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Sample records for spectroscopic methods examples

  1. 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.

  2. 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.

  3. Outstanding Examples of Innovative Methods.

    ERIC Educational Resources Information Center

    Fink, David R., Jr.

    1983-01-01

    The author describes a conference on exploring some educational methods that have proved effective in other fields and at other levels of medical education to see if they have application to continuing medical education. (SSH)

  4. Mass spectroscopic apparatus and method

    DOEpatents

    Bomse, David S.; Silver, Joel A.; Stanton, Alan C.

    1991-01-01

    The disclosure is directed to a method and apparatus for ionization modulated mass spectrometric analysis. Analog or digital data acquisition and processing can be used. Ions from a time variant source are detected and quantified. The quantified ion output is analyzed using a computer to provide a two-dimensional representation of at least one component present within an analyte.

  5. Spectroscopic chemical analysis methods and apparatus

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor)

    2009-01-01

    Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted simultaneously with native fluorescence spectroscopy to provide high levels of sensitivity and specificity in the same instrument.

  6. Spectroscopic chemical analysis methods and apparatus

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor)

    2010-01-01

    Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted simultaneously with native fluorescence spectroscopy to provide high levels of sensitivity and specificity in the same instrument.

  7. Spectroscopic chemical analysis methods and apparatus

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor); Bhartia, Rohit (Inventor)

    2013-01-01

    Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument.

  8. Spectroscopic Chemical Analysis Methods and Apparatus

    NASA Technical Reports Server (NTRS)

    Hug, William F.; Reid, Ray D.

    2012-01-01

    This invention relates to non-contact spectroscopic methods and apparatus for performing chemical analysis and the ideal wavelengths and sources needed for this analysis. It employs deep ultraviolet (200- to 300-nm spectral range) electron-beam-pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor lightemitting devices, and hollow cathode metal ion lasers. Three achieved goals for this innovation are to reduce the size (under 20 L), reduce the weight [under 100 lb (.45 kg)], and reduce the power consumption (under 100 W). This method can be used in microscope or macroscope to provide measurement of Raman and/or native fluorescence emission spectra either by point-by-point measurement, or by global imaging of emissions within specific ultraviolet spectral bands. In other embodiments, the method can be used in analytical instruments such as capillary electrophoresis, capillary electro-chromatography, high-performance liquid chromatography, flow cytometry, and related instruments for detection and identification of unknown analytes using a combination of native fluorescence and/or Raman spectroscopic methods. This design provides an electron-beampumped semiconductor radiation-producing method, or source, that can emit at a wavelength (or wavelengths) below 300 nm, e.g. in the deep ultraviolet between about 200 and 300 nm, and more preferably less than 260 nm. In some variations, the method is to produce incoherent radiation, while in other implementations it produces laser radiation. In some variations, this object is achieved by using an AlGaN emission medium, while in other implementations a diamond emission medium may be used. This instrument irradiates a sample with deep UV radiation, and then uses an improved filter for separating wavelengths to be detected. This provides a multi-stage analysis of the sample. To avoid the difficulties related to producing deep UV semiconductor sources, a pumping approach has been developed that uses ballistic electron beam injection directly into the active region of a wide bandgap semiconductor material.

  9. Selective spectroscopic methods for water analysis

    SciTech Connect

    Vaidya, B.

    1997-06-24

    This dissertation explores in large part the development of a few types of spectroscopic methods in the analysis of water. Methods for the determination of some of the most important properties of water like pH, metal ion content, and chemical oxygen demand are investigated in detail. This report contains a general introduction to the subject and the conclusions. Four chapters and an appendix have been processed separately. They are: chromogenic and fluorogenic crown ether compounds for the selective extraction and determination of Hg(II); selective determination of cadmium in water using a chromogenic crown ether in a mixed micellar solution; reduction of chloride interference in chemical oxygen demand determination without using mercury salts; structural orientation patterns for a series of anthraquinone sulfonates adsorbed at an aminophenol thiolate monolayer chemisorbed at gold; and the role of chemically modified surfaces in the construction of miniaturized analytical instrumentation.

  10. Tutorial examples for uncertainty quantification methods.

    SciTech Connect

    De Bord, Sarah

    2015-08-01

    This report details the work accomplished during my 2015 SULI summer internship at Sandia National Laboratories in Livermore, CA. During this internship, I worked on multiple tasks with the common goal of making uncertainty quantification (UQ) methods more accessible to the general scientific community. As part of my work, I created a comprehensive numerical integration example to incorporate into the user manual of a UQ software package. Further, I developed examples involving heat transfer through a window to incorporate into tutorial lectures that serve as an introduction to UQ methods.

  11. Advances in spectroscopic methods for quantifying soil carbon

    USGS Publications Warehouse

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

    2012-01-01

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

  12. Apparatus and method for spectroscopic analysis of scattering media

    DOEpatents

    Strobl, Karlheinz; Bigio, Irving J.; Loree, Thomas R.

    1994-01-01

    Apparatus and method for spectroscopic analysis of scattering media. Subtle differences in materials have been found to be detectable from plots of intensity as a function of wavelength of collected emitted and scattered light versus wavelength of excitation light.

  13. Whispering Gallery Optical Resonator Spectroscopic Probe and Method

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S. (Inventor)

    2014-01-01

    Disclosed herein is a spectroscopic probe comprising at least one whispering gallery mode optical resonator disposed on a support, the whispering gallery mode optical resonator comprising a continuous outer surface having a cross section comprising a first diameter and a second diameter, wherein the first diameter is greater than the second diameter. A method of measuring a Raman spectrum and an Infra-red spectrum of an analyte using the spectroscopic probe is also disclosed.

  14. Search for planets by spectroscopic methods

    NASA Technical Reports Server (NTRS)

    Serkowski, K.

    1980-01-01

    Spectroscopic means of detecting the motion of a star around a star-planet barycenter are considered. The precision of such an observation, which requires a radial velocity error of not more than 5 m/sec, is discussed in relation to the spectral resolutions of the detectors utilized. The University of Arizona radial velocity spectrometer is then presented, with particular attention given to the location of the absorption cell in a beam of light from an incandescent bulb, high-accuracy wavelength calibration involving the use of a Fabry-Perot interferometer in front of an echelle spectrograph, and future plans for the use of light reflected from a Fabry-Perot etalon to improve transmittance. On the basis of these techniques, it is expected that radial velocities with accuracies sufficient for the detection of extrasolar planets will be obtained.

  15. 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. PMID:20062364

  16. Experimental Mathemataics: Examples, Methods andImplications

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2005-01-31

    Recent years have seen the flowering of ''experimental'' mathematics, namely the utilization of modern computer technology as an active tool in mathematical research. This development is not limited to a handful of researchers, nor to a handful of universities, nor is it limited to one particular field of mathematics. Instead, it involves hundreds of individuals, at many different institutions, who have turned to the remarkable new computational tools now available to assist in their research, whether it be in number theory, algebra, analysis, geometry or even topology. These tools are being used to work out specific examples, generate plots, perform various algebraic and calculus manipulations, test conjectures, and explore routes to formal proof. Using computer tools to test conjectures is by itself a major time saver for mathematicians, as it permits them to quickly rule out false notions.

  17. Plasmonic nanostructures for surface enhanced spectroscopic methods.

    PubMed

    Jahn, Martin; Patze, Sophie; Hidi, Izabella J; Knipper, Richard; Radu, Andreea I; Mühlig, Anna; Yüksel, Sezin; Peksa, Vlastimil; Weber, Karina; Mayerhöfer, Thomas; Cialla-May, Dana; Popp, Jürgen

    2016-02-01

    A comprehensive review of theoretical approaches to simulate plasmonic-active metallic nano-arrangements is given. Further, various fabrication methods based on bottom-up, self-organization and top-down techniques are introduced. Here, analytical approaches are discussed to investigate the optical properties of isotropic and non-magnetic spherical or spheroidal particles. Furthermore, numerical methods are introduced to research complex shaped structures. A huge variety of fabrication methods are reviewed, e.g. bottom-up preparation strategies for plasmonic nanostructures to generate metal colloids and core-shell particles as well as complex-shaped structures, self-organization as well as template-based methods and finally, top-down processes, e.g. electron beam lithography and its variants as well as nanoimprinting. The review article is aimed at beginners in the field of surface enhanced spectroscopy (SES) techniques and readers who have a general interest in theoretical modelling of plasmonic substrates for SES applications as well as in the fabrication of the desired structures based on methods of the current state of the art. PMID:26759831

  18. Least squares methods of analyzing spectroscopic data

    NASA Technical Reports Server (NTRS)

    Shaw, J. H.

    1984-01-01

    The development of efficient techniques for extracting the maximum amount of information from the spectra of atmospheric molecules with a minimum of observer bias is discussed. In particular, an overview of the methods of line by line and whole band analysis is presented.

  19. Role of Optical Spectroscopic Methods in Neuro-Oncological Sciences

    PubMed Central

    Bahreini, Maryam

    2015-01-01

    In the surgical treatment of malignant tumors, it is crucial to characterize the tumor as precisely as possible. The determination of the exact tumor location as well as the analysis of its properties is very important in order to obtain an accurate diagnosis as early as possible. In neurosurgical applications, the optical, non-invasive and in situ techniques allow for the label-free analysis of tissue, which is helpful in neuropathology. In the past decades, optical spectroscopic methods have been investigated drastically in the management of cancer. In the optical spectroscopic techniques, tissue interrogate with sources of light which are ranged from the ultraviolet to the infrared wavelength in the spectrum. The information accumulation of light can be in a reflection which is named reflectance spectroscopy; or interactions with tissue at different wavelengths which are called fluorescence and Raman spectroscopy. This review paper introduces the optical spectroscopic methods which are used to characterize brain tumors (neuro-oncology). Based on biochemical information obtained from these spectroscopic methods, it is possible to identify tumor from normal brain tissues, to indicate tumor margins, the borders towards normal brain tissue and infiltrating gliomas, to distinguish radiation damage of tissues, to detect particular central nervous system (CNS) structures to identify cell types using particular neurotransmitters, to detect cells or drugs which are optically labeled within therapeutic intermediations and to estimate the viability of tissue and the prediction of apoptosis beginning in vitro and in vivo. The label-free, optical biochemical spectroscopic methods can provide clinically relevant information and need to be further exploited to develop a safe and easy-to-use technology for in situ diagnosis of malignant tumors. PMID:25987969

  20. Role of optical spectroscopic methods in neuro-oncological sciences.

    PubMed

    Bahreini, Maryam

    2015-01-01

    In the surgical treatment of malignant tumors, it is crucial to characterize the tumor as precisely as possible. The determination of the exact tumor location as well as the analysis of its properties is very important in order to obtain an accurate diagnosis as early as possible. In neurosurgical applications, the optical, non-invasive and in situ techniques allow for the label-free analysis of tissue, which is helpful in neuropathology. In the past decades, optical spectroscopic methods have been investigated drastically in the management of cancer. In the optical spectroscopic techniques, tissue interrogate with sources of light which are ranged from the ultraviolet to the infrared wavelength in the spectrum. The information accumulation of light can be in a reflection which is named reflectance spectroscopy; or interactions with tissue at different wavelengths which are called fluorescence and Raman spectroscopy. This review paper introduces the optical spectroscopic methods which are used to characterize brain tumors (neuro-oncology). Based on biochemical information obtained from these spectroscopic methods, it is possible to identify tumor from normal brain tissues, to indicate tumor margins, the borders towards normal brain tissue and infiltrating gliomas, to distinguish radiation damage of tissues, to detect particular central nervous system (CNS) structures to identify cell types using particular neurotransmitters, to detect cells or drugs which are optically labeled within therapeutic intermediations and to estimate the viability of tissue and the prediction of apoptosis beginning in vitro and in vivo. The label-free, optical biochemical spectroscopic methods can provide clinically relevant information and need to be further exploited to develop a safe and easy-to-use technology for in situ diagnosis of malignant tumors. PMID:25987969

  1. Mixed Methods Sampling: A Typology with Examples

    ERIC Educational Resources Information Center

    Teddlie, Charles; Yu, Fen

    2007-01-01

    This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

  2. Plant roots and spectroscopic methods analyzing species, biomass and vitality

    PubMed Central

    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. PMID:24130565

  3. Spectroscopic studies of protein folding: Linear and nonlinear methods

    PubMed Central

    Serrano, Arnaldo L; Waegele, Matthias M; Gai, Feng

    2012-01-01

    Although protein folding is a simple outcome of the underlying thermodynamics, arriving at a quantitative and predictive understanding of how proteins fold nevertheless poses huge challenges. Therefore, both advanced experimental and computational methods are continuously being developed and refined to probe and reveal the atomistic details of protein folding dynamics and mechanisms. Herein, we provide a concise review of recent developments in spectroscopic studies of protein folding, with a focus on new triggering and probing methods. In particular, we describe several laser-based techniques for triggering protein folding/unfolding on the picosecond and/or nanosecond timescales and various linear and nonlinear spectroscopic techniques for interrogating protein conformations, conformational transitions, and dynamics. PMID:22109973

  4. Scanning Tunneling Microscopy methods for spectroscopic imaging of subsurface interfaces

    NASA Technical Reports Server (NTRS)

    Bell, L. D.; Kaiser, W. J.

    1988-01-01

    A new method for spatially-resolved, spectroscopic investigation of subsurface interface structure has been developed. The method, Ballistic Electron Emission Microscopy (BEEM), is based on Scanning Tunneling Microscopy (STM) techniques. BEEM combines STM vacuum tunneling with unique ballistic electron spectroscopy capabilities. BEEM enables, for the first time, direct imaging of subsurface interface electronic properties with nanometer spatial resolution. STM topographic images of surface structure and BEEM images of subsurface properties are obtained simultaneously. BEEM capabilities are demonstrated by investigation of important metal-semiconductor interfaces.

  5. Advances in spectroscopic methods for quantifying soil carbon

    USGS Publications Warehouse

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

    2012-01-01

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

  6. Spectroscopic Methods of Remote Sensing for Vegetation Characterization

    NASA Astrophysics Data System (ADS)

    Kokaly, R. F.

    2013-12-01

    Imaging spectroscopy (IS), often referred to as hyperspectral remote sensing, is one of the latest innovations in a very long history of spectroscopy. Spectroscopic methods have been used for understanding the composition of the world around us, as well as, the solar system and distant parts of the universe. Continuous sampling of the electromagnetic spectrum in narrow bands is what separates IS from previous forms of remote sensing. Terrestrial imaging spectrometers often have hundreds of channels that cover the wavelength range of reflected solar radiation, including the visible, near-infrared (NIR), and shortwave infrared (SWIR) regions. In part due to the large number of channels, a wide variety of methods have been applied to extract information from IS data sets. These can be grouped into several broad classes, including: multi-channel indices, statistical procedures, full spectrum mixing models, and spectroscopic methods. Spectroscopic methods carry on the more than 150 year history of laboratory-based spectroscopy applied to material identification and characterization. Spectroscopic methods of IS relate the positions and shapes of spectral features resolved by airborne and spaceborne sensors to the biochemical and physical composition of vegetation in a pixel. The chlorophyll 680nm, water 980nm, water 1200nm, SWIR 1700nm, SWIR 2100nm, and SWIR 2300nm features have been the subject of study. Spectral feature analysis (SFA) involves isolating such an absorption feature using continuum removal (CR) and calculating descriptors of the feature, such as center position, depth, width, area, and asymmetry. SFA has been applied to quantify pigment and non-pigment biochemical concentrations in leaves, plants, and canopies. Spectral feature comparison (SFC) utilizes CR of features in each pixel's spectrum and linear regression with continuum-removed features in reference spectra in a library of known vegetation types to map vegetation species and communities. SFC has been applied to map the distributions of minerals in soils and rocks; however, its application to characterize vegetation cover has been less widespread than SFA. Using IS data and the USGS Processing Routines in IDL for Spectroscopic Measurements (PRISM; http://pubs.usgs.gov/of/2011/1155/), this talk will examine requirements for and limitations in applying SFA and SFC to characterize vegetation. A time series of Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS) data collected in the marshes of Louisiana following the Deepwater Horizon oil spill will be used to examine the impact of varying leaf water content on the shapes of the SWIR 1700, 2100, and 2300 nm features and the implications of these changes on vegetation identification and biochemical estimation. The USGS collection of HyMap data over Afghanistan, the largest terrestrial coverage of IS data to date, will be used to demonstrate the characterization of vegetation in arid and semi-arid regions, in which chlorophyll absorption is often weak and soil and rock mineral absorption features overlap vegetation features. Hyperion data, overlapping the HyMap data, will be presented to illustrate the complications that arise when signal-to-noise is low. The benefits of and challenges to applying a spectroscopic remote sensing approach to imaging spectrometer data will be discussed.

  7. Method of absorbance correction in a spectroscopic heating value sensor

    SciTech Connect

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  8. Can the electronegativity equalization method predict spectroscopic properties?

    NASA Astrophysics Data System (ADS)

    Verstraelen, T.; Bultinck, P.

    2015-02-01

    The electronegativity equalization method is classically used as a method allowing the fast generation of atomic charges using a set of calibrated parameters and provided knowledge of the molecular structure. Recently, it has started being used for the calculation of other reactivity descriptors and for the development of polarizable and reactive force fields. For such applications, it is of interest to know whether the method, through the inclusion of the molecular geometry in the Taylor expansion of the energy, would also allow sufficiently accurate predictions of spectroscopic data. In this work, relevant quantities for IR spectroscopy are considered, namely the dipole derivatives and the Cartesian Hessian. Despite careful calibration of parameters for this specific task, it is shown that the current models yield insufficiently accurate results.

  9. Can the electronegativity equalization method predict spectroscopic properties?

    PubMed

    Verstraelen, T; Bultinck, P

    2015-02-01

    The electronegativity equalization method is classically used as a method allowing the fast generation of atomic charges using a set of calibrated parameters and provided knowledge of the molecular structure. Recently, it has started being used for the calculation of other reactivity descriptors and for the development of polarizable and reactive force fields. For such applications, it is of interest to know whether the method, through the inclusion of the molecular geometry in the Taylor expansion of the energy, would also allow sufficiently accurate predictions of spectroscopic data. In this work, relevant quantities for IR spectroscopy are considered, namely the dipole derivatives and the Cartesian Hessian. Despite careful calibration of parameters for this specific task, it is shown that the current models yield insufficiently accurate results. PMID:24290357

  10. Methods for Raman spectroscopic imaging of biological systems

    NASA Astrophysics Data System (ADS)

    Barnett, Steven M.; Carrabba, Michael M.; Bormett, Richard W.; Whitley, Andrew

    1999-04-01

    Imaging methodologies present some of the most exciting new frontiers in the biological and medical sciences. Raman spectroscopic imaging combines the power of chemical imaging with the spatial resolution for translating microscopic spectroscopic information into statements relevant to biological and medical function. Imaging results will be presented using mapping, dielectric filters, and liquid- crystalline tunable filters at different excitation wavelengths for selectively determining the spatial distribution of biomaterials in a variety of biological systems.

  11. Methods and apparatus for distributed resource discovery using examples

    NASA Technical Reports Server (NTRS)

    Bergman, Lawrence David (Inventor); Castelli, Vittorio (Inventor); Chang, Yuan-Chi (Inventor); Hill, Matthew L. (Inventor); Li, Chung-Sheng (Inventor); Smith, John Richard (Inventor)

    2005-01-01

    Distributed resource discovery is an essential step for information retrieval and/or providing information services. This step is usually used for determining the location of an information or data repository which has relevant information. The most fundamental challenge is the usual lack of semantic interoperability of the requested resource. In accordance with the invention, a method is disclosed where distributed repositories achieve semantic interoperability through the exchange of examples and, optionally, classifiers. The outcome of the inventive method can be used to determine whether common labels are referring to the same semantic meaning.

  12. Markov chain Monte Carlo methods: an introductory example

    NASA Astrophysics Data System (ADS)

    Klauenberg, Katy; Elster, Clemens

    2016-02-01

    When the Guide to the Expression of Uncertainty in Measurement (GUM) and methods from its supplements are not applicable, the Bayesian approach may be a valid and welcome alternative. Evaluating the posterior distribution, estimates or uncertainties involved in Bayesian inferences often requires numerical methods to avoid high-dimensional integrations. Markov chain Monte Carlo (MCMC) sampling is such a method—powerful, flexible and widely applied. Here, a concise introduction is given, illustrated by a simple, typical example from metrology. The Metropolis-Hastings algorithm is the most basic and yet flexible MCMC method. Its underlying concepts are explained and the algorithm is given step by step. The few lines of software code required for its implementation invite interested readers to get started. Diagnostics to evaluate the performance and common algorithmic choices are illustrated to calibrate the Metropolis-Hastings algorithm for efficiency. Routine application of MCMC algorithms may be hindered currently by the difficulty to assess the convergence of MCMC output and thus to assure the validity of results. An example points to the importance of convergence and initiates discussion about advantages as well as areas of research. Available software tools are mentioned throughout.

  13. A method for Hamiltonian truncation: a four-wave example

    NASA Astrophysics Data System (ADS)

    Viscondi, Thiago F.; Caldas, Iberê L.; Morrison, Philip J.

    2016-04-01

    A method for extracting finite-dimensional Hamiltonian systems from a class of 2 + 1 Hamiltonian mean field theories is presented. These theories possess noncanonical Poisson brackets, which normally resist Hamiltonian truncation, but a process of beatification by coordinate transformation near a reference state is described in order to perturbatively overcome this difficulty. Two examples of four-wave truncation of Euler’s equation for scalar vortex dynamics are given and compared: one a direct non-Hamiltonian truncation of the equations of motion, the other obtained by beatifying the Poisson bracket and then truncating.

  14. 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.

  15. The Young Solar Analogs Project. I. Spectroscopic and Photometric Methods and Multi-year Timescale Spectroscopic Results

    NASA Astrophysics Data System (ADS)

    Gray, R. O.; Saken, J. M.; Corbally, C. J.; Briley, M. M.; Lambert, R. A.; Fuller, V. A.; Newsome, I. M.; Seeds, M. F.; Kahvaz, Y.

    2015-12-01

    This is the first in a series of papers presenting methods and results from the Young Solar Analogs Project, which began in 2007. This project monitors both spectroscopically and photometrically a set of 31 young (300-1500 Myr) solar-type stars with the goal of gaining insight into the space environment of the Earth during the period when life first appeared. From our spectroscopic observations we derive the Mount Wilson S chromospheric activity index (SMW), and describe the method we use to transform our instrumental indices to SMW without the need for a color term. We introduce three photospheric indices based on strong absorption features in the blue-violet spectrum—the G-band, the Ca i resonance line, and the Hydrogen-γ line—with the expectation that these indices might prove to be useful in detecting variations in the surface temperatures of active solar-type stars. We also describe our photometric program, and in particular our "Superstar technique" for differential photometry which, instead of relying on a handful of comparison stars, uses the photon flux in the entire star field in the CCD image to derive the program star magnitude. This enables photometric errors on the order of 0.005-0.007 magnitude. We present time series plots of our spectroscopic data for all four indices, and carry out extensive statistical tests on those time series demonstrating the reality of variations on timescales of years in all four indices. We also statistically test for and discover correlations and anti-correlations between the four indices. We discuss the physical basis of those correlations. As it turns out, the "photospheric" indices appear to be most strongly affected by emission in the Paschen continuum. We thus anticipate that these indices may prove to be useful proxies for monitoring emission in the ultraviolet Balmer continuum. Future papers in this series will discuss variability of the program stars on medium (days-months) and short (minutes to hours) timescales.

  16. Denoising spectroscopic data by means of the improved least-squares deconvolution method

    NASA Astrophysics Data System (ADS)

    Tkachenko, A.; Van Reeth, T.; Tsymbal, V.; Aerts, C.; Kochukhov, O.; Debosscher, J.

    2013-12-01

    Context. The MOST, CoRoT, and Kepler space missions have led to the discovery of a large number of intriguing, and in some cases unique, objects among which are pulsating stars, stars hosting exoplanets, binaries, etc. Although the space missions have delivered photometric data of unprecedented quality, these data are lacking any spectral information and we are still in need of ground-based spectroscopic and/or multicolour photometric follow-up observations for a solid interpretation. Aims: The faintness of most of the observed stars and the required high signal-to-noise ratio (S/N) of spectroscopic data both imply the need to use large telescopes, access to which is limited. In this paper, we look for an alternative, and aim for the development of a technique that allows the denoising of the originally low S/N (typically, below 80) spectroscopic data, making observations of faint targets with small telescopes possible and effective. Methods: We present a generalization of the original least-squares deconvolution (LSD) method by implementing a multicomponent average profile and a line strengths correction algorithm. We tested the method on simulated and real spectra of single and binary stars, among which are two intrinsically variable objects. Results: The method was successfully tested on the high-resolution spectra of Vega and a Kepler star, KIC 04749989. Application to the two pulsating stars, 20 Cvn and HD 189631, showed that the technique is also applicable to intrinsically variable stars: the results of frequency analysis and mode identification from the LSD model spectra for both objects are in good agreement with the findings from literature. Depending on the S/N of the original data and spectral characteristics of a star, the gain in S/N in the LSD model spectrum typically ranges from 5 to 15 times. Conclusions: The technique introduced in this paper allows an effective denoising of the originally low S/N spectroscopic data. The high S/N spectra obtained this way can be used to determine fundamental parameters and chemical composition of the stars. The restored LSD model spectra contain all the information on line profile variations present in the original spectra of pulsating stars, for example. The method is applicable to both high- (>30 000) and low- (<30 000) resolution spectra, although the information that can be extracted from the latter is limited by the resolving power itself. Based on the data gathered with the hermes spectrograph, installed at the Mercator Telescope, operated on the island of La Palma by the Flemish Community, at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias and supported by the Fund for Scientific Research of Flanders (FWO), Belgium, the Research Council of K.U. Leuven, Belgium, the Fonds National de la Recherche Scientifique (F.R.S.-FNRS), Belgium, the Royal Observatory of Belgium, the Observatoire de Genève, Switzerland, and the Thüringer Landessternwarte Tautenburg, Germany.Based on the data extracted from the ELODIE archive and the ESO Science Archive Facility under request number TVanReeth63233.The software presented in this work is available upon request from: Andrew.Tkachenko@ster.kuleuven.be

  17. Using crowdsourcing to evaluate published scientific literature: methods and example.

    PubMed

    Brown, Andrew W; Allison, David B

    2014-01-01

    Systematically evaluating scientific literature is a time consuming endeavor that requires hours of coding and rating. Here, we describe a method to distribute these tasks across a large group through online crowdsourcing. Using Amazon's Mechanical Turk, crowdsourced workers (microworkers) completed four groups of tasks to evaluate the question, "Do nutrition-obesity studies with conclusions concordant with popular opinion receive more attention in the scientific community than do those that are discordant?" 1) Microworkers who passed a qualification test (19% passed) evaluated abstracts to determine if they were about human studies investigating nutrition and obesity. Agreement between the first two raters' conclusions was moderate (κ = 0.586), with consensus being reached in 96% of abstracts. 2) Microworkers iteratively synthesized free-text answers describing the studied foods into one coherent term. Approximately 84% of foods were agreed upon, with only 4 and 8% of ratings failing manual review in different steps. 3) Microworkers were asked to rate the perceived obesogenicity of the synthesized food terms. Over 99% of responses were complete and usable, and opinions of the microworkers qualitatively matched the authors' expert expectations (e.g., sugar-sweetened beverages were thought to cause obesity and fruits and vegetables were thought to prevent obesity). 4) Microworkers extracted citation counts for each paper through Google Scholar. Microworkers reached consensus or unanimous agreement for all successful searches. To answer the example question, data were aggregated and analyzed, and showed no significant association between popular opinion and attention the paper received as measured by Scimago Journal Rank and citation counts. Direct microworker costs totaled $221.75, (estimated cost at minimum wage: $312.61). We discuss important points to consider to ensure good quality control and appropriate pay for microworkers. With good reliability and low cost, crowdsourcing has potential to evaluate published literature in a cost-effective, quick, and reliable manner using existing, easily accessible resources. PMID:24988466

  18. Using Crowdsourcing to Evaluate Published Scientific Literature: Methods and Example

    PubMed Central

    Brown, Andrew W.; Allison, David B.

    2014-01-01

    Systematically evaluating scientific literature is a time consuming endeavor that requires hours of coding and rating. Here, we describe a method to distribute these tasks across a large group through online crowdsourcing. Using Amazon's Mechanical Turk, crowdsourced workers (microworkers) completed four groups of tasks to evaluate the question, “Do nutrition-obesity studies with conclusions concordant with popular opinion receive more attention in the scientific community than do those that are discordant?” 1) Microworkers who passed a qualification test (19% passed) evaluated abstracts to determine if they were about human studies investigating nutrition and obesity. Agreement between the first two raters' conclusions was moderate (κ = 0.586), with consensus being reached in 96% of abstracts. 2) Microworkers iteratively synthesized free-text answers describing the studied foods into one coherent term. Approximately 84% of foods were agreed upon, with only 4 and 8% of ratings failing manual review in different steps. 3) Microworkers were asked to rate the perceived obesogenicity of the synthesized food terms. Over 99% of responses were complete and usable, and opinions of the microworkers qualitatively matched the authors' expert expectations (e.g., sugar-sweetened beverages were thought to cause obesity and fruits and vegetables were thought to prevent obesity). 4) Microworkers extracted citation counts for each paper through Google Scholar. Microworkers reached consensus or unanimous agreement for all successful searches. To answer the example question, data were aggregated and analyzed, and showed no significant association between popular opinion and attention the paper received as measured by Scimago Journal Rank and citation counts. Direct microworker costs totaled $221.75, (estimated cost at minimum wage: $312.61). We discuss important points to consider to ensure good quality control and appropriate pay for microworkers. With good reliability and low cost, crowdsourcing has potential to evaluate published literature in a cost-effective, quick, and reliable manner using existing, easily accessible resources. PMID:24988466

  19. Spectroscopic Analysis of Wall Conditioning Methods in NSTX

    NASA Astrophysics Data System (ADS)

    Forbes, Eleanor; Soukhanovskii, Vlad

    2015-11-01

    Plasma confinement and performance in NSTX are reliant upon well-conditioned plasma facing components (PFCs). Past conditioning techniques used in NSTX include hot and cold boronization, lithium pellet injection (LPI), and lithium evaporation. The influx of hydrogen-containing molecules and radicals can be studied through spectroscopic observation of the hydrogen to deuterium (H/D) intensity ratio in the edge plasma. A code to determine H/D ratios has been developed and tested on known light sources before being applied to data from prior NSTX experiments. In general, boronization was found to reduce the H/D ratio, with further H reduction seen from cold boronization when compared to hot boronization. No correlation between LPI and H/D ratio was observed. Lithium evaporation produced a significant H decrease. In the future this analysis will be applied immediately following NSTX-U pulses to provide data on plasma-surface interactions. This work was made possible by funding from the Department of Energy for the Summer Undergraduate Laboratory Internship (SULI) program. This work is supported by the US DOE Contract No.DE-AC02-09CH11466 and DE-AC52-07NA27344.

  20. Spectroscopically Enhanced Method and System for Multi-Factor Biometric Authentication

    NASA Astrophysics Data System (ADS)

    Pishva, Davar

    This paper proposes a spectroscopic method and system for preventing spoofing of biometric authentication. One of its focus is to enhance biometrics authentication with a spectroscopic method in a multifactor manner such that a person's unique ‘spectral signatures’ or ‘spectral factors’ are recorded and compared in addition to a non-spectroscopic biometric signature to reduce the likelihood of imposter getting authenticated. By using the ‘spectral factors’ extracted from reflectance spectra of real fingers and employing cluster analysis, it shows how the authentic fingerprint image presented by a real finger can be distinguished from an authentic fingerprint image embossed on an artificial finger, or molded on a fingertip cover worn by an imposter. This paper also shows how to augment two widely used biometrics systems (fingerprint and iris recognition devices) with spectral biometrics capabilities in a practical manner and without creating much overhead or inconveniencing their users.

  1. Methods for trend analysis: Examples with problem/failure data

    NASA Technical Reports Server (NTRS)

    Church, Curtis K.

    1989-01-01

    Statistics are emphasized as an important role in quality control and reliability. Consequently, Trend Analysis Techniques recommended a variety of statistical methodologies that could be applied to time series data. The major goal of the working handbook, using data from the MSFC Problem Assessment System, is to illustrate some of the techniques in the NASA standard, some different techniques, and to notice patterns of data. Techniques for trend estimation used are: regression (exponential, power, reciprocal, straight line) and Kendall's rank correlation coefficient. The important details of a statistical strategy for estimating a trend component are covered in the examples. However, careful analysis and interpretation is necessary because of small samples and frequent zero problem reports in a given time period. Further investigations to deal with these issues are being conducted.

  2. Advances in spectroscopic methods for quantifying soil carbon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gold standard for soil C determination is combustion. However, this method requires expensive consumables, is limited to the determination of the total carbon and in the number of samples which can be processed (~100/d). With increased interest in soil C sequestration, faster methods are needed....

  3. Diagnostic of the surface micro-discharge using spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Li, Yang-Fang; Morfill, Gregor

    2012-10-01

    A handheld and battery-driven CAP device is designed for clinical studies. The accomplished medical phase I study has shown high bactericidal efficacy in vitro, ex vivo as well as in vivo. Although tests have been done concerning the biological safety and toxic gas emissions accordingly to the electrical safety, the chemical production of this device is not well addressed. In particular, the ozone production remains to be a big issue for safety reasons and reactive Nitrogen and Oxygen species (RNOS) are regarded to the key players for the biological and medical effects of CAPs. Given the application time for the clinical trial would be in the range of 30 seconds, we will present the temporal evolution of several RNOS within running time of a few minutes. The measurement is done mainly by the optical emission and absorption spectroscopies. Depending on the characteristic parameters of the applied voltage signal for discharge, the production of the RNOS may evolve in different profiles. Especially for high power operation, the discharge takes around 30 seconds to reach a steady state. Although the discharge power is found to be the most important factor, the characteristic frequency and even the gas temperature in ambient air, which in our case is the working gas, may alter the yields of several species, for example ozone and atomic Oxygen. The result will help for developing CAP devices for different applications and to design the protocol for the clinical test concerning the efficacy and safety.

  4. Survival analysis using Medicare data: example and methods.

    PubMed Central

    Virnig, B A; Ash, A; Kind, S; Mesler, D E

    2000-01-01

    OBJECTIVE: To describe key methods and issues in conducting survival analyses, especially using Medicare (and other) administrative data. PRINCIPAL FINDINGS: Survival analyses are rich , informative, and underutilized methods for examining out comes whose timing is important . Medicare files contain the necessary information for conducting such analyses, including identification of cohorts, definition of events, censoring of observations, and adjustment for covariates. CONCLUSION: Survival analyses can readily be conducted using the information contained in administrative data files. PMID:16148954

  5. Conceptual evaluation of population health surveillance programs: method and example.

    PubMed

    El Allaki, Farouk; Bigras-Poulin, Michel; Ravel, André

    2013-03-01

    Veterinary and public health surveillance programs can be evaluated to assess and improve the planning, implementation and effectiveness of these programs. Guidelines, protocols and methods have been developed for such evaluation. In general, they focus on a limited set of attributes (e.g., sensitivity and simplicity), that are assessed quantitatively whenever possible, otherwise qualitatively. Despite efforts at standardization, replication by different evaluators is difficult, making evaluation outcomes open to interpretation. This ultimately limits the usefulness of surveillance evaluations. At the same time, the growing demand to prove freedom from disease or pathogen, and the Sanitary and Phytosanitary Agreement and the International Health Regulations require stronger surveillance programs. We developed a method for evaluating veterinary and public health surveillance programs that is detailed, structured, transparent and based on surveillance concepts that are part of all types of surveillance programs. The proposed conceptual evaluation method comprises four steps: (1) text analysis, (2) extraction of the surveillance conceptual model, (3) comparison of the extracted surveillance conceptual model to a theoretical standard, and (4) validation interview with a surveillance program designer. This conceptual evaluation method was applied in 2005 to C-EnterNet, a new Canadian zoonotic disease surveillance program that encompasses laboratory based surveillance of enteric diseases in humans and active surveillance of the pathogens in food, water, and livestock. The theoretical standard used for evaluating C-EnterNet was a relevant existing structure called the "Population Health Surveillance Theory". Five out of 152 surveillance concepts were absent in the design of C-EnterNet. However, all of the surveillance concept relationships found in C-EnterNet were valid. The proposed method can be used to improve the design and documentation of surveillance programs. It complements existing surveillance evaluation methods. Conceptual evaluation is not a performance-oriented evaluation method and so it is particularly useful for surveillance programs with a valid conceptual framework but limited technical capacity and resources. Such programs would be penalized using existing performance-based evaluation methods. Applying conjointly the conceptual evaluation along with existing performance-oriented evaluation methods will better judge the worth of surveillance programs. We recommend developing a comprehensive surveillance evaluation framework for veterinary and public health surveillance programs that integrates all existing surveillance evaluation tools and provides an appropriate way to evaluate various types of surveillance programs. PMID:23174216

  6. Synoptic typing: interdisciplinary application methods with three practical hydroclimatological examples

    NASA Astrophysics Data System (ADS)

    Siegert, C. M.; Leathers, D. J.; Levia, D. F.

    2016-01-01

    Synoptic classification is a methodology that represents diverse atmospheric variables and allows researchers to relate large-scale atmospheric circulation patterns to regional- and small-scale terrestrial processes. Synoptic classification has often been applied to questions concerning the surface environment. However, full applicability has been under-utilized to date, especially in disciplines such as hydroclimatology, which are intimately linked to atmospheric inputs. This paper aims to (1) outline the development of a daily synoptic calendar for the Mid-Atlantic (USA), (2) define seasonal synoptic patterns occurring in the region, and (3) provide hydroclimatological examples whereby the cascading response of precipitation characteristics, soil moisture, and streamflow are explained by synoptic classification. Together, achievement of these objectives serves as a guide for development and use of a synoptic calendar for hydroclimatological studies. In total 22 unique synoptic types were identified, derived from a combination of 12 types occurring in the winter (DJF), 13 in spring (MAM), 9 in summer (JJA), and 11 in autumn (SON). This includes six low pressure systems, four high pressure systems, one cold front, three north/northwest flow regimes, three south/southwest flow regimes, and five weakly defined regimes. Pairwise comparisons indicated that 84.3 % had significantly different rainfall magnitudes, 86.4 % had different rainfall durations, and 84.7 % had different rainfall intensities. The largest precipitation-producing classifications were not restricted to low pressure systems, but rather to patterns with access to moisture sources from the Atlantic Ocean and easterly (on-shore) winds, which transport moisture inland. These same classifications resulted in comparable rates of soil moisture recharge and streamflow discharge, illustrating the applicability of synoptic classification for a range of hydroclimatological research objectives.

  7. The Erosion of a Method: Examples from Grounded Theory

    ERIC Educational Resources Information Center

    Greckhamer, Thomas; Koro-Ljungberg, Mirka

    2005-01-01

    Since its original inception in the 1960s grounded theory has been widely used by many qualitative researchers. However, recently epistemologically different versions of grounded theory have been presented and this epistemological diversity among grounded theorists and the erosion of the method will be the major focus of this paper. The first…

  8. The Erosion of a Method: Examples from Grounded Theory

    ERIC Educational Resources Information Center

    Greckhamer, Thomas; Koro-Ljungberg, Mirka

    2005-01-01

    Since its original inception in the 1960s grounded theory has been widely used by many qualitative researchers. However, recently epistemologically different versions of grounded theory have been presented and this epistemological diversity among grounded theorists and the erosion of the method will be the major focus of this paper. The first

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

    PubMed

    Huck, Christian W

    2014-01-01

    During the last couple of years great advances in vibrational spectroscopy including near-infrared (NIR), mid-infrared (MIR), attenuated total reflection (ATR) and imaging and also mapping techniques could be achieved. On the other hand spectral treatment features have improved dramatically allowing filtering out relevant information from spectral data much more efficiently and providing new insights into the biochemical composition. These advances offer new possible quality control strategies in phytomics and enable to get deeper insights into biochemical background in terms of medicinal relevant questions. It is the aim of the present article pointing out the technical and methodological advancements in the NIR and MIR field and to demonstrate the individual methods efficiency by discussing distinct selected applications. PMID:23787354

  10. Design principles for elementary gene circuits: Elements, methods, and examples

    NASA Astrophysics Data System (ADS)

    Savageau, Michael A.

    2001-03-01

    The control of gene expression involves complex circuits that exhibit enormous variation in design. For years the most convenient explanation for these variations was historical accident. According to this view, evolution is a haphazard process in which many different designs are generated by chance; there are many ways to accomplish the same thing, and so no further meaning can be attached to such different but equivalent designs. In recent years a more satisfying explanation based on design principles has been found for at least certain aspects of gene circuitry. By design principle we mean a rule that characterizes some biological feature exhibited by a class of systems such that discovery of the rule allows one not only to understand known instances but also to predict new instances within the class. The central importance of gene regulation in modern molecular biology provides strong motivation to search for more of these underlying design principles. The search is in its infancy and there are undoubtedly many design principles that remain to be discovered. The focus of this three-part review will be the class of elementary gene circuits in bacteria. The first part reviews several elements of design that enter into the characterization of elementary gene circuits in prokaryotic organisms. Each of these elements exhibits a variety of realizations whose meaning is generally unclear. The second part reviews mathematical methods used to represent, analyze, and compare alternative designs. Emphasis is placed on particular methods that have been used successfully to identify design principles for elementary gene circuits. The third part reviews four design principles that make specific predictions regarding (1) two alternative modes of gene control, (2) three patterns of coupling gene expression in elementary circuits, (3) two types of switches in inducible gene circuits, and (4) the realizability of alternative gene circuits and their response to phased environmental cues. In each case, the predictions are supported by experimental evidence. These results are important for understanding the function, design, and evolution of elementary gene circuits.

  11. 26 CFR 1.482-8T - Examples of the best method rule (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... research capabilities of MDI). In this case, application of the market capitalization method, based on the... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Examples of the best method rule (temporary). 1... (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Adjustments § 1.482-8T Examples of the best method...

  12. 26 CFR 1.482-8 - Examples of the best method rule.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... research capabilities of MDI). In this case, application of the market capitalization method, based on the... 26 Internal Revenue 6 2012-04-01 2012-04-01 false Examples of the best method rule. 1.482-8... TAX (CONTINUED) INCOME TAXES (CONTINUED) Adjustments § 1.482-8 Examples of the best method rule....

  13. 26 CFR 1.482-8 - Examples of the best method rule.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... research capabilities of MDI). In this case, application of the market capitalization method, based on the... 26 Internal Revenue 6 2014-04-01 2014-04-01 false Examples of the best method rule. 1.482-8... TAX (CONTINUED) INCOME TAXES (CONTINUED) Adjustments § 1.482-8 Examples of the best method rule....

  14. 26 CFR 1.482-8T - Examples of the best method rule (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Examples of the best method rule (temporary). 1.482-8T Section 1.482-8T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Adjustments § 1.482-8T Examples of the best method rule (temporary). (a) . For further...

  15. 26 CFR 1.482-8 - Examples of the best method rule.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 6 2013-04-01 2013-04-01 false Examples of the best method rule. 1.482-8 Section 1.482-8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Adjustments § 1.482-8 Examples of the best method rule. (a) Introduction. In accordance with the best...

  16. 26 CFR 1.482-8 - Examples of the best method rule.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Examples of the best method rule. 1.482-8 Section 1.482-8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Adjustments § 1.482-8 Examples of the best method rule. (a) Introduction. In accordance with the best...

  17. Ghanaian cocoa bean fermentation characterized by spectroscopic and chromatographic methods and chemometrics.

    PubMed

    Aculey, Patrick C; Snitkjaer, Pia; Owusu, Margaret; Bassompiere, Marc; Takrama, Jemmy; Nørgaard, Lars; Petersen, Mikael A; Nielsen, Dennis S

    2010-08-01

    Export of cocoa beans is of great economic importance in Ghana and several other tropical countries. Raw cocoa has an astringent, unpleasant taste, and flavor, and has to be fermented, dried, and roasted to obtain the characteristic cocoa flavor and taste. In an attempt to obtain a deeper understanding of the changes in the cocoa beans during fermentation and investigate the possibility of future development of objective methods for assessing the degree of fermentation, a novel combination of methods including cut test, colorimetry, fluorescence spectroscopy, NIR spectroscopy, and GC-MS evaluated by chemometric methods was used to examine cocoa beans sampled at different durations of fermentation and samples representing fully fermented and dried beans from all cocoa growing regions of Ghana. Using colorimetry it was found that samples moved towards higher a* and b* values as fermentation progressed. Furthermore, the degree of fermentation could, in general, be well described by the spectroscopic methods used. In addition, it was possible to link analysis of volatile compounds with predictions of fermentation time. Fermented and dried cocoa beans from the Volta and the Western regions clustered separately in the score plots based on colorimetric, fluorescence, NIR, and GC-MS indicating regional differences in the composition of Ghanaian cocoa beans. The study demonstrates the potential of colorimetry and spectroscopic methods as valuable tools for determining the fermentation degree of cocoa beans. Using GC-MS it was possible to demonstrate the formation of several important aroma compounds such 2-phenylethyl acetate, propionic acid, and acetoin and the breakdown of others like diacetyl during fermentation. Practical Application: The present study demonstrates the potential of using colorimetry and spectroscopic methods as objective methods for determining cocoa bean quality along the processing chain. Development of objective methods for determining cocoa bean quality will be of great importance for quality insurance within the fields of cocoa processing and raw material control in chocolate producing companies. PMID:20722952

  18. Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan

    PubMed Central

    Kumirska, Jolanta; Czerwicka, Małgorzata; Kaczyński, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr

    2010-01-01

    Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds. PMID:20559489

  19. Structures and Encapsulation Motifs of Functional Molecules Probed by Laser Spectroscopic and Theoretical Methods

    PubMed Central

    Kusaka, Ryoji; Inokuchi, Yoshiya; Xantheas, Sotiris S.; Ebata, Takayuki

    2010-01-01

    We report laser spectroscopic and computational studies of host/guest hydration interactions between functional molecules (hosts) and water (guest) in supersonic jets. The examined hosts include dibenzo-18-crown-6-ether (DB18C6), benzo-18-crown-6-ether (B18C6) and calix[4]arene (C4A). The gaseous complexes between the functional molecular hosts and water are generated under jet-cooled conditions. Various laser spectroscopic methods are applied for these species: the electronic spectra are observed by laser-induced fluorescence (LIF), mass-selected resonance enhanced multiphoton ionization (REMPI) and ultraviolet-ultraviolet hole-burning (UV-UV HB) spectroscopy, whereas the vibrational spectra for each individual species are observed by infrared-ultraviolet double resonance (IR-UV DR) spectroscopy. The obained results are analyzed by first principles electronic structure calculations. We discuss the conformations of the host molecules, the structures of the complexes, and key interactions forming the specific complexes. PMID:22319310

  20. Structures and encapsulation motifs of functional molecules probed by laser spectroscopic and theoretical methods.

    PubMed

    Kusaka, Ryoji; Inokuchi, Yoshiya; Xantheas, Sotiris S; Ebata, Takayuki

    2010-01-01

    We report laser spectroscopic and computational studies of host/guest hydration interactions between functional molecules (hosts) and water (guest) in supersonic jets. The examined hosts include dibenzo-18-crown-6-ether (DB18C6), benzo-18-crown-6-ether (B18C6) and calix[4]arene (C4A). The gaseous complexes between the functional molecular hosts and water are generated under jet-cooled conditions. Various laser spectroscopic methods are applied for these species: the electronic spectra are observed by laser-induced fluorescence (LIF), mass-selected resonance enhanced multiphoton ionization (REMPI) and ultraviolet-ultraviolet hole-burning (UV-UV HB) spectroscopy, whereas the vibrational spectra for each individual species are observed by infrared-ultraviolet double resonance (IR-UV DR) spectroscopy. The obained results are analyzed by first principles electronic structure calculations. We discuss the conformations of the host molecules, the structures of the complexes, and key interactions forming the specific complexes. PMID:22319310

  1. Optical caries diagnostics: comparison of laser spectroscopic PNC method with method of laser integral fluorescence

    NASA Astrophysics Data System (ADS)

    Masychev, Victor I.

    2000-11-01

    In this research we present the results of approbation of two methods of optical caries diagnostics: PNC-spectral diagnostics and caries detection by laser integral fluorescence. The research was conducted in a dental clinic. PNC-method analyses parameters of probing laser radiation and PNC-spectrums of stimulated secondary radiations: backscattering and endogenous fluorescence of caries-involved bacterias. He-Ne-laser ((lambda) =632,8 nm, 1-2mW) was used as a source of probing (stimulated) radiation. For registration of signals, received from intact and pathological teeth PDA-detector was applied. PNC-spectrums were processed by special algorithms, and were displayed on PC monitor. The method of laser integral fluorescence was used for comparison. In this case integral power of fluorescence of human teeth was measured. As a source of probing (stimulated) radiation diode lasers ((lambda) =655 nm, 0.1 mW and 630nm, 1mW) and He-Ne laser were applied. For registration of signals Si-photodetector was used. Integral power was shown in a digital indicator. Advantages and disadvantages of these methods are described in this research. It is disclosed that the method of laser integral power of fluorescence has the following characteristics: simplicity of construction and schema-technical decisions. However the method of PNC-spectral diagnostics are characterized by considerably more sensitivity in diagnostics of initial caries and capability to differentiate pathologies of various stages (for example, calculus/initial caries). Estimation of spectral characteristics of PNC-signals allows eliminating a number of drawbacks, which are character for detection by method of laser integral fluorescence (for instance, detection of fluorescent fillings, plagues, calculus, discolorations generally, amalgam, gold fillings as if it were caries.

  2. Combining sequence-based prediction methods and circular dichroism and infrared spectroscopic data to improve protein secondary structure determinations

    PubMed Central

    Lees, Jonathan G; Janes, Robert W

    2008-01-01

    Background A number of sequence-based methods exist for protein secondary structure prediction. Protein secondary structures can also be determined experimentally from circular dichroism, and infrared spectroscopic data using empirical analysis methods. It has been proposed that comparable accuracy can be obtained from sequence-based predictions as from these biophysical measurements. Here we have examined the secondary structure determination accuracies of sequence prediction methods with the empirically determined values from the spectroscopic data on datasets of proteins for which both crystal structures and spectroscopic data are available. Results In this study we show that the sequence prediction methods have accuracies nearly comparable to those of spectroscopic methods. However, we also demonstrate that combining the spectroscopic and sequences techniques produces significant overall improvements in secondary structure determinations. In addition, combining the extra information content available from synchrotron radiation circular dichroism data with sequence methods also shows improvements. Conclusion Combining sequence prediction with experimentally determined spectroscopic methods for protein secondary structure content significantly enhances the accuracy of the overall results obtained. PMID:18197968

  3. Weighted partial least squares method to improve calibration precision for spectroscopic noise-limited data

    SciTech Connect

    Haaland, D.M.; Jones, H.D.T.

    1997-09-01

    Multivariate calibration methods have been applied extensively to the quantitative analysis of Fourier transform infrared (FT-IR) spectral data. Partial least squares (PLS) methods have become the most widely used multivariate method for quantitative spectroscopic analyses. Most often these methods are limited by model error or the accuracy or precision of the reference methods. However, in some cases, the precision of the quantitative analysis is limited by the noise in the spectroscopic signal. In these situations, the precision of the PLS calibrations and predictions can be improved by the incorporation of weighting in the PLS algorithm. If the spectral noise of the system is known (e.g., in the case of detector-noise-limited cases), then appropriate weighting can be incorporated into the multivariate spectral calibrations and predictions. A weighted PLS (WPLS) algorithm was developed to improve the precision of the analysis in the case of spectral-noise-limited data. This new PLS algorithm was then tested with real and simulated data, and the results compared with the unweighted PLS algorithm. Using near-infrared (NIR) calibration precision when the WPLS algorithm was applied. The best WPLS method improved prediction precision for the analysis of one of the minor components by a factor of nearly 9 relative to the unweighted PLS algorithm.

  4. 26 CFR 1.482-8 - Examples of the best method rule.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Examples of the best method rule. 1.482-8 Section 1.482-8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Adjustments § 1.482-8 Examples of the best method rule. (a) Introduction. In accordance with the best method rule of...

  5. Interaction of methotrexate with trypsin analyzed by spectroscopic and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Wang, Yanqing; Zhang, Hongmei; Cao, Jian; Zhou, Qiuhua

    2013-11-01

    Trypsin is one of important digestive enzymes that have intimate correlation with human health and illness. In this work, the interaction of trypsin with methotrexate was investigated by spectroscopic and molecular modeling methods. The results revealed that methotrexate could interact with trypsin with about one binding site. Methotrexate molecule could enter into the primary substrate-binding pocket, resulting in inhibition of trypsin activity. Furthermore, the thermodynamic analysis implied that electrostatic force, hydrogen bonding, van der Waals and hydrophobic interactions were the main interactions for stabilizing the trypsin-methotrexate system, which agreed well with the results from the molecular modeling study.

  6. Spectroscopic networks

    NASA Astrophysics Data System (ADS)

    Csaszar, A. G.; Furtenbacher, T.

    2011-05-01

    Approaches related to graph theory are given which allow a better understanding of and yield routes for systematic enlargement and improvement of experimental spectroscopic line lists of molecules. The protocols are based on the fact that the information in line lists can be related to large-scale, weighted, undirected graphs, whereby the vertices are discrete energy levels, the edges are transitions, and the weights are transition intensities. The resulting graph is what one may call a spectroscopic network (SN). It is shown on the example of the HD16O isotopologue of the water molecule that both its measured and first-principles one-photon absorption SNs have a scale-free behavior with all of the usual consequences, including appearance of hubs, robustness, error tolerance, and the "small-world" property. The graph-theoretical view of molecular spectra offers several new ideas for improving the accuracy and robustness of the information systems containing high-resolution spectroscopic data.

  7. Detailed spectroscopic analysis of SN 1987A: The distance to the LMC using the SEAM method

    SciTech Connect

    Mitchell, Robert C.; Baron, E.; Branch, David; Hauschildt, Peter H.; Nugent, Peter E.; Lundqvist, Peter; Blinnikov, Sergei; Pun, Chun S.J.

    2002-05-21

    Supernova 1987A remains the most well-studied supernova to date. Observations produced excellent broad-band photometric and spectroscopic coverage over a wide wavelength range at all epochs. We model the observed spectra from Day 1 to Day 81 using a hydrodynamical model. We show that good agreement can be obtained at times up to about 60 days, if we allow for extended nickel mixing. Later than about 60 days the observed Balmer lines become stronger than our models can reproduce. We show that this is likely due to a more complicated distribution of gamma-rays than we allow for in our spherically symmetric calculations. We present synthetic light curves in UBVRIJHK and a synthetic bolometric light curve. Using this broad baseline of detailed spectroscopic models we find a distance modulus mu = 18.5 +/- 0.2 using the SEAM method of determining distances to supernovae. We find that the explosion time agrees with that of the neutrino burst and is constrained at 68 percent confidence to within +/- 0.9 days. We argue that the weak Balmer lines of our detailed model calculations casts doubt on the accuracy of the purely photometric EPM method. We also suggest that Type IIP supernovae will be most useful as distance indicators at early times due to a variety of effects.

  8. Spectroscopic characterization and quantitative determination of atorvastatin calcium impurities by novel HPLC method

    NASA Astrophysics Data System (ADS)

    Gupta, Lokesh Kumar

    2012-11-01

    Seven process related impurities were identified by LC-MS in the atorvastatin calcium drug substance. These impurities were identified by LC-MS. The structure of impurities was confirmed by modern spectroscopic techniques like 1H NMR and IR and physicochemical studies conducted by using synthesized authentic reference compounds. The synthesized reference samples of the impurity compounds were used for the quantitative HPLC determination. These impurities were detected by newly developed gradient, reverse phase high performance liquid chromatographic (HPLC) method. The system suitability of HPLC analysis established the validity of the separation. The analytical method was validated according to International Conference of Harmonization (ICH) with respect to specificity, precision, accuracy, linearity, robustness and stability of analytical solutions to demonstrate the power of newly developed HPLC method.

  9. A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples.

    PubMed

    Song, Young Kyoung; Hong, Sang Hee; Jang, Mi; Han, Gi Myung; Rani, Manviri; Lee, Jongmyoung; Shim, Won Joon

    2015-04-15

    The analysis of microplastics in various environmental samples requires the identification of microplastics from natural materials. The identification technique lacks a standardized protocol. Herein, stereomicroscope and Fourier transform infrared spectroscope (FT-IR) identification methods for microplastics (<1mm) were compared using the same samples from the sea surface microlayer (SML) and beach sand. Fragmented microplastics were significantly (p<0.05) underestimated and fiber was significantly overestimated using the stereomicroscope both in the SML and beach samples. The total abundance by FT-IR was higher than by microscope both in the SML and beach samples, but they were not significantly (p>0.05) different. Depending on the number of samples and the microplastic size range of interest, the appropriate identification method should be determined; selecting a suitable identification method for microplastics is crucial for evaluating microplastic pollution. PMID:25682567

  10. Novel spectroscopic methods for determination of Cromolyn sodium and Oxymetazoline hydrochloride in binary mixture

    NASA Astrophysics Data System (ADS)

    Abdel-Aziz, Omar; El-Kosasy, A. M.; Magdy, N.; El Zahar, N. M.

    2014-10-01

    New accurate, sensitive and selective spectrophotometric and spectrofluorimetric methods were developed and subsequently validated for determination of Cromolyn sodium (CS) and Oxymetazoline HCl (OXY) in binary mixture. These methods include ‘H-point standard addition method (HPSAM) and area under the curve (AUC)' spectrophotometric method and first derivative synchronous fluorescence spectroscopic (FDSFS) method. For spectrophotometric methods, absorbances were recorded at 241.5 nm and 274.9 nm for HPSAM and the wavelength was selected in ranges 232.0-254.0 nm and 216.0-229.0 nm for AUC method, where the concentration was obtained by applying Cramer's rule. For FDSFS method, the first-derivative synchronous fluorescence signal was measured at 290.0 nm, using Δλ = 145.0 nm. The suggested methods were validated according to International Conference of Harmonization (ICH) guidelines and the results revealed that they were precise and reproducible. All the obtained results were statistically compared with those of the reported method and there was no significant difference.

  11. Using Mixed Methods to Analyze Video Data: A Mathematics Teacher Professional Development Example

    ERIC Educational Resources Information Center

    DeCuir-Gunby, Jessica T.; Marshall, Patricia L.; McCulloch, Allison W.

    2012-01-01

    This article uses data from 65 teachers participating in a K-2 mathematics professional development research project as an example of how to analyze video recordings of teachers' classroom lessons using mixed methods. Through their discussion, the authors demonstrate how using a mixed methods approach to classroom video analysis allows researchers…

  12. Structures and Encapsulation Motifs of Functional Molecules probed by Laser Spectroscopic and Theoretical methods

    SciTech Connect

    Kusaka, Ryoji; Inokuchi, Yoshiya; Xantheas, Sotiris S.; Ebata, Takayuki

    2010-04-01

    We report laser spectroscopic studies of host/guest hydration interactions between functional molecules (hosts) and water (guest) in supersonic jets. The examined hosts include dibenzo-18-crown-6-ether (DB18C6), benzo-18-crown-6-ether (B18C6) and calix[4]arene (C4A). The gaseous complexes between the functional molecular hosts and water are generated under jet-cooled conditions. Various laser spectroscopic methods are applied for these species: the electronic spectra are observed by laser-induced fluorescence (LIF) , massselected resonance enhanced multiphoton ionization (REMPI) and ultraviolet-ultraviolet holeburning (UV-UV HB) spectroscopy, whereas the vibrational spectra for each individual species are observed by infrared-ultraviolet double resonance (IR-UV DR) spectroscopy. The obained results are analyzed by first principles electronic structure calculations. We discuss the conformations of the host molecules, the various structures of the complexes and the key interactions that result in the complexation as well as the effect of the host conformation in the resulting complexation mechanism.

  13. Laser apparatus and method for microscopic and spectroscopic analysis and processing of biological cells

    DOEpatents

    Gourley, P.L.; Gourley, M.F.

    1997-03-04

    An apparatus and method are disclosed for microscopic and spectroscopic analysis and processing of biological cells. The apparatus comprises a laser having an analysis region within the laser cavity for containing one or more biological cells to be analyzed. The presence of a cell within the analysis region in superposition with an activated portion of a gain medium of the laser acts to encode information about the cell upon the laser beam, the cell information being recoverable by an analysis means that preferably includes an array photodetector such as a CCD camera and a spectrometer. The apparatus and method may be used to analyze biomedical cells including blood cells and the like, and may include processing means for manipulating, sorting, or eradicating cells after analysis. 20 figs.

  14. Laser apparatus and method for microscopic and spectroscopic analysis and processing of biological cells

    DOEpatents

    Gourley, Paul L.; Gourley, Mark F.

    1997-01-01

    An apparatus and method for microscopic and spectroscopic analysis and processing of biological cells. The apparatus comprises a laser having an analysis region within the laser cavity for containing one or more biological cells to be analyzed. The presence of a cell within the analysis region in superposition with an activated portion of a gain medium of the laser acts to encode information about the cell upon the laser beam, the cell information being recoverable by an analysis means that preferably includes an array photodetector such as a CCD camera and a spectrometer. The apparatus and method may be used to analyze biomedical cells including blood cells and the like, and may include processing means for manipulating, sorting, or eradicating cells after analysis thereof.

  15. Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

    PubMed Central

    Irfan, Madiha; Samra, Shahid Ameen

    2011-01-01

    Summary The synthesis, as well as spectroscopic and thermochemical studies of a novel class of carbazole-4-phenylpyridine co-polymers are described. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole–pyridine copolymers which involve costly catalysts. Thus, two series of polymers were synthesized by a modified Chichibabin reaction, i.e., by the condensation of diacetylated N-alkylcarbazoles with 3-substituted benzaldehydes in the presence of ammonium acetate in refluxing acetic acid. All the polymers were characterized by FTIR, 1H NMR, 13C NMR, UV–vis spectroscopy, fluorimetry, TGA and DSC. The weight average molecular masses (M w) of the polymers were estimated by the laser light scattering (LLS) technique. PMID:21647253

  16. Data processing method applying principal component analysis and spectral angle mapper for imaging spectroscopic sensors

    NASA Astrophysics Data System (ADS)

    García-Allende, P. B.; Conde, O. M.; Mirapeix, J.; Cubillas, A. M.; López-Higuera, J. M.

    2007-07-01

    A data processing method for hyperspectral images is presented. Each image contains the whole diffuse reflectance spectra of the analyzed material for all the spatial positions along a specific line of vision. This data processing method is composed of two blocks: data compression and classification unit. Data compression is performed by means of Principal Component Analysis (PCA) and the spectral interpretation algorithm for classification is the Spectral Angle Mapper (SAM). This strategy of classification applying PCA and SAM has been successfully tested on the raw material on-line characterization in the tobacco industry. In this application case the desired raw material (tobacco leaves) should be discriminated from other unwanted spurious materials, such as plastic, cardboard, leather, candy paper, etc. Hyperspectral images are recorded by a spectroscopic sensor consisting of a monochromatic camera and a passive Prism- Grating-Prism device. Performance results are compared with a spectral interpretation algorithm based on Artificial Neural Networks (ANN).

  17. Method and apparatus for differential spectroscopic atomic-imaging using scanning tunneling microscopy

    DOEpatents

    Kazmerski, Lawrence L.

    1990-01-01

    A Method and apparatus for differential spectroscopic atomic-imaging is disclosed for spatial resolution and imaging for display not only individual atoms on a sample surface, but also bonding and the specific atomic species in such bond. The apparatus includes a scanning tunneling microscope (STM) that is modified to include photon biasing, preferably a tuneable laser, modulating electronic surface biasing for the sample, and temperature biasing, preferably a vibration-free refrigerated sample mounting stage. Computer control and data processing and visual display components are also included. The method includes modulating the electronic bias voltage with and without selected photon wavelengths and frequency biasing under a stabilizing (usually cold) bias temperature to detect bonding and specific atomic species in the bonds as the STM rasters the sample. This data is processed along with atomic spatial topography data obtained from the STM raster scan to create a real-time visual image of the atoms on the sample surface.

  18. Apparatus for and method of performing spectroscopic analysis on an article

    DOEpatents

    Powell, George Louis; Hallman, Jr., Russell Louis

    1999-01-01

    An apparatus for and method of analyzing an article having an entrance and an exit in communication with the entrance. The apparatus comprises: a spectrometer having an emission source with a focal point; a plurality of mirrors; and a detector connected to the spectroscope. The emission source is positioned so that its focal point is substantially coextensive with the entrance of the article. The mirrors comprise: a first mirror positionable adjacent the exit of the article and a second mirror positioned relative to the other of said plurality of mirrors. The first mirror receives scattered emissions exiting the article and substantially collimates the scattered emissions. The second mirror substantially focuses the collimated emissions into a focused emission. The detector receives the focused emission from the mirrors.

  19. Apparatus for and method of performing spectroscopic analysis on an article

    DOEpatents

    Powell, G.L.; Hallman, R.L. Jr.

    1999-04-20

    An apparatus and method are disclosed for analyzing an article having an entrance and an exit in communication with the entrance. The apparatus comprises: a spectrometer having an emission source with a focal point; a plurality of mirrors; and a detector connected to the spectroscope. The emission source is positioned so that its focal point is substantially coextensive with the entrance of the article. The mirrors comprise: a first mirror positionable adjacent the exit of the article and a second mirror positioned relative to the other of said plurality of mirrors. The first mirror receives scattered emissions exiting the article and substantially collimates the scattered emissions. The second mirror substantially focuses the collimated emissions into a focused emission. The detector receives the focused emission from the mirrors. 6 figs.

  20. Examples of geomorphic reclamation on mined lands in Spain by using the GeoFluv method

    NASA Astrophysics Data System (ADS)

    Martín Duque, José F.; Bugosh, Nicholas; de Francisco, Cristina; Hernando, Néstor; Martín, Cristina; Nicolau, José M.; Nyssen, Sara; Tejedor, María; Zapico, Ignacio

    2015-04-01

    This paper describes seven examples of geomorphic reclamation on mined lands of Spain, as solutions for complex environmental problems, by using the GeoFluv method through the Natural Regrade software (Carlson). Of these seven examples, four of them have been partially or totally constructed. Each of them has its own particularities and contributions, becoming innovative geomorphic solutions to existing environmental (ecological, social and economic) problems. The Quebraderos de la Serrana example (Toledo province) allowed a local company to get permission for slate quarrying in a highly ecologically vulnerable area; before that, the permission for extracting rocks had been rejected with a conventional reclamation approach. The Somolinos case is, to this date, the most complete geomorphic reclamation in Spain, and the first one in Europe to have been built by using the GeoFluv method. This restoration has healed a degraded area of about six hectares at the outskirts of the Somolinos hamlet, in a valuable rural landscape of the Guadalajara province. The Arlanza example (Leon province) shows a design which proposes to restore the hydrological connectivity of a coal mine dump which blocked a valley. The Machorro and María Jose examples (Guadalajara province) are allowing kaolin mining to be compatible with the preservation of protected areas at the edge of the Upper Tagus Natural Park (UTNP), in highly vulnerable conditions for water erosion. The Campredó case (Tarragona province) shows an agreement between a mining company, the academia, and the Catalonian Agency of Water, to combine a high standard of geomorphic reclamation with solving problems caused by flooding downstream of a clay mining area. Finally, the Nuria example is also located at the UTNP area; the goals here are to stabilize a large landslide in a waste dump and to minimize the risk of occurrence of flash floods from mining ponds. Additional information on these examples and about the state of art of the Geomorphic Reclamation practice in Spain can be found at http://www.restauraciongeomorfologica.es.

  1. New method for determination of the photoresist Dill parameters using spectroscopic ellipsometry

    NASA Astrophysics Data System (ADS)

    Boher, Pierre; Defranoux, Christophe; Piel, Jean-Philippe; Stehle, Jean-Louis P.

    1999-06-01

    In this paper a new method to determine photoresist DIll parameters is presented. Based on spectroscopic ellipsometry (SE) measurements, this new method is more precise than standard techniques based on transmittance measurements. Indeed, compared to photometry, SE technique is a self calibrated technique which provide directly two independent parameters Tan (Psi) and Cos (Delta) which can be used to extract directly thickness but also optical indices of a layer inside a multilayer structure. Moreover, the wavelength dependence introduces more restrictions for the data analysis since thickness and optical indices can be deduced directly in many cases. We apply this technique to different kinds of photoresist designed for 365nm and 248nm. At each wavelength ellipsometric parameters are simulate directly versus the exposure dose without any assumption on the thickness and on the index of refraction evolution. On 365nm photoresist this new method provides Dill parameters in good agreement with the standard method. On 248nm photoresist we show that the influence of the exposure is more important on the refractive index and on the thickness of the layer than on its absorption.

  2. New method for determination of the photoresist Dill parameters using spectroscopic ellipsometry

    NASA Astrophysics Data System (ADS)

    Boher, Pierre; Defranoux, Christophe; Piel, Jean-Philippe; Stehle, Jean-Louis P.

    1999-04-01

    In this paper a new method to determine photoresist Dill parameters is presented. Based on spectroscopic ellipsometry (SE) measurements, this new method is more precise than standard techniques based on transmittance measurements. Indeed, compared to photometry, SE technique is a self calibrated technique which provide directly two independent parameters Tan (Psi) and Cos (Delta) which can be used to extract directly thickness but also optical indices of a layer inside a multilayer structure. Moreover, the wavelength dependence introduces more restrictions for the data analysis since thickness and optical indices can be deduced directly in many cases. We apply this technique to different kinds of photoresist designed for 365nm and 248nm. At each wavelength ellipsometric parameters are simulated directly versus the exposure dose without any assumption on the thickness and on the index of refraction evolution. On 365nm photoresist this new method provides Dill parameters in good agreement with the standard method. On 248nm photoresist we show that the influence of the exposure is more important on the refractive index and on the thickness of the layer than on its absorption.

  3. Automatic diagnosis of melanoma using machine learning methods on a spectroscopic system

    PubMed Central

    2014-01-01

    Background Early and accurate diagnosis of melanoma, the deadliest type of skin cancer, has the potential to reduce morbidity and mortality rate. However, early diagnosis of melanoma is not trivial even for experienced dermatologists, as it needs sampling and laboratory tests which can be extremely complex and subjective. The accuracy of clinical diagnosis of melanoma is also an issue especially in distinguishing between melanoma and mole. To solve these problems, this paper presents an approach that makes non-subjective judgements based on quantitative measures for automatic diagnosis of melanoma. Methods Our approach involves image acquisition, image processing, feature extraction, and classification. 187 images (19 malignant melanoma and 168 benign lesions) were collected in a clinic by a spectroscopic device that combines single-scattered, polarized light spectroscopy with multiple-scattered, un-polarized light spectroscopy. After noise reduction and image normalization, features were extracted based on statistical measurements (i.e. mean, standard deviation, mean absolute deviation, L 1 norm, and L 2 norm) of image pixel intensities to characterize the pattern of melanoma. Finally, these features were fed into certain classifiers to train learning models for classification. Results We adopted three classifiers – artificial neural network, naïve bayes, and k-nearest neighbour to evaluate our approach separately. The naive bayes classifier achieved the best performance - 89% accuracy, 89% sensitivity and 89% specificity, which was integrated with our approach in a desktop application running on the spectroscopic system for diagnosis of melanoma. Conclusions Our work has two strengths. (1) We have used single scattered polarized light spectroscopy and multiple scattered unpolarized light spectroscopy to decipher the multilayered characteristics of human skin. (2) Our approach does not need image segmentation, as we directly probe tiny spots in the lesion skin and the image scans do not involve background skin. The desktop application for automatic diagnosis of melanoma can help dermatologists get a non-subjective second opinion for their diagnosis decision. PMID:25311811

  4. Applying Process Improvement Methods to Clinical and Translational Research: Conceptual Framework and Case Examples.

    PubMed

    Daudelin, Denise H; Selker, Harry P; Leslie, Laurel K

    2015-12-01

    There is growing appreciation that process improvement holds promise for improving quality and efficiency across the translational research continuum but frameworks for such programs are not often described. The purpose of this paper is to present a framework and case examples of a Research Process Improvement Program implemented at Tufts CTSI. To promote research process improvement, we developed online training seminars, workshops, and in-person consultation models to describe core process improvement principles and methods, demonstrate the use of improvement tools, and illustrate the application of these methods in case examples. We implemented these methods, as well as relational coordination theory, with junior researchers, pilot funding awardees, our CTRC, and CTSI resource and service providers. The program focuses on capacity building to address common process problems and quality gaps that threaten the efficient, timely and successful completion of clinical and translational studies. PMID:26332869

  5. Development of vibrational spectroscopic methods to rapidly and non-destructively assess quality of chicken breast meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of Vibrational Spectroscopic Methods to Rapidly and Non-Destructively Assess Quality of Chicken Breast Meat H. Zhuang1, M. Sohn2, S. Trabelsi1 and K. Lawrence1 1Quality and Safety Assessment Research Unit, ARS-USDA, 950 College Station Road, Athens, GA 30605 2University of Georgia, De...

  6. Spectroscopic studies on the interaction between tetrandrine and two serum albumins by chemometrics methods

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengjun; Liu, Rong; jiang, Xiaohui

    2013-11-01

    The binding interactions of tetrandrine (TETD) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by spectroscopic methods. These experimental data were further analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method, and the concentration profiles and pure spectra for three species (BSA/HSA, TETD and TETD-BSA/HSA) existed in the interaction procedure, as well as, the apparent equilibrium constants Kapp were evaluated. The binding sites number n and the binding constants K were obtained at various temperatures. The binding distance between TETD and BSA/HSA was 1.455/1.451 nm. The site markers competitive experiments indicated that TETD primarily bound to the tryptophan residue of BSA/HSA within site I. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TETD-BSA was mainly depended on the hydrophobic interaction strongly and electrostatic interaction, and yet the binding of TETD-HSA was strongly relied on the hydrophobic interaction. The results of synchronous fluorescence, 3D fluorescence and FT-IR spectra show that the conformation of proteins has altered in the presence of TETD. In addition, the effect of some common ions on the binding constants between TETD and proteins were also discussed.

  7. Comparability of a Three-Dimensional Structure in Biopharmaceuticals Using Spectroscopic Methods

    PubMed Central

    Abad-Javier, Mario E.; Romero-Díaz, Alexis J.; Villaseñor-Ortega, Francisco; Pérez, Néstor O.; Flores-Ortiz, Luis F.

    2014-01-01

    Protein structure depends on weak interactions and covalent bonds, like disulfide bridges, established according to the environmental conditions. Here, we present the validation of two spectroscopic methodologies for the measurement of free and unoxidized thiols, as an attribute of structural integrity, using 5,5′-dithionitrobenzoic acid (DTNB) and DyLight Maleimide (DLM) as derivatizing agents. These methods were used to compare Rituximab and Etanercept products from different manufacturers. Physicochemical comparability was demonstrated for Rituximab products as DTNB showed no statistical differences under native, denaturing, and denaturing-reducing conditions, with Student's t-test P values of 0.6233, 0.4022, and 0.1475, respectively. While for Etanercept products no statistical differences were observed under native (P = 0.0758) and denaturing conditions (P = 0.2450), denaturing-reducing conditions revealed cysteine contents of 98% and 101%, towards the theoretical value of 58, for the evaluated products from different Etanercept manufacturers. DLM supported equality between Rituximab products under native (P = 0.7499) and denaturing conditions (P = 0.8027), but showed statistical differences among Etanercept products under native conditions (P < 0.001). DLM suggested that Infinitam has fewer exposed thiols than Enbrel, although DTNB method, circular dichroism (CD), fluorescence (TCSPC), and activity (TNFα neutralization) showed no differences. Overall, this data revealed the capabilities and drawbacks of each thiol quantification technique and their correlation with protein structure. PMID:24963443

  8. Characterization of organic matter from composting of different residues by physicochemical and spectroscopic methods.

    PubMed

    Fialho, Lucimar Lopes; Lopes da Silva, Wilson Tadeu; Milori, Débora M B P; Simões, Marcelo Luiz; Martin-Neto, Ladislau

    2010-03-01

    Chemical and spectroscopic methods were used to characterize organic matter transformations during the composting process. Four different residue mixtures were studied: P1--garden trimmings (GT) only, P2 - GT plus fresh cattle manure, P3--GT plus orange pomace and P4--GT plus filter cake. The thermophilic phase was not reached in P1 compost, but the P2, P3 and P4 composts showed all three typical process phases. The thermophilic phase and CEC/C ratio stabilized after 90 days, while C/N ratio and the ash content stabilized after 60 days. The increasing E(4)/E(6) ratio indicated oxidation reactions occurring during the process in the material from P2, P3 and P4. The (13)C NMR and FTIR results suggested extraction of both pectin and lignin in the HA-like fraction. The CEC/C ratio, temperature and E(4)/E(6) ratio showed that within 90 days P2, P3 and P4 composts were humified. However, material from P1 did not show characteristics of humified compost. From these data, it is apparent that C/N ratio and ash content are not reliable methods for monitoring the composting process. PMID:19954966

  9. Comparability of a three-dimensional structure in biopharmaceuticals using spectroscopic methods.

    PubMed

    Pérez Medina Martínez, Víctor; Abad-Javier, Mario E; Romero-Díaz, Alexis J; Villaseñor-Ortega, Francisco; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

    2014-01-01

    Protein structure depends on weak interactions and covalent bonds, like disulfide bridges, established according to the environmental conditions. Here, we present the validation of two spectroscopic methodologies for the measurement of free and unoxidized thiols, as an attribute of structural integrity, using 5,5'-dithionitrobenzoic acid (DTNB) and DyLight Maleimide (DLM) as derivatizing agents. These methods were used to compare Rituximab and Etanercept products from different manufacturers. Physicochemical comparability was demonstrated for Rituximab products as DTNB showed no statistical differences under native, denaturing, and denaturing-reducing conditions, with Student's t-test P values of 0.6233, 0.4022, and 0.1475, respectively. While for Etanercept products no statistical differences were observed under native (P = 0.0758) and denaturing conditions (P = 0.2450), denaturing-reducing conditions revealed cysteine contents of 98% and 101%, towards the theoretical value of 58, for the evaluated products from different Etanercept manufacturers. DLM supported equality between Rituximab products under native (P = 0.7499) and denaturing conditions (P = 0.8027), but showed statistical differences among Etanercept products under native conditions (P < 0.001). DLM suggested that Infinitam has fewer exposed thiols than Enbrel, although DTNB method, circular dichroism (CD), fluorescence (TCSPC), and activity (TNF α neutralization) showed no differences. Overall, this data revealed the capabilities and drawbacks of each thiol quantification technique and their correlation with protein structure. PMID:24963443

  10. Borehole-to-surface electromagnetic methods -- System design and field examples

    SciTech Connect

    Bartel, L.C.; Wilt, M.J.; Tseng, H.W.

    1995-05-01

    Borehole-to-surface electromagnetic (EM) methods are an attractive alternative to Surface-based EM methods for a variety of environmental and engineering applications. They have improved sensitivity to the subsurface resistivity distribution because of the closer proximity to the area of interest offered by the borehole for the source or the receiver. For the borehole-to-surface measurements the source is in the borehole and the receivers are on the surface. On the other hand, for the surface-to-borehole methods, the source is on the surface and the receiver is in a borehole. The surface-to-borehole method has an added advantage since measurements are often more accurate due to the lower noise environment for the receiver. For these methods, the source can be a grounded electric dipole or a vertical magnetic dipole source. An added benefit of these techniques is field measurements are made using a variety of arrays where the system is tailored to the application and where one can take advantage of some new imaging methods. In this short paper the authors describe the application of the borehole-to-surface method, discuss benefits and shortcomings, and give two field examples where they have been used for underground imaging. The examples were the monitoring of a salt water flooding of an oil well and the characterization of a fuel oil spill.

  11. Pedagogies in Action: A Community Resource Linking Teaching Methods to Examples of their Use

    NASA Astrophysics Data System (ADS)

    Manduca, C. A.; Fox, S. P.; Iverson, E. A.; Kirk, K.; Ormand, C. J.

    2009-12-01

    The Pedagogies in Action portal (http://serc.carleton.edu/sp) provides access to information on more than 40 teaching methods with examples of their use in geoscience and beyond. Each method is described with pages addressing what the method is, why or when it is useful, and how it can be implemented. New methods added this year include Teaching with Google Earth, Jigsaw, Teaching the Process of Science, Guided Discovery Problems, Teaching Urban Students, and Using ConceptTests. Examples then show specifically how the method has been used to teach concepts in a variety of disciplines. The example collection now includes 775 teaching activities of which more than 550 are drawn from the geosciences. Geoscience faculty are invited to add their own examples to this collection or to test examples in the collection and provide a review. Evaluation results show that the combination of modules and activities inspires teachers at all levels to use a new pedagogy and increases their confidence that they can use it successfully. In addition, submitting activities to the collection, including writing summary information for other instructors, helps them think more carefully about the design of their activity. The activity collections are used both for ready to use activities and to find ideas for new activities. The portal provides overarching access to materials developed by a wide variety of collaborating partners each of which uses the service to create a customized pedagogic portal addressing a more specific audience. Of interest to AGU members are pedagogic portals on Starting Point: Teaching Introductory Geoscience (http://serc.carleton.edu/introgeo); On the Cutting Edge (http://serc.carleton.edu/NAGTWorkshops); Enduring Resources for Earth System Education (http://earthref.org/ERESE) Microbial Life Educational Resources (http://serc.carleton.edu/microbe_life); the National Numeracy Network (http://serc.carleton.edu/nnn/index.html); CAUSE: The Consortium for Undergraduate Statistics Education (http://causeweb.org); ComPADRE: Digital Resources for Physics and Astronomy Education (http://www.compadre.org) and Project Kaleidoscope (http://pkal.org). Pedagogies in Action is part of the National Science Digital Library (http://nsdl.org). Projects or groups interested in exploring use of the service can find information about using the service on the project website or contact the authors.

  12. An effective selection method for low-mass active black holes and first spectroscopic identification

    NASA Astrophysics Data System (ADS)

    Morokuma, Tomoki; Tominaga, Nozomu; Tanaka, Masaomi; Yasuda, Naoki; Furusawa, Hisanori; Taniguchi, Yuki; Kato, Takahiro; Jiang, Ji-an; Nagao, Tohru; Kuncarayakti, Hanindyo; Morokuma-Matsui, Kana; Ikeda, Hiroyuki; Blinnikov, Sergei; Nomoto, Ken'ichi; Kokubo, Mitsuru; Doi, Mamoru

    2016-06-01

    We present a new method for effectively selecting objects which may be low-mass active black holes (BHs) at galaxy centers using high-cadence optical imaging data, and our first spectroscopic identification of an active 2.7 × 106 M⊙ BH at z = 0.164. This active BH was originally selected due to its rapid optical variability, from a few hours to a day, based on Subaru Hyper Suprime-Cam g-band imaging data taken with a 1 hr cadence. Broad and narrow Hα lines and many other emission ones are detected in our optical spectra taken with Subaru FOCAS, and the BH mass is measured via the broad Hα emission line width (1880 km s-1) and luminosity (4.2 × 1040 erg s-1) after careful correction to the atmospheric absorption around 7580-7720 Å. We measure the Eddington ratio and find it to be as low as 0.05, considerably smaller than those in a previous SDSS sample with similar BH mass and redshift, which indicates one of the special potentials of our Subaru survey. The g - r color and morphology of the extended component indicate that the host galaxy is a star-forming galaxy. We also show the effectiveness of our variability selection for low-mass active BHs.

  13. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH = 7.4) were 1.41 × 105 M- 1 and about 1 at 310 K, respectively. The values of the enthalpic change (ΔH0), entropic change (ΔS0) and Gibbs free energy (ΔG0) in the binding process of atorvastatin with BSA at 310 K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.

  14. Structure of Scots pine defensin 1 by spectroscopic methods and computational modeling.

    PubMed

    Ermakova, Elena A; Faizullin, Dzhigangir A; Idiyatullin, Bulat Z; Khairutdinov, Bulat I; Mukhamedova, Liya N; Tarasova, Nadezhda B; Toporkova, Yana Y; Osipova, Elena V; Kovaleva, Valentina; Gogolev, Yuri V; Zuev, Yuriy F; Nesmelova, Irina V

    2016-03-01

    Defensins are part of the innate immune system in plants with activity against a broad range of pathogens, including bacteria, fungi and viruses. Several defensins from conifers, including Scots pine defensin 1 (Pinus sylvestris defensin 1, (PsDef1)) have shown a strong antifungal activity, however structural and physico-chemical properties of the family, needed for establishing the structure-dynamics-function relationships, remain poorly characterized. We use several spectroscopic and computational methods to characterize the structure, dynamics, and oligomeric state of PsDef1. The three-dimensional structure was modeled by comparative modeling using several programs (Geno3D, SWISS-MODEL, I-TASSER, Phyre(2), and FUGUE) and verified by circular dichroism (CD) and infrared (FTIR) spectroscopy. Furthermore, FTIR data indicates that the structure of PsDef1 is highly resistant to high temperatures. NMR diffusion experiments show that defensin exists in solution in the equilibrium between monomers and dimers. Four types of dimers were constructed using the HADDOCK program and compared to the known dimer structures of other plant defensins. Gaussian network model was used to characterize the internal dynamics of PsDef1 in monomer and dimer states. PsDef1 is a typical representative of P. sylvestris defensins and hence the results of this study are applicable to other members of the family. PMID:26687241

  15. Study of Ellagic Acid as a Natural Elastase Inhibitor by Spectroscopic Methods

    NASA Astrophysics Data System (ADS)

    Xing, X.; Yang, X.; Cao, Yu.

    2016-03-01

    A new natural inhibitor, ellagic acid (EA), was developed, and its inhibition efficiency on elastase was studied by spectroscopic methods. The experimental results proved that EA is a potent elastase inhibitor with an IC50 value of 1.44 mg/mL by UV-vis spectroscopy, and the inhibition mechanism of elastase was confirmed by fluorescence quenching. The interacting between EA and elastase was mainly based on the static quenching owing to the complex formation when the concentration of EA was ≤40 μM. Fluorescence quenching mainly occurred via dynamic quenching with increasing EA concentration. The thermodynamic parameters such as ΔH and ΔS were calculated to be -86.35 kJ/mol and -165.88 J/mol · K, respectively, indicating that the interactions between EA and elastase were mainly due to van der Waals forces or hydrogen bonding. The synchronous fl uorescence spectra showed that binding of EA to elastase can induce conformational changes in elastase.

  16. An effective selection method for low-mass active black holes and first spectroscopic identification

    NASA Astrophysics Data System (ADS)

    Morokuma, Tomoki; Tominaga, Nozomu; Tanaka, Masaomi; Yasuda, Naoki; Furusawa, Hisanori; Taniguchi, Yuki; Kato, Takahiro; Jiang, Ji-an; Nagao, Tohru; Kuncarayakti, Hanindyo; Morokuma-Matsui, Kana; Ikeda, Hiroyuki; Blinnikov, Sergei; Nomoto, Ken'ichi; Kokubo, Mitsuru; Doi, Mamoru

    2016-04-01

    We present a new method for effectively selecting objects which may be low-mass active black holes (BHs) at galaxy centers using high-cadence optical imaging data, and our first spectroscopic identification of an active 2.7 × 106 M⊙ BH at z = 0.164. This active BH was originally selected due to its rapid optical variability, from a few hours to a day, based on Subaru Hyper Suprime-Cam g-band imaging data taken with a 1 hr cadence. Broad and narrow Hα lines and many other emission ones are detected in our optical spectra taken with Subaru FOCAS, and the BH mass is measured via the broad Hα emission line width (1880 km s-1) and luminosity (4.2 × 1040 erg s-1) after careful correction to the atmospheric absorption around 7580-7720 Å. We measure the Eddington ratio and find it to be as low as 0.05, considerably smaller than those in a previous SDSS sample with similar BH mass and redshift, which indicates one of the special potentials of our Subaru survey. The g - r color and morphology of the extended component indicate that the host galaxy is a star-forming galaxy. We also show the effectiveness of our variability selection for low-mass active BHs.

  17. Analysis of interaction between tamoxifen and ctDNA in vitro by multi-spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Cai, Changqun; Chen, Xiaoming; Ge, Fei

    2010-07-01

    Multi-spectroscopic methods including resonance light scattering (RLS), ultraviolet spectra (UV), fluorescence spectra, 1H NMR spectroscopy, coupled with thermo-denaturation experiments were firstly used to study the interaction of antitumor drug tamoxifen (TMX) with calf thymus (ctDNA) in acetate buffer solutions (pH 4.55). The interaction of TMX with ctDNA could cause a significant enhancement of RLS intensity, the hyperchromic effect, red shift of absorption spectra and the fluorescence quenching of TMX, indicating that there is an inserting interaction between TMX and ctDNA. This inference was confirmed by 1H NMR spectroscopy. The chemical shift of the benzene proton changes significantly which indicates that TMX could insert into the base pairs of ctDNA. These studies are valuable for a better understanding the mode of TMX-ctDNA interaction further, which are important and useful for designing of new ctDNA targeted drug. And the antitumor drug TMX inserted directly into ctDNA in vitro, which can provide a lot of useful information to explore the development of new and highly effective anti-cancer drugs.

  18. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking.

    PubMed

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH=7.4) were 1.41 × 10(5) M(-1) and about 1 at 310K, respectively. The values of the enthalpic change (ΔH(0)), entropic change (ΔS(0)) and Gibbs free energy (ΔG(0)) in the binding process of atorvastatin with BSA at 310K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA. PMID:26688207

  19. Dissection of the binding of hydrogen peroxide to trypsin using spectroscopic methods and molecular modeling

    NASA Astrophysics Data System (ADS)

    Song, Wei; Yu, Zehua; Hu, Xinxin; Liu, Rutao

    2015-02-01

    Studies on the effects of environmental pollutants to protein in vitro has become a global attention. Hydrogen peroxide (H2O2) is used as an effective food preservative and bleacher in industrial production. The toxicity of H2O2 to trypsin was investigated by multiple spectroscopic techniques and the molecular docking method at the molecular level. The intrinsic fluorescence of trypsin was proved to be quenched in a static process based on the results of fluorescence lifetime experiment. Hydrogen bonds interaction and van der Waals forces were the main force to generate the trypsin-H2O2 complex on account of the negative ΔH0 and ΔS0. The binding of H2O2 changed the conformational structures and internal microenvironment of trypsin illustrated by UV-vis absorption, fluorescence, synchronous fluorescence, three-dimensional (3D) fluorescence and circular dichroism (CD) results. However, the binding site was far away from the active site of trypsin and the trypsin activity was only slightly affected by H2O2, which was further explained by molecular docking investigations.

  20. Dissection of the binding of hydrogen peroxide to trypsin using spectroscopic methods and molecular modeling.

    PubMed

    Song, Wei; Yu, Zehua; Hu, Xinxin; Liu, Rutao

    2015-02-25

    Studies on the effects of environmental pollutants to protein in vitro has become a global attention. Hydrogen peroxide (H2O2) is used as an effective food preservative and bleacher in industrial production. The toxicity of H2O2 to trypsin was investigated by multiple spectroscopic techniques and the molecular docking method at the molecular level. The intrinsic fluorescence of trypsin was proved to be quenched in a static process based on the results of fluorescence lifetime experiment. Hydrogen bonds interaction and van der Waals forces were the main force to generate the trypsin-H2O2 complex on account of the negative ΔH(0) and ΔS(0). The binding of H2O2 changed the conformational structures and internal microenvironment of trypsin illustrated by UV-vis absorption, fluorescence, synchronous fluorescence, three-dimensional (3D) fluorescence and circular dichroism (CD) results. However, the binding site was far away from the active site of trypsin and the trypsin activity was only slightly affected by H2O2, which was further explained by molecular docking investigations. PMID:25228036

  1. Fluorescent-spectroscopic and imaging methods of investigations for diagnostics of head and neck tumors and control of PDT

    NASA Astrophysics Data System (ADS)

    Edinak, N. J.; Shental, Victor V.; Komov, D. V.; Vacoulovskaia, E. G.; Tabolinovskaia, T. D.; Abdullin, N. A.; Pustynsky, I.; Chatikchine, V. H.; Loschenov, Victor B.; Meerovich, Gennadii A.; Stratonnikov, Alexander A.; Linkov, Kirill G.; Agafonov, Vladimir I.; Zuravleva, V.; Lukjanets, Eugeny A.

    1996-01-01

    Methodics of PDT control and fluorescent-spectroscopic diagnostic of head and neck tumors and mammary gland cancer (nodular) with the use of Kr, He-Ne and semiconductor lasers and photosensitizer (PS) -- Al phtalocyanin (Photosense) are discussed. The results show that applied diagnostic methods permit us not only to identify the topology and malignancy of a tumor but also to correct PDT process directly during irradiation.

  2. A Review of Computational Methods in Materials Science: Examples from Shock-Wave and Polymer Physics

    PubMed Central

    Steinhauser, Martin O.; Hiermaier, Stefan

    2009-01-01

    This review discusses several computational methods used on different length and time scales for the simulation of material behavior. First, the importance of physical modeling and its relation to computer simulation on multiscales is discussed. Then, computational methods used on different scales are shortly reviewed, before we focus on the molecular dynamics (MD) method. Here we survey in a tutorial-like fashion some key issues including several MD optimization techniques. Thereafter, computational examples for the capabilities of numerical simulations in materials research are discussed. We focus on recent results of shock wave simulations of a solid which are based on two different modeling approaches and we discuss their respective assets and drawbacks with a view to their application on multiscales. Then, the prospects of computer simulations on the molecular length scale using coarse-grained MD methods are covered by means of examples pertaining to complex topological polymer structures including star-polymers, biomacromolecules such as polyelectrolytes and polymers with intrinsic stiffness. This review ends by highlighting new emerging interdisciplinary applications of computational methods in the field of medical engineering where the application of concepts of polymer physics and of shock waves to biological systems holds a lot of promise for improving medical applications such as extracorporeal shock wave lithotripsy or tumor treatment. PMID:20054467

  3. Methodical study on plaque characterization using integrated vascular ultrasound, strain and spectroscopic photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Graf, Iulia M.; Su, Jimmy; Yeager, Doug; Amirian, James; Smalling, Richard; Emelianov, Stanislav

    2011-03-01

    Carotid atherosclerosis has been identified as a potential risk factor for cerebrovascular events, but information about its direct effect on the risk of recurrent stroke is limited due to incomplete diagnosis. The combination of vascular ultrasound, strain rate and spectroscopic photoacoustics could improve the timely diagnosis of plaque status and risk of rupturing. Current ultrasound techniques can noninvasively image the anatomy of carotid arteries. The spatio-temporal variation in displacement of different regions within the arterial wall can be derived from ultrasound radio frequency data; therefore an ultrasound based strain rate imaging modality can be used to reveal changes in arterial mechanical properties. Additionally, spectroscopic photoacoustic imaging can provide information on the optical absorption properties of arterial tissue and it can be used to identify the location of specific tissue components, such as lipid pools. An imaging technique combining ultrasound, strain rate and spectroscopic photoacoustics was tested on an excised atherosclerotic rabbit aorta. The ultrasound image illustrates inhomogeneities in arterial wall thickness, the strain rate indicates the arterial segment with reduced elasticity and the spectroscopic photoacoustic image illustrates the accumulation of lipids. The results demonstrated that ultrasound, strain rate and spectroscopic photoacoustic imaging are complementary. Thus the integration of the three imaging modalities advances the characterization of atherosclerotic plaques.

  4. Military applications and examples of near-surface seismic surface wave methods (Invited)

    NASA Astrophysics Data System (ADS)

    sloan, S.; Stevens, R.

    2013-12-01

    Although not always widely known or publicized, the military uses a variety of geophysical methods for a wide range of applications--some that are already common practice in the industry while others are truly novel. Some of those applications include unexploded ordnance detection, general site characterization, anomaly detection, countering improvised explosive devices (IEDs), and security monitoring, to name a few. Techniques used may include, but are not limited to, ground penetrating radar, seismic, electrical, gravity, and electromagnetic methods. Seismic methods employed include surface wave analysis, refraction tomography, and high-resolution reflection methods. Although the military employs geophysical methods, that does not necessarily mean that those methods enable or support combat operations--often times they are being used for humanitarian applications within the military's area of operations to support local populations. The work presented here will focus on the applied use of seismic surface wave methods, including multichannel analysis of surface waves (MASW) and backscattered surface waves, often in conjunction with other methods such as refraction tomography or body-wave diffraction analysis. Multiple field examples will be shown, including explosives testing, tunnel detection, pre-construction site characterization, and cavity detection.

  5. A Systematic Method For Tracer Test Analysis: An Example Using Beowawe Tracer Data

    SciTech Connect

    G. Michael Shook

    2005-01-01

    Quantitative analysis of tracer data using moment analysis requires a strict adherence to a set of rules which include data normalization, correction for thermal decay, deconvolution, extrapolation, and integration. If done correctly, the method yields specific information on swept pore volume, flow geometry and fluid velocity, and an understanding of the nature of reservoir boundaries. All calculations required for the interpretation can be done in a spreadsheet. The steps required for moment analysis are reviewed in this paper. Data taken from the literature is used in an example calculation.

  6. Importance of Tissue Preparation Methods in FTIR Micro-Spectroscopical Analysis of Biological Tissues: ‘Traps for New Users’

    PubMed Central

    Zohdi, Vladislava; Whelan, Donna R.; Wood, Bayden R.; Pearson, James T.; Bambery, Keith R.; Black, M. Jane

    2015-01-01

    Fourier Transform Infrared (FTIR) micro-spectroscopy is an emerging technique for the biochemical analysis of tissues and cellular materials. It provides objective information on the holistic biochemistry of a cell or tissue sample and has been applied in many areas of medical research. However, it has become apparent that how the tissue is handled prior to FTIR micro-spectroscopic imaging requires special consideration, particularly with regards to methods for preservation of the samples. We have performed FTIR micro-spectroscopy on rodent heart and liver tissue sections (two spectroscopically very different biological tissues) that were prepared by desiccation drying, ethanol substitution and formalin fixation and have compared the resulting spectra with that of fully hydrated freshly excised tissues. We have systematically examined the spectra for any biochemical changes to the native state of the tissue caused by the three methods of preparation and have detected changes in infrared (IR) absorption band intensities and peak positions. In particular, the position and profile of the amide I, key in assigning protein secondary structure, changes depending on preparation method and the lipid absorptions lose intensity drastically when these tissues are hydrated with ethanol. Indeed, we demonstrate that preserving samples through desiccation drying, ethanol substitution or formalin fixation significantly alters the biochemical information detected using spectroscopic methods when compared to spectra of fresh hydrated tissue. It is therefore imperative to consider tissue preparative effects when preparing, measuring, and analyzing samples using FTIR spectroscopy. PMID:25710811

  7. Optical spectroscopic methods for probing the conformational stability of immobilised enzymes.

    PubMed

    Ganesan, Ashok; Moore, Barry D; Kelly, Sharon M; Price, Nicholas C; Rolinski, Olaf J; Birch, David J S; Dunkin, Ian R; Halling, Peter J

    2009-07-13

    We report the development of biophysical techniques based on circular dichroism (CD), diffuse reflectance infrared Fourier transform (DRIFT) and tryptophan (Trp) fluorescence to investigate in situ the structure of enzymes immobilised on solid particles. Their applicability is demonstrated using subtilisin Carlsberg (SC) immobilised on silica gel and Candida antartica lipase B immobilised on Lewatit VP.OC 1600 (Novozyme 435). SC shows nearly identical secondary structure in solution and in the immobilised state as evident from far UV CD spectra and amide I vibration bands. Increased near UV CD intensity and reduced Trp fluorescence suggest a more rigid tertiary structure on the silica surface. After immobilised SC is inactivated, these techniques reveal: a) almost complete loss of near UV CD signal, suggesting loss of tertiary structure; b) a shift in the amide I vibrational band from 1658 cm(-1) to 1632 cm(-1), indicating a shift from alpha-helical structure to beta-sheet; c) a substantial blue shift and reduced dichroism in the far UV CD, supporting a shift to beta-sheet structure; d) strong increase in Trp fluorescence intensity, which reflects reduced intramolecular quenching with loss of tertiary structure; and e) major change in fluorescence lifetime distribution, confirming a substantial change in Trp environment. DRIFT measurements suggest that pressing KBr discs may perturb protein structure. With the enzyme on organic polymer it was possible to obtain near UV CD spectra free of interference by the carrier material. However, far UV CD, DRIFT and fluorescence measurements showed strong signals from the organic support. In conclusion, the spectroscopic methods described here provide structural information hitherto inaccessible, with their applicability limited by interference from, rather than the particulate nature of, the support material. PMID:19360797

  8. Fast proton spectroscopic imaging using steady-state free precession methods.

    PubMed

    Dreher, Wolfgang; Geppert, Christian; Althaus, Matthias; Leibfritz, Dieter

    2003-09-01

    Various pulse sequences for fast proton spectroscopic imaging (SI) using the steady-state free precession (SSFP) condition are proposed. The sequences use either only the FID-like signal S(1), only the echo-like signal S(2), or both signals in separate but adjacent acquisition windows. As in SSFP imaging, S(1) and S(2) are separated by spoiler gradients. RF excitation is performed by slice-selective or chemical shift-selective pulses. The signals are detected in absence of a B(0) gradient. Spatial localization is achieved by phase-encoding gradients which are applied prior to and rewound after each signal acquisition. Measurements with 2D or 3D spatial resolution were performed at 4.7 T on phantoms and healthy rat brain in vivo allowing the detection of uncoupled and J-coupled spins. The main advantages of SSFP based SI are the short minimum total measurement time (T(min)) and the high signal-to-noise ratio per unit measurement time (SNR(t)). The methods are of particular interest at higher magnetic field strength B(0), as TR can be reduced with increasing B(0) leading to a reduced T(min) and an increased SNR(t). Drawbacks consist of the limited spectral resolution, particularly at lower B(0), and the dependence of the signal intensities on T(1) and T(2). Further improvements are discussed including optimized data processing and signal detection under oscillating B(0) gradients leading to a further reduction in T(min). PMID:12939751

  9. Variational method for nonconservative field theories: Formulation and two PT-symmetric case examples

    NASA Astrophysics Data System (ADS)

    Kevrekidis, P. G.

    2014-01-01

    In a recent publication [5 Galley, Phys. Rev. Lett. 110, 174301 (2013), 10.1103/PhysRevLett.110.174301], Galley proposed an initial value problem formulation of Hamilton's principle that enables consideration of dissipative systems. Here we explore this formulation at the level of field theories with infinite degrees of freedom. In particular, we illustrate that it affords a previously unwarranted and appealing as well as broadly relevant possibility, namely, to generalize the popular collective coordinate or variational method to open systems, i.e., nonconservative ones. To showcase the relevance or validity of the method we explore two case examples from the timely area of PT-symmetric variants of field theories, in this case for a sine-Gordon and for a ϕ4 model.

  10. Teaching Research Methods and Statistics in eLearning Environments: Pedagogy, Practical Examples, and Possible Futures.

    PubMed

    Rock, Adam J; Coventry, William L; Morgan, Methuen I; Loi, Natasha M

    2016-01-01

    Generally, academic psychologists are mindful of the fact that, for many students, the study of research methods and statistics is anxiety provoking (Gal et al., 1997). Given the ubiquitous and distributed nature of eLearning systems (Nof et al., 2015), teachers of research methods and statistics need to cultivate an understanding of how to effectively use eLearning tools to inspire psychology students to learn. Consequently, the aim of the present paper is to discuss critically how using eLearning systems might engage psychology students in research methods and statistics. First, we critically appraise definitions of eLearning. Second, we examine numerous important pedagogical principles associated with effectively teaching research methods and statistics using eLearning systems. Subsequently, we provide practical examples of our own eLearning-based class activities designed to engage psychology students to learn statistical concepts such as Factor Analysis and Discriminant Function Analysis. Finally, we discuss general trends in eLearning and possible futures that are pertinent to teachers of research methods and statistics in psychology. PMID:27014147

  11. Teaching Research Methods and Statistics in eLearning Environments: Pedagogy, Practical Examples, and Possible Futures

    PubMed Central

    Rock, Adam J.; Coventry, William L.; Morgan, Methuen I.; Loi, Natasha M.

    2016-01-01

    Generally, academic psychologists are mindful of the fact that, for many students, the study of research methods and statistics is anxiety provoking (Gal et al., 1997). Given the ubiquitous and distributed nature of eLearning systems (Nof et al., 2015), teachers of research methods and statistics need to cultivate an understanding of how to effectively use eLearning tools to inspire psychology students to learn. Consequently, the aim of the present paper is to discuss critically how using eLearning systems might engage psychology students in research methods and statistics. First, we critically appraise definitions of eLearning. Second, we examine numerous important pedagogical principles associated with effectively teaching research methods and statistics using eLearning systems. Subsequently, we provide practical examples of our own eLearning-based class activities designed to engage psychology students to learn statistical concepts such as Factor Analysis and Discriminant Function Analysis. Finally, we discuss general trends in eLearning and possible futures that are pertinent to teachers of research methods and statistics in psychology. PMID:27014147

  12. Determining uranium speciation in contaminated soils by molecular spectroscopic methods: Examples from the Uranium in Soils Integrated Demonstration

    SciTech Connect

    Allen, P.G.; Berg, J.M.; Chisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

    1994-03-01

    The US Department of Energy`s former uranium production facility located at Fernald, OH (18 mi NW of Cincinnati) is the host site for an Integrated Demonstration for remediation of uranium-contaminated soils. A wide variety of source terms for uranium contamination have been identified reflecting the diversity of operations at the facility. Most of the uranium contamination is contained in the top {approximately}1/2 m of soil, but uranium has been found in perched waters indicating substantial migration. In support of the development of remediation technologies and risk assessment, we are conducting uranium speciation studies on untreated and treated soils using molecular spectroscopies. Untreated soils from five discrete sites have been analyzed. We have found that {approximately}80--90% of the uranium exists as hexavalent UO{sub 2}{sup 2+} species even though many source terms consisted of tetravalent uranium species such as UO{sub 2}. Much of the uranium exists as microcrystalline precipitates (secondary minerals). There is also clear evidence for variations in uranium species from the microscopic to the macroscopic scale. However, similarities in speciation at sites having different source terms suggest that soil and groundwater chemistry may be as important as source term in defining the uranium speciation in these soils. Characterization of treated soils has focused on materials from two sites that have undergone leaching using conventional extractants (e.g., carbonate, citrate) or novel chelators such as Tiron. Redox reagents have also been used to facilitate the leaching process. Three different classes of treated soils have been identified based on the speciation of uranium remaining in the soils. In general, the effective treatments decrease the total uranium while increasing the ratio of U(IV) to U(VI) species.

  13. Comparison of laser spectroscopic PNC method with laser integral fluorescence in optical caries diagnostics

    NASA Astrophysics Data System (ADS)

    Masychev, Victor I.

    2001-05-01

    In this research we represent the results of approbation of two methods of optical caries diagnostics: PNC-spectral diagnostics and caries detection by laser integral fluorescence. The research was conducted in a dental clinic. PNC-method analyzes parameters of probing laser radiation and PNC-spectrums of stimulated secondary radiations: backscattering and endogenous fluorescence of caries- involved bacteria. Ia-Ne laser ((lambda) equals632.8 nm, 1-2 mW) was used as a source of probing (stimulated) radiation. For registration of signals, received from intact and pathological teeth PDA-detector was applied. PNC-spectrums were processed by special algorithms, and were displayed on PC monitor. The method of laser integral fluorescence was used for comparison. In this case integral power of fluorescence of human teeth was measured. As a source of probing (stimulated) radiation diode lasers ((lambda) equals655 nm, 0.1 mW and 630 nm, 1 mW) and Ia-Na laser were applied. For registration of signals Si-photodetector was used. Integral power was shown in a digital indicator. Advantages and disadvantages of these methods are described in this research. It is disclosed that the method of laser integral power of fluorescence has the following characteristics: simplicity of construction and schema-technical decisions. However the method of PNC-spectral diagnostics are characterized by considerably more sensitivity in diagnostics of initial caries and capability to differentiate pathologies of various stages (for example, calculus/initial caries). Estimation of spectral characteristics of PNC-signals allows eliminating a number of drawbacks, which are character for detection by method of laser integral fluorescence (for instance, detection of fluorescent fillings, plagues, calculus, discolorations generally, amalgam, gold fillings as if it were caries).

  14. Remote determination of exposure degree and iron concentration of lunar soils using VIS-NIR spectroscopic methods

    NASA Technical Reports Server (NTRS)

    Fischer, Erich M.; Pieters, Carle M.

    1994-01-01

    On the Moon, space weathering processes such as micrometeorite bombardment alter the optical properties of lunar soils. As a consequence, lunar soil optical properties are a function not only of composition, but of degree of exposure on the lunar surface as well. In order to accurately assess the compositional properties of the lunar surface using remotely acquired visible and near-infrared spectroscopic data, it is thus necessary either (1) to compare optical properties only of soils characterized by similar degrees of exposure or (2) to otherwise normalize or remove the optical effects due to exposure. Laboratory spectroscopic data for lunar soils are used to develop and test remote spectrocopic methods for determining degree of exposure and for distinguishing between the optical effects due to exposure and those due to composition. A method employing a ratio between reflectances within and outside of the 1 micrometer Fe(2+) crystal field absorption band was developed for remotely identifying highland soils that have reached a steady-state maturity. The relative optical properties of these soils are a function solely of composition and as such can be directly compared. Spectroscopic techniques for accurate quantitative determination of iron content for lunar highland soils are investigated as well. It is shown that approximations of the 1 micrometer Fe(2+) absorption band depth using few to several channel multispectral data or spectroscopic data of inadequate spectral range cannot be used with confidence for compositional analysis. However, band depth measurements derived from continuum-removed high spectral resolution data can be used to calculate the weight percent FeO and relative proportion of iron-bearing silicates in mature lunar highland and mare/highland mixture soils. A preliminary effort to calibrate telescopic band depth to laboratory soil measurements is described.

  15. Modification of atomic solids via electronic subsystem probed by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Savchenko, E. V.; Khyzhniy, I. V.; Uyutnov, S. A.; Gumenchuk, G. B.; Ponomaryov, A. N.; Zimmerer, G.; Bondybey, V. E.

    2009-05-01

    The role of electronic excitations in the modification of surface properties of atomic solids (AS) is considered using solid Kr as an example. The study is focused on the novel phenomenon found recently in AS: anomalous low temperature "post-desorption" (ALTpD) observed after irradiation of AS with low-energy electron beam. The experiments were performed employing cathodoluminescence (CL) method in combination with correlated in real time measurements of thermally stimulated luminescence (TSL), thermally stimulated exoelectron emission (TSEE) and detection of the "post-desorption" yield. Analysis of the yields correlation enabled us to verify a two-stage mechanism of the ALTpD: (i) thermally assisted release of electrons from their traps followed by (ii) intrinsic charge recombination resulting in "excimer dissociation" via radiative transition to a repulsive part of the ground state potential curve.

  16. Accurate spectroscopic constants of the lowest two electronic states in S2 molecule with explicitly correlated method

    NASA Astrophysics Data System (ADS)

    Changli, Wei; Xiaomei, Zhang; Dajun, Ding; Bing, Yan

    2016-01-01

    A computational scheme for accurate spectroscopic constants was presented in this work and applied to the lowest two electronic states of sulfur dimer. A high-level ab initio calculation utilizing explicitly correlated multireference configuration interaction method (MRCI-F12) was performed to compute the potential energy curves (PECs) of the ground triplet and first excited singlet a1Δg states of sulfur dimer with cc-pCVXZ-F12(X = T, Q) basis sets. The effects of Davidson modification, core-valence correlation correction, and scalar relativistic correction on the spectroscopic constants were examined. The vibration-rotation spectra of the two electronic states were provided. Our computational results show excellent agreement with existing available experimental values, and the errors of main spectroscopic constants are within 0.1% order of magnitude. The present computational scheme is cheap and accurate, which is expected for extensive investigations on the potential energy curves or surfaces of other molecular systems. Project supported by the National Natural Science Foundation of China (Grand No. 11574114) and the Natural Science Foundation of Jilin Province, China (Grand No. 20150101003JC).

  17. Characterizing the collision of potassium atoms with a siloxane coated glass surface using spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Morgus, Tyler Christophe

    2001-07-01

    We have developed a series of three experiments to characterize the collisions between potassium atoms and a siloxane coated non-stick surface on a glass substrate. The first experiment looks at the aggregate effect of multiple collisions of the potassium atoms with the surface. The atoms are observed spectroscopically. The spectroscopic information allows for the calculation of the flux, average velocity, and density of the potassium atoms. These quantities are also calculated with a computer model. The parameters of the model are the probability that a potassium atom will stick to the surface during a collision, and the probabilities that the collision is specular or diffuse. The second experiment uses the photo-desorption effect to create a spatially peaked non-equilibrium density distribution. The rate of decay of this distribution is fit with a computer model whose free parameter is proportional to the probability that an atom will stick to the siloxane coated wall during a collision. The third experiment is designed to observe the results of a single collision with a siloxane coated surface. Again, the potassium atoms are observed spectroscopically, the Doppler effect providing velocity resolution. The intensity of the fluorescence is related to the velocity-density distribution. The density is then theoretically modeled using the same simple kernel, accounting for contributions to the density from the potassium source, specular collisions, and diffuse collisions.

  18. Differential-Integral method in polymer processing: Taking melt electrospinning technique for example

    NASA Astrophysics Data System (ADS)

    Haoyi, Li; Weimin, Yang; Hongbo, Chen; Jing, Tan; Pengcheng, Xie

    2016-03-01

    A concept of Differential-Integral (DI) method applied in polymer processing and molding was proposed, which included melt DI injection molding, DI nano-composites extrusion molding and melt differential electrospinning principle and equipment. Taking the melt differential electrospinning for example to introduce the innovation research progress, two methods preparing polymer ultrafine fiber have been developed: solution electro-spinning and melt electro-spinning, between which solution electro-spinning is much simpler to realize in lab. More than 100 institutions have endeavored to conduct research on it and more than 30 thousand papers have been published. However, its industrialization was restricted to some extend because of the existence of toxic solvent during spinning process and poor mechanical strength of resultant fibers caused by small pores on fiber surface. Solvent-free melt electrospinning is environmentally friendly and highly productive. However, problems such as the high melt viscosity, thick fiber diameter and complex equipment makes it relatively under researched compared with solution electrospinning. With the purpose of solving the shortage of traditional electro-spinning equipment with needles or capillaries, a melt differential electro-spinning method without needles or capillaries was firstly proposed. Nearly 50 related patents have been applied since 2005, and systematic method innovations and experimental studies have also been conducted. The prepared fiber by this method had exhibited small diameter and smooth surface. The average fiber diameter can reach 200-800 nm, and the single nozzle can yield two orders of magnitude more than the capillaries. Based on the above principle, complete commercial techniques and equipment have been developed to produce ultra-fine non-woven fabrics for the applications in air filtration, oil spill recovery and water treatment, etc.

  19. High-energy spectroscopic astrophysics

    NASA Astrophysics Data System (ADS)

    Güdel, Manuel; Walter, Roland

    After three decades of intense research in X-ray and gamma-ray astronomy, the time was ripe to summarize basic knowledge on X-ray and gamma-ray spectroscopy for interested students and researchers ready to become involved in new high-energy missions. This volume exposes both the scientific basics and modern methods of high-energy spectroscopic astrophysics. The emphasis is on physical principles and observing methods rather than a discussion of particular classes of high-energy objects, but many examples and new results are included in the three chapters as well.

  20. A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations

    NASA Astrophysics Data System (ADS)

    Mallah, Muhammad Ali; Sherazi, Syed Tufail Hussain; Bhanger, Muhammad Iqbal; Mahesar, Sarfaraz Ahmed; Bajeer, Muhammad Ashraf

    2015-04-01

    A transmission FTIR spectroscopic method was developed for direct, inexpensive and fast quantification of paracetamol content in solid pharmaceutical formulations. In this method paracetamol content is directly analyzed without solvent extraction. KBr pellets were formulated for the acquisition of FTIR spectra in transmission mode. Two chemometric models: simple Beer's law and partial least squares employed over the spectral region of 1800-1000 cm-1 for quantification of paracetamol content had a regression coefficient of (R2) of 0.999. The limits of detection and quantification using FTIR spectroscopy were 0.005 mg g-1 and 0.018 mg g-1, respectively. Study for interference was also done to check effect of the excipients. There was no significant interference from the sample matrix. The results obviously showed the sensitivity of transmission FTIR spectroscopic method for pharmaceutical analysis. This method is green in the sense that it does not require large volumes of hazardous solvents or long run times and avoids prior sample preparation.

  1. A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations.

    PubMed

    Mallah, Muhammad Ali; Sherazi, Syed Tufail Hussain; Bhanger, Muhammad Iqbal; Mahesar, Sarfaraz Ahmed; Bajeer, Muhammad Ashraf

    2015-04-15

    A transmission FTIR spectroscopic method was developed for direct, inexpensive and fast quantification of paracetamol content in solid pharmaceutical formulations. In this method paracetamol content is directly analyzed without solvent extraction. KBr pellets were formulated for the acquisition of FTIR spectra in transmission mode. Two chemometric models: simple Beer's law and partial least squares employed over the spectral region of 1800-1000 cm(-1) for quantification of paracetamol content had a regression coefficient of (R(2)) of 0.999. The limits of detection and quantification using FTIR spectroscopy were 0.005 mg g(-(1) and 0.018 mg g(-1), respectively. Study for interference was also done to check effect of the excipients. There was no significant interference from the sample matrix. The results obviously showed the sensitivity of transmission FTIR spectroscopic method for pharmaceutical analysis. This method is green in the sense that it does not require large volumes of hazardous solvents or long run times and avoids prior sample preparation. PMID:25659814

  2. The utilisation of health research in policy-making: concepts, examples and methods of assessment

    PubMed Central

    Hanney, Stephen R; Gonzalez-Block, Miguel A; Buxton, Martin J; Kogan, Maurice

    2003-01-01

    The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions. The utilisation of health research in policy-making should contribute to policies that may eventually lead to desired outcomes, including health gains. In this article, exploration of these issues is combined with a review of various forms of policy-making. When this is linked to analysis of different types of health research, it assists in building a comprehensive account of the diverse meanings of research utilisation. Previous studies report methods and conceptual frameworks that have been applied, if with varying degrees of success, to record utilisation in policy-making. These studies reveal various examples of research impact within a general picture of underutilisation. Factors potentially enhancing utilisation can be identified by exploration of: priority setting; activities of the health research system at the interface between research and policy-making; and the role of the recipients, or 'receptors', of health research. An interfaces and receptors model provides a framework for analysis. Recommendations about possible methods for assessing health research utilisation follow identification of the purposes of such assessments. Our conclusion is that research utilisation can be better understood, and enhanced, by developing assessment methods informed by conceptual analysis and review of previous studies. PMID:12646071

  3. Fiber optic spectroscopic digital imaging sensor and method for flame properties monitoring

    DOEpatents

    Zelepouga, Serguei A.; Rue, David M.; Saveliev, Alexei V.

    2011-03-15

    A system for real-time monitoring of flame properties in combustors and gasifiers which includes an imaging fiber optic bundle having a light receiving end and a light output end and a spectroscopic imaging system operably connected with the light output end of the imaging fiber optic bundle. Focusing of the light received by the light receiving end of the imaging fiber optic bundle by a wall disposed between the light receiving end of the fiber optic bundle and a light source, which wall forms a pinhole opening aligned with the light receiving end.

  4. Mining unusual and rare stellar spectra from large spectroscopic survey data sets using the outlier-detection method

    NASA Astrophysics Data System (ADS)

    Wei, Peng; Luo, Ali; Li, Yinbi; Pan, Jingchang; Tu, Liangping; Jiang, Bin; Kong, Xiao; Shi, Zhixin; Yi, Zhenping; Wang, Fengfei; Liu, Jie; Zhao, Yongheng

    2013-05-01

    The large number of spectra obtained from sky surveys such as the Sloan Digital Sky Survey (SDSS) and the survey executed by the Large sky Area Multi-Object fibre Spectroscopic Telescope (LAMOST, also called GuoShouJing Telescope) provide us with opportunities to search for peculiar or even unknown types of spectra. In response to the limitations of existing methods, a novel outlier-mining method, the Monte Carlo Local Outlier Factor (MCLOF), is proposed in this paper, which can be used to highlight unusual and rare spectra from large spectroscopic survey data sets. The MCLOF method exposes outliers automatically and efficiently by marking each spectrum with a number, i.e. using outlier index as a flag for an unusual and rare spectrum. The Local Outlier Factor (LOF) represents how unusual and rare a spectrum is compared with other spectra and the Monte Carlo method is used to compute the global LOF for each spectrum by randomly selecting samples in each independent iteration. Our MCLOF method is applied to over half a million stellar spectra (classified as STAR by the SDSS Pipeline) from the SDSS data release 8 (DR8) and a total of 37 033 spectra are selected as outliers with signal-to-noise ratio (S/N) ≥ 3 and outlier index ≥0.85. Some of these outliers are shown to be binary stars, emission-line stars, carbon stars and stars with unusual continuum. The results show that our proposed method can efficiently highlight these unusual spectra from the survey data sets. In addition, some relatively rare and interesting spectra are selected, indicating that the proposed method can also be used to mine rare, even unknown, spectra. The proposed method can be applicable not only to spectral survey data sets but also to other types of survey data sets. The spectra of all peculiar objects selected by our MCLOF method are available from a user-friendly website: http://sciwiki.lamost.org/Miningdr8/.

  5. Evaluation of vibrational spectroscopic methods to identify and quantify multiple adulterants in herbal medicines.

    PubMed

    Rooney, Jeremy S; McDowell, Arlene; Strachan, Clare J; Gordon, Keith C

    2015-06-01

    To counter the growth of herbal medicines adulterated with pharmaceuticals crossing borders, rapid, inexpensive and non-destructive analytical techniques, that can handle complex matrices, are required. Since mid-infrared (MIR), near infrared (NIR) and Raman spectroscopic techniques meet these criteria, their performance in identifying adulterants in seized weightloss herbal medicines is definitively determined. Initially a validated high pressure liquid chromatography methodology was used for reference identification and quantification of the adulterants sibutramine H2O·HCl, fenfluramine HCl and phenolphthalein. Of 38 products, only sibutramine and phenolphthalein were detected by HPLC. The spectroscopic measurements showed Raman was ill-suited due to sample burning and emission while NIR lacked adulterant selectivity. Conversely, MIR demonstrated apt identification performance, which manifested as spectrally meaningful separation based on the presence and type of adulterant during principal component analysis (test set validated). Partial least squares regression models were constructed from the MIR training sets for sibutramine and phenolphthalein - both models fitted the training set data well. Average test set prediction errors were 0.8% for sibutramine and 2.2% for phenolphthalein over the respective concentration ranges of 1.7-11.7% and 0.9-34.4%. MIR is apposite for the screening of anorectic and laxative adulterants and is the most viable technique for wider adulterant screening in herbal medicines. PMID:25863375

  6. Spectroscopic aspects of differential method for sounding gas composition of the atmosphere

    NASA Technical Reports Server (NTRS)

    Zuev, V. V.; Ippolitov, I. I.; Ponomarev, Y. N.

    1986-01-01

    The problems concerning the dynamics of populations of the sounded atmospheric gas molecule levels taking into account the nonmonochromatic character of radiation, durations of exciting and sounding pulses, rates of relaxation of excited vibration-rotation states population along different channels in a natural multicomponent mixture of gases and air were investigated. The problems of spectroscopic software, completeness and accuracy of the initial spectroscopic information, information on channels and rates of relaxation from the viewpoint of developing specific schemes of sounding are discussed. The values of deviations of vibration-rotation level populations of some atmospheric molecules from their equilibrium value at simultaneous action of double frequency radiation on the sounding path and the corresponding dynamic variation of lidar return amplitude were estimated. The importance of nonlinear spectrosopic effects in the lidar return value variation at sounding radiation frequency equaling the resonance frequency of vibration-rotation transition in the problem on sounding the humidity profiles and concentrations of gaseous pollutants was also estimated.

  7. Biophysical study on the interaction of ceftriaxone sodium with bovine serum albumin using spectroscopic methods.

    PubMed

    Pan, Jiongwei; Ye, Zaiting; Cai, Xiaoping; Wang, Liangxing; Cao, Zhuo

    2012-12-01

    The interaction of ceftriaxone sodium (CS), a cephalosporin antibiotic, with the major transport protein, bovine serum albumin (BSA), was investigated using different spectroscopic techniques such as fluorescence, circular dichroism (CD), and UV-vis spectroscopy. Values of binding parameters for BSA-CS interaction in terms of binding constant and number of binding sides were found to be 9.00 × 10(3), 3.24 × 10(3), and 2.30 × 10(3) M(-1) at 281, 301, and 321 K, respectively. Thermodynamic analysis of the binding data obtained at different temperatures showed that the binding process was spontaneous and was primarily mediated by van der Waals force or hydrogen bonding. CS binding to BSA caused secondary structural alterations in the protein as revealed by CD results. The distance between CS and Trp of BSA was determined as 3.23 nm according to the Förster resonance energy transfer theory. PMID:23169700

  8. Determining uranium speciation in Fernald soils by molecular spectroscopic methods. FY 1993 progress report

    SciTech Connect

    Allen, P.G.; Berg, J.M.; Crisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

    1994-07-01

    This progress report describes new experimental results and interpretations for data collected from October 1, 1992, through September 30, 1993, as part of the Characterization Task of the Uranium in Soils Integrated Demonstration of the Office of Technology Development, Office of Environmental Restoration and Waste Management of the US Department of Energy. X-ray absorption, optical luminescence, and Raman vibrational spectroscopies were used to determine uranium speciation in contaminated soils from the US DOE`s former uranium production facility at Fernald, Ohio. These analyses were carried out both before and after application of one of the various decontamination technologies being developed within the Integrated Demonstration. This year the program focused on characterization of the uranium speciation remaining in the soils after decontamination treatment. X-ray absorption and optical luminescence spectroscopic data were collected for approximately 40 Fernald soil samples, which were treated by one or more of the decontamination technologies.

  9. Measuring maps graphical density via digital image processing method on the example of city maps

    NASA Astrophysics Data System (ADS)

    Ciolkosz-Styk, A.; Styk, A.

    2012-06-01

    During the centuries the main problem on mapping was to obtain the sufficient and reliable source data; presently, an appropriate selection of the desired information from the deluge of available data I a problem. An availability of large amount of data induces to transfer the possibly rich information by mean of map. It often results in overloading the cartographic documents, that is why they become less communicative and difficult to read. This situation is well illustrated by the example of city maps which are the most commonly used and thus the most frequently published cartographic products. Many user groups with different needs as well as preparation to read maps use these high volume publications. Therefore, the maps communication effectiveness problem is of particular importance. The city maps are the most complex cartographic presentations, because the presented areas are the places with the greatest concentration of different kinds of objects and forms of human activity arising from the civilization development. Conveying these specific features on the city maps leads to the problem of selecting the most relevant elements of content in terms of user's needs, since presenting all objects and their characteristics is impossible if the city map readability is to be kept. Although complexity has been the cartographers' object of interest for many years, because it exerts an impact on readability and effectiveness of cartographic documents, none of the measures used so far may be applied for automatic determination of complexity of such graphically complicated objects as city maps. Therefore a novel approach was needed for these applications. For that purpose digital image processing techniques have been proposed and successfully applied by the authors. The analysis of the spatial distribution of the objects' edges on the map surface, calculated using continuous wavelet transform, is the basis of the proposed measure. The method allows for comparison of complexity of city maps loaded by different type of graphical elements (point signatures, lines, text, etc.). Extended analyses of selected cartographic materials proved the usability of the method for quantitative estimation of city map complexity via formal index

  10. Spectrophotometric, difference spectroscopic, and high-performance liquid chromatographic methods for the determination of cefixime in pharmaceutical formulations.

    PubMed

    Shah, Paresh B; Pundarikakshudu, Kilambi

    2006-01-01

    Three simple and sensitive spectrophotometric, difference spectroscopic, and liquid chromatographic (LC) methods are described for the determination of cefixime. The first method is based on the oxidative coupling reaction of cefixime with 3-methyl-2-benzothiazolinon hydrazone HCI in presence of ferric chloride. The absorbance of reaction product was measured at the maximum absorbance wavelength (wavelength(max)), 630 nm. The difference spectroscopic method is based on the measurement of absorbance of cefixime at the absorbance maximum, 268 nm, and minimum, 237 nm. The measured value was the amplitude of maxima and minima between 2 equimolar solutions of the analyte in different chemical forms, which exhibited different spectral characteristics. The conditions were optimized, and Beer's law was obeyed for cefixime at 1 to 16 microg/mL and 10 to 50 microg/mL, respectively. The third method, high-performance LC, was developed for the determination of cefixime using 50 mM potassium dihydrogen phosphate (pH 3.0)-methanol (78 + 22, v/v) as the mobile phase and measuring the response at wavelength(max) 286 nm. The analysis was performed on a Lichrospher RPC18 column. The calibration curve was obtained for cefixime at 5 to 250 microg/mL, and the mean recovery was 99.71 +/- 0.01%. The methods were validated according to the guidelines of the U.S. Pharmacopoeia and also assessed by applying the standard addition technique. The results obtained in the analysis of dosage forms agreed well with the contents stated on the labels. PMID:16915834

  11. Specific binding and inhibition of 6-benzylaminopurine to catalase: multiple spectroscopic methods combined with molecular docking study.

    PubMed

    Xu, Qin; Lu, Yanni; Jing, Longyun; Cai, Lijuan; Zhu, Xinfeng; Xie, Ju; Hu, Xiaoya

    2014-04-01

    6-Benzylaminopurine (6-BA) is a kind of cytokinin which could regulate the activities of the antioxidant defense system of plants. In this work, its interaction with and inhibition of beef liver catalase have been systematically investigated using spectroscopic, isothermal titration calorimetric and molecular docking methods under physiological conditions. The fluorescence quenching of beef liver catalase (BLC) by 6-BA is due to the formation of 6-BA-BLC complex. Hydrogen bonds and van der Waals interactions play major roles in stabilizing the complex. The Stern-Volmer quenching constant, binding constant, the corresponding thermodynamic parameters and binding numbers were measured. The results of UV-vis absorption, three-dimensional fluorescence, synchronous fluorescence and circular dichroism spectroscopic results demonstrate that the binding of 6-BA results in the micro-environment change around tyrosine (Tyr) and tryptophan (Trp) residues of BLC. The BLC-mediated conversion of H2O2 to H2O and O2, in the presence and absence of 6-BA, was also studied. Lineweaver-Burk plot indicates a noncompetitive type of inhibition. Molecular docking study was used to find the binding sites. PMID:24412785

  12. Vibrational spectroscopic methods to characterize the bionanoparticles originating from newly developed self-forming synthetic PEGylated lipids (QuSomes)

    NASA Astrophysics Data System (ADS)

    Bista, Rajan K.; Bruch, Reinhard F.; Covington, Aaron M.

    2011-03-01

    Vibrational spectroscopy has been used to elucidate the temperature dependence of structural and conformational changes in lipids and liposomes. In this work, the thermal properties of lipid-based nanovesicles originating from a newly developed self-forming synthetic PEGylated lipids has been investigated by variable-temperature Fourier-transform infrared (FTIR) absorption and Raman spectroscopic methods. Thermally-induced changes in infrared and Raman spectra of these artificial lipid based nanovesicles composed of 1,2-dimyristoyl-rac-glycerol-3-dodecaethylene glycol (GDM-12) and 1,2-distearoyl-rac-glycerol-3-triicosaethylene glycol (GDS-23) were acquired by using a thin layered FTIR spectrometer in conjunction with a unique custom built temperature-controlled demountable liquid cell and variable-temperature controlled Raman microscope, respectively. The lipids under consideration have long hydrophobic acyl chains and contain various units of hydrophilic polyethylene glycol headgroups. In contrast to conventional phospholipids, this new kind of lipid is forming liposomes or nanovesicles spontaneously upon hydration, without supplying external activation energy. We have found that the thermal stability of such PEGylated lipids and nanovesicles differs greatly depending upon the acyl chain-lengths as well as associated head group units. However, the thermal behavior observed from both spectroscopic vibrational techniques are in good agreement.

  13. Detection of Hg2+ in water environment by fluorescence spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Zhang, Jinsong; Hu, Hong; Wan, Ruyi; Yao, Youwei

    2015-08-01

    Inorganic mercury (Hg2+) produces toxic effects even at very low concentration. High sensitive fluorescent probes for Hg2+ detection has been researched and synthesized. A fluorescence detection system is built for Hg2+ detection in water environment with fluorescent probes as the detection reagent. Fiber coupled LED with high brightness is developed and used as excitation light source. And the optimized excitation wavelength is about 520 nm. The measurements of fluorescence spectra is obtained by means of optical fiber spectroscopic techniques. Fluorescence detection experiments are carried out for a range of different concentrations of Hg2+ in aqueous solutions. The center wavelength of the fluorescence spectra is about 580 nm which is unchanged in the experiments. Relationship between Hg2+ concentrations and the fluorescence intensity is studied. A positive correlation exists between the intensity of fluorescence spectrum and the concentrations of Hg2+. The fluorescence intensity grows with increasing the concentration of Hg2+ for the same excitation light. When the concentration of Hg2+ is high enough, the fluorescence intensity increases slowly. And a numerical model is built for the concentration calculating. The detection limit is 0.005 μmol/L in the experiments. The Hg2+ detection system reported has many advantages such as small size, rapid response, high-sensitivity, and can be used for on-site testing of the water quality.

  14. Studies on the interaction of apigenin with calf thymus DNA by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Zhang, Shufang; Sun, Xuejun; Kong, Rongmei; Xu, Mingming

    2015-02-01

    The interaction between apigenin and calf thymus deoxyribonucleic acid (ctDNA) in a pH 7.4 Tris-HCl buffer solution was investigated by UV-Vis spectroscopy, fluorescence spectroscopy, DNA melting techniques, and viscosity measurements. It was found that apigenin molecules could intercalate into the base pairs of DNA, forming a apigenin-DNA complex with a binding constant of K310K = 6.4 × 104 L mol-1. The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) and Gibbs free energy (ΔG) were calculated to be 7.36 × 104 J mol-1, 329 J K-1 mol-1 and -2.84 × 104 J mol-1 at 310 K, respectively. Hydrophobic interaction was the predominant intermolecular force in stabilizing the apigenin-DNA complex. Thermal denaturation study suggested that the stabilization of the ctDNA helix was increased when the apigenin binding to ctDNA as indicated by the increase in thermal denaturation temperature of ctDNA at around 5.0 °C in the presence of apigenin. Spectroscopic techniques together with melting techniques and viscosity determination provided evidences of intercalation mode of binding for the interaction between apigenin and ctDNA.

  15. [Spectroscopic methods applied to component determination and species identification for coffee].

    PubMed

    Chen, Hua-zhou; Xu, Li-li; Qin, Qiang

    2014-06-01

    Spectroscopic analysis was applied to the determination of the nutrient quality of ground, instant and chicory coffees. By using inductively coupled plasma atomic emission spectrometry (ICP-ES), nine mineral elements were determined in solid coffee samples. Caffeine was determined by ultraviolet (UV) spectrometry and organic matter was investigated by Fourier transform infrared (FTIR) spectroscopy. Oxidation-reduction titration was utilized for measuring the oxalate. The differences between ground coffee and instant coffee was identified on the basis of the contents of caffeine, oxalate and mineral elements. Experimental evidence showed that, caffeine in instant coffee was 2-3 times higher than in ground coffee. Oxalate in instant coffee was significantly higher in ground coffee. Mineral elements of Mg, P and Zn in ground coffee is lower than in instant coffee, while Cu is several times higher. The mineral content in chicory coffee is overall lower than the instant coffee. In addition, we determined the content of Ti for different types of coffees, and simultaneously detected the elements of Cu, Ti and Zn in chicory coffee. As a fast detection technique, FTIR spectroscopy has the potential of detecting the differences between ground coffee and instant coffee, and is able to verify the presence of caffeine and oxalate. PMID:25358189

  16. The spectroscopic and the QTAIM properties of pyridine and phenanthroline derivatives using experimental and computational methods.

    PubMed

    Adeniyi, Adebayo A; Ajibade, Peter A

    2014-07-15

    The experimental and theoretical properties of ligands consisting of pyridine and phenanthroline derivatives have been studied. The results show a very high correlation between the experimental and theoretical spectroscopic properties of the ligands such as the IR, NMR chemical shift and UV. The carboxylic units in the ligands lead to increase in the dipole and anisotropic properties of the molecules while the methyl group lead to increase in the isotropic shielding tensor of the molecules. Most of the observed UV λmax in the ligands are predominantly excitation of electrons from the HOMO-2 or HOMO-1 or HOMO to the LUMO of the ligands. The ligand 2,2-dicarboxylphenanthroline (dcphn) is predicted to be the best starting material for non-linear optical (NLO) application due to its far higher first static hyperpolarizability tensor compare to other ligands and its lowest band gap. The same ligand can also be best for DNA binding because it has the lowest value of LUMO. The atomic charge of the nitrogen is found to be highly correlated with molecular HOMO, LUMO and non-Lewis orbital. The (15)N NMR chemical shift is found to be highly correlated atomic anisotropy, energy and intra-atomic isotropic shielding tensor. PMID:24691368

  17. Interaction of tetramethylpyrazine with two serum albumins by a hybrid spectroscopic method

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengjun

    The interactions of tetramethylpyrazine (TMPZ) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by various spectroscopic techniques. Fluorescence tests showed that TMPZ could bind to BSA/HSA to form complexes. The binding constants of TMPZ-BSA and TMPZ-HSA complexes were observed to be 1.442 × 104 and 3.302 × 104 M-1 at 298 K, respectively. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TMPZ-HSA was mainly depended on hydrophobic interaction, and yet the binding of TMPZ-BSA might involve hydrophobic interaction strongly and electrostatic interaction. The results of synchronous fluorescence, three-dimensional fluorescence, UV-vis absorption, FT-IR and CD spectra showed that the conformations of both BSA and HSA altered with the addition of TMPZ. The binding average distance between TMPZ and BSA/HSA was evaluated according to Föster non-radioactive energy transfer theory. In addition, with the aid of site markers (such as, phenylbutazone, ibuprofen and digitoxin), TMPZ primarily bound to tryptophan residues of BSA/HSA within site I (sub-domain II A).

  18. Interaction of erucic acid with bovine serum albumin using a multi-spectroscopic method and molecular docking technique.

    PubMed

    Shu, Yang; Xue, Weiwei; Xu, Xiaoying; Jia, Zhimin; Yao, Xiaojun; Liu, Shuwen; Liu, Lihong

    2015-04-15

    Overconsumption of erucic acid has been shown to cause heart damage in animals. The aim of this study is to evaluate the binding behaviour between erucic acid and bovine serum albumin using multi-spectroscopic methods and a molecular docking technique under physiological conditions. We find that erucic acid can quench the intrinsic fluorescence of BSA by dynamic quenching and there is a single class of binding site on BSA. In addition, the thermodynamic functions ?H and ?S are 119.14 kJ mol(-1) and 488.89 J mol(-1) K(-1), indicating that the hydrophobic force is a main acting force. Furthermore, the protein secondary structure changes with an increase in the content of ?-helix, measured using synchronous fluorescence, circular dichroism and Fourier transform infrared spectroscopies. The molecular docking results illustrate that erucic acid can bind with the subdomain IIA of the BSA, and hydrogen bonding is also an acting force. PMID:25465991

  19. Spectroscopic methods of process monitoring for safeguards of used nuclear fuel separations

    NASA Astrophysics Data System (ADS)

    Warburton, Jamie Lee

    To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations. The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By evaluating the impact of process conditions, such as acid concentration, metal concentration and flow rate, on the sensitivity of the UV-Visible detection system, the process-monitoring concept is developed from an advanced application of fundamental spectroscopy. Systematic benchtop-scale studies investigated the system relevant to UREX or PUREX type reprocessing systems, encompassing 0.01-1.26 M U and 0.01-8 M HNO3. A laboratory-scale TRansUranic Extraction (TRUEX) demonstration was performed and used both to analyze for potential online monitoring opportunities in the TRUEX process, and to provide the foundation for building and demonstrating a laboratory-scale UREX demonstration. The secondary goal of the project is to simulate a diversion scenario in UREX and successfully detect changes in metal concentration and solution chemistry in a counter current contactor system with a UV-Visible spectroscopic process monitor. UREX uses the same basic solvent extraction flowsheet as PUREX, but has a lower acid concentration throughout and adds acetohydroxamic acid (AHA) as a complexant/reductant to the feed solution to prevent the extraction of Pu. By examining UV-Visible spectra gathered in real time, the objective is to detect the conversion from the UREX process, which does not separate Pu, to the PUREX process, which yields a purified Pu product. The change in process chemistry can be detected in the feed solution, aqueous product or in the raffinate stream by identifying the acid concentration, metal distribution and the presence or absence of AHA. A fiber optic dip probe for UV-Visible spectroscopy was integrated into a bank of three counter-current centrifugal contactors to demonstrate the online process monitoring concept. Nd, Fe and Zr were added to the uranyl nitrate system to explore spectroscopic interferences and identify additional species as candidates for online monitoring. This milestone is a demonstration of the potential of this technique, which lies in the ability to simultaneously and directly monitor the chemical process conditions in a reprocessing plant, providing inspectors with another tool to detect nuclear material diversion attempts. Lastly, dry processing of used nuclear fuel is often used as a head-end step before solvent extraction-based separations such as UREX or TRUEX. A non-aqueous process, used fuel treatment by dry processing generally includes chopping of used fuel rods followed by repeated oxidation-reduction cycles and physical separation of the used fuel from the cladding. Thus, dry processing techniques are investigated and opportunities for online monitoring are proposed for continuation of this work in future studies.

  20. Paleohydrological methods and some examples from Swedish fluvial environments. II - River meanders.

    USGS Publications Warehouse

    Williams, G.P.

    1984-01-01

    Empirical relations are developed between river-meander features and water-discharge characteristics for 19 reaches along Swedish rivers. In these relations, either average channel width or average radius of curvature of meander arcs can be used to estimate average annual peak discharge and average daily discharge. By accepting certain assumptions, the relations can be applied to other meandering Swedish rivers, present or ancient. The Oster-Dalalven River near Mora is used as an example.-Author

  1. Development of new UV-vis spectroscopic microwave-assisted method for determination of glucose in pharmaceutical samples.

    PubMed

    Mabood, Fazal; Hussain, Z; Haq, H; Arian, M B; Boqué, R; Khan, K M; Hussain, K; Jabeen, F; Hussain, J; Ahmed, M; Alharasi, A; Naureen, Z; Hussain, H; Khan, A; Perveen, S

    2016-01-15

    A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wavelength, temperature, and pH of the medium and relative concentration ratio of the reactants were investigated. It was found that the optimal wavelength for the reaction is 610 nm, the optimal reaction time is 80s, the optimal reaction temperature is 160°C, the optimal reaction pH is 4, and the optimal concentration ratio aniline/ammonium molybdate solution was found to be 1:1. The limits of detection and quantification of the method are 0.82 and 2.75 ppm for glucose solution, respectively. The use of microwaves improved the speed of the method while the use of aniline improved the sensitivity of the method by shifting the wavelength. PMID:26312738

  2. Development of new UV-vis spectroscopic microwave-assisted method for determination of glucose in pharmaceutical samples

    NASA Astrophysics Data System (ADS)

    Mabood, Fazal; Hussain, Z.; Haq, H.; Arian, M. B.; Boqué, R.; Khan, K. M.; Hussain, K.; Jabeen, F.; Hussain, J.; Ahmed, M.; Alharasi, A.; Naureen, Z.; Hussain, H.; Khan, A.; Perveen, S.

    2016-01-01

    A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wavelength, temperature, and pH of the medium and relative concentration ratio of the reactants were investigated. It was found that the optimal wavelength for the reaction is 610 nm, the optimal reaction time is 80 s, the optimal reaction temperature is 160 °C, the optimal reaction pH is 4, and the optimal concentration ratio aniline/ammonium molybdate solution was found to be 1:1. The limits of detection and quantification of the method are 0.82 and 2.75 ppm for glucose solution, respectively. The use of microwaves improved the speed of the method while the use of aniline improved the sensitivity of the method by shifting the wavelength.

  3. Modern geodetic methods for high-accuracy survey coordination on the example of magnetic exploration

    NASA Astrophysics Data System (ADS)

    Krasnoperov, R. I.; Sidorov, R. V.; Soloviev, A. A.

    2015-07-01

    The purposes and problems of the international network of geomagnetic observatories INTERMAGNET are briefly described in the work. The importance of the development of the Russian segment of the network as a part of a system for monitoring and estimating geomagnetic conditions on the Russian territory is emphasized. An example of the use of modern high-precision geodetic equipment for coor-dinate referencing of field geophysical observation is described. Factors that distort the referencing of field observations in problems of survey, engineering, and technical geophysics are listed, as well as those related to detail and high-resolution geophysical surveying and those that require a corresponding accuracy of observation point coordination. The magnetic exploration at the site of the Yamal INTERMAGNET-standard observatory serves an example to describe a technique for geodetic provision of a detailed geophysical survey by means of joint use of differential GNSS measurements and electronic tacheometry. The main advantages and disadvantages of the technique suggested are listed.

  4. Using a Three-Step Method in a Calculus Class: Extending the Worked Example

    ERIC Educational Resources Information Center

    Miller, David

    2010-01-01

    This article discusses a three-step method that was used in a college calculus course. The three-step method was developed to help students understand the course material and transition to be more independent learners. In addition, the method helped students to transfer concepts from short-term to long-term memory while lowering cognitive load.…

  5. Applications of interpretive and constructionist research methods in adolescent research: philosophy, principles and examples.

    PubMed

    Chen, Yan-Yan; Shek, Daniel T L; Bu, Fei-Fei

    2011-01-01

    This paper attempts to give a brief introduction to interpretivism, constructionism and constructivism. Similarities and differences between interpretivism and constructionism in terms of their histories and branches, ontological and epistemological stances, as well as research applications are highlighted. This review shows that whereas interpretivism can be viewed as a relatively mature orientation that contains various traditions, constructionism is a looser trend in adolescent research, and in the narrow sense denotes the "pure" relativist position, which refers to a discursive approach of theory and research. Both positions call for the importance of clearly identifying what type of knowledge and knowledge process the researcher is going to create, and correctly choosing methodology matching with the epistemological stance. Examples of adolescent research adopting interpretivist and constructionist orientations are presented. PMID:21870675

  6. A method to derive vegetation distribution maps for pollen dispersion models using birch as an example

    NASA Astrophysics Data System (ADS)

    Pauling, A.; Rotach, M. W.; Gehrig, R.; Clot, B.

    2012-09-01

    Detailed knowledge of the spatial distribution of sources is a crucial prerequisite for the application of pollen dispersion models such as, for example, COSMO-ART (COnsortium for Small-scale MOdeling - Aerosols and Reactive Trace gases). However, this input is not available for the allergy-relevant species such as hazel, alder, birch, grass or ragweed. Hence, plant distribution datasets need to be derived from suitable sources. We present an approach to produce such a dataset from existing sources using birch as an example. The basic idea is to construct a birch dataset using a region with good data coverage for calibration and then to extrapolate this relationship to a larger area by using land use classes. We use the Swiss forest inventory (1 km resolution) in combination with a 74-category land use dataset that covers the non-forested areas of Switzerland as well (resolution 100 m). Then we assign birch density categories of 0%, 0.1%, 0.5% and 2.5% to each of the 74 land use categories. The combination of this derived dataset with the birch distribution from the forest inventory yields a fairly accurate birch distribution encompassing entire Switzerland. The land use categories of the Global Land Cover 2000 (GLC2000; Global Land Cover 2000 database, 2003, European Commission, Joint Research Centre; resolution 1 km) are then calibrated with the Swiss dataset in order to derive a Europe-wide birch distribution dataset and aggregated onto the 7 km COSMO-ART grid. This procedure thus assumes that a certain GLC2000 land use category has the same birch density wherever it may occur in Europe. In order to reduce the strict application of this crucial assumption, the birch density distribution as obtained from the previous steps is weighted using the mean Seasonal Pollen Index (SPI; yearly sums of daily pollen concentrations). For future improvement, region-specific birch densities for the GLC2000 categories could be integrated into the mapping procedure.

  7. Spectroscopic method for the determination of the ionic site concentration in solvent polymeric membranes and membrane plasticizers.

    PubMed

    Gyurcsányi, Robert E; Lindner, Erno

    2002-08-15

    The built-in site density of either fixed sites or mobile hydrophobic ion sites determines whether a membrane is permselective for cations or anions of the sample. The molar ratio of the ionophore to the intrinsic or added ionic sites in an ion-selective membrane significantly influences the potentiometric response of ionophore-based electrodes. Consequently, full knowledge of the "site inventory" in an ion-selective membrane maybe essential when new, uncharacterized polymers or plasticizers are implemented for ion-selective electrode fabrication. A simple spectroscopic method was developed for the fast and accurate determination of the ionic site concentration (covalently attached functionalized groups or impurities) in plasticized polymeric membranes and membrane plasticizers. The method is based on the determination of the degree of protonation of hydrogen ion-selective chromoionophores incorporated into these membranes or dissolved in the membrane plasticizers. In electroneutral membranes, the concentration of the positively charged, protonated ionophore and the total concentration of negative sites are equal. The method was applied for the determination of ionic sites (both positively and negatively charged) in PVC materials (different purity grade, and bearing various functional groups), polyurethanes (aliphatic, aromatic, and polycarbonate-based), and selected Fluka plasticizers (2-nitrophenyl octyl ether and 2-ethylhexyl sebacate). The technique proved to be appropriate for fast quantification of ionic impurities in hydrophobic, optically transparent materials. PMID:12199575

  8. Comparison of methods used to estimate conventional undiscovered petroleum resources: World examples

    USGS Publications Warehouse

    Ahlbrandt, T.S.; Klett, T.R.

    2005-01-01

    Various methods for assessing undiscovered oil, natural gas, and natural gas liquid resources were compared in support of the USGS World Petroleum Assessment 2000. Discovery process, linear fractal, parabolic fractal, engineering estimates, PETRIMES, Delphi, and the USGS 2000 methods were compared. Three comparisons of these methods were made in: (1) the Neuquen Basin province, Argentina (different assessors, same input data); (2) provinces in North Africa, Oman, and Yemen (same assessors, different methods); and (3) the Arabian Peninsula, Arabian (Persian) Gulf, and North Sea (different assessors, different methods). A fourth comparison (same assessors, same assessment methods but different geologic models), between results from structural and stratigraphic assessment units in the North Sea used only the USGS 2000 method, and hence compared the type of assessment unit rather than the method. In comparing methods, differences arise from inherent differences in assumptions regarding: (1) the underlying distribution of the parent field population (all fields, discovered and undiscovered), (2) the population of fields being estimated; that is, the entire parent distribution or the undiscovered resource distribution, (3) inclusion or exclusion of large outlier fields; (4) inclusion or exclusion of field (reserve) growth, (5) deterministic or probabilistic models, (6) data requirements, and (7) scale and time frame of the assessment. Discovery process, Delphi subjective consensus, and the USGS 2000 method yield comparable results because similar procedures are employed. In mature areas such as the Neuquen Basin province in Argentina, the linear and parabolic fractal and engineering methods were conservative compared to the other five methods and relative to new reserve additions there since 1995. The PETRIMES method gave the most optimistic estimates in the Neuquen Basin. In less mature areas, the linear fractal method yielded larger estimates relative to other methods. A geologically based model, such as one using the total petroleum system approach, is preferred in that it combines the elements of petroleum source, reservoir, trap and seal with the tectono-stratigraphic history of basin evolution with petroleum resource potential. Care must be taken to demonstrate that homogeneous populations in terms of geology, geologic risk, exploration, and discovery processes are used in the assessment process. The USGS 2000 method (7th Approximation Model, EMC computational program) is robust; that is, it can be used in both mature and immature areas, and provides comparable results when using different geologic models (e.g. stratigraphic or structural) with differing amounts of subdivisions, assessment units, within the total petroleum system. ?? 2005 International Association for Mathematical Geology.

  9. Qualitative Methods Can Enrich Quantitative Research on Occupational Stress: An Example from One Occupational Group

    ERIC Educational Resources Information Center

    Schonfeld, Irvin Sam; Farrell, Edwin

    2010-01-01

    The chapter examines the ways in which qualitative and quantitative methods support each other in research on occupational stress. Qualitative methods include eliciting from workers unconstrained descriptions of work experiences, careful first-hand observations of the workplace, and participant-observers describing "from the inside" a particular…

  10. A validated near-infrared spectroscopic method for methanol detection in biodiesel

    NASA Astrophysics Data System (ADS)

    Paul, Andrea; Bräuer, Bastian; Nieuwenkamp, Gerard; Ent, Hugo; Bremser, Wolfram

    2016-06-01

    Biodiesel quality control is a relevant issue as biodiesel properties influence diesel engine performance and integrity. Within the European metrology research program (EMRP) ENG09 project ‘Metrology for Biofuels’, an on-line/at-site suitable near-infrared spectroscopy (NIRS) method has been developed in parallel with an improved EN14110 headspace gas chromatography (GC) analysis method for methanol in biodiesel. Both methods have been optimized for a methanol content of 0.2 mass% as this represents the maximum limit of methanol content in FAME according to EN 14214:2009. The NIRS method is based on a mobile NIR spectrometer equipped with a fiber-optic coupled probe. Due to the high volatility of methanol, a tailored air-tight adaptor was constructed to prevent methanol evaporation during measurement. The methanol content of biodiesel was determined from evaluation of NIRS spectra by partial least squares regression (PLS). Both GC analysis and NIRS exhibited a significant dependence on biodiesel feedstock. The NIRS method is applicable to a content range of 0.1% (m/m) to 0.4% (m/m) of methanol with uncertainties at around 6% relative for the different feedstocks. A direct comparison of headspace GC and NIRS for samples of FAMEs yielded that the results of both methods are fully compatible within their stated uncertainties.

  11. Spectrophotometric method for the determination, validation, spectroscopic and thermal analysis of diphenhydramine in pharmaceutical preparation

    NASA Astrophysics Data System (ADS)

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2010-09-01

    A sensitive, simple and rapid spectrophotometric method was developed for the determination of diphenhydramine in pharmaceutical preparation. The method was based on the charge-transfer complex of the drug, as n-electron donor, with 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ), as π-acceptor. The formation of this complex was also confirmed by UV-vis, FTIR and 1H NMR spectra techniques and thermal analysis. The proposed method was validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and robustness. The linearity range for concentrations of diphenhydramine was found to be 12.5-150 μg/mL with acceptable correlation coefficients. The detection and quantification limits were found to be 2.09 and 6.27 μg/mL, respectively. The proposed and references methods were applied to the determination of drug in syrup. This preparation were also analyzed with an reference method and statistical comparison by t- and F-tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level.

  12. Development and validation spectroscopic methods for the determination of lomefloxacin in bulk and pharmaceutical formulations

    NASA Astrophysics Data System (ADS)

    El-Didamony, A. M.; Hafeez, S. M.

    2016-01-01

    Four simple, sensitive spectrophotometric and spectrofluorimetric methods (A-D) for the determination of antibacterial drug lomefloxacin (LMFX) in pharmaceutical formulations have been developed. Method A is based on formation of ternary complex between Pd(II), eosin and LMFX in the presence of methyl cellulose as surfactant and acetate-HCl buffer pH 4.0. Spectrophotometrically, under the optimum conditions, the ternary complex showed absorption maximum at 530 nm. Methods B and C are based on redox reaction between LMFX and KMnO4 in acid and alkaline media. In indirect spectrophotometry method B the drug solution is treated with a known excess of KMnO4 in H2SO4 medium and subsequent determination of unreacted oxidant by reacting it with safronine O in the same medium at λmax = 520 nm. Direct spectrophotometry method C involves treating the alkaline solution of LMFX with KMnO4 and measuring the bluish green product at 604 nm. Method D is based on the chelation of LMFX with Zr(IV) to produce fluorescent chelate. At the optimum reaction conditions, the drug-metal chelate showed excitation maxima at 280 nm and emission maxima at 443 nm. The optimum experimental parameters for the reactions have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drug in pharmaceutical preparations with good recoveries.

  13. Mouse ENU Mutagenesis to Understand Immunity to Infection: Methods, Selected Examples, and Perspectives

    PubMed Central

    Caignard, Grégory; Eva, Megan M.; van Bruggen, Rebekah; Eveleigh, Robert; Bourque, Guillaume; Malo, Danielle; Gros, Philippe; Vidal, Silvia M.

    2014-01-01

    Infectious diseases are responsible for over 25% of deaths globally, but many more individuals are exposed to deadly pathogens. The outcome of infection results from a set of diverse factors including pathogen virulence factors, the environment, and the genetic make-up of the host. The completion of the human reference genome sequence in 2004 along with technological advances have tremendously accelerated and renovated the tools to study the genetic etiology of infectious diseases in humans and its best characterized mammalian model, the mouse. Advancements in mouse genomic resources have accelerated genome-wide functional approaches, such as gene-driven and phenotype-driven mutagenesis, bringing to the fore the use of mouse models that reproduce accurately many aspects of the pathogenesis of human infectious diseases. Treatment with the mutagen N-ethyl-N-nitrosourea (ENU) has become the most popular phenotype-driven approach. Our team and others have employed mouse ENU mutagenesis to identify host genes that directly impact susceptibility to pathogens of global significance. In this review, we first describe the strategies and tools used in mouse genetics to understand immunity to infection with special emphasis on chemical mutagenesis of the mouse germ-line together with current strategies to efficiently identify functional mutations using next generation sequencing. Then, we highlight illustrative examples of genes, proteins, and cellular signatures that have been revealed by ENU screens and have been shown to be involved in susceptibility or resistance to infectious diseases caused by parasites, bacteria, and viruses. PMID:25268389

  14. Mouse ENU Mutagenesis to Understand Immunity to Infection: Methods, Selected Examples, and Perspectives.

    PubMed

    Caignard, Grégory; Eva, Megan M; van Bruggen, Rebekah; Eveleigh, Robert; Bourque, Guillaume; Malo, Danielle; Gros, Philippe; Vidal, Silvia M

    2014-01-01

    Infectious diseases are responsible for over 25% of deaths globally, but many more individuals are exposed to deadly pathogens. The outcome of infection results from a set of diverse factors including pathogen virulence factors, the environment, and the genetic make-up of the host. The completion of the human reference genome sequence in 2004 along with technological advances have tremendously accelerated and renovated the tools to study the genetic etiology of infectious diseases in humans and its best characterized mammalian model, the mouse. Advancements in mouse genomic resources have accelerated genome-wide functional approaches, such as gene-driven and phenotype-driven mutagenesis, bringing to the fore the use of mouse models that reproduce accurately many aspects of the pathogenesis of human infectious diseases. Treatment with the mutagen N-ethyl-N-nitrosourea (ENU) has become the most popular phenotype-driven approach. Our team and others have employed mouse ENU mutagenesis to identify host genes that directly impact susceptibility to pathogens of global significance. In this review, we first describe the strategies and tools used in mouse genetics to understand immunity to infection with special emphasis on chemical mutagenesis of the mouse germ-line together with current strategies to efficiently identify functional mutations using next generation sequencing. Then, we highlight illustrative examples of genes, proteins, and cellular signatures that have been revealed by ENU screens and have been shown to be involved in susceptibility or resistance to infectious diseases caused by parasites, bacteria, and viruses. PMID:25268389

  15. From Simulation to Real Robots with Predictable Results: Methods and Examples

    NASA Astrophysics Data System (ADS)

    Balakirsky, S.; Carpin, S.; Dimitoglou, G.; Balaguer, B.

    From a theoretical perspective, one may easily argue (as we will in this chapter) that simulation accelerates the algorithm development cycle. However, in practice many in the robotics development community share the sentiment that “Simulation is doomed to succeed” (Brooks, R., Matarić, M., Robot Learning, Kluwer Academic Press, Hingham, MA, 1993, p. 209). This comes in large part from the fact that many simulation systems are brittle; they do a fair-to-good job of simulating the expected, and fail to simulate the unexpected. It is the authors' belief that a simulation system is only as good as its models, and that deficiencies in these models lead to the majority of these failures. This chapter will attempt to address these deficiencies by presenting a systematic methodology with examples for the development of both simulated mobility models and sensor models for use with one of today's leading simulation engines. Techniques for using simulation for algorithm development leading to real-robot implementation will be presented, as well as opportunities for involvement in international robotics competitions based on these techniques.

  16. Comparative analysis of sequence covariation methods to mine evolutionary hubs: examples from selected GPCR families.

    PubMed

    Pelé, Julien; Moreau, Matthieu; Abdi, Hervé; Rodien, Patrice; Castel, Hélène; Chabbert, Marie

    2014-09-01

    Covariation between positions in a multiple sequence alignment may reflect structural, functional, and/or phylogenetic constraints and can be analyzed by a wide variety of methods. We explored several of these methods for their ability to identify covarying positions related to the divergence of a protein family at different hierarchical levels. Specifically, we compared seven methods on a model system composed of three nested sets of G-protein-coupled receptors (GPCRs) in which a divergence event occurred. The covariation methods analyzed were based on: χ2 test, mutual information, substitution matrices, and perturbation methods. We first analyzed the dependence of the covariation scores on residue conservation (measured by sequence entropy), and then we analyzed the networking structure of the top pairs. Two methods out of seven--OMES (Observed minus Expected Squared) and ELSC (Explicit Likelihood of Subset Covariation)--favored pairs with intermediate entropy and a networking structure with a central residue involved in several high-scoring pairs. This networking structure was observed for the three sequence sets. In each case, the central residue corresponded to a residue known to be crucial for the evolution of the GPCR family and the subfamily specificity. These central residues can be viewed as evolutionary hubs, in relation with an epistasis-based mechanism of functional divergence within a protein family. PMID:24677372

  17. Towards a stable and absolute atmospheric carbon dioxide instrument using spectroscopic null method

    NASA Astrophysics Data System (ADS)

    Xiang, B.; Nelson, D. D.; McManus, J. B.; Zahniser, M. S.; Wofsy, S. C.

    2013-02-01

    We present a novel spectral method to measure atmospheric carbon dioxide (CO2) with high precision and stability without resorting to calibration tanks during long-term operation. This spectral null method improves precision by reducing spectral proportional noise associated with laser emission instabilities. We employ sealed quartz cells with known CO2 column densities to serve as the permanent internal references in the null method, which improve the instrument's stability and accuracy. A prototype instrument - ABsolute Carbon dioxide (ABC) is developed using this new approach. The instrument has one-second precision of 0.02 ppm, which averages down to 0.007 ppm within one minute. Long-term stability of within 0.1 ppm is achieved without any calibrations for over a one-month period. These results have the potential for eliminating the need for calibration cylinders for high accuracy field measurements of carbon dioxide.

  18. Towards a stable and absolute atmospheric carbon dioxide instrument using spectroscopic null method

    NASA Astrophysics Data System (ADS)

    Xiang, B.; Nelson, D. D.; McManus, J. B.; Zahniser, M. S.; Wofsy, S. C.

    2013-07-01

    We present a novel spectral method to measure atmospheric carbon dioxide (CO2) with high precision and stability without resorting to calibration tanks during long-term operation. This spectral null method improves precision by reducing spectral proportional noise associated with laser emission instabilities. We employ sealed quartz cells with known CO2 column densities to serve as the permanent internal references in the null method, which improve the instrument's stability and accuracy. A prototype instrument - ABsolute Carbon dioxide (ABC) is developed using this new approach. The instrument has a one-second precision of 0.02 ppm, which averages down to 0.007 ppm within one minute. Long-term stability of within 0.1 ppm is achieved without any calibrations for over a one-month period. These results have the potential for eliminating the need for calibration cylinders for high accuracy field measurements of carbon dioxide.

  19. Using Google Analytics as a process evaluation method for Internet-delivered interventions: an example on sexual health.

    PubMed

    Crutzen, Rik; Roosjen, Johanna L; Poelman, Jos

    2013-03-01

    The study aimed to demonstrate the potential of Google Analytics as a process evaluation method for Internet-delivered interventions, using a website about sexual health as an example. This study reports visitors' behavior until 21 months after the release of the website (March 2009-December 2010). In total, there were 850 895 visitors with an average total visiting time (i.e. dose) of 5:07 min. Google Analytics provided data to answer three key questions in terms of process evaluation of an Internet-delivered intervention: (i) How do visitors behave?; (ii) Where do visitors come from? and (iii) What content are visitors exposed to? This real-life example demonstrated the potential of Google Analytics as a method to be used in a process evaluation of Internet-delivered interventions. This is highly relevant given the current expansion of these interventions within the field of health promotion. PMID:22377974

  20. Theoretical assessment of 3-D magnetotelluric method for oil and gas exploration: Synthetic examples

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Wei, Wenbo; Lu, Qingtian; Dong, Hao; Li, Yanqing

    2014-07-01

    In petroleum explorations, seismic reflection technique has been almost always the preferred method for its high exploration depth and resolution. However, with the development of three dimensional (3D) inversion and interpretation schemes, much potential has been shown in MT method dealing with complex geological structures as in oil and gas exploration. In this study, synthetic geophysical models of petroleum reservoir structures are modeled and utilized to demonstrate that feasibility of 3-D MT technique for hydrocarbon exploration. A series of typical reservoir structure models are constructed and used to generate synthetic MT and seismic data to test the capabilities of 2-D/3-D MT and 2-D seismic inversion techniques. According to the inversion comparison, in addition to correctly retrieve the original forward model, the 3-D MT method also has some advantages over the reflective seismology method, which suffered from the lack of reflection wave and multiple wave problems. With the presented 3-D high resolution MT inversion method, MT techniques should be employed as one of the first choices for petroleum explorations.

  1. Fuzzy-logic based strategy for validation of multiplex methods: example with qualitative GMO assays.

    PubMed

    Bellocchi, Gianni; Bertholet, Vincent; Hamels, Sandrine; Moens, W; Remacle, Jos; Van den Eede, Guy

    2010-02-01

    This paper illustrates the advantages that a fuzzy-based aggregation method could bring into the validation of a multiplex method for GMO detection (DualChip GMO kit, Eppendorf). Guidelines for validation of chemical, bio-chemical, pharmaceutical and genetic methods have been developed and ad hoc validation statistics are available and routinely used, for in-house and inter-laboratory testing, and decision-making. Fuzzy logic allows summarising the information obtained by independent validation statistics into one synthetic indicator of overall method performance. The microarray technology, introduced for simultaneous identification of multiple GMOs, poses specific validation issues (patterns of performance for a variety of GMOs at different concentrations). A fuzzy-based indicator for overall evaluation is illustrated in this paper, and applied to validation data for different genetically modified elements. Remarks were drawn on the analytical results. The fuzzy-logic based rules were shown to be applicable to improve interpretation of results and facilitate overall evaluation of the multiplex method. PMID:19533405

  2. EVALUATION OF EXTRACTION AND SPECTROSCOPIC METHODS FOR PB SPECIATION IN AN AMENDED SOIL

    EPA Science Inventory

    Immobilization of pyromorphite (Pbs(PO4hCI) via P amendments to Pb contaminated soils is proving to be a viable method of remediation. However, the issue of ascertaining the amount of soil Pb converted to pyromorphite is difficult in heterogeneous soil systems. Previous attempts ...

  3. Methods for Streamlining Intervention Fidelity Checklists: An Example from the Chronic Disease Self-Management Program

    PubMed Central

    Ahn, SangNam; Smith, Matthew Lee; Altpeter, Mary; Belza, Basia; Post, Lindsey; Ory, Marcia G.

    2015-01-01

    Maintaining intervention fidelity should be part of any programmatic quality assurance (QA) plan and is often a licensure requirement. However, fidelity checklists designed by original program developers are often lengthy, which makes compliance difficult once programs become widely disseminated in the field. As a case example, we used Stanford’s original Chronic Disease Self-Management Program (CDSMP) fidelity checklist of 157 items to demonstrate heuristic procedures for generating shorter fidelity checklists. Using an expert consensus approach, we sought feedback from active master trainers registered with the Stanford University Patient Education Research Center about which items were most essential to, and also feasible for, assessing fidelity. We conducted three sequential surveys and one expert group-teleconference call. Three versions of the fidelity checklist were created using different statistical and methodological criteria. In a final group-teleconference call with seven national experts, there was unanimous agreement that all three final versions (e.g., a 34-item version, a 20-item version, and a 12-item version) should be made available because the purpose and resources for administering a checklist might vary from one setting to another. This study highlights the methodology used to generate shorter versions of a fidelity checklist, which has potential to inform future QA efforts for this and other evidence-based programs (EBP) for older adults delivered in community settings. With CDSMP and other EBP, it is important to differentiate between program fidelity as mandated by program developers for licensure, and intervention fidelity tools for providing an “at-a-glance” snapshot of the level of compliance to selected program indicators. PMID:25964941

  4. Capturing Intuition Through Interactive Inverse Methods: Examples Drawn From Mechanical Non-Linearities in Structural Geology

    NASA Astrophysics Data System (ADS)

    Moresi, L.; May, D.; Peachey, T.; Enticott, C.; Abramson, D.; Robinson, T.

    2004-12-01

    Can you teach intuition ? Obviously we think that this is possible (though it's still just a hunch). People undoubtedly develop intuition for non-linear systems through painstaking repetition of complex tasks until they have sufficient feedback to begin to "see" the emergent behaviour. The better the exploration of the system can be exposed, the quicker the potential for developing an intuitive understanding. We have spent some time considering how to incorporate the intuitive knowledge of field geologists into mechanical modeling of geological processes. Our solution has been to allow expert geologist to steer (via a GUI) a genetic algorithm inversion of a mechanical forward model towards "structures" or patterns which are plausible in nature. The expert knowledge is then captured by analysis of the individual model parameters which are constrained by the steering (and by analysis of those which are unconstrained). The same system can also be used in reverse to expose the influence of individual parameters to the non-expert who is trying to learn just what does make a good match between model and observation. The ``distance'' between models preferred by experts, and those by an individual can be shown graphically to provide feedback. The examples we choose are from numerical models of extensional basins. We will first try to give each person some background information on the scientific problem from the poster and then we will let them loose on the numerical modeling tools with specific tasks to achieve. This will be an experiment in progress - we will later analyse how people use the GUI and whether there is really any significant difference between so-called experts and self-styled novices.

  5. Flow cytometry for intracellular SPION quantification: specificity and sensitivity in comparison with spectroscopic methods

    PubMed Central

    Friedrich, Ralf P; Janko, Christina; Poettler, Marina; Tripal, Philipp; Zaloga, Jan; Cicha, Iwona; Dürr, Stephan; Nowak, Johannes; Odenbach, Stefan; Slabu, Ioana; Liebl, Maik; Trahms, Lutz; Stapf, Marcus; Hilger, Ingrid; Lyer, Stefan; Alexiou, Christoph

    2015-01-01

    Due to their special physicochemical properties, iron nanoparticles offer new promising possibilities for biomedical applications. For bench to bedside translation of super-paramagnetic iron oxide nanoparticles (SPIONs), safety issues have to be comprehensively clarified. To understand concentration-dependent nanoparticle-mediated toxicity, the exact quantification of intracellular SPIONs by reliable methods is of great importance. In the present study, we compared three different SPION quantification methods (ultraviolet spectrophotometry, magnetic particle spectroscopy, atomic adsorption spectroscopy) and discussed the shortcomings and advantages of each method. Moreover, we used those results to evaluate the possibility to use flow cytometric technique to determine the cellular SPION content. For this purpose, we correlated the side scatter data received from flow cytometry with the actual cellular SPION amount. We showed that flow cytometry provides a rapid and reliable method to assess the cellular SPION content. Our data also demonstrate that internalization of iron oxide nanoparticles in human umbilical vein endothelial cells is strongly dependent to the SPION type and results in a dose-dependent increase of toxicity. Thus, treatment with lauric acid-coated SPIONs (SEONLA) resulted in a significant increase in the intensity of side scatter and toxicity, whereas SEONLA with an additional protein corona formed by bovine serum albumin (SEONLA-BSA) and commercially available Rienso® particles showed only a minimal increase in both side scatter intensity and cellular toxicity. The increase in side scatter was in accordance with the measurements for SPION content by the atomic adsorption spectroscopy reference method. In summary, our data show that flow cytometry analysis can be used for estimation of uptake of SPIONs by mammalian cells and provides a fast tool for scientists to evaluate the safety of nanoparticle products. PMID:26170658

  6. Effects of Instruction-Supported Learning with Worked Examples in Quantitative Method Training

    ERIC Educational Resources Information Center

    Wagner, Kai; Klein, Martin; Klopp, Eric; Puhl, Thomas; Stark, Robin

    2013-01-01

    An experimental field study at a German university was conducted in order to test the effectiveness of an integrated learning environment to improve the acquisition of knowledge about empirical research methods. The integrated learning environment was based on the combination of instruction-oriented and problem-oriented design principles and…

  7. Commentary: A Response to Reckase's Conceptual Framework and Examples for Evaluating Standard Setting Methods

    ERIC Educational Resources Information Center

    Schulz, E. Matthew

    2006-01-01

    A look at real data shows that Reckase's psychometric theory for standard setting is not applicable to bookmark and that his simulations cannot explain actual differences between methods. It is suggested that exclusively test-centered, criterion-referenced approaches are too idealized and that a psychophysics paradigm and a theory of group…

  8. Quantitative analysis of uranium in aqueous solutions using a semiconductor laser-based spectroscopic method.

    PubMed

    Cho, Hye-Ryun; Jung, Euo Chang; Cha, Wansik; Song, Kyuseok

    2013-05-01

    A simple analytical method based on the simultaneous measurement of the luminescence of hexavalent uranium ions (U(VI)) and the Raman scattering of water, was investigated for determining the concentration of U(VI) in aqueous solutions. Both spectra were measured using a cw semiconductor laser beam at a center wavelength of 405 nm. The empirical calibration curve for the quantitative analysis of U(VI) was obtained by measuring the ratio of the luminescence intensity of U(VI) at 519 nm to the Raman scattering intensity of water at 469 nm. The limit of detection (LOD) in the parts per billion range and a dynamic range from the LOD up to several hundred parts per million were achieved. The concentration of uranium in groundwater determined by this method is in good agreement with the results determined by kinetic phosphorescence analysis and inductively coupled plasma mass spectrometry. PMID:23534889

  9. [Interaction between ambroxol hydrochloride and human serum albumin studied by spectroscopic and molecular modeling methods].

    PubMed

    Liang, Jing; Feng, Su-Ling

    2011-04-01

    In the present paper, the interaction between ambroxol hydrochloride (ABX) and human serum albumin (HSA) was studied under simulative physiological condition by spectroscopy and molecular modeling method. Stern-Volmer curvers at different temperatures and UV-Vis absorption spectroscopy showed that ABX quenched the fluorescence of HSA mainly through dynamic quenching mode. On the basis of the thermodynamic data, the main binding force between them is hydrophobic interaction. According to the theory of Forster non-radiation energy transfer, the binding distance between the donor and the acceptor was 3.01 nm. The effect of ABX on the conformation of HSA was analyzed by the synchronous and three-dimensional fluorescence spectroscopy. Furthermore, using the molecular modeling method, the interaction between them was predicted from molecular angle: ABX might locate in the subdomain III A of HSA. PMID:21714251

  10. Spectroscopic studies of biologically active coumarin laser dye: Evaluation of dipole moments by solvatochromic shift method

    NASA Astrophysics Data System (ADS)

    Koppal, V. V.; Muddapur, G. V.; Patil, N. R.; Melavanki, R. M.

    2016-05-01

    In this paper we attempted to record absorption and emission spectra of 2-acetyl-3H-benzo[f]chromen-3-one [2AHBC] laser dye in different solvents of varying polarities to investigate its solvatochromic behavior. The two electronic states dipole moments of 2AHBC are calculated using solvatochromic spectral shifts which are correlated with dielectric constant (ɛ) refractive index (n) of various solvents. A systematic approach is made to estimate ground and excited state dipole moments on the basis of different solvent correlation methods like Bilot-Kawski equations, Lippert-Mataga, Bakhsheiv, Kawaski-Chamma-Viallet and Reichardt methods. Dipole moments in the excited state was found to be higher than the ground state by confirming π→π* transition.

  11. Spectroscopic method for measuring plasma magnetic fields having arbitrary distributions of direction and amplitude.

    PubMed

    Stambulchik, E; Tsigutkin, K; Maron, Y

    2007-06-01

    An approach for measurements of magnetic fields, based on the comparison of the magnetic-field-induced contributions to the line shapes of different fine-structure components of an atomic multiplet, is proposed and experimentally demonstrated. Contrary to the methods based on detecting an anisotropy in either the emitted radiation or in the dispersion properties of the medium, the present method is applicable when the field direction or amplitude vary significantly in the region viewed or during the time of observation. The technique can be used even when the line shapes are Stark or Doppler dominated. It has potential applications in laser-matter interactions, plasmas driven by high-current pulses, and astrophysics. PMID:17677852

  12. An infrared spectroscopic based method for mercury(II) detection in aqueous solutions.

    PubMed

    Chandrasoma, Asela; Hamid, Amer Al Abdel; Bruce, Alice E; Bruce, Mitchell R M; Tripp, Carl P

    2012-05-30

    A new method that uses solid phase extraction (SPE) coupled with FTIR spectroscopy to detect Hg(II) in aqueous samples is described. The technique is envisioned for on-site, field evaluation rather than lab-based techniques. This paper presents the "proof of principle" of this new approach toward measurements of Hg(II) in water and identifies mass transport issues that would need to be overcome in order to migrate from a lab based method to field operation. The SPE material supported on a Si wafer is derivatized with an acylthiosemicarbazide, which undergoes a reaction in the presence of aqueous Hg(II) to form an oxadiazole ring. The progress of the reaction is monitored by IR spectroscopy. Following EPA guidelines, the method of detection limit (MDL) for the SPE/IR was 5 μg of Hg(II)cm(-2). In a 1L sample and a 1cm(2) Si wafer, this translates to a detection limit of 5 ppb. This system shows a high selectivity toward aqueous Hg(II) over other thiophilic heavy metal ions such as Pb(II), Cd(II), Fe(III), and Zn(II) and other metal ions such as Ni(II), Mn(II), Co(II), Cu(II), In(III), Ru(III), Na(I), and Ag(I) in aqueous solutions. PMID:22560281

  13. Results of Bayesian methods depend on details of implementation: An example of estimating salmon escapement goals

    USGS Publications Warehouse

    Adkison, M.D.; Peterman, R.M.

    1996-01-01

    Bayesian methods have been proposed to estimate optimal escapement goals, using both knowledge about physical determinants of salmon productivity and stock-recruitment data. The Bayesian approach has several advantages over many traditional methods for estimating stock productivity: it allows integration of information from diverse sources and provides a framework for decision-making that takes into account uncertainty reflected in the data. However, results can be critically dependent on details of implementation of this approach. For instance, unintended and unwarranted confidence about stock-recruitment relationships can arise if the range of relationships examined is too narrow, if too few discrete alternatives are considered, or if data are contradictory. This unfounded confidence can result in a suboptimal choice of a spawning escapement goal.

  14. Paleohydrological methods and some examples from Swedish fluvial environments I. Cobble and boulder deposits.

    USGS Publications Warehouse

    Williams, G.P.

    1983-01-01

    Establishes approximate empirical relations for determining the minimum unit stream power, bed shear stress and mean flow velocity capable of moving cobbles and boulders on streambeds. The derived equations then are used to estimate the minimum paleoflows that could have transported the boulders of two ancient fluvial deposits in Sweden. The flow estimates are compared with those made by more conventional hydraulic methods. Bankfull flows also are estimated for one of the two deposits, using various hydraulic equations.-Author

  15. Wavelet modelling of the gravity field by domain decomposition methods: an example over Japan

    NASA Astrophysics Data System (ADS)

    Panet, Isabelle; Kuroishi, Yuki; Holschneider, Matthias

    2011-01-01

    With the advent of satellite gravity, large gravity data sets of unprecedented quality at low and medium resolution become available. For local, high resolution field modelling, they need to be combined with the surface gravity data. Such models are then used for various applications, from the study of the Earth interior to the determination of oceanic currents. Here we show how to realize such a combination in a flexible way using spherical wavelets and applying a domain decomposition approach. This iterative method, based on the Schwarz algorithms, allows to split a large problem into smaller ones, and avoids the calculation of the entire normal system, which may be huge if high resolution is sought over wide areas. A subdomain is defined as the harmonic space spanned by a subset of the wavelet family. Based on the localization properties of the wavelets in space and frequency, we define hierarchical subdomains of wavelets at different scales. On each scale, blocks of subdomains are defined by using a tailored spatial splitting of the area. The data weighting and regularization are iteratively adjusted for the subdomains, which allows to handle heterogeneity in the data quality or the gravity variations. Different levels of approximations of the subdomains normals are also introduced, corresponding to building local averages of the data at different resolution levels. We first provide the theoretical background on domain decomposition methods. Then, we validate the method with synthetic data, considering two kinds of noise: white noise and coloured noise. We then apply the method to data over Japan, where we combine a satellite-based geopotential model, EIGEN-GL04S, and a local gravity model from a combination of land and marine gravity data and an altimetry-derived marine gravity model. A hybrid spherical harmonics/wavelet model of the geoid is obtained at about 15 km resolution and a corrector grid for the surface model is derived.

  16. Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting

    PubMed Central

    Torres-Climent, A.; Gomis, P.; Martín-Mata, J.; Bustamante, M. A.; Marhuenda-Egea, F. C.; Pérez-Murcia, M. D.; Pérez-Espinosa, A.; Paredes, C.; Moral, R.

    2015-01-01

    The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques), to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc) and animal manures (cattle manure and poultry manure). The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1) and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively), indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio. PMID:26418458

  17. Traditional and modern plant breeding methods with examples in rice (Oryza sativa L.).

    PubMed

    Breseghello, Flavio; Coelho, Alexandre Siqueira Guedes

    2013-09-01

    Plant breeding can be broadly defined as alterations caused in plants as a result of their use by humans, ranging from unintentional changes resulting from the advent of agriculture to the application of molecular tools for precision breeding. The vast diversity of breeding methods can be simplified into three categories: (i) plant breeding based on observed variation by selection of plants based on natural variants appearing in nature or within traditional varieties; (ii) plant breeding based on controlled mating by selection of plants presenting recombination of desirable genes from different parents; and (iii) plant breeding based on monitored recombination by selection of specific genes or marker profiles, using molecular tools for tracking within-genome variation. The continuous application of traditional breeding methods in a given species could lead to the narrowing of the gene pool from which cultivars are drawn, rendering crops vulnerable to biotic and abiotic stresses and hampering future progress. Several methods have been devised for introducing exotic variation into elite germplasm without undesirable effects. Cases in rice are given to illustrate the potential and limitations of different breeding approaches. PMID:23551250

  18. Simultaneous analysis of climatic trends in multiple variables: an example of application of multivariate statistical methods

    NASA Astrophysics Data System (ADS)

    Huth, Radan; Pokorná, Lucie

    2005-03-01

    This paper introduces into the research on trends in climate elements the multivariate statistical methods, namely principal component analysis (PCA) and cluster analysis, and demonstrates the benefits of their use. We also introduce the idea of normalization of the trends by their confidence interval, which facilitates the comparison of trends among different variables and allows their fair treatment by the multivariate methods. The study is performed for 11 climate elements at 21 stations in the Czech Republic. Temperatures are rising in winter, spring and summer, but decreasing in autumn. Consistent with these changes are trends in sunshine duration, cloudiness and daily temperature range. Correlation analysis and PCA confirm the mutual relationships among the trends in these variables in all seasons. The two methods also uncover other groups of variables whose trends vary similarly at individual stations, which, however, occur in several seasons only, not throughout the year. This implies that the trend analyses based on seasonal values should be preferred to analyses of annual trends. The cluster analysis of stations allows the quantification of the spatial consistency of trends. The groupings of stations are spatially incoherent and seasonally variable, which indicates that local peculiarities of the relatively complex terrain affect the station trends to a considerable extent.

  19. Identification of different iron sites in ?-Ga2O3 nanoparticles by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Toloman, D.; Popa, A.; Stan, M.; Silipas, T. D.; Biris, A. R.

    2015-12-01

    This paper reports the influence of Fe doping degree (1%, 3%, 5%) on structural and optical characteristics of gallium oxide nanoparticles evidenced by XRD, Raman, UV-vis and EPR methods. XRD studies reveal a monoclinic ?-Ga2O3 structure. The lattice expansion sustains the substitutional incorporation of Fe ions in Ga2O3 host. The presence of a ?Fe2O3 secondary phase was evidenced for the samples doped with 3 and 5 % Fe only by Raman scattering. From UV-Vis absorption and EPR spectroscopy was evidenced the presence of isolated Fe3+ ions in octahedral sites, Fe2O3 particles, Fex3+Oy and oligomeric clusters.

  20. Retrieval of terahertz spectroscopic signatures in the presence of rough surface scattering using wavelet methods

    NASA Astrophysics Data System (ADS)

    Arbab, M. H.; Winebrenner, D. P.; Thorsos, E. I.; Chen, A.

    2010-11-01

    Scattering of terahertz waves by surface roughness can obscure spectral signatures of chemicals at these frequencies. We demonstrate this effect using controlled levels of surface scattering on α-lactose monohydrate pellets. Furthermore, we show an implementation of wavelet methods that can retrieve terahertz spectral information from rough surface targets. We use a multiresolution analysis of the rough-surface-scattered signal utilizing the maximal overlap discrete wavelet transform (MODWT) to extract the resonant signature of lactose. We present a periodic extension technique to circumvent the circular boundary conditions of MODWT, which can be robustly used in an automated terahertz stand-off detection device.

  1. Magnetic resonance spectroscopic methods for the assessment of metabolic functions in the diseased brain.

    PubMed

    Hall, Hlne; Cuellar-Baena, Sandra; Dahlberg, Carina; In't Zandt, Ren; Denisov, Vladimir; Kirik, Deniz

    2012-01-01

    Magnetic resonance spectroscopy (MRS) is a non-invasive technique that can be used to detect and quantify multiple metabolites. This chapter will review some of the applications of MRS to the study of brain functions. Typically, (1)H-MRS can detect metabolites reflecting neuronal density and integrity, markers of energy metabolism or inflammation, as well as neurotransmitters. The complexity of the proton spectrum has however led to the development of other nuclei-based methods, such as (31)P- and (13)C-MRS, which offer a broader chemical shift range and therefore can provide more detailed information at the level of single metabolites. The versatility of MRS allows for a wide range of clinical applications, of which neurodegeneration is an interesting target for spectroscopy-based studies. In particular, MRS can identify patterns of altered brain chemistry in Alzheimer's patients and can help establish differential diagnosis in Alzheimer's and Parkinson's diseases. Using MRS to follow less abundant neurotransmitters is currently out of reach and will most likely depend on the development of methods such as hyperpolarization that can increase the sensitivity of detection. In particular, dynamic nuclear polarization has opened up a new and exciting area of medical research, with developments that could greatly impact on the real-time monitoring of in vivo metabolic processes in the brain. PMID:22076698

  2. Investigation on the protein-binding properties of icotinib by spectroscopic and molecular modeling method

    NASA Astrophysics Data System (ADS)

    Zhang, Hua-xin; Xiong, Hang-xing; Li, Li-wei

    2016-05-01

    Icotinib is a highly-selective epidermal growth factor receptor tyrosine kinase inhibitor with preclinical and clinical activity in non-small cell lung cancer, which has been developed as a new targeted anti-tumor drug in China. In this work, the interaction of icotinib and human serum albumin (HSA) were studied by three-dimensional fluorescence spectra, ultraviolet spectra, circular dichroism (CD) spectra, molecular probe and molecular modeling methods. The results showed that icotinib binds to Sudlow's site I in subdomain IIA of HSA molecule, resulting in icotinib-HSA complexes formed at ground state. The number of binding sites, equilibrium constants, and thermodynamic parameters of the reaction were calculated at different temperatures. The negative enthalpy change (ΔHθ) and entropy change (ΔSθ) indicated that the structure of new complexes was stabilized by hydrogen bonds and van der Waals power. The distance between donor and acceptor was calculated according to Förster's non-radiation resonance energy transfer theory. The structural changes of HSA caused by icotinib binding were detected by synchronous spectra and circular dichroism (CD) spectra. Molecular modeling method was employed to unfold full details of the interaction at molecular level, most of which could be supported by experimental results. The study analyzed the probability that serum albumins act as carriers for this new anticarcinogen and provided fundamental information on the process of delivering icotinib to its target tissues, which might be helpful in understanding the mechanism of icotinib in cancer therapy.

  3. Investigation on the protein-binding properties of icotinib by spectroscopic and molecular modeling method.

    PubMed

    Zhang, Hua-Xin; Xiong, Hang-Xing; Li, Li-Wei

    2016-05-15

    Icotinib is a highly-selective epidermal growth factor receptor tyrosine kinase inhibitor with preclinical and clinical activity in non-small cell lung cancer, which has been developed as a new targeted anti-tumor drug in China. In this work, the interaction of icotinib and human serum albumin (HSA) were studied by three-dimensional fluorescence spectra, ultraviolet spectra, circular dichroism (CD) spectra, molecular probe and molecular modeling methods. The results showed that icotinib binds to Sudlow's site I in subdomain IIA of HSA molecule, resulting in icotinib-HSA complexes formed at ground state. The number of binding sites, equilibrium constants, and thermodynamic parameters of the reaction were calculated at different temperatures. The negative enthalpy change (ΔH(θ)) and entropy change (ΔS(θ)) indicated that the structure of new complexes was stabilized by hydrogen bonds and van der Waals power. The distance between donor and acceptor was calculated according to Förster's non-radiation resonance energy transfer theory. The structural changes of HSA caused by icotinib binding were detected by synchronous spectra and circular dichroism (CD) spectra. Molecular modeling method was employed to unfold full details of the interaction at molecular level, most of which could be supported by experimental results. The study analyzed the probability that serum albumins act as carriers for this new anticarcinogen and provided fundamental information on the process of delivering icotinib to its target tissues, which might be helpful in understanding the mechanism of icotinib in cancer therapy. PMID:26963729

  4. A spectroscopic method for identifying terrestrial biocarbonates and application to Mars

    NASA Astrophysics Data System (ADS)

    Blanco, A.; Orofino, V.; D'Elia, M.; Fonti, S.; Mastandrea, A.; Guido, A.; Russo, F.

    2011-06-01

    Searching for traces of extinct and/or extant life on Mars is one of the major objectives for remote-sensing and in situ exploration of the planet. In previous laboratory works we have investigated the infrared spectral modifications induced by thermal processing on different carbonate samples, in the form of fresh shells and fossils of different ages, whose biotic origin is easily recognizable. The goal was to discriminate them from their abiotic counterparts. In general, it is difficult to identify biotic signatures, especially when the organisms inducing the carbonate precipitation have low fossilization potential (i.e. microbes, bacteria, archaea). A wide variety of microorganisms are implicated in carbonate genesis, and their direct characterization is very difficult to evaluate by traditional methods, both in ancient sedimentary systems and even in recent environments. In the present work we apply our analysis to problematic carbonate samples, in which there is no clear evidence of controlled or induced biomineralization. This analysis indicates a very likely biotic origin of the aragonite samples under study, in agreement with the conclusion previously reported by Guido et al. (2007) who followed a completely different approach based on a complex set of sedimentary, petrographic, geochemical and biochemical analyses. We show that our method is reliable for discriminating between biotic and abiotic carbonates, and therefore it is a powerful tool in the search for life on Mars in the next generation of space missions to the planet.

  5. Estimation of σ- and π-donor properties of heterocyclic thioamides by spectroscopic and magnetic resonance methods

    NASA Astrophysics Data System (ADS)

    Chernov'yants, Margarita S.; Khohlov, Evgeniy V.; Bondarenko, Gennadiy I.; Burykin, Igor V.

    2011-10-01

    The charge-transfer complexes (CTC) of few thioamide: 1-methylimidazoline-2-thione (MMI), 3-methyl-1-ethoxycarbonilimidazoline-2-thione (Carb), 5-methylbenzimidazoline-2-thione (BIZ), benzothiazoline-2-thione (BTZ), benzoxazoline-2-thione (BOZ) as σ-donors and diiodine as σ-acceptor were studied by spectroscopic methods (UV/Vis, 1H NMR). CTC formation constants of thioamides with diiodine were determined using the function of the average-iodine number. The charge-transfer complexes of thioamides as π-donors with tetracyanoethylene (TCNE) as π-electron acceptor, were studied by UV-spectroscopy in dichloromethane and chloroform solutions. The mechanism of interaction MMI and Carb with TCNE have been studied by EPR spectroscopy. Spectral characteristics and formation constants are discussed in the terms of electron donor affinity of thioamides and the nature of the organic solvent used. The ionization potentials of donors were estimated from the CT transition energies of their complexes. The photolytic equilibrium constants of five thioamides are determined using pH-metric titrations.

  6. Possibilities and limitations of imaging spectroscopic reflectometry in optical characterization of thin films

    NASA Astrophysics Data System (ADS)

    Ohlídal, Miloslav; Ohlidal, Ivan; Nečas, David; Vodák, Jiří; Franta, Daniel; Nádaský, Pavel; Vižd'a, František

    2015-09-01

    It is possible to encounter thin films exhibiting various defects in practice. One of these defects is area non-uniformity in optical parameters (e.g. in thickness). Therefore it is necessary to have methods for an optical characterization of nonuniform thin films. Imaging spectroscopic reflectometry provides methods enabling us to perform an efficient optical characterization of such films. It gives a possibility to determine spectral dependencies of a local reflectance at normal incidence of light belonging to small areas (37 μm × 37 μm in our case) on these non-uniform films. The local reflectance is measured by individual pixels of a CCD camera serving as a detector of an imaging spectroscopic reflectometer. It is mostly possible to express the local reflectance using formulas corresponding to a uniform thin film. It allows a relatively simple treatment of the experimental data obtained by imaging spectroscopic reflectometry. There are three methods for treating these experimental data in the special case of thickness non-uniformity, i.e. in the case of the same optical constants within a certain area of the film - single pixel imaging spectroscopic reflectometry method, combination of single-pixel imaging spectroscopic reflectometry method and conventional methods (conventional single spot spectroscopic ellipsometry and spectrophotometry), and multi-pixel imaging spectroscopic reflectometry method. These methods are discussed and examples of the optical characterization of thin films non-uniform in thickness corresponding to these methods are presented in this contribution.

  7. Analysis of binding interaction between (-)-epigallocatechin (EGC) and β-lactoglobulin by multi-spectroscopic method

    NASA Astrophysics Data System (ADS)

    Wu, Xuli; Wu, Hui; Liu, Meixia; Liu, Zhigang; Xu, Hong; Lai, Furao

    2011-11-01

    The binding interaction between (-)-epigallocatechin (EGC) with bovine β-lactoglobulin (βLG) was investigated by fluorescence, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy methods. The binding parameters were determined by Stern-Volmer equation and the thermodynamic parameters were calculated according to the van't Hoff equation. The results suggested that βLG was bound by EGC, which resulted in change of native conformation of βLG. van der Waals interactions and hydrogen bonding probably played major roles in the binding process. Our study is helpful for further elucidation of binding interactions between catechins with milk proteins, which would contribute to the development of novel milk products.

  8. Characterization of the Interaction between Eupatorin and Bovine Serum Albumin by Spectroscopic and Molecular Modeling Methods

    PubMed Central

    Xu, Hongliang; Yao, Nannan; Xu, Haoran; Wang, Tianshi; Li, Guiying; Li, Zhengqiang

    2013-01-01

    This study investigated the interaction between eupatorin and bovine serum albumin (BSA) using ultraviolet-visible (UV-vis) absorption, fluorescence, synchronous fluorescence, circular dichroism (CD) spectroscopies, and molecular modeling at pH 7.4. Results of UV-vis and fluorescence spectroscopies illustrated that BSA fluorescence was quenched by eupatorin via a static quenching mechanism. Thermodynamic parameters revealed that hydrophobic and electrostatic interactions played major roles in the interaction. Moreover, the efficiency of energy transfer, and the distance between BSA and acceptor eupatorin, were calculated. The effects of eupatorin on the BSA conformation were analyzed using UV-vis, CD, and synchronous fluorescence. Finally, the binding of eupatorin to BSA was modeled using the molecular docking method. PMID:23839090

  9. Spectroscopic characterizations of Er doped LaPO4 submicron phosphors prepared by homogeneous precipitation method

    NASA Astrophysics Data System (ADS)

    Saltmarsh, N.; Kumar, G. A.; Kailasnath, M.; Shenoy, Vittal; Santhosh, C.; Sardar, D. K.

    2016-03-01

    Hexagonal shaped LaPO4 submicron particles doped with various concentrations of Er were successfully prepared by homogenous precipitation method using metal nitrates and ammonium phosphate. Particles of approximate particle size 125 nm and size distribution of 85 nm are obtained with good crystallinity. After heat treatment at 1200 °C for 2 h, the particles are characterized for their various optical properties such as absorption, emission, fluorescence decay and optical band gap. Optical absorption and emission data are numerically analyzed with the help of Judd-Ofelt model to evaluate various radiative spectral properties such as radiative decay rates, radiative quantum yield, emission cross-section and fluorescence branching ratios of various emission transitions. Though the radiative quantum yield of 1554 nm emission approaches the theoretical limit of 100%, the experimentally measured quantum yield is only 11% at 12 W/cm2 at 980 nm excitation power density in 2% Er doped LaPO4.

  10. Synthesis and spectroscopic characterization of gold nanobipyramids prepared by a chemical reduction method

    NASA Astrophysics Data System (ADS)

    Thanh Ngo, Vo Ke; Phat Huynh, Trong; Giang Nguyen, Dang; Phuong Uyen Nguyen, Hoang; Lam, Quang Vinh; Dat Huynh, Thanh

    2015-12-01

    Gold nanobipyramids (NBPs) have attracted much attention because they have potential for applications in smart sensing devices, such as medical diagnostic equippments. This is due to the fact that they show more advantageous plasmonic properties than other gold nanostructures. We describe a chemical reduction method for synthesizing NBPs using conventional heating with ascorbic acid reduction and cetyltrimethylamonium bromide (CTAB) + AgNO3 as capping agents. The product was characterized by ultraviolet-visible spectroscopy (UV-vis), Fourier transmission infrared spectroscopy (FTIR), transmission electron microscopy (TEM), x-ray powder diffraction (XRD). The results showed that gold nanoparticles were formed with bipyramid shape (tip-to-tip distance of 88.4 ± 9.4 nm and base length of 29.9 ± 3.2 nm) and face-centered-cubic crystalline structure. Optimum parameters for preparation of NBPs are also found.

  11. Vibrational spectroscopic methods for the overall quality analysis of washing powders.

    PubMed

    Bittner, L K; Schönbichler, S A; Schmutzler, M; Lutz, O M D; Huck, C W

    2016-02-01

    The aim of this study was to compare and evaluate the ability of near infrared- (NIR), Raman- and attenuated-total-reflection infrared (ATR-IR) spectroscopy as tools for the identification of washing powder brands as well as for an overall quantitative analysis of all ingredients of the analyzed laundry detergents. The laundry detergents used in this work were composed of 22 different ingredients. For this purpose, principal component analysis (PCA) cluster models and partial least-squares (PLS) regression models were developed and different data pre-processing algorithms such as standard-normal-variate (SNV), multiplicative scatter correction (MSC), first derivative BCAP (db1), second derivative smoothing (ds2), smoothing Savitzky Golay 9 points (sg9) as well as different normalization procedures such as normalization between 0 and 1 (n01), normalization unit length (nle) or normalization by closure (ncl) were applied to reduce the influence of systematic disturbances. The performance of the methods was evaluated by comparison of the number of principal components (PCs), regression coefficient (r), Bias, Standard error of prediction (SEP), ratio performance deviation (RPD) and range error ratio (RER) for each calibration model. For each of the 22 ingredients separate calibration models were developed. Raman spectroscopy was suitable for the analysis of only two ingredients (dye transfer inhibitor 1 and surfactant 6) and it was not possible to record all Raman spectra due to high fluorescence. NIR and ATR-IR are powerful methods to analyze washing detergents with low numbers of PCs being necessary, regression coefficients of only little below 1, small Biases and SEPs compared to the range and high RPDs and RERs. PMID:26653457

  12. Structural and spectroscopic properties of an aliphatic boronic acid studied by combination of experimental and theoretical methods

    NASA Astrophysics Data System (ADS)

    Cyrański, Michał K.; Jezierska, Aneta; Klimentowska, Paulina; Panek, Jarosław J.; Żukowska, GraŻyna Z.; Sporzyński, Andrzej

    2008-03-01

    Boronic acids have emerged as one of the most useful class of organoboron molecules, with application in synthesis, catalysis, analytical chemistry, supramolecular chemistry, biology, and medicine. In this study, the structural and spectroscopic properties of n-butylboronic acid were investigated using experimental and theoretical approaches. X-ray crystallography method provided structural information on the studied compound in the solid state. Infrared and Raman spectroscopy served as tools for the data collection on vibrational modes of the analyzed system. Car-Parrinello molecular dynamics simulations in solid state were carried out at 100 and 293K to investigate an environmental and temperature influence on molecular properties of the n-butylboronic acid. Analysis of interatomic distances of atoms involved in the intermolecular hydrogen bond was performed to study the proton motion in the crystal. Subsequently, Fourier transform of autocorrelation functions of atomic velocities and dipole moment was applied to study the vibrational properties of the compound. In addition, the inclusion of quantum nature of proton motion was performed for O-H stretching vibrational mode by application of the envelope method for intermolecular hydrogen-bonded system. The second part of the computational study consists of simulations performed in vacuo. Monomeric and dimeric forms of the n-butylboronic acid were investigated using density functional theory and Møller-Plesset second-order perturbation method. The basis set superposition error was estimated. Finally, atoms in molecules (AIM) theory was applied to study electron density topology and properties of the intermolecular hydrogen bond. Successful reproduction of the molecular properties of the n-butylboronic acid by computational methodologies, presented in the manuscript, indicates the way for future studies of large boron-containing organic systems of importance in biology or materials science.

  13. Use of recursively generated intermediates in state selective multireference coupled-cluster method: A numerical example

    SciTech Connect

    Ghose, K.B.; Adamowicz, L.

    1995-12-01

    The present work represents the first attempt to utilize the idea of recursively generated intermediates (RGI) in the framework of the state-selective multi-reference coupled-cluster method truncated at triple excitations [SS CCSD(T)]. The expressions for stepwise generation of intermediates are so structured that the spin and point symmetry simplifications can be easily applied during computation. Suitable modifications in SS CCSD(T) equations are introduced to allow for optional quasilinearization of nonlinear terms in difficult convergence situations. The computational code is, as expected, much faster than the SS CCSD(T) code without RGI adaptation. This has been numerically demonstrated by potential energy surface (PES) calculation of the HF molecule using a double zeta basis. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  14. Finite-frequency tomography using adjoint methods-Methodology and examples using membrane surface waves

    NASA Astrophysics Data System (ADS)

    Tape, Carl; Liu, Qinya; Tromp, Jeroen

    2007-03-01

    We employ adjoint methods in a series of synthetic seismic tomography experiments to recover surface wave phase-speed models of southern California. Our approach involves computing the Frchet derivative for tomographic inversions via the interaction between a forward wavefield, propagating from the source to the receivers, and an `adjoint' wavefield, propagating from the receivers back to the source. The forward wavefield is computed using a 2-D spectral-element method (SEM) and a phase-speed model for southern California. A `target' phase-speed model is used to generate the `data' at the receivers. We specify an objective or misfit function that defines a measure of misfit between data and synthetics. For a given receiver, the remaining differences between data and synthetics are time-reversed and used as the source of the adjoint wavefield. For each earthquake, the interaction between the regular and adjoint wavefields is used to construct finite-frequency sensitivity kernels, which we call event kernels. An event kernel may be thought of as a weighted sum of phase-specific (e.g. P) banana-doughnut kernels, with weights determined by the measurements. The overall sensitivity is simply the sum of event kernels, which defines the misfit kernel. The misfit kernel is multiplied by convenient orthonormal basis functions that are embedded in the SEM code, resulting in the gradient of the misfit function, that is, the Frchet derivative. A non-linear conjugate gradient algorithm is used to iteratively improve the model while reducing the misfit function. We illustrate the construction of the gradient and the minimization algorithm, and consider various tomographic experiments, including source inversions, structural inversions and joint source-structure inversions. Finally, we draw connections between classical Hessian-based tomography and gradient-based adjoint tomography.

  15. Revisiting the Accelerating Moment Release method: examples of application to Italian seismic sequences

    NASA Astrophysics Data System (ADS)

    De Santis, Angelo; Di Giovambattista, Rita; Cianchini, Gianfranco

    2015-04-01

    From simple considerations we propose a revision of the Accelerating Moment Release (AMR) methodology for improving our knowledge of seismic sequences and then, hopefully in a close future, to reach the capability of predicting the main-shock location and occurrence with sufficient accuracy. The proposed revision is based on the introduction of a "reduced" Benioff strain for the earthquakes of the seismic sequence where, for the same magnitude and after a certain distance from the main-shock epicentre, the closer the events the more they are weighted. In addition, we retain the usual expressions proposed by the ordinary AMR method for the estimation of the corresponding main-shock magnitude, although this parameter is the weakest of the analysis. Then, we apply the revised method (that we call Revised AMR, or shortly R-AMR) to four case studies in Italy, three of which are the most recent seismic sequences of the last 9 years culminating with a shallow main-shock, and one is instead a 1995-1996 swarm with no significant main-shock. The application of the R-AMR methodology provides the best results in detecting the precursory seismic acceleration, when compared with those found by ordinary AMR technique. We verify also the stability of the results in space, applying the analysis to real data with moving circles in a large area around each mainshock epicentre, and the efficiency of the revised technique in time, comparing the results with those obtained when applying the same analysis to simulated seismic sequences.

  16. Investigation on interaction between Ligupurpuroside A and pepsin by spectroscopic and docking methods

    NASA Astrophysics Data System (ADS)

    Shen, Liangliang; Xu, Hong; Huang, Fengwen; Li, Yi; Xiao, Huafeng; Yang, Zhen; Hu, Zhangli; He, Zhendan; Zeng, Zheling; Li, Yinong

    2015-01-01

    Ligupurpuroside A is one of the major glycoside in Ku-Din-Cha, a type of Chinese functional tea. In order to better understand its digestion and metabolism in humans, the interaction between Ligupurpuroside A and pepsin has been investigated by fluorescence spectra, UV-vis absorption spectra and synchronous fluorescence spectra along with molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can effectively quench the intrinsic fluorescence of pepsin through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The binding constant, binding sites of Ligupurpuroside A with pepsin have been calculated. The thermodynamic analysis suggests that non-covalent reactions, including electrostatic force, hydrophobic interaction and hydrogen bond are the main forces stabilizing the complex. According to the Frster's non-radiation energy transfer theory, the binding distance between pepsin and Ligupurpuroside A was calculated to be 3.15 nm, which implies that energy transfer occurs between pepsin and Ligupurpuroside A. Conformation change of pepsin was observed from UV-vis absorption spectra and synchronous fluorescence spectra under experimental conditions. In addition, all these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A is located in the cleft between the domains of pepsin.

  17. A method for the quantitative gamma spectroscopic analysis of an unusually shaped unknown source.

    PubMed

    Kearfott, Kimberlee J; Dewey, Steven C

    2009-02-01

    An unmarked cylindrical device, identified as a ceramic high voltage capacitor, needed its radioactivity assessed so that proper disposal and shipping requirements could be met. Using a high purity germanium detector, naturally occurring 232Th was identified as the source of radioactivity. A series of point source measurements was made along the length of the item's axis using 60Co, having a gamma ray of nearly the same energy as one of the primary 232Th progeny photopeaks. These measurements were then numerically integrated to determine the response of the detector to a line source. A correction for the self shielding of the item was estimated using Monte Carlo simulations. The item was found to contain approximately 1.85 x 10(5) Bq of uniformly distributed 232Th. The overall method has application to any unusually shaped source, with point source measurements performed using an appropriate radionuclide used to establish an overall sensitivity of the detector, including its dead layer, to the radioactivity in a simple geometric representation of the object. An estimation of self shielding from Monte Carlo is then applied to that result. PMID:19125054

  18. Structure activity studies of an analgesic drug tapentadol hydrochloride by spectroscopic and quantum chemical methods

    NASA Astrophysics Data System (ADS)

    Arjunan, V.; Santhanam, R.; Marchewka, M. K.; Mohan, S.; Yang, Haifeng

    2015-11-01

    Tapentadol is a novel opioid pain reliever drug with a dual mechanism of action, having potency between morphine and tramadol. Quantum chemical calculations have been carried out for tapentadol hydrochloride (TAP.Cl) to determine the properties. The geometry is optimised and the structural properties of the compound were determined from the optimised geometry by B3LYP method using 6-311++G(d,p), 6-31G(d,p) and cc-pVDZ basis sets. FT-IR and FT-Raman spectra are recorded in the solid phase in the region of 4000-400 and 4000-100 cm-1, respectively. Frontier molecular orbital energies, LUMO-HOMO energy gap, ionisation potential, electron affinity, electronegativity, hardness and chemical potential are also calculated. The stability of the molecule arising from hyperconjugative interactions and charge delocalisation has been analysed using NBO analysis. The 1H and 13C nuclear magnetic resonance chemical shifts of the molecule are analysed.

  19. Investigation on interaction between Ligupurpuroside A and pepsin by spectroscopic and docking methods.

    PubMed

    Shen, Liangliang; Xu, Hong; Huang, Fengwen; Li, Yi; Xiao, Huafeng; Yang, Zhen; Hu, Zhangli; He, Zhendan; Zeng, Zheling; Li, Yinong

    2015-01-25

    Ligupurpuroside A is one of the major glycoside in Ku-Din-Cha, a type of Chinese functional tea. In order to better understand its digestion and metabolism in humans, the interaction between Ligupurpuroside A and pepsin has been investigated by fluorescence spectra, UV-vis absorption spectra and synchronous fluorescence spectra along with molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can effectively quench the intrinsic fluorescence of pepsin through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The binding constant, binding sites of Ligupurpuroside A with pepsin have been calculated. The thermodynamic analysis suggests that non-covalent reactions, including electrostatic force, hydrophobic interaction and hydrogen bond are the main forces stabilizing the complex. According to the Förster's non-radiation energy transfer theory, the binding distance between pepsin and Ligupurpuroside A was calculated to be 3.15 nm, which implies that energy transfer occurs between pepsin and Ligupurpuroside A. Conformation change of pepsin was observed from UV-vis absorption spectra and synchronous fluorescence spectra under experimental conditions. In addition, all these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A is located in the cleft between the domains of pepsin. PMID:25078459

  20. Characterization of U(VI)-phases in corroded cement products by micro(μ)-spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Rothe, J.; Brendebach, B.; Bube, C.; Dardenne, K.; Denecke, M. A.; Kienzler, B.; Metz, V.; Prüßmann, T.; Rickers-Appel, K.; Schild, D.; Soballa, E.; Vitova, T.

    2013-04-01

    Cementation is an industrial scale conditioning method applied to fix and solidify liquid low and intermediate level radioactive wastes (LLW/ILW) prior to underground disposal in geological formations.To assist prognosis of the long-term safety of cemented waste, alteration of uranium doped cement productswas studied in chloride-rich solutions relevant for final LLW/ILW disposal in rock salt. After long-time exposure of the full-scale LLW/ILW simulates to concentrated NaCl and MgCl2 brines, solid samples were retrieved for chemical and mineralogical analysis with an emphasis on uranium speciation in the corroded cement matrix.Bulk and recent spatially resolved micro(μ) U L3-XAFS measurements point to the occurrence of a diuranate type U(VI) phase forming throughout the corroded cement monoliths. U-enriched hot spots with dimensions up to several tens of μm turn out to be generally X-ray amorphous.

  1. Studies on the interactions of kaempferol to calcineurin by spectroscopic methods and docking.

    PubMed

    Lei, Hong; Qi, Yao; Jia, Zhi-Guang; Lin, Wei-Lin; Wei, Qun

    2009-08-01

    Kaempferol, in our previous study, was a new immunosuppressant on calcineurin (CN), the Ca(2+)/calmodulin (CaM)-dependent protein phosphatase. Here, we examined the interactions of kaempferol with CN by fluorescence spectroscopy (FS), circular dichroism spectroscopy (CD) and docking. Data of kaempferol with CN catalytic subunit (CN A) and its truncated mutant CNAa obtained by FS method showed that the binding stoichiometry of kaempferol/CN A was 1:1, catalytic domain of CN A was the concrete domain for kaempferol binding while other domains contributed a lot to this binding. Distances from kaempferol to each tryptophan (Trp) in CN A by energy transfer experiments and the subsequent docking study interestingly provided the same binding sites for kaempferol, which all located in the non-active site area of CN A catalytic domain, also consisted with our previous conclusion from CN activity assay. Furthermore, CD results showed a much tighter structure of CN A for the inhibitor binding; on the other hand, presence of Ca(2+) and Mn(2+) decreased kaempferol binding on CN A. PMID:19439201

  2. Synergic application of spectroscopic and theoretical methods to the chlorogenic acid structure elucidation.

    PubMed

    Marković, Svetlana; Tošović, Jelena; Dimitrić Marković, Jasmina M

    2016-07-01

    Although chlorogenic acid (5-O-caffeoylquinic acid, 5CQA) is a dietary polyphenol known for its pharmacological and nutritional properties, its structural features have not been completely elucidated. This is the first study whose aim is to contribute to clarification of the 5CQA structure by comparing the experimental and simulated IR, Raman, (1)H NMR, (13)C NMR, and UV spectra. For this purpose, a comprehensive conformational analysis of 5CQA was performed to reveal its most stable conformations in the gas-state and solution (DMSO and methanol). The lowest-energy conformers were used to predict the spectra at two levels of theory: B3LYP-D3/and M06-2X/6-311+G(d,p) in combination with the CPCM solvation model. Both methods provide very good agreement between all experimental and simulated spectra, thus indicating correct arrangement of the atoms in the 5CQA molecule. The quinic moiety is characterized with directed hydrogen bonds, where the carboxylic hydrogen is not oriented towards the carbonyl oxygen of the carboxylic group, but towards the oxygen of the proximate hydroxyl group. In the gas-state the lowest-energy conformers are characterized with the O4H4⋯O9' hydrogen bond, whereas in the solvated state the structures with the O4H4⋯O10' hydrogen bond prevail. Knowing the fine structural details, i.e. the proper conformation of 5CQA, provides a solid base for all further investigations related to this compound. PMID:27082653

  3. [Study on two different aromas styles of tobacco from Guizhou by characteristics spectroscopic methods].

    PubMed

    Ran, Xia; Mu, Lan; Liu, Ren-Xiang; Cong, Hang; Zhang, Qing-Min; Wang, Fang

    2014-03-01

    This paper made use of three-dimensional fluorescence and ultraviolet-absorption spectrum to analyze the spectral characteristics of etroleum ether extract from Guizhou flue-cured tobacco and the overall characteristic spectral information of tobacco chemical substances were obtained. The three dimensional fluorescence and ultraviolet-visible absorption spectrum of each petroleum ether extract of flue-cured tobacco from different areas are generally similar, but their intensity is different. There have three characteristic peaks in three dimensional fluorescence spectra: I: Ex/Em = 297/326 nm, II: Ex/Em = 250/330 nm, III: Ex/Em = 225/336 nm respectively and meanwhile the order of these peaks intensity is I > III > II. The ultraviolet-visible absorption spectrum in 300-300 nm range presents four characteristic absorption peaks, whose maximum absorption wavelength are 329, 419, 445 and 419 nm respectively. Meanwhile, in accord with the relative intensity of characteristic peaks, it is known that there exist differences in the relative contents of the total chemical substances obtained from different flavor styles of the flue-cured tobacco. The clustering analysis results of three-dimensional fluorescence intensity score (D) and intensity ratio (R) show that in a certain range of distance coefficient, the flue-cured tobacco from different regions in Guizhou can be clearly divided into two classes "mildly sweet "and "alcohol sweet ". The classification can be well achieved in the smaller distance coefficient according to the ratio cluster of fluorescence intensity instead of the score cluster of fluorescence intensity. The method of three-dimensional fluorescence was better than that of ultraviolet-visible spectrometry in the matter of the clustering characteristic. PMID:25208411

  4. IR spectroscopic methods for the investigation of the CO release from CORMs.

    PubMed

    Klein, Moritz; Neugebauer, Ute; Gheisari, Ali; Malassa, Astrid; Jazzazi, Taghreed M A; Froehlich, Frank; Westerhausen, Matthias; Schmitt, Michael; Popp, Jürgen

    2014-07-24

    Carbon monoxide (CO) is a toxic gas for mammals, and despite this fact, it is naturally produced in these organisms and has been proven to be beneficial in medical treatments, too. Therefore, CO-releasing molecules (CORMs) are intensively developed to administer and dose CO for physiological applications. Nearly all of these compounds are metal carbonyl complexes, which have been synthesized and investigated. However, for most of these CORMs, the exact reaction mechanisms of CO release is not completely elucidated, although it is of utmost importance. The widely used myoglobin assay for testing the CO release has several disadvantages, and therefore, different methods have to be applied to characterize CORMs. In this work, different setups of IR absorption spectroscopy are used to analyze and quantify the CO release during the decay of various CORMs: IR spectroscopy of the gas phase is applied to follow the CO liberation, and attenuated total reflection (ATR) IR spectroscopy is used to record the decay of the metal carbonyl. IR spectroscopy supported by DFT calculations yields valuable insights in the CO release reaction mechanism. The focus is set on two different CORMs: CORM-2 (Ru2(CO)(6)Cl(4)) and on the photoactive CORM-S1 (photoCORM [Fe(CO)2(SCH2CH2NH2)2]). Our results indicate that the CO liberation from CORM-2 strongly depends on sodium dithionite, which is required for the commonly applied myoglobin assay and that CORM-S1 loses all its bound CO molecules upon irradiation with blue light. PMID:24978105

  5. High Resolution Seismic Imaging of Fault Zones: Methods and Examples From The San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Catchings, R. D.; Rymer, M. J.; Goldman, M.; Prentice, C. S.; Sickler, R. R.; Criley, C.

    2011-12-01

    Seismic imaging of fault zones at shallow depths is challenging. Conventional seismic reflection methods do not work well in fault zones that consist of non-planar strata or that have large variations in velocity structure, two properties that occur in most fault zones. Understanding the structure and geometry of fault zones is important to elucidate the earthquake hazard associated with fault zones and the barrier effect that faults impose on subsurface fluid flow. In collaboration with the San Francisco Public Utilities Commission (SFPUC) at San Andreas Lake on the San Francisco peninsula, we acquired combined seismic P-wave and S-wave reflection, refraction, and guided-wave data to image the principal strand of the San Andreas Fault (SAF) that ruptured the surface during the 1906 San Francisco earthquake and additional fault strands east of the rupture. The locations and geometries of these fault strands are important because the SFPUC is seismically retrofitting the Hetch Hetchy water delivery system, which provides much of the water for the San Francisco Bay area, and the delivery system is close to the SAF at San Andreas Lake. Seismic reflection images did not image the SAF zone well due to the brecciated bedrock, a lack of layered stratigraphy, and widely varying velocities. Tomographic P-wave velocity images clearly delineate the fault zone as a low-velocity zone at about 10 m depth in more competent rock, but due to soil saturation above the rock, the P-waves do not clearly image the fault strands at shallower depths. S-wave velocity images, however, clearly show a diagnostic low-velocity zone at the mapped 1906 surface break. To image the fault zone at greater depths, we utilized guided waves, which exhibit high amplitude seismic energy within fault zones. The guided waves appear to image the fault zone at varying depths depending on the frequency of the seismic waves. At higher frequencies (~30 to 40 Hz), the guided waves show strong amplification at the 1906 surface break and at about 20 m to the east, but at lower frequencies (2-5 Hz), the guided waves show strong amplification approximately 10 m east of the 1906 surface break. We attribute the difference in amplification of guided waves to an east-dipping fault strand that merges with other strands below about 10 m depth. Vp/Vs and Poisson's ratios clearly delineate multiple fault strands about 2 km north of the mapped 1906 surface break at the SFPUC intake structure. Combining these fault-imaging methods provide a powerful set of tools for mapping fault zones in the shallow subsurface in areas of complex geology.

  6. Recognizing impact glass on Mars using surface texture, mechanical properties, and mid-infrared spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Bradley, James Thomson

    A primary goal of future Mars sample return missions is to obtain samples whose isotopic ages can be used to place absolute time constraints on the relative Martian crater chronology. Thus, identifying the origin of surface material as impact or volcanic prior to its return to Earth will be critical. This dissertation focuses on four strategies for identifying and characterizing impact melt breccias from both landed and orbital perspectives. In Part 1, the geology of Viking 2 Landing (VL2) site is re-evaluated using recently acquired orbital data. Measurements of relict landform topography indicate that a layer of sedimentary material at least 120 m thick has been eroded from the site. Crater counts indicate an extreme deficiency of small-diameter craters (<500 m), indicating that resurfacing has continued up to the present. Thermal inertia data over the site is consistent with some rocks being impact-emplaced and possibly impact-derived. In Part 2, three textural characteristics were identified as potential discriminants between vesicular impact and volcanic glasses: vesicle shape (elongation), orientation, and spatial density. Additionally, a theoretical model was developed to constrain the conditions necessary for the preservation of deformed bubble textures. The results suggest that deformed bubbles are unlikely to be preserved in typical Martian basalts or basaltic andesites. Part 3 is an endeavor to extract science from mission support operations. First, a method for determining the bulk density of rocks via a pushing (i.e., by a robotic spacecraft arm) was developed and applied to VL2 rock-pushing data. Although the large measurement uncertainties preclude drawing firm conclusions, the results demonstrate the feasibility of the technique. Second, results from the Rock Abrasion Tool (RAT) on the Spirit rover were analyzed to infer the mechanical strength of ground surfaces. Rocks in the Columbia Hills were found to be mechanically consistent with impact melt breccias. In Part 4, systematic variations in glass mid-infrared reststrahlen band positions were determined with variations in glass chemistry, degree of crystallinity, and quench rate. Results indicate that the spectra of rapidly quenched glasses with a high fictive temperature exhibit shifts to shorter wavelengths, causing them to appear more silica-rich.

  7. Problems in estimating self-supplied industrial water use by indirect methods, the California example

    USGS Publications Warehouse

    Burt, R.J.

    1983-01-01

    Consumptive fresh-water use by industry in California is estimated at about 230 million gallons per day, or about one-half of one percent of agricultural withdrawals in the State , and only about 1 percent of agricultural consumptive use. Therefore, a significant State-wide realignment of the total water resources could not be made by industrial conservation measures. Nevertheless, considerable latitude for water conservation exists in industry -- fresh water consumed by self-supplied industry amounts to about 40 percent of its withdrawals in California, and only about 10 to 15 percent nationally (not including power-plant use). Furthermore, where firms withdraw and consume less water there is more for others nearby to use. The main question in attempting to estimate self-supplied industrial water use in California by indirect methods was whether accurate estimates of industrial water use could be made from data on surrogates such as production and employment. The answer is apparently not. A fundamental problem was that different data bases produced variable coefficients of water use for similar industries. Much of the potential for error appeared to lie in the water data bases rather than the production or employment data. The apparent reasons are that water-use data are based on responses to questionnaires, which are prone to errors in reporting, and because the data may be aggregated inappropriately for this kind of correlation. Industries within an apparently similar category commonly use different amounts of water, both because of differences in the product and because of differences in production processes even where the end-product is similar. (USGS)

  8. Using new luminescence methods to date the Palaeolithic: the example of Kalambo Falls

    NASA Astrophysics Data System (ADS)

    Duller, Geoff; Tooth, Stephen; Barham, Larry

    2013-04-01

    The Palaeolithic site of Kalambo Falls in the north of Zambia was the subject of detailed study by J.D. Clark in the 1950s with 4 excavations being located within 1 km of each other in a basin upstream of the falls. A rich palaeolithic tool record was recovered, but the value of this record was limited by the lack of chronological information available. In 2006, one of the excavation sites was re-investigated (Barham et al., 2009), including examination of the stratigraphic context and collection of samples for luminescence dating. Many of the sediments in the Kalambo basin were deposited by fluvial activity. Dose distributions in the single grain quartz optically stimulated luminescence (OSL) measurements of the youngest sediments are consistent with incomplete bleaching. However, the residual doses obtained are typically less than 10 Gy, and so for older sediments the impact of incomplete bleaching becomes insignificant. The oldest samples are affected by a different problem, namely saturation of the OSL signal, and many grains are saturated. However in all cases some grains give finite equivalent dose values, making it feasible to calculate single grain quartz OSL ages, but it is difficult to assess whether these ages are reliable or not. Thermally transferred OSL (TT-OSL) from quartz is able to date much older samples due to the high saturation dose of this signal (Duller and Wintle, 2012). Comparison of the TT-OSL and OSL demonstrates that the OSL signal yields age underestimates as samples near saturation. Only by using the two luminescence methods is it possible to create an absolute chronology for this key site stretching back over half a million years. This study demonstrates the potential of using these two luminescence signals together for dating Palaeolithic sites throughout Africa and beyond. Barham, L., Duller, G. A. T., Plater, A. J., Tooth, S. and Turner, S. (2009). Recent excavations at Kalambo Falls, Zambia. Antiquity 83(322). Duller, G. A. T. and Wintle, A. G. (2012). The potential of the thermally transferred optically stimulated luminescence signal from quartz for dating sediments. Quaternary Geochronology 7: 6-20.

  9. Quantification of sediment supply : a method and an example from Triassic of Western European basins

    NASA Astrophysics Data System (ADS)

    Peron, S.; Bourquin, S.; Duran, M.; Fluteau, F.; Guillocheau, F.

    2003-04-01

    Triassic is a key period of Earth history, with tectonic, climatic and eustatic events. It corresponds to (i) the initial fragmentation of the Pangea, (ii) a transition from Paleozoic ice house to Mesozoic green house, (iii) a sea-level rise from Upper Triassic, followed by an eustatic fall during Lias. This special geological setting has led to the formation of large Mesozoic basins, mainly characterized by a continental sedimentation, with fluvial and/or evaporitic environments, well-conserved in Pangean supercontinent. This Triassic specificity implies a total free space for sedimentation, i.e. accommodation (A), balanced with an important sediment supply (S), as SgeA.The purpose of this study is to develop a good methodology for understanding the S parameter in past geological systems, as Triassic. Firstly, by considering three key periods of Triassic : (1) the Lower Scythian, (2) the Lower Ladinian, (3) the Carnian-Norien ; we have realized paleogeographic and paleotopographic maps either for Western Europe or entire world. These reconstructions allow us to precise (i) erosional or sedimentary areas, (ii) coastal lines and sebkha boundaries, (iii) river basins and continental systems associated. Moreover, by using an atmospheric general circulation model (AGCM), we are actually simulating the climatic response by applying data of maps for Triassic European areas. By this way, we are able to obtain different parameters of climate (rainfall, temperature variations,...) in order to test the effect on topography, evaporitic plains and climate interactions. In parallel, paleoenvironmental maps allow us to separate three main fluvial systems developed during the Triassic period : (1) larged braided alluvial systems in vast endoreic basins that characterize the transitional stage between the Zeichstein system (Permian) and the Tethyan system (Triassic) ; (2) anastomosed systems whose preservation is controlled by sea-level (Anisian and Middle Carnian) ; (3) alluvial fans/lacustrine mixed systems, whose base-level is locally controlled by a lake but topography and local tectonic play a major role in the formation of these systems (Norian). A SW-NE transect and lithologies surimposed on isopach maps are also realized for the Buntsandstein (Scythian to Lower Anisian), from the Paris Basin to North Sea, via German Basin. It allows us to realize (i) high-resolution sequence stratigraphy correlations with surimposed paleoenvironements, and (ii) a quantification of siliciclastic volumes (sand/shale) for each stratigraphic interval. This integrated method has for ultimate question to understand the role of sediments supplies (S parameter) in stratigraphic architecture acquisition and fluviatil systems evolution.

  10. A REVISED METHOD FOR ESTIMATING OXIDE BASICITY PER THE SMITH SCALE WITH EXAMPLE APPLICATION TO GLASS DURABILITY

    SciTech Connect

    REYNOLDS JG

    2011-07-27

    Previous researchers have developed correlations between oxide electronegativity and oxide basicity. The present paper revises those correlations using a newer method of calculating electronegativity of the oxygen anion. Basicity is expressed using the Smith {alpha} parameter scale. A linear relation was found between the oxide electronegativity and the Smith {alpha} parameter, with an R{sup 2} of 0.92. An example application of this new correlation to the durability of high-level nuclear waste glass is demonstrated. The durability of waste glass was found to be directly proportional to the quantity and basicity of the oxides of tetrahedrally coordinated network forming ions.

  11. Combination of spectroscopic and computational methods to get an understanding of supramolecular chemistry of drugs: from simple host systems to biomolecules.

    PubMed

    Monti, Sandra; Manet, Ilse; Marconi, Giancarlo

    2011-12-21

    Circular dichroism (CD) spectra of non-covalent ligand : biomolecule couples contain information on the equilibrium geometries of the associated structures that can be retrieved upon comparison of the sign and intensity of the experimental CD bands with the quantum mechanically calculated rotational strengths of low energy supramolecular complexes, obtained from molecular modelling methods. For both chiral and achiral ligands this approach proved useful to reach a structure based rationale of ground and excited state properties of the non-covalent ligand : protein associates. In this Perspective we illustrate the potential of this method focusing on the main achievements of our recent spectroscopic, conformational and photochemical studies on drug-albumin complexes and collocate it in the frame of current methodologies of molecular modelling and spectroscopic investigation of ligand : biomolecule binding. PMID:22006101

  12. Insights into Kinetics of Agitation-Induced Aggregation of Hen Lysozyme under Heat and Acidic Conditions from Various Spectroscopic Methods

    PubMed Central

    Chaari, Ali; Fahy, Christine; Chevillot-Biraud, Alexandre; Rholam, Mohamed

    2015-01-01

    Protein misfolding and amyloid formation are an underlying pathological hallmark in a number of prevalent diseases of protein aggregation ranging from Alzheimer’s and Parkinson’s diseases to systemic lysozyme amyloidosis. In this context, we have used complementary spectroscopic methods to undertake a systematic study of the self-assembly of hen egg-white lysozyme under agitation during a prolonged heating in acidic pH. The kinetics of lysozyme aggregation, monitored by Thioflavin T fluorescence, dynamic light scattering and the quenching of tryptophan fluorescence by acrylamide, is described by a sigmoid curve typical of a nucleation-dependent polymerization process. Nevertheless, we observe significant differences between the values deduced for the kinetic parameters (lag time and aggregation rate). The fibrillation process of lysozyme, as assessed by the attenuated total reflection-Fourier transform infrared spectroscopy, is accompanied by an increase in the β-sheet conformation at the expense of the α-helical conformation but the time-dependent variation of the content of these secondary structures does not evolve as a gradual transition. Moreover, the tryptophan fluorescence-monitored kinetics of lysozyme aggregation is described by three phases in which the temporal decrease of the tryptophan fluorescence quantum yield is of quasilinear nature. Finally, the generated lysozyme fibrils exhibit a typical amyloid morphology with various lengths (observed by atomic force microscopy) and contain exclusively the full-length protein (analyzed by highly performance liquid chromatography). Compared to the data obtained by other groups for the formation of lysozyme fibrils in acidic pH without agitation, this work provides new insights into the structural changes (local, secondary, oligomeric/fibrillar structures) undergone by the lysozyme during the agitation-induced formation of fibrils. PMID:26571264

  13. Near-infrared diode laser based spectroscopic detection of ammonia: a comparative study of photoacoustic and direct optical absorption methods

    NASA Technical Reports Server (NTRS)

    Bozoki, Zoltan; Mohacsi, Arpad; Szabo, Gabor; Bor, Zsolt; Erdelyi, Miklos; Chen, Weidong; Tittel, Frank K.

    2002-01-01

    A photoacoustic spectroscopic (PAS) and a direct optical absorption spectroscopic (OAS) gas sensor, both using continuous-wave room-temperature diode lasers operating at 1531.8 nm, were compared on the basis of ammonia detection. Excellent linear correlation between the detector signals of the two systems was found. Although the physical properties and the mode of operation of both sensors were significantly different, their performances were found to be remarkably similar, with a sub-ppm level minimum detectable concentration of ammonia and a fast response time in the range of a few minutes.

  14. Simulation of a method for determining one-dimensional 137 Cs distribution using multiple gamma spectroscopic measurements with an adjustable cylindrical collimator and center shield.

    PubMed

    Whetstone, Z D; Dewey, S C; Kearfott, K J

    2011-05-01

    With multiple in situ gamma spectroscopic measurements obtained with an adjustable cylindrical collimator and a circular shield, the arbitrary one-dimensional distribution of radioactive material can be determined. The detector responses are theoretically calculated, field measurements obtained, and a system of equations relating detector response to measurement geometry and activity distribution solved to estimate the distribution. This paper demonstrates the method by simulating multiple scenarios and providing analysis of the system conditioning. PMID:21310624

  15. A New Method to Address Verification Bias in Studies of Clinical Screening Tests: Cervical Cancer Screening Assays as an Example

    PubMed Central

    Xue, Xiaonan; Kim, Mimi Y; Castle, Philip E; Strickler, Howard D

    2013-01-01

    Objective Studies to evaluate clinical screening tests often face the problem that the “gold standard” diagnostic approach is costly and/or invasive. It is therefore common to verify only a subset of negative screening tests using the gold standard method. However, under-sampling the screen-negatives can lead to substantial overestimation of the sensitivity and underestimation of the specificity of the diagnostic test. Our objective was to develop a simple and accurate statistical method to address this “verification bias”. Study Design and Setting We developed a weighted generalized estimating equation approach to estimate, in a single model, the accuracy (e.g., sensitivity/specificity) of multiple assays as well as simultaneously compare results between assays while addressing verification bias. This approach can be implemented using standard statistical software. Simulations were conducted to assess the proposed method. An example is provided using a cervical cancer screening trial that compared the accuracy of human papillomavirus and Pap tests, with histological data as the gold standard. Results The proposed approach performed well in estimating and comparing the accuracy of multiple assays in the presence of verification bias. Conclusion The proposed approach is an easy to apply and accurate method for addressing verification bias in studies of multiple screening methods. PMID:24332397

  16. Development of multidimensional HPLC and atomic spectroscopic methods for the separation and determination of metal compounds in petroleum

    SciTech Connect

    Danna, M.R.

    1986-01-01

    The research presented in this thesis focused on two goals: (1) to develop a direct method for metal determinations in fuels; and (2) to utilize this method in conjunction with a chromatographic separation to produce metal speciation information. A four step approach was taken to achieve these goals. Initially a column chromatographic technique, sequential elution solvent chromatography (SESC), was employed to separate the residual fuel being studied into nine compound class fractions. The question of how the chromatographic behavior of metal-containing compounds compares to that of nonmetal-containing analogs was investigated by subjecting metal-containing complexes to SESC. The fuel fractions were then analyzed by a direct atomic absorption technique, which was developed as the second part of this research. These results were used to produce metal distribution profiles, according to compound class. In the third part of this work, the SESC fractions were further characterized by HPLC techniques. This work included single-column, size-exclusion and normal phase separations. A computer-controlled multidimensional HPLC system, which was developed in this laboratory, was employed to develop methods applicable to this research. An example is the mode-coupling of a size-exclusion column with a reverse-phase column to produce a size polarity matrix. The final step of this project involved the interface of the HPLC to an element-specific detector. This was investigated for both an atomic absorption spectrometer and an inductively-coupled plasma optical emission spectrometer.

  17. Infrared spectroscopic method for analysis of Mg 2Ca(SO 4) 3 in mixtures with MgSO 4 and/or CaSO 4

    NASA Astrophysics Data System (ADS)

    Smith, Duane H.; Seshadri, Kal S.

    1999-04-01

    Mg 2Ca(SO 4) 3 is prepared from, and may be found in, mixtures with MgSO 4 and CaSO 4. Such mixtures frequently occur in the ash produced by various types of coal combustion, especially in filter cakes from pressurized fluidized bed combustion with dolomite as a SO x sorbent. Previously, qualitative analyses could be performed for Mg 2Ca(SO 4) 3 in these mixtures, but no quantitative analytical method was available. An infrared spectroscopic method has been developed that provides reasonably quantitative results for Mg 2Ca(SO 4) 3, MgSO 4,and CaSO 4 in their mixtures.

  18. A Simple Three-Step Method for Design and Affinity Testing of New Antisense Peptides: An Example of Erythropoietin

    PubMed Central

    Štambuk, Nikola; Manojlović, Zoran; Turčić, Petra; Martinić, Roko; Konjevoda, Paško; Weitner, Tin; Wardega, Piotr; Gabričević, Mario

    2014-01-01

    Antisense peptide technology is a valuable tool for deriving new biologically active molecules and performing peptide–receptor modulation. It is based on the fact that peptides specified by the complementary (antisense) nucleotide sequences often bind to each other with a higher specificity and efficacy. We tested the validity of this concept on the example of human erythropoietin, a well-characterized and pharmacologically relevant hematopoietic growth factor. The purpose of the work was to present and test simple and efficient three-step procedure for the design of an antisense peptide targeting receptor-binding site of human erythropoietin. Firstly, we selected the carboxyl-terminal receptor binding region of the molecule (epitope) as a template for the antisense peptide modeling; Secondly, we designed an antisense peptide using mRNA transcription of the epitope sequence in the 3'→5' direction and computational screening of potential paratope structures with BLAST; Thirdly, we evaluated sense–antisense (epitope–paratope) peptide binding and affinity by means of fluorescence spectroscopy and microscale thermophoresis. Both methods showed similar Kd values of 850 and 816 µM, respectively. The advantages of the methods were: fast screening with a small quantity of the sample needed, and measurements done within the range of physicochemical parameters resembling physiological conditions. Antisense peptides targeting specific erythropoietin region(s) could be used for the development of new immunochemical methods. Selected antisense peptides with optimal affinity are potential lead compounds for the development of novel diagnostic substances, biopharmaceuticals and vaccines. PMID:24865486

  19. Rapidly evolving genes in pathogens: methods for detecting positive selection and examples among fungi, bacteria, viruses and protists.

    PubMed

    Aguileta, Gabriela; Refrégier, Guislaine; Yockteng, Roxana; Fournier, Elisabeth; Giraud, Tatiana

    2009-07-01

    The ongoing coevolutionary struggle between hosts and pathogens, with hosts evolving to escape pathogen infection and pathogens evolving to escape host defences, can generate an 'arms race', i.e., the occurrence of recurrent selective sweeps that each favours a novel resistance or virulence allele that goes to fixation. Host-pathogen coevolution can alternatively lead to a 'trench warfare', i.e., balancing selection, maintaining certain alleles at loci involved in host-pathogen recognition over long time scales. Recently, technological and methodological progress has enabled detection of footprints of selection directly on genes, which can provide useful insights into the processes of coevolution. This knowledge can also have practical applications, for instance development of vaccines or drugs. Here we review the methods for detecting genes under positive selection using divergence data (i.e., the ratio of nonsynonymous to synonymous substitution rates, d(N)/d(S)). We also review methods for detecting selection using polymorphisms, such as methods based on F(ST) measures, frequency spectrum, linkage disequilibrium and haplotype structure. In the second part, we review examples where targets of selection have been identified in pathogens using these tests. Genes under positive selection in pathogens have mostly been sought among viruses, bacteria and protists, because of their paramount importance for human health. Another focus is on fungal pathogens owing to their agronomic importance. We finally discuss promising directions in pathogen studies, such as detecting selection in non-coding regions. PMID:19442589

  20. 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.

  1. Fast and Simultaneous Determination of the Number and Mass Concentrations of Gold Nanorod Colloid Using an Improved Optical Extinction-Scattering Spectroscopic Method.

    PubMed

    Yang, Guoce; Bai, Benfeng; Liu, Wenqi; Wu, Xiaochun

    2016-04-01

    Accurate determination of the concentrations, including the mass concentration (MC) and number concentration (NC), of metal nanoparticle (NP) colloid is highly demanded in the synthesis, metrology, and application of NPs. The commonly used inductively coupled plasma mass spectrometry (ICP-MS) can only measure the MC of NPs, which is destructive to the NPs and requires advanced operation skills. Here, we present a simple approach based on an improved optical extinction-scattering spectroscopic (OESS) method to fast determining the MC and NC of metal nanorod colloids simultaneously. Unlike most existing spectroscopic methods that can only deal with low-concentration NP colloids, the improved OESS method can accurately solve the inverse scattering problem of NP colloids with higher concentrations, so that a two-dimensional joint probability density function of both the width and aspect ratio of nanorods can be retrieved, which makes the basis for the accurate determination of the MC and NC of the colloids in a large range of concentration. The reliability and accuracy of the method are validated by measuring several typical nanorod colloids with different concentrations and comparing the results with those obtained by the standard ICP-MS method. It is shown that the improved OESS method can cover a broad MC measurement range of at least 10-50 µg/mL and a NC measurement range of 10(9)-10(11)/mL. The uncertainty and sources of error in the measurement are also analyzed. Since the improved OESS method is fast, cost-effective, non-destructive, and easy to implement, it provides a simple way to determine the concentrations of metal NPs and has the potential to be extended to other metal NPs. PMID:26940003

  2. Empirical evaluation of decision support systems: Needs, definitions, potential methods, and an example pertaining to waterfowl management

    USGS Publications Warehouse

    Sojda, R.S.

    2007-01-01

    Decision support systems are often not empirically evaluated, especially the underlying modelling components. This can be attributed to such systems necessarily being designed to handle complex and poorly structured problems and decision making. Nonetheless, evaluation is critical and should be focused on empirical testing whenever possible. Verification and validation, in combination, comprise such evaluation. Verification is ensuring that the system is internally complete, coherent, and logical from a modelling and programming perspective. Validation is examining whether the system is realistic and useful to the user or decision maker, and should answer the question: “Was the system successful at addressing its intended purpose?” A rich literature exists on verification and validation of expert systems and other artificial intelligence methods; however, no single evaluation methodology has emerged as preeminent. At least five approaches to validation are feasible. First, under some conditions, decision support system performance can be tested against a preselected gold standard. Second, real-time and historic data sets can be used for comparison with simulated output. Third, panels of experts can be judiciously used, but often are not an option in some ecological domains. Fourth, sensitivity analysis of system outputs in relation to inputs can be informative. Fifth, when validation of a complete system is impossible, examining major components can be substituted, recognizing the potential pitfalls. I provide an example of evaluation of a decision support system for trumpeter swan (Cygnus buccinator) management that I developed using interacting intelligent agents, expert systems, and a queuing system. Predicted swan distributions over a 13-year period were assessed against observed numbers. Population survey numbers and banding (ringing) studies may provide long term data useful in empirical evaluation of decision support.

  3. Extraction of weak PcP phases using the slant-stacklet transform - I: method and examples

    NASA Astrophysics Data System (ADS)

    Ventosa, Sergi; Romanowicz, Barbara

    2015-04-01

    In order to study fine scale structure of the Earth's deep interior, it is necessary to extract generally weak body wave phases from seismograms that interact with various discontinuities and heterogeneities. The recent deployment of large-scale dense arrays providing high-quality data, in combination with efficient seismic data processing techniques, may provide important and accurate observations over large portions of the globe poorly sampled until now. Major challenges are low signal-to-noise ratios (SNR) and interference with unwanted neighbouring phases. We address these problems by introducing scale-dependent slowness filters that preserve time-space resolution. We combine complex wavelet and slant-stack transforms to obtain the slant-stacklet transform. This is a redundant high-resolution directional wavelet transform with a direction (here slowness) resolution that can be adapted to the signal requirements. To illustrate this approach, we use this expansion to design coherence-driven filters that allow us to obtain clean PcP observations (a weak phase often hidden in the coda of the P wave), for events with magnitude Mw > 5.4 and distances up to 80°. In this context, we then minimize a linear misfit between P and PcP waveforms to improve the quality of PcP-P traveltime measurements as compared to a standard cross-correlation method. This significantly increases both the quantity and the quality of PcP-P differential traveltime measurements available for the modelling of structure near the core-mantle boundary. The accuracy of our measurements is limited mainly by the highest frequencies of the signals used and the level of noise. We apply this methodology to two examples of high-quality data from dense arrays located in north America. While focusing here on body-wave separation, the tools we propose are more general and may contribute to enhancing seismic signal observations in global seismology in situations of low SNR and high signal interference.

  4. Sorption of selenium oxyanions on TiO2 (rutile) studied by batch or column experiments and spectroscopic methods.

    PubMed

    Svecova, Lenka; Dossot, Manuel; Cremel, Sébastien; Simonnot, Marie-Odile; Sardin, Michel; Humbert, Bernard; Den Auwer, Christophe; Michot, Laurent J

    2011-05-30

    Selenium is a known toxic element released in the environment by anthropogenic activities. The present study is devoted to the aqueous sorption behaviour of selenium oxyanions (selenate and selenite) on a reference oxide surface, namely rutile TiO(2). Batch sorption kinetics and isotherms have been studied using different physico-chemical conditions of the solution (changes of pH and ionic strength). The sorption was favoured for both anions in acidic conditions, in agreement with a surface complexation mechanism and CD-MUSIC predictions. Spectroscopic investigations of the sorbed rutile powder were also consistent with such a mechanism. EXAFS spectra confirmed that for selenite anions, an inner-sphere mechanism was the most probable process observed. Dynamic sorption experiments using a column filled with rutile powder also substantiated that a part of the surface complexes follows the inner-sphere mechanism, but also evidenced that an outer-sphere mechanism cannot be excluded, especially for selenate anions. PMID:21458156

  5. The correlation of attenuated total reflectance infrared (ATR-FTIR) spectroscopic data with X-ray diffraction (XRD) parameters and its potential use for mineral identification and quantification in drilling cores: examples from the Pannonian Basin, Hungar

    NASA Astrophysics Data System (ADS)

    Udvardi, Beatrix; Kovács, István; Viczián, István; Hámor-Vidó, Mária; Mihály, Judith; Németh, Csaba

    2013-04-01

    Four thick sediment sequences in the following boreholes, Vízvár-I (0,0-2965,0 m) in the Dráva Basin, Som-I (999,5-1150,6 m) in southern Transdanubia, and two other boreholes, Doboz-I (3490-4434 m) and Doboz-III (2190-3400 m) in the Békés Basin, Hungary, were investigated in detail. Each drillings cut across Neogene sequences and contain shales, carbonates and clay rocks (Tanács & Viczián, 1995). The selection of these cores is due to the various amounts of smectite, illite and kaolinite minerals that are well manifested during comparison of infrared spectroscopic and former XRD dataset. During preparation, powdered core samples were settled (

  6. A Single Chiroptical Spectroscopic Method May Not Be Able To Establish the Absolute Configurations of Diastereomers: Dimethylesters of Hibiscus and Garcinia Acids

    PubMed Central

    Polavarapu, Prasad L.; Donahue, Emily A.; Shanmugam, Ganesh; Scalmani, Giovanni; Hawkins, Edward K.; Rizzo, Carmelo; Ibnusaud, Ibrahim; Thomas, Grace; Habel, Deenamma; Sebastian, Dellamol

    2013-01-01

    Electronic circular dichroism (ECD), optical rotatory dispersion (ORD), and vibrational circular dichroism (VCD) spectra of hibiscus acid dimethyl ester have been measured and analyzed in combination with quantum chemical calculations of corresponding spectra. These results, along with those reported previously for garcinia acid dimethyl ester, reveal that none of these three (ECD, ORD, or VCD) spectroscopic methods, in isolation, can unequivocally establish the absolute configurations of diastereomers. This deficiency is eliminated when a combined spectral analysis of either ECD and VCD or ORD and VCD methods is used. It is also found that the ambiguities in the assignment of absolute configurations of diastereomers may also be overcome when unpolarized vibrational absorption is included in the spectral analysis. PMID:21568330

  7. Determination of the acid dissociation constant of the biosurfactant monorhamnolipid in aqueous solution by potentiometric and spectroscopic methods.

    PubMed

    Lebrón-Paler, Ariel; Pemberton, Jeanne E; Becker, Bridget A; Otto, William H; Larive, Cynthia K; Maier, Raina M

    2006-11-15

    The acid dissociation constant in water for a monorhamnolipid mixture extracted from Pseudomonas aeruginosa ATCC 9027 has been determined using potentiometry and two spectroscopic approaches at concentrations below and above the critical micelle concentration (cmc). Potentiometric titrations resulted in pKa values ranging from 4.28 +/- 0.16 to 5.50 +/- 0.06 depending on concentration. 1H NMR spectrochemical titrations at concentrations below the cmc revealed a pKa value of 4.39 +/- 0.06. ATR-FT-IR spectrochemical titrations on solutions well above the cmc gave a pKa value of 4.84 +/- 0.05. The value of 4.28 for the free rhamnolipid molecule for concentrations below the cmc differs markedly from that reported previously. However, the pKa of 5.50 for surface-adsorbed and solution aggregates correlates closely to that previously reported. Differences in these pKa values are rationalized in terms of the pH- and concentration-dependent aggregation behavior of rhamnolipids in aqueous solution. PMID:17105155

  8. Mid-Infrared Spectroscopic Method for the Identification and Quantification of Dissolved Oil Components in Marine Environments.

    PubMed

    Stach, Robert; Pejcic, Bobby; Crooke, Emma; Myers, Matthew; Mizaikoff, Boris

    2015-12-15

    The use of mid-infrared sensors based on conventional spectroscopic equipment for oil spill monitoring and fingerprinting in aqueous systems has to date been mainly confined to laboratory environments. This paper presents a portable-based mid-infrared attenuated total reflectance (MIR-ATR) sensor system that was used to quantify a number of environmentally relevant hydrocarbon contaminants in marine water. The sensor comprises a polymer-coated diamond waveguide in combination with a room-temperature operated pyroelectric detector, and the analytical performance was optimized by evaluating the influence of polymer composition, polymer film thickness, and solution flow rate on the sensor response. Uncertainties regarding the analytical performance and instrument specifications for dissolved oil detection were investigated using real-world seawater matrices. The reliability of the sensor was tested by exposition to known volumes of different oils; crude oil and diesel samples were equilibrated with seawater and then analyzed using the developed MIR-ATR sensor system. For validation, gas chromatographic measurements were performed revealing that the MIR-ATR sensor is a promising on-site monitoring tool for determining the concentration of a range of dissolved oil components in seawater at ppb to ppm levels. PMID:26599809

  9. X-ray spectroscopic methods in the studies of nonstoichiometric TiO2-x thin films

    NASA Astrophysics Data System (ADS)

    Kollbek, K.; Sikora, M.; Kapusta, Cz.; Szlachetko, J.; Zakrzewska, K.; Kowalski, K.; Radecka, M.

    2013-09-01

    X-ray spectroscopic techniques have been used in the studies of electronic and structural properties of nonstoichiometric TiO2-x thin films obtained by reactive sputtering from Ti target. Films characterisation has been completed by means of X-ray diffraction in grazing incidence, GID, UV Raman and impedance spectroscopy, optical spectrophotometry, 1s3p Resonant X-ray Emission Spectroscopy, RXES, and X-ray Photoelectron Spectroscopy, XPS. Stoichiometric thin films of TiO2 are composed of a well-crystallised anatase-rutile mixture with the predominance of anatase while the films with higher oxygen deficit are amorphous to larger extent. Oxidation state changes from Ti4+ in stoichiometric films towards Ti3+ upon increasing departure from stoichiometric composition. This change is accompanied by the significant decrease in the electrical resistivity. The comparison of band gap energies, determined independently from optical and valence band X-ray absorption/emission spectra is good assuming direct allowed transitions.

  10. Hybrid coupled cluster methods based on the split virtual orbitals: barrier heights of reactions and spectroscopic constants of open-shell diatomic molecules.

    PubMed

    Kou, Zhuangfei; Shen, Jun; Xu, Enhua; Li, Shuhua

    2013-01-24

    We report an efficient implementation of the coupled cluster (CC) singles, doubles, and a hybrid treatment of triples based on the split virtual orbitals (SVO-CCSD(T)-h) method [J. Chem. Phys.2012, 136, 044101]. In this approach, virtual orbitals are split into two subsets, and correspondingly triple excitations are divided into active and inactive subsets. The active triple excitations are treated with the CCSDt (CC singles, doubles, and active triples) method, while the inactive triple excitations are treated with the CCSD(T) (CC singles, doubles, and perturbative triples) method. In the present work, the use of semicanonical molecular orbitals allows the CCSD(T)-like equations in SVO-CCSD(T)-h to be solved without iteration. As a result, the present SVO-CCSD(T)-h scheme does not need a large disk space to store the large number of triple excitation amplitudes, which is required by the original scheme. Test applications indicate that the present method can give results almost identical to those of the original scheme. The present method is then applied to investigate the reaction barriers for a number of simple reactions and spectroscopic constants including the equilibrium bond lengths and vibrational frequencies in several open-shell diatomic molecules. The SVO-CCSD(T)-h method is demonstrated to provide a significant improvement upon the CCSD(T) method in many cases. PMID:23270485

  11. Synthesis, spectroscopic and structural studies on YOF, LaOF and GdOF nanocrystals doped with Eu3+, synthesized via stearic acid method

    NASA Astrophysics Data System (ADS)

    Grzyb, Tomasz; Węcławiak, Mariusz; Pędziński, Tomasz; Lis, Stefan

    2013-10-01

    Nanocrystalline Eu3+ doped REOF oxofluorides (where RE = Y, La, Gd) were synthesized using stearic acid as the reaction medium. Optimal conditions for the synthesis of pure and single-phased oxyfluorides were found. The obtained products were analysed using thermogravimetric analysis, X-ray analysis, transmission electron microscopy and the Rietveld method. The influence of calcination temperature on the physicochemical properties was studied. Spectroscopic properties of the tetragonal and rhombohedral oxyfluoride nanocrystals were investigated using excitation and emission spectra and luminescence lifetime measurements. Effectiveness of the Eu3+ dopant red emission intensity and energy transfer processes were examined in relation to the structure and the presence of the RE ion in oxyfluorides studied. The highest luminescence efficiency was observed for the GdOF:Eu3+ nanomaterial. Judd-Ofelt intensity parameters were calculated and analysed.

  12. Characterization by spectroscopic, kinetic and equilibrium methods of the interaction between recombinant human cystatin A (stefin A) and cysteine proteinases.

    PubMed Central

    Pol, E; Olsson, S L; Estrada, S; Prasthofer, T W; Björk, I

    1995-01-01

    The near-UV spectroscopic changes induced by the binding of recombinant human cystatin A to papain were appreciably different from those induced by cystatin C, reflecting mainly interactions involving the single tryptophan of cystatin C, Trp-106. Cystatin A bound tightly and rapidly to papain and cathepsin L, with dissociation equilibrium constants of approximately 10(-11)-10(-13) M and association rate constants of 3 x 10(6)-5 x 10(6) M-1.s-1. These affinities are at least 50-100-fold higher than previously reported values. The kinetics of binding to papain were consistent with a simple reversible bimolecular reaction mechanism, indicating that cystatin A, like chicken cystatin and cystatin C, binds to papain with no appreciable conformational adaptation of either reacting protein. Cystatin A bound more weakly to actinidin and cathepsins B, C and H, with dissociation equilibrium constants of 10(-8)-10(-9) M. The weaker binding to cathepsin B was largely due to a considerably reduced association rate constant (approximately 4 x 10(4) M-1.s-1), consistent with the 'occluding loop' of cathepsin B markedly restricting the access of cystatin A to the active site. The lower affinities for actinidin and cathepsins C and H were due partly to lower association rate constants (2 x 10(5)-6 x 10(5) M-1.s-1) but primarily to higher dissociation rate constants. The mode of binding of cystatin A to inactivated papains indicated that there is appreciably less space around the active-site cysteine of papain in the complex with cystatin A than in the complexes with chicken cystatin and cystatin C. An N-terminally truncated form of cystatin A, lacking the first six residues, had considerably lower affinity for papain than the full-length inhibitor, consistent with an intact N-terminal region being of importance for proteinase binding. PMID:7575465

  13. Spectroscopic evaluation of thymol dissolved by different methods and influence on acaricidal activity against larvae of Rhipicephalus microplus (Acari: Ixodidae).

    PubMed

    Daemon, Erik; Monteiro, Caio Mrcio Oliveira; Maturano, Ralph; Senra, Tatiane Oliveira Souza; Calmon, Fernanda; Faza, Aline; de Azevedo Prata, Mrcia Cristina; Georgopoulos, Stfanos Leite; de Oliveira, Luiz Fernando Cappa

    2012-11-01

    The acaricidal activity of three thymol formulations was investigated at five concentrations (1.25, 2.5, 5.0, 7.5, and 10.0 mg/ml) on Rhipicephalus microplus larvae, and the behavior of its solubility in these formulations was analyzed. The thymol was dissolved in distilled water plus 1 % dimethylsulfoxide as adjuvant under two heating regimes (water bath in formulation 1 and hot plate in formulation 2) as well as without heating in 50 % ethanol and 50 % water (v/v). The acaricidal activity was assessed by the modified larval packet test, and the solubilization behavior was investigated by ultraviolet-visible spectroscopy, based on the Beer-Lambert law. With formulations 1 and 2, the mortality was greater than 95 % starting at the thymol concentrations of 5.0 and 7.5 mg/ml, respectively, while with formulation 3, this mortality level was reached starting at a concentration of 2.5 mg/ml, showing that the addition of ethanol in the solution enhanced the acaricidal action of thymol. This result was supported by the LC 90 values, which were 3.3, 2.4, and 1.6 mg/ml of thymol for formulations 1, 2, and 3, respectively. This result is related to the better solubility of thymol in the hydroethanolic formulation, since the spectroscopic analysis revealed that the thymol dissolved more completely in this formulation. This fact was evident once the R (2) obtained from the linear regression analysis of the relation absorbance concentration of the formulations 1, 2, and 3 approached the optimal value (R (2)?=?1) in the following sequence: 1, 2, and 3 (0.717, 0.901, and 0.968, respectively). PMID:22797607

  14. Exploration of Porphyrin-based Semiconductors for Negative Charge Transport Applications Using Synthetic, Spectroscopic, Potentiometric, Magnetic Resonance, and Computational Methods

    NASA Astrophysics Data System (ADS)

    Rawson, Jeffrey Scott

    Organic pi-conjugated materials are emerging as commercially relevant components in electronic applications that include transistors, light-emitting diodes, and solar cells. One requirement common to all of these functions is an aptitude for accepting and transmitting charges. It is generally agreed that the development of organic semiconductors that favor electrons as the majority carriers (n-type) lags behind the advances in hole transporting (p-type) materials. This shortcoming suggests that the design space for n-type materials is not yet well explored, presenting researchers with the opportunity to develop unconventional architectures. In this regard, it is worth noting that discrete molecular materials are demonstrating the potential to usurp the preeminent positions that pi-conjugated polymers have held in these areas of organic electronics research. This dissertation describes how an extraordinary class of molecules, meso-to-meso ethyne-bridged porphyrin arrays, has been bent to these new uses. Chapter one describes vis-NIR spectroscopic and magnetic resonance measurements revealing that these porphyrin arrays possess a remarkable aptitude for the delocalization of negative charge. In fact, the miniscule electron-lattice interactions exhibited in these rigid molecules allow them to host the most vast electron-polarons ever observed in a pi-conjugated material. Chapter two describes the development of an ethyne-bridged porphyrin-isoindigo hybrid chromophore that can take the place of fullerene derivatives in the conventional thin film solar cell architecture. Particularly noteworthy is the key role played by the 5,15-bis(heptafluoropropyl)porphyrin building block in the engineering of a chromophore that, gram for gram, is twice as absorptive as poly(3-hexyl)thiophene, exhibits a lower energy absorption onset than this polymer, and yet possesses a photoexcited singlet state sufficiently energetic to transfer a hole to this polymer. Chapter three describes synthetic efforts that expand the repertoire of readily available meso-heptafluoropropyl porphyrin building blocks. The findings suggest that the remaining challenges to the exploitation of these pigments will be overcome by a sufficiently firm grasp of their subtle electronic structures, and a willingness to eschew the customary strategies of chromophore assembly.

  15. Measuring Second-Order Factors Using Confirmatory Methods: A Case Study Example with the Hendrick-Hendrick Love Instrument.

    ERIC Educational Resources Information Center

    Thompson, Bruce; Borrello, Gloria M.

    The application and utility of confirmatory second-order factor analytic methods are discussed. Factor analysis is central to concerns regarding measurement validity. Confirmatory methods are especially useful because they explicitly consider measurement error influences and because the methods are inherently theory-driven and theory-oriented.…

  16. An efficient, maintenance free and approved method for spectroscopic control and monitoring of blend uniformity: The moving F-test.

    PubMed

    Besseling, Rut; Damen, Michiel; Tran, Thanh; Nguyen, Thanh; van den Dries, Kaspar; Oostra, Wim; Gerich, Ad

    2015-10-10

    Dry powder mixing is a wide spread Unit Operation in the Pharmaceutical industry. With the advent of in-line Near Infrared (NIR) Spectroscopy and Quality by Design principles, application of Process Analytical Technology to monitor Blend Uniformity (BU) is taking a more prominent role. Yet routine use of NIR for monitoring, let alone control of blending processes is not common in the industry, despite the improved process understanding and (cost) efficiency that it may offer. Method maintenance, robustness and translation to regulatory requirements have been important barriers to implement the method. This paper presents a qualitative NIR-BU method offering a convenient and compliant approach to apply BU control for routine operation and process understanding, without extensive calibration and method maintenance requirements. The method employs a moving F-test to detect the steady state of measured spectral variances and the endpoint of mixing. The fundamentals and performance characteristics of the method are first presented, followed by a description of the link to regulatory BU criteria, the method sensitivity and practical considerations. Applications in upscaling, tech transfer and commercial production are described, along with evaluation of the method performance by comparison with results from quantitative calibration models. A full application, in which end-point detection via the F-test controls the blending process of a low dose product, was successfully filed in Europe and Australia, implemented in commercial production and routinely used for about five years and more than 100 batches. PMID:26257268

  17. A high-resolution phosphorus-31 nuclear magnetic resonance (NMR) spectroscopic method for the non-phosphorus markers of chemical warfare agents.

    PubMed

    Mazumder, Avik; Kumar, Ajeet; Purohit, Ajay K; Dubey, Devendra K

    2012-02-01

    A high-resolution phosphorus-31 nuclear magnetic resonance (NMR) spectroscopic method has been developed for detection, identification and quantification of non-phosphorus markers of toxic nerve agents (soman and V-class), vesicants (HD, HN-2, HN-3), and incapacitating agent (Bz). These analytes were converted to phosphorus-containing derivatives via phosphitylation reaction of their hydroxyl and sulfhydryl functions (using 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane). This was followed by (31)P{(1)H} and (31)P NMR analysis of these derivatives. The chemical shifts (δ) and coupling constants ((3)J(P-H)) of derivatives were used for their specific detection and identification. The method allowed clear distinction between the alcohols and thiols. The lower limits of detection of these analytes were found to be between 12 and 28 μg obtained from 128 transients of (31)P{(1)H} quantitative NMR experiments. Utility of the method was ensured by the detection and identification of triethanolamine present (at an original concentration of 5 μg/mL) in an aqueous sample from 28th OPCW Official Proficiency Tests. PMID:22160203

  18. NMR, FT-IR, FT-Raman, UV spectroscopic, HOMO-LUMO and NBO analysis of cumene by quantum computational methods

    NASA Astrophysics Data System (ADS)

    Sivaranjani, T.; Xavier, S.; Periandy, S.

    2015-03-01

    This work presents the investigation of cumene using the FT-IR, FT-Raman, NMR and UV spectra obtained through various spectroscopic techniques. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been scaled and compared with the corresponding experimental data. 1H and 13C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, and potential energy surface (PES) is performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. NLO properties related to polarizability and hyperpolarizability are also discussed.

  19. Reexamination of Statistical Methods for Comparative Anatomy: Examples of Its Application and Comparisons with Other Parametric and Nonparametric Statistics

    PubMed Central

    Aversi-Ferreira, Roqueline A. G. M. F.; Nishijo, Hisao; Aversi-Ferreira, Tales Alexandre

    2015-01-01

    Various statistical methods have been published for comparative anatomy. However, few studies compared parametric and nonparametric statistical methods. Moreover, some previous studies using statistical method for comparative anatomy (SMCA) proposed the formula for comparison of groups of anatomical structures (multiple structures) among different species. The present paper described the usage of SMCA and compared the results by SMCA with those by parametric test (t-test) and nonparametric analyses (cladistics) of anatomical data. In conclusion, the SMCA can offer a more exact and precise way to compare single and multiple anatomical structures across different species, which requires analyses of nominal features in comparative anatomy. PMID:26413553

  20. Reexamination of Statistical Methods for Comparative Anatomy: Examples of Its Application and Comparisons with Other Parametric and Nonparametric Statistics.

    PubMed

    Aversi-Ferreira, Roqueline A G M F; Nishijo, Hisao; Aversi-Ferreira, Tales Alexandre

    2015-01-01

    Various statistical methods have been published for comparative anatomy. However, few studies compared parametric and nonparametric statistical methods. Moreover, some previous studies using statistical method for comparative anatomy (SMCA) proposed the formula for comparison of groups of anatomical structures (multiple structures) among different species. The present paper described the usage of SMCA and compared the results by SMCA with those by parametric test (t-test) and nonparametric analyses (cladistics) of anatomical data. In conclusion, the SMCA can offer a more exact and precise way to compare single and multiple anatomical structures across different species, which requires analyses of nominal features in comparative anatomy. PMID:26413553

  1. Example of Occupational Surveillance in a Telemedicine Setting: Application of Epidemiologic Methods at NASA Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Babiak-Vazquez, Adriana; Ruffaner, Lanie M.; Wear, Mary L.; Crucian, Brian; Sams, Clarence; Lee, Lesley R.; Van Baalen, Mary

    2016-01-01

    In 2010, NASA implemented Lifetime Surveillance of Astronaut Health, a formal occupational surveillance program for the U.S. astronaut corps. Because of the nature of the space environment, space medicine presents unique challenges and opportunities for epidemiologists. One such example is the use of telemedicine while crewmembers are in flight, where the primary source of information about crew health is verbal communication between physicians and their crewmembers. Due to restricted medical capabilities, the available health information is primarily crewmember report of signs and symptoms, rather than diagnoses. As epidemiologists at NASA, Johnson Space Center, we have shifted our paradigm from tracking diagnoses based on traditional terrestrial clinical practice to one in which we also incorporate reported symptomology as potential antecedents of disease. In this presentation we describe how characterization of reported signs and symptoms can be used to establish incidence rates for inflight immunologic events. We describe interdisciplinary data sources of information that are used in combination with medical information to analyze the data. We also delineate criteria for symptom classification inclusion. Finally, we present incidence tables and graphs to illustrate the final outcomes. Using signs and symptoms reported via telemedicine, the epidemiologists provide summary evidence regarding incidence of potential inflight medical conditions. These results inform our NASA physicians and scientists, and support evaluation of the occupational health risks associated with spaceflight.

  2. A simple spectroscopic method to determine the degree of dissociation in hydrogen plasmas with wide-range spectrometer

    NASA Astrophysics Data System (ADS)

    Dang, Jeong-Jeung; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-05-01

    A new and simple method for determining the degree of dissociation in hydrogen plasmas is presented. In this method, wide-range spectrum covering from an atomic H-γ line (434.05 nm) to molecular Fulcher-α band (600-640 nm) is measured simultaneously by a wide-range miniature spectrometer. Since the wide-range spectrum measured by the miniature spectrometer is too broadened to resolve respective lines in the Fulcher-α band, a synthetic spectrum method is applied to improve the accuracy in the Q-branch of Fulcher-α band intensity measurement. In order to reduce the influence from other transitions or anomalous P- and R-branch of Fulcher-α spectrum, the Fulcher-α spectra of which vibrational states are higher than 1 (υ ≥ 1) are synthesized using the rotational temperature obtained by the 0-0 Fulcher-α spectrum. The degree of dissociation is determined from the intensity ratio between H-γ line and the synthesized Fulcher-α band spectrum. A comparative study carried out in a volume-produced negative hydrogen ion source shows that the degree of dissociation determined by this method agrees well with the measured values using a spectrometer with high spectral resolution. The present method is expected to be useful to characterize the plasma sources with molecular species since it provides important parameters for understanding neutral particle behaviors.

  3. Multi-spectroscopic method study the interaction of anti-inflammatory drug ketoprofen and calf thymus DNA and its analytical application

    NASA Astrophysics Data System (ADS)

    Guo, Hongqin; Cai, Changqun; Gong, Hang; Chen, Xiaoming

    2011-06-01

    Interactions of the anti-inflammatory drug ketoprofen with calf thymus DNA (ctDNA) in aqueous solution have been studied by multi-spectroscopic method including resonance light scattering (RLS) technique, ultraviolet spectra (UV), 1H NMR, etc. The characteristics of RLS spectra, the effective factors and optimum conditions of the reaction have been unequivocally investigated. Mechanism investigations have shown that ketoprofen can bind to ctDNA by groove binding and form large particles, which resulted in the enhancement of RLS intensity. In Critic acid-Na 2HPO 4 buffer (pH = 6.5), ketoprofen has a maximum peak 451.5 nm and the RLS intensity is remarkably enhanced by trace amount of ctDNA due to the interaction between ketoprofen and ctDNA. The enhancement of RLS signal is directly proportional to the concentration of ctDNA in the range of 1.20 × 10 -6-1.0 × 10 -5 mol/L, and its detection limit (3 σ) is 1.33 × 10 -9 mol/L. The method is simple, rapid, practical and relatively free from interference generated by coexisting substance, and was applied to the determination of trace amounts of nucleic acid in synthetic samples with satisfactory results.

  4. Improved method to visualize lipid distribution within arterial vessel walls by 1.7 μm spectroscopic spectral-domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Hirano, Mitsuharu; Tonosaki, Shozo; Ueno, Takahiro; Tanaka, Masato; Hasegawa, Takemi

    2014-02-01

    We report an improved method to visualize lipid distribution in axial and lateral direction within arterial vessel walls by spectroscopic spectral-domain Optical Coherence Tomography (OCT) at 1.7μm wavelength for identification of lipidrich plaque that is suspected to cause coronary events. In our previous method, an extended InGaAs-based line camera detects an OCT interferometric spectrum from 1607 to 1766 nm, which is then divided into twenty subbands, and A-scan OCT profile is calculated for each subband, resulting in a tomographic spectrum. This tomographic spectrum is decomposed into lipid spectrum having an attenuation peak at 1730 nm and non-lipid spectrum independent of wavelength, and the weight of each spectrum, that is, lipid and non-lipid score is calculated. In this paper, we present an improved algorithm, in which we have combined the lipid score and the non-lipid score to derive a corrected lipid score. We have found that the corrected lipid score is better than the raw lipid score in that the former is more robust against false positive occurring due to abrupt change in reflectivity at vessel surface. In addition, we have optimized spatial smoothing filter and reduced false positive and false negative due to detection noise and speckle. We have verified this improved algorithm by the use of measuring data of normal porcine coronary artery and lard as a model of lipid-rich plaque and confirmed that both the sensitivity and the specificity of lard are 92%.

  5. Biodegradability of Poly-3-hydroxybutyrate/Bacterial Cellulose Composites under Aerobic Conditions, Measured via Evolution of Carbon Dioxide and Spectroscopic and Diffraction Methods.

    PubMed

    Ruka, Dianne R; Sangwan, Parveen; Garvey, Christopher J; Simon, George P; Dean, Katherine M

    2015-08-18

    Poly-3-hydroxybutyrate (PHB) and bacterial cellulose (BC) are both natural polymeric materials that have the potential to replace traditional, nonrenewable polymers. In particular, the nanofibrillar form of bacterial cellulose makes it an effective reinforcement for PHB. Neat PHB, bacterial cellulose, and a composite of PHB/BC produced with 10 wt % cellulose were composted under accelerated aerobic test conditions, with biodegradability measured by the carbon dioxide evolution method, in conjunction with spectroscopic and diffraction methods to assess crystallinity changes during the biodegradation process. The PHB/BC composite biodegraded at a greater rate and extent than that of PHB alone, reaching 80% degradation after 30 days, whereas PHB did not reach this level of degradation until close to 50 days of composting. The relative crystallinity of PHB and PHB in the PHB/BC composite was found to increase in the initial weeks of degradation, with degradation occurring primarily in the amorphous region of the material and some recrystallization of the amorphous PHB. Small angle X-ray scattering indicates that the change in PHB crystallinity is accompanied by a change in morphology of semicrystalline lamellae. The increased rate of biodegradability suggests that these materials could be applicable to single-use applications and could rapidly biodegrade in compost on disposal. PMID:25763925

  6. Multi-spectroscopic method study the interaction of anti-inflammatory drug ketoprofen and calf thymus DNA and its analytical application.

    PubMed

    Guo, Hongqin; Cai, Changqun; Gong, Hang; Chen, Xiaoming

    2011-06-01

    Interactions of the anti-inflammatory drug ketoprofen with calf thymus DNA (ctDNA) in aqueous solution have been studied by multi-spectroscopic method including resonance light scattering (RLS) technique, ultraviolet spectra (UV), (1)H NMR, etc. The characteristics of RLS spectra, the effective factors and optimum conditions of the reaction have been unequivocally investigated. Mechanism investigations have shown that ketoprofen can bind to ctDNA by groove binding and form large particles, which resulted in the enhancement of RLS intensity. In Critic acid-Na(2)HPO(4) buffer (pH=6.5), ketoprofen has a maximum peak 451.5 nm and the RLS intensity is remarkably enhanced by trace amount of ctDNA due to the interaction between ketoprofen and ctDNA. The enhancement of RLS signal is directly proportional to the concentration of ctDNA in the range of 1.2010(-6)-1.010(-5) mol/L, and its detection limit (3?) is 1.3310(-9) mol/L. The method is simple, rapid, practical and relatively free from interference generated by coexisting substance, and was applied to the determination of trace amounts of nucleic acid in synthetic samples with satisfactory results. PMID:21420349

  7. Using Visualized Matrix Effects to Develop and Improve LC-MS/MS Bioanalytical Methods, Taking TRAM-34 as an Example

    PubMed Central

    Ye, Jia-Hung; Pao, Li-Heng

    2015-01-01

    Matrix effects (MEs) continue to be an obstacle in the development of the LC-MS/MS method, with phospholipids being the major cause of MEs. Changing the mobile phase has been a common strategy to reduce MEs; however, the underlying mechanism is unclear. "In-source multiple-reaction monitoring" (IS-MRM) for glycerophosphocholines (PCs) has been commonly applied in many bioanalytical methods. "Visualized MEs" is a suitable term to describe the application of IS-MRM to visualize the elution pattern of phospholipids. We selected a real case to discuss the relationship of MEs and phospholipids in different mobile phases by quantitative, qualitative, and visualized MEs in LC-MS/MS bioanalysis. The application of visualized MEs not only predicts the ion-suppression zone but also helps in selecting an appropriate (1) mobile phase, (2) column, (3) needle wash solvent for the residue of analyte and phospholipids, and (4) evaluates the clean-up efficiency of sample preparation. The TRAM-34 LC-MS/MS method, improved by using visualized MEs, was shown to be a precise and accurate analytical method. All data indicated that the use of visualized MEs indeed provided useful information about the LC-MS/MS method development and improvement. In this study, an integrative approach for the qualitative, quantitative, and visualized MEs was used to decipher the complexity of MEs. PMID:25909956

  8. A generalized method for high throughput in-situ experiment data analysis: An example of battery materials exploration

    NASA Astrophysics Data System (ADS)

    Aoun, Bachir; Yu, Cun; Fan, Longlong; Chen, Zonghai; Amine, Khalil; Ren, Yang

    2015-04-01

    A generalized method is introduced to extract critical information from series of ranked correlated data. The method is generally applicable to all types of spectra evolving as a function of any arbitrary parameter. This approach is based on correlation functions and statistical scedasticity formalism. Numerous challenges in analyzing high throughput experimental data can be tackled using the herein proposed method. We applied this method to understand the reactivity pathway and formation mechanism of a Li-ion battery cathode material during high temperature synthesis using in-situ high-energy X-ray diffraction. We demonstrate that Pearson's correlation function can easily unravel all major phase transition and, more importantly, the minor structural changes which cannot be revealed by conventionally inspecting the series of diffraction patterns. Furthermore, a two-dimensional (2D) reactivity pattern calculated as the scedasticity along all measured reciprocal space of all successive diffraction pattern pairs unveils clearly the structural evolution path and the active areas of interest during the synthesis. The methods described here can be readily used for on-the-fly data analysis during various in-situ operando experiments in order to quickly evaluate and optimize experimental conditions, as well as for post data analysis and large data mining where considerable amount of data hinders the feasibility of the investigation through point-by-point inspection.

  9. Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia

    USGS Publications Warehouse

    Bazuhair, A.S.; Wood, W.W.

    1996-01-01

    The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

  10. Melt Structure and Properties: a Spectroscopic Perspective

    NASA Astrophysics Data System (ADS)

    Stebbins, J.

    2006-12-01

    Entropy, volume, and their P/T derivatives are at the heart of models of the thermodynamics of silicate melts and magmas. Quantitative characterization of glass structure is leading to important new insights into the links from "Microscopic to Macroscopic" that can at least guide interpretations of data and in some cases even have predictive power. A few recent examples will be discussed here. The often-large configurational components to heat capacities, thermal expansivities, and compressibilities of melts strongly indicate that structural changes with temperature and pressure are of key importance. At least some aspects of thermal increases in configurational (as opposed to vibrational) disorder are amenable to spectroscopic detection, either with in situ methods or on glasses with varying quench rates and thus varying fictive temperatures. In some systems, such changes are now clear, and can be shown to make significant contributions to properties. These include network cation coordination in systems such as borate liquids (BO4 to BO3 at higher T), and Al-Si disordering in aluminosilicates. In general, however, progress in this rich problem has only begun. It has long been suspected from thermodynamic analyses (and theoretical simulations) that configurational changes in melts play a key role in volume compression at high pressure, over and above that which can be expressed in "normal" equations of state or from those expected from bond compression and bending. Scattering and spectroscopic studies have revealed some of the important aspects of pressure-induced structural changes, but again we are just at the beginning of full understanding. For example, binary silicate glasses quenched from high-P melts clearly record some systematic increases in Si coordination, while aluminosilicates record systematic pressure and compositional (modifier cation field strength) effects on Al coordination in recovered samples with large, quenched-in density increases. Compositional effects on the network structure of other oxide melts and glasses such as borates and germanates continue to provide clues to high P/T structural changes in silicates. Recent spectroscopic studies (e.g. O-17 NMR), for example, provide clear new constraints on network cation coordination and linkages in such materials that suggest processes exactly analogous to those proposed for silicates, and may help in formulating more realistic models.

  11. Using Case-Mix Adjustment Methods To Measure the Effectiveness of Substance Abuse Treatment: Three Examples Using Client Employment Outcomes.

    ERIC Educational Resources Information Center

    Koenig, Lane; Fields, Errol L.; Dall, Timothy M.; Ameen, Ansari Z.; Harwood, Henrick J.

    This report demonstrates three applications of case-mix methods using regression analysis. The results are used to assess the relative effectiveness of substance abuse treatment providers. The report also examines the ability of providers to improve client employment outcomes, an outcome domain relatively unexamined in the assessment of provider…

  12. A Simple Method to Predict Regional Fish Abundance: An Example in the McKenzie River Basin, Oregon

    EPA Science Inventory

    Regional assessments of fisheries resources are increasingly called for, but tools with which to perform them are limited. We present a simple method that can be used to estimate regional carrying capacity and apply it to the McKenzie River Basin, Oregon. First, we use a macroeco...

  13. Mass Spectroscopic Fingerprinting Method for Differentiation Between Scutellaria lateriflora and the Germander (Teucrium canadense and T. chamaedrys) Species

    PubMed Central

    Chen, Pei; Lin, Long-Ze; Harnly, James M.

    2013-01-01

    Scutellaria lateriflora, commonly known as skullcap, is used as an ingredient in numerous herbal products. However, it has been occasionally adulterated/contaminated with Teucrium canadense and T. chamaedrys, commonly known as germander, which contain hepatotoxic diterpenes. Due to the morphological similarities between the two genera, analytical methodologies to distinguish authentic S. lateriflora from the Teucrium species are needed to ensure public safety. In this study, a direct-injection electrospray ionization/MS method was used to generate spectral fingerprints of extracts from 21 skullcap and germander samples at a rate of 90 s/sample. MS fingerprints were analyzed by principal component analysis. The newly developed method offers a rapid and easy way to differentiate between skullcap and germander samples. PMID:20922946

  14. Study on photophysical and aggregation induced emission recognition of 1,8-naphthalimide probe for casein by spectroscopic method

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Liu, Zhen; Liang, Xuhua; Fan, Jun; Han, Quan

    2013-05-01

    A novel water-soluble 1,8-naphthalimide derivative 1, bearing two acetic carboxylic groups, exhibited fluorescent turn-on recognition for casein based on the aggregation induced emission (AIE) character. The photophysical properties of 1 consisting of donor and acceptor units were investigated in different solutions. The fluorescence intensity decreased through taking advantage of twisted intramolecular charge transfer (TICT) and self-association emission with increasing solvent polarity. Moreover, the spectral red-shift and intensity quench in protic solvents were caused by the excited-state hydrogen bond strengthening effect. Density Functional Theory (DFT) calculations revealed that 1 exhibited a strong TICT character. The AIE mechanism of 1 with casein was due to 1 docked in the hydrophobic cavity between sub-micelles and bound with Tyr and Trp residues, resulting in the aggregation of 1 on the casein surface and emission enhancement. Based on this, a novel casein assay method was developed. The proposed exhibited a good linear range from 0.1 to 22 μg mL-1, with the detection limit of 2.8 ng mL-1. Satisfactory reproducibility, reversibility and a short response time were realized. This method was applied to the determination of casein in milk powder samples and the results were in good agreement with the result of Biuret method.

  15. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of fluoroquinolone antibiotics using ammonium reineckate ion-pair complex formation

    NASA Astrophysics Data System (ADS)

    Ragab, Gamal H.; Amin, Alaa S.

    2004-03-01

    Three accurate, rapid and simple atomic absorption spectrometric, conductometric and colorimetric methods were developed for the determination of norfloxacin (NRF), ciprofloxacin (CIP), ofloxacin (OFL) and enrofloxacin (ENF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone in the range 5.0-65, 4.0-48, 5.0-56 and 6.0-72 μg ml -1 of NRF, CPF, OFL and ENF, respectively. The optimizations of various experimental conditions were described. The results obtained showed good recoveries of 99.15±1.15, 99.30±1.40, 99.60±1.50, and 99.00±1.25% with relative standard deviations of 0.81, 1.06, 0.97, and 0.69% for NRF, CPF, OFL, and ENF, respectively. Applications of the proposed methods to representative pharmaceutical formulations are successfully presented.

  16. Variations and anisotropy of the elastic thickness of the lithosphere determined by the wavelet method: Examples from the Canadian Shield.

    NASA Astrophysics Data System (ADS)

    Audet, P.; Mareschal, J.

    2005-12-01

    Different spectral methods have been used to estimate the elastic thickness and the mechanical properties of the lithosphere. We have used a wavelet transform to compute the local variations of the coherence between Bouguer gravity and topography in eastern Canada. The isotropic coherence is calculated by averaging the wavelet spectra from optimally overlapping 2-D Morlet wavelets having an isotropic spectral enveloppe in adjacent directions within 180 °, defining the so-called 'fan' wavelet. The local isotropic wavelet coherence is inverted to obtain local estimates of the elastic thickness (T_e) of the lithosphere. We calculate the anisotropic coherence by spatially averaging adjacent local wavelet spectra obtained from the rotation of the Morlet wavelet. The anisotropic direction of maximum observed coherence is diagnostic of the direction of preferred isostatic compensation, or the direction of mechanically weak lithosphere. We have carried out extensive tests on synthetic topography and Bouguer gravity data sets to verify that: (1) the wavelet method can recover T_e for simple models with either homogeneous or spatially variable rigidity patterns; and that:(2) the method can determine azimuthal variations in the 2-D coherence for homogeneous models with anisotropic T_e. We have then used real data from the Canadian Shield to infer the variations in T_e and the anisotropy of the coherence. The relative variations in T_e agree remarkably well with our previous studies where we used the maximum entropy method to determine the elastic thickness [ Audet & Mareschal, 2004a]. The wavelet transform gives T_e values between 20 and 90 km. T_e is generally high (>70 km) throughout eastern Canada. Lower values (30-50 km) are found around Hudson and James Bay, and near the Abitibi subprovince. High values are found within Hudson Bay, which is consistent with the previous studies. The main difference between this study and the one by Audet & Mareschal [2004a] is the absence of a low T_e region in the southeastern Churchill Province. While T_e was poorly estimated by both the maximum entropy and multitaper methods in the Appalachians [ Audet & Mareschal, 2004b], the wavelet method yields values ranging from 60 to 80 km. The direction of maximum coherence obtained from the wavelet method is also consistent with our previous results obtained with the multitaper method and shows that the weak mechanical axis is perpendicular to the fast seismic axis where seismic anisotropy has been detected. Audet, P., & Mareschal, J.C., 2004a, Variations in elastic thickness in the Canadian Shield, Earth Planet. Sci. Lett., 226, 17-31, doi:10.1016/j.epsl.2004.07.035. Audet, P., & Mareschal, J.C., 2004b, Anisotropy of the flexural response of the lithosphere in the Canadian Shield, Geophys. Res. Lett., 31, L20601, doi:10.1029/2004GL021080.

  17. A new method for the determination of the setting temperature of pyroclastic deposits (example of guadeloupe: french west indies)

    NASA Astrophysics Data System (ADS)

    Zlotnicki, J.; Pozzi, J. P.; Boudon, G.; Moreau, M. G.

    1984-08-01

    When pyroclastic deposits settle at high temperature in a terrestrial magnetic field they memorize their setting temperature. This temperature varies from one type of deposit to the other, from ambient temperature for some airfall ashes up to hundreds of degrees centigrade for nuées ardentes or pumice flows. These temperatures also vary significantly with distance from the eruptive vent. At old events, it is often very difficult first to establish the nature of the deposit because of crystallizations or cements created by diagenesis, and then to locate the eroded eruptive centers. The exact assessment of the setting temperature allows one, on the one hand, to find both the nature and the emplacement process of the deposit and, on the other hand, to find the location of the eruptive centers, by working out a temperature map. The methods used up to now are all based on the analysis of objects buried in the flow, or on that of the surrounding rocks. Where burnt wood or heated objects are concerned, this analysis may be chemical or based on fossil thermoremanent magnetization in the case of potteries or rocks. Such objects are not always to be found, so the method proposed here uses samples drawn from the deposit itself. The principle, derived from Thellier's method, compares the natural magnetization lost during heating to the loss of total thermoremanent magnetization acquired during cooling in a known field. This method essentially differs from that of Thellier by a direct reading of the magnetization left at any high temperature. This process, which requires only two heatings, enables one to avoid any difficulty linked to magnetic interactions and to lessen the effect of mineralogical transformations.

  18. Noninvasive molecular methods to identify live scarab larvae: an example of sympatric pest and nonpest species in New Zealand.

    PubMed

    Lefort, M-C; Boyer, S; Worner, S P; Armstrong, K

    2012-05-01

    Despite the negative impact that many scarab larvae have on agro-ecosystems, very little attention has been paid to their taxonomy. Their often extremely similar morphological characteristics have probably contributed to this impediment, which has also meant that they are very difficult to identify in the field. Molecular methods can overcome this challenge and are particularly useful for the identification of larvae to enable management of pest species occurring sympatrically with nonpest species. However, the invasive collection of DNA samples for such molecular methods is not compatible with subsequent behavioural, developmental or fitness studies. Two noninvasive DNA sampling and DNA analysis methods suitable for the identification of larvae from closely related scarab species were developed here. Using the frass and larval exuviae as sources of DNA, field-collected larvae of Costelytra zealandica (White) and Costelytra brunneum (Broun) (Scarabaeidae: Melolonthinae) were identified by multiplex PCR based on the difference in size of the resulting PCR products. This study also showed that small quantities of frass can be used reliably even 7 days after excretion. This stability of the DNA is of major importance in ecological studies where timeframes rarely allow daily monitoring. The approach developed here is readily transferable to the study of any holometabolous insect species for which morphological identification of larval stages is difficult. PMID:22189059

  19. Switching industrial production processes from complex to defined media: method development and case study using the example of Penicillium chrysogenum

    PubMed Central

    2012-01-01

    Background Filamentous fungi are versatile cell factories and widely used for the production of antibiotics, organic acids, enzymes and other industrially relevant compounds at large scale. As a fact, industrial production processes employing filamentous fungi are commonly based on complex raw materials. However, considerable lot-to-lot variability of complex media ingredients not only demands for exhaustive incoming components inspection and quality control, but unavoidably affects process stability and performance. Thus, switching bioprocesses from complex to defined media is highly desirable. Results This study presents a strategy for strain characterization of filamentous fungi on partly complex media using redundant mass balancing techniques. Applying the suggested method, interdependencies between specific biomass and side-product formation rates, production of fructooligosaccharides, specific complex media component uptake rates and fungal strains were revealed. A 2-fold increase of the overall penicillin space time yield and a 3-fold increase in the maximum specific penicillin formation rate were reached in defined media compared to complex media. Conclusions The newly developed methodology enabled fast characterization of two different industrial Penicillium chrysogenum candidate strains on complex media based on specific complex media component uptake kinetics and identification of the most promising strain for switching the process from complex to defined conditions. Characterization at different complex/defined media ratios using only a limited number of analytical methods allowed maximizing the overall industrial objectives of increasing both, method throughput and the generation of scientific process understanding. PMID:22727013

  20. An example of an application of the semiotic inspection method in the domain of computerized patient record system.

    PubMed

    Tancredi, Weronika; Torgersson, Olof

    2013-01-01

    Efficiently navigating through an interface and conducting work tasks in flow is what GUI designers strive for. Dental professionals, who alternate between examination and treatment of a patient and insertion of data into the Computerized Patient Record system, particularly need an interface that would facilitate the workflow. In this paper we present an inspection evaluation of an existing and widely used Computerized Patient Record system. The Semiotic Inspection Method was applied with the expectation that the method could provide evidence that task flow, navigation and wayfinding were major usability issues of the interface. Also expected was that the Semiotic Inspection would reveal the means and strategies used in the interface in order to communicate the flow. The analysis conducted using the Semiotic Inspection Method showed inconsistencies in the communication of the way forward through the interface. In addition, the profile of the users, regarding digital skills, appears to be ambiguous. Finally, the strategies used in the interface for conveying the workflow could be identified as well. PMID:23920599

  1. Reconstructing former urban environments by combining geophysical electrical methods and geotechnical investigations—an example from Chania, Greece

    NASA Astrophysics Data System (ADS)

    Soupios, P. M.; Loupasakis, C.; Vallianatos, F.

    2008-06-01

    Nowadays, geophysical prospecting is implemented in order to resolve a diversity of geological, hydrogeological, environmental and geotechnical problems. Although plenty of applications and a lot of research have been conducted in the countryside, only a few cases have been reported in the literature concerning urban areas, mainly due to high levels of noise present that aggravate most of the geophysical methods or due to spatial limitations that hinder normal method implementation. Among all geophysical methods, electrical resistivity tomography has proven to be a rapid technique and the most robust with regard to urban noise. This work presents a case study in the urban area of Chania (Crete Island, Greece), where electrical resistivity tomography (ERT) has been applied for the detection and identification of possible buried ancient ruins or other man-made structures, prior to the construction of a building. The results of the detailed geophysical survey indicated eight areas of interest providing resistivity anomalies. Those anomalies were analysed and interpreted combining the resistivity readings with the geotechnical borehole data and the historical bibliographic reports—referring to the 1940s (Xalkiadakis 1997 Industrial Archaeology in Chania Territory pp 51-62). The collected ERT-data were processed by applying advanced algorithms in order to obtain a 3D-model of the study area that depicts the interesting subsurface structures more clearly and accurately.

  2. Method of Determining the Filtration Properties of oil-Bearing Crops in the Process of Their Pressing by the Example of Rape-oil Extrusion

    NASA Astrophysics Data System (ADS)

    Slavnov, E. V.; Petrov, I. A.

    2014-07-01

    A method of determining the change in the fi ltration properties of oil-bearing crops in the process of their pressing by repeated dynamic loading is proposed. The use of this method is demonstrated by the example of rape-oil extrusion. It was established that the change in the mass concentration of the oil in a rape mix from 0.45 to 0.23 leads to a decrease in the permeability of the mix by 101.5-102 times depending on the pressure applied to it. It is shown that the dependence of the permeability of this mix on the pressure applied to it is nonmonotone in character.

  3. Insights into accelerated liposomal release of topotecan in plasma monitored by a non-invasive fluorescence spectroscopic method

    PubMed Central

    Fugit, Kyle D.; Jyoti, Amar; Upreti, Meenakshi; Anderson, Bradley D.

    2014-01-01

    A non-invasive fluorescence method was developed to monitor liposomal release kinetics of the anticancer agent topotecan (TPT) in physiological fluids and subsequently used to explore the cause of accelerated release in plasma. Analyses of fluorescence excitation spectra confirmed that unencapsulated TPT exhibits a red shift in its spectrum as pH is increased. This property was used to monitor TPT release from actively loaded liposomal formulations having a low intravesicular pH. Mathematical release models were developed to extract reliable rate constants for TPT release in aqueous solutions monitored by fluorescence and release kinetics obtained by HPLC. Using the fluorescence method, accelerated TPT release was observed in plasma as previously reported in the literature. Simulations to estimate the intravesicular pH were conducted to demonstrate that accelerated release correlated with alterations in the low intravesicular pH. This was attributed to the presence of ammonia in plasma samples rather than proteins and other plasma components generally believed to alter release kinetics in physiological samples. These findings shed light on the critical role that ammonia may play in contributing to the preclinical/clinical variability and performance seen with actively-loaded liposomal formulations of TPT and other weakly-basic anticancer agents. PMID:25456833

  4. Nuclear magnetic resonance, vibrational spectroscopic studies, physico-chemical properties and computational calculations on (nitrophenyl) octahydroquinolindiones by DFT method.

    PubMed

    Pasha, M A; Siddekha, Aisha; Mishra, Soni; Azzam, Sadeq Hamood Saleh; Umapathy, S

    2015-02-01

    In the present study, 2'-nitrophenyloctahydroquinolinedione and its 3'-nitrophenyl isomer were synthesized and characterized by FT-IR, FT-Raman, (1)H NMR and (13)C NMR spectroscopy. The molecular geometry, vibrational frequencies, (1)H and (13)C NMR chemical shift values of the synthesized compounds in the ground state have been calculated by using the density functional theory (DFT) method with the 6-311++G (d,p) basis set and compared with the experimental data. The complete vibrational assignments of wave numbers were made on the basis of potential energy distribution using GAR2PED programme. Isotropic chemical shifts for (1)H and (13)C NMR were calculated using gauge-invariant atomic orbital (GIAO) method. The experimental vibrational frequencies, (1)H and (13)C NMR chemical shift values were found to be in good agreement with the theoretical values. On the basis of vibrational analysis, molecular electrostatic potential and the standard thermodynamic functions have been investigated. PMID:25440584

  5. Visualization techniques (colposcopy, direct visual inspection, and spectroscopic and other visual methods). Summary of task force 7.

    PubMed

    Wright, Thomas C; Menton, Michael; Myrtle, James F; Chow, Carl; Singer, Albert

    2002-01-01

    Visual screening techniques include both low-technology approaches, such as direct visual inspection (DVI), and high-technology approaches, such as those that utilize electrooptical detectors to identify cervical cancer precursors and invasive cervical cancer. Simple visual screening techniques, such as DVI, consist of washing the cervix with a solution of 5% acetic acid (e.g., vinegar) and then inspecting it using either the naked eye or with a low-power magnifying device to identify areas of acetowhitening, which frequently correspond to cervical squamous intraepithelial lesions (SILs). The simple visual screening methods are being evaluated as an alternative to cytology in low-resource settings where screening using cervical cytology is not feasible. Multiple studies have shown DVI to have sensitivity similar to that of cervical cytology for identifying women with high grade SIL but much lower specificity. The novel high-technology visual screening methods that utilize electrooptical sensors to identify cervical abnormalities are still in the developmental phases but offer considerable potential. PMID:12365209

  6. Nitranilic acid hexahydrate, a novel benchmark system of the Zundel cation in an intrinsically asymmetric environment: spectroscopic features and hydrogen bond dynamics characterised by experimental and theoretical methods.

    PubMed

    Molčanov, Krešimir; Stare, Jernej; Vener, Mikhail V; Kojić-Prodić, Biserka; Mali, Gregor; Grdadolnik, Jože; Mohaček-Grošev, Vlasta

    2014-01-21

    Nitranilic acid (2,5-dihydroxy-3,6-dinitro-2,5-cyclohexadiene-1,4-dione) as a strong dibasic acid in acidic aqueous media creates the Zundel cation, H5O2(+). The structural unit in a crystal comprises (H5O2)2(+) (2,5-dihydroxy-3,6-dinitro-1,4-benzoquinonate)(2-) dihydrate where the Zundel cation reveals no symmetry, being an ideal case for studying proton dynamics and its stability. The Zundel cation and proton transfer dynamics are studied by variable-temperature X-ray diffraction, IR and solid-state NMR spectroscopy, and various quantum chemical methods, including periodic DFT calculations, ab initio molecular dynamics simulation, and quantization of nuclear motion along three fully coupled internal coordinates. The Zundel cation features a short H-bond with the O···O distance of 2.433(2) Å with an asymmetric placement of hydrogen. The proton potential is of a single well type and, due to the non-symmetric surroundings, of asymmetric shape. The formation of the Zundel cation is facilitated by the electronegative NO2 groups. The employed spectroscopic techniques supported by calculations confirm the presence of a short H-bond with a complex proton dynamics. PMID:24281720

  7. Thermally induced rearrangement of hydrogen-bonded helices in solid 4-isopropylphenol as studied by calorimetric, proton NMR, dielectric and near IR spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Wójcik, G.; Szostak, M. M.; Misiaszek, T.; Pająk, Z.; Wąsicki, J.; Kołodziej, H. A.; Freundlich, P.

    1999-11-01

    Calorimetric, dielectric and Fourier transform near infrared (IR) spectroscopic methods were used to study molecular dynamics and structural transition in solid 4-isopropylphenol (4IP) above room temperature. Pulse proton nuclear magnetic resonance (NMR) measurements were performed in the 100-340 K temperature range. A phase transition was found at 331.5 K, 1.5 K below the melting point. Energetically inequivalent methyl groups reorientations were observed in differently prepared samples and this suggested that a high-temperature polymorph occurs below the transition point as a metastable phase. Dielectric relaxation measurements showed an electric conductivity similar in value to that in water. This was detected as a pronounced contribution to the imaginary part of dielectric permittivity at temperatures higher than 310 K. Near IR spectra revealed that hydrogen bondings are stronger in the high-temperature phase than in the room-temperature-stable one. We propose that thermally induced molecular rearrangements enable proton transfer in hydrogen bonds (HBs) and this stimulates protonic conduction.

  8. A mass spectroscopic method for analysis of AHH-inducing and other polychlorinated biphenyl congeners and selected pesticides in fish

    USGS Publications Warehouse

    Schmidt, Larry J.; Hesselberg, Robert J.

    1992-01-01

    The 209 polychlorinated biphenyl (PCB) congeners exhibit a wide range in toxicity to fish, birds, and mammals. This paper discusses the use of gas chromatography/mass spectrometry negative chemical ionization (GC/MS-NCI) to quantify congeners of highly suspected toxicity such as IUPAC #77 (3,3',4,4'-tetrachlorobiphenyl) and #126 (3,3',4,4',5-pentachlorobiphenyl). GC/MS analysis time needed to produce the necessary resolution was reduced to 1 h per sample or standard, allowing an autosampler to inject 12 samples in 24 hours, plus 12 standards/QC samples. Identification and quantification of some 60+ congeners and several selected pesticides and estimation of total PCBs are also possible within the 1 h analysis. For congeners of high chlorination (penta through octa), the method exhibited excellent sensitivity, such that we could not locate a fish which exhibited PCB levels below our calibrated quantitation range. NCI was not as sensitive for mono through tri and for some tetrachlorinated PCB congeners, an exception being PCB #77, for which sensitivity was of the same order as for the more highly chlorinated biphenyls. Long term stability was excellent. Over a 6-mo period, results of replicate analyses for PCB congeners and pesticides in a composited sample of lake trout (Salvelinus namaycush) from Lake Michigan had a relative standard deviation of 12% of the mean. Over the same time period, mean recoveries for samples spiked at concentrations similar to those in Lake Michigan lake trout were 90-102%. Response was linear over a wide range of concentrations for each of the analyzed compounds. This method is now being used for routine analysis of PCB congeners and selected pesticides in our laboratory.

  9. An Efficient Method of Modeling Material Properties Using a Thermal Diffusion Analogy: An Example Based on Craniofacial Bone

    PubMed Central

    Davis, Julian L.; Dumont, Elizabeth R.; Strait, David S.; Grosse, Ian R.

    2011-01-01

    The ability to incorporate detailed geometry into finite element models has allowed researchers to investigate the influence of morphology on performance aspects of skeletal components. This advance has also allowed researchers to explore the effect of different material models, ranging from simple (e.g., isotropic) to complex (e.g., orthotropic), on the response of bone. However, bone's complicated geometry makes it difficult to incorporate complex material models into finite element models of bone. This difficulty is due to variation in the spatial orientation of material properties throughout bone. Our analysis addresses this problem by taking full advantage of a finite element program's ability to solve thermal-structural problems. Using a linear relationship between temperature and modulus, we seeded specific nodes of the finite element model with temperatures. We then used thermal diffusion to propagate the modulus throughout the finite element model. Finally, we solved for the mechanical response of the finite element model to the applied loads and constraints. We found that using the thermal diffusion analogy to control the modulus of bone throughout its structure provides a simple and effective method of spatially varying modulus. Results compare favorably against both experimental data and results from an FE model that incorporated a complex (orthotropic) material model. This method presented will allow researchers the ability to easily incorporate more material property data into their finite element models in an effort to improve the model's accuracy. PMID:21347288

  10. A method for improving predictive modeling by taking into account lag time: Example of selenium bioaccumulation in a flowing system.

    PubMed

    Beckon, William N

    2016-07-01

    For bioaccumulative substances, efforts to predict concentrations in organisms at upper trophic levels, based on measurements of environmental exposure, have been confounded by the appreciable but hitherto unknown amount of time it may take for bioaccumulation to occur through various pathways and across several trophic transfers. The study summarized here demonstrates an objective method of estimating this lag time by testing a large array of potential lag times for selenium bioaccumulation, selecting the lag that provides the best regression between environmental exposure (concentration in ambient water) and concentration in the tissue of the target organism. Bioaccumulation lag is generally greater for organisms at higher trophic levels, reaching times of more than a year in piscivorous fish. Predictive modeling of bioaccumulation is improved appreciably by taking into account this lag. More generally, the method demonstrated here may improve the accuracy of predictive modeling in a wide variety of other cause-effect relationships in which lag time is substantial but inadequately known, in disciplines as diverse as climatology (e.g., the effect of greenhouse gases on sea levels) and economics (e.g., the effects of fiscal stimulus on employment). PMID:27149556

  11. Methodical questions and accuracy problems of GPS observations by the example of the geodynamic proving ground in Bishkek

    NASA Astrophysics Data System (ADS)

    Kuzikov, S. I.

    2014-11-01

    The key questions concerning the modern methodical tasks and accuracy of GPS measurements of crustal motion spanning are discussed for a full cycle of the survey from the organization of the field operations to the interpretation of the final results. The presented data rely on the 20-year experience of the geophysicists of the Research Station of the Russian Academy of Sciences in Bishkek (RS RAS) in GPS monitoring at the Geodynamic Proving Ground in Bishkek (GPGB) and in a large part of Central Asia. The comparative characteristics of the constellations of visible GPS and GLONASS satellites are analyzed from the standpoint of their practical application for precise scientific observations of crustal motions. The studies of the contemporary movements of the Earth's crust by the methods of satellite geodesy generally comprise three stages: (1) organization of the measurement networks and acquisition of the data; (2) data processing; and (3) interpretation of the results. Each stage is associated with its own block of the tasks and problems, and neither is guaranteed against uncertainties and errors which may affect the results, conclusions, and reconstructions.

  12. A target enrichment method for gathering phylogenetic information from hundreds of loci: An example from the Compositae1

    PubMed Central

    Mandel, Jennifer R.; Dikow, Rebecca B.; Funk, Vicki A.; Masalia, Rishi R.; Staton, S. Evan; Kozik, Alex; Michelmore, Richard W.; Rieseberg, Loren H.; Burke, John M.

    2014-01-01

    • Premise of the study: The Compositae (Asteraceae) are a large and diverse family of plants, and the most comprehensive phylogeny to date is a meta-tree based on 10 chloroplast loci that has several major unresolved nodes. We describe the development of an approach that enables the rapid sequencing of large numbers of orthologous nuclear loci to facilitate efficient phylogenomic analyses. • Methods and Results: We designed a set of sequence capture probes that target conserved orthologous sequences in the Compositae. We also developed a bioinformatic and phylogenetic workflow for processing and analyzing the resulting data. Application of our approach to 15 species from across the Compositae resulted in the production of phylogenetically informative sequence data from 763 loci and the successful reconstruction of known phylogenetic relationships across the family. • Conclusions: These methods should be of great use to members of the broader Compositae community, and the general approach should also be of use to researchers studying other families. PMID:25202605

  13. Novel Method To Identify the Optimal Antimicrobial Peptide in a Combination Matrix, Using Anoplin as an Example

    PubMed Central

    Ritz, C.; Fliedner, F. P.; Frimodt-Møller, N.

    2014-01-01

    Microbial resistance is an increasing health concern and a true danger to human well-being. A worldwide search for new compounds is ongoing, and antimicrobial peptides are promising lead candidates for tomorrow's antibiotics. The decapeptide anoplin (GLLKRIKTLL-NH2) is an especially interesting candidate because of its small size as well as its antimicrobial and nonhemolytic properties. Optimization of the properties of an antimicrobial peptide such as anoplin requires multidimensional searching in a complex chemical space. Typically, such optimization is performed by labor-intensive and costly trial-and-error methods. In this study, we show the benefit of fractional factorial design for identification of the optimal antimicrobial peptide in a combination matrix. We synthesized and analyzed a training set of 12 anoplin analogs, representative of 64 analogs in total. Using MIC, hemolysis, and high-performance liquid chromatography retention time data, we constructed analysis-of-variance models that describe the relationship between these properties and the structural characteristics of the analogs. We show that the mathematical models derived from the training set data can be used to predict the properties of other analogs in the chemical space. Hence, this method provides an efficient means of identification of the optimal peptide in the searched chemical space. PMID:24277042

  14. An exploratory method to detect tephras from quantitative XRD scans: Examples from Iceland and east Greenland marine sediments

    USGS Publications Warehouse

    Andrews, John T.; Eberl, D.D.; Kristjansdottir, G.B.

    2006-01-01

    Tephras, mainly from Iceland, are becoming increasingly important in interpreting leads and lags in the Holocene climate system across NW Europe. Here we demonstrate that Quantitative Phase Analysis of x-ray diffractograms of the 150 um fraction and identify these same peaks in XRD scans - two of these correlate geochemically and chronologically with Hekla 1104 and 3. At a distal site to the WNW of Iceland, on the East Greenland margin (core MD99-2317), the weight% of volcanic glass reaches values of 11% at about the time of the Saksunarvatn tephra. The XRD method identifies the presence of volcanic glass but not its elemental composition; hence it will assist in focusing attention on specific sections of sediment cores for subsequent geochemical fingerprinting of tephras. ?? 2006 SAGE Publications.

  15. Quantitative and qualitative approaches in educational research — problems and examples of controlled understanding through interpretive methods

    NASA Astrophysics Data System (ADS)

    Neumann, Karl

    1987-06-01

    In the methodological discussion of recent years it has become apparent that many research problems, including problems relating to the theory of educational science, cannot be solved by using quantitative methods. The multifaceted aspects of human behaviour and all its environment-bound subtle nuances, especially the process of education or the development of identity, cannot fully be taken into account within a rigid neopositivist approach. In employing the paradigm of symbolic interactionism as a suitable model for the analysis of processes of education and formation, the research has generally to start out from complex reciprocal social interactions instead of unambigious connections of causes. In analysing several particular methodological problems, the article demonstrates some weaknesses of quantitative approaches and then shows the advantages in and the necessity for using qualitative research tools.

  16. A comparison of bivariate statistical model and deterministic model-based landslide susceptibility mapping methods: An example from North Turkey

    NASA Astrophysics Data System (ADS)

    Akgun, Aykut; Erkan, Oguzhan

    2015-04-01

    In Turkey, landslide is one of the most important natural hazards. Due to landslide occurrence, several landforms and man made structures are adversely affected, and may cause many injuries and loss of life. In this context, landslide susceptibility assessment is important task to determine susceptible areas to landslide occurrence. Especially, several dam reservoir areas in Turkey are threated by landslide phenomena. For this reason, in this study, a dam reservoir area located in North Turkey was selected, and investigated in point of landslide susceptibility assessment. A landslide susceptibility assessment for the Kurtun dam reservoir area (Gumushane, North Turkey) was carried out by geographical information systems (GIS)-based statistical and deterministic models. For this purpose, frequency ratio (FR) and stability index mapping (SINMAP) methodologies were applied. In this context, eight conditioning parameters such as altitude, lithology, slope gradient, slope aspect, distance to drainage, distance to lineament, stream power index (SPI) and topographical wetness index (TWI) were considered. After assessment of these parameters by FR and SINMAP methods in a GIS environment, two landslide susceptibility maps were obtained. Then, the maps obtained were analyzed for verification purpose. For this purpose, area under curvature (AUC) approach was used. At the end of this process, the AUC values of 0.73 and 0.70 were found for FR and SINMAP methods, respectively. Additionally, the SINMAP statistical results showed that the 93.8% of the observed landslides in the area falls into the lower and upper threshold showing the stability index classes. These values indicate that the accuracies of landslide susceptibility maps are acceptable, and the maps are feasible for further natural hazard management affairs in the area.

  17. Investigation of trypsin-CdSe quantum dot interactions via spectroscopic methods and effects on enzymatic activity

    NASA Astrophysics Data System (ADS)

    Kaur, Gurvir; Tripathi, S. K.

    2015-01-01

    The paper presents the interactions between trypsin and water soluble cadmium selenide (CdSe) quantum dots investigated by spectrophotometric methods. CdSe quantum dots have strong ability to quench the intrinsic fluorescence of trypsin by a static quenching mechanism. The quenching has been studied at three different temperatures where the results revealed that electrostatic interactions exist between CdSe quantum dots and trypsin and are responsible to stabilize the complex. The Scatchard plot from quenching revealed 1 binding site for quantum dots by trypsin, the same has been confirmed by making isothermal titrations of quantum dots against trypsin. The distance between donor and acceptor for trypsin-CdSe quantum dot complexes is calculated to be 2.8 nm by energy transfer mechanisms. The intrinsic fluorescence of CdSe quantum dots has also been enhanced by the trypsin, and is linear for concentration of trypsin ranging 1-80 μl. All the observations evidence the formation of trypsin-CdSe quantum dot conjugates, where trypsin retains the enzymatic activity which in turn is temperature and pH dependent.

  18. Spectroscopic investigations on the photodegradation of toluidine blue dye using cadmium sulphide nanoparticles prepared by a novel method

    NASA Astrophysics Data System (ADS)

    Neelakandeswari, N.; Sangami, G.; Dharmaraj, N.; Taek, Nam Ki; Kim, Hak Yong

    2011-05-01

    A novel method to prepare cadmium sulphide nanoparticles (CdS NPs) possessing nearly uniform size was adopted using eggshell membrane (ESM), under different pH conditions. Significant yield of CdS NPs with smallest possible size was obtained by increasing the pH of the reaction medium from acidic to alkaline. The above prepared CdS NPs have been characterized by UV-vis absorption as well as emission spectra, powder X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The efficiency of the above prepared CdS NPs as a catalyst for the photodegradation of toluidine blue (TB) dye, as a function of pH as well as the ratio between the catalyst and the substrate was studied after irradiation with UV light. The results showed that an efficient interaction took place between the catalyst and the substrate to cause degradation of the selected dye. A maximum degradation of toluidine blue dye (90%) was observed at pH 8 which is higher than that of the efficiencies at pH 4 and pH 6.

  19. Spectroscopic investigations on the synthesis of nano-hydroxyapatite from calcined eggshell by hydrothermal method using cationic surfactant as template

    NASA Astrophysics Data System (ADS)

    Prabakaran, K.; Rajeswari, S.

    2009-12-01

    The present work reports the successful synthesis of nano-hydroxyapatite, Ca 10(PO 4) 6(OH) 2 (denoted HAP) from calcined eggshell by hydrothermal method using cationic surfactant (CTAB) as regulator of nucleation and crystal growth. The reaction involved in the synthesis was studied elaborately. The influence of reaction temperature, ageing time and CTAB concentration on the synthesis of nano-HAP are also studied in addition to the effect of sintering temperature on the crystal growth. Spectral characterization involving Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were performed for functional group analysis and phase identification of the materials, respectively. Thermal stability of nano-HAP was investigated by thermal analysis (TG/DTA). The physical characteristics, such as morphology and particle size of the synthesized nano-HAP were assessed thoroughly by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The results have revealed that well-crystallized nano-HAP was synthesized by hydrothermal treatment at 160 °C for 10 h with the addition of CTAB at critical micelle concentration (CMC). It was also found that the synthesized nano-HAP was thermally stable up to 1100 °C.

  20. Combining microscopy with spectroscopic and chemical methods for tracing the origin of atmospheric fallouts from mining sites.

    PubMed

    Navel, Aline; Uzu, Gaëlle; Spadini, Lorenzo; Sobanska, Sophie; Martins, Jean M F

    2015-12-30

    Populations living close to mining sites are often exposed to important heavy metal concentrations, especially through atmospheric fallouts. Identifying the main sources of metal-rich particles remains a challenge because of the similarity of the particle signatures from the polluted sites. This work provides an original combination of physical and chemical methods to determine the main sources of airborne particles impacting inhabited zones. Raman microspectrometry (RMS), X-ray diffraction (DRX), morphology analyses by microscopy and chemical composition were assessed. Geochemical analysis allowed the identification of target and source areas; XRD and RMS analysis identified the main mineral phases in association with their metal content and speciation. The characterization of the dominant minerals was combined with particle morphology analysis to identify fallout sources. The complete description of dust morphologies permitted the successful determination of a fingerprint of each source site. The analysis of these chemical and morphological fingerprints allowed identification of the mine area as the main contributor of metal-rich particles impacting the inhabited zone. In addition to the identification of the main sources of airborne particles, this study will also permit to better define the extent of polluted zones requiring remediation or protection from eolian erosion inducing metal-rich atmospheric fallouts. PMID:26253233

  1. Spectroscopic analysis of phase constitution of high quality VO2 thin film prepared by facile sol-gel method

    NASA Astrophysics Data System (ADS)

    Wu, Y. F.; Fan, L. L.; Chen, S. M.; Chen, S.; Zou, C. W.; Wu, Z. Y.

    2013-04-01

    VO2 thin films with large-area were prepared on Al2O3 substrates by a simple sol-gel method. After an annealing treatment under low vacuum condition, all the VO2 films showed a preferred growth direction and exhibited excellent semiconductor-metal transition (SMT) characteristics. The structure and electrical properties of the obtained VO2 films were investigated systematically. Raman spectra, X-ray diffraction and X-ray absorption spectra measurements pointed out that the VO2 film on Al_2 O_3 ( {10overline 1 0}) substrate showed a M1 phase instead of M2 phase as reported in previous studies. Based on the experiment results, it was suggested that the strained structure of oriented VO2 films could be a mechanism for the formation of the intermediate M2 phase, whereas it is difficult to access the pure M2 phase of undoped VO2 films. VO2 film on Al_2 O_3 ( {10overline 1 0} ) substrate showed a lower SMT temperature compared to VO2 film on Al2O3 (0001), which can be mostly attributed to the differences of both lattice mismatch and thermal stress. The present results confirm and make clear the relevance of the substrate orientation in the growth of VO2 film and their different contributions to the SMT characteristics in vanadate systems.

  2. A Formal Method for Identifying Distinct States of Variability in Time-varying Sources: Sgr A* as an Example

    NASA Astrophysics Data System (ADS)

    Meyer, L.; Witzel, G.; Longstaff, F. A.; Ghez, A. M.

    2014-08-01

    Continuously time variable sources are often characterized by their power spectral density and flux distribution. These quantities can undergo dramatic changes over time if the underlying physical processes change. However, some changes can be subtle and not distinguishable using standard statistical approaches. Here, we report a methodology that aims to identify distinct but similar states of time variability. We apply this method to the Galactic supermassive black hole, where 2.2 μm flux is observed from a source associated with Sgr A* and where two distinct states have recently been suggested. Our approach is taken from mathematical finance and works with conditional flux density distributions that depend on the previous flux value. The discrete, unobserved (hidden) state variable is modeled as a stochastic process and the transition probabilities are inferred from the flux density time series. Using the most comprehensive data set to date, in which all Keck and a majority of the publicly available Very Large Telescope data have been merged, we show that Sgr A* is sufficiently described by a single intrinsic state. However, the observed flux densities exhibit two states: noise dominated and source dominated. Our methodology reported here will prove extremely useful to assess the effects of the putative gas cloud G2 that is on its way toward the black hole and might create a new state of variability.

  3. A formal method for identifying distinct states of variability in time-varying sources: SGR A* as an example

    SciTech Connect

    Meyer, L.; Witzel, G.; Ghez, A. M.; Longstaff, F. A.

    2014-08-10

    Continuously time variable sources are often characterized by their power spectral density and flux distribution. These quantities can undergo dramatic changes over time if the underlying physical processes change. However, some changes can be subtle and not distinguishable using standard statistical approaches. Here, we report a methodology that aims to identify distinct but similar states of time variability. We apply this method to the Galactic supermassive black hole, where 2.2 μm flux is observed from a source associated with Sgr A* and where two distinct states have recently been suggested. Our approach is taken from mathematical finance and works with conditional flux density distributions that depend on the previous flux value. The discrete, unobserved (hidden) state variable is modeled as a stochastic process and the transition probabilities are inferred from the flux density time series. Using the most comprehensive data set to date, in which all Keck and a majority of the publicly available Very Large Telescope data have been merged, we show that Sgr A* is sufficiently described by a single intrinsic state. However, the observed flux densities exhibit two states: noise dominated and source dominated. Our methodology reported here will prove extremely useful to assess the effects of the putative gas cloud G2 that is on its way toward the black hole and might create a new state of variability.

  4. Methods and approaches to support Indigenous water planning: An example from the Tiwi Islands, Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Hoverman, Suzanne; Ayre, Margaret

    2012-12-01

    SummaryIndigenous land owners of the Tiwi Islands, Northern Territory Australia have begun the first formal freshwater allocation planning process in Australia entirely within Indigenous lands and waterways. The process is managed by the Northern Territory government agency responsible for water planning, the Department of Natural Resources, Environment, The Arts and Sport, in partnership with the Tiwi Land Council, the principal representative body for Tiwi Islanders on matters of land and water management and governance. Participatory planning methods ('tools') were developed to facilitate community participation in Tiwi water planning. The tools, selected for their potential to generate involvement in the planning process needed both to incorporate Indigenous knowledge of water use and management and raise awareness in the Indigenous community of Western science and water resources management. In consultation with the water planner and Tiwi Land Council officers, the researchers selected four main tools to develop, trial and evaluate. Results demonstrate that the tools provided mechanisms which acknowledge traditional management systems, improve community engagement, and build confidence in the water planning process. The researchers found that participatory planning approaches supported Tiwi natural resource management institutions both in determining appropriate institutional arrangements and clarifying roles and responsibilities in the Islands' Water Management Strategy.

  5. [Thoughts and methods of study on acupuncture medical history: an example of Mr. MA Ji-Xing].

    PubMed

    Yang, Feng; Zhu, Ling

    2014-03-01

    Mr. MA Ji-xing has devoted himself into the study of acupuncture medical history for more than 70 years. As a result, a great work of Zhenjiuxue Tongshi (see text), History of Acupuncture-Moxibustion) has been completed. The author has expensively studied for history of acupuncture medicine in time and space. Base on abundant historical materials, deliberate textual research as well as strategically situated academic view, it is considered as a masterpiece of acupuncture on real significance. It is worthwhile to note that the book has a systematic and profound explanation on Bian-stone therapy, unearthed literature relics of acupuncture, the bronze figure or illustration of acupoint as well as special topics of Japan and Korea acupuncture history. Filled several gaps of the field, and explored some significant new paths of study, it laid the groundwork for the profound study and unscramble of traditional acupuncture theory as well as the investigation of the academic history, which is considered to have a profound and persistent influence. The careful sorting and profound digging of many distinguish thoughts and methods of Mr. MA Ji-xing in the study of acupuncture medical history has significant meaning in references and enlightenment of the future research on acupuncture medical history. PMID:24843982

  6. Thermodynamic evaluation and restoration of volcanic gas analyses: an example based on modern collection and analytical methods

    USGS Publications Warehouse

    Gerlach, T.M.

    1993-01-01

    Thermodynamic evaluation and restoration procedures are applied to a set of 10 volcanic gas analyses obtained by modern collection and analytical methods. The samples were collected from a vigorously fuming fissure during episode 1 of the Puu Oo eruption of Kilauea Volcano in 1983. A variety of analytical techniques were used to determine the gas compositions. In most samples, the combined amounts of N2 + Ar + O2 are far less abundant than H2, CO, or H2S, suggesting little or no contamination or reaction with atmospheric gases. Thermodynamic evaluation shows that 6 of the 10 analyses are equilibrium compositions, and 4 analyses are disequilibrium compositions. Three of the disequilibrium analyses involve samples affected by minor spilling of NaOH solution from the sample bottles during collection. The deviation of these analyses from equilibrium is dominated by the effects of disequilibrium water-loss. The fourth disequilibrium analysis is contaminated with meteoric water. In all 4 cases, the restoration procedures retrieve the original equilibrium compositions. -from Author

  7. Enhancement of Electron Spin Echo Envelope Modulation Spectroscopic Methods to Investigate the Secondary Structure of Membrane Proteins

    PubMed Central

    Liu, Lishan; Sahu, Indra D.; Mayo, Daniel J.; McCarrick, Robert M.; Troxel, Kaylee; Zhou, Andy; Shockley, Erin; Lorigan, Gary A.

    2012-01-01

    This paper reports on a significant improvement of a new structural biology approach designed to probe the secondary structure of membrane proteins using the pulsed EPR technique of Electron Spin Echo Envelope Modulation (ESEEM) spectroscopy. Previously, we showed that we could characterize an α-helical secondary structure with ESEEM spectroscopy using a 2H-labeled Val side chain coupled with site-directed spin-labeling (SDSL). In order to further develop this new approach, molecular dynamic (MD) simulations were conducted on several different hydrophobic residues that are commonly found in membrane proteins. 2H-SL distance distributions from the MD results indicated that 2H-labeled Leu was a very strong candidate to significantly improve this ESEEM approach. In order to test this hypothesis, the secondary structure of the α-helical M2δ peptide of the acetylcholine receptor (AChR) incorporated into a bicelle was investigated with 2H-labeled Leu d10 at position 10 (i) and nitroxide spin labels positioned 1, 2, 3 and 4 residues away (denoted i+1 to i+4) with ESEEM spectroscopy. The ESEEM data reveal a unique pattern that is characteristic of an α-helix (3.6 residues per turn). Strong 2H modulation was detected for the i+3 and i+4 samples, but not for the i+2 sample. The 2H modulation depth observed for 2H-labeled d10 Leu was significantly enhanced (x4) when compared to previous ESEEM measurements that used 2H-labeled d8 Val. Computational studies indicate that deuterium nuclei on the Leu sidechain are closer to the spin label when compared to Val. The enhancement of 2H modulation and the corresponding Fourier Transform (FT) peak intensity for 2H-labeled Leu significantly reduces the ESEEM data acquisition time for Leu when compared to Val. This research demonstrates that a different 2H-labeled amino acid residue can be used as an efficient ESEEM probe further substantiating this important biophysical technique. Finally, this new method can provide pertinent qualitative structural information on membrane proteins in a short time (few minutes) at low sample concentrations (~50 μM). PMID:22908896

  8. Enhancement of electron spin echo envelope modulation spectroscopic methods to investigate the secondary structure of membrane proteins.

    PubMed

    Liu, Lishan; Sahu, Indra D; Mayo, Daniel J; McCarrick, Robert M; Troxel, Kaylee; Zhou, Andy; Shockley, Erin; Lorigan, Gary A

    2012-09-13

    This paper reports on a significant improvement of a new structural biology approach designed to probe the secondary structure of membrane proteins using the pulsed EPR technique of electron spin echo envelope modulation (ESEEM) spectroscopy. Previously, we showed that we could characterize an α-helical secondary structure with ESEEM spectroscopy using a (2)H-labeled Val side chain coupled with site-directed spin-labeling (SDSL). In order to further develop this new approach, molecular dynamic (MD) simulations were conducted on several different hydrophobic residues that are commonly found in membrane proteins. (2)H-SL distance distributions from the MD results indicated that (2)H-labeled Leu was a very strong candidate to significantly improve this ESEEM approach. In order to test this hypothesis, the secondary structure of the α-helical M2δ peptide of the acetylcholine receptor (AChR) incorporated into a bicelle was investigated with (2)H-labeled Leu d(10) at position 10 (i) and nitroxide spin labels positioned 1, 2, 3, and 4 residues away (denoted i+1 to i+4) with ESEEM spectroscopy. The ESEEM data reveal a unique pattern that is characteristic of an α-helix (3.6 residues per turn). Strong (2)H modulation was detected for the i+3 and i+4 samples, but not for the i+2 sample. The (2)H modulation depth observed for (2)H-labeled d(10) Leu was significantly enhanced (×4) when compared to previous ESEEM measurements that used (2)H-labeled d(8) Val. Computational studies indicate that deuterium nuclei on the Leu side chain are closer to the spin label when compared to Val. The enhancement of (2)H modulation and the corresponding Fourier Transform (FT) peak intensity for (2)H-labeled Leu significantly reduces the ESEEM data acquisition time for Leu when compared to Val. This research demonstrates that a different (2)H-labeled amino acid residue can be used as an efficient ESEEM probe further substantiating this important biophysical technique. Finally, this new method can provide pertinent qualitative structural information on membrane proteins in a short time (few minutes) at low sample concentrations (~50 μM). PMID:22908896

  9. [Study of interaction between levofloxacin and human serum albumin by multi-spectroscopic and molecular modeling methods].

    PubMed

    Huang, Fang; Dong, Cheng-Yu; Zhang, Li-Yang; Liu, Ying

    2014-04-01

    Levofloxacin (LVFX) is widely used in clinical treatment due to it has a broad spectrum of in vitro activity against Gram-positive and Gram-negative bacteria. Human serum albumin (HSA) is the most abundant protein in plasma and constitutes approximately half of the protein founds in human blood. And more than 90% of the drugs used in people are bound to HSA. So it is commonly used for the investigation of drug-serum albumin interaction because the binding will significantly influence the absorption, distribution, metabolism excretion, stability and toxicity of the drugs. Therefore, detailed investigating the interaction of LVFX with HSA is very important to understand the pharmacokinetic behavior of the LVFX. In this paper, the interaction of LVFX and HSA has been studied fluorescence, UV, Fourier transform infrared (FT-IR) and molecular modeling method. The results indicated that LVFX induced the intrinsic fluorescence quenching of HSA though a static quenching procedure, and the effective binding constants (K(a)) were calculated to be 9.44 x 10(4) L x mol(-1) (294 K) and 2.74 x 10(4) L x mol(-1) (310 K) by used of the Stern-Volmer equation. According to the Vant's Hoff equation, the reaction was characterized by negative enthalpy (deltaH = -59.00 kJ x mol(-1)) and negative entropy (delta S = - 105.38 J x mol(-1) x K(-1)), indicated that the predominant forces in the LVFX-HSA complex were hydrogen bonding and van der Waals forces. By displacement measurements, the specific binding of LVFX in the vicinity of Site I of HSA was clarified. The binding distance of 3.66 nm between Trp214 and HSA was obtained by the Förster theory on resonance energy transfer. Furthermore, the binding details between LVFX and HSA were further confirmed by molecular docking studies, which were consistent with the experimental results. The alternations of protein secondary structure were calculated from FT-IR spectra. Upon formation of LVFX-HSA complexes, the amount of alpha-helical structures were decrease, but the numbers of beta-sheet structures, beta-turn structures and random structures were increase, respectively. This result indicated that LVFX induced unfolding of the polypeptides of HSA. PMID:25007630

  10. On the recovery of effective elastic thickness using spectral methods: Examples from synthetic data and from the Fennoscandian Shield

    NASA Astrophysics Data System (ADS)

    PéRez-Gussinyé, Marta; Lowry, Anthony R.; Watts, Anthony B.; Velicogna, Isabella

    2004-10-01

    There is considerable controversy regarding the long-term strength of continents (Te). While some authors obtain both low and high Te estimates from the Bouguer coherence and suggest that both crust and mantle contribute to lithospheric strength, others obtain estimates of only <25 km using the free-air admittance and suggest that the mantle is weak. At the root of this controversy is how accurately Te can be recovered from coherence and admittance. We investigate this question by using synthetic topography and gravity anomaly data for which Te is known. We show that the discrepancies stem from comparison of theoretical curves to multitaper power spectral estimates of free-air admittance. We reformulate the admittance method and show that it can recover synthetic Te estimates similar to those recovered using coherence. In light of these results, we estimate Te in Fennoscandia and obtain similar results using both techniques. Te is 20-40 km in the Caledonides, 40-60 km in the Swedish Svecofennides, 40-60 km in the Kola peninsula, and 70-100 km in southern Karelia and Svecofennian central Finland. Independent rheological modeling, using a xenolith-controlled geotherm, predicts similar high Te in central Finland. Because Te exceeds crustal thickness in this area, the mantle must contribute significantly to the total strength. Te in Fennoscandia increases with tectonic age, seismic lithosphere thickness, and decreasing heat flow, and low Te correlates with frequent seismicity. However, in Proterozoic and Archean lithosphere the relationship of Te to age is ambiguous, suggesting that compositional variations may influence the strength of continents.

  11. Method for Finding Metabolic Properties Based on the General Growth Law. Liver Examples. A General Framework for Biological Modeling

    PubMed Central

    Shestopaloff, Yuri K.

    2014-01-01

    We propose a method for finding metabolic parameters of cells, organs and whole organisms, which is based on the earlier discovered general growth law. Based on the obtained results and analysis of available biological models, we propose a general framework for modeling biological phenomena and discuss how it can be used in Virtual Liver Network project. The foundational idea of the study is that growth of cells, organs, systems and whole organisms, besides biomolecular machinery, is influenced by biophysical mechanisms acting at different scale levels. In particular, the general growth law uniquely defines distribution of nutritional resources between maintenance needs and biomass synthesis at each phase of growth and at each scale level. We exemplify the approach considering metabolic properties of growing human and dog livers and liver transplants. A procedure for verification of obtained results has been introduced too. We found that two examined dogs have high metabolic rates consuming about 0.62 and 1 gram of nutrients per cubic centimeter of liver per day, and verified this using the proposed verification procedure. We also evaluated consumption rate of nutrients in human livers, determining it to be about 0.088 gram of nutrients per cubic centimeter of liver per day for males, and about 0.098 for females. This noticeable difference can be explained by evolutionary development, which required females to have greater liver processing capacity to support pregnancy. We also found how much nutrients go to biomass synthesis and maintenance at each phase of liver and liver transplant growth. Obtained results demonstrate that the proposed approach can be used for finding metabolic characteristics of cells, organs, and whole organisms, which can further serve as important inputs and constraints for many applications in biology (such as protein expression), biotechnology (synthesis of substances), and medicine. PMID:24940740

  12. On the recovery of effective elastic thickness using spectral methods: examples from synthetic data and from the Fennoscandian Shield

    NASA Astrophysics Data System (ADS)

    Perez-Gussinye, M.; Lowry, A. R.; Watts, A. B.; Velicogna, I.

    2003-12-01

    The effective elastic thickness, Te, represents the response to long-term loading of the lithosphere; it is thus a useful measure of its strength. However, the use of different methods and assumptions to calculate Te yield different results, leading to controversial interpretations of the relationship of Te to rheology. We investigate the ability of the Bouguer coherence and free air admittance to recover Te assuming that surface and subsurface loads exist. We use synthetic data to show that the estimated Te using both functions is similar; the recovery with admittance is somewhat poorer due to leakage problems. When the underlying Te is constant, the bias and variance of the resulting Te increases with decreasing analysis window size and increasing underlying Te value. When Te varies spatially, Te estimation using sliding, overlapping windows retrieves a structure that approximates the true spatial variability, but window sizes must be chosen carefully. In light of these results, we analyse Te in Fennoscandia using both techniques and obtain similar estimates. Te is 20-40 km in the Caledonides, 40- 60 km in the Swedish Svecofennides, 40-60 km in the Kola peninsula and 70-100 km in southern Karelia and Svecofennian central Finland. These estimates are not biased by unrecovered post-glacial rebound and also potential noise introduced by long-term erosion and sedimentation does not appear to affect Te. An independent estimate of Te using rheological modelling, confirms that Te in central Finland should be high. Because Te exceeds crustal thickness ( ˜ 60 km), the mantle must contribute significant strength to the total. Te is also larger than the seismogenic thickness, thus indicating that they represent different physical behaviours. In general, Te in Fennoscandia increases with tectonic age, seismic lid thickness and decreasing heat flow. Te is low where seismicity is frequent and high where it is reduced. In Proterozoic and Archean lithosphere, the relationship of Te to age breaks down, indicating that compositional effects might be more important for the strength of stable continental lithosphere than tectonothermal age.

  13. USING AN INTENSIVE ASSESSMENT METHOD TO CALIBRATE A RAPID WETLAND ASSESSMENT METHOD: AN EXAMPLE FROM NANTICOKE BASIN, DELAWARE AND MARYLAND, USA

    EPA Science Inventory

    The development of rapid assessment methods has become a priority for many organizations that want to report on the condition of wetlands at larger scales requiring many sampling sites. To have faith in these rapid methods, however, requires that they be verified with more compr...

  14. Development and validation of a laser-induced breakdown spectroscopic method for ultra-trace determination of Cu, Mn, Cd and Pb metals in aqueous droplets after drying.

    PubMed

    Aras, Nadir; Yalçın, Şerife

    2016-03-01

    The present study reports a fast and accurate methodology for laser-induced breakdown spectroscopic, LIBS, analysis of aqueous samples for environmental monitoring purposes. This methodology has two important attributes: one is the use of a 300nm oxide coated silicon wafer substrate (Si+SiO2) for the first time for manual injection of 0.5 microliter aqueous metal solutions, and two is the use of high energy laser pulses focused outside the minimum focus position of a plano convex lens at which relatively large laser beam spot covers the entire droplet area for plasma formation. Optimization of instrumental LIBS parameters like detector delay time, gate width and laser energy has been performed to maximize atomic emission signal of target analytes; Cu, Mn, Cd and Pb. Under the optimal conditions, calibration curves were constructed and enhancements in the LIBS emission signal were obtained compared to the results of similar studies given in the literature. The analytical capability of the LIBS technique in liquid analysis has been improved. Absolute detection limits of 1.3pg Cu, 3.3pg Mn, 79pg Cd and 48pg Pb in 0.5 microliter volume of droplets were obtained from single shot analysis of five sequential droplets. The applicability of the proposed methodology to real water samples was tested on the Certified Reference Material, Trace Metals in Drinking Water, CRM-TMDW and on ICP multi-element standard samples. The accuracy of the method was found at a level of minimum 92% with relative standard deviations of at most 20%. Results suggest that 300nm oxide coated silicon wafer has an excellent potential to be used as a substrate for direct analysis of contaminants in water supplies by LIBS and further research, development and engineering will increase the performance and applicability of the methodology. PMID:26717813

  15. Comparison of one-particle basis set extrapolation to explicitly correlated methods for the calculation of accurate quartic force fields, vibrational frequencies, and spectroscopic constants: application to H2O, N2H+, NO2+, and C2H2.

    PubMed

    Huang, Xinchuan; Valeev, Edward F; Lee, Timothy J

    2010-12-28

    One-particle basis set extrapolation is compared with one of the new R12 methods for computing highly accurate quartic force fields (QFFs) and spectroscopic data, including molecular structures, rotational constants, and vibrational frequencies for the H(2)O, N(2)H(+), NO(2)(+), and C(2)H(2) molecules. In general, agreement between the spectroscopic data computed from the best R12 and basis set extrapolation methods is very good with the exception of a few parameters for N(2)H(+) where it is concluded that basis set extrapolation is still preferred. The differences for H(2)O and NO(2)(+) are small and it is concluded that the QFFs from both approaches are more or less equivalent in accuracy. For C(2)H(2), however, a known one-particle basis set deficiency for C-C multiple bonds significantly degrades the quality of results obtained from basis set extrapolation and in this case the R12 approach is clearly preferred over one-particle basis set extrapolation. The R12 approach used in the present study was modified in order to obtain high precision electronic energies, which are needed when computing a QFF. We also investigated including core-correlation explicitly in the R12 calculations, but conclude that current approaches are lacking. Hence core-correlation is computed as a correction using conventional methods. Considering the results for all four molecules, it is concluded that R12 methods will soon replace basis set extrapolation approaches for high accuracy electronic structure applications such as computing QFFs and spectroscopic data for comparison to high-resolution laboratory or astronomical observations, provided one uses a robust R12 method as we have done here. The specific R12 method used in the present study, CCSD(T)(R12), incorporated a reformulation of one intermediate matrix in order to attain machine precision in the electronic energies. Final QFFs for N(2)H(+) and NO(2)(+) were computed, including basis set extrapolation, core-correlation, scalar relativity, and higher-order correlation and then used to compute highly accurate spectroscopic data for all isotopologues. Agreement with high-resolution experiment for (14)N(2)H(+) and (14)N(2)D(+) was excellent, but for (14)N(16)O(2)(+) agreement for the two stretching fundamentals is outside the expected residual uncertainty in the theoretical values, and it is concluded that there is an error in the experimental quantities. It is hoped that the highly accurate spectroscopic data presented for the minor isotopologues of N(2)H(+) and NO(2)(+) will be useful in the interpretation of future laboratory or astronomical observations. PMID:21197977

  16. Comparison of one-particle basis set extrapolation to explicitly correlated methods for the calculation of accurate quartic force fields, vibrational frequencies, and spectroscopic constants: Application to H2O, N2H+, NO2+, and C2H2

    NASA Astrophysics Data System (ADS)

    Huang, Xinchuan; Valeev, Edward F.; Lee, Timothy J.

    2010-12-01

    One-particle basis set extrapolation is compared with one of the new R12 methods for computing highly accurate quartic force fields (QFFs) and spectroscopic data, including molecular structures, rotational constants, and vibrational frequencies for the H2O, N2H+, NO2+, and C2H2 molecules. In general, agreement between the spectroscopic data computed from the best R12 and basis set extrapolation methods is very good with the exception of a few parameters for N2H+ where it is concluded that basis set extrapolation is still preferred. The differences for H2O and NO2+ are small and it is concluded that the QFFs from both approaches are more or less equivalent in accuracy. For C2H2, however, a known one-particle basis set deficiency for C-C multiple bonds significantly degrades the quality of results obtained from basis set extrapolation and in this case the R12 approach is clearly preferred over one-particle basis set extrapolation. The R12 approach used in the present study was modified in order to obtain high precision electronic energies, which are needed when computing a QFF. We also investigated including core-correlation explicitly in the R12 calculations, but conclude that current approaches are lacking. Hence core-correlation is computed as a correction using conventional methods. Considering the results for all four molecules, it is concluded that R12 methods will soon replace basis set extrapolation approaches for high accuracy electronic structure applications such as computing QFFs and spectroscopic data for comparison to high-resolution laboratory or astronomical observations, provided one uses a robust R12 method as we have done here. The specific R12 method used in the present study, CCSD(T)R12, incorporated a reformulation of one intermediate matrix in order to attain machine precision in the electronic energies. Final QFFs for N2H+ and NO2+ were computed, including basis set extrapolation, core-correlation, scalar relativity, and higher-order correlation and then used to compute highly accurate spectroscopic data for all isotopologues. Agreement with high-resolution experiment for 14N2H+ and 14N2D+ was excellent, but for 14N16O2+ agreement for the two stretching fundamentals is outside the expected residual uncertainty in the theoretical values, and it is concluded that there is an error in the experimental quantities. It is hoped that the highly accurate spectroscopic data presented for the minor isotopologues of N2H+ and NO2+ will be useful in the interpretation of future laboratory or astronomical observations.

  17. Spatially Resolved Chemical Imaging for Biosignature Analysis: Terrestrial and Extraterrestrial Examples

    NASA Astrophysics Data System (ADS)

    Bhartia, R.; Wanger, G.; Orphan, V. J.; Fries, M.; Rowe, A. R.; Nealson, K. H.; Abbey, W. J.; DeFlores, L. P.; Beegle, L. W.

    2014-12-01

    Detection of in situ biosignatures on terrestrial and planetary missions is becoming increasingly more important. Missions that target the Earth's deep biosphere, Mars, moons of Jupiter (including Europa), moons of Saturn (Titan and Enceladus), and small bodies such as asteroids or comets require methods that enable detection of materials for both in-situ analysis that preserve context and as a means to select high priority sample for return to Earth. In situ instrumentation for biosignature detection spans a wide range of analytical and spectroscopic methods that capitalize on amino acid distribution, chirality, lipid composition, isotopic fractionation, or textures that persist in the environment. Many of the existing analytical instruments are bulk analysis methods and while highly sensitive, these require sample acquisition and sample processing. However, by combining with triaging spectroscopic methods, biosignatures can be targeted on a surface and preserve spatial context (including mineralogy, textures, and organic distribution). To provide spatially correlated chemical analysis at multiple spatial scales (meters to microns) we have employed a dual spectroscopic approach that capitalizes on high sensitivity deep UV native fluorescence detection and high specificity deep UV Raman analysis.. Recently selected as a payload on the Mars 2020 mission, SHERLOC incorporates these optical methods for potential biosignatures detection on Mars. We present data from both Earth analogs that operate as our only examples known biosignatures and meteorite samples that provide an example of abiotic organic formation, and demonstrate how provenance effects the spatial distribution and composition of organics.

  18. 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.

  19. Probing the interaction of a new synthesized CdTe quantum dots with human serum albumin and bovine serum albumin by spectroscopic methods.

    PubMed

    Bardajee, Ghasem Rezanejade; Hooshyar, Zari

    2016-05-01

    A novel CdTe quantum dots (QDs) were prepared in aqueous phase via a facile method. At first, poly (acrylic amide) grafted onto sodium alginate (PAAm-g-SA) were successfully synthesized and then TGA capped CdTe QDs (CdTe-TGA QDs) were embed into it. The prepared CdTe-PAAm-g-SA QDs were optimized and characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FT-IR), UV-vis and fluorescence spectroscopy. The characterization results indicated that CdTe-TGA QDs, with particles size of 2.90nm, were uniformly dispersed on the chains of PAAm-g-SA biopolymer. CdTe-PAAm-g-SA QDs also exhibited excellent UV-vis absorption and high fluorescence intensity. To explore biological behavior of CdTe-PAAm-g-SA QDs, the interactions between CdTe-PAAm-g-SA QDs and human serum albumin (HSA) (or bovine serum albumin (BSA)) were investigated by cyclic voltammetry, FT-IR, UV-vis, and fluorescence spectroscopic. The results confirmed the formation of CdTe-PAAm-g-SA QDs-HSA (or BSA) complex with high binding affinities. The thermodynamic parameters (ΔG<0, ΔH<0 and ΔS<0) were indicated that binding reaction was spontaneous and van der Waals interactions and hydrogen-bond interactions played a major role in stabilizing the CdTe-PAAm-g-SA QDs-HSA (or BSA) complexes. The binding distance between CdTe-PAAm-g-SA QDs and HSA (or BSA)) was calculated about 1.37nm and 1.27nm, respectively, according to Forster non-radiative energy transfer theory (FRET). Analyzing FT-IR spectra showed that the formation of QDs-HSA and QDs-BSA complexes led to conformational changes of the HSA and BSA proteins. All these experimental results clarified the effective transportation and elimination of CdTe-PAAm-g-SA QDs in the body by binding to HSA and BSA, which could be a useful guideline for the estimation of QDs as a drug carrier. PMID:26952487

  20. Retrieval of greenhouse gases from space-based spectroscopic measurements with the photon pathlength probability density function method: application to GOSAT observations

    NASA Astrophysics Data System (ADS)

    Oshchepkov, Sergey; Morino, Isamu; Yoshida, Yukio; Yokota, Tatsuya; Bril, Andrey

    The Greenhouse Gases Observing Satellite “IBUKI” (GOSAT) is the world’s first satellite to observe concentrations of carbon dioxide (CO2) and methane (CH4) through the atmosphere. The spacecraft is in orbit since 23rd January, 2009. A large number of high-resolution spectroscopic observational data of reflected sunlight measured with the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) are available from the National Institute for Environmental Studies (NIES). The major source of error in retrieving gas amounts from space-based measurements of reflected sunlight is atmospheric light scattering. Several algorithms have been developed in different groups throughout the world to process the GOSAT data for retrieving global and temporal distributions of the gas amounts. These algorithms mainly differ in how they account for atmospheric light scattering. This presentation describes application of the photon Path length Probability Density Function (PPDF) method to process GOSAT observations from three TANSO-FTS Short-Wavelength InfraRed (SWIR) bands (centered at 0.76 µm, 1.6 µm, and 2.0 µm). The retrieval procedure includes constrained minimization of the residual between the modeled and observed GOSAT spectra. We retrieve the column-averaged dry air mole fractions of the greenhouse gases (XCO2 and XCH4) simultaneously with PPDF parameters from each GOSAT single sounding. PPDF parameters characterize light path shortening and light path lengthening that could take place depending on the amount and location of thin clouds and aerosols as well as depending on surface properties. As a part of validation study, we compared PPDF-based gas retrievals with those derived from FTS ground-based measurements over twelve sites included in the Total Carbon Column Observing Network (TCCON). The sites are located in both the Southern (3 sites) and the Northern (9 sites) Hemispheres. TCCON is a reliable reference source of greenhouse gas measurements due to the direct solar-viewing geometry, which virtually eliminates the impact of atmospheric light scattering on the measurements. Both seasonal trends and pairwise GOSAT-TCCON statistical comparisons have been considered. We also evaluated XCO2 and XCH4 retrievals globally using atmospheric transport model.

  1. Optical remote sensing to quantify fugitive particulate mass emissions from stationary short-term and mobile continuous sources: part I. Method and examples.

    PubMed

    Du, Ke; Rood, Mark J; Welton, Ellsworth J; Varma, Ravi M; Hashmonay, Ram A; Kim, Byung J; Kemme, Michael R

    2011-01-15

    The emissions of particulate matter (PM) from anthropogenic sources raise public concern. A new method is described here that was developed to complete in situ rapid response measurements of PM mass emissions from fugitive dust sources by use of optical remote sensing (ORS) and an anemometer. The ORS system consists of one ground-based micropulse light detection and ranging (MPL) device that was mounted on a positioner, two open path-Fourier transform infrared (OP-FTIR) spectrometers, and two open path-laser transmissometers (OP-LT). An algorithm was formulated to compute PM light extinction profiles along each of the plume's cross sections that were determined with the MPL. Size-specific PM mass emission factors were then calculated by integrating the light extinction profiles with particle mass extinction efficiencies (determined with the OP-FTIRs/OP-LTs) and the wind's speed and direction. This method also quantifies the spatial and temporal variability of the plume's PM mass concentrations across each of the plume's cross sections. Example results from three field studies are also described to demonstrate how this new method is used to determine mass emission factors as well as characterize the dust plumes' horizontal and vertical dimensions and temporal variability of the PM's mass concentration. PMID:21142142

  2. 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.

  3. Spectroscopic full polarimeters using spatial carriers

    NASA Astrophysics Data System (ADS)

    Oka, Kazuhiko; Haga, Yujin; Komaki, Yoshihiko

    2013-09-01

    Several implementations of spectroscopic polarimeters using spatial carriers are presented. The first implementation incorporates two Savart plates and a spectrometer including a two-dimensional CCD to generate a spectrum with spatial carriers. The frequency filtering along the spatial coordinate at each wavelength allows us to conduct the snapshot measurement of the wavelength-resolved Stokes parameters. The spectral resolution of the SOP measurement can be enhanced up to that of the spectrometer. In the second implementation, two achromatic birefringent prism pairs are used to decrease the limitation in the design of the spectroscopic polarimeter. Finally, the present method is combined with a channeled spectroscopic polarization state generator so that the spectroscopic Mueller matrix of a sample can be determined by the snapshot measurement of the two-dimensional spectrum.

  4. Evaluation of Polycyclic Aromatic Hydrocarbons Using Analytical Methods, Toxicology, and Risk Assessment Research: Seafood Safety after a Petroleum Spill as an Example

    PubMed Central

    Overton, Edward; Frickel, Scott; Howard, Jessi; Wilson, Mark; Simon, Bridget; Echsner, Stephen; Nguyen, Daniel; Gauthe, David; Blake, Diane; Miller, Charles; Elferink, Cornelis; Ansari, Shakeel; Fernando, Harshica; Trapido, Edward; Kane, Andrew

    2013-01-01

    Background: Polycyclic aromatic hydrocarbons (PAHs) are abundant and widespread environmental chemicals. They are produced naturally and through man-made processes, and they are common in organic media, including petroleum. Several PAHs are toxic, and a subset exhibit carcinogenic activity. PAHs represent a range of chemical structures based on two or more benzene rings and, depending on their source, can exhibit a variety of side modifications resulting from oxygenation, nitrogenation, and alkylation. Objectives: Here we discuss the increasing ability of contemporary analytical methods to distinguish not only different chemical structures among PAHs but also their concentrations in environmental media. Using seafood contamination following the Deepwater Horizon accident as an example, we identify issues that are emerging in the PAH risk assessment process because of increasing analytical sensitivity for individual PAHs, and we describe the paucity of toxicological literature for many of these compounds. Discussion: PAHs, including the large variety of chemically modified or substituted PAHs, are naturally occurring and may constitute health risks if human populations are exposed to hazardous levels. However, toxicity evaluations have not kept pace with modern analytic methods and their increased ability to detect substituted PAHs. Therefore, although it is possible to measure these compounds in seafood and other media, we do not have sufficient information on the potential toxicity of these compounds to incorporate them into human health risk assessments and characterizations. Conclusions: Future research efforts should strategically attempt to fill this toxicological knowledge gap so human health risk assessments of PAHs in environmental media or food can be better determined. This is especially important in the aftermath of petroleum spills. Citation: Wickliffe J, Overton E, Frickel S, Howard J, Wilson M, Simon B, Echsner S, Nguyen D, Gauthe D, Blake D, Miller C, Elferink C, Ansari S, Fernando H, Trapido E, Kane A. 2014. Evaluation of polycyclic aromatic hydrocarbons using analytical methods, toxicology, and risk assessment research: seafood safety after a petroleum spill as an example. Environ Health Perspect 122:6–9; http://dx.doi.org/10.1289/ehp.1306724 PMID:24213154

  5. Potential and limitations of the ESR dating method applied to Lower Pleistocene epoch: some examples from Orce (Guadix-Baza basin, Andalusia, Spain)

    NASA Astrophysics Data System (ADS)

    Duval, Mathieu; Falguères, Christophe; Bahain, Jean-Jacques; Voinchet, Pierre; Grün, Rainer

    2010-05-01

    The range of absolute dating methods potentially applicable in archaeological and/or geological context appears quite limited for the Lower Pleistocene epoch. Indeed, their use is constrained by several factors such as the sedimentary context, the kind of material in situ available or the studied time range. Among these methods, Electron Spin Resonance (ESR) is undoubtedly the most commonly used for ancient archaeological sites, mainly because it can be applied to a large range of material: flowstone, sedimentary quartz and fossil teeth for example. The development of this method is therefore really crucial in order to complete the chronostratigraphical framework of the first human settlement in Europe. To illustrate this, we worked on several sites in the Guadix-Baza basin (Andalusia, Spain), one of the foremost places in Europe with evidence of early human occupation. The basin has accumulated a massive sequence of Neogen-Quaternary sediments which contains a detailed archive of palaeoenvironmental and palaeoclimatic changes since the Miocene. The numerous palaeontological remains discovered from more than a hundred sites, together with a well-defined magnetostratigraphical framework, have established the basin as a reference sequence for the European Pliocene-Quaternary period. The most famous Plio-Pleistocene localities are located in the eastern part of the basin, near the village of Orce. The sites of Fuente Nueva III and Barranco León have delivered an archaic lithic industry associated with Early Pleistocene fauna, indicating one of the oldest occupations of Western Europe. A third site, Venta Micena, which contained large and detailed palaeontological assemblages (several thousands of remains), has become a reference locality for the Early Pleistocene biochronology. The chronostratigraphical framework of these sites was established mainly by the combination of several methods: biochronology (small and large-mammals) and palaeomagnetism. In order to complement this framework and to test the reliability of the ESR dating method, fossil teeth and sedimentary quartz recovered from these three localities were analysed. Our results unambiguously demonstrate the antiquity of the sites and their Early Pleistocene ages, but show also some methodological limits of the ESR method for such ancient periods in fluvio-lacustrine sedimentary environments.

  6. A method to analyse observer disagreement in visual grading studies: example of assessed image quality in paediatric cerebral multidetector CT images.

    PubMed

    Ledenius, K; Svensson, E; Stålhammar, F; Wiklund, L-M; Thilander-Klang, A

    2010-07-01

    The purpose was to demonstrate a non-parametric statistical method that can identify and explain the components of observer disagreement in terms of systematic disagreement as well as additional individual variability, in visual grading studies. As an example, the method was applied to a study where the effect of reduced tube current on diagnostic image quality in paediatric cerebral multidetector CT (MDCT) images was investigated. Quantum noise, representing dose reductions equivalent to steps of 20 mA, was artificially added to the raw data of 25 retrospectively selected paediatric cerebral MDCT examinations. Three radiologists, blindly and randomly, assessed the resulting images from two different levels of the brain with regard to the reproduction of high- and low-contrast structures and overall image quality. Images from three patients were assessed twice for the analysis of intra-observer disagreement. The intra-observer disagreement in test-retest assessments could mainly be explained by a systematic change towards lower image quality the second time the image was reviewed. The inter-observer comparisons showed that the paediatric radiologist was more critical of the overall image quality, while the neuroradiologists were more critical of the reproduction of the basal ganglia. Differences between the radiologists regarding the extent to which they used the whole classification scale were also found. The statistical method used was able to identify and separately measure a presence of bias apart from additional individual variability within and between the radiologists which is, at the time of writing, not attainable by any other statistical approach suitable for paired, ordinal data. PMID:20335429

  7. Use of new field methods of semen analysis in the study of occupational hazards to reproduction: the example of ethylene dibromide

    SciTech Connect

    Schrader, S.M.; Ratcliffe, J.M.; Turner, T.W.; Hornung, R.W.

    1987-12-01

    Increasing attention has been paid to the use of semen analysis as an indicator of exposure to potential mutagenic and reproductive hazards. In the infertility clinic setting, semen evaluations include the measurement of sperm concentration, volume, pH, motility, velocity and morphology, the analysis of seminal plasma to evaluate accessory sex gland function and, in some cases, the in vitro evaluation of fertilization capacity and sperm-cervical mucus interaction. To date, however, the study of semen characteristics of occupationally exposed populations has been confined principally to the measurement of sperm concentration and sperm morphology. This has been largely due to the unavailability of portable equipment suitable for the measurement of other semen characteristics and the difficulty of obtaining fresh semen samples in the field setting. National Institute for Occupational Safety and Health researchers have developed mobile laboratory facilities which enable us to evaluate fresh samples, in the field, for semen characteristics in addition to concentration and morphology. This paper describes the application of these methods using the example of our recent cross-sectional study of workers occupationally exposed to ethylene dibromide in the papaya fumigation industry. We discuss our findings in the context of the usefulness of semen analysis as an indicator of occupational hazards to male reproduction.

  8. Research on the calculation method of shale and tuff content: taking tuffaceous reservoirs of X depression in the Hailar-Tamtsag Basin as an example

    NASA Astrophysics Data System (ADS)

    Liu, Sihui; Huang, Buzhou; Pan, Baozhi; Wang, Guiping; Sun, Fengxian; Qiu, Haibo; Guo, Yuhang; Fang, Chunhui; Jiang, Bici

    2015-10-01

    Shale content is known in reservoir evaluation as an important parameter in well logging. However, the log response characteristics are simultaneously affected by shale and tuff existing in tuffaceous sandstone reservoirs. Due to the fact that tuff content exerts an influence on the calculation of shale content, the former is equally important as the latter. Owing to the differences in the source and composition between shale and tuff, the calculation of tuff content using the same methods for shale content cannot meet the accuracy requirements of logging evaluation. The present study takes the tuffaceous reservoirs in the X depression of the Hailar-Tamtsag Basin as an example. The differences in the log response characteristics between shale and tuff are theoretically analyzed and verified using core analysis data. The tuff is then divided into fine- and coarse-grained fractions, according to the differences in the distribution of the radioactive elements, uranium, thorium and potassium. Next, a volume model suitable for tuffaceous sandstone reservoirs is established to include a sandstone matrix, shale, fine-grained tuff, coarse-grained tuff and pore. A comparison of three optimization algorithms shows that the particle swarm optimization (PSO) yields better calculation results with small mean errors. The resistivity differences among shale, fine-grained tuff and coarse-grained tuff are considered in the calculation of saturation. The water saturation of tuffaceous reservoirs is computed using the improved Poupon’s equation, which is suitable for tuffaceous sandstone reservoirs with low water salinity. The method is used in well Y, and is shown to have a good application effect.

  9. X-Ray Absorption And EPR Spectroscopic Studies of the Biotransformations of Chromium(Vi) in Mammalian Cells. Is Chromodulin An Artifact of Isolation Methods?

    SciTech Connect

    Levina, A.; Harris, H.H.; Lay, P.A.; /Sydney U.

    2007-07-10

    Very different biological activities are usually ascribed to Cr(VI) (a toxin and carcinogen) and Cr(III) (an antidiabetic agent), although recent evidence suggests that both these types of actions are likely to arise from cellular uptake of varying concentrations of Cr(VI). The first systematic study of XANES spectra of Cr(III) complexes formed in Cr(VI)-treated mammalian cells (A549, HepG2, V79, and C2C12 cell lines), and in subcellular fractions of A549 cells, has been performed using a library of XANES spectra of model Cr(III) complexes. The results of multiple linear regression analyses of XANES spectra, in combination with multiple-scattering fits of XAFS spectra, indicate that Cr(III) formed in Cr(VI)-treated cells is most likely to bind to carboxylato, amine, and imidazole residues of amino acids, and to a lesser extent to hydroxo or aqua ligands. A combination of XANES and EPR spectroscopic data for Cr(VI)-treated cells indicates that the main component of Cr(III) formed in such cells is bound to high-molecular-mass ligands (>30 kDa, probably proteins), but significant redistribution of Cr(III) occurs during the cell lysis, which leads to the formation of a low-molecular-mass (<30 kDa) Cr(III)-containing fraction. The spectroscopic (XANES, XAFS, and EPR) properties of this fraction were strikingly similar to those of the purported natural Cr(III)-containing factor, chromodulin, that was reported to be isolated from the reaction of Cr(VI) with liver. These data support the hypothesis that a chromodulin-like species, which is formed from such a reaction, is an artifact of the reported isolation procedure.

  10. Discussion about decision support systems using continuous multi-criteria methods for planning in areas with hydro-basins, agriculture and forests, from examples in Argentine.

    NASA Astrophysics Data System (ADS)

    Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Andina, D.; Cisneros, J. M.; Sanchez, E.

    2012-04-01

    The authors were involved last years in projects considering diverse decision problems on the use of some regions in Argentine, and also related to rivers or rural services in them. They used sets of multi-criteria decision methods, first discrete when the problem included few distinct alternatives, such as e.g. forestry, traditional or intensive agriculture. For attributes they were different effects, classified then in environmental, economic and social criteria. Extending to other gentler areas, such as at South of the Province of Córdoba, Arg., they have balanced more delicately effects of continuous levels of actions, with a combination of Goal Programming linked methods, and they adopted compromises to have precise solutions. That has shown, and in part open, a line of research, as the setting of such models require various kinds of definitions and valuations, including optimizations, goals with penalties in deviations and restrictions. That can be in diverse detail level and horizon, in presence of various technical and human horizons, and that can influence politics of use of terrain and production that will require public and private agents. The research will consider consideration of use and conservation of soils, human systems and agro productions, and hence models for optimization, preferably in such Goal Programming ways. That will require considering various systems of models, first in theory to be reliable, and then in different areas to evaluate the quality of conclusions, and maybe that successively if results are found advantageous. The Bayesian ways will be considered, but they would require a prospective of sets of precise future states of nature or markets with elicited probabilities, which are neither evident nor decisive for the moment, as changes may occur in years but will be very unexpected or uncertain. The results will be lines of models to aid to establish policies of use of territories, by public agencies setting frames for private agents of different size and kinds, with different horizons of climatic and human changes. The usable models will depend somehow on the type of areas, which have different climates and soils, population, markets and maybe civilizations, starting with Argentine examples, if possible compared in cases with Spain.

  11. 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…

  12. The Origin, Composition and History of Comets from Spectroscopic Studies

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.

    1997-01-01

    A wealth of information essential to understanding the composition and physical structure of cometary ice and hence gain deep insight into the comet's origin and history, can be gleaned by carrying out a full range of spectroscopic studies on the returned sample. These studies ought to be among the first performed as they are generally non-destructive and will provide a broad data bank which will be crucial in planning subsequent analysis. Examples of the spectroscopic techniques along with relative sensitivities and transitions probed, are discussed. Different kind of "spectroscopy" is summarized, with emphasis placed on the kind of information each provides. Infrared spectroscopy should be the premier method of analysis as the mid-IR absorption spectrum of a substance contains more global information about the identity and structure of that material than any other property. In fact, the greatest strides in our understanding of the composition of interstellar ices (thought by many to be the primordial material from which comets have formed) have been taken during the past ten years or so because this was when high quality infrared spectra of the interstellar medium (ISM) first became available. The interpretation of the infrared spectra of mixtures, such as expected in comets, is often (not always) ambiguous. Consequently, a full range of other non-destructive, complementary spectroscopic measurements are required to fully characterize the material, to probe for substances for which the IR is not well suited and to lay the groundwork for future analysis. Given the likelihood that the icy component (including some of the organic and mineral phases) of the returned sample will be exceedingly complex, these techniques must be intensely developed over the next decade and then made ready to apply flawlessly to what will certainly be one of the most precious, and most challenging, samples ever analyzed.

  13. Spectroscopic wear detector

    NASA Technical Reports Server (NTRS)

    Madzsar, George C. (Inventor)

    1993-01-01

    The elemental composition of a material exposed to hot gases and subjected to wear is determined. Atoms of an elemental species not appearing in this material are implanted in a surface at a depth based on the maximum allowable wear. The exhaust gases are spectroscopically monitored to determine the exposure of these atoms when the maximum allowable wear is reached.

  14. Study on the interaction between methyl jasmonate and the coiled-coil domain of rice blast resistance protein Pi36 by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Liu, Xin Q.; Zhang, Dan; Zhang, Xiang M.; Wang, Chun T.; Liu, Xue Q.; Tan, Yan P.; Wu, Yun H.

    2012-03-01

    Interaction between the coiled-coil domain of rice blast resistance protein Pi36 and methyl-jasmonate (MeJA) was studied by fluorescence and UV-vis spectroscopic techniques. The quenching mechanism of fluorescence of MeJA by this domain was discussed to be a static quenching procedure. Fluorescence quenching was explored to measure the number of binding sites n and apparent binding constants K. The thermodynamics parameters ΔH, ΔG, ΔS were also calculated. The results indicate the binding reaction was not entropy-driven but enthalpy-driven, and hydrophobic binding played major role in the interaction. The binding sites of MeJA with the coiled-coil structural domain of rice blast resistance protein Pi36 were found to approach the microenvironment of both Tyr and Trp by the synchronous fluorescence spectrometry. The distance r between donor (the coiled-coil domain of rice blast resistance protein Pi36) and acceptor (MeJA) was obtained according to Förster theory of non-radioactive energy transfer.

  15. How specific Raman spectroscopic models are: a comparative study between different cancers

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Kumar, K. Kalyan; Chowdary, M. V. P.; Maheedhar, K.; Krishna, C. Murali

    2010-02-01

    Optical spectroscopic methods are being contemplated as adjunct/ alternative to existing 'Gold standard' of cancer diagnosis, histopathological examination. Several groups are actively pursuing diagnostic applications of Ramanspectroscopy in cancers. We have developed Raman spectroscopic models for diagnosis of breast, oral, stomach, colon and larynx cancers. So far, specificity and applicability of spectral- models has been limited to particular tissue origin. In this study we have evaluated explicitly of spectroscopic-models by analyzing spectra from already developed spectralmodels representing normal and malignant tissues of breast (46), cervix (52), colon (25), larynx (53), and oral (47). Spectral data was analyzed by Principal Component Analysis (PCA) using scores of factor, Mahalanobis distance and Spectral residuals as discriminating parameters. Multiparametric limit test approach was also explored. The preliminary unsupervised PCA of pooled data indicates that normal tissue types were always exclusive from their malignant counterparts. But when we consider tissue of different origin, large overlap among clusters was found. Supervised analysis by Mahalanobis distance and spectral residuals gave similar results. The 'limit test' approach where classification is based on match / mis-match of the given spectrum against all the available spectra has revealed that spectral models are very exclusive and specific. For example breast normal spectral model show matches only with breast normal spectra and mismatch to rest of the spectra. Same pattern was seen for most of spectral models. Therefore, results of the study indicate the exclusiveness and efficacy of Raman spectroscopic-models. Prospectively, these findings might open new application of Raman spectroscopic models in identifying a tumor as primary or metastatic.

  16. 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.

  17. 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...

  18. Example based lesion segmentation

    NASA Astrophysics Data System (ADS)

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2014-03-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer's disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  19. Spectroscopic diversity of type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Hsiao, Yi Chi Eric

    Type Ia supernovae (SNe Ia) are excellent tools in cosmology. Their intrinsic luminosities are found to vary systematically with the light-curve widths, providing an empirical calibration. This property, called the width-luminosity relation (WLR), is the basis of modern SN Ia cosmology and led to the unexpected discovery of the current accelerated rate of cosmic expansion. By examining the spectroscopic diversity of SNe Ia, this thesis aims to improve both the use of SNe Ia in cosmology and the physical understanding of the observed properties. Spectra of SNe Ia contain a wealth of information, but are difficult to organize. In this thesis, new methods are developed to consistently quantify and analyze the spectral features of supernovae. The efficacy of the methods is tested on a large library of observed spectra encompassing a wide range of properties. The spectroscopic diversity of SNe Ia enters cosmology through K-correction calculations. Before this work, K-correction was a major contributor of the systematic errors in cosmology. It is shown here that the systematic errors can be largely diminished by carefully quantifying the mean spectroscopic properties of SNe Ia. The remaining statistical errors are also quantified and shown to be redshift dependent. With the aid of principal component analysis (PCA), the multidimensional spectral information is reduced to a few components describing the largest variations in the spectral library. Using this tool, it is shown here that SN Ia intrinsic luminosity is the main driver of the spectroscopic diversity at maximum light, for every spectral feature from the ultraviolet to the near-infrared. These spectroscopic sequences can potentially account for a large fraction of the K-correction statistical errors and even enable the use of SN Ia spectra as independent indicators of intrinsic luminosity and colors. The established relations will also disentangle the effects of demographic shift and true evolution in high-redshift SN Ia spectra. The temporal evolution of the spectral features is shown to exhibit the persistence of the spectroscopic sequences throughout other epochs. The effect is attributed to the more rapid spectroscopic temporal evolution of fainter SNe Ia. This conclusion supports the theory that WLR is primarily a spectroscopic effect, rather than a bolometric one.

  20. Spectroscopic Monitoring of Be type Stars

    NASA Astrophysics Data System (ADS)

    Desnoux, V.; Buil, C.

    2005-05-01

    The study of Be stars is a perfect example of spectrography that amateurs can participate in. Several types of spectroscopes can be used depending of what physical parameters are monitored: classical surveys at low-resolution or high-resolution profile study of the H-alpha line are just two examples of what can be monitored. By grouping observations on long time scales, a database of stellar spectra can be built and placed at the disposal of professionals. Over a period of 10 years, starting at the Pic du Midi observ- atory and continuing later on by Christian Buil, and other French amateur groups using Musicos professional spectroscope, the monitoring of Be stars produced scientific results and are now supported by professional astron- omers. Some are already using the ARAS (Astronomical Ring for Amateur Spec- troscopy) list to ask for specific monitoring and get additional observations from the amateur community. Spectral processing will be also discussed, using Visual Spec and Iris freeware, from the basic calibration up to time reso- lution H-alpha profile evolution and Equivalent Width computation. Be Stars survey is just an example of how powerful spectroscopy can be, and can be practiced by amateurs. Amateurs are really capable of playing a key part in astrophysical studies.

  1. Simultaneous determination of methocarbamol and Ibuprofen by first derivative synchronous fluorescence spectroscopic method in their binary mixture and spiked human plasma.

    PubMed

    Abdelwahab, Nada S; Abdelrahman, Maha M

    2014-01-01

    Methocarbamol is formulated with Ibuprofen for treatment of alleviated pain associated with muscle spasm. This manuscript describes a sensitive and selective first derivative synchronous spectrofluorimetric method for simultaneous determination of both drugs. Factors affecting method selectivity were studied where best results were obtained upon using Δ λ = 20 and water as a solvent. Methocartbamol was determined at 283 nm while Ibuprofen at 285.5 nm in the concentration ranges of 0.4-5 and 0.2-4.8 μg/mL, respectively. The applicability of the proposed method was ascertained by application to different laboratory prepared mixtures and marketed formulation. The high sensitivity achieved by the proposed method permitted its application for determination of the drugs in human plasma spiked with pure drugs and their combined tablets. The proposed method showed no significant difference when compared with the reported HPLC method using student's t-test and F-ratio test. PMID:23912962

  2. Validation of a near-infrared transmission spectroscopic procedure. Part B: Application to alternate content uniformity and release assay methods for pharmaceutical solid dosage forms.

    PubMed

    Ritchie, Gary E; Roller, Robert W; Ciurczak, Emil W; Mark, Howard; Tso, Cindy; MacDonald, Stacy A

    2002-06-20

    NIR analytical methods can be validated to meet the requirement of demonstrating that it is suitable for the analysis of the materials for which it is being used. Applying previously described protocols for NIR methods to the analysis of two types of pharmaceutical products shows that for these products, NIR is suitable as an alternate analytical method for assay and for content uniformity. PMID:12062675

  3. Spectroscopic Follow Up of Kepler Planet Candidates

    NASA Astrophysics Data System (ADS)

    Latham, David W.; Cochran, W. D.; Marcy, G. W.; Buchhave, L.; Endl, M.; Isaacson, H.; Gautier, T. N.; Borucki, W. J.; Koch, D.; Kepler Team

    2010-01-01

    Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using high-resolution spectrometers on the Lick 3.0-m Shane Telescope, the McDonald 2.7-m Reflector, the 2.5-m Nordic Optical Telescope, and the 1.5-m Tillinghast Reflector at the Whipple observatory. In this paper we will summarize the scope and organization of the spectroscopic follow-up observations, showing examples of the types of false positives found and ending with a presentation of the characteristics of a confirmed planet.

  4. An example of using a decision making framework designed for non-medical prescribers as a method for enhancing prescribing safety for inhaled corticosteroids (ICS).

    PubMed

    Almarshad, Saja

    2015-01-01

    Non-medical prescribing is needed especially with the increased demand for health care and the physicians' time constrains. Also, it is not well regulated in Saudi Arabia unlike the United Kingdom. This report aims to demonstrate the urged need for regulations to maintain a safe non-medical prescribing process. It also adapts the single competency framework provided by the United Kingdom national prescribing centre (NPC, 2012) to be utilised by the respiratory therapist for a safe prescribing process for inhaled corticosteroids (ICS) to control adult asthma as an example. The framework is thought to be an effective tool for safe non-medical prescribing and it is highly recommended to develop a national Saudi framework to maintain the patients' safety and utilise resources. PMID:25685042

  5. An example of using a decision making framework designed for non-medical prescribers as a method for enhancing prescribing safety for inhaled corticosteroids (ICS)

    PubMed Central

    Almarshad, Saja

    2014-01-01

    Non-medical prescribing is needed especially with the increased demand for health care and the physicians’ time constrains. Also, it is not well regulated in Saudi Arabia unlike the United Kingdom. This report aims to demonstrate the urged need for regulations to maintain a safe non-medical prescribing process. It also adapts the single competency framework provided by the United Kingdom national prescribing centre (NPC, 2012) to be utilised by the respiratory therapist for a safe prescribing process for inhaled corticosteroids (ICS) to control adult asthma as an example. The framework is thought to be an effective tool for safe non-medical prescribing and it is highly recommended to develop a national Saudi framework to maintain the patients’ safety and utilise resources. PMID:25685042

  6. Spectroscopic Studies of Abell Clusters

    NASA Astrophysics Data System (ADS)

    Way, Michael Joseph

    The objectives of this work are to use spectroscopic techniques to accurately categorize galaxies as either HII region star forming galaxies or as Active Galactic Nuclei powered via a black hole, and to use radial velocities and projected positions of galaxies in clusters to obtain the total cluster mass and its distribution. The masses and distributions compare well to X-ray mass measurements. The commonly used Dressler, A., Thompson, I. & Shectman, S. 1985, ApJ, 288, 481 technique for discriminating between Active Galactic Nuclei and HII region galaxies uses the measurement of the equivalent width of the emission lines (OII) 3727 A, H/beta, and (OIII) 5007 A. High quality spectra from 42 galaxies were taken and it is shown that their method is not capable of distinguishing between Active Galactic Nuclei and HII region galaxies. The emission line flux from H/beta, (OIII) 5007 A, (OI) 6300 A, Hα, (NII) 6583 A, and (SII) 6716+6731 A in combination with the method of Veilleux, S. & Osterbrock, D. E. 1987, ApJS, 63, 295 must be used to accurately distinguish between Active Galactic Nuclei and HII region galaxies. Galaxy radial velocities from spectroscopic data and their projected 2-D positions in clusters are used to obtain robust estimates of the total mass and mass distribution in two clusters. The total mass is calculated using the Virial theorem after removing substructure. The mass distribution is estimated via several robust statistical tests for 1-D, 2-D and 3-D structure. It is shown that the derived mass estimates agree well with those found independently from hot X-ray gas emission in clusters.

  7. Methods for comparing data across differently designed agronomic studies: examples of different meta-analysis methods used to compare relative composition of plant foods grown using organic or conventional production methods and a protocol for a systematic review.

    PubMed

    Brandt, Kirsten; Srednicka-Tober, Dominika; Barański, Marcin; Sanderson, Roy; Leifert, Carlo; Seal, Chris

    2013-07-31

    Meta-analyses are methods to combine outcomes from different studies to investigate consistent effects of relatively small magnitude, which are difficult to distinguish from random variation within a single study. Several published meta-analyses addressed whether organic and conventional production methods affect the composition of plant foods differently. The meta-analyses were carried out using different options for the methodology and resulted in different conclusions. The types of designs of field trials and farm comparisons widely used in horticultural and agronomic research differ substantially from the clinical trials and epidemiological studies that most meta-analysis methodologies were developed for. Therefore, it is proposed that a systematic review and meta-analysis be carried out with the aim of developing a consolidated methodology. If successful, this methodology can then be used to determine effects of different production systems on plant food composition as well as other comparable factors with small but systematic effects across studies. PMID:23692216

  8. Benefits and challenges to using DNA-based identification methods: An example study of larval fish from nearshore areas of Lake Superior

    EPA Science Inventory

    DNA-based identification methods could increase the ability of aquatic resource managers to track patterns of invasive species, especially for taxa that are difficult to identify morphologically. Nonetheless, use of DNA-based identification methods in aquatic surveys is still unc...

  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. Raw material enzymatic activity determination: a specific case for validation and comparison of analytical methods--the example of superoxide dismutase (SOD).

    PubMed

    Zhou, Jiang Yan; Prognon, Patrice

    2006-03-18

    Implementation of ICH guideline for validation of analytical methods was tested in the case of two enzymatic assays of determination of superoxide dismutase (SOD) activity. Analytical figures of merits of two tested methods (NBT reference method and the so called WST-1 method) demonstrate the feasibility of such approach. Nevertheless specification usually admitted for physicochemical method (e.g., HPLC), needs to be clearly enlarged, for instance, up to 10% for repeatability and 20% for reproducibility. On the other hand, the cross-validation performed between the two enzymatic activity determination techniques, though based on the same principle, clearly shows that the quality of results depends on small variation in the experimental conditions. This shows that an enzymatic activity determination should be strictly related to the technique used, especially in the pharmaceutical control quality field, and confirms that analytical figures of merits are strongly function of the technique used. Finally, it was demonstrated that both NBT reference method and WST-1 method give strictly similar results. PMID:16280223

  11. Spectroscopic remote sensing for material identification, vegetation characterization, and mapping

    USGS Publications Warehouse

    Kokaly, Raymond F.

    2012-01-01

    Identifying materials by measuring and analyzing their reflectance spectra has been an important procedure in analytical chemistry for decades. Airborne and space-based imaging spectrometers allow materials to be mapped across the landscape. With many existing airborne sensors and new satellite-borne sensors planned for the future, robust methods are needed to fully exploit the information content of hyperspectral remote sensing data. A method of identifying and mapping materials using spectral feature analyses of reflectance data in an expert-system framework called MICA (Material Identification and Characterization Algorithm) is described. MICA is a module of the PRISM (Processing Routines in IDL for Spectroscopic Measurements) software, available to the public from the U.S. Geological Survey (USGS) at http://pubs.usgs.gov/of/2011/1155/. The core concepts of MICA include continuum removal and linear regression to compare key diagnostic absorption features in reference laboratory/field spectra and the spectra being analyzed. The reference spectra, diagnostic features, and threshold constraints are defined within a user-developed MICA command file (MCF). Building on several decades of experience in mineral mapping, a broadly-applicable MCF was developed to detect a set of minerals frequently occurring on the Earth's surface and applied to map minerals in the country-wide coverage of the 2007 Afghanistan HyMap data set. MICA has also been applied to detect sub-pixel oil contamination in marshes impacted by the Deepwater Horizon incident by discriminating the C-H absorption features in oil residues from background vegetation. These two recent examples demonstrate the utility of a spectroscopic approach to remote sensing for identifying and mapping the distributions of materials in imaging spectrometer data.

  12. Spectroscopic remote sensing for material identification, vegetation characterization, and mapping

    NASA Astrophysics Data System (ADS)

    Kokaly, Raymond F.

    2012-06-01

    Identifying materials by measuring and analyzing their reflectance spectra has been an important procedure in analytical chemistry for decades. Airborne and space-based imaging spectrometers allow materials to be mapped across the landscape. With many existing airborne sensors and new satellite-borne sensors planned for the future, robust methods are needed to fully exploit the information content of hyperspectral remote sensing data. A method of identifying and mapping materials using spectral feature analyses of reflectance data in an expert-system framework called MICA (Material Identification and Characterization Algorithm) is described. MICA is a module of the PRISM (Processing Routines in IDL for Spectroscopic Measurements) software, available to the public from the U.S. Geological Survey (USGS) at http://pubs.usgs.gov/of/2011/1155/. The core concepts of MICA include continuum removal and linear regression to compare key diagnostic absorption features in reference laboratory/field spectra and the spectra being analyzed. The reference spectra, diagnostic features, and threshold constraints are defined within a user-developed MICA command file (MCF). Building on several decades of experience in mineral mapping, a broadly-applicable MCF was developed to detect a set of minerals frequently occurring on the Earth's surface and applied to map minerals in the country-wide coverage of the 2007 Afghanistan HyMap data set. MICA has also been applied to detect sub-pixel oil contamination in marshes impacted by the Deepwater Horizon incident by discriminating the C-H absorption features in oil residues from background vegetation. These two recent examples demonstrate the utility of a spectroscopic approach to remote sensing for identifying and mapping the distributions of materials in imaging spectrometer data.

  13. Comparison of a new GIS-based technique and a manual method for determining sinkhole density: An example from Illinois' sinkhole plain

    USGS Publications Warehouse

    Angel, J.C.; Nelson, D.O.; Panno, S.V.

    2004-01-01

    A new Geographic Information System (GIS) method was developed as an alternative to the hand-counting of sinkholes on topographic maps for density and distribution studies. Sinkhole counts were prepared by hand and compared to those generated from USGS DLG data using ArcView 3.2 and the ArcInfo Workstation component of ArcGIS 8.1 software. The study area for this investigation, chosen for its great density of sinkholes, included the 42 public land survey sections that reside entirely within the Renault Quadrangle in southwestern Illinois. Differences between the sinkhole counts derived from the two methods for the Renault Quadrangle study area were negligible. Although the initial development and refinement of the GIS method required considerably more time than counting sinkholes by hand, the flexibility of the GIS method is expected to provide significant long-term benefits and time savings when mapping larger areas and expanding research efforts. ?? 2004 by The National Speleological Society.

  14. Validated spectrophotometric method for the determination, spectroscopic characterization and thermal structural analysis of duloxetine with 1,2-naphthoquinone-4-sulphonate

    NASA Astrophysics Data System (ADS)

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2012-03-01

    A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation of this complex was also confirmed by UV-visible, FTIR, 1H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines. Beer's law is obeyed in a range of 5.0-60 μg/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99 μg/mL and the recovery rate is in a range of 98.10-99.57%. The proposed methods was validated and applied to the determination of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of a reference UV spectrophotometric method.

  15. A Cell Derived Active Contour (CDAC) Method for Robust Tracking in Low Frame Rate, Low Contrast Phase Microscopy - an Example: The Human hNT Astrocyte

    PubMed Central

    Nejati Javaremi, Alireza; Unsworth, Charles P.; Graham, E. Scott

    2013-01-01

    The problem of automated segmenting and tracking of the outlines of cells in microscope images is the subject of active research. While great progress has been made on recognizing cells that are of high contrast and of predictable shape, many situations arise in practice where these properties do not exist and thus many interesting potential studies - such as the migration patterns of astrocytes to scratch wounds - have been relegated to being largely qualitative in nature. Here we analyse a select number of recent developments in this area, and offer an algorithm based on parametric active contours and formulated by taking into account cell movement dynamics. This Cell-Derived Active Contour (CDAC) method is compared with two state-of-the-art segmentation methods for phase-contrast microscopy. Specifically, we tackle a very difficult segmentation problem: human astrocytes that are very large, thin, and irregularly-shaped. We demonstrate quantitatively better results for CDAC as compared to similar segmentation methods, and we also demonstrate the reliable segmentation of qualitatively different data sets that were not possible using existing methods. We believe this new method will enable new and improved automatic cell migration and movement studies to be made. PMID:24358233

  16. Methods and Tools to Align Curriculum to the Skills and Competencies Needed by the Workforce - an Example from Geospatial Science and Technology

    NASA Astrophysics Data System (ADS)

    Johnson, A. B.

    2012-12-01

    Geospatial science and technology (GST) including geographic information systems, remote sensing, global positioning systems and mobile applications, are valuable tools for geoscientists and students learning to become geoscientists. GST allows the user to analyze data spatially and temporarily and then visualize the data and outcomes in multiple formats (digital, web and paper). GST has evolved rapidly and it has been difficult to create effective curriculum as few guidelines existed to help educators. In 2010, the US Department of Labor (DoL), in collaboration with the National Geospatial Center of Excellence (GeoTech Center), a National Science Foundation supported grant, approved the Geospatial Technology Competency Mode (GTCM). The GTCM was developed and vetted with industry experts and provided the structure and example competencies needed across the industry. While the GTCM was helpful, a more detailed list of skills and competencies needed to be identified in order to build appropriate curriculum. The GeoTech Center carried out multiple DACUM events to identify the skills and competencies needed by entry-level workers. DACUM (Developing a Curriculum) is a job analysis process whereby expert workers are convened to describe what they do for a specific occupation. The outcomes from multiple DACUMs were combined into a MetaDACUM and reviewed by hundreds of GST professionals. This provided a list of more than 320 skills and competencies needed by the workforce. The GeoTech Center then held multiple workshops across the U.S. where more than 100 educators knowledgeable in teaching GST parsed the list into Model Courses and a Model Certificate Program. During this process, tools were developed that helped educators define which competency should be included in a specific course and the depth of instruction for that competency. This presentation will provide details about the process, methodology and tools used to create the Models and suggest how they can be used to create customized curriculum integrating geospatial science and technology into geoscience programs.

  17. Near-infrared spectroscopic method for the identification of Fusarium head blight damage and prediction of deoxynivalenol in single wheat kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium Head Blight (FHB), or scab, can result in significant crop yield losses and contaminated grain in wheat (Triticum aestivum L.). Growing less susceptible varieties is one of the most effective methods for managing FHB and for reducing deoxynivalenol (DON) levels in grain, but breeding progra...

  18. A cross-site comparison of methods used for hydrogeologic characterization of the Galena-Platteville aquifer in Illinois and Wisconsin, with examples from selected Superfund sites

    USGS Publications Warehouse

    Kay, Robert T.; Mills, Patrick C.; Dunning, Charles P.; Yeskis, Douglas J.; Ursic, James R.; Vendl, Mark

    2004-01-01

    The effectiveness of 28 methods used to characterize the fractured Galena-Platteville aquifer at eight sites in northern Illinois and Wisconsin is evaluated. Analysis of government databases, previous investigations, topographic maps, aerial photographs, and outcrops was essential to understanding the hydrogeology in the area to be investigated. The effectiveness of surface-geophysical methods depended on site geology. Lithologic logging provided essential information for site characterization. Cores were used for stratigraphy and geotechnical analysis. Natural-gamma logging helped identify the effect of lithology on the location of secondary- permeability features. Caliper logging identified large secondary-permeability features. Neutron logs identified trends in matrix porosity. Acoustic-televiewer logs identified numerous secondary-permeability features and their orientation. Borehole-camera logs also identified a number of secondary-permeability features. Borehole ground-penetrating radar identified lithologic and secondary-permeability features. However, the accuracy and completeness of this method is uncertain. Single-point-resistance, density, and normal resistivity logs were of limited use. Water-level and water-quality data identified flow directions and indicated the horizontal and vertical distribution of aquifer permeability and the depth of the permeable features. Temperature, spontaneous potential, and fluid-resistivity logging identified few secondary-permeability features at some sites and several features at others. Flowmeter logging was the most effective geophysical method for characterizing secondary-permeability features. Aquifer tests provided insight into the permeability distribution, identified hydraulically interconnected features, the presence of heterogeneity and anisotropy, and determined effective porosity. Aquifer heterogeneity prevented calculation of accurate hydraulic properties from some tests. Different methods, such as flowmeter logging and slug testing, occasionally produced different interpretations. Aquifer characterization improved with an increase in the number of data points, the period of data collection, and the number of methods used.

  19. Spectroscopic Databases for Astronomical Applications

    NASA Astrophysics Data System (ADS)

    Brown, L. R.

    2011-05-01

    Astronomers detect new species (atoms, molecules, ions, radicals present in gas, liquid and solid phase) and determine their abundances, temperatures, pressures, velocities etc. through spectroscopic remote sensing. Nearly every physical phenomenon that in uences the radiative transfer of an astronomical body can be detected and quantified using specific spectral features, provided sufficient spectroscopic knowledge is available. Collections of spectroscopic information are formed and then revised as new objectives and techniques evolve. The resulting spectroscopic databases should be complete, accurate and organized in convenient forms. Much is accessible for far- and mid-IR applications, but the available compilations are often deficient at shorter wavelengths. In this presentation, the current status of these molecular spectroscopic databases will be reviewed.

  20. Monte Carlo Example Programs

    Energy Science and Technology Software Center (ESTSC)

    2006-05-09

    The Monte Carlo example programs VARHATOM and DMCATOM are two small, simple FORTRAN programs that illustrate the use of the Monte Carlo Mathematical technique for calculating the ground state energy of the hydrogen atom.

  1. Methods for Estimating Uncertainty in PMF Solutions: Examples with Ambient Air and Water Quality Data and Guidance on Reporting PMF Results

    EPA Science Inventory

    The new version of EPA’s positive matrix factorization (EPA PMF) software, 5.0, includes three error estimation (EE) methods for analyzing factor analytic solutions: classical bootstrap (BS), displacement of factor elements (DISP), and bootstrap enhanced by displacement (BS-DISP)...

  2. Methods for Estimating Uncertainty in PMF Solutions: Examples with Ambient Air and Water Quality Data and Guidance on Reporting PMF Results

    EPA Science Inventory

    The new version of EPAs positive matrix factorization (EPA PMF) software, 5.0, includes three error estimation (EE) methods for analyzing factor analytic solutions: classical bootstrap (BS), displacement of factor elements (DISP), and bootstrap enhanced by displacement (BS-DISP)...

  3. Vector image method for the derivation of elastostatic solutions for point sources in a plane layered medium. Part 1: Derivation and simple examples

    NASA Technical Reports Server (NTRS)

    Fares, Nabil; Li, Victor C.

    1986-01-01

    An image method algorithm is presented for the derivation of elastostatic solutions for point sources in bonded halfspaces assuming the infinite space point source is known. Specific cases were worked out and shown to coincide with well known solutions in the literature.

  4. Application of Blind Deconvolution Methods in two Complex Seismological Examples: Transfert Function Evaluation (Site Effect Assessment at GVDA) and Source Wavelet Evaluation (Kursk).

    NASA Astrophysics Data System (ADS)

    Sebe, O.; Guilbert, J.; Bard, P.

    2002-12-01

    In seismology the source and the Green function are unknown, the only available information is surface or deep seismograms. So the deconvolution associated with the classical input-output system identification is impossible without strong physical assumption. Many blind deconvolution methods, recently developped in the domain of communications, aim to retrieve the unknown information of a system from output only. We apply two of these methods to seismology: the multichannel blind deconvolution to retrieve the transfert function and high order statistics to estimate source wavelet. In the first case, the multichannel method is applied in the scope of site effect estimation. It treats the problem of a signal transmitted through different channels (propagation mediums) and recorded at several receivers. From seismograms recorded at different sites, it intends to separate the common convolutive part of the signals (identified as the incident wave) and the specific site impulse response. The two main advantages of this method are that we don't need any reference site record and that the result contains the temporal properties of site responses. We test the method on a synthetic set of seismic signals based on a 1D model. We then apply it on the recordings obtained at various depths in the Garner Valley Down-hole Array. In the second case, the high order statistics blind deconvolution is applied to study the main caracteristics of Kurk's underwater explosion. It treats the problem of a source transmitted through a specific channel and recorded on single receiver. This blind deconvolution computed in bispectral and cepstral domains, gives us the opportunity to separate the wavelet (source function) and the propagation with one single geophysical assumption on the transfer function. It allows us to extract the bubble effect and the reflection at the sea surface as well as the source (amplitude and phase) from seismograms recorded at regional distance.

  5. Spectroscopically Accurate Line Lists for Application in Sulphur Chemistry

    NASA Astrophysics Data System (ADS)

    Underwood, D. S.; Azzam, A. A. A.; Yurchenko, S. N.; Tennyson, J.

    2013-09-01

    Monitoring sulphur chemistry is thought to be of great importance for exoplanets. Doing this requires detailed knowledge of the spectroscopic properties of sulphur containing molecules such as hydrogen sulphide (H2S) [1], sulphur dioxide (SO2), and sulphur trioxide (SO3). Each of these molecules can be found in terrestrial environments, produced in volcano emissions on Earth, and analysis of their spectroscopic data can prove useful to the characterisation of exoplanets, as well as the study of planets in our own solar system, with both having a possible presence on Venus. A complete, high temperature list of line positions and intensities for H32 2 S is presented. The DVR3D program suite is used to calculate the bound ro-vibration energy levels, wavefunctions, and dipole transition intensities using Radau coordinates. The calculations are based on a newly determined, spectroscopically refined potential energy surface (PES) and a new, high accuracy, ab initio dipole moment surface (DMS). Tests show that the PES enables us to calculate the line positions accurately and the DMS gives satisfactory results for line intensities. Comparisons with experiment as well as with previous theoretical spectra will be presented. The results of this study will form an important addition to the databases which are considered as sources of information for space applications; especially, in analysing the spectra of extrasolar planets, and remote sensing studies for Venus and Earth, as well as laboratory investigations and pollution studies. An ab initio line list for SO3 was previously computed using the variational nuclear motion program TROVE [2], and was suitable for modelling room temperature SO3 spectra. The calculations considered transitions in the region of 0-4000 cm-1 with rotational states up to J = 85, and includes 174,674,257 transitions. A list of 10,878 experimental transitions had relative intensities placed on an absolute scale, and were provided in a form suitable for inclusion in standard atmospheric and planetary spectroscopic databases. The methods involved in computing the ab initio potential energy and dipole moment surfaces involved minor corrections to the equilibrium S-O distance, which produced a good agreement with experimentally determined rotational energies. However the purely ab initio method was not been able to reproduce an equally spectroscopically accurate representation of vibrational motion. We therefore present an empirical refinement to this original, ab initio potential surface, based on the experimental data available. This will not only be used to reproduce the room-temperature spectrum to a greater degree of accuracy, but is essential in the production of a larger, accurate line list necessary for the simulation of higher temperature spectra: we aim for coverage suitable for T ? 800 K. Our preliminary studies on SO3 have also shown it to exhibit an interesting "forbidden" rotational spectrum and "clustering" of rotational states; to our knowledge this phenomenon has not been observed in other examples of trigonal planar molecules and is also an investigative avenue we wish to pursue. Finally, the IR absorption bands for SO2 and SO3 exhibit a strong overlap, and the inclusion of SO2 as a complement to our studies is something that we will be interested in doing in the near future.

  6. New validated liquid chromatographic and chemometrics-assisted UV spectroscopic methods for the determination of two multicomponent cough mixtures in syrup.

    PubMed

    Hadad, Ghada M; El-Gindy, Alaa; Mahmoud, Waleed M M

    2008-01-01

    Multivariate spectrophotometric calibration and liquid chromatographic (LC) methods were applied to the determination of 2 multicomponent mixtures containing diprophylline, guaiphenesin, methylparaben, and propylparaben (Mixture 1), or clobutinol, orciprenaline, saccharin sodium, and sodium benzoate (Mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least-squares regression (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in 0.1 M HCl. Analytical figures of merit such as sensitivity, selectivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC separation was achieved on a reversed-phase C18 analytical column by using isocratic elution with 20 mM potassium dihydrogen phosphate, pH 3.3-acetonitrile (55 + 45, v/v) as the mobile phase and UV detection at 260 and 220 nm for Mixture 1 and Mixture 2, respectively. The proposed methods were validated and successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations. PMID:18376584

  7. Post mortem energy metabolism and meat quality of porcine M. longissimus dorsi as influenced by stunning method - A (31)P NMR spectroscopic study.

    PubMed

    Bertram, Hanne Christine; Stødkilde-Jørgensen, Hans; Karlsson, Anders Hans; Andersen, Henrik Jørgen

    2002-09-01

    Post mortem changes in phosphorus metabolites and pH were studied in M. longissimus dorsi from pigs (n=10) stunned either by CO(2) (n=3), electrical (n=2), captive bolt pistol (n=2) or by anesthesia (ketamine) (n=3). (31)P-NMR spectroscopy revealed significant effects of stunning method on changes of the various phosphorus metabolites in the muscle post mortem, with the effect being most pronounced on the degradation of phosphocreatine (PCr). Moreover, the four stunning methods gave rise to large differences in the progress of pH as determined by (31)P-NMR spectroscopy. Using anesthesia as the reference showed that the captive bolt pistol caused the highest rates of post mortem degradation of phosphorus metabolites, electrical stunning intermediate, and CO(2)-stunning causing the lowest post mortem degradation rates, even though CO(2)-stunning also was associated with higher post mortem degradation rates compared with anesthesia. Finally, it was demonstrated that the water-holding capacity (WHC) of the meat was affected by the applied stunning method, as CO(2)-stunning, electrical stunning and captive bolt pistol resulted in mean drip losses of 6.4, 8.3 and 8.6%, respectively (P=0.02). The result displays the significance of induction and progress in post mortem changes on WHC in meat. PMID:22061199

  8. Tuberculosis - A global emergency: Tools and methods to monitor, understand, and control the epidemic with specific example of the Beijing lineage.

    PubMed

    Couvin, David; Rastogi, Nalin

    2015-06-01

    We argue in favor of a concerted and coordinated response to stop tuberculosis (TB) by monitoring global TB spread, drug-resistance surveillance and populations at risk using available molecular and web tools to identify circulating clones of Mycobacterium tuberculosis complex (MTBC). We took specific example of the Beijing lineage associated with worldwide emergence of both multiple, and extensively drug resistant (MDR/XDR)-TB. The study dataset (n=10,850 isolates, 92 countries of patient origin) was extracted from our multimarker SITVIT2 database on MTBC genotyping (n=111,635 isolates, 169 countries of patient origin). Epidemiological and demographic information in conjunction with spoligotyping (n=10,850), MIRU-VNTR minisatellites (n=2896), and drug resistance (n=2846) data was mapped at macro-geographical (United Nations subregions) and country level, followed by statistical, bioinformatical, and phylogenetical analysis. The global male/female sex ratio was 1.96, the highest being 4.93 in Russia vs. range of 0.8-1.13 observed in Central America, Caribbean, Eastern Africa and Northern Europe (p < 0.0001). The major patient age-group was 21-40 yrs worldwide except Japan (with majority of patients >60 yrs). Younger patients were more common in South America, South Asia, and Western Africa since 25-33% of TB cases due to Beijing genotype occurred in the age group 0-20 yrs. A continuous progression in the proportion of MDR and XDR strains is visible worldwide since 2003 and 2009 respectively. Pansusceptible TB mainly concerned older patients >60 yrs (44%) whereas Drug resistant, MDR and XDR-TB concerned patients preferentially aged 21-40 yrs (between 52 and 58%). Although the proportion of SIT1 pattern vs. other patterns was very high (93%); the proportion of MDR was highest for an emerging genotype SIT190 (p < 0.0001). Lastly, proportion of pansusceptible strains was highest in Japan, while MDR/XDR strains were most common in Russia and Northern Europe. We underline remarkable macro/micro-geographical cleavages in phylogenetic and epidemiologic diversity of Beijing genotype, with phylogeographical specificity of certain genotypes. PMID:25797613

  9. Spectroscopic Detection of Caries Lesions

    PubMed Central

    Ruohonen, Mika; Palo, Katri; Alander, Jarmo

    2013-01-01

    Background. A caries lesion causes changes in the optical properties of the affected tissue. Currently a caries lesion can be detected only at a relatively late stage of development. Caries diagnosis also suffers from high interobserver variance. Methods. This is a pilot study to test the suitability of an optical diffuse reflectance spectroscopy for caries diagnosis. Reflectance visible/near-infrared spectroscopy (VIS/NIRS) was used to measure caries lesions and healthy enamel on extracted human teeth. The results were analysed with a computational algorithm in order to find a rule-based classification method to detect caries lesions. Results. The classification indicated that the measured points of enamel could be assigned to one of three classes: healthy enamel, a caries lesion, and stained healthy enamel. The features that enabled this were consistent with theory. Conclusions. It seems that spectroscopic measurements can help to reduce false positives at in vitro setting. However, further research is required to evaluate the strength of the evidence for the method's performance.

  10. Methods for estimating uncertainty in PMF solutions: examples with ambient air and water quality data and guidance on reporting PMF results.

    PubMed

    Brown, Steven G; Eberly, Shelly; Paatero, Pentti; Norris, Gary A

    2015-06-15

    The new version of EPA's positive matrix factorization (EPA PMF) software, 5.0, includes three error estimation (EE) methods for analyzing factor analytic solutions: classical bootstrap (BS), displacement of factor elements (DISP), and bootstrap enhanced by displacement (BS-DISP). These methods capture the uncertainty of PMF analyses due to random errors and rotational ambiguity. To demonstrate the utility of the EE methods, results are presented for three data sets: (1) speciated PM2.5 data from a chemical speciation network (CSN) site in Sacramento, California (2003-2009); (2) trace metal, ammonia, and other species in water quality samples taken at an inline storage system (ISS) in Milwaukee, Wisconsin (2006); and (3) an organic aerosol data set from high-resolution aerosol mass spectrometer (HR-AMS) measurements in Las Vegas, Nevada (January 2008). We present an interpretation of EE diagnostics for these data sets, results from sensitivity tests of EE diagnostics using additional and fewer factors, and recommendations for reporting PMF results. BS-DISP and BS are found useful in understanding the uncertainty of factor profiles; they also suggest if the data are over-fitted by specifying too many factors. DISP diagnostics were consistently robust, indicating its use for understanding rotational uncertainty and as a first step in assessing a solution's viability. The uncertainty of each factor's identifying species is shown to be a useful gauge for evaluating multiple solutions, e.g., with a different number of factors. PMID:25776202

  11. Spectroscopic (FT-IR, FT-Raman, FT-NMR and UV-Vis) investigation on benzil dioxime using quantum computational methods

    NASA Astrophysics Data System (ADS)

    Bakkiyaraj, D.; Periandy, S.; Xavier, S.

    2016-03-01

    The spectral analysis of benzil dioxime is carried out using the FTIR, FT Raman, FT NMR and UV-Vis spectra of the compound with the help of quantum computations by density functional theories. The FT-IR (4000 - 400 cm-1) and FT-Raman (4000-100 cm-1) spectra are recorded in solid phase, the 1H and 13C NMR spectra in DMSO phase and the UV spectrum (200-400 nm) in ethanol phase. The different conformers of the compound and their minimum energies are studied by potential energy surface scan, using semi-empirical method PM6. The computed wavenumbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the fundamental modes have been assigned based on the potential energy distribution (PED) values and the structure the molecule is analyzed interms of parameters like bond length, bond angle and dihedral angles predicted byB3LYP and CAM-B3LYP methods with cc-pVDZ basis sets. The values of dipole moment (μ), polarizability (α) and hyperpolarizability (β) of the molecule are reported, using which the non -linear optical property of the molecule is discussed. The HOMO-LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for 1H and 13C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts and the same is discussed in comparison with atomic charges, predicted by Mullikan and APT charge analysis. NBO analysis is carried out to picture the probable electronic transitions in the molecule.

  12. An Improved Method for TIMS High Precision Nd Isotopic Analysis of Very Small Aliquots (1- 10ng) With Example Application in Garnet Sm/Nd Geochronology

    NASA Astrophysics Data System (ADS)

    Baxter, E. F.; Harvey, J.; Mehl, L. Y.; Peterman, E. M.

    2007-12-01

    Technological and scientific developments have demonstrated both the attainability and the utility of very high precision (i.e. 5-20ppm 2 σ) Nd isotopic measurements with TIMS. However such high precision has been limited to relatively large aliquots of Nd, on the order of several hundred nanograms. Several potential applications of precise Nd isotopic measurements, including garnet Sm/Nd geochronology, do not always permit such large samples, instead yielding only a few nanograms of Nd. We have explored and tested an improved method for Nd isotopic analysis of such small (1-10ng) aliquots of Nd using the NdO+ method with a Triton TIMS at Boston University. Analyzing Nd isotopes as the oxide is a well known technique, frequently involving an oxygen bleed valve. Instead, we forego the bleed valve and load samples with a TaO slurry which provides the oxygen source. Using an in-house Nd isotopic standard solution, 4ng loads easily yield stable 2.0-2.5 volt beams resulting in internal precisions of 10ppm 2 σ RSE. Within barrel external precision of 4ng loads of the Nd standard is 13ppm 2 σ RSD (n=20). Long term (6 months, six analysts) external precision of 4ng loads of the standard is currently 23ppm 2 σ RSD (n=55) suggesting that further improvements are possible. As a further test of this method, we dissolved a natural rock sample (a metapelite), separated the Nd using TRU- spec and MLA column chemistry, and loaded nineteen 4ng loads in one barrel. Within barrel external precision was 21ppm 2 σ RSD (n=18). This precision represents a significant advance over previous NdO+ analyses of small samples using an oxygen bleed valve. The TaO loading method for small Nd aliquots is useful in Sm/Nd garnet geochronology as exemplified by two case studies. Garnets from eclogite facies gneisses from Norway ran very well with 2.4-18ng loads and yielded age precision as good as 0.8 million years 2 σ. Conversely, garnets from blueschist facies rocks from Sifnos, Greece, ran poorly with similarly sized 1-17ng loads and consequently yielded generally poorer age precision. Differences between the two garnet sample suites must relate to the garnets themselves (notably including much lower Nd concentration in Sifnos garnets), not the identical column chemistry nor the TaO loading method. Additional procedures may be required to cleanly separate Nd from samples where Nd concentrations are very low (≪1ppm). As always, clean separation and column chemistry represents an unavoidable limiting factor in achieving precise isotopic measurements.

  13. Quantitative spectroscopic imaging of the human brain.

    PubMed

    Pan, J W; Twieg, D B; Hetherington, H P

    1998-09-01

    A method to provide B1 correction and cerebrospinal fluid (CSF) referencing is developed and applied to spectroscopic imaging of the human brain at 4.1 T using a volume head coil. The B1 image allows rapid determination of the spatially dependent B1 that is then used to compensate for the B1 sensitivity of the spectroscopic sequence. The reference signal is acquired from CSF located in a lateral ventricular position using a point-resolved echo spectroscopy (PRESS) acquisition. The CSF spectrum is also corrected for B1 dependence. Together with T2 and T1 corrections, this method is used to provide quantitative values of N-acetylaspartate (NAA), creatine (Cr), and choline (Ch). The metabolite concentrations obtained from a spectroscopic imaging slice through the ventricles in seven normal controls are in good agreement with previously published literature values. This method is applied in a patient with secondary progressive multiple sclerosis, showing separate areas of abnormalities in both NAA and Cr. PMID:9727938

  14. Early stage phase separation in pharmaceutical solid dispersion thin films under high humidity: improved spatial understanding using probe-based thermal and spectroscopic nanocharacterization methods.

    PubMed

    Qi, Sheng; Moffat, Jonathan G; Yang, Ziyi

    2013-03-01

    Phase separation in pharmaceutical solid dispersion thin films under high humidity is still poorly understood on the submicrometer scale. This study investigated the phase separation of a model solid dispersion thin film, felodipine-PVP K29/32, prepared by spin-coating and analyzed using probe-based methods including atomic force microscopy, nanothermal analysis, and photothermal infrared microspectroscopy. The combined use of these techniques revealed that the phase separation process occurring in the thin films under high humidity is different from that in dry conditions reported previously. The initial stage of phase separation is primarily initiated in the bulk of the films as amorphous drug domains. Drug migration toward the surface of the solid dispersion film was then observed to occur under exposure to increased humidity. PVP cannot prevent phase separation of felodipine under high humidity but can minimize the crystallization of amorphous felodipine domains in the solid dispersion thin films. This study demonstrates the unique abilities of these nanocharacterization methods for studying, in three dimensions, the phase separation of thin films for pharmaceutical applications. PMID:23320617

  15. A comparison between univariate probabilistic and multivariate (logistic regression) methods for landslide susceptibility analysis: the example of the Febbraro valley (Northern Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Rossi, M.; Apuani, T.; Felletti, F.

    2009-04-01

    The aim of this paper is to compare the results of two statistical methods for landslide susceptibility analysis: 1) univariate probabilistic method based on landslide susceptibility index, 2) multivariate method (logistic regression). The study area is the Febbraro valley, located in the central Italian Alps, where different types of metamorphic rocks croup out. On the eastern part of the studied basin a quaternary cover represented by colluvial and secondarily, by glacial deposits, is dominant. In this study 110 earth flows, mainly located toward NE portion of the catchment, were analyzed. They involve only the colluvial deposits and their extension mainly ranges from 36 to 3173 m2. Both statistical methods require to establish a spatial database, in which each landslide is described by several parameters that can be assigned using a main scarp central point of landslide. The spatial database is constructed using a Geographical Information System (GIS). Each landslide is described by several parameters corresponding to the value of main scarp central point of the landslide. Based on bibliographic review a total of 15 predisposing factors were utilized. The width of the intervals, in which the maps of the predisposing factors have to be reclassified, has been defined assuming constant intervals to: elevation (100 m), slope (5 °), solar radiation (0.1 MJ/cm2/year), profile curvature (1.2 1/m), tangential curvature (2.2 1/m), drainage density (0.5), lineament density (0.00126). For the other parameters have been used the results of the probability-probability plots analysis and the statistical indexes of landslides site. In particular slope length (0 ÷ 2, 2 ÷ 5, 5 ÷ 10, 10 ÷ 20, 20 ÷ 35, 35 ÷ 260), accumulation flow (0 ÷ 1, 1 ÷ 2, 2 ÷ 5, 5 ÷ 12, 12 ÷ 60, 60 ÷27265), Topographic Wetness Index 0 ÷ 0.74, 0.74 ÷ 1.94, 1.94 ÷ 2.62, 2.62 ÷ 3.48, 3.48 ÷ 6,00, 6.00 ÷ 9.44), Stream Power Index (0 ÷ 0.64, 0.64 ÷ 1.28, 1.28 ÷ 1.81, 1.81 ÷ 4.20, 4.20 ÷ 9.40). Geological map and land use map were also used, considering geological and land use properties as categorical variables. Appling the univariate probabilistic method the Landslide Susceptibility Index (LSI) is defined as the sum of the ratio Ra/Rb calculated for each predisposing factor, where Ra is the ratio between number of pixel of class and the total number of pixel of the study area, and Rb is the ratio between number of landslides respect to the pixel number of the interval area. From the analysis of the Ra/Rb ratio the relationship between landslide occurrence and predisposing factors were defined. Then the equation of LSI was used in GIS to trace the landslide susceptibility maps. The multivariate method for landslide susceptibility analysis, based on logistic regression, was performed starting from the density maps of the predisposing factors, calculated with the intervals defined above using the equation Rb/Rbtot, where Rbtot is a sum of all Rb values. Using stepwise forward algorithms the logistic regression was performed in two successive steps: first a univariate logistic regression is used to choose the most significant predisposing factors, then the multivariate logistic regression can be performed. The univariate regression highlighted the importance of the following factors: elevation, accumulation flow, drainage density, lineament density, geology and land use. When the multivariate regression was applied the number of controlling factors was reduced neglecting the geological properties. The resulting final susceptibility equation is: P = 1 / (1 + exp-(6.46-22.34*elevation-5.33*accumulation flow-7.99* drainage density-4.47*lineament density-17.31*land use)) and using this equation the susceptibility maps were obtained. To easy compare the results of the two methodologies, the susceptibility maps were reclassified in five susceptibility intervals (very high, high, moderate, low and very low) using natural breaks. Then the maps were validated using two cumulative distribution curves, one related to the landslides (number of landslides in each susceptibility class) and one to the basin (number of pixel covering each class). Comparing the curves for each method, it results that the two approaches (univariate and multivariate) are appropriate, providing acceptable results. In both maps the distribution of high susceptibility condition is mainly localized on the left slope of the catchment in agreement with the field evidences. The comparison between the methods was obtained by subtraction of the two maps. This operation shows that about 40% of the basin is classified by the same class of susceptibility. In general the univariate probabilistic method tends to overestimate the areal extension of the high susceptibility class with respect to the maps obtained by the logistic regression method.

  16. A double-deletion method to quantifying incremental binding energies in proteins from experiment: example of a destabilizing hydrogen bonding pair.

    PubMed

    Campos, Luis A; Cuesta-López, Santiago; López-Llano, Jon; Falo, Fernando; Sancho, Javier

    2005-02-01

    The contribution of a specific hydrogen bond in apoflavodoxin to protein stability is investigated by combining theory, experiment and simulation. Although hydrogen bonds are major determinants of protein structure and function, their contribution to protein stability is still unclear and widely debated. The best method so far devised to estimate the contribution of side-chain interactions to protein stability is double mutant cycle analysis, but the interaction energies so derived are not identical to incremental binding energies (the energies quantifying net contributions of two interacting groups to protein stability). Here we introduce double-deletion analysis of 'isolated' residue pairs as a means to precisely quantify incremental binding. The method is exemplified by studying a surface-exposed hydrogen bond in a model protein (Asp96/Asn128 in apoflavodoxin). Combined substitution of these residues by alanines slightly destabilizes the protein due to a decrease in hydrophobic surface burial. Subtraction of this effect, however, clearly indicates that the hydrogen-bonded groups in fact destabilize the native conformation. In addition, molecular dynamics simulations and classic double mutant cycle analysis explain quantitatively that, due to frustration, the hydrogen bond must form in the native structure because when the two groups get approximated upon folding their binding becomes favorable. We would like to remark that 1), this is the first time the contribution of a specific hydrogen bond to protein stability has been measured by experiment; and 2), more hydrogen bonds need to be analyzed to draw general conclusions on protein hydrogen bond energetics. To that end, the double-deletion method should be of help. PMID:15556980

  17. An alternative NMR method to determine nuclear shielding anisotropies for molecules in liquid-crystalline solutions with (13)C shielding anisotropy of methyl iodide as an example.

    PubMed

    Tallavaara, Pekka; Jokisaari, Jukka

    2008-03-28

    An alternative NMR method for determining nuclear shielding anisotropies in molecules is proposed. The method is quite simple, linear and particularly applicable for heteronuclear spin systems. In the technique, molecules of interest are dissolved in a thermotropic liquid crystal (LC) which is confined in a mesoporous material, such as controlled pore glass (CPG) used in this study. CPG materials consist of roughly spherical particles with a randomly oriented and connected pore network inside. LC Merck Phase 4 was confined in the pores of average diameter from 81 to 375 A and LC Merck ZLI 1115 in the pores of average diameter 81 A. In order to demonstrate the functionality of the method, the (13)C shielding anisotropy of (13)C-enriched methyl iodide, (13)CH(3)I, was determined as a function of temperature using one dimensional (13)C NMR spectroscopy. Methane gas, (13)CH(4), was used as an internal chemical shift reference. It appeared that methyl iodide molecules experience on average an isotropic environment in LCs inside the smallest pores within the whole temperature range studied, ranging from bulk solid to isotropic phase. In contrast, in the spaces in between the particles, whose diameter is approximately 150 microm, LCs behave as in the bulk. Consequently, isotropic values of the shielding tensor can be determined from spectra arising from molecules inside the pores at exactly the same temperature as the anisotropic ones from molecules outside the pores. Thus, for the first time in the solution state, shielding anisotropies can easily be determined as a function of temperature. The effects of pore size as well as of different LC media on the shielding anisotropy are examined and discussed. PMID:18338070

  18. Differential cross sections and product rotational polarization in A + BC reactions using wave packet methods: H+ + D2 and Li + HF examples.

    PubMed

    Zanchet, A; Roncero, O; González-Lezana, T; Rodríguez-López, A; Aguado, A; Sanz-Sanz, C; Gómez-Carrasco, S

    2009-12-31

    The state-to-state differential cross sections for some atom + diatom reactions have been calculated using a new wave packet code, MAD-WAVE3, which is described in some detail and uses either reactant or product Jacobi coordinates along the propagation. In order to show the accuracy and efficiency of the coordinate transformation required when using reactant Jacobi coordinates, as recently proposed [ J. Chem. Phys. 2006 , 125 , 054102 ], the method is first applied to the H + D(2) reaction as a benchmark, for which exact time-independent calculations are also performed. It is found that the use of reactant coordinates yields accurate results, with a computational effort slightly lower than that when using product coordinates. The H(+) + D(2) reaction, with the same masses but a much deeper insertion well, is also studied and exhibits a completely different mechanism, a complex-forming one which can be treated by statistical methods. Due to the longer range of the potential, product Jacobi coordinates are more efficient in this case. Differential cross sections for individual final rotational states of the products are obtained based on exact dynamical calculations for some selected total angular momenta, combined with the random phase approximation to save the high computational time required to calculate all partial waves with very long propagations. The results obtained are in excellent agreement with available exact time-independent calculations. Finally, the method is applied to the Li + HF system for which reactant coordinates are very well suited, and quantum differential cross sections are not available. The results are compared with recent quasiclassical simulations and experimental results [J. Chem. Phys. 2005, 122, 244304]. Furthermore, the polarization of the product angular momenta is also analyzed as a function of the scattering angle. PMID:20028163

  19. Spectroscopic Studies of Quantum Well Structures in Pulsed Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Perry, Clive H.

    1998-03-01

    Magneto-photoluminescence spectroscopy (MPS) at low temperatures is a powerful technique for investigating the ground and excited states of high quality quantum well-type semiconductor heterostructures. The spectra are strongly influenced by electron-electron interactions and the method offers a complimentary tool to electrical transport studies. We have established a MPS facility at NHMFL-LANL and have undertaken a comprehensive investigation of magneto-excitonic and Landau transitions in a large variety of undoped and doped (two-dimensional electron gas, 2DEG) GaAs/AlGaAs and InGaAs/GaAs quantum-well structures. Excitation energies are provided by UV, visible, and NIR lasers. Fiber optic probes are used to switch between steady state (to 18 tesla) and short-pulsed (to 65 tesla) magnetic fields applied perpendicular (Faraday geometry) and parallel (Voigt geometry) to the growth axis of the 2D layers. The experimental techniques, optical layout, and data acquisition are reviewed i n some detail. Short-pulse magnets require that the spectroscopic data acquisition to be obtained in a 2 ms time-frame in the 'flat-top' region at the peak of the field. A broad range of samples have been investigated as a function of temperature, sample geometry, and high pressure. Examples of MPL spectra of single and coupled double quantum wells, modulation-doped quantum wells, single interface structures, and other related semiconductor heterojunction structures are given. The recently commissioned long-pulse magnet at NHMFL-LANL offers several new exciting possibilities: (i) The long exponential decay associated with the crow-bar mode has the potential for spectroscopic studies from 60 -10 T in 0.5 T intervals from a single pulse. (ii) Field steps programmed to last from 100-500 ms or longer offer the opportunity for time-resolved MPL spectroscopy in the 60 - 10 T range.

  20. Satellite-bound ultraviolet spectroscopy of interstellar absorption lines using digital image evaluation - an example of modern research methods in astronomy

    NASA Astrophysics Data System (ADS)

    Skuppin, R.

    Four aspects of modern research methods in astronomy are discussed. They include: (1) the study of interstellar material, using stellar light as background illumination; (2) the study of radiation not visible to the naked eye; (3) the use of outer space detectors to study certain types of radiation; and (4) the use of computers in observations and data processing. The UV part of the nonoptical spectrum is stressed. The evaluation of data from the IUE satellite is discussed, and research results on interstellar elemental abundances are reviewed.

  1. Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

    SciTech Connect

    Stratton, B. C.; Biter, M.; Hill, K. W.; Hillis, D. L.; Hogan, J. T.

    2007-07-18

    Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

  2. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    SciTech Connect

    Banerjee, Amit; Banerjee, S. S.

    2014-05-15

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ∼0.9 nms{sup −1}. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  3. A numerical method for retrieving high oxygen isotope temperatures from plutonic igneous rocks: An example from the Laramie Anorthosite Complex, Wyoming, USA

    SciTech Connect

    Farquhar, J.; Chacko, T. . Dept. of Geology); Frost, B.R. )

    1992-01-01

    The Sybille Pit is a late-stage magnetite-ilmenite-plagioclase-bearing differentiate of the Laramie Anorthosite with a wide range of grain sizes and modal mineralogy. This variability makes Sybille an ideal locality in which to study the factors that affect isotopic thermometry in plutonic environments. The authors have developed a numerical model based on isotope exchange trajectories that retrieves close to magmatic temperatures for samples from Sybille. This method is based on the premise that hand sample-scale sub-systems close to exchange with each other at temperatures that exceed those of the constituent minerals. The temperature of hand-sample scale closure is retrieved by back calculating the isotope exchange trajectories to the temperature at which two samples with widely different model compositions are in isotopic equilibrium. Application of these methods to samples from Sybille provides promising results. Whereas conventional isotopic thermometry of individual samples yields a wide range of temperatures ([approximately]600 to > 1000 C) depending on the mineral-pair chosen, application of this numerical model to multiple samples yields temperatures of 1,070 [+-] 100 C which corresponds closely to the inferred solidus for these rocks.

  4. Complex-scaled equation-of-motion coupled-cluster method with single and double substitutions for autoionizing excited states: Theory, implementation, and examples

    NASA Astrophysics Data System (ADS)

    Bravaya, Ksenia B.; Zuev, Dmitry; Epifanovsky, Evgeny; Krylov, Anna I.

    2013-03-01

    Theory and implementation of complex-scaled variant of equation-of-motion coupled-cluster method for excitation energies with single and double substitutions (EOM-EE-CCSD) is presented. The complex-scaling formalism extends the EOM-EE-CCSD model to resonance states, i.e., excited states that are metastable with respect to electron ejection. The method is applied to Feshbach resonances in atomic systems (He, H-, and Be). The dependence of the results on one-electron basis set is quantified and analyzed. Energy decomposition and wave function analysis reveal that the origin of the dependence is in electron correlation, which is essential for the lifetime of Feshbach resonances. It is found that one-electron basis should be sufficiently flexible to describe radial and angular electron correlation in a balanced fashion and at different values of the scaling parameter, θ. Standard basis sets that are optimized for not-complex-scaled calculations (θ = 0) are not sufficiently flexible to describe the θ-dependence of the wave functions even when heavily augmented by additional sets.

  5. 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-destructive advantages of NIRS.

  6. Infrared and Raman spectroscopic methods for characterization of Taxus baccata L.--Improved taxane isolation by accelerated quality control and process surveillance.

    PubMed

    Gudi, Gennadi; Krähmer, Andrea; Koudous, Iraj; Strube, Jochen; Schulz, Hartwig

    2015-10-01

    Different yew species contain poisonous taxane alkaloids which serve as resources for semi-synthesis of anticancer drugs. The highly variable amounts of taxanes demand new methods for fast characterization of the raw plant material and the isolation of the target structures during phyto extraction. For that purpose, applicability of different vibrational spectroscopy methods in goods receipt of raw plant material and in process control was investigated and demonstrated in online tracking isolation and purification of the target taxane 10-deacetylbaccatin III (10-DAB) during solvent extraction. Applying near (NIRS) and mid infrared spectroscopy (IRS) the amount of botanical impurities in mixed samples of two different yew species (R(2)=0.993), the leave-to-wood ratio for Taxus baccata material (R(2)=0.94) and moisture in dried yew needles (R(2)=0.997) can be quantified. By partial least square analysis (PCA) needles of different Coniferales species were successfully discriminated by Attenuated Total Reflectance-Fourier-Transform Infrared Spectroscopy (ATR-FT-IR). The analytical potential of ATR-FT-IR and Fourier Transform-Raman Spectroscopy (FT-RS) in process control of extraction and purification of taxanes is demonstrated for determination of the water content in methanolic yew extracts (R(2)=0.999) and for quantification of 10-DAB (R(2)=0.98) on a highly sophisticated level. The decrease of 10-DAB in the plant tissue during extraction was successfully visualized by FT-IR imaging of thin cross sections providing new perspectives for process control and design. PMID:26078126

  7. Linking geophysics and soil function modelling - two examples

    NASA Astrophysics Data System (ADS)

    Krüger, J.; Franko, U.; Werban, U.; Dietrich, P.; Behrens, T.; Schmidt, K.; Fank, J.; Kroulik, M.

    2011-12-01

    iSOIL - "Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping" is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment. The iSOIL project aims at reliable mapping of soil properties and soil functions with various methods including geophysical, spectroscopic and monitoring techniques. The general procedure contains three steps (i) geophysical monitoring, (ii) generation of soil property maps and (iii) process modelling. The objective of this work is to demonstrate the methodological procedure on two different examples. Example A focuses on the turnover conditions for soil organic matter (SOM) since many soil functions in a direct or indirect way depend on SOM and SOM depletion is amongst the worst soil threats. Example B deals with the dynamics of soil water and the direct influence on crop biomass production. The applied CANDY model (Franko et al. 1995) was developed to describe dynamics of soil organic matter and mineral nitrogen as well as soil water and temperature. The new module PLUS extends CANDY to simulate crop biomass production based on environmental influences (Krüger et al. 2011). The methodological procedure of example A illustrates a model application for a field site in the Czech Republic using generated soil maps from combined geophysical data. Modelling requires a complete set of soil parameters. Combining measured soil properties and data of geophysical measurements (electrical conductivity and gamma spectrometry) is the basis for digital soil mapping which provided data about clay, silt and sand as well as SOC content. With these data pedotransfer functions produce detailed soil input data (e.g. bulk and particle density, field capacity, wilting point, saturated conductivity) for the rooted soil profile. CANDY calculated different indicators for SOM and gave hints about potential hot spots where local adaptations of agricultural management would be required to improve soil functions. Example B realizes a soil function modelling with an adapted model parameterization based on data of ground penetration radar (GPR). This work shows an approach to handle heterogeneity of soil properties with geophysical data used for modelling. The field site in Austria is characterised by highly heterogenic soil with fluvioglacial gravel sediments. The variation of thickness of topsoil above a sandy subsoil with gravels strongly influences the soil water balance. GPR detected exact soil horizon depth between topsoil and subsoil. The extension of the input data improves the model performance of CANDY PLUS for plant biomass production. Both examples demonstrate how geophysics provide a surplus of data for agroecosystem modelling which identifies and contributes alternative options for agricultural management decisions.

  8. Active Learning with Irrelevant Examples

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri; Mazzoni, Dominic

    2009-01-01

    An improved active learning method has been devised for training data classifiers. One example of a data classifier is the algorithm used by the United States Postal Service since the 1960s to recognize scans of handwritten digits for processing zip codes. Active learning algorithms enable rapid training with minimal investment of time on the part of human experts to provide training examples consisting of correctly classified (labeled) input data. They function by identifying which examples would be most profitable for a human expert to label. The goal is to maximize classifier accuracy while minimizing the number of examples the expert must label. Although there are several well-established methods for active learning, they may not operate well when irrelevant examples are present in the data set. That is, they may select an item for labeling that the expert simply cannot assign to any of the valid classes. In the context of classifying handwritten digits, the irrelevant items may include stray marks, smudges, and mis-scans. Querying the expert about these items results in wasted time or erroneous labels, if the expert is forced to assign the item to one of the valid classes. In contrast, the new algorithm provides a specific mechanism for avoiding querying the irrelevant items. This algorithm has two components: an active learner (which could be a conventional active learning algorithm) and a relevance classifier. The combination of these components yields a method, denoted Relevance Bias, that enables the active learner to avoid querying irrelevant data so as to increase its learning rate and efficiency when irrelevant items are present. The algorithm collects irrelevant data in a set of rejected examples, then trains the relevance classifier to distinguish between labeled (relevant) training examples and the rejected ones. The active learner combines its ranking of the items with the probability that they are relevant to yield a final decision about which item to present to the expert for labeling. Experiments on several data sets have demonstrated that the Relevance Bias approach significantly decreases the number of irrelevant items queried and also accelerates learning speed.

  9. Utilization of the limit equilibrium and finite element methods for the stability analysis of the slope debris: An example of the Kalebasi District (NE Turkey)

    NASA Astrophysics Data System (ADS)

    Alemdag, Selcuk; Kaya, Ayberk; Karadag, Mustafa; Gurocak, Zulfu; Bulut, Fikri

    2015-06-01

    The stability of the slope debris in residential area of the Kalebasi District (Ozkurtun-Gumushane) was investigated using the Limit Equilibrium (LE) and Finite Element Shear-Strength Reduction (FE-SSR) methods. Along the survey lines, four trial pits were dug and fourteen boreholes having a total length of 345 m were drilled. Also, seismic refraction studies were conducted along the five lines. According to the field studies, thickness of the slope debris covering the 98 ha of the study area varies between 1 and 36 m. To determine the physical and shear strength properties of the slope debris, undisturbed samples were taken from the trial pits. As a result of the laboratory tests, soil categories of the debris were found to be as Clayey Sand (SC), Silty Sand (SM) and Low Plasticity Clay (CL). The deformation-controlled shear box tests were carried out to determine the shear strength parameters of the slope debris. According to these tests it was found that the peak cohesion and peak friction angle varies between 2.63-16.35 kN/m2 and 20-27°, respectively. Stability analyses were performed using the obtained data from field and laboratory investigations in the Slide v5.0 and Phase2 v6.0 software programs and results were compared. In LE stability analyses, the factor of safety (FOS) of survey lines were found to be as 1.44, 1.80, 1.96, and 1.72; however for the FE-SSR method they were determined as 1.39, 1.72, 1.59, and 1.58, respectively.

  10. Development of a local-scale urban stream assessment method using benthic macroinvertebrates: An example from the Santa Clara Basin, California

    USGS Publications Warehouse

    Carter, J.L.; Purcell, A.H.; Fend, S.V.; Resh, V.H.

    2009-01-01

    Research that explores the biological response to urbanization on a site-specific scale is necessary for management of urban basins. Recent studies have proposed a method to characterize the biological response of benthic macroinvertebrates along an urban gradient for several climatic regions in the USA. Our study demonstrates how this general framework can be refined and applied on a smaller scale to an urbanized basin, the Santa Clara Basin (surrounding San Jose, California, USA). Eighty-four sampling sites on 14 streams in the Santa Clara Basin were used for assessing local stream conditions. First, an urban index composed of human population density, road density, and urban land cover was used to determine the extent of urbanization upstream from each sampling site. Second, a multimetric biological index was developed to characterize the response of macroinvertebrate assemblages along the urban gradient. The resulting biological index included metrics from 3 ecological categories: taxonomic composition ( Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (shredder richness), and habit ( clingers). The 90th-quantile regression line was used to define the best available biological conditions along the urban gradient, which we define as the predicted biological potential. This descriptor was then used to determine the relative condition of sites throughout the basin. Hierarchical partitioning of variance revealed that several site-specific variables (dissolved O2 and temperature) were significantly related to a site's deviation from its predicted biological potential. Spatial analysis of each site's deviation from its biological potential indicated geographic heterogeneity in the distribution of impaired sites. The presence and operation of local dams optimize water use, but modify natural flow regimes, which in turn influence stream habitat, dissolved O2, and temperature. Current dissolved O2 and temperature regimes deviate from natural conditions and appear to affect benthic macroinvertebrate assemblages. The assessment methods presented in our study provide finer-scale assessment tools for managers in urban basins. ?? North American Benthological Society.

  11. Are AB Initio Quantum Chemistry Methods Able to Predict Vibrational States up to the Dissociation Limit for Multi-Electron Molecules Close to Spectroscopic Accuracy?

    NASA Astrophysics Data System (ADS)

    Szalay, Péter G.; Holka, Filip; Fremont, Julien; Rey, Michael; Tyuterev, Vladimir G.

    2011-06-01

    The aim of the study was to explore the limits of initio methods towards the description of excited vibrational levels up to the dissociation limit for molecules having more than two electrons. To this end a high level ab initio potential energy function was constructed for the four-electron LiH molecule in order to accurately predict a complete set of bound vibrational levels corresponding to the electronic ground state. It was composed from: a) an ab initio non-relativistic potential obtained at the MR-CISD level including size-extensivity corrections and quintuple-sextuple ζ extrapolation of the basis, b) MVD (Mass-velocity-Darwin) relativistic corrections obtained at icMR-CISD/cc-pwCV5Z level, and c) DBOC (Diagonal Born-Oppenheimer correction) obtained at the MR-CISD/cc-pwCVTZ level. Finally, the importance of non-adiabatic effects was also tested by using atomic masses in the vibrational kinetic energy operator and by calculation of non-adiabatic coupling by ab initio methods. The calculated vibrational levels were compared with those obtained from experimental data [J.A. Coxon and C.S. Dickinson, J. Chem. Phys., 2004, 121, 9378]. Our best estimate of the potential curve results in vibrational energies with a RMS deviation of only ˜1 wn\\ for the entire set of all empirically determined vibrational levels known so far. These results represent a drastic improvement over previous theoretical predictions of vibrational levels of ^7LiH up to dissociation, D_0, which was predicted to be 19594 Cm-1. In addition, rotational levels have also been calculated. The RMS deviation between our ab initio calculations and empirical results by Coxon and Dickinson for rotational spacings Δ E = E(v, J = 1)-E(v, J = 0) over all available vibrational states of ^7LiH from v = 0 to v= 20 is 0.010 wn (with nuclear masses) and 0.006 wn (with atomic masses). Note that for high vibrational states with v > 6 this falls within the uncertainty of the measurements.

  12. Elemental and structural analysis of silicon forms in herbal drugs using silicon-29 MAS NMR and WD-XRF spectroscopic methods.

    PubMed

    Pajchel, L; Nykiel, P; Kolodziejski, W

    2011-12-01

    The objective of this work was to study concentration of silicon and its structural forms present in herbal drugs. Equisetum arvense and Urtica dioica L. from teapot bags, dietary supplements (tablets and capsules) containing those herbs, dry extract obtained from a teapot bag of E. arvense, and samples of the latter herb harvested in wild habitat over four months were studied using wavelength dispersive X-ray spectroscopy (WD-XRF) and high-resolution solid-state (29)Si NMR. The highest concentration of Si, ca. 27mg/g, was found in the herbal material from the teapot bags containing E. arvense. The Si content in natural E. arvense (whole plants) increased from May to August by ca. 7mg/g, reaching value 26mg/g. Three different silicon forms were detected in the studied herbal samples: Si(OSi)4 (Q(4)), Si(OH)(OSi)3 (Q(3)) and Si(OH)2(OSi)2 (Q(2)). Those sites were populated in E. arvense in the following order: Q(4)≫Q(3)>Q(2). A dramatic, ca. 50-fold decrease of the Si concentration during the infusion process was observed. The infusion process and the subsequent drying procedure augmented population of the Q(4) sites at the cost of the Q(2) sites. The WD-XRF and (29)Si NMR methods occurred useful and complementary in the study of herbal materials. PMID:21813258

  13. A grid matrix-based Raman spectroscopic method to characterize different cell milieu in biopsied axillary sentinel lymph nodes of breast cancer patients.

    PubMed

    Som, Dipasree; Tak, Megha; Setia, Mohit; Patil, Asawari; Sengupta, Amit; Chilakapati, C Murali Krishna; Srivastava, Anurag; Parmar, Vani; Nair, Nita; Sarin, Rajiv; Badwe, R

    2016-01-01

    Raman spectroscopy which is based upon inelastic scattering of photons has a potential to emerge as a noninvasive bedside in vivo or ex vivo molecular diagnostic tool. There is a need to improve the sensitivity and predictability of Raman spectroscopy. We developed a grid matrix-based tissue mapping protocol to acquire cellular-specific spectra that also involved digital microscopy for localizing malignant and lymphocytic cells in sentinel lymph node biopsy sample. Biosignals acquired from specific cellular milieu were subjected to an advanced supervised analytical method, i.e., cross-correlation and peak-to-peak ratio in addition to PCA and PC-LDA. We observed decreased spectral intensity as well as shift in the spectral peaks of amides and lipid bands in the completely metastatic (cancer cells) lymph nodes with high cellular density. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to create an automated smart diagnostic tool for bench side screening of sampled lymph nodes. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to develop an automated smart diagnostic tool for bench side screening of sampled lymph nodes supported by ongoing global research in developing better technology and signal and big data processing algorithms. PMID:26552923

  14. Spectroscopic and electrical studies on Nd3+, Zr4+ ions doped nano-sized BaTiO3 ferroelectrics prepared by sol-gel method

    NASA Astrophysics Data System (ADS)

    Sameera Devi, Ch.; Kumar, G. S.; Prasad, G.

    2015-02-01

    Lead free ferroelectric ceramics in the form of Ba(1-3x)Nd(2x)Ti(1-y)ZryO3 ((where x = 0.025, y = 0 (BT1), 0.025 (BT2), 0.05 (BT3)) were prepared using sol-gel method. The surface morphology and the orientation of grains of the present ceramics were examined using Field Emission Scanning Electron Microscope (FESEM) images. The effect of Nd3+, Zr4+ ions content on the BaTiO3 was studied using Raman and Fourier Transform Infrared (FTIR) spectroscopies. From the Raman analysis the band observed at ∼838 cm-1 was attributed due to the presence of Nd3+-barium vacancy pairs. The FTIR studies suggested that the addition of Nd3+ ions in A-site of BaTiO3 (ABO3) perovskite create lattice distortion by forming A-site vacancies and Zr4+ ions in B-site of BaTiO3 induce the lattice distortion by forming ZrO6 octahedra in the place of TiO6 octahedra. Dielectric measurements of the samples were done at different frequencies from RT-150 °C. Charge transportation phenomenon is explained using DC conductivity, which is found to increase with temperature.

  15. Study of fluorescence interaction and conformational changes of bovine serum albumin with histamine H₁ -receptor--drug epinastine hydrochloride by spectroscopic and time-resolved fluorescence methods.

    PubMed

    Ariga, Girish G; Naik, Praveen N; Nandibewoor, Sharanappa T; Chimatadar, Shivamurti A

    2015-11-01

    The fluorescence, ultraviolet (UV) absorption, time resolved techniques, circular dichroism (CD), and infrared spectral methods were explored as tools to investigate the interaction between histamine H1 drug, epinastine hydrochloride (EPN), and bovine serum albumin (BSA) under simulated physiological conditions. The experimental results showed that the quenching of the BSA by EPN was static quenching mechanism and also confirmed by lifetime measurements. The value of n close to unity indicated that one molecule of EPN was bound to protein molecule. The binding constants (K) at three different temperatures were calculated (7.1 × 10(4), 5.5 × 10(4), and 3.9 × 10(4) M(-1)). Based on the thermodynamic parameters (ΔH(0), ΔG(0), and ΔS(0)), the nature of binding forces operating between drug and protein was proposed. The site of binding of EPN in the protein was proposed to be Sudlow's site I based on displacement experiments using site markers viz, warfarin, ibuprofen, and digitoxin. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r between the donor (BSA) and acceptor (EPN) was evaluated and found to be 4.48 nm. The UV-visible, synchronous fluorescence, CD, and three-dimensional fluorescence spectral results revealed the changes in secondary structure of the protein upon its interaction with EPN. PMID:26215421

  16. Application of spectroscopic methods for identification (FT-IR, Raman spectroscopy) and determination (UV, EPR) of quercetin-3-O-rutinoside. Experimental and DFT based approach

    NASA Astrophysics Data System (ADS)

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-01

    Vibrational (FT-IR, Raman) and electronic (UV, EPR) spectral measurements were performed for an analysis of rutin (quercetin-3-O-rutinoside) obtained from Rutaofficinalis. The identification of rutin was done with the use of FT-IR and Raman spectra. Those experimental spectra were determined with the support of theoretical calculations based on a DFT method with the B3LYP hybrid functional and 6-31G(d,p) basis set. The application of UV and EPR spectra was found to be a suitable analytical approach to the evaluation of changes in rutin exposed to certain physicochemical factors. Differences in absorbance observed in direct UV spectra were used to monitor changes in the concentration of rutin in degraded samples. Spectra of electron paramagnetic resonance allowed studying the process of free-radical quenching in rutin following its exposure to light. The molecular electrostatic potential (MEP) and frontier molecular orbitals (LUMO-HOMO) were also determined in order to predict structural changes and reactive sites in rutin.

  17. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Gersonde, I.; Meinke, M.; Sterry, W.; Lademann, J.

    2005-08-01

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar+ laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm-1, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm2. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group.

  18. Spectroscopic investigation (FTIR spectrum), NBO, HOMO-LUMO energies, NLO and thermodynamic properties of 8-Methyl-N-vanillyl-6-nonenamideby DFT methods

    NASA Astrophysics Data System (ADS)

    Sherin Percy Prema Leela, J.; Hemamalini, R.; Muthu, S.; Al-Saadi, Abdulaziz A.

    2015-07-01

    Capsicum a hill grown vegetable is also known as red pepper or chili pepper. Capsaicin(8-Methyl-N-vanillyl-6-nonenamide) is the active component in chili peppers, which is currently used in the treatment of osteoarthritis, psoriasis and cancer. Fourier transform infrared (FT-IR) spectrum of Capsaicin in the solid phase were recorded in the region 4000-400 cm-1 and analyzed. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set and were compared with Fourier transform infrared spectrum. Complete vibrational assignment analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization and intra molecular hydrogen bond-like weak interaction has been analyzed using Natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalization energies E (2) confirm the occurrence of intra molecular charge transfer (ICT) within the molecule. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated.

  19. Spectroscopic Imaging of Strongly Correlated Electronic States

    NASA Astrophysics Data System (ADS)

    Yazdani, Ali; da Silva Neto, Eduardo H.; Aynajian, Pegor

    2016-03-01

    The study of correlated electronic systems from high-Tc cuprates to heavy-fermion systems continues to motivate the development of experimental tools to probe electronic phenomena in new ways and with increasing precision. In the past two decades, spectroscopic imaging with scanning tunneling microscopy has emerged as a powerful experimental technique. The combination of high energy and spatial resolutions provided by this technique reveals unprecedented detail of the electronic properties of strongly correlated metals and superconductors. This review examines specific experiments, theoretical concepts, and measurement methods that have established the application of these techniques to correlated materials. A wide range of applications, such as the study of collective responses to single atomic impurities, the characterization of quasiparticle-like excitations through their interference, and the identification of competing electronic phases using spectroscopic imaging, are discussed.

  20. Data Acquisition System for Instructional Spectroscopes

    NASA Astrophysics Data System (ADS)

    Almeida, C. B. S. B.; Hetem, A.

    2014-10-01

    This article aims to present the software for data acquisition developed in scientific initiation program - IC, for use in the design of a spectrometer built by students. The program was built in C++, a language in wide use today. The origin of spectra used is a simplified model of rustic spectroscope. This equipment basically consists of a box that does not allow light to enter, except through a slit made in the side of it, a diffraction media and a camera for data acquisition. After the image acquisition, one executes the data processing, followed by the usual steps of reduction and analysis of this type of tool. We have implemented a method for calibrating the spectroscope, through which one can compare the incidence of the photons with characteristic of each monochromatic wave. The final result is a one-dimensional spectrum that can be subsequently analyzed.

  1. Spectroscopic investigation (FTIR spectrum), NBO, HOMO-LUMO energies, NLO and thermodynamic properties of 8-Methyl-N-vanillyl-6-nonenamideby DFT methods.

    PubMed

    Leela, J Sherin Percy Prema; Hemamalini, R; Muthu, S; Al-Saadi, Abdulaziz A

    2015-07-01

    Capsicum a hill grown vegetable is also known as red pepper or chili pepper. Capsaicin(8-Methyl-N-vanillyl-6-nonenamide) is the active component in chili peppers, which is currently used in the treatment of osteoarthritis, psoriasis and cancer. Fourier transform infrared (FT-IR) spectrum of Capsaicin in the solid phase were recorded in the region 4000-400 cm(-1) and analyzed. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set and were compared with Fourier transform infrared spectrum. Complete vibrational assignment analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization and intra molecular hydrogen bond-like weak interaction has been analyzed using Natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalization energies E (2) confirm the occurrence of intra molecular charge transfer (ICT) within the molecule. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated. PMID:25813174

  2. High-Resolution Infrared-Vacuum Ultraviolet Photoion and Pulsed Field Ionization-Photoelectron Methods for Spectroscopic Studies of Neutrals and Cations

    NASA Astrophysics Data System (ADS)

    Xing, Xi; Reed, Beth; Bahng, Mi Kyung; Wang, Peng; Woo, Hin Koo; Jong Baek, Sun; Lam, Chee Shing; Yiu Ng, Cheuk

    2008-06-01

    We show that by scanning the frequency of a single mode infrared (IR) optical parametric oscillator (IR-OPO) laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet (VUV) laser to photoionize the IR excited species, high-resolution IR spectra of polyatomic neutrals can be obtained with high sensitivity. The fact that this IR-VUV-photoion (IR-VUV-PI) method is based on VUV photoionization probe, and thus, allows the identification of the neutral IR absorber, makes it applicable for IR spectroscopy measurements of isotopemers, radicals, and clusters, which usually exist as impure samples. The highly resolved IR-VUV-PI measurements achieved using the single mode IR-OPO laser have made possible the selection of single rovibrational states of CH3X (X = Br and I), C2H4, and C3H4 for VUV-pulsed field ionization-photoelectron (VUV-PFI-PE) measurements, resulting in rovibrationally resolved photoelectron spectra for these polyatomic molecules. These experiments show that the signal-to-noise ratios of the IR-VUV-PI and IR-VUV-PFI-PE spectra obtained by employing the high-resolution IR-OPO laser are significantly higher than those observed in previous IR-VUV-PI and IR-VUV-PFI-PE studies using a low-resolution IR-OPO laser. Further improvement in sensitivity of IR-VUV-PI and IR-VUV-PFI-PE measurements by using the collinear arrangement of IR-VUV lasers and molecular beam is discussed.

  3. Flux measurements using the BATSE spectroscopic detectors

    NASA Astrophysics Data System (ADS)

    McNamara, Bernard

    1993-11-01

    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.

  4. 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.

  5. Infrared spectroscopic imaging of kidney tumor tissue

    NASA Astrophysics Data System (ADS)

    Sablinskas, V.; Steiner, G.; Koch, E.; Ceponkus, J.; Pucetaite, M.; Strazdaite, S.; Urboniene, V.; Jankevicius, F.

    2011-02-01

    Infrared spectroscopic imaging of cancerous kidney tissue was performed by means of FTIR microscopy. The spectra of thin tissue cryosections were collected with 64x64 MCT FPA detector and imaging area was increased up to 5.4×5.4 mm by mapping by means of PC controlled x,y stage. Chemical images of the samples were constructed using statistical treatment of the raw spectra. Several unsupervised and supervised statistical methods were used. The imaging results are compared with results of the standard histopathological analysis. It was concluded that application of method of cluster analysis ensures the best contrast of the images. It was found that border between cancerous and normal tissues visible in the infrared spectroscopic image corresponds with the border visible in histopathological image. Closer examination of the infrared spectroscopic image reveals that small domains of cancerous cells are found beyond the border in areas distant from the border up to 3 mm. Such domains are not visible in the histopathological images. The smallest domains found in the infrared images are approx. 60 μm.

  6. Is the amphibian X. laevis WEC a good alternative method to rodent WEC teratogenicity assay? The example of the three triazole derivative fungicides Triadimefon, Tebuconazole, Cyproconazole.

    PubMed

    Di Renzo, Francesca; Bacchetta, Renato; Bizzo, Andrea; Giavini, Erminio; Menegola, Elena

    2011-09-01

    The aim of the present work is the assessment of teratogenic effects of three triazole-derived fungicides (Triadimefon, FON, Tebuconazole, TEBU, Cyproconazole, CYPRO) on rat and Xenopus laevis embryos cultured in vitro. Rat embryos, exposed to FON 31.25-250μM, CYPRO 31.25-62.5μM and to TEBU 62.5-250μM, showed specific malformations (fusions) at the level of the first and second branchial arches, with a concentration-dependent increase of severity of malformative pictures. After immunostaining, the ectomesenchyme has been identified as the target tissue. X. laevis larvae showed, at the same concentrations, specific malformations at the level of cartilaginous element derived from the first and second branchial arch ectomesenchyme. This work indicates the three tested triazoles as teratogenic both in rodents and in amphibian, inducing ectomesenchymal abnormalities, and suggests, at least for this class of molecules, the X. laevis method as adequate alternative model for teratogenic screening. PMID:21601633

  7. Improved gold chloride staining method for anatomical analysis of sensory nerve endings in the shoulder capsule and labrum as examples of loose and dense fibrous tissues

    PubMed Central

    Witherspoon, J W; Smirnova, IV; McIff, TE

    2014-01-01

    Consistency in gold chloride staining is essential for anatomical analysis of sensory nerve endings. The gold chloride stain for this purpose has been modified by many investigators, but often yields inconsistent staining, which makes it difficult to differentiate structures and to determine nerve ending distribution in large tissue samples. We introduce additional steps and major changes to the modified Gairns protocol. We controlled the temperature and mixing rate during tissue staining to achieve consistent staining and complete solution penetration. We subjected samples to sucrose dehydration to improve cutting efficiency. We then exposed samples to a solution containing lemon juice, formic acid and paraformaldehyde to produce optimal tissue transparency with minimal tissue deformity. We extended the time for gold chloride impregnation 1.5 fold. Gold chloride was reduced in the labrum using 25% formic acid in water for 18 h and in the capsule using 25% formic acid in citrate phosphate buffer for 2 h. Citrate binds gold nanoparticles, which minimizes aggregation in the tissue. We stored samples in fresh ultrapure water at 4 C to slow reduction and to maintain color contrast in the tissue. Tissue samples were embedded in Tissue Tek and sectioned at 80 and 100 ?m instead of using glycerin and teasing the tissue apart as in Gairns modified gold chloride method. We attached sections directly to gelatin subbed slides after sectioning with a cryostat. The slides then were processed and coverslipped with Permount. Staining consistency was demonstrated throughout the tissue sections and neural structures were clearly identifiable. PMID:24476562

  8. A new scheme for perturbative triples correction to (0,1) sector of Fock space multi-reference coupled cluster method: Theory, implementation, and examples

    SciTech Connect

    Dutta, Achintya Kumar E-mail: s.pal@ncl.res.in; Vaval, Nayana; Pal, Sourav E-mail: s.pal@ncl.res.in

    2015-01-28

    We propose a new elegant strategy to implement third order triples correction in the light of many-body perturbation theory to the Fock space multi-reference coupled cluster method for the ionization problem. The computational scaling as well as the storage requirement is of key concerns in any many-body calculations. Our proposed approach scales as N{sup 6} does not require the storage of triples amplitudes and gives superior agreement over all the previous attempts made. This approach is capable of calculating multiple roots in a single calculation in contrast to the inclusion of perturbative triples in the equation of motion variant of the coupled cluster theory, where each root needs to be computed in a state-specific way and requires both the left and right state vectors together. The performance of the newly implemented scheme is tested by applying to methylene, boron nitride (B{sub 2}N) anion, nitrogen, water, carbon monoxide, acetylene, formaldehyde, and thymine monomer, a DNA base.

  9. A new scheme for perturbative triples correction to (0,1) sector of Fock space multi-reference coupled cluster method: Theory, implementation, and examples

    NASA Astrophysics Data System (ADS)

    Dutta, Achintya Kumar; Vaval, Nayana; Pal, Sourav

    2015-01-01

    We propose a new elegant strategy to implement third order triples correction in the light of many-body perturbation theory to the Fock space multi-reference coupled cluster method for the ionization problem. The computational scaling as well as the storage requirement is of key concerns in any many-body calculations. Our proposed approach scales as N6 does not require the storage of triples amplitudes and gives superior agreement over all the previous attempts made. This approach is capable of calculating multiple roots in a single calculation in contrast to the inclusion of perturbative triples in the equation of motion variant of the coupled cluster theory, where each root needs to be computed in a state-specific way and requires both the left and right state vectors together. The performance of the newly implemented scheme is tested by applying to methylene, boron nitride (B2N) anion, nitrogen, water, carbon monoxide, acetylene, formaldehyde, and thymine monomer, a DNA base.

  10. Whole Class Laboratories: More Examples

    NASA Astrophysics Data System (ADS)

    Kouh, Minjoon

    2016-03-01

    Typically, introductory physics courses are taught with a combination of lectures and laboratories in which students have opportunities to discover the natural laws through hands-on activities in small groups. This article reports the use of Google Drive, a free online document-sharing tool, in physics laboratories for pooling experimental data from the whole class. This pedagogical method was reported earlier, and the present article offers a few more examples of such "whole class" laboratories.

  11. [A new herbs traceability method based on DNA barcoding-origin-morphology analysis--an example from an adulterant of 'Heiguogouqi'].

    PubMed

    Gu, Xuan; Zhang, Xiao-qin; Song, Xiao-na; Zang, Yi-mei; Li Yan-peng; Ma, Chang-hua; Zhao, Bai-xiao; Liu, Chun-sheng

    2014-12-01

    The fruit of Lycium ruthenicum is a common folk medicine in China. Now it is popular for its antioxidative effect and other medical functions. The adulterants of the herb confuse consumers. In order to identify a new adulterant of L. ruthenicum, a research was performed based on NCBI Nucleotide Database ITS Sequence, combined analysis of the origin and morphology of the adulterant to traceable varieties. Total genomic DNA was isolated from the materials, and nuclear DNA ITS sequences were amplified and sequenced; DNA fragments were collated and matched by using ContingExpress. Similarity identification of BLAST analysis was performed. Besides, the distribution of plant origin and morphology were considered to further identification and verification. Families and genera were identified by molecular identification method. The adulterant was identified as plant belonging to Berberis. Origin analysis narrowed the range of sample identification. Seven different kinds of plants in Berberis were potential sources of the sample. Adulterants variety was traced by morphological analysis. The united molecular identification-origin-morphology research proves to be a preceding way to medical herbs traceability with time-saving and economic advantages and the results showed the new adulterant of L. ruthenicum was B. kaschgarica. The main differences between B. kaschgarica and L. ruthenicum are as follows: in terms of the traits, the surface of B. kaschgarica is smooth and crispy, and that of L. ruthenicum is shrinkage, solid and hard. In microscopic characteristics, epicarp cells of B. aschgarica thickening like a string of beads, stone cells as the rectangle, and the stone cell walls of L. ruthenicum is wavy, obvious grain layer. In molecular sequences, the length of ITS sequence of B. kaschgarica is 606 bp, L. ruthenicum is 654 bp, the similarity of the two sequences is 53.32%. PMID:25898573

  12. Evaluation of endogenous allergens for the safety evaluation of genetically engineered food crops: review of potential risks, test methods, examples and relevance.

    PubMed

    Goodman, Richard E; Panda, Rakhi; Ariyarathna, Harsha

    2013-09-01

    The safety of food produced from genetically engineered (GE) crops is assessed for potential risks of food allergy on the basis of an international consensus guideline outlined by the Codex Alimentarius Commission (2003). The assessment focuses on evaluation of the potential allergenicity of the newly expressed protein(s) as the primary potential risk using a process that markedly limits risks to allergic consumers. However, Codex also recommended evaluating a second concern, potential increases in endogenous allergens of commonly allergenic food crops that might occur due to insertion of the gene. Unfortunately, potential risks and natural variation of endogenous allergens in non-GE varieties are not understood, and risks from increases have not been demonstrated. Because regulatory approvals in some countries are delayed due to increasing demands for measuring endogenous allergens, we present a review of the potential risks of food allergy, risk management for food allergy, and test methods that may be used in these evaluations. We also present new data from our laboratory studies on the variation of the allergenic lipid transfer protein in non-GE maize hybrids as well as data from two studies of endogenous allergen comparisons for three GE soybean lines, their nearest genetic soy lines, and other commercial lines. We conclude that scientifically based limits of acceptable variation cannot been established without an understanding of natural variation in non-GE crops. Furthermore, the risks from increased allergen expression are minimal as the risk management strategy for food allergy is for allergic individuals to avoid consuming any food containing their allergenic source, regardless of the crop variety. PMID:23848840

  13. A Unifying Probability Example.

    ERIC Educational Resources Information Center

    Maruszewski, Richard F., Jr.

    2002-01-01

    Presents an example from probability and statistics that ties together several topics including the mean and variance of a discrete random variable, the binomial distribution and its particular mean and variance, the sum of independent random variables, the mean and variance of the sum, and the central limit theorem. Uses Excel to illustrate these…

  14. Teaching Responsibility through Example

    ERIC Educational Resources Information Center

    Notar, Toni A.

    2008-01-01

    As Literacy Outreach Coordinator for Opportunity to Read (OTR), the Watsonville (CA) Public Library literacy program, this author has recognized the concept of responsibility through example. Adult learners incorporate concepts easily when these concepts are specifically demonstrated for them by someone similar to them. Sounds simple, but putting…

  15. Utility of telephone survey methods in population-based health studies of older adults: an example from the Alberta Older Adult Health Behavior (ALERT) study

    PubMed Central

    2014-01-01

    Background Random digit dialing is often used in public health research initiatives to accrue and establish a study sample; however few studies have fully described the utility of this approach. The primary objective of this paper was to describe the implementation and utility of using random digit dialing and Computer Assisted Telephone Interviewing (CATI) for sampling, recruitment and data collection in a large population-based study of older adults [Alberta Older Adult Health Behavior (ALERT) study]. Methods Using random digit dialing, older adults (> = 55 years) completed health behavior and outcome and demographic measures via CATI. After completing the CATI, participants were invited to receive a step pedometer and waist circumference tape measure via mail to gather objectively derived ambulatory activity and waist circumference assessments. Results Overall, 36,000 telephone numbers were called of which 7,013 were deemed eligible for the study. Of those, 4,913 (70.1%) refused to participate in the study and 804 (11.4%) participants were not included due to a variety of call dispositions (e.g., difficult to reach, full quota for region). A total of 1,296 participants completed telephone interviews (18.5% of those eligible and 3.6% of all individuals approached). Overall, 22.8% of households did not have an age 55+ resident and 13.6% of individuals refused to participate, Average age was 66.5 years, and 43% were male. A total of 1,081 participants (83.4%) also submitted self-measured ambulatory activity (i.e., via step pedometer) and anthropometric data (i.e., waist circumference). With the exception of income (18.7%), the rate of missing data for demographics, health behaviors, and health measures was minimal (<1%). Conclusions Older adults are willing to participate in telephone-based health surveys when randomly contacted. Researchers can use this information to evaluate the feasibility and the logistics of planned studies using a similar population and study design. PMID:24884997

  16. 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).

  17. 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

  18. 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 needle can give additional information of needle position, assuring the needle tip is directed into intervertebral disc material. Spectroscopic analysis of intervertebral disc removed during open surgery, creates background for further investigation on intervertebral disc degeneration spectral classification.

  19. Raman spectroscopic sensing using whispering gallery microresonators

    NASA Astrophysics Data System (ADS)

    Edwards, Perry; Janisch, Corey; Peng, Bo; Ozdemir, Sahin K.; Yang, Lan; Liu, Zhiwen

    2013-09-01

    We investigate Raman spectroscopic sensing using whispering gallery microresonators as a label-free method toward single particle detection. Whispering gallery mode microresonators are used as platforms to perform sensitive particle detection by exploiting the strong, evanescent field of a resonant mode exposed on the surface of the microresonator. Particles adhered to the microresonator surface interact with the field and scatter photons circulating within the resonator. In particular, Raman scattered photons are detected, providing molecular-specific "fingerprint" information regarding the adhered particles. The exploitation of a resonant mode allows for enhancement of generated Raman signal over traditional methods of spontaneous Raman scattering. Preliminary proof-of-concept experimental results are shown.

  20. Systematic reviews. Some examples.

    PubMed Central

    Knipschild, P.

    1994-01-01

    Reviewing the literature is a scientific inquiry that needs a clear design to preclude bias. It is a real enterprise if one aims at completeness of the literature on a certain subject. Going through refereed English language journals is not enough. On line databases are helpful, but mainly as a starting point. This article gives examples of systematic reviews on vitamin C and the common cold, pyridoxine against the premenstrual syndrome, homeopathy, and physiotherapy. Images p720-a PMID:7950526

  1. 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 from analysis of trace evidence (e.g. in soil), tablets, drugs, fibres, tape explosives, biological samples to detection of gunshot residues and imaging of fingerprints.

  2. Photometric and spectroscopic study of cD galaxies

    NASA Astrophysics Data System (ADS)

    Kemp, S. N.; Pérez-Hernández, Ernesto; Ramírez-Siordia, Víctor Hugo

    2016-02-01

    We have carried out photometry and spectroscopy on a sample of 10 cD galaxies. The photometry shows, in general, fairly flat and red profile colours, implying an envelope with the same stellar population as the central galaxy. This may indicate a possible primordial origin for both structures, consistent with ideas of downsizing. Preliminary spectroscopic results are generally in agreement with the photometry, with for example younger populations at large radii for A2199, but A2589 has only younger populations.

  3. Paleomagnetic dating: Methods, MATLAB software, example

    NASA Astrophysics Data System (ADS)

    Hnatyshin, Danny; Kravchinsky, Vadim A.

    2014-09-01

    A MATLAB software tool has been developed to provide an easy to use graphical interface for the plotting and interpretation of paleomagnetic data. The tool takes either paleomagnetic directions or paleopoles and compares them to a user defined apparent polar wander path or secular variation curve to determine the age of a paleomagnetic sample. Ages can be determined in two ways, either by translating the data onto the reference curve, or by rotating it about a set location (e.g. sampling location). The results are then compiled in data tables which can be exported as an excel file. This data can also be plotted using variety of built-in stereographic projections, which can then be exported as an image file. This software was used to date the giant Sukhoi Log gold deposit in Russia. Sukhoi Log has undergone a complicated history of faulting, folding, metamorphism, and is the vicinity of many granitic bodies. Paleomagnetic analysis of Sukhoi Log allowed for the timing of large scale thermal or chemical events to be determined. Paleomagnetic analysis from gold mineralized black shales was used to define the natural remanent magnetization recorded at Sukhoi Log. The obtained paleomagnetic direction from thermal demagnetization produced a paleopole at 61.3°N, 155.9°E, with the semi-major axis and semi-minor axis of the 95% confidence ellipse being 16.6° and 15.9° respectively. This paleopole is compared to the Siberian apparent polar wander path (APWP) by translating the paleopole to the nearest location on the APWP. This produced an age of 255.2- 31.0+ 32.0Ma and is the youngest well defined age known for Sukhoi Log. We propose that this is the last major stage of activity at Sukhoi Log, and likely had a role in determining the present day state of mineralization seen at the deposit.

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

    PubMed

    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

  5. An investigation using Spectroscopic Ellipsometery in Bio-Physical

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Galen; Thompson, Daniel; Berberov, Emil; Woollam, John; Bleiweiss, Michael; Datta, Timir

    2001-03-01

    The present work is an investigation of bio-physical systems using spectroscopic ellipsometry (SE), with wavelengths ranging from deep-ultraviolet to the far infrared. Recent advances in SE hardware, software and data analysis permit rapid, non-contact investigation of physical properties of nano-dimensional soft-material films and interfaces such as bio-films under liquids. The kinetics of attachment, layer thickness, density of coverage, and identification of interfacial chemistry of proteins, for example, on surfaces is of practical and fundamental importance in biology and medicine, and are potentially measurable by SE. Our initial findings determine adsorption rates of Bovine Serum Albumin (BSA) and other bio-films on gold and polystyrene substrates, as well as their spatial distributions. We were also able to identify attachment of a 2.5 nm layer of the diarrhea causing E. coli enterotoxin (LT) to ganglioside (GM1) receptor, potentially simplifying and providing more information to standard enzyme linked immuno sorbent assay (ELISA) methods. Results of studies of several different bio-physical systems using SE will be discussed.

  6. 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

  7. Polarization sensitive spectroscopic optical coherence tomography for multimodal imaging

    NASA Astrophysics Data System (ADS)

    Strąkowski, Marcin R.; Kraszewski, Maciej; Strąkowska, Paulina; Trojanowski, Michał

    2015-03-01

    Optical coherence tomography (OCT) is a non-invasive method for 3D and cross-sectional imaging of biological and non-biological objects. The OCT measurements are provided in non-contact and absolutely safe way for the tested sample. Nowadays, the OCT is widely applied in medical diagnosis especially in ophthalmology, as well as dermatology, oncology and many more. Despite of great progress in OCT measurements there are still a vast number of issues like tissue recognition or imaging contrast enhancement that have not been solved yet. Here we are going to present the polarization sensitive spectroscopic OCT system (PS-SOCT). The PS-SOCT combines the polarization sensitive analysis with time-frequency analysis. Unlike standard polarization sensitive OCT the PS-SOCT delivers spectral information about measured quantities e.g. tested object birefringence changes over the light spectra. This solution overcomes the limits of polarization sensitive analysis applied in standard PS-OCT. Based on spectral data obtained from PS-SOCT the exact value of birefringence can be calculated even for the objects that provide higher order of retardation. In this contribution the benefits of using the combination of time-frequency and polarization sensitive analysis are being expressed. Moreover, the PS-SOCT system features, as well as OCT measurement examples are presented.

  8. Effects of Worked Examples, Example-Problem, and Problem-Example Pairs on Novices' Learning

    ERIC Educational Resources Information Center

    van Gog, Tamara; Kester, Liesbeth; Paas, Fred

    2011-01-01

    Research has demonstrated that instruction that relies more heavily on example study is more effective for novices' learning than instruction consisting of problem solving. However, "a heavier reliance on example study" has been implemented in different ways. For example, worked examples only (WE), example-problem pairs (WE-PS), or problem-example…

  9. [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

  10. Analysis of spectroscopic ellipsometric measurements

    NASA Astrophysics Data System (ADS)

    Verbruggen, M. H. W.; de Nijs, J. M. M.

    1992-02-01

    In recent years spectroscopic ellipsometry has been succesfully to non-destructive characterize multi-layer materials and to monitor surface processes as a function of time. The extraction of the relevant parameters of these samples from the spectroscopic data requires extensive computer analysis. For this purpose the sample is described by means of a stratified-layer theory in combination with an effective medium approximation. The computer program presently discussed performs this analysis of spectroscopic-ellipsometric data for any arbitrary model and any arbitrary number of data points. It applies a least-squares fitting procedure based on a modified Levenberg-Marquardt routine. A special feature of the program is the implementation of linked list to obtain a very efficient data structure that allows a high flexibility of the program.

  11. Spectroscopic measurement of an atomic wave function

    SciTech Connect

    Kapale, Kishore T.; Qamar, Shahid; Zubairy, M. Suhail

    2003-02-01

    We present a simple spectroscopic method based on Autler-Townes spectroscopy to determine the center-of-mass atomic wave function. The detection of spontaneously emitted photons from a three-level atom, in which two upper levels are driven by a classical standing light, yields information about the position and momentum distribution of the atom [A. M. Herkommer, W. P. Schleich, and M. S. Zubairy, J. Mod. Opt. 44, 2507 (1997)]. In this paper, we show that both the amplitude and phase information of the center-of-mass atomic wave function can be obtained from these distributions after a series of conditional measurements on the atom and the emitted photon.

  12. 2-Chloroethylisocyanate. Thermal decomposition and spectroscopic properties.

    PubMed

    Martínez Córdoba, Gustavo A; Ramos, Luis A; Ulic, Sonia E; Jios, Jorge L; DellaVédova, Carlos O; Pepino, Julieta; Burgos Paci, Maxi A; Argüello, Gustavo A; Ge, Maofa; Beckers, Helmut; Willner, Helge

    2011-08-11

    2-Chloroethylisocyanate has been studied in a thorough way. NMR, Raman, FTIR, and Ar-matrix vibrational spectra of the molecule are presented and discussed with the complement of ab initio and DFT methods. The spectroscopic results reveal the existence of anti and gauche conformers that are equally populated in the gas phase. Thermal decomposition between 393 and 648 K shows two different pathways depending on the temperature, which can be interpreted in terms of simple second- and first-order mechanisms, respectively. Quantum mechanical calculations reproduce the experimental results. PMID:21718037

  13. Spectroscopic analysis of insulating crystal fibers

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Byvik, C. E.; Albin, S.

    1988-01-01

    A new technique is described for investigating the optical properties of solid-state laser materials using single-crystal fibers grown by a laser-heated pedestal-growth technique. Single-crystal fiber samples can be prepared more rapidly and less expensively than crystals grown by more conventional methods; however, they are smaller and less uniform, making spectroscopic measurements difficult. A simple procedure for extracting the optical absorption and emission spectra of insulating crystal fibers is demonstrated with a titanium-doped sapphire fiber sample; results are comparable to those from Czochralski-grown material.

  14. Spectroscopic investigation of protein corona

    NASA Astrophysics Data System (ADS)

    Choudhary, Poonam

    Nanotechnology has revolutionalized the landscape of modern science and technology, including materials, electronics, therapeutics, bioimaging, sensing, and the environment. Research in the past decade has examined the fate of nanomaterials in vitro and in vivo, as well as the interactions between nanoparticles and biological and ecosystems using primarily toxicological and ecotoxicological approaches. However, due to the versatility in the physical and physicochemical properties of nanoparticles, and due to the vast complexity of their hosting systems, the solubility, transformation, and biocompatibility of nanomaterials are still poorly understood. Nanotechnology has been undergoing tremendous development in recent decades, driven by realized perceived applications of nanomaterials in electronics, therapeutics, imaging, sensing, environmental remediation, and consumer products. Nanoparticles on entering the blood stream undergo an identity change, they become coated with proteins. There are different kind of proteins present in blood. Proteins compete for getting coated over the surface of nanoparticle and this whole entity of proteins coated over nanoparticle surface is called Protein Corona. Proteins tightly bound to the surface of nanoparticle form hard corona and the ones loosely bound on the outer surface form soft corona. This dissertation is aimed at spectroscopic investigation of Protein Corona. Chapter I of this dissertation offers a comprehensive review of the literature based on nanomaterials with the focus on carbon based nanomaterilas and introduction to Protein Corona. Chapter II is based different methods used for Graphene Synthesis,different types of defects and doping. In Chapter III influence of defects on Graphene Protein Corona was investigated. Chapter IV is based on the study of Apoptosis induced cell death by Gold and silver nanoparticles. In vitro study of effect of Protein Corona on toxicity of cells was done.

  15. FLAPS (Fatigue Life Analysis Programs): Computer Programs to Predict Cyclic Life Using the Total Strain Version of Strainrange Partitioning and Other Life Prediction Methods. Users' Manual and Example Problems, Version 1.0

    NASA Technical Reports Server (NTRS)

    Arya, Vinod K.; Halford, Gary R. (Technical Monitor)

    2003-01-01

    This manual presents computer programs FLAPS for characterizing and predicting fatigue and creep-fatigue resistance of metallic materials in the high-temperature, long-life regime for isothermal and nonisothermal fatigue. The programs use the Total Strain version of Strainrange Partitioning (TS-SRP), and several other life prediction methods described in this manual. The user should be thoroughly familiar with the TS-SRP and these life prediction methods before attempting to use any of these programs. Improper understanding can lead to incorrect use of the method and erroneous life predictions. An extensive database has also been developed in a parallel effort. The database is probably the largest source of high-temperature, creep-fatigue test data available in the public domain and can be used with other life-prediction methods as well. This users' manual, software, and database are all in the public domain and can be obtained by contacting the author. The Compact Disk (CD) accompanying this manual contains an executable file for the FLAPS program, two datasets required for the example problems in the manual, and the creep-fatigue data in a format compatible with these programs.

  16. Working Towards Accreditation by the International Standards Organization 15189 Standard: How to Validate an In-house Developed Method an Example of Lead Determination in Whole Blood by Electrothermal Atomic Absorption Spectrometry

    PubMed Central

    Ramirez, Jose Manuel; Vest, Philippe; Chianea, Denis; Renard, Christophe

    2014-01-01

    Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics. PMID:25187889

  17. Working towards accreditation by the International Standards Organization 15189 Standard: how to validate an in-house developed method an example of lead determination in whole blood by electrothermal atomic absorption spectrometry.

    PubMed

    Garcia Hejl, Carine; Ramirez, Jose Manuel; Vest, Philippe; Chianea, Denis; Renard, Christophe

    2014-09-01

    Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics. PMID:25187889

  18. 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…

  19. Soft tissue imaging with photon counting spectroscopic CT.

    PubMed

    Shikhaliev, Polad M

    2015-03-21

    The purpose of this work was experimental investigation of photon counting spectroscopic CT (PCS-CT) imaging of anatomical soft tissue with clinically relevant size. The imaging experiments were performed using a spectroscopic CT system based on CdZnTe photon counting detector with two rows of pixels, 256 pixels in each row, 1  ×  1 mm(2) pixel size, and 25.6 cm detector length. The detector could split the x-ray energy spectrum to 5 regions (energy bins), and acquire 5 multi-energy (spectroscopic) CT images in a single CT scan. A sample of round shaped anatomical soft tissue of 14 cm diameter including lean and fat was used for imaging. To avoid the negative effect of anatomical noise on quantitative analysis, a spectroscopic CT phantom with tissue equivalent solid materials was used. The images were acquired at 60, 90, and 120 kVp tube voltages, and spectroscopic image series were acquired with 3 and 5 energy bins. Spectroscopic CT numbers were introduced and used to evaluate an energy selective image series. The anatomical soft tissue with 14 cm diameter was visualized with good quality and without substantial artifacts by the photon counting spectroscopic CT system. The effects of the energy bin crosstalk on spectroscopic CT numbers were quantified and analyzed. The single and double slice PCS-CT images were acquired and compared. Several new findings were observed, including the effect of soft tissue non-uniformity on image artifacts, unique status of highest energy bin, and material dependent visualization in spectroscopic image series. Fat-lean decomposition was performed using dual energy subtraction and threshold segmentation methods, and compared. Using K-edge filtered x-rays improved fat-lean decomposition as compared to conventional x-rays. Several new and important aspects of the PCS-CT were investigated. These include imaging soft tissue with clinically relevant size, single- and double-slice PCS-CT imaging, using spectroscopic CT numbers to quantify multi-energy PCS-CT images, application of K-edge filtered x-rays for improved soft tissue decomposition, and several others. The study suggests that the presented PCS-CT technology meets the requirements of a particular clinical application, i.e. dedicated breast CT. PMID:25739788

  20. Soft tissue imaging with photon counting spectroscopic CT

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.

    2015-03-01

    The purpose of this work was experimental investigation of photon counting spectroscopic CT (PCS-CT) imaging of anatomical soft tissue with clinically relevant size. The imaging experiments were performed using a spectroscopic CT system based on CdZnTe photon counting detector with two rows of pixels, 256 pixels in each row, 1  ×  1 mm2 pixel size, and 25.6 cm detector length. The detector could split the x-ray energy spectrum to 5 regions (energy bins), and acquire 5 multi-energy (spectroscopic) CT images in a single CT scan. A sample of round shaped anatomical soft tissue of 14 cm diameter including lean and fat was used for imaging. To avoid the negative effect of anatomical noise on quantitative analysis, a spectroscopic CT phantom with tissue equivalent solid materials was used. The images were acquired at 60, 90, and 120 kVp tube voltages, and spectroscopic image series were acquired with 3 and 5 energy bins. Spectroscopic CT numbers were introduced and used to evaluate an energy selective image series. The anatomical soft tissue with 14 cm diameter was visualized with good quality and without substantial artifacts by the photon counting spectroscopic CT system. The effects of the energy bin crosstalk on spectroscopic CT numbers were quantified and analyzed. The single and double slice PCS-CT images were acquired and compared. Several new findings were observed, including the effect of soft tissue non-uniformity on image artifacts, unique status of highest energy bin, and material dependent visualization in spectroscopic image series. Fat-lean decomposition was performed using dual energy subtraction and threshold segmentation methods, and compared. Using K-edge filtered x-rays improved fat-lean decomposition as compared to conventional x-rays. Several new and important aspects of the PCS-CT were investigated. These include imaging soft tissue with clinically relevant size, single- and double-slice PCS-CT imaging, using spectroscopic CT numbers to quantify multi-energy PCS-CT images, application of K-edge filtered x-rays for improved soft tissue decomposition, and several others. The study suggests that the presented PCS-CT technology meets the requirements of a particular clinical application, i.e. dedicated breast CT.

  1. Reconstruction of Detached Divertor Plasma Conditions in DIII-D Using Spectroscopic and Probe Data

    SciTech Connect

    Stangeby, P; Fenstermacher, M

    2004-12-03

    For some divertor aspects, such as detached plasmas or the private flux zone, it is not clear that the controlling physics has been fully identified. This is a particular concern when the details of the plasma are likely to be important in modeling the problem--for example, modeling co-deposition in detached inner divertors. An empirical method of ''reconstructing'' the plasma based on direct experimental measurements may be useful in such situations. It is shown that a detached plasma in the outer divertor leg of DIII-D can be reconstructed reasonably well using spectroscopic and probe data as input to a simple onion-skin model and the Monte Carlo hydrogenic code, EIRENE. The calculated 2D distributions of n{sub e} and T{sub e} in the detached divertor were compared with direct measurements from the divertor Thomson scattering system, a diagnostic capability unique to DIII-D.

  2. Starfish: Robust spectroscopic inference tools

    NASA Astrophysics Data System (ADS)

    Czekala, Ian; Andrews, Sean M.; Mandel, Kaisey S.; Hogg, David W.; Green, Gregory M.

    2015-05-01

    Starfish is a set of tools used for spectroscopic inference. It robustly determines stellar parameters using high resolution spectral models and uses Markov Chain Monte Carlo (MCMC) to explore the full posterior probability distribution of the stellar parameters. Additional potential applications include other types of spectra, such as unresolved stellar clusters or supernovae spectra.

  3. Fourier transform infared spectroscopic imaging for the identification of concealed drug residue particles and fingerprints

    NASA Astrophysics Data System (ADS)

    Ricci, Camilla; Chan, K. L. Andrew; Kazarian, Sergei G.

    2006-09-01

    Conventional FTIR spectroscopy and microscopy has been widely used in forensic science. New opportunities exist to obtain rapid chemical images and to enhance the sensitivity of detection of trace materials using attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy coupled with a focal-plane array (FPA) detector. In this work, the sensitivity of ATR-FTIR spectroscopic imaging using three different kinds of ATR crystals (Ge coupled with an infrared microscope, ZnSe and diamond) and resulting in three different optical arrangements for the detection of model drug particles is discussed. Model systems of ibuprofen and paracetamol particles having a size below 32 micrometers have been prepared by sieving. The sensitivity level in the three different approaches has been compared and it has been found that both micro and macro-ATR imaging methods have proven to be a promising techniques for the identification of concealed drug particles. To demonstrate the power and applicability of FTIR chemical imaging to forensic research, various examples are discussed. This includes investigation of the changes of chemical nature of latent fingerprint residue under controlled conditions of humidity and temperature studied by ATR-FTIR imaging. This study demonstrates the potential of spectroscopic imaging for visualizing the chemical changes of fingerprints.

  4. Extracting spectroscopic factors from direct reactions

    NASA Astrophysics Data System (ADS)

    Jones, Kate

    2009-10-01

    Direct reactions have been used to probe the structure of the nucleus for decades. After some decline in the 80's and 90's these methods have more recently had a surge in popularity, and new techniques have been added to the experimentalists toolbox. One goal of direct reaction experiments is to extract spectroscopic factors (SFs), related to the shell occupancy. SFs extracted from neutron knockout reactions show reductions, compared to the theoretical value, that are related to the neutron separation energy [1], whereas SFs from the well-established (e,e'p) reaction on stable nuclei are consistently 50% - 60% lower than those expected from the independent-particle shell model [2] over a wide range of masses. pardAs the extraction of spectroscopic factors from direct reaction measurements requires the comparison of data with calculated differential cross sections, the results are by nature model dependent. The influence of different scattering (commonly optical), and bound state potentials, should not be over-looked. Recent attempts to reanalyze single-neutron transfer data using a consistent approach have shown agreement with large basis shell model calculations [3], clearly conflicting with both the (e,e'p) and the knockout data. It has been suggested that the Asymptotic Normalization Coefficient (ANC) is a more valid quantity to extract when the reaction is peripheral [4]. spectroscopic factors are, how they are extracted and what they really mean will be discussed in this talk.[4pt] [1] Alexandra Gade, and Thomas Glasmacher, Prog Part. Nucl. Phys. 60 (2008) 161-224.[0pt] [2] G.J. Kramer, H.P. Blok, and L. Lapik'as, Nucl. Phys. A679 (2001) 267-286.[0pt] [3] Jenny Lee, M.B. Tsang, and W.G. Lynch, Phys. Rev C 75, (2007), 064320.[0pt] [4] D.Y. Pan, F.M. Nunes, and A.M. Mukhamedzhanov, Phys. Rev. C 75, (2007) 024601.

  5. Learning by Example.

    ERIC Educational Resources Information Center

    Butts, Thomas

    1982-01-01

    A dialog shows how student-teacher interaction on problems can help students learn. Fifty sample problems are provided as starting points for class discussions from grade three through college. Six purposes such problems can serve are identified. A method of classroom presentation, the mathematical scavenger hunt, is discussed. (MP)

  6. Optical wavelength selection for improved spectroscopic photoacoustic imaging☆

    PubMed Central

    Luke, Geoffrey P.; Nam, Seung Yun; Emelianov, Stanislav Y.

    2013-01-01

    Spectroscopic photoacoustic imaging has the potential to become a powerful tool that can estimate distributions of optically absorbing chromophores in the body. We have developed an algorithm to select imaging wavelengths for spectroscopic photoacoustics given the spectra of expected chromophores. The algorithm uses the smallest singular value of a matrix constructed from the absorption spectra as a criterion to remove extraneous wavelengths. The method performed significantly better than an approach where evenly spaced wavelengths were used in the presence of noise and wavelength-dependent attenuation of light in tissue. Finally, the algorithm was applied to photoacoustic imaging of a phantom containing indocyanine green dye and silica-coated gold nanorods, demonstrating significant improvements in the ability to estimate relative contrast agent concentrations compared to the case where evenly spaced wavelengths were chosen. In summary, our work provides a versatile framework to select optical wavelengths and evaluate sets of absorbers for spectroscopic photoacoustic imaging. PMID:25302148

  7. 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.

  8. Utility of magnetic resonance spectroscopic imaging for human epilepsy

    PubMed Central

    Kuzniecky, Ruben I.

    2015-01-01

    This review discusses the potential utility of broad based use of magnetic resonance (MR) spectroscopic imaging for human epilepsy and seizure localization. The clinical challenges are well known to the epilepsy community, intrinsic in the variability of location, volumetric size and network extent of epileptogenic tissue in individual patients. The technical challenges are also evident, with high performance requirements in multiple steps, including magnet homogeneity, detector performance, sequence design, speed of acquisition in addition to large territory spectral processing. We consider how MR spectroscopy and spectroscopic imaging has been informative for epilepsy thus far, with specific attention to what is measured, the interpretation of such measurements and technical performance challenges. Examples are shown from medial temporal lobe and neocortical epilepsies are considered from 4T, 7T and most recently 3T. PMID:25853088

  9. 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. PMID:23515866

  10. Host dependence of spectroscopic properties of cerium-doped glasses

    NASA Astrophysics Data System (ADS)

    Jiang, Chun; Zeng, QingJi; Gan, Fuxi

    2000-11-01

    Oxide glasses containing Ce were prepared by the conventional melting method under reducing atmosphere. Spectroscopic properties of the glasses were studied by steady-state luminescence spectroscopy. In the present paper we made a report to summarize the characteristics of excitation and emission spectra in difference oxide hosts.

  11. Review of Spectroscopic Data for Measurements of Stratospheric Species

    NASA Technical Reports Server (NTRS)

    Goldman, A. (Editor); Hoell, J. M., Jr. (Editor)

    1980-01-01

    Results and recommendations from a two day workshop are discussed. A review of the current status of experimental and theoretical spectroscopic data on molecules of stratospheric interest is given along with recommendations for additional research. Methods for disseminating new and existing data are also discussed.

  12. Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation

    EPA Science Inventory

    Arsenate adsorption on amorphous (RuO2•1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

  13. Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation

    EPA Science Inventory

    Arsenate adsorption on amorphous (RuO21.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

  14. Statistical analysis of the impact of spectral correlation on observed formation constants from UV-visible spectroscopic measurements.

    PubMed

    Meinrath, Günther; Lis, Stefan; Piskula, Zbigniew

    2004-01-01

    Information retrieved from UV-visible spectroscopic data by application of a self-modelling factor analysis algorithm showed apparently systematically shifted thermodynamic properties for the same chemical system as a function of spectral slit widths. This empirical observation triggered a systematic investigation into the likely effects of residual and spectral correlation on the numerical results from quantitative spectroscopic investigations. If slit width was a nuisance factor it would reduce the comparability of information evaluated from spectroscopic data. The influence of spectral slit width was investigated by simulation, i.e. by generating and evaluating synthetic spectra with known properties. The simulations showed that increasing spectral correlation may introduce bias into factor analysis evaluations. By evaluation of the complete measurement uncertainty budget using threshold bootstrap target factor (TB CAT) analysis, the apparent shifts are insignificant relative to the total width of the quantity's measurement uncertainty. Increasing the slit widths causes some systematic effects, for example broadening of the registered spectral bands and reduction of spectral noise, because of higher light intensity passing to the detector. Hence, the observed systematic shifts in mean values might be caused by some latent correlation. As a general conclusion, slit width does not affect bias. However, the simulations show that spectral correlation and residual correlation may cause bias. Residual correlation can be taken into account by computer-intensive statistical methods, for example moving block or threshold bootstrap analysis. Spectral correlation is a property of the chemical system under study and cannot be manipulated. As a major result, evidence is given showing that stronger spectral correlation ( r<-0.7) causes non-negligible bias in the evaluated thermodynamic information from such a system. PMID:14615865

  15. Application of a probabilistic neural network in radial-velocity curve analysis of the spectroscopic binary stars HD 152218, HD 143511, HD 27149, and ER Vul

    NASA Astrophysics Data System (ADS)

    Pirkhedri, A.; Ghaderi, K.; Javadi, H. H. S.; Karimizadeh, K.

    2012-04-01

    We use an Artificial Neural Network (ANN) to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of four double-lined spectroscopic binary systems HD 152218, HD 143511, HD 27149, and ER Vul, we find corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by others using more traditional methods.

  16. The power of example

    NASA Astrophysics Data System (ADS)

    Liliana Gheorghian, Mariana

    2014-05-01

    The Secondary School "Teodor Balan" was evaluated by the National Agency for Quality Assurance with the highest score in an urban area of the county, and is part of the community Gura Humorului, a tourist resort of national interest since 2005. Starting with 2006 the local government implemented a Local Plan, which promotes the concept of sustainable development adopted at the Earth Summit in Rio de Janeiro, in 1992. Our school shares the concept of sustainable development and regularly re-evaluates the relationship between man and nature, advocates solidarity between generations, and has constantly developed various successful programs with the students, parents, teachers, and local companies and administration. Quarterly, we maintain and protect the river valley of Moldova arboretum nearby the reserve Oligocene "Stone Pine" and the natural reserve "Stone Hawk". Regarding the preservation of forests, teams of students and teachers from the school conduct activities of afforestation and greening, for the protection of birds. In order to raise public awareness about the harmful effects of radiation on the environment, my work degree in Physics, sustained in 2007, had as theme: Ionizing radiation and radiation protection. The effects of climate change and increasing temperature, as well as the extinction of species such as Amanita regalis and Tremiscus helvelloides mushrooms was studied by my biology colleague, Adriana. She obtained her Ist teaching degree in 2008, with the study "Diversity of macromycetes reported in natural ecosystems surrounding Gura Humorului". There were also organized 3 roundtables in a public awareness campaign initiated by the Ministry of Environment and Climate Change on "Integrated Nutrient Pollution Control", and the students learned to take test samples to determine water quality in wells and springs. In order to promote these activities performed by both teachers and students, we organized a National Symposium on "Life sciences at the beginning of the XXI century" with the participation of several schools in the country in 2009 and 2011. The papers presented were diverse and gave examples of various teaching experiences and scientific information. Topics by the teachers: The impact of tourism on the environment, Tornadoes, Natural science and environmental education in school, Air Pollution and health, Ecological education of children from primary school, The effects of electromagnetic radiation, Formation of an ecological mentality using chemistry, Why should we protect water, Environmental education, Education for the future, SOS Nature, Science in the twenty-first century, etc. Topics by students: Nature- the palace of thermal phenomena, Life depends on heat, Water Mysteries, Global Heating, The Mysterious universe, etc. In March 2013 our school hosted an interesting exchange of ideas on environmental issues between our students and those from Bulgaria, Poland and Turkey, during a symposium of the Comenius multilateral project "Conserving Nature". In order to present the results of protecting nature in their communities, two projects "Citizen" qualified in the Program Civitas in the autumn of 2013. "The Battle" continues both in nature and in classrooms, in order to preserve the environment.

  17. Synergies between spectroscopic and asteroseismic surveys

    NASA Astrophysics Data System (ADS)

    Fu, Jianning; De Cat, Peter; Ren, An-Bing; Yang, Xiao-Hu; Catanzaro, Giovanni; Corbally, Christopher J.; Frasca, Antonio; Gray, Richard O.; Cecylia Molenda-Zakowicz, Joanna; Shi, Jian-Rong; Ali, Luo; Zhang, Haotong

    2015-08-01

    The NASA Kepler satellite has provided unprecedented high duty-cycle, high-precision light curves for a large number of stars by continuously monitoring a field of view in Cygnus-Lyra region, leading to great progress in both discovering exoplanets and characterizing planet-hosting stars by means of asteroseismic methods. The asteroseismic survey allows the investigation of stars covering the whole H-R diagram. However, the low precision of effective temperatures and surface gravities in the KIC10 catalogue and the lack of information on chemical composition, metallicity and rotation rate prevent asteroseismic modeling, requiring spectroscopic observations for thousands of asteroseismic targets in the Kepler field in a homogeneous way.In 2010, we initiated the LAMOST-Kepler project which aimed at collecting low-resolution spectra for as many objects from the KIC10 catalogue as possible, with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), a 4-m telescope equipped with 4,000 optical fibers. The first round of observations has been completed in fall 2014, covering all the 14 sub-fields at least once, resulting in more than 100,000 low-resolution spectra. The stellar atmospheric parameters are then derived and the results have been confirmed to be consistent with those reported in the literature based on high-resolution spectroscopy.

  18. Optoacoustic spectroscopic imaging of radiolucent foreign bodies

    NASA Astrophysics Data System (ADS)

    Page, Leland; Maswadi, Saher; Glickman, Randolph D.

    2010-03-01

    One of the leading causes of medical malpractice claims in emergency medicine is the misdiagnosis of the presence of foreign bodies. Radiolucent foreign bodies are especially difficult to differentiate from surrounding soft tissue, gas, and bone. Current imaging modalities employed for the detection of foreign bodies include: X-ray computed tomography, magnetic resonance, and ultrasound; however, there is no consensus as to which modality is optimal for diagnosis. Because many radiolucent foreign bodies have sufficient contrast for imaging in the optical domain, we are exploring the use of laser-induced optoacoustic imaging for the detection of foreign bodies, especially in craniofacial injuries, in which the foreign bodies are likely to lie within the penetration depth of visible and near infrared wavelengths. Tissue-simulating phantoms containing various common foreign bodies have been constructed. Images of these phantoms have been successfully generated using two laser-based optoacoustic imaging methods with different detection modalities. In order to enhance the image contrast, common foreign bodies are being scanned over a wide range of wavelengths to obtain the spectroscopic properties of the materials commonly associated with these foreign bodies. This spectroscopic characterization will help select specific wavelengths to be used for imaging specific objects and provide useful diagnostic data about the material properties of the object.

  19. Spectroscopic studies of coumarin in micelles.

    PubMed

    Marques, A D; Marques, G S

    1994-02-01

    Steady-state and time-resolved emission spectroscopic techniques have been employed to characterize the coumarin species and identify which species is solubilized in the hydrocarbon core micelles of triton X-100 (neutral), hexadecyltrimethyl ammonium bromide (cationic) and dodecyl lithium sulfate (anionic) solutions under physiological conditions at 77 K. The emission and absorption spectra for the following species of coumarin-monomer, hydrogenbonded complex, molecular aggregation and strong hydrophobic aggregates-were recorded in methylcyclohexane (MCH), ethanol, buffers and aqueous solutions. The fluorescence and phosphorescence emissions of monomer in MCH at 77 K are assigned as resulting from 1(pi, pi*)1 and 3(pi, pi*)1 states, respectively, originated from the ethylenic bond and carbonyl of the pyrone ring. Molecular orbital calculations using the Hydrogenic Atoms in Molecule, version 3, method were carried out to help interpretation of the spectroscopic results. The photophysical properties from each species are used to probe which species penetrates in the hydrophobic region of micelles. It was found that a fifth species of coumarin assigned as the "action species" is solubilized into the interior of micelles. These observations could lend some insight into the mechanism of transporting coumarins across the membrane. PMID:8165234

  20. Spectroscopic characterization of isomerization transition states.

    PubMed

    Baraban, Joshua H; Changala, P Bryan; Mellau, Georg Ch; Stanton, John F; Merer, Anthony J; Field, Robert W

    2015-12-11

    Transition state theory is central to our understanding of chemical reaction dynamics. We demonstrate a method for extracting transition state energies and properties from a characteristic pattern found in frequency-domain spectra of isomerizing systems. This pattern-a dip in the spacings of certain barrier-proximal vibrational levels-can be understood using the concept of effective frequency, ω(eff). The method is applied to the cis-trans conformational change in the S1 state of C2H2 and the bond-breaking HCN-HNC isomerization. In both cases, the barrier heights derived from spectroscopic data agree extremely well with previous ab initio calculations. We also show that it is possible to distinguish between vibrational modes that are actively involved in the isomerization process and those that are passive bystanders. PMID:26659051

  1. Spectroscopic characterization of isomerization transition states

    NASA Astrophysics Data System (ADS)

    Baraban, Joshua H.; Changala, P. Bryan; Mellau, Georg Ch.; Stanton, John F.; Merer, Anthony J.; Field, Robert W.

    2015-12-01

    Transition state theory is central to our understanding of chemical reaction dynamics. We demonstrate a method for extracting transition state energies and properties from a characteristic pattern found in frequency-domain spectra of isomerizing systems. This pattern—a dip in the spacings of certain barrier-proximal vibrational levels—can be understood using the concept of effective frequency, ωeff. The method is applied to the cis-trans conformational change in the S1 state of C2H2 and the bond-breaking HCN-HNC isomerization. In both cases, the barrier heights derived from spectroscopic data agree extremely well with previous ab initio calculations. We also show that it is possible to distinguish between vibrational modes that are actively involved in the isomerization process and those that are passive bystanders.

  2. 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.

  3. Wavelength modulation imaging with tunable mid-infrared semiconductor laser: spectroscopic and geometrical effects

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Peng, Chuan; Zhang, Huanlin; Le, Han Q.

    2004-10-01

    Wavelength modulation imaging (WMI) is capable of determining both spectroscopic and geometrical properties of a target, but the latter is often ignored in spectroscopic studies. This work theoretically and experimentally demonstrates the importance of both in WMI applications. Experiments were performed with an all-digital signal processing approach employing a tunable mid-infrared laser capable of digital wavelength modulation. All three orders of wavelength-derivative images, 0th, 1st, and 2nd are generated simultaneously. Higher order images can reveal or enhance features that are not evident in the 0th order. An example shows a synthetic imaging approach that combines the 2nd order WMI of CO gas with a focal plane array image to allow chemical visualization with minimal background clutter. In another example, fine geometrical features were revealed for a target that has little intrinsic spectroscopic signatures.

  4. An overview of methods for monitoring social disparities in cancer with an example using trends in lung cancer incidence by area-socioeconomic position and race-ethnicity, 1992-2004.

    PubMed

    Harper, Sam; Lynch, John; Meersman, Stephen C; Breen, Nancy; Davis, William W; Reichman, Marsha E

    2008-04-15

    The authors provide an overview of methods for summarizing social disparities in health using the example of lung cancer. They apply four measures of relative disparity and three measures of absolute disparity to trends in US lung cancer incidence by area-socioeconomic position and race-ethnicity from 1992 to 2004. Among females, measures of absolute and relative disparity suggested that area-socioeconomic and race-ethnic disparities increased over these 12 years but differed widely with respect to the magnitude of the change. Among males, the authors found substantial disagreement among summary measures of relative disparity with respect to the magnitude and the direction of change in disparities. Among area-socioeconomic groups, the index of disparity increased by 47% and the relative concentration index decreased by 116%, while for race-ethnicity the index of disparity increased by 36% and the Theil index increased by 13%. The choice of a summary measure of disparity may affect the interpretation of changes in health disparities. Important issues to consider are the reference point from which differences are measured, whether to measure disparity on the absolute or relative scale, and whether to weight disparity measures by population size. A suite of indicators is needed to provide a clear picture of health disparity change. PMID:18344513

  5. Maya blue: a computational and spectroscopic study.

    PubMed

    Giustetto, Roberto; Llabrés I Xamena, Francesc X; Ricchiardi, Gabriele; Bordiga, Silvia; Damin, Alessandro; Gobetto, Roberto; Chierotti, Michele R

    2005-10-20

    Maya Blue pigment, used in pre-Colombian America by the ancient Mayas, is a complex between the clay palygorskite and the indigo dye. The pigment can be manufactured by mixing palygorskite and indigo and heating to T > 120 degrees C. The most quoted hypothesis states that the dye molecules enter the microchannels which permeate the clay structure, thus creating a stable complex. Maya Blue shows a remarkable chemical stability, presumably caused by interactions formed between indigo and clay surfaces. This work aims at studying the nature of these interactions by means of computational and spectroscopic techniques. The encapsulation of indigo inside the clay framework was tested by means of molecular modeling techniques. The calculation of the reaction energies confirmed that the formation of the clay-organic complex can occur only if palygorskite is heated at temperatures well above the water desorption step, when the release of water is entropically favored. H-bonds between the clay framework and the indigo were detected by means of spectroscopic methods. FTIR spectroscopy on outgassed palygorskite and freshly synthesized Maya Blue samples showed that the presence of indigo modifies the spectroscopic features of both structural and zeolitic water, although no clear bands of the dye groups could be observed, presumably due to its very low concentration. The positions and intensities of delta(H2O) and nu(H2O) modes showed that part of the structural water molecules interact via a hydrogen bond with the C=O or N-H groups of indigo. Micro-Raman spectra clearly evidenced the presence of indigo both in original and in freshly synthesized Maya Blue. The nu(C=O) symmetric mode of Maya Blue red-shifts with respect to pure indigo, as the result of the formation of H-bonds with the nearest clay structural water. Ab initio quantum methods were applied on the indigo molecule, both isolated and linked through H-bonds with water, to calculate the magnitude of the expected vibrational shifts. Calculated and experimental vibrational shifts appeared to be in good agreement. The presence of a peak at 17.8 ppm and the shift of the N-H signal in the 1H MAS NMR spectrum of Maya Blue provide evidence of hydrogen bond interactions between indigo and palygorskite in agreement with IR and ab initio methods. PMID:16853500

  6. Data mining in big data sets of spectroscopic surveys

    NASA Astrophysics Data System (ADS)

    Luo, A.-Li

    2015-08-01

    More and more spectroscopic surveys provide many big datasets, in which various rare objects could be found. In this presentation, we suggested two different data mining approaches based on spectral feature by detection and machine learning way respectively. The most difficult thing of data mining is try to understand the result, and most of found outliers were finally identified as bad data. Candidates need follow up observations or multi waveband data to be confirmed. Some successful examples of newly discovered rare objects in SDSS and LAMOST data release are presented in this talk.

  7. Label free molecular sexing of monomorphic birds using infrared spectroscopic imaging.

    PubMed

    Steiner, Gerald; Preusse, Grit; Zimmerer, Cordelia; Krautwald-Junghanns, Maria-Elisabeth; Sablinskas, Valdas; Fuhrmann, Herbert; Koch, Edmund; Bartels, Thomas

    2016-04-01

    The absence of sexual dimorphism in many birds often makes sex determination difficult. In particular immature birds and adults of monomorphic species show no external sex characteristics. Molecular techniques based on DNA hybridization or polymerase chain reaction (PCR) are standard methods for sex identification. However, these methods are expensive and time consuming procedures and require special sample preparation. Noninvasive methods for a rapid determination of bird's gender are of increasing importance for ornithologists, breeders as well as for successful captive-breeding programs. Fourier transform infrared (FT-IR) spectroscopy is one such technique that can provide gender specific information. In this study, using the example of domestic pigeons (Columba livia f. dom.) we demonstrate that only a small amount of the feather pulp is needed to determine the gender. FT-IR spectroscopic images of feather pulp suspensions were recorded in transmission mode. Principal component analysis (PCA) and linear discriminant analysis (LDA) were performed to identify the sex. The gender related information are described by 2nd and 4th principal component principle component (PC). The 2nd PC represents different amounts of proteins while the 4th PC shows variations within the amide I and amide II bands as well as in the region of phosphate vibrations of nucleic acids. Blood cells of male pigeons exhibit a significantly higher amount of proteins and nucleic acids than those of female pigeons. Feather pulp samples of male species were assigned with 100% accuracy. Seven from eight female samples were assigned correctly while one sample could not be classified. This study demonstrates that the sex of domestic pigeons can be accurately and and rapidly identified by infrared spectroscopic imaging. PMID:26838394

  8. Spectroscopic Observation of Chemical Interaction Between Impact-induced Vapor Clouds and the Ambient Atmosphere

    NASA Technical Reports Server (NTRS)

    Sugita, S.; Heineck, J. T.; Schultz, P. H.

    2000-01-01

    Chemical reactions within impact-induced vapor clouds were observed in laboratory experiments using a spectroscopic method. The results indicate that projectile-derived carbon-rich vapor reacts intensively with atmospheric nitrogen.

  9. 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.

  10. Compact fluorescence spectroscopic tool for cancer detection

    NASA Astrophysics Data System (ADS)

    Nadeau, Valerie; Hamdan, Khaled; Hewett, Jacqueline; Makaryceva, Juljia; Tait, Iain; Cuschieri, Alfred; Padgett, Miles J.

    2002-05-01

    We describe a compact fluorescence spectroscopic tool for in vivo point monitoring of aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence and autofluorescence, as a non-invasive method of differentiating normal and cancerous tissue. This instrument incorporates a 405nm diode laser with a shutter to prevent exposure of tissue to harmful light doses and reduce photobleaching, a bifurcated optical fibre to allow illumination of tissue and collection of fluorescence with a single fibre, a compact grating spectrometer for collection of spectra and a PC for system control. We present spectra obtained using this system both during routine gastro-intestinal (GI) endoscopy for cancer detection and during photodynamic therapy (PDT) of anal intraepithelial neoplasia (AIN) for monitoring of treatment progress. These results illustrate the potential of the system to be used for fluorescence monitoring in a variety of clinical applications.

  11. 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. PMID:26767631

  12. Combining spectroscopic and photometric surveys: Same or different sky?

    NASA Astrophysics Data System (ADS)

    Eriksen, Martin; Gaztañaga, Enrique

    2015-08-01

    This paper looks at the combined constraints from a photometric and spectroscopic survey. These surveys will measure cosmology using weak lensing (WL), galaxy clustering, baryon acoustic oscillations (BAO) and redshift space distortions (RSD). We find, contrary to some findings in the recent literature, that overlapping surveys can give important benefits when measuring dark energy. We therefore try to clarify the status of this issue with a full forecast of two stage-IV surveys using a new approach to properly account for covariance between the different probes in the overlapping samples. The benefit of the overlapping survey can be traced back to two factors: additional observables and sample variance cancellation. Both needs to be taken into account and contribute equally when combining 3D power spectrum and 2D correlations for lensing. With an analytic example we also illustrate that for optimal constraints, one should minimize the (Pearson) correlation coefficient between cosmological and nuisance parameters and maximize the one among nuisance parameters (e.g. galaxy bias) in the two samples. This can be achieved by increasing the overlap between the spectroscopic and photometric surveys. We show how BAO, WL and RSD contribute to this benefit and also look at some other survey designs, such as photometric redshift errors and spectroscopic density.

  13. New Insight into the Observation of Spectroscopic Strength Reduction in Atomic Nuclei: Implication for the Physical Meaning of Spectroscopic Factors

    SciTech Connect

    Timofeyuk, N. K.

    2009-12-11

    Experimental studies of one-nucleon knockout from magic nuclei suggest that their nucleon orbits are not fully occupied. This conflicts a commonly accepted view of the shell closure associated with such nuclei. The conflict can be reconciled if the overlap between initial and final nuclear states in a knockout reaction are calculated by a nonstandard method. The method employs an inhomogeneous equation based on correlation-dependent effective nucleon-nucleon interactions and allows the simplest wave functions, in which all nucleons occupy only the lowest nuclear orbits, to be used. The method also reproduces the recently established relation between reduction of spectroscopic strength, observed in knockout reactions on other nuclei, and nucleon binding energies. The implication of the inhomogeneous equation method for the physical meaning of spectroscopic factors is discussed.

  14. Effects of Example Choice on Interest, Control, and Learning

    ERIC Educational Resources Information Center

    Reber, Rolf; Hetland, Hilde; Chen, Weiqin; Norman, Elisabeth; Kobbeltvedt, Therese

    2009-01-01

    We investigated example choice as a new method for the teaching of formal theoretical principles. Formal principles are presented with several examples from different topics, and students choose the one that interests them most. Example choice might be related to prior knowledge, interest, or perceived control. In an experimental study, we…

  15. 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.

  16. Rent Seeking: A Textbook Example

    ERIC Educational Resources Information Center

    Pecorino, Paul

    2007-01-01

    The author argues that the college textbook market provides a clear example of monopoly seeking as described by Tullock (1967, 1980). This behavior is also known as rent seeking. Because this market is important to students, this example of rent seeking will be of particular interest to them. (Contains 24 notes.)

  17. Proton magnetic resonance spectroscopic imaging in patients with cerebellar degeneration.

    PubMed

    Tedeschi, G; Bertolino, A; Massaquoi, S G; Campbell, G; Patronas, N J; Bonavita, S; Barnett, A S; Alger, J R; Hallett, M

    1996-01-01

    Using proton magnetic resonance spectroscopic imaging, we studied the cerebellum of 9 patients with cerebellar degeneration and of 9 age-matched normal control subjects. This technique permits the simultaneous measurement of N-acetylaspartate, choline-containing compounds, creatine/phosphocreatine, and lactate signal intensities from four 15-mm slices divided into 0.84-ml single-volume elements. Because patients with cerebellar degeneration often show substantial atrophy on magnetic resonance imaging (MRI), we specifically chose to analyze the spectroscopic signals only from tissue that did not have an atrophic appearance on the MRI. The spectroscopic findings showed a significant reduction of N-acetylaspartate in all parts of the cerebellum, a significant correlation with MRI scores of cerebellar atrophy, and a significant correlation with clinical rating scores of cerebellar disturbance. Our method of analysis suggests the presence of a neurodegenerative process in cerebellar areas that do not appear to be atrophic on the MRI. Some limitations of proton magnetic resonance spectroscopic imaging in the present study were related to the partial field inhomogeneity characteristics of the posterior fossa, the anatomical location of the cerebellum, and the particularly severe cerebellar atrophy in some of the patients. PMID:8572670

  18. 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.

  19. 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.

  20. Spectroscopic insight for tablet compression.

    PubMed

    Lakio, S; Ylinärä, H; Antikainen, O; Räikkönen, H; Yliruusi, J

    2015-02-01

    Tablet compression process has been studied over the years from various perspectives. However what exactly happens to material during compression is still unknown. In this study a novel compression die which enables real-time spectroscopic measurements during the compression of material is represented. Both near infrared and Raman spectroscope probes can be attached to the die. In this study the usage of the die is demonstrated by using Raman spectroscopy. Eicosane, d-glucose anhydrate, α-lactose monohydrate and xylitol were used in the study because their compression behavior and bonding properties during compression were assumed to be different. The intensity of the Raman signal changed during compression with all of the materials. However, the intensity changes were different within the materials. The biggest differences were within the xylitol spectra. It was noticed that some peaks disappeared with higher compression pressures indicating that the pressure affected variously on different bonds in xylitol structure. These reversible changes were supposed to relate the changes in conformation and crystal structure. As a conclusion, the die was found to be a significant addition for studying compression process in real-time. It can help to reveal Process induced transformations (PITs) occurring during powder compaction. PMID:25448072

  1. Spectroscopic Needs for Imaging Dark Energy Experiments

    DOE PAGESBeta

    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 scatter further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%); Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (λ/Δλ > ~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4 m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST; Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimize the uncertainty in their mean redshift, RMS dispersion, etc. – rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 30–60% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy – training and calibration of photometric redshifts – will require two separate solutions. For ongoing and future projects to reach their full potential, new spectroscopic samples of faint objects will be needed for training; those new samples may be suitable for calibration, but the latter possibility is uncertain. In contrast, wide-area samples of bright objects are poorly suited for training, but can provide high-precision calibrations via cross-correlation techniques. Additional training/calibration redshifts and/or host galaxy spectroscopy would enhance the use of supernovae and galaxy clusters for cosmology. We also summarize additional work on photometric redshift techniques that will be needed to prepare for data from ongoing and future dark energy experiments.« less

  2. 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 further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%); Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (λ/Δλ > ~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4 m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST; Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimize the uncertainty in their mean redshift, RMS dispersion, etc. – rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 30–60% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy – training and calibration of photometric redshifts – will require two separate solutions. For ongoing and future projects to reach their full potential, new spectroscopic samples of faint objects will be needed for training; those new samples may be suitable for calibration, but the latter possibility is uncertain. In contrast, wide-area samples of bright objects are poorly suited for training, but can provide high-precision calibrations via cross-correlation techniques. Additional training/calibration redshifts and/or host galaxy spectroscopy would enhance the use of supernovae and galaxy clusters for cosmology. We also summarize additional work on photometric redshift techniques that will be needed to prepare for data from ongoing and future dark energy experiments.

  3. 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; DellAntonio, 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-zs): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-zs 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 further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%); Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (?/?? > ~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4 m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST; Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimize the uncertainty in their mean redshift, RMS dispersion, etc. rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 3060% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy training and calibration of photometric redshifts will require two separate solutions. For ongoing and future projects to reach their full potential, new spectroscopic samples of faint objects will be needed for training; those new samples may be suitable for calibration, but the latter possibility is uncertain. In contrast, wide-area samples of bright objects are poorly suited for training, but can provide high-precision calibrations via cross-correlation techniques. Additional training/calibration redshifts and/or host galaxy spectroscopy would enhance the use of supernovae and galaxy clusters for cosmology. We also summarize additional work on photometric redshift techniques that will be needed to prepare for data from ongoing and future dark energy experiments.

  4. Determination of the asymptotic normalization coefficients for 14C + n <--> 15C, the 14C(n, gamma)15C reaction rate, and evaluation of a new method to determine spectroscopic factors

    SciTech Connect

    McCleskey, M.; Mukhamedzhanov, A. M.; Trache, L.; Tribble, R. E.; Banu, A.; Eremenko, V.; Goldberg, V. Z.; Lui, Y. W.; McCleskey, E.; Roeder, B. T.; Spiridon, A.; Carstoiu, F.; Burjan, V.; Hons, Z.; Thompson, I. J.

    2014-04-17

    The 14C + n <--> 15C system has been used as a test case in the evaluation of a new method to determine spectroscopic factors that uses the asymptotic normalization coefficient (ANC). The method proved to be unsuccessful for this case. As part of this experimental program, the ANCs for the 15C ground state and first excited state were determined using a heavy-ion neutron transfer reaction as well as the inverse kinematics (d,p) reaction, measured at the Texas A&M Cyclotron Institute. The ANCs were used to evaluate the astrophysical direct neutron capture rate on 14C, which was then compared with the most recent direct measurement and found to be in good agreement. A study of the 15C SF via its mirror nucleus 15F and a new insight into deuteron stripping theory are also presented.

  5. In vivo analysis of burns in a mouse model using spectroscopic optical coherence tomography

    PubMed Central

    Maher, Jason R.; Jaedicke, Volker; Medina, Manuel; Levinson, Howard; Selim, Maria Angelica; Brown, William J.; Wax, Adam

    2015-01-01

    Spectroscopic analysis of biological tissues can provide insight into changes in structure and function due to disease or injury. Depth resolved spectroscopic measurements can be implemented for tissue imaging using optical coherence tomography (OCT). Here spectroscopic OCT is applied to in vivo measurement of burn injury in a mouse model. Data processing and analysis methods are compared for their accuracy. Overall accuracy in classifying burned tissue was found to be as high as 91%, producing an area under the curve of a receiver operator characteristic curve of 0.97. The origins of the spectral changes are identified by correlation with histopathology. PMID:25360936

  6. Programmatic perspectives with technical examples for THz materials characterization

    NASA Astrophysics Data System (ADS)

    Buchwald, Walter

    2011-06-01

    THz technology has a rich history of use in the field of interstellar molecule identification where a variety of molecule specific vibrational and rotational spectroscopic signatures exist and has been aggressively investigated for use in advanced radar applications because of the immediate improvement in object resolution obtained at higher frequencies. Traditionally, high power THz systems have relied upon millimeter wave sources and frequency multiplication techniques to achieve acceptable output power levels, while lower power, table top spectroscopic systems, have relied on broadband incoherent light sources. With the advent of high power lasers, advances in non-linear optics, and new material systems, a number of promising techniques for the generation, detection and manipulation of THz radiation are currently under development and are considered the enabling technologies behind a variety of advanced THz applications. This work presents a programmatic overview of current trends in THz technology of interest to a variety of government organizations. It focuses on those techniques currently under investigation for the generation and detection of THz fields motivated, for example, by such diverse applications as metamaterial spectroscopy, TH imaging, long standoff chem/bio detection and THz communications. Examples of these new techniques will be presented which in turn will motivate the need for the characterization of application specific active and passive THz components.

  7. The GEISA Spectroscopic Database System in its latest Edition

    NASA Astrophysics Data System (ADS)

    Jacquinet-Husson, N.; Crépeau, L.; Capelle, V.; Scott, N. A.; Armante, R.; Chédin, A.

    2009-04-01

    GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information)[1] is a computer-accessible spectroscopic database system, designed to facilitate accurate forward planetary radiative transfer calculations using a line-by-line and layer-by-layer approach. It was initiated in 1976. Currently, GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer on board the METOP European satellite -http://earth-sciences.cnes.fr/IASI/)) through the GEISA/IASI database[2] derived from GEISA. Since the Metop (http://www.eumetsat.int) launch (October 19th 2006), GEISA/IASI is the reference spectroscopic database for the validation of the level-1 IASI data, using the 4A radiative transfer model[3] (4A/LMD http://ara.lmd.polytechnique.fr; 4A/OP co-developed by LMD and Noveltis with the support of CNES). Also, GEISA is involved in planetary research, i.e.: modelling of Titan's atmosphere, in the comparison with observations performed by Voyager: http://voyager.jpl.nasa.gov/, or by ground-based telescopes, and by the instruments on board the Cassini-Huygens mission: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html. The updated 2008 edition of GEISA (GEISA-08), a system comprising three independent sub-databases devoted, respectively, to line transition parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols, will be described. Spectroscopic parameters quality requirement will be discussed in the context of comparisons between observed or simulated Earth's and other planetary atmosphere spectra. GEISA is implemented on the CNES/CNRS Ether Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated management software facilities. More than 350 researchers are registered for on line use of GEISA. Refs: 1. Jacquinet-Husson N., N.A. Scott, A. Chédin,L. Crépeau, R. Armante, V. Capelle, J. Orphal, A. Coustenis, C. Boonne, N. Poulet-Crovisier, et al. THE GEISA SPECTROSCOPIC DATABASE: Current and future archive for Earth and planetary atmosphere studies. JQSRT, 109, 1043-1059, 2008 2. Jacquinet-Husson N., N.A. Scott, A. Chédin, K. Garceran, R. Armante, et al. The 2003 edition of the GEISA/IASI spectroscopic database. JQSRT, 95, 429-67, 2005. 3. Scott, N.A. and A. Chedin, 1981: A fast line-by-line method for atmospheric absorption computations: The Automatized Atmospheric Absorption Atlas. J. Appl. Meteor., 20,556-564.

  8. More examples of chimpanzees teaching.

    PubMed

    Scheel, Matthew H; Shaw, Heidi L; Gardner, R Allen

    2015-01-01

    Darwinism is a principle of biological continuity. This commentary argues against any claim of discontinuity between humans and other animals that must be based on absence of evidence. Instead, we offer additional examples of active teaching by chimpanzees. PMID:26787532

  9. Traversable wormholes: Some simple examples

    SciTech Connect

    Visser, M.

    1989-05-15

    Building on the work of Morris, Thorne, and Yurtsever, some particularlysimple examples of traversable wormholes are exhibited. These examples arenotable both because the analysis is not limited to spherically symmetric casesand because it is possible to in some sense minimize the use of exotic matter.In particular, it is possible for a traveler to traverse such a wormholewithout passing through a region of exotic matter. As in previous analyses, theweak-energy condition is violated in these traversable wormholes.

  10. Homogeneous spectroscopic parameters for bright planet host stars from the northern hemisphere . The impact on stellar and planetary mass

    NASA Astrophysics Data System (ADS)

    Sousa, S. G.; Santos, N. C.; Mortier, A.; Tsantaki, M.; Adibekyan, V.; Delgado Mena, E.; Israelian, G.; Rojas-Ayala, B.; Neves, V.

    2015-04-01

    Aims: In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods: To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius. Results: We show that the spectroscopic parameters, masses, and radii are generally in good agreement with the values available in online databases of exoplanets. There are some exceptions, especially for the evolved stars. These are analyzed in detail focusing on the effect of the stellar mass on the derived planetary mass. Conclusions: We conclude that the stellar mass estimations for giant stars should be managed with extreme caution when using them to compute the planetary masses. We report examples within this sample where the differences in planetary mass can be as high as 100% in the most extreme cases. Based on observations obtained at the Telescope Bernard Lyot (USR5026) operated by the Observatoire Midi-Pyrénées and the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique of France (Run ID L131N11 - OPTICON_2013A_027).

  11. Water referencing for spectroscopic imaging.

    PubMed

    Spielman, D; Webb, P; Macovski, A

    1989-10-01

    A water referencing algorithm for addressing the spectroscopic imaging problems of low SNR and main field inhomogeneities is proposed. Using the location of the water peak from each voxel and additional a priori information results in a parametric estimation problem. Optimum estimates of the desired metabolite concentration can then be computed and displayed in an image format. The algorithm is shown to be very stable in the presence of noise and is insensitive to Bo inhomogeneity. A detailed error analysis as well as extensions to the basic data model are also discussed. Results from both 1H and 31P experiments are presented to verify the predicted good performance even with extremely low signal-to-noise ratio data. PMID:2607959

  12. 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.

  13. Remote spectroscopic identification of bloodstains.

    PubMed

    Bremmer, Rolf H; Edelman, Gerda; Vegter, Tessa Dijn; Bijvoets, Ted; Aalders, Maurice C G

    2011-11-01

    Blood detection and identification at crime scenes are crucial for harvesting forensic evidence. Unfortunately, most tests for the identification of blood are destructive and time consuming. We present a fast and nondestructive identification test for blood, using noncontact reflectance spectroscopy. We fitted reflectance spectra of 40 bloodstains and 35 nonbloodstains deposited on white cotton with spectroscopic features of the main compounds of blood. Each bloodstain was measured 30 times to account for aging effects. The outcome of the blood measurements was compared with the reflectance of blood-mimicking stains and various body fluids. We found that discrimination between blood and nonblood deposited on white cotton is possible with a specificity of 100% and a sensitivity of 98%. In conclusion, a goodness of fit between the sample's reflectance and the blood component fit may allow identification of blood at crime scenes by remote spectroscopy. PMID:21827464

  14. 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.

  15. Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection

    SciTech Connect

    Loui, A; McCall, S K

    2011-10-24

    The ability to monitor the integrity of gas volumes is of interest to the stockpile surveillance community. Specifically, the leak detection of noble gases, at relevant concentration ranges and distinguished from other chemical species that may be simultaneously present, is particularly challenging. Aside from the laboratory-based method of gas chromatography-mass spectrometry (GC-MS), where samples may be collected by solid-phase microextraction (SPME) or cryofocusing, the other major approaches for gas-phase detection employ lasers typically operating in the mid-infrared wavelength region. While mass spectrometry can readily detect noble gases - the helium leak detector is an obvious example - laser-based methods such as infrared (IR) or Raman spectroscopy are completely insensitive to them as their monatomic nature precludes a non-zero dipole moment or changes in polarizability upon excitation. Therefore, noble gases can only be detected by one of two methods: (1) atomic emission spectroscopies which require the generation of plasmas through laser-induced breakdown, electrical arcing, or similar means; (2) non-spectroscopic methods which measure one or more physical properties (e.g., mass, thermal conductivity, density). In this report, we present our progress during Fiscal Year 2011 (FY11) in the research and development of a non-spectroscopic method for noble gas detection. During Fiscal Year 2010 (FY10), we demonstrated via proof-of-concept experiments that the combination of thermal conductivity detection (TCD) and coating-free damped resonance detection (CFDRD) using micro-electromechanical systems (MEMS) could provide selective sensing of these inert species. Since the MEMS-based TCD technology was directly adapted from a brassboard prototype commissioned by a previous chemical sensing project, FY11 efforts focused on advancing the state of the newer CFDRD method. This work, guided by observations previously reported in the open literature, has not only resulted in a substantially measureable increase in selectivity but has also revealed a potential method for mitigating or eliminating thermal drift that does not require a secondary reference sensor. The design of an apparatus to test this drift compensation scheme will be described. We will conclude this report with a discussion of planned efforts in Fiscal Year 2012 (FY12).

  16. Surface spectroscopic characterization of titanium implant materials

    NASA Astrophysics Data System (ADS)

    Lausmaa, Jukka; Kasemo, Bengt; Mattsson, Håkan

    1990-04-01

    Titanium is one of the most commonly used biomaterials for dental and orthopedic applications. Its excellent tissue compatibility is mainly due to the properties of the stable oxide layer which is present on the surface. This paper reports a detailed spectroscopic characterization of the surface composition of non-alloyed Ti implant materials, prepared according to procedures commonly used in clinical practice (machining, ultrasonic cleaning and sterilization). The main methods of characterization are XPS and AES, and complementary information is obtained by SIMS, EDX and NMA (nuclear microanalysis). The surface of the implants is found to consist of a thin surface oxide which is covered by a carbon-dominated contamination layer. By comparison with reference spectra from single crystal TiO 2 (rutile) the composition of the surface oxide is shown to be mainly TiO 2, with minor amounts of suboxides and TiN x. The thickness of the surface oxides is 2-6 nm, depending on the method of sterilization. The surface contamination layer is found to vary considerably from sample to sample and consists of mainly hydrocarbons with trace amounts of Ca, N, S, P, Cl. Some differences in surface composition between directly prepared surfaces, and some possible contamination sources, are identified and discussed shortly.

  17. Improved gate process control at the 130-nm node using spectroscopic-ellipsometry-based profile metrology

    NASA Astrophysics Data System (ADS)

    Hodges, J. Scott; Lin, Yu-Lun C.; Burrows, Dale R.; Chiao, Ray H.; Peters, Robert M.; Rangarajan, Srinivasan; Bhatia, Kamal N.; Lakkapragada, Suresh

    2003-05-01

    The ability to control the cross-sectional profile of polysilicon gate structures on semiconductor devices is paramount to maximize product yield and transistor performance. Tighter control of gate profile parameters leads to a tighter distribution of transistor speeds, resulting in more optimized and consistent device performance. Furthermore, the ability to correlate physical in-line profile measurements taken at gate patterning process steps, to back-end-of-line device parametric test results, enables semiconductor manufacturers to minimize the cost per good die produced, by accurately screening out-of-spec product early in the process flow. The significant increase in the number of chips on today's 300mm wafers heightens the importance of obtaining reliable in-line data. In addition, the reduction of design rules to 130nm and below is driving precision requirements on metrology to <1nm, in order to maintain acceptable precision-to-tolerance (P/T) ratios. Historical methods of in-line metrology (Low Voltage Scanning Electron Microscopy, Atomic Force Microscopy, Electrical Critical Dimension Measurement) all face limitations with regards to precision, correlation, or throughput. This paper will demonstrate the use of Spectroscopic Ellipsometry to provide fast, accurate, and precise two-dimensional profile information on polysilicon gate structures. This metrology technique is currently being utilized for in-line process control and product disposition, at the gate lithography and etch process steps, on 130nm generation logic devices manufactured in Texas Instruments' DMOS 6 300mm wafer fabrication facility. A brief description of the measurement theory and gate profile measurement solution for both dense and isolated structures will be given. This will be followed by data generated from DMOS 6 production material. Using Spectroscopic Ellipsometry, precision results of <0.5nm for CD and height, and <0.25 degrees for profile sidewall angle were obtained at both the lithography and etch measurement steps. The use of CD and sidewall angle information in an APC loop to improve control over the gate trim etch process will also be discussed. Data will be presented showing univariate and multivariate correlation of gate etch profile parameters to post-metalization transistor drive current (IDrive) that is equivalent or superior to existing metrology techniques. Finally, examples of where Spectroscopic Ellipsometry has both increased sensitivity and shortened response time to gate etch process excursions will be presented.

  18. Data mining of spectroscopic data for biomarker discovery.

    PubMed

    Norton, S M; Huyn, P; Hastings, C A; Heller, J C

    2001-05-01

    The goals of precise diagnosis, prevention and treatment of disease can be realized through the discovery of biological markers. Spectroscopic tools can simultaneously detect and quantify multiple small molecule and macromolecular components of biological samples, and are therefore ideal methods for the discovery of previously uncharacterized markers. However, the identification of meaningful spectral features is complicated by the lack of foreknowledge of the molecular nature of a disease, spectral noise and biological variability that is uncorrelated with the disease state. Pattern recognition techniques, both statistical and machine-learning, have been increasingly used in recent years with spectroscopic data to identify markers and classify patients into disease subsets. This review summarizes recent developments, limitations and future prospects in the use of data mining techniques with magnetic resonance spectroscopy, mass spectrometry and optical spectroscopy for the discovery of biomarkers. PMID:11560066

  19. A UNIX Based Computer Workstation For Spectroscopic Data Manipulation

    NASA Astrophysics Data System (ADS)

    Moffatt, D. J.; Yang, P. W.

    1985-12-01

    A UNIX-based computer workstation for spectroscopic data reduction is described. A Heurikon Corp. HK-68 microcomputer (with Motorola 68000 CPU and UNIX operting system) accepts data downloaded from five spectrometer systems. Various hardware and software devices are used to optimize the downloading of data to the multi-user UNIX system. Software tools, written in Fortran 77, include: 1) screen interactive routines for Fourier smoothing, Fourier derivatives, Fourier self-deconvolution; 2) mathematical manipulation and plotting of spectra and of measurable spectroscopic parameters (e.g., peak position, halfwidth, intensity); 3) methods of displaying series of spectra. UNIX system features like shell script, shell variables, I/O redirection, and background processing are fully utilized to enhance the power and flexibility for the programs used in data reduction.

  20. Orbital lesions: proton spectroscopic phase-dependent contrast MR imaging.

    PubMed

    Atlas, S W; Grossman, R I; Axel, L; Hackney, D B; Bilaniuk, L T; Goldberg, H I; Zimmerman, R A

    1987-08-01

    Thirteen orbital lesions in 12 patients were evaluated with both conventional spin-echo magnetic resonance (MR) imaging and phase-dependent proton spectroscopic imaging. This technique, which makes use of small differences in the resonant frequencies of water and fat protons, provides excellent high-resolution images with simultaneous chemical shift information. In this method, there is 180 degrees opposition of phase between fat protons and water protons at the time of the gradient echo, resulting in signal cancellation in voxels containing equal signals from fat and water. In this preliminary series, advantages of spectroscopic images in orbital lesions included better lesion delineation, with superior anatomic definition of orbital apex involvement; more specific characterization of high-intensity hemorrhage with a single pulse sequence; elimination of potential confusion from chemical shift misregistration artifact; further clarification of possible intravascular flow abnormalities; and improved apparent intralesional contrast. PMID:3602394

  1. Benford analysis: A useful paradigm for spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Bhole, Gaurav; Shukla, Abhishek; Mahesh, T. S.

    2015-10-01

    Benford's law is a statistical inference to predict the frequency of significant digits in naturally occurring numerical databases. In such databases this law predicts a higher occurrence of the digit 1 in the most significant place and decreasing occurrences to other larger digits. Although counter-intuitive at first sight, Benford's law has seen applications in a wide variety of fields like physics, earth-science, biology, finance, etc. In this work, we have explored the use of Benford's law for various spectroscopic applications. Although, we use NMR signals as our databases, the methods described here may also be extended to other spectroscopic techniques. In particular, with the help of Benford analysis, we demonstrate emphasizing weak NMR signals and spectral corrections. We also explore a potential application of Benford analysis in the image-processing of MRI data.

  2. New Spectroscopic Solution of the Eclipsing Binary HX Vel A

    NASA Astrophysics Data System (ADS)

    Sürgit, D.; Erdem, A.; Özkardeş, B.; Butland, R.; Budding, E.

    2015-07-01

    We present a preliminary analysis of new spectroscopic observations of the southern binary HX Vel A. High-resolution spectroscopic observations were made at the Mt. John University Observatory in 2014. Radial velocities for HX Vel A were determined from the Gaussian profile-fitting method. The Keplerian radial velocity model gives the close binary mass ratio as 0.57±0.06. The resulting orbital elements are a1sin i=0.0086 ±0.0003 au, a2sin i=0.0151 ±0.0003 au, M1 sin3i =0.887 ±0.046 M⊙, and M2 sin3i =0.504 ±0.032 M⊙.

  3. Spectroscopic characteristics of polar plumes

    NASA Astrophysics Data System (ADS)

    Del Zanna, G.; Bromage, B. J. I.; Mason, H. E.

    2003-02-01

    Extreme ultraviolet observations of plumes in polar coronal holes are presented and their spectroscopic signatures discussed. The study focuses on the base of plumes seen on the disk of the Sun with the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) satellite. Spectroscopic diagnostic techniques are applied to characterise the plumes in terms of density, temperature, emission measure and element abundance. Attention is drawn to the particular limitations of some of the techniques when applied to plume structures. In particular, we revisit the Widing & Feldman (1992) findings of a plume having a large first ionization potential (FIP) effect of 10, showing that instead the Skylab data are consistent with no FIP effect. We present for the first time CDS-GIS (grazing incidence spectrometer) observations of a plume. These observations have been used to confirm the results obtained from normal incidence (NIS) observations. We find that polar plumes exhibit the same characteristics as the Elephant's Trunk equatorial plume. The most striking characteristic of the plume bases is that they are near-isothermal with a peak emission measure at transition region temperatures =~ 8 x 105 K. At these temperatures, plumes have averaged densities Nlo {e} =~ 1.2 x 109 cm-3, about twice the value of the surrounding coronal hole region. Element abundances in the plumes are found to be close to photospheric, with the exception of neon which appears to be depleted by 0.2 dex relative to oxygen. The absence of a significant FIP effect in plumes is consistent with fast solar wind plasma, although it is not sufficient to prove a link between the two. Finally, we present a comparison between GIS spectra and the SOHO EIT (EUV Imaging Telescope) broad-band images, showing that temperatures derived from the EIT ratio technique are largely overestimated, for plumes and coronal holes. This is partly due to the fact that the so called ``Fe XII 195 Å'' and ``Fe XV 284 Å'' filters are not isothermal, and in coronal holes and plumes lower-temperature lines dominate the EIT signal.

  4. 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).

  5. Statistics by Example, Detecting Patterns.

    ERIC Educational Resources Information Center

    Mosteller, Frederick; And Others

    This booklet is part of a series of four pamphlets, each intended to stand alone, which provide problems in probability and statistics at the secondary school level. Twelve different real-life examples (written by professional statisticians and experienced teachers) have been collected in this booklet to illustrate the ideas of mean, variation,…

  6. Astrochemistry Examples in the Classroom

    ERIC Educational Resources Information Center

    Hudson, Reggie L.

    2006-01-01

    Astronomy and astronomy-related topics have sufficient appeal and depth that they can be used to motivate students, illustrate important chemical concepts, and demonstrate that chemistry and chemists are concerned with all parts of nature. In this article some recent developments in astrochemistry are suggested as examples for the teaching of…

  7. Astrochemistry Examples in the Classroom

    ERIC Educational Resources Information Center

    Hudson, Reggie L.

    2006-01-01

    Astronomy and astronomy-related topics have sufficient appeal and depth that they can be used to motivate students, illustrate important chemical concepts, and demonstrate that chemistry and chemists are concerned with all parts of nature. In this article some recent developments in astrochemistry are suggested as examples for the teaching of

  8. Calculation of multicomponent chemical equilibria in gas-solid- liquid systems: calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mount St. Helens

    USGS Publications Warehouse

    Symonds, R.B.; Reed, M.H.

    1993-01-01

    This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. Examples of gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mount St. Helens are shown. -from Authors

  9. CSP spectroscopic classification of two supernovae

    NASA Astrophysics Data System (ADS)

    Stritzinger, M.; Hsiao, E.; Taddia, F.; Morrell, N.

    2015-01-01

    On behalf of the Carnegie Supernova Project, we report spectroscopic classification of PSN J08293820-1717473 and ASASSN-14my (ATel#6860), based on visual-wavelength spectra obtained with the Nordic Optical Telescope (+Alfosc).

  10. CSP Spectroscopic Classification of LSQ16oi

    NASA Astrophysics Data System (ADS)

    Morrell, N.; Phillips, M.; Lira, P.; Ellman, N.; Baltay, C.; Rabinowitz, D.; Rostami, S.; Hsiao, E. Y.

    2016-02-01

    We report the spectroscopic classification of a La Silla-QUEST (LSQ) supernova (Baltay et al. 2013, PASP, 125, 683) taken using WFCCD on the 2.5-m du Pont Telescope as part of the Carnegie Supernova Project (CSP).

  11. Asiago spectroscopic classification of one SN candidates

    NASA Astrophysics Data System (ADS)

    Ochner, P.; Pastorello, A.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Tartaglia, L.; Tomasella, L.; Turatto, M.

    2015-09-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of PSN J06280368+7418338 in the galaxy UGC 3460, discovered by P. Campaner (ISSP).

  12. Asiago spectroscopic classification of AT2016ajo

    NASA Astrophysics Data System (ADS)

    Terreran, G.; Pastorello, A.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Ochner, P.; Tartaglia, L.; Tomasella, L.; Turatto, M.

    2016-03-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of AT2016ajo, discovered by Y. Ding, W. Gao and X. Gao in an anonymous galaxy near UGC 11344.

  13. Monitoring spectroscopic binaries in anticipation of Gaia

    NASA Astrophysics Data System (ADS)

    Pourbaix, Dimitri; Halbwachs, Jean-Louis; Arenou, Frederic

    2015-08-01

    For several already known spectroscopic binaries, it is anticipated that Gaia will provide an exquisite astrometric orbit of the photocenter. In case of double-lined spectroscopic binaries, the orbital inclination supplied by Gaia will lead to the mass of both components.. For those masses to be useful, an accuracy of 2-3% is required. This can only be achieved if the spectroscopic orbit is very accurate too. A long term monitoring of good spectroscopic candidates in on going on Sophie at the Observatory of Haute Provence and on Hermes on the Mercator telescope in La Palma. For some of these systems, we have already derived a definitive SB2 orbital solution while, for others, the secondary remains unreachable. We present these new solutions in conjunction with the possible impact on the Hipparcos astrometric solution.

  14. Asiago spectroscopic classification of AT2016bry

    NASA Astrophysics Data System (ADS)

    Ochner, P.; Tinella, V.; Righetti, G. L.; Belligoli, R.; Castellani, F.; Pastorello, A.; Cappellaro, E.; Benetti, S.; Tomasella, L.; Elias-Rosa, N.; Tartaglia, L.; Terreran, G.; Turatto, M.

    2016-05-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of AT2016bry, discovered by V. Tinella in UGC 11635, and preliminary photometric follow-up.

  15. Adaptive optics photoacoustic spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Jian, Xiaohua; Cui, Yaoyao; Xiang, Yongjia; Han, Zhile; Gu, Tianming; Lv, Tiejun

    2013-01-01

    For decreasing wavefront error and obtaining higher resolution image of biological tissues, an adaptive optics photoacoustic spectroscopic imaging (AOPSI) system is proposed in this paper. In this system, an adaptive optics (AO) sub-system consisting of a Shack-Hartmann wavefront sensor (SHWS) and a liquid crystal on silicon (LCOS) is designed to correct the wavefront aberration of the illuminating light for getting high resolution image. The photoacoustic (PA) signals of AOPSI generated by irradiating the sample with a tunable optical parametric oscillator (OPO) lasers emitting light at 680-950 nm are received by a broadband ultrasound transducer. The received data are rearranged according to the wavelength sequences and decoded for image reconstruction. Moreover, the PA spectroscopy is used to obtain different wavelength PA images, with which one can accurately distinguish organization structures and identify organizational components, etc. The final simulation results demonstrated that when the wavefront errors were corrected by the AO system, the AOPSI images showed significant quality improvement which will be helpful to enhance the ability and application of PA imaging.

  16. Handbook of Basic Atomic Spectroscopic Data

    National Institute of Standards and Technology Data Gateway

    SRD 108 Handbook of Basic Atomic Spectroscopic Data (Web, free access)   This handbook provides a selection of the most important and frequently used atomic spectroscopic data. The compilation includes data for the neutral and singly-ionized atoms of all elements hydrogen through einsteinium (Z = 1-99). The wavelengths, intensities, and spectrum assignments are given for each element, and the data for the approximately 12,000 lines of all elements are also collected into a single table.

  17. Spectroscopic o