferably the temporal profile) of the ultrashort electron bunch is essential for understanding the physics associated with the bunch compression and transportation. However, the shorter and shorter electron bunch greatly challenges the present beam diagnostic methods. In this paper we review the recent advances in the measurement of ultra-short electron bunches. We will focus on several techniques and their variants that provide the state-of-the-art temporal resolution. Methods to further improve the resolution of these techniques and the promise to break the 1 fs time barrier is discussed. We review recent advances in the measurement of ultrashort relativistic electron bunches. We will focus on several techniques and their variants that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. Techniques for measuring beam longitudinal phase space as well as the x-ray pulse shape in an x-ray FEL are also discussed.

  20. Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques

    SciTech Connect

    Gerald J. Keeler; Masako Morishita

    2006-12-31

    The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed that the contributions of local combustion sources - including coal fired utilities - to ultrafine particle levels were significant. Although this combination of advanced electron microscopy techniques by itself can not identify source categories, these techniques can be utilized as complementary analytical tools that are capable of providing detailed information on individual particles.

  1. Luminescence and advanced mass spectroscopic characterization of sodium zinc orthophosphate phosphor for low-cost light-emitting diodes.

    PubMed

    Mishra, Savvi; Swati, G; Rajesh, B; Tyagi, Kriti; Gahtori, Bhasker; Sivaiah, B; Vijayan, N; Dalai, M K; Dhar, A; Auluck, S; Jayasimhadri, M; Haranath, D

    2016-03-01

    A new rare-earth-free NaZnPO4:Mn(2+) (NZP:Mn) phosphor powder has been developed by our group and investigated meticulously for the first time using secondary ion mass spectroscopy and chemical imaging techniques. The studies confirmed the effective incorporation of Mn(2+) into the host lattice, resulting in an enhancement of photoluminescence intensity. Phase purity has been verified and structure parameters have been determined successfully by Rietveld refinement studies. The NZP:Mn phosphor powder exhibits strong absorption bands in the ultraviolet and visible (300-470 nm) regions with a significant broad yellow-green (~543 nm) emission due to the characteristic spin forbidden d-d transition ((4)T1→(6)A1) of Mn(2+) ions, indicating weak crystal field strength at the zinc-replaced manganese site. The decay constants are a few milliseconds, which is a pre-requisite for applications in many display devices. The results obtained suggest that this new phosphor powder will find many interesting applications in semiconductor physics, as cost-effective light-emitting diodes (LEDs), as solar cells and in photo-physics. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Assessment of improved organ at risk sparing for advanced cervix carcinoma utilizing precision radiotherapy techniques.

    PubMed

    Georg, Dietmar; Georg, Petra; Hillbrand, Martin; Pötter, Richard; Mock, Ulrike

    2008-11-01

    To evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer. In five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and proton therapy (IMPT) as well as proton beam therapy (PT) based on passive scattering. Planning target volumes (PTVs) included primary tumor and pelvic and para-aortic lymph nodes. Dose-volume histograms (DVHs) were analyzed for the PTV and various organs at risk (OARs) (rectal wall, bladder, small bowel, colon, femoral heads, and kidneys). In addition dose conformity, dose inhomogeneity and overall volumes of 50% isodoses were assessed. All plans were comparable concerning PTV parameters. Large differences between photon and proton techniques were seen in volumes of the 50% isodoses and conformity indices. DVH for colon and small bowel were significantly improved with PT and IMPT compared to IMXT, with D(mean) reductions of 50-80%. Doses to kidneys and femoral heads could also be substantially reduced with PT and IMPT. Sparing of rectum and bladder was superior with protons as well but less pronounced. Proton beam RT has significant potential to improve treatment related side effects in the bowel compared to photon beam RT in patients with advanced cervix carcinoma.

  3. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques.

    PubMed

    Dirk, Brennan S; Van Nynatten, Logan R; Dikeakos, Jimmy D

    2016-10-19

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell-cell transmission and cell-free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle.

  4. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    PubMed Central

    Dirk, Brennan S.; Van Nynatten, Logan R.; Dikeakos, Jimmy D.

    2016-01-01

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle. PMID:27775563

  5. Evaluating the abnormal ossification in tibiotarsi of developing chick embryos exposed to 1.0ppm doses of platinum group metals by spectroscopic techniques.

    PubMed

    Stahler, Adam C; Monahan, Jennifer L; Dagher, Jessica M; Baker, Joshua D; Markopoulos, Marjorie M; Iragena, Diane B; NeJame, Britney M; Slaughter, Robert; Felker, Daniel; Burggraf, Larry W; Isaac, Leon A C; Grossie, David; Gagnon, Zofia E; Sizemore, Ioana E Pavel

    2013-04-01

    Platinum group metals (PGMs), i.e., palladium (Pd), platinum (Pt) and rhodium (Rh), are found at pollutant levels in the environment and are known to accumulate in plant and animal tissues. However, little is known about PGM toxicity. Our previous studies showed that chick embryos exposed to PGM concentrations of 1mL of 5.0ppm (LD50) and higher exhibited severe skeletal deformities. This work hypothesized that 1.0ppm doses of PGMs will negatively impact the mineralization process in tibiotarsi. One milliliter of 1.0ppm of Pd(II), Pt(IV), Rh(III) aqueous salt solutions and a PGM-mixture were injected into the air sac on the 7th and 14th day of incubation. Control groups with no-injection and vehicle injections were included. On the 20th day, embryos were sacrificed to analyze the PGM effects on tibiotarsi using four spectroscopic techniques. 1) Micro-Raman imaging: Hyperspectral Raman data were collected on paraffin embedded cross-sections of tibiotarsi, and processed using in-house-written MATLAB codes. Micro-Raman univariate images that were created from the ν1(PO4(3-)) integrated areas revealed anomalous mineral inclusions within the bone marrow for the PGM-mixture treatment. The age of the mineral crystals (ν(CO3(2-))/ν1(PO4(3-))) was statistically lower for all treatments when compared to controls (p≤0.05). 2) FAAS: The percent calcium content of the chemically digested tibiotarsi in the Pd and Pt groups changed by ~45% with respect to the no-injection control (16.1±0.2%). 3) Micro-XRF imaging: Abnormal calcium and phosphorus inclusions were found within the inner longitudinal sections of tibiotarsi for the PGM-mixture treatment. A clear increase in the mineral content was observed for the outer sections of the Pd treatment. 4) ICP-OES: PGM concentrations in tibiotarsi were undetectable (<5ppb). The spectroscopic techniques gave corroborating results, confirmed the hypothesis, and explained the observed pathological (skeletal developmental abnormalities

  6. Applications of Advanced, Waveform Based AE Techniques for Testing Composite Materials

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1996-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been previously used to evaluate damage progression in laboratory tests of composite coupons. In these tests, broad band, high fidelity acoustic sensors were used to detect signals which were then digitized and stored for analysis. Analysis techniques were based on plate mode wave propagation characteristics. This approach, more recently referred to as Modal AE, provides an enhanced capability to discriminate and eliminate noise signals from those generated by damage mechanisms. This technique also allows much more precise source location than conventional, threshold crossing arrival time determination techniques. To apply Modal AE concepts to the interpretation of AE on larger composite structures, the effects of wave propagation over larger distances and through structural complexities must be well characterized and understood. In this research, measurements were made of the attenuation of the extensional and flexural plate mode components of broad band simulated AE signals in large composite panels. As these materials have applications in a cryogenic environment, the effects of cryogenic insulation on the attenuation of plate mode AE signals were also documented.

  7. Advanced techniques for array processing. Final report, 1 Mar 89-30 Apr 91

    SciTech Connect

    Friedlander, B.

    1991-05-30

    Array processing technology is expected to be a key element in communication systems designed for the crowded and hostile environment of the future battlefield. While advanced array processing techniques have been under development for some time, their practical use has been very limited. This project addressed some of the issues which need to be resolved for a successful transition of these promising techniques from theory into practice. The main problem which was studied was that of finding the directions of multiple co-channel transmitters from measurements collected by an antenna array. Two key issues related to high-resolution direction finding were addressed: effects of system calibration errors, and effects of correlation between the received signals due to multipath propagation. A number of useful theoretical performance analysis results were derived, and computationally efficient direction estimation algorithms were developed. These results include: self-calibration techniques for antenna arrays, sensitivity analysis for high-resolution direction finding, extensions of the root-MUSIC algorithm to arbitrary arrays and to arrays with polarization diversity, and new techniques for direction finding in the presence of multipath based on array interpolation. (Author)

  8. Advanced condition monitoring techniques and plant life extension studies at EBR-2

    SciTech Connect

    Singer, R.M.; Gross, K.C. ); Perry, W.H.; King, R.W. )

    1991-01-01

    Numerous advanced techniques have been evaluated and tested at EBR-2 as part of a plant-life extension program for detection of degradation and other abnormalities in plant systems. Two techniques have been determined to be of considerable assistance in planning for the extended-life operation of EBR-2. The first, a computer-based pattern-recognition system (System State Analyzer or SSA) is used for surveillance of the primary system instrumentation, primary sodium pumps and plant heat balances. This surveillance has indicated that the SSA can detect instrumentation degradation and system performance degradation over varying time intervals and can be used to provide derived signal values to replace signals from failed sensors. The second technique, also a computer-based pattern-recognition system (Sequential Probability Ratio Test or SPRT) is used to validate signals and to detect incipient failures in sensors and components or systems. It is being used on the failed fuel detection system and is experimentally used on the primary coolant pumps. Both techniques are described and experience with their operation presented.

  9. Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research.

    PubMed

    Lewis, Jennifer R; Kotur, Mark S; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A; Ferrell, Nick; Sullivan, Kathryn D; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.

  10. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    PubMed Central

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors. PMID:12587031

  11. Advancement of an Infra-Red Technique for Whole-Field Concentration Measurements in Fluidized Beds

    PubMed Central

    Medrano, Jose A.; de Nooijer, Niek C. A.; Gallucci, Fausto; van Sint Annaland, Martin

    2016-01-01

    For a better understanding and description of the mass transport phenomena in dense multiphase gas-solids systems such as fluidized bed reactors, detailed and quantitative experimental data on the concentration profiles is required, which demands advanced non-invasive concentration monitoring techniques with a high spatial and temporal resolution. A novel technique based on the selective detection of a gas component in a gas mixture using infra-red properties has been further developed. The first stage development was carried out using a very small sapphire reactor and CO2 as tracer gas. Although the measuring principle was demonstrated, the real application was hindered by the small reactor dimensions related to the high costs and difficult handling of large sapphire plates. In this study, a new system has been developed, that allows working at much larger scales and yet with higher resolution. In the new system, propane is used as tracer gas and quartz as reactor material. In this study, a thorough optimization and calibration of the technique is presented which is subsequently applied for whole-field measurements with high temporal resolution. The developed technique allows the use of a relatively inexpensive configuration for the measurement of detailed concentration fields and can be applied to a large variety of important chemical engineering topics. PMID:26927127

  12. Observational and laboratory studies of optical properties of black and brown carbon particles in the atmosphere using spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomoki; Matsumi, Yutaka

    2015-04-01

    Light absorption and scattering by aerosols are as an important contributor to radiation balance in the atmosphere. Black carbon (BC) is considered to be the most potent light absorbing material in the visible region of the spectrum, although light absorbing organic carbon (brown carbon or BrC) and mineral dust may also act as sources of significant absorption, especially in the ultraviolet (UV) and shorter visible wavelength regions. The optical properties of such particles depend on wavelength, particle size and shape, morphology, coating, and complex refractive index (or chemical composition), and therefore accurate in situ measurements of the wavelength dependence of the optical properties of particles are needed. Recently, cavity ring-down spectroscopy (CRDS) and photoacoustic spectroscopy (PAS) have been used for the direct measurements of extinction and absorption coefficients of particles suspended in air. We have applied these techniques to the observational studies of optical properties of BC and BrC in an urban site in Japan and to the laboratory studies of optical properties of secondary organic aerosols (SOAs) generated from a variety of biogenic and anthropogenic volatile organic compounds and those of diesel exhaust particles (DEPs). In the presentation, the basic principles of these techniques and the results obtained in our studies and in the recent literatures will be overviewed. References Guo, X. et al., Measurement of the light absorbing properties of diesel exhaust particles using a three-wavelength photoacoustic spectrometer, Atmos. Environ., 94, 428-437 (2014). Nakayama, T. et al., Measurements of aerosol optical properties in central Tokyo during summertime using cavity ring-down spectroscopy: Comparison with conventional techniques, Atmos. Environ., 44, 3034-3042 (2010). Nakayama, T. et al., Laboratory studies on optical properties of secondary organic aerosols generated during the photooxidation of toluene and the ozonolysis of alpha

  13. Advanced microscopy techniques to assess solid-state properties of inhalation medicines.

    PubMed

    Shur, Jagdeep; Price, Robert

    2012-03-30

    Efficient control and characterisation of the physico-chemical properties of active pharmaceutical ingredients (APIs) and excipients for orally inhaled drug products (OIDPs) are critical to successful product development. Control and reduction of risk require the introduction of a material science based approach to product development and the use of advanced analytical tools in understanding how the solid-state properties of the input materials influence structure and product functionality. The key issues to be addressed, at a microscopic scale, are understanding how the critical quality attributes of input materials influence surface, interfacial and particulate interactions within OIDPs. This review offers an in-depth discussion on the use of advanced microscopy techniques in characterising of the solid-state properties of particulate materials for OIDPs. The review covers the fundamental principles of the techniques, instrumentation types, data interpretation and specific applications in relation to the product development of OIDPs. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  14. Advanced grazing-incidence techniques for modern soft-matter materials analysis.

    PubMed

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities for in situ and in operando GISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.

  15. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    PubMed Central

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities for in situ and in operando GISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed. PMID:25610632

  16. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder

    PubMed Central

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A.; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C.; Tenembaum, Silvia N.; Banwell, Brenda; Greenberg, Benjamin M.; Bennett, Jeffrey L.; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T.

    2016-01-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease. PMID:26010909

  17. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder.

    PubMed

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C; Tenembaum, Silvia N; Banwell, Brenda; Greenberg, Benjamin M; Bennett, Jeffrey L; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T; Cabre, Philippe; Marignier, Romain; Tedder, Thomas; van Pelt, Danielle; Broadley, Simon; Chitnis, Tanuja; Wingerchuk, Dean; Pandit, Lekha; Leite, Maria Isabel; Apiwattanakul, Metha; Kleiter, Ingo; Prayoonwiwat, Naraporn; Han, May; Hellwig, Kerstin; van Herle, Katja; John, Gareth; Hooper, D Craig; Nakashima, Ichiro; Sato, Douglas; Yeaman, Michael R; Waubant, Emmanuelle; Zamvil, Scott; Stüve, Olaf; Aktas, Orhan; Smith, Terry J; Jacob, Anu; O'Connor, Kevin

    2015-07-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease.

  18. Retrievable IVC Filters: Comprehensive Review of Device-related Complications and Advanced Retrieval Techniques.

    PubMed

    Desai, Kush R; Pandhi, Mithil B; Seedial, Stephen M; Errea, Martin F; Salem, Riad; Ryu, Robert K; Lewandowski, Robert J

    2017-01-01

    Use of retrievable inferior vena cava filters (RIVCFs) has grown exponentially since their introduction into clinical practice, but many of these devices are not retrieved. Some are not retrieved due to poor clinical follow-up, but other devices remain in situ for extended periods because they present significant technical challenges during retrieval. Because of these and other factors, many of these devices were thus left in place permanently. However, recent data have placed a renewed emphasis on device retrieval due to increased risk of RIVCF-related complications, which are positively correlated with filter dwell time. Development of advanced filter retrieval techniques has had a significant impact on the removal of embedded RIVCFs, permitting retrieval of the majority of devices. The purpose of this article is to present an imaging and data review of the dominant device-related factors that complicate RIVCF retrieval and to describe the relevant advanced retrieval techniques to manage these factors. RIVCF imaging is frequently encountered in daily clinical practice via various imaging modalities. Therefore, diagnostic radiologists can play a vital role in identifying filter-related issues. Familiarity with the context for managing these issues in the interventional suite is essential for improving triage and care of patients with RIVCFs. (©) RSNA, 2017.

  19. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    DOE PAGES

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities forin situandin operandoGISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in themore » soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.« less

  20. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    SciTech Connect

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities forin situandin operandoGISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.

  1. Advanced MRI Techniques in the Evaluation of Complex Cystic Breast Lesions

    PubMed Central

    Popli, Manju Bala; Gupta, Pranav; Arse, Devraj; Kumar, Pawan; Kaur, Prabhjot

    2016-01-01

    OBJECTIVE The purpose of this research work was to evaluate complex cystic breast lesions by advanced MRI techniques and correlating imaging with histologic findings. METHODS AND MATERIALS In a cross-sectional design from September 2013 to August 2015, 50 patients having sonographically detected complex cystic lesions of the breast were included in the study. Morphological characteristics were assessed. Dynamic contrast-enhanced MRI along with diffusion-weighted imaging and MR spectroscopy were used to further classify lesions into benign and malignant categories. All the findings were correlated with histopathology. RESULTS Of the 50 complex cystic lesions, 32 proved to be benign and 18 were malignant on histopathology. MRI features of heterogeneous enhancement on CE-MRI (13/18), Type III kinetic curve (13/18), reduced apparent diffusion coefficient (18/18), and tall choline peak (17/18) were strong predictors of malignancy. Thirteen of the 18 lesions showed a combination of Type III curve, reduced apparent diffusion coefficient value, and tall choline peak. CONCLUSIONS Advanced MRI techniques like dynamic imaging, diffusion-weighted sequences, and MR spectroscopy provide a high level of diagnostic confidence in the characterization of complex cystic breast lesion, thus allowing early diagnosis and significantly reducing patient morbidity and mortality. From our study, lesions showing heterogeneous contrast enhancement, Type III kinetic curve, diffusion restriction, and tall choline peak were significantly associated with malignant complex cystic lesions of the breast. PMID:27330299

  2. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Obland, M. D.; Liu, Z.; Browell, E. V.; Chen, S.; Kooi, S. A.; Fan, T. F.

    2015-12-01

    Global and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and Atmospheric Carbon and Transport (ACT) - America airborne investigation are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are being investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the mission science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of intervening optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the Earth's surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques and provides very high (at sub-meter level) range resolution. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These techniques are used in a new data processing architecture to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs.

  3. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for ASCENDS O2 Column Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Meadows, Byron

    2015-01-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  4. Advanced intensity-modulation continuous-wave lidar techniques for ASCENDS CO2 column measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. W.; Obland, Michael D.; Meadows, Byron

    2015-10-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  5. A new approach for the modelling of chestnut wood photo-degradation monitored by different spectroscopic techniques.

    PubMed

    Bonifazi, G; Calienno, L; Capobianco, G; Monaco, A Lo; Pelosi, C; Picchio, R; Serranti, S

    2017-06-01

    The aim of this work is to study the colour and chemical modifications of the surfaces in chestnut wood samples as a consequence of irradiating in a controlled environment. The changes were investigated by a new analytical approach by combining traditional techniques such as reflectance spectrophotometry in the visible range and Fourier transform infrared spectroscopy with new hyperspectral imaging, in order to obtain forecast models to describe the phenomenon. The statistical elaboration of the experimental data allowed to validate the measurements and to obtain models enabling to relate the investigated parameters; the elaboration of the hyperspectral images by chemometric methods allowed for studying the changes in the reflectance spectra. A result of great importance is the possibility to correlate the oxidation of wood chemical components with the colour change in a totally non-invasive modality. This result is particularly relevant in the field of cultural heritage and in general in the control processes of wooden materials.

  6. Chemical and morphological changes in hydrochars derived from microcrystalline cellulose and investigated by chromatographic, spectroscopic and adsorption techniques.

    PubMed

    Diakité, Mamadou; Paul, Andrea; Jäger, Christian; Pielert, Judith; Mumme, Jan

    2013-12-01

    Hydrothermal carbonization (HTC) can be used for converting the biomass into a carbon-rich material, whose application as a fuel requires higher heating value, whereas soil amendment needs stable carbon. This work was focused on the characterization of hydrochars derived from microcrystalline cellulose. The chars were investigated using elemental analysis, Brunauer-Emmett-Teller technique, nuclear magnetic resonance spectroscopy, Raman, Fourier transform infrared, and electron spin resonance spectroscopy. Severity in temperature between 230 and 270°C with reaction times between 2 and 10 h only affect the carbon content moderately. The results show that aromatization of HTC chars correlates well with temperature, which was further supported by the increase of organic radicals with decreasing g values at higher temperatures. Based on these results, the energetic use of chars favors mild HTC (T<230°C and t≤6 h), while the soil amendement favors serve conditions (T≥230°C, and t>6 h).

  7. Development of synchrotron x-ray micro-spectroscopic techniques and application to problems in low temperature geochemistry. Progress report

    SciTech Connect

    Not Available

    1993-10-01

    The focus of the technical development effort has been the development of apparatus and techniques for the utilization of X-ray Fluorescence (XRF), Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES) spectroscopies in a microprobe mode. The present XRM uses white synchrotron radiation (3 to 30 keV) from a bending magnet for trace element analyses using the x-ray fluorescence technique Two significant improvements to this device have been recently implemented. Focusing Mirror: An 8:1 ellipsoidal mirror was installed in the X26A beamline to focus the incident synchrotron radiation and thereby increase the flux on the sample by about a factor of 30. Incident Beam Monochromator: The monochromator has been successfully installed and commissioned in the X26A beamline upstream of the mirror to permit analyses with focused monochromatic radiation. The monochromator consists of a channel-cut silicon (111) crystal driven by a Klinger stepping motor translator. We have demonstrated the operating range of this instrument is 4 and 20 keV with 0.01 eV steps and produces a beam with a {approximately}10{sup {minus}4} energy bandwidth. The primary purpose of the monochromator is for x-ray absorption spectroscopy (XAS) measurements but it is also used for selective excitation in trace element microanalysis. To date, we have conducted XANES studies on Ti, Cr, Fe, Ce and U, spanning the entire accessible energy range and including both K and L edge spectra. Practical detection limits for microXANES are 10--100 ppM for 100 {mu}m spots.

  8. Precise oxygen and hydrogen isotope determination in nanoliter quantities of speleothem inclusion water by cavity ring-down spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Uemura, Ryu; Nakamoto, Masashi; Asami, Ryuji; Mishima, Satoru; Gibo, Masakazu; Masaka, Kosuke; Jin-Ping, Chen; Wu, Chung-Che; Chang, Yu-Wei; Shen, Chuan-Chou

    2016-01-01

    Speleothem inclusion-water isotope compositions are a promising new climatic proxy, but their applicability is limited by their low content in water and by analytical challenges. We have developed a precise and accurate isotopic technique that is based on cavity ring-down spectroscopy (CRDS). This method features a newly developed crushing apparatus, a refined sample extraction line, careful evaluation of the water/carbonate adsorption effect. After crushing chipped speleothem in a newly-developed crushing device, released inclusion water is purified and mixed with a limited amount of nitrogen gas in the extraction line for CRDS measurement. We have measured 50-260 nL of inclusion water from 77 to 286 mg of stalagmite deposits sampled from Gyokusen Cave, Okinawa Island, Japan. The small sample size requirement demonstrates that our analytical technique can offer high-resolution inclusion water-based paleoclimate reconstructions. The 1σ reproducibility for different stalagmites ranges from ±0.05 to 0.61‰ for δ18O and ±0.0 to 2.9‰ for δD. The δD vs. δ18O plot for inclusion water from modern stalagmites is consistent with the local meteoric water line. The 1000 ln α values based on calcite and fluid inclusion measurements from decades-old stalagmites are in agreement with the data from present-day farmed calcite experiment. Combination of coeval carbonate and fluid inclusion data suggests that past temperatures at 9-10 thousand years ago (ka) and 26 ka were 3.4 ± 0.7 °C and 8.2 ± 2.4 °C colder than at present, respectively.

  9. System Design Techniques for Reducing the Power Requirements of Advanced life Support Systems

    NASA Technical Reports Server (NTRS)

    Finn, Cory; Levri, Julie; Pawlowski, Chris; Crawford, Sekou; Luna, Bernadette (Technical Monitor)

    2000-01-01

    The high power requirement associated with overall operation of regenerative life support systems is a critical Z:p technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems. Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented. The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified. The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.

  10. Use of advanced neuroimaging techniques in the evaluation of pediatric traumatic brain injury.

    PubMed

    Ashwal, Stephen; Holshouser, Barbara A; Tong, Karen A

    2006-01-01

    Advanced neuroimaging techniques are now used to expand our knowledge of traumatic brain injury, and increasingly, they are being applied to children. This review will examine four of these methods as they apply to children who present acutely after injury. (1) Susceptibility weighted imaging is a 3-dimensional high-resolution magnetic resonance imaging technique that is more sensitive than conventional imaging in detecting hemorrhagic lesions that are often associated with diffuse axonal injury. (2) Magnetic resonance spectroscopy acquires metabolite information reflecting neuronal integrity and function from multiple brain regions and provides sensitive, noninvasive assessment of neurochemical alterations that offers early prognostic information regarding the outcome. (3) Diffusion weighted imaging is based on differences in diffusion of water molecules within the brain and has been shown to be very sensitive in the early detection of ischemic injury. It is now being used to study the direct effects of traumatic injury as well as those due to secondary ischemia. (4) Diffusion tensor imaging is a form of diffusion weighted imaging and allows better evaluation of white matter fiber tracts by taking advantage of the intrinsic directionality (anisotropy) of water diffusion in human brain. It has been shown to be useful in identifying white matter abnormalities after diffuse axonal injury when conventional imaging appears normal. An important aspect of these advanced methods is that they demonstrate that 'normal-appearing' brain in many instances is not normal, i.e. there is evidence of significant undetected injury that may underlie a child's clinical status. Availability and integration of these advanced imaging methods will lead to better treatment and change the standard of care for use of neuroimaging to evaluate children with traumatic brain injury.

  11. System Design Techniques for Reducing the Power Requirements of Advanced life Support Systems

    NASA Technical Reports Server (NTRS)

    Finn, Cory; Levri, Julie; Pawlowski, Chris; Crawford, Sekou; Luna, Bernadette (Technical Monitor)

    2000-01-01

    The high power requirement associated with overall operation of regenerative life support systems is a critical Z:p technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems. Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented. The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified. The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.

  12. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Obland, M. D.; Liu, Z.; Kooi, S. A.; Fan, T. F.; Nehrir, A. R.; Meadows, B.; Browell, E. V.

    2016-12-01

    Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 MeasurementsJoel F. Campbell1, Bing Lin1, Michael D. Obland1, Zhaoyan Liu1, Susan Kooi2, Tai-Fang Fan2, Amin R. Nehrir1, Byron Meadows1, Edward V. Browell31NASA Langley Research Center, Hampton, VA 23681 2SSAI, NASA Langley Research Center, Hampton, VA 23681 3STARSS-II Affiliate, NASA Langley Research Center, Hampton, VA 23681 AbstractGlobal and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and the Atmospheric Carbon and Transport (ACT) - America project are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the ASCENDS and ACT-America science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new sub-meter hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. These techniques are used in a new data processing

  13. Use of radiocarbon and spectroscopic analyses to characterise soil organic matter pools isolated using different fractionation techniques.

    NASA Astrophysics Data System (ADS)

    Miller, Gemma; Cloy, Joanna; Garnett, Mark; Sohi, Saran; Rees, Robert; Griffiths, Bryan

    2015-04-01

    Experimental division of soil organic matter (SOM) into functional pools has the potential to improve soil C modelling. Soil physical fractionation techniques seek to quantify these pools, however the fractions isolated vary in number, size, ecological role and composition. The use of different techniques to quantify soil C fractions in different studies presents a question - do similar fractions isolated by different methods fit the same conceptual definition? This study examined a sandy loam from the south-west of Scotland, sampled in summer, which had been under grassland management for at least 20 years. We compared average 14C ages of SOM fractions isolated using three published and frequently applied physical fractionation methods (1) a density separation technique isolating three fractions - free light (FLF) < 1.8 cm 3, intra-aggregate light (IALF) < 1.8 cm-3 after aggregate disruption, and organo-mineral (O-min) > 1.8 g cm 3 (Sohi et al, 2001); (2) a combined physical and chemical separation isolating five fractions: sand and aggregates (S+A) > 63 µm and > 1.8 g cm-3, particulate organic matter (POM) > 63 µm and < 1.8 g cm 3, silt and clay (s+c) < 63 but > 45 µm, residual organic carbon (rSOC) the residue left after s+c is oxidised with NaOCl, and dissolved organic carbon (DOC) < 45 µm (Zimmermann et al, 2007); and (3) a hot water extraction method isolating two fractions: water soluble C (WSC) at 20 °C and hot water extractable C (HWEC) at 80 °C (Ghani et al, 2003). The fractions from Method 1 had the most distinct average 14C ages with O-min, FLF and IALF assessed as 206, 1965 and 6172 years before present (BP) respectively. The fractions from Method 2 fell into two age groups, < ~1000 years BP for s+c, rSOC and S+A and > 4000 years BP for DOC and POM. Both Method 3 fractions were dominated by modern C. The average 14C ages of FLF, IALF, DOC and POM were surprisingly higher than the mineral bound fractions, although they made up a relatively small

  14. PREFACE: 16th International workshop on Advanced Computing and Analysis Techniques in physics research (ACAT2014)

    NASA Astrophysics Data System (ADS)

    Fiala, L.; Lokajicek, M.; Tumova, N.

    2015-05-01

    This volume of the IOP Conference Series is dedicated to scientific contributions presented at the 16th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2014), this year the motto was ''bridging disciplines''. The conference took place on September 1-5, 2014, at the Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic. The 16th edition of ACAT explored the boundaries of computing system architectures, data analysis algorithmics, automatic calculations, and theoretical calculation technologies. It provided a forum for confronting and exchanging ideas among these fields, where new approaches in computing technologies for scientific research were explored and promoted. This year's edition of the workshop brought together over 140 participants from all over the world. The workshop's 16 invited speakers presented key topics on advanced computing and analysis techniques in physics. During the workshop, 60 talks and 40 posters were presented in three tracks: Computing Technology for Physics Research, Data Analysis - Algorithms and Tools, and Computations in Theoretical Physics: Techniques and Methods. The round table enabled discussions on expanding software, knowledge sharing and scientific collaboration in the respective areas. ACAT 2014 was generously sponsored by Western Digital, Brookhaven National Laboratory, Hewlett Packard, DataDirect Networks, M Computers, Bright Computing, Huawei and PDV-Systemhaus. Special appreciations go to the track liaisons Lorenzo Moneta, Axel Naumann and Grigory Rubtsov for their work on the scientific program and the publication preparation. ACAT's IACC would also like to express its gratitude to all referees for their work on making sure the contributions are published in the proceedings. Our thanks extend to the conference liaisons Andrei Kataev and Jerome Lauret who worked with the local contacts and made this conference possible as well as to the program

  15. Advanced Ecosystem Mapping Techniques for Large Arctic Study Domains Using Calibrated High-Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Macander, M. J.; Frost, G. V., Jr.

    2015-12-01

    Regional-scale mapping of vegetation and other ecosystem properties has traditionally relied on medium-resolution remote sensing such as Landsat (30 m) and MODIS (250 m). Yet, the burgeoning availability of high-resolution (<=2 m) imagery and ongoing advances in computing power and analysis tools raises the prospect of performing ecosystem mapping at fine spatial scales over large study domains. Here we demonstrate cutting-edge mapping approaches over a ~35,000 km² study area on Alaska's North Slope using calibrated and atmospherically-corrected mosaics of high-resolution WorldView-2 and GeoEye-1 imagery: (1) an a priori spectral approach incorporating the Satellite Imagery Automatic Mapper (SIAM) algorithms; (2) image segmentation techniques; and (3) texture metrics. The SIAM spectral approach classifies radiometrically-calibrated imagery to general vegetation density categories and non-vegetated classes. The SIAM classes were developed globally and their applicability in arctic tundra environments has not been previously evaluated. Image segmentation, or object-based image analysis, automatically partitions high-resolution imagery into homogeneous image regions that can then be analyzed based on spectral, textural, and contextual information. We applied eCognition software to delineate waterbodies and vegetation classes, in combination with other techniques. Texture metrics were evaluated to determine the feasibility of using high-resolution imagery to algorithmically characterize periglacial surface forms (e.g., ice-wedge polygons), which are an important physical characteristic of permafrost-dominated regions but which cannot be distinguished by medium-resolution remote sensing. These advanced mapping techniques provide products which can provide essential information supporting a broad range of ecosystem science and land-use planning applications in northern Alaska and elsewhere in the circumpolar Arctic.

  16. The transnasal advancement flap: A technique for medial canthal area defects.

    PubMed

    Sciscio, Andrea; Joshi, Naresh

    2001-06-01

    AIM. To illustrate an alternative technique for reconstructing defects in the medial canthal area following tumour removal. MATERIALS AND METHODS. Eight consecutive patients who underwent Mohs(1) micrographic surgery for removal of a basal cell carcinoma in the medial canthal area were prospectively recruited. An experienced dermatologist trained in Mohs(1) micrographic surgery removed the tumour, and subsequently an oculoplastic surgeon reconstructed the defect. An incision is made from the superior end of the defect superomedially towards the midline of the dorsum of the nose following one of the natural lines of the skin (spec name). The incision runs in arcuate fashion just medial to the eyebrow and then reaches the dorsum of the nose and extends on the contralateral aspect of the nose towards the medial canthal area. The skin is then undermined to free up the newly formed flap. The flap is advanced towards the lesion and fixed intra-dermally with Vicryl Rapide(R) sutures to ensure anchoring into the concavity of the medial canthal region. The skin is then sutured with prolene sutures. RESULTS. The defects presented were oval or round in shape with diameters ranging from 0.5 to 2 cm. In all cases the transnasal flap covered the entire area and the defect was successfully reconstructed. Mean follow-up is 10.8 months (+/-4.5 SD) (range 4-17 months); all patients had an excellent cosmetic result and were subjectively satisfied. CONCLUSIONS. The transnasal advancement flap seems to have some advantages over the usual reconstruction techniques in use to repair medium defects in the medial canthal area. These are the avoidance of vertical scars in the glabellar area, eyebrow hair is not transposed into the medial canthal area, the skin match is excellent, both in colour and thickness, and surgical scars are hidden within the natural lines of the nasal bridge. We advocate the use of this technique for all minor to medium skin defects.

  17. Process window enhancement using advanced RET techniques for 20nm contact layer

    NASA Astrophysics Data System (ADS)

    Ping, Yang; McGowan, Sarah; Gong, Ying; Foong, Yee Mei; Liu, Jian; Qiu, Jianhong; Shu, Vincent; Yan, Bo; Ye, Jun; Li, Pengcheng; Zhou, Hui; Pandey, Taksh; Liang, Jiao; Aquino, Chris; Baron, Stanislas; Kapasi, Sanjay

    2014-03-01

    At the 20nm technology node, it is challenging for simple resolution enhancements techniques (RET) to achieve sufficient process margin due to significant coupling effects for dense features. Advanced computational lithography techniques including Source Mask Optimization (SMO), thick mask modeling (M3D), Model Based Sub Resolution Assist Features (MB-SRAF) and Process Window Solver (PW Solver) methods are now required in the mask correction processes to achieve optimal lithographic goals. An OPC solution must not only converge to a nominal condition with high fidelity, but also provide this fidelity over an acceptable process window condition. The solution must also be sufficiently robust to account for potential scanner or OPC model tuning. In many cases, it is observed that with even a small change in OPC parameters, the mask correction could have a big change, therefore making OPC optimization quite challenging. On top of this, different patterns may have significantly different optimum source maps and different optimum OPC solution paths. Consequently, the need for finding a globally optimal OPC solution becomes important. In this work, we introduce a holistic solution including source and mask optimization (SMO), MB-SRAF, conventional OPC and Co-Optimization OPC, in which each technique plays a unique role in process window enhancement: SMO optimizes the source to find the best source solution for all critical patterns; Co-Optimization provides the optimized location and size of scattering bars and guides the optimized OPC solution; MB-SRAF and MB-OPC then utilizes all information from advanced solvers and performs a globally optimized production solution.

  18. Using terahertz time-domain spectroscopical technique to monitor cocrystal formation between piracetam and 2,5-dihydroxybenzoic acid

    NASA Astrophysics Data System (ADS)

    Du, Yong; Xia, Yi; Zhang, Huili; Hong, Zhi

    2013-07-01

    Far-infrared vibrational absorption of cocrystal formation between 2,5-dihydroxybenzoic acid (2,5-DHBA) and piracetam compounds under solvent evaporation and grinding methods have been investigated using terahertz time-domain spectroscopy (THz-TDS) at room temperature. The experimental results show large difference among absorption spectra of the formed cocrystals and the involved individual parent molecules in 0.20-1.50 THz region, which probably originated from the intra-molecular and inter-molecular hydrogen bonds due to the presence of two hydroxyl groups in 2,5-DHBA and amide moieties in piracetam compound. The THz absorption spectra of two formed cocrystals with different methods are almost identical. With grinding method, the reaction process can be monitored directly from both time-domain and frequency-domain spectra using THz-TDS technique. The results indicate that THz-TDS technology can absolutely offer us a high potential method to identify and characterize the formed cocrystals, and also provide the rich information about their reaction dynamic process involving two or more molecular crystals in situ to better know the corresponding reaction mechanism in pharmaceutical fields.

  19. Using terahertz time-domain spectroscopical technique to monitor cocrystal formation between piracetam and 2,5-dihydroxybenzoic acid.

    PubMed

    Du, Yong; Xia, Yi; Zhang, Huili; Hong, Zhi

    2013-07-01

    Far-infrared vibrational absorption of cocrystal formation between 2,5-dihydroxybenzoic acid (2,5-DHBA) and piracetam compounds under solvent evaporation and grinding methods have been investigated using terahertz time-domain spectroscopy (THz-TDS) at room temperature. The experimental results show large difference among absorption spectra of the formed cocrystals and the involved individual parent molecules in 0.20-1.50 THz region, which probably originated from the intra-molecular and inter-molecular hydrogen bonds due to the presence of two hydroxyl groups in 2,5-DHBA and amide moieties in piracetam compound. The THz absorption spectra of two formed cocrystals with different methods are almost identical. With grinding method, the reaction process can be monitored directly from both time-domain and frequency-domain spectra using THz-TDS technique. The results indicate that THz-TDS technology can absolutely offer us a high potential method to identify and characterize the formed cocrystals, and also provide the rich information about their reaction dynamic process involving two or more molecular crystals in situ to better know the corresponding reaction mechanism in pharmaceutical fields. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. [IR/UV spectroscopic analysis of gangliosides and their microstructures of polymeric aggregates observed by AFM technique].

    PubMed

    Wang, Hai-long; Sun, Run-guang; Zhang, Jing; Hao, Chang-chun

    2009-04-01

    Gangliosides, a kind of acid glycosphingolipid containing sialic acid, plays a very important physiological role in biomembrane as one of the important components of neurocyte membrane. They were extracted from bovine brain by the Folch method and purified by silica gel and DEAE-Sephadex A-25 column chromatograph. Their molecular functional groups and microstructures of polymeric aggregates were studied by infrared spectrum (IR), ultraviolet spectrum (UV) and atomic force microscope (AFM). The experimental results indicate that: 55.2 mg of Gls from 100 g of wet bovine brain had a certain purity, 62.84%. And their UV absorption spectra appeared at 195 nm, near to the results reported by other peoples. Compared with the IR spectra of sialic acid, the experimental results showed that the structures of the products had the units of sialic acid. In order to investigate the aggregate structures of ganglioside. AFM technique was applied in water, and the results showed that gangliosides can form spherical or ellipsoidal structures in water. It was determined that the size of polymeric aggregates of gangliosides varies between 55 and 380 nm, the average size is (148.9+/-66.7) nm; the height is between 1.0 and 5.0 nm, and the average height is (3.25+/-1.01) nm. The experimental results provide a theoretical and experimental basis for investigating biological activity and the exploitation and utilization of neural drugs.