Science.gov

Sample records for adaptive spectroscopic techniques

  1. 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.

  2. Spectroscopic Techniques for Atmospheric Analysis

    SciTech Connect

    Bililign, Solomon

    2009-07-06

    Several analytical and optical techniques for atmospheric analysis are discussed. Environmental constraints for real world applications are mentioned. Special emphasis is given to the cavity ring Down Spectroscopy as a very sensitive method for atmospheric trace gas detection is described.

  3. Air pollution monitoring by advanced spectroscopic techniques.

    PubMed

    Hodgeson, J A; McClenny, W A; Hanst, P L

    1973-10-19

    The monitoring requirements related to air pollution are many and varied. The molecules of concern differ greatly in their chemical and physical properties, in the nature of their environment, and in their concentration ranges. Furthermore, the application may have specific requirements such as rapid response time, ultrasensitivity, multipollutant capability, or capability for remote measurements. For these reasons, no single spectroscopic technique appears to offer a panacea for all monitoring needs. Instead we have attempted to demonstrate in the above discussion that, regardless of the difficulty and complexity of the monitoring problems, spectroscopy offers many tools by which such problems may be solved.

  4. Coherent optical adaptive techniques.

    PubMed

    Bridges, W B; Brunner, P T; Lazzara, S P; Nussmeier, T A; O'Meara, T R; Sanguinet, J A; Brown, W P

    1974-02-01

    The theory of multidither adaptive optical radar phased arrays is briefly reviewed as an introduction to the experimental results obtained with seven-element linear and three-element triangular array systems operating at 0.6328 microm. Atmospheric turbulence compensation and adaptive tracking capabilities are demonstrated.

  5. Adaptive cancellation techniques

    NASA Astrophysics Data System (ADS)

    1983-11-01

    An adaptive signal canceller has been evaluated for the enhancement of pulse signal reception during the transmission of a high power ECM jamming signal. The canceller design is based on the use of DRFM(Digital RF Memory) technology as part of an adaptive multiple tapped delay line. The study includes analysis of relationship of tap spacing and waveform bandwidth, survey of related documents in areas of sidelobe cancellers, transversal equalizers, and adaptive filters, and derivation of control equations and corresponding control processes. The simulation of overall processes included geometric analysis of the multibeam transmitting antenna, multiple reflection sources and the receiving antenna; waveforms, tap spacings and bandwidths; and alternate control algorithms. Conclusions are provided regarding practical system control algorithms, design characteristics and limitations.

  6. 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.

  7. 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

  8. 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

  9. Optical spectroscopic techniques and instrumentation for atmospheric and space research

    SciTech Connect

    Wang, J.; Hays, P.B.

    1994-12-31

    The objective of this conference was to bring together scientists and engineers involved in atmospheric science, space physics, aeronomy, remote sensing, and optical instrumentation to exchange ideas and discuss recent developments in spectroscopic techniques and instrumentation in atmospheric and space research. There is growing concern about the human environment: the atmosphere, ocean, and space. To address those concerns and understand their changing environment, increasingly complex computer models have been developed with the advent of more powerful computers. Therefore, the validation of those models against direct measurements with advanced techniques and instruments is becoming increasingly more difficult and important. Optical spectroscopic techniques and instrumentation have contributed greatly to the validation of those models and their understanding of the earth`s atmosphere and space environment. Improving techniques and instrumentation is becoming ever more important with more demanding requirements on the accuracy and resolution of atmospheric and space observations. This conference had sessions addressing current techniques and instrumentation from the ultraviolet to the infrared and microwave, and from ground-based facilities to satellite-borne missions. Separate abstracts were prepared for most of the papers in this volume.

  10. Atmospheric trace gases monitoring by UV-vis spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Xie, Pinhua; Li, Ang; Wu, Fengcheng; Qin, Min; Hu, Rezhi; Xu, Jin; Si, Fuqi; Liu, Jianguo; Liu, Wenqing

    2016-04-01

    Due to rapidly economic development, air pollution has become an important issue in China. Phenomena such as regional haze in winter and high O3 concentration in summer are strongly related to increasing trace species. For better understanding the air pollution formation, it is necessary to know spatial and temporal distribution of trace species in the atmosphere. UV-vis spectroscopic techniques are of great advantages for trace species monitoring to meet several requirements, e.g. versatility, high sensitivity, good temporal resolution and field applicability. We have studied and developed various trace gases monitoring techniques and instruments based on UV-vis spectroscopic technique for in-situ measurements and remote sensing, e.g. LP-DOAS, IBBCEAS, CRDS, MAX-DOAS and mobile DOAS for NO2, SO2, HCHO, HONO, NO3, and N2O5 etc. The principle, instrumentation and inversion algorithm are presented. As typical applications of these techniques, investigation of the evolution of HONO and NO3 radicals over Beijing area, measurements of regional pollution in NCP and YRD are discussed in the aspects of HONO and nocturnal NO3 radical characteristics, trace gases (NO2, SO2 etc.) temporal and spatial distribution, pollution transport pathway, emission sources.

  11. 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

  12. Adaptive techniques in electrical impedance tomography reconstruction.

    PubMed

    Li, Taoran; Isaacson, David; Newell, Jonathan C; Saulnier, Gary J

    2014-06-01

    We present an adaptive algorithm for solving the inverse problem in electrical impedance tomography. To strike a balance between the accuracy of the reconstructed images and the computational efficiency of the forward and inverse solvers, we propose to combine an adaptive mesh refinement technique with the adaptive Kaczmarz method. The iterative algorithm adaptively generates the optimal current patterns and a locally-refined mesh given the conductivity estimate and solves for the unknown conductivity distribution with the block Kaczmarz update step. Simulation and experimental results with numerical analysis demonstrate the accuracy and the efficiency of the proposed algorithm.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. Adaptive interference techniques for mobile antennas

    NASA Astrophysics Data System (ADS)

    Griffiths, Lloyd J.; Satorius, E.

    1988-05-01

    The results of a study performed to investigate effective, low cost adaptive signal processing techniques for suppressing mutual satellite interference that can arise in a mobile satellite (MSAT) communication system are discussed. The study focused on the use of adaptive sidelobe cancelling as a method to overcome undesired interference caused by a multiplicity of satellite transmissions within the field of view of the ground station. Results are presented which show that the conventional sidelobe canceller produces undesired reduction of the useful signal. This effect is due to the presence of the useful component in the reference antenna element. An alternative structure, the generalized sidelobe canceller (GSC), has been proposed to overcome this difficulty. A preliminary investigation of possible implementations of the GSC was conducted. It was found that at most 8 bits would be required to implement the GSC processor under conditions in which the desired signal-to-interference ratio is 25 dB.

  18. Adaptive interference techniques for mobile antennas

    NASA Technical Reports Server (NTRS)

    Griffiths, Lloyd J.; Satorius, E.

    1988-01-01

    The results of a study performed to investigate effective, low cost adaptive signal processing techniques for suppressing mutual satellite interference that can arise in a mobile satellite (MSAT) communication system are discussed. The study focused on the use of adaptive sidelobe cancelling as a method to overcome undesired interference caused by a multiplicity of satellite transmissions within the field of view of the ground station. Results are presented which show that the conventional sidelobe canceller produces undesired reduction of the useful signal. This effect is due to the presence of the useful component in the reference antenna element. An alternative structure, the generalized sidelobe canceller (GSC), has been proposed to overcome this difficulty. A preliminary investigation of possible implementations of the GSC was conducted. It was found that at most 8 bits would be required to implement the GSC processor under conditions in which the desired signal-to-interference ratio is 25 dB.

  19. Adaptive node techniques for Maxwell's equations

    SciTech Connect

    Hewett, D W

    2000-04-01

    The computational mesh in numerical simulation provides a framework on which to monitor the spatial dependence of function and their derivatives. Spatial mesh is therefore essential to the ability to integrate systems in time without loss of fidelity. Several philosophies have emerged to provide such fidelity (Eulerian, Lagrangian, Arbitrary Lagrangian Eulerian ALE, Adaptive Mesh Refinement AMR, and adaptive node generation/deletion). Regardless of the type of mesh, a major difficulty is in setting up the initial mesh. Clearly a high density of grid points is essential in regions of high geometric complexity and/or regions of intense, energetic activity. For some problems, mesh generation is such a crucial part of the problem that it can take as much computational effort as the run itself, and these tasks are now taking weeks of massively parallel CPU time. Mesh generation is no less crucial to electromagnetic calculations. In fact EM problem set up can be even more challenging without the clues given by fluid motion in hydrodynamic systems. When the mesh is advected with the fluid (Lagrangian), mesh points naturally congregate in regions of high activity. Similarly in AMR algorithms, strong gradients in the fluid flow are one of the triggers for mesh refinement. In the hyperbolic Maxwell's equations without advection, mesh point placement/motion is not so intuitive. In fixed geometry systems, it at least feasible to finely mesh high leverage, geometrically challenged areas. For other systems, where the action takes place far from the boundaries and, likely, changes position in time, the options are limited to either using a high resolution (expensive) mesh in all regions that could require such resolution or adaptively generating nodes to resolve the physics as it evolves. The authors have developed a new time of adaptive node technique for Maxwell's equations to deal with this set of issues.

  20. UV-fluorescence spectroscopic technique in the diagnosis of breast, ovarian, uterus, and cervix cancer

    NASA Astrophysics Data System (ADS)

    Das, Bidyut B.; Glassman, Wenling S.; Alfano, Robert R.; Cleary, Joseph; Prudente, R.; Celmer, Edward J.; Lubicz, Stephanie

    1991-06-01

    Malignant breast tumors can be separated from benign and normal tissues using uv-fluorescence spectroscopic technique. Using the same method one can also distinguish cancerous tissues from noncancerous ones in case of cervix, uterus and ovary.

  1. A recursive technique for adaptive vector quantization

    NASA Technical Reports Server (NTRS)

    Lindsay, Robert A.

    1989-01-01

    Vector Quantization (VQ) is fast becoming an accepted, if not preferred method for image compression. The VQ performs well when compressing all types of imagery including Video, Electro-Optical (EO), Infrared (IR), Synthetic Aperture Radar (SAR), Multi-Spectral (MS), and digital map data. The only requirement is to change the codebook to switch the compressor from one image sensor to another. There are several approaches for designing codebooks for a vector quantizer. Adaptive Vector Quantization is a procedure that simultaneously designs codebooks as the data is being encoded or quantized. This is done by computing the centroid as a recursive moving average where the centroids move after every vector is encoded. When computing the centroid of a fixed set of vectors the resultant centroid is identical to the previous centroid calculation. This method of centroid calculation can be easily combined with VQ encoding techniques. The defined quantizer changes after every encoded vector by recursively updating the centroid of minimum distance which is the selected by the encoder. Since the quantizer is changing definition or states after every encoded vector, the decoder must now receive updates to the codebook. This is done as side information by multiplexing bits into the compressed source data.

  2. Munitions classification using an Acoustic Resonance Spectroscopic technique

    SciTech Connect

    Roberts, R.S.; Chen, J.T.; Vela, O.A.; Lewis, P.S.

    1993-12-01

    In support of the Bilateral Chemical Weapons Agreement between the United States and Russia, Los Alamos National Laboratory has developed a nondestructive evaluation (NDE) technique that discriminates between different types of artillery munitions. This NDE classification technique allows on-site inspectors to rapidly classify the munitions as chemical or high explosive, and furthermore discriminates between various subclasses of these types of munitions. This technique, based on acoustic resonance measurements, has been successfully demonstrated on a wide variety of high explosive and chemical munitions. The technique consists of building templates of spectral features from sets of known munitions. Spectral features of unknown munitions are compared with a library of templates, and the degree of match between the features and the templates is used to classify the munition. This paper describes the technique, including the feature extraction, clustering and classification algorithms.

  3. Characterization of the solid-state: spectroscopic techniques.

    PubMed

    Bugay, D E

    2001-05-16

    The physical characterization of pharmaceutical solids is an integral aspect of the drug development process. This review summarizes the use of solid-state spectroscopy techniques used in the physical characterization of the active pharmaceutical ingredient, excipients, physical mixtures, and the final dosage form. A brief introduction to infrared, Raman, and solid-state NMR experimental techniques are described as well as a more thorough description of qualitative and quantitative applications. The use of solid-state imaging techniques such as IR, Raman, and TOF-SIMS is also introduced to the reader.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities. PMID:25813024

  11. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities.

  12. A novel bit-wise adaptable entropy coding technique

    NASA Technical Reports Server (NTRS)

    Kiely, A.; Klimesh, M.

    2001-01-01

    We present a novel entropy coding technique which is adaptable in that each bit to be encoded may have an associated probability esitmate which depends on previously encoded bits. The technique may have advantages over arithmetic coding. The technique can achieve arbitrarily small redundancy and admits a simple and fast decoder.

  13. Diagnostic analysis of vibration signals using adaptive digital filtering techniques

    NASA Technical Reports Server (NTRS)

    Jewell, R. E.; Jones, J. H.; Paul, J. E.

    1983-01-01

    Signal enhancement techniques are described using recently developed digital adaptive filtering equipment. Adaptive filtering concepts are not new; however, as a result of recent advances in microprocessor-based electronics, hardware has been developed that has stable characteristics and of a size exceeding 1000th order. Selected data processing examples are presented illustrating spectral line enhancement, adaptive noise cancellation, and transfer function estimation in the presence of corrupting noise.

  14. Adaptive mesh refinement techniques for electrical impedance tomography.

    PubMed

    Molinari, M; Cox, S J; Blott, B H; Daniell, G J

    2001-02-01

    Adaptive mesh refinement techniques can be applied to increase the efficiency of electrical impedance tomography reconstruction algorithms by reducing computational and storage cost as well as providing problem-dependent solution structures. A self-adaptive refinement algorithm based on an a posteriori error estimate has been developed and its results are shown in comparison with uniform mesh refinement for a simple head model.

  15. A novel online adaptive time delay identification technique

    NASA Astrophysics Data System (ADS)

    Bayrak, Alper; Tatlicioglu, Enver

    2016-05-01

    Time delay is a phenomenon which is common in signal processing, communication, control applications, etc. The special feature of time delay that makes it attractive is that it is a commonly faced problem in many systems. A literature search on time-delay identification highlights the fact that most studies focused on numerical solutions. In this study, a novel online adaptive time-delay identification technique is proposed. This technique is based on an adaptive update law through a minimum-maximum strategy which is firstly applied to time-delay identification. In the design of the adaptive identification law, Lyapunov-based stability analysis techniques are utilised. Several numerical simulations were conducted with Matlab/Simulink to evaluate the performance of the proposed technique. It is numerically demonstrated that the proposed technique works efficiently in identifying both constant and disturbed time delays, and is also robust to measurement noise.

  16. 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.

  17. 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.

  18. 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.

  19. A novel pulse height analysis technique for nuclear spectroscopic and imaging systems

    NASA Astrophysics Data System (ADS)

    Tseng, H. H.; Wang, C. Y.; Chou, H. P.

    2005-08-01

    The proposed pulse height analysis technique is based on the constant and linear relationship between pulse width and pulse height generated from front-end electronics of nuclear spectroscopic and imaging systems. The present technique has successfully implemented into the sump water radiation monitoring system in a nuclear power plant. The radiation monitoring system uses a NaI(Tl) scintillator to detect radioactive nuclides of Radon daughters brought down by rain. The technique is also used for a nuclear medical imaging system. The system uses a position sensitive photomultiplier tube coupled with a scintillator. The proposed techniques has greatly simplified the electronic design and made the system a feasible one for potable applications.

  20. Development of Laser Spectroscopic Techniques and Their Application to the Study of Self-Organizing Molecular Assemblies.

    NASA Astrophysics Data System (ADS)

    Reed, Wayne Frederick

    Laser spectroscopic techniques have been developed and adapted to computer based data gathering, reduction and analysis. The systems implemented are a laser flash photolysis and transient dichroism spectrometer, a single photon counting spectrometer for determination of fluorescence lifetimes and time-resolved fluorescence polarization anisotropy, and a light scattering system for both static and dynamic measurements. These techniques have been concerted to study self-organizing molecular assemblies, particularly surfactant vesicles. Quaternary ammonium surfactant monomers with polymerizable styrene moieties on the headgroup have been sonicated into unilamellar vesicles and these in turn have been photopolymerized by both steady state and pulsed laser irradiation. The detailed kinetics of photopolymerization have been determined and a model developed which permits, in conjunction with the laser spectroscopic data, the characterization of the process in terms of average polymer chain length, quantum efficiency of free radical formation, free radical lifetime, and a characteristic rate parameter. Subsequent to characterizing and modelling the photopolymerization process the consequences of it on vesicle surface properties have been investigated with molecular probes. Strong evidence has been obtained that indicates that photopolymerization leads to the formation of clefts or pockets on the vesicle surface and to extensive surface inhomogeneity. Based on the experimental data, a computer simulation has been developed to help graphically visualize the photopolymerization process and to semi-quantitatively characterize the resulting surface inhomogeneity. As a first step in exploring the possibilities opened up by the discovery of clefts in the vesicle surface, the interaction between a photoexcitable proton transfer agent, 8-hydroxy-1,3,6 - pyrenetrisulfonate (POH), and vesicles has been studied. In unpolymerized vesicles POH loses its proton ejection capacity after

  1. Application of adaptive antenna techniques to future commercial satellite communication

    NASA Technical Reports Server (NTRS)

    Ersoy, L.; Lee, E. A.; Matthews, E. W.

    1987-01-01

    The purpose of this contract was to identify the application of adaptive antenna technique in future operational commercial satellite communication systems and to quantify potential benefits. The contract consisted of two major subtasks. Task 1, Assessment of Future Commercial Satellite System Requirements, was generally referred to as the Adaptive section. Task 2 dealt with Pointing Error Compensation Study for a Multiple Scanning/Fixed Spot Beam Reflector Antenna System and was referred to as the reconfigurable system. Each of these tasks was further sub-divided into smaller subtasks. It should also be noted that the reconfigurable system is usually defined as an open-loop system while the adaptive system is a closed-loop system. The differences between the open- and closed-loop systems were defined. Both the adaptive and reconfigurable systems were explained and the potential applications of such systems were presented in the context of commercial communication satellite systems.

  2. 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.

  3. Spectroscopic photothermal radiometry as a deep subsurface depth profilometric technique in semiconductors

    NASA Astrophysics Data System (ADS)

    Shaughnessy, D.; Mandelis, A.

    2003-01-01

    The theoretical and experimental aspects of spectroscopic photothermal radiometry (PTR) of semiconductors are presented and the potential of the technique for depth profilometry is established. A three-dimensional model of the PTR signal from a semiconductor excited by light of arbitrary optical penetration depth is presented. Numerical simulations of the PTR response to the electronic transport parameters and the optical penetration depth of the excitation source are presented. Intensity-modulated frequency scans and two-dimensional surface scans at fixed frequencies have been performed at several different absorption depths on a Si wafer with various degrees of mechanical damage introduced to either the front or the back surface. The electronic transport parameters obtained from fitting the frequency scans to the theoretical model and analysis of the experimental curves show that while the surface recombination velocities extracted from the fits do not vary significantly with excitation wavelength, the carrier recombination lifetime and the overall sensitivity of the photothermal radiometric signal to spatially localized damage is strongly influenced by the proximity of the injected excess carrier density centroid to the defect location. This correlation between the sensitivity of the PTR signal to a localized defect and the proximity of the injected carriers to the defect demonstrates the potential for spectroscopic PTR as a depth profilometric technique for semiconductors.

  4. Adaptive radiation therapy for bladder cancer: a review of adaptive techniques used in clinical practice.

    PubMed

    Kibrom, Awet Z; Knight, Kellie A

    2015-12-01

    Significant changes in the shape, size and position of the bladder during radiotherapy (RT) treatment for bladder cancer have been correlated with high local failure rates; typically due to geographical misses. To account for this, large margins are added around the target volumes in conventional RT; however, this increases the volume of healthy tissue irradiation. The availability of cone beam computed tomography (CBCT) has not only allowed in-room volumetric imaging of the bladder, but also the development of adaptive radiotherapy (ART) for modification of plans to patient-specific changes. The aim of this review is to: (1) identify and explain the different ART techniques being used in clinical practice and (2) compare and contrast these different ART techniques to conventional RT in terms of target coverage and dose to healthy tissue: A literature search was conducted using EMBASE, MEDLINE and Scopus with the key words 'bladder, adaptive, radiotherapy/radiation therapy'. 11 studies were obtained that compared different adaptive RT techniques to conventional RT in terms of target volume coverage and healthy tissue sparing. All studies showed superior target volume coverage and/or healthy tissue sparing in adaptive RT compared to conventional RT. Cross-study comparison between different adaptive techniques could not be made due to the difference in protocols used in different studies. However, one study found daily re-optimisation of plans to be superior to plan of the day technique. The use of adaptive RT for bladder cancer is promising. Further study is required to assess adaptive RT versus conventional RT in terms of local control and long-term toxicity. PMID:27512574

  5. 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.

  6. Mesh adaptation technique for Fourier-domain fluorescence lifetime imaging

    SciTech Connect

    Soloviev, Vadim Y.

    2006-11-15

    A novel adaptive mesh technique in the Fourier domain is introduced for problems in fluorescence lifetime imaging. A dynamical adaptation of the three-dimensional scheme based on the finite volume formulation reduces computational time and balances the ill-posed nature of the inverse problem. Light propagation in the medium is modeled by the telegraph equation, while the lifetime reconstruction algorithm is derived from the Fredholm integral equation of the first kind. Stability and computational efficiency of the method are demonstrated by image reconstruction of two spherical fluorescent objects embedded in a tissue phantom.

  7. Adaptive near-field beamforming techniques for sound source imaging.

    PubMed

    Cho, Yong Thung; Roan, Michael J

    2009-02-01

    Phased array signal processing techniques such as beamforming have a long history in applications such as sonar for detection and localization of far-field sound sources. Two sometimes competing challenges arise in any type of spatial processing; these are to minimize contributions from directions other than the look direction and minimize the width of the main lobe. To tackle this problem a large body of work has been devoted to the development of adaptive procedures that attempt to minimize side lobe contributions to the spatial processor output. In this paper, two adaptive beamforming procedures-minimum variance distorsionless response and weight optimization to minimize maximum side lobes--are modified for use in source visualization applications to estimate beamforming pressure and intensity using near-field pressure measurements. These adaptive techniques are compared to a fixed near-field focusing technique (both techniques use near-field beamforming weightings focusing at source locations estimated based on spherical wave array manifold vectors with spatial windows). Sound source resolution accuracies of near-field imaging procedures with different weighting strategies are compared using numerical simulations both in anechoic and reverberant environments with random measurement noise. Also, experimental results are given for near-field sound pressure measurements of an enclosed loudspeaker.

  8. Adaptive mesh refinement techniques for 3-D skin electrode modeling.

    PubMed

    Sawicki, Bartosz; Okoniewski, Michal

    2010-03-01

    In this paper, we develop a 3-D adaptive mesh refinement technique. The algorithm is constructed with an electric impedance tomography forward problem and the finite-element method in mind, but is applicable to a much wider class of problems. We use the method to evaluate the distribution of currents injected into a model of a human body through skin contact electrodes. We demonstrate that the technique leads to a significantly improved solution, particularly near the electrodes. We discuss error estimation, efficiency, and quality of the refinement algorithm and methods that allow for preserving mesh attributes in the refinement process.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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.

  12. A successive overrelaxation iterative technique for an adaptive equalizer

    NASA Technical Reports Server (NTRS)

    Kosovych, O. S.

    1973-01-01

    An adaptive strategy for the equalization of pulse-amplitude-modulated signals in the presence of intersymbol interference and additive noise is reported. The successive overrelaxation iterative technique is used as the algorithm for the iterative adjustment of the equalizer coefficents during a training period for the minimization of the mean square error. With 2-cyclic and nonnegative Jacobi matrices substantial improvement is demonstrated in the rate of convergence over the commonly used gradient techniques. The Jacobi theorems are also extended to nonpositive Jacobi matrices. Numerical examples strongly indicate that the improvements obtained for the special cases are possible for general channel characteristics. The technique is analytically demonstrated to decrease the mean square error at each iteration for a large range of parameter values for light or moderate intersymbol interference and for small intervals for general channels. Analytically, convergence of the relaxation algorithm was proven in a noisy environment and the coefficient variance was demonstrated to be bounded.

  13. 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.

  14. Fixed gain and adaptive techniques for rotorcraft vibration control

    NASA Technical Reports Server (NTRS)

    Roy, R. H.; Saberi, H. A.; Walker, R. A.

    1985-01-01

    The results of an analysis effort performed to demonstrate the feasibility of employing approximate dynamical models and frequency shaped cost functional control law desgin techniques for helicopter vibration suppression are presented. Both fixed gain and adaptive control designs based on linear second order dynamical models were implemented in a detailed Rotor Systems Research Aircraft (RSRA) simulation to validate these active vibration suppression control laws. Approximate models of fuselage flexibility were included in the RSRA simulation in order to more accurately characterize the structural dynamics. The results for both the fixed gain and adaptive approaches are promising and provide a foundation for pursuing further validation in more extensive simulation studies and in wind tunnel and/or flight tests.

  15. Maneuver tracking using an adaptive Gaussian sum technique

    NASA Astrophysics Data System (ADS)

    Stubberud, Stephen C.; Kramer, Kathleen A.

    2005-03-01

    The best method to track through a maneuver is to know the motion model of the maneuvering target. Unfortunately, a priori knowledge of the maneuver is not usually known. If the motion model of the maneuver can be estimated quickly from the measurements then the resulting track estimate will be better than the a priori static model. An adaptive function approximation technique to improve the motion model while tracking is analyzed for its potential to track through various maneuvers. The basic function approximation technique is that of a Gaussian sum. The Gaussian sum approximates the function which represents the error between the initial static model and the actual model of the maneuver. The parameters of the Gaussian sum are identified on-line using a Kalman filter identification scheme. This scheme, used in conjunction with a Kalman filter tracker, creates a coupled technique that can improve the motion model quickly. This adaptive Gaussian sum approach to maneuver tracking has its performance analyzed for three maneuvers. These maneuvers include a maneuvering ballistic target, a target going through an s-curve, and real target with a multiple racetrack flight path. The results of these test cases demonstrate the capabilities of this approach to track maneuvering targets.

  16. Experiments on Adaptive Techniques for Host-Based Intrusion Detection

    SciTech Connect

    DRAELOS, TIMOTHY J.; COLLINS, MICHAEL J.; DUGGAN, DAVID P.; THOMAS, EDWARD V.; WUNSCH, DONALD

    2001-09-01

    This research explores four experiments of adaptive host-based intrusion detection (ID) techniques in an attempt to develop systems that can detect novel exploits. The technique considered to have the most potential is adaptive critic designs (ACDs) because of their utilization of reinforcement learning, which allows learning exploits that are difficult to pinpoint in sensor data. Preliminary results of ID using an ACD, an Elman recurrent neural network, and a statistical anomaly detection technique demonstrate an ability to learn to distinguish between clean and exploit data. We used the Solaris Basic Security Module (BSM) as a data source and performed considerable preprocessing on the raw data. A detection approach called generalized signature-based ID is recommended as a middle ground between signature-based ID, which has an inability to detect novel exploits, and anomaly detection, which detects too many events including events that are not exploits. The primary results of the ID experiments demonstrate the use of custom data for generalized signature-based intrusion detection and the ability of neural network-based systems to learn in this application environment.

  17. Rapid Structured Volume Grid Smoothing and Adaption Technique

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.

    2006-01-01

    A rapid, structured volume grid smoothing and adaption technique, based on signal processing methods, was developed and applied to the Shuttle Orbiter at hypervelocity flight conditions in support of the Columbia Accident Investigation. Because of the fast pace of the investigation, computational aerothermodynamicists, applying hypersonic viscous flow solving computational fluid dynamic (CFD) codes, refined and enhanced a grid for an undamaged baseline vehicle to assess a variety of damage scenarios. Of the many methods available to modify a structured grid, most are time-consuming and require significant user interaction. By casting the grid data into different coordinate systems, specifically two computational coordinates with arclength as the third coordinate, signal processing methods are used for filtering the data [Taubin, CG v/29 1995]. Using a reverse transformation, the processed data are used to smooth the Cartesian coordinates of the structured grids. By coupling the signal processing method with existing grid operations within the Volume Grid Manipulator tool, problems related to grid smoothing are solved efficiently and with minimal user interaction. Examples of these smoothing operations are illustrated for reductions in grid stretching and volume grid adaptation. In each of these examples, other techniques existed at the time of the Columbia accident, but the incorporation of signal processing techniques reduced the time to perform the corrections by nearly 60%. This reduction in time to perform the corrections therefore enabled the assessment of approximately twice the number of damage scenarios than previously possible during the allocated investigation time.

  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. Feasibility of measuring density and temperature of laser produced plasmas using spectroscopic techniques.

    SciTech Connect

    Edens, Aaron D.

    2008-09-01

    A wide variety of experiments on the Z-Beamlet laser involve the creation of laser produced plasmas. Having a direct measurement of the density and temperature of these plasma would an extremely useful tool, as understanding how these quantities evolve in space and time gives insight into the causes of changes in other physical processes, such as x-ray generation and opacity. We propose to investigate the possibility of diagnosing the density and temperature of laser-produced plasma using temporally and spatially resolved spectroscopic techniques that are similar to ones that have been successfully fielded on other systems. Various researchers have measured the density and temperature of laboratory plasmas by looking at the width and intensity ratio of various characteristic lines in gases such as nitrogen and hydrogen, as well as in plasmas produced off of solid targets such as zinc. The plasma conditions produce two major measurable effects on the characteristic spectral lines of that plasma. The 1st is the Stark broadening of an individual line, which depends on the electron density of the plasma, with higher densities leading to broader lines. The second effect is a change in the ratio of various lines in the plasma corresponding to different ionization states. By looking at the ratio of these lines, we can gain some understanding of the plasma ionization state and consequently its temperature (and ion density when coupled with the broadening measurement). The hotter a plasma is, the higher greater the intensity of lines corresponding to higher ionization states. We would like to investigate fielding a system on the Z-Beamlet laser chamber to spectroscopically study laser produced plasmas from different material targets.

  20. Adaptive density partitioning technique in the auxiliary plane wave method

    NASA Astrophysics Data System (ADS)

    Kurashige, Yuki; Nakajima, Takahito; Hirao, Kimihiko

    2006-01-01

    We have developed the adaptive density partitioning technique (ADPT) in the auxiliary plane wave method, in which a part of the density is expanded to plane waves, for the fast evaluation of Coulomb matrix. Our partitioning is based on the error estimations and allows us to control the accuracy and efficiency. Moreover, we can drastically reduce the core Gaussian products that are left in Gaussian representation (its analytical integrals is the bottleneck in this method). For the taxol molecule with 6-31G** basis, the core Gaussian products accounted only for 5% in submicrohartree error.

  1. 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.

  2. New analytical expressions of the Rossiter-McLaughlin effect adapted to different observation techniques

    NASA Astrophysics Data System (ADS)

    Boué, G.; Montalto, M.; Boisse, I.; Oshagh, M.; Santos, N. C.

    2013-02-01

    The Rossiter-McLaughlin (hereafter RM) effect is a key tool for measuring the projected spin-orbit angle between stellar spin axes and orbits of transiting planets. However, the measured radial velocity (RV) anomalies produced by this effect are not intrinsic and depend on both instrumental resolution and data reduction routines. Using inappropriate formulas to model the RM effect introduces biases, at least in the projected velocity Vsini⋆ compared to the spectroscopic value. Currently, only the iodine cell technique has been modeled, which corresponds to observations done by, e.g., the HIRES spectrograph of the Keck telescope. In this paper, we provide a simple expression of the RM effect specially designed to model observations done by the Gaussian fit of a cross-correlation function (CCF) as in the routines performed by the HARPS team. We derived a new analytical formulation of the RV anomaly associated to the iodine cell technique. For both formulas, we modeled the subplanet mean velocity vp and dispersion βp accurately taking the rotational broadening on the subplanet profile into account. We compare our formulas adapted to the CCF technique with simulated data generated with the numerical software SOAP-T and find good agreement up to Vsini⋆ ≲ 20 km s-1. In contrast, the analytical models simulating the two different observation techniques can disagree by about 10σ in Vsini⋆ for large spin-orbit misalignments. It is thus important to apply the adapted model when fitting data. A public code implementing the expressions derived in this paper is available at http://www.astro.up.pt/resources/arome. A copy of the code is also available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/550/A53

  3. 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).

  4. Optical Cluster-Finding with an Adaptive Matched-Filter Technique: Algorithm and Comparison with Simulations

    SciTech Connect

    Dong, Feng; Pierpaoli, Elena; Gunn, James E.; Wechsler, Risa H.

    2007-10-29

    We present a modified adaptive matched filter algorithm designed to identify clusters of galaxies in wide-field imaging surveys such as the Sloan Digital Sky Survey. The cluster-finding technique is fully adaptive to imaging surveys with spectroscopic coverage, multicolor photometric redshifts, no redshift information at all, and any combination of these within one survey. It works with high efficiency in multi-band imaging surveys where photometric redshifts can be estimated with well-understood error distributions. Tests of the algorithm on realistic mock SDSS catalogs suggest that the detected sample is {approx} 85% complete and over 90% pure for clusters with masses above 1.0 x 10{sup 14}h{sup -1} M and redshifts up to z = 0.45. The errors of estimated cluster redshifts from maximum likelihood method are shown to be small (typically less that 0.01) over the whole redshift range with photometric redshift errors typical of those found in the Sloan survey. Inside the spherical radius corresponding to a galaxy overdensity of {Delta} = 200, we find the derived cluster richness {Lambda}{sub 200} a roughly linear indicator of its virial mass M{sub 200}, which well recovers the relation between total luminosity and cluster mass of the input simulation.

  5. 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. PMID:25205526

  6. 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.

  7. 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%).

  8. Optical Waveguide Lightmode Spectroscopic Techniques for Investigating Membrane-Bound Ion Channel Activities

    PubMed Central

    Székács, Inna; Kaszás, Nóra; Gróf, Pál; Erdélyi, Katalin; Szendrő, István; Mihalik, Balázs; Pataki, Ágnes; Antoni, Ferenc A.; Madarász, Emilia

    2013-01-01

    Optical waveguide lightmode spectroscopic (OWLS) techniques were probed for monitoring ion permeation through channels incorporated into artificial lipid environment. A novel sensor set-up was developed by depositing liposomes or cell-derived membrane fragments onto hydrophilic polytetrafluoroethylene (PTFE) membrane. The fibrous material of PTFE membrane could entrap lipoid vesicles and the water-filled pores provided environment for the hydrophilic domains of lipid-embedded proteins. The sensor surface was kept clean from the lipid holder PTFE membrane by a water- and ion-permeable polyethylene terephthalate (PET) mesh. The sensor set-up was tested with egg yolk lecithin liposomes containing gramicidin ion channels and with cell-derived membrane fragments enriched in GABA-gated anion channels. The method allowed monitoring the move of Na+ and organic cations through gramicidin channels and detecting the Cl–-channel functions of the (α5β2γ2) GABAA receptor in the presence or absence of GABA and the competitive GABA-blocker bicuculline. PMID:24339925

  9. Structural studies of E. coli ribosomes by spectroscopic techniques: A specialized review

    NASA Astrophysics Data System (ADS)

    Bonicontro, Adalberto; Risuleo, Gianfranco

    2005-12-01

    We present a review on our interdisciplinary line of research based on strategies of molecular biology and biophysics. These have been applied to the study of the prokaryotic ribosome of the bacterium Escherichia coli. Our investigations on this organelle have continued for more than a decade and we have adopted different spectroscopic biophysical techniques such as: dielectric and fluorescence spectroscopy as well as light scattering (photon correlation spectroscopy). Here we report studies on the whole 70S ribosomes and on the separated subunits 30S and 50S. Our results evidence intrinsic structural features of the subunits: the small shows a more "floppy" structure, while the large one appears to be more rigid. Also, an inner "kernel" formed by the RNA/protein association is found within the ribosome. This kernel is surrounded by a ribonucleoprotein complex more exposed to the solvent. Initial analyses were done on the so called Kaldtschmit-Wittmann ribosome: more recently we have extended the studies to the "tight couple" ribosome known for its better functional performance in vitro. Data evidence a phenomenological correlation between the differential biological activity and the intrinsic structural properties of the two-ribosome species. Finally, investigations were also conducted on particles treated at sub-denaturing temperatures and on ribosomes partially deproteinized by salt treatment (ribosomal cores). Results suggest that the thermal treatment and the selective removal of proteins cause analogous structural alterations.

  10. 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

    2016-01-01

    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%). PMID:27355937

  11. 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.

  12. 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.

  13. A Solution Adaptive Technique Using Tetrahedral Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar Z.

    2000-01-01

    An adaptive unstructured grid refinement technique has been developed and successfully applied to several three dimensional inviscid flow test cases. The method is based on a combination of surface mesh subdivision and local remeshing of the volume grid Simple functions of flow quantities are employed to detect dominant features of the flowfield The method is designed for modular coupling with various error/feature analyzers and flow solvers. Several steady-state, inviscid flow test cases are presented to demonstrate the applicability of the method for solving practical three-dimensional problems. In all cases, accurate solutions featuring complex, nonlinear flow phenomena such as shock waves and vortices have been generated automatically and efficiently.

  14. [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. PMID:20101970

  15. [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.

  16. Sensor Web Dynamic Measurement Techniques and Adaptive Observing Strategies

    NASA Technical Reports Server (NTRS)

    Talabac, Stephen J.

    2004-01-01

    Sensor Web observing systems may have the potential to significantly improve our ability to monitor, understand, and predict the evolution of rapidly evolving, transient, or variable environmental features and events. This improvement will come about by integrating novel data collection techniques, new or improved instruments, emerging communications technologies and protocols, sensor mark-up languages, and interoperable planning and scheduling systems. In contrast to today's observing systems, "event-driven" sensor webs will synthesize real- or near-real time measurements and information from other platforms and then react by reconfiguring the platforms and instruments to invoke new measurement modes and adaptive observation strategies. Similarly, "model-driven" sensor webs will utilize environmental prediction models to initiate targeted sensor measurements or to use a new observing strategy. The sensor web concept contrasts with today's data collection techniques and observing system operations concepts where independent measurements are made by remote sensing and in situ platforms that do not share, and therefore cannot act upon, potentially useful complementary sensor measurement data and platform state information. This presentation describes NASA's view of event-driven and model-driven Sensor Webs and highlights several research and development activities at the Goddard Space Flight Center.

  17. Optical techniques to understand biofunctional adaptation in human dentine

    NASA Astrophysics Data System (ADS)

    Kishen, Anil; Asundi, Anand K.

    2004-08-01

    Human tooth structure in the oral environment is subjected to mechanical forces and thermal fluctuations. Dentine, the major component of the tooth structure, is a bio-composite, mainly composed of a highly mineralized phase and a collagenous phase. When subjected to changes in load and/or temperature, dentine will experience stresses and strains distribution within their structure. Though such effects are found to cause deleterious effects on artificial dental restorations, biological structures such as dentine seem to posses an inherent ability to adapt to functional thermo-mechanical loads. Optical techniques enable visualization and quantification of deformation, strain and stress on dental structures and provide a better understanding on their thermo-mechanical response. In this study 2-dimensional and 3-dimensional digital photoelasticity, digital moiré interferometry and Electronic Speckle Pattern Interferometry (ESPI) are all shown to be quite promising in this application. This paper will highlight these techniques and the corresponding applications. These experiments will aid in designing and development of better dental restorations and implants in clinical practice.

  18. Adaptive Techniques for Intelligent Onboard Magnetospheric/Ionospheric Radar

    NASA Astrophysics Data System (ADS)

    Galkin, I. A.; Huang, X.; Reinisch, B. W.; Benson, R. F.

    2006-12-01

    Rapid detection and response to sudden changes in the space plasma surrounding the Earth is instrumental to achieving the strategic goals in Sun-Earth Connection and Space Weather research conducted by NASA. It also provides important knowledge for adaptive planning of the science instrument operations that have to accommodate tremendous plasma variability along the orbit. Radio sounding has been used by multiple space missions to accurately determine plasma density, both locally and remotely. Its major science product, however, is an image of signal strength in the frequency vs. travel time frame, whose autonomous analysis onboard is a non-trivial, intelligent system task. We present a fully-autonomous technique for analysis of relaxation sounding data collected by the Radio Plasma Imager (RPI) on IMAGE satellite during 2000-2005. The technique interprets data by detecting signatures of major plasma resonances in the image and then interpreting them by seeking the best match to the theoretical model of resonance inter-dependencies. Testing of the algorithm against collected RPI data indicate partial success in evaluation of resonance frequencies. Whereas robust and accurate determination of the electron gyro-frequency from RPI data appears possible, the plasma frequency signatures can often be too weak to be detected and interpreted automatically. We discuss the conditions for correct evaluation of the plasma frequency in the RPI data, derive requirements to the radar instrument design from the analysis results, and outline potential for onboard implementation and utility in subsequent decision making process.

  19. 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.

  20. 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

  1. Study on the interaction between ginsenoside Rh2 and calf thymus DNA by spectroscopic techniques.

    PubMed

    Wu, Dudu; Chen, Zhi

    2015-12-01

    The interaction between ginsenoside Rh2 (G-Rh2) and calf thymus DNA (ctDNA) was investigated by spectroscopic methods including UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy, coupled with DNA melting techniques and viscosity measurements. Stern-Volmer plots at different temperatures proved that the quenching mechanism was a static quenching procedure. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated to be -22.83 KJ · mol(-1) and 15.11 J · mol(-1) · K(-1) by van 't Hoff equation, suggesting that hydrophobic force might play a major role in the binding of G-Rh2 to ctDNA. Moreover, the fluorescence quenching study with potassium iodide as quencher indicated that the KSV (Stern-Volmer quenching constant) value for the bound G-Rh2 with ctDNA was lower than the free G-Rh2. The relative viscosity of ctDNA increased with the addition of G-Rh2 and also the ctDNA melting temperature increased in the presence of G-Rh2. Denatured DNA studies showed that quenching by single-stranded DNA was less than that by double-stranded DNA. The observed changes in CD spectra also demonstrated that the intensities of the positive and negative bands decreased with the addition of G-Rh2. The experimental results suggest that G-Rh2 molecules bind to ctDNA via an intercalative binding mode.

  2. Study on the interaction between ginsenoside Rh2 and calf thymus DNA by spectroscopic techniques.

    PubMed

    Wu, Dudu; Chen, Zhi

    2015-12-01

    The interaction between ginsenoside Rh2 (G-Rh2) and calf thymus DNA (ctDNA) was investigated by spectroscopic methods including UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy, coupled with DNA melting techniques and viscosity measurements. Stern-Volmer plots at different temperatures proved that the quenching mechanism was a static quenching procedure. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated to be -22.83 KJ · mol(-1) and 15.11 J · mol(-1) · K(-1) by van 't Hoff equation, suggesting that hydrophobic force might play a major role in the binding of G-Rh2 to ctDNA. Moreover, the fluorescence quenching study with potassium iodide as quencher indicated that the KSV (Stern-Volmer quenching constant) value for the bound G-Rh2 with ctDNA was lower than the free G-Rh2. The relative viscosity of ctDNA increased with the addition of G-Rh2 and also the ctDNA melting temperature increased in the presence of G-Rh2. Denatured DNA studies showed that quenching by single-stranded DNA was less than that by double-stranded DNA. The observed changes in CD spectra also demonstrated that the intensities of the positive and negative bands decreased with the addition of G-Rh2. The experimental results suggest that G-Rh2 molecules bind to ctDNA via an intercalative binding mode. PMID:25727213

  3. 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. PMID:25801382

  4. Indirect techniques for adaptive input-output linearization of non-linear systems

    NASA Technical Reports Server (NTRS)

    Teel, Andrew; Kadiyala, Raja; Kokotovic, Peter; Sastry, Shankar

    1991-01-01

    A technique of indirect adaptive control based on certainty equivalence for input output linearization of nonlinear systems is proven convergent. It does not suffer from the overparameterization drawbacks of the direct adaptive control techniques on the same plant. This paper also contains a semiindirect adaptive controller which has several attractive features of both the direct and indirect schemes.

  5. Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique

    NASA Technical Reports Server (NTRS)

    Li, Lihua; Coon, Michael; McLinden, Matthew

    2013-01-01

    Pulse compression has been widely used in radars so that low-power, long RF pulses can be transmitted, rather than a highpower short pulse. Pulse compression radars offer a number of advantages over high-power short pulsed radars, such as no need of high-power RF circuitry, no need of high-voltage electronics, compact size and light weight, better range resolution, and better reliability. However, range sidelobe associated with pulse compression has prevented the use of this technique on spaceborne radars since surface returns detected by range sidelobes may mask the returns from a nearby weak cloud or precipitation particles. Research on adaptive pulse compression was carried out utilizing a field-programmable gate array (FPGA) waveform generation board and a radar transceiver simulator. The results have shown significant improvements in pulse compression sidelobe performance. Microwave and millimeter-wave radars present many technological challenges for Earth and planetary science applications. The traditional tube-based radars use high-voltage power supply/modulators and high-power RF transmitters; therefore, these radars usually have large size, heavy weight, and reliability issues for space and airborne platforms. Pulse compression technology has provided a path toward meeting many of these radar challenges. Recent advances in digital waveform generation, digital receivers, and solid-state power amplifiers have opened a new era for applying pulse compression to the development of compact and high-performance airborne and spaceborne remote sensing radars. The primary objective of this innovative effort is to develop and test a new pulse compression technique to achieve ultrarange sidelobes so that this technique can be applied to spaceborne, airborne, and ground-based remote sensing radars to meet future science requirements. By using digital waveform generation, digital receiver, and solid-state power amplifier technologies, this improved pulse compression

  6. The retention of uranium and europium onto sepiolite investigated by macroscopic, spectroscopic and modeling techniques

    NASA Astrophysics Data System (ADS)

    Sun, Yubing; Li, Jiaxing; Wang, Xiangke

    2014-09-01

    Clay minerals have been proposed for the potential retention of the high-level radioactive wastes in deep geological repositories. The retention of uranium (U(VI)) and europium (Eu(III)) onto well-characterized sepiolite was elucidated by using microscopic adsorption, spectroscopic techniques and surface complexation modeling. The results of macroscopic adsorption experiments showed that the uptake of U(VI) and Eu(III) onto sepiolite significantly increased with increasing pH 4.0-7.0, whereas the decrease adsorption of U(VI) at pH > 7.0 and in the presence of carbonate (10-3 mol/L) was attributed to the electrostatic repulsion. The chemical affinity of U(VI) with sepiolite was stronger than that of Eu(III) with sepiolite in terms of batch desorption tests. Based on the EXAFS spectra analysis, the interatomic distances of U-Si at ∼3.16 Å was observed in U(VI)/sepiolite systems, which indicated that the inner-sphere surface species were coordinated on SiO4 tetrahedra via bidentate configuration. The U-C shell at ∼2.9 Å in the presence of carbonate revealed the U(VI)-carbonate ternary complexes at sepiolite-water interface. The results from the three common surface complexation models (SCMs), including constant-capacitance model (CCM), diffuse-layer model (DLM), and triple-layer model (TLM), can give an excellent fit to the experimental data with the bidentate edge-sharing (E2, >SO2M(n - 2)+), bidentate corner-sharing (C2, (>SO)2M(OH)2(n - 4)+) and >SOMCO3(n - 3)+ inner-sphere surface complexes in ambient environments. However, the second ternary surface complex >SOCO2M(n - 1)+ was determined in the presence of carbonate. The findings presented in this study are significant toward the description and predication of fate and transport of radionuclides at the water-mineral interface in the natural environment.

  7. Characterization of fresh and aged natural ingredients used in historical ointments by molecular spectroscopic techniques: IR, Raman and fluorescence.

    PubMed

    Brambilla, L; Riedo, C; Baraldi, C; Nevin, A; Gamberini, M C; D'Andrea, C; Chiantore, O; Goidanich, S; Toniolo, L

    2011-10-01

    Natural organic materials used to prepare pharmaceutical mixtures including ointments and balsams have been characterized by a combined non-destructive spectroscopic analytical approach. Three classes of materials which include vegetable oils (olive, almond and palm tree), gums (Arabic and Tragacanth) and beeswax are considered in this study according to their widespread use reported in ancient recipes. Micro-FTIR, micro-Raman and fluorescence spectroscopies have been applied to fresh and mildly thermally aged samples. Vibrational characterization of these organic compounds is reported together with tabulated frequencies, highlighting all spectral features and changes in spectra which occur following artificial aging. Synchronous fluorescence spectroscopy has been shown to be particularly useful for the assessment of changes in oils after aging; spectral difference between Tragacanth and Arabic gum could be due to variations in origin and processing of raw materials. Analysis of these materials using non-destructive spectroscopic techniques provided important analytical information which could be used to guide further study.

  8. Development of adaptive resonator techniques for high-power lasers

    SciTech Connect

    An, J; Brase, J; Carrano, C; Dane, C B; Flath, L; Fochs, S; Hurd, R; Kartz, M; Sawvel, R

    1999-07-12

    The design of an adaptive wavefront control system for a high-power Nd:Glass laser will be presented. Features of this system include: an unstable resonator in confocal configuration, a multi-module slab amplifier, and real-time intracavity adaptive phase control using deformable mirrors and high-speed wavefront sensors. Experimental results demonstrate the adaptive correction of an aberrated passive resonator (no gain).

  9. Techniques for radar imaging using a wideband adaptive array

    NASA Astrophysics Data System (ADS)

    Curry, Mark Andrew

    A microwave imaging approach is simulated and validated experimentally that uses a small, wideband adaptive array. The experimental 12-element linear array and microwave receiver uses stepped frequency CW signals from 2--3 GHz and receives backscattered energy from short range objects in a +/-90° field of view. Discone antenna elements are used due to their wide temporal bandwidth, isotropic azimuth beam pattern and fixed phase center. It is also shown that these antennas have very low mutual coupling, which significantly reduces the calibration requirements. The MUSIC spectrum is used as a calibration tool. Spatial resampling is used to correct the dispersion effects, which if not compensated causes severe reduction in detection and resolution for medium and large off-axis angles. Fourier processing provides range resolution and the minimum variance spectral estimate is employed to resolve constant range targets for improved angular resolution. Spatial smoothing techniques are used to generate signal plus interference covariance matrices at each range bin. Clutter affects the angular resolution of the array due to the increase in rank of the signal plus clutter covariance matrix, whereas at the same time the rank of this matrix is reduced for closely spaced scatterers due to signal coherence. A method is proposed to enhance angular resolution in the presence of clutter by an approximate signal subspace projection (ASSP) that maps the received signal space to a lower effective rank approximation. This projection operator has a scalar control parameter that is a function of the signal and clutter amplitude estimates. These operations are accomplished without using eigendecomposition. The low sidelobe levels allow the imaging of the integrated backscattering from the absorber cones in the chamber. This creates a fairly large clutter signature for testing ASSP. We can easily resolve 2 dihedrals placed at about 70% of a beamwidth apart, with a signal to clutter ratio

  10. 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.

  11. 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. PMID:26210796

  12. Beaconless adaptive-optics technique for HEL beam control

    NASA Astrophysics Data System (ADS)

    Khizhnyak, Anatoliy; Markov, Vladimir

    2016-05-01

    Effective performance of forthcoming laser systems capable of power delivery on a distant target requires an adaptive optics system to correct atmospheric perturbations on the laser beam. The turbulence-induced effects are responsible for beam wobbling, wandering, and intensity scintillation, resulting in degradation of the beam quality and power density on the target. Adaptive optics methods are used to compensate for these negative effects. In its turn, operation of the AOS system requires a reference wave that can be generated by the beacon on the target. This report discusses a beaconless approach for wavefront correction with its performance based on the detection of the target-scattered light. Postprocessing of the beacon-generated light field enables retrieval and detailed characterization of the turbulence-perturbed wavefront -data that is essential to control the adaptive optics module of a high-power laser system.

  13. Techniques for grid manipulation and adaptation. [computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Choo, Yung K.; Eisemann, Peter R.; Lee, Ki D.

    1992-01-01

    Two approaches have been taken to provide systematic grid manipulation for improved grid quality. One is the control point form (CPF) of algebraic grid generation. It provides explicit control of the physical grid shape and grid spacing through the movement of the control points. It works well in the interactive computer graphics environment and hence can be a good candidate for integration with other emerging technologies. The other approach is grid adaptation using a numerical mapping between the physical space and a parametric space. Grid adaptation is achieved by modifying the mapping functions through the effects of grid control sources. The adaptation process can be repeated in a cyclic manner if satisfactory results are not achieved after a single application.

  14. 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.

  15. Studies on the binding behavior of prodigiosin with bovine hemoglobin by multi-spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Yang, Chao; Zhou, Lin; Ma, Fei; Liu, Shuchao; Wei, Shaohua; Zhou, Jiahong; Zhou, Yanhuai

    2012-10-01

    In this article, the interaction mechanism of prodigiosin (PG) with bovine hemoglobin (BHb) is studied in detail using various spectroscopic technologies. UV-vis absorption and fluorescence spectra demonstrate the interaction process. The Stern-Volmer plot and the time-resolved fluorescence study suggest the quenching mechanism of fluorescence of BHb by PG is a static quenching procedure, and the hydrophobic interactions play a major role in binding of PG to BHb. Furthermore, synchronous fluorescence studies, Fourier transform infrared (FTIR) and circular dichroism (CD) spectra reveal that the conformation of BHb is changed after conjugation with PG.

  16. Studies on the binding behavior of prodigiosin with bovine hemoglobin by multi-spectroscopic techniques.

    PubMed

    Tang, Jing; Yang, Chao; Zhou, Lin; Ma, Fei; Liu, Shuchao; Wei, Shaohua; Zhou, Jiahong; Zhou, Yanhuai

    2012-10-01

    In this article, the interaction mechanism of prodigiosin (PG) with bovine hemoglobin (BHb) is studied in detail using various spectroscopic technologies. UV-vis absorption and fluorescence spectra demonstrate the interaction process. The Stern-Volmer plot and the time-resolved fluorescence study suggest the quenching mechanism of fluorescence of BHb by PG is a static quenching procedure, and the hydrophobic interactions play a major role in binding of PG to BHb. Furthermore, synchronous fluorescence studies, Fourier transform infrared (FTIR) and circular dichroism (CD) spectra reveal that the conformation of BHb is changed after conjugation with PG.

  17. Diffusion-weighted line-scan echo-planar spectroscopic imaging technique to reduce motion artifacts in metabolite diffusion imaging.

    PubMed

    Bito, Yoshitaka; Hirata, Koji; Ebisu, Toshihiko; Kawai, Yuko; Otake, Yosuke; Hirata, Satoshi; Shirai, Toru; Soutome, Yoshihisa; Ochi, Hisaaki; Yamamoto, Etsuji; Umeda, Masahiro; Higuchi, Toshihiro; Tanaka, Chuzo

    2015-01-01

    Metabolite diffusion is expected to provide more specific microstructural and functional information than water diffusion. However, highly accurate measurement techniques have still not been developed, especially for reducing motion artifacts caused by cardiac pulsation and respiration. We developed a diffusion-weighted line-scan echo-planar spectroscopic imaging (DW-LSEPSI) technique to reduce such motion artifacts in measuring diffusion-weighted images (DWI) of metabolites. Our technique uses line-scan and echo-planar techniques to reduce phase errors induced by such motion during diffusion time. The phase errors are corrected using residual water signals in water suppression for each acquisition and at each spatial pixel specified by combining the line-scan and echo-planar techniques. We apply this technique to a moving phantom and a rat brain in vivo to demonstrate the reduction of motion artifacts in DWI and apparent diffusion coefficient (ADC) maps of metabolites. DW-LSEPSI will be useful for investigating a cellular diffusion environment using metabolites as probes.

  18. 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.

  19. 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.

  20. Scientific Motivational Techniques Adaptable to Social Studies Lessons

    ERIC Educational Resources Information Center

    Steiner, Robert L.

    1975-01-01

    Two science classroom techniques that can be used in the social studies classroom to motivate students involve puzzling phenomena and relating science to social issues such as over-population, energy, and pollution. (JR)

  1. 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.

  2. Swarm Intelligence: New Techniques for Adaptive Systems to Provide Learning Support

    ERIC Educational Resources Information Center

    Wong, Lung-Hsiang; Looi, Chee-Kit

    2012-01-01

    The notion of a system adapting itself to provide support for learning has always been an important issue of research for technology-enabled learning. One approach to provide adaptivity is to use social navigation approaches and techniques which involve analysing data of what was previously selected by a cluster of users or what worked for…

  3. Corrosion detection in steel-reinforced concrete using a spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Garboczi, E. J.; Stutzman, P. E.; Wang, S.; Martys, N. S.; Hassan, A. M.; Duthinh, D.; Provenzano, V.; Chou, S. G.; Plusquellic, D. F.; Surek, J. T.; Kim, S.; McMichael, R. D.; Stiles, M. D.

    2014-02-01

    Detecting the early corrosion of steel that is embedded in reinforced concrete (rebar) is a goal that would greatly facilitate the inspection and measurement of corrosion in the US physical infrastructure. Since 2010, the National Institute of Standards and Technology (NIST) has been working on a large project to develop an electromagnetic (EM) probe that detects the specific corrosion products via spectroscopic means. Several principal iron corrosion products, such as hematite and goethite, are antiferromagnetic at field temperatures. At a given applied EM frequency, which depends on temperature, these compounds undergo a unique absorption resonance that identifies the presence of these particular iron corrosion products. The frequency of the resonances tends to be on the order of 100 GHz or higher, so transmitting EM waves through the cover concrete and back out again at a detectable level has been challenging. NIST has successfully detected these two iron corrosion products, and is developing equipment and methodologies that will be capable of penetrating the typical 50 mm of cover concrete in the field. The novel part of this project is the detection of specific compounds, rather than only geometrical changes in rebar cross-section. This method has the potential of providing an early-corrosion probe for steel in reinforced concrete, and for other applications where steel is covered by various layers and coatings.

  4. Develop techniques for ion implantation of PLZT for adaptive optics

    NASA Astrophysics Data System (ADS)

    Craig, R. A.; Batishko, C. R.; Brimhall, J. L.; Pawlewicz, W. T.; Stahl, K. A.

    1989-11-01

    Battelle Pacific Northwest Laboratory (PNL) conducted research into the preparation and characterization of ion-implanted adaptive optic elements based on lead-lanthanum-zirconate-titanate (PLZT). Over the 4-yr effort beginning FY 1985, the ability to increase the photosensitivity of PLZT and extend it to longer wavelengths was developed. The emphasis during the last two years was to develop a model to provide a basis for choosing implantation species and parameters. Experiments which probe the electronic structure were performed on virgin and implanted PLZT samples. Also performed were experiments designed to connect the developing conceptual model with the experimental results. The emphasis in FY 1988 was to extend the photosensitivity out to diode laser wavelengths. The experiments and modelling effort indicate that manganese will form appropriate intermediate energy states to achieve the longer wavelength photosensitivity. Preliminary experiments were also conducted to deposit thin film PLZT.

  5. Study of second-order nonlinear hyperpolarisability of all-trans-β-carotene in solutions by linear spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Fang, Wen-Hui; Men, Zhi-Wei; Sun, Cheng-Lin; Qu, Guan-Nan; Yang, Guang; Li, Zuo-Wei; Gao, Shu-Qin; Lu, Guo-Hui

    2010-06-01

    This paper demonstrates the second-order nonlinear hyperpolarisability γ of all-trans-β-carotene in different solvents by linear spectroscopic technique that is based on resonance Raman scattering and UV-VIS (Ultraviolet-visible) absorption spectroscopy. Owing to the two-level model well describing the link that exists between the resonance Raman scattering and stimulated Raman scattering, the stimulated Raman polarisability αR can be calculated through the two-photon resonance system. The value of γ of all-trans-β-carotene in carbon bisulfide solution is 6.435 × 10-33 esu (1 esu of resistance = 8.98755 × 1011 ω) that is close to the true value, because the solution of all-trans-β-carotene in carbon bisulfide satisfies the rigid resonance Raman scattering condition. This method is expected to be worthy of applications to measure the second-order nonlinear hyperpolarisability of a conjugate organic molecule.

  6. 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.

  7. 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.

  8. Assessment of Service Protocols Adaptability Using a Novel Path Computation Technique

    NASA Astrophysics Data System (ADS)

    Zhou, Zhangbing; Bhiri, Sami; Haller, Armin; Zhuge, Hai; Hauswirth, Manfred

    In this paper we propose a new kind of adaptability assessment that determines whether service protocols of a requestor and a provider are adaptable, computes their adaptation degree, and identifies conditions that determine when they can be adapted. We also propose a technique that implements this adaptability assessment: (1) we construct a complete adaptation graph that captures all service interactions adaptable between these two service protocols. The emptiness or non-emptiness of this graph corresponds to the fact that whether or not they are adaptable; (2) we propose a novel path computation technique to generate all instance sub-protocols which reflect valid executions of a particular service protocol, and to derive all instance sub-protocol pairs captured by the complete adaptation graph. An adaptation degree is computed as a ratio between the number of instance sub-protocols captured by these instance sub-protocol pairs with respect to a service protocol and that of this service protocol; (3) and finally we identify a set of conditions based on these instance sub-protocol pairs. A condition is the conjunction of all conditions specified on the transitions of a given pair of instance sub-protocols. This assessment is a comprehensive means of selecting the suitable service protocol among functionally-equivalent candidates according to the requestor's business requirements.

  9. Parallel adaptive mesh refinement techniques for plasticity problems

    NASA Technical Reports Server (NTRS)

    Barry, W. J.; Jones, M. T.; Plassmann, P. E.

    1997-01-01

    The accurate modeling of the nonlinear properties of materials can be computationally expensive. Parallel computing offers an attractive way for solving such problems; however, the efficient use of these systems requires the vertical integration of a number of very different software components, we explore the solution of two- and three-dimensional, small-strain plasticity problems. We consider a finite-element formulation of the problem with adaptive refinement of an unstructured mesh to accurately model plastic transition zones. We present a framework for the parallel implementation of such complex algorithms. This framework, using libraries from the SUMAA3d project, allows a user to build a parallel finite-element application without writing any parallel code. To demonstrate the effectiveness of this approach on widely varying parallel architectures, we present experimental results from an IBM SP parallel computer and an ATM-connected network of Sun UltraSparc workstations. The results detail the parallel performance of the computational phases of the application during the process while the material is incrementally loaded.

  10. Time domain and frequency domain design techniques for model reference adaptive control systems

    NASA Technical Reports Server (NTRS)

    Boland, J. S., III

    1971-01-01

    Some problems associated with the design of model-reference adaptive control systems are considered and solutions to these problems are advanced. The stability of the adapted system is a primary consideration in the development of both the time-domain and the frequency-domain design techniques. Consequentially, the use of Liapunov's direct method forms an integral part of the derivation of the design procedures. The application of sensitivity coefficients to the design of model-reference adaptive control systems is considered. An application of the design techniques is also presented.

  11. Transdental photo-activation technique: hardness and marginal adaptation of composite restorations using different light sources.

    PubMed

    Alves, Eliane Bemerguy; Alonso, Roberta Caroline Bruschi; Correr, Gisele Maria; Correr, Américo Bortolazzo; de Moraes, Rafael Ratto; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço

    2008-01-01

    This study investigated the influence of different light sources associated with a transdental photoactivation technique on the marginal adaptation and hardness of composite restorations. Cavities (3 mm wide x 3 mm long x 1.5 mm in deep) were prepared on flattened bovine dentin and filled with Z250 composite (3M ESPE). Nine groups (n=10) were defined according to the curing technique (direct; transdental--photo-activation through 1 mm of enamel and 2 mm of dentin; mixed--transdental + direct) and light source (QTH XL2500, 3M ESPE; PAC Apollo 95E, DMD; LED Ultrablue Is, DMC) combination. Marginal adaptation was evaluated using a dye staining method, and the percentage of stained margins was recorded. Knoop Hardness readings were made across the transversal section of the fillings. Data were submitted to two-way ANOVA and Tukey's test (p< or =0.05). For margin analysis, although none of the curing conditions provided perfect adaptation, the mixed technique showed lower gap formation. No significant differences were detected between the transdental and other techniques, and no significant differences were detected among the light sources. For hardness, the direct technique showed slightly greater hardness than the mixed technique. Also, the mixed technique yielded greater hardness than the transdental technique. Among the light sources, the LED showed greater hardness than the PAC; whereas, no significant differences between the QTH and other sources were detected. The mixed technique might improve the marginal adaptation of restorations, while not being detrimental to composite hardness.

  12. Baseline Adaptive Wavelet Thresholding Technique for sEMG Denoising

    NASA Astrophysics Data System (ADS)

    Bartolomeo, L.; Zecca, M.; Sessa, S.; Lin, Z.; Mukaeda, Y.; Ishii, H.; Takanishi, Atsuo

    2011-06-01

    The surface Electromyography (sEMG) signal is affected by different sources of noises: current technology is considerably robust to the interferences of the power line or the cable motion artifacts, but still there are many limitations with the baseline and the movement artifact noise. In particular, these sources have frequency spectra that include also the low-frequency components of the sEMG frequency spectrum; therefore, a standard all-bandwidth filtering could alter important information. The Wavelet denoising method has been demonstrated to be a powerful solution in processing white Gaussian noise in biological signals. In this paper we introduce a new technique for the denoising of the sEMG signal: by using the baseline of the signal before the task, we estimate the thresholds to apply to the Wavelet thresholding procedure. The experiments have been performed on ten healthy subjects, by placing the electrodes on the Extensor Carpi Ulnaris and Triceps Brachii on right upper and lower arms, and performing a flexion and extension of the right wrist. An Inertial Measurement Unit, developed in our group, has been used to recognize the movements of the hands to segment the exercise and the pre-task baseline. Finally, we show better performances of the proposed method in term of noise cancellation and distortion of the signal, quantified by a new suggested indicator of denoising quality, compared to the standard Donoho technique.

  13. Stochastic Leader Gravitational Search Algorithm for Enhanced Adaptive Beamforming Technique

    PubMed Central

    Darzi, Soodabeh; Islam, Mohammad Tariqul; Tiong, Sieh Kiong; Kibria, Salehin; Singh, Mandeep

    2015-01-01

    In this paper, stochastic leader gravitational search algorithm (SL-GSA) based on randomized k is proposed. Standard GSA (SGSA) utilizes the best agents without any randomization, thus it is more prone to converge at suboptimal results. Initially, the new approach randomly choses k agents from the set of all agents to improve the global search ability. Gradually, the set of agents is reduced by eliminating the agents with the poorest performances to allow rapid convergence. The performance of the SL-GSA was analyzed for six well-known benchmark functions, and the results are compared with SGSA and some of its variants. Furthermore, the SL-GSA is applied to minimum variance distortionless response (MVDR) beamforming technique to ensure compatibility with real world optimization problems. The proposed algorithm demonstrates superior convergence rate and quality of solution for both real world problems and benchmark functions compared to original algorithm and other recent variants of SGSA. PMID:26552032

  14. Adaptation of a coculture technique to the Minitek anaerobe system.

    PubMed Central

    Hussain, Z; Lannigan, R; Bürger, H; Groves, D

    1985-01-01

    A method to produce anaerobic conditions by coculture with a nonfermentative organism was utilized in conjunction with the Minitek anaerobe system (BBL Microbiology Systems, Cockeysville, Md.) for identification of anaerobic bacteria from clinical specimens. With the coculture method, the Minitek anaerobe identification tests could be incubated under aerobic conditions. In 1,900 individual biochemical reactions, 1,826 (96%) were identical whether anaerobic conditions were achieved by conventional or coculture techniques. In comparison with the reference identification (Virginia Polytechnic Institute and State University, Blacksburg), both systems of incubation identified 91 of 99 strains (92%) correctly. The method of incubation had an effect on identification to the genus level in 1 of 99 (1%) strains and to the species level in 3 of 99 (3%) strains. PMID:3886697

  15. Adaptive array technique for differential-phase reflectometry in QUEST

    SciTech Connect

    Idei, H. Hanada, K.; Zushi, H.; Nagata, K.; Mishra, K.; Itado, T.; Akimoto, R.; Yamamoto, M. K.

    2014-11-15

    A Phased Array Antenna (PAA) was considered as launching and receiving antennae in reflectometry to attain good directivity in its applied microwave range. A well-focused beam was obtained in a launching antenna application, and differential-phase evolution was properly measured by using a metal reflector plate in the proof-of-principle experiment at low power test facilities. Differential-phase evolution was also evaluated by using the PAA in the Q-shu University Experiment with Steady State Spherical Tokamak (QUEST). A beam-forming technique was applied in receiving phased-array antenna measurements. In the QUEST device that should be considered as a large oversized cavity, standing wave effect was significantly observed with perturbed phase evolution. A new approach using derivative of measured field on propagating wavenumber was proposed to eliminate the standing wave effect.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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.).

  18. My Solar System: A Developmentally Adapted Eco-Mapping Technique for Children

    ERIC Educational Resources Information Center

    Curry, Jennifer R.; Fazio-Griffith, Laura J.; Rohr, Shannon N.

    2008-01-01

    Counseling children requires specific skills and techniques, such as play therapy and expressive arts, to address developmental manifestations and to facilitate the understanding of presenting problems. This article outlines an adapted eco-mapping activity that can be used as a creative counseling technique with children in order to promote…

  19. Identification of polycyclic aromatic hydrocarbons (PAHs) in suspended particulate matter by synchronous fluorescence spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Sharma, Homdutt; Jain, V. K.; Khan, Zahid H.

    2007-09-01

    The synchronous fluorescence (SF) technique has been used in the identification of polycyclic aromatic hydrocarbons (PAHs) from air particulate sample in an urban environment of Delhi, Jawaharlal Nehru University. Suspended particulate matter samples of 24 h duration were collected on glass fiber filter papers. PAHs were extracted from the filter papers using dichloromethane (DCM) + hexane with ultrasonication method. Qualitative measurements of the polycyclic aromatic hydrocarbons (PAHs) were carried out using the SF technique at various wavelength intervals (Δ λ). Due to the difference in chemical structure, each PAH gives specific characteristic spectrum for each Δ λ. Following PAHs were detected in our measurement: benz(a)anthracene (BaA), pyrene (Pyr), chrysene (Chry), fluoranthene (Flan), phenanthrene (Phen), and benz(ghi)perylene (BghiP). This is in agreement with our earlier work for determination of these PAHs using gas chromatography (GC). The seasonal variation of the PAHs was found to be maximum in winter and minimum during the monsoon.

  20. 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.

  1. 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. PMID:20541637

  2. 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.

  3. Adaptive Remote-Sensing Techniques Implementing Swarms of Mobile Agents

    SciTech Connect

    Asher, R.B.; Cameron, S.M.; Loubriel, G.M.; Robinett, R.D.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1998-11-25

    In many situations, stand-off remote-sensing and hazard-interdiction techniques over realistic operational areas are often impractical "and difficult to characterize. An alternative approach is to implement an adap- tively deployable array of sensitive agent-specific devices. Our group has been studying the collective be- havior of an autonomous, multi-agent system applied to chedbio detection and related emerging threat applications, The current physics-based models we are using coordinate a sensor array for mukivanate sig- nal optimization and coverage as re,alized by a swarm of robots or mobile vehicles. These intelligent control systems integrate'glob"ally operating decision-making systems and locally cooperative learning neural net- works to enhance re+-timp operational responses to dynarnical environments examples of which include obstacle avoidance, res~onding to prevailing wind patterns, and overcoming other natural obscurants or in- terferences. Collectively',tkensor nefirons with simple properties, interacting according to basic community rules, can accomplish complex interconnecting functions such as generalization, error correction, pattern recognition, sensor fusion, and localization. Neural nets provide a greater degree of robusmess and fault tolerance than conventional systems in that minor variations or imperfections do not impair performance. The robotic platforms would be equipped with sensor devices that perform opticaI detection of biologicais in combination with multivariate chemical analysis tools based on genetic and neural network algorithms, laser-diode LIDAR analysis, ultra-wideband short-pulsed transmitting and receiving antennas, thermal im- a:ing sensors, and optical Communication technology providing robust data throughput pathways. Mission scenarios under consideration include ground penetrating radar (GPR) for detection of underground struc- tures, airborne systems, and plume migration and mitigation. We will describe our research in

  4. Adaptive Remote-Sensing Techniques Implementing Swarms of Mobile Agents

    SciTech Connect

    Cameron, S.M.; Loubriel, G.M.; Rbinett, R.D. III; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1999-04-01

    This paper focuses on our recent work at Sandia National Laboratories toward engineering a physics-based swarm of mobile vehicles for distributed sensing applications. Our goal is to coordinate a sensor array that optimizes sensor coverage and multivariate signal analysis by implementing artificial intelligence and evolutionary computational techniques. These intelligent control systems integrate both globally operating decision-making systems and locally cooperative information-sharing modes using genetically-trained neural networks. Once trained, neural networks have the ability to enhance real-time operational responses to dynamical environments, such as obstacle avoidance, responding to prevailing wind patterns, and overcoming other natural obscurants or interferences (jammers). The swarm realizes a collective set of sensor neurons with simple properties incorporating interactions based on basic community rules (potential fields) and complex interconnecting functions based on various neural network architectures, Therefore, the swarm is capable of redundant heterogeneous measurements which furnishes an additional degree of robustness and fault tolerance not afforded by conventional systems, while accomplishing such cognitive tasks as generalization, error correction, pattern recognition, and sensor fission. The robotic platforms could be equipped with specialized sensor devices including transmit/receive dipole antennas, chemical or biological sniffers in combination with recognition analysis tools, communication modulators, and laser diodes. Our group has been studying the collective behavior of an autonomous, multi-agent system applied to emerging threat applications. To accomplish such tasks, research in the fields of robotics, sensor technology, and swarms are being conducted within an integrated program. Mission scenarios under consideration include ground penetrating impulse radar (GPR) for detection of under-ground structures, airborne systems, and plume

  5. Quantitative determination of copper in a glass matrix using double pulse laser induced breakdown and electron paramagnetic resonance spectroscopic techniques.

    PubMed

    Khalil, Ahmed A I; Morsy, Mohamed A

    2016-07-01

    A series of lithium-lead-borate glasses of a variable copper oxide loading were quantitatively analyzed in this work using two distinct spectroscopic techniques, namely double pulse laser induced breakdown spectroscopy (DP-LIBS) and electron paramagnetic resonance (EPR). DP-LIBS results measured upon a combined nanosecond lasers irradiation running at 266nm and 1064nm pulses of a collinear configuration directed to the surface of borate glass samples with a known composition. This arrangement was employed to predict the electron's temperature (Te) and density (Ne) of the excited plasma from the recorded spectra. The intensity of elements' responses using this scheme is higher than that of single-pulse laser induced breakdown spectroscopy (SP-LIBS) setup under the same experimental conditions. On the other hand, the EPR data shows typical Cu (II) EPR-signals in the borate glass system that is networked at a distorted tetragonal Borate-arrangement. The signal intensity of the Cu (II) peak at g⊥=2.0596 has been used to quantify the Cu-content accurately in the glass matrix. Both techniques produced linear calibration curves of Cu-metals in glasses with excellent linear regression coefficient (R(2)) values. This study establishes a good correlation between DP-LIBS analysis of glass and the results obtained using EPR spectroscopy. The proposed protocols prove the great advantage of DP-LIBS system for the detection of a trace copper on the surface of glasses. PMID:27154655

  6. Adaptability of laser diffraction measurement technique in soil physics methodology

    NASA Astrophysics Data System (ADS)

    Barna, Gyöngyi; Szabó, József; Rajkai, Kálmán; Bakacsi, Zsófia; Koós, Sándor; László, Péter; Hauk, Gabriella; Makó, András

    2016-04-01

    There are intentions all around the world to harmonize soils' particle size distribution (PSD) data by the laser diffractometer measurements (LDM) to that of the sedimentation techniques (pipette or hydrometer methods). Unfortunately, up to the applied methodology (e. g. type of pre-treatments, kind of dispersant etc.), PSDs of the sedimentation methods (due to different standards) are dissimilar and could be hardly harmonized with each other, as well. A need was arisen therefore to build up a database, containing PSD values measured by the pipette method according to the Hungarian standard (MSZ-08. 0205: 1978) and the LDM according to a widespread and widely used procedure. In our current publication the first results of statistical analysis of the new and growing PSD database are presented: 204 soil samples measured with pipette method and LDM (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Applying usual size limits at the LDM, clay fraction was highly under- and silt fraction was overestimated compared to the pipette method. Subsequently soil texture classes determined from the LDM measurements significantly differ from results of the pipette method. According to previous surveys and relating to each other the two dataset to optimizing, the clay/silt boundary at LDM was changed. Comparing the results of PSDs by pipette method to that of the LDM, in case of clay and silt fractions the modified size limits gave higher similarities. Extension of upper size limit of clay fraction from 0.002 to 0.0066 mm, and so change the lower size limit of silt fractions causes more easy comparability of pipette method and LDM. Higher correlations were found between clay content and water vapor adsorption, specific surface area in case of modified limit, as well. Texture classes were also found less dissimilar. The difference between the results of the two kind of PSD measurement methods could be further reduced knowing other routinely analyzed soil parameters

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Adaptations of advanced safety and reliability techniques to petroleum and other industries

    NASA Technical Reports Server (NTRS)

    Purser, P. E.

    1974-01-01

    The underlying philosophy of the general approach to failure reduction and control is presented. Safety and reliability management techniques developed in the industries which have participated in the U.S. space and defense programs are described along with adaptations to nonaerospace activities. The examples given illustrate the scope of applicability of these techniques. It is indicated that any activity treated as a 'system' is a potential user of aerospace safety and reliability management techniques.

  12. High-Throughput Structure/Function Screening of Materials and Catalysts with Multiple Spectroscopic Techniques

    SciTech Connect

    Tromp, Moniek; Russu, Sergio; Russell, Andrea E.; Guerin, Sam; Hayden, Brian E.; Suchsland, Jens-Peter; Frey, Jeremy G.; Binsted, Norman; Dent, Andy J.; Mosselmans, J. Fred W.; Harvey, Ian; Hayama, Shu; Fiddy, Steven; Meacham, Ken; Surridge, Michael; Tsapatsaris, Nikolaos; Beesley, Angela M.; Schroeder, Sven L. M.; Newton, Mark A.; Safonova, Olga V.

    2007-02-02

    High throughput screening methodologies are expanded to synchrotron based x-ray absorption techniques. An environmental chamber, based on ultra-high vacuum equipment, has been developed allowing in situ studies on arrays of samples while X-ray absorption fine structure spectroscopy, Raman spectroscopy, mass spectrometry and/or X-ray diffraction can be applied simultaneously to characterize the system under process conditions in a time-resolved manner. The chamber accommodates a diverse range of samples from surface science to materials chemistry to heterogeneous catalysis. Data acquisition and data logging software is developed to handle large quantities of divers but related information. New data logging, processing and analysis procedures and programs are developed which will allow fast structure-function relationships characterization.

  13. 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.

  14. Study on the interaction of sodium morin-5-sulfonate with bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Mohammadpour, Mahnaz

    2012-02-01

    In the present investigation, an attempt has been made to study the interaction of sodium morin-5-sulfonate (NaMSA) with the transport proteins, bovine serum albumin (BSA) employing UV-vis, fluorometric and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the compound was a static procedure. Various binding parameters were evaluated. The negative value of Δ H, positive value of Δ S and the negative value of Δ G indicated that electrostatic interactions and hydrogen bonding play major roles in the binding of the NaMSA and BSA. Based on the Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (NaMSA) was evaluated. The results of CD and UV-vis spectroscopy showed that the binding of this complex to BSA induces some conformational changes in BSA.

  15. Study on the interaction of food colourant quinoline yellow with bovine serum albumin by spectroscopic techniques.

    PubMed

    Shahabadi, Nahid; Maghsudi, Maryam; Rouhani, Shohre

    2012-12-01

    The interaction of a food colourant, quinoline yellow (Qy), and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorometry, FT-IR and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the dye 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 Qy and BSA. Based on Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (Qy) was evaluated. The results of CD and UV-vis spectroscopy showed that this dye could bind to BSA and the conformation of BSA changed.

  16. 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).

  17. Adaptive Readout Technique For A Sixteen Channel Peak Sensing ADC In the FERA Format

    SciTech Connect

    Yaver, H.; Maier, M.R.; Lindstrom, D.; Ludewigt, B.A.

    1998-11-01

    An adaptive, variable block-size readout technique for use with multiple, sixteen-channel CAMAC ADCs with a FERA-bus readout has been developed and designed. It can be used to read data from experiments with or without coincidence, i.e. singles, without having to change the readout protocol. Details of the implementation are discussed and initial results are presented. Further applications of the adaptive readout are also discussed.

  18. A sequential adaptation technique and its application to the Mark 12 IFF system

    NASA Astrophysics Data System (ADS)

    Bailey, John S.; Mallett, John D.; Sheppard, Duane J.; Warner, F. Neal; Adams, Robert

    1986-07-01

    Sequential adaptation uses only two sets of receivers, correlators, and A/D converters which are time multiplexed to effect spatial adaptation in a system with (N) adaptive degrees of freedom. This technique can substantially reduce the hardware cost over what is realizable in a parallel architecture. A three channel L-band version of the sequential adapter was built and tested for use with the MARK XII IFF (identify friend or foe) system. In this system the sequentially determined adaptive weights were obtained digitally but implemented at RF. As a result, many of the post RF hardware induced sources of error that normally limit cancellation, such as receiver mismatch, are removed by the feedback property. The result is a system that can yield high levels of cancellation and be readily retrofitted to currently fielded equipment.

  19. Adaptive Postprocessing Techniques for Myocardial Tissue Tracking with Displacement-encoded MR Imaging1

    PubMed Central

    Wen, Han; Marsolo, Keith A.; Bennett, Eric E.; Kutten, Kwame S.; Lewis, Ryan P.; Lipps, David B.; Epstein, Neal D.; Plehn, Jonathan F.; Croisille, Pierre

    2010-01-01

    The purpose of this study was to prospectively assess the effects of two adaptive postprocessing techniques on the evaluation of myocardial function with displacement-encoded magnetic resonance (MR) imaging, including sensitivity for abnormal wall motion, with two-dimensional echocardiography as the reference standard. Sixteen patients (11 men, five women; age range, 26–74 years) and 12 volunteers (six men, six women; age range, 29–53 years) underwent breath-hold MR imaging. Institutional review board approval and informed consent were obtained. Adaptive phase-unwrapping and spatial filtering techniques were compared with conventional phase-unwrapping and spatial filtering techniques. Use of the adaptive techniques led to a reduced rate of failure with the phase-unwrapping technique from 18.9% to 0.6% (P < .001), resulted in lower variability of segmental strain measurements among healthy volunteers (P < .001 to P = .02), and increased the sensitivity of quantitative detection of abnormal segments in patients from 82.5% to 87.7% (P = .034). The adaptive techniques improved the semiautomated postprocessing of displacement-encoded cardiac images and increased the sensitivity of detection of abnormal wall motion in patients. PMID:18096537

  20. 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.

  1. [Adaptive procedures for measuring arterial blood flow velocity in retinal vessels using indicator technique].

    PubMed

    Vilser, W; Schack, B; Bareshova, E; Senff, I; Bräuer-Burchardt, C; Münch, K; Strobel, J

    1995-10-01

    There are highly significant differences in the measuring results of arterial blood velocity between the indicator and laser-Doppler techniques (up to 800%). A new measuring procedure for the analysis of indicator dilution curves was developed based on indicator model and experimental results. The use of this new measuring procedure results in reduced mean systematic error between the indicator and laser-Doppler techniques to values around 10%. With the introduction of adaptive measuring arrays for the creation of indicator dilution curves and the application of adaptive algorithms for centering and spectral normalizing of the dilution curves, improved reproducibility can be expected.

  2. Development of advanced laser systems and spectroscopic techniques for combustion diagnostic applications

    NASA Astrophysics Data System (ADS)

    Kulatilaka, Waruna Dasal

    50 ppm in H2/air flames using ERE-CARS. NO ERE-CARS signals were also recorded in heavily sooting C2H2/air flames with minimal background interferences. These findings are very significant for the development of ERE-CARS as a technique for measuring NO concentrations in high-pressure combustion environments.

  3. 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

  4. Application of adaptive antenna techniques to future commercial satellite communications. Executive summary

    NASA Technical Reports Server (NTRS)

    Ersoy, L.; Lee, E. A.; Matthews, E. W.

    1987-01-01

    The purpose of this contract was to identify the application of adaptive antenna technique in future operational commercial satellite communication systems and to quantify potential benefits. The contract consisted of two major subtasks. Task 1, Assessment of Future Commercial Satellite System Requirements, was generally referred to as the Adaptive section. Task 2 dealt with Pointing Error Compensation Study for a Multiple Scanning/Fixed Spot Beam Reflector Antenna System and was referred to as the reconfigurable system. Each of these tasks was further subdivided into smaller subtasks. It should also be noted that the reconfigurable system is usually defined as an open-loop system while the adaptive system is a closed-loop system. The differences between the open- and closed-loop systems were defined. Both the adaptive and reconfigurable systems were explained and the potential applications of such systems were presented in the context of commercial communication satellite systems.

  5. Impulse radar imaging for dispersive concrete using inverse adaptive filtering techniques

    SciTech Connect

    Arellano, J.; Hernandez, J.M.; Brase, J.

    1993-05-01

    This publication addresses applications of a delayed inverse model adaptive filter for modeled data obtained from short-pulse radar reflectometry. To determine the integrity of concrete, a digital adaptive filter was used, which allows compensation of dispersion and clutter generated by the concrete. A standard set of weights produced by an adaptive filter are used on modeled data to obtain the inverse-impulse response of the concrete. The data for this report include: Multiple target, nondispersive data; single-target, variable-size dispersive data; single-target, variable-depth dispersive data; and single-target, variable transmitted-pulse-width dispersive data. Results of this simulation indicate that data generated by the weights of the adaptive filter, coupled with a two-dimensional, synthetic-aperture focusing technique, successfully generate two-dimensional images of targets within the concrete from modeled data.

  6. SWAT system performance predictions. Project report. [SWAT (Short-Wavelength Adaptive Techniques)

    SciTech Connect

    Parenti, R.R.; Sasiela, R.J.

    1993-03-10

    In the next phase of Lincoln Laboratory's SWAT (Short-Wavelength Adaptive Techniques) program, the performance of a 241-actuator adaptive-optics system will be measured using a variety of synthetic-beacon geometries. As an aid in this experimental investigation, a detailed set of theoretical predictions has also been assembled. The computational tools that have been applied in this study include a numerical approach in which Monte-Carlo ray-trace simulations of accumulated phase error are developed, and an analytical analysis of the expected system behavior. This report describes the basis of these two computational techniques and compares their estimates of overall system performance. Although their regions of applicability tend to be complementary rather than redundant, good agreement is usually obtained when both sets of results can be derived for the same engagement scenario.... Adaptive optics, Phase conjugation, Atmospheric turbulence Synthetic beacon, Laser guide star.

  7. An Approach for Automatic Generation of Adaptive Hypermedia in Education with Multilingual Knowledge Discovery Techniques

    ERIC Educational Resources Information Center

    Alfonseca, Enrique; Rodriguez, Pilar; Perez, Diana

    2007-01-01

    This work describes a framework that combines techniques from Adaptive Hypermedia and Natural Language processing in order to create, in a fully automated way, on-line information systems from linear texts in electronic format, such as textbooks. The process is divided into two steps: an "off-line" processing step, which analyses the source text,…

  8. Voice Therapy Techniques Adapted to Treatment of Habit Cough: A Pilot Study.

    ERIC Educational Resources Information Center

    Blager, Florence B.; And Others

    1988-01-01

    Individuals with long-standing habit cough having no organic basis can be successfully treated with a combination of psychotherapy and speech therapy. Techniques for speech therapy are adapted from those used with hyperfunctional voice disorders to fit this debilitating laryngeal disorder. (Author)

  9. 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

  10. Determination of acetamiprid partial-intercalative binding to DNA by use of spectroscopic, chemometrics, and molecular docking techniques.

    PubMed

    Zhang, Yue; Zhang, Guowen; Zhou, Xiaoyue; Li, Yu

    2013-11-01

    Acetamiprid (ACT) is an insecticide widely used for controlling a variety of insect pests. The binding mode associated with calf thymus DNA (ctDNA) upon interaction with ACT was determined using spectroscopic, chemometrics, and molecular docking techniques to clarify the interaction mechanism at the molecular level. Fluorescence titration suggested that the fluorescence quenching of ACT by ctDNA is a static procedure. The binding constants between ACT and ctDNA at different temperatures were calculated to be of the order 10(3)-10(4) L mol(-1). The positive values of enthalpy and entropy change suggested that the binding process is primarily driven by hydrophobic interactions. Multivariate curve resolution-alternating least squares (MCR-ALS), a chemometrics approach, was used to resolve the expanded UV-visible spectral data matrix. The concentration profiles and the spectra for the three reaction components (ACT, ctDNA, and ACT-ctDNA complex) of the system, which formed a highly overlapping composite response, were then successfully obtained and used to evaluate the progress of ACT interacting with ctDNA. The results of the single-stranded ctDNA and iodide quenching experiments, ctDNA-melting investigations, and viscosity measurements indicated that ACT binds to ctDNA by means of a partial intercalation. Molecular docking studies showed that the specific binding site is mainly located between the ACT and G-C base pairs of ctDNA. This docking prediction was confirmed by use of Fourier-transform infrared (FT-IR) spectral analysis. Results from circular dichroism (CD) spectroscopy revealed that ACT induced a conformational change from the B-ctDNA form to the A-ctDNA form. PMID:23975088

  11. Auto-adaptive robot-aided therapy using machine learning techniques.

    PubMed

    Badesa, Francisco J; Morales, Ricardo; Garcia-Aracil, Nicolas; Sabater, J M; Casals, Alicia; Zollo, Loredana

    2014-09-01

    This paper presents an application of a classification method to adaptively and dynamically modify the therapy and real-time displays of a virtual reality system in accordance with the specific state of each patient using his/her physiological reactions. First, a theoretical background about several machine learning techniques for classification is presented. Then, nine machine learning techniques are compared in order to select the best candidate in terms of accuracy. Finally, first experimental results are presented to show that the therapy can be modulated in function of the patient state using machine learning classification techniques.

  12. Pulsed laser deposition: the road to hybrid nanocomposites coatings and novel pulsed laser adaptive technique.

    PubMed

    Serbezov, Valery

    2013-01-01

    The applications of Pulsed Laser Deposition (PLD) for producing nanoparticles, nanostructures and nanocomposites coatings based on recently developed laser ablating techniques and their convergence are being reviewed. The problems of in situ synthesis of hybrid inorganic-organic nanocomposites coatings by these techniques are being discussed. The novel modification of PLD called Pulsed Laser Adaptive Deposition (PLAD) technique is presented. The in situ synthesized inorganic/organic nanocomposites coatings from Magnesium (Mg) alloy/Rhodamine B and Mg alloy/ Desoximetasone by PLAD are described. The trends, applications and future development of discussed patented methods based on the laser ablating technologies for producing hybrid nanocomposite coatings have also been discussed in this review.

  13. Adaptive technique for P and T wave delineation in electrocardiogram signals.

    PubMed

    Bayasi, Nourhan; Tekeste, Temesghen; Saleh, Hani; Khandoker, Ahsan; Mohammad, Baker; Ismail, Mohammed

    2014-01-01

    The T and P waves of electrocardiogram signals are excellent indicators in the analysis and interpretation of cardiac arrhythmia. As such, the need to address and develop an accurate delineation technique for the detection of these waves is necessary. In this paper, we present a novel robust and adaptive T and P wave delineation method for real-time analysis and nonstandard ECG morphologies. The proposed method is based on ECG signal filtering, value estimation of different fiducial points, applying backward and forward search windows as well as adaptive thresholds. Simulations and evaluations prove the accuracy of the proposed technique in comparison to those proposed techniques in the literature. The mean error for the T peak, T offset, P peak and P offset values are found to be 9.8, 2.3, 7.3 and 3.5 milliseconds, respectively, based on the Physionet QT database, rendering our algorithm as an excellent candidate for ECG signal analysis. PMID:25569904

  14. 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

  15. Multi-Level Adaptive Techniques (MLAT) for singular-perturbation problems

    NASA Technical Reports Server (NTRS)

    Brandt, A.

    1978-01-01

    The multilevel (multigrid) adaptive technique, a general strategy of solving continuous problems by cycling between coarser and finer levels of discretization is described. It provides very fast general solvers, together with adaptive, nearly optimal discretization schemes. In the process, boundary layers are automatically either resolved or skipped, depending on a control function which expresses the computational goal. The global error decreases exponentially as a function of the overall computational work, in a uniform rate independent of the magnitude of the singular-perturbation terms. The key is high-order uniformly stable difference equations, and uniformly smoothing relaxation schemes.

  16. Key techniques and applications of adaptive growth method for stiffener layout design of plates and shells

    NASA Astrophysics Data System (ADS)

    Ding, Xiaohong; Ji, Xuerong; Ma, Man; Hou, Jianyun

    2013-11-01

    The application of the adaptive growth method is limited because several key techniques during the design process need manual intervention of designers. Key techniques of the method including the ground structure construction and seed selection are studied, so as to make it possible to improve the effectiveness and applicability of the adaptive growth method in stiffener layout design optimization of plates and shells. Three schemes of ground structures, which are comprised by different shell elements and beam elements, are proposed. It is found that the main stiffener layouts resulted from different ground structures are almost the same, but the ground structure comprised by 8-nodes shell elements and both 3-nodes and 2-nodes beam elements can result in clearest stiffener layout, and has good adaptability and low computational cost. An automatic seed selection approach is proposed, which is based on such selection rules that the seeds should be positioned on where the structural strain energy is great for the minimum compliance problem, and satisfy the dispersancy requirement. The adaptive growth method with the suggested key techniques is integrated into an ANSYS-based program, which provides a design tool for the stiffener layout design optimization of plates and shells. Typical design examples, including plate and shell structures to achieve minimum compliance and maximum bulking stability are illustrated. In addition, as a practical mechanical structural design example, the stiffener layout of an inlet structure for a large-scale electrostatic precipitator is also demonstrated. The design results show that the adaptive growth method integrated with the suggested key techniques can effectively and flexibly deal with stiffener layout design problem for plates and shells with complex geometrical shape and loading conditions to achieve various design objectives, thus it provides a new solution method for engineering structural topology design optimization.

  17. Adaptive polynomial chaos techniques for uncertainty quantification of a gas cooled fast reactor transient

    SciTech Connect

    Perko, Z.; Gilli, L.; Lathouwers, D.; Kloosterman, J. L.

    2013-07-01

    Uncertainty quantification plays an increasingly important role in the nuclear community, especially with the rise of Best Estimate Plus Uncertainty methodologies. Sensitivity analysis, surrogate models, Monte Carlo sampling and several other techniques can be used to propagate input uncertainties. In recent years however polynomial chaos expansion has become a popular alternative providing high accuracy at affordable computational cost. This paper presents such polynomial chaos (PC) methods using adaptive sparse grids and adaptive basis set construction, together with an application to a Gas Cooled Fast Reactor transient. Comparison is made between a new sparse grid algorithm and the traditionally used technique proposed by Gerstner. An adaptive basis construction method is also introduced and is proved to be advantageous both from an accuracy and a computational point of view. As a demonstration the uncertainty quantification of a 50% loss of flow transient in the GFR2400 Gas Cooled Fast Reactor design was performed using the CATHARE code system. The results are compared to direct Monte Carlo sampling and show the superior convergence and high accuracy of the polynomial chaos expansion. Since PC techniques are easy to implement, they can offer an attractive alternative to traditional techniques for the uncertainty quantification of large scale problems. (authors)

  18. Stable adaptive PI control for permanent magnet synchronous motor drive based on improved JITL technique.

    PubMed

    Zheng, Shiqi; Tang, Xiaoqi; Song, Bao; Lu, Shaowu; Ye, Bosheng

    2013-07-01

    In this paper, a stable adaptive PI control strategy based on the improved just-in-time learning (IJITL) technique is proposed for permanent magnet synchronous motor (PMSM) drive. Firstly, the traditional JITL technique is improved. The new IJITL technique has less computational burden and is more suitable for online identification of the PMSM drive system which is highly real-time compared to traditional JITL. In this way, the PMSM drive system is identified by IJITL technique, which provides information to an adaptive PI controller. Secondly, the adaptive PI controller is designed in discrete time domain which is composed of a PI controller and a supervisory controller. The PI controller is capable of automatically online tuning the control gains based on the gradient descent method and the supervisory controller is developed to eliminate the effect of the approximation error introduced by the PI controller upon the system stability in the Lyapunov sense. Finally, experimental results on the PMSM drive system show accurate identification and favorable tracking performance.

  19. Adaptive staircase techniques in psychoacoustics: a comparison of human data and a mathematical model.

    PubMed

    Kollmeier, B; Gilkey, R H; Sieben, U K

    1988-05-01

    Data from a simple tone-in-noise simultaneous masking task were used to evaluate each of two common adaptive staircase rules (a "1 up 2 down" rule and a "1 up 3 down" rule) and the parameter estimation by sequential testing (PEST) technique in combination with each of two psychophysical procedures [a two-alternative forced-choice (2AFC) and a three-alternative forced-choice (3AFC) procedure]. These human data were compared to predictions generated by a mathematical model based on Markov theory. The model predicts that threshold estimates obtained with the adaptive techniques should be equal to those derived with equivalent "fixed signal level" techniques. However, the human data indicate that the adaptive techniques tend to yield lower thresholds. The model predicts that the standard error of a threshold estimate obtained from an adaptive technique will decrease and approach zero as the number of trials used to compute the estimate increases. The human data show greater variability than predicted and approach a nonzero value as the number of trials increases. The predictions of the model suggest that the commonly used combination of the 2AFC procedure and the 1 up 2 down rule is the least efficient method of estimating a threshold and that the 3AFC procedure in combination with the 1 up 3 down rule is the most efficient method. The human data are less consistent, but generally show the combination of the 2AFC procedure and the 1 up 2 down rule to be one of the least efficient methods. Possible explanations for the differences between the model's predictions and the human data, as well as suggestions for laboratory practice, are discussed. PMID:3403801

  20. General adaptive-neighborhood technique for improving synthetic aperture radar interferometric coherence estimation.

    PubMed

    Vasile, Gabriel; Trouvé, Emmanuel; Ciuc, Mihai; Buzuloiu, Vasile

    2004-08-01

    A new method for filtering the coherence map issued from synthetic aperture radar (SAR) interferometric data is presented. For each pixel of the interferogram, an adaptive neighborhood is determined by a region-growing technique driven by the information provided by the amplitude images. Then pixels in the derived adaptive neighborhood are complex averaged to yield the filtered value of the coherence, after a phase-compensation step is performed. An extension of the algorithm is proposed for polarimetric interferometric SAR images. The proposed method has been applied to both European Remote Sensing (ERS) satellite SAR images and airborne high-resolution polarimetric interferometric SAR images. Both subjective and objective performance analysis, including coherence edge detection, shows that the proposed method provides better results than the standard phase-compensated fixed multilook filter and the Lee adaptive coherence filter.

  1. Grid and basis adaptive polynomial chaos techniques for sensitivity and uncertainty analysis

    SciTech Connect

    Perkó, Zoltán Gilli, Luca Lathouwers, Danny Kloosterman, Jan Leen

    2014-03-01

    The demand for accurate and computationally affordable sensitivity and uncertainty techniques is constantly on the rise and has become especially pressing in the nuclear field with the shift to Best Estimate Plus Uncertainty methodologies in the licensing of nuclear installations. Besides traditional, already well developed methods – such as first order perturbation theory or Monte Carlo sampling – Polynomial Chaos Expansion (PCE) has been given a growing emphasis in recent years due to its simple application and good performance. This paper presents new developments of the research done at TU Delft on such Polynomial Chaos (PC) techniques. Our work is focused on the Non-Intrusive Spectral Projection (NISP) approach and adaptive methods for building the PCE of responses of interest. Recent efforts resulted in a new adaptive sparse grid algorithm designed for estimating the PC coefficients. The algorithm is based on Gerstner's procedure for calculating multi-dimensional integrals but proves to be computationally significantly cheaper, while at the same it retains a similar accuracy as the original method. More importantly the issue of basis adaptivity has been investigated and two techniques have been implemented for constructing the sparse PCE of quantities of interest. Not using the traditional full PC basis set leads to further reduction in computational time since the high order grids necessary for accurately estimating the near zero expansion coefficients of polynomial basis vectors not needed in the PCE can be excluded from the calculation. Moreover the sparse PC representation of the response is easier to handle when used for sensitivity analysis or uncertainty propagation due to the smaller number of basis vectors. The developed grid and basis adaptive methods have been implemented in Matlab as the Fully Adaptive Non-Intrusive Spectral Projection (FANISP) algorithm and were tested on four analytical problems. These show consistent good performance both

  2. A Novel Wideband Subarray Technique for Shaped Pattern Generation and Adaptively Interference Rejection

    NASA Astrophysics Data System (ADS)

    Alfred, Q. Md.; Chakravarty, T.; Singh, G.; Sanyal, S. K.

    2008-03-01

    In this article, a simple and efficient technique for the wideband shaped beam and sector beam pattern generation with their adaptive interference rejection is proposed. A microcontroller controlled and time delay based beam forming network for simultaneously generating multiple beams, shaped beam and sector beam is conceptualized. The antenna patterns considered here is formed by linear array of isotropic elements grouped as subarray. The shaped and sector beam synthesis procedure is practically simplified by simultaneous adding the constituents beams from the subarrays, was theoretically established by Woodward and Lawson (Proc. IEE. 95(1):362 370, 1948). Apart from the shaped beam generation a technique for adaptive interference rejection in shaped patterns using combination of time delay and phase shifter is discussed. This topic promises good prospect for wideband pattern generation and interference rejection.

  3. An adaptive SK technique and its application for fault detection of rolling element bearings

    NASA Astrophysics Data System (ADS)

    Wang, Yanxue; Liang, Ming

    2011-07-01

    In this paper, we propose an adaptive spectral kurtosis (SK) technique for the fault detection of rolling element bearings. The primary contribution is adaptive determination of the bandwidth and center frequency. This is implemented with successive attempts to right-expand a given window along the frequency axis by merging it with its subsequent neighboring windows. Influence of the parameters such as the initial window function, bandwidth and window overlap on the merged windows as well as how to choose those parameters in practical applications are explored. Based on simulated experiments, it can be found that the proposed technique can further enhance the SK-based method as compared to the kurtogram approach. The effectiveness of the proposed method in fault detection of the rolling element bearings is validated using experimental signals.

  4. Adaptive data rate control TDMA systems as a rain attenuation compensation technique

    NASA Technical Reports Server (NTRS)

    Sato, Masaki; Wakana, Hiromitsu; Takahashi, Takashi; Takeuchi, Makoto; Yamamoto, Minoru

    1993-01-01

    Rainfall attenuation has a severe effect on signal strength and impairs communication links for future mobile and personal satellite communications using Ka-band and millimeter wave frequencies. As rain attenuation compensation techniques, several methods such as uplink power control, site diversity, and adaptive control of data rate or forward error correction have been proposed. In this paper, we propose a TDMA system that can compensate rain attenuation by adaptive control of transmission rates. To evaluate the performance of this TDMA terminal, we carried out three types of experiments: experiments using a Japanese CS-3 satellite with Ka-band transponders, in house IF loop-back experiments, and computer simulations. Experimental results show that this TDMA system has advantages over the conventional constant-rate TDMA systems, as resource sharing technique, in both bit error rate and total TDMA burst lengths required for transmitting given information.

  5. Efficient simulation of blood flow past complex endovascular devices using an adaptive embedding technique.

    PubMed

    Cebral, Juan R; Löhner, Rainald

    2005-04-01

    The simulation of blood flow past endovascular devices such as coils and stents is a challenging problem due to the complex geometry of the devices. Traditional unstructured grid computational fluid dynamics relies on the generation of finite element grids that conform to the boundary of the computational domain. However, the generation of such grids for patient-specific modeling of cerebral aneurysm treatment with coils or stents is extremely difficult and time consuming. This paper describes the application of an adaptive grid embedding technique previously developed for complex fluid structure interaction problems to the simulation of endovascular devices. A hybrid approach is used: the vessel walls are treated with body conforming grids and the endovascular devices with an adaptive mesh embedding technique. This methodology fits naturally in the framework of image-based computational fluid dynamics and opens the door for exploration of different therapeutic options and personalization of endovascular procedures. PMID:15822805

  6. Development of a clinical pathways analysis system with adaptive Bayesian nets and data mining techniques.

    PubMed

    Kopec, D; Shagas, G; Reinharth, D; Tamang, S

    2004-01-01

    The use and development of software in the medical field offers tremendous opportunities for making health care delivery more efficient, more effective, and less error-prone. We discuss and explore the use of clinical pathways analysis with Adaptive Bayesian Networks and Data Mining Techniques to perform such analyses. The computation of "lift" (a measure of completed pathways improvement potential) leads us to optimism regarding the potential for this approach.

  7. 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.

  8. An adaptive image enhancement technique by combining cuckoo search and particle swarm optimization algorithm.

    PubMed

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper. PMID:25784928

  9. Adaptive digital fringe projection technique for high dynamic range three-dimensional shape measurement.

    PubMed

    Lin, Hui; Gao, Jian; Mei, Qing; He, Yunbo; Liu, Junxiu; Wang, Xingjin

    2016-04-01

    It is a challenge for any optical method to measure objects with a large range of reflectivity variation across the surface. Image saturation results in incorrect intensities in captured fringe pattern images, leading to phase and measurement errors. This paper presents a new adaptive digital fringe projection technique which avoids image saturation and has a high signal to noise ratio (SNR) in the three-dimensional (3-D) shape measurement of objects that has a large range of reflectivity variation across the surface. Compared to previous high dynamic range 3-D scan methods using many exposures and fringe pattern projections, which consumes a lot of time, the proposed technique uses only two preliminary steps of fringe pattern projection and image capture to generate the adapted fringe patterns, by adaptively adjusting the pixel-wise intensity of the projected fringe patterns based on the saturated pixels in the captured images of the surface being measured. For the bright regions due to high surface reflectivity and high illumination by the ambient light and surfaces interreflections, the projected intensity is reduced just to be low enough to avoid image saturation. Simultaneously, the maximum intensity of 255 is used for those dark regions with low surface reflectivity to maintain high SNR. Our experiments demonstrate that the proposed technique can achieve higher 3-D measurement accuracy across a surface with a large range of reflectivity variation. PMID:27137056

  10. An adaptive image enhancement technique by combining cuckoo search and particle swarm optimization algorithm.

    PubMed

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper.

  11. An Adaptive Image Enhancement Technique by Combining Cuckoo Search and Particle Swarm Optimization Algorithm

    PubMed Central

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper. PMID:25784928

  12. An Autonomous Self-Aware and Adaptive Fault Tolerant Routing Technique for Wireless Sensor Networks

    PubMed Central

    Abba, Sani; Lee, Jeong-A

    2015-01-01

    We propose an autonomous self-aware and adaptive fault-tolerant routing technique (ASAART) for wireless sensor networks. We address the limitations of self-healing routing (SHR) and self-selective routing (SSR) techniques for routing sensor data. We also examine the integration of autonomic self-aware and adaptive fault detection and resiliency techniques for route formation and route repair to provide resilience to errors and failures. We achieved this by using a combined continuous and slotted prioritized transmission back-off delay to obtain local and global network state information, as well as multiple random functions for attaining faster routing convergence and reliable route repair despite transient and permanent node failure rates and efficient adaptation to instantaneous network topology changes. The results of simulations based on a comparison of the ASAART with the SHR and SSR protocols for five different simulated scenarios in the presence of transient and permanent node failure rates exhibit a greater resiliency to errors and failure and better routing performance in terms of the number of successfully delivered network packets, end-to-end delay, delivered MAC layer packets, packet error rate, as well as efficient energy conservation in a highly congested, faulty, and scalable sensor network. PMID:26295236

  13. Adaptive-compression based congestion control technique for wireless sensor networks.

    PubMed

    Lee, Joa-Hyoung; Jung, In-Bum

    2010-01-01

    Congestion in a wireless sensor network causes an increase in the amount of data loss and delays in data transmission. In this paper, we propose a new congestion control technique (ACT, Adaptive Compression-based congestion control Technique) based on an adaptive compression scheme for packet reduction in case of congestion. The compression techniques used in the ACT are Discrete Wavelet Transform (DWT), Adaptive Differential Pulse Code Modulation (ADPCM), and Run-Length Coding (RLC). The ACT first transforms the data from the time domain to the frequency domain, reduces the range of data by using ADPCM, and then reduces the number of packets with the help of RLC before transferring the data to the source node. It introduces the DWT for priority-based congestion control because the DWT classifies the data into four groups with different frequencies. The ACT assigns priorities to these data groups in an inverse proportion to the respective frequencies of the data groups and defines the quantization step size of ADPCM in an inverse proportion to the priorities. RLC generates a smaller number of packets for a data group with a low priority. In the relaying node, the ACT reduces the amount of packets by increasing the quantization step size of ADPCM in case of congestion. Moreover, in order to facilitate the back pressure, the queue is controlled adaptively according to the congestion state. We experimentally demonstrate that the ACT increases the network efficiency and guarantees fairness to sensor nodes, as compared with the existing methods. Moreover, it exhibits a very high ratio of the available data in the sink. PMID:22319280

  14. Adaptive-Compression Based Congestion Control Technique for Wireless Sensor Networks

    PubMed Central

    Lee, Joa-Hyoung; Jung, In-Bum

    2010-01-01

    Congestion in a wireless sensor network causes an increase in the amount of data loss and delays in data transmission. In this paper, we propose a new congestion control technique (ACT, Adaptive Compression-based congestion control Technique) based on an adaptive compression scheme for packet reduction in case of congestion. The compression techniques used in the ACT are Discrete Wavelet Transform (DWT), Adaptive Differential Pulse Code Modulation (ADPCM), and Run-Length Coding (RLC). The ACT first transforms the data from the time domain to the frequency domain, reduces the range of data by using ADPCM, and then reduces the number of packets with the help of RLC before transferring the data to the source node. It introduces the DWT for priority-based congestion control because the DWT classifies the data into four groups with different frequencies. The ACT assigns priorities to these data groups in an inverse proportion to the respective frequencies of the data groups and defines the quantization step size of ADPCM in an inverse proportion to the priorities. RLC generates a smaller number of packets for a data group with a low priority. In the relaying node, the ACT reduces the amount of packets by increasing the quantization step size of ADPCM in case of congestion. Moreover, in order to facilitate the back pressure, the queue is controlled adaptively according to the congestion state. We experimentally demonstrate that the ACT increases the network efficiency and guarantees fairness to sensor nodes, as compared with the existing methods. Moreover, it exhibits a very high ratio of the available data in the sink. PMID:22319280

  15. Adaptive meshing technique applied to an orthopaedic finite element contact problem.

    PubMed

    Roarty, Colleen M; Grosland, Nicole M

    2004-01-01

    Finite element methods have been applied extensively and with much success in the analysis of orthopaedic implants. Recently a growing interest has developed, in the orthopaedic biomechanics community, in how numerical models can be constructed for the optimal solution of problems in contact mechanics. New developments in this area are of paramount importance in the design of improved implants for orthopaedic surgery. Finite element and other computational techniques are widely applied in the analysis and design of hip and knee implants, with additional joints (ankle, shoulder, wrist) attracting increased attention. The objective of this investigation was to develop a simplified adaptive meshing scheme to facilitate the finite element analysis of a dual-curvature total wrist implant. Using currently available software, the analyst has great flexibility in mesh generation, but must prescribe element sizes and refinement schemes throughout the domain of interest. Unfortunately, it is often difficult to predict in advance a mesh spacing that will give acceptable results. Adaptive finite-element mesh capabilities operate to continuously refine the mesh to improve accuracy where it is required, with minimal intervention by the analyst. Such mesh adaptation generally means that in certain areas of the analysis domain, the size of the elements is decreased (or increased) and/or the order of the elements may be increased (or decreased). In concept, mesh adaptation is very appealing. Although there have been several previous applications of adaptive meshing for in-house FE codes, we have coupled an adaptive mesh formulation with the pre-existing commercial programs PATRAN (MacNeal-Schwendler Corp., USA) and ABAQUS (Hibbit Karlson and Sorensen, Pawtucket, RI). In doing so, we have retained several attributes of the commercial software, which are very attractive for orthopaedic implant applications.

  16. Application of adaptive and neural network computational techniques to Traffic Volume and Classification Monitoring

    SciTech Connect

    Mead, W.C.; Fisher, H.N.; Jones, R.D.; Bisset, K.R.; Lee, L.A.

    1993-09-01

    We are developing a Traffic Volume and Classification Monitoring (TVCM) system based on adaptive and neural network computational techniques. The value of neutral networks in this application lies in their ability to learn from data and to form a mapping of arbitrary topology. The piezoelectric strip and magnetic loop sensors typically used for TVCM provide signals that are complicated and variable, and that correspond in indirect ways with the desired FWHA 13-class classification system. Further, the wide variety of vehicle configurations adds to the complexity of the classification task. Our goal is to provide a TVCM system featuring high accuracy, adaptability to wide sensor and envirorunental variations, and continuous fault detection. We have instrumented an experimental TVCM site, developed PC-based on-line data acquisition software, collected a large database of vehicles` signals together with accurate ground truth determination, and analyzed the data off-line with a neural net classification system that can distinguish between class 2 (automobiles) and class 3 (utility vehicles) with better than 90% accuracy. The neural network used, called the Connectionist Hyperprism Classification (CHC) network, features simple basis functions; rapid, linear training algorithms for basis function amplitudes and widths; and basis function elimination that enhances network speed and accuracy. Work is in progress to extend the system to other classes, to quantify the system`s adaptability, and to develop automatic fault detection techniques.

  17. A simple focal-length measurement technique for adaptive microlenses using z-scan

    NASA Astrophysics Data System (ADS)

    Abdelaziez, Yasser; Banerjee, Partha P.

    2004-10-01

    A simple technique for focal length measurements of adaptive micro-lenses using z-scan is reported. Focal length is one of the most important parameters of any lens. The effective focal length is measured with reference to the principal points that are not easy to find especially for micro-lenses. In addition, variable focal length microlenses pose a different challenge that makes the process of determining their exact focal length a tedious and difficult process. Classical methods such as nodal slide and magnification have been used for focal length determination. Also, advanced Interference techniques such as Talbot, Moire, Digital Speckle, Zygo and Joint Fourier Transform were used for focal length measurements. These techniques require more elaborate setups and difficult to implement, especially for microlenses. Recently a power meter was used to find the focal length of an unknown lens. Most of the techniques mentioned above proof to be not simple for microlens characterization. The z-scan technique has been implemented, for quite sometimes, to characterize the third-order effects of a nonlinear optical material. The z-scan provides information on both the sign and magnitude of the non-linear refractive index and offer advantage of simplicity. We have used a regular lens to collimate and focus light unto the lens under test. By scanning the lens under test and measuring the on-axis intensity, one can find the focal length. This is because the on-axis intensity is proportional to the phase of the lens and therefore the focal length. In the case of an adaptive lens with its focal length is a function of the applied voltage, the scanning occurs for each voltage value that will correspond to the on-axis refractive index change and therefore the far field on-axis intensity. This described technique above is easy to implement and can achieve good accuracy due to the inherent sensitivity of the z-scan.

  18. 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.

  19. Forward-Inverse Adaptive Techniques for Reservoir Characterization and Simulation: Theory and Applications

    SciTech Connect

    Doss, S D; Ezzedine, S; Gelinas, R; Chawathe, A

    2001-06-11

    A novel approach called Forward-Inverse Adaptive Techniques (FIAT) for reservoir characterization is developed and applied to three representative exploration cases. Inverse modeling refers to the determination of the entire reservoir permeability under steady state single-phase flow regime, given only field permeability, pressure and production well measurements. FIAT solves the forward and inverse partial differential equations (PDEs) simultaneously by adding a regularization term and filtering pressure gradients. An implicit adaptive-grid, Galerkin, numerical scheme is used to numerically solve the set of PDEs subject to pressure and permeability boundary conditions. Three examples are presented. Results from all three cases demonstrate attainable and reasonably accurate solutions and, more importantly, provide insights into the consequences of data undersampling.

  20. Error analysis applied to several inversion techniques used for the retrieval of middle atmospheric constituents from limb-scanning MM-wave spectroscopic measurements

    NASA Technical Reports Server (NTRS)

    Puliafito, E.; Bevilacqua, R.; Olivero, J.; Degenhardt, W.

    1992-01-01

    The formal retrieval error analysis of Rodgers (1990) allows the quantitative determination of such retrieval properties as measurement error sensitivity, resolution, and inversion bias. This technique was applied to five numerical inversion techniques and two nonlinear iterative techniques used for the retrieval of middle atmospheric constituent concentrations from limb-scanning millimeter-wave spectroscopic measurements. It is found that the iterative methods have better vertical resolution, but are slightly more sensitive to measurement error than constrained matrix methods. The iterative methods converge to the exact solution, whereas two of the matrix methods under consideration have an explicit constraint, the sensitivity of the solution to the a priori profile. Tradeoffs of these retrieval characteristics are presented.

  1. Comparison of adaptive radiotherapy techniques for external radiation therapy of canine bladder cancer.

    PubMed

    Nieset, Jessica R; Harmon, Joseph F; Johnson, Thomas E; Larue, Susan M

    2014-01-01

    Daily bladder variations make it difficult to utilize standard radiotherapy as a primary treatment option for muscle-invasive bladder cancer. Our purpose was to develop a model comparing dose distributions of image-guided and adaptive radiotherapy (ART) techniques for canine bladder cancer. Images were obtained retrospectively from cone-beam computed tomography (CBCT) scans used for daily positioning of four dogs undergoing fractionated image-guided radiotherapy (IGRT). Four different treatment plans were modeled for each dog, and dosimetric data were compared. Two plans were developed using planning target volumes based on planning computed tomography (CT) bladder volume. These plans then used bony anatomy or soft tissue anatomy for daily positioning and dosimetric modeling. The third plan type was a hybrid IGRT and ART technique utilizing a library of premade anisotropic planning target volumes using bladder wall motion data and selection of a "plan-of-the-day" determined from positioning CBCT bladder volumes. The fourth plan was an ART technique that constructed a new planning target volume each day based on daily bladder volume as determined by pretreatment CBCT. Dose volume histograms were generated for each plan type and dose distribution for the bladder and rectum were compared between plan types. Irradiated rectal volume decreased and irradiated bladder volume increased as plan conformality increased. ART provided the greatest rectal sparing, with lowest irradiated rectal volume (P < 0.001), and largest bladder volume receiving 95% of the prescription dose (P < 0.001). In our model, adaptive radiotherapy techniques for canine bladder cancer showed significant reduction in rectal volume irradiated when compared to nonadaptive techniques, while maintaining appropriate bladder coverage.

  2. Simulation of macromolecular liquids with the adaptive resolution molecular dynamics technique

    NASA Astrophysics Data System (ADS)

    Peters, J. H.; Klein, R.; Delle Site, L.

    2016-08-01

    We extend the application of the adaptive resolution technique (AdResS) to liquid systems composed of alkane chains of different lengths. The aim of the study is to develop and test the modifications of AdResS required in order to handle the change of representation of large molecules. The robustness of the approach is shown by calculating several relevant structural properties and comparing them with the results of full atomistic simulations. The extended scheme represents a robust prototype for the simulation of macromolecular systems of interest in several fields, from material science to biophysics.

  3. Simulation of macromolecular liquids with the adaptive resolution molecular dynamics technique.

    PubMed

    Peters, J H; Klein, R; Delle Site, L

    2016-08-01

    We extend the application of the adaptive resolution technique (AdResS) to liquid systems composed of alkane chains of different lengths. The aim of the study is to develop and test the modifications of AdResS required in order to handle the change of representation of large molecules. The robustness of the approach is shown by calculating several relevant structural properties and comparing them with the results of full atomistic simulations. The extended scheme represents a robust prototype for the simulation of macromolecular systems of interest in several fields, from material science to biophysics. PMID:27627414

  4. Forward scattering detection of a submerged moving target based on adaptive filtering technique.

    PubMed

    He, Chuanlin; Yang, Kunde; Lei, Bo; Ma, Yuanliang

    2015-09-01

    Forward scattered waves are always overwhelmed by severely intense direct blasts when a submerged target crosses the source-receiver line. A processing scheme called direct blast suppression based on adaptive filtering (DBS-AF) is proposed to suppress such blasts. A verification experiment was conducted in a lake with a vertical hydrophone array and 10 kHz CW impulses. Processing results show that the direct blast is suppressed in a single channel, and an intruding target is identified by the lobes in the detection curve. The detection performance is improved by adopting a time-delay beam-former on the array as a pre-processing technique. PMID:26428829

  5. Adaptively Reevaluated Bayesian Localization (ARBL). A Novel Technique for Radiological Source Localization

    SciTech Connect

    Miller, Erin A.; Robinson, Sean M.; Anderson, Kevin K.; McCall, Jonathon D.; Prinke, Amanda M.; Webster, Jennifer B.; Seifert, Carolyn E.

    2015-01-19

    Here we present a novel technique for the localization of radiological sources in urban or rural environments from an aerial platform. The technique is based on a Bayesian approach to localization, in which measured count rates in a time series are compared with predicted count rates from a series of pre-calculated test sources to define likelihood. Furthermore, this technique is expanded by using a localized treatment with a limited field of view (FOV), coupled with a likelihood ratio reevaluation, allowing for real-time computation on commodity hardware for arbitrarily complex detector models and terrain. In particular, detectors with inherent asymmetry of response (such as those employing internal collimation or self-shielding for enhanced directional awareness) are leveraged by this approach to provide improved localization. Our results from the localization technique are shown for simulated flight data using monolithic as well as directionally-aware detector models, and the capability of the methodology to locate radioisotopes is estimated for several test cases. This localization technique is shown to facilitate urban search by allowing quick and adaptive estimates of source location, in many cases from a single flyover near a source. In particular, this method represents a significant advancement from earlier methods like full-field Bayesian likelihood, which is not generally fast enough to allow for broad-field search in real time, and highest-net-counts estimation, which has a localization error that depends strongly on flight path and cannot generally operate without exhaustive search

  6. Optical spectroscopic instrumentation and techniques for the 1990s - Applications in astronomy, chemistry, and physics; Proceedings of the Meeting, Las Cruces, NM, June 4-6, 1990

    SciTech Connect

    Mcnamara, B.J.; Lerner, J.M.

    1990-01-01

    Fiber spectroscopy and a new generation of large ground-based telescopes are addressed, adaptive imaging spectrometers in astronomy are discussed along with two-dimensional spectroscopy with a universal birefringent filter and a Fabry-Perot interferometer, resonance-ionization mass spectrometry for material analysis and characterization, and time-resolved coherent anti-Stokes Raman spectroscopy and the measurement of vibrational spectra in shock-compressed molecular materials. Present and future roles of high-performance charge-transfer-device detectors in spectrochemical analysis are outlined as well as recent developments in near-infrared Hadamard transform Raman spectroscopy and special heterodyne spectroscopy. Influence of the laser characteristics on laser-sampling inductively coupled plasma-mass spectrometry, high-precision measurements of stellar radial velocity variations, and the on-line spectroscopic monitoring of metal ions for environmental and space applications using photodiode-array spectroscopy are covered.

  7. Optical spectroscopic instrumentation and techniques for the 1990s - Applications in astronomy, chemistry, and physics; Proceedings of the Meeting, Las Cruces, NM, June 4-6, 1990

    NASA Astrophysics Data System (ADS)

    McNamara, Bernard J.; Lerner, Jeremy M.

    Fiber spectroscopy and a new generation of large ground-based telescopes are addressed, adaptive imaging spectrometers in astronomy are discussed along with two-dimensional spectroscopy with a universal birefringent filter and a Fabry-Perot interferometer, resonance-ionization mass spectrometry for material analysis and characterization, and time-resolved coherent anti-Stokes Raman spectroscopy and the measurement of vibrational spectra in shock-compressed molecular materials. Present and future roles of high-performance charge-transfer-device detectors in spectrochemical analysis are outlined as well as recent developments in near-infrared Hadamard transform Raman spectroscopy and special heterodyne spectroscopy. Influence of the laser characteristics on laser-sampling inductively coupled plasma-mass spectrometry, high-precision measurements of stellar radial velocity variations, and the on-line spectroscopic monitoring of metal ions for environmental and space applications using photodiode-array spectroscopy are covered.

  8. Linear dichroism amplification: Adapting a long-known technique for ultrasensitive femtosecond IR spectroscopy

    SciTech Connect

    Rehault, Julien; Helbing, Jan; Zanirato, Vinicio; Olivucci, Massimo

    2011-03-28

    We demonstrate strong amplification of polarization-sensitive transient IR signals using a pseudo-null crossed polarizer technique first proposed by Keston and Lospalluto [Fed. Proc. 10, 207 (1951)] and applied for nanosecond flash photolysis in the visible by Che et al. [Chem. Phys. Lett. 224, 145 (1994)]. We adapted the technique to ultrafast pulsed laser spectroscopy in the infrared using photoelastic modulators, which allow us to measure amplified linear dichroism at kilohertz repetition rates. The method was applied to a photoswitch of the N-alkylated Schiff base family in order to demonstrate its potential of strongly enhancing sensitivity and signal to noise in ultrafast transient IR experiments, to simplify spectra and to determine intramolecular transition dipole orientations.

  9. Adaptive Wavelet Techniques, Wigner Distributions and the Direct Simulation of the Vlasov Equation

    NASA Astrophysics Data System (ADS)

    Afeyan, Bedros; Douglas, Melissa; Spielman, Rick

    2000-10-01

    The formal analogy between the quantum Liouville equation satisfied by the Wigner function in Quantum Mechanics, and the Vlasov equation satisfied by the single particle distribution function in plasma physics is exploited in order to study the long term evolution of nonlinear electrostatic wave phenomena dictated by the Vlasov-Poisson equations. Adaptive wavelet techniques are used to tile phase space in an optimal manner so as to minimize computational domain sizes and simultaneously to retain accuracy over disparate scales. Traditional MHD calculations will also be analyzed with our wavelet techniques to show the favorable data compression and feature extraction capabilities of multiresolution analysis. Specifically Z51 and Z179 will be compared to show the nature of the improvements in double wire array (Z179) implosions on Z to those obtained with a single wire array (Z51).

  10. Hydrological time series modeling: A comparison between adaptive neuro-fuzzy, neural network and autoregressive techniques

    NASA Astrophysics Data System (ADS)

    Lohani, A. K.; Kumar, Rakesh; Singh, R. D.

    2012-06-01

    SummaryTime series modeling is necessary for the planning and management of reservoirs. More recently, the soft computing techniques have been used in hydrological modeling and forecasting. In this study, the potential of artificial neural networks and neuro-fuzzy system in monthly reservoir inflow forecasting are examined by developing and comparing monthly reservoir inflow prediction models, based on autoregressive (AR), artificial neural networks (ANNs) and adaptive neural-based fuzzy inference system (ANFIS). To take care the effect of monthly periodicity in the flow data, cyclic terms are also included in the ANN and ANFIS models. Working with time series flow data of the Sutlej River at Bhakra Dam, India, several ANN and adaptive neuro-fuzzy models are trained with different input vectors. To evaluate the performance of the selected ANN and adaptive neural fuzzy inference system (ANFIS) models, comparison is made with the autoregressive (AR) models. The ANFIS model trained with the input data vector including previous inflows and cyclic terms of monthly periodicity has shown a significant improvement in the forecast accuracy in comparison with the ANFIS models trained with the input vectors considering only previous inflows. In all cases ANFIS gives more accurate forecast than the AR and ANN models. The proposed ANFIS model coupled with the cyclic terms is shown to provide better representation of the monthly inflow forecasting for planning and operation of reservoir.

  11. An adaptive technique to maximize lossless image data compression of satellite images

    NASA Technical Reports Server (NTRS)

    Stewart, Robert J.; Lure, Y. M. Fleming; Liou, C. S. Joe

    1994-01-01

    Data compression will pay an increasingly important role in the storage and transmission of image data within NASA science programs as the Earth Observing System comes into operation. It is important that the science data be preserved at the fidelity the instrument and the satellite communication systems were designed to produce. Lossless compression must therefore be applied, at least, to archive the processed instrument data. In this paper, we present an analysis of the performance of lossless compression techniques and develop an adaptive approach which applied image remapping, feature-based image segmentation to determine regions of similar entropy and high-order arithmetic coding to obtain significant improvements over the use of conventional compression techniques alone. Image remapping is used to transform the original image into a lower entropy state. Several techniques were tested on satellite images including differential pulse code modulation, bi-linear interpolation, and block-based linear predictive coding. The results of these experiments are discussed and trade-offs between computation requirements and entropy reductions are used to identify the optimum approach for a variety of satellite images. Further entropy reduction can be achieved by segmenting the image based on local entropy properties then applying a coding technique which maximizes compression for the region. Experimental results are presented showing the effect of different coding techniques for regions of different entropy. A rule-base is developed through which the technique giving the best compression is selected. The paper concludes that maximum compression can be achieved cost effectively and at acceptable performance rates with a combination of techniques which are selected based on image contextual information.

  12. 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

    2015-02-01

    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.

  13. 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.

  14. Study of the effect of Cal-Red on the secondary structure of human serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Dong, Lijun; Chen, Xingguo; Hu, Zhide

    2007-11-01

    The effect of Cal-Red on the structure of human serum albumin (HSA) was studied using Resonance light scattering (RLS), Fourier transformed Infrared (FT-IR) and Circular dichroism (CD) spectroscopic methods. The RLS spectroscopic results show that the RLS intensity of HSA was significantly increased in the presence of Cal-Red. The binding parameters of HSA with Cal-Red were studied at different temperatures of 289, 299, 309 and 319 K at pH 4.1. It is indicated by the Scatchard plots that the binding constant K decreased from 4.03 × 10 8 to 7.59 × 10 7 l/mol and the maximum binding number N decreased from 215 to 152 with increasing the temperature, respectively. The binding process was exothermic and spontaneous, as indicated by the thermodynamic analyses, and the major part of the binding energy is hydrophobic interaction. The enthalpy change Δ H0, the free energy change Δ G0 and the entropy change Δ S0 of 289 K were calculated to be -42.75 kJ/mol, -47.56 kJ/mol and 16.66 J/mol K, respectively. The alterations of protein secondary structure in the presence of Cal-Red in aqueous solution were quantitatively calculated from FT-IR and CD spectroscopy with reductions of α-helices content about 5%, β-turn from 10% to 2% and with increases of β-sheet from 38% to 51%.

  15. Protein Secondary Structure Prediction Using Local Adaptive Techniques in Training Neural Networks

    NASA Astrophysics Data System (ADS)

    Aik, Lim Eng; Zainuddin, Zarita; Joseph, Annie

    2008-01-01

    One of the most significant problems in computer molecular biology today is how to predict a protein's three-dimensional structure from its one-dimensional amino acid sequence or generally call the protein folding problem and difficult to determine the corresponding protein functions. Thus, this paper involves protein secondary structure prediction using neural network in order to solve the protein folding problem. The neural network used for protein secondary structure prediction is multilayer perceptron (MLP) of the feed-forward variety. The training set are taken from the protein data bank which are 120 proteins while 60 testing set is the proteins which were chosen randomly from the protein data bank. Multiple sequence alignment (MSA) is used to get the protein similar sequence and Position Specific Scoring matrix (PSSM) is used for network input. The training process of the neural network involves local adaptive techniques. Local adaptive techniques used in this paper comprises Learning rate by sign changes, SuperSAB, Quickprop and RPROP. From the simulation, the performance for learning rate by Rprop and Quickprop are superior to all other algorithms with respect to the convergence time. However, the best result was obtained using Rprop algorithm.

  16. Adaptive Neural Control of Pure-Feedback Nonlinear Time-Delay Systems via Dynamic Surface Technique.

    PubMed

    Min Wang; Xiaoping Liu; Peng Shi

    2011-12-01

    This paper is concerned with robust stabilization problem for a class of nonaffine pure-feedback systems with unknown time-delay functions and perturbed uncertainties. Novel continuous packaged functions are introduced in advance to remove unknown nonlinear terms deduced from perturbed uncertainties and unknown time-delay functions, which avoids the functions with control law to be approximated by radial basis function (RBF) neural networks. This technique combining implicit function and mean value theorems overcomes the difficulty in controlling the nonaffine pure-feedback systems. Dynamic surface control (DSC) is used to avoid "the explosion of complexity" in the backstepping design. Design difficulties from unknown time-delay functions are overcome using the function separation technique, the Lyapunov-Krasovskii functionals, and the desirable property of hyperbolic tangent functions. RBF neural networks are employed to approximate desired virtual controls and desired practical control. Under the proposed adaptive neural DSC, the number of adaptive parameters required is reduced significantly, and semiglobal uniform ultimate boundedness of all of the signals in the closed-loop system is guaranteed. Simulation studies are given to demonstrate the effectiveness of the proposed design scheme.

  17. Experimental evaluation of shape memory alloy actuation technique in adaptive antenna design concepts

    NASA Technical Reports Server (NTRS)

    Kefauver, W. Neill; Carpenter, Bernie F.

    1994-01-01

    Creation of an antenna system that could autonomously adapt contours of reflecting surfaces to compensate for structural loads induced by a variable environment would maximize performance of space-based communication systems. Design of such a system requires the comprehensive development and integration of advanced actuator, sensor, and control technologies. As an initial step in this process, a test has been performed to assess the use of a shape memory alloy as a potential actuation technique. For this test, an existing, offset, cassegrain antenna system was retrofit with a subreflector equipped with shape memory alloy actuators for surface contour control. The impacts that the actuators had on both the subreflector contour and the antenna system patterns were measured. The results of this study indicate the potential for using shape memory alloy actuation techniques to adaptively control antenna performance; both variations in gain and beam steering capabilities were demonstrated. Future development effort is required to evolve this potential into a useful technology for satellite applications.

  18. Statistical adaptive reversible steganographic technique using bicubic interpolation and difference expansion

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Chi; Tsai, Chwei-Shyong; Yang, Wen-Lung; Tsai, Yi-Chang; Yu, Shyr-Shen

    2010-08-01

    The reversible steganographic technique allows extraction of secret messages and restoration of original images without any distortion from the embedded image. In this work, a statistical adaptive reversible steganographic technique is proposed to improve difference expansion (DE)-based schemes, consisting of two parts. First, bicubic interpolation is adopted as the pixel prediction to obtain more embeddable pixels. Meanwhile, since differences are generated between the accurate predicted value and its original value, quality of difference is also considered. Second, a statistical adaptive reversible embedding algorithm is proposed to overcome the restriction of the embedding capacity under single-layer embedding. The relationship between the complexity of the neighboring pixels and the difference distribution for the image is generalized as the variance conditional in statistics. With the maximum modifiable degree of the predicted pixel, the proposed scheme provides a suitable embedding capacity for all embeddable pixels with less additional information. The experimental results demonstrate advantages of the proposed scheme and prove that it is able to provide high capacity with good visual quality for the embedded image.

  19. Grand-Canonical-like Molecular-Dynamics Simulations by Using an Adaptive-Resolution Technique

    NASA Astrophysics Data System (ADS)

    Wang, Han; Hartmann, Carsten; Schütte, Christof; Delle Site, Luigi

    2013-01-01

    In this work, we provide a detailed theoretical analysis, supported by numerical tests, of the reliability of the adaptive-resolution-simulation (AdResS) technique in sampling the grand-canonical ensemble. We demonstrate that the correct density and radial distribution functions in the hybrid region, where molecules change resolution, are two necessary conditions for considering the atomistic and coarse-grained regions in AdResS to be equivalent to subsystems of a full atomistic system with an accuracy up to the second order with respect to the probability distribution of the system. Moreover, we show that the work done by the thermostat and a thermodynamic force in the transition region is formally equivalent to balancing the chemical potential difference between the different resolutions. From these results follows the main conclusion that the atomistic region exchanges molecules with the coarse-grained region in a grand-canonical fashion with an accuracy up to (at least) second order. Numerical tests, for the relevant case of liquid water at ambient conditions, are carried out to strengthen the conclusions of the theoretical analysis. Finally, in order to show the computational convenience of AdResS as a grand-canonical setup, we compare our method to the insertion particle method in its most efficient computational implementation. This fruitful combination of theoretical principles and numerical evidence makes the adaptive-resolution technique a candidate for a natural, general, and efficient protocol for grand-canonical molecular dynamics for the case of large systems.

  20. Adaptive technique for matching the spectral response in skin lesions' images

    NASA Astrophysics Data System (ADS)

    Pavlova, P.; Borisova, E.; Pavlova, E.; Avramov, L.

    2015-03-01

    The suggested technique is a subsequent stage for data obtaining from diffuse reflectance spectra and images of diseased tissue with a final aim of skin cancer diagnostics. Our previous work allows us to extract patterns for some types of skin cancer, as a ratio between spectra, obtained from healthy and diseased tissue in the range of 380 - 780 nm region. The authenticity of the patterns depends on the tested point into the area of lesion, and the resulting diagnose could also be fixed with some probability. In this work, two adaptations are implemented to localize pixels of the image lesion, where the reflectance spectrum corresponds to pattern. First adapts the standard to the personal patient and second - translates the spectrum white point basis to the relative white point of the image. Since the reflectance spectra and the image pixels are regarding to different white points, a correction of the compared colours is needed. The latest is done using a standard method for chromatic adaptation. The technique follows the steps below: -Calculation the colorimetric XYZ parameters for the initial white point, fixed by reflectance spectrum from healthy tissue; -Calculation the XYZ parameters for the distant white point on the base of image of nondiseased tissue; -Transformation the XYZ parameters for the test-spectrum by obtained matrix; -Finding the RGB values of the XYZ parameters for the test-spectrum according sRGB; Finally, the pixels of the lesion's image, corresponding to colour from the test-spectrum and particular diagnostic pattern are marked with a specific colour.

  1. Evaluation of an adaptive unstructured remeshing technique for integrated fluid-thermal-structural analysis

    NASA Technical Reports Server (NTRS)

    Dechaumphai, Pramote

    1990-01-01

    An adaptive unstructured remeshing technique is evaluated for integrated fluid-thermal-structural analysis. The technique is combined with the finite element method to solve: (1) the Navier-Stokes equations for high-speed compressible flow; (2) the energy equation for the structural-thermal response; and (3) the quasi-static equilibrium equations for the structural response. The remeshing technique and the analysis solution procedure are described. The effectiveness of the approach is evaluated with two application studies. The flow analysis of Mach 8 shock-shock interference on a three-inch-diameter cylinder is used as the first application study to demonstrate the capability of the remeshing technique and to examine proper remeshing indicators for the inviscid and boundary layer regions. The applicability of the approach for the thermal and structural analyses of the structure is evaluated in the second application study of a 0.25-inch-diameter convectively cooled leading edge subjected to intense aerodynamic heating. Issues associated with remeshing indicators for thermal stress problems are identified.

  2. Adaptive narrow-band interference rejection in a DS spread-spectrum intercept receiver using transform domain signal processing techniques

    NASA Technical Reports Server (NTRS)

    Gevargiz, John; Das, Pankaj K.; Milstein, Laurence B.

    1989-01-01

    An intercept receiver which uses a transform-domain-processing filter is described. This receiver detects direct-sequence BPSK spread-spectrum signals in the presence of narrowband interference by employing adaptive narrowband interference rejection techniques. The improvement in the system performance over that of conventional detection techniques is shown by presenting the results of experimental measurements of probability of detection versus false alarm for an enhanced total power detector. Also presented are certain results corresponding to detection of the spectral lines generated at twice the carrier frequency, wherein the goal is often not just signal detection, but also carrier frequency estimation. The receiver uses one of two transform-domain-processing techniques for adaptive narrowband interference rejection. In the first technique, the narrowband interference is detected and excised in the transform domain by using an adaptive notch filter. In the second technique, the interference is suppressed using soft-limiting in the transform domain.

  3. 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.

  4. 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. PMID:26190602

  5. EPA Water Resources Adaptation Program (WRAP) Research and Development Activities Methods and Techniques

    EPA Science Inventory

    Adaptation to environmental change is not a new concept. Humans have shown throughout history a capacity for adapting to different climates and environmental changes. Farmers, foresters, civil engineers, have all been forced to adapt to numerous challenges to overcome adversity...

  6. Adaptive Phase Synchronization Techniques for Unbalanced and Distorted Three-Phase Voltage System

    NASA Astrophysics Data System (ADS)

    Woinowsky-Krieger, Alexis

    Interfacing and operating AC power electronic systems requires rapid and accurate estimation of the phase angle of the power source, and specifically of the positive sequence of the three-phase utility grid voltage. This is needed to ensure reliable operation of the power control devices and of the resulting power flow. However, the quality of this information is undermined by various distortions and unbalanced conditions of the three-phase grid voltage. Phase estimation and power control can both be performed in real time by a DSP, but a DSP typically has limited computational resources, especially in regards to speed and memory, which motivates the search for computationally efficient algorithms to accomplish these tasks. In contrast to conventional PLL techniques, recent approaches have used adaptive amplitude estimation to enhance the acquisition of the phase information, resulting in faster response and improved performance. This thesis presents a novel technique to estimate the phase of the positive sequence of a three-phase voltage in the presence of frequency variations and unbalanced conditions, referred to as hybrid negative sequence adaptive synchronous amplitude estimation with PLL, or H-NSASAE-PLL. The key feature consists of a feedback structure which embeds a positive sequence PLL and an adaptive synchronous negative sequence estimator to enhance the performance of the PLL. The resulting benefits include faster estimation of the phase of the positive sequence under unbalanced conditions with zero steady state error, simplified tuning of PLL parameters to address a wide range of application requirements, robust performance with respect to distortions and PLL parameters, a structure of minimal dynamical order (fifth) to estimate the main signal parameters of interest, simplified discretization, and reduced computational costs, making the proposed technique suitable for real time execution on a DSP. The H-NSASAE-PLL is developed in the Matlab

  7. A Background Noise Reduction Technique Using Adaptive Noise Cancellation for Microphone Arrays

    NASA Technical Reports Server (NTRS)

    Spalt, Taylor B.; Fuller, Christopher R.; Brooks, Thomas F.; Humphreys, William M., Jr.; Brooks, Thomas F.

    2011-01-01

    Background noise in wind tunnel environments poses a challenge to acoustic measurements due to possible low or negative Signal to Noise Ratios (SNRs) present in the testing environment. This paper overviews the application of time domain Adaptive Noise Cancellation (ANC) to microphone array signals with an intended application of background noise reduction in wind tunnels. An experiment was conducted to simulate background noise from a wind tunnel circuit measured by an out-of-flow microphone array in the tunnel test section. A reference microphone was used to acquire a background noise signal which interfered with the desired primary noise source signal at the array. The technique s efficacy was investigated using frequency spectra from the array microphones, array beamforming of the point source region, and subsequent deconvolution using the Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) algorithm. Comparisons were made with the conventional techniques for improving SNR of spectral and Cross-Spectral Matrix subtraction. The method was seen to recover the primary signal level in SNRs as low as -29 dB and outperform the conventional methods. A second processing approach using the center array microphone as the noise reference was investigated for more general applicability of the ANC technique. It outperformed the conventional methods at the -29 dB SNR but yielded less accurate results when coherence over the array dropped. This approach could possibly improve conventional testing methodology but must be investigated further under more realistic testing conditions.

  8. Acceptance and Mindfulness Techniques as Applied to Refugee and Ethnic Minority Populations with PTSD: Examples from "Culturally Adapted CBT"

    ERIC Educational Resources Information Center

    Hinton, Devon E.; Pich, Vuth; Hofmann, Stefan G.; Otto, Michael W.

    2013-01-01

    In this article we illustrate how we utilize acceptance and mindfulness techniques in our treatment (Culturally Adapted CBT, or CA-CBT) for traumatized refugees and ethnic minority populations. We present a Nodal Network Model (NNM) of Affect to explain the treatment's emphasis on body-centered mindfulness techniques and its focus on psychological…

  9. Dynamically adaptive mesh refinement technique for image reconstruction in optical tomography.

    PubMed

    Soloviev, Vadim Y; Krasnosselskaia, Lada V

    2006-04-20

    A novel adaptive mesh technique is introduced for problems of image reconstruction in luminescence optical tomography. A dynamical adaptation of the three-dimensional scheme based on the finite-volume formulation reduces computational time and balances the ill-posed nature of the inverse problem. The arbitrary shape of the bounding surface is handled by an additional refinement of computational cells on the boundary. Dynamical shrinking of the search volume is introduced to improve computational performance and accuracy while locating the luminescence target. Light propagation in the medium is modeled by the telegraph equation, and the image-reconstruction algorithm is derived from the Fredholm integral equation of the first kind. Stability and computational efficiency of the introduced method are demonstrated for image reconstruction of one and two spherical luminescent objects embedded within a breastlike tissue phantom. Experimental measurements are simulated by the solution of the forward problem on a grid of 5x5 light guides attached to the surface of the phantom.

  10. The Novel Nonlinear Adaptive Doppler Shift Estimation Technique and the Coherent Doppler Lidar System Validation Lidar

    NASA Technical Reports Server (NTRS)

    Beyon, Jeffrey Y.; Koch, Grady J.

    2006-01-01

    The signal processing aspect of a 2-m wavelength coherent Doppler lidar system under development at NASA Langley Research Center in Virginia is investigated in this paper. The lidar system is named VALIDAR (validation lidar) and its signal processing program estimates and displays various wind parameters in real-time as data acquisition occurs. The goal is to improve the quality of the current estimates such as power, Doppler shift, wind speed, and wind direction, especially in low signal-to-noise-ratio (SNR) regime. A novel Nonlinear Adaptive Doppler Shift Estimation Technique (NADSET) is developed on such behalf and its performance is analyzed using the wind data acquired over a long period of time by VALIDAR. The quality of Doppler shift and power estimations by conventional Fourier-transform-based spectrum estimation methods deteriorates rapidly as SNR decreases. NADSET compensates such deterioration in the quality of wind parameter estimates by adaptively utilizing the statistics of Doppler shift estimate in a strong SNR range and identifying sporadic range bins where good Doppler shift estimates are found. The authenticity of NADSET is established by comparing the trend of wind parameters with and without NADSET applied to the long-period lidar return data.

  11. Brain surgery in the bush: adapting techniques and technology to fit the developing world.

    PubMed

    Vargas, Jan; Mayegga, Emanuel; Nuwas, Emmanuel; Ellegala, Dilantha B; Kucia, Elisa J; Nicholas, Joyce

    2013-11-01

    The critical shortage of surgical services in many areas of the world has profound effects on local communities. Approximately 11% of global disease burden can be attributed to causes that are surgically treatable. Efforts have been made to recruit professionals from developed nations to compensate for the lack of such expertise. However, this practice has created a cycle of dependency on foreign-trained physicians and the medical tools they bring. Recognition of this problem calls for adaptation of a novel problem-solving approach. This article describes techniques and technology available in east Africa that have been adapted to allow basic and emergency neurosurgery to be performed in the absence of complex medical infrastructure and equipment. Commonplace items found in the local environment can be used to emulate more sophisticated instruments, and community-specific engineering programs can be developed to provide locally produced appropriate technology that promotes independence from Western sources. The local economy benefits from much-needed stimulation when these tools are created locally, and this allows for readily available replacement and repair. More studies are under way to identify problems and implement interventions that are realistic and appropriate for these populations.

  12. Improvement of SVM-Based Speech/Music Classification Using Adaptive Kernel Technique

    NASA Astrophysics Data System (ADS)

    Lim, Chungsoo; Chang, Joon-Hyuk

    In this paper, we propose a way to improve the classification performance of support vector machines (SVMs), especially for speech and music frames within a selectable mode vocoder (SMV) framework. A myriad of techniques have been proposed for SVMs, and most of them are employed during the training phase of SVMs. Instead, the proposed algorithm is applied during the test phase and works with existing schemes. The proposed algorithm modifies a kernel parameter in the decision function of SVMs to alter SVM decisions for better classification accuracy based on the previous outputs of SVMs. Since speech and music frames exhibit strong inter-frame correlation, the outputs of SVMs can guide the kernel parameter modification. Our experimental results show that the proposed algorithm has the potential for adaptively tuning classifications of support vector machines for better performance.

  13. Adaptive technique for three-dimensional MR imaging of moving structures.

    PubMed

    Korin, H W; Felmlee, J P; Ehman, R L; Riederer, S J

    1990-10-01

    The authors describe an adaptive motion correction method for three-dimensional magnetic resonance (MR) imaging. Three-dimensional imaging offers many advantages over two-dimensional multisection imaging but is susceptible to image corruption due to motion. Thus, it has been of limited use in the imaging of mobile structures, and the relatively long imaging times required have hindered its use in patients who tend to move during imaging. The authors' technique uses interleaved "navigator" echoes to provide a measure of displacement for each image echo in the acquisition and then uses this information to allow correction of the image data. The theory for signal corruption due to motion and the correction scheme that follows from it are presented. This method can produce excellent results when the motion is correctly modeled.

  14. Adaptive noise suppression technique for dense 3D point cloud reconstructions from monocular vision

    NASA Astrophysics Data System (ADS)

    Diskin, Yakov; Asari, Vijayan K.

    2012-10-01

    Mobile vision-based autonomous vehicles use video frames from multiple angles to construct a 3D model of their environment. In this paper, we present a post-processing adaptive noise suppression technique to enhance the quality of the computed 3D model. Our near real-time reconstruction algorithm uses each pair of frames to compute the disparities of tracked feature points to translate the distance a feature has traveled within the frame in pixels into real world depth values. As a result these tracked feature points are plotted to form a dense and colorful point cloud. Due to the inevitable small vibrations in the camera and the mismatches within the feature tracking algorithm, the point cloud model contains a significant amount of misplaced points appearing as noise. The proposed noise suppression technique utilizes the spatial information of each point to unify points of similar texture and color into objects while simultaneously removing noise dissociated with any nearby objects. The noise filter combines all the points of similar depth into 2D layers throughout the point cloud model. By applying erosion and dilation techniques we are able to eliminate the unwanted floating points while retaining points of larger objects. To reverse the compression process, we transform the 2D layer back into the 3D model allowing points to return to their original position without the attached noise components. We evaluate the resulting noiseless point cloud by utilizing an unmanned ground vehicle to perform obstacle avoidance tasks. The contribution of the noise suppression technique is measured by evaluating the accuracy of the 3D reconstruction.

  15. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques.

    PubMed

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E; Lo, Yeh-Chi

    2016-04-21

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients.

  16. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques

    NASA Astrophysics Data System (ADS)

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E.; Lo, Yeh-Chi

    2016-04-01

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as  -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients.

  17. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques.

    PubMed

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E; Lo, Yeh-Chi

    2016-04-21

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients. PMID:27008349

  18. Adaptive one-dimensional dimming technique for liquid crystal displays with low power consumption and high image quality

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Ryeol; Lee, Seung-Woo

    2015-07-01

    An adaptive one-dimensional (1-D) dimming technique for liquid crystal displays that compensates for nonuniform backlight distribution is proposed. Dimming techniques that do not consider luminance distribution may cause severe visual artifacts, such as a block artifact. However, an adaptive 1-D dimming technique that considers luminance distribution can reduce power consumption without causing any visual artifacts. Hardware implementation results verified that our method achieved lower power consumption compared to nondimming techniques and removed block artifacts from International Electrotechnical Commission 62087 standard images. The power consumption using the proposed method ranged from 85.5% to 94.7% compared to nondimming techniques. Furthermore, the contrast ratio increased by up to 231% and 165% on average compared to nondimming techniques.

  19. 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.

  20. 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. PMID:26748824

  1. 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.

  2. 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.

  3. Adaptation of the 70 kV INP ion implanter to the IBAD technique

    NASA Astrophysics Data System (ADS)

    Rajchel, B.; Drwiega, M.; Lipińska, E.; Wierba, M.

    1994-05-01

    The ion implanter facility of the Institute of Nuclear Physics in Cracow was used during many years in different fields of research and technical application. This laboratory type machine equipped with a mass analyzer gives the possibility to accelerate single charged ions of almost all the elements up to the energy of 70 keV with the beam current reaching (e.g. for N 2+) several mA. Mass resolution of the implanter is about 350, and the typical current density during implantation is in the range of 0.1 {μA}/{cm 2} to 100 {μA}/{cm 2}. Adaptation works at the INP implanter to the Ion Beam Assisted Deposition technique were performed. The present research activity due to the modified implanter includes: investigation of high temperature corrosion resistant surfaces (alloys of the type Al-Mo); investigation of special (e.g. ceramics, composites) thin layers produced on crystal surfaces; production of the surfaces of improved mechanical properties. Targets produced by the IBAD technique are investigated next by the RBS method using a 3 MV Van de Graaff setup at the Institute of Nuclear Physics in Cracow.

  4. Efficient low-bit-rate adaptive mesh-based motion compensation technique

    NASA Astrophysics Data System (ADS)

    Mahmoud, Hanan A.; Bayoumi, Magdy A.

    2001-08-01

    This paper proposes a two-stage global motion estimation method using a novel quadtree block-based motion estimation technique and an active mesh model. In the first stage, motion parameters are estimated by fitting block-based motion vectors computed using a new efficient quadtree technique, that divides a frame into equilateral triangle blocks using the quad-tree structure. Arbitrary partition shapes are achieved by allowing 4-to-1, 3-to-1 and 2-1 merge/combine of sibling blocks having the same motion vector . In the second stage, the mesh is constructed using an adaptive triangulation procedure that places more triangles over areas with high motion content, these areas are estimated during the first stage. finally the motion compensation is achieved by using a novel algorithm that is carried by both the encoder and the decoder to determine the optimal triangulation of the resultant partitions followed by affine mapping at the encoder. Computer simulation results show that the proposed method gives better performance that the conventional ones in terms of the peak signal-to-noise ration (PSNR) and the compression ratio (CR).

  5. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  6. ADAPTIVE FINITE ELEMENT MODELING TECHNIQUES FOR THE POISSON-BOLTZMANN EQUATION.

    PubMed

    Holst, Michael; McCammon, James Andrew; Yu, Zeyun; Zhou, Youngcheng; Zhu, Yunrong

    2012-01-01

    We consider the design of an effective and reliable adaptive finite element method (AFEM) for the nonlinear Poisson-Boltzmann equation (PBE). We first examine the two-term regularization technique for the continuous problem recently proposed by Chen, Holst, and Xu based on the removal of the singular electrostatic potential inside biomolecules; this technique made possible the development of the first complete solution and approximation theory for the Poisson-Boltzmann equation, the first provably convergent discretization, and also allowed for the development of a provably convergent AFEM. However, in practical implementation, this two-term regularization exhibits numerical instability. Therefore, we examine a variation of this regularization technique which can be shown to be less susceptible to such instability. We establish a priori estimates and other basic results for the continuous regularized problem, as well as for Galerkin finite element approximations. We show that the new approach produces regularized continuous and discrete problems with the same mathematical advantages of the original regularization. We then design an AFEM scheme for the new regularized problem, and show that the resulting AFEM scheme is accurate and reliable, by proving a contraction result for the error. This result, which is one of the first results of this type for nonlinear elliptic problems, is based on using continuous and discrete a priori L(∞) estimates to establish quasi-orthogonality. To provide a high-quality geometric model as input to the AFEM algorithm, we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures, based on the intrinsic local structure tensor of the molecular surface. All of the algorithms described in the article are implemented in the Finite Element Toolkit (FETK), developed and maintained at UCSD. The stability advantages of the new regularization scheme

  7. ADAPTIVE FINITE ELEMENT MODELING TECHNIQUES FOR THE POISSON-BOLTZMANN EQUATION

    PubMed Central

    HOLST, MICHAEL; MCCAMMON, JAMES ANDREW; YU, ZEYUN; ZHOU, YOUNGCHENG; ZHU, YUNRONG

    2011-01-01

    We consider the design of an effective and reliable adaptive finite element method (AFEM) for the nonlinear Poisson-Boltzmann equation (PBE). We first examine the two-term regularization technique for the continuous problem recently proposed by Chen, Holst, and Xu based on the removal of the singular electrostatic potential inside biomolecules; this technique made possible the development of the first complete solution and approximation theory for the Poisson-Boltzmann equation, the first provably convergent discretization, and also allowed for the development of a provably convergent AFEM. However, in practical implementation, this two-term regularization exhibits numerical instability. Therefore, we examine a variation of this regularization technique which can be shown to be less susceptible to such instability. We establish a priori estimates and other basic results for the continuous regularized problem, as well as for Galerkin finite element approximations. We show that the new approach produces regularized continuous and discrete problems with the same mathematical advantages of the original regularization. We then design an AFEM scheme for the new regularized problem, and show that the resulting AFEM scheme is accurate and reliable, by proving a contraction result for the error. This result, which is one of the first results of this type for nonlinear elliptic problems, is based on using continuous and discrete a priori L∞ estimates to establish quasi-orthogonality. To provide a high-quality geometric model as input to the AFEM algorithm, we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures, based on the intrinsic local structure tensor of the molecular surface. All of the algorithms described in the article are implemented in the Finite Element Toolkit (FETK), developed and maintained at UCSD. The stability advantages of the new regularization scheme

  8. Comparison of different automatic adaptive threshold selection techniques for estimating discharge from river width

    NASA Astrophysics Data System (ADS)

    Elmi, Omid; Javad Tourian, Mohammad; Sneeuw, Nico

    2015-04-01

    The importance of river discharge monitoring is critical for e.g., water resource planning, climate change, hazard monitoring. River discharge has been measured at in situ gauges for more than a century. Despite various attempts, some basins are still ungauged. Moreover, a reduction in the number of worldwide gauging stations increases the interest to employ remote sensing data for river discharge monitoring. Finding an empirical relationship between simultaneous in situ measurements of discharge and river widths derived from satellite imagery has been introduced as a straightforward remote sensing alternative. Classifying water and land in an image is the primary task for defining the river width. Water appears dark in the near infrared and infrared bands in satellite images. As a result low values in the histogram usually represent the water content. In this way, applying a threshold on the image histogram and separating into two different classes is one of the most efficient techniques to build a water mask. Beside its simple definition, finding the appropriate threshold value in each image is the most critical issue. The threshold is variable due to changes in the water level, river extent, atmosphere, sunlight radiation, onboard calibration of the satellite over time. These complexities in water body classification are the main source of error in river width estimation. In this study, we are looking for the most efficient adaptive threshold algorithm to estimate the river discharge. To do this, all cloud free MODIS images coincident with the in situ measurement are collected. Next a number of automatic threshold selection techniques are employed to generate different dynamic water masks. Then, for each of them a separate empirical relationship between river widths and discharge measurements are determined. Through these empirical relationships, we estimate river discharge at the gauge and then validate our results against in situ measurements and also

  9. Adaptive gain, equalization, and wavelength stabilization techniques for silicon photonic microring resonator-based optical receivers

    NASA Astrophysics Data System (ADS)

    Palermo, Samuel; Chiang, Patrick; Yu, Kunzhi; Bai, Rui; Li, Cheng; Chen, Chin-Hui; Fiorentino, Marco; Beausoleil, Ray; Li, Hao; Shafik, Ayman; Titriku, Alex

    2016-03-01

    Interconnect architectures based on high-Q silicon photonic microring resonator devices offer a promising solution to address the dramatic increase in datacenter I/O bandwidth demands due to their ability to realize wavelength-division multiplexing (WDM) in a compact and energy efficient manner. However, challenges exist in realizing efficient receivers for these systems due to varying per-channel link budgets, sensitivity requirements, and ring resonance wavelength shifts. This paper reports on adaptive optical receiver design techniques which address these issues and have been demonstrated in two hybrid-integrated prototypes based on microring drop filters and waveguide photodetectors implemented in a 130nm SOI process and high-speed optical front-ends designed in 65nm CMOS. A 10Gb/s powerscalable architecture employs supply voltage scaling of a three inverter-stage transimpedance amplifier (TIA) that is adapted with an eye-monitor control loop to yield the necessary sensitivity for a given channel. As reduction of TIA input-referred noise is more critical at higher data rates, a 25Gb/s design utilizes a large input-stage feedback resistor TIA cascaded with a continuous-time linear equalizer (CTLE) that compensates for the increased input pole. When tested with a waveguide Ge PD with 0.45A/W responsivity, this topology achieves 25Gb/s operation with -8.2dBm sensitivity at a BER=10-12. In order to address microring drop filters sensitivity to fabrication tolerances and thermal variations, efficient wavelength-stabilization control loops are necessary. A peak-power-based monitoring loop which locks the drop filter to the input wavelength, while achieving compatibility with the high-speed TIA offset-correction feedback loop is implemented with a 0.7nm tuning range at 43μW/GHz efficiency.

  10. Preliminary Benchmarking of Plinian Eruption Simulations Using an Adaptive Grid Eulerian Technique

    NASA Astrophysics Data System (ADS)

    Peterson, A. H.; Ogden, D. E.; Wohletz, K. H.; Gisler, G.; Glatzmaier, G. A.

    2005-12-01

    The SAGE (SAIC Adaptive Grid Eulerian) code is an Eulerian hydrodynamics numerical technique employing adaptive mesh refinement at each cycle for every cell in 1-, 2-, and 3-D grids. It is primarily designed to solve high deformation flow of multiple materials and thus provides important capabilities for simulating volcanic eruption phenomena. Its multimaterial equation of state libraries includes a comprehensive coverage of water from solid ice through two-phase liquid and vapor to supercritical states approaching the Hugoniot, and extremely important aspect for simulating volcanic gases in general. In development are strength and failure rules that model non-Newtonian fluid/solid deformation. Because of the low effective sound speeds of eruptive mixtures, the facts that SAGE uses a piecewise, linear, multi-material, Gudonov numerical method to resolve shocks with second-order precision and exactly conserves mass, momentum, and energy, are a highly desirable attributes. Although this code has been previously used to simulate a volcanic eruption (i.e., eruption through a crater lake at Ruapehu volcano by Morrissey and Gisler), we are embarking in an effort to benchmark the code with CFDLib, a well-validated arbitrary Lagrangian-Eulerian code developed at Los Alamos National Laboratory. Through this effort we expect to better understand the strengths and weaknesses, the limitations, and provide direction for important enhancement of SAGE, and potentially provide the volcanological community with a powerful alternative to numerical codes currently available. At this point in our benchmarking, we demonstrate some results for fluid convection within a chamber and fluid jetting through a conduit.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. In vitro study of damaging effects of 2,4-dichlorophenoxyacetic acid on DNA structure by spectroscopic and voltammetric techniques.

    PubMed

    Ahmadi, Farhad; Bakhshandeh, Fatemeh

    2009-10-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) is a genotoxic organochlorinated herbicide, and its interaction with DNA was studied by UV/Vis, fluorescence, circular dichroism viscosity measurements, and alternative current voltammetry techniques. Using these analyses, the binding constant of 2,4-D to DNA has been calculated by two different techniques. The binding constant of 2,4-D to DNA calculated by fluorescence and circular dichroism spectra was found to be 3.5 x 10(3) M(-1) and 5.02 x 10(3) M(-1), respectively. Analyses of fluorescence spectra, viscosity measurements, and alternative current voltammetry interactions indicated that 2,4-D is a groove binder of DNA. Ethidium bromide displacement studies revealed that 2,4-D does not have any effect on ethidium bromide-bound DNA, which is indicative of groove binding.

  16. Combining spectroscopic data in the forensic analysis of paint: Application of a multiblock technique as chemometric tool.

    PubMed

    Lambert, Danny; Muehlethaler, Cyril; Esseiva, Pierre; Massonnet, Geneviève

    2016-06-01

    A study (Muehlethaler et al. [9]) has demonstrated the application of chemometrics for the analysis of domestic red paints. The paints have been analyzed with IR and Raman spectroscopies. As a result of these analyses, exploratory techniques, such as principal component analysis (PCA) and hierarchical clusters analysis (HCA) have been applied to both IR and Raman spectra. This allowed to observe the structure of the data among those red paints, and infer potential groups among them and to propose a classification model based on their chemical composition. IR spectroscopy showed group patterns related mainly to the binder and extender composition of the paints, whereas Raman spectroscopy data were mainly related to the pigment composition. The aim of the present study is to evaluate the potential of a Multiblock algorithm applied to the same data set. The concept of Multiblock, as a chemometric tool, is to combine data from several different analytical techniques in order to visualize most of the information at once. IR and Raman spectroscopy are then considered as "blocks" of data of the same dataset. One algorithm called common component and specific weight analysis (CCSWA) has been used in order to produce independent PCAs for each block, and the combined (common) information in a score plot. The results of this study showed group patterns of the analyzed paints, related to both binder and pigment compositions in one single score plot. Moreover, the number of groups observed with the multiblock representation (20 groups) is higher than independent PCAs projections (12 and 7 groups for IR and Raman respectively). This new application of chemometrics showed a great potential in forensic science, as practitioners often use a combination of several analytical techniques in order to characterize samples. This could be helpful when multiple and complementary analytical techniques are used in order to characterize and compare paint samples.

  17. 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.

  18. Parametric Characterization of Porous 3D Bioscaffolds Fabricated by an Adaptive Foam Reticulation Technique

    NASA Astrophysics Data System (ADS)

    Winnett, James; Mallick, Kajal K.

    2014-04-01

    Commercially pure titanium (Ti) and its alloys, in particular, titanium-vanadium-aluminium (Ti-6Al-4V), have been used as biomaterials due to their mechanical similarities to bone, good biocompatibility, and inertness in vivo. The introduction of porosity to the scaffolds leads to optimized mechanical properties and enhanced biological activity. The adaptive foam reticulation (AFR) technique has been previously used to generate hydroxyapatite bioscaffolds with enhanced cell behavior due to the generation of macroporous structures with microporous struts that provided routes for cell infiltration as well as attachment sites. Sacrificial polyurethane templates of 45 ppi and 90 ppi were coated in biomaterial-based slurries containing either Ti or Ti-6Al-4V as the biomaterial and camphene as the porogen. The resultant macropore sizes of 100-550 μm corresponded well with the initial template pore sizes while camphene produced micropores of 1-10 μm, with the level of microporosity related to the amount of porogen inclusion.

  19. 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.

  20. 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.

  1. Evaluation of structure-reactivity descriptors and biological activity spectra of 4-(6-methoxy-2-naphthyl)-2-butanone using spectroscopic techniques.

    PubMed

    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 3THz.

  2. Evaluation of structure-reactivity descriptors and biological activity spectra of 4-(6-methoxy-2-naphthyl)-2-butanone using spectroscopic techniques.

    PubMed

    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 3THz. PMID:27284764

  3. Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique.

    PubMed

    Chan, K L; Jiang, S Y N; Ning, Z

    2016-03-31

    In this study, we present the development and evaluation of a dispersive absorption spectroscopic technique for trace level soluble ferrous detection. The technique makes use of the broadband absorption spectra of the ferrous-ferrozine complex with a novel spectral fitting algorithm to determine soluble ferrous concentrations in samples and achieves much improved measurement precision compared to conventional methods. The developed method was evaluated by both model simulations and experimental investigations. The results demonstrated the robustness of the method against the spectral fluctuation, wavelength drift and electronic noise, while achieving excellent linearity (R(2) > 0.999) and low detection limit (0.06 μg L(-1)) for soluble ferrous detection. The developed method was also used for the speciation of soluble iron in size segregated atmospheric aerosols. The measurement was carried out during Spring and Summer in typical urban environment in Hong Kong. The measured total iron concentrations are in good agreement compared to conventional Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES) measurements. Investigation on ambient particulate matter samples shows the size dependent characteristic of iron speciation in the atmosphere with a more active role of fine particles in transforming between ferrous and ferric. The method demonstrated in this study provides a cost and time effective approach for the speciation of iron in ambient aerosols. PMID:26965332

  4. Adaptive optics correction based on stochastic parallel gradient descent technique under various atmospheric scintillation conditions: numerical simulation

    NASA Astrophysics Data System (ADS)

    Ma, H.; Fan, C.; Zhang, P.; Zhang, J.; Qiao, C.; Wang, H.

    2012-03-01

    An adaptive optics system utilizing a Shack-Hartmann wavefront sensor and a deformable mirror can successfully correct a distorted wavefront by the conjugation principle. However, if a wave propagates over such a path that scintillation is not negligible, the appearance of branch points makes least-squares reconstruction fail to estimate the wavefront effectively. An adaptive optics technique based on the stochastic parallel gradient descent (SPGD) control algorithm is an alternative approach which does not need wavefront information but optimizes the performance metric directly. Performance was evaluated by simulating a SPGD control system and conventional adaptive correction with least-squares reconstruction in the context of a laser beam projection system. We also examined the relative performance of coping with branch points by the SPGD technique through an example. All studies were carried out under the conditions of assuming the systems have noise-free measurements and infinite time control bandwidth. Results indicate that the SPGD adaptive system always performs better than the system based on the least-squares wavefront reconstruction technique in the presence of relatively serious intensity scintillations. The reason is that the SPGD adaptive system has the ability of compensating a discontinuous phase, although the phase is not detected and reconstructed.

  5. Automatic online adaptive radiation therapy techniques for targets with significant shape change: a feasibility study.

    PubMed

    Court, Laurence E; Tishler, Roy B; Petit, Joshua; Cormack, Robert; Chin, Lee

    2006-05-21

    This work looks at the feasibility of an online adaptive radiation therapy concept that would detect the daily position and shape of the patient, and would then correct the daily treatment to account for any changes compared with planning position. In particular, it looks at the possibility of developing algorithms to correct for large complicated shape change. For co-planar beams, the dose in an axial plane is approximately associated with the positions of a single multi-leaf collimator (MLC) pair. We start with a primary plan, and automatically generate several secondary plans with gantry angles offset by regular increments. MLC sequences for each plan are calculated keeping monitor units (MUs) and number of segments constant for a given beam (fluences are different). Bulk registration (3D) of planning and daily CT images gives global shifts. Slice-by-slice (2D) registration gives local shifts and rotations about the longitudinal axis for each axial slice. The daily MLC sequence is then created for each axial slice/MLC leaf pair combination, by taking the MLC positions from the pre-calculated plan with the nearest rotation, and shifting using a beam's-eye-view calculation to account for local linear shifts. A planning study was carried out using two head and neck region MR images of a healthy volunteer which were contoured to simulate a base-of-tongue treatment: one with the head straight (used to simulate the planning image) and the other with the head tilted to the left (the daily image). Head and neck treatment was chosen to evaluate this technique because of its challenging nature, with varying internal and external contours, and multiple degrees of freedom. Shape change was significant: on a slice-by-slice basis, local rotations in the daily image varied from 2 to 31 degrees, and local shifts ranged from -0.2 to 0.5 cm and -0.4 to 0.0 cm in right-left and posterior-anterior directions, respectively. The adapted treatment gave reasonable target coverage (100

  6. 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.

  7. Aquifer Storage and Recovery as a Viable Climate Change Adaptation Technique: Sustainable Development under the Current Regulatory Framework

    EPA Science Inventory

    A holistic investigation of aquifer storage and recovery (ASR) technique and application in the U.S. is being conducted as a part of the USEPA Water Resources Adaptation Program (WRAP). The research focus is to evaluate the potential of ASR application as a practical climate chan...

  8. 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

  9. 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

  10. 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).

  11. 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.

  12. 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

  13. Study on the interaction of the epilepsy drug, zonisamide with human serum albumin (HSA) by spectroscopic and molecular docking techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Khorshidi, Aref; Moghadam, Neda Hossinpour

    2013-10-01

    In the present investigation, an attempt has been made to study the interaction of zonisamide (ZNS) with the transport protein, human serum albumin (HSA) employing UV-Vis, fluorometric, circular dichroism (CD) and molecular docking techniques. The results indicated that binding of ZNS to HSA caused strong fluorescence quenching of HSA through static quenching mechanism, hydrogen bonds and van der Waals contacts are the major forces in the stability of protein ZNS complex and the process of the binding of ZNS with HSA was driven by enthalpy (ΔH = -193.442 kJ mol-1). The results of CD and UV-Vis spectroscopy showed that the binding of this drug to HSA induced conformational changes in HSA. Furthermore, the study of molecular docking also indicated that zonisamide could strongly bind to the site I (subdomain IIA) of HSA mainly by hydrophobic interaction and there were hydrogen bond interactions between this drug and HSA, also known as the warfarin binding site.

  14. Binding studies of the anti-retroviral drug, efavirenz to calf thymus DNA using spectroscopic and voltammetric techniques.

    PubMed

    Sadeghi, Marzieh; Bayat, Maryam; Cheraghi, Shekofeh; Yari, Khirollah; Heydari, Rouhollah; Dehdashtian, Sara; Shamsipur, Mojtaba

    2016-02-01

    Interactions between efavirenz (EFZ) with calf thymus DNA (CT-DNA) were investigated in vitro under stimulated physiological conditions using multispectroscopic techniques, cyclic voltammetry viscosity measurement, and gel electrophoresis. Methylene blue and acridine orange dyes were used as spectral probes by fluorescence spectroscopy. Hypochromicity was observed in ultra-violet (UV) absorption band of EFZ. Considerable fluorescence enhancement of EFZ was observed in the presence of increasing amounts of DNA solution and the binding constants (Kf ) and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters including enthalpy change (ΔH) and entropy change (ΔS) were calculated to be -304.78 kJ mol(-1) and -924.52 J mol(-1)  K(-1) according to the van 't Hoff equation, which indicated that reaction is predominantly enthalpically driven. In addition, UV/vis absorption titration of DNA bases confirmed that EFZ interacted with guanine and cytosine preferentially. Gel electrophoresis of DNA with EFZ demonstrated that EFZ also has the ability to cleave supercoiled plasmid DNA. Circular dichroism study showed stabilization of the right-handed B form of CT-DNA. All results suggest that EFZ interacts with CT-DNA via an intercalative mode of binding.

  15. X-ray spectroscopic technique for energetic electron transport studies in short-pulse laser/plasma interactions

    SciTech Connect

    Tutt, T.E.

    1994-12-01

    When a solid target is irradiated by a laser beam, the material is locally heated to a high temperature and a plasma forms. The interaction of the laser with plasma can produce energetic electrons. By observing the behavior of these {open_quotes}hot{close_quotes} electrons, we hope to obtain a better understanding of Laser/Plasma Interactions. In this work we employ a layered-fluorescer technique to study the transport, and therefore the energetics, of the electrons. The plasma forms on a thin foil of metallic Pd which is bonded to thin layer of metallic Sn. Electrons formed from the plasma penetrate first the Pd and then the Sn. In both layers the energetic electrons promote inner (K) shell ionization of the metallic atoms which leads to the emission of characteristic K{sub {alpha}} x-rays of the fluorescers. By recording the x-ray spectrum emitted by the two foils, we can estimate the energy-dependent range of the electrons and their numbers.

  16. Segmental extracellular and intracellular water distribution and muscle glycogen after 72-h carbohydrate loading using spectroscopic techniques.

    PubMed

    Shiose, Keisuke; Yamada, Yosuke; Motonaga, Keiko; Sagayama, Hiroyuki; Higaki, Yasuki; Tanaka, Hiroaki; Takahashi, Hideyuki

    2016-07-01

    Body water content increases during carbohydrate loading because 2.7-4-g water binds each 1 g of glycogen. Bioelectrical impedance spectroscopy (BIS) allows separate assessment of extracellular and intracellular water (ECW and ICW, respectively) in the whole body and each body segment. However, BIS has not been shown to detect changes in body water induced by carbohydrate loading. Here, we aimed to investigate whether BIS had sufficient sensitivity to detect changes in body water content and to determine segmental water distribution after carbohydrate loading. Eight subjects consumed a high-carbohydrate diet containing 12 g carbohydrates·kg body mass(-1)·day(-1) for 72 h after glycogen depletion cycling exercise. Changes in muscle glycogen concentration were measured by (13)C-magnetic resonance spectroscopy, and total body water (TBW) was measured by the deuterium dilution technique (TBWD2O). ICW and ECW in the whole body (wrist-to-ankle) and in each body segment (arm, trunk, and leg) were assessed by BIS. Muscle glycogen concentration [72.7 ± 10.0 (SD) to 169.4 ± 55.9 mmol/kg wet wt, P < 0.001] and TBWD2O (39.3 ± 3.2 to 40.2 ± 3.0 kg, P < 0.05) increased significantly 72 h after exercise compared with baseline, respectively. Whole-body BIS showed significant increases in ICW (P < 0.05), but not in ECW. Segmental BIS showed significant increases in ICW in the legs (P < 0.05), but not in the arms or trunk. Our results suggest that increase in body water after carbohydrate loading can be detected by BIS and is caused by segment-specific increases in ICW. PMID:27231310

  17. Studying Iron Mineralogy to Understand Redox Conditions in the Mesoproterozoic Belt Basin, USA Using Complementary Microscopic, Spectroscopic, and Magnetic Techniques

    NASA Astrophysics Data System (ADS)

    Slotznick, S. P.; Webb, S.; Kirschvink, J. L.; Fischer, W. W.

    2015-12-01

    Observations of iron chemistry and mineralogy over time provide a valuable tool for studying paleoenvironments, but questions still remain as to the redox character of Proterozoic basins after the rise of oxygen. To evaluate the mechanisms of iron mineralization in Proterozoic samples, we developed an approach that pairs the microscale textural techniques of light microscopy, magnetic scanning microscopy, and (synchrotron-based) microprobe x-ray spectroscopy with sensitive bulk rock magnetic experiments. Samples were collected from stratigraphic sections across the ~1.4 Ga lower Belt Group, Belt Supergroup, MT and ID, USA with a focus on excellently preserved sedimentary rocks, but also including those altered by a variety of diagenetic, metamorphic, and metasomatic events. Results show that even in the best-preserved parts of the Belt Basin, late diagenetic and/or metasomatic fluids affected (in some cases very mildly) the primary iron phases as evidenced by prevalent post-depositional alterations such as rare base metal sulfides. In more heavily altered rocks, the appearance of pyrrhotite and other minerals signaled transformations in iron mineralogy through metamorphism and metasomatism. Despite these secondary phases crystallizing in an open fluid-rich system, primary records of redox chemistry were preserved in the recrystallized early diagenetic framboidal pyrite and (sub)micron-sized detrital magnetite grains. Detrital magnetite is not the most abundant iron-bearing phase in any of the samples (typically <0.01 wt%), but is widely observed in both proximal and deeper basin facies, illustrating an important detrital flux of iron to the basin and a highly reactive iron source for early diagenetic pyrite. Based on our analyses, we interpret the shallow waters of the Belt Basin to be oxic with sulfidic pore fluids and deeper waters in parts of the basin as likely euxinic, consistent with the results of some bulk geochemical proxies. This redox reconstruction also

  18. Test techniques: A survey paper on cryogenic tunnels, adaptive wall test sections, and magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.; Dress, David A.; Wolf, Stephen W. D.; Britcher, Colin P.

    1989-01-01

    The ability to get good experimental data in wind tunnels is often compromised by things seemingly beyond our control. Inadequate Reynolds number, wall interference, and support interference are three of the major problems in wind tunnel testing. Techniques for solving these problems are available. Cryogenic wind tunnels solve the problem of low Reynolds number. Adaptive wall test sections can go a long way toward eliminating wall interference. A magnetic suspension and balance system (MSBS) completely eliminates support interference. Cryogenic tunnels, adaptive wall test sections, and MSBS are surveyed. A brief historical overview is given and the present state of development and application in each area is described.

  19. Studies on the interaction between promethazine and human serum albumin in the presence of flavonoids by spectroscopic and molecular modeling techniques.

    PubMed

    He, Ling-Ling; Wang, Zhi-Xin; Wang, Yong-Xia; Liu, Xian-Ping; Yang, Yan-Jie; Gao, Yan-Ping; Wang, Xin; Liu, Bin; Wang, Xin

    2016-09-01

    Fluorescence, absorption, time-correlated single photon counting (TCSPC), and circular dichroism (CD) spectroscopic techniques as well as molecular modeling methods were used to study the binding characterization of promethazine (PMT) to human serum albumin (HSA) and the influence of flavonoids, rutin and baicalin, on their affinity. The results indicated that the fluorescence quenching mechanism of HSA by PMT is a static quenching due to the formation of complex. The reaction was spontaneous and mainly mediated by hydrogen bonds and hydrophobic interactions. The binding distance between the tryptophan residue of HSA and PMT is less than 8nm, which indicated that the energy transfer from the tryptophan residue of HSA to PMT occurred. The binding site of PMT on HSA was located in sites I and the presence of PMT can cause the conformational changes of HSA. There was the competitive binding to HSA between PMT and flavonoids because of the overlap of binding sites in HSA. The flavonoids could decrease the association constant and increase the binding distance. In addition, their synergistic effect can further change the conformation of HSA. The decrease in the affinities of PMT binding to HSA in the presence of flavonoids may lead to the increase of free drug in blood, which would affect the transportation or disposition of drug and evoke an adverse or toxic effect. Hence, rationalising dosage and diet regimens should be taken into account in clinical application of PMT.

  20. Use of spectroscopic and imaging techniques to evaluate pretreated sugarcane bagasse as a substrate for cellulase production under solid-state fermentation.

    PubMed

    Rodríguez-Zúñiga, Ursula Fabiola; Bertucci Neto, Victor; Couri, Sonia; Crestana, Silvio; Farinas, Cristiane Sanchez

    2014-03-01

    The enzymatic cocktail of cellulases is one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels and other chemicals. Here, the influence of liquid hot water, dilute acid, alkali, and combined acid/alkali pretreatments on sugarcane bagasse (SCB) used for cellulase production was investigated by means of spectroscopic and imaging techniques. Chemical composition and structural characteristics, such as crystallinity (determined by X-ray diffraction), functional groups (Fourier transform infrared spectroscopy), and microstructure (scanning electron microscopy), were used to correlate SCB pretreatments with enzymatic biosynthesis by a strain of the filamentous fungus Aspergillus niger under solid-state fermentation. The combined acid/alkali pretreatment resulted in a SCB with higher cellulose content (86.7%). However, the high crystallinity (74%) of the resulting biomass was detrimental to microbial uptake and enzyme production. SCB pretreated with liquid hot water yielded the highest filter paper cellulase (FPase), carboxymethyl cellulase (CMCase), and xylanase activities (0.4, 14.9, and 26.1 U g(-1), respectively). The results showed that a suitable pretreatment for SCB to be used as a substrate for cellulase production should avoid severe conditions in order to preserve amorphous cellulose and to enhance the physical properties that assist microbial access. PMID:24363237

  1. Studies on the interaction between promethazine and human serum albumin in the presence of flavonoids by spectroscopic and molecular modeling techniques.

    PubMed

    He, Ling-Ling; Wang, Zhi-Xin; Wang, Yong-Xia; Liu, Xian-Ping; Yang, Yan-Jie; Gao, Yan-Ping; Wang, Xin; Liu, Bin; Wang, Xin

    2016-09-01

    Fluorescence, absorption, time-correlated single photon counting (TCSPC), and circular dichroism (CD) spectroscopic techniques as well as molecular modeling methods were used to study the binding characterization of promethazine (PMT) to human serum albumin (HSA) and the influence of flavonoids, rutin and baicalin, on their affinity. The results indicated that the fluorescence quenching mechanism of HSA by PMT is a static quenching due to the formation of complex. The reaction was spontaneous and mainly mediated by hydrogen bonds and hydrophobic interactions. The binding distance between the tryptophan residue of HSA and PMT is less than 8nm, which indicated that the energy transfer from the tryptophan residue of HSA to PMT occurred. The binding site of PMT on HSA was located in sites I and the presence of PMT can cause the conformational changes of HSA. There was the competitive binding to HSA between PMT and flavonoids because of the overlap of binding sites in HSA. The flavonoids could decrease the association constant and increase the binding distance. In addition, their synergistic effect can further change the conformation of HSA. The decrease in the affinities of PMT binding to HSA in the presence of flavonoids may lead to the increase of free drug in blood, which would affect the transportation or disposition of drug and evoke an adverse or toxic effect. Hence, rationalising dosage and diet regimens should be taken into account in clinical application of PMT. PMID:27315330

  2. Structure and spectroscopic analysis of the graphene monolayer film directly grown on the quartz substrate via the HF-CVD technique

    NASA Astrophysics Data System (ADS)

    Mahmoud, Waleed E.; Al-Hazmi, Farag S.; Al-Ghamdi, A. A.; Shokr, F. S.; Beall, Gary W.; Bronstein, Lyudmila M.

    2016-08-01

    Direct growth of a monolayer graphene film on a quartz substrate by a hot filament chemical vapor deposition technique is reported. The monolayer graphene film prepared was characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), and atomic force microscopy (AFM). The optical properties were studied by spectroscopic elliposmetry. The experimental data were fitted by the Forouhi-Bloomer model to estimate the extinction coefficient and the refractive index of the monolayer graphene film. The refractive index spectrum in the visible region was studied based on the harmonic oscillator model. The lattice dielectric constant, real and imaginary dielectric constants and the ratio of the charge carrier number to the effective mass were determined. The surface and volume energy loss parameters were also found and showed that the value of the surface energy loss is greater than the volume energy loss. The determination of these optical constants will open new avenue for novel applications of graphene films in the field of wave plates, light modulators, ultrahigh-frequency signal processing and LCDs.

  3. Adaptive Meshing Techniques for Viscous Flow Calculations on Mixed Element Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1997-01-01

    An adaptive refinement strategy based on hierarchical element subdivision is formulated and implemented for meshes containing arbitrary mixtures of tetrahendra, hexahendra, prisms and pyramids. Special attention is given to keeping memory overheads as low as possible. This procedure is coupled with an algebraic multigrid flow solver which operates on mixed-element meshes. Inviscid flows as well as viscous flows are computed an adaptively refined tetrahedral, hexahedral, and hybrid meshes. The efficiency of the method is demonstrated by generating an adapted hexahedral mesh containing 3 million vertices on a relatively inexpensive workstation.

  4. Electrical hand tools and techniques: A compilation. [utilization of space technology for tools and adapters

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Space technology utilization for developing tools, adapters, and fixtures and procedures for assembling, installing, and servicing electrical components and equipment are discussed. Some of the items considered are: (1) pivotal screwdriver, (2) termination locator tool for shielded cables, (3) solder application tools, (4) insulation and shield removing tool, and (5) torque wrench adapter for cable connector engaging ring. Diagrams of the various tools and devices are provided.

  5. Determination of Judo Endurance Performance Using the Uchi - Komi Technique and an Adapted Lactate Minimum Test

    PubMed Central

    Azevedo, Paulo H.S.M.; Drigo, Alexandre J.; Carvalho, Mauro C.G.A.; Oliveira, João C.; Nunes, João E.D.; Baldissera, Vilmar; Perez, Sérgio E.A.

    2007-01-01

    This study aimed to evaluate the viability to use Uchi-komi (UK) in the evaluation of the judo endurance performance and using lactate threshold the analysis of the blood lactate ([Lac]) and heart rate (HR) determined through a lactate minimum test. The subjects were a group of 6 male, volunteer judokas, from 25.17 ± 5.76 years old, weight 84.50 ± 23.78 kg and height 1.78 ± 0.10 m, competitors of different levels of performance (from regional to international competitions) and match experience of (11 ± 6) years old. Three tests were performed: a) 3000 m dash in track, b) the adapted test of lactate minimum for running and c) for UK, with execution of the blow ippon-seoi-nague. No significant difference was evident for the track tests and UK in relation to blood lactate and heart rate (p > 0.05) (3.87 ± 0.38 vs 4.17 ± 0.54 mmol·L-1 and 167 ± 2 vs 152 ± 7 b·min-1, respectively). In conclusion it is stressed that: 1) The specific test for lactate minimum in judo sport is a promising possibility of aerobic capacity evaluation and a instrument of intensity training control; 2) The metabolic profile in Vlm and UKlm is similar, because there are not differences in the [Lac] and in the HR at this intensity; 3) It is possible to estimate the training intensity through the determination of the lactate minimum intensity in running (Vlm) and the Heart Rate associated (HR) from the execution of ippon-seoi- nague (uchi-komi) in judo training; 4) The Vlm for judo athletes is approximately 88% of the V3000. Key points The specific test for lactate minimum in judo sport is a promising possibility of aerobic capacity evaluation; This is a instrument for intensity training control for judo players; The metabolic profile is similar between running and uki-komi (ippon-seoi-nague techniques) at lactate minimum intensity. PMID:24198697

  6. ADAPTATION OF CRACK GROWTH DETECTION TECHNIQUES TO US MATERIAL TEST REACTORS

    SciTech Connect

    A. Joseph Palmer; Sebastien P. Teysseyre; Kurt L. Davis; Gordon Kohse; Yakov Ostrovsky; David M. Carpenter; Joy L. Rempe

    2015-04-01

    A key component in evaluating the ability of Light Water Reactors to operate beyond 60 years is characterizing the degradation of materials exposed to radiation and various water chemistries. Of particular concern is the response of reactor materials to Irradiation Assisted Stress Corrosion Cracking (IASCC). Some test reactors outside the United States, such as the Halden Boiling Water Reactor (HBWR), have developed techniques to measure crack growth propagation during irradiation. The basic approach is to use a custom-designed compact loading mechanism to stress the specimen during irradiation, while the crack in the specimen is monitored in-situ using the Direct Current Potential Drop (DCPD) method. In 2012 the US Department of Energy commissioned the Idaho National Laboratory and the MIT Nuclear Reactor Laboratory (MIT NRL) to take the basic concepts developed at the HBWR and adapt them to a test rig capable of conducting in-pile IASCC tests in US Material Test Reactors. The first two and half years of the project consisted of designing and testing the loader mechanism, testing individual components of the in-pile rig and electronic support equipment, and autoclave testing of the rig design prior to insertion in the MIT Reactor. The load was applied to the specimen by means of a scissor like mechanism, actuated by a miniature metal bellows driven by pneumatic pressure and sized to fit within the small in-core irradiation volume. In addition to the loader design, technical challenges included developing robust connections to the specimen for the applied current and voltage measurements, appropriate ceramic insulating materials that can endure the LWR environment, dealing with the high electromagnetic noise environment of a reactor core at full power, and accommodating material property changes in the specimen, due primarily to fast neutron damage, which change the specimen resistance without additional crack growth. The project culminated with an in

  7. The adaptive statistical iterative reconstruction-V technique for radiation dose reduction in abdominal CT: comparison with the adaptive statistical iterative reconstruction technique

    PubMed Central

    Cho, Jinhan; Oh, Jongyeong; Kim, Dongwon; Cho, Junghyun; Kim, Sanghyun; Lee, Sangyun; Lee, Jihyun

    2015-01-01

    Objective: To investigate whether reduced radiation dose abdominal CT images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V) compromise the depiction of clinically competent features when compared with the currently used routine radiation dose CT images reconstructed with ASIR. Methods: 27 consecutive patients (mean body mass index: 23.55 kg m−2 underwent CT of the abdomen at two time points. At the first time point, abdominal CT was scanned at 21.45 noise index levels of automatic current modulation at 120 kV. Images were reconstructed with 40% ASIR, the routine protocol of Dong-A University Hospital. At the second time point, follow-up scans were performed at 30 noise index levels. Images were reconstructed with filtered back projection (FBP), 40% ASIR, 30% ASIR-V, 50% ASIR-V and 70% ASIR-V for the reduced radiation dose. Both quantitative and qualitative analyses of image quality were conducted. The CT dose index was also recorded. Results: At the follow-up study, the mean dose reduction relative to the currently used common radiation dose was 35.37% (range: 19–49%). The overall subjective image quality and diagnostic acceptability of the 50% ASIR-V scores at the reduced radiation dose were nearly identical to those recorded when using the initial routine-dose CT with 40% ASIR. Subjective ratings of the qualitative analysis revealed that of all reduced radiation dose CT series reconstructed, 30% ASIR-V and 50% ASIR-V were associated with higher image quality with lower noise and artefacts as well as good sharpness when compared with 40% ASIR and FBP. However, the sharpness score at 70% ASIR-V was considered to be worse than that at 40% ASIR. Objective image noise for 50% ASIR-V was 34.24% and 46.34% which was lower than 40% ASIR and FBP. Conclusion: Abdominal CT images reconstructed with ASIR-V facilitate radiation dose reductions of to 35% when compared with the ASIR. Advances in knowledge: This study represents the first

  8. Improvement of near infrared spectroscopic (NIRS) analysis of caffeine in roasted Arabica coffee by variable selection method of stability competitive adaptive reweighted sampling (SCARS)

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Li, Wei; Yin, Bin; Chen, Weizhong; Kelly, Declan P.; Wang, Xiaoxin; Zheng, Kaiyi; Du, Yiping

    2013-10-01

    Coffee is the most heavily consumed beverage in the world after water, for which quality is a key consideration in commercial trade. Therefore, caffeine content which has a significant effect on the final quality of the coffee products requires to be determined fast and reliably by new analytical techniques. The main purpose of this work was to establish a powerful and practical analytical method based on near infrared spectroscopy (NIRS) and chemometrics for quantitative determination of caffeine content in roasted Arabica coffees. Ground coffee samples within a wide range of roasted levels were analyzed by NIR, meanwhile, in which the caffeine contents were quantitative determined by the most commonly used HPLC-UV method as the reference values. Then calibration models based on chemometric analyses of the NIR spectral data and reference concentrations of coffee samples were developed. Partial least squares (PLS) regression was used to construct the models. Furthermore, diverse spectra pretreatment and variable selection techniques were applied in order to obtain robust and reliable reduced-spectrum regression models. Comparing the respective quality of the different models constructed, the application of second derivative pretreatment and stability competitive adaptive reweighted sampling (SCARS) variable selection provided a notably improved regression model, with root mean square error of cross validation (RMSECV) of 0.375 mg/g and correlation coefficient (R) of 0.918 at PLS factor of 7. An independent test set was used to assess the model, with the root mean square error of prediction (RMSEP) of 0.378 mg/g, mean relative error of 1.976% and mean relative standard deviation (RSD) of 1.707%. Thus, the results provided by the high-quality calibration model revealed the feasibility of NIR spectroscopy for at-line application to predict the caffeine content of unknown roasted coffee samples, thanks to the short analysis time of a few seconds and non

  9. Improvement of near infrared spectroscopic (NIRS) analysis of caffeine in roasted Arabica coffee by variable selection method of stability competitive adaptive reweighted sampling (SCARS).

    PubMed

    Zhang, Xuan; Li, Wei; Yin, Bin; Chen, Weizhong; Kelly, Declan P; Wang, Xiaoxin; Zheng, Kaiyi; Du, Yiping

    2013-10-01

    Coffee is the most heavily consumed beverage in the world after water, for which quality is a key consideration in commercial trade. Therefore, caffeine content which has a significant effect on the final quality of the coffee products requires to be determined fast and reliably by new analytical techniques. The main purpose of this work was to establish a powerful and practical analytical method based on near infrared spectroscopy (NIRS) and chemometrics for quantitative determination of caffeine content in roasted Arabica coffees. Ground coffee samples within a wide range of roasted levels were analyzed by NIR, meanwhile, in which the caffeine contents were quantitative determined by the most commonly used HPLC-UV method as the reference values. Then calibration models based on chemometric analyses of the NIR spectral data and reference concentrations of coffee samples were developed. Partial least squares (PLS) regression was used to construct the models. Furthermore, diverse spectra pretreatment and variable selection techniques were applied in order to obtain robust and reliable reduced-spectrum regression models. Comparing the respective quality of the different models constructed, the application of second derivative pretreatment and stability competitive adaptive reweighted sampling (SCARS) variable selection provided a notably improved regression model, with root mean square error of cross validation (RMSECV) of 0.375 mg/g and correlation coefficient (R) of 0.918 at PLS factor of 7. An independent test set was used to assess the model, with the root mean square error of prediction (RMSEP) of 0.378 mg/g, mean relative error of 1.976% and mean relative standard deviation (RSD) of 1.707%. Thus, the results provided by the high-quality calibration model revealed the feasibility of NIR spectroscopy for at-line application to predict the caffeine content of unknown roasted coffee samples, thanks to the short analysis time of a few seconds and non

  10. Some adaptive filtering techniques applied to the passive remote sensing problem. [for Tiros-N and Nimbus 6 experiments

    NASA Technical Reports Server (NTRS)

    Toldalagi, P. M.

    1980-01-01

    A review is made of recursive statistical regression techniques incorporating past or past and future observations through smoothing and Kalman filtering, respectively; with results for the cases of the Tiros-N/MSU and Nimbus-6/Scams remote sensing satellite experiments. In response to the lack of a satisfactory model for the medium sounded, which is presently a major limitation on retrieval technique performance, a novel, global approach is proposed which casts the retrieval problem into the framework of adaptive filtering. A numerical implementation of such an adaptive system is presented, with a multilayer, semi-spectral general circulation model for the atmosphere being used to fine-tune the sensor as well as the dynamical equations of a Kalman filter. It is shown that the assimilation of radiometric data becomes a straightforward subproblem.

  11. Radiation treatment for the right naris in a pediatric anesthesia patient using an adaptive oral airway technique

    SciTech Connect

    Sponseller, Patricia Pelly, Nicole; Trister, Andrew; Ford, Eric; Ermoian, Ralph

    2015-10-01

    Radiation therapy for pediatric patients often includes the use of intravenous anesthesia with supplemental oxygen delivered via the nasal cannula. Here, we describe the use of an adaptive anesthesia technique for electron irradiation of the right naris in a preschool-aged patient treated under anesthesia. The need for an intranasal bolus plug precluded the use of standard oxygen supplementation. This novel technique required the multidisciplinary expertise of anesthesiologists, radiation therapists, medical dosimetrists, medical physicists, and radiation oncologists to ensure a safe and reproducible treatment course.

  12. Application of Physiological Self-Regulation and Adaptive Task Allocation Techniques for Controlling Operator Hazardous States of Awareness

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Pope, Alan T.; Freeman, Frederick G.

    2001-01-01

    Prinzel, Hadley, Freeman, and Mikulka found that adaptive task allocation significantly enhanced performance only when used at the endpoints of the task workload continuum (i.e., very low or high workload), but that the technique degraded performance if invoked during other levels of task demand. These researchers suggested that other techniques should be used in conjunction with adaptive automation to help minimize the onset of hazardous states of awareness (HSA) and keep the operator 'in-the-loop.' The paper reports on such a technique that uses psychophysiological self-regulation to modulate the level of task engagement. Eighteen participants were assigned to three groups (self-regulation, false feedback, and control) and performed a compensatory tracking task that was cycled between three levels of task difficulty on the basis of the electroencephalogram (EEG) record. Those participants who had received self-regulation training performed significantly better and reported lower NASA-TLX scores than participants in the false feedback and control groups. Furthermore, the false feedback and control groups had significantly more task allocations resulting in return-to-manual performance decrements and higher EEG difference scores. Theoretical and practical implications of these results for adaptive automation are discussed.

  13. Observation of the origin of d0 magnetism in ZnO nanostructures using X-ray-based microscopic and spectroscopic techniques.

    PubMed

    Singh, Shashi B; Wang, Yu-Fu; Shao, Yu-Cheng; Lai, Hsuan-Yu; Hsieh, Shang-Hsien; Limaye, Mukta V; Chuang, Chen-Hao; Hsueh, Hung-Chung; Wang, Hsaiotsu; Chiou, Jau-Wern; Tsai, Hung-Ming; Pao, Chih-Wen; Chen, Chia-Hao; Lin, Hong-Ji; Lee, Jyh-Fu; Wu, Chun-Te; Wu, Jih-Jen; Pong, Way-Faung; Ohigashi, Takuji; Kosugi, Nobuhiro; Wang, Jian; Zhou, Jigang; Regier, Tom; Sham, Tsun-Kong

    2014-08-01

    Efforts have been made to elucidate the origin of d(0) magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defects are present at the O sites than at the Zn sites. Specifically, the results of O K-edge scanning transmission X-ray microscopy (STXM) and the corresponding X-ray-absorption near-edge structure (XANES) spectroscopy demonstrated that the impurity (non-stoichiometric) region in ZnO NCs contains a greater defect population than the thick region. The intensity of O K-edge STXM-XANES in the impurity region is more predominant in ZnO NCs than in NWs. The increase in the unoccupied (occupied) density of states at/above (at/below) the conduction-band minimum (valence-band maximum) or the Fermi level is related to the population of defects at the O sites, as revealed by comparing the ZnO NCs to the NWs. The results of O K-edge and Zn L3,2-edge X-ray magnetic circular dichroism demonstrated that the origin of magnetization is attributable to the O 2p orbitals rather than the Zn d orbitals. Further, the local density approximation (LDA) + U verified that vacancies in the form of dangling or unpaired 2p states (due to Zn vacancies) induced a significant local spin moment in the nearest-neighboring O atoms to the defect center, which was determined from the uneven local spin density by analyzing the partial density of states of O 2p in ZnO.

  14. Systematic Strategic Planning at a State University: A Case Study of Adapting Corporate Planning Techniques.

    ERIC Educational Resources Information Center

    Aggarwal, Raj

    1987-01-01

    The adaptation of a typical corporate strategic planning process to a midwestern state university is discussed. The university found that an ongoing planning process with a yearly cycle offers several advantages not available with prior approaches, and that strategic planning is a culture that takes time before it becomes pervasive in any…

  15. Effect of restorative technique and thermal/mechanical treatment on marginal adaptation and compressive strength of esthetic restorations.

    PubMed

    de Paula, Andréia Bolzan; Duque, Cristiane; Correr-Sobrinho, Lourenço; Puppin-Rontani, Regina M

    2008-01-01

    This study evaluated the compressive strength and marginal adaptation of composite onlays using indirect and direct techniques after thermal and mechanical cycling. Onlay standardized cavities were prepared in 50 permanent molars and restored with Z-250 resin composite using indirect (IRT) or direct (DRT) restorative techniques. The restorations were either submitted or not submitted to thermal (500 cycles, 5 degrees to 55 degrees C) and mechanical cycling (50,000 cycles, 50N). The teeth were distributed to five groups (n=10): G1-IRT/cycling; G2-IRT/no cycling; G3-DRT/cycling; G4-DRT/no cycling and G5 (control group)-sound teeth. All prepared teeth were stored in 100% relative humidity at 37 degrees C for 24 hours, followed by finishing with Sof-Lex discs. A caries detector solution was applied on the tooth-restoration interface of all teeth for five seconds, followed by washing and drying. Four digital photographs were taken of each tooth surface. The extent of gaps was measured using standard software (Image Tool 3.0). All groups were submitted to compression testing in a universal testing machine (INSTRON) at a crosshead speed of 1 mm/minute until failure. The compressive strength (CS) and marginal adaptation data were submitted to ANOVA and Tukey test (p<0.05). For both evaluation criteria (compressive strength and marginal adaptation), there were no statistically significant differences among the restorative techniques. Deterioration over time was observed for both types of restorations. However, the prevalence of catastrophic fractures increased among direct restorations. The application of thermal/mechanical cycling only influenced marginal adaptation.

  16. An Example of a Hakomi Technique Adapted for Functional Analytic Psychotherapy

    ERIC Educational Resources Information Center

    Collis, Peter

    2012-01-01

    Functional Analytic Psychotherapy (FAP) is a model of therapy that lends itself to integration with other therapy models. This paper aims to provide an example to assist others in assimilating techniques from other forms of therapy into FAP. A technique from the Hakomi Method is outlined and modified for FAP. As, on the whole, psychotherapy…

  17. Assessment of Multi-Joint Coordination and Adaptation in Standing Balance: A Novel Device and System Identification Technique.

    PubMed

    Engelhart, Denise; Schouten, Alfred C; Aarts, Ronald G K M; van der Kooij, Herman

    2015-11-01

    The ankles and hips play an important role in maintaining standing balance and the coordination between joints adapts with task and conditions, like the disturbance magnitude and type, and changes with age. Assessment of multi-joint coordination requires the application of multiple continuous and independent disturbances and closed loop system identification techniques (CLSIT). This paper presents a novel device, the double inverted pendulum perturbator (DIPP), which can apply disturbing forces at the hip level and between the shoulder blades. In addition to the disturbances, the device can provide force fields to study adaptation of multi-joint coordination. The performance of the DIPP and a novel CLSIT was assessed by identifying a system with known mechanical properties and model simulations. A double inverted pendulum was successfully identified, while force fields were able to keep the pendulum upright. The estimated dynamics were similar as the theoretical derived dynamics. The DIPP has a sufficient bandwidth of 7 Hz to identify multi-joint coordination dynamics. An experiment with human subjects where a stabilizing force field was rendered at the hip (1500 N/m), showed that subjects adapt by lowering their control actions around the ankles. The stiffness from upper and lower segment motion to ankle torque dropped with 30% and 48%, respectively. Our methods allow to study (pathological) changes in multi-joint coordination as well as adaptive capacity to maintain standing balance. PMID:25423654

  18. Assessment of Multi-Joint Coordination and Adaptation in Standing Balance: A Novel Device and System Identification Technique.

    PubMed

    Engelhart, Denise; Schouten, Alfred C; Aarts, Ronald G K M; van der Kooij, Herman

    2015-11-01

    The ankles and hips play an important role in maintaining standing balance and the coordination between joints adapts with task and conditions, like the disturbance magnitude and type, and changes with age. Assessment of multi-joint coordination requires the application of multiple continuous and independent disturbances and closed loop system identification techniques (CLSIT). This paper presents a novel device, the double inverted pendulum perturbator (DIPP), which can apply disturbing forces at the hip level and between the shoulder blades. In addition to the disturbances, the device can provide force fields to study adaptation of multi-joint coordination. The performance of the DIPP and a novel CLSIT was assessed by identifying a system with known mechanical properties and model simulations. A double inverted pendulum was successfully identified, while force fields were able to keep the pendulum upright. The estimated dynamics were similar as the theoretical derived dynamics. The DIPP has a sufficient bandwidth of 7 Hz to identify multi-joint coordination dynamics. An experiment with human subjects where a stabilizing force field was rendered at the hip (1500 N/m), showed that subjects adapt by lowering their control actions around the ankles. The stiffness from upper and lower segment motion to ankle torque dropped with 30% and 48%, respectively. Our methods allow to study (pathological) changes in multi-joint coordination as well as adaptive capacity to maintain standing balance.

  19. Adaptive mesh refinement techniques for the immersed interface method applied to flow problems.

    PubMed

    Li, Zhilin; Song, Peng

    2013-06-01

    In this paper, we develop an adaptive mesh refinement strategy of the Immersed Interface Method for flow problems with a moving interface. The work is built on the AMR method developed for two-dimensional elliptic interface problems in the paper [12] (CiCP, 12(2012), 515-527). The interface is captured by the zero level set of a Lipschitz continuous function φ(x, y, t). Our adaptive mesh refinement is built within a small band of |φ(x, y, t)| ≤ δ with finer Cartesian meshes. The AMR-IIM is validated for Stokes and Navier-Stokes equations with exact solutions, moving interfaces driven by the surface tension, and classical bubble deformation problems. A new simple area preserving strategy is also proposed in this paper for the level set method.

  20. Adaptive mesh refinement techniques for the immersed interface method applied to flow problems

    PubMed Central

    Li, Zhilin; Song, Peng

    2013-01-01

    In this paper, we develop an adaptive mesh refinement strategy of the Immersed Interface Method for flow problems with a moving interface. The work is built on the AMR method developed for two-dimensional elliptic interface problems in the paper [12] (CiCP, 12(2012), 515–527). The interface is captured by the zero level set of a Lipschitz continuous function φ(x, y, t). Our adaptive mesh refinement is built within a small band of |φ(x, y, t)| ≤ δ with finer Cartesian meshes. The AMR-IIM is validated for Stokes and Navier-Stokes equations with exact solutions, moving interfaces driven by the surface tension, and classical bubble deformation problems. A new simple area preserving strategy is also proposed in this paper for the level set method. PMID:23794763

  1. A game-theoretic architecture for visible watermarking system of ACOCOA (adaptive content and contrast aware) technique

    NASA Astrophysics Data System (ADS)

    Tsai, Min-Jen; Liu, Jung

    2011-12-01

    Digital watermarking techniques have been developed to protect the intellectual property. A digital watermarking system is basically judged based on two characteristics: security robustness and image quality. In order to obtain a robust visible watermarking in practice, we present a novel watermarking algorithm named adaptive content and contrast aware (ACOCOA), which considers the host image content and watermark texture. In addition, we propose a powerful security architecture against attacks for visible watermarking system which is based on game-theoretic approach that provides an equilibrium condition solution for the decision maker by studying the effects of transmission power on intensity and perceptual efficiency. The experimental results demonstrate that the feasibility of the proposed approach not only provides effectiveness and robustness for the watermarked images, but also allows the watermark encoder to obtain the best adaptive watermarking strategy under attacks.

  2. Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

    USGS Publications Warehouse

    Roseman, Edward F.; Kennedy, Gregory W.; Craig, Jaquelyn; Boase, James; Soper, Karen

    2011-01-01

    In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8 m) Detroit River using an anchor and buoy system.

  3. An in-line micro-pyrolysis system to remove contaminating organic species for precise and accurate water isotope analysis by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Panetta, R. J.; Hsiao, G.

    2011-12-01

    Trace levels of organic contaminants such as short alcohols and terpenoids have been shown to cause spectral interference in water isotope analysis by spectroscopic techniques. The result is degraded precision and accuracy in both δD and δ18O for samples such as beverages, plant extracts or slightly contaminated waters. An initial approach offered by manufacturers is post-processing software that analyzes spectral features to identify and flag contaminated samples. However, it is impossible for this software to accurately reconstruct the water isotope signature, thus it is primarily a metric for data quality. Here, we describe a novel in-line pyrolysis system (Micro-Pyrolysis Technology, MPT) placed just prior to the inlet of a cavity ring-down spectroscopy (CRDS) analyzer that effectively removes interfering organic molecules without altering the isotope values of the water. Following injection of the water sample, N2 carrier gas passes the sample through a micro-pyrolysis tube heated with multiple high temperature elements in an oxygen-free environment. The temperature is maintained above the thermal decomposition threshold of most organic compounds (≤ 900 oC), but well below that of water (~2000 oC). The main products of the pyrolysis reaction are non-interfering species such as elemental carbon and H2 gas. To test the efficacy and applicability of the system, waters of known isotopic composition were spiked with varying amounts of common interfering alcohols (methanol, ethanol, propanol, hexanol, trans-2-hexenol, cis-3-hexanol up to 5 % v/v) and common soluble plant terpenoids (carveol, linalool, geraniol, prenol). Spiked samples with no treatment to remove the organics show strong interfering absorption peaks that adversely affect the δD and δ18O values. However, with the MPT in place, all interfering absorption peaks are removed and the water absorption spectrum is fully restored. As a consequence, the δD and δ18O values also return to their original

  4. Adaptive feature extraction techniques for subpixel target detections in hyperspectral remote sensing

    NASA Astrophysics Data System (ADS)

    Yuen, Peter W. T.; Bishop, Gary J.

    2004-12-01

    Most target detection algorithms employed in hyperspectral remote sensing rely on a measurable difference between the spectral signature of the target and background. Matched filter techniques which utilise a set of library spectra as filter for target detection are often found to be unsatisfactory because of material variability and atmospheric effects in the field data. The aim of this paper is to report an algorithm which extracts features directly from the scene to act as matched filters for target detection. Methods based upon spectral unmixing using geometric simplex volume maximisation (SVM) and independent component analysis (ICA) were employed to generate features of the scene. Target and background like features are then differentiated, and automatically selected, from the endmember set of the unmixed result according to their statistics. Anomalies are then detected from the selected endmember set and their corresponding spectral characteristics are subsequently extracted from the scene, serving as a bank of matched filters for detection. This method, given the acronym SAFED, has a number of advantages for target detection, compared to previous techniques which use orthogonal subspace of the background feature. This paper reports the detection capability of this new technique by using an example simulated hyperspectral scene. Similar results using hyperspectral military data show high detection accuracy with negligible false alarms. Further potential applications of this technique for false alarm rate (FAR) reduction via multiple approach fusion (MAF), and, as a means for thresholding the anomaly detection technique, are outlined.

  5. An adaptive threshold based image processing technique for improved glaucoma detection and classification.

    PubMed

    Issac, Ashish; Partha Sarathi, M; Dutta, Malay Kishore

    2015-11-01

    Glaucoma is an optic neuropathy which is one of the main causes of permanent blindness worldwide. This paper presents an automatic image processing based method for detection of glaucoma from the digital fundus images. In this proposed work, the discriminatory parameters of glaucoma infection, such as cup to disc ratio (CDR), neuro retinal rim (NRR) area and blood vessels in different regions of the optic disc has been used as features and fed as inputs to learning algorithms for glaucoma diagnosis. These features which have discriminatory changes with the occurrence of glaucoma are strategically used for training the classifiers to improve the accuracy of identification. The segmentation of optic disc and cup based on adaptive threshold of the pixel intensities lying in the optic nerve head region. Unlike existing methods the proposed algorithm is based on an adaptive threshold that uses local features from the fundus image for segmentation of optic cup and optic disc making it invariant to the quality of the image and noise content which may find wider acceptability. The experimental results indicate that such features are more significant in comparison to the statistical or textural features as considered in existing works. The proposed work achieves an accuracy of 94.11% with a sensitivity of 100%. A comparison of the proposed work with the existing methods indicates that the proposed approach has improved accuracy of classification glaucoma from a digital fundus which may be considered clinically significant.

  6. Direct adaptive performance optimization of subsonic transports: A periodic perturbation technique

    NASA Technical Reports Server (NTRS)

    Espana, Martin D.; Gilyard, Glenn

    1995-01-01

    Aircraft performance can be optimized at the flight condition by using available redundancy among actuators. Effective use of this potential allows improved performance beyond limits imposed by design compromises. Optimization based on nominal models does not result in the best performance of the actual aircraft at the actual flight condition. An adaptive algorithm for optimizing performance parameters, such as speed or fuel flow, in flight based exclusively on flight data is proposed. The algorithm is inherently insensitive to model inaccuracies and measurement noise and biases and can optimize several decision variables at the same time. An adaptive constraint controller integrated into the algorithm regulates the optimization constraints, such as altitude or speed, without requiring and prior knowledge of the autopilot design. The algorithm has a modular structure which allows easy incorporation (or removal) of optimization constraints or decision variables to the optimization problem. An important part of the contribution is the development of analytical tools enabling convergence analysis of the algorithm and the establishment of simple design rules. The fuel-flow minimization and velocity maximization modes of the algorithm are demonstrated on the NASA Dryden B-720 nonlinear flight simulator for the single- and multi-effector optimization cases.

  7. Accurate Adaptive Level Set Method and Sharpening Technique for Three Dimensional Deforming Interfaces

    NASA Technical Reports Server (NTRS)

    Kim, Hyoungin; Liou, Meng-Sing

    2011-01-01

    In this paper, we demonstrate improved accuracy of the level set method for resolving deforming interfaces by proposing two key elements: (1) accurate level set solutions on adapted Cartesian grids by judiciously choosing interpolation polynomials in regions of different grid levels and (2) enhanced reinitialization by an interface sharpening procedure. The level set equation is solved using a fifth order WENO scheme or a second order central differencing scheme depending on availability of uniform stencils at each grid point. Grid adaptation criteria are determined so that the Hamiltonian functions at nodes adjacent to interfaces are always calculated by the fifth order WENO scheme. This selective usage between the fifth order WENO and second order central differencing schemes is confirmed to give more accurate results compared to those in literature for standard test problems. In order to further improve accuracy especially near thin filaments, we suggest an artificial sharpening method, which is in a similar form with the conventional re-initialization method but utilizes sign of curvature instead of sign of the level set function. Consequently, volume loss due to numerical dissipation on thin filaments is remarkably reduced for the test problems

  8. Improving seasonal matching in the STARS model by adaptation of the resampling technique

    NASA Astrophysics Data System (ADS)

    Lutz, Julia; Gerstengarbe, Friedrich-Wilhelm

    2015-05-01

    The STatistical Analogue Resampling Scheme (STARS) has already been used for several climate projection studies in different parts of the world and climate projections obtained by STARS play an important role in several impact studies. Thus, it is crucial to provide results that are reasonable in terms of physical consistency. This also includes the annual cycle of the different variables. In this paper, we address the seasonal inconsistency that appears in the results if a demanding setting is used. This is shown on the example of applying STARS to the entire European continent, where the size and the climatological variety of the region determine the demanding setting. In this setting, the current model is not able to provide results with a realistic annual cycle, as it replaces days in autumn with days from spring. This problem is solved by an adaptation of the resampling method, resulting in a new model version of STARS which yields physically reasonable annual cycles. This model adaptation and its effects on the model results are presented in this work. While the old model results show a large overestimation of shortwave radiation in autumn, the annual cycles provided by the new model version are in agreement with observations.

  9. Removing ECG Artifact from the Surface EMG Signal Using Adaptive Subtraction Technique

    PubMed Central

    Abbaspour, S; Fallah, A

    2014-01-01

    Background: The electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. Objective: Removing electrocardiogram contamination from electromyogram signals. Methods: In this paper, the clean electromyogram signal, electrocardiogram artifact and electrocardiogram signal were recorded from leg muscles, the pectoralis major muscle of the left side and V4, respectively. After the pre-processing, contaminated electromyogram signal is simulated with a combination of clean electromyogram and electrocardiogram artifact. Then, contaminated electromyogram is cleaned using adaptive subtraction method. This method contains some steps; (1) QRS detection, (2) formation of electrocardiogram template by averaging the electrocardiogram complexes, (3) using low pass filter to remove undesirable artifacts, (4) subtraction. Results: Performance of our method is evaluated using qualitative criteria, power spectrum density and coherence and quantitative criteria signal to noise ratio, relative error and cross correlation. The result of signal to noise ratio, relative error and cross correlation is equal to 10.493, 0.04 and %97 respectively. Finally, there is a comparison between proposed method and some existing methods. Conclusion: The result indicates that adaptive subtraction method is somewhat effective to remove electrocardiogram artifact from contaminated electromyogram signal and has an acceptable result. PMID:25505766

  10. Optimization and vibration suppression of adaptive composite panels using genetic algorithm and disturbance observer technique

    NASA Astrophysics Data System (ADS)

    Yan, Su; Ghasemi-Nejhad, Mehrdad N.

    2003-07-01

    In this paper, a model of the adaptive composite panel surfaces with piezoelectric patches is built using the Rayleigh-Ritz method based on the laminate theory. The interia and stiffness of the actuators are considered in the developed model. An optimal actuator location has been proved to be desirable since the piezoelectric actuators often have limitations of delivering large power oiutputs. Due to its effectiveness in seraching optimal design parameters and obtaining globally optimal solutions, the genetic algorithm has been applied to find optimal locations of piezoelectric actuators for the vibration control of a smart composite beam. In addition, the effects of population size, the crossover probability, and the mutation probability on the convergence of the genetic algorithm are investigated. Meanwhile, linear quadric regulator (LQR) and disturbance observer (DOB) are employed for the vibration suppression of the optimized adaptive composite beam (ACB). The experimental results show the robustness of the DOB, which can successfully suppress the vibrations of the cantilevered ACB according to the optimization results in an uncertain system.

  11. The adaptation of GDL motion recognition system to sport and rehabilitation techniques analysis.

    PubMed

    Hachaj, Tomasz; Ogiela, Marek R

    2016-06-01

    The main novelty of this paper is presenting the adaptation of Gesture Description Language (GDL) methodology to sport and rehabilitation data analysis and classification. In this paper we showed that Lua language can be successfully used for adaptation of the GDL classifier to those tasks. The newly applied scripting language allows easily extension and integration of classifier with other software technologies and applications. The obtained execution speed allows using the methodology in the real-time motion capture data processing where capturing frequency differs from 100 Hz to even 500 Hz depending on number of features or classes to be calculated and recognized. Due to this fact the proposed methodology can be used to the high-end motion capture system. We anticipate that using novel, efficient and effective method will highly help both sport trainers and physiotherapist in they practice. The proposed approach can be directly applied to motion capture data kinematics analysis (evaluation of motion without regard to the forces that cause that motion). The ability to apply pattern recognition methods for GDL description can be utilized in virtual reality environment and used for sport training or rehabilitation treatment. PMID:27106581

  12. Adaptive critic learning techniques for engine torque and air-fuel ratio control.

    PubMed

    Liu, Derong; Javaherian, Hossein; Kovalenko, Olesia; Huang, Ting

    2008-08-01

    A new approach for engine calibration and control is proposed. In this paper, we present our research results on the implementation of adaptive critic designs for self-learning control of automotive engines. A class of adaptive critic designs that can be classified as (model-free) action-dependent heuristic dynamic programming is used in this research project. The goals of the present learning control design for automotive engines include improved performance, reduced emissions, and maintained optimum performance under various operating conditions. Using the data from a test vehicle with a V8 engine, we developed a neural network model of the engine and neural network controllers based on the idea of approximate dynamic programming to achieve optimal control. We have developed and simulated self-learning neural network controllers for both engine torque (TRQ) and exhaust air-fuel ratio (AFR) control. The goal of TRQ control and AFR control is to track the commanded values. For both control problems, excellent neural network controller transient performance has been achieved.

  13. Observation of the origin of d0 magnetism in ZnO nanostructures using X-ray-based microscopic and spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Singh, Shashi B.; Wang, Yu-Fu; Shao, Yu-Cheng; Lai, Hsuan-Yu; Hsieh, Shang-Hsien; Limaye, Mukta V.; Chuang, Chen-Hao; Hsueh, Hung-Chung; Wang, Hsaiotsu; Chiou, Jau-Wern; Tsai, Hung-Ming; Pao, Chih-Wen; Chen, Chia-Hao; Lin, Hong-Ji; Lee, Jyh-Fu; Wu, Chun-Te; Wu, Jih-Jen; Pong, Way-Faung; Ohigashi, Takuji; Kosugi, Nobuhiro; Wang, Jian; Zhou, Jigang; Regier, Tom; Sham, Tsun-Kong

    2014-07-01

    Efforts have been made to elucidate the origin of d0 magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defects are present at the O sites than at the Zn sites. Specifically, the results of O K-edge scanning transmission X-ray microscopy (STXM) and the corresponding X-ray-absorption near-edge structure (XANES) spectroscopy demonstrated that the impurity (non-stoichiometric) region in ZnO NCs contains a greater defect population than the thick region. The intensity of O K-edge STXM-XANES in the impurity region is more predominant in ZnO NCs than in NWs. The increase in the unoccupied (occupied) density of states at/above (at/below) the conduction-band minimum (valence-band maximum) or the Fermi level is related to the population of defects at the O sites, as revealed by comparing the ZnO NCs to the NWs. The results of O K-edge and Zn L3,2-edge X-ray magnetic circular dichroism demonstrated that the origin of magnetization is attributable to the O 2p orbitals rather than the Zn d orbitals. Further, the local density approximation (LDA) + U verified that vacancies in the form of dangling or unpaired 2p states (due to Zn vacancies) induced a significant local spin moment in the nearest-neighboring O atoms to the defect center, which was determined from the uneven local spin density by analyzing the partial density of states of O 2p in ZnO.Efforts have been made to elucidate the origin of d0 magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defects are present at the O sites than at the Zn sites

  14. A comparison of deghosting techniques in adaptive nonuniformity correction for IR focal-plane array systems

    NASA Astrophysics Data System (ADS)

    Rossi, Alessandro; Diani, Marco; Corsini, Giovanni

    2010-10-01

    Focal-plane array (FPA) IR systems are affected by fixed-pattern noise (FPN) which is caused by the nonuniformity of the responses of the detectors that compose the array. Due to the slow temporal drift of FPN, several scene-based nonuniformity correction (NUC) techniques have been developed that operate calibration during the acquisition only by means of the collected data. Unfortunately, such algorithms are affected by a collateral damaging problem: ghosting-like artifacts are generated by the edges in the scene and appear as a reverse image in the original position. In this paper, we compare the performance of representative methods for reducing ghosting. Such methods relate to the least mean square (LMS)-based NUC algorithm proposed by D.A. Scribner. In particular, attention is focused on a recently proposed technique which is based on the computation of the temporal statistics of the error signal in the aforementioned LMS-NUC algorithm. In this work, the performances of the deghosting techniques have been investigated by means of IR data corrupted with simulated nonuniformity noise over the detectors of the FPA. Finally, we have made some considerations on the computational aspect which is a challenging task for the employment of such techniques in real-time systems.

  15. Adaptive enhancement and visualization techniques for 3D THz images of breast cancer tumors

    NASA Astrophysics Data System (ADS)

    Wu, Yuhao; Bowman, Tyler; Gauch, John; El-Shenawee, Magda

    2016-03-01

    This paper evaluates image enhancement and visualization techniques for pulsed terahertz (THz) images of tissue samples. Specifically, our research objective is to effectively differentiate between heterogeneous regions of breast tissues that contain tumors diagnosed as triple negative infiltrating ductal carcinoma (IDC). Tissue slices and blocks of varying thicknesses were prepared and scanned using our lab's THz pulsed imaging system. One of the challenges we have encountered in visualizing the obtained images and differentiating between healthy and cancerous regions of the tissues is that most THz images have a low level of details and narrow contrast, making it difficult to accurately identify and visualize the margins around the IDC. To overcome this problem, we have applied and evaluated a number of image processing techniques to the scanned 3D THz images. In particular, we employed various spatial filtering and intensity transformation techniques to emphasize the small details in the images and adjust the image contrast. For each of these methods, we investigated how varying filter sizes and parameters affect the amount of enhancement applied to the images. Our experimentation shows that several image processing techniques are effective in producing THz images of breast tissue samples that contain distinguishable details, making further segmentation of the different image regions promising.

  16. Spectroscopic detection

    DOEpatents

    Woskov, Paul P.; Hadidi, Kamal

    2003-01-01

    In embodiments, spectroscopic monitor monitors modulated light signals to detect low levels of contaminants and other compounds in the presence of background interference. The monitor uses a spectrometer that includes a transmissive modulator capable of causing different frequency ranges to move onto and off of the detector. The different ranges can include those with the desired signal and those selected to subtract background contributions from those with the desired signal. Embodiments of the system are particularly useful for monitoring metal concentrations in combustion effluent.

  17. Studies of osmoregulation in salt adaptation of cyanobacteria with ESR spin-probe techniques

    PubMed Central

    Blumwald, Eduardo; Mehlhorn, Rolf J.; Packer, Lester

    1983-01-01

    Sucrose is accumulated in response to NaCl-induced stress in the cyanobacterium Synechococcus 6311. Internal cell volume was measured by ESR spectra with 2,2,6,6-tetramethyl-4-oxopiperidinoxy free radical (TEMPONE) as a spin probe in order to calculate sucrose concentrations inside the cell. This method is rapid and reliable and provides an unambiguous measurement of absolute volumes in different osmotic environments. Because the osmolar concentration of sucrose does not counter-balance the osmolar concentrations of ions in the growth medium, we suggest that sucrose accumulation is one of the mechanisms involved in the process of adaptation to salt of Synechococcus 6311. The accumulation of sucrose in non-N2-fixing cyanobacteria such as Synechococcus 6311 and in N2-fixing cyanobacteria such as Nostoc muscorum suggests a common mechanism of osmoregulation of fresh water cyanobacteria in response to increasing NaCl concentrations in the growth medium. Images PMID:16593309

  18. Adapting Industry Multiple Attenuation Techniques to Crustal-Scale Marine Seismic Surveys

    NASA Astrophysics Data System (ADS)

    Gunther, R. H.; Levin, S. A.; Taylor, B. L.; Klemperer, S. L.; Goodliffe, A. M.; Oakley, A. J.; Taylor, B.

    2004-12-01

    Academic marine seismic surveys often focus on crustal targets situated in areas with deep water and rough topography. Thinly-sedimented seafloor creates strong and late-arriving water-column reverberations, often termed multiples, that can completely obscure deeper primary reflections. In a 2002 survey of the Mariana back-arc, arc, and fore-arc regions, large topographic variations produced strong multiples which were not significantly attenuated by stacking or migration. Using swath bathymetry, collected by the onboard multi-beam sonar system, we adapt industry multiple attenuation tools to extract useable data from below the water-bottom multiple. Standard approaches to multiple removal either take advantage of differences in move-out velocities between primary and multiple arrivals in order to filter out multiples or attempt to model multiples so that they can be adaptively subtracted from the data. Until recently, most modeling tools were restricted to 2D but still performed effectively against the well-behaved multiples often encountered in commercially important areas. But these algorithms have limited effectiveness against multiples generated from 3D structures such as salt domes, so the petroleum industry has recently made a strong push for 3D algorithms. In academic surveys, out-of-plane effects are all-too-often too large for successful application of 2D models, but due to the large regions of interest and budget constraints, 3D surveys are typically out of reach. Surface-Related Multiple Elimination (SRME) is a powerful approach that predicts multiples that reflect at least once off the free surface and can model any multiples that bounce off the surface along the source-receiver line. Developed from 1D theory laid down in the late `70s at Stanford University and extended to 2D in the `80s by Delft University, it has become widely used in commercial hydrocarbon exploration. The version of SRME we adapt to the Marianas survey convolves field shot gathers

  19. Semiactive vibration control of nonlinear structures through adaptive backstepping techniques with H ∞ performance

    NASA Astrophysics Data System (ADS)

    Zapateiro, Mauricio; Karimi, Hamid Reza; Luo, Ningsu

    2011-05-01

    This article presents a new approach to the vibration mitigation problem in structures subject to seismic motions. These kinds of structures are characterised by the uncertainties of the parameters that describe their dynamics, such as stiffness and damping coefficients. Moreover, the dampers used to mitigate the vibrations caused by earthquakes are usually nonlinear devices with frictional or hysteretic dynamics. We propose an adaptive backstepping controller to account for the uncertainties and the nonlinearities. The controller is formulated in such a way that it satisfies an H ∞ performance. It is designed for a 10-storey building whose base is isolated with a frictional damper (passive device) and a magnetorheological damper (semiactive device). Controller performance is analysed through numerical simulations.

  20. Automatic ultrasonic imaging system with adaptive-learning-network signal-processing techniques

    SciTech Connect

    O'Brien, L.J.; Aravanis, N.A.; Gouge, J.R. Jr.; Mucciardi, A.N.; Lemon, D.K.; Skorpik, J.R.

    1982-04-01

    A conventional pulse-echo imaging system has been modified to operate with a linear ultrasonic array and associated digital electronics to collect data from a series of defects fabricated in aircraft quality steel blocks. A thorough analysis of the defect responses recorded with this modified system has shown that considerable improvements over conventional imaging approaches can be obtained in the crucial areas of defect detection and characterization. A combination of advanced signal processing concepts with the Adaptive Learning Network (ALN) methodology forms the basis for these improvements. Use of established signal processing algorithms such as temporal and spatial beam-forming in concert with a sophisticated detector has provided a reliable defect detection scheme which can be implemented in a microprocessor-based system to operate in an automatic mode.

  1. A New Simulation Technique for Study of Collisionless Shocks: Self-Adaptive Simulations

    SciTech Connect

    Karimabadi, H.; Omelchenko, Y.; Driscoll, J.; Krauss-Varban, D.; Fujimoto, R.; Perumalla, K.

    2005-08-01

    The traditional technique for simulating physical systems modeled by partial differential equations is by means of time-stepping methodology where the state of the system is updated at regular discrete time intervals. This method has inherent inefficiencies. In contrast to this methodology, we have developed a new asynchronous type of simulation based on a discrete-event-driven (as opposed to time-driven) approach, where the simulation state is updated on a 'need-to-be-done-only' basis. Here we report on this new technique, show an example of particle acceleration in a fast magnetosonic shockwave, and briefly discuss additional issues that we are addressing concerning algorithm development and parallel execution.

  2. Adaptive InSAR combined with surveying techniques for an improved characterisation of active landslides (El Portalet)

    NASA Astrophysics Data System (ADS)

    Duro, Javier; Albiol, David; Sánchez, Francisco; Herrera, Gerardo; García Davalillo, Juan Carlos; Fernandez Merodo, Jose Antonio; Allasia, Paolo; Lollino, Piernicola; Manconi, Andrea

    2014-05-01

    InSAR and the Persistent Scatterer Interferometry (PSI) are well established techniques for monitoring urban and rural areas. Besides the large number of available SAR data in the past, the current and forthcoming space-borne SAR sensors offer the possibility of selecting the optimal acquisition configuration (wavelength, resolution, incidence angle, etc.) for each application. However, optimal data takes are not always possible and/or the processing area is difficult to analyse under an InSAR point of view. In such situations, additional and adaptive InSAR developments combined with other surveying techniques provide consistent solutions that meet the requirements of different application cases This work presents an advanced InSAR processing adapted for an active slow deformation landslide in a mountainous area. The presentation will show the benefits of applying advanced and adaptive filtering strategies for improving the InSAR quality in highly decorrelated environments. The availability of Artificial Corner Reflectors over the area of interest enables to tune the filtering procedure and thus maximize the detection and exploitation of natural targets (bare soil, roads, rocks) as measurement points while preserving the phase characteristics over individual and punctual targets (building corners, poles). The new results will be evaluated in terms of final density and quality of measurement points that can be retrieved. The results will show that a very high density of measurements improves the detection of the deformation gradients and its perimeters resulting in a more accurate characterization of the landslide area. The area of study is El Portalet, an active slow deformation landslide area in Central Spanish Pyrenees. During many years the slope of interest has been monitored with several surveying techniques like DGPS, extensometers, inclinometers, GB-SAR and InSAR jointly with an extensive geological interpretation. Currently, in the frame of the FP7 Project

  3. Finite-difference lattice Boltzmann method with a block-structured adaptive-mesh-refinement technique.

    PubMed

    Fakhari, Abbas; Lee, Taehun

    2014-03-01

    An adaptive-mesh-refinement (AMR) algorithm for the finite-difference lattice Boltzmann method (FDLBM) is presented in this study. The idea behind the proposed AMR is to remove the need for a tree-type data structure. Instead, pointer attributes are used to determine the neighbors of a certain block via appropriate adjustment of its children identifications. As a result, the memory and time required for tree traversal are completely eliminated, leaving us with an efficient algorithm that is easier to implement and use on parallel machines. To allow different mesh sizes at separate parts of the computational domain, the Eulerian formulation of the streaming process is invoked. As a result, there is no need for rescaling the distribution functions or using a temporal interpolation at the fine-coarse grid boundaries. The accuracy and efficiency of the proposed FDLBM AMR are extensively assessed by investigating a variety of vorticity-dominated flow fields, including Taylor-Green vortex flow, lid-driven cavity flow, thin shear layer flow, and the flow past a square cylinder.

  4. A framework for automated contour quality assurance in radiation therapy including adaptive techniques

    NASA Astrophysics Data System (ADS)

    Altman, M. B.; Kavanaugh, J. A.; Wooten, H. O.; Green, O. L.; DeWees, T. A.; Gay, H.; Thorstad, W. L.; Li, H.; Mutic, S.

    2015-07-01

    Contouring of targets and normal tissues is one of the largest sources of variability in radiation therapy treatment plans. Contours thus require a time intensive and error-prone quality assurance (QA) evaluation, limitations which also impair the facilitation of adaptive radiotherapy (ART). Here, an automated system for contour QA is developed using historical data (the ‘knowledge base’). A pilot study was performed with a knowledge base derived from 9 contours each from 29 head-and-neck treatment plans. Size, shape, relative position, and other clinically-relevant metrics and heuristically derived rules are determined. Metrics are extracted from input patient data and compared against rules determined from the knowledge base; a computer-learning component allows metrics to evolve with more input data, including patient specific data for ART. Nine additional plans containing 42 unique contouring errors were analyzed. 40/42 errors were detected as were 9 false positives. The results of this study imply knowledge-based contour QA could potentially enhance the safety and effectiveness of RT treatment plans as well as increase the efficiency of the treatment planning process, reducing labor and the cost of therapy for patients.

  5. Differences in bill form of the oystercatcher haematopus ostralegus; a dynamic adaptation to specific foraging techniques

    NASA Astrophysics Data System (ADS)

    Swennen, C.; De Bruijn, L. L. M.; Duiven, P.; Leopold, M. F.; Marteijn, E. C. L.

    In wintering European oystercatchers 3 bill types: pointed, chisel-shaped, and blunt were found as well as their intermediates. The distribution of the different bill types varied widely in both time and space. Pointed bills had a larger mean length than both chisel-shaped and blunt bills, and occurred more often in young birds than in adults, and more often in females than in males. On an average, females had longer bills than males. In oystercatchers in the Wadden Sea area bill length was found to increase with age, but in the Delta area no increase was found. In semi-natural cage experiments each bill type proved to be most suitable for a specific manner of localization and handling of prey. Bills of individual oystercatchers were shown to change shape when the bird was forced to change its feeding method. A change in method accompanied by a gradual change in bill form only caused a temporary loss of feeding efficiency. It is concluded that differences in bill length influence prey choice and feeding method and hence induce different bill forms. Age- and sex-dependent differences in bill length and form, together with the ability of the individual to adapt bill form and feeding behaviour, enable the oystercatcher to lessen interspecific competition and to respond to changing environmental conditions.

  6. Adapting simultaneous analysis phylogenomic techniques to study complex disease gene relationships.

    PubMed

    Romano, Joseph D; Tharp, William G; Sarkar, Indra Neil

    2015-04-01

    The characterization of complex diseases remains a great challenge for biomedical researchers due to the myriad interactions of genetic and environmental factors. Network medicine approaches strive to accommodate these factors holistically. Phylogenomic techniques that can leverage available genomic data may provide an evolutionary perspective that may elucidate knowledge for gene networks of complex diseases and provide another source of information for network medicine approaches. Here, an automated method is presented that leverages publicly available genomic data and phylogenomic techniques, resulting in a gene network. The potential of approach is demonstrated based on a case study of nine genes associated with Alzheimer Disease, a complex neurodegenerative syndrome. The developed technique, which is incorporated into an update to a previously described Perl script called "ASAP," was implemented through a suite of Ruby scripts entitled "ASAP2," first compiles a list of sequence-similarity based orthologues using PSI-BLAST and a recursive NCBI BLAST+ search strategy, then constructs maximum parsimony phylogenetic trees for each set of nucleotide and protein sequences, and calculates phylogenetic metrics (Incongruence Length Difference between orthologue sets, partitioned Bremer support values, combined branch scores, and Robinson-Foulds distance) to provide an empirical assessment of evolutionary conservation within a given genetic network. In addition to the individual phylogenetic metrics, ASAP2 provides results in a way that can be used to generate a gene network that represents evolutionary similarity based on topological similarity (the Robinson-Foulds distance). The results of this study demonstrate the potential for using phylogenomic approaches that enable the study of multiple genes simultaneously to provide insights about potential gene relationships that can be studied within a network medicine framework that may not have been apparent using

  7. Adapting content-based image retrieval techniques for the semantic annotation of medical images.

    PubMed

    Kumar, Ashnil; Dyer, Shane; Kim, Jinman; Li, Changyang; Leong, Philip H W; Fulham, Michael; Feng, Dagan

    2016-04-01

    The automatic annotation of medical images is a prerequisite for building comprehensive semantic archives that can be used to enhance evidence-based diagnosis, physician education, and biomedical research. Annotation also has important applications in the automatic generation of structured radiology reports. Much of the prior research work has focused on annotating images with properties such as the modality of the image, or the biological system or body region being imaged. However, many challenges remain for the annotation of high-level semantic content in medical images (e.g., presence of calcification, vessel obstruction, etc.) due to the difficulty in discovering relationships and associations between low-level image features and high-level semantic concepts. This difficulty is further compounded by the lack of labelled training data. In this paper, we present a method for the automatic semantic annotation of medical images that leverages techniques from content-based image retrieval (CBIR). CBIR is a well-established image search technology that uses quantifiable low-level image features to represent the high-level semantic content depicted in those images. Our method extends CBIR techniques to identify or retrieve a collection of labelled images that have similar low-level features and then uses this collection to determine the best high-level semantic annotations. We demonstrate our annotation method using retrieval via weighted nearest-neighbour retrieval and multi-class classification to show that our approach is viable regardless of the underlying retrieval strategy. We experimentally compared our method with several well-established baseline techniques (classification and regression) and showed that our method achieved the highest accuracy in the annotation of liver computed tomography (CT) images.

  8. Restoring the interproximal zone using the proximal adaptation technique--part 1.

    PubMed

    Terry, Douglas A

    2004-12-01

    The concepts of the preadhesive era sanctioned the mechanical removal of healthy, sound tooth structure to perform restorative procedures. This mechanical systematic approach to enhance the retention of the restoration by modifying the cavity form included 6 principles: outline form, resistance form, retention form, convenience form, removal of caries, and finish of the enamel walls, margins, and toilet of the cavity. This philosophy was challenged during the adhesive era with a biologic approach. Dramatic changes in the understanding and control of caries, with a reduction in the incidence and severity of caries, and even the process of detecting decay with chemical agents, has forced clinicians to re-think and modify their preparation designs and principles. Some of the mechanical principles are still being used with current adhesive dentistry and clinicians wonder why they continue to have microleakage, recurrent decay, and sensitivity. The effect of this misdirection could be one of the reasons for the relatively short longevity for some adhesively placed restorations. These adhesive design concepts require the clinician to modify nonadhesive techniques when considering preparation design, restorative material selection, adhesive protocol, and placement procedures and techniques. Although the original design principles are outdated by today's standards they are still applicable in the modern dental practice by simply modifying the 6 basic principles. The clinical objectives in the era of minimally invasive adhesive dentistry has become prevention, preservation, and conservation.

  9. Adaptation of Crack Growth Detection Techniques to US Material Test Reactors

    SciTech Connect

    A. Joseph Palmer; Sebastien P. Teysseyre; Kurt L. Davis; Joy L. Rempe; Gordon Kohse; Yakov Ostrovsky; David M. Carpenter

    2014-04-01

    A key component in evaluating the ability of Light Water Reactors to operate beyond 60 years is characterizing the degradation of materials exposed to radiation and various water chemistries. Of particular concern is the response of reactor materials to Irradiation Assisted Stress Corrosion Cracking (IASCC). Some materials testing reactors (MTRs) outside the U.S., such as the Halden Boiling Water Reactor (HBWR), have deployed a technique to measure crack growth propagation during irradiation. This technique incorporates a compact loading mechanism to stress the specimen during irradiation. A crack in the specimen is monitored using the Direct Current Potential Drop (DCPD) method. A project is underway to develop and demonstrate the performance of a similar type of test rig for use in U.S. MTRs. The first year of this three year project was devoted to designing, analyzing, fabricating, and bench top testing a mechanism capable of applying a controlled stress to specimens while they are irradiated in a pressurized water loop (simulating PWR reactor conditions). During the second year, the mechanism will be tested in autoclaves containing high pressure, high temperature water with representative water chemistries. In addition, necessary documentation and safety reviews for testing in a reactor environment will be completed. In the third year, the assembly will be tested in the Massachusetts Institute of Technology Reactor (MITR) and Post Irradiation Examinations (PIE) will be performed.

  10. Path integral molecular dynamics within the grand canonical-like adaptive resolution technique: Simulation of liquid water

    SciTech Connect

    Agarwal, Animesh Delle Site, Luigi

    2015-09-07

    Quantum effects due to the spatial delocalization of light atoms are treated in molecular simulation via the path integral technique. Among several methods, Path Integral (PI) Molecular Dynamics (MD) is nowadays a powerful tool to investigate properties induced by spatial delocalization of atoms; however, computationally this technique is very demanding. The above mentioned limitation implies the restriction of PIMD applications to relatively small systems and short time scales. One of the possible solutions to overcome size and time limitation is to introduce PIMD algorithms into the Adaptive Resolution Simulation Scheme (AdResS). AdResS requires a relatively small region treated at path integral level and embeds it into a large molecular reservoir consisting of generic spherical coarse grained molecules. It was previously shown that the realization of the idea above, at a simple level, produced reasonable results for toy systems or simple/test systems like liquid parahydrogen. Encouraged by previous results, in this paper, we show the simulation of liquid water at room conditions where AdResS, in its latest and more accurate Grand-Canonical-like version (GC-AdResS), is merged with two of the most relevant PIMD techniques available in the literature. The comparison of our results with those reported in the literature and/or with those obtained from full PIMD simulations shows a highly satisfactory agreement.

  11. Real time algorithm invariant to natural lighting with LBP techniques through an adaptive thresholding implemented in GPU processors

    NASA Astrophysics Data System (ADS)

    Orjuela-Vargas, S. A.; Triana-Martinez, J.; Yañez, J. P.; Philips, W.

    2014-03-01

    Video analysis in real time requires fast and efficient algorithms to extract relevant information from a considerable number, commonly 25, of frames per second. Furthermore, robust algorithms for outdoor visual scenes may retrieve correspondent features along the day where a challenge is to deal with lighting changes. Currently, Local Binary Pattern (LBP) techniques are widely used for extracting features due to their robustness to illumination changes and the low requirements for implementation. We propose to compute an automatic threshold based on the distribution of the intensity residuals resulting from the pairwise comparisons when using LBP techniques. The intensity residuals distribution can be modelled by a Generalized Gaussian Distribution (GGD). In this paper we compute the adaptive threshold using the parameters of the GGD. We present a CUDA implementation of our proposed algorithm. We use the LBPSYM technique. Our approach is tested on videos of four different urban scenes with mobilities captured during day and night. The extracted features can be used in a further step to determine patterns, identify objects or detect background. However, further research must be conducted for blurring correction since the scenes at night are commonly blurred due to artificial lighting.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  13. Adaptation and optimization of the emulsification-diffusion technique to prepare lipidic nanospheres.

    PubMed

    Quintanar-Guerrero, David; Tamayo-Esquivel, David; Ganem-Quintanar, Adriana; Allémann, Eric; Doelker, Eric

    2005-10-01

    In this study, the emulsification-diffusion method traditionally used to prepare polymeric nanoparticles was adapted to obtain lipidic nanospheres (LN) using four model lipids. The method consists of dissolving the lipid in a partially water-miscible solvent (previously saturated with water) at room temperature or at controlled temperature depending on lipid solubility. This organic phase is emulsified in an aqueous solution of a stabilizing agent (saturated with solvent) by conventional stirring at the same temperature used to dissolve the lipid. This oil-in-water emulsion is then diluted with an excess of water at controlled temperature in order to provoke the diffusion from the internal phase into the external phase thereby causing lipid aggregation in the form of LN. This new approach for the preparation of LN has clear advantages over the existing methods, namely: (i) it is efficient and versatile; (ii) easy implementation and scaling up (with no need of high energy sources); (iii) high reproducibility and narrow size distribution; (iv) less physical stress (i.e., long exposure to high temperatures and to mechanical dispersion); (v) it is not necessary to dissolve the drug in the melted lipid. The selection of the water-miscible solvent and the stabilizers are critical parameters to obtain lipidic particles in the nanometric range. In general, solvents with high water miscibility and stabilizers able to form stable emulsions are preferred. The results demonstrated that it was possible to reduce the particle size by increasing the process temperature, the stirring rate, the amount of stabilizer, and by lowering the amount of lipid. Control of the preparative variables allowed to obtain LN with diameters under 100 nm. It was found that the influence of preparative parameters was associated with a mechanism based on a physicochemical instability. In this sense, it is suggested that the rapid solvent diffusion produces regions of local supersaturation near the

  14. Spectroscopically Unlocking Exoplanet Characteristics

    NASA Astrophysics Data System (ADS)

    Lewis, Nikole

    2016-05-01

    Spectroscopy plays a critical role in a number of areas of exoplanet research. The first exoplanets were detected by precisely measuring Doppler shifts in high resolution (R ~ 100,000) stellar spectra, a technique that has become known as the Radial Velocity (RV) method. The RV method provides critical constraints on exoplanet masses, but is currently limited to some degree by robust line shape predictions. Beyond the RV method, spectroscopy plays a critical role in the characterization of exoplanets beyond their mass and radius. The Hubble Space Telescope has spectroscopically observed the atmospheres of exoplanets that transit their host stars as seen from Earth giving us key insights into atmospheric abundances of key atomic and molecular species as well as cloud optical properties. Similar spectroscopic characterization of exoplanet atmospheres will be carried out at higher resolution (R ~ 100-3000) and with broader wavelength coverage with the James Webb Space Telescope. Future missions such as WFIRST that seek to the pave the way toward the detection and characterization of potentially habitable planets will have the capability of directly measuring the spectra of exoplanet atmospheres and potentially surfaces. Our ability to plan for and interpret spectra from exoplanets relies heavily on the fidelity of the spectroscopic databases available and would greatly benefit from further laboratory and theoretical work aimed at optical properties of atomic, molecular, and cloud/haze species in the pressure and temperature regimes relevant to exoplanet atmospheres.

  15. An adaptive high-dimensional stochastic model representation technique for the solution of stochastic partial differential equations

    SciTech Connect

    Ma Xiang; Zabaras, Nicholas

    2010-05-20

    A computational methodology is developed to address the solution of high-dimensional stochastic problems. It utilizes high-dimensional model representation (HDMR) technique in the stochastic space to represent the model output as a finite hierarchical correlated function expansion in terms of the stochastic inputs starting from lower-order to higher-order component functions. HDMR is efficient at capturing the high-dimensional input-output relationship such that the behavior for many physical systems can be modeled to good accuracy only by the first few lower-order terms. An adaptive version of HDMR is also developed to automatically detect the important dimensions and construct higher-order terms using only the important dimensions. The newly developed adaptive sparse grid collocation (ASGC) method is incorporated into HDMR to solve the resulting sub-problems. By integrating HDMR and ASGC, it is computationally possible to construct a low-dimensional stochastic reduced-order model of the high-dimensional stochastic problem and easily perform various statistic analysis on the output. Several numerical examples involving elementary mathematical functions and fluid mechanics problems are considered to illustrate the proposed method. The cases examined show that the method provides accurate results for stochastic dimensionality as high as 500 even with large-input variability. The efficiency of the proposed method is examined by comparing with Monte Carlo (MC) simulation.

  16. Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

    USGS Publications Warehouse

    Roseman, E.F.; Boase, J.; Kennedy, G.; Craig, J.; Soper, K.

    2011-01-01

    In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8m) Detroit River using an anchor and buoy system. ?? 2011 Blackwell Verlag, Berlin.

  17. Material damage diagnosis and characterization for turbine rotors using three-dimensional adaptive ultrasonic NDE data reconstruction techniques.

    PubMed

    Guan, Xuefei; Zhang, Jingdan; Rasselkorde, El Mahjoub; Abbasi, Waheed A; Kevin Zhou, S

    2014-02-01

    Damage diagnosis for turbine rotors plays an essential role in power plant management. Ultrasonic non-destructive examinations (NDEs) have increasingly been utilized as an effective tool to provide comprehensive information for damage diagnosis. This study presents a general methodology of damage diagnosis for turbine rotors using three-dimensional adaptive ultrasonic NDE data reconstruction techniques. Volume reconstruction algorithms and data fusion schemes are proposed to map raw ultrasonic NDE data back to the structural model of the object being examined. The reconstructed volume is used for automatic damage identification and quantification using region-growing algorithms and the method of distance-gain-size. Key reconstruction parameters are discussed and suggested based on industrial experiences. A software tool called AutoNDE Rotor is developed to automate the overall analysis workflow. Effectiveness of the proposed methods and AutoNDE Rotor are explored using realistic ultrasonic NDE data.

  18. Material damage diagnosis and characterization for turbine rotors using three-dimensional adaptive ultrasonic NDE data reconstruction techniques.

    PubMed

    Guan, Xuefei; Zhang, Jingdan; Rasselkorde, El Mahjoub; Abbasi, Waheed A; Kevin Zhou, S

    2014-02-01

    Damage diagnosis for turbine rotors plays an essential role in power plant management. Ultrasonic non-destructive examinations (NDEs) have increasingly been utilized as an effective tool to provide comprehensive information for damage diagnosis. This study presents a general methodology of damage diagnosis for turbine rotors using three-dimensional adaptive ultrasonic NDE data reconstruction techniques. Volume reconstruction algorithms and data fusion schemes are proposed to map raw ultrasonic NDE data back to the structural model of the object being examined. The reconstructed volume is used for automatic damage identification and quantification using region-growing algorithms and the method of distance-gain-size. Key reconstruction parameters are discussed and suggested based on industrial experiences. A software tool called AutoNDE Rotor is developed to automate the overall analysis workflow. Effectiveness of the proposed methods and AutoNDE Rotor are explored using realistic ultrasonic NDE data. PMID:23978617

  19. Hybrid nanocomposite coatings from metal (Mg alloy)-drug deposited onto medical implant by laser adaptive ablation deposition technique

    NASA Astrophysics Data System (ADS)

    Serbezov, Valery; Sotirov, Sotir; Serbezov, Svetlin

    2013-03-01

    Drug-eluting medical implants are active implants whose function is to create healing effects. The current requirements for active medical coatings for Drug-eluting medical implants are to be biocompatible, biodegradable, polymer free, mechanically stable and enable a controlled release of one or more drugs and defined degradation. This brings hybrid nanocomposite coatings into focus especially in the field of cardiovascular implants. We studied the properties of Metal (Mg alloy)-Paclitaxel coatings obtained by novel Laser Adaptive Ablation Deposition Technique (LAAD) onto cardiovascular stents from 316 LVM stainless steel material. The morphology and topology of coatings were studied by Bright field / Fluorescence optical microscope and Scanning Electron Microscope (SEM). Comparative measurements were made of the morphology and topology of hybrid, polymer free nanocomposite coatings deposited by LAAD and polymerdrug coatings deposited by classical spray technique. The coatings obtained by LAAD are homogeneous without damages and cracks. Metal nanoparticles with sizes from 40 nm to 230 nm were obtained in drug matrixes. Energy Dispersive X-ray Spectroscopy (EDX) was used for identification of metal nanoparticles presence in hybrid nanocomposites coatings. The new technology opens up possibilities to obtain new hybrid nanocomposite coatings with applications in medicine, pharmacy and biochemistry.

  20. Linear parameter-varying model and adaptive filtering technique for detecting neuronal activities: an fNIRS study

    NASA Astrophysics Data System (ADS)

    Kamran, M. Ahmad; Hong, Keum-Shik

    2013-10-01

    Objective. Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique that measures brain activities by using near-infrared light of 650-950 nm wavelength. The major advantages of fNIRS are its low cost, portability, and good temporal resolution as a plausible solution to real-time imaging. Recent research has shown the great potential of fNIRS as a tool for brain-computer interfaces. Approach. This paper presents the first novel technique for fNIRS-based modelling of brain activities using the linear parameter-varying (LPV) method and adaptive signal processing. The output signal of each channel is assumed to be an output of an LPV system with unknown coefficients that are optimally estimated by the affine projection algorithm. The parameter vector is assumed to be Gaussian. Main results. The general linear model (GLM) is very popular and is a commonly used method for the analysis of functional MRI data, but it has certain limitations in the case of optical signals. The proposed model is more efficient in the sense that it allows the user to define more states. Moreover, unlike most previous models, it is online. The present results, showing improvement, were verified by random finger-tapping tasks in extensive experiments. We used 24 states, which can be reduced or increased depending on the cost of computation and requirements. Significance. The t-statistics were employed to determine the activation maps and to verify the significance of the results. Comparison of the proposed technique and two existing GLM-based algorithms shows an improvement in the estimation of haemodynamic response. Additionally, the convergence of the proposed algorithm is shown by error reduction in consecutive iterations.

  1. Appraisal of adaptive neuro-fuzzy computing technique for estimating anti-obesity properties of a medicinal plant.

    PubMed

    Kazemipoor, Mahnaz; Hajifaraji, Majid; Radzi, Che Wan Jasimah Bt Wan Mohamed; Shamshirband, Shahaboddin; Petković, Dalibor; Mat Kiah, Miss Laiha

    2015-01-01

    This research examines the precision of an adaptive neuro-fuzzy computing technique in estimating the anti-obesity property of a potent medicinal plant in a clinical dietary intervention. Even though a number of mathematical functions such as SPSS analysis have been proposed for modeling the anti-obesity properties estimation in terms of reduction in body mass index (BMI), body fat percentage, and body weight loss, there are still disadvantages of the models like very demanding in terms of calculation time. Since it is a very crucial problem, in this paper a process was constructed which simulates the anti-obesity activities of caraway (Carum carvi) a traditional medicine on obese women with adaptive neuro-fuzzy inference (ANFIS) method. The ANFIS results are compared with the support vector regression (SVR) results using root-mean-square error (RMSE) and coefficient of determination (R(2)). The experimental results show that an improvement in predictive accuracy and capability of generalization can be achieved by the ANFIS approach. The following statistical characteristics are obtained for BMI loss estimation: RMSE=0.032118 and R(2)=0.9964 in ANFIS testing and RMSE=0.47287 and R(2)=0.361 in SVR testing. For fat loss estimation: RMSE=0.23787 and R(2)=0.8599 in ANFIS testing and RMSE=0.32822 and R(2)=0.7814 in SVR testing. For weight loss estimation: RMSE=0.00000035601 and R(2)=1 in ANFIS testing and RMSE=0.17192 and R(2)=0.6607 in SVR testing. Because of that, it can be applied for practical purposes.

  2. Appraisal of adaptive neuro-fuzzy computing technique for estimating anti-obesity properties of a medicinal plant.

    PubMed

    Kazemipoor, Mahnaz; Hajifaraji, Majid; Radzi, Che Wan Jasimah Bt Wan Mohamed; Shamshirband, Shahaboddin; Petković, Dalibor; Mat Kiah, Miss Laiha

    2015-01-01

    This research examines the precision of an adaptive neuro-fuzzy computing technique in estimating the anti-obesity property of a potent medicinal plant in a clinical dietary intervention. Even though a number of mathematical functions such as SPSS analysis have been proposed for modeling the anti-obesity properties estimation in terms of reduction in body mass index (BMI), body fat percentage, and body weight loss, there are still disadvantages of the models like very demanding in terms of calculation time. Since it is a very crucial problem, in this paper a process was constructed which simulates the anti-obesity activities of caraway (Carum carvi) a traditional medicine on obese women with adaptive neuro-fuzzy inference (ANFIS) method. The ANFIS results are compared with the support vector regression (SVR) results using root-mean-square error (RMSE) and coefficient of determination (R(2)). The experimental results show that an improvement in predictive accuracy and capability of generalization can be achieved by the ANFIS approach. The following statistical characteristics are obtained for BMI loss estimation: RMSE=0.032118 and R(2)=0.9964 in ANFIS testing and RMSE=0.47287 and R(2)=0.361 in SVR testing. For fat loss estimation: RMSE=0.23787 and R(2)=0.8599 in ANFIS testing and RMSE=0.32822 and R(2)=0.7814 in SVR testing. For weight loss estimation: RMSE=0.00000035601 and R(2)=1 in ANFIS testing and RMSE=0.17192 and R(2)=0.6607 in SVR testing. Because of that, it can be applied for practical purposes. PMID:25453384

  3. Adaptive Data Processing Technique for Lidar-Assisted Control to Bridge the Gap between Lidar Systems and Wind Turbines: Preprint

    SciTech Connect

    Schlipf, David; Raach, Steffen; Haizmann, Florian; Cheng, Po Wen; Fleming, Paul; Scholbrock, Andrew, Krishnamurthy, Raghu; Boquet, Mathieu

    2015-12-14

    This paper presents first steps toward an adaptive lidar data processing technique crucial for lidar-assisted control in wind turbines. The prediction time and the quality of the wind preview from lidar measurements depend on several factors and are not constant. If the data processing is not continually adjusted, the benefit of lidar-assisted control cannot be fully exploited, or can even result in harmful control action. An online analysis of the lidar and turbine data are necessary to continually reassess the prediction time and lidar data quality. In this work, a structured process to develop an analysis tool for the prediction time and a new hardware setup for lidar-assisted control are presented. The tool consists of an online estimation of the rotor effective wind speed from lidar and turbine data and the implementation of an online cross correlation to determine the time shift between both signals. Further, initial results from an ongoing campaign in which this system was employed for providing lidar preview for feed-forward pitch control are presented.

  4. Forecasting maximum wave height at selected sites based on high resolution hindcast modeling and local adaptation techniques

    NASA Astrophysics Data System (ADS)

    Kalogeri, Christina; Galanis, George; Kallos, George

    2014-05-01

    Extreme wave heights play a major role in many deep offshore and coastal activities today. As a result, it is of significant importance to understand and accurately simulate their behavior. The lack of a dense in-situ and remote sensing observational network implies non trivial difficulties in this framework. A way out can be given by the utilization of high resolution third generation spectral wave models that incorporate advanced formulations for the estimation of maximum wave height conditions along with local adaptation techniques which can simulate in a credible way the non-frequent values for a specific area. For this study, a 10-year (2001-2010) hourly high resolution dataset of the main metocean parameters that covers the entire European coastline with a resolution of 5km, developed by the Atmospheric Modeling and Weather Forecasting Group of the National and Kapodistrian University of Athens in the framework of the FP7 project MARINA Platform (http://www.marina-platform.info/index.aspx) was utilized. The hindcast wave data, based on the latest version of the wave model WAM, in conjunction with non-conventional statistical methods and available buoy measurements for selected locations in the Spanish coastline formed an integrated system able to provide accurate maximum wave height estimations taking into consideration the climatological characteristics of the area.

  5. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2014-07-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate. As a national large scientific project, LAMOST project was proposed formally in 1996. The construction was started in 2001 and completed in 2008. After commission period, LAMOST pilot survey was started in October 2011 and spectroscopic survey began in September 2012. From October 2011 to June 2013, LAMOST has obtained more than 2 million spectra of celestial objects. There are 1.7 million spectra of stars, in which the stellar parameters (effective temperature, surface gravity, metalicitiy and radial velocity) of more than 1 million stars was obtained. In the first period of spectroscopic survey of LAMOST, 5 million of stellar spectra will be obtained and will make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  6. Evaluations of an adaptive planning technique incorporating dose feedback in image-guided radiotherapy of prostate cancer

    SciTech Connect

    Liu Han; Wu Qiuwen

    2011-12-15

    Purpose: Online image guidance (IG) has been used to effectively correct the setup error and inter-fraction rigid organ motion for prostate cancer. However, planning margins are still necessary to account for uncertainties such as deformation and intra-fraction motion. The purpose of this study is to investigate the effectiveness of an adaptive planning technique incorporating offline dose feedback to manage inter-fraction motion and residuals from online correction. Methods: Repeated helical CT scans from 28 patients were included in the study. The contours of prostate and organs-at-risk (OARs) were delineated on each CT, and online IG was simulated by matching center-of-mass of prostate between treatment CTs and planning CT. A seven beam intensity modulated radiation therapy (IMRT) plan was designed for each patient on planning CT for a total of 15 fractions. Dose distribution at each fraction was evaluated based on actual contours of the target and OARs from that fraction. Cumulative dose up to each fraction was calculated by tracking each voxel based on a deformable registration algorithm. The cumulative dose was compared with the dose from initial plan. If the deviation exceeded the pre-defined threshold, such as 2% of the D{sub 99} to the prostate, an adaptive planning technique called dose compensation was invoked, in which the cumulative dose distribution was fed back to the treatment planning system and the dose deficit was made up through boost radiation in future treatment fractions. The dose compensation was achieved by IMRT inverse planning. Two weekly compensation delivery strategies were simulated: one intended to deliver the boost dose in all future fractions (schedule A) and the other in the following week only (schedule B). The D{sub 99} to prostate and generalized equivalent uniform dose (gEUD) to rectal wall and bladder were computed and compared with those without the dose compensation. Results: If only 2% underdose is allowed at the end of the

  7. 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

    Di-2-pyridylketone-4,4,-dimethyl-3-thiosemicarbazone (Dp44mT) exhibits significant antitumor activity. However, the mechanism of its pharmacological interaction with human serum albumin (HSA) and DNA remains poorly understood. Here, we aimed to elucidate the interactions of Dp44mT with HSA and DNA using MTT assays, spectroscopic methods, and molecular docking analysis. Our results indicated that addition of HSA at a ratio of 1:1 did not alter the cytotoxicity of Dp44mT, but did affect the cytotoxicity of the Dp44mT-Cu complex. Data from fluorescence quenching and UV-VIS absorbance measurements demonstrated that Dp44mT could bind to HSA with a moderate affinity (Ka = approximately 104 M−1). CD spectra revealed that Dp44mT could slightly disrupt the secondary structure of HSA. Dp44mT could also interact with Ct-DNA, but had a moderate binding constant (KEB = approximately 104 M−1). Docking studies indicated that the IB site of HSA, but not the IIA and IIIA sites, could be favorable for Dp44mT and that binding of Dp44mT to HSA involved hydrogen bonds and hydrophobic force, consistent with thermodynamic results from spectral investigations. Thus, the moderate binding affinity of Dp44mT with HSA and DNA partially contributed to its antitumor activity and may be preferable in drug design approaches. PMID:27376275

  8. Structure analysis and spectroscopic characterization of 2-Fluoro-3-Methylpyridine-5-Boronic Acid with experimental (FT-IR, Raman, NMR and XRD) techniques and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Alver, Özgür; Dikmen, Gökhan

    2016-03-01

    Possible stable conformers, geometrical molecular structures, vibrational properties as well as band assignments, nuclear magnetic shielding tensors of 2-Fluoro-3-Methylpyridine-5-Boronic Acid (2F3MP5BA) were studied experimentally and theoretically using FT-IR, Raman, (CP/MAS) NMR and XRD spectroscopic methods. FT-IR and Raman spectra were evaluated in the region of 3500-400 cm-1, and 3200-400 cm-1, respectively. The optimized geometric structures, vibrational wavenumbers and nuclear magnetic shielding tensors were examined using Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. 1H, 13C NMR chemical shifts were calculated using the gauge invariant atomic orbital (GIAO) method. 1H, 13C, APT and HETCOR NMR experiments of title molecule were carried out in DMSO solution. 13C CP/MAS NMR measurement was done with 4 mm zirconium rotor and glycine was used as an external standard. Single crystal of 2F3MP5BA was also prepared for XRD measurements. Assignments of vibrational wavenumbers were also strengthened by calculating the total energy distribution (TED) values using scaled quantum mechanical (SQM) method.

  9. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2015-08-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate.In the spectroscopic survey of LAMOST from October 2011 to June 2014, LAMOST has obtained more than 4.13 million spectra of celestial objects. There are 3.27 million spectra of stars, in which the stellar parameters of 2.16 million stars were obtained.In the five-year regular survey upto 2017, LAMOST will obtaine 5 million stellar spectra, which would make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  10. Adaptation and Recommendation Techniques to Improve the Quality of Annotations and the Relevance of Resources in Web 2.0 and Semantic Web-Based Applications

    NASA Astrophysics Data System (ADS)

    Torre, Ilaria

    The Web 2.0 and the Semantic Web represent different forms of evolution of the first-generation Web, and both of them enrich Web resources with semantic annotations. Recommendation and personalization of Web resources is another trend that becomes more and more important with the growth of information, and both the Web 2.0 and the Semantic Web are deeply connected to it. The objective of this paper is to analyze the contribution of recommendation and adaptation techniques to these paradigms and to investigate if these techniques can be used as a bridge for their integration. More specifically, the paper will focus on the contribution of adaptation and recommendation techniques to improve the quality of annotations in the Web 2.0, Semantic Web, and mixed approaches and the relevance of annotated resources that are retrieved or filtered to users.

  11. Application of Spectroscopic Techniques (FT-IR, 13C NMR) to the analysis of humic substances in volcanic soils along an environmental gradient (Tenerife, Canary Islands, Spain)

    NASA Astrophysics Data System (ADS)

    Rodriguez Rodriguez, Antonio; María Armas Herrera, Cecilia; González Pérez, José Antonio; González-Vila, Francisco Javier; Arbelo Rodríguez, Carmen Dolores; Mora Hernández, Juan Luis; Polvillo Polo, Oliva

    2010-05-01

    Andosols and andic soils are considered as efficient C-sinks in terms of C sequestration. These soils are usually developed from volcanic materials, and are characterized by a predominance of short-range ordered minerals like allophanes, imogolite and other Fe and Al oxyhydroxides. Such materials occur commonly associated with organic compounds, thus generating highly stable organo-mineral complexes and leading to the accumulation of a high amount of organic carbon. Spectroscopic methods like FT-IR and 13C NMR are suitable for the analysis of the chemical structure of soil humic substances, and allow identifying distinct functional groups and protein, lipids, lignin, carbohydrate-derived fragments. In this work we study the structural features of four soils developed on Pleistocene basaltic lavae in Tenerife (Canary Island, Spain), distributed along an altitudinal climatic gradient. The soil sequence comprises soils with different degree of geochemical evolution and andic character, including a mineral ‘Hypersalic Solonchak' (Tabaibal de Rasca), a slightly vitric ‘Luvic Phaeozem' (Los Frailes), a degraded and shallow ‘Endoleptic, fulvic, silandic Andosol' (Siete Lomas), and a well-developed and deep ‘Fulvic, silandic, Andosol' (Ravelo). Samples of the raw soil and humic and fulvic acids isolated from the surface horizons were analyzed. The results show a low content of organic carbon in the mineral soil, the inherited humin predominating, and a very high content of humic and fulvic acids in Andosols. The FT-IR and 13C NMR spectra of the raw soil samples show a low resolution, related to interferences from mineral complexes signals, particularly in soils with lower organic carbon content. 13C NMR shows a predominance of O-alkyl carbon (derived of carbohydrates) in andic soils, whereas O-alkyl and aromatic fractions are most evident in the mineral soil. The humic acids spectra are characterized by a dominance of alkyl and aromatic fractions with a high degree

  12. Monomeric and dimeric structures analysis and spectroscopic characterization of 3,5-difluorophenylboronic acid with experimental (FT-IR, FT-Raman, 1H and 13C NMR, UV) techniques and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Karabacak, Mehmet; Kose, Etem; Atac, Ahmet; Asiri, Abdullah M.; Kurt, Mustafa

    2014-01-01

    The spectroscopic properties of 3,5-difluorophenylboronic acid (3,5-DFPBA, C6H3F2B(OH)2) were investigated by FT-IR, FT-Raman UV-Vis, 1H and 13C NMR spectroscopic techniques. FT-IR (4000-400 cm-1) and FT-Raman spectra (3500-10 cm-1) in the solid phase and 1H and 13C NMR spectra in DMSO solution were recorded. The UV spectra that dissolved in ethanol and water were recorded in the range of 200-400 nm for each solution. The structural and spectroscopic data of the molecule have been obtained for possible three conformers from DFT (B3LYP) with 6-311++G(d,p) basis set calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. Hydrogen-bonded dimer of title molecule, optimized by counterpoise correction, was also studied B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H⋯O hydrogen bonding have been discussed. 1H and 13C NMR chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT) results complements with the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were presented. The effects due to the substitutions of boric acid group and halogen were investigated. The results of the calculations were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP), nonlinear optical properties (NLO) and thermodynamic features were performed.

  13. XRF, μ-XRD and μ-spectroscopic techniques for revealing the composition and structure of paint layers on polychrome sculptures after multiple restorations.

    PubMed

    Franquelo, M L; Duran, A; Castaing, J; Arquillo, D; Perez-Rodriguez, J L

    2012-01-30

    This paper presents the novel application of recently developed analytical techniques to the study of paint layers on sculptures that have been restored/repainted several times across centuries. Analyses were performed using portable XRF, μ-XRD and μ-Raman instruments. Other techniques, such as optical microscopy, SEM-EDX and μ-FTIR, were also used. Pigments and other materials including vermilion, minium, red lac, ivory black, lead white, barium white, zinc white (zincite), titanium white (rutile and anatase), lithopone, gold and brass were detected. Pigments from both ancient and modern times were found due to the different restorations/repaintings carried out. μ-Raman was very useful to characterise some pigments that were difficult to determine by μ-XRD. In some cases, pigments identification was only possible by combining results from the different analytical techniques used in this work. This work is the first article devoted to the study of sculpture cross-section samples using laboratory-made μ-XRD systems.

  14. A Comparison of FTNMR and FTIR Techniques.

    ERIC Educational Resources Information Center

    Ahn, Myong-Ku

    1989-01-01

    Nuclear magnetic resonance and infrared are two spectroscopic methods that commonly use the Fourier transform technique. Discussed are the similarities and differences in the use of the Fourier transform in these two spectroscopic techniques. (CW)

  15. Robust fault detection of turbofan engines subject to adaptive controllers via a Total Measurable Fault Information Residual (ToMFIR) technique.

    PubMed

    Chen, Wen; Chowdhury, Fahmida N; Djuric, Ana; Yeh, Chih-Ping

    2014-09-01

    This paper provides a new design of robust fault detection for turbofan engines with adaptive controllers. The critical issue is that the adaptive controllers can depress the faulty effects such that the actual system outputs remain the pre-specified values, making it difficult to detect faults/failures. To solve this problem, a Total Measurable Fault Information Residual (ToMFIR) technique with the aid of system transformation is adopted to detect faults in turbofan engines with adaptive controllers. This design is a ToMFIR-redundancy-based robust fault detection. The ToMFIR is first introduced and existing results are also summarized. The Detailed design process of the ToMFIRs is presented and a turbofan engine model is simulated to verify the effectiveness of the proposed ToMFIR-based fault-detection strategy.

  16. Novel, near-infrared spectroscopic, label-free, techniques to assess bone abnormalities such as Paget's disease, osteoporosis and bone fractures

    NASA Astrophysics Data System (ADS)

    Sordillo, Diana C.; Sordillo, Laura A.; Shi, Lingyan; Budansky, Yury; Sordillo, Peter P.; Alfano, Robert R.

    2015-02-01

    Near- infrared (NIR) light with wavelengths from 650 nm to 950 nm (known as the first NIR window) has conventionally been used as a non-invasive technique that can reach deeper penetration depths through media than light at shorter wavelengths. Recently, several novel, NIR, label-free, techniques have been developed to assess Paget's disease of bone, osteoporosis and bone microfractures. We designed a Bone Optical Analyzer (BOA) which utilizes the first window to measure changes of Hb and HbO2. Paget's disease is marked by an increase in vascularization in bones, and this device can enable easy diagnosis and more frequent monitoring of the patient's condition, without exposing him to a high cumulative dose of radiation. We have also used inverse imaging algorithms to reconstruct 2D and 3D maps of the bone's structure. This device could be used to assess diseases such as osteoporosis. Using 800 nm femtosecond excitation with two-photon (2P) microscopy, we acquired 2PM images of the periosteum and spatial frequency spectra (based on emission of collagen) from the periosteal regions. This technique can provide information on the structure of the periosteum and can detect abnormalities which may be an indication of disease. Most recently, we showed that longer NIR wavelengths in the second and third NIR windows (1100 nm-1350 nm, 1600 nm-1870 nm), could be used to image bone microfractures. Use of NIR light could allow for repeated studies in patients with diseases such as Paget's and osteoporosis quickly and non-invasively, and could impact the current management for these diseases.

  17. Fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave and free-space-optics architecture with an adaptive diversity combining technique.

    PubMed

    Zhang, Junwen; Wang, Jing; Xu, Yuming; Xu, Mu; Lu, Feng; Cheng, Lin; Yu, Jianjun; Chang, Gee-Kung

    2016-05-01

    We propose and experimentally demonstrate a novel fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave (MMW) and free-space-optics (FSO) architecture using an adaptive combining technique. Both 60 GHz MMW and FSO links are demonstrated and fully integrated with optical fibers in a scalable and cost-effective backhaul system setup. Joint signal processing with an adaptive diversity combining technique (ADCT) is utilized at the receiver side based on a maximum ratio combining algorithm. Mobile backhaul transportation of 4-Gb/s 16 quadrature amplitude modulation frequency-division multiplexing (QAM-OFDM) data is experimentally demonstrated and tested under various weather conditions synthesized in the lab. Performance improvement in terms of reduced error vector magnitude (EVM) and enhanced link reliability are validated under fog, rain, and turbulence conditions. PMID:27128036

  18. Fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave and free-space-optics architecture with an adaptive diversity combining technique.

    PubMed

    Zhang, Junwen; Wang, Jing; Xu, Yuming; Xu, Mu; Lu, Feng; Cheng, Lin; Yu, Jianjun; Chang, Gee-Kung

    2016-05-01

    We propose and experimentally demonstrate a novel fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave (MMW) and free-space-optics (FSO) architecture using an adaptive combining technique. Both 60 GHz MMW and FSO links are demonstrated and fully integrated with optical fibers in a scalable and cost-effective backhaul system setup. Joint signal processing with an adaptive diversity combining technique (ADCT) is utilized at the receiver side based on a maximum ratio combining algorithm. Mobile backhaul transportation of 4-Gb/s 16 quadrature amplitude modulation frequency-division multiplexing (QAM-OFDM) data is experimentally demonstrated and tested under various weather conditions synthesized in the lab. Performance improvement in terms of reduced error vector magnitude (EVM) and enhanced link reliability are validated under fog, rain, and turbulence conditions.

  19. Elemental and spectroscopic characterization of plasters from Fatih Mosque-Istanbul (Turkey) by combined micro-Raman, FTIR and EDXRF techniques.

    PubMed

    Akyuz, Tanil; Akyuz, Sevim; Gulec, Ahmet

    2015-10-01

    The characterization of the plasters and coloring agents of the wall paintings of Fatih Mosque have been performed using combined micro-Raman, FTIR and EDXRF techniques. The investigations show that the plaster used on the walls has mixed gypsum-lime binders. Cinnabar {HgS}, lead red {Pb3O4} and hematite {α-Fe2O3} were identified in the red surfaces. Blue color is attributed to ultramarine blue {Na8-10Al6Si6O24S2-4}. Green color is assigned to mixtures of green earth, copper phthalocyanine {Cu(C32Cl16N8)} and brochantite {CuSO4·3Cu(OH)2}. Strontium yellow {SrCrO4} and zinc white {ZnO} were also used to ensure the color tone. The results provide a basis for future restoration of wall paints. PMID:25989612

  20. An investigation of the chemical and physical properties of pristine, electrochromically damaged, and photochromically damaged KTiOPO{sub 4} (KTP) using surface analytical and optical spectroscopic techniques

    SciTech Connect

    Quagliano, J.R.; Petrin, R.R.; Trujillo, T.C.; Cockroft, N.J.; Paffett, M.T.; Maggiore, C.J.; Jacco, J.C.

    1995-03-01

    A variety of experimental techniques were employed to study the properties of electrochromically (EC) damaged, photochromically (PC) damaged, and pristine KTiOP0{sub 4} (KTP). Additionally, nonlinear optical calculations were performed to complement the experimental work in an effort to elucidate the respective mechanisms operative in producing EC and PC damage to KTP. Several independent experiments indicate that there is Ti deficiency in the EC damaged material, which is due to migration of these ions to the electrode surface. The laser experiments indicate that UV radiation can produce reversible PC damage. UV-producing SFG processes accidentally occurring in SHG cut KTP may lead to macroscopic damage. It must be emphasized that a fundamentally different mechanism is responsible for EC damaged versus PC damaged KTP.

  1. Spectroscopic optical coherence elastography

    PubMed Central

    Adie, Steven G.; Liang, Xing; Kennedy, Brendan F.; John, Renu; Sampson, David D.; Boppart, Stephen A.

    2010-01-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  2. Spectroscopic optical coherence elastography.

    PubMed

    Adie, Steven G; Liang, Xing; Kennedy, Brendan F; John, Renu; Sampson, David D; Boppart, Stephen A

    2010-12-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  3. In vitro studies on the behavior of salmeterol xinafoate and its interaction with calf thymus DNA by multi-spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Zhao, Tingting; Bi, Shuyun; Wang, Yu; Wang, Tianjiao; Pang, Bo; Gu, Tingting

    2014-11-01

    The salmeterol xinafoate (SX) binding to calf thymus DNA in vitro was explored by fluorescence, resonance light scattering (RLS), UV-vis absorption, as well as viscometry, ionic strength effect and DNA melting techniques. It was found that SX could bind to DNA weakly, and the binding constants (Ka) were determined as 8.52 × 103, 8.31 × 103 and 6.14 × 103 L mol-1 at 18, 28 and 38 °C respectively. When bound to DNA, SX showed fluorescence quenching in the fluorescence spectra and hyperchromic effect in the absorption spectra. Stern-Volmer plots revealed that the quenching of fluorescence of SX by DNA was a static quenching. Furthermore, the relative viscosity and melting temperature of DNA solution were hardly influenced by SX, while the fluorescence intensity of SX-DNA was observed to decrease with the increasing ionic strength of system. Also, the binding constant between SX and double stranded DNA (dsDNA) was much weaker than that between SX and single stranded DNA (ssDNA). All these results suggested that the binding mode of SX to DNA should be groove binding. The obtained thermodynamic parameters indicated that electrostatic force might play a predominant role in SX binding to DNA. The quantum yield (φ) of SX was measured as 0.13 using comparative method. Based on the Förster resonance energy transfer theory (FRET), the binding distance (r0) between the acceptor and donor was calculated as 4.10 nm.

  4. Structural and spectroscopic characterization of 2,3-difluorobenzoic acid and 2,4-difluorobenzoic acid with experimental techniques and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Karabacak, Mehmet; Cinar, Zeliha; Cinar, Mehmet

    2011-09-01

    In this study, the molecular conformation, vibrational and electronic transition analysis of 2,3-difluorobenzoic acid and 2,4-difluorobenzoic acid (C 7H 4F 2O 2) were presented using experimental techniques (FT-IR, FT-Raman and UV) and quantum chemical calculations. FT-IR and FT-Raman spectra in solid state were recorded in the region 4000-400 cm -1 and 4000-5 cm -1, respectively. The UV absorption spectra of the compounds that dissolved in ethanol were recorded in the range of 200-800 nm. The structural properties of the molecules in the ground state were calculated using density functional theory (DFT) and second order Møller-Plesset perturbation theory (MP2) employing 6-311++G(d,p) basis set. Optimized structure of compounds was interpreted and compared with the earlier reported experimental values. The scaled vibrational wavenumbers were compared with experimental results. The complete assignments were performed on the basis of the experimental data and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. A study on the electronic properties, such as absorption wavelength, excitation energy, dipole moment and frontier molecular orbital energy, were performed by time dependent DFT (TD-DFT) approach. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands of steady compounds were discussed. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecules.

  5. Thermal inkjet application in the preparation of oral dosage forms: dispensing of prednisolone solutions and polymorphic characterization by solid-state spectroscopic techniques.

    PubMed

    Meléndez, Peter A; Kane, Kevin M; Ashvar, Claudine S; Albrecht, Mary; Smith, Pamela A

    2008-07-01

    The utility of thermal inkjet (TIJ) technology for preparing solid dosage forms of drugs was examined. Solutions of prednisolone in a solvent mixture of ethanol, water, and glycerol (80/17/3 by volume) were dispensed onto poly(tetrafluoroethylene)-coated fiberglass films using TIJ cartridges and a personal printer and using a micropipette for comparison. The post-dried, TIJ-dispensed samples were shown to contain a mixture of prednisolone Forms I and III based on PXRD analyses that were confirmed by Raman analyses. The starting commercial material was determined to be Form I. Samples prepared by dispensing the solution from a micropipette initially showed only Form I; subsequent Raman mapping of these samples revealed the presence of two polymorphs. Raman mapping of the TIJ-dispensed samples also showed both polymorphs. The results indicate that the solvent mixture used in the dispensing solution combined with the thermal treatment of the samples after dispensing were likely the primary reason for the generation of the two polymorphs. The advantages of using a multidisciplinary approach to characterize drug delivery systems are demonstrated using solid state mapping techniques. Both PXRD and Raman spectroscopy were needed to fully characterize the samples. Finally, this report clarifies prednisolone's polymorphic nomenclature existent in the scientific literature.

  6. The Fast Spiral-SelMQC Technique for In Vivo MR Spectroscopic Imaging of Polyunsaturated Fatty Acids (PUFA) in Human Breast Tissue‡

    PubMed Central

    Zhu, He; Rubin, Denis; He, Qiuhong

    2011-01-01

    The Selective Multiple-Quantum Coherence Transfer (Sel-MQC) method has been applied to image polyunsaturated fatty acids (PUFA) distributions in human breast tissues in vivo for cancer detection, with complete suppression of the unwanted lipid and water signals in a single scan. The Cartesian k-space mapping of PUFA in vivo using the Sel-MQC CSI technique, however, requires excessive MR scan time. In this article, we report a fast Spiral-SelMQC sequence employing a rapid spiral k-space sampling scheme. The Spiral-SelMQC images of PUFA distribution in human breast were acquired using two-interleaved spirals on a 3T GE Signa MRI scanner. Approximately 160-fold reduction of acquisition time was observed as compared to the corresponding Sel-MQC CSI method with an equivalent number of scans, permitting acquisition of high-resolution PUFA images in minutes. The reconstructed Spiral-SelMQC PUFA images of human breast tissues achieved a sub-millimeter resolution of 0.54×0.54 or 0.63×0.63mm2/pixel for FOV = 14 or 16cm, respectively. The Spiral-SelMQC parameters for PUFA detection were optimized in 2D Sel-MQC experiments to suppress monounsaturated fatty acids (MUFA) and other lipid signals. The fast in vivo Spiral-SelMQC imaging method will be applied to study human breast cancer and other human diseases in extracranial organs. PMID:22028250

  7. Use of Applied Behavioral Techniques and an Adaptive Device to Teach Lip Closure to Severely Handicapped Children.

    ERIC Educational Resources Information Center

    Petersen, Paul; Ottenbacher, Kenneth

    1986-01-01

    The effectiveness of applied behavioral programming in teaching lip closure was investigated with three severely retarded students (9-13 years old) with oral motor dysfunction. Results revealed dramatic increases in functional lip closure when an appropriate adaptive device was combined with behavioral intervention. Functional lip closure…

  8. Characterization of the deterioration of bone black in the 17 th century Oranjezaal paintings using electron-microscopic and micro-spectroscopic imaging techniques

    NASA Astrophysics Data System (ADS)

    van Loon, Annelies; Boon, Jaap J.

    2004-10-01

    A whitish deterioration product was observed on the dark paint in a number of large-scale oil paintings that are part of the Oranjezaal interior decoration in the Royal Palace Huis ten Bosch (The Hague). The whitened areas of a painting by Pieter Soutman dating from 1648 were micro-sampled and compared with "healthy" black paint using different analytical imaging techniques. The dark paint was identified as bone black in linseed oil with a lead drier added. Microscopic images of the cross-section revealed a white top layer of 10-20 μm in the black paint layer. Imaging the cross-section surface with scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and specular reflection Fourier transform infrared (FTIR) showed homogeneous distributions of phosphate, phosphorus and calcium over the black and the white degraded bone black. X-ray diffraction (XRD) showed the presence of calcium phosphate hydrate (Ca 3(PO 4) 2· xH 2O), monetite (CaHPO 4) with possibly some poorly crystalline or amorphous hydroxyapatite (Ca 5(OH)(PO 4) 3). The EDX maps of lead and carbon, however, showed some discontinuity between the degraded and non-degraded bone black. There was an increase in the lead concentration in the white top layer, and a slight decrease of carbon. Transmission FTIR demonstrated that aromatic network polymers from the carbon black are markedly diminished in the white deterioration product. It is proposed that the carbonized organic matter in the bone black is vulnerable to photo bleaching in the presence of a lead catalyst under these circumstances.

  9. In vitro studies on the behavior of salmeterol xinafoate and its interaction with calf thymus DNA by multi-spectroscopic techniques.

    PubMed

    Zhao, Tingting; Bi, Shuyun; Wang, Yu; Wang, Tianjiao; Pang, Bo; Gu, Tingting

    2014-11-11

    The salmeterol xinafoate (SX) binding to calf thymus DNA in vitro was explored by fluorescence, resonance light scattering (RLS), UV-vis absorption, as well as viscometry, ionic strength effect and DNA melting techniques. It was found that SX could bind to DNA weakly, and the binding constants (Ka) were determined as 8.52×10(3), 8.31×10(3) and 6.14×10(3) L mol(-1) at 18, 28 and 38°C respectively. When bound to DNA, SX showed fluorescence quenching in the fluorescence spectra and hyperchromic effect in the absorption spectra. Stern-Volmer plots revealed that the quenching of fluorescence of SX by DNA was a static quenching. Furthermore, the relative viscosity and melting temperature of DNA solution were hardly influenced by SX, while the fluorescence intensity of SX-DNA was observed to decrease with the increasing ionic strength of system. Also, the binding constant between SX and double stranded DNA (dsDNA) was much weaker than that between SX and single stranded DNA (ssDNA). All these results suggested that the binding mode of SX to DNA should be groove binding. The obtained thermodynamic parameters indicated that electrostatic force might play a predominant role in SX binding to DNA. The quantum yield (φ) of SX was measured as 0.13 using comparative method. Based on the Förster resonance energy transfer theory (FRET), the binding distance (r0) between the acceptor and donor was calculated as 4.10 nm.

  10. Stock price forecasting for companies listed on Tehran stock exchange using multivariate adaptive regression splines model and semi-parametric splines technique

    NASA Astrophysics Data System (ADS)

    Rounaghi, Mohammad Mahdi; Abbaszadeh, Mohammad Reza; Arashi, Mohammad

    2015-11-01

    One of the most important topics of interest to investors is stock price changes. Investors whose goals are long term are sensitive to stock price and its changes and react to them. In this regard, we used multivariate adaptive regression splines (MARS) model and semi-parametric splines technique for predicting stock price in this study. The MARS model as a nonparametric method is an adaptive method for regression and it fits for problems with high dimensions and several variables. semi-parametric splines technique was used in this study. Smoothing splines is a nonparametric regression method. In this study, we used 40 variables (30 accounting variables and 10 economic variables) for predicting stock price using the MARS model and using semi-parametric splines technique. After investigating the models, we select 4 accounting variables (book value per share, predicted earnings per share, P/E ratio and risk) as influencing variables on predicting stock price using the MARS model. After fitting the semi-parametric splines technique, only 4 accounting variables (dividends, net EPS, EPS Forecast and P/E Ratio) were selected as variables effective in forecasting stock prices.

  11. Optical Spectroscopic Monitoring of Parachute Yarn Aging

    SciTech Connect

    Tallant, D.R.; Garcia, M.J.; Simpson, R.L.; Behr, V.L.; Whinery, L.D.; Peng, L.W.

    1999-04-01

    Optical spectroscopic techniques were evaluated as nondestructive monitors of the aging of parachutes in nuclear weapons. We analyzed thermally aged samples of nylon and Kevlar webbing by photoluminescence spectroscopy and reflection spectroscopy. Infrared analysis was also performed to help understand the degradation mechanisms of the polymer materials in the webbing. The photoluminescence and reflection spectra were analyzed by chemometric data treatment techniques to see if aged-induced changes in the spectra correlated to changes in measured tensile strength. A correlation was found between the shapes of the photoluminescent bands and the measured tensile strengths. Photoluminescent spectra can be used to predict the tensile strengths of nylon and Kevlar webbing with sufficient accuracy to categorize the webbing sample as above rated tensile strength, marginal or below rated tensile strength. The instrumentation required to perform the optical spectroscopic measurement can be made rugged, compact and portable. Thus, optical spectroscopic techniques offer a means for nondestructive field monitoring of parachutes in the enduring stockpile/

  12. [Marginal adaptation of posterior resins: effect of hygroscopic expansion and layer placement technique on Class II and V fillings].

    PubMed

    Navarro Majo, J L

    Human teeth were filled with two posterior resins, Heliomolar and P-50, using Gluma as dentin adhesive. After this the teeth were extracted and the author studied the microleakage. The composite filling of the cavities was done following two techniques, one by layers and other with the bulk technique. The teeth were kept in saline solution at 37 degrees C and after 30 days the teeth were studied. The Heliomolar composite was able to avoid the microleakage in almost 100% of the samples independently of the inserting technique used. The P-50 composite was not able to avoid the microleakage unless in a very small number of teeth and this happened only when the layer technique was used. The difference between both is due to the greater amount of organic component in the microfilled resins producing thus a greater higroscopic expansion.

  13. Simultaneous microscopic measurements of thermal and spectroscopic fields of a phase change material

    NASA Astrophysics Data System (ADS)

    Romano, M.; Ryu, M.; Morikawa, J.; Batsale, J. C.; Pradere, C.

    2016-05-01

    In this paper, simultaneous microscopic measurements of thermal and spectroscopic fields of a paraffin wax n-alkane phase change material are reported. Measurements collected using an original set-up are presented and discussed with emphasis on the ability to perform simultaneous characterization of the system when the proposed imaging process is used. Finally, this work reveals that the infrared wavelength contains two sets of important information. Furthermore, this versatile and flexible technique is well adapted to characterize many systems in which the mass and heat transfers effects are coupled.

  14. Spectroscopic characterization of biological agents using FTIR, normal Raman and surface-enhanced Raman spectroscopies

    NASA Astrophysics Data System (ADS)

    Luna-Pineda, Tatiana; Soto-Feliciano, Kristina; De La Cruz-Montoya, Edwin; Pacheco Londoño, Leonardo C.; Ríos-Velázquez, Carlos; Hernández-Rivera, Samuel P.

    2007-04-01

    FTIR, Raman spectroscopy and Surface Enhanced Raman Scattering (SERS) requires a minimum of sample allows fast identification of microorganisms. The use of this technique for characterizing the spectroscopic signatures of these agents and their stimulants has recently gained considerable attention due to the fact that these techniques can be easily adapted for standoff detection from considerable distances. The techniques also show high sensitivity and selectivity and offer near real time detection duty cycles. This research focuses in laying the grounds for the spectroscopic differentiation of Staphylococcus spp., Pseudomonas spp., Bacillus spp., Salmonella spp., Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, and E. coli, together with identification of their subspecies. In order to achieve the proponed objective, protocols to handle, cultivate and analyze the strains have been developed. Spectroscopic similarities and marked differences have been found for Spontaneous or Normal Raman spectra and for SERS using silver nanoparticles have been found. The use of principal component analysis (PCA), discriminate factor analysis (DFA) and a cluster analysis were used to evaluate the efficacy of identifying potential threat bacterial from their spectra collected on single bacteria. The DFA from the bacteria Raman spectra show a little discrimination between the diverse bacterial species however the results obtained from the SERS demonstrate to be high discrimination technique. The spectroscopic study will be extended to examine the spores produced by selected strains since these are more prone to be used as Biological Warfare Agents due to their increased mobility and possibility of airborne transport. Micro infrared spectroscopy as well as fiber coupled FTIR will also be used as possible sensors of target compounds.

  15. An innovative technique for contrast enhancement of computed tomography images using normalized gamma-corrected contrast-limited adaptive histogram equalization

    NASA Astrophysics Data System (ADS)

    Al-Ameen, Zohair; Sulong, Ghazali; Rehman, Amjad; Al-Dhelaan, Abdullah; Saba, Tanzila; Al-Rodhaan, Mznah

    2015-12-01

    Image contrast is an essential visual feature that determines whether an image is of good quality. In computed tomography (CT), captured images tend to be low contrast, which is a prevalent artifact that reduces the image quality and hampers the process of extracting its useful information. A common tactic to process such artifact is by using histogram-based techniques. However, although these techniques may improve the contrast for different grayscale imaging applications, the results are mostly unacceptable for CT images due to the presentation of various faults, noise amplification, excess brightness, and imperfect contrast. Therefore, an ameliorated version of the contrast-limited adaptive histogram equalization (CLAHE) is introduced in this article to provide a good brightness with decent contrast for CT images. The novel modification to the aforesaid technique is done by adding an initial phase of a normalized gamma correction function that helps in adjusting the gamma of the processed image to avoid the common errors of the basic CLAHE of the excess brightness and imperfect contrast it produces. The newly developed technique is tested with synthetic and real-degraded low-contrast CT images, in which it highly contributed in producing better quality results. Moreover, a low intricacy technique for contrast enhancement is proposed, and its performance is also exhibited against various versions of histogram-based enhancement technique using three advanced image quality assessment metrics of Universal Image Quality Index (UIQI), Structural Similarity Index (SSIM), and Feature Similarity Index (FSIM). Finally, the proposed technique provided acceptable results with no visible artifacts and outperformed all the comparable techniques.

  16. Recording Light-evoked Postsynaptic Responses in Neurons in Dark-adapted, Mouse Retinal Slice Preparations Using Patch Clamp Techniques

    PubMed Central

    Hellmer, Chase B.; Ichinose, Tomomi

    2015-01-01

    The retina is the gateway to the visual system. To understand visual signal processing mechanisms, we investigate retinal neural network functions. Retinal neurons in the network comprise of numerous subtypes. More than 10 subtypes of bipolar cells, ganglion cells, and amacrine cells have been identified by morphological studies. Multiple subtypes of retinal neurons are thought to encode distinct features of visual signaling, such as motion and color, and form multiple neural pathways. However, the functional roles of each neuron in visual signal processing are not fully understood. The patch clamp method is useful to address this fundamental question. Here, a protocol to record light-evoked synaptic responses in mouse retinal neurons using patch clamp recordings in dark-adapted conditions is provided. The mouse eyes are dark-adapted O/N, and retinal slice preparations are dissected in a dark room using infrared illumination and viewers. Infrared light does not activate mouse photoreceptors and thus preserves their light responsiveness. Patch clamp is used to record light-evoked responses in retinal neurons. A fluorescent dye is injected during recordings to characterize neuronal morphological subtypes. This procedure enables us to determine the physiological functions of each neuron in the mouse retina. PMID:25741904

  17. Laser Patterning Pretreatment before Thermal Spraying: A Technique to Adapt and Control the Surface Topography to Thermomechanical Loading and Materials

    NASA Astrophysics Data System (ADS)

    Kromer, Robin; Costil, Sophie; Cormier, Jonathan; Berthe, Laurent; Peyre, Patrice; Courapied, Damien

    2016-02-01

    Coating characteristics are highly dependent on substrate preparation and spray parameters. Hence, the surface must be adapted mechanically and physicochemically to favor coating-substrate adhesion. Conventional surface preparation methods such as grit blasting are limited by surface embrittlement and produce large plastic deformations throughout the surface, resulting in compressive stress and potential cracks. Among all such methods, laser patterning is suitable to prepare the surface of sensitive materials. No embedded grit particles can be observed, and high-quality coatings are obtained. Finally, laser surface patterning adapts the impacted surface, creating large anchoring area. Optimized surface topographies can then be elaborated according to the material as well as the application. The objective of this study is to compare the adhesive bond strength between two surface preparation methods, namely grit blasting and laser surface patterning, for two material couples used in aerospace applications: 2017 aluminum alloy and AISI 304L stainless steel coated with NiAl and YSZ, respectively. Laser patterning significantly increases adherence values for similar contact area due to mixed-mode (cohesive and adhesive) failure. The coating is locked in the pattern.

  18. One-step synthesis of hybrid inorganic-organic nanocomposite coatings by novel laser adaptive ablation deposition technique

    NASA Astrophysics Data System (ADS)

    Serbezov, Valery; Sotirov, Sotir

    2013-03-01

    A novel approach for one-step synthesis of hybrid inorganic-organic nanocomposite coatings by new modification of Pulsed Laser Deposition technology called Laser Adaptive Ablation Deposition (LAAD) is presented. Hybrid nanocomposite coatings including Mg- Rapamycin and Mg- Desoximetasone were produced by UV TEA N2 laser under low vacuum (0.1 Pa) and room temperature onto substrates from SS 316L, KCl and NaCl. The laser fluence for Mg alloy was 1, 8 J/cm2 and for Desoximetasone 0,176 J/cm2 and for Rapamycin 0,118 J/cm2 were respectively. The threedimensional two-segmented single target was used to adapt the interaction of focused laser beam with inorganic and organic material. Magnesium alloy nanoparticles with sizes from 50 nm to 250 nm were obtained in organic matrices. The morphology of nanocomposites films were studied by Bright field / Fluorescence optical microscope and Scanning Electron Microscope (SEM). Fourier Transform Infrared (FTIR) spectroscopy measurements were applied in order to study the functional properties of organic component before and after the LAAD process. Energy Dispersive X-ray Spectroscopy (EDX) was used for identification of Mg alloy presence in hybrid nanocomposites coatings. The precise control of process parameters and particularly of the laser fluence adjustment enables transfer on materials with different physical chemical properties and one-step synthesis of complex inorganic- organic nanocomposites coatings.

  19. A Spectroscopic-Based Laboratory Experiment for Protein Conformational Studies

    ERIC Educational Resources Information Center

    Ramos, Carlos Henrique I.

    2004-01-01

    This article describes a practical experiment for teaching basic spectroscopic techniques to introduce the topic of protein conformational change to students in the field of molecular biology, biochemistry, or structural biology. The spectroscopic methods employed in the experiment are absorbance, for protein concentration measurements, and…

  20. Glacier and climate changes in the Western Indian Himalayas (Ladakh and Lahul-Spiti): remote sensing, field techniques and adaptation techniques

    NASA Astrophysics Data System (ADS)

    Racoviteanu, Adina; Williams, Mark

    2010-05-01

    Anecdotal evidence from glacier termini observations in the Himalayas suggest that these glaciers have been in a state of general retreat since the last century, and point to "alarming" rates of retreat in the past decades. Concomitantly, local communities in the Western Himalayas have reported changes in glacier extents, snow cover and weather patterns. In response to "alarming" rates of glacial retreat, some indigenous cultures in the Himalayan area have begun a number of adaptive responses such as meltwater harvesting to construct "artificial" glaciers, which store the water during the dry season. There is urgency in: a) scientifically evaluating whether such practices of glacier regeneration can help provide water in a timely manner and 2) developing glacier datasets to assist such local efforts to ensure water supply in these data-scarce mountainous areas. Here we compare and contrast scientific and indigenous perspectives on spatial patterns of glacier changes in the dry areas of Ladakh (34.10°N and 77.34°E ) and Lahul-Spiti district (31.11°N and 77.15°E ) in the Western Indian Himalaya. A new glacier inventory of Lahul-Spiti was constructed using a combination of data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor with Shuttle Radar Topography Mission (SRTM), GPS field data and ground photography. Glacier changes were quantified by comparison with older ASTER inventory and topographic maps. We present changes reported by local communities and recorded in video, oral testimonies and ground photography. We focus on two indigenous practices of water harvesting for glacier regeneration: a) artificial glaciers and b) kul irrigation systems. Field data of artificial glaciers was acquired at Sabu, Stakmo and Phuktsey glaciers using a differential GPS system. Kul irrigation systems were documented in Spiti valley (Lara and Kibber villages). We will present the results of mapping these water harvesting systems with the goal

  1. Contour adaptation.

    PubMed

    Anstis, Stuart

    2013-01-01

    It is known that adaptation to a disk that flickers between black and white at 3-8 Hz on a gray surround renders invisible a congruent gray test disk viewed afterwards. This is contrast adaptation. We now report that adapting simply to the flickering circular outline of the disk can have the same effect. We call this "contour adaptation." This adaptation does not transfer interocularly, and apparently applies only to luminance, not color. One can adapt selectively to only some of the contours in a display, making only these contours temporarily invisible. For instance, a plaid comprises a vertical grating superimposed on a horizontal grating. If one first adapts to appropriate flickering vertical lines, the vertical components of the plaid disappears and it looks like a horizontal grating. Also, we simulated a Cornsweet (1970) edge, and we selectively adapted out the subjective and objective contours of a Kanisza (1976) subjective square. By temporarily removing edges, contour adaptation offers a new technique to study the role of visual edges, and it demonstrates how brightness information is concentrated in edges and propagates from them as it fills in surfaces.

  2. Assessment of adaptability of zebu cattle ( Bos indicus) breeds in two different climatic conditions: using cytogenetic techniques on genome integrity

    NASA Astrophysics Data System (ADS)

    Kumar, Anil; Waiz, Syma Ashraf; Sridhar Goud, T.; Tonk, R. K.; Grewal, Anita; Singh, S. V.; Yadav, B. R.; Upadhyay, R. C.

    2016-06-01

    The aim of this study was to evaluate the genome integrity so as to assess the adaptability of three breeds of indigenous cattle reared under arid and semi-arid regions of Rajasthan (Bikaner) and Haryana (Karnal) India. The cattle were of homogenous group (same age and sex) of indigenous breeds viz. Sahiwal, Tharparkar and Kankrej. A total of 100 animals were selected for this study from both climatic conditions. The sister chromatid exchanges (SCE's), chromosomal gaps and chromatid breaks were observed in metaphase plates of chromosome preparations obtained from in vitro culture of peripheral blood lymphocytes. The mean number of breaks and gaps in Sahiwal and Tharparkar of semi-arid zone were 8.56 ± 3.16, 6.4 ± 3.39 and 8.72 ± 2.04, 3.52 ± 6.29, respectively. Similarly, the mean number of breaks and gaps in Tharparkar and Kankrej cattle of arid zone were 5.26 ± 1.76, 2.74 ± 1.76 and 5.24 ± 1.84, 2.5 ± 1.26, respectively. The frequency of SCEs in chromosomes was found significantly higher ( P < 0.05) in Tharparkar of semi-arid region (4.72 ± 1.55) compared to arid region (2.83 ± 1.01). Similarly, the frequency of SCEs was found to be 4.0 ± 1.41 in the Sahiwal of semi-arid region and 2.69 ± 1.12 in Kankrej of arid zone. Statistical analysis revealed significant differences ( P < 0.05) amongst the different zones, i.e. arid and semi-arid, whereas no significant difference ( P > 0.05) was observed in the same zone. The analysis of frequency of CAs and SCEs revealed significant effects of environmental conditions on the genome integrity of animals, thereby indicating an association with their adaptability.

  3. Calibration method for spectroscopic systems

    DOEpatents

    Sandison, David R.

    1998-01-01

    Calibration spots of optically-characterized material placed in the field of view of a spectroscopic system allow calibration of the spectroscopic system. Response from the calibration spots is measured and used to calibrate for varying spectroscopic system operating parameters. The accurate calibration achieved allows quantitative spectroscopic analysis of responses taken at different times, different excitation conditions, and of different targets.

  4. Calibration method for spectroscopic systems

    DOEpatents

    Sandison, D.R.

    1998-11-17

    Calibration spots of optically-characterized material placed in the field of view of a spectroscopic system allow calibration of the spectroscopic system. Response from the calibration spots is measured and used to calibrate for varying spectroscopic system operating parameters. The accurate calibration achieved allows quantitative spectroscopic analysis of responses taken at different times, different excitation conditions, and of different targets. 3 figs.

  5. In vitro measurement of nucleus pulposus swelling pressure: A new technique for studies of spinal adaptation to gravity

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Glover, M. G.; Mahmood, M. M.; Gott, S.; Garfin, S. R.; Ballard, R.; Murthy, G.; Brown, M. D.

    1992-01-01

    Swelling of the intervertebral disc nucleus pulposus is altered by posture and gravity. We have designed and tested a new osmometer for in vitro determination of nucleus pulposus swelling pressure. The functional principle of the osmometer involves compressing a sample of nucleus pulposus with nitrogen gas until saline pressure gradients across a 0.45 microns Millipore filter are eliminated. Swelling pressure of both pooled dog and pooled pig lumbar disc nucleus pulposus were measured on the new osmometer and compared to swelling pressures determined using the equilibrium dialysis technique. The osmometer measured swelling pressures comparable to those obtained by the dialysis technique. This osmometer provides a rapid, direct, and accurate measurement of swelling pressure of the nucleus pulposus.

  6. Spectroscopic study in Z-pinch discharge

    SciTech Connect

    Garamoon, A.A.; Saudy, A.H.; Shark, W.

    1995-12-31

    The temporal variation of the emitted line intensity has been investigated, and thus an important information about the dynamic ionization stages in the Z-pinch discharge has been studied. Also the electron temperature Te, has been deduced by using a spectroscopic technique.

  7. An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight

    NASA Astrophysics Data System (ADS)

    Whitfield, Clifford A.

    2009-12-01

    A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window of possible vehicle destinations and orientation built from the UAV kinematics. The intermittent results are pursued by a dynamic optimization technique to determine the flight path. This sequential optimization technique is a multi-objective optimization procedure consisting of two goals, without requiring additional information to combine the conflicting objectives into a single-objective. An example case-study and additional applications are developed and the results are discussed; including the application to the field of Solar Regenerative (SR) High Altitude Long Endurance (HALE) UAV flight. Harnessing solar energy has recently been adapted for use on high altitude UAV platforms. An aircraft that uses solar panels and powered by the sun during the day and through the night by SR systems, in principle could sustain flight for weeks or months. The requirements and limitations of solar powered flight were determined. The SR-HALE UAV platform geometry and flight characteristics were selected from an existing aircraft that has demonstrated the capability for sustained flight through flight tests. The goals were to maintain continual Situational Awareness (SA) over a case-study selected Area of Interest (AOI) and existing UAV power and surveillance systems. This was done for still wind and constant wind conditions at altitude along with variations in latitude. The characteristics of solar flux and the dependence on the surface location and orientation were established along with fixed flight maneuvers for

  8. Using Adaptive Tools and Techniques To Teach a Class of Students Who Are Blind or Low-Vision

    NASA Astrophysics Data System (ADS)

    Supalo, Cary A.; Mallouk, Thomas E.; Lanouette, James; Amorosi, Christeallia; Wohlers, H. David; McEnnis, Kathleen

    2009-05-01

    A brief overview of the 2007 National Federation of the Blind-Jernigan Institute Youth Slam Chemistry Track, a course of study within a science camp that provided firsthand experimental experience to 200 students who are blind and low-vision, is given. For many of these students, this was their first hands-on experience with laboratory chemistry. Several new blind and low vision-accessible laboratory technologies were successfully debuted. These tools and techniques bring a greater degree of freedom and independence to students with visual impairments in their science classes. Modifications of standard chemistry experiments that incorporated these new tools are described.

  9. Pulse transient hot strip technique adapted for slab sample geometry to study anisotropic thermal transport properties of μm-thin crystalline films.

    PubMed

    Ma, Y; Gustavsson, J S; Haglund, A; Gustavsson, M; Gustafsson, S E

    2014-04-01

    A new method based on the adaptation of the Pulse Transient Hot Strip technique to slab sample geometry has been developed for studying thermal conductivity and thermal diffusivity of anisotropic thin film materials (<50 μm) with thermal conductivity in the 0.01-100 W/mK range, deposited on thin substrates (i.e., wafers). Strength of this technique is that it provides a well-controlled thermal probing depth, making it possible to probe a predetermined depth of the sample layer and thereby avoiding the influence from material(s) deeper down in the sample. To verify the technique a series of measurements were conducted on a y-cut single crystal quartz wafer. A Hot Strip sensor (32-μm wide, 3.2-mm long) was deposited along two orthogonal crystallographic (x- and z-) directions and two independent pulse transients were recorded. Thereafter, the data was fitted to our theoretical model, and the anisotropic thermal transport properties were determined. Using a thermal probing depth of only 30 μm, we obtained a thermal conductivity along the perpendicular (parallel) direction to the z-, i.e., optic axis of 6.48 (11.4) W/mK, and a thermal diffusivity of 3.62 (6.52) mm(2)/s. This yields a volumetric specific heat of 1.79 MJ/mK. These values agree well with tabulated data on bulk crystalline quartz supporting the accuracy of the technique, and the obtained standard deviation of less than 2.7% demonstrates the precision of this new measurement technique.

  10. Bioinspired, roughness-induced, water and oil super-philic and super-phobic coatings prepared by adaptable layer-by-layer technique.

    PubMed

    Brown, Philip S; Bhushan, Bharat

    2015-01-01

    Coatings with specific surface wetting properties are of interest for anti-fouling, anti-fogging, anti-icing, self-cleaning, anti-smudge, and oil-water separation applications. Many previous bioinspired surfaces are of limited use due to a lack of mechanical durability. Here, a layer-by-layer technique is utilized to create coatings with four combinations of water and oil repellency and affinity. An adapted layer-by-layer approach is tailored to yield specific surface properties, resulting in a durable, functional coating. This technique provides necessary flexibility to improve substrate adhesion combined with desirable surface chemistry. Polyelectrolyte binder, SiO2 nanoparticles, and silane or fluorosurfactant layers are deposited, combining surface roughness and necessary chemistry to result in four different coatings: superhydrophilic/superoleophilic, superhydrophobic/superoleophilic, superhydrophobic/superoleophobic, and superhydrophilic/superoleophobic. The superoleophobic coatings display hexadecane contact angles >150° with tilt angles <5°, whilst the superhydrophobic coatings display water contact angles >160° with tilt angles <2°. One coating combines both oleophobic and hydrophobic properties, whilst others mix and match oil and water repellency and affinity. Coating durability was examined through the use of micro/macrowear experiments. These coatings display transparency acceptable for some applications. Fabrication via this novel combination of techniques results in durable, functional coatings displaying improved performance compared to existing work where either durability or functionality is compromised. PMID:26353971

  11. Adaption of a fragment analysis technique to an automated high-throughput multicapillary electrophoresis device for the precise qualitative and quantitative characterization of microbial communities.

    PubMed

    Trotha, René; Reichl, Udo; Thies, Frank L; Sperling, Danuta; König, Wolfgang; König, Brigitte

    2002-04-01

    The analysis of microbial communities is of increasing importance in life sciences and bioengineering. Traditional techniques of investigations like culture or cloning methods suffer from many disadvantages. They are unable to give a complete qualitative and quantitative view of the total amount of microorganisms themselves, their interactions among each other and with their environment. Obviously, the determination of static or dynamic balances among microorganisms is of fast growing interest. The generation of species specific and fluorescently labeled 16S ribosomal DNA (rDNA) fragments by the terminal restriction fragment length polymorphism (T-RFLP) technique is a suitable tool to overcome the problems other methods have. For the separation of these fragments polyacrylamide gel sequencers are preferred as compared to capillary sequencers using linear polymers until now because of their higher electrophoretic resolution and therefore sizing accuracy. But modern capillary sequencers, especially multicapillary sequencers, offer an advanced grade of automation and an increased throughput necessary for the investigation of complex communities in long-time studies. Therefore, we adapted a T-RFLP technique to an automated high-throughput multicapillary electrophoresis device (ABI 3100 Genetic Analysis) with regard to a precise qualitative and quantitative characterization of microbial communities. PMID:11981854

  12. Bioinspired, roughness-induced, water and oil super-philic and super-phobic coatings prepared by adaptable layer-by-layer technique

    PubMed Central

    Brown, Philip S.; Bhushan, Bharat

    2015-01-01

    Coatings with specific surface wetting properties are of interest for anti-fouling, anti-fogging, anti-icing, self-cleaning, anti-smudge, and oil-water separation applications. Many previous bioinspired surfaces are of limited use due to a lack of mechanical durability. Here, a layer-by-layer technique is utilized to create coatings with four combinations of water and oil repellency and affinity. An adapted layer-by-layer approach is tailored to yield specific surface properties, resulting in a durable, functional coating. This technique provides necessary flexibility to improve substrate adhesion combined with desirable surface chemistry. Polyelectrolyte binder, SiO2 nanoparticles, and silane or fluorosurfactant layers are deposited, combining surface roughness and necessary chemistry to result in four different coatings: superhydrophilic/superoleophilic, superhydrophobic/superoleophilic, superhydrophobic/superoleophobic, and superhydrophilic/superoleophobic. The superoleophobic coatings display hexadecane contact angles >150° with tilt angles <5°, whilst the superhydrophobic coatings display water contact angles >160° with tilt angles <2°. One coating combines both oleophobic and hydrophobic properties, whilst others mix and match oil and water repellency and affinity. Coating durability was examined through the use of micro/macrowear experiments. These coatings display transparency acceptable for some applications. Fabrication via this novel combination of techniques results in durable, functional coatings displaying improved performance compared to existing work where either durability or functionality is compromised. PMID:26353971

  13. Bioinspired, roughness-induced, water and oil super-philic and super-phobic coatings prepared by adaptable layer-by-layer technique

    NASA Astrophysics Data System (ADS)

    Brown, Philip S.; Bhushan, Bharat

    2015-09-01

    Coatings with specific surface wetting properties are of interest for anti-fouling, anti-fogging, anti-icing, self-cleaning, anti-smudge, and oil-water separation applications. Many previous bioinspired surfaces are of limited use due to a lack of mechanical durability. Here, a layer-by-layer technique is utilized to create coatings with four combinations of water and oil repellency and affinity. An adapted layer-by-layer approach is tailored to yield specific surface properties, resulting in a durable, functional coating. This technique provides necessary flexibility to improve substrate adhesion combined with desirable surface chemistry. Polyelectrolyte binder, SiO2 nanoparticles, and silane or fluorosurfactant layers are deposited, combining surface roughness and necessary chemistry to result in four different coatings: superhydrophilic/superoleophilic, superhydrophobic/superoleophilic, superhydrophobic/superoleophobic, and superhydrophilic/superoleophobic. The superoleophobic coatings display hexadecane contact angles >150° with tilt angles <5°, whilst the superhydrophobic coatings display water contact angles >160° with tilt angles <2°. One coating combines both oleophobic and hydrophobic properties, whilst others mix and match oil and water repellency and affinity. Coating durability was examined through the use of micro/macrowear experiments. These coatings display transparency acceptable for some applications. Fabrication via this novel combination of techniques results in durable, functional coatings displaying improved performance compared to existing work where either durability or functionality is compromised.

  14. Bioinspired, roughness-induced, water and oil super-philic and super-phobic coatings prepared by adaptable layer-by-layer technique.

    PubMed

    Brown, Philip S; Bhushan, Bharat

    2015-09-10

    Coatings with specific surface wetting properties are of interest for anti-fouling, anti-fogging, anti-icing, self-cleaning, anti-smudge, and oil-water separation applications. Many previous bioinspired surfaces are of limited use due to a lack of mechanical durability. Here, a layer-by-layer technique is utilized to create coatings with four combinations of water and oil repellency and affinity. An adapted layer-by-layer approach is tailored to yield specific surface properties, resulting in a durable, functional coating. This technique provides necessary flexibility to improve substrate adhesion combined with desirable surface chemistry. Polyelectrolyte binder, SiO2 nanoparticles, and silane or fluorosurfactant layers are deposited, combining surface roughness and necessary chemistry to result in four different coatings: superhydrophilic/superoleophilic, superhydrophobic/superoleophilic, superhydrophobic/superoleophobic, and superhydrophilic/superoleophobic. The superoleophobic coatings display hexadecane contact angles >150° with tilt angles <5°, whilst the superhydrophobic coatings display water contact angles >160° with tilt angles <2°. One coating combines both oleophobic and hydrophobic properties, whilst others mix and match oil and water repellency and affinity. Coating durability was examined through the use of micro/macrowear experiments. These coatings display transparency acceptable for some applications. Fabrication via this novel combination of techniques results in durable, functional coatings displaying improved performance compared to existing work where either durability or functionality is compromised.

  15. Ultrasonic separation of a suspension for in situ spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Nogo, Kosuke; Qi, Wei; Mori, Keita; Ogawa, Satoshi; Inohara, Daichi; Hosono, Satsuki; Kawashima, Natsumi; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

    2016-04-01

    Application of spectroscopic techniques to suspensions is difficult because optical scattering caused by solid particles reduces the accuracy. At the extreme, dense suspensions like blood cannot be analyzed by spectroscopic techniques. In the present study, an ultrasonic standing wave was used to agglomerate fluorescent particles in an aqueous ethanol suspension at the nodes of the standing wave. Relatively clear liquid regions, which contained few particles that could cause optical scattering, appeared around the anti-nodes and were used for spectroscopic imaging. This produced a spectrum that was similar to that of clear aqueous ethanol without any fluorescent particles.

  16. Adaptation of Soil Physical Measurement Techniques for the Delineation of Mud and Lakebed Sediments at Neusiedler See

    PubMed Central

    Kogelbauer, Ilse; Heine, Erwin; D'Amboise, Christopher; Müllebner, Christoph; Sokol, Wolfgang; Loiskandl, Willibald

    2013-01-01

    For many water management issues of shallow lakes with non-consolidated sediments hydrographic surveys of the open water area and reed belt areas are required. In the frame of water management strategy for the steppe lake Neusiedler See, located between Austria and Hungary, a hydrographic survey was conducted. In the open water area (water depth ≥1 m) a sediment echosounder was used. To validate these measurements and to distinguish between water, mud, and sediment layers in the shallow lake and reed belt area additional measurements were needed. As no common standard methods are available yet, we developed a measurement system based on two commonly applied soil physical measurement techniques providing reproducible physical values: a capacitive sensor and a cone penetrometer combined with GNSS-positioning enable dynamic measurements of georeferenced vertical water-mud-bedsediments profiles. The system bases on site-specific calibrated sensors and allows instantaneous, in situ measurements. The measurements manifest a sharp water-mud interface by a sudden decline to smaller water content which is a function of the dielectric permittivity. A second decline indicates the transition to compacted mud. That is concurrently the density where the penetrometer starts registering significant penetration resistance. The penetrometer detects shallow lakebed-sediment layers. Within the lake survey this measurement system was successfully tested. PMID:24351626

  17. Apple flavonols during fruit adaptation to solar radiation: spectral features and technique for non-destructive assessment.

    PubMed

    Merzlyak, Mark N; Solovchenko, Alexei E; Smagin, Alexei I; Gitelson, Anatoly A

    2005-02-01

    Spectral properties of flavonols of three varieties (Golden Delicious, Antonovka, and Renet Simirenko) of anthocyanin-free apple fruit were investigated with reflectance spectroscopy. The results of spectral and biochemical analyses suggested that fruit reflectance in a broad spectral range 365-430 nm is strongly dependent on and, in sunlit fruit surfaces, governed by flavonols. The build up of peel flavonols (mainly rutin and other quercetin glycosides) resulted in a dramatic decrease of fruit reflectance in this range, flattening of the spectrum, and extending the region with low reflectance (4-5%) to ca. 410 nm. The spectral features observed suggest that flavonols contribute significantly to screening of excessive radiation, not only UV-A, but in the short-wave bands of chlorophyll and carotenoid absorption in the visible part of the spectrum as well. To retrieve quantitatively flavonol content from reflectance spectra, we tested the applicability of an inversion technique developed for non-destructive leaf pigment assessment. The model for flavonol content assessment was suggested in the form (R(-1)410 - R(-1)460)R800, where Rlambda is reflectance at wavelength lambda. The model was linearly related to flavonol content between 8 and 220nmol/cm2 with the coefficient of determination r2=0.92 and root mean square error of flavonol estimation of 20 nmol/ cm2 regardless of cultivar, chlorophyll, and carotenoid content.

  18. Changing teaching techniques and adapting new technologies to improve student learning in an introductory meteorology and climate course

    NASA Astrophysics Data System (ADS)

    Cutrim, E. M.; Rudge, D.; Kits, K.; Mitchell, J.; Nogueira, R.

    2006-06-01

    Responding to the call for reform in science education, changes were made in an introductory meteorology and climate course offered at a large public university. These changes were a part of a larger project aimed at deepening and extending a program of science content courses that model effective teaching strategies for prospective middle school science teachers. Therefore, revisions were made to address misconceptions about meteorological phenomena, foster deeper understanding of key concepts, encourage engagement with the text, and promote inquiry-based learning. Techniques introduced include: use of a flash cards, student reflection questionnaires, writing assignments, and interactive discussions on weather and forecast data using computer technology such as Integrated Data Viewer (IDV). The revision process is described in a case study format. Preliminary results (self-reflection by the instructor, surveys of student opinion, and measurements of student achievement), suggest student learning has been positively influenced. This study is supported by three grants: NSF grant No. 0202923, the Unidata Equipment Award, and the Lucia Harrison Endowment Fund.

  19. Adaptation of soil physical measurement techniques for the delineation of mud and lakebed sediments at Neusiedler See.

    PubMed

    Kogelbauer, Ilse; Heine, Erwin; D'Amboise, Christopher; Müllebner, Christoph; Sokol, Wolfgang; Loiskandl, Willibald

    2013-12-12

    For many water management issues of shallow lakes with non-consolidated sediments hydrographic surveys of the open water area and reed belt areas are required. In the frame of water management strategy for the steppe lake Neusiedler See, located between Austria and Hungary, a hydrographic survey was conducted. In the open water area (water depth ≥1 m) a sediment echosounder was used. To validate these measurements and to distinguish between water, mud, and sediment layers in the shallow lake and reed belt area additional measurements were needed. As no common standard methods are available yet, we developed a measurement system based on two commonly applied soil physical measurement techniques providing reproducible physical values: a capacitive sensor and a cone penetrometer combined with GNSS-positioning enable dynamic measurements of georeferenced vertical water-mud-bedsediments profiles. The system bases on site-specific calibrated sensors and allows instantaneous, in situ measurements. The measurements manifest a sharp water-mud interface by a sudden decline to smaller water content which is a function of the dielectric permittivity. A second decline indicates the transition to compacted mud. That is concurrently the density where the penetrometer starts registering significant penetration resistance. The penetrometer detects shallow lakebed-sediment layers. Within the lake survey this measurement system was successfully tested.

  20. Inversion of monthly GRACE potentials for climate-based mass transports by a novel technique with locally adapted and increased resolution

    NASA Astrophysics Data System (ADS)

    Michel, Volker; Fischer, Doreen

    2013-04-01

    We show the applicability of a novel method called the Regularized Functional Matching Pursuit (RFMP) to the local analysis of mass transports. We consider monthly GRACE potentials for South America during one year and subtract a temporal mean. The resulting difference fields are denoised with Freeden's spherical wavelets. Finally, the obtained monthly potential anomalies are inverted for volumetric mass density anomalies with the RFMP. The calculated results clearly show seasonal variations in the mass density distribution in the Amazon area. For another application, we consider the detection of droughts and a flood in the summers of 2005 to 2010. The novel technique combines the advantages of global basis functions (spherical harmonics) and local trial functions (splines or wavelets) and yields a resolution which is locally adapted to the detail structure of the solution. We believe that this can contribute to an increased spatial resolution of the result.

  1. Estimation of Basal Depth of Magnetic Sources from High Resolution Aeromagnetic Data of Middle Niger Basin, Nigeria using Adapted Centroid Technique for Fractal Distribution of Sources

    NASA Astrophysics Data System (ADS)

    Nwankwo, L.

    2015-12-01

    An estimate of depths to the bottom of magnetic sources in the Middle Niger Basin, north-central Nigeria has been made from a recently acquired high-resolution aeromagnetic data using adapted centroid technique for fractal distribution of sources. The result shows that the depth varies between 11.71 and 26.53 km. Deeper values are found in northern and central regions while values as low as 12 km were observed in the southern part. The shallower depths to the bottom of magnetic sources may be representing the thermal/petrological boundaries in the basin. This study is therefore crucial for quantitative understanding of the geo-processes and geothermal parameters in the study area.

  2. Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients

    SciTech Connect

    Frederick, B.deB. |

    1994-12-01

    Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

  3. MAMA Spectroscopic Throughputs

    NASA Astrophysics Data System (ADS)

    Lennon, Daniel

    2009-07-01

    This activity sets new baseline post-SM4 sensitivity/throughput measurements for all the STIS/MAMA spectroscopic modes, and establishes if there changes with respect to perfomance prior to the LVPS failure. It also checks the NUV focus of STIS and its dependence on wavelength.

  4. In situ sensor techniques in modern bioprocess monitoring.

    PubMed

    Beutel, Sascha; Henkel, Steffen

    2011-09-01

    New reactor concepts as multi-parallel screening systems or disposable bioreactor systems for decentralized and reproducible production increase the need for new and easy applicable sensor technologies to access data for process control. These sophisticated reactor systems require sensors to work with the lowest sampling volumes or, even better, to measure directly in situ, but in situ sensors are directly incorporated into a reactor or fermenter within the sterility barrier and have therefore to stand the sterilization procedures. Consequently, these in situ sensor technologies should enable the measurement of multi-analytes simultaneously online and in real-time at a low price for the robust sensing element. Current research therefore focuses on the implementation of noninvasive spectroscopic and optical technologies, and tries to employ them through fiber optics attached to disposable sensing connectors. Spectroscopic methods reach from ultraviolet to infrared and further comprising fluorescence and Raman spectroscopy. Also, optic techniques like microscopy are adapted for the direct use in bioreactor systems (Ulber et al. in Anal Bioanal Chem 376:342-348, 2003) as well as various electrochemical methods (Joo and Brown in Chem Rev 108:638-651, 2008). This review shows the variety of modern in situ sensing principles in bioprocess monitoring with emphasis on spectroscopic and optical techniques and the progress in the adaption to latest reactor concepts. PMID:21785932

  5. Spectroscopic Low Coherence Interferometry

    NASA Astrophysics Data System (ADS)

    Bosschaart, Nienke; van Leeuwen, T. G.; Aalders, Maurice C.; Hermann, Boris; Drexler, Wolfgang; Faber, Dirk J.

    Low-coherence interferometry (LCI) allows high-resolution volumetric imaging of tissue morphology and provides localized optical properties that can be related to the physiological status of tissue. This chapter discusses the combination of spatial and spectroscopic information by means of spectroscopic OCT (sOCT) and low-coherence spectroscopy (LCS). We describe the theory behind these modalities for the assessment of spatially resolved optical absorption and (back)scattering coefficient spectra. These spectra can be used for the highly localized quantification of chromophore concentrations and assessment of tissue organization on (sub)cellular scales. This leads to a wealth of potential clinical applications, ranging from neonatology for the determination of billibrubin concentrations, to oncology for the optical assessment of the aggressiveness of a cancerous lesion.

  6. Spectroscopic Binary Stars

    NASA Astrophysics Data System (ADS)

    Batten, A.; Murdin, P.

    2000-11-01

    Historically, spectroscopic binary stars were binary systems whose nature was discovered by the changing DOPPLER EFFECT or shift of the spectral lines of one or both of the component stars. The observed Doppler shift is a combination of that produced by the constant RADIAL VELOCITY (i.e. line-of-sight velocity) of the center of mass of the whole system, and the variable shift resulting from the o...

  7. Quantitative analysis of terahertz spectra for illicit drugs using adaptive-range micro-genetic algorithm

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Ma, Yong; Lu, Zheng; Peng, Bei; Chen, Qin

    2011-08-01

    In the field of anti-illicit drug applications, many suspicious mixture samples might consist of various drug components—for example, a mixture of methamphetamine, heroin, and amoxicillin—which makes spectral identification very difficult. A terahertz spectroscopic quantitative analysis method using an adaptive range micro-genetic algorithm with a variable internal population (ARVIPɛμGA) has been proposed. Five mixture cases are discussed using ARVIPɛμGA driven quantitative terahertz spectroscopic analysis in this paper. The devised simulation results show agreement with the previous experimental results, which suggested that the proposed technique has potential applications for terahertz spectral identifications of drug mixture components. The results show agreement with the results obtained using other experimental and numerical techniques.

  8. Flux measurements using the BATSE spectroscopic detectors

    NASA Technical Reports Server (NTRS)

    Mcnamara, Bernard

    1993-01-01

    Among the Compton Gama-Ray Observatory instruments, the BATSE Spectroscopic Detectors (SD) have the distinction of being able to detect photons of energies less than about 20 keV. This is an interesting energy range for the examination of low mass X-ray binaries (LMXB's). In fact, Sco X-1, the prototype LMXB, is easily seen even in the raw BATSE spectroscopic data. The all-sky coverage afforded by these detectors offers a unique opportunity to monitor this source over time periods never before possible. The aim of this investigation was to test a number of ways in which both continous and discrete flux measurements can be obtained using the BATSE spectroscopic datasets. A instrumental description of a SD can be found in the Compton Workshop of Apr. 1989, this report will deal only with methods which can be used to analyze its datasets. Many of the items discussed below, particularly in regard to the earth occultation technique, have been developed, refined, and applied by the BATSE team to the reduction of BATSE LAD data. Code written as part of this project utilizes portions of that work. The following discussions will first address issues related to the reduction of SD datasets using the earth occultation technique. It will then discuss methods for the recovery of the flux history of strong sources while they are above the earth's limb. The report will conclude with recommended reduction procedures.

  9. 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.

  10. Large-scale symmetry-adapted perturbation theory computations via density fitting and Laplace transformation techniques: investigating the fundamental forces of DNA-intercalator interactions.

    PubMed

    Hohenstein, Edward G; Parrish, Robert M; Sherrill, C David; Turney, Justin M; Schaefer, Henry F

    2011-11-01

    Symmetry-adapted perturbation theory (SAPT) provides a means of probing the fundamental nature of intermolecular interactions. Low-orders of SAPT (here, SAPT0) are especially attractive since they provide qualitative (sometimes quantitative) results while remaining tractable for large systems. The application of density fitting and Laplace transformation techniques to SAPT0 can significantly reduce the expense associated with these computations and make even larger systems accessible. We present new factorizations of the SAPT0 equations with density-fitted two-electron integrals and the first application of Laplace transformations of energy denominators to SAPT. The improved scalability of the DF-SAPT0 implementation allows it to be applied to systems with more than 200 atoms and 2800 basis functions. The Laplace-transformed energy denominators are compared to analogous partial Cholesky decompositions of the energy denominator tensor. Application of our new DF-SAPT0 program to the intercalation of DNA by proflavine has allowed us to determine the nature of the proflavine-DNA interaction. Overall, the proflavine-DNA interaction contains important contributions from both electrostatics and dispersion. The energetics of the intercalator interaction are are dominated by the stacking interactions (two-thirds of the total), but contain important contributions from the intercalator-backbone interactions. It is hypothesized that the geometry of the complex will be determined by the interactions of the intercalator with the backbone, because by shifting toward one side of the backbone, the intercalator can form two long hydrogen-bonding type interactions. The long-range interactions between the intercalator and the next-nearest base pairs appear to be negligible, justifying the use of truncated DNA models in computational studies of intercalation interaction energies.

  11. Coupling a local adaptive grid refinement technique with an interface sharpening scheme for the simulation of two-phase flow and free-surface flows using VOF methodology

    NASA Astrophysics Data System (ADS)

    Malgarinos, Ilias; Nikolopoulos, Nikolaos; Gavaises, Manolis

    2015-11-01

    This study presents the implementation of an interface sharpening scheme on the basis of the Volume of Fluid (VOF) method, as well as its application in a number of theoretical and real cases usually modelled in literature. More specifically, the solution of an additional sharpening equation along with the standard VOF model equations is proposed, offering the advantage of "restraining" interface numerical diffusion, while also keeping a quite smooth induced velocity field around the interface. This sharpening equation is solved right after volume fraction advection; however a novel method for its coupling with the momentum equation has been applied in order to save computational time. The advantages of the proposed sharpening scheme lie on the facts that a) it is mass conservative thus its application does not have a negative impact on one of the most important benefits of VOF method and b) it can be used in coarser grids as now the suppression of the numerical diffusion is grid independent. The coupling of the solved equation with an adaptive local grid refinement technique is used for further decrease of computational time, while keeping high levels of accuracy at the area of maximum interest (interface). The numerical algorithm is initially tested against two theoretical benchmark cases for interface tracking methodologies followed by its validation for the case of a free-falling water droplet accelerated by gravity, as well as the normal liquid droplet impingement onto a flat substrate. Results indicate that the coupling of the interface sharpening equation with the HRIC discretization scheme used for volume fraction flux term, not only decreases the interface numerical diffusion, but also allows the induced velocity field to be less perturbed owed to spurious velocities across the liquid-gas interface. With the use of the proposed algorithmic flow path, coarser grids can replace finer ones at the slight expense of accuracy.

  12. Raman spectroscopic studies of the cure of dicyclopentadiene (DCPD)

    NASA Astrophysics Data System (ADS)

    Barnes, S. E.; Brown, E. C.; Corrigan, N.; Coates, P. D.; Harkin-Jones, E.; Edwards, H. G. M.

    2005-10-01

    The cure of polydicyclopentadiene conducted by ring-opening metathesis polymerisation in the presence of a Grubbs catalyst was studied using non-invasive Raman spectroscopy. The spectra of the monomer precursor and polymerised product were fully characterised and all stages of polymerisation monitored. Because of the monomer's high reactivity, the cure process is adaptable to reaction injection moulding and reactive rotational moulding. The viscosity of the dicyclopentadiene undergoes a rapid change at the beginning of the polymerisation process and it is critical that the induction time of the viscosity increase is determined and controlled for successful manufacturing. The results from this work show non-invasive Raman spectroscopic monitoring to be an effective method for monitoring the degree of cure, paving the way for possible implementation of the technique as a method of real-time analysis for control and optimisation during reactive processing. Agreement is shown between Raman measurements and ultrasonic time of flight data acquired during the initial induction period of the curing process.

  13. Raman spectroscopic studies of the cure of dicyclopentadiene (DCPD).

    PubMed

    Barnes, S E; Brown, E C; Corrigan, N; Coates, P D; Harkin-Jones, E; Edwards, H G M

    2005-10-01

    The cure of polydicyclopentadiene conducted by ring-opening metathesis polymerisation in the presence of a Grubbs catalyst was studied using non-invasive Raman spectroscopy. The spectra of the monomer precursor and polymerised product were fully characterised and all stages of polymerisation monitored. Because of the monomer's high reactivity, the cure process is adaptable to reaction injection moulding and reactive rotational moulding. The viscosity of the dicyclopentadiene undergoes a rapid change at the beginning of the polymerisation process and it is critical that the induction time of the viscosity increase is determined and controlled for successful manufacturing. The results from this work show non-invasive Raman spectroscopic monitoring to be an effective method for monitoring the degree of cure, paving the way for possible implementation of the technique as a method of real-time analysis for control and optimisation during reactive processing. Agreement is shown between Raman measurements and ultrasonic time of flight data acquired during the initial induction period of the curing process.

  14. Vibrational spectroscopic characterization of fluoroquinolones

    NASA Astrophysics Data System (ADS)

    Neugebauer, U.; Szeghalmi, A.; Schmitt, M.; Kiefer, W.; Popp, J.; Holzgrabe, U.

    2005-05-01

    Quinolones are important gyrase inhibitors. Even though they are used as active agents in many antibiotics, the detailed mechanism of action on a molecular level is so far not known. It is of greatest interest to shed light on this drug-target interaction to provide useful information in the fight against growing resistances and obtain new insights for the development of new powerful drugs. To reach this goal, on a first step it is essential to understand the structural characteristics of the drugs and the effects that are caused by the environment in detail. In this work we report on Raman spectroscopical investigations of a variety of gyrase inhibitors (nalidixic acid, oxolinic acid, cinoxacin, flumequine, norfloxacin, ciprofloxacin, lomefloxacin, ofloxacin, enoxacin, sarafloxacin and moxifloxacin) by means of micro-Raman spectroscopy excited with various excitation wavelengths, both in the off-resonance region (532, 633, 830 and 1064 nm) and in the resonance region (resonance Raman spectroscopy at 244, 257 and 275 nm). Furthermore DFT calculations were performed to assign the vibrational modes, as well as for an identification of intramolecular hydrogen bonding motifs. The effect of small changes in the drug environment was studied by adding successively small amounts of water until physiological low concentrations of the drugs in aqueous solution were obtained. At these low concentrations resonance Raman spectroscopy proved to be a useful and sensitive technique. Supplementary information was obtained from IR and UV/vis spectroscopy.

  15. Multimodal Spectroscopic Study of Amyloid Fibril Polymorphism.

    PubMed

    VandenAkker, Corianne C; Schleeger, Michael; Bruinen, Anne L; Deckert-Gaudig, Tanja; Velikov, Krassimir P; Heeren, Ron M A; Deckert, Volker; Bonn, Mischa; Koenderink, Gijsje H

    2016-09-01

    Amyloid fibrils are a large class of self-assembled protein aggregates that are formed from unstructured peptides and unfolded proteins. The fibrils are characterized by a universal β-sheet core stabilized by hydrogen bonds, but the molecular structure of the peptide subunits exposed on the fibril surface is variable. Here we show that multimodal spectroscopy using a range of bulk- and surface-sensitive techniques provides a powerful way to dissect variations in the molecular structure of polymorphic amyloid fibrils. As a model system, we use fibrils formed by the milk protein β-lactoglobulin, whose morphology can be tuned by varying the protein concentration during formation. We investigate the differences in the molecular structure and composition between long, straight fibrils versus short, wormlike fibrils. We show using mass spectrometry that the peptide composition of the two fibril types is similar. The overall molecular structure of the fibrils probed with various bulk-sensitive spectroscopic techniques shows a dominant contribution of the β-sheet core but no difference in structure between straight and wormlike fibrils. However, when probing specifically the surface of the fibrils with nanometer resolution using tip-enhanced Raman spectroscopy (TERS), we find that both fibril types exhibit a heterogeneous surface structure with mainly unordered or α-helical structures and that the surface of long, straight fibrils contains markedly more β-sheet structure than the surface of short, wormlike fibrils. This finding is consistent with previous surface-specific vibrational sum-frequency generation (VSFG) spectroscopic results ( VandenAkker et al. J. Am. Chem. Soc. , 2011 , 133 , 18030 - 18033 , DOI: 10.1021/ja206513r ). In conclusion, only advanced vibrational spectroscopic techniques sensitive to surface structure such as TERS and VSFG are able to reveal the difference in structure that underlies the distinct morphology and rigidity of different amyloid

  16. Infrared laser spectroscopic trace gas sensing

    NASA Astrophysics Data System (ADS)

    Sigrist, Markus

    2016-04-01

    Chemical sensing and analyses of gas samples by laser spectroscopic methods are attractive owing to several advantages such as high sensitivity and specificity, large dynamic range, multi-component capability, and lack of pretreatment or preconcentration procedures. The preferred wavelength range comprises the fundamental molecular absorption range in the mid-infared between 3 and 15 μm, whereas the near-infrared range covers the (10-100 times weaker) higher harmonics and combination bands. The availability of near-infrared and, particularly, of broadly tunable mid-infrared sources like external cavity quantum cascade lasers (EC-QCLs), interband cascade lasers (ICLs), difference frequency generation (DFG), optical parametric oscillators (OPOs), recent developments of diode-pumped lead salt semiconductor lasers, of supercontinuum sources or of frequency combs have eased the implementation of laser-based sensing devices. Sensitive techniques for molecular absorption measurements include multipass absorption, various configurations of cavity-enhanced techniques such as cavity ringdown (CRD), or of photoacoustic spectroscopy (PAS) including quartz-enhanced (QEPAS) or cantilever-enhanced (CEPAS) techniques. The application requirements finally determine the optimum selection of laser source and detection scheme. In this tutorial talk I shall discuss the basic principles, present various experimental setups and illustrate the performance of selected systems for chemical sensing of selected key atmospheric species. Applications include an early example of continuous vehicle emission measurements with a mobile CO2-laser PAS system [1]. The fast analysis of C1-C4 alkanes at sub-ppm concentrations in gas mixtures is of great interest for the petrochemical industry and was recently achieved with a new type of mid-infrared diode-pumped piezoelectrically tuned lead salt vertical external cavity surface emitting laser (VECSEL) [2]. Another example concerns measurements on short

  17. Spectroscopic Parameters of Lumbar Intervertebral Disc Material

    NASA Astrophysics Data System (ADS)

    Terbetas, G.; Kozlovskaja, A.; Varanius, D.; Graziene, V.; Vaitkus, J.; Vaitkuviene, A.

    2009-06-01

    There are numerous methods of investigating intervertebral disc. Visualization methods are widely used in clinical practice. Histological, imunohistochemical and biochemical methods are more used in scientific research. We propose that a new spectroscopic investigation would be useful in determining intervertebral disc material, especially when no histological specimens are available. Purpose: to determine spectroscopic parameters of intervertebral disc material; to determine emission spectra common for all intervertebral discs; to create a background for further spectroscopic investigation where no histological specimen will be available. Material and Methods: 20 patients, 68 frozen sections of 20 μm thickness from operatively removed intervertebral disc hernia were excited by Nd:YAG microlaser STA-01-TH third harmonic 355 nm light throw 0, 1 mm fiber. Spectrophotometer OceanOptics USB2000 was used for spectra collection. Mathematical analysis of spectra was performed by ORIGIN multiple Gaussian peaks analysis. Results: In each specimen of disc hernia were found distinct maximal spectral peaks of 4 types supporting the histological evaluation of mixture content of the hernia. Fluorescence in the spectral regions 370-700 nm was detected in the disc hernias. The main spectral component was at 494 nm and the contribution of the components with the peak wavelength values at 388 nm, 412 nm and 435±5 nm were varying in the different groups of samples. In comparison to average spectrum of all cases, there are 4 groups of different spectral signatures in the region 400-500 nm in the patient groups, supporting a clinical data on different clinical features of the patients. Discussion and Conclusion: besides the classical open discectomy, new minimally invasive techniques of treating intervertebral disc emerge (PLDD). Intervertebral disc in these techniques is assessed by needle, no histological specimen is taken. Spectroscopic investigation via fiber optics through the

  18. Adaptive antennas

    NASA Astrophysics Data System (ADS)

    Barton, P.

    1987-04-01

    The basic principles of adaptive antennas are outlined in terms of the Wiener-Hopf expression for maximizing signal to noise ratio in an arbitrary noise environment; the analogy with generalized matched filter theory provides a useful aid to understanding. For many applications, there is insufficient information to achieve the above solution and thus non-optimum constrained null steering algorithms are also described, together with a summary of methods for preventing wanted signals being nulled by the adaptive system. The three generic approaches to adaptive weight control are discussed; correlation steepest descent, weight perturbation and direct solutions based on sample matrix conversion. The tradeoffs between hardware complexity and performance in terms of null depth and convergence rate are outlined. The sidelobe cancellor technique is described. Performance variation with jammer power and angular distribution is summarized and the key performance limitations identified. The configuration and performance characteristics of both multiple beam and phase scan array antennas are covered, with a brief discussion of performance factors.

  19. Mobile Spectroscopic Instrumentation in Archaeometry Research.

    PubMed

    Vandenabeele, Peter; Donais, Mary Kate

    2016-01-01

    Mobile instrumentation is of growing importance to archaeometry research. Equipment is utilized in the field or at museums, thus avoiding transportation or risk of damage to valuable artifacts. Many spectroscopic techniques are nondestructive and micro-destructive in nature, which preserves the cultural heritage objects themselves. This review includes over 160 references pertaining to the use of mobile spectroscopy for archaeometry. Following a discussion of terminology related to mobile instrumental methods, results of a literature survey on their applications for cultural heritage objects is presented. Sections devoted to specific techniques are then provided: Raman spectroscopy, X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, laser-induced breakdown spectroscopy, and less frequently used techniques. The review closes with a discussion of combined instrumental approaches.

  20. FRIENDS OF HOT JUPITERS. III. AN INFRARED SPECTROSCOPIC SEARCH FOR LOW-MASS STELLAR COMPANIONS

    SciTech Connect

    Piskorz, Danielle; Knutson, Heather A.; Ngo, Henry; Batygin, Konstantin; Muirhead, Philip S.; Crepp, Justin R.; Hinkley, Sasha; Morton, Timothy D.

    2015-12-01

    Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary techniques to search for stellar companions to known planet-hosting stars: radial velocity monitoring, adaptive optics imaging, and near-infrared spectroscopy. In this paper, we examine high-resolution K band infrared spectra of fifty stars hosting gas giant planets on short-period orbits. We use spectral fitting to search for blended lines due to the presence of cool stellar companions in the spectra of our target stars, where we are sensitive to companions with temperatures between 3500 and 5000 K and projected separations less than 100 AU in most systems. We identify eight systems with candidate low-mass companions, including one companion that was independently detected in our AO imaging survey. For systems with radial velocity accelerations, a spectroscopic non-detection rules out scenarios involving a stellar companion in a high inclination orbit. We use these data to place an upper limit on the stellar binary fraction at small projected separations, and show that the observed population of candidate companions is consistent with that of field stars and also with the population of wide-separation companions detected in our previous AO survey. We find no evidence that spectroscopic stellar companions are preferentially located in systems with short-period gas giant planets on eccentric and/or misaligned orbits.

  1. Spectroscopic Detection of Pathogens

    SciTech Connect

    ALAM,M. KATHLEEN; TIMLIN,JERILYN A.; MARTIN,LAURA E.; HJELLE,DRIAN; LYONS,RICK; GARRISON,KRISTIN

    2000-11-01

    The goal of this LDRD Research project was to provide a preliminary examination of the use of infrared spectroscopy as a tool to detect the changes in cell cultures upon activation by an infectious agent. Due to a late arrival of funding, only 5 months were available to transfer and setup equipment at UTTM,develop cell culture lines, test methods of in-situ activation and collect kinetic data from activated cells. Using attenuated total reflectance (ATR) as a sampling method, live cell cultures were examined prior to and after activation. Spectroscopic data were collected from cells immediately after activation in situ and, in many cases for five successive hours. Additional data were collected from cells activated within a test tube (pre-activated), in both transmission mode as well as in ATR mode. Changes in the infrared data were apparent in the transmission data collected from the pre-activated cells as well in some of the pre-activated ATR data. Changes in the in-situ activated spectral data were only occasionally present due to (1) the limited time cells were studied and (2) incomplete activation. Comparison of preliminary data to infrared bands reported in the literature suggests the primary changes seen are due an increase in ribonucleic acid (RNA) production. This work will be continued as part of a 3 year DARPA grant.

  2. Spectroscopic classification of supernova candidates

    NASA Astrophysics Data System (ADS)

    Hodgkin, S. T.; Hall, A.; Fraser, M.; Campbell, H.; Wyrzykowski, L.; Kostrzewa-Rutkowska, Z.; Pietro, N.

    2014-09-01

    We report the spectroscopic classification of four supernovae at the 2.5m Isaac Newton Telescope on La Palma, using the Intermediate Dispersion Spectrograph and the R300V grating (3500-8000 Ang; ~6 Ang resolution).

  3. Method For Model-Reference Adaptive Control

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun

    1990-01-01

    Relatively simple method of model-reference adaptive control (MRAC) developed from two prior classes of MRAC techniques: signal-synthesis method and parameter-adaption method. Incorporated into unified theory, which yields more general adaptation scheme.

  4. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    SciTech Connect

    Rizzo, T.R.

    1993-12-01

    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  5. Ultraminiature one-shot Fourier-spectroscopic tomography

    NASA Astrophysics Data System (ADS)

    Sato, Shun; Qi, Wei; Kawashima, Natsumi; Nogo, Kosuke; Hosono, Satsuki; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

    2016-02-01

    We propose one-shot Fourier-spectroscopic tomography as a method of ultraminiature spectroscopic imaging. The apparatus used in this technique consists solely of a glass slab with a portion of its surface polished at a certain inclination angle-a device we term a relative-inclination phase shifter-simply mounted on an infinite-distance-corrected optical imaging system. For this reason, the system may be ultraminiaturized to sizes on the order of a few tens of millimeters. Moreover, because our technique uses a near-common-path wavefront-division phase-shift interferometer and has absolutely no need for a mechanical drive unit, it is highly robust against mechanical vibrations. In addition, because the proposed technique uses Fourier-transform spectroscopy, it offers highly efficient light utilization and an outstanding signal-to-noise ratio compared to devices that incorporate distributed or hyperspectral acousto-optical tunable filters. The interferogram, which is a pattern formed by interference of waves at all wavelengths, reflects the spatial variation in the intensity of the interference depending on the magnitude of the phase shift. We first discuss the design of the phase shifter and the results of tests to validate the principles underlying one-shot Fourier-spectroscopic tomography. We then report the results of one-dimensional spectroscopic imaging using this technique.

  6. Dynamic modeling of breast tissue with application of model reference adaptive system identification technique based on clinical robot-assisted palpation.

    PubMed

    Keshavarz, M; Mojra, A

    2015-11-01

    Accurate identification of breast tissue's dynamic behavior in physical examination is critical to successful diagnosis and treatment. In this study a model reference adaptive system identification (MRAS) algorithm is utilized to estimate the dynamic behavior of breast tissue from mechanical stress-strain datasets. A robot-assisted device (Robo-Tac-BMI) is going to mimic physical palpation on a 45 year old woman having a benign mass in the left breast. Stress-strain datasets will be collected over 14 regions of both breasts in a specific period of time. Then, a 2nd order linear model is adapted to the experimental datasets. It was confirmed that a unique dynamic model with maximum error about 0.89% is descriptive of the breast tissue behavior meanwhile mass detection may be achieved by 56.1% difference from the normal tissue.

  7. Maximum-likelihood spectral estimation and adaptive filtering techniques with application to airborne Doppler weather radar. Thesis Technical Report No. 20

    NASA Technical Reports Server (NTRS)

    Lai, Jonathan Y.

    1994-01-01

    This dissertation focuses on the signal processing problems associated with the detection of hazardous windshears using airborne Doppler radar when weak weather returns are in the presence of strong clutter returns. In light of the frequent inadequacy of spectral-processing oriented clutter suppression methods, we model a clutter signal as multiple sinusoids plus Gaussian noise, and propose adaptive filtering approaches that better capture the temporal characteristics of the signal process. This idea leads to two research topics in signal processing: (1) signal modeling and parameter estimation, and (2) adaptive filtering in this particular signal environment. A high-resolution, low SNR threshold maximum likelihood (ML) frequency estimation and signal modeling algorithm is devised and proves capable of delineating both the spectral and temporal nature of the clutter return. Furthermore, the Least Mean Square (LMS) -based adaptive filter's performance for the proposed signal model is investigated, and promising simulation results have testified to its potential for clutter rejection leading to more accurate estimation of windspeed thus obtaining a better assessment of the windshear hazard.

  8. Adaptation of Laser Microdissection Technique for the Study of a Spontaneous Metastatic Mammary Carcinoma Mouse Model by NanoString Technologies.

    PubMed

    Castro, Nadia P; Merchant, Anand S; Saylor, Karen L; Anver, Miriam R; Salomon, David S; Golubeva, Yelena G

    2016-01-01

    Laser capture microdissection (LCM) of tissue is an established tool in medical research for collection of distinguished cell populations under direct microscopic visualization for molecular analysis. LCM samples have been successfully analyzed in a number of genomic and proteomic downstream molecular applications. However, LCM sample collection and preparation procedure has to be adapted to each downstream analysis platform. In this present manuscript we describe in detail the adaptation of LCM methodology for the collection and preparation of fresh frozen samples for NanoString analysis based on a study of a model of mouse mammary gland carcinoma and its lung metastasis. Our adaptation of LCM sample preparation and workflow to the requirements of the NanoString platform allowed acquiring samples with high RNA quality. The NanoString analysis of such samples provided sensitive detection of genes of interest and their associated molecular pathways. NanoString is a reliable gene expression analysis platform that can be effectively coupled with LCM. PMID:27077656

  9. Adaptation of Laser Microdissection Technique for the Study of a Spontaneous Metastatic Mammary Carcinoma Mouse Model by NanoString Technologies

    PubMed Central

    Saylor, Karen L.; Anver, Miriam R.; Salomon, David S.; Golubeva, Yelena G.

    2016-01-01

    Laser capture microdissection (LCM) of tissue is an established tool in medical research for collection of distinguished cell populations under direct microscopic visualization for molecular analysis. LCM samples have been successfully analyzed in a number of genomic and proteomic downstream molecular applications. However, LCM sample collection and preparation procedure has to be adapted to each downstream analysis platform. In this present manuscript we describe in detail the adaptation of LCM methodology for the collection and preparation of fresh frozen samples for NanoString analysis based on a study of a model of mouse mammary gland carcinoma and its lung metastasis. Our adaptation of LCM sample preparation and workflow to the requirements of the NanoString platform allowed acquiring samples with high RNA quality. The NanoString analysis of such samples provided sensitive detection of genes of interest and their associated molecular pathways. NanoString is a reliable gene expression analysis platform that can be effectively coupled with LCM. PMID:27077656

  10. Laser spectroscopic measurement of helium isotope ratios.

    SciTech Connect

    Wang, L.-B.; Mueller, P.; Holt, R. J.; Lu, Z.-T.; O'Connor, T. P.; Sano, Y.; Sturchio, N.; Univ. of Illinois; Univ. of Tokyo; Univ. of Illinois at Chicago

    2003-06-13

    A sensitive laser spectroscopic method has been applied to the quantitative determination of the isotope ratio of helium at the level of {sup 3}He/{sup 4}He = 10{sup -7}--10{sup -5}. The resonant absorption of 1083 nm laser light by the metastable {sup 3}He atoms in a discharge cell was measured with the frequency modulation saturation spectroscopy technique while the abundance of {sup 4}He was measured by a direct absorption technique. The results on three different samples extracted from the atmosphere and commercial helium gas were in good agreement with values obtained with mass spectrometry. The achieved 3{sigma} detection limit of {sup 3}He in helium is 4 x 10{sup -9}. This demonstration required a 200 {mu}L STP sample of He. The sensitivity can be further improved, and the required sample size reduced, by several orders of magnitude with the addition of cavity enhanced spectroscopy.

  11. A computer method for the automatic reduction of spectroscopic data.

    PubMed

    Ditzel, E F; Giddings, L E

    1967-12-01

    A computer program, written in Fortran IV and for use with an associated spectral comparator, has been developed at The Naval Research Laboratory for the purpose of automatically reducing spectroscopic data. A Datex digitalizing magnetic tape recorder in conjunction with a modified Jarrell-Ash microphotometer allows the reading of spectral information from a photographic plate at the rate of twentyfive data pairs per second. Spectra of local interest analyzed by this method are (1) absorption, (2) emission, (3) plasma type, obtained from time-resolved spectroscopic techniques, and (4) solar echellegrams obtained from rocket probings of the upper atmosphere. Markedly useful features of the program are its capabilities of (a) recognizing spectral peaks from a background of variable density, (b) obtaining absolute values for the radiance or irradiance. An essential characteristic of the method is the saving of significant amounts of time in the reduction of photographic spectroscopic data.

  12. Using a non-invasive technique in nutrition: synchrotron radiation infrared microspectroscopy spectroscopic characterization of oil seeds treated with different processing conditions on molecular spectral factors influencing nutrient delivery.

    PubMed

    Zhang, Xuewei; Yu, Peiqiang

    2014-07-01

    Non-invasive techniques are a key to study nutrition and structure interaction. Fourier transform infrared microspectroscopy coupled with a synchrotron radiation source (SR-IMS) is a rapid, non-invasive, and non-destructive bioanalytical technique. To understand internal structure changes in relation to nutrient availability in oil seed processing is vital to find optimal processing conditions. The objective of this study was to use a synchrotron-based bioanalytical technique SR-IMS as a non-invasive and non-destructive tool to study the effects of heat-processing methods and oil seed canola type on modeled protein structure based on spectral data within intact tissue that were randomly selected and quantify the relationship between the modeled protein structure and protein nutrient supply to ruminants. The results showed that the moisture heat-related processing significantly changed (p<0.05) modeled protein structures compared to the raw canola (control) and those processing by dry heating. The moisture heating increased (p<0.05) spectral intensities of amide I, amide II, α-helices, and β-sheets but decreased (p<0.05) the ratio of modeled α-helices to β-sheet spectral intensity. There was no difference (p>0.05) in the protein spectral profile between the raw and dry-heated canola tissue and between yellow- and brown-type canola tissue. The results indicated that different heat processing methods have different impacts on the protein inherent structure. The protein intrinsic structure in canola seed tissue was more sensitive and more response to the moisture heating in comparison to the dry heating. These changes are expected to be related to the nutritive value. However, the current study is based on limited samples, and more large-scale studies are needed to confirm our findings.

  13. Using a non-invasive technique in nutrition: synchrotron radiation infrared microspectroscopy spectroscopic characterization of oil seeds treated with different processing conditions on molecular spectral factors influencing nutrient delivery.

    PubMed

    Zhang, Xuewei; Yu, Peiqiang

    2014-07-01

    Non-invasive techniques are a key to study nutrition and structure interaction. Fourier transform infrared microspectroscopy coupled with a synchrotron radiation source (SR-IMS) is a rapid, non-invasive, and non-destructive bioanalytical technique. To understand internal structure changes in relation to nutrient availability in oil seed processing is vital to find optimal processing conditions. The objective of this study was to use a synchrotron-based bioanalytical technique SR-IMS as a non-invasive and non-destructive tool to study the effects of heat-processing methods and oil seed canola type on modeled protein structure based on spectral data within intact tissue that were randomly selected and quantify the relationship between the modeled protein structure and protein nutrient supply to ruminants. The results showed that the moisture heat-related processing significantly changed (p<0.05) modeled protein structures compared to the raw canola (control) and those processing by dry heating. The moisture heating increased (p<0.05) spectral intensities of amide I, amide II, α-helices, and β-sheets but decreased (p<0.05) the ratio of modeled α-helices to β-sheet spectral intensity. There was no difference (p>0.05) in the protein spectral profile between the raw and dry-heated canola tissue and between yellow- and brown-type canola tissue. The results indicated that different heat processing methods have different impacts on the protein inherent structure. The protein intrinsic structure in canola seed tissue was more sensitive and more response to the moisture heating in comparison to the dry heating. These changes are expected to be related to the nutritive value. However, the current study is based on limited samples, and more large-scale studies are needed to confirm our findings. PMID:24920208

  14. Enhancing forensic science with spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Ricci, Camilla; Kazarian, Sergei G.

    2006-09-01

    This presentation outlines the research we are developing in the area of Fourier Transform Infrared (FTIR) spectroscopic imaging with the focus on materials of forensic interest. FTIR spectroscopic imaging has recently emerged as a powerful tool for characterisation of heterogeneous materials. FTIR imaging relies on the ability of the military-developed infrared array detector to simultaneously measure spectra from thousands of different locations in a sample. Recently developed application of FTIR imaging using an ATR (Attenuated Total Reflection) mode has demonstrated the ability of this method to achieve spatial resolution beyond the diffraction limit of infrared light in air. Chemical visualisation with enhanced spatial resolution in micro-ATR mode broadens the range of materials studied with FTIR imaging with applications to pharmaceutical formulations or biological samples. Macro-ATR imaging has also been developed for chemical imaging analysis of large surface area samples and was applied to analyse the surface of human skin (e.g. finger), counterfeit tablets, textile materials (clothing), etc. This approach demonstrated the ability of this imaging method to detect trace materials attached to the surface of the skin. This may also prove as a valuable tool in detection of traces of explosives left or trapped on the surfaces of different materials. This FTIR imaging method is substantially superior to many of the other imaging methods due to inherent chemical specificity of infrared spectroscopy and fast acquisition times of this technique. Our preliminary data demonstrated that this methodology will provide the means to non-destructive detection method that could relate evidence to its source. This will be important in a wider crime prevention programme. In summary, intrinsic chemical specificity and enhanced visualising capability of FTIR spectroscopic imaging open a window of opportunities for counter-terrorism and crime-fighting, with applications ranging

  15. Human heat adaptation.

    PubMed

    Taylor, Nigel A S

    2014-01-01

    In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation.

  16. Adaptive Multi-Layer LMS Controller Design and Application to Active Vibration Suppression on a Truss and Proposed Impact Analysis Technique

    NASA Technical Reports Server (NTRS)

    Barney, Timothy A.; Shin, Y. S.; Agrawal, B. N.

    2001-01-01

    This research develops an adaptive controller that actively suppresses a single frequency disturbance source at a remote position and tests the system on the NPS Space Truss. The experimental results are then compared to those predicted by an ANSYS finite element model. The NPS space truss is a 3.7-meter long truss that simulates a space-borne appendage with sensitive equipment mounted at its extremities. One of two installed piezoelectric actuators and an Adaptive Multi-Layer LMS control law were used to effectively eliminate an axial component of the vibrations induced by a linear proof mass actuator mounted at one end of the truss. Experimental and analytical results both demonstrate reductions to the level of system noise. Vibration reductions in excess of 50dB were obtained through experimentation and over 100dB using ANSYS, demonstrating the ability to model this system with a finite element model. This report also proposes a method to use distributed quartz accelerometers to evaluate the location, direction, and energy of impacts on the NPS space truss using the dSPACE data acquisition and processing system to capture the structural response and compare it to known reference Signals.

  17. Application of Bayesian techniques to model the burden of human salmonellosis attributable to U.S. food commodities at the point of processing: adaptation of a Danish model.

    PubMed

    Guo, Chuanfa; Hoekstra, Robert M; Schroeder, Carl M; Pires, Sara Monteiro; Ong, Kanyin Liane; Hartnett, Emma; Naugle, Alecia; Harman, Jane; Bennett, Patricia; Cieslak, Paul; Scallan, Elaine; Rose, Bonnie; Holt, Kristin G; Kissler, Bonnie; Mbandi, Evelyne; Roodsari, Reza; Angulo, Frederick J; Cole, Dana

    2011-04-01

    Mathematical models that estimate the proportion of foodborne illnesses attributable to food commodities at specific points in the food chain may be useful to risk managers and policy makers to formulate public health goals, prioritize interventions, and document the effectiveness of mitigations aimed at reducing illness. Using human surveillance data on laboratory-confirmed Salmonella infections from the Centers for Disease Control and Prevention and Salmonella testing data from U.S. Department of Agriculture Food Safety and Inspection Service's regulatory programs, we developed a point-of-processing foodborne illness attribution model by adapting the Hald Salmonella Bayesian source attribution model. Key model outputs include estimates of the relative proportions of domestically acquired sporadic human Salmonella infections resulting from contamination of raw meat, poultry, and egg products processed in the United States from 1998 through 2003. The current model estimates the relative contribution of chicken (48%), ground beef (28%), turkey (17%), egg products (6%), intact beef (1%), and pork (<1%) across 109 Salmonella serotypes found in food commodities at point of processing. While interpretation of the attribution estimates is constrained by data inputs, the adapted model shows promise and may serve as a basis for a common approach to attribution of human salmonellosis and food safety decision-making in more than one country.

  18. Amorphous drug-PVP dispersions: application of theoretical, thermal and spectroscopic analytical techniques to the study of a molecule with intermolecular bonds in both the crystalline and pure amorphous state.

    PubMed

    Tobyn, Michael; Brown, Jonathan; Dennis, Andrew B; Fakes, Michael; Gao, Qi; Gamble, John; Khimyak, Yaroslav Z; McGeorge, Gary; Patel, Chhaya; Sinclair, Wayne; Timmins, Peter; Yin, Shawn

    2009-09-01

    We report the case of BMS-488043-PVP solid dispersions which when analysed using modulated DSC showed compliance with the Gordon-Taylor model, confirming ideal mixing behaviour of the two components. The nature or presence of stabilising interactions between drug and PVP could not be confirmed using this technique. Use of FT-IR, Raman and solid-state NMR spectroscopy confirmed the presence of stabilising hydrogen bond interactions between the drug and PVP. Similar interactions are present as intermolecular bonds in the crystalline and pure amorphous drug system. The Gordon-Taylor equation, as it is not predictive of the presence of intermolecular bonds such as hydrogen bonding in an amorphous dispersion, may underestimate the likely physical stability of solid dispersions which are produced and stabilised by these interactions.

  19. Spectroscopic methods for the photodiagnosis of nonmelanoma skin cancer.

    PubMed

    Drakaki, Eleni; Vergou, Theognosia; Dessinioti, Clio; Stratigos, Alexander J; Salavastru, Carmen; Antoniou, Christina

    2013-06-01

    The importance of dermatological noninvasive imaging techniques has increased over the last decades, aiming at diagnosing nonmelanoma skin cancer (NMSC). Technological progress has led to the development of various analytical tools, enabling the in vivo/in vitro examination of lesional human skin with the aim to increase diagnostic accuracy and decrease morbidity and mortality. The structure of the skin layers, their chemical composition, and the distribution of their compounds permits the noninvasive photodiagnosis of skin diseases, such as skin cancers, especially for early stages of malignant tumors. An important role in the dermatological diagnosis and disease monitoring has been shown for promising spectroscopic and imaging techniques, such as fluorescence, diffuse reflectance, Raman and near-infrared spectroscopy, optical coherence tomography, and confocal laser-scanning microscopy. We review the use of these spectroscopic techniques as noninvasive tools for the photodiagnosis of NMSC.

  20. A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

    ERIC Educational Resources Information Center

    Wakabayashi, Fumitaka; Hamada, Kiyohito

    2006-01-01

    Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

  1. A New Diagnostic Mechanism of Instruction: A Dynamic, Real-Time and Non-Interference Quantitative Measurement Technique for Adaptive E-Learning

    ERIC Educational Resources Information Center

    Hsu, Pi-Shan; Chang, Te-Jeng; Wu, Ming-Hsiung

    2009-01-01

    The level of learners' expertise has been used as a metric and diagnostic mechanism of instruction. This metric influences mental effort directly according to the applications of cognitive load theory. Cognitive efficiency, an optimal measurement technique of expertise, was developed by Kalyuga and Sweller to replace instructional efficiency in…

  2. Estimation of the most influential factors on the laser cutting process heat affected zone (HAZ) by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Petković, Dalibor; Nikolić, Vlastimir; Milovančević, Miloš; Lazov, Lyubomir

    2016-07-01

    Heat affected zone (HAZ) of the laser cutting process may be developed on the basis on combination of different factors. In this investigation was analyzed the HAZ forecasting based on the different laser cutting parameters. The main aim in this article was to analyze the influence of three inputs on the HAZ of the laser cutting process. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for HAZ forecasting. Three inputs are considered: laser power, cutting speed and gas pressure. According the results the cutting speed has the highest influence on the HAZ forecasting (RMSE: 0.0553). Gas pressure has the smallest influence on the HAZ forecasting (RMSE: 0.0801). The results can be used in order to simplify HAZ prediction and analyzing.

  3. sick: The Spectroscopic Inference Crank

    NASA Astrophysics Data System (ADS)

    Casey, Andrew R.

    2016-03-01

    There exists an inordinate amount of spectral data in both public and private astronomical archives that remain severely under-utilized. The lack of reliable open-source tools for analyzing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick is agnostic to the wavelength coverage, resolving power, or general data format, allowing any user to easily construct a generative model for their data, regardless of its source. sick can be used to provide a nearest-neighbor estimate of model parameters, a numerically optimized point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalize on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-dimensional interpolation, or a Cannon-based model. Additional phenomena that transform the data (e.g., redshift, rotational broadening, continuum, spectral resolution) are incorporated as free parameters and can be marginalized away. Outlier pixels (e.g., cosmic rays or poorly modeled regimes) can be treated with a Gaussian mixture model, and a noise model is included to account for systematically underestimated variance. Combining these phenomena into a scalar-justified, quantitative model permits precise inferences with credible uncertainties on noisy data. I describe the common model features, the implementation details, and the default behavior, which is balanced to be suitable for most astronomical applications. Using a forward model on low-resolution, high signal

  4. Adaptation of the pseudo-metal-oxide-semiconductor field effect transistor technique to ultrathin silicon-on-insulator wafers characterization: Improved set-up, measurement procedure, parameter extraction, and modeling

    NASA Astrophysics Data System (ADS)

    Van Den Daele, W.; Malaquin, C.; Baumel, N.; Kononchuk, O.; Cristoloveanu, S.

    2013-10-01

    This paper revisits and adapts of the pseudo-MOSFET (Ψ-MOSFET) characterization technique for advanced fully depleted silicon on insulator (FDSOI) wafers. We review the current challenges for standard Ψ-MOSFET set-up on ultra-thin body (12 nm) over ultra-thin buried oxide (25 nm BOX) and propose a novel set-up enabling the technique on FDSOI structures. This novel configuration embeds 4 probes with large tip radius (100-200 μm) and low pressure to avoid oxide damage. Compared with previous 4-point probe measurements, we introduce a simplified and faster methodology together with an adapted Y-function. The models for parameters extraction are revisited and calibrated through systematic measurements of SOI wafers with variable film thickness. We propose an in-depth analysis of the FDSOI structure through comparison of experimental data, TCAD (Technology Computed Aided Design) simulations, and analytical modeling. TCAD simulations are used to unify previously reported thickness-dependent analytical models by analyzing the BOX/substrate potential and the electrical field in ultrathin films. Our updated analytical models are used to explain the results and to extract correct electrical parameters such as low-field electron and hole mobility, subthreshold slope, and film/BOX interface traps density.

  5. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  6. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Heidary, Saeed; Setayeshi, Saeed

    2015-01-01

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous 99mTc/201Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of 201Tl (77±10% keV) and 99mTc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  7. Selection of the most influential factors on the water-jet assisted underwater laser process by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Nikolić, Vlastimir; Petković, Dalibor; Lazov, Lyubomir; Milovančević, Miloš

    2016-07-01

    Water-jet assisted underwater laser cutting has shown some advantages as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. It is important to determine which parameters are the most important for the process. In this investigation was analyzed the water-jet assisted underwater laser cutting parameters forecasting based on the different parameters. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for water-jet assisted underwater laser cutting parameters forecasting. Three inputs are considered: laser power, cutting speed and water-jet speed. The ANFIS process for variable selection was also implemented in order to detect the predominant factors affecting the forecasting of the water-jet assisted underwater laser cutting parameters. According to the results the combination of laser power cutting speed forms the most influential combination foe the prediction of water-jet assisted underwater laser cutting parameters. The best prediction was observed for the bottom kerf-width (R2 = 0.9653). The worst prediction was observed for dross area per unit length (R2 = 0.6804). According to the results, a greater improvement in estimation accuracy can be achieved by removing the unnecessary parameter.

  8. Raman spectroscopic evaluation of the dissemination of road de-icers in the environment

    NASA Astrophysics Data System (ADS)

    Durickovic, Ivana; Marchetti, Mario; Suaire, Remi; Derombise, Guillaume

    2013-04-01

    Raman spectroscopy is nowadays a well established technique for the investigation of the molecular structure of a substance (solid, liquid or gas) through the study of its vibrational properties. This technique has been shown as particularly adapted for the characterization of water and aqueous solutions. The ERA 31 of the CÉTÉ de l'Est is developing methods based on that technique for domains such as water pollution detection and pollutant dissemination, mainly linked to transport infrastructures. A specific application of the Raman spectroscopy is the monitoring of the road de-icing materials' evolution after application on the road's surface. Indeed, in order to avoid traffic disruption during winter, roads and airports are the subject of a specific maintenance based on the application of de-icing materials. However, these chemicals are transported out of the roads, and end up either in the surrounding environment (splashed out by the vehicles or blown away by the wind) or in ponds used for road water runoff remediation and flow control (by flows after precipitations). The first aspect of the road de-icing surveillance is therefore their follow-up in the transport infrastructure's surrounding environment. A spectroscopic tool was hence developed for the measurement of these products on roads and in water located next to transport infrastructures, and adapted for the measurement on soils. The second aspect concerns the tracking of the de-icing material in the detention ponds. The instrumentation of a specific pond has been set in order to determine the road de-icing material's evolution and influence on the pond's environmental media (water, soil and vegetation). The goal is to evaluate in what way and how long, the road de-icer will spread in a detention pond. It will permit us to estimate the pond retention period, as well as its remediation efficiency.

  9. Spectroscopic detection of chemotherapeutics and antioxidants

    NASA Astrophysics Data System (ADS)

    Latka, Ines; Grüner, Roman; Matthäus, Christian; Dietzek, Benjamin; Werncke, W.; Lademann, Jürgen; Popp, Jürgen

    2012-06-01

    The hand-foot-syndrome presents a severe dermal side-effect of chemotherapeutic cancer treatment. The cause of this side-effect is the elimination of systemically administered chemotherapeutics with the sweat. Transported to the skin surface, the drugs subsequently penetrate into the skin in the manner of topically applied substances. Upon accumulation of the chemotherapeutics in the skin the drugs destroy cells and tissue - in the same way as they are supposed to act in cancer cells. Aiming at the development of strategies to illuminate the molecular mechanism underlying the handfoot- syndrome (and, in a second step, strategies to prevent this severe side-effect), it might be important to evaluate the concentration and distribution of chemotherapeutics and antioxidants in the human skin. The latter can be estimated by the carotenoid concentration, as carotenoids serve as marker substances for the dermal antioxidative status.Following the objectives outlined above, this contribution presents a spectroscopic study aiming at the detection and quantification of carotenoids and selected chemotherapeutics in human skin. To this end, spontaneous Raman scattering and coherent anti-Stokes Raman scattering (CARS) microspectroscopy are combined with two-photon excited fluorescence. While the latter technique is Please verify that (1) all pages are present, (2) all figures are correct, (3) all fonts and special characters are correct, and (4) all text and figures fit within the red margin lines shown on this review document. Complete formatting information is available at http://SPIE.org/manuscripts Return to your MySPIE To Do List at http://myspie.org and approve or disapprove this submission. Your manuscript will not be published without this approval.restricted to the detection of fluorescent chemotherapeutics, e.g., doxorubicin, the vibrational spectroscopic techniques can - in principle - be applied to any type of analyte molecules. Furthermore, we will present the

  10. Development of hot slumping technique and last optical performances obtained on a 500mm diameter slumped segment prototype for adaptive optics

    NASA Astrophysics Data System (ADS)

    Ghigo, M.; Basso, S.; Canestrari, R.; Proserpio, L.

    2009-08-01

    In the framework of the E-ELT Design Study financed by the European Community under OPTICON-FP6, the INAF Astronomical Observatory of Brera (INAF-OAB) has developed a technique for the manufacturing of thin optical segments. Thin glass segments are produced by mean of an hot slumping technique that makes use of an optical quality ceramic mould and a precise thermal circle to impart the desired shape to a glass sheet. In the present paper we summarize the results obtained during this study and report the last results of the effort in scaling-up the procedure: in particular the overall process has been refined in order to optimize the parameters (such as time, maximum temperature and amount of pressure) used to slump a 500 mm diameter glass segment. The thickness of these glass segments is of about 1.7 mm, making the optical surface very floppy and easy to be deformed. For this reason optical tests have been performed using a astatic support implemented into a vertical optical bench.

  11. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  12. Computational Improvements to Quantum Wave Packet ab Initio Molecular Dynamics Using a Potential-Adapted, Time-Dependent Deterministic Sampling Technique.

    PubMed

    Jakowski, Jacek; Sumner, Isaiah; Iyengar, Srinivasan S

    2006-09-01

    In a recent publication, we introduced a computational approach to treat the simultaneous dynamics of electrons and nuclei. The method is based on a synergy between quantum wave packet dynamics and ab initio molecular dynamics. Atom-centered density-matrix propagation or Born-Oppenheimer dynamics can be used to perform ab initio dynamics. In this paper, wave packet dynamics is conducted using a three-dimensional direct product implementation of the distributed approximating functional free-propagator. A fundamental computational difficulty in this approach is that the interaction potential between the two components of the methodology needs to be calculated frequently. Here, we overcome this problem through the use of a time-dependent deterministic sampling measure that predicts, at every step of the dynamics, regions of the potential which are important. The algorithm, when combined with an on-the-fly interpolation scheme, allows us to determine the quantum dynamical interaction potential and gradients at every dynamics step in an extremely efficient manner. Numerical demonstrations of our sampling algorithm are provided through several examples arranged in a cascading level of complexity. Starting from a simple one-dimensional quantum dynamical treatment of the shared proton in [Cl-H-Cl](-) and [CH3-H-Cl](-) along with simultaneous dynamical treatment of the electrons and classical nuclei, through a complete three-dimensional treatment of the shared proton in [Cl-H-Cl](-) as well as treatment of a hydrogen atom undergoing donor-acceptor transitions in the biological enzyme, soybean lipoxygenase-1 (SLO-1), we benchmark the algorithm thoroughly. Apart from computing various error estimates, we also compare vibrational density of states, inclusive of full quantum effects from the shared proton, using a novel unified velocity-velocity, flux-flux autocorrelation function. In all cases, the potential-adapted, time-dependent sampling procedure is seen to improve the

  13. Beam transport and focusing layout based on adaptive optics for the SQS scientific instrument at the European XFEL

    NASA Astrophysics Data System (ADS)

    Mazza, Tommaso; Signorato, Riccardo; Meyer, Michael; La Civita, Daniele; Vannoni, Maurizio; Sinn, Harald

    2014-09-01

    The SQS scientific instrument at the European XFEL is dedicated to investigations in the soft X-rays regime, in particular to studies of non-linear and ultrafast processes in atoms, molecules and clusters using a variety of spectroscopic techniques. It will be equipped with a Kirkpatrick-Baez (KB) adaptive mirror system enabling submicron focusing and access to variable focal distances. In this paper we describe the conceptual design of the beam transport and focusing layout based on the KB system. The design includes a study of feasibility based on the comparison between the required source and image positions and the theoretical limits for the accessible mirror profiles.

  14. Spectroscopic studies of cold, gas-phase biomolecular ions

    NASA Astrophysics Data System (ADS)

    Rizzo, Thomas R.; Stearns, Jaime A.; Boyarkin, Oleg V.

    While the marriage of mass spectrometry and laser spectroscopy is not new, developments over the last few years in this relationship have opened up new horizons for the spectroscopic study of biological molecules. The combination of electrospray ionisation for producing large biological molecules in the gas phase together with cooled ion traps and multiple-resonance laser schemes are allowing spectroscopic investigation of individual conformations of peptides with more than a dozen amino acids. Highly resolved infrared spectra of single conformations of such species provide important benchmarks for testing the accuracy of theoretical calculations. This review presents a number of techniques employed in our laboratory and in others for measuring the spectroscopy of cold, gas-phase protonated peptides. We show examples that demonstrate the power of these techniques and evaluate their extension to still larger biological molecules.

  15. Unstructured mesh generation and adaptivity

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1995-01-01

    An overview of current unstructured mesh generation and adaptivity techniques is given. Basic building blocks taken from the field of computational geometry are first described. Various practical mesh generation techniques based on these algorithms are then constructed and illustrated with examples. Issues of adaptive meshing and stretched mesh generation for anisotropic problems are treated in subsequent sections. The presentation is organized in an education manner, for readers familiar with computational fluid dynamics, wishing to learn more about current unstructured mesh techniques.

  16. Fireplace adapters

    SciTech Connect

    Hunt, R.L.

    1983-12-27

    An adapter is disclosed for use with a fireplace. The stove pipe of a stove standing in a room to be heated may be connected to the flue of the chimney so that products of combustion from the stove may be safely exhausted through the flue and outwardly of the chimney. The adapter may be easily installed within the fireplace by removing the damper plate and fitting the adapter to the damper frame. Each of a pair of bolts has a portion which hooks over a portion of the damper frame and a threaded end depending from the hook portion and extending through a hole in the adapter. Nuts are threaded on the bolts and are adapted to force the adapter into a tight fit with the adapter frame.

  17. Making Accurate Topographic Maps of the Schoolyard Using Ideas and Techniques Learned and Adapted from Multi-beam Sonar Mapping of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Fuerst, S. I.; Roberts, J. D.

    2010-12-01

    Having participated in a University of Rhode Island Project Armada expedition to join the University of New Hampshire Center for Coastal and Oceanographic Studies in making multi-beam sonar contour maps of the Arctic Ocean floor, I was able to bring the principles learned from this trip to my earth science high school students and create a project in our "mapping the earth" unit. Students learn basic surveying techniques and create authentic, accurately detailed topographic maps of the schoolyard. Models of their maps are then constructed of either Styrofoam or wood which enables them to make the transition from a 2-dimensional map to a 3-dimensional representation. Even though our maps are created using sticks, line levels, compasses and GPS, the scientific concepts of using location and elevation data to draw contour lines are identical to those used in underwater mapping. Once the students understand the science in mapping and creating contour maps to scale on graph paper by hand, they are able to easily relate this knowledge to what I was doing onboard ship using multi-beam sonar and computer mapping programs. We would like to share with you the lab and techniques that we have developed to make this activity possible with minimal materials and simple technology. As a background extension, it is also possible to replicate sonar measurements using an aquarium, food coloring, and a surface grid to map the topography of a teacher created landscape on the aquarium bottom. Earth Science students using simple tools to accurately map the topography of the school grounds

  18. An empirical evaluation of three vibrational spectroscopic methods for detection of aflatoxins in maize.

    PubMed

    Lee, Kyung-Min; Davis, Jessica; Herrman, Timothy J; Murray, Seth C; Deng, Youjun

    2015-04-15

    Three commercially available vibrational spectroscopic techniques, including Raman, Fourier transform near infrared reflectance (FT-NIR), and Fourier transform infrared (FTIR) were evaluated to help users determine the spectroscopic method best suitable for aflatoxin analysis in maize (Zea mays L.) grain based on their relative efficiency and predictive ability. Spectral differences of Raman and FTIR spectra were more marked and pronounced among aflatoxin contamination groups than those of FT-NIR spectra. From the observations and findings in our current and previous studies, Raman and FTIR spectroscopic methods are superior to FT-NIR method in terms of predictive power and model performance for aflatoxin analysis and they are equally effective and accurate in predicting aflatoxin concentration in maize. The present study is considered as the first attempt to assess how spectroscopic techniques with different physical processes can influence and improve accuracy and reliability for rapid screening of aflatoxin contaminated maize samples.

  19. Terahertz spectroscopic imaging of a rabbit VX2 hepatoma model

    NASA Astrophysics Data System (ADS)

    Park, Jae Yeon; Choi, Hyuck Jae; Cho, Kyoung-Sik; Kim, Kyu-Rae; Son, Joo-Hiuk

    2011-03-01

    Terahertz (THz) spectroscopic imaging technique was applied to classify the tumor region in the rabbit liver with VX2 hepatocellular carcinoma. Within the measurement range of 0.1-2 THz, the average reflectance values for all tumor samples were more than 4% higher than those for healthy cells, and the terahertz measurements correlated well with histological analysis results. This study on paraffin-embedded tissues showed the alteration of cell density and protein content in tumors, excluding the effect of water.

  20. The 1997 spectroscopic GEISA databank.

    NASA Astrophysics Data System (ADS)

    Jacquinet-Husson, N.; Arie, E.; Ballard, J.; Barbe, A.; Bjoraker, G.; Bonnet, B.; Brown, L. R.; Camy-Peyret, C.; Champion, J. P.; Chedin, A.; Chursin, A.; Clerbaux, C.; Duxbury, G.; Flaud, J.-M.; Fourrie, N.; Fayt, A.; Graner, G.; Gamache, R.; Goldman, A.; Golovko, V.; Guelachvili, G.; Hartmann, J. M.; Hilico, J. C.; Hillman, J.; Lefevre, G.; Lellouch, E.; Mikhailenko, S. N.; Naumenko, O. V.; Nemtchinov, V.; Newnham, D. A.; Nikitin, A.; Orphal, J.; Perrin, A.; Reuter, D. C.; Rinsland, C. P.; Rosenmann, L.; Rothman, L. S.; Scott, N. A.; Selby, J.; Sinitsa, L. N.; Sirota, J. M.; Smith, A. M.; Smith, K. M.; Tyuterev, V. G.; Tipping, R. H.; Urban, S.; Varanasi, P.; Weber, M.

    1999-05-01

    The current version GEISA-97 of the computer-accessible database system GEISA (Gestion et Etude des Informations Spectroscopiques Atmospheriques: Management and Study of Atmospheric Spectroscopic Information) is described. This catalogue contains 1,346,266 entries. These are the spectroscopic parameters required to describe adequately the individual spectral lines belonging to 42 molecules (96 isotopic species) and located between 0 and 22656 cm-1. The featured molecules are of interest in studies of the terrestrial as well as the other planetary atmospheres, especially those of the giant planets. GEISA-97 contains also a catalog of absorption cross-sections of molecules such as chlorofluorocarbons which exhibit unresolvable spectra. The modifications and improvements made to the earlier edition (GEISA-92) and the data management software are described.

  1. Mid-infrared spectroscopic investigation

    NASA Technical Reports Server (NTRS)

    Salisbury, John W.; Vergo, Norma; Walter, Louis

    1987-01-01

    Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed.

  2. Spectroscopic ellipsometry on lamellar gratings

    NASA Astrophysics Data System (ADS)

    Antos, R.; Ohlidal, I.; Mistrik, J.; Murakami, K.; Yamaguchi, T.; Pistora, J.; Horie, M.; Visnovsky, S.

    2005-05-01

    Deep lamellar diffraction gratings fabricated by etching a transparent quartz plate are studied using spectroscopic ellipsometry. The rigorous coupled-wave analysis is used to calculate the optical response of the gratings. Three parameters of the rectangular profile are determined by utilizing the least-square method. Detailed investigation of the spectral dependences demonstrates the uniqueness of the solution. Observing the spectral dependences of Wood anomalies suggests that even complicated profiles can be fitted with high authenticity.

  3. Single nanoparticle tracking spectroscopic microscope

    DOEpatents

    Yang, Haw; Cang, Hu; Xu, Cangshan; Wong, Chung M.

    2011-07-19

    A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

  4. An adaptive computer vision technique for estimating the biomass and density of loblolly pine plantations using digital orthophotography and LiDAR imagery

    NASA Astrophysics Data System (ADS)

    Bortolot, Zachary J.

    Forests have been proposed as a means of reducing atmospheric carbon dioxide levels due to their ability to store carbon as biomass. To quantify the amount of atmospheric carbon sequestered by forests, biomass and density estimates are oven needed. This study develops, implements, and tests an individual tree-based algorithm for obtaining forest density and biomass using orthophotographs and small footprint LiDAR imagery. It was designed to work with a range of forests and image types without modification, which is accomplished by using generic properties of trees found in many types of images. Multiple parameters are employed to determine how these generic properties are used. To set these parameters, training data is used in conjunction with an optimization algorithm (a modified Nelder-Mead simplex algorithm or a genetic algorithm). The training data consist of small images in which density and biomass are known. A first test of this technique was performed using 25 circular plots (radius = 15 m) placed in young pine plantations in central Virginia, together with false color orthophotograph (spatial resolution = 0.5 m) or small footprint LiDAR (interpolated to 0.5 m) imagery. The highest density prediction accuracies (r2 up to 0.88, RMSE as low as 83 trees/ha) were found for runs where photointerpreted densities were used for training and testing. For tests run using density measurements made on the ground, accuracies were consistency higher for orthophotograph-based results than for LiDAR-based results, and were higher for trees with DBH ≥10cm than for trees with DBH ≥7 cm. Biomass estimates obtained by the algorithm using LiDAR imagery had a lower RMSE (as low as 15.6 t/ha) than most comparable studies. The correlations between the actual and predicted values (r2 up to 0.64) were lower than comparable studies, but were generally highly significant (p ≤ 0.05 or 0.01). In all runs there was no obvious sensitive to which training and testing data were

  5. An adaptive technique for multiscale approximate entropy (MAEbin) threshold (r) selection: application to heart rate variability (HRV) and systolic blood pressure variability (SBPV) under postural stress.

    PubMed

    Singh, Amritpal; Saini, Barjinder Singh; Singh, Dilbag

    2016-06-01

    Multiscale approximate entropy (MAE) is used to quantify the complexity of a time series as a function of time scale τ. Approximate entropy (ApEn) tolerance threshold selection 'r' is based on either: (1) arbitrary selection in the recommended range (0.1-0.25) times standard deviation of time series (2) or finding maximum ApEn (ApEnmax) i.e., the point where self-matches start to prevail over other matches and choosing the corresponding 'r' (rmax) as threshold (3) or computing rchon by empirically finding the relation between rmax, SD1/SD2 ratio and N using curve fitting, where, SD1 and SD2 are short-term and long-term variability of a time series respectively. None of these methods is gold standard for selection of 'r'. In our previous study [1], an adaptive procedure for selection of 'r' is proposed for approximate entropy (ApEn). In this paper, this is extended to multiple time scales using MAEbin and multiscale cross-MAEbin (XMAEbin). We applied this to simulations i.e. 50 realizations (n = 50) of random number series, fractional Brownian motion (fBm) and MIX (P) [1] series of data length of N = 300 and short term recordings of HRV and SBPV performed under postural stress from supine to standing. MAEbin and XMAEbin analysis was performed on laboratory recorded data of 50 healthy young subjects experiencing postural stress from supine to upright. The study showed that (i) ApEnbin of HRV is more than SBPV in supine position but is lower than SBPV in upright position (ii) ApEnbin of HRV decreases from supine i.e. 1.7324 ± 0.112 (mean ± SD) to upright 1.4916 ± 0.108 due to vagal inhibition (iii) ApEnbin of SBPV increases from supine i.e. 1.5535 ± 0.098 to upright i.e. 1.6241 ± 0.101 due sympathetic activation (iv) individual and cross complexities of RRi and systolic blood pressure (SBP) series depend on time scale under consideration (v) XMAEbin calculated using ApEnmax is correlated with cross-MAE calculated using ApEn (0.1-0.26) in steps of 0

  6. Spectroscopic Needs for Imaging Dark Energy Experiments

    SciTech Connect

    Newman, Jeffrey A.; Slosar, Anze; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; Blanton, Michael R.; Brodwin, Mark; Brownstein, Joel R.; Brunner, Robert J.; Carrasco-Kind, Matias; Cervantes-Cota, Jorge; Chisari, Nora Elisa; Colless, Matthew; Comparat, Johan; Coupon, Jean; Cheu, Elliott; Cunha, Carlos E.; de la Macorra, Alex; Dell’Antonio, Ian P.; Frye, Brenda L.; Gawiser, Eric J.; Gehrels, Neil; Grady, Kevin; Hagen, Alex; Hall, Patrick B.; Hearin, Andrew P.; Hildebrandt, Hendrik; Hirata, Christopher M.; Ho, Shirley; Honscheid, Klaus; Huterer, Dragan; Ivezic, Zeljko; Kneib, Jean -Paul; Kruk, Jeffrey W.; Lahav, Ofer; Mandelbaum, Rachel; Marshall, Jennifer L.; Matthews, Daniel J.; Menard, Brice; Miquel, Ramon; Moniez, Marc; Moos, H. W.; Moustakas, John; Papovich, Casey; Peacock, John A.; Park, Changbom; Rhodes, Jason; Sadeh, Iftach; Schmidt, Samuel J.; Stern, Daniel K.; Tyson, J. Anthony; von der Linden, Anja; Wechsler, Risa H.; Wood-Vasey, W. M.; Zentner, A.

    2015-03-15

    Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z’s): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z’s will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes: Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our “training set” of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments; Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20 arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce scatter

  7. Spectroscopic Needs for Imaging Dark Energy Experiments

    DOE PAGES

    Newman, Jeffrey A.; Slosar, Anze; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; et al

    2015-03-15

    Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z’s): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z’s will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large setsmore » of objects with spectroscopically-determined redshifts, for two purposes: Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our “training set” of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments; Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20 arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce

  8. Interaction studies of Epirubicin with DNA using spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Charak, Sonika; Jangir, Deepak K.; Tyagi, Gunjan; Mehrotra, Ranjana

    2011-08-01

    Epirubicin (EPR) is an anticancer chemotherapeutic drug which exerts its cytotoxic effect by inhibiting DNA synthesis and DNA replication. We report the structural and conformational effect of EPR binding on DNA duplex under physiological conditions. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-visible) spectroscopy and circular dichroism (CD) spectroscopy were used to determine the binding mode and binding constant of EPR with DNA. The effect of EPR-DNA complexation on stability and secondary structure of DNA was studied. FTIR measurements showed that EPR-DNA interaction occurs through guanine and cytosine bases. External binding of EPR with DNA was observed through phosphate backbone. UV-visible measurements revealed the intercalative mode of binding of EPR with DNA. The binding constant was estimated to be K = 3.4 × 10 4 which is indicative of moderate binding between EPR and DNA helix. FTIR and CD studies suggested partial transition from B-conformation of DNA to A-conformation of DNA after EPR binding to DNA duplex.

  9. Characterization of used mineral oil condition by spectroscopic techniques.

    PubMed

    Vanhanen, Jarmo; Rinkiö, Marcus; Aumanen, Jukka; Korppi-Tommola, Jouko; Kolehmainen, Erkki; Kerkkänen, Tuula; Törmä, Päivi

    2004-08-20

    Optical absorption, fluorescence, and quantitative 13C NMR spectroscopy have been used to study the degradation of mineral gearbox oil. Samples of used oil were collected from field service. Measured absorption, fluorescence, and quantitative 13C NMR spectra of used oils show characteristic changes from the spectra of a fresh oil sample. A clearly observable, approximately 20-nm blueshift of the fluorescence emission occurs during the early stages of oil use and correlates with changes in intensity of some specific 13C NMR resonance lines. These changes correlate with oil age because of the connection between the blueshift and breaking of the larger conjugated hydrocarbons of oil as a result of use.

  10. Raman Spectroscopic Techniques for Planetary Exploration: Detecting Microorganisms through Minerals.

    PubMed

    Verkaaik, Mattheus F C; Hooijschuur, Jan-Hein; Davies, Gareth R; Ariese, Freek

    2015-08-01

    Raman spectroscopy can provide highly specific chemical fingerprints of inorganic and organic materials and is therefore expected to play a significant role in interplanetary missions, especially for the search for life elsewhere in our solar system. A major challenge will be the unambiguous detection of low levels of biomarkers on a mineral background. In addition, these biomarkers may not be present at the surface but rather inside or underneath minerals. Strong scattering may prevent focusing deeper into the sample. In this paper, we report the detection of carotenoid-containing microorganisms behind mineral layers using time-resolved Raman spectroscopy (TRRS). Two extremophiles, the bacterium Deinococcus radiodurans and the cyanobacterium Chroococcidiopsis, were detected through translucent and transparent minerals using 440 nm excitation under resonance conditions to selectively enhance the detection of carotenoids. Using 3 ps laser pulses and a 250 ps gated intensified CCD camera provided depth selectivity for the subsurface microorganisms over the mineral surface layer and in addition lowered the contribution of the fluorescent background. Raman spectra of both organisms could be detected through 5 mm of translucent calcite or 20 mm of transparent halite. Multilayered mineral samples were used to further test the applied method. A separate tunable laser setup for resonance Raman and a commercial confocal Raman microscope, both with continuous (non-gated) detection, were used for comparison. This study demonstrates the capabilities of TRRS for the depth-selective analysis through scattering samples, which could be used in future planetary exploration to detect microorganisms or biomarkers within or behind minerals.

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

    SciTech Connect

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

    2009-09-01

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

  12. Raman Spectroscopic Techniques for Planetary Exploration: Detecting Microorganisms through Minerals.

    PubMed

    Verkaaik, Mattheus F C; Hooijschuur, Jan-Hein; Davies, Gareth R; Ariese, Freek

    2015-08-01

    Raman spectroscopy can provide highly specific chemical fingerprints of inorganic and organic materials and is therefore expected to play a significant role in interplanetary missions, especially for the search for life elsewhere in our solar system. A major challenge will be the unambiguous detection of low levels of biomarkers on a mineral background. In addition, these biomarkers may not be present at the surface but rather inside or underneath minerals. Strong scattering may prevent focusing deeper into the sample. In this paper, we report the detection of carotenoid-containing microorganisms behind mineral layers using time-resolved Raman spectroscopy (TRRS). Two extremophiles, the bacterium Deinococcus radiodurans and the cyanobacterium Chroococcidiopsis, were detected through translucent and transparent minerals using 440 nm excitation under resonance conditions to selectively enhance the detection of carotenoids. Using 3 ps laser pulses and a 250 ps gated intensified CCD camera provided depth selectivity for the subsurface microorganisms over the mineral surface layer and in addition lowered the contribution of the fluorescent background. Raman spectra of both organisms could be detected through 5 mm of translucent calcite or 20 mm of transparent halite. Multilayered mineral samples were used to further test the applied method. A separate tunable laser setup for resonance Raman and a commercial confocal Raman microscope, both with continuous (non-gated) detection, were used for comparison. This study demonstrates the capabilities of TRRS for the depth-selective analysis through scattering samples, which could be used in future planetary exploration to detect microorganisms or biomarkers within or behind minerals. PMID:26186197

  13. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  14. In vivo evaluation of the penetration of topically applied drugs into human skin by spectroscopic methods.

    PubMed

    Sennhenn, B; Giese, K; Plamann, K; Harendt, N; Kölmel, K

    1993-01-01

    Spectroscopic techniques are reported on which allow to study in vivo the penetration behaviour of topically applied light-absorbing drugs into human skin. Remittance spectroscopy, a purely optical method, provides a good tool in both, skin adaptation by use of a remote viewing head coupled to the spectrometer via optical fibres, and adequate sensitivity for the detection of small amounts of the applied drugs. The measuring depth in the skin is determined by the wavelength-dependent optical penetration depth, which itself depends on light absorption and light scattering. In the UV-spectral region the optical penetration depth is of the order of the thickness of the stratum corneum (UV-A) or of only a superficial part of it (UV-B, UV-C). Fluorescence spectroscopy, another optical method, offers two kinds of drug detection, a direct one in case of self-fluorescent drugs or an indirect one being based on the light absorption of the drug, which may give rise to a screening of the self-fluorescence of the skin itself or of an applied marker. The measuring depth is comparable to that achieved with remittance spectroscopy. A third method is photothermal spectroscopy which is determined by thermal properties of the skin in addition to optical properties. Photothermal spectroscopy is unique in that it allows depth profiles of drug concentration to be measured non-invasively, as the photothermal measuring depth can be changed by varying the modulation frequency of the intensity-modulated incident light. Results of measurements demonstrating the potentials of these spectroscopic methods are presented.

  15. Adaptive Computing.

    ERIC Educational Resources Information Center

    Harrell, William

    1999-01-01

    Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

  16. Does DFT-SAPT method provide spectroscopic accuracy?

    SciTech Connect

    Shirkov, Leonid; Makarewicz, Jan

    2015-02-14

    Ground state potential energy curves for homonuclear and heteronuclear dimers consisting of noble gas atoms from He to Kr were calculated within the symmetry adapted perturbation theory based on the density functional theory (DFT-SAPT). These potentials together with spectroscopic data derived from them were compared to previous high-precision coupled cluster with singles and doubles including the connected triples theory calculations (or better if available) as well as to experimental data used as the benchmark. The impact of midbond functions on DFT-SAPT results was tested to study the convergence of the interaction energies. It was shown that, for most of the complexes, DFT-SAPT potential calculated at the complete basis set (CBS) limit is lower than the corresponding benchmark potential in the region near its minimum and hence, spectroscopic accuracy cannot be achieved. The influence of the residual term δ(HF) on the interaction energy was also studied. As a result, we have found that this term improves the agreement with the benchmark in the repulsive region for the dimers considered, but leads to even larger overestimation of potential depth D{sub e}. Although the standard hybrid exchange-correlation (xc) functionals with asymptotic correction within the second order DFT-SAPT do not provide the spectroscopic accuracy at the CBS limit, it is possible to adjust empirically basis sets yielding highly accurate results.

  17. Adaptable Multivariate Calibration Models for Spectral Applications

    SciTech Connect

    THOMAS,EDWARD V.

    1999-12-20

    Multivariate calibration techniques have been used in a wide variety of spectroscopic situations. In many of these situations spectral variation can be partitioned into meaningful classes. For example, suppose that multiple spectra are obtained from each of a number of different objects wherein the level of the analyte of interest varies within each object over time. In such situations the total spectral variation observed across all measurements has two distinct general sources of variation: intra-object and inter-object. One might want to develop a global multivariate calibration model that predicts the analyte of interest accurately both within and across objects, including new objects not involved in developing the calibration model. However, this goal might be hard to realize if the inter-object spectral variation is complex and difficult to model. If the intra-object spectral variation is consistent across objects, an effective alternative approach might be to develop a generic intra-object model that can be adapted to each object separately. This paper contains recommendations for experimental protocols and data analysis in such situations. The approach is illustrated with an example involving the noninvasive measurement of glucose using near-infrared reflectance spectroscopy. Extensions to calibration maintenance and calibration transfer are discussed.

  18. Climate adaptation

    NASA Astrophysics Data System (ADS)

    Kinzig, Ann P.

    2015-03-01

    This paper is intended as a brief introduction to climate adaptation in a conference devoted otherwise to the physics of sustainable energy. Whereas mitigation involves measures to reduce the probability of a potential event, such as climate change, adaptation refers to actions that lessen the impact of climate change. Mitigation and adaptation differ in other ways as well. Adaptation does not necessarily have to be implemented immediately to be effective; it only needs to be in place before the threat arrives. Also, adaptation does not necessarily require global, coordinated action; many effective adaptation actions can be local. Some urban communities, because of land-use change and the urban heat-island effect, currently face changes similar to some expected under climate change, such as changes in water availability, heat-related morbidity, or changes in disease patterns. Concern over those impacts might motivate the implementation of measures that would also help in climate adaptation, despite skepticism among some policy makers about anthropogenic global warming. Studies of ancient civilizations in the southwestern US lends some insight into factors that may or may not be important to successful adaptation.

  19. Spectroscopic signature for ferroelectric ice

    NASA Astrophysics Data System (ADS)

    Wójcik, Marek J.; Gług, Maciej; Boczar, Marek; Boda, Łukasz

    2014-09-01

    Various forms of ice exist within our galaxy. Particularly intriguing type of ice - ‘ferroelectric ice' was discovered experimentally and is stable in temperatures below 72 K. This form of ice can generate enormous electric fields and can play an important role in planetary formation. In this letter we present Car-Parrinello simulation of infrared spectra of ferroelectric ice and compare them with spectra of hexagonal ice. Librational region of the spectra can be treated as spectroscopic signature of ice XI and can be of help to identify ferroelectric ice in the Universe.

  20. Spectroscopic Survey of Cool Stars

    NASA Astrophysics Data System (ADS)

    Linsky, J.

    This program will obtain far-UV spectra of cool stars that span a broad range of spectral type and luminosity class. It is our intention to obtain these spectra early in the FUSE program and to provide the spectra quickly to the user community in order to guide potential guest investigators in designing their observing programs. The specific science objectives include: (1) studying transition region dynamics (winds and downflows), (2) modeling the thermal structure of transition regions, (3) measuring electron densities, (4) search for low temperature coronae, (5) studying molecular excitation and fluorescence processes, and (6) inferring how the transition regions of spectroscopic binary systems differ from those of single stars.

  1. The far ultraviolet spectroscopic explorer

    NASA Technical Reports Server (NTRS)

    Boggess, A.

    1982-01-01

    The scientific objectives and performance characteristics of a new astronomy mission referred to as the far ultraviolet spectroscopic explorer, or FUSE are being defined by a team involving people experienced instrumental requirements that best meet the scientific needs. The team is intended to have a lifetime of about one year, ending with the submission of a report to NASA which could be used as the basis for an engineering design study. The principal objective of FUSE is to obtain astronomical spectra at wavelengths shorter than is possible with the Space Telescope.

  2. Spectroscopic Classifications of Optical Transients with SOAR

    NASA Astrophysics Data System (ADS)

    Foley, R. J.; Hounsell, R. A.; Downing, S.; Pan, Y.-C.; Scolnic, D.; Jha, S. W.; Rest, A.; Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.

    2015-07-01

    We report the following classifications of optical transients from spectroscopic observations with the Goodman spectrograph (wavelength range 3100 - 7100) on the Southern Astrophysical Research (SOAR) telescope.

  3. Spectroscopic imaging of serum proteins using quantum cascade lasers.

    PubMed

    Mukherjee, Anadi; Bylund, Quentin; Prasanna, Manu; Margalit, Yotam; Tihan, Tarik

    2013-03-01

    First measurements of biomedical imaging using quantum cascade lasers (QCL) are presented. We report spectroscopic imaging of serum proteins using QCLs as an example for monitoring surface biocontamination. We found that dry smears of human serum can be spectroscopically imaged, identified, and quantified with high sensitivity and specificity. The core parts of the imaging platform consist of optically multiplexing three QCLs and an uncooled microbolometer camera. We show imaging of human serum proteins at 6.1, 9.25, and 9.5 μm QCLs with high sensitivity and specificity. The sensitivity limit of 3  μg/cm² of the human serum spot was measured at an S/N=3.The specificity of human serum detection was measured at 99% probability at a threshold of 77  μg/cm². We anticipate our imaging technique to be a starting point for more sophisticated biomolecular diagnostic applications.

  4. Spectroscopic studies of the several isomers of UO3

    NASA Astrophysics Data System (ADS)

    Sweet, Lucas E.; Reilly, Dallas D.; Abrecht, David G.; Buck, Edgar C.; Meier, David E.; Su, Yin-Fong; Brauer, Carolyn S.; Schwantes, Jon M.; Tonkyn, Russell G.; Szecsody, James E.; Blake, Thomas A.; Johnson, Timothy J.

    2013-10-01

    Uranium trioxide is known to adopt seven different structural forms. While these structural forms have been well characterized using x-ray or neutron diffraction techniques, little work has been done to characterize their spectroscopic properties, particularly of the pure phases. Since the structural isomers of UO3 all have similar thermodynamic stabilities and most tend to hydrolyze under open atmospheric conditions, mixtures of UO3 phases and the hydrolysis products are common. Much effort went into isolating pure phases of UO3. Utilizing x-ray diffraction as a sample identification check, UV/Vis/NIR spectroscopic signatures of α-UO3, β-UO3, γ-UO3 and α-UO2(OH)2 products were obtained. The spectra of the pure phases can now be used to characterize typical samples of UO3, which are often mixtures of isomers.

  5. Spectroscopic Studies of the Several Isomers of UO3

    SciTech Connect

    Sweet, Lucas E.; Reilly, Dallas D.; Abrecht, David G.; Buck, Edgar C.; Meier, David E.; Su, Yin-Fong; Brauer, Carolyn S.; Schwantes, Jon M.; Tonkyn, Russell G.; Szecsody, James E.; Blake, Thomas A.; Johnson, Timothy J.

    2013-09-26

    Uranium trioxide is known to adopt seven different structural forms. While these structural forms have been well characterized using x-ray or neutron diffraction techniques, little work has been done to characterize their spectroscopic properties, particularly of the pure phases. Since the structural isomers of UO3 all have similar thermodynamic stabilities and most tend to hydrolyze under open atmospheric conditions, mixtures of UO3 phases and the hydrolysis products are common. Much effort went into isolating pure phases of UO3. Utilizing x-ray diffraction as a sample identification check, UV/Vis/NIR spectroscopic signatures of α-UO3, β-UO3, γ-UO3 and UO2(OH)2 products were obtained. The spectra of the pure phases can now be used to characterize typical samples of UO3, which are often mixtures of isomers.

  6. Adaptive passive fathometer processing.

    PubMed

    Siderius, Martin; Song, Heechun; Gerstoft, Peter; Hodgkiss, William S; Hursky, Paul; Harrison, Chris

    2010-04-01

    Recently, a technique has been developed to image seabed layers using the ocean ambient noise field as the sound source. This so called passive fathometer technique exploits the naturally occurring acoustic sounds generated on the sea-surface, primarily from breaking waves. The method is based on the cross-correlation of noise from the ocean surface with its echo from the seabed, which recovers travel times to significant seabed reflectors. To limit averaging time and make this practical, beamforming is used with a vertical array of hydrophones to reduce interference from horizontally propagating noise. The initial development used conventional beamforming, but significant improvements have been realized using adaptive techniques. In this paper, adaptive methods for this process are described and applied to several data sets to demonstrate improvements possible as compared to conventional processing.

  7. Spectroscopic Engineering in the Submillimeter

    NASA Astrophysics Data System (ADS)

    De Lucia, Frank C.

    2013-06-01

    The field of high-resolution spectroscopy, as represented by the community that supports this meeting, has continued to grow and prosper, in no small part because the field has continued to evolve. Much of this evolution could fall under the rubric, Spectroscopic Engineering. This is especially true in the submillimeter where spectroscopists have taken on much broader roles in fields that have grown out of submillimeter spectroscopy. With specific examples from spectroscopic remote and point sensing, astronomy and atmospheric science, imaging, and process control, opportunities and paths forward for will be considered. Emphasis will be placed on the underlying physics that drives the optimization of applications. Since this is Columbus, at least one complex Hamiltonian will be shown. We will also discuss: What are the opportunities for young people entering the field and how might they be optimized? Is spectroscopy as a tool, less noble than spectroscopy as a science? Is what we do really physics (or even chemistry)? Where does what we do fit into the structure of academia, government, and industry?

  8. Spectroscopic imaging in electron microscopy

    SciTech Connect

    Pennycook, Stephen J; Colliex, C.

    2012-01-01

    In the scanning transmission electron microscope, multiple signals can be simultaneously collected, including the transmitted and scattered electron signals (bright field and annular dark field or Z-contrast images), along with spectroscopic signals such as inelastically scattered electrons and emitted photons. In the last few years, the successful development of aberration correctors for the electron microscope has transformed the field of electron microscopy, opening up new possibilities for correlating structure to functionality. Aberration correction not only allows for enhanced structural resolution with incident probes into the sub-angstrom range, but can also provide greater probe currents to facilitate mapping of intrinsically weak spectroscopic signals at the nanoscale or even the atomic level. In this issue of MRS Bulletin, we illustrate the power of the new generation of electron microscopes with a combination of imaging and spectroscopy. We show the mapping of elemental distributions at atomic resolution and also the mapping of electronic and optical properties at unprecedented spatial resolution, with applications ranging from graphene to plasmonic nanostructures, and oxide interfaces to biology.

  9. Verification of Adaptive Systems

    SciTech Connect

    Pullum, Laura L; Cui, Xiaohui; Vassev, Emil; Hinchey, Mike; Rouff, Christopher; Buskens, Richard

    2012-01-01

    Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance for them. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

  10. Toothbrush Adaptations.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1987

    1987-01-01

    Suggestions are presented for helping disabled individuals learn to use or adapt toothbrushes for proper dental care. A directory lists dental health instructional materials available from various organizations. (CB)

  11. Adaptive processing for LANDSAT data

    NASA Technical Reports Server (NTRS)

    Crane, R. B.; Reyer, J. F.

    1975-01-01

    Analytical and test results on the use of adaptive processing on LANDSAT data are presented. The Kalman filter was used as a framework to contain different adapting techniques. When LANDSAT MSS data were used all of the modifications made to the Kalman filter performed the functions for which they were designed. It was found that adaptive processing could provide compensation for incorrect signature means, within limits. However, if the data were such that poor classification accuracy would be obtained when the correct means were used, then adaptive processing would not improve the accuracy and might well lower it even further.

  12. Nonchemical decontamination techniques

    SciTech Connect

    Allen, R.P.

    1985-06-01

    The decontamination techniques summarized in this article represent a variety of surface cleaning methods developed or adapted for component and facility-type decontamination applications ranging from small hand tools to reactor cavities and other large surface areas. Representative nonchemical decontamination techniques include: ultrasonics, abrasive cleaning, high-pressure Freon cleaning, and vibratory finishing.

  13. Adaptive differential pulse-code modulation with adaptive bit allocation

    NASA Astrophysics Data System (ADS)

    Frangoulis, E. D.; Yoshida, K.; Turner, L. F.

    1984-08-01

    Studies have been conducted regarding the possibility to obtain good quality speech at data rates in the range from 16 kbit/s to 32 kbit/s. The techniques considered are related to adaptive predictive coding (APC) and adaptive differential pulse-code modulation (ADPCM). At 16 kbit/s adaptive transform coding (ATC) has also been used. The present investigation is concerned with a new method of speech coding. The described method employs adaptive bit allocation, similar to that used in adaptive transform coding, together with adaptive differential pulse-code modulation, employing first-order prediction. The new method has the objective to improve the quality of the speech over that which can be obtained with conventional ADPCM employing a fourth-order predictor. Attention is given to the ADPCM-AB system, the design of a subjective test, and the application of switched preemphasis to ADPCM.

  14. The Hubble Spectroscopic Legacy Archive

    NASA Astrophysics Data System (ADS)

    Peeples, Molly S.; Tumlinson, Jason; Fox, Andrew; Aloisi, Alessandra; Ayres, Thomas R.; Danforth, Charles; Fleming, Scott W.; Jenkins, Edward B.; Jedrzejewski, Robert I.; Keeney, Brian A.; Oliveira, Cristina M.

    2016-01-01

    With no future space ultraviolet instruments currently planned, the data from the UV spectrographs aboard the Hubble Space Telescope have a legacy value beyond their initial science goals. The Hubble Spectroscopic Legacy Archive will provide to the community new science-grade combined spectra for all publicly available data obtained by the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS). These data will be packaged into "smart archives" according to target type and scientific themes to facilitate the construction of archival samples for common science uses. A new "quick look" capability will make the data easy for users to quickly access, assess the quality of, and download for archival science starting in Cycle 24, with the first generation of these products for the FUV modes of COS available online via MAST in early 2016.

  15. Multifunction Imaging and Spectroscopic Instrument

    NASA Technical Reports Server (NTRS)

    Mouroulis, Pantazis

    2004-01-01

    A proposed optoelectronic instrument would perform several different spectroscopic and imaging functions that, heretofore, have been performed by separate instruments. The functions would be reflectance, fluorescence, and Raman spectroscopies; variable-color confocal imaging at two different resolutions; and wide-field color imaging. The instrument was conceived for use in examination of minerals on remote planets. It could also be used on Earth to characterize material specimens. The conceptual design of the instrument emphasizes compactness and economy, to be achieved largely through sharing of components among subsystems that perform different imaging and spectrometric functions. The input optics for the various functions would be mounted in a single optical head. With the exception of a targeting lens, the input optics would all be aimed at the same spot on a specimen, thereby both (1) eliminating the need to reposition the specimen to perform different imaging and/or spectroscopic observations and (2) ensuring that data from such observations can be correlated with respect to known positions on the specimen. The figure schematically depicts the principal components and subsystems of the instrument. The targeting lens would collect light into a multimode optical fiber, which would guide the light through a fiber-selection switch to a reflection/ fluorescence spectrometer. The switch would have four positions, enabling selection of spectrometer input from the targeting lens, from either of one or two multimode optical fibers coming from a reflectance/fluorescence- microspectrometer optical head, or from a dark calibration position (no fiber). The switch would be the only moving part within the instrument.

  16. A newly adapted pulsed-field gel electrophoresis technique allows to detect distinct types of DNA damage at low frequencies in human dermal fibroblasts upon exposure to non-toxic H2O2 concentrations.

    PubMed

    Brenneisen, P; Wenk, J; Wlaschek, M; Blaudschun, R; Scharffetter-Kochanek, K

    1999-11-01

    Reactive oxygen species (ROS) comprise several oxygen containing compounds, among them hydrogen peroxide (H2O2), which are generated by internal and external sources and play pleiotropic roles in physiological and pathological states. Skin cells as well as cells from other tissues have developed antioxidant defense mechanisms to protect themselves from high concentrations of ROS. Although biological and pathological roles of ROS have previously been elucidated, so far only limited knowledge exists regarding ROS-mediated generation of DNA breaks and base lesions occurring at low frequency in intact skin cells. This study was therefore designed to probe a newly adapted pulsed-field gel electrophoresis technique for the adequate measurement of high molecular weight DNA fragments as well as to investigate the protective role of the antioxidant enzyme catalase against H2O2-mediated damage in human dermal fibroblasts. We stably transfected and overexpressed the full-length catalase cDNA in the human dermal fibroblast cell line 1306 in culture and found that these cells are significantly more protected from cytotoxicity, overall DNA strand breaks, and 8-oxodeoxyguanine base lesions resulting from H2O2-triggered oxidative stress compared to vector-transfected 1306 cells or secondary dermal fibroblasts. This work has outlined the importance of catalase in the protection from H2O2-mediated cytotoxicity and DNA damage which--if unbalanced--even when occurring at low frequency are known to lead to genomic instability, a hallmark in carcinogenesis and premature aging.

  17. Spectroscopic Subsystems in Nearby Wide Binaries

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei

    2015-12-01

    Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5 m telescope to study short-period systems. The data reduction is described, and mean and individual RVs of 163 observed objects are given. New spectroscopic binaries are discovered or suspected in 17 objects, and for some of them the orbital periods could be determined. Subsystems are efficiently detected even in a single observation by double lines and/or by the RV difference between the components of visual binaries. The potential of this detection technique is quantified by simulation and used for statistical assessment of 96 wide binaries within 67 pc. It is found that 43 binaries contain at least one subsystem, and the occurrence of subsystems is equally probable in either primary or secondary components. The frequency of subsystems and their periods matches the simple prescription proposed by the author. The remaining 53 simple wide binaries with a median projected separation of 1300 AU have an RV difference distribution between their components that is not compatible with the thermal eccentricity distribution f (e) = 2e but rather matches the uniform eccentricity distribution.

  18. SPECTROSCOPIC SUBSYSTEMS IN NEARBY WIDE BINARIES

    SciTech Connect

    Tokovinin, Andrei

    2015-12-15

    Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5 m telescope to study short-period systems. The data reduction is described, and mean and individual RVs of 163 observed objects are given. New spectroscopic binaries are discovered or suspected in 17 objects, and for some of them the orbital periods could be determined. Subsystems are efficiently detected even in a single observation by double lines and/or by the RV difference between the components of visual binaries. The potential of this detection technique is quantified by simulation and used for statistical assessment of 96 wide binaries within 67 pc. It is found that 43 binaries contain at least one subsystem, and the occurrence of subsystems is equally probable in either primary or secondary components. The frequency of subsystems and their periods matches the simple prescription proposed by the author. The remaining 53 simple wide binaries with a median projected separation of 1300 AU have an RV difference distribution between their components that is not compatible with the thermal eccentricity distribution f (e) = 2e but rather matches the uniform eccentricity distribution.

  19. IMPROVED SPECTROSCOPIC PARAMETERS FOR TRANSITING PLANET HOSTS

    SciTech Connect

    Torres, Guillermo; Holman, Matthew J.; Carter, Joshua A.; Fischer, Debra A.; Sozzetti, Alessandro; Buchhave, Lars A.; Winn, Joshua N.

    2012-10-01

    We report homogeneous spectroscopic determinations of the effective temperature, metallicity, and projected rotational velocity for the host stars of 56 transiting planets. Our analysis is based primarily on the stellar parameter classification (SPC) technique. We investigate systematic errors by examining subsets of the data with two other methods that have often been used in previous studies (Spectroscopy Made Easy (SME) and MOOG). The SPC and SME results, both based on comparisons between synthetic spectra and actual spectra, show strong correlations between T{sub eff}, [Fe/H], and log g when solving for all three quantities simultaneously. In contrast the MOOG results, based on a more traditional curve-of-growth approach, show no such correlations. To combat the correlations and improve the accuracy of the temperatures and metallicities, we repeat the SPC analysis with a constraint on log g based on the mean stellar density that can be derived from the analysis of the transit light curves. Previous studies that have not taken advantage of this constraint have been subject to systematic errors in the stellar masses and radii of up to 20% and 10%, respectively, which can be larger than other observational uncertainties, and which also cause systematic errors in the planetary mass and radius.

  20. A Raman spectroscopic approach for the cultivation-free identification of microbes

    NASA Astrophysics Data System (ADS)

    Rösch, Petra; Stöckel, Stephan; Meisel, Susann; Münchberg, Ute; Kloß, Sandra; Kusic, Dragana; Schumacher, Wilm; Popp, Jürgen

    2011-12-01

    In the last years the identification of microorganisms by means of different IR and Raman spectroscopic techniques has become quite popular. Most of the studies however apply the various vibrational spectroscopic methods to bulk samples which require at least a short cultivation time of several hours. Nevertheless, bulk identification methods achieve high classification rates which enable even the discrimination between closely related strains or the distinction between resistance capabilities. However, applying micro-Raman spectroscopy with visible excitation wavelengths enables for the detection of single microorganisms. Especially for time critical process like the fast diagnosis of severe diseases or the identification of bacterial contamination on food samples or pharmaceuticals, a cultivation-free identification of bacteria is required. In doing so, we established different isolation techniques in combination with Raman spectroscopic identification. Isolating bacteria from different matrixes always has an impact on the Raman spectroscopic identification capability. Therefore, these isolation techniques have to be specially designed to fulfill the spectroscopic requirements. In total the method should enable the identification of pathogens within the first 3 hours.

  1. Plant roots and spectroscopic methods - analyzing species, biomass and vitality.

    PubMed

    Rewald, Boris; Meinen, Catharina

    2013-01-01

    In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species' identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted.

  2. Spectroscopic Confirmation of a Massive Red-sequence Selected Galaxy Cluster at Z=1.34 in the SpARCS-South Cluster Survey

    NASA Technical Reports Server (NTRS)

    Wilson, Gillian; Demarco, Ricardo; Muzzin, Adam; Yee, H.K.C.; Lacy, Mark; Surace, Jason; Gilbank, David; Blindert, Kris; Hoekstra, Henk; Majumdar, Subhabrata; Gardner, Jonathan P; Gladders, Michael D.; Lonsdale, Carol

    2008-01-01

    The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z'-passband imaging survey, consisting of deep (z' approx. 24 AB) observations made from both hemispheres using the CFHT 3.6m and CTIO 4m telescopes. The survey was designed with the primary aim of detecting galaxy clusters at z > 1. In tandem with pre-existing 3.6 micron observations from the Spitzer Space Telescope SWIRE Legacy Survey, SpARCS detects clusters using an infrared adaptation of the two-filter red-sequence cluster technique. The total effective area of the SpARCS cluster survey is 41.9 sq deg. In this paper, we provide an overview of the 13.6 sq deg Southern CTIO/MOSAICII observations. The 28.3 sq deg Northern CFHT/MegaCam observations are summarized in a companion paper by Muzzin et al. (2008a). In this paper, we also report spectroscopic confirmation of SpARCS J003550-431224, a very rich galaxy cluster at z = 1.335, discovered in the ELAIS-S1 field. To date, this is the highest spectroscopically confirmed redshift for a galaxy cluster discovered using the red-sequence technique. Based on nine confirmed members, SpARCS J003550-431224 has a preliminary velocity dispersion of 1050+/-230 km/s. With its proven capability for efficient cluster detection, SpARCS is a demonstration that we have entered an era of large, homogeneously-selected z > 1 cluster surveys.

  3. Genomics of local adaptation with gene flow.

    PubMed

    Tigano, Anna; Friesen, Vicki L

    2016-05-01

    Gene flow is a fundamental evolutionary force in adaptation that is especially important to understand as humans are rapidly changing both the natural environment and natural levels of gene flow. Theory proposes a multifaceted role for gene flow in adaptation, but it focuses mainly on the disruptive effect that gene flow has on adaptation when selection is not strong enough to prevent the loss of locally adapted alleles. The role of gene flow in adaptation is now better understood due to the recent development of both genomic models of adaptive evolution and genomic techniques, which both point to the importance of genetic architecture in the origin and maintenance of adaptation with gene flow. In this review, we discuss three main topics on the genomics of adaptation with gene flow. First, we investigate selection on migration and gene flow. Second, we discuss the three potential sources of adaptive variation in relation to the role of gene flow in the origin of adaptation. Third, we explain how local adaptation is maintained despite gene flow: we provide a synthesis of recent genomic models of adaptation, discuss the genomic mechanisms and review empirical studies on the genomics of adaptation with gene flow. Despite predictions on the disruptive effect of gene flow in adaptation, an increasing number of studies show that gene flow can promote adaptation, that local adaptations can be maintained despite high gene flow, and that genetic architecture plays a fundamental role in the origin and maintenance of local adaptation with gene flow.

  4. Adaptive Development

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

  5. Study Of Adaptive-Array Signal Processing

    NASA Technical Reports Server (NTRS)

    Satorius, Edgar H.; Griffiths, Lloyd

    1990-01-01

    Report describes study of adaptive signal-processing techniques for suppression of mutual satellite interference in mobile (on ground)/satellite communication system. Presents analyses and numerical simulations of performances of two approaches to signal processing for suppression of interference. One approach, known as "adaptive side lobe canceling", second called "adaptive temporal processing".

  6. Adaptive management

    USGS Publications Warehouse

    Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  7. Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle.

    PubMed

    Guo, Junyu; Patay, Zoltan; Reddick, Wilburn E

    2016-01-01

    Magnetic resonance (MR) spectroscopic imaging has become an important tool in clinical settings for noninvasively obtaining spatial and metabolic information on a molecular scale. Conventional spectroscopic imaging is acquired in the time domain, and its clinical application is limited by the long acquisition time, restricted spatial coverage, and complex suppression and reconstruction procedures. We introduce a fast MR spectroscopic imaging technique in the frequency domain, termed phase-cycled spectroscopic imaging (PCSI). PCSI uses a balanced steady-state free precession (bSSFP) sequence with an ultra-low flip angle to achieve very high acquisition efficiency with a short repetition time. This approach enables faster frequency sweeping by changing the cycled RF phase and using flexible non-uniform sampling, and it greatly reduces the RF energy deposition in tissue. With its intrinsic water and fat suppression, PCSI more closely resembles routine clinical scans because it eliminates the suppression steps. We demonstrate that it is feasible to acquire PCSI spectra in a phantom and in humans and that PCSI provides an efficient spectroscopic imaging method, even for J-coupled metabolites. PCSI may enable spectroscopic imaging to play a larger role in the clinical assessment of the spatial tissue distribution of metabolites. PMID:27440077

  8. Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle

    PubMed Central

    Guo, Junyu; Patay, Zoltan; Reddick, Wilburn E.

    2016-01-01

    Magnetic resonance (MR) spectroscopic imaging has become an important tool in clinical settings for noninvasively obtaining spatial and metabolic information on a molecular scale. Conventional spectroscopic imaging is acquired in the time domain, and its clinical application is limited by the long acquisition time, restricted spatial coverage, and complex suppression and reconstruction procedures. We introduce a fast MR spectroscopic imaging technique in the frequency domain, termed phase-cycled spectroscopic imaging (PCSI). PCSI uses a balanced steady-state free precession (bSSFP) sequence with an ultra-low flip angle to achieve very high acquisition efficiency with a short repetition time. This approach enables faster frequency sweeping by changing the cycled RF phase and using flexible non-uniform sampling, and it greatly reduces the RF energy deposition in tissue. With its intrinsic water and fat suppression, PCSI more closely resembles routine clinical scans because it eliminates the suppression steps. We demonstrate that it is feasible to acquire PCSI spectra in a phantom and in humans and that PCSI provides an efficient spectroscopic imaging method, even for J-coupled metabolites. PCSI may enable spectroscopic imaging to play a larger role in the clinical assessment of the spatial tissue distribution of metabolites. PMID:27440077

  9. The Galactic O-Star Spectroscopic Survey (GOSSS). III. 142 Additional O-type Systems.

    NASA Astrophysics Data System (ADS)

    Maíz Apellániz, J.; Sota, A.; Arias, J. I.; Barbá, R. H.; Walborn, N. R.; Simón-Díaz, S.; Negueruela, I.; Marco, A.; Leão, J. R. S.; Herrero, A.; Gamen, R. C.; Alfaro, E. J.

    2016-05-01

    This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R ˜ 2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al. The GOSSS spectroscopic data in this article were gathered with five facilities: the 1.5 m Telescope at the Observatorio de Sierra Nevada (OSN), the 2.5 m du Pont Telescope at Las Campanas Observatory (LCO), the 3.5 m Telescope at Calar Alto Observatory (CAHA), and the 4.2 m William Herschel Telescope (WHT) and 10.4 m Gran Telescopio Canarias (GTC) at Observatorio del Roque de los Muchachos (ORM).

  10. Spectroscopic and dynamical studies of highly energized small polyatomic molecules

    SciTech Connect

    Field, R.W.; Silbey, R.J.

    1993-12-01

    The authors have initiated a program to perform spectroscopic and dynamic studies of small molecules. Large amplitude motions in excited acetylene were discussed along with plans to record the dispersed fluorescence (DF) and the stimulated emission pumping (SEP) spectra. SEP spectra were reported for the formyl radical. A Fourier transform spectrometer was discussed with respect to its ability to probe the structure of radicals. This instrument is capable of performing studies using various techniques such as magnetic rotation spectroscopy and sub-Doppler sideband-OODR Zeman (SOODRZ) spectroscopy.

  11. Characterization by spectroscopic Ellipsometry, the physical properties of silver nanoparticles.

    NASA Astrophysics Data System (ADS)

    Coanga, Jean-Maurice

    2013-04-01

    Physicists are able to change their minds through their experiments. I think it is time to go kick the curse and go further in research if we want a human future. I work in the Nano-Optics and Plasmonics research. I defined with ellipsomètrie the structure of new type of Nano particles of silver. It's same be act quickly to replace the old dirty leaded electronic-connexion chip and by the other hand to find a new way for the heath care of cancer disease by nanoparticles the next killers of bad cells. Silver nanoparticle layers are obtained by Spark Plasma Sintering are investigated as an alternative to lead alloy based material for solder joint in power mechatronics modules. These layers are characterized by mean of conventional techniques that is the dilatometry technique, the resistivity measurement through the van der Pauw method, and the flash laser technique. Furthermore, the nanoparticles of silver layer are deeply studied by UV-Visible spectroscopic ellipsometry. Spectroscopic angles parameters are determined in function of temperature and dielectric constants are deduced and analyzed through an optical model which takes into account a Drude and a Lorentz component within the Bruggeman effective medium approximation (EMA). The relaxation times and the electrical conductivity are plot in function of temperature. The obtained electrical conductivity give significant result in good agreement to those reported by four points electrical measurement method.

  12. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance

    NASA Astrophysics Data System (ADS)

    Edwards, Howell G. M.

    2011-10-01

    The Renaissance represented a major advance in painting techniques, subject matter, artistic style and the use of pigments and pigment mixtures. However, most pigments in general use were still mineral-based as most organic dyes were believed to be fugitive; the historical study of artists' palettes and recipes has assumed importance for the attribution of art works to the Renaissance period. Although the application of diagnostic elemental and molecular spectroscopic techniques play vital and complementary roles in the analysis of art works, elemental techniques alone cannot definitively provide the data needed for pigment identification. The advantages and limitations of Raman spectroscopy for the definitive diagnostic characterisation of yellow pigments that were in use during the Renaissance is demonstrated here in consideration of heavy metal oxides and sulphides; these data will be compared with those obtained from analyses of synthetic yellow pigments that were available during the eighteenth and nineteenth Centuries which could have been used in unrecorded restorations of Renaissance paintings.

  13. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance.

    PubMed

    Edwards, Howell G M

    2011-10-01

    The Renaissance represented a major advance in painting techniques, subject matter, artistic style and the use of pigments and pigment mixtures. However, most pigments in general use were still mineral-based as most organic dyes were believed to be fugitive; the historical study of artists' palettes and recipes has assumed importance for the attribution of art works to the Renaissance period. Although the application of diagnostic elemental and molecular spectroscopic techniques play vital and complementary roles in the analysis of art works, elemental techniques alone cannot definitively provide the data needed for pigment identification. The advantages and limitations of Raman spectroscopy for the definitive diagnostic characterisation of yellow pigments that were in use during the Renaissance is demonstrated here in consideration of heavy metal oxides and sulphides; these data will be compared with those obtained from analyses of synthetic yellow pigments that were available during the eighteenth and nineteenth Centuries which could have been used in unrecorded restorations of Renaissance paintings.

  14. Adaptive Thresholds

    SciTech Connect

    Bremer, P. -T.

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  15. Automated pipelines for spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Allende Prieto, C.

    2016-09-01

    The Gaia mission will have a profound impact on our understanding of the structure and dynamics of the Milky Way. Gaia is providing an exhaustive census of stellar parallaxes, proper motions, positions, colors and radial velocities, but also leaves some glaring holes in an otherwise complete data set. The radial velocities measured with the on-board high-resolution spectrograph will only reach some 10 % of the full sample of stars with astrometry and photometry from the mission, and detailed chemical information will be obtained for less than 1 %. Teams all over the world are organizing large-scale projects to provide complementary radial velocities and chemistry, since this can now be done very efficiently from the ground thanks to large and mid-size telescopes with a wide field-of-view and multi-object spectrographs. As a result, automated data processing is taking an ever increasing relevance, and the concept is applying to many more areas, from targeting to analysis. In this paper, I provide a quick overview of recent, ongoing, and upcoming spectroscopic surveys, and the strategies adopted in their automated analysis pipelines.

  16. SDSS spectroscopic survey of stars

    SciTech Connect

    Ivezic, Zeljko; Schlegel, D.; Uomoto, A.; Bond, N.; Beers, T.; Allende Prieto, C.; Wilhelm, R.; Lee, Y.Sun; Sivarani, T.; Juric, M.; Lupton, R.; /Washington U., Seattle, Astron. Dept. /LBL, Berkeley /Johns Hopkins U. /Princeton U. /Michigan State U. /Texas U. /Texas Tech. /UC, Santa Cruz /Fermilab /Naval Observ., Flagstaff /Drexel U.

    2007-01-01

    In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is also producing a massive spectroscopic database. They discuss determination of stellar parameters, such as effective temperature, gravity and metallicity from SDSS spectra, describe correlations between kinematics and metallicity, and study their variation as a function of the position in the Galaxy. They show that stellar parameter estimates by Beers et al. show a good correlation with the position of a star in the g-r vs. u-g color-color diagram, thereby demonstrating their robustness as well as a potential for photometric parameter estimation methods. Using Beers et al. parameters, they find that the metallicity distribution of the Milky Way stars at a few kpc from the galactic plane is bimodal with a local minimum at [Z/Z{sub {circle_dot}}] {approx} -1.3. The median metallicity for the low-metallicity [Z/Z{sub {circle_dot}}] < =1.3 subsample is nearly independent of Galactic cylindrical coordinates R and z, while it decreases with z for the high-metallicity [Z/Z{sub {circle_dot}}] > -1.3 sample. they also find that the low-metallicity sample has {approx} 2.5 times larger velocity dispersion and that it does not rotate (at the {approx} 10 km/s level), while the rotational velocity of the high-metallicity sample decreases smoothly with the height above the galactic plane.

  17. Spectroscopic Classifications of Optical Transients with SOAR

    NASA Astrophysics Data System (ADS)

    Hounsell, R. A.; Miller, J. A.; Pan, Y.-C.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.; Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.

    2016-06-01

    We report the following classifications of optical transients from spectroscopic observations with the Goodman spectrograph on the SOAR 4-m telescope. Targets were supplied by the Pan-STARRS Survey for Transients (PSST).

  18. Spectroscopic observations of ASASSN-15bp

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Darnley, M. J.; Bode, M. F.; Copperwheat, C. M.

    2015-01-01

    We report spectroscopic observations of the optical transient ASASSN-15bp (ATel #6981) taken on 2015 January 25.31 UT using the FRODOSpec spectrograph (Barnsley et al. 2012) on the Liverpool Telescope (Steele et al. 2004).

  19. Asiago spectroscopic classification of SN 2016gdt

    NASA Astrophysics Data System (ADS)

    Ochner, P.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Pastorello, A.; Tomasella, L.; Turatto, M.; Terreran, G.

    2016-09-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of SN2016gdt in IC1407. The target was supplied by the Italian Supernovae Search Project (ISSP).

  20. MAMA Spectroscopic Sensitivity and Focus Monitor

    NASA Astrophysics Data System (ADS)

    Lennon, Daniel

    2009-07-01

    Monitor sensitivity of each MAMA grating mode to detect any change due tocontamination or other causes. Also monitor the STIS focus in a spectroscopic and animaging mode.Whenever possible, obtain parallel airglow spectra with COS.