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1

Calibration method for spectroscopic systems  

DOEpatents

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.

Sandison, David R. (Edgewood, NM)

1998-01-01

2

Calibration method for spectroscopic systems  

DOEpatents

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.

Sandison, D.R.

1998-11-17

3

Optical spectroscopic methods for intraoperative diagnosis.  

PubMed

Molecular analytical methods are increasingly needed for a quick and reliable analysis of tissue in an operating room to provide more information during operations. In this Trends article, we highlight the current state and the developments of optical spectroscopic methods as intra operative tools. The clinical problem and challenges are illustrated on the example of brain tumor surgery. While fluorescence microscopy is already used, vibrational spectroscopy techniques will complement the standard method for brain tissue diagnostics. New portable instruments are currently available and can be stationed in the operating room for quick evaluation of tissue. The promise and limitations of fluorescence and vibrational spectroscopy as intraoperative tools are surveyed in this report. PMID:24136252

Steiner, Gerald; Kirsch, Matthias

2014-01-01

4

Spectroscopic methods in gas hydrate research.  

PubMed

Gas hydrates are crystalline structures comprising a guest molecule surrounded by a water cage, and are particularly relevant due to their natural occurrence in the deep sea and in permafrost areas. Low molecular weight molecules such as methane and carbon dioxide can be sequestered into that cage at suitable temperatures and pressures, facilitating the transition to the solid phase. While the composition and structure of gas hydrates appear to be well understood, their formation and dissociation mechanisms, along with the dynamics and kinetics associated with those processes, remain ambiguous. In order to take advantage of gas hydrates as an energy resource (e.g., methane hydrate), as a sequestration matrix in (for example) CO(2) storage, or for chemical energy conservation/storage, a more detailed molecular level understanding of their formation and dissociation processes, as well as the chemical, physical, and biological parameters that affect these processes, is required. Spectroscopic techniques appear to be most suitable for analyzing the structures of gas hydrates (sometimes in situ), thus providing access to such information across the electromagnetic spectrum. A variety of spectroscopic methods are currently used in gas hydrate research to determine the composition, structure, cage occupancy, guest molecule position, and binding/formation/dissociation mechanisms of the hydrate. To date, the most commonly applied techniques are Raman spectroscopy and solid-state nuclear magnetic resonance (NMR) spectroscopy. Diffraction methods such as neutron and X-ray diffraction are used to determine gas hydrate structures, and to study lattice expansions. Furthermore, UV-vis spectroscopic techniques and scanning electron microscopy (SEM) have assisted in structural studies of gas hydrates. Most recently, waveguide-coupled mid-infrared spectroscopy in the 3-20 ?m spectral range has demonstrated its value for in situ studies on the formation and dissociation of gas hydrates. This comprehensive review summarizes the importance of spectroscopic analytical techniques to our understanding of the structure and dynamics of gas hydrate systems, and highlights selected examples that illustrate the utility of these individual methods. PMID:22094590

Rauh, Florian; Mizaikoff, Boris

2012-01-01

5

Spectroscope  

NSDL National Science Digital Library

In this activity (posted on March 12, 2011), learners follow the steps to construct a spectroscope, a tool used to analyze light and color. First, learners use relatively simple materials to construct the device. Then, learners look through their spectroscopes at a variety of different light sources including incandescents, LEDs, compact fluorescents, sun light, etc. and compare what they observe. This resource includes a few examples of how certain chemicals form different colors of light.

Center, Oakland D.

2011-01-01

6

Mass spectroscopic apparatus and method  

DOEpatents

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.

Bomse, David S. (Santa Fe, NM); Silver, Joel A. (Santa Fe, NM); Stanton, Alan C. (Santa Fe, NM)

1991-01-01

7

Spectroscopic chemical analysis methods and apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

8

Spectroscopic chemical analysis methods and apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

9

Advances in spectroscopic methods for quantifying soil carbon  

USGS Publications Warehouse

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.

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

2012-01-01

10

Apparatus and method for spectroscopic analysis of scattering media  

DOEpatents

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.

Strobl, Karlheinz (Los Angeles, CA); Bigio, Irving J. (Los Alamos, NM); Loree, Thomas R. (Santa Fe, NM)

1994-01-01

11

Spectroscope  

NSDL National Science Digital Library

In this activity, learners construct their own spectroscope as they explore and observe spectra from familiar light sources. Learners can be challenged to make technological improvements to their spectroscopes and/or participate in extension activities that expand their understanding of different kinds of spectra and sharpen their observing skills.

Observatory, Mcdonald

2008-01-01

12

Experimental Mathemataics: Examples, Methods andImplications  

SciTech Connect

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.

Bailey, David H.; Borwein, Jonathan M.

2005-01-31

13

Spectroscopic Techniques: Cavity-Enhanced Methods  

NASA Astrophysics Data System (ADS)

Cavity enhanced spectroscopy (CES) methodology provides a much higher degree of sensitivity than that available from conventional absorption spectrometers. The aim of this chapter is to present the fundamentals of the method, and the various modifications and extensions that have been developed. In order to set the stage, the limitations of traditional absorption spectrometers are first discussed, followed by a description of cavity ring-down spectroscopy (CRDS), the most popular CES embodiment. A few other well-known CES approaches are also described in detail. The chapter concludes with a discussion of recent work on extending CRDS to the study of liquids and solids.

Paldus, Barbara; Kachanov, Alexander

14

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

PubMed

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

Rewald, Boris; Meinen, Catharina

2013-01-01

15

Plant roots and spectroscopic methods - analyzing species, biomass and vitality  

PubMed Central

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

Rewald, Boris; Meinen, Catharina

2013-01-01

16

Spectroscopic studies of protein folding: Linear and nonlinear methods  

PubMed Central

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

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

2012-01-01

17

Example  

NSDL National Science Digital Library

Named for the early Greek philosopher/teacher Socrates, a Socratic approach to teaching is one in which the instructor poses thoughtful questions to help students learn. Short Example of Socratic Questioning The ...

18

Scanning Tunneling Microscopy methods for spectroscopic imaging of subsurface interfaces  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

19

Quantitative comparison of analysis methods for spectroscopic optical coherence tomography  

PubMed Central

Spectroscopic optical coherence tomography (sOCT) enables the mapping of chromophore concentrations and image contrast enhancement in tissue. Acquisition of depth resolved spectra by sOCT requires analysis methods with optimal spectral/spatial resolution and spectral recovery. In this article, we quantitatively compare the available methods, i.e. the short time Fourier transform (STFT), wavelet transforms, the Wigner-Ville distribution and the dual window method through simulations in tissue-like media. We conclude that all methods suffer from the trade-off in spectral/spatial resolution, and that the STFT is the optimal method for the specific application of the localized quantification of hemoglobin concentration and oxygen saturation. PMID:24298417

Bosschaart, Nienke; van Leeuwen, Ton G.; Aalders, Maurice C. G.; Faber, Dirk J.

2013-01-01

20

Microplate spectroscopic methods for determination of the organophosphate soman.  

PubMed

Two microplate spectroscopic methods for determination of organophosphates, based on inhibition of acetylcholinesterase activity, have been elaborated and evaluated for determination of the chemical weapon agent soman. The principal difference between the methods is that one measures reaction substrate concentration (elaborated from Hestrin), while the other measures reaction product (elaborated from Ellman). The linear ranges of the two methods were found to be similar. Although the limit of quantification was lower for the Ellman method (110 pM), the sensitivity coefficient was in favor of the Hestrin method (1.55-fold higher). The effects of the main soman hydrolysis products were consistent for the two methods: both methylphosphonic acid and pinacolyl methylphosphonic acid did not inhibit acetylcholinesterase activity. The main components of decontaminating solutions showed differential effects: while monoethanolamine had no influence upon results obtained by either method, hydrogen peroxide interfered with the Ellman method at far lower concentrations than with the Hestrin method. In practical applications involving samples containing hydrogen peroxide, the method based on Hestrin should be regarded as much more specific for OP determination than the Ellman method. PMID:20411202

Prokofieva, Daria Stanislavovna; Voitenko, Natalia Gennadievna; Gustyleva, Lyudmila Konstantinovna; Babakov, Vladimir Nikolaevich; Savelieva, Elena Igorevna; Jenkins, Richard Owen; Goncharov, Nikolay Vasilievich

2010-06-01

21

Spectroscopic method to measure the superfluid fraction of an ultracold atomic gas  

SciTech Connect

We perform detailed analytical and numerical studies of a recently proposed method for a spectroscopic measurement of the superfluid fraction of an ultracold atomic gas [N. R. Cooper and Z. Hadzibabic, Phys. Rev. Lett. 104, 030401 (2010)]. Previous theoretical work is extended by explicitly including the effects of nonzero temperature and interactions, and assessing the quantitative accuracy of the proposed measurement for a one-component Bose gas. We show that for suitably chosen experimental parameters the method yields an experimentally detectable signal and a sufficiently accurate measurement. This is illustrated by explicitly considering two key examples: First, for a weakly interacting three-dimensional Bose gas it reproduces the expected result that below the critical temperature the superfluid fraction closely follows the condensate fraction. Second, it allows a clear quantitative differentiation of the superfluid and the condensate density in a strongly interacting Bose gas.

John, S. T.; Hadzibabic, Z.; Cooper, N. R. [Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave. Cambridge CB3 0HE (United Kingdom)

2011-02-15

22

Methods and apparatus for distributed resource discovery using examples  

NASA Technical Reports Server (NTRS)

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.

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

23

Spectroscopic Temperature Determination after the Two-Line Method for Time-Varying Temperatures.  

National Technical Information Service (NTIS)

Theoretical analysis and experimental results indicate that spectroscopic temperature measurements after the 2-line method, applying an integrating rather than a time-resolving technique, yield both too high and too low temperatures if the temperature in ...

R. F. Neubauer

1976-01-01

24

Spectroscopic Temperature Determination after the 2-Line Method for Time-Varying Temperatures.  

National Technical Information Service (NTIS)

Theoretical analysis and experimental results indicate that spectroscopic temperature measurements following the 2-line method - applying an integrating rather than a time-resolving technique - yield both too high and too low temperatures, if the temperat...

R. F. Neubauer

1975-01-01

25

Spectroscopic methods for the photodiagnosis of nonmelanoma skin cancer  

NASA Astrophysics Data System (ADS)

The importance of dermatological noninvasive imaging techniques has increased over the last decades, aiming at diagnosing nonmelanoma skin cancer (NMSC). Technological progress has led to the development of various analytical tools, enabling the in vivo/in vitro examination of lesional human skin with the aim to increase diagnostic accuracy and decrease morbidity and mortality. The structure of the skin layers, their chemical composition, and the distribution of their compounds permits the noninvasive photodiagnosis of skin diseases, such as skin cancers, especially for early stages of malignant tumors. An important role in the dermatological diagnosis and disease monitoring has been shown for promising spectroscopic and imaging techniques, such as fluorescence, diffuse reflectance, Raman and near-infrared spectroscopy, optical coherence tomography, and confocal laser-scanning microscopy. We review the use of these spectroscopic techniques as noninvasive tools for the photodiagnosis of NMSC.

Drakaki, Eleni; Vergou, Theognosia; Dessinioti, Clio; Stratigos, Alexander J.; Salavastru, Carmen; Antoniou, Christina

2013-06-01

26

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

27

A UV spectroscopic method for monitoring aromatic hydrocarbons dissolved in water  

Microsoft Academic Search

An enhanced UV spectrometric method is applied to trace measurements of aromatic hydrocarbons dissolved in water. This approach gains selectivity and sensitivity by the use of optically generated first and second derivatives of transmission spectra. The augmented spectroscopic technique is combined with chemometric algorithms like principal component regression or partial least squares which are used for calibration of the spectrometer

F. Vogt; M. Tacke; M. Jakusch; B. Mizaikoff

2000-01-01

28

Spectroscopic temperature determination after the two-line method for time-varying temperatures  

Microsoft Academic Search

Theoretical analysis and experimental results indicate that spectroscopic temperature measurements after the 2-line method, applying an integrating rather than a time-resolving technique, yield both too high and too low temperatures if the temperature in the gas varies with time. Temperatures were measured for a rotating arc (T = 8000 K and T = 12000 K) and within a hot jet

R. F. Neubauer

1976-01-01

29

Spectroscopic temperature determination after the 2-line method for time-varying temperatures  

Microsoft Academic Search

Theoretical analysis and experimental results indicate that spectroscopic temperature measurements following the 2-line method - applying an integrating rather than a time-resolving technique - yield both too high and too low temperatures, if the temperature in the gas varies with time. Temperatures were measured for a rotating arc (T = 8,000 K and T = 12,000 K) and within a

R. F. Neubauer

1975-01-01

30

Quantifying prefibrillar amyloids in vitro by using a "thioflavin-like" spectroscopic method.  

PubMed

In Alzheimer's disease (AD) and other neurodegenerative disorders, proteins accumulate into ordered aggregates, called amyloids. Recent evidence suggests that these structures include both large, insoluble fibrils and smaller, prefibrillar structures, such as dimers, oligomers, and protofibrils. Recently, focus has shifted to the prefibrillar aggregates because they are highly neurotoxic and their levels appear to correlate with cognitive impairment. Thus, there is interest in finding methods for specifically quantifying these structures. One of the classic ways of detecting amyloid formation is through the fluorescence of the benzothiazole dye, thioflavin T (ThT). This reagent has been a "workhorse" of the amyloid field because it is robust and inexpensive. However, one of its limitations is that it does not distinguish between prefibrillar and fibrillar aggregates. We screened a library of 37 indoles for those that selectively change fluorescence in the presence of prefibrillar amyloid-beta (Abeta). From this process, we selected the most promising example, tryptophanol (TROL), to use in a quantitative "thioflavin-like" assay. Using this probe in combination with electron microscopy, we found that prefibrils are largely depleted during Abeta aggregation in vitro but that they remain present after the apparent saturation of the ThT signal. These results suggest that a combination of TROL and ThT provides greater insight into the process of amyloid formation by Abeta. In addition, we found that TROL also recognizes other amyloid-prone proteins, including ataxin-3, amylin, and CsgA. Thus, this assay might be an inexpensive spectroscopic method for quantifying amyloid prefibrils in vitro. PMID:20677203

Reinke, Ashley A; Abulwerdi, Gelareh A; Gestwicki, Jason E

2010-09-01

31

Diagnostic of the surface micro-discharge using spectroscopic methods  

NASA Astrophysics Data System (ADS)

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.

Li, Yang-Fang; Morfill, Gregor

2012-10-01

32

The Erosion of a Method: Examples from Grounded Theory  

ERIC Educational Resources Information Center

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…

Greckhamer, Thomas; Koro-Ljungberg, Mirka

2005-01-01

33

Advances of vibrational spectroscopic methods in phytomics and bioanalysis.  

PubMed

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

Huck, Christian W

2014-01-01

34

Raman spectroscopic instrumentation and plasmonic methods for material characterization  

NASA Astrophysics Data System (ADS)

The advent of nanotechnology has led to incredible growth in how we consume, make and approach advanced materials. By exploiting nanoscale material properties, unique control of optical, thermal, mechanical, and electrical characteristics becomes possible. This thesis describes the development of a novel localized surface plasmon resonant (LSPR) color sensitive photosensor, based on functionalization of gold nanoparticles onto tianium dioxide nanowires and sensing by a metal-semiconducting nanowire-metal photodiode structure. This LSPR photosensor has been integrated into a system that incorporates Raman spectroscopy, microfluidics, optical trapping, and sorting flow cytometry into a unique material characterization system called the microfluidic optical fiber trapping Raman sorting flow cytometer (MOFTRSFC). Raman spectroscopy is utilized as a powerful molecular characterization technique used to analyze biological, mineralogical and nanomaterial samples. To combat the inherently weak Raman signal, plasmonic methods have been applied to exploit surface enhanced Raman scattering (SERS) and localized surface plasmon resonance (LSPR), increasing Raman intensity by up to 5 orders of magnitude. The resultant MOFTRSFC system is a prototype instrument that can effectively trap, analyze, and sort micron-sized dielectric particles and biological cells. Raman spectroscopy has been presented in several modalities, including the development of a portable near-infrared Raman spectrometer and other emerging technologies.

Tanaka, Kazuki

35

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

PubMed

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

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

2010-08-01

36

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

PubMed Central

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

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

2010-01-01

37

Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan  

PubMed Central

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

Kumirska, Jolanta; Czerwicka, Ma?gorzata; Kaczy?ski, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr

2010-01-01

38

Investigation on the interaction of pyrene with bovine serum albumin using spectroscopic methods  

NASA Astrophysics Data System (ADS)

This paper was designed to investigate the interaction of pyrene with bovine serum albumin (BSA) under physiological condition by spectroscopic methods. Spectroscopic analysis of the emission quenching revealed that the quenching mechanism of BSA by pyrene was static. The binding sites and constants of pyrene-BSA complex were observed to be 1.20 and 2.63 × 106 L mol-1 at 298 K, respectively. The enthalpy change (?H) and entropy change (?S) revealed that van der Waals forces and hydrogen bonds stabilized the pyrene-BSA complex. Energy transfer from tryptophan to pyrene occurred by a FRET (fluorescence resonance energy transfer) mechanism, and the distance (r = 2.72 nm) had been determined. The results of synchronous, three-dimensional fluorescence, and circular dichroism spectra showed that the pyrene induced conformational changes of BSA.

Xu, Chengbin; Gu, Jiali; Ma, Xiping; Dong, Tian; Meng, Xuelian

39

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

40

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

SciTech Connect

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.

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

2002-05-21

41

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

NASA Astrophysics Data System (ADS)

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.

Gupta, Lokesh Kumar

2012-11-01

42

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

43

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

NASA Astrophysics Data System (ADS)

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 ?? = 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.

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

2014-10-01

44

Monitoring, Controlling and Safeguarding Radiochemical Streams at Spent Fuel Reprocessing Facilities, Part 1: Optical Spectroscopic Methods  

SciTech Connect

Abstract: The International Atomic Energy Agency (IAEA) has established international safeguards standards for fissionable material at spent fuel reprocessing plants to ensure that significant quantities of weapons-useable nuclear material are not diverted from these facilities. For large throughput nuclear facilities, it is difficult to satisfy the IAEA safeguards accountancy goal for detection of abrupt diversion. Currently, methods to verify material control and accountancy (MC&A) at these facilities require time-consuming and resource-intensive destructive assay (DA). Leveraging new on-line non-destructive assay (NDA) process monitoring techniques in conjunction with the traditional and highly precise DA methods may provide an additional measure to nuclear material accountancy which would potentially result in a more timely, cost-effective and resource efficient means for safeguards verification at such facilities. By monitoring process control measurements (e.g. flowrates, temperatures, or concentrations of reagents, products or wastes), abnormal plant operations can be detected. Pacific Northwest National Laboratory (PNNL) is developing on-line NDA process monitoring technologies based upon gamma-ray and optical spectroscopic measurements to potentially reduce the time and resource burden associated with current techniques. The Multi-Isotope Process (MIP) Monitor uses gamma spectroscopy and multivariate analysis to identify off-normal conditions in process streams. The spectroscopic monitor continuously measures chemical compositions of the process streams including actinide metal ions (U, Pu, Np), selected fission products, and major stable flowsheet reagents using UV-Vis, Near IR and Raman spectroscopy. Multi-variate analysis is also applied to the optical measurements in order to quantify concentrations of analytes of interest within a complex array of radiochemical streams. This paper will provide an overview of these methods and reports on-going efforts to develop and demonstrate the technologies. This paper is Part 1 of a two part series, and focuses on the optical spectroscopy based process monitoring methods.

Bryan, Samuel A.; Levitskaia, Tatiana G.; Schwantes, Jon M.; Orton, Christopher R.; Peterson, James M.; Casella, Amanda J.

2012-02-07

45

12—AN ENERGY METHOD FOR CALCULATIONS IN FABRIC MECHANICS PART II: EXAMPLES OF APPLICATION OF THE METHOD TO WOVEN FABRICS  

Microsoft Academic Search

In the preceding paper, an energy method for performing calculations in fabric mechanics, together with appropriate computational techniques, was described. The present paper contains examples of applications of this method to woven fabrics, particularly to various models of plainweave fabric subject to tension, but also briefly to fabric-bending and to other weaves.

W. J. Shanahan; J. W. S. Hearle

1978-01-01

46

Apparatus for and method of performing spectroscopic analysis on an article  

DOEpatents

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.

Powell, George Louis (Oak Ridge, TN); Hallman, Jr., Russell Louis (Knoxville, TN)

1999-01-01

47

Energy transduction in the functional membrane of photosynthesis results by pulse spectroscopic methods  

Microsoft Academic Search

1. Methods The functional membrane of photosynthesis performs molecular events which are also realized in membranes of photoreceptors, mitochondria, nerves and muscles. These events are light quanta phenomena, electron transfer, electrical field generation, ion translocation, ATP synthesis and hydrolysis respectively. Therefore photosynthesis provides a good example for studying principles of molecular dynamics and energetics in biomembranes in general. The molecular

H. T. Witt

1972-01-01

48

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

PubMed Central

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

2014-01-01

49

Spectroscopic database  

NASA Technical Reports Server (NTRS)

Several aspects of quantitative atmospheric spectroscopy are considered, using a classification of the molecules according to the gas amounts in the stratosphere and upper troposphere, and reviews of quantitative atmospheric high-resolution spectroscopic measurements and field measurements systems are given. Laboratory spectroscopy and spectral analysis and prediction are presented with a summary of current laboratory spectroscopy capabilities. Spectroscopic data requirements for accurate derivation of atmospheric composition are discussed, where examples are given for space-based remote sensing experiments of the atmosphere: the ATMOS (Atmospheric Trace Molecule) and UARS (Upper Atmosphere Research Satellite) experiment. A review of the basic parameters involved in the data compilations; a summary of information on line parameter compilations already in existence; and a summary of current laboratory spectroscopy studies are used to assess the data base.

Husson, N.; Barbe, A.; Brown, L. R.; Carli, B.; Goldman, A.; Pickett, H. M.; Roche, A. E.; Rothman, L. S.; Smith, M. A. H.

1985-01-01

50

A survey of population analysis methods and software for complex pharmacokinetic and pharmacodynamic models with examples  

Microsoft Academic Search

An overview is provided of the present population analysis methods and an assessment of which software packages are most appropriate\\u000a for various PK\\/PD modeling problems. Four PK\\/PD example problems were solved using the programs NONMEM VI beta version, PDx-MCPEM,\\u000a S-ADAPT, MONOLIX, and WinBUGS, informally assessed for reasonable accuracy and stability in analyzing these problems. Also,\\u000a for each program we describe

Robert J. Bauer; Serge Guzy; Chee Ng

2007-01-01

51

Development and validation of a spectroscopic method to predict wheat protein digestibility.  

PubMed

The CP digestibility is traditionally measured by chemical analyses of CP and marker concentration in digesta and diets. Potentially, CP digestibility can also be predicted by marker concentrations and spectral analyses of digesta and diet. Spectroscopy is a rapid, nondestructive method to ascertain qualitative and quantitative chemical information. Based on Beer's law, a spectroscopic method was developed to predict in vivo CP digestibility. To validate, samples of digesta and diet of wheat grain with predetermined apparent ileal digestibility (AID) of CP were scanned on a Fourier transform midinfrared (FTIR) instrument with a single-reflection attenuated total reflectance attachment. The AID of CP was calculated from peak intensities of spectra and measured marker concentrations in digesta and diet and then compared with in vivo AID of CP. The AID of CP of a wheat-based diet was predicted accurately with a deviation of 0.68 ± 0.86% from in vivo AID of CP ranging from 60.4 to 87.8%. Functional group digestibility based on the peak at 1,643 cm(-1) or the Amide I region was strongly correlated (r ? 0.99; P < 0.001) with in vivo AID of CP. In conclusion, instead of predictions based on calibrations, CP digestibility can also be potentially predicted directly from FTIR spectra. PMID:23365397

Wang, L F; Swift, M L; Zijlstra, R T

2012-12-01

52

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

PubMed

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

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

2010-03-01

53

The interaction of plant-growth regulators with serum albumin: molecular modeling and spectroscopic methods.  

PubMed

The affinity between two plant-growth regulators (PGRs) and human serum albumin (HSA) was investigated by molecular modeling techniques and spectroscopic methods. The results of molecular modeling simulations revealed that paclobutrazol (PAC) could bind on both site I and site II in HSA where the interaction was easier, while uniconazole (UNI) could not bind with HSA. Furthermore, the results of fluorescence spectroscopy, three-dimensional (3D) fluorescence spectroscopy and circular dichroism (CD) spectroscopy suggested that PAC had a strong ability to quench the intrinsic fluorescence of HSA. The binding affinity (Kb) and the amounts of binding sites (n) between PAC and HSA at 291 K were estimated as 2.37×10(5) mol L(-1) and 1, respectively, which confirm that PAC mainly binds on site II of HSA. An apparent distance between the Trp214 and PAC was 4.41 nm. Additionally, the binding of PAC induced the conformational changes of disulfide bridges of HSA with the decrease of ?-helix content. These studies provide more information on the potential toxicological effects and environmental risk assessment of PGRs. PMID:24569069

Dong, Sheying; Li, Zhiqin; Shi, Ling; Huang, Guiqi; Chen, Shuangli; Huang, Tinglin

2014-05-01

54

Fast method for brain image segmentation: application to proton magnetic resonance spectroscopic imaging.  

PubMed

The interpretation of brain metabolite concentrations measured by quantitative proton magnetic resonance spectroscopic imaging (MRSI) is assisted by knowledge of the percentage of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) within each MRSI voxel. Usually, this information is determined from T(1)-weighted magnetic resonance images (MRI) that have a much higher spatial resolution than the MRSI data. While this approach works well, it is time-consuming. In this article, a rapid data acquisition and analysis procedure for image segmentation is described, which is based on collection of several, thick slice, fast spin echo images (FSE) of different contrast. Tissue segmentation is performed with linear "Eigenimage" filtering and normalization. The method was compared to standard segmentation techniques using high-resolution 3D T(1)-weighted MRI in five subjects. Excellent correlation between the two techniques was obtained, with voxel-wise regression analysis giving GM: R2 = 0.893 +/- 0.098, WM: R2 = 0.892 +/- 0.089, ln(CSF): R2 = 0.831 +/- 0.082). Test-retest analysis in one individual yielded an excellent agreement of measurements with R2 higher than 0.926 in all three tissue classes. Application of FSE/EI segmentation to a sample proton MRSI dataset yielded results similar to prior publications. It is concluded that FSE imaging in conjunction with Eigenimage analysis is a rapid and reliable way of segmenting brain tissue for application to proton MRSI. PMID:16187272

Bonekamp, David; Horská, Alena; Jacobs, Michael A; Arslanoglu, Atilla; Barker, Peter B

2005-11-01

55

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

SciTech Connect

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.

G. Michael Shook

2005-01-01

56

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

57

Chemical Characterization of Riverine Dissolved Organic Matter Using a Combination of Spectroscopic and Pyrolytic Methods  

NASA Astrophysics Data System (ADS)

It is now well established that riverine dissolved organic matter (DOM) play a major role in environmental processes. However natural organic matter exhibit different properties depending on their sources and the fractions considered. As a result chemical characterization of DOM has appeared essential for a better understanding of their reactivity. The purpose of this work was to characterize all of the DOM at molecular level, including the non-hydrolysable fraction, which is a major part of this OM. To this aim a new analytical approach had to be considered. A combination of spectroscopic and pyrolytic methods has been applied to various fractions of DOM originating from different catchments (French and Amazonian rivers). The fractions were termed hydrophilic, transphilic and colloids according to the IHSS fractionation procedure, and account for at least 70% of the total dissolved organic carbon. Solid state 13C NMR and FTIR afford information on the nature and relative abundance of the chemical functions occurring in macromolecules. Differential thermogravimetric analysis allows to determine the thermal behaviour of the studied material and hence to optimize analytical pyrolysis conditions. Curie point pyrolysis combined to gas chromatography and mass spectrometry leads to identification of characteristic pyrolysis products, some of them being specific of a macromolecular source. Additional information can be provided by thermochemolysis with tetramethylammonium hydroxide (TMAH). TMAH was shown to allow an increase in the efficiency of the cracking of macromolecular structures and an enhancement of the detection of the polar pyrolysis products especially due to methylation of the alcohol, phenol and acid groups. The results obtained have established the importance of terrestrial contribution to DOM. Hydrophobic fractions mainly originate from lignin-derived units, whereas transphilic fractions mostly contain cellulose units together with lignin derived ones and substantial amount of nitrogen-containing moieties. Characterization of colloidal fraction has indicated the presence of compounds from bacterial origin, especially specific nitrogen-containing molecules that are characteristic pyrolysis products of peptidoglycans, along with lignin-derived units. However pyrolysis has revealed significant differences in the detection of nitrogen-containing molecules, which do not parallel nitrogen content of the fractions. Moreover in hydrophobic and transphilic fractions the molecular structure of these compounds, which are mainly nitrogen- and oxygen- containing molecules, has not allowed to ascertain their origin. As the major biological sources of organic nitrogen (proteins, amino sugars, or tetrapyrrole pigments) involve differences in the main nitrogen functionality, two additional spectroscopic methods, namely X-ray photoelectron spectroscopy (XPS) and solid state 15N NMR, have been used to determine the nitrogen functional groups (amide, amine, and N-heterocycle) present in the different fractions of DOM. The combination of these two methods has revealed the occurrence of different functionality of nitrogen, with relative contributions depending on the considered fraction. It has also appeared that Curie point pyrolysis does not account for the presence of nitrogen in macromolecules with the same efficiency depending on the functional group involved. This study has highlighted the importance of combining different analytical approaches to obtain a whole insight into chemical structure of OM and avoid biased information.

Templier, J.; Derenne, S.

2006-12-01

58

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

PubMed

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

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

59

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

NASA Technical Reports Server (NTRS)

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.

Fischer, Erich M.; Pieters, Carle M.

1994-01-01

60

Mesh Deformation Based on Fully Stressed Design: The Method and Two-Dimensional Examples  

NASA Technical Reports Server (NTRS)

Mesh deformation in response to redefined boundary geometry is a frequently encountered task in shape optimization and analysis of fluid-structure interaction. We propose a simple and concise method for deforming meshes defined with three-node triangular or four-node tetrahedral elements. The mesh deformation method is suitable for large boundary movement. The approach requires two consecutive linear elastic finite-element analyses of an isotropic continuum using a prescribed displacement at the mesh boundaries. The first analysis is performed with homogeneous elastic property and the second with inhomogeneous elastic property. The fully stressed design is employed with a vanishing Poisson s ratio and a proposed form of equivalent strain (modified Tresca equivalent strain) to calculate, from the strain result of the first analysis, the element-specific Young s modulus for the second analysis. The theoretical aspect of the proposed method, its convenient numerical implementation using a typical linear elastic finite-element code in conjunction with very minor extra coding for data processing, and results for examples of large deformation of two-dimensional meshes are presented in this paper. KEY WORDS: Mesh deformation, shape optimization, fluid-structure interaction, fully stressed design, finite-element analysis, linear elasticity, strain failure, equivalent strain, Tresca failure criterion

Hsu, Su-Yuen; Chang, Chau-Lyan

2007-01-01

61

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

PubMed Central

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

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

2003-01-01

62

Integrable models for quantum media excited by laser radiation: a method, physical interpretation, and examples  

E-print Network

A method to build various integrable models for description of coherent excitation of multilevel media by laser pulses is suggested. Distribution functions over the energy levels of quantum systems depending on the time and frequency detuning are obtained. The distributions follow from Schr\\"odinger equation exact solutions and give the complete dynamical description of laser-excited quantum multilevel systems. Interpretation based on the Fourier spectra of the probability amplitudes of a quantum system is presented. The spectra are expressed in terms of orthonormal polynomials and their weight functions. Matrix elements of the dipole transitions between levels are equal to coefficients of the recurrence formula for the orthonormal polynomial system. Some examples are presented. The Kravchuk oscillator family as an integrable model is constructed to describe the coherent excitation dynamics of multilevel resonance media. It is based on the use of the Kravchuk orthogonal polynomials. The Kravchuk oscillator excitation dynamics is described by the binomial distribution of energy level populations and the distribution parameter depends on excitation conditions. Two known basic models in quantum physics -- the harmonic oscillator and two-level system are the special representatives of the Kravchuk oscillator family.

Vadim A. Savva; Vadim I. Zelenkov

2014-03-31

63

Spectroscopic methods for the determination of surface-active substances in water (a review)  

SciTech Connect

Synthetic surfactants, for their ability to mingle with and transform chemicals more toxic in nature such as petroleum products, oils, pesticides, and chlorinated hydrocarbons into substances that easily permeate and move through the hydrosphere into water reservoirs and other exposure pathways, pose a grave danger to water quality control. This paper reviews predominantly the spectrophotometric procedures available for monitoring these surfactants but also discusses fluorimetric, infrared spectroscopic, and atomic absorption procedures, and compares a wide range of solvents and reagents for the extraction and preparatory activation of the surfactants.

Subbotina, E.I.; Dedkov, Yu.M.

1987-12-01

64

Simultaneous quantitation of five active principles in a pharmaceutical preparation: development and validation of a near infrared spectroscopic method.  

PubMed

A near infrared spectroscopic method for the simultaneous determination of the active principles paracetamol, ascorbic acid, dextrometorphan hydrobromide, caffeine and chlorpheniramine maleate in a pharmaceutical preparation was developed. The five active principles are quantified using a partial least-squares regression method (PLS1). The proposed method is applicable over a wide analyte concentration range (0.04-6.50 wt.%), so it requires careful selection of the calibration set. Also, there is the difficulty of ensuring thorough homogenization of the product. The method was validated in accordance with the ICH standard and the EMEA validation guidelines for NIR spectroscopy by determining its selectivity, linearity, accuracy, precision and robustness. Based on the results, it is an effective alternative to existing choices (HPLC and redox titrimetry) for the same purpose. PMID:16359847

Blanco, M; Alcalá, M

2006-02-01

65

Investigation of vibrational and electronic properties of oxide nanopowders by spectroscopic methods  

NASA Astrophysics Data System (ADS)

Raman spectroscopy technique has been successfully used to study the microscopic nature of structural and/or morphological properties of investigated nanopowders. The phonon confinement model has been applied for the estimation of nanocrystals dimensions (TiO2 and CeO2), as well as the correlation length (ZnO), from the frequency shift and asymmetrical broadening of Raman optical phonon modes. The particle size distribution in nanopowders has been estimated from the low frequency Raman spectra, using the fact that the acoustic phonon modes in nanosized TiO2 and CeO2 can be well described by the elastic continuum model. In addition, the appearance of surface optical phonon modes has been predicted theoretically by the dielectric functions approach and detected experimentally in the Raman spectra of ZnO nanopowders, whereas the resonant behaviour of the first and second order ZnO Raman modes has been used for estimation of the electron-phonon interaction in this kind of nanomaterial. The optical properties of oxide nanopowders have been investigated by spectroscopic ellipsometry and photoluminescence spectroscopy. It has been shown that bandgap energy, as well as the energies of the other interband electronic transitions in investigated nanopowders can be determined by spectroscopic ellipsometry. On the other side, the existence of the broad bands in visible region of the photoluminescence spectra of TiO2 and ZnO nanopowders points out to the various electronic transitions mediated by defect levels within the bandgap.

Š?epanovi?, Maja; Gruji?-Broj?in, Mirjana; Doh?evi?-Mitrovi?, Zorana; Popovi?, Zoran V.

2010-11-01

66

Structural, Spectroscopic, and Magnetic Properties of Eu(3+)-Doped GdVO4 Nanocrystals Synthesized by a Hydrothermal Method.  

PubMed

New interesting aspects of the spectroscopic properties, magnetism, and method of synthesis of gadolinium orthovanadates doped with Eu(3+) ions are discussed. Gd1-xEuxVO4 (x = 0, 0.05, 0.2) bifunctional luminescent materials with complex magnetic properties were synthesized by a microwave-assisted hydrothermal method. Products were formed in situ without previous precipitation. The crystal structures and morphologies of the obtained nanomaterials were analyzed by X-ray diffraction and transmission and scanning electron microscopy. Crystallographic data were analyzed using Rietveld refinement. The products obtained were nanocrystalline with average grain sizes of 70-80 nm. The qualitative and quantitative elemental composition as well as mapping of the nanocrystals was proved using energy-dispersive X-ray spectroscopy. The spectroscopic properties of red-emitting nanophosphors were characterized by their excitation and emission spectra and luminescence decays. Magnetic measurements were performed by means of vibrating sample magnetometry. GdVO4 and Gd0.8Eu0.2VO4 exhibited paramagnetic behavior with a weak influence of antiferromagnetic couplings between rare-earth ions. In the substituted sample, an additional magnetic contribution connected with the population of low-lying excited states of europium was observed. PMID:25383487

Szczeszak, Agata; Grzyb, Tomasz; Sniadecki, Zbigniew; Andrzejewska, Nina; Lis, Stefan; Matczak, Micha?; Nowaczyk, Grzegorz; Jurga, Stefan; Idzikowski, Bogdan

2014-12-01

67

Inclusion interaction of chloramphenicol and heptakis (2,6-di- O-methyl)-?-cyclodextrin: Phase solubility and spectroscopic methods  

NASA Astrophysics Data System (ADS)

The inclusion interaction between chloramphenicol and heptakis (2,6-di- O-methyl)-?-cyclodextrin (DMBCD) had been investigated by phase solubility and spectroscopic methods such as UV-vis spectroscopy, circular dichroism, Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance spectroscopy ( 1H NMR) as well as 2D-ROESY spectra. Phase solubility analysis showed A L-type diagram with DMBCD, which suggested the formation of 1:1 inclusion complex of DMBCD with chloramphenicol. The estimated stability constant ( Ks) of the inclusion complex of chloramphenicol with DMBCD is 493 M -1 at 293 K. The solubility enhancement of chloramphenicol in the presence of DMBCD is stronger than that in the presence of ?-CD, HP-?-CD and M-?-CD. The results obtained by spectroscopic methods showed that the nitrophenyl moiety of chloramphenicol is deeply inserted into inner cavity of DMBCD from the narrow rim of DMBCD, which the inclusion model of chloramphenicol with DMBCD differs from that with ?-CD.

Shi, Jie-Hua; Zhou, Ya-fang

2011-12-01

68

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

SciTech Connect

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.

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

69

Monitoring, Controlling and Safeguarding Radiochemical Streams at Spent Fuel Reprocessing Facilities, Part 2: Gamma-Ray Spectroscopic Methods  

SciTech Connect

The International Atomic Energy Agency (IAEA) has established international safeguards standards for fissionable material at spent fuel reprocessing plants to ensure that significant quantities of weapons-useable nuclear material are not diverted from these facilities. For large throughput nuclear facilities, it is difficult to satisfy the IAEA safeguards accountancy goal for detection of abrupt diversion. Currently, methods to verify material control and accountancy (MC&A) at these facilities require time-consuming and resource-intensive destructive assay (DA). Leveraging new on-line non-destructive assay (NDA) process monitoring techniques in conjunction with the traditional and highly precise DA methods may provide an additional measure to nuclear material accountancy which would potentially result in a more timely, cost-effective and resource efficient means for safeguards verification at such facilities. By monitoring process control measurements (e.g. flowrates, temperatures, or concentrations of reagents, products or wastes), abnormal plant operations can be detected. Pacific Northwest National Laboratory (PNNL) is developing on-line NDA process monitoring technologies based upon gamma-ray and optical spectroscopic measurements to potentially reduce the time and resource burden associated with current techniques. The Multi-Isotope Process (MIP) Monitor uses gamma spectroscopy and multivariate analysis to identify off-normal conditions in process streams. The spectroscopic monitor continuously measures chemical compositions of the process streams including actinide metal ions (U, Pu, Np), selected fission products, and major stable flowsheet reagents using UV-Vis, Near IR and Raman spectroscopy. Multi-variate analysis is also applied to the optical measurements in order to quantify concentrations of analytes of interest within a complex array of radiochemical streams. This paper will provide an overview of these methods and reports on-going efforts to develop and demonstrate the technologies. This paper is Part 2 of a two part series, and focuses on the gamma spectroscopy based, Multi-Isotope Process (MIP) Monitor method.

Schwantes, Jon M.; Bryan, Samuel A.; Orton, Christopher R.; Levitskaia, Tatiana G.; Fraga, Carlos G.

2012-02-10

70

Monitoring, Controlling and Safeguarding Radiochemical Streams at Spent Fuel Reprocessing Facilities with Optical and Gamma-Ray Spectroscopic Methods  

SciTech Connect

The International Atomic Energy Agency (IAEA) has established international safeguards standards for fissionable material at spent fuel reprocessing plants to ensure that significant quantities of weapons-useable nuclear material are not diverted from these facilities. For large throughput nuclear facilities, it is difficult to satisfy the IAEA safeguards accountancy goal for detection of abrupt diversion. Currently, methods to verify material control and accountancy (MC&A) at these facilities require time-consuming and resourceintensive destructive assay (DA). Leveraging new on-line non-destructive assay (NDA) process monitoring techniques in conjunction with the traditional and highly precise DA methods may provide an additional measure to nuclear material accountancy which would potentially result in a more timely, cost-effective and resource efficient means for safeguards verification at such facilities. By monitoring process control measurements (e.g. flowrates, temperatures, or concentrations of reagents, products or wastes), abnormal plant operations can be detected. Pacific Northwest National Laboratory (PNNL) is developing on-line NDA process monitoring technologies based upon gamma-ray and optical spectroscopic measurements to potentially reduce the time and resource burden associated with current techniques. The Multi-Isotope Process (MIP) Monitor uses gamma spectroscopy and multivariate analysis to identify offnormal conditions in process streams. The spectroscopic monitor continuously measures chemical compositions of the process streams including actinide metal ions (U, Pu, Np), selected fission products, and major stable flowsheet reagents using UV-Vis, Near IR and Raman spectroscopy. Multi-variate analysis is also applied to the optical measurements in order to quantify concentrations of analytes of interest within a complex array of radiochemical streams. This paper will provide an overview of these methods and reports on-going efforts to develop and demonstrate the technologies.

Schwantes, Jon M.; Bryan, Samuel A.; Orton, Christopher R.; Levitskaia, Tatiana G.; Fraga, Carlos G.

2012-11-06

71

Assessment of new cationic porphyrin binding to plasma proteins by planar microarray and spectroscopic methods.  

PubMed

Porphyrins have a unique aromatic structure determining particular photochemical properties that make them promising photosensitizers for anticancer therapy. Previously, we synthesized a set of artificial porphyrins by modifying side-chain functional groups and introducing different metals into the core structure. Here, we have performed a comparative study of the binding properties of 29 cationic porphyrins with plasma proteins by using microarray and spectroscopic approaches. The porphyrins were noncovalently immobilized onto hydrogel-covered glass slides and probed to bio-conjugated human and bovine serum albumins, as well as to human hemoglobin. The signal detection was carried out at the near-infrared fluorescence wavelength (800?nm) that enabled the effect of intrinsic visible wavelength fluorescence emitted by the porphyrins tested to be discarded. Competition assays on porphyrin microarrays indicated that long-chain fatty acids (FAs) (palmitic and stearic acids) decrease porphyrin binding to both serum albumin and hemoglobin. The binding affinity of different types of cationic porphyrins for plasma proteins was quantitatively assessed in the absence and presence of FAs by fluorescent and absorption spectroscopy. Molecular docking analysis confirmed results that new porphyrins and long-chain FAs compete for the common binding site FA1 in human serum albumin and meso-substituted functional groups in porphyrins play major role in the modulation of conformational rearrangements of the protein. PMID:22871064

Gyulkhandanyan, Aram; Gyulkhandanyan, Lusine; Ghazaryan, Robert; Fleury, Fabrice; Angelini, Marie; Gyulkhandanyan, Grigor; Sakanyan, Vehary

2013-04-01

72

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

NASA Astrophysics Data System (ADS)

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 ?max 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 15N NMR chemical shift is found to be highly correlated atomic anisotropy, energy and intra-atomic isotropic shielding tensor.

Adeniyi, Adebayo A.; Ajibade, Peter A.

2014-07-01

73

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

NASA Astrophysics Data System (ADS)

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 (?G, ?H and ?S) 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).

Cheng, Zhengjun

74

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

PubMed

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 ?max 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

Adeniyi, Adebayo A; Ajibade, Peter A

2014-07-15

75

A revised method for estimating oxide basicity per the smith scale, with example application to glass durability  

Microsoft Academic Search

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 ? parameter scale. A linear relation was found between the oxide electronegativity and the Smith ? parameter, with an R2 of 0.92. An example application of

Jacob G. Reynolds

2011-01-01

76

Modified Fowler-Milne method for the spectroscopic determination of thermal plasma temperature without the measurement of continuum radiation.  

PubMed

A technique based on the Fowler-Milne method for the spectroscopic determination of thermal plasma temperatures without measuring continuum radiation is presented. This technique avoids the influence of continuum radiation with the combined line and continuum emission coefficients to derive the plasma temperatures. The amount of continuum emission coefficient is estimated by using an expression related to the Biberman factors. Parameters that affect the accuracy of the proposed technique and errors in the measured plasma temperatures are analyzed. It is shown that, by using the Ar I 696.5 nm line with a bandwidth of 3.27 nm without taking into account the continuum radiation, the plasma temperature measured will be lower on the order of up to 1000-3000 K for temperatures from 20,000 to 24,000 K. The theoretically predicted temperature errors are in good agreement with the experimental results, indicating that the proposed technique is reliable for plasma temperature measurement. PMID:21280813

Ma, Shuiliang; Gao, Hongming; Wu, Lin

2011-01-01

77

Modified Fowler-Milne method for the spectroscopic determination of thermal plasma temperature without the measurement of continuum radiation  

SciTech Connect

A technique based on the Fowler-Milne method for the spectroscopic determination of thermal plasma temperatures without measuring continuum radiation is presented. This technique avoids the influence of continuum radiation with the combined line and continuum emission coefficients to derive the plasma temperatures. The amount of continuum emission coefficient is estimated by using an expression related to the Biberman factors. Parameters that affect the accuracy of the proposed technique and errors in the measured plasma temperatures are analyzed. It is shown that, by using the Ar I 696.5 nm line with a bandwidth of 3.27 nm without taking into account the continuum radiation, the plasma temperature measured will be lower on the order of up to 1000-3000 K for temperatures from 20 000 to 24 000 K. The theoretically predicted temperature errors are in good agreement with the experimental results, indicating that the proposed technique is reliable for plasma temperature measurement.

Ma Shuiliang [State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001 (China); Plasma Research Laboratory, Australian National University, Canberra ACT 0200 (Australia); Gao Hongming; Wu Lin [State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001 (China)

2011-01-15

78

Integrating case study and survey research methods: an example in information systems  

Microsoft Academic Search

The case for combining research methods generally, and more specifically that for combining qualitative and quantitative methods, is strong. Yet, research designs that extensively integrate both fieldwork (e.g. case studies) and survey research are rare. Moreover, some journals tend tacitly to specialize by methodology thereby encouraging purity of method. The multi-method model of research while not new, has not been

Guy G. Gable

1994-01-01

79

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

NASA Astrophysics Data System (ADS)

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.

Warburton, Jamie Lee

80

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

ERIC Educational Resources Information Center

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.…

Miller, David

2010-01-01

81

Using mixed methods effectively in prevention science: designs, procedures, and examples.  

PubMed

There is growing interest in using a combination of quantitative and qualitative methods to generate evidence about the effectiveness of health prevention, services, and intervention programs. With the emerging importance of mixed methods research across the social and health sciences, there has been an increased recognition of the value of using mixed methods for addressing research questions in different disciplines. We illustrate the mixed methods approach in prevention research, showing design procedures used in several published research articles. In this paper, we focused on two commonly used mixed methods designs: concurrent and sequential mixed methods designs. We discuss the types of mixed methods designs, the reasons for, and advantages of using a particular type of design, and the procedures of qualitative and quantitative data collection and integration. The studies reviewed in this paper show that the essence of qualitative research is to explore complex dynamic phenomena in prevention science, and the advantage of using mixed methods is that quantitative data can yield generalizable results and qualitative data can provide extensive insights. However, the emphasis of methodological rigor in a mixed methods application also requires considerable expertise in both qualitative and quantitative methods. Besides the necessary skills and effective interdisciplinary collaboration, this combined approach also requires an open-mindedness and reflection from the involved researchers. PMID:23801237

Zhang, Wanqing; Watanabe-Galloway, Shinobu

2014-10-01

82

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

PubMed

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

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

2011-01-01

83

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

84

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

USGS Publications Warehouse

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.

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

2005-01-01

85

Methods to estimate effective population size using pedigree data: Examples in dog, sheep, cattle and horse  

PubMed Central

Background Effective population sizes of 140 populations (including 60 dog breeds, 40 sheep breeds, 20 cattle breeds and 20 horse breeds) were computed using pedigree information and six different computation methods. Simple demographical information (number of breeding males and females), variance of progeny size, or evolution of identity by descent probabilities based on coancestry or inbreeding were used as well as identity by descent rate between two successive generations or individual identity by descent rate. Results Depending on breed and method, effective population sizes ranged from 15 to 133 056, computation method and interaction between computation method and species showing a significant effect on effective population size (P < 0.0001). On average, methods based on number of breeding males and females and variance of progeny size produced larger values (4425 and 356, respectively), than those based on identity by descent probabilities (average values between 93 and 203). Since breeding practices and genetic substructure within dog breeds increased inbreeding, methods taking into account the evolution of inbreeding produced lower effective population sizes than those taking into account evolution of coancestry. The correlation level between the simplest method (number of breeding males and females, requiring no genealogical information) and the most sophisticated one ranged from 0.44 to 0.60 according to species. Conclusions When choosing a method to compute effective population size, particular attention should be paid to the species and the specific genetic structure of the population studied. PMID:23281913

2013-01-01

86

A new method of discovering primary management history: two examples where “little things mean a lot”  

Microsoft Academic Search

Outlines a new method of discovering original documents related to management history. Uses seemingly insignificant statements in books, articles or original documents to locate documents not listed on any computer database or public archive records, but which are undiscovered in attics or basements. The method involves the use of sources not commonly used by management scholars: obituaries, wills, cemetery records,

Charles D. Wrege; Ronald G. Greenwood; Regina Greenwood

1997-01-01

87

Potential of a spectroscopic measurement method using adding-doubling to retrieve the bulk optical properties of dense microalgal media.  

PubMed

In the context of algal mass cultivation, current techniques used for the characterization of algal cells require time-consuming sample preparation and a large amount of costly, standard instrumentation. As the physical and chemical properties of the algal cells strongly affect their optical properties, the optical characterization is seen as a promising method to provide an early diagnosis in the context of mass cultivation monitoring. This article explores the potential of a spectroscopic measurement method coupled with the inversion of the radiative transfer theory for the retrieval of the bulk optical properties of dense algal samples. Total transmittance and total reflectance measurements were performed over the 380-1020 nm range on dense algal samples with a double integrating sphere setup. The bulk absorption and scattering coefficients were thus extracted over the 380-1020 nm range by inverting the radiative transfer theory using inverse-adding-doubling computations. The experimental results are presented and discussed; the configuration of the optical setup remains a critical point. The absorption coefficients obtained for the four samples of this study appear not to be more informative about pigment composition than would be classical methods in analytical spectroscopy; however, there is a real added value in measuring the reduced scattering coefficient, as it appears to be strongly correlated to the size distribution of the algal cells. PMID:25198389

Bellini, Sarah; Bendoula, Ryad; Latrille, Eric; Roger, Jean-Michel

2014-10-01

88

A rapid and accurate spectroscopic method for alkalinity measurements in sea water samples  

Microsoft Academic Search

The authors propose a new spectrophotometric method for the determination of sea water alkalinity. The method consists to neutralize all the basic species taken into account in the alkalinity expression by a weak acid (formic acid) mixed with a pH sensitive dye, the Bromo-Phenol Blue, which has a dissociation constant close to those of formic acid. The neutralization reaction leads

Gérard Sarazin; Gil Michard; François Prevot

1999-01-01

89

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

...applied in a particular case only if the comparability, quality of data, and reliability...Therefore, given the close functional comparability between the controlled and uncontrolled...method achieves a higher degree of comparability and will provide a more reliable...

2014-04-01

90

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

Code of Federal Regulations, 2013 CFR

...applied in a particular case only if the comparability, quality of data, and reliability...Therefore, given the close functional comparability between the controlled and uncontrolled...method achieves a higher degree of comparability and will provide a more reliable...

2013-04-01

91

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

Code of Federal Regulations, 2012 CFR

...applied in a particular case only if the comparability, quality of data, and reliability...Therefore, given the close functional comparability between the controlled and uncontrolled...method achieves a higher degree of comparability and will provide a more reliable...

2012-04-01

92

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

Microsoft Academic Search

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

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

1995-01-01

93

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

PubMed

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: ?2 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

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

2014-09-01

94

Spectroscopic holography - A new method for mode analysis of randomly excited structures  

NASA Astrophysics Data System (ADS)

A method was developed for analyzing modes and amplitudes of vibration of a randomly excited object. Time-average holography, in which the reference beam was mechanically excited at any given frequency in the spectral range of the random excitation, was applied. The phase of the exciting vibration of the reference beam was locked to the phase of the specific frequency in the random band. This method was applied as successfully as for objects excited with swept sinusoidal vibration.

Politch, Jacob

1990-08-01

95

Development of ultraviolet spectroscopic method for the estimation of metronidazole benzoate from pharmaceutical formulation  

PubMed Central

Background: The present study was undertaken with an objective to develop a simple, accurate, cost-effective and reproducible ultraviolet spectrophotometric method for the estimation of metronidazole benzoate (MB) from pharmaceutical formulations. Materials and Methods: The analysis was performed on ?max 268 nm by using 0.1 NHCl as diluents. The proposed method was validated on International Conference Harmonization guideline including the parameters viz., accuracy, linearity, precision, specificity and reproducibility. The proposed method was also used to access the content of MB in two commercial brands of Indian market. Results: Beer's law was obeyed in the concentration range of 1-10 ?g/ml having regression equation y = 0.078 x-0.012. The accuracy value for 4 ?g/ml and 5 ?g/ml concentration of MB was found to be 99.37% and 98.9% respectively. The relative standard deviation of interday and intraday was lesser than 1%. The developed method was applied on two different marketed brands and contents of MB were found to be 98.62% and 98.59% incompliance with labeled claim. The results were under the limit of acceptance statistically. Conclusion: It was concluded that the proposed method can be used for routine analysis of MB in bulk and commercial formulations. PMID:25097394

Mishra, Arun K.; Kumar, Arvind; Mishra, Amrita; Mishra, Hari V.

2014-01-01

96

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

97

STRUCTURE IN THE THREE-DIMENSIONAL GALAXY DISTRIBUTION. I. METHODS AND EXAMPLE RESULTS  

SciTech Connect

Three methods for detecting and characterizing structure in point data, such as that generated by redshift surveys, are described: classification using self-organizing maps, segmentation using Bayesian blocks, and density estimation using adaptive kernels. The first two methods are new, and allow detection and characterization of structures of arbitrary shape and at a wide range of spatial scales. These methods should elucidate not only clusters, but also the more distributed, wide-ranging filaments and sheets, and further allow the possibility of detecting and characterizing an even broader class of shapes. The methods are demonstrated and compared in application to three data sets: a carefully selected volume-limited sample from the Sloan Digital Sky Survey redshift data, a similarly selected sample from the Millennium Simulation, and a set of points independently drawn from a uniform probability distribution-a so-called Poisson distribution. We demonstrate a few of the many ways in which these methods elucidate large-scale structure in the distribution of galaxies in the nearby universe.

Way, M. J.; Gazis, P. R.; Scargle, Jeffrey D., E-mail: Michael.J.Way@nasa.gov, E-mail: PGazis@sbcglobal.net, E-mail: Jeffrey.D.Scargle@nasa.gov [NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035 (United States)

2011-01-20

98

Research Methods for Collaboration Engineering: An Assessment of Applicability Using Collaborative PolicyMaking Example  

Microsoft Academic Search

Collaboration Engineering (CE) is a new field of research and practice which involves the design of recurring collaboration processes that are meant to cause predictable and success among organizations' recurring mission-critical collaborative tasks. To measure the effectiveness of CE research efforts, we would need to use a research methodology. This article therefore provides an overview of selected research methods, and

Josephine Nabukenya; Gert-Jan de Vreede

2007-01-01

99

Monte Carlo method for determining earthquake recurrence parameters from short paleoseismic catalogs: Example calculations  

E-print Network

Monte Carlo method for determining earthquake recurrence parameters from short paleoseismic paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach

100

A new method for an objective, $\\chi^2$-based spectroscopic analysis of early-type stars  

E-print Network

A precise quantitative spectral analysis - encompassing atmospheric parameter and chemical elemental abundance determination - is time consuming due to its iterative nature and the multi-parameter space to be explored, especially when done "by eye". A robust automated fitting technique that is as trustworthy as traditional methods would allow for large samples of stars to be analyzed in a consistent manner in reasonable time. We present a semi-automated quantitative spectral analysis technique for early-type stars based on the concept of $\\chi^2$ minimization. The method's main features are: far less subjective than typical "by eye" methods, correction for inaccurate continuum normalization, consideration of the whole useful spectral range, simultaneous sampling of the entire multi-parameter space (effective temperature, surface gravity, microturbulence, macroturbulence, projected rotational velocity, radial velocity, elemental abundances) to find the global best solution, applicable also to composite spectra...

Irrgang, Andreas; Heber, Ulrich; Böck, Moritz; Hanke, Manfred; Nieva, Maria-Fernanda; Butler, Keith

2014-01-01

101

A spectroscopic temperature measurement of converging detonations by the emission spectral matching method  

Microsoft Academic Search

The emission of CN violet bands from a converging point is analyzed using a microdensitometer. To determine the temperature at the converging point of a detonation, a method of matching the entire emission spectra is utilized. The anticipated emission spectra of the observed band can be calculated theoretically with a combination of the gasdynamic quantities, assuming Boltzmann distributions for rotational,

T. Sugimura; T. Fujiwara

1981-01-01

102

The molecular spectroscopic methods of CBR-temperature measurement in epochs with large redshifts  

Microsoft Academic Search

Investigations of the properties of the matter in earlier cosmological epochs by using methods of studying of the interstellar gas clouds at large cosmological distances by analyzing QSO absorption line systems is reviewed. It is suggested that it is also possible to detect the absorption lines of the most abundant molecules such as CO, OH, CH, and CN in QSO

V. K. Khersonskii; I. E. Val'tts

1990-01-01

103

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 ...

104

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

PubMed

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

Breseghello, Flavio; Coelho, Alexandre Siqueira Guedes

2013-09-01

105

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

PubMed

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

Liang, Jing; Feng, Su-Ling

2011-04-01

106

RAPID COMMUNICATION: Note on the temperature measurements in surface treatment reactors using the spectroscopic method  

Microsoft Academic Search

The authors investigate the validity of the rotational distribution of N2+(B) to N2+(X) emissions as a tool to determine the substrate temperature in surface treatment reactors. They show that the method is not valid for processes involving pure nitrogen at p>1.3*102 Pa. In N2-H2 mixtures, however, they show that the technique can be used for temperature measurements for all pressure

A. Brand; J. L. R. Muzart; A. R. de Souza

1990-01-01

107

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

PubMed

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 ?g 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

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

2012-05-30

108

Spectroscopic Observations  

NSDL National Science Digital Library

This is a series of three activities about light and spectra. First, learners will construct their own spectroscope, observe common light sources, record the observed spectra, and compare their findings. Next, learners will use their spectroscopes to observe the spectra from different gas tubes and compare each observed spectrum to known spectra. Finally, they will observe a solar spectrum created by a prism, view a solar spectrum on paper, and attempt to determine the elements present in the Sun. This activity requires spectroscope posters and gratings available from the Stanford Solar Center (http://solar-center.stanford.edu/posters/), fluorescent and incandescent light sources, and emission lamps and power sources. This activity is from the Stanford Solar Center's All About the Sun: Sun and Stars activity guide for Grades 5-8 and can also accompany the Stanford Solar Center's Build Your Own Spectroscope activity.

109

An example of Newton's method for an equation in Gevrey series  

NASA Astrophysics Data System (ADS)

In the context of complex WKB analysis, we discuss a one-dimensional Schrödinger equation -h2?x2f(x,h)+[Q(x)+hQ1(x,h)]f(x,h)=0, h?0, where Q(x), Q1(x,h) are analytic near the origin x=0, Q(0)=0, and Q1(x,h) is a factorially divergent power series in h. We show that there is a change of independent variable y=y(x,h), analytic near x=0 and factorially divergent with respect to h, that transforms the above Schrödinger equation to a canonical form. The proof goes by reduction to a mildly nonlinear equation on y(x,h) and by solving it using an appropriately modified Newton's method of tangents.

Getmanenko, Alexander

2014-12-01

110

Identification of pyrazosulfuron-ethyl binding affinity and binding site subdomain IIA in human serum albumin by spectroscopic methods.  

PubMed

Pyrazosulfuron-ethyl (PY) is a sulfonylurea herbicide developed by DuPont which has been widely used for weed control in cereals. The determination of PY binding affinity and binding site in human serum albumin (HSA) by spectroscopic methods is the subject of this work. From the fluorescence emission, circular dichroism and three-dimensional fluorescence results, the interaction of PY with HSA caused secondary structure changes in the protein. Fluorescence data demonstrated that the quenching of HSA fluorescence by PY was the result of the formation of HSA-PY complex at 1:1 molar ratio, a static mechanism was confirmed to lead to the fluorescence quenching. Hydrophobic probe 8-anilino-1-naphthalenesulfonic acid (ANS) displacement results show that hydrophobic patches are the major sites for PY binding on HSA. The thermodynamic parameters DeltaH degrees and DeltaS degrees were calculated to be -36.32 kJ mol(-1) and -35.91 J mol(-1)K(-1), which illustrated van der Waals forces and hydrogen bonds interactions were the dominant intermolecular force in stabilizing the complex. Also, site marker competitive experiments showed that the binding of PY to HSA took place primarily in subdomain IIA (Sudlow's site I). What presented in this paper binding research enriches our knowledge of the interaction between sulfonylurea herbicides and the physiologically important protein HSA. PMID:20064739

Ding, Fei; Liu, Wei; Zhang, Xi; Wu, Li-Jun; Zhang, Li; Sun, Ying

2010-03-01

111

Identification of pyrazosulfuron-ethyl binding affinity and binding site subdomain IIA in human serum albumin by spectroscopic methods  

NASA Astrophysics Data System (ADS)

Pyrazosulfuron-ethyl (PY) is a sulfonylurea herbicide developed by DuPont which has been widely used for weed control in cereals. The determination of PY binding affinity and binding site in human serum albumin (HSA) by spectroscopic methods is the subject of this work. From the fluorescence emission, circular dichroism and three-dimensional fluorescence results, the interaction of PY with HSA caused secondary structure changes in the protein. Fluorescence data demonstrated that the quenching of HSA fluorescence by PY was the result of the formation of HSA-PY complex at 1:1 molar ratio, a static mechanism was confirmed to lead to the fluorescence quenching. Hydrophobic probe 8-anilino-1-naphthalenesulfonic acid (ANS) displacement results show that hydrophobic patches are the major sites for PY binding on HSA. The thermodynamic parameters ? H° and ? S° were calculated to be -36.32 kJ mol -1 and -35.91 J mol -1 K -1, which illustrated van der Waals forces and hydrogen bonds interactions were the dominant intermolecular force in stabilizing the complex. Also, site marker competitive experiments showed that the binding of PY to HSA took place primarily in subdomain IIA (Sudlow's site I). What presented in this paper binding research enriches our knowledge of the interaction between sulfonylurea herbicides and the physiologically important protein HSA.

Ding, Fei; Liu, Wei; Zhang, Xi; Wu, Li-Jun; Zhang, Li; Sun, Ying

2010-03-01

112

Utilising a collective case study system theory mixed methods approach: a rural health example  

PubMed Central

Background Insight into local health service provision in rural communities is limited in the literature. The dominant workforce focus in the rural health literature, while revealing issues of shortage of maldistribution, does not describe service provision in rural towns. Similarly aggregation of data tends to render local health service provision virtually invisible. This paper describes a methodology to explore specific aspects of rural health service provision with an initial focus on understanding rurality as it pertains to rural physiotherapy service provision. Method A system theory-case study heuristic combined with a sequential mixed methods approach to provide a framework for both quantitative and qualitative exploration across sites. Stakeholder perspectives were obtained through surveys and in depth interviews. The investigation site was a large area of one Australian state with a mix of rural, regional and remote communities. Results 39 surveys were received from 11 locations within the investigation site and 19 in depth interviews were conducted. Stakeholder perspectives of rurality and workforce numbers informed the development of six case types relevant to the exploration of rural physiotherapy service provision. Participant perspective of rurality often differed with the geographical classification of their location. The numbers of onsite colleagues and local access to health services contributed to participant perceptions of rurality. Conclusions The complexity of understanding the concept of rurality was revealed by interview participants when providing their perspectives about rural physiotherapy service provision. Dual measures, such as rurality and workforce numbers, provide more relevant differentiation of sites to explore specific services, such rural physiotherapy service provision, than single measure of rurality as defined by geographic classification. The system theory-case study heuristic supports both qualitative and quantitative exploration in rural health services research. PMID:25066241

2014-01-01

113

Combining the tape-lift method and Fourier transform infrared spectroscopic imaging for forensic applications.  

PubMed

Conventional Fourier transform infrared (FT-IR) spectroscopy and microscopy have been widely used in forensic science. New opportunities exist to obtain chemical images and to enhance the spatial resolution using attenuated total reflection (ATR) FT-IR spectroscopy coupled with a focal-plane array (FPA) detector. In this paper, the sensitivity limits of FT-IR imaging using three different ATR crystals (Ge, ZnSe, and diamond) in three different optical arrangements for the detection of model particles is discussed. Model systems of ibuprofen and paracetamol particles having sizes below 32 mum were studied. The collection of drug particles was achieved with the aid of two different tapes: common adhesive tape and a film of polydimethylsiloxane (PDMS). The surface of the film with collected particles was measured directly via ATR-FT-IR imaging. Since the removal of tape from porous surfaces can be difficult, the application of micro ATR-FT-IR imaging directly to the surface of a newspaper contaminated with particles of model drugs is also discussed. In order to assess the feasibility of the chosen method in a forensic case study, the detection of diacetylmorphine hydrochloride traces in PDMS matrix and the finger surface is investigated. The scenarios considered were that of the detection of evidence collected at a crime scene with the tape lift method and the analysis of the finger of an individual after drug handling. The results show broad implications in the detection of drugs of abuse. PMID:17002827

Ricci, Camilla; Chan, K L Andrew; Kazarian, Sergei G

2006-09-01

114

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

USGS Publications Warehouse

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)

Burt, R. J.

1983-01-01

115

PDT in the thoracic cavity: Spectroscopic methods and fluence modeling for treatment planning  

NASA Astrophysics Data System (ADS)

PDT for the thoracic cavity provides a promising cancer treatment modality, but improvements in treatment planning, particularly in PDT dosimetry, can be made to improve uniformity of light delivery. When a cavity of arbitrary geometry is illuminated, the fluence increases due to multiple-scattered photons, referred to as the Integrating Sphere Effect (ISE). Current pleural PDT treatment protocol at the University of Pennsylvania monitors light fluence (hereafter simply fluence, measured in W/cm2) via seven isotropic detectors sutured at different locations in thoracic cavity of a patient. This protocol monitors light at discrete locations, but does not provide a measurement of fluence for the thoracic cavity as a whole. Current calculation of light fluence includes direct light only and thus does not account for the unique optical properties of each tissue type present, which in turn affects the accuracy of the calculated light distribution in the surrounding tissue and, in turn, the overall cell death and treatment efficacy. Treatment planning for pleural PDT can be improved, in part, by considering the contribution of scattered light, which is affected by the two factors of geometry and in vivo optical properties. We expanded the work by Willem Star in regards to the ISE in a spherical cavity. A series of Monte Carlo (MC) simulations were run for semi-infinite planar, spherical, and ellipsoidal geometries for a range of optical properties. The results of these simulations are compared to theory and numerical solutions for fluence in the cavity and at the cavity-medium boundary. The development via MC simulations offers a general method of calculating the required light fluence specialized to each patient, based on the treatment surface area. The scattered fluence calculation is dependent on in vivo optical properties (?a and ?s') of the tissues treated. Diffuse reflectance and fluorescence spectroscopy methods are used to determine the optical properties and oxygenation (reflectance measurements) and drug concentration (fluorescence measurements) of different tissues in vivo, before and after treatment, in patients enrolled the Phase I HPPH study ongoing at the University of Pennsylvania. This work aims to provide the building blocks essential to pleural PDT treatment planning by more accurately calculating the required fluence using a model that accounts for the effects of treatment geometry and optical properties measured in vivo.

Meo, Julia Lauren

116

Chemometric optimization of the robustness of the near infrared spectroscopic method in wheat quality control.  

PubMed

A chemometric approach was applied for the optimization of the robustness of the NIRS method for wheat quality control. Due to the high number of experimental (n=6) and response variables to be studied (n=7) the optimization experiment was divided into two stages: screening stage in order to evaluate which of the considered variables were significant, and optimization stage to optimize the identified factors in the previously selected experimental domain. The significant variables were identified by using fractional factorial experimental design, whilst Box-Wilson rotatable central composite design (CCRD) was run to obtain the optimal values for the significant variables. The measured responses included: moisture, protein and wet gluten content, Zeleny sedimentation value and deformation energy. In order to achieve the minimal variation in responses, the optimal factor settings were found by minimizing the propagation of error (POE). The simultaneous optimization of factors was conducted by desirability function. The highest desirability of 87.63% was accomplished by setting up experimental conditions as follows: 19.9°C for sample temperature, 19.3°C for ambient temperature and 240V for instrument voltage. PMID:25281098

Poji?, Milica; Raki?, Dušan; Lazi?, Zivorad

2015-01-01

117

Vibrational spectroscopic study and NBO analysis on tranexamic acid using DFT method  

NASA Astrophysics Data System (ADS)

In this work, we reported the vibrational spectra of tranexamic acid (TA) by experimental and quantum chemical calculation. The solid phase FT-Raman and FT-IR spectra of the title compound were recorded in the region 4000 cm-1 to 100 cm-1 and 4000 cm-1 to 400 cm-1 respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of TA in the ground state have been calculated by using density functional theory (DFT) B3LYP method with standard 6-31G(d,p) basis set. The scaled theoretical wavenumber showed very good agreement with the experimental values. The vibrational assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes. Stability of the molecule, arising from hyperconjugative interactions and charge delocalization, has been analyzed using Natural Bond Orbital (NBO) analysis. The results show that ED in the ?* and ?* antibonding orbitals and second order delocalization energies E(2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. The electrostatic potential mapped onto an isodensity surface has been obtained. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures were calculated in gas phase.

Muthu, S.; Prabhakaran, A.

2014-08-01

118

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

PubMed

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

Kearfott, Kimberlee J; Dewey, Steven C

2009-02-01

119

Insights into in vitro binding of parecoxib to human serum albumin by spectroscopic methods.  

PubMed

Herein, we report the effect of parecoxib on the structure and function of human serum albumin (HSA) by using fluorescence, circular dichroism (CD), Fourier transforms infrared (FTIR), three-dimensional (3D) fluorescence spectroscopy, and molecular docking techniques. The Stern-Volmer quenching constants KSV and the corresponding thermodynamic parameters ?H, ?G, and ?S have been estimated by the fluorescence quenching method. The results indicated that parecoxib binds spontaneously with HSA through van der Waals forces and hydrogen bonds with binding constant of 3.45 × 10(4) M(-1) at 298 K. It can be seen from far-UV CD spectra that the ?-helical network of HSA is disrupted and its content decreases from 60.5% to 49.6% at drug:protein = 10:1. Protein tertiary structural alterations induced by parecoxib were also confirmed by FTIR and 3D fluorescence spectroscopy. The molecular docking study indicated that parecoxib is embedded into the hydrophobic pocket of HSA. PMID:24939449

Shang, Shujun; Liu, Qingling; Gao, Jiandong; Zhu, Yulin; Liu, Jingying; Wang, Kaiyan; Shao, Wei; Zhang, Shudong

2014-10-01

120

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

PubMed

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 3.15nm, 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

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

2015-01-25

121

Localized and Spectroscopic Orbitals: Squirrel Ears on Water.  

ERIC Educational Resources Information Center

Reexamines the electronic structure of water considering divergent views. Discusses several aspects of molecular orbital theory using spectroscopic molecular orbitals and localized molecular orbitals. Gives examples for determining lowest energy spectroscopic orbitals. (ML)

Martin, R. Bruce

1988-01-01

122

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

PubMed

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

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

2014-03-01

123

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

PubMed

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

Monti, Sandra; Manet, Ilse; Marconi, Giancarlo

2011-12-21

124

Study on the interaction of Co (III) DiAmsar with serum albumins: Spectroscopic and molecular docking methods.  

PubMed

This study was designed to examine the interaction of cobalt-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine (Co(III) DiAmsar) as a hexadentate ligand with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in Tris-HCl buffer solution at pH 7.4. To this aim, at first, Co (III) DiAmsar was synthesized and characterized by nuclear magnetic resonance (NMR), and mass spectroscopy and then its interaction with HSA and BSA was investigated by means of various spectroscopic methods (Fourier transform infrared (FT-IR), UV-visible (UV-vis), fluorescence, and cyclic voltammetry (CV)) and molecular docking technique. The results of fluorescence titration revealed that the Co (III) DiAmsar strongly quench the intrinsic fluorescence of HSA and BSA through a static quenching procedure. Binding constants (Ka) and the number of binding sites (n?1) were calculated using Stern-Volmer equations. The ?G parameters at different temperatures were calculated. Subsequently, the values of ?H and ?S were also calculated, which revealed that the van der Waals and hydrogen bonding interaction splay a major role in Co (III) DiAmsar-HSA and Co (III) DiAmsar-BSA associations. The distance r between donor (HSA and BSA) and acceptor (Co (III) DiAmsar) was obtained according to fluorescence resonance energy transfer. The data obtained by the molecular modeling study revealed the surrounding residues of HSA and BSA around Co (III) DiAmsar. PMID:25105263

Farahani, Bahman Vasheghani; Bardajee, Ghasem Rezanejade; Rajabi, Farzaneh Hosseinpour; Hooshyar, Zari

2015-01-25

125

CD Spectroscope  

NSDL National Science Digital Library

In this activity, learners use an old CD to construct a spectroscope, a device that separates light into its component colors. Learners will hold it up to various light sources to examine how different light has different color strengths. Use this activity to introduce learners to the color spectrum and the tools scientists use to study it.

University, Colorado S.

2009-01-01

126

A simple three-step method for design and affinity testing of new antisense peptides: an example of erythropoietin.  

PubMed

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

Štambuk, Nikola; Manojlovi?, Zoran; Tur?i?, Petra; Martini?, Roko; Konjevoda, Paško; Weitner, Tin; Wardega, Piotr; Gabri?evi?, Mario

2014-01-01

127

Recent advances in time-frequency analysis methods for machinery fault diagnosis: A review with application examples  

NASA Astrophysics Data System (ADS)

Nonstationary signal analysis is one of the main topics in the field of machinery fault diagnosis. Time-frequency analysis can identify the signal frequency components, reveals their time variant features, and is an effective tool to extract machinery health information contained in nonstationary signals. Various time-frequency analysis methods have been proposed and applied to machinery fault diagnosis. These include linear and bilinear time-frequency representations (e.g., wavelet transform, Cohen and affine class distributions), adaptive parametric time-frequency analysis (based on atomic decomposition and time-frequency auto-regressive moving average models), adaptive non-parametric time-frequency analysis (e.g., Hilbert-Huang transform, local mean decomposition, and energy separation), and time varying higher order spectra. This paper presents a systematic review of over 20 major such methods reported in more than 100 representative articles published since 1990. Their fundamental principles, advantages and disadvantages, and applications to fault diagnosis of machinery have been examined. Some examples have also been provided to illustrate their performance.

Feng, Zhipeng; Liang, Ming; Chu, Fulei

2013-07-01

128

An improved "hand calculation" technique for analyzing pressure build-up data from low permeability, vertically fractured gas wells-camparison to other methods using field examples  

E-print Network

AN IMPROVED "HAND CALCULATION" TECVNI(UE FOR ANALYZING PRESSURE BUILD-UP DATA FROM LOW PERMEABILITY, VERTICALLY FRACTURED GAS WELLS-COMPARISON TO OTHER METHODS USING FIELD EXAMPLES A Thesis by JAMES HERMAN MCGEE Submitted to the Graduate... PFRMEABILITY, VERTICALLY FRACTURED GAS WELLS-COMPARISON TO OTHER METHODS USING FIELD EXAMPLES A Thesis by JAMES HERMAN MCGEE Approved as to style and content by: Chairman of Committ e (Head of apartment Mem , Member May 1980 ABSTRACT An Improved...

McGee, James Herman

2012-06-07

129

Investigation of a half-wave method for birefringence or thickness measurements of a thick, semitransparent, uniaxial, anisotropic substrate by use of spectroscopic ellipsometry.  

PubMed

A half-wave method of measurement of wafer birefringence that is based on interference fringes recorded from a uniaxial wafer by use of a standard phase-modulated spectroscopic ellipsometer is investigated. The birefringence of uniaxial wafers is calculated from the extremal points in the recorded oscillating intensities. A formalism is developed to incorporate the change in birefringence with wavelength as a correction factor. The correction explains the overestimation of the birefringence from previous similar research on thick uniaxial sapphire substrates. The enhanced derivative of the birefringence that is due to polarization-dependent intraconduction band transitions is detected. Furthermore, for well-characterized wafers it is shown that this method can be used in wafer-thickness mapping of 4H-SiC and similar uniaxial high-bandgap semiconductors. PMID:18350056

Kildemo, M; Mooney, M; Sudre, C; Kelly, P V

2000-09-01

130

Studies on the interactions of SAP-1 (an N-terminal truncated form of cystatin S) with its binding partners by CD-spectroscopic and molecular docking methods.  

PubMed

SAP-1 is a 113 amino acid long single-chain protein which belongs to the type 2 cystatin gene family. In our previous study, we have purified SAP-1 from human seminal plasma and observed its cross-class inhibitory property. At this time, we report the interaction of SAP-1 with diverse proteases and its binding partners by CD-spectroscopic and molecular docking methods. The circular dichroism (CD) spectroscopic studies demonstrate that the conformation of SAP-1 is changed after its complexation with proteases, and the alterations in protein secondary structure are quantitatively calculated with increase of ?-helices and reduction of ?-strand content. To get insight into the interactions between SAP-1 and proteases, we make an effort to model the three-dimensional structure of SAP-1 by molecular modeling and verify its stability and viability through molecular dynamics simulations and finally complexed with different proteases using ClusPro 2.0 Server. A high degree of shape complementarity is examined within the complexes, stabilized by a number of hydrogen bonds (HBs) and hydrophobic interactions. Using HB analyses in different protein complexes, we have identified a series of key residues that may be involved in the interactions between SAP-1 and proteases. These findings will assist to understand the mechanism of inhibition of SAP-1 for different proteases and provide intimation for further research. PMID:24261636

Yadav, Vikash Kumar; Mandal, Rahul Shubhra; Puniya, Bhanwar Lal; Singh, Sarman; Yadav, Savita

2015-01-01

131

A new microwave spectroscope  

E-print Network

A NEW MICROWAVE SPECTROSCOPE A Dissertation By Andrew E. Sail* June 1951 Approved as to style and content by Chairman of Com ttee A NEW MICROWAVE SPECTROSCOPE A Dissertation Submitted to the Faculty of the Agricultural and Mechanical.... THEORETICAL APPROACH TO THE DESIGNING OP A MICROWAVE SPECTROSCOPE .................... 7 III. DESIGN OF THE EXPERIMENTAL MICROWAVE SPECTROSCOPE .......................... 14 Microwave Source .............................. 17 Microwave Circuit...

Salis, Andrew E.

2013-10-04

132

Insight into the roles of earthworm in vermicomposting of sewage sludge by determining the water-extracts through chemical and spectroscopic methods.  

PubMed

This work illustrated the effects of earthworm in vermicomposting (Eisenia fetida) by determining the water-extracts through chemical and spectroscopic methods. A field experiment with sludge as the only feed was subjected to vermicomposting and the control (without worms) for three weeks. Compared to the control, vermicomposting resulted in lower pH and water-extractable organic carbon (WEOC) along with higher electrical conductivity (EC). Moreover, vermicomposting caused nearly two times higher content of water-extractable nitrate (WEN-NO3(-)) than the control. Furthermore, fourier transform infrared spectra (FT-IR) revealed that vermicomposting promoted the hydrolysis/transformation of macromolecular organic matters and accelerated the degradation of polysaccharide-like and protein-like materials. Fluorescence spectroscopy also reflected vermicomposting led to higher humification degree than the control. In all, this study supplies a new view to assess the roles of earthworm in vermicomposting of sewage sludge by evaluating the water extracts. PMID:24384315

Yang, Jian; Lv, Baoyi; Zhang, Jie; Xing, Meiyan

2014-02-01

133

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

PubMed

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

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

2012-11-01

134

Thin layers in electrical engineering-example of shell models in analysing eddy-currents by boundary and finite element methods  

Microsoft Academic Search

The authors propose a didactical approach to thin regions in electromagnetics and, as an example, derive the boundary conditions and surface equation for eddy currents flowing inside a thin ferromagnetic shell. The numerical tests are done using the boundary-element-method (BEM) software package PH13-D, but the results could easily be transposed in a finite-element-method (FEM) context. The practical applications my concern

L. Krahenbuhl; D. Muller

1993-01-01

135

Selection method of quasi-continuous wavelength combination with applications to the near-infrared spectroscopic analysis of soil organic matter.  

PubMed

Equidistant combination multiple linear regression (EC-MLR) for the quasi-continuous wavelength selection of spectroscopic analysis was proposed and successfully applied to the reagent-free determination of soil organic matter with near-infrared spectroscopy. For comparison, the continuous-mode moving window partial least squares (MWPLS) and the discrete-mode successive projections algorithm (SPA) were improved by considering the stability and applied to the same analysis object as well. All methods exhibited good effect, but the modeling accuracy, stability, and validation effect of EC-MLR were better than that of the other two methods. Compared with MWPLS, the optimal EC-MLR model contained only 16 wavelengths, and method complexity was substantially reduced. Compared with SPA-MLR, the optimal EC-MLR model could easily undergo spectral preprocessing to improve predictive capability. Moreover, appropriate equidistant discrete wavelength combination with EC-MLR corresponded to the spectral absorption band with proper resolution and can effectively overcome co-linearity interruption for the MLR model. Thus, the EC-MLR method has great potential in practical application and instrument design. PMID:24666942

Pan, Tao; Li, Minmiao; Chen, Jiemei

2014-03-01

136

Spectroscopic diffraction phase microscopy.  

PubMed

We present spectroscopic diffraction phase microscopy (sDPM) as a method capable of measuring quantitative phase images at multiple wavelengths. sDPM uses a spatial light modulator at the Fourier plane of a lens to select desired wavelengths from the white light illumination of a grating. The quantitative phase information at different wavelengths allows us to decouple the refractive index and the thickness from the phase shift induced by biological cells. We demonstrate the capability of the setup by dispersion measurements of microsphere beads and RBCs. PMID:23381283

Pham, Hoa; Bhaduri, Basanta; Ding, Huafeng; Popescu, Gabriel

2012-08-15

137

AquaFuel: An example of the emerging new energies and the new methods for their scientific study  

E-print Network

In this paper we initiate studies of the emerging new forms of energy by using as a representative example the new combustible gas called AquaFuel, discovered and patented by William H. Richardson, jr., whose rights are now owned by Toups Technology Licensing, Inc. (TTL), of Largo, Florida. In essence, AquaFuel is a new energy converter capable of transforming Carbon and water into a new combustible gas via an electric discharge. We show that AquaFuel can be produced easily, safely and rapidly in large amounts, and exhibits greatly reduced emission pollutants as compared to fossil fuels of current use. Despite its simplicity, the chemical and physical characteristics of AquaFuel are largely unknown at this writing. We then review nine basic experimental measurements which are necessary for a scientific appraisal of AquaFuel. We outline the limitations of quantum mechanics and chemistry for the treatment of {\\it new} forms of energy, namely, energies which by definition should be {\\it beyond} said theories. We finally point out the availability of broader theories specifically constructed for the study of new energies and point out available applications.

Ruggero Maria Santilli

1998-05-23

138

New methods for estimating the tuberculosis case detection rate in high-HIV prevalence countries: the example of Kenya  

Microsoft Academic Search

Objective To develop new methods for estimating the sputum smear-positive tuberculosis case detection rate (CDR) in a country where infection with HIV is prevalent. Methods We estimated the smear-positive tuberculosis CDR in HIV-negative and HIV-positive adults, and in all adults in Kenya. Data on time trends in tuberculosis case notification rates and on HIV infection prevalence in adults and in

Brian Williams; Suzanne Scheele; Katherine Floyd; Christopher Dye; Joseph Sitienei

2009-01-01

139

Meta-analysis of environmental and occupational epidemiological studies: A method demonstrated using the carcinogenicity of PCBs as an example  

Microsoft Academic Search

Summary A method for a meta-analysis of several environmental or occupational epidemiological studies with small prevalences and\\/or incidences and long latency periods is presented. A combination of statistical evaluations of small prevalences should be done in the following way: (1) selecting relevant and comparable studies, (2) computing exact p-values of Poisson tests and aggregating them by Fisher's method, (3) estimating

Marlis Herbold

1993-01-01

140

Operator splitting methods for degenerate convection–diffusion equations II: numerical examples with emphasis on reservoir simulation and sedimentation  

Microsoft Academic Search

We present an accurate numerical method for a large class of scalar, strongly degenerate convection–diffusion equations. Important subclasses are hyperbolic conservation laws, porous medium type equations, two-phase reservoir flow equations, and strongly degenerate equations coming from the recent theory of sedimentation–consolidation processes. The method is based on splitting the convective and the diffusive terms. The nonlinear, convective part is solved

Helge Holden; Kenneth Hvistendahl Karlsen; Knut-Andreas Lie

2000-01-01

141

Catalase in fluvial biofilms: a comparison between different extraction methods and example of application in a metal-polluted river  

Microsoft Academic Search

Antioxidant enzymes are involved in important processes of cell detoxification during oxidative stress and have, therefore,\\u000a been used as biomarkers in algae. Nevertheless, their limited use in fluvial biofilms may be due to the complexity of such\\u000a communities. Here, a comparison between different extraction methods was performed to obtain a reliable method for catalase\\u000a extraction from fluvial biofilms. Homogenization followed

Chloé Bonnineau; Berta Bonet; Natàlia Corcoll; Helena Guasch

2011-01-01

142

Comparative Methods for the Analysis of Gene-Expression Evolution: An Example Using Yeast Functional Genomic Data  

Microsoft Academic Search

Understanding the evolution of gene function is a primary challenge of modern evolutionary biology. Despite an expanding database from genomic and developmental studies, we are lacking quantitative methods for analyzing the evolution of some important measures of gene function, such as gene-expression patterns. Here, we introduce phylogenetic comparative methods to compare different models of gene-expression evolution in a maximum-likelihood framework.

Todd H. Oakley; Zhenglong Gu; Ehab Abouheif; Nipam H. Patel; Wen-Hsiung Li

2004-01-01

143

Study of XAFS spectroscopic methods of speciation using mixtures of Cu(I) and Cu(II) chlorides  

NASA Astrophysics Data System (ADS)

Speciation concerns determination of the chemical forms along with the relative quantities of the different species in a given sample. The aim of the present work is to make a comparative study of the different methods of speciation using X-ray absorption fine structure (XAFS) spectroscopy. For this purpose, mixtures have been prepared by mixing CuCl2 and CuCl in different proportions. The X-ray absorption spectra have been recorded at the copper K-edge in the mixtures and the two chlorides separately. The different characteristic features of the XANES spectra of the two chlorides, useful for speciation, have been identified. Firstly, Principal component analysis (PCA) and target transformation (TT) methods have been used to check the number and identity of components in the mixtures. After the identification of the components, the percentages of the species in the mixtures have been quantitatively determined by linear combination fitting (LCF) of XANES, derivative XANES, and EXAFS (k3chi and k2chi) spectra. The other methods of speciation which have been employed are normalized difference absorption edge spectra analysis (NDAES), methods based on derivative XANES spectra of species and the method based on the relative position of the absorption edge. Results obtained from these methods have been compared and their relative merits discussed. It is probably for the first time that such a study has been done. The first section in your paper

Gaur, A.; Shrivastava, B. D.; Khalid, S.

2013-04-01

144

Lipid Monolayer and Sparse Matrix Screening for Growing Two-Dimensional Crystals for Electron Crystallography: Methods and Examples  

PubMed Central

Electron microscopy provides an efficient method for rapidly assessing whether a solution of macromolecules is homogeneous and monodisperse. If the macromolecules can be induced to form two-dimensional crystals that are a single layer in thickness, then electron crystallography of frozen-hydrated crystals has the potential of achieving three-dimensional density maps at sub-nanometer or even atomic resolution. Here we describe the lipid monolayer and sparse matrix screening methods for growing two-dimensional crystals and present successful applications to soluble macromolecular complexes: carboxysome shell proteins and HIV CA, respectively. Since it is common to express recombinant proteins with poly-His tags for purification by metal affinity chromatography, the monolayer technique using bulk lipids doped with Ni2+ lipids has the potential for broad application. Likewise, the sparse matrix method uses screening conditions for three-dimensional crystallization and is therefore of broad applicability. PMID:23132079

Yeager, Mark; Dryden, Kelly A.; Ganser-Pornillos, Barbie K.

2014-01-01

145

Improved method to visualize lipid distribution within arterial vessel walls by 1.7 ?m spectroscopic spectral-domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

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 1.7?m 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%.

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

2014-02-01

146

Electromagnetic induction in spherical earth containing oceans and continents in electrical contact with underlying section: Theory, method, example  

Microsoft Academic Search

The problem of allowance for the influence of surface inhomogeneities on the results of deep electromagnetic sounding is one of the most important in geoelectrics. In an effort to solve this problem, the character of electromagnetic induction in a spherical earth containing oceans and continents, theoretical principles are set forth of the so-called iterative-dissipative method as applicable to the problem

B. Sh. Zinger; A. V. Kuvshinov; E. B. Faynberg

1987-01-01

147

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)

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.

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

2014-07-01

148

Spectroscopic method for temperature measurements in active zone of AlxGa1-xAs DQW laser diodes  

Microsoft Academic Search

A new method for measurement of bulk temperature in the laser diode active zone using the spectral position of the peak gain is offered. The facet and bulk temperatures of a few diodes with output power from 1 to 10 W are measured. The obtained results allow us to conclude that the main reason for bulk temperature increasing is ohmic

A. J. Semjonov; B. Kolesov

1995-01-01

149

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

PubMed Central

• 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

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

150

Operator splitting methods for degenerate convection-diffusion equations II: numerical examples with emphasis on reservoir simulation and sedimentation  

Microsoft Academic Search

. We present an accurate numerical method for a large class of scalar, strongly degenerateconvection-diusion equations. Important subclasses are hyperbolic conservation laws,porous medium type equations, two-phase reservoir ow equations, and strongly degenerateequations coming from the recent theory of sedimentation-consolidation processes. The methodis based on splitting the convective and the diusive terms. The nonlinear, convective part issolved using front tracking and

Helge Holden; Kenneth Hvistendahl Karlsen; Knut-Andreas Lie

1999-01-01

151

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

PubMed

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

Tancredi, Weronika; Torgersson, Olof

2013-01-01

152

A Quantitative Method for Delineating Regions: An Example for theWestern Corn Belt Plains Ecoregion of the USA  

PubMed

/ A method was developed to systematically delineate boundaries forecological classification of regions. The process entailed the use ofsmall-scale digital data to quantify spatial concordance among environmentalattribute data sets. The data sets were grouped into spatially related themesusing cluster analysis and multidimensional scaling. Selected data sets werethen used either individually or collectively to divide the study area intosubregions that exhibited different environmental attributes. The method wasapplied to a previously defined ecological unit, the western Corn Belt of thecentral United States. The results showed that the portion of the study areawith intensive corn and soybean production was identifiable using each of thethree input data sets selected for partitioning (soil associations; AVHRRremote-sensing imagery; and a combined data set of landform, forest, andsoils data). The classification of other portions of the study area washighly dependent on the type and scale of the input data. The systematicmethodology used here offers advantages over other methods for identifyingecological regions in that the results from the systematic approach can bereproduced, the boundaries between ecological units can be revised based onnew or more accurate data, important ecological processes are explicitlychosen to delineate boundaries, and transition zones between regions can bequantified.KEY WORDS: Ecoregions; Spatial analysis; Corn Belt; Iowa; GIS;Regionalization PMID:9106414

Bernert; Eilers; Sullivan; Freemark; Ribic

1997-05-01

153

Mass spectroscopic fingerprinting method for differentiation between Scutellaria lateriflora and the germander (Teucrium canadense and T. chamaedrys) species.  

PubMed

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

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

2010-01-01

154

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

PubMed Central

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

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

2013-01-01

155

Structural and spectroscopic properties of LaOF:Eu3+ nanocrystals prepared by the sol-gel Pechini method.  

PubMed

A new method was used to obtain Eu(3+)-doped LaOF nanocrystals. The obtained nanocrystals were synthesized for the first time using a modified Pechini sol-gel method. The products were analyzed by X-ray powder diffraction and the Rietveld method. Optimal conditions for the synthesis were found. Luminescent properties of the tetragonal and rhombohedral LaOF:Eu(3+) nanocrystals were investigated by collecting excitation and luminescence spectra. The most effective dopant concentrations in both hosts were found. Luminescent lifetimes were also measured. The time-resolved luminescent traces showed both a growth and a decay, which pointed to energy transfer processes between Eu(3+) ions in the LaOF host. In order to explain these phenomena, an adequate mechanism has been proposed. Intensity parameters ?(2), ?(4) and quantum efficiencies were calculated using the Judd-Ofelt theory, allowing for an extensive study of the luminescent properties of Eu(3+) ion in the LaOF matrix. PMID:21805994

Grzyb, Tomasz; Lis, Stefan

2011-09-01

156

Using field-based epidemiological methods to investigate FMD outbreaks: an example from the 2002 outbreak in Korea.  

PubMed

Relevant to foot and mouth disease (FMD), most published epidemiological studies have been conducted using quantitative methods and substantial regional or national datasets. Veterinary epidemiology also plays a critical role during outbreak investigations, both to assist with herd-level decision-making and to contribute relevant information to assist with ongoing national or regional control strategies. Despite the importance of this role, however, little information has been published on the use of applied (field-based) epidemiological methods during disease outbreaks. In this study, we outline an investigative template for FMD, and a case study of its use during the 2002 FMD outbreak in Korea. Suitable for use during field-based epidemiological investigations of individual farms within a broader regional/national response, the template considers three steps including confirming infection, estimating date of introduction and determining method of introduction. A case study was conducted on IP13 (the 13th infected premises), the only IP during the 2002 FMD outbreak in Korea that was geographically isolated from all other known cases. The authorities first became aware of FMD on IP13 on 2 June, however, infection may have been present from 12 May. Infection was confirmed on 3 June 2002. FMD was probably spread to IP13 by a contract worker who had participated during 2-4 May in the culling operations on IP1. Other routes of spread were ruled out during the investigation. The contract worker lived in the locality of IP13 and worked on a part-time basis at a pork-processing plant that was adjacent to this farm. The contractor became heavily contaminated during the cull, but did not comply fully with cleaning and disinfection requirements once the cull had been completed. The investigative template contributed structure and focus to the field-based investigation. Results from this case study demonstrate the need for strict management of personnel in disease control and adherence to the sanitary rules by all those involved. PMID:18803614

Wee, S-H; Nam, H-M; Moon, O-K; Yoon, H; Park, J-Y; More, S J

2008-12-01

157

Two independent methods for mapping the grounding line of an outlet glacier - example from the Astrolabe Glacier, Terre Adélie, Antarctica  

NASA Astrophysics Data System (ADS)

The grounding line is a key element acting on the dynamics of coastal outlet glaciers. Knowing its position accurately is fundamental for both modelling the glacier dynamics and establishing a benchmark to which one can later refer in case of change. Here we map the grounding line of the Astrolabe Glacier in East Antarctica (66°41´ S; 140°05´ E), using hydrostatic and tidal methods. The first method is based on new surface and ice thickness data from which the line of buoyant flotation is found. We compare this hydrostatic map with kinematic GPS measurements of the tidal response of the ice surface. By detecting the transitions where the ice starts to move vertically in response to the tidal forcing we find control points for the grounding line position along GPS profiles. %If it can be shown that the long-term viscous mechanical behaviour of the ice slab validates the hydrostatic approach, mapping the grounding line from the ice supper surface displacements conversely requires correcting for the rigid elastic slab effect that dominates at tidal frequencies. With the help of a 2-dimensional elastic plate model, rigid elastic deviations are computed and applied to these control points. Once the extent of the grounding zone, the kinematic approach is consistent with the hydrostatic map. These two approaches lead us to propose a grounding line for the Astrolabe Glacier that significantly deviates from those obtained so far from satellite imagery.

Le Meur, E.; Sacchettini, M.; Garambois, S.; Berthier, E.; Drouet, A. S.; Durand, G.; Young, D.; Greenbaum, J. S.; Blankenship, D. D.; Holt, J. W.; Rignot, E.; Mouginot, J.; Gim, Y.; Kirchner, D.; de Fleurian, B.; Gagliardini, O.; Gillet-Chaulet, F.

2013-08-01

158

A statistical method for characterizing the noise in nonlinearly reconstructed images from undersampled MR data: the POCS example.  

PubMed

The projection-onto-convex-sets (POCS) algorithm is a powerful tool for reconstructing high-resolution images from undersampled k-space data. It is a nonlinear iterative method that attempts to estimate values for missing data. The convergence of the algorithm and its other deterministic properties are well established, but relatively little is known about how noise in the source data influences noise in the final reconstructed image. In this paper, we present an experimental treatment of the statistical properties in POCS and investigate 12 stochastic models for its noise distribution beside its nonlinear point spread functions. Statistical results show that as the ratio of the missing k-space data increases, the noise distribution in POCS images is no longer Rayleigh as with conventional linear Fourier reconstruction. Instead, the probability density function for the noise is well approximated by a lognormal distribution. For small missing data ratios, however, the noise remains Rayleigh distributed. Preliminary results show that in the presence of noise, POCS images are often dominated by POCS-enhanced noise rather than POCS-induced artifacts. Implicit in this work is the presentation of a general statistical method that can be used to assess the noise properties in other nonlinear reconstruction algorithms. PMID:23895872

Sabati, Mohammad; Peng, Haidong; Lauzon, M Louis; Frayne, Richard

2013-11-01

159

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

PubMed Central

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

Ritz, C.; Fliedner, F. P.; Frimodt-M?ller, N.

2014-01-01

160

A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager  

SciTech Connect

We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and {gamma}-ray telescope has much greater sensitivity than previous experiments in the 3-25 keV range, but is normally not well suited to detecting extended sources since their signal is not modulated by RHESSI's rotating grids. When the spacecraft is offpointed from the target source, however, the fan-beam modulation time-modulates the transmission by shadowing resulting from exploiting the finite thickness of the grids. In this article we detail how the technique is implemented and verify its consistency with sources with clear known signals that have occurred during RHESSI offpointing: microflares and the Crab Nebula. In both cases the results are consistent with previous and complementary measurements. Preliminary work indicates that this new technique allows RHESSI to observe the integrated hard x-ray spectrum of weak extended sources on the quiet Sun.

Hannah, Iain G.; Hurford, Gordon J.; Hudson, Hugh S.; Lin, Robert P. [Space Sciences Laboratory, University of California at Berkeley, Berkeley, California 94720-7450 (United States)

2007-02-15

161

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

USGS Publications Warehouse

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.

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

2006-01-01

162

Statistical analysis of astronomical data containing upper bounds - General methods and examples drawn from X-ray astronomy  

NASA Technical Reports Server (NTRS)

Statistical procedures taken from the field of survival analysis have been adapted to astronomical usage and have been applied to a sample of stars in the B-V color range between 0.1 and 0.5 with measured soft X-ray luminosities and projected equatorial velocities. The two-sample problem and linear regression problem with arbitrarily censored data were studied. A new method for determining the linear regression between two random variables in the presence of arbitrary censoring has been developed which can also be used for a likelihood-ratio test for the independence of two random variables and for principal-component analysis in the presence of arbitrary censoring. The required numerical computations can be carried out straightforwardly and rapidly.

Schmitt, J. H. M. M.

1985-01-01

163

Spectroscopic and molecular structure investigation of 2-furanacrylic acid monomer and dimer using HF and DFT methods  

NASA Astrophysics Data System (ADS)

In the present work, we reported a combined experimental and theoretical study on molecular structure and vibrational spectra of 2-furanacrylic acid (abbreviated as 2FAA). The FT-IR and FT-Raman spectra of 2FAA have been recorded in the regions 4000-400 and 4000-100 cm-1. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The monomer and dimer structures of the title molecule have been obtained from Hartree-Fock (HF) and density functional theory (DFT) B3LYP methods with 6-311++G(d,p) as basis set calculations. The vibrational frequencies were calculated by DFT method and compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. Intermolecular OH⋯O hydrogen bonds are discussed in dimer structure of the molecule. The infrared and Raman spectra were also predicted from the calculated intensities. The polarizability and first order hyperpolarizabilty of the title molecule were calculated and interpreted. A study on the electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, are performed by time-dependent DFT (TD-DFT) approach. In addition, Milliken atomic charges, possible charge transfer, natural bond orbital (NBO) and AIM topological analysis were performed. Moreover, molecular electrostatic potential (MEP) and the thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures were calculated in gas phase.

Ghalla, H.; Issaoui, N.; Govindarajan, M.; Flakus, H. T.; Jamroz, M. H.; Oujia, B.

2014-02-01

164

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

USGS Publications Warehouse

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.

Schmidt, Larry J.; Hesselberg, Robert J.

1992-01-01

165

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

USGS Publications Warehouse

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

Gerlach, T.M.

1993-01-01

166

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

PubMed Central

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

Shestopaloff, Yuri K.

2014-01-01

167

Near-infrared spectroscopic observation of the ageing process in archaeological wood using a deuterium exchange method.  

PubMed

The ageing degradation of the fine wood structure of dry-exposed archaeological wood was investigated by Fourier transform near-infrared spectroscopy with the aid of a deuterium exchange method. The archaeological wood sample was taken from an old wooden temple in Japan (late 7th century), which has been designated as a UNESCO world heritage site. Comparing the analytical results with those of a modern wood sample of the same species, the ageing process of archaeological wood was clarified as a change in the state of order on a macromolecular structural level. It can be concluded from NIR spectra that the amorphous region, and partially semi-crystalline region, in cellulose, hemicellulose, and lignin decreased by the ageing degradation, whereas the crystalline region in cellulose was not affected by the ageing. The accessibility of the diffusant to effect H/D-exchange was monitored by an OH-related absorption band obtained from FT-NIR transmission spectroscopy and characteristically varied with the ageing process of the wood samples, the absorption bands characteristic of a specific state of order and the diffusion agent. Finally, we proposed a morphological model to describe the variation of the fine structure of the microfibrils in the cell wall with ageing degradation. The state of microfibrils changed loosely by ageing, so that elementary fibrils were arranged loosely under 5 A, whereas several elementary fibrils in the modern wood were arranged in very close proximity under 3 A to each other. PMID:15724168

Tsuchikawa, Satoru; Yonenobu, Hitoshi; Siesler, H W

2005-03-01

168

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

NASA Astrophysics Data System (ADS)

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.

Prabakaran, K.; Rajeswari, S.

2009-12-01

169

Chiral selectors for enantioresolution and quantitation of the antidepressant drug fluoxetine in pharmaceutical formulations by (19)F NMR spectroscopic method.  

PubMed

(19)F NMR spectroscopy was applied to the quantitative determination of fluoxetine enantiomers using different chiral recognition agents in pharmaceutical formulations. Several parameters affecting the enantioresolution including the type and concentration of chiral selector, concentration of fluoxetine and temperature were studied. The chiral selectors investigated are the cyclic oligosaccharides alpha-, beta- and gamma-cyclodextrin and a diamino derivative of methylated alpha-cyclodextrin (DAM-alpha-CD), linear polysaccharides (maltodextrin with dextrose equivalents of 4.0-7.0, 13.0-17.0 and 16.5-19.5) and the macrocyclic antibiotic vancomycin. Among the chiral selectors used, DAM-alpha-CD turned out to give the best resolution of the (19)F NMR signals of (R)- and (S)-fluoxetine. The calibration curve was linear for (R)- and (S)-fluoxetine over the range 0.10-1.35 mgmL(-1), the detection limits (S/N=3) being 5.9 and 7.5 microgmL(-1) for the pure solutions of (R)- and (S)-fluoxetine, respectively. The recovery studies performed on pharmaceutical samples ranged from about 90 to 110% with relative standard deviations of <8%. The results showed that the proposed method is rapid, precise and accurate. Applying statistical Student's t-test revealed insignificant difference between the real and measured contents at the 95% confidence level. PMID:17904479

Shamsipur, Mojtaba; Dastjerdi, Leila Shafiee; Haghgoo, Soheila; Armspach, Dominique; Matt, Dominique; Aboul-Enein, Hassan Y

2007-10-01

170

Hardware and methods of the optical end-to-end test of the Far-Ultraviolet Spectroscopic Explorer (FUSE)  

NASA Astrophysics Data System (ADS)

The FUSE, successfully launched in June 1999, is an astrophysics satellite designed to provide high spectral resolving power over the interval 90.5-118.7 nm. The FUSE optical path consists of four co-aligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographic gratings and delay line microchannel plate detectors. We describe the hardware and methods used for the optical 'end- to-end' test of the FUSE instrument during satellite integration and test. Cost and schedule constraints forced us to devise a simplified version of the planned optical test which occurred in parallel with satellite thermal- vacuum testing. The optical test employed a collimator assembly which consisted of four co-aligned, 381 mm diameter Cassegrain telescopes positioned above the FUSE instrument, providing a collimated beam for each optical channel. A windowed UV light source, remotely adjustable in three axes, was mounted at the focal plane of each collimator. Problems with the UV light sources, including high f-number and window failures, were the only major difficulties encountered during the test. The test succeeded in uncovering a significant problem with the secondary structure used for the instrument cavity and, furthermore, showed that the mechanical solution was successful, the hardware was also used extensively for simulations of science observations, providing both UV light for spectra and visible light for the fine error sensor camera.

Conard, Steven J.; Redman, Kevin W.; Barkhouser, Robert H.; McGuffey, Douglas B.; Smee, Stephen; Ohl, Raymond G.; Kushner, Gary D.

1999-10-01

171

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

PubMed

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 ?l. 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. PMID:25011044

Kaur, Gurvir; Tripathi, S K

2015-01-01

172

Spectroscopic Monitoring of Be type Stars  

Microsoft Academic Search

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

V. Desnoux; C. Buil

2005-01-01

173

A noncalibration spectroscopic method to estimate ether extract and fatty acid digestibility of feed and its validation with flaxseed and field pea in pigs.  

PubMed

Digestibility of ether extract (EE) or fatty acids (FA) is traditionally measured by chemical analyses for EE or GLC methods for FA combined with marker concentration in diet and digesta or feces. Digestibility of EE or FA may be predicted by marker concentrations and spectral analyses of diet and digesta or feces. On the basis of Beer's law, a noncalibration spectroscopic method, which used functional group digestibility (FGD) determined with marker concentration and peak intensity of spectra of diets and undigested residues (digesta or feces), was developed to predict the apparent ileal digestibility (AID) of total FA and apparent total tract digestibility (ATTD) of EE. To validate, 4 diets containing 30% flaxseed and field pea coextruded with 4 extruder treatments and a wheat and soybean basal diet with predetermined AID of total FA and ATTD of EE were used. Samples of ingredients, diets, and freeze-dried digesta and feces were scanned on a Fourier transform infrared (FT-IR) instrument with a single-reflection attenuated total reflection (ATR) accessory. The intensity of either the methylene (CH2) antisymmetric stretching peak at 2,923 cm(-1) (R(2) = 0.90, P < 0.01) or the symmetric stretching peak at 2,852 cm(-1) (R(2) = 0.86, P < 0.01) of ingredients, diet, and digesta spectra was related strongly to the concentration of total FA. The AID of total FA of diets measured using GLC was predicted by the spectroscopic method using FGD at 2,923 and 2,852 cm(-1) (R(2) = 0.75, P < 0.01) with a bias of 0.54 (SD = 3.78%) and -1.35 (SD = 3.74%), respectively. The accumulated peak intensity in the region between 1,766 and 1,695 cm(-1) of spectra was related to EE concentration in ingredients and diets (R(2) = 0.61, P = 0.01) and feces (R(2) = 0.88, P < 0.01). The relation was improved by using second-derivative spectra of the sum of peak intensities at 1,743 and 1,710 cm(-1) for ingredients and diets (R(2) = 0.90, P = 0.01) and at 1,735 and 1,710 cm(-1) for feces (R(2) = 0.92, P < 0.01). The ATTD of EE of test diets determined with proximate analysis was estimated by the FGD of nonderivative spectra with or without baseline (R(2) = 0.90, P < 0.01) with a bias of 3.15 (SD = 3.14%) and 3.50 (SD = 3.24%), respectively. In conclusion, instead of using GLC methods or predictions based on calibrations, the AID of total FA and ATTD of EE can also be estimated directly from ATR FT-IR spectra, provided the ratio of marker in the diet and undigested residue is known. PMID:25186953

Wang, L F; Swift, M L; Zijlstra, R T

2014-10-01

174

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

PubMed Central

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 ?-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 ?-helical M2? 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 ?-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 ?M). PMID:22908896

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

2012-01-01

175

Using Low-Field Magnetic Susceptibility (MS) in Caves and Deep Rock Shelters with Examples from North America, Europe, Africa, and Asia: Methods and Results (Invited)  

NASA Astrophysics Data System (ADS)

The low-field magnetic susceptibility (MS) method, when carefully applied to archaeological sites, can be used for correlation and to characterize the paleoclimate at the time sediments were deposited in protected environments, such as within caves or deep rock shelters. This method works because the MS of sediments outside caves, that are eventually deposited in caves, is controlled by pedogenesis that in turn is driven by climate. We will summarize the method that we use and give examples of our past and ongoing research from globally distributed sites. This work will illustrate correlation methods, within site (building composite reference sections [CRS]), between sites in Europe, and between sites in Europe and Asia. Site ages discussed will range from 6000 BP to >90,000 BP. Problem areas will be identified and ways to evaluate these problems will be discussed. Our current research activity in Vietnamese caves will be described and we will show that using a climate model we can correlate between the CRS established for multiple European caves and a new, preliminary CRS developed from samples from four caves in Vietnam.

Ellwood, B. B.; Luu, T.; Petruso, K. M.; Harrold, F.; El Hassani, A.

2009-12-01

176

Estimating the basis set superposition error in the CCSD(T)(F12) explicitly correlated method using the example of a water dimer  

NASA Astrophysics Data System (ADS)

Changes in the basis set superposition errors upon transitioning from conventional CCSD(T) to the CCSD(T)(F12) explicitly correlated method is studied using the example of a water dimer. A comparison of the compensation errors for CCSD(T) and CCSD(T)(F12) reveals a substantial reduction in the superposition error upon use of the latter. Numerical experiments with water dimers show it is possible theoretically predict an equilibrium distance between oxygen atoms that is similar to the experimental data (2.946 Å), as is the predicted energy of dissociation of a dimer (5.4 ± 0.7 kcal/mol). It is found that the structural and energy parameters of hydrogen bonds in water dimers can be calculated precisely even with two-exponential correlation-consistent basis sets if we use the explicitly correlated approach and subsequently correct the basis set superposition error.

Belikov, V. V.; Bokhan, D. A.; Trubnikov, D. N.

2014-04-01

177

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)

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.

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

178

Spectroscopic Detection of Pathogens  

SciTech Connect

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.

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

2000-11-01

179

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

PubMed Central

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

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

180

NMR-spectroscopic analysis of mixtures: from structure to function  

PubMed Central

NMR spectroscopy as a particularly information-rich method offers unique opportunities for improving the structural and functional characterization of metabolomes, which will be essential for advancing the understanding of many biological processes. Whereas traditionally NMR spectroscopy was mostly relegated to the characterization of pure compounds, the last few years have seen a surge of interest in using NMR spectroscopic techniques for characterizing complex metabolite mixtures. Development of new methods was motivated partly by the realization that using NMR for the analysis of metabolite mixtures can help identify otherwise inaccessible small molecules, for example compounds that are prone to chemical decomposition and thus cannot be isolated. Furthermore, comparative metabolomics and statistical analyses of NMR-spectra have proven highly effective at identifying novel and known metabolites that correlate with changes in genotype or phenotype. In this review, we provide an overview of the range of NMR spectroscopic techniques recently developed for characterizing metabolite mixtures, including methods used in discovery-oriented natural product chemistry, in the study of metabolite biosynthesis and function, or for comparative analyses of entire metabolomes. PMID:21071261

Forseth, Ry R.; Schroeder, Frank C.

2010-01-01

181

Spectroscopic signatures of isomnerization  

E-print Network

This thesis explores spectroscopic signatures of isomerization, especially new patterns that emerge and report on chemically relevant portions of the potential energy surface, such as the transition state. The most important ...

Baraban, Joshua Herschel Goldblum

2013-01-01

182

Build Your Own Spectroscope  

NSDL National Science Digital Library

This is an activity about spectroscopy. Learners will build a spectroscope and use it to observe various types of lights. This activity requires spectroscope kits and diffraction gratings available from the Stanford Solar Center (http://solar-center.stanford.edu/posters/) and fluorescent and incandescent light sources. A variety of resources accompany this activity, including PowerPoint presentations, online videos, activities, and activity guides for both grades 2-4 and grades 5-8.

183

Building a Spectroscope  

NSDL National Science Digital Library

Students learn about the variations of white light in this Moveable Museum unit, in which they build a pocket-sized spectroscope from readily available materials and examine different light sources in school, at home, and around their town or city. The seven-page PDF guide includes suggested general background readings for educators, activity and safety notes, step-by-step directions, and a spectroscope template.

184

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

SciTech Connect

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.

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

1987-12-01

185

Learning From Snapshot Examples  

E-print Network

Examples are a powerful tool for teaching both humans and computers.In order to learn from examples, however, a student must first extractthe examples from its stream of perception. Snapshot learning is ageneral approach ...

Beal, Jacob

2005-04-13

186

Example: Estimating the cerebral metabolic rate for glucose using fluoro deoxyglucose (FDG) PET Examining a simple linear equation The Method of Regularization for Sele Algorithms Towards Reducing Data Uncertainty in Image Analysis Problems  

E-print Network

Example: Estimating the cerebral metabolic rate for glucose using fluoro deoxyglucose (FDG) PET metabolic rate for glucose using fluoro deoxyglucose (FDG) PET Examining a simple linear equation The Method deoxyglucose (FDG) PET 2 Examining a simple linear equation 3 The Method of Regularization for Selecting

Renaut, Rosemary

187

Lensing Probabilities for Spectroscopically Selected Galaxy-Galaxy Strong Lenses  

E-print Network

Spectroscopic galaxy-galaxy lens searches are presently the most prolific method of identifying strong lens systems in large data sets. We study the probabilities associated with these lens searches, namely the probability of identifying a candidate with rogue [OII] emission lines in a galaxy's spectrum, and the probability that the candidate will show features of strong lensing in follow-up photometric observations. We include selection effects unique to spectroscopic data, and apply them to the Sloan Lens ACS (SLACS) survey (Bolton et al. 2006). The most significant selection effect is the finite size of the spectroscopic fiber which selects against large separation lenses and results in a non-monotonic dependence of the rogue line probability on velocity dispersion. For example, with the 3 arcsec diameter SDSS fiber and 2 arcsec FWHM seeing, we find that the probability that a given LRG has a rogue [OII] line in its spectrum decreases with velocity dispersion from 150 km/s to 300 km/s and then increases up to 400 km/s for a given source size. The total probability for observing a rogue line in a single survey spectrum is ~0.9-3.0%, and the total lensing rate is ~0.5-1.3%. The range is due to uncertainties in the physical size of [OII] emission regions, and in the evolution of the [OII] luminosity function. Our estimates are a factor of ~5 higher than the results of the SLACS survey, a discrepancy which we attribute to the SLACS requirement that multiple rogue lines be observed simultaneously.

Gregory Dobler; Charles R. Keeton; Adam S. Bolton; Scott Burles

2008-03-17

188

Studying Light: Spectroscopes  

NSDL National Science Digital Library

In this activity about spectroscopy, learners build a spectroscope, learn about graphing spectra, and then identify elements in gas tubes using their spectra. The activity concludes as learners graph the spectra of different materials. Essential materials required for this activity include spectrum light tubes, the power source for spectrum light tubes, and diffraction grating material.

189

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)

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 ?H, ?G, ?S 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.

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

2012-03-01

190

Comparative investigation of methods for the numerical prediction of motion of asteroids that approach the Earth: Example of the 99942 Apophis asteroid  

NASA Astrophysics Data System (ADS)

Using the 99942 Apophis asteroid (currently known as one of the most dangerous asteroids that is approaching the Earth) as an example, we estimate the error of predicting its motion with the use of several integrators over the time interval from 2012 to 2029. The minimum distance (and its error) between the Earth's center and Apophis was estimated for the rendezvous moment on April 13, 2029. It is shown that this error for various integrators is comparable in the order of magnitude with the influence of certain components of the dynamic model of motion, such as, for example, the influence of harmonics of the Earth's gravitational filed, solar-light pressure, the Jarkowski effect, etc.

Smirnov, E. A.; Timoshkova, E. I.

2014-03-01

191

Spectroscopic Monitoring of Be type Stars  

NASA Astrophysics Data System (ADS)

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.

Desnoux, V.; Buil, C.

2005-05-01

192

A comparison between univariate probabilistic and multivariate (logistic regression) methods for landslide susceptibility analysis: the example of the Febbraro valley (Northern Alps, Italy)  

Microsoft Academic Search

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

M. Rossi; T. Apuani; F. Felletti

2009-01-01

193

Models for stellar coronae: Numerical methods and examples - Comparison with the minimum flux corona theory - Differences between hydrostatic and dynamic models  

Microsoft Academic Search

A numerical method for the calculation of models of stellar coronae by the solution of the coupled equations of motion, continuity and energy balance is introduced. The method considers the equations as a two-boundary value problem, with the only free parameter being the flux of mechanical energy deep in the photosphere and the position of the transition region being determined

A. G. Hearn; I. M. Vardavas

1981-01-01

194

Electromagnetic and geochemical methods applied to investigations of hydrothermal/volcanic unrests: Examples of Taal (Philippines) and Miyake-jima (Japan) volcanoes  

NASA Astrophysics Data System (ADS)

Magnetic, -electric and -electromagnetic phenomena (EM) are almost always observed on volcanoes before and during volcanic eruptions, if EM methods are well-designed and applied on the field. But unfortunately these methods are, most often, still used independently. They also do not benefit of dense inter-correlated networks which should allow more accurate results and fine modelling of the volcanic activity. On volcanoes which display hydrothermal/magmatic unrests, EM methods can be combined with geochemical (GC) methods. The integration of these methods allows us to image in detail hydrothermal systems, to find out possible scenarios of volcanic unrest, and to monitor the on-going activity with some knowledge on the sources of heat, gas and fluid transfers. The objectives of this paper is (1) to outline the appearance and the characteristics of EM signals before an eruptive event when multi-EM methods are applied on the field, (2) to sketch out the complementary between EM and GC methods when these methods are jointly applied on volcanic/hydrothermal systems. Two case studies are given in the paper. On Miyake-jima volcano in Japan integrated EM methods started in 1995. Although the seismicity only appeared 13 days before the July 8, 2000 collapse of the summit, changes in the magnetic field, electrical resistivity and electric potential have progressively appeared after 1996. Based on geophysical observations and on continuous magnetotelluric soundings, a synthesis of the EM observations allows proposing a coherent model of the volcano unrest. The second case study is Taal volcano in Philippines on which sporadic, but sometimes intense, seismic crises are observed since 1992. A strong and large scale hydrothermal system stands on the volcano and is periodically re-activated. Commonly applied since 2005, combined EM and GC methods give an accurate description of the hydrothermal activity and heat discharge. EM methods, as magnetic and self-potential, map the hydrothermal system and locate the source of thermal and fluid transfers at depth, while soil degassing and thermal imageries clearly point out the location of the most active areas where thermal discharges take place. GC methods also specify the origin of the gas and fluids escaping from faults, fumaroles, and geothermal areas. Between 2005 and 2007, no large change in the hydrothermal activity took place, in spite of sporadic seismic swarms and surface activities which could lead to sudden phreatic explosions. The heat discharge of the volcano is estimated and monitored with time, based on repeated surveys. Such combined EM and GC methods are now integrated in the monitoring of the slow unrest of the volcano.

Zlotnicki, Jacques; Sasai, Y.; Toutain, J. P.; Villacorte, E.; Harada, M.; Yvetot, P.; Fauquet, F.; Bernard, A.; Nagao, T.; Phivolcs Team

195

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

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

Nejati Javaremi, Alireza; Unsworth, Charles P.; Graham, E. Scott

2013-01-01

196

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)

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.

Johnson, A. B.

2012-12-01

197

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

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.

Kay, Robert T.; Mills, Patrick C.; Dunning, Charles P.; Yeskis, Douglas J.; Ursic, James R.; Vendl, Mark

2004-01-01

198

How to Build a Spectroscope  

NSDL National Science Digital Library

This site from the Exploratorium provides instructions to make a spectroscope from a shoebox and a diffraction grating. Such a spectroscope is used to show that a white light is really made up of the combination of colors called a spectrum. The site contains photographs and step-by-step instructions to easily build the instrument.

2006-07-18

199

Validating Raman spectroscopic calibrations of phonon deformation potentials in silicon single crystals: A comparison between ball-on-ring and micro-indentation methods  

NASA Astrophysics Data System (ADS)

Of main interest in the present work is a quantitative comparison between the phonon deformation potential (PDP) values determined for silicon single crystals by two different calibration methods: (i) a macroscopic method exploiting the stress field developed in a ball-on-ring (biaxial) bending configuration; and (ii) a microscopic method using the residual stress field stored around an indentation print. A comparison between the two methods helps to establish the reliability limits for experimental stress analyses in the (001), (011), and (111) planes of silicon devices by means of polarized Raman spectroscopy. Emphasis is also placed on evaluating the degree of precision involved with using a closed-form equation (i.e., as proposed by other authors), which describes the stress state when different crystallographic planes of the Si sample are loaded in the ball-on- ring jig. A comparison between stress profiles obtained by such equations and those computed by the finite element method (FEM) in the loaded disk reveals a clear discrepancy for the (011) plane. Such a discrepancy could be attributed to elastic coupling and anisotropic effects (particularly relevant along the <011> direction), which can lead to errors up to 15% in computing the stress field stored in the silicon lattice.

Miyatake, Takahiro; Pezzotti, Giuseppe

2011-11-01

200

Practical example for use of the supervised vicarious calibration (SVC) method on multisource hyperspectral imagery data - ValCalHyp airborne hyperspectral campaign under the EUFAR framework  

NASA Astrophysics Data System (ADS)

A novel approach for radiometric calibration and atmospheric correction of airborne hyperspectral (HRS) data, termed supervised vicarious calibration (SVC) was proposed by Brook and Ben-Dor in 2010. The present study was aimed at validating this SVC approach by simultaneously using several different airborne HSR sensors that acquired HSR data over several selected sites at the same time. The general goal of this study was to apply a cross-calibration approach to examine the capability and stability of the SVC method and to examine its validity. This paper reports the result of the multi sensors campaign took place over Salon de Provenance, France on behalf of the ValCalHyp project took place in 2011. The SVC method enabled the rectification of the radiometric drift of each sensor and improves their performance significantly. The flight direction of the SVC targets was found to be a critical issue for such correction and recommendations have been set for future utilization of this novel method. The results of the SVC method were examined by comparing ground-truth spectra of several selected validation targets with the image spectra as well as by comparing the classified water quality images generated from all sensors over selected water bodies.

Brook, A.; Ben Dor, E.

2014-09-01

201

A novel ensemble construction method for multi-view data using random cross-view correlation between within-class examples  

Microsoft Academic Search

Correlated information between multiple views can provide useful information for building robust classifiers. One way to extract correlated features from different views is using canonical correlation analysis (CCA). However, CCA is an unsupervised method and can not preserve discriminant information in feature extraction. In this paper, we first incorporate discriminant information into CCA by using random cross-view correlations between within-class

Jianchun Zhang; Daoqiang Zhang

2011-01-01

202

A Double-Deletion Method to Quantifying Incremental Binding Energies in Proteins from Experiment: Example of a Destabilizing Hydrogen Bonding Pair  

Microsoft Academic Search

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

Luis A. Campos; Santiago Cuesta-López; Jon López-Llano; Fernando Falo; Javier Sancho

2005-01-01

203

Are AB Initio Quantum Chemistry Methods Able to Predict Vibrational States up to the Dissociation Limit for Multi-Electron Molecules Close to Spectroscopic Accuracy?  

Microsoft Academic Search

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

Péter G. Szalay; Filip Holka; Julien Fremont; Michael Rey; Vladimir G. Tyuterev

2011-01-01

204

Linking geophysics and soil function modelling - two examples  

NASA Astrophysics Data System (ADS)

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.

Krüger, J.; Franko, U.; Werban, U.; Dietrich, P.; Behrens, T.; Schmidt, K.; Fank, J.; Kroulik, M.

2011-12-01

205

On the optimal method for evaluating cloud products from passive satellite imagery using CALIPSO-CALIOP data: example investigating the CM SAF CLARA-A1 dataset  

NASA Astrophysics Data System (ADS)

A method for detailed evaluation of a new satellite-derived global 28 yr cloud and radiation climatology (Climate Monitoring SAF Clouds, Albedo and Radiation from AVHRR data, named CLARA-A1) from polar-orbiting NOAA and Metop satellites is presented. The method combines 1 km and 5 km resolution cloud datasets from the CALIPSO-CALIOP (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation - Cloud-Aerosol Lidar with Orthogonal Polarization) cloud lidar for estimating cloud detection limitations and the accuracy of cloud top height estimations. Cloud detection is shown to work efficiently for clouds with optical thicknesses above 0.30 except for at twilight conditions when this value increases to 0.45. Some misclassifications of cloud-free surfaces during daytime were revealed for semi-arid land areas in the sub-tropical and tropical regions leading to up to 20% overestimated cloud amounts. In addition, a substantial fraction (at least 20-30%) of all clouds remains undetected in the polar regions during the polar winter season due to the lack of or an inverted temperature contrast between Earth surfaces and clouds. Subsequent cloud top height evaluation took into account the derived information about the cloud detection limits. It was shown that this has fundamental importance for the achieved results. An overall bias of -274 m was achieved compared to a bias of -2762 m when no measures were taken to compensate for cloud detection limitations. Despite this improvement it was concluded that high-level clouds still suffer from substantial height underestimations, while the opposite is true for low-level (boundary layer) clouds. The validation method and the specifically collected satellite dataset with optimal matching in time and space are suggested for a wider use in the future for evaluation of other cloud retrieval methods based on passive satellite imagery.

Karlsson, K.-G.; Johansson, E.

2013-05-01

206

On the optimal method for evaluating cloud products from passive satellite imagery using CALIPSO-CALIOP data: example investigating the CM SAF CLARA-A1 dataset  

NASA Astrophysics Data System (ADS)

A method for detailed evaluation of a new satellite-derived global 28-yr cloud and radiation climatology (Climate Monitoring SAF Cloud, Albedo and Radiation dataset from AVHRR data, named CLARA-A1) from polar orbiting NOAA and Metop satellites is presented. The method combines 1 km and 5 km resolution cloud datasets from the CALIPSO-CALIOP cloud lidar for estimating cloud detection limitations and the accuracy of cloud top height estimations. Cloud detection is shown to work efficiently for clouds with optical thicknesses above 0.30 except for at twilight conditions when this value increases to 0.45. Some misclassifications generating erroneous clouds over land surfaces in semi-arid regions in the sub-tropical and tropical regions are revealed. In addition, a substantial fraction of all clouds remains undetected in the Polar regions during the polar winter season due to the lack of or an inverted temperature contrast between Earth surfaces and clouds. Subsequent cloud top height evaluation took into account the derived information about the cloud detection limits. It was shown that this has fundamental importance for the achieved results. An overall bias of -274 m was achieved compared to a bias of -2762 m if no measures were taken to compensate for cloud detection limitations. Despite this improvement it was concluded that high-level clouds still suffer from substantial height underestimations while the opposite is true for low-level (boundary layer) clouds. The validation method and the specifically collected satellite dataset with optimal matching in time and space are suggested for a wider use in the future for evaluation of other cloud retrieval methods based on passive satellite imagery.

Karlsson, K.-G.; Johansson, E.

2013-02-01

207

Improving survey methods in sero-epidemiological studies of injecting drug users: a case example of two cross sectional surveys in Serbia and Montenegro  

Microsoft Academic Search

BACKGROUND: Little is known about the prevalence of HIV or HCV in injecting drug users (IDUs) in Serbia and Montenegro. We measured prevalence of antibodies to HIV (anti-HIV) and hepatitis C virus (anti-HCV), and risk factors for anti-HCV, in community-recruited IDUs in Belgrade and Podgorica, and determined the performance of a parallel rapid HIV testing algorithm. METHODS: Respondent driven sampling

Ali Judd; Tim Rhodes; Lisa G Johnston; Lucy Platt; Violeta Andjelkovic; Danijela Simi?; Boban Mugosa; Milena Simi?; Sonja Žerjav; Ruth P Parry; John V Parry

2009-01-01

208

Galaxy Luminosity Functions from Deep Spectroscopic Samples of Rich Clusters  

Microsoft Academic Search

Using a new spectroscopic sample and methods accounting for spectroscopic sampling fractions that vary in magnitude and surface brightness, we present R-band galaxy luminosity functions (GLFs) for six nearby galaxy clusters with redshifts of 4000 km s-1

Daniel Christlein; Ann I. Zabludoff

2003-01-01

209

Crystal growth and spectroscopic properties of MoO 3 and WO 3 doped Bi 4Ge 3O 12 by optical floating zone method  

Microsoft Academic Search

MoO3 and WO3 doped Bi4Ge3O12 (BGO) crystals were grown by the optical floating zone (OFZ) method. The structure of doped crystals was determined by XRD. The fluorescence spectra and fluorescence decay curves of these BGO crystals at room temperature were also studied. The emission intensity of BGO crystals increased with WO3 dopant but decreased with MoO3 dopant. A heavily WO3

Pingsheng Yu; Anhua Wu; Liangbi Su; Xin Guo; YaBin Wang; Hengyu Zhao; Yan Yang; Qiuhong Yang; Jun Xu

2010-01-01

210

Using the informational Fisher-Shannon method to investigate the influence of long-term deformation processes on geoelectrical signals: An example from the Taiwan orogeny  

NASA Astrophysics Data System (ADS)

The time dynamics of geoelectrical signals measured at three sites in Taiwan were investigated by using the Fisher-Shannon method in order to investigate the possible correlation between their properties with deformation processes. The three sites are located along an almost perpendicular direction to the orogenic collision zone where each site experiences different amounts of crustal deformation. Our findings point out to a clear discrimination of the three sites on the basis of the informational properties of the recorded geoelectrical signals. In particular a relationship is found between the differential strain intensity of the sites where the geoelectrical stations are located and the Fisher-Shannon quantities.

Telesca, Luciano; Lovallo, Michele; Romano, Gerardo; Konstantinou, Konstantinos I.; Hsu, Han-Lun; Chen, Chien-chih

2014-11-01

211

A numerical method for retrieving high oxygen isotope temperatures from plutonic igneous rocks: An example from the Laramie Anorthosite Complex, Wyoming, USA  

SciTech Connect

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.

Farquhar, J.; Chacko, T. (Univ. of Alberta, Edmonton (Canada). Dept. of Geology); Frost, B.R. (Univ. of Wyoming, Laramie, WY (United States))

1992-01-01

212

Determination of structural and vibrational spectroscopic features of neutral and anion forms of dinicotinic acid by using NMR, infrared and Raman experimental methods combined with DFT and HF  

NASA Astrophysics Data System (ADS)

In this study; the experimental (NMR, infrared and Raman) and theoretical (HF and DFT) analysis of dinicotinic acid were presented. 1H and 13C NMR spectra were recorded in DMSO solution and chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The vibrational spectra of dinicotinic acid were recorded by FT-Raman and FT-IR spectra in the range of 4000-10 cm-1 and 4000-400 cm-1, respectively. To determine the most stable neutral conformer of molecule, the selected torsion angle was changed every 10° and molecular energy profile was calculated from 0° to 360°. The geometrical parameters and energies were obtained for all conformers form from density functional theory (DFT/B3LYP) and HF with 6-311++G(d,p) basis set calculations. However, the results of the most stable neutral and two anion forms (anion-1 and anion-2 forms) of dinicotinic acid are reported here. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational wavenumbers, calculated with scaled quantum mechanics (SQM) method and PQS program.

Kose, E.; Bardak, F.; Atac, A.; Karabacak, M.; Cipiloglu, M. A.

2013-10-01

213

Vibrational spectroscopic studies, normal co-ordinate analysis, first order hyperpolarizability, HOMO-LUMO of midodrine by using density functional methods.  

PubMed

The FTIR (4000-400 cm(-1)), FT-Raman (4000-100 cm(-1)) and UV-Visible (400-200 nm) spectra of midodrine were recorded in the condensed state. The complete vibrational frequencies, optimized geometry, intensity of vibrational bands and atomic charges were obtained by using Density Functional Theory (DFT) with the help of 6-311++G(d,p) basis set. The first order hyperpolarizability (?) and related properties (?, ? and ??) of this molecular system were calculated by using DFT/6-311++G(d,p) method based on the finite-field approach. The assignments of the vibrational spectra have been carried out with the help of Normal Co-ordinate Analysis (NCA) following the scaled quantum mechanical force methodology. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using NBO analysis. From the recorded UV-Visible spectrum, the electronic properties such as excitation energies, oscillator strength and wavelength are calculated by DFT in water and gas methods using 6-311++G(d,p) basis set. The calculated HOMO and LUMO energies confirm that charge transfer occurs within the molecule. Besides MEP, NLO and thermodynamic properties were also calculated and interpreted. The electron density-based local reactivity descriptor such as Fukui functions was calculated to explain the chemical selectivity or reactivity site in midodrine. PMID:25011041

Shahidha, R; Al-Saadi, Abdulaziz A; Muthu, S

2015-01-01

214

Standard test method for determination of impurities in plutonium: acid dissolution, ion exchange matrix separation, and inductively coupled plasma-atomic emission spectroscopic (ICP/AES) analysis  

E-print Network

1.1 This specification covers blended uranium trioxide (UO3), U3O8, or mixtures of the two, powders that are intended for conversion into a sinterable uranium dioxide (UO2) powder by means of a direct reduction process. The UO2 powder product of the reduction process must meet the requirements of Specification C 753 and be suitable for subsequent UO2 pellet fabrication by pressing and sintering methods. This specification applies to uranium oxides with a 235U enrichment less than 5 %. 1.2 This specification includes chemical, physical, and test method requirements for uranium oxide powders as they relate to the suitability of the powder for storage, transportation, and direct reduction to UO2 powder. This specification is applicable to uranium oxide powders for such use from any source. 1.3 The scope of this specification does not comprehensively cover all provisions for preventing criticality accidents, for health and safety, or for shipping. Observance of this specification does not relieve the user of th...

American Society for Testing and Materials. Philadelphia

2003-01-01

215

Development of a local-scale urban stream assessment method using benthic macroinvertebrates: An example from the Santa Clara Basin, California  

USGS Publications Warehouse

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.

Carter, J.L.; Purcell, A.H.; Fend, S.V.; Resh, V.H.

2009-01-01

216

Aplisulfamines, New Sulfoxide-Containing Metabolites from an Aplidium Tunicate: Absolute Stereochemistry at Chiral Sulfur and Carbon Atoms Assigned Through an Original Combination of Spectroscopic and Computational Methods  

PubMed Central

Two new sulfoxide-containing metabolites, aplisulfamines A (1) and B (2), have been isolated from an Aplidium sp. collected in the Bay of Naples. Their planar structure and geometry of a double bond were readily determined by using standard methods, mainly NMR spectroscopy. An original approach was used to assign the absolute configuration at the three contiguous chiral centers present in the structures of both aplisulfamines, two at carbon and one at sulfur. This involved Electronic Circular Dichroism (ECD) studies, J-based configuration analysis and Density Functional Theory (DFT) calculations and represents an interesting integration of modern techniques in stereoanalysis, which could contribute to the enhancement of theoretical protocols recently applied to solve stereochemical aspects in structure elucidation. PMID:22363220

Aiello, Anna; Fattorusso, Ernesto; Imperatore, Concetta; Luciano, Paolo; Menna, Marialuisa; Vitalone, Rocco

2012-01-01

217

Nuclear magnetic resonance spectroscopic analysis of ethyl ester yield in the transesterification of vegetable oil: an accurate method for a truly quantitative analysis.  

PubMed

Biodiesel has recently gained importance as an alternative to fossil diesel. However, the development of more efficient biodiesel formation processes still depends on the use of fast and accurate analytical techniques to evaluate the conversion degree of the transesterification reaction. Nuclear magnetic resonance (NMR) spectroscopy has been used for this purpose, but some experimental details still need to be addressed. Therefore, in this communication, the experimental conditions for a truly quantitative NMR analysis of biodiesel formation are presented. The longitudinal relaxation time (T(1) ), which is the determining factor for quantitative analysis, was measured using an inversion-recovery method, and a maximum value of 2.35?s was obtained for a biodiesel sample. A linear determination coefficient of r(2) ?=?0.99 was obtained when a time delay between pulses longer than 5T(1) ?=15?s was used, whereas strong deviations were observed when using shorter delays. PMID:22307949

Mambrini, Giovanni Pimenta; Ribeiro, Caue; Colnago, Luiz Alberto

2012-01-01

218

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)

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.

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

2013-10-01

219

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

PubMed

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. PMID:23786975

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

2013-10-01

220

IZ Applet: Example 3  

NSDL National Science Digital Library

The unknown circuit component in IZApplet is a data source. It can, therefore, pass its current and voltage values to a data listener. In this example, the current, voltage, and power absorbed by the unknown device are plotted on a data graph.

Christian, Wolfgang; Belloni, Mario

2008-02-09

221

Load Applet: Example 2  

NSDL National Science Digital Library

The unknown component in the Load Applet is a data source object. It can, therefore, pass its current and voltage values to any data listener. In this example the voltage across the load and the unknown resistor are plotted on a data graph as the resistance slider is moved.

Christian, Wolfgang; Belloni, Mario

2008-02-09

222

Data Acquisition System for Instructional Spectroscopes  

NASA Astrophysics Data System (ADS)

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.

Almeida, C. B. S. B.; Hetem, A.

2014-10-01

223

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

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

Witherspoon, J W; Smirnova, I V; McIff, T E

2014-07-01

224

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)

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 ? 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 ? 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.

Szalay, Péter G.; Holka, Filip; Fremont, Julien; Rey, Michael; Tyuterev, Vladimir G.

2011-06-01

225

A new method to quantify the impact of soil carbon management on biophysical soil properties: the example of two apple orchard systems in New Zealand.  

PubMed

A new method to diagnose the environmental sustainability of specific orchard management practices was derived and tested. As a significant factor for soil quality, the soil carbon (C) management in the topsoil of the tree-row of an integrated and organic apple orchard was selected and compared. Soil C management was defined as land management practices that maintain or increase soil C. We analyzed the impact of the soil C management on biological (microbial biomass C, basal respiration, dehydrogenase activity, respiratory quotient) and physical (aggregate stability, amount of plant-available water, conductive mean pore diameter near water saturation) soil properties. Soil in the alley acted as a reference for the managed soil in the tree row. The total and hot-water-extractable C amounts served as a combined proxy for the soil C management. The soil C management accounted for 0 to 81% of the degradation or enhancement of biophysical soil properties in the integrated and organic system. In the integrated system, soil C management led to a loss of C in the top 0.3 m of the tree row within 12 yr, causing a decrease in microbial activities. In the tree row of the organic orchard, C loss occurred in the top 0.1 m, and the decrease in microbial activities was small or not significant. Regarding physical soil properties, the C loss in the integrated system led to a decrease of the aggregate stability, whereas it increased in the organic system. Generally, the impact of soil C management was better correlated with soil microbial than with the physical properties. With respect to environmental soil functions that are sensitive to the decrease in microbial activity or aggregate stability, soil C management was sustainable in the organic system but not in the integrated system. PMID:18453414

Deurer, Markus; Sivakumaran, Siva; Ralle, Stefanie; Vogeler, Iris; McIvor, Ian; Clothier, Brent; Green, Steve; Bachmann, Jörg

2008-01-01

226

Elemental and structural analysis of silicon forms in herbal drugs using silicon-29 MAS NMR and WD-XRF spectroscopic methods.  

PubMed

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

Pajchel, L; Nykiel, P; Kolodziejski, W

2011-12-01

227

The spectroscopic (FT-IR, FT-Raman), MESP, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 1,5-dimethyl napthalene by density functional method  

NASA Astrophysics Data System (ADS)

The Fourier-transform infrared and FT-Raman spectra of 1,5-Dimethyl Napthalene (15DMN) was recorded in the region 4000-400 cm-1 and 3500-50 cm-1 respectively. Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of 6M2C were carried out by density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The values of the total dipole moment (?) and the first order hyperpolarizability (?) of the investigated compound were computed using B3LYP/6-311++G(d,p) calculations. The calculated results also show that 15DMN might have microscopic non-linear optical, MESP, NBO analysis with non-zero values. A detailed interpretation of infrared and Raman spectra of 15DMN is also reported. The calculated HOMO7-LUMO energy gap shows that charge transfer occur within the molecule. The molecular electrostatic potential map shows that the negative potential sites are on the electronegative atoms as well as the positive potential sites are around the hydrogen atoms.

Arivazhagan, M.; Subhasini, V. P.; Kavitha, R.; Senthilkumar, R.

2014-10-01

228

The spectroscopic (FT-IR, FT-Raman), MESP, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 1,5-dimethyl napthalene by density functional method.  

PubMed

The Fourier-transform infrared and FT-Raman spectra of 1,5-Dimethyl Napthalene (15DMN) was recorded in the region 4000-400cm(-1) and 3500-50cm(-1) respectively. Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of 6M2C were carried out by density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The values of the total dipole moment (?) and the first order hyperpolarizability (?) of the investigated compound were computed using B3LYP/6-311++G(d,p) calculations. The calculated results also show that 15DMN might have microscopic non-linear optical, MESP, NBO analysis with non-zero values. A detailed interpretation of infrared and Raman spectra of 15DMN is also reported. The calculated HOMO7-LUMO energy gap shows that charge transfer occur within the molecule. The molecular electrostatic potential map shows that the negative potential sites are on the electronegative atoms as well as the positive potential sites are around the hydrogen atoms. PMID:24915765

Arivazhagan, M; Subhasini, V P; Kavitha, R; Senthilkumar, R

2014-10-15

229

Spectroscopic and molecular modeling methods to investigate the interaction between 5-Hydroxymethyl-2-furfural and calf thymus DNA using ethidium bromide as a probe.  

PubMed

In this work, the interaction of 5-Hydroxymethyl-2-furfural (5-HMF) with calf thymus DNA (ctDNA) under simulated physiological conditions (Tris-HCl buffer of pH 7.40), was explored by UV absorption spectroscopy, fluorescence spectroscopy and molecular modeling method, using ethidium bromide (EB) as a fluorescence probe of DNA. The fluorescence quenching mechanism of EB-ctDNA by 5-HMF was confirmed to be a static quenching, which derived from the formation of a new complex. The binding constants of 5-HMF with DNA in the presence of EB were calculated to be 2.17×10(3), 4.24×10(3) and 6.95×10(3) L mol(-1) at 300, 305 and 310 K, respectively. The calculated thermodynamic parameters, enthalpy change ?H and entropy change ?S, suggested that both hydrophobic interactions and hydrogen bonds played a predominant role in the binding of 5-HMF to DNA. According to the UV absorption spectroscopy and melting temperature (Tm) curve results, the binding mode of 5-HMF with DNA was indicative of a non-intercalative binding, which was supposed to be a groove binding. The molecular modeling results showed that 5-HMF could bind into the hydrophobic region of ctDNA and supported the conclusions obtained from the above experiments. PMID:24463243

Zhu, Jinhua; Chen, Lanlan; Dong, Yingying; Li, Jiazhong; Liu, Xiuhua

2014-04-24

230

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

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

2014-01-01

231

Impact of different tillage practices on molecular characteristics of humic acids in a long-term field experiment - an application of three different spectroscopic methods.  

PubMed

The present paper describes changes in soil organic carbon (SOC) and extractable humic acids (HAs) in a long-term field experiment with different tillage treatments (minimum tillage (MT), reduced tillage (RT) and conventional tillage (CT)). This field experiment is located in the east of Vienna in a Pannonian climate and it was started in 1988. The methodological approach included elemental analyses, FT-IR, 13C NMR and fluorimetric measurements. Both MT and RT revealed significant depth gradients of yields of extractable HAs. In CT no depth gradient was observable, neither for HA yields nor for observed molecular characteristics. This indicated a destruction of the gradient by mixing of the soil in CT. Especially MT showed an increase of aromatic moieties with depth, suggesting an increased humification of HAs in the lower soil layers. Gradients with similar trends were indicated for the carbonylic, the amidic and probably the hydroxylic groups in HAs extracted from MT and RT samples. The data revealed with FT-IR and solid-state 13C NMR spectroscopy were convincing, plausible and meaningful, the highly sensitive fluorescence spectroscopy was limited because of strong quenching by inner filter effects, compromising data reliability. However, the fluorescence results based on a defined HAs concentration (and comparing soils from the same site) were in line with results from the other methods (13C NMR and FT-IR). As a consequence, the influence of tillage treatments can be followed by absence or presence of depth gradients of the according molecular characteristics in extracted HAs. PMID:18789814

Tatzber, Michael; Stemmer, Michael; Spiegel, Heide; Katzlberger, Christian; Haberhauer, Georg; Gerzabek, Martin H

2008-11-15

232

Spectroscopic Parameters of Lumbar Intervertebral Disc Material  

NASA Astrophysics Data System (ADS)

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 ?m 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.

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

2009-06-01

233

Spectroscopic optical coherence elastography  

PubMed Central

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

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

2010-01-01

234

Spectroscopic studies of glass structure  

SciTech Connect

Today`s understanding of the molecular-level structure of inorganic glasses has been transformed by the availability of a wide range of sensitive spectroscopic probes. Today we can relate glass composition to quantitative distributions of glass-forming cations and to changes in oxygen bonding and modifying cation geometries. Future spectroscopic studies will result in improved descriptions of anion and cation geometries and should provide glass scientists with the capability to optimize atomic arrangements for specific optical, electrical, and thermal properties.

Brow, R.K.

1994-08-01

235

SDSS spectroscopic survey of stars  

SciTech Connect

In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is also producing a massive spectroscopic database. They discuss determination of stellar parameters, such as effective temperature, gravity and metallicity from SDSS spectra, describe correlations between kinematics and metallicity, and study their variation as a function of the position in the Galaxy. They show that stellar parameter estimates by Beers et al. show a good correlation with the position of a star in the g-r vs. u-g color-color diagram, thereby demonstrating their robustness as well as a potential for photometric parameter estimation methods. Using Beers et al. parameters, they find that the metallicity distribution of the Milky Way stars at a few kpc from the galactic plane is bimodal with a local minimum at [Z/Z{sub {circle_dot}}] {approx} -1.3. The median metallicity for the low-metallicity [Z/Z{sub {circle_dot}}] < =1.3 subsample is nearly independent of Galactic cylindrical coordinates R and z, while it decreases with z for the high-metallicity [Z/Z{sub {circle_dot}}] > -1.3 sample. they also find that the low-metallicity sample has {approx} 2.5 times larger velocity dispersion and that it does not rotate (at the {approx} 10 km/s level), while the rotational velocity of the high-metallicity sample decreases smoothly with the height above the galactic plane.

Ivezic, Zeljko; Schlegel, D.; Uomoto, A.; Bond, N.; Beers, T.; Allende Prieto, C.; Wilhelm, R.; Lee, Y.Sun; Sivarani, T.; Juric, M.; Lupton, R.; /Washington U., Seattle,

2007-01-01

236

Enhancing forensic science with spectroscopic imaging  

NASA Astrophysics Data System (ADS)

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.

Ricci, Camilla; Kazarian, Sergei G.

2006-09-01

237

Raman spectroscopic biochemical mapping of tissues  

NASA Astrophysics Data System (ADS)

Advances in technologies have brought us closer to routine spectroscopic diagnosis of early malignant disease. However, there is still a poor understanding of the carcinogenesis process. For example it is not known whether many cancers follow a logical sequence from dysplasia, to carcinoma in situ, to invasion. Biochemical tissue changes, triggered by genetic mutations, precede morphological and structural changes. These can be probed using Raman or FTIR microspectroscopy and the spectra analysed for biochemical constituents. Local microscopic distribution of various constituents can then be visualised. Raman mapping has been performed on a number of tissues including oesophagus, breast, bladder and prostate. The biochemical constituents have been calculated at each point using basis spectra and least squares analysis. The residual of the least squares fit indicates any unfit spectral components. The biochemical distribution will be compared with the defined histopathological boundaries. The distribution of nucleic acids, glycogen, actin, collagen I, III, IV, lipids and others appear to follow expected patterns.

Stone, Nicholas; Hart Prieto, Maria C.; Kendall, Catherine A.; Shetty, Geeta; Barr, Hugh

2006-02-01

238

Characterization of clinohumite by selected spectroscopic methods.  

PubMed

Clinohumite, a humite group mineral, originated from Pamir Mountains, USSR, is used in the present work. Optical absorption, electron paramagnetic resonance (EPR), near infrared (NIR) and Mössbauer techniques are used in the characterization of the mineral sample. The optical absorption spectrum indicates that Fe(II) impurity is present in two sites with distorted octahedral structure. NIR results are attributed to water fundamentals. EPR studies on powder sample confirm the presence of Mn(II) in three different sites and also an iron impurity. Mössbauer studies confirm the presence of iron impurity in two different sites. PMID:16527527

Reddy, S Lakshmi; Reddy, N C Gangi; Reddy, G Siva; Reddy, B Jagannatha; Frost, Ray L

2006-11-01

239

Some examples of pulse radiolysis  

NASA Astrophysics Data System (ADS)

In order to demonstrate the versatility of pulse radiolysis, three examples from various fields of physical chemistry are given: (a) the formation and disappearance of a short-lived thallium-silver cluster is described, (b) as a new method to determine the "salting-out" effect, the concentration of nitrous oxide in aqueous solutions of various sodium chloride content is measured kinetically by monitoring the decay of hydrated electrons, and, (c) the rate constants for the reactions of hydroxyl radicals and hydrogen atoms with a series of aliphatic alcohols are determined from the increase in optical absorption in the UV region typical for alcohol radicals.

Janata, E.

2003-06-01

240

Optimal slit orientation for long multi-object spectroscopic exposures  

NASA Astrophysics Data System (ADS)

Historically, long-slit spectroscopic observations were carried out using the parallactic angle for the slit orientation if slit loss was an important consideration (either to maximize the signal-to-noise or to do spectrophotometry). This requires periodic realignment of the slit position angle as the parallactic angle changes. This is not possible for multi-slit observations where one slit position angle must be chosen for the entire exposure. Common wisdom suggests using the parallactic angle at the meridian (HA=0). In this paper, I examine what the best strategy is for long, multi-slit exposures. I find that in extreme cases (very long exposure time) the best choice is to orient the slit perpendicular to the parallactic angle at the meridian. There are two effects to consider: the increasing dispersion with increasing airmass and the changing angle between the parallactic angle and the slit. In the case of traditional slit orientation, the two effects amplify each other, thus rendering a significant fraction of the observation useless. Using the perpendicular orientation, the two processes work against each other, thus most of the observation remains useful. I will use, as an example, our 8 h Lockman Hole observations using the Keck telescope, but generic methods are given to evaluate a particular observation. I also make the tools available to the community.

Szokoly, G. P.

2005-11-01

241

Learning from examples: from theory to practice  

SciTech Connect

This tutorial provides an overview of the problem of learning from examples. Emphasis is placed on fundamental limitations in three areas: approximation, estimation and computation. Each of these is compared and contrasted in situations where the problem is one of regression verses pattern classification, parametric versus nonparametric, and linear versus nonlinear. General methods for improving generalization and computation speed are discussed, and practical examples are used to illustrate these methods.

Hush, D. R. (Donald R.); Scovel, James C.; Kelly, P. M. (Patrick M.); Howse, J. W. (James W.); Fugate, M. L. (Michael L.); Cannon, A. (Adam)

2001-01-01

242

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

PubMed

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

Zhao, Hong-Xia; Gan, Fu-Xi

2009-11-01

243

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)

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.

Arya, Vinod K.; Halford, Gary R. (Technical Monitor)

2003-01-01

244

Spectroscopic study of laser irradiated chromatin  

NASA Astrophysics Data System (ADS)

The effects of three UV excimer laser radiations, with wavelengths of 193, 248 and 282 nm respectively, on the structure of chromatin (the complex of deoxyribonucleic acid with proteins that exists in eukaryotic cells nuclei) were investigated. The chromatin was extracted from livers of Winstar rats. The spectroscopic methods used are: fluorescence (Förster) resonance energy transfer (FRET), time resolved fluorescence and steady-state fluorescence. A chromatin deoxyribonucleic acid radiolysis, a chromatin proteins damage and a change of the global chromatin structure on lasers action were indicated by this study. It exists some small differences between the actions of these three laser radiations.

Radu, Liliana; Mihailescu, I.; Gazdaru, Doina; Preoteasa, V.

2013-04-01

245

Spectroscopic measurement of an atomic wave function  

SciTech Connect

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.

Kapale, Kishore T. [Institute for Quantum Studies, and Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Qamar, Shahid [Institute for Quantum Studies, and Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Science, Nilore, Islamabad (Pakistan); Zubairy, M. Suhail [Institute for Quantum Studies, and Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Department of Electronics, Quaid-i-Azam University, Islamabad (Pakistan)

2003-02-01

246

Spectroscopic investigation of protein corona  

NASA Astrophysics Data System (ADS)

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.

Choudhary, Poonam

247

Spectroscopic characterization and reactivity studies of a mononuclear nonheme Mn(III)-hydroperoxo complex.  

PubMed

We report the first example of a mononuclear nonheme manganese(III)-hydroperoxo complex derived from protonation of an isolated manganese(III)-peroxo complex bearing an N-tetramethylated cyclam (TMC) ligand, [Mn(III)(TMC)(OOH)](2+). The Mn(III)-hydroperoxo intermediate is characterized with various spectroscopic methods as well as with density functional theory (DFT) calculations, showing the binding of a hydroperoxide ligand in an end-on fashion. The Mn(III)-hydroperoxo species is a competent oxidant in oxygen atom transfer (OAT) reactions, such as the oxidation of sulfides. The electrophilic character of the Mn(III)-hydroperoxo complex is demonstrated unambiguously in the sulfoxidation of para-substituted thioanisoles. PMID:25116698

So, Hee; Park, Young Jun; Cho, Kyung-Bin; Lee, Yong-Min; Seo, Mi Sook; Cho, Jaeheung; Sarangi, Ritimukta; Nam, Wonwoo

2014-09-01

248

A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope  

ERIC Educational Resources Information Center

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…

Wakabayashi, Fumitaka; Hamada, Kiyohito

2006-01-01

249

Fourier transform infared spectroscopic imaging for the identification of concealed drug residue particles and fingerprints  

NASA Astrophysics Data System (ADS)

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.

Ricci, Camilla; Chan, K. L. Andrew; Kazarian, Sergei G.

2006-09-01

250

Spectroscope: Fingerprinting the Luminous Suspects  

NSDL National Science Digital Library

This is an activity about spectroscopy. Learners will build a spectroscope with a scale for measuring wavelength and use it to observe various light sources. They will identify spectral lines in more than one light source and analyze the collected data. This activity requires diffraction grating material, several light sources, and gas emission lamps and power sources.

251

Build an Overhead Projector Spectroscope  

NSDL National Science Digital Library

This activity guide includes instructions for building a spectroscope using a standard classroom overhead projector. Learners can participate in the construction of the device or simply use it to explore light and the color spectrum. Learners can experiment with colored acetate film filters and bottles of colored solutions to see how they absorb and transmit light.

Katz, David A.

2002-01-01

252

EJS Programming by Example  

NSDL National Science Digital Library

Chapter 2 of Open Source tools for Computational Physics: An introduction to EJS and Python. After brief instructions on setting up EJS, this chapter demonstrates how to do basic computer programming using EJS. All of the most basic, fundamental aspects of programming are covered: variables, mathematical operations, loops, if-statements, using and creating methods (a.k.a., subroutines), etc.

Engelhardt, Larry

2011-11-25

253

A worked example of \\  

Microsoft Academic Search

Background  A variety of different approaches to the synthesis of qualitative data are advocated in the literature. The aim of this paper\\u000a is to describe the application of a pragmatic method of qualitative evidence synthesis and the lessons learned from adopting\\u000a this \\

Christopher Carroll; Andrew Booth; Katy Cooper

2011-01-01

254

Hard examples for resolution  

Microsoft Academic Search

Exponential lower bounds are proved for the length-of-resolution refutations of sets of disjunctions constructed from expander graphs, using the method of Tseitin. Since these sets of clauses encode biconditionals, they have short (polynomial-length) refutations in a standard axiomatic formulation of propositional calculus.

Alasdair Urquhart

1987-01-01

255

Spectroscopic studies of cold, gas-phase biomolecular ions  

NASA Astrophysics Data System (ADS)

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.

Rizzo, Thomas R.; Stearns, Jaime A.; Boyarkin, Oleg V.

256

Spectroscopic imaging of serum proteins using quantum cascade lasers.  

PubMed

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 ?m QCLs with high sensitivity and specificity. The sensitivity limit of 3???g/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???g/cm². We anticipate our imaging technique to be a starting point for more sophisticated biomolecular diagnostic applications. PMID:23515866

Mukherjee, Anadi; Bylund, Quentin; Prasanna, Manu; Margalit, Yotam; Tihan, Tarik

2013-03-01

257

Optical wavelength selection for improved spectroscopic photoacoustic imaging?  

PubMed Central

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.

Luke, Geoffrey P.; Nam, Seung Yun; Emelianov, Stanislav Y.

2013-01-01

258

Calibration of the SDSS\\/SEGUE Spectroscopic Pipeline  

Microsoft Academic Search

We describe an ongoing effort to validate the estimated atmospheric parameters (Teff, log g, [Fe\\/H]) obtained from SDSS spectroscopy (R = 2000) and ugriz photometry, which are being employed for both the previous SDSS-I and the ongoing SEGUE surveys. The spectroscopic pipeline makes use of a number of methods for the estimation of each parameter, with estimated internal errors in

T. Sivarani; T. C. Beers; Y. Lee; C. Rockosi; D. Lai; B. Yanny; D. Tucker; J. A. Smith; R. Wilhelm; C. Allende Prieto; J. Norris; H. Morrison; B. Plez

2005-01-01

259

Review of Spectroscopic Data for Measurements of Stratospheric Species  

NASA Technical Reports Server (NTRS)

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.

Goldman, A. (editor); Hoell, J. M., Jr. (editor)

1980-01-01

260

The power of example  

NASA Astrophysics Data System (ADS)

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.

Liliana Gheorghian, Mariana

2014-05-01

261

Spectroscopic metallicities of Vega-like stars  

E-print Network

Aims: To determine the metallicities of 113 Southern Hemisphere Vega-like candidate stars in relation to the Exoplanet host group and field stars. Methods: We applied two spectroscopic methods of abundance determinations: equivalent width measurements together with the ATLAS9 (Kurucz 1993) model atmospheres and the WIDTH9 program, and a comparison of observed spectra with the grid of synthetic spectra of Munari et al. (2005). Results: For the Vega-like group, the metallicities are indistinguishable from those of field stars not known to be associated with planets or disks. This result is quite different from the metallicities of Exoplanet host stars which are metal-rich in comparison to field stars.

C. Saffe; M. Gomez; O. Pintado; E. Gonzalez

2008-05-26

262

Optoacoustic spectroscopic imaging of radiolucent foreign bodies  

NASA Astrophysics Data System (ADS)

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.

Page, Leland; Maswadi, Saher; Glickman, Randolph D.

2010-03-01

263

Single nanoparticle tracking spectroscopic microscope  

DOEpatents

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.

Yang, Haw (Moraga, CA); Cang, Hu (Berkeley, CA); Xu, Cangshan (Berkeley, CA); Wong, Chung M. (San Gabriel, CA)

2011-07-19

264

Spectroscopic investigation of old planetaries V. Distance scales  

E-print Network

We use the results of our recent NLTE model atmosphere analysis of central stars of old planetary nebulae (PN) to calculate distances. We perform a comparison with three other methods (trigonometric parallaxes, interstellar NaD lines, and Shklovsky distances) and discuss the problem of the PNe distance scale. The result of the comparison of our spectroscopic distances with the trigonometric distances is that the spectroscopic distances are 55% larger. Since using trigonometric parallaxes with large relative measurement errors can introduce systematic errors, we carried out a Monte Carlo simulation of the biases introduced by selection effects and measurement errors. It turns out that a difference between both distance scales of the observed size is expected for the present day data if the underlying distance scales are identical. Thus our finding is essentially a confirmation of the spectroscopic distance scale! Good agreement is found between the spectroscopic distances and distances derived from the interstellar NaD lines. All three independent methods of distance measurement indicate that the widely used "statistical" distance scales of the Shklovsky type are too short for old PNe. A correlation with nebular radii exists. The most likely explanation is an underestimate of the nebula masses for large PN. Implications for the nebula masses are discussed. Estimates of the PNe space density and birthrate, which are based on Shklovsky type distances, therefore give too large values.

Ralf Napiwotzki

2000-12-01

265

Effects of Example Choice on Interest, Control, and Learning  

ERIC Educational Resources Information Center

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…

Reber, Rolf; Hetland, Hilde; Chen, Weiqin; Norman, Elisabeth; Kobbeltvedt, Therese

2009-01-01

266

Spectroscopic phase microscopy for quantifying hemoglobin concentrations in intact red blood cells  

E-print Network

We report a practical method for label-free quantification of specific molecules using spectroscopic imaging of sample-induced phase shifts. Diffraction phase microscopy equipped with various wavelengths of light source ...

Park, YongKeun

267

Novel high-resolved spectroscopic studies of positive streamer corona  

Microsoft Academic Search

We have developed a fully self-consistent method of diagnostics of streamer discharge plasmas based on analysis of absolute intensities of the second positive (SPS) and first negative (FNS) systems of molecular nitrogen. The theory of the method combines a spectroscopic technique for calculation of temporal waveforms of the nitrogen absolute SPS and FNS (0,0)-band emission and a self-consistent semi-analytical parametric

Yuri V. Shcherbakov

2007-01-01

268

Acquisition of the EELS data cube by tomographic spectroscopic imaging  

Microsoft Academic Search

The EELS data cube combines spatial and spectral information because it has an EELS spectrum in each pixel of a spatial image.\\u000a The two major methods of acquiring it are image-spectroscopy (or an Energy Filtered Series or EFS) and spectrum-imaging. In\\u000a [1] we proposed a new method: Tomographic Spectroscopic Imaging (TSI). A proper defocus of the energy filter induces a

W. Broek; J. Verbeeck; S. Backer; D. Schryvers; P. Scheunders

269

Metonymy Interpretation Using X NO Y Examples  

Microsoft Academic Search

This paper describes a new Japanese metonymy interpretation method using the examplebasedmethod (Nagao 1984; Murata and Nagao 1997; Murata et al. 1999b; Murata et al.1999a). Metonymy is a metaphorical expression in which the name of something is substitutedfor another thing associated with the thing named. For example, in the Japanesesentence of "boku ga torusutoi wo yomu (I read Tolstoi)," the

Masaki Murata; Qing Ma; Atsumu Yamamoto; Hitoshi Isahara

2000-01-01

270

Synthesis and spectroscopic characterization of cannabinolic acid.  

PubMed

Cannabinoids, the main constituents of the cannabis plant, are being increasingly studied for their medicinal properties. Cannabinolic acid (CBNA; 1) was synthesized from tetrahydrocannabinolic acid (THCA; 2), a major constituent of the cannabis plant, by aromatization using selenium dioxide mixed with trimethylsilyl polyphosphate as catalyst in chloroform. Purification was achieved by centrifugal partition chromatography, and the final product had a purity of over 96% by GC analysis. Spectroscopic data on CBNA such as 1H-NMR and IR, and molar extinction coefficients, as well as chromatographic data are presented as useful references for further research on CBNA. The developed method allows production of CBNA on a preparative scale, making it available for further studies on its biological activities as well as use as a reference standard for analytical procedures. PMID:17354173

Bastola, Krishna Prasad; Hazekamp, Arno; Verpoorte, Robert

2007-03-01

271

Reduction of Integral Field Spectroscopic Data from the Gemini Multi-Object Spectrograph (a commented example)  

E-print Network

The use of integral field spectroscopy is becoming increasingly popular, hovewer data reduction is still a difficult process. Here I present a step-by-step guide to the reduction of integral field data acquired with the Gemini Multi-Object Spectrograph (GMOS) on GEMINI. The reduction process, separately applied to a standard star and to the science data, includes bias and sky subtraction, flat-fielding, trimming, wavelength and flux calibration, creation of the cubes for each exposure and final combination into a single cube. Typical problems encoutered during the reduction process are discussed. The command list has been adapted from IRAF scripts given as tutorials at the South American Gemini Data Workshop (S\\~{a}o Jos\\'e dos Campos, Brazil, October 27-30, 2011) and scripts kindly provided by collaborators.

Lena, Davide

2014-01-01

272

Spectroscopic signature for ferroelectric ice  

NASA Astrophysics Data System (ADS)

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.

Wójcik, Marek J.; G?ug, Maciej; Boczar, Marek; Boda, ?ukasz

2014-09-01

273

MK Classifications of Spectroscopic Binaries  

NASA Astrophysics Data System (ADS)

New MK spectral classifications are given for 145 spectroscopic binaries (SBs) with AF primaries because two-dimensional types are lacking for more than one-third of the AF SBs with known orbital elements in the current catalog. Compared with the classifications by Morgan, Keenan, and their students, the new classifications give types that are 1.1 ± 0.2 subclasses later and 0.7 ± 0.1 luminosity classes fainter. Also listed are selected published MK types from Brian Skiff's recent compilation.

Abt, Helmut A.

2009-01-01

274

Spectroscopic classification of LSQ transients  

NASA Astrophysics Data System (ADS)

We report the optical spectroscopic classification of four supernovae candidates. The targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812). All observations were performed on 25th Aug 2013 with the 4.2m William Herschel Telescope using ISIS, with R300B (3300 - 6000A, 3.4A resolution), R158R (5250 - 9746A, 7.2A resolution) and a dichroic at 5300A. Classifications were done with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al., 2008, A&A, 488, 383).

Wright, D.; Polshaw, J.; Fraser, M.; Smartt, S. J.; Kotak, R.; Smith, K.; Young, D.; Inserra, C.; Nicholl, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.

2013-08-01

275

Post Canonical System: Examples First The definition follows some examples.  

E-print Network

Post Canonical System: Examples First The definition follows some examples. A Post system for sums: N Nx Nx | Ny +y = y x +y = z x | +y = z | A Post system for Hoftstadter's MU puzzle: MI xI xIU Mx Mxx xIIIy xUy xUUy xy #12;Post Canonical System A Post system consists of a list of signs, a list

Stansifer, Ryan

276

THE SPECTROSCOPIC DIVERSITY OF TYPE Ia SUPERNOVAE  

SciTech Connect

We present 2603 spectra of 462 nearby Type Ia supernovae (SNe Ia), including 2065 previously unpublished spectra, obtained during 1993-2008 through the Center for Astrophysics Supernova Program. There are on average eight spectra for each of the 313 SNe Ia with at least two spectra. Most of the spectra were obtained with the FAST spectrograph at the Fred Lawrence Whipple Observatory 1.5 m telescope and reduced in a consistent manner, making this data set well suited for studies of SN Ia spectroscopic diversity. Using additional data from the literature, we study the spectroscopic and photometric properties of SNe Ia as a function of spectroscopic class using the classification schemes of Branch et al. and Wang et al. The width-luminosity relation appears to be steeper for SNe Ia with broader lines, although the result is not statistically significant with the present sample. Based on the evolution of the characteristic Si II {lambda}6355 line, we propose improved methods for measuring velocity gradients, revealing a larger range than previously suspected, from {approx}0 to {approx}400 km s{sup -1} day{sup -1} considering the instantaneous velocity decline rate at maximum light. We find a weaker and less significant correlation between Si II velocity and intrinsic B - V color at maximum light than reported by Foley et al., owing to a more comprehensive treatment of uncertainties and host galaxy dust. We study the extent of nuclear burning and the presence of unburnt carbon in the outermost layers of the ejecta and report new detections of C II {lambda}6580 in 23 early-time SN Ia spectra. The frequency of C II detections is not higher in SNe Ia with bluer colors or narrower light curves, in conflict with the recent results of Thomas et al. Based on nebular spectra of 27 SNe Ia, we find no relation between the FWHM of the iron emission feature at {approx}4700 A and {Delta}m{sub 15}(B) after removing the two low-luminosity SN 1986G and SN 1991bg, suggesting that the peak luminosity is not strongly dependent on the kinetic energy of the explosion for most SNe Ia. Finally, we confirm the correlation of velocity shifts in some nebular lines with the intrinsic B - V color of SNe Ia at maximum light, although several outliers suggest a possible non-monotonic behavior for the largest blueshifts.

Blondin, S. [Centre de Physique des Particules de Marseille, Aix-Marseille Universite, CNRS/IN2P3, 163 avenue de Luminy, 13288 Marseille Cedex 9 (France); Matheson, T. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Kirshner, R. P.; Mandel, K. S.; Challis, P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Berlind, P.; Calkins, M. [F. L. Whipple Observatory, 670 Mt. Hopkins Road, P.O. Box 97, Amado, AZ 85645 (United States); Garnavich, P. M. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Jha, S. W. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Modjaz, M. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Riess, A. G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Schmidt, B. P., E-mail: blondin@cppm.in2p3.fr [Research School of Astronomy and Astrophysics, The Australian National University, Mount Stromlo and Siding Spring Observatories, Via Cotter Road, Weston Creek, PO 2611 (Australia)

2012-05-15

277

New examples of flux vacua  

NASA Astrophysics Data System (ADS)

Type IIB toroidal orientifolds are among the earliest examples of flux vacua. By applying T-duality, we construct the first examples of massive IIA flux vacua with Minkowski space-times, along with new examples of type IIA flux vacua. The backgrounds are surprisingly simple with no four-form flux at all. They serve as illustrations of the ingredients needed to build type IIA and massive IIA solutions with scale separation. To check that these backgrounds are actually solutions, we formulate the complete set of type II supergravity equations of motion in a very useful form that treats the R-R fields democratically.

Maxfield, Travis; McOrist, Jock; Robbins, Daniel; Sethi, Savdeep

2013-12-01

278

Correlated Knowledge Gradients: Example alternatives  

E-print Network

Correlated Knowledge Gradients: Example -4 -2 0 2 4 alternatives value 0 10 20 30 -10 -8 -6 -4 -2 0;Correlated Knowledge Gradients: Example -4 -2 0 2 4 alternatives value 0 10 20 30 -10 -8 -6 -4 -2 0 num measurements log(KGfactor) 0 10 20 30 0 0.5 1 1.5 2 num measurements opportunitycost #12;Correlated Knowledge

Keinan, Alon

279

Enhancing forensic science with spectroscopic imaging  

Microsoft Academic Search

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

Camilla Ricci; Sergei G. Kazarian

2006-01-01

280

Spectroscopic investigation of the interaction between ?-cyclodextrin and ascorbic acid  

NASA Astrophysics Data System (ADS)

Inclusion compound of vitamin C (ascorbic acid) with ?-cyclodextrin (?-CD), prepared by different methods (kneading, co-precipitation and freeze-drying) has been caracterized by several spectroscopic techniques (FTIR, 1H NMR, UV-Vis), powder X-ray diffraction and DSC technique. Based on the chemical shifts observed in the 1H-NMR and on FTIR spectra the tentative conclusion is that vitamin C probably enters the cyclodextrin torus forming the inclusion complex.

Bratu, Ioan; Muresan-Pop, Marieta; Kacso, Irina; F?rca?, Sorin I.

2009-08-01

281

Statistical analysis of single-lined red giant spectroscopic binaries  

Microsoft Academic Search

This article reports a statistical analysis of the orbital elements (period, eccentricity, mass function) performed on a sample of 194 single-lined red giant spectroscopic binaries. From the eccentricity-period diagram, the authors deduce a circularization cut-off period of 70 days and find an eccentricity-period correlation that seemingly does not result from an observational bias. With the aid of two complementary methods,

H. M. J. Boffin; G. Paulus; N. Cerf

1992-01-01

282

Multifunction Imaging and Spectroscopic Instrument  

NASA Technical Reports Server (NTRS)

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.

Mouroulis, Pantazis

2004-01-01

283

David Maloney's Physics Examples: Thermo Example 3-Ideal Gas Behavior  

NSDL National Science Digital Library

This item is an annotated homework problem involving an ideal gas contained in a cylinder with a movable piston. The author provides explicit explanations of isothermal, adiabatic, isobaric, and isochoric processes to guide users in solving for a number of unknowns. This item is part of a larger collection of introductory physics homework examples.

Maloney, David

2008-10-03

284

Benford Analysis: A useful paradigm for spectroscopic analysis  

E-print Network

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 the detection of weak NMR signals and spectral corrections. We also explore a potential application of Benford analysis in the image-processing of MRI data.

Bhole, Gaurav; Mahesh, T S

2014-01-01

285

AN H-BAND SPECTROSCOPIC METALLICITY CALIBRATION FOR M DWARFS  

SciTech Connect

We present an empirical near-infrared (NIR) spectroscopic method for estimating M dwarf metallicities, based on features in the H band, as well as an implementation of a similar published method in the K band. We obtained R {approx} 2000 NIR spectra of a sample of M dwarfs using the NASA IRTF-SpeX spectrograph, including 22 M dwarf metallicity calibration targets that have FGK companions with known metallicities. The H-band and K-band calibrations provide equivalent fits to the metallicities of these binaries, with an accuracy of {+-}0.12 dex. We derive the first empirically calibrated spectroscopic metallicity estimate for the giant planet-hosting M dwarf GJ 317, confirming its supersolar metallicity. Combining this result with observations of eight other M dwarf planet hosts, we find that M dwarfs with giant planets are preferentially metal-rich compared to those that host less massive planets. Our H-band calibration relies on strongly metallicity-dependent features in the H band, which will be useful in compositional studies using mid- to high-resolution NIR M dwarf spectra, such as those produced by multiplexed surveys like SDSS-III APOGEE. These results will also be immediately useful for ongoing spectroscopic surveys of M dwarfs.

Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Ramsey, Lawrence W.; Bochanski, John J., E-mail: rct151@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2012-03-10

286

Astrochemistry Examples in the Classroom  

ERIC Educational Resources Information Center

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…

Hudson, Reggie L.

2006-01-01

287

Simple (?) examples of second quantization  

E-print Network

-Wigner transformation · Hubbard model · Noninteracting fermions/bosons ensembles Fermi sphere Bose-Einstein condensationSimple (?) examples of second quantization --A summary of Coleman's Ch.6 2007.11.12 Solid State) · Applications to 1D Heisenberg model ·Heisenberg ferromagnet Jz=J ·x-y ferromagnet Jz=0 #12;The Hubbard Model (1

Hellsing, Bo

288

Influence of the line-shape model on the spectroscopic determination of the Boltzmann constant  

SciTech Connect

Recent high-resolution spectroscopic experiments demonstrated the possibility of measuring the Boltzmann constant directly from the Doppler width of atomic or molecular lines; however, both experimental setups and data analysis methods still need to be improved to compete with the best acoustic methods. In this paper, the influence of choice of spectral line-shape model for data analysis on systematical error of the Doppler-width determination is analyzed on the example of the oxygen line near {lambda}=687 nm. Profile simulations were performed for many different models at pressures ranging from 0.012 Pa to 120 kPa, taking into account such line-shape effects as the speed dependence of collisional broadening and Dicke narrowing. We discuss limitations of an applicability of the Voigt profile for purposes of the Boltzmann constant determination. The influence of the model line-shape profile and the gas pressure range on the Doppler width extrapolated to the zero-pressure value is investigated.

Cygan, A.; Lisak, D.; Trawinski, R. S.; Ciurylo, R. [Instytut Fizyki, Uniwersytet Mikolaja Kopernika, ul. Grudziadzka 5/7, 87-100 Torun (Poland)

2010-09-15

289

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

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

Symonds, R.B.; Reed, M.H.

1993-01-01

290

Determination of depleted uranium in environmental samples by gamma-spectroscopic techniques  

Microsoft Academic Search

The military use of depleted uranium initiated the need for an efficient and reliable method to detect and quantify DU contamination in environmental samples. This paper presents such a method, based on the gamma spectroscopic determination of 238U and 235U. The main advantage of this method is that it allows for a direct determination of the U isotope ratio, while

D. J Karangelos; M. J Anagnostakis; E. P Hinis; S. E Simopoulos; Z. S Zunic

2004-01-01

291

Effects of cold boundary layers on spectroscopic temperature measurements in combustion gas flows  

Microsoft Academic Search

A study of the effect of cold wall boundary layers on spectroscopic temperature measurements in combustion gas flows is presented. Numerical calculations are made for the monochromatic and integrated line reversal and relative intensity methods. For the monochromatic line reversal method we have shown that there exists an optimum optical depth for making the measurement and for which the method

J. W. Daily; C. H. Kruger

1976-01-01

292

Improved spectroscopic parameters for transiting planet hosts  

E-print Network

We report homogeneous spectroscopic determinations of the effective temperature, metallicity, and projected rotational velocity for the host stars of 56 transiting planets. Our analysis is based primarily on the stellar ...

Winn, Joshua Nathan

293

Asiago spectroscopic observation of two CRTS transients  

NASA Astrophysics Data System (ADS)

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of two targets supplied by the Catalina Real-Time Transient Survey CRTS (http://crts.caltech.edu).

Tomasella, L.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Ochner, P.; Pastorello, A.; Turatto, M.

2014-09-01

294

Interaction of salmon gonadotropin subunits : spectroscopic studies  

E-print Network

Interaction of salmon gonadotropin subunits : spectroscopic studies R. SALESSE, J. GARNIER, B en Josas, France Summary. Pituitary gonadotropins of female and male pacific salmon Oncorhynchus) and in salmon (Donaldson et al., 1972), although physicochemical, biological or immunological evidence for two

Paris-Sud XI, Université de

295

Spectroscopic Temperature Measurements in Interior Ballistic Environments.  

National Technical Information Service (NTIS)

Spectroscopic temperature measurements during the interior ballistic cycle of a 20 mm test fixture gun and inside the muzzle flash of a 7.62 mm rifle are described. The investigation yields information on temperature distribution in the burning propellant...

G. Klingenberg, H. Mach

1984-01-01

296

Vibrational spectroscopic characterization of fluoroquinolones  

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

297

Very Large Spectroscopic Surveys with the VLT  

E-print Network

Recently, it has been recognised that very large spectroscopic surveys (several million spectra) are required to advance our understanding of Dark Energy (via baryonic wiggles) and the detailed history of our Local Group of galaxies (via Galactic Archeology or near-field cosmology). In this paper I make a preliminary exploration of how this might be done by putting a wide field, optical, prime-focus fibre-fed spectroscopic facility on one of the VLT's UTs.

Ian R. Parry

2008-03-26

298

Examples of to supersymmetry breaking  

NASA Astrophysics Data System (ADS)

In this paper we consider gauged supergravities which arise in the low-energy limit of type II string theories and study examples which exhibit spontaneous partial supersymmetry breaking. For the quantum STU model we derive the scalar field space and the scalar potential of the supersymmetric low-energy effective action. We also study the properties of the Minkowskian supersymmetric ground states for a broader class of supergravities including the quantum STU model.

Hansen, Tobias; Louis, Jan

2013-11-01

299

Raman spectroscopic studies on p-terphenyl under high pressure  

NASA Astrophysics Data System (ADS)

High-pressure Raman scattering studies are performed on p-terphenyl up to 5 GPa. The Raman activities of different symmetric molecules were analyzed by means of group theory methods. A phase transition was detected at 1.3 GPa from changes in the slope on plots of frequency versus pressure. The diminishing of internal modes indicated that the molecule symmetry transformed from C2 to D2h. This is an effective method for detecting planar molecular structure of p-terphenyl by ring-ring stretching vibration mode, which can provide a new spectroscopic evidence of planar conjugated polyphenyl molecular conformation.

Liu, Tianyuan; Xu, Shengnan; Sun, Chenglin; Zhou, Mi

2014-11-01

300

Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.

Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.

1999-02-01

301

IMPROVED SPECTROSCOPIC PARAMETERS FOR TRANSITING PLANET HOSTS  

SciTech Connect

We report homogeneous spectroscopic determinations of the effective temperature, metallicity, and projected rotational velocity for the host stars of 56 transiting planets. Our analysis is based primarily on the stellar parameter classification (SPC) technique. We investigate systematic errors by examining subsets of the data with two other methods that have often been used in previous studies (Spectroscopy Made Easy (SME) and MOOG). The SPC and SME results, both based on comparisons between synthetic spectra and actual spectra, show strong correlations between T{sub eff}, [Fe/H], and log g when solving for all three quantities simultaneously. In contrast the MOOG results, based on a more traditional curve-of-growth approach, show no such correlations. To combat the correlations and improve the accuracy of the temperatures and metallicities, we repeat the SPC analysis with a constraint on log g based on the mean stellar density that can be derived from the analysis of the transit light curves. Previous studies that have not taken advantage of this constraint have been subject to systematic errors in the stellar masses and radii of up to 20% and 10%, respectively, which can be larger than other observational uncertainties, and which also cause systematic errors in the planetary mass and radius.

Torres, Guillermo; Holman, Matthew J.; Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Sozzetti, Alessandro [INAF-Osservatorio Astronomico di Torino, I-10025 Pino Torinese (Italy); Buchhave, Lars A. [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Winn, Joshua N., E-mail: gtorres@cfa.harvard.edu [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2012-10-01

302

Atmospheric and Spectroscopic Research in the Far Infrared  

NASA Technical Reports Server (NTRS)

The spectroscopic measurements of molecular parameters constitute one of the major areas of our research program. This part of our program has been conducted in close collaboration with Smithsonian Astrophysical Observatory (SAO) and National Institute of Standards and Technology (NIST). The references on HO2, OH, and O2 that appear on the publication list are examples of this type of work completed during the grant period. These pressure-broadening studies have provided the kind of improvements needed in the database for retrieving atmospheric profiles from far infrared limb sensing data. Authors summarized the laboratory spectroscopic studies conducted during the grant period. We attempted to measure the pressure broadening coefficients of the O2 lines in the 50 and 117/ cm regions. An accurate characterization of these lines using the IBEX detector system was needed to analyze the flight data. These are difficult lines to measure because they arise from weak magnetic dipole transitions. We used a 4-meter absorption cell to obtain the pressure broadening coefficients for the 50 and 83 /cm lines. We also completed the pressure broadening studies including the temperature dependence of two lines of OH at 83 and 118 /cm. These two lines are important not only for the balloon data retrieval work but also for the future project proposals.Another area of focus in our program is the far infrared detector research. The third area of focus deals with data distribution and dissemination.

Park, Kwangjai

1998-01-01

303

Influence of solvent on the spectroscopic properties of cyano complexes of ruthenium(II)  

Microsoft Academic Search

Specific solute-solvent interactions are known to play an important role in optical and thermal electron transfer involving transition-metal complexes. These interactions can influence both spectroscopic energies and redox potentials in a significant way. Their existence has been documented in the literature, and qualitative models have been proposed, but they have yet to be examined quantitatively. Literature examples include mixed cyano-pyridyl

Cliff J. Timpson; J. M. Meyer; C. A. Bignozzi; P. B. Sullivan; E. M. Kober

1996-01-01

304

Spectroscopic Needs for Calibration of LSST Photometric Redshifts  

E-print Network

This white paper summarizes the conclusions of the Snowmass White Paper "Spectroscopic Needs for Imaging Dark Energy Experiments" (arXiv:1309.5384) which are relevant to the calibration of LSST photometric redshifts; i.e., the accurate characterization of biases and uncertainties in photo-z's. Any significant miscalibration will lead to systematic errors in photo-z's, impacting nearly all extragalactic science with LSST. As existing deep redshift samples have failed to yield highly-secure redshifts for a systematic 20%-60% of their targets, it is a strong possibility that future deep spectroscopic samples will not solve the calibration problem on their own. The best options in this scenario are provided by cross-correlation methods that utilize clustering with objects from spectroscopic surveys (which need not be fully representative) to trace the redshift distribution of the full sample. For spectroscopy, the eBOSS survey would enable a basic calibration of LSST photometric redshifts, while the expected LSST...

Schmidt, Samuel J; Abate, Alexandra

2014-01-01

305

Spectroscopic charge pumping investigation of the amphoteric nature of Si/SiO2 interface states  

NASA Astrophysics Data System (ADS)

The amphoteric nature of Si/SiO2 interface states in submicron sized metal-oxide-silicon-field-effect-transistors is observed using an enhanced spectroscopic charge pumping method. The method's simplicity and high sensitivity makes it a powerful tool for interrogating the true nature of electrically measured interface states in samples which exhibit extremely low defect densities. The spectroscopic results obtained clearly illustrate a signature "double peak" density of states consistent with amphoteric Pb center data obtained from electron spin resonance measurements. Since the method is a hybrid of the commonly used charge pumping methodology, it should find widespread use in electronic device characterization.

Ryan, J. T.; Yu, L. C.; Han, J. H.; Kopanski, J. J.; Cheung, K. P.; Zhang, F.; Wang, C.; Campbell, J. P.; Suehle, J. S.

2011-06-01

306

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 Mt. St. Helens  

SciTech Connect

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. The programs interface with a thermo-chemical data base, GASTHERM, which contains coefficients for retrieval of the equilibrium constants from 25[degrees] to 1200[degrees]C. The programs and data base model dynamic chemical processes in 30- to 40-component volcanic-gas systems. The authors can model gas evaporation from magma, mixing of magmatic and hydrothermal gases, precipitation of minerals during pressure and temperature decrease, mixing of volcanic gas with air, and reaction of gases with wall rock. Examples are given of the gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mt. St. Helens in September 1981. The authors predict: (1) the amounts of trace elements volatilized from shallow magma, deep magma, and wall rock, and (2) the solids that precipitate from the gas upon cooling. The predictions are tested by comparing them with the measured trace-element concentrations in gases and the observed sublimate sequence. This leads to the following conclusions: (1) most of the trace elements in the Mt. St. Helens gases are volatilized from shallow magma as simple chlorides; (2) some elements (for example, Al, Ca) exist dominantly in rock aerosols, not gases, in the gas stream; (3) near-surface cooling of the gases triggers precipitation of oxides, sulfides, halides, tungstates, and native elements; and (4) equilibrium cooling of the gases to 100[degrees]C causes most trace elements, except for Hg, Sb, and Se, to precipitate from the gas. 94 refs., 30 figs., 7 tabs.

Symonds, R.B. (Michigan Technology Univ., Houghton, MI (United States)); Reed, M.H. (Univ. of Oregon, Eugene, OR (United States))

1993-10-01

307

8.10 Signal Processing Examples of LS We'll briefly look at two examples from the book...  

E-print Network

Examples 1. Digital Filter Design 2. AR Parameter Estimation for the ARMA Model 3. Adaptive Noise emitter location examples not in the book #12;2 Ex. 8.11 Filter Design by Prony's LS Method The problem[n] View: hd[n] as the observed "data"!!! Rational TF model's coefficients as the parameters General LS

Fowler, Mark

308

complete-linkage clustering example 1 complete-linkage clustering example 1  

E-print Network

complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage clustering example 1 #12;complete-linkage

Perkins, Theodore J.

309

average-linkage clustering example 1 average-linkage clustering example 1  

E-print Network

average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage clustering example 1 #12;average-linkage

Perkins, Theodore J.

310

single-linkage clustering example 1 single-linkage clustering example 1  

E-print Network

single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering example 1 #12;single-linkage clustering

Perkins, Theodore J.

311

Single-linkage clustering example 1 Single-linkage clustering example 1  

E-print Network

Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering example 1 #12;Single-linkage clustering

Perkins, Theodore J.

312

EXAMPLES OF RADIATION SHIELDING MODELS  

SciTech Connect

The attached pictures are examples of shielding models used by WSMS. The models were used in shielding evaluations for Tank 50 pump replacement. They show the relative location of shielding to radiation sources for pumps and pipes. None of the calculations that were associated with these models involved UCNI. The last page contains two pictures from a shielding calculation for the saltstone area. The upper picture is a conceptual drawing. The lower picture is an image copied from the website of a supplier for the project.

Willison, J

2006-07-27

313

Face detection by learning from positive examples  

NASA Astrophysics Data System (ADS)

Many existing methods for face detection using both the positive examples (faces) and negative examples (nonfaces). By learning only from the positive examples, a novel face detection algorithm is invented, which is made up of two parts of research works. The first one is a frontal-view upright face detection algorithm based on the well-known singular value feature (SVF) and Hidden Markov models (HMM). The algorithm couples the virtues of both the SVF and HMM and produces excellent detection results. Firstly, it is tested on the second part of a large face image library NUSTFDB603-II whose first part is used to train the HMM and where there are 954 face images of 96 persons. The detection rate is 98.32% while only one false alarm is reported. Then it is tested on a collect photo album and has detected the 85.1 percent of its 484 people, while 97 false alarms are also reported. The second part of our algorithm is the extension of the first one to rotation-invariant face detection. Several HMMs are employed simultaneously and the angle of the í«faceí image is obtained. Then the HMM for detecting the upright faces is employed to verify the faceness of the test pattern. This rotation-invariant algorithm is tested on another image set where there are 173 persons whose faces are rotated randomly. The detection rate is 72.2%, and 34 false alarms are reported.

Li, Shijin; Lu, Jianfeng; Yang, Jingyu

2000-10-01

314

On determining dose rate constants spectroscopically  

SciTech Connect

Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of {sup 125}I and {sup 103}Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089-6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated {sup 125}I and {sup 103}Pd sources. Methods: Spectra generated by 14 {sup 125}I and 6 {sup 103}Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 Multiplication-Sign 2.7 Multiplication-Sign 0.05 cm{sup 3} voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the {sup 125}I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for {sup 103}Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were Less-Than-Or-Slanted-Equal-To 0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in {sup 125}I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The {sup 103}Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different investigations are in much better agreement with the calculations using the NCRP Report 58 and NNDC(2000) initial spectra with average discrepancies of 0.9% and 1.7% for the {sup 125}I and {sup 103}Pd seeds, respectively. However, there are no differences in the calculated TG-43U1 brachytherapy parameters using either initial spectrum in both cases. Similarly, there were no differences outside the statistical uncertainties of 0.1% or 0.2%, in the average energy, air kerma/history, dose rate/history, and dose rate constant when calculated using either the full photon spectrum or the main-peaks-only spectrum. Conclusions: Our calculated dose rate constants based on using the calculated on-axis spectrum and a line or dual-point source model are in excellent agreement (0.5% on average) with the values of Chen and Nath, verifying the accuracy of their more approximate method of going from the spectrum to the dose rate constant. However, the dose rate constants based on full seed models differ by between +4.6% and -1.5% from those based on the line or dual-point source approximations. These results suggest that the main value of spectroscopic measurements is to verify full Monte Carlo models of the seeds by comparison to the calculated spectra.

Rodriguez, M.; Rogers, D. W. O. [Carleton Laboratory for Radiotherapy Physics, Carleton University, Ottawa K1S 5B6 (Canada)

2013-01-15

315

NEW EXAMPLES OF COMPACT CLIFFORD-KLEIN FORMS  

E-print Network

), there are again no interesting examples unless H is compact. This was proved by Y. Benoist when H is reductive. Generalizing the same method to other subgroups leads to the following: 1.3. Theorem (Benoist [Ben], Oh

Oh, Hee

316

Truly random number generation: an example  

NASA Astrophysics Data System (ADS)

Randomness is crucial for a variety of applications, ranging from gambling to computer simulations, and from cryptography to statistics. However, many of the currently used methods for generating randomness do not meet the criteria that are necessary for these applications to work properly and safely. A common problem is that a sequence of numbers may look random but nevertheless not be truly random. In fact, the sequence may pass all standard statistical tests and yet be perfectly predictable. This renders it useless for many applications. For example, in cryptography, the predictability of a "andomly" chosen password is obviously undesirable. Here, we review a recently developed approach to generating true | and hence unpredictable | randomness.

Frauchiger, Daniela; Renner, Renato

2013-10-01

317

Selecting asteroids for a targeted spectroscopic survey  

E-print Network

Asteroid spectroscopy reflects surface mineralogy. There are few thousand asteroids whose surfaces have been observed spectrally. Determining the surface properties of those objects is important for many practical and scientific applications, such as for example developing impact deflection strategies or studying history and evolution of the Solar System and planet formation. The aim of this study is to develop a pre-selection method that can be utilized in searching for asteroids of any taxonomic complex. The method could then be utilized im multiple applications such as searching for the missing V-types or looking for primitive asteroids. We used the Bayes Naive Classifier combined with observations obtained in the course of the Sloan Digital Sky Survey and the Wide-field Infrared Survey Explorer surveys as well as a database of asteroid phase curves for asteroids with known taxonomic type. Using the new classification method we have selected a number of possible V-type candidates. Some of the candidates we...

Oszkiewicz, D A; Tomov, T; Birlan, M; Geier, S; Penttilä, A; Poli?ska, M

2014-01-01

318

Optimum spectroscopic performance from CZT ?- and X-ray detectors with pad and strip segmentation  

Microsoft Academic Search

We describe a method for obtaining optimum spectroscopic performance from CZT ?- and X-ray detectors with segmented readout. This method allows to circumvent the effects of incomplete charge collection and to obtain energy resolution approaching the limitation due to detector and electronic noise. It is insensitive to hole trapping over most of the detector volume, while a modest amount of

A. Shor; Y. Eisen; I. Mardor

1999-01-01

319

Application of optical spectroscopic techniques for disease diagnosis  

NASA Astrophysics Data System (ADS)

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

Saha, Anushree

320

High-speed terahertz spectroscopic imaging using noncollinear electro-optic sampling and a multistep mirror.  

PubMed

We propose a method for high-speed terahertz spectroscopic imaging that is based on electro-optic sampling with a noncollinear geometry of the THz beam and probe laser beam and has a multistep mirror in the path of the probe beam. We made an imaging system that operates in the over 2.0-THz range and enables the sample region corresponding to a (28 × 28)-pixel area on the sensor to be imaged with a spatial resolution of 1.07 mm and a frequency resolution of 0.079 THz. We also show how the proposed method might be extended for faster THz spectroscopic imaging. PMID:21935141

Maruyama, Kazunori; Itani, Norihiko; Hasegawa, Shin-ya; Wakana, Shinichi

2011-08-29

321

The ab initio potential energy surface and spectroscopic constants of HOCl  

NASA Astrophysics Data System (ADS)

The potential energy surface of hypochlorous acid, HOCl, has been determined from large-scale ab initio calculations using the coupled-cluster method CCSD(T), with basis sets of quadruple- and quintuple-zeta quality. The effect of core-electron correlation on the calculated structural parameters has been investigated. The vibrational-rotational energy levels of the three isotopic species of HOCl have then been calculated using the variational method and have been further characterized by the spectroscopic constants determined using the perturbational approach. The spectroscopic constants determined, are found to be in excellent agreement with experimental data.

Koput, Jacek; Peterson, Kirk A.

1998-02-01

322

NIR spectroscopic method for the in-line moisture assessment during drying in a six-segmented fluid bed dryer of a continuous tablet production line: Validation of quantifying abilities and uncertainty assessment.  

PubMed

This study focuses on the thorough validation of an in-line NIR based moisture quantification method in the six-segmented fluid bed dryer of a continuous from-powder-to-tablet manufacturing line (ConsiGma™ 25, GEA Pharma Systems nv, Wommelgem, Belgium). The moisture assessment ability of an FT-NIR spectrometer (Matrix™-F Duplex, Bruker Optics Ltd, UK) equipped with a fiber-optic Lighthouse Probe™ (LHP, GEA Pharma Systems nv, Wommelgem, Belgium) was investigated. Although NIR spectroscopy is a widely used technique for in-process moisture determination, a minority of NIR spectroscopy methods is thoroughly validated. A moisture quantification PLS model was developed. Twenty calibration experiments were conducted, during which spectra were collected at-line and then regressed versus the corresponding residual moisture values obtained via Karl Fischer measurements. The developed NIR moisture quantification model was then validated by calculating the accuracy profiles on the basis of the analysis results of independent in-line validation experiments. Furthermore, as the aim of the NIR method is to replace the destructive, time-consuming Karl Fischer titration, it was statistically demonstrated that the new NIR method performs at least as good as the Karl Fischer reference method. PMID:25124155

Fonteyne, Margot; Arruabarrena, Julen; de Beer, Jacques; Hellings, Mario; Van Den Kerkhof, Tom; Burggraeve, Anneleen; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

2014-11-01

323

Spectroscopic characterization of femtosecond laser filament in argon gas  

SciTech Connect

We report a spectroscopic approach to measure the plasma density and electron temperature inside a filament created by an intense femtosecond laser pulse in atmospheric pressure argon gas. The technique relies on the proportionality between the Stark broadened argon fluorescence line width due to electron impact and the plasma density, while the electron temperature is determined from the well known Boltzmann plot. The obtained maximum plasma density is about 5.5x10{sup 16} cm{sup -3}, and the electron temperature is about 5800 K. Our method provides a promising and convenient way to characterize the filament for further understanding the fundamental physics and potential applications of filamentation.

Liu, W.; Bernhardt, J.; Theberge, F.; Chin, S. L.; Chateauneuf, M.; Dubois, J. [Institute of Modern Optics, Nankai University, Key Laboratory of Opto-electronic Information Science and Technology, Education Ministry of China, Tianjin 300071 (China); Centre d'Optique, Photonique et Laser (COPL) and Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada); Defence Research and Development Canada--Valcartier, 2459 Pie-XI Blvd. North, Quebec, Quebec, G3J 1X5 Canada (Canada)

2007-08-01

324

Algebraic methods in vibrational spectroscopy  

SciTech Connect

These lectures review some advances in the algebraic description of molecules from two point of views: structure and dynamics. We start by presenting the basic ideas involved in the traditional description of molecular structure in configuration space, where the Born-Oppenheimer and rotor-rigid approximations are assumed to be valid. We then focus on the vibrational degrees of freedom in order to introduce the traditional algebraic realization in terms of bosonic operators of harmonic oscillators. This analysis allows the algebraic methods based on dynamical unitary groups to be introduced as a anharmonization procedure where the local bosonic operators are translated into operators satisfying the su(2) commutation relations. Some examples of the vibrational spec-troscopic description are presented. Concerned with the dynamical point of view an algebraic model to describe collinear collisions in the semiclassical approximation is presented.

Lemus, Renato [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico, DF (Mexico)

2011-03-21

325

Raman Spectroscopic Investigation of Dyes in Spices  

NASA Astrophysics Data System (ADS)

In this study, a number of synthetic colorants for spices have been investigated by means of Raman spectroscopy, resonance Raman spectroscopy, and surface enhanced (resonance) Raman spectroscopy (SER(S)). The aim of the study was the determination of limits of detection for each dye separately and in binary mixtures of dyes in spiked samples of the spices. Most of the investigated dyes have been azo dyes, some being water-soluble, the other being fat-soluble. Investigating the composition of food preparations is an ongoing and important branch of analytical sciences. On one hand, new ingredients have to be analyzed with regard to their contents, on the other hand, raw materials that have been tampered have to be eliminated from food production processes. In the last decades, the various Raman spectroscopic methods have proven to be successful in many areas of life and materials sciences. The ability of Raman spectroscopy to distinguish even structural very similar analytes by means of their vibrational fingerprint will also be important in this study. Nevertheless, Raman scattering is a very weak process that is oftentimes overlaid by matrix interferences or fluorescence. In order to achieve limits of detection in the nanomolar range, the signal intensity has to be increased. According to the well-known equations, there are several ways of achieving this increase: •increasing sample concentration •increasing laser power •decreasing the laser wavelength •using electronic resonance •increasing the local electromagnetic field In this study, nearly all of the above-mentioned principles were applied. In a first step, all dyes were investigated in solution at different concentrations to determine a limit of detection. In the second step, spiked spice samples have been extracted with a variety of solvents and process parameters tested. To lower the limit of detection even further, SERS spectroscopy has been used as well in as out of electronic resonance.

Uhlemann, Ute; Ramoji, Anuradha; Rösch, Petra; Da Costa Filho, Paulo Augusto; Robert, Fabien; Popp, Jürgen

2010-08-01

326

Rapid identification of single microbes by various Raman spectroscopic techniques  

NASA Astrophysics Data System (ADS)

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

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

2006-02-01

327

A new method for an objective, ?2-based spectroscopic analysis of early-type stars. First results from its application to single and binary B- and late O-type stars  

NASA Astrophysics Data System (ADS)

Context. A precise quantitative spectral analysis, encompassing atmospheric parameter and chemical elemental abundance determination, is time-consuming due to its iterative nature and the multi-parameter space to be explored, especially when done by the naked eye. Aims: A robust automated fitting technique that is as trustworthy as traditional methods would allow for large samples of stars to be analyzed in a consistent manner in reasonable time. Methods: We present a semi-automated quantitative spectral analysis technique for early-type stars based on the concept of ?2 minimization. The method's main features are as follows: far less subjectivity than the naked eye, correction for inaccurate continuum normalization, consideration of the whole useful spectral range, and simultaneous sampling of the entire multi-parameter space (effective temperature, surface gravity, microturbulence, macroturbulence, projected rotational velocity, radial velocity, and elemental abundances) to find the global best solution, which is also applicable to composite spectra. Results: The method is fast, robust, and reliable as seen from formal tests and from a comparison with previous analyses. Conclusions: Consistent quantitative spectral analyses of large samples of early-type stars can be performed quickly with very high accuracy. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program IDs 074.D-0021(A), 088.A-9003(A), and 091.C-0713(A). Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias, proposal 41-027. Figures 2 and 3 are available in electronic form at http://www.aanda.org

Irrgang, A.; Przybilla, N.; Heber, U.; Böck, M.; Hanke, M.; Nieva, M.-F.; Butler, K.

2014-05-01

328

Hopf algebras: motivations and examples  

E-print Network

This paper provides motivation as well as a method of construction for Hopf algebras, starting from an associative algebra. The dualization technique involved relies heavily on the use of Sweedler's dual.

G. H. E. Duchamp; P. Blasiak; A. Horzela; K. A. Penson; A. I. Solomon

2009-12-19

329

Molecular structure, vibrational spectroscopic, first hyperpolarizability, NBO and HOMO, LUMO studies of P-Iodobenzene sulfonyl chloride  

Microsoft Academic Search

In this work, the experimental and theoretical vibrational spectra of P-Iodobenzene sulfonyl chloride (P-IBSC) were studied. P-IBSC and its derivatives present in many biologically active compounds. Because of their spectroscopic properties and chemical significance in particular, sulfonyl chloride and its derivatives have been studied extensively by spectroscopic (FTIR and FT-Raman spectra) and theoretical methods. The infrared spectra of these compounds

M. Arivazhagan; S. Prabhakaran; R. Gayathri

2011-01-01

330

Study of the effect of CalRed on the secondary structure of human serum albumin by spectroscopic techniques  

Microsoft Academic Search

The effect of Cal-Red on the structure of human serum albumin (HSA) was studied using Resonance light scattering (RLS), Fourier transformed Infrared (FT-IR) and Circular dichroism (CD) spectroscopic methods. The RLS spectroscopic results show that the RLS intensity of HSA was significantly increased in the presence of Cal-Red. The binding parameters of HSA with Cal-Red were studied at different temperatures

Lijun Dong; Xingguo Chen; Zhide Hu

2007-01-01

331

An Improved Diffraction Grating Spectroscope Experiment.  

ERIC Educational Resources Information Center

Discusses problems associated with standard diffraction grating experiments involving a diffraction grating, a straight meter stick, and a slit. Describes the use of a new spectroscope to overcome these problems using a curved scale to simplify calculations and help students obtain results from simple and straightforward measurements, thus giving…

Scherzer, Robert

1995-01-01

332

Spectroscopic study in Z-pinch discharge  

SciTech Connect

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

Garamoon, A.A.; Saudy, A.H.; Shark, W. [Al-Azhar Univ., Cairo (Egypt)] [and others

1995-12-31

333

The Electromagnetic Spectrum: Cereal Box Analytical Spectroscope  

NSDL National Science Digital Library

In this activity, students construct an analytical spectroscope and analyze the spectrum produced when various substances are heated or excited with electricity. This activity is part of Unit 2 in the Space Based Astronomy guide that contains background information, worksheets, assessments, extensions, and standards.

334

Study of bacteria by spectroscopic techniques  

Microsoft Academic Search

Raman and Laser Induced Fluorescence (LIF) spectroscopic techniques were used for studying Azotobacter vinelandii- a genus of free-living diazotrophic soil bacteria. Azotobacter has generated a great deal of interest owing to their unique mode of metabolism. It is a large, obligately aerobic soil bacterium, which has one of the highest respiratory rates known among living organisms and is able to

Vidhu S. Tiwari; Chan Kyu Kim; Fang-Yu Yueh; Jagdish P. Singh; Michael Cunningham Jr.; Lakshmi Pulakat; Nara Gavini; Paresh Chandra Ray

2006-01-01

335

Spectroscopic observation of the rotational Doppler effect  

E-print Network

We report on the first spectroscopic observation of the rotational Doppler shift associated with light beams carrying orbital angular momentum. The effect is evidenced as the broadening of a Hanle/EIT coherence resonance on Rb vapor when the two incident Laguerre-Gaussian laser beams have opposite topological charges. The observations closely agree with theoretical predictions.

Barreiro, S; Lezama, A; Tabosa, J W R

2006-01-01

336

Spectroscopic temperature measurements in interior ballistic environments  

Microsoft Academic Search

Spectroscopic temperature measurements during the interior ballistic cycle of a 20 mm test fixture gun and inside the muzzle flash of a 7.62 mm rifle are described. The investigation yields information on temperature distribution in the burning propellant charge of the 20 mm test fixture and on radial temperature profiles in the 7.62 mm muzzle flash region. A technique to

G. Klingenberg; H. Mach

1984-01-01

337

Laser Spectroscopic Measurement Of Temperature And Density  

NASA Technical Reports Server (NTRS)

Report discusses research on use of laser-induced fluorescence in oxygen and Raman scattering in air for simultaneous measurement of temperature and density of air. Major application of laser spectroscopic techniques, measurement of fluctuations of temperature and density in hypersonic flows in wind tunnels.

Mckenzie, Robert L.; Laufer, Gabriel

1991-01-01

338

Spectroscopic Atmospheric Calibration for Pan-STARRS  

Microsoft Academic Search

This project, as part of a National Science Foundation REU summer program, explores the feasibility of a new atmospheric calibration system that would involve mounting a small, Spectroscopic Sky Probe (SSP) on the side of the Pan-STARRS telescope in order to use its measurements for atmospheric calibration purposes. The Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) will use the

Kimberly DeRose

2007-01-01

339

A method for rapidly assessing and refining simple solvent treatments in molecular modelling. Example studies on the antigen-combining loop H2 from FAB fragment McPC603.  

PubMed

Different simple solvent models have been implemented in an extended simulated annealing process (ESAP), developed by Higo et al. [(1992) Biopolymers, 32, 33-43] and proven to be able to predict ab initio the conformation of the antigen-combining loop H2 from FAB McPC603. The rationale used here provides a useful new method for testing solvent models in general. The different solvent models comprise a high dielectric constant, a screened coulomb potential, a dummy water model and a statistical continuum treatment of the solvent effect in which the reaction field and the solvent accessible area is accounted for. To assess the effect of the solvent, we tested the ability of simulations to retain the experimental conformation of loop H2. We compared the different structures obtained at the end of the annealing process in terms of root mean square deviation (r.m.s.d.), for both the backbone and for all atoms, root mean square (r.m.s.) fluctuation, solvent accessible surface area (ASA), hydrogen bonding network and phi-psi plot distribution. The relationship between the r.m.s.d. and the internal energy of a structure is also evaluated in terms of precision and another possible method for obtaining the best conformation is discussed. The accuracy of modelling the coarse effect of the solvent and the similarities of the resulting structures with respect to the X-ray reference structure are examined. The possible choice of one of these solvent models in the structure determination of an unknown loop structure is discussed. PMID:8170926

Collura, V P; Greaney, P J; Robson, B

1994-02-01

340

The use and generation of illustrative examples in computer-based instructional systems  

NASA Technical Reports Server (NTRS)

A method is proposed whereby the underlying domain knowledge is represented such that illustrative examples may be generated on demand. This method has the advantage that the generated example can follow changes in the domain in addition to allowing automatic customization of the example to the individual.

Selig, William John; Johannes, James D.

1987-01-01

341

Characterization by spectroscopic Ellipsometry, the physical properties of silver nanoparticles.  

NASA Astrophysics Data System (ADS)

Physicists are able to change their minds through their experiments. I think it is time to go kick the curse and go further in research if we want a human future. I work in the Nano-Optics and Plasmonics research. I defined with ellipsomètrie the structure of new type of Nano particles of silver. It's same be act quickly to replace the old dirty leaded electronic-connexion chip and by the other hand to find a new way for the heath care of cancer disease by nanoparticles the next killers of bad cells. Silver nanoparticle layers are obtained by Spark Plasma Sintering are investigated as an alternative to lead alloy based material for solder joint in power mechatronics modules. These layers are characterized by mean of conventional techniques that is the dilatometry technique, the resistivity measurement through the van der Pauw method, and the flash laser technique. Furthermore, the nanoparticles of silver layer are deeply studied by UV-Visible spectroscopic ellipsometry. Spectroscopic angles parameters are determined in function of temperature and dielectric constants are deduced and analyzed through an optical model which takes into account a Drude and a Lorentz component within the Bruggeman effective medium approximation (EMA). The relaxation times and the electrical conductivity are plot in function of temperature. The obtained electrical conductivity give significant result in good agreement to those reported by four points electrical measurement method.

Coanga, Jean-Maurice

2013-04-01

342

Spectroscopic confirmation of redshifts predicted by gravitational lensing  

NASA Astrophysics Data System (ADS)

We present deep spectroscopic measurements of 18 distant field galaxies identified as gravitationally lensed arcs in a Hubble Space Telescope image of the cluster Abell 2218. Redshifts of these objects were predicted by Kneib et al. using a lensing analysis constrained by the properties of two bright arcs of known redshift and other multiply imaged sources. The new spectroscopic identifications were obtained using long exposures with the LDSS-2 spectrograph on the William Herschel Telescope, and demonstrate the capability of that instrument to reach new limits, R = 24; the lensing magnification implies true source magnitudes as faint as R = 25. Statistically, our measured redshifts are in excellent agreement with those predicted from Kneib et al.'s lensing analysis, and this gives considerable support to the redshift distribution derived by the lensing inversion method for the more numerous and fainter arclets extending to R = 25.5. We explore the remaining uncertainties arising from both the mass distribution in the central regions of Abell 2218 and the inversion method itself, and conclude that the mean redshift of the faint field population at R = 25.5 (B = 26-27) is low, (z = 0.8-1). We discuss this result in the context of redshift distributions estimated from multicolor photometry.

Ebbels, Tim; Ellis, Richard; Kneib, Jean-Paul; Le Borgne, Jean-Francois; Pello, Roser; Smail, Ian; Sanahuja, Blai

1998-03-01

343

State of the Art in Example-based Texture Synthesis  

Microsoft Academic Search

Recent years have witnessed significant progress in example-based texture synthesis algorithms. Given an example texture, these methods produce a larger texture that is tailored to the user's needs. In this state-of-the-art report, we aim to achieve three goals: (1) provide a tutorial that is easy to follow for readers who are not already familiar with the subject, (2) make a

Li-Yi Wei; Sylvain Lefebvre; Vivek Kwatra; Greg Turk

2009-01-01

344

[Determining the possibility of collecting reliable data for use in decision making in health care on the example of cost-effectiveness analysis of methods used in smoking cessation].  

PubMed

Reports on Polish Health care system found that the evidence from systematic reviews and cost-effectiveness analyses is not sufficiently used in decision-making. The aim of this study was to determine the possibility of reliable cost and other data collection in Poland to inform cost-effectiveness analysis of smoking cessation methods in Poland, which could be used to support decisions from the perspective of National Health Fund. In order to estimate long term effects of smoking cessation Markov model was built. Direct medical costs of the following smoking related diseases were sought: chronic obstructive pulmonary disease, coronary heart disease, lung cancer and stroke. Analysis was performed from National Health Fund perspective. Published cost data were insufficient for the analysis, so an attempt was made to obtain cost data from National Insurance Fund, which was not very successful due to their lack. Mortality data were obtained from National Office of Statistics. Lung cancer incidence and mortality were obtained from national register. No registries systematically and routinely collecting incidence and prevalence data for other diseases were localized. No studies exploring utilities of Polish population in the analyzed health states were found. As no disease registries, except for cancer, systematically collecting epidemiologic data and no unified system of collecting cost data were found, less reliable data has to be used in cost-effectiveness analyses supporting the decisions in health care in Poland. PMID:15794284

Ba?a, Ma?gorzata

2004-01-01

345

Spectroscopic Imaging of Bladder Cancer  

SciTech Connect

The feasibility of developing bladder cancer detection methods using intrinsic tissue optical properties is the focus of this investigation. In vitro experiments have been performed using polarized elastic light scattering in combination with tissue autofluorescence in the NIR spectral region under laser excitation in the green and red spectral regions. The experimental results obtained from a set of tissue specimens from 25 patients reveal the presence of optical fingerprint characteristics suitable for cancer detection with high contrast and accuracy. These photonic methods are compatible with existing endoscopic imaging modalities which make them suitable for in-vivo application.

Demos, S G; Gandour-Edwards, R; Ramsamooj, R; deVere White, R

2003-01-01

346

26 CFR 20.2013-6 - Examples.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2010-04-01 true Examples. 20.2013-6 Section 20.2013-6 Internal Revenue INTERNAL REVENUE SERVICE...AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-6 Examples. The application of §§...

2011-04-01

347

26 CFR 20.2013-6 - Examples.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Examples. 20.2013-6 Section 20.2013-6 Internal Revenue INTERNAL REVENUE SERVICE...AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-6 Examples. The application of §§...

2012-04-01

348

26 CFR 20.2013-6 - Examples.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Examples. 20.2013-6 Section 20.2013-6 Internal Revenue INTERNAL REVENUE SERVICE...AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-6 Examples. The application of §§...

2010-04-01

349

Density Ratio Examples Semiparametric Statistical Formulation  

E-print Network

UMinformal Density Ratio Examples Semiparametric Statistical Formulation Combined semiparametric density estimators Semiparametric regression Application to Testicular Germ Cell Cancer Semiparametric Density Ratio Examples Semiparametric Statistical Formulation Combined semiparametric density estimators

Johnson, Raymond L.

350

Analog Computer Laboratory with Biological Examples.  

ERIC Educational Resources Information Center

The use of biological examples in teaching applications of the analog computer is discussed and several examples from mathematical ecology, enzyme kinetics, and tracer dynamics are described. (Author/GA)

Strebel, Donald E.

1979-01-01

351

Simple Perturbation Example for Quantum Chemistry.  

ERIC Educational Resources Information Center

Presents a simple example that illustrates various aspects of the Rayleigh-Schrodinger perturbation theory. The example is a particularly good one because it is straightforward and can be compared with both the exact solution and with experimental data. (JN)

Goodfriend, P. L.

1985-01-01

352

34 CFR Appendix B to Part 403 - Examples for 34 CFR 403.194-Comparability Requirements  

Code of Federal Regulations, 2012 CFR

...false Examples for 34 CFR 403.194-Comparability Requirements B Appendix B to Part...Examples for 34 CFR 403.194—Comparability Requirements Methods by which a...demonstrate its compliance with the comparability requirements in 34 CFR...

2012-07-01

353

34 CFR Appendix B to Part 403 - Examples for 34 CFR 403.194-Comparability Requirements  

Code of Federal Regulations, 2013 CFR

...false Examples for 34 CFR 403.194-Comparability Requirements B Appendix B to Part...Examples for 34 CFR 403.194—Comparability Requirements Methods by which a...demonstrate its compliance with the comparability requirements in 34 CFR...

2013-07-01

354

New Developments of Broadband Cavity Enhanced Spectroscopic Techniques  

NASA Astrophysics Data System (ADS)

In recent years, cavity enhanced spectroscopic techniques, such as cavity ring-down spectroscopy (CRDS), cavity enhanced absorption spectroscopy (CEAS), and broadband cavity enhanced absorption spectroscopy (BBCEAS), have been widely employed as ultra-sensitive methods for the measurement of weak absorptions and in the real-time detection of trace species. In this contribution, we introduce two new cavity enhanced spectroscopic concepts: a) Optomechanical shutter modulated BBCEAS, a variant of BBCEAS capable of measuring optical absorption in pulsed systems with typically low duty cycles. In conventional BBCEAS applications, the latter substantially reduces the signal-to-noise ratio (S/N), consequently also reducing the detection sensitivity. To overcome this, we incorporate a fast optomechanical shutter as a time gate, modulating the detection scheme of BBCEAS and increasing the effective duty cycle reaches a value close to unity. This extends the applications of BBCEAS into pulsed samples and also in time-resolved studies. b) Cavity enhanced self-absorption spectroscopy (CESAS), a new spectroscopic concept capable of studying light emitting matter (plasma, flames, combustion samples) simultaneously in absorption and emission. In CESAS, a sample (plasma, flame or combustion source) is located in an optically stable cavity consisting of two high reflectivity mirrors, and here it acts both as light source and absorbing medium. A high detection sensitivity of weak absorption is reached without the need of an external light source, such as a laser or broadband lamp. The performance is illustrated by the first CESAS result on a supersonically expanding hydrocarbon plasma. We expect CESAS to become a generally applicable analytical tool for real time and in situ diagnostics. A. Walsh, D. Zhao, W. Ubachs, H. Linnartz, J. Phys. Chem. A, {dx.doi.org/10.1021/jp310392n}, in press, 2013. A. Walsh, D. Zhao, H. Linnartz Rev. Sci. Instrum. {84}(2), 021608 2013. A. Walsh, D. Zhao, H. Linnartz Appl. Phys. Lett. {101}(9), 091111 2012.

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

2013-06-01

355

2D-1D Wavelet Reconstruction as a Tool for Source Finding in Spectroscopic Imaging Surveys  

NASA Astrophysics Data System (ADS)

Today, image denoising by thresholding of wavelet coefficients is a commonly used tool for 2D image enhancement. Since the data product of spectroscopic imaging surveys has two spatial dimensions and one spectral dimension, the techniques for denoising have to be adapted to this change in dimensionality. In this paper we will review the basic method of denoising data by thresholding wavelet coefficients and implement a 2D-1D wavelet decomposition to obtain an efficient way of denoising spectroscopic data cubes. We conduct different simulations to evaluate the usefulness of the algorithm as part of a source finding pipeline.

Flöer, L.; Winkel, B.

2012-01-01

356

Molecular structure, spectroscopic (FT-IR, FT-Raman, NMR, UV) studies and first-order molecular hyperpolarizabilities of 1,2-bis(3-methoxy-4-hydroxybenzylidene)hydrazine by density functional method.  

PubMed

Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of 1,2-bis(3-methoxy-4-hydroxybenzylidene)hydrazine [vanillin azine (VA)] were carried out by using density functional (DFT/B3LYP) method with 6-31G(d) as basis set. The optimized geometrical parameters obtained by DFT calculations are in good agreement with single crystal XRD data. The vibrational spectral data obtained from solid phase FT-IR and FT-Raman spectra are assigned based on the results of the theoretical calculations. The observed spectra are found to be in good agreement with calculated values. The electric dipole moment (mu) and the first hyperpolarizability (beta) values of the investigated molecule have been computed using ab initio quantum mechanical calculations. The calculation results also show that the VA molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. A detailed interpretation of the infrared and Raman spectra of VA was also reported. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) results complements with the experimental findings. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The theoretical NMR chemical shifts complement with experimentally measured ones. PMID:20413344

Subramanian, N; Sundaraganesan, N; Jayabharathi, J

2010-07-01

357

Spectroscopic (FT-IR, FT-Raman), first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 2,4-bis(2-methoxyphenyl)-1-phenylanthracene-9,10-dione by ab initio HF and density functional methods.  

PubMed

Anthraquinone derivatives are most important class of a system that absorb in the visible region. In this work, the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 2,4-bis(2-methoxyphenyl)-1-phenylanthracene-9,10-dione. Theoretical calculations were performed by ab initio HF and DFT methods using 6-31G(*) basis set. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated geometrical parameters (DFT) are in agreement with that of similar derivatives. The calculated first hyperpolarizability of the title compound is 4.69×10(-30) esu, which is 36.08 times that of urea and the title compound and the series of compounds it represents are attractive candidates for further studies in non linear optical applications. PMID:24012980

Joseph, Tomy; Varghese, Hema Tresa; Panicker, C Yohannan; Thiemann, Thies; Viswanathan, K; Van Alsenoy, Christian; Manojkumar, T K

2014-01-01

358

Modular pixelated detector system with the spectroscopic capability and fast parallel read-out  

NASA Astrophysics Data System (ADS)

A modular pixelated detector system was developed for imaging applications, where spectroscopic analysis of detected particles is advantageous e.g. for energy sensitive X-ray radiography, fluorescent and high resolution neutron imaging etc. The presented system consists of an arbitrary number of independent versatile modules. Each module is equipped with pixelated edgeless detector with spectroscopic ability and has its own fast read-out electronics. Design of the modules allows assembly of various planar and stacked detector configurations, to enlarge active area or/and to improve detection efficiency, while each detector is read-out separately. Consequently read-out speed is almost the same as that for a single module (up to 850 fps). The system performance and application examples are presented.

Vavrik, D.; Holik, M.; Jakubek, J.; Jakubek, M.; Kraus, V.; Krejci, F.; Soukup, P.; Turecek, D.; Vacik, J.; Zemlicka, J.

2014-06-01

359

Spectroscopic modeling of water molecule  

NASA Astrophysics Data System (ADS)

This research is devoted to the vibrational spectroscopy inverse problem solution that gives a possibility to design a molecule and make conclusions about its geometry. The valence angle finding based on the usage of inverse spectral vibrational spectroscopy problem is a well-known task. 3N-matrix method was chosen to solve the proposed task. The usage of this method permits to make no assumptions about the molecule force field, besides it can be applied to molecules of matter in liquid state. Anharmonicity constants assessment is an important part of the valence angle finding. The reduction to zero vibrations is necessary because used matrix analytical expression were found in the harmonic approach. In order to find the single-valued inverse spectral problem of vibrational spectroscopy solution a shape parameter characterizing "mixing" of ?1 and ?2 vibrations forms must be found. The minimum of such a function ? called a divergence parameter was found. This function characterizes method's accuracy. The valence angle assessment was reduced to the divergence parameter minimization. The ? value concerning divergence parameter minimum was interpreted as the desired valence angle. The proposed method was applied for water molecule in liquid state: ? = (88,8 ±1,7)° . The found angle fits the water molecule nearest surrounding tetrahedral model including hydrogen bond curvature in the first approximation.

Danylo, R. I.; Okhrimenko, B. A.

2013-12-01

360

SPECTROSCOPIC STUDIES OF PETROLEUM RESINS  

Microsoft Academic Search

Resin fractions containing heteroatoms obtained from deasphaltened oils of petroleum residues (500C+) of Bombay High 7lpar;BH) and Gujrat Crude Mix (GCM) have been separated into acidic, basic and neutral Lewis base (NLB) types employing chromatographic methods. Ultimate compositions of these fractions have been determined for deducing the average molecular formulae. Infrared spectroscopy has been employed for assigning various heteroatomic functional

S. L. S. Sarowha; I. D. Singh

1988-01-01

361

Spectroscopic data and Stark broadening of Cu I and Ag I spectral lines: Selection and analysis  

NASA Astrophysics Data System (ADS)

Optical emission and linear laser absorption spectroscopy techniques were used in investigation of plasma with copper and silver admixture. The method of selection of spectral lines and spectroscopic data with the aim of diagnostics of multicomponent air plasma with two metal vapors admixture was developed. Energy level populations behavior on the Boltzmann plot were used for Cu I and Ag I spectroscopic data selection. In this way the selection of spectroscopic data for some of Cu I and Ag I lines was realized. Stark broadening parameters of Cu I and Ag I were examined. Experimentally obtained temperature and electron density radial distributions were used in the calculation of plasma composition in the assumption of local thermodynamic equilibrium. Linear laser absorption spectroscopy was used to examine the state of plasma.

Babich, I. L.; Boretskij, V. F.; Veklich, A. N.; Semenyshyn, R. V.

2014-10-01

362

Accurate Spectroscopic Characterization of Protonated Oxirane: A Potential Prebiotic Species in Titan's Atmosphere  

NASA Astrophysics Data System (ADS)

An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10 cm–1 for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.

Puzzarini, Cristina; Ali, Ashraf; Biczysko, Malgorzata; Barone, Vincenzo

2014-09-01

363

Recent advances and remaining challenges for the spectroscopic detection of explosive threats.  

PubMed

In 2010, the U.S. Army initiated a program through the Edgewood Chemical Biological Center to identify viable spectroscopic signatures of explosives and initiate environmental persistence, fate, and transport studies for trace residues. These studies were ultimately designed to integrate these signatures into algorithms and experimentally evaluate sensor performance for explosives and precursor materials in existing chemical point and standoff detection systems. Accurate and validated optical cross sections and signatures are critical in benchmarking spectroscopic-based sensors. This program has provided important information for the scientists and engineers currently developing trace-detection solutions to the homemade explosive problem. With this information, the sensitivity of spectroscopic methods for explosives detection can now be quantitatively evaluated before the sensor is deployed and tested. PMID:25061781

Fountain, Augustus W; Christesen, Steven D; Moon, Raphael P; Guicheteau, Jason A; Emmons, Erik D

2014-08-01

364

Proton NMR Spectroscopic Studies on Tissue Extracts of Invertebrate Species with Pollution Indicator Potential  

Microsoft Academic Search

High resolution proton nuclear magnetic resonance (1H NMR) spectroscopic methods have been used to characterise tissue extracts of a series of common British invertebrate species with pollution indicator potential. These include two earthworm species Lumbricus rubellus (Hoffmeister) and Eisenia andrei (Savigny), two terrestrial isopods, Oniscus asellus (L.) and Porcellio scaber (Latreille), the diplopodous arthropod, Glomeris marginata (Villers) and a pulmonate

J. O. T Gibb; E Holmes; J. K Nicholson

1997-01-01

365

Preoperative Proton MR Spectroscopic Imaging of Brain Tumors: Correlation with Histopathologic Analysis of Resection Specimens  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Tumor progression is often difficult to distinguish from nonneoplastic treatment response on the basis of MR images alone. This study correlates me- tabolite levels measured by preoperative MR spectroscopic (MRS) imaging with histologic find- ings of biopsies, obtained during image-guided resections of brain mass lesions, to clarify the potential role of MRS in making this distinction. METHODS:

Chris Dowling; Andrew W. Bollen; Susan M. Noworolski; Michael W. McDermott; Nicholas M. Barbaro; Roland G. Henry; Susan M. Chang; William P. Dillon; Sarah J. Nelson; Daniel B. Vigneron

2001-01-01

366

Stability of UV exposed RR-P3BT films by spectroscopic ellipsometry  

SciTech Connect

Stability of regioregular poly(3-butylthiophene) (RR-P3BT) films under irradiation of ultra-violet (UV) light has been studied by spectroscopic ellipsometry at room temperature. Consistent decrease in dielectric function with UV exposure time showed the degree of degradation of polymer. This work suggests that, protective methods are mandatory to use this kind of material in optical devices.

Diware, Mangesh S.; Byun, J. S.; Hwang, S. Y.; Kim, T. J.; Kim, Y. D. [Nano-Optical Property Laboratory and Department of Physics, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

2013-02-05

367

Speciation of heavy metals in cement-stabilized waste forms: A micro-spectroscopic study  

E-print Network

whether the locally observed Ni and Co phases are representative of the entire cement system. 2. Method 2.1. Sample preparation The cement samples were prepared from a com- mercial sulfate-resisting Portland cementSpeciation of heavy metals in cement-stabilized waste forms: A micro-spectroscopic study M. Vespa

368

Novel generation of pH indicators for proton magnetic resonance spectroscopic imaging.  

PubMed

We describe the synthesis of 1,omega-di-1H-imidazoles 2 and 3, derived from l-threitol and d-mannitol, respectively, showing suitable magnetic and toxicological properties, as novel extracellular pH indicators for 1H spectroscopic imaging by magnetic resonance methods. PMID:17691761

Soler-Padrós, Jordi; Pérez-Mayoral, Elena; Domínguez, Laura; López-Larrubia, Pilar; Soriano, Elena; Marco-Contelles, José Luis; Cerdan, Sebastian; Ballesteros, Paloma

2007-09-01

369

MULTI-OBJECTIVE SPECTROSCOPIC DATA ANALYSIS OF INERTIAL CONFINEMENT FUSION IMPLOSION CORES  

E-print Network

MULTI-OBJECTIVE SPECTROSCOPIC DATA ANALYSIS OF INERTIAL CONFINEMENT FUSION IMPLOSION CORES: PLASMA-ray images and X-ray line spectra. The method performs a search in multi-dimensional parameter space confinement fusion implosion cores based on the self-consistent analysis of simultaneous narrow-band X

Louis, Sushil J.

370

Spectroscopic Studies of Low-Pressure Flames; Temperature Measurements in Acetylene Flames  

Microsoft Academic Search

Flames at very low pressure have a relatively thick reaction zone (or flame front) and are especially suitable for detailed study of the combustion processes and of the distribution of energy during the reaction. Temperature measurements have been made, by various spectroscopic methods, on flames of acetylene with air, oxygen and nitrous oxide, in some cases down to a pressure

A. G. Gaydon; H. G. Wolfhard

1948-01-01

371

Electron temperature measurements in uhv systems by spectroscopic and Langmuir probe techniques  

Microsoft Academic Search

The spectroscopic and Langmuir probe characteristics of a low pressure argon glow discharge plasma were studied and the electron temperature (Te) was measured independently by both methods. The experiments were carried out in a SS 304 uhv chamber used for studying glow discharge cleaning techniques. Two types of excitation sources, dc and rf, were used. The Corona model was used

GL Bhale

1995-01-01

372

REVIEW ARTICLE: Spectroscopic temperature measurements in high temperature gases and plasmas  

Microsoft Academic Search

Various methods of determining temperature distributions in hot gases and plasmas by spectroscopic techniques are reviewed. A large range of temperature from approximately 103 to 20*103 K is considered. Particular attention is paid to the meaning of temperature at these high temperatures, and in this context the concept of 'local thermodynamic equilibrium' is introduced and approximate conditions for its validity

K. C. Lapworth

1974-01-01

373

Quantum mechanical study and spectroscopic (FT-IR, FT-Raman, UV-Visible) study, potential energy surface scan, Fukui function analysis and HOMO-LUMO analysis of 3-tert-butyl-4-methoxyphenol by DFT methods.  

PubMed

This study represents an integral approach towards understanding the electronic and structural aspects of 3-tert-butyl-4-methoxyphenol (TBMP). Fourier-transform Infrared (FT-IR) and Fourier-transform Raman (FT-Raman) spectra of TBMP was recorded in the region 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The molecular structures, vibrational wavenumbers, infrared intensities and Raman activities were calculated using DFT (B3LYP and LSDA) methods using 6-311++G (d,p) basis set. The most stable conformer of TBMP was identified from the computational results. The assignments of vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability (?0) and related properties (?, ?0 and ??) of TBMP have been discussed. The stability and charge delocalization of the molecule was studied by Natural Bond Orbital (NBO) analysis. UV-Visible spectrum and effects of solvents have been discussed and the electronic properties such as HOMO and LUMO energies were determined by time-dependent TD-DFT approach with B3LYP/6-311++G (d,p) level of theory. The molecule orbital contributions are studied by density of energy states (DOSs). The reactivity sites are identified by mapping the electron density into electrostatic potential surface (MEP). Mulliken analysis of atomic charges is also calculated. The thermodynamic properties at different temperatures were calculated, revealing the correlations between standard heat capacities, standard entropy and standard enthalpy changes with temperatures. Global hardness, global softness, global electrophilicity and ionization potential of the title compound are determined. PMID:24813291

Saravanan, S; Balachandran, V

2014-09-15

374

Conditions and Effects of Example Elaboration.  

ERIC Educational Resources Information Center

Reanalyzed findings of an earlier study on learning with worked-out examples (n=56 vocational school students) and identified different ways of dealing with worked-out examples and related them to learning outcomes and learners' mental efforts. Results show that elaboration training had a positive effect on the quality of example elaboration.…

Stark, Robin; Mandl, Heinz; Gruber, Hans; Renkl, Alexander

2002-01-01

375

The Work of Examples in Classroom Instruction  

ERIC Educational Resources Information Center

Providing examples is part of the daily routine that classroom teachers carry out in the course of their lessons, and yet we rarely examine how examples are produced and what kinds of work they do in the lively context of classroom interaction. The present study inquires into how instructional examples are portrayed in prior literature by…

Lee, Yo-An

2004-01-01

376

Introduction Examples Packages The Joys of LATEX  

E-print Network

.pdf ED BC@A pdf viewer/printer GF // #12;Introduction Examples Packages TeXnicCenter #12;Introduction Examples Packages Simplified Usage vadim.tex BC EDGF text editor @A // LATEX compiler #12;#12; vadim.pdf ED BC@A pdf viewer/printer GF // #12;Introduction Examples Packages Less Simplified Usage vadim

Ponomarenko, Vadim

377

Copy to contiguous example using C descriptor  

SciTech Connect

In N1838-2 there is an example of how to use the CFI-cdesc-t type in a C implementation of a BIND (C) interface. This paper provides another example of using the CFI-cdesc-t type in C. This new example provides code to copy an array (possibly noncontiguous) into a contiguous buffer.

Rasmussen, Craig E [Los Alamos National Laboratory

2011-01-18

378

Approval Voting: Three Examples Francesco De Sinopoli  

E-print Network

Approval Voting: Three Examples Francesco De Sinopoli , Bhaskar Dutta , Jean-Franc¸ois Laslier Abstract In this paper we discuss three examples of approval voting games. The first one illustrates. The second example shows that sophisticated voting can imply that the Condorcet winner gets no vote

Paris-Sud XI, Université de

379

Selecting asteroids for a targeted spectroscopic survey  

NASA Astrophysics Data System (ADS)

Context. Asteroid spectroscopy reflects surface mineralogy. There are a few thousand asteroids whose surfaces have been observed spectrally. Determining their surface properties is important for many practical and scientific applications, such as developing impact deflection strategies or studying the history and evolution of the solar system and planet formation. Aims: The aim of this study is to develop a preselection method that can be used to search for asteroids of any taxonomic complex. The method could then be utilized in multiple applications, such as searching for the missing V-types or looking for primitive asteroids. Methods: We used the Bayes Naive Classifier combined with observations obtained in the course of the Sloan Digital Sky Survey and the Wide-field Infrared Survey Explorer surveys, as well as a database of asteroid phase curves for asteroids with a known taxonomic type. With this new classification method, we selected a number of possible V-type candidates. Some of the candidates were then spectrally observed at the Nordic Optical Telescope and South African Large Telescope. Results: We developed and tested the new preselection method. We found three asteroids in the mid-to-outer main belt that probably have differentiated types. Near-infrared observations are still required to confirm this discovery. As in other studies we found that V-type candidates cluster around the Vesta family and are rare in the mid-to-outer main belt. Conclusions: The new method shows that even largely explored large databases when combined could still be exploited further in, for example, solving the missing dunite problem. Tables 6 and A.1 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A29

Oszkiewicz, D. A.; Kwiatkowski, T.; Tomov, T.; Birlan, M.; Geier, S.; Penttilä, A.; Poli?ska, M.

2014-12-01

380

The galaxy population of Abell 1367: photometric and spectroscopic data  

NASA Astrophysics Data System (ADS)

Aims: Photometric and spectroscopic observations of the galaxy population of the galaxy cluster Abell 1367 have been obtained, over a field of 34' × 90', covering the cluster centre out to a radius of ~2.2 Mpc. Optical broad- and narrow-band imaging was used to determine galaxy luminosities, diameters and morphologies, and to study current star formation activity of a sample of cluster galaxies. Near-infrared imaging was obtained to estimate integrated stellar masses, and to aid the determination of mean stellar ages and metallicities for the future investigation of the star formation history of those galaxies. Optical spectroscopic observations were also taken, to confirm cluster membership of galaxies in the sample through their recession velocities. Methods.U, B and R broad-band and H? narrow-band imaging observations were carried out using the Wide Field Camera (WFC) on the 2.5 m Isaac Newton Telescope on La Palma, covering the field described above. J and K near-infrared imaging was obtained using the Wide Field Camera (WFCAM) on the 3.8 m UK Infrared Telescope on Mauna Kea, covering a somewhat smaller field of 0.75 square degrees on the cluster centre. The spectroscopic observations were carried out using a multifibre spectrograph (WYFFOS) on the 4.2 m William Herschel Telecope on La Palma, over the same field as the optical imaging observations. Results: Our photometric data give optical and near-infrared isophotal magnitudes for 303 galaxies in our survey regions, down to stated diameter and B-band magnitude limits, determined within R24 isophotal diameters. Our spectroscopic data of 328 objects provide 84 galaxies with detections of emission and/or absorption lines. Combining these with published spectroscopic data gives 126 galaxies within our sample for which recession velocities are known. Of these, 72 galaxies are confirmed as cluster members of Abell 1367, 11 of which are identified in this study and 61 are reported in the literature. H? equivalent widths and fluxes are presented for all cluster galaxies with detected line emission. Conclusions: Spectroscopic and photometric data are presented for galaxies in the nearby cluster Abell 1367, as the first stage of a study of their stellar population and star formation properties. Based on observations made with the Isaac Newton Telescope and the William Herschel Telescope, operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias and the United Kingdom Infra-Red Telescope operated on Mauna Kea, Hawaii by the Joint Astronomy Centre.Tables 8-11 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/527/A101

Kriwattanawong, W.; Moss, C.; James, P. A.; Carter, D.

2011-03-01

381

Effects of cold boundary layers on spectroscopic temperature measurements in combustion gas flows  

Microsoft Academic Search

A study of the effect of cold-wall boundary layers on spectroscopic temperature measurements in combustion gas flows is presented. Numerical calculations are made for the monochromatic and integrated-line reversal and relative intensity methods. For the monochromatic-line reversal method, we have shown that there exists an optimum optical depth for making the measurements, and for which the method gives significantly better

J. W. Daily; C. H. Kruger

1977-01-01

382

Vibronic spectra of polyatomic molecules in the adiabatic approximation: The inverse spectroscopic problem  

NASA Astrophysics Data System (ADS)

A method of solving the inverse spectroscopic problem, the so-called partial analysis method, is considered. This method enables one to find the parameters Sik and ?i of the Duschinsky transformation, q' = Sq + ?, and the dependence of the electronic transition dipole moment, overlined, on the normal coordinates, q, from the relative intensities, Ivv' , of a few selected vibronic bands. A simple approximate solution of the inverse problem in case of small mixing of normal coordinates is proposed.

Chigiryov, A. R.

1986-02-01

383

Software Engineering Education by Example  

E-print Network

Based on the old but famous distinction between "in the small" and "in the large" software development, at Nancy Universit\\'e, UHP Nancy 1, we experience for a while software engineering education thanks to actual project engineering. This education method has the merit to enable students to discover and to overcome actual problems when faced to a large project which may be conducted by a large development team. The mode of education is a simulation of an actual software engineering project as encountered in "real life\\'e" activities.

Boudjlida, Nacer; Urso, Pascal

2009-01-01

384

Nondestructive and Rapid Concurrent Estimation of Paracetamol and Nimesulide in Their Combined Dosage Form Using Raman Spectroscopic Technique  

PubMed Central

A rapid, nondestructive Raman spectroscopic method was developed for quantitative estimation of paracetamol and nimesulide in their combined dosage form. A Raman univariate calibration model was developed by measuring the peak intensities of paracetamol and nimesulide at 853 cm?1 and 1336 cm?1, respectively. The developed method was successfully applied for in situ, concurrent estimation of paracetamol and nimesulide in their combined dosage and method was also validated according to International Conference on Harmonisation guidelines. Thus, the developed Raman spectroscopic method can be applied for simultaneous estimation of paracetamol and nimesulide in their combined dosage form as a process analytical technology tool by pharmaceutical industries for routine quality control. PMID:24019571

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

2013-01-01

385

Detection of optical path in spectroscopic space-based observations of greenhouse gases: Application to GOSAT data processing  

NASA Astrophysics Data System (ADS)

We present a method to detect optical path modification due to atmospheric light scattering in space-based greenhouse gas spectroscopic sounding. This method, which was applied to the analysis of radiance spectra measured by the Greenhouse Gases Observing Satellite (GOSAT), is based on the path length probability density function (PPDF) and on retrieval of PPDF parameters from radiance spectra in the oxygen A-band of absorption at 0.76 ?m. We show that these parameters can be effectively used to characterize the impact of atmospheric light scattering on carbon dioxide retrieval in the atmospheric carbon dioxide (CO2) absorption bands at 1.6 ?m and 2.0 ?m. The threshold for PPDF parameters is set so that the optical-path modification is negligible, and these settings are recommended as a basic guideline for selecting the clearest atmospheric scenarios. An example of data processing for six global GOSAT repeat cycles in April and July 2009 shows that PPDF-based selection efficiently removes CO2 retrieval biases associated with subvisible cirrus and sandstorm activities.

Oshchepkov, Sergey; Bril, Andrey; Maksyutov, Shamil; Yokota, Tatsuya

2011-07-01

386

Examplers based image fusion features for face recognition  

E-print Network

Examplers of a face are formed from multiple gallery images of a person and are used in the process of classification of a test image. We incorporate such examplers in forming a biologically inspired local binary decisions on similarity based face recognition method. As opposed to single model approaches such as face averages the exampler based approach results in higher recognition accu- racies and stability. Using multiple training samples per person, the method shows the following recognition accuracies: 99.0% on AR, 99.5% on FERET, 99.5% on ORL, 99.3% on EYALE, 100.0% on YALE and 100.0% on CALTECH face databases. In addition to face recognition, the method also detects the natural variability in the face images which can find application in automatic tagging of face images.

James, Alex Pappachen

2012-01-01

387

Lineshapes in phase-encoded spectroscopic imaging experiments  

NASA Astrophysics Data System (ADS)

Two procedures for recording spectroscopic images with pure absorption mode lineshapes using phase-encoding pulsed field gradients are discussed and compared experimentally. Using a small phantom sample, both methods are shown to give significant improvements compared to the conventional absolute value display. It is found that the method based on the use of a symmetric data set is preferable to that based on a reversed precession experiment. To demonstrate its applicability to in vivo31P NMR, a surface coil placed over the scalp of a rabbit was used to record a one-dimensional phase-encoded spectrum. While the absolute value display of this data set contains overlap between the low-field ATP and the phosphocreatine resonances, these signals are completely resolved in the phase-sensitive spectrum.

Barker, P. B.; Ross, Brian D.

388

Three-dimensional spherical analyses of cosmological spectroscopic surveys  

NASA Astrophysics Data System (ADS)

Spectroscopic redshift surveys offer great prospects for constraining the dark sector in cosmology. Future surveys will however be both deep and wide and will thus require an analysis in three-dimensional spherical geometry. We review and compare several methods which have been proposed in the literature for this purpose, focusing in particular on implementations of the spherical harmonic tomography (SHT) power spectrum Clij and the spherical Fourier Bessel (SFB) power spectrum Cl(k ,k'). Using a Fisher analysis, we compare the forecasted constraints on cosmological parameters using these statistics. These constraints typically rely on approximations such as the Limber approximation and make specific choices in the numerical implementation of each statistic. Using a series of toy models, we explore the applicability of these approximations and study the sensitivity of the SHT and SFB statistics to the details of their implementation. In particular, we show that overlapping redshift bins may improve cosmological constraints using the SHT statistic when the number of bins is small, and that the SFB constraints are quite robust to changes in the assumed distance-redshift relation. We also find that the SHT can be tailored to be more sensitive to modes at redshifts close to the survey boundary, while the SFB appears better suited to capture information beyond the smooth shape of the power spectrum. In this context, we discuss the pros and cons of the different techniques and their impact on the design and analysis of future wide field spectroscopic surveys.

Nicola, Andrina; Refregier, Alexandre; Amara, Adam; Paranjape, Aseem

2014-09-01

389

Spectroscopic properties of dipicolinic acid and its dianion  

NASA Astrophysics Data System (ADS)

If robust spectroscopic techniques are to be developed for the detection and identification of pathogens, one must understand the relevant spectroscopic properties of the target molecules. In this paper, we employ density functional theory (DFT) to study the structural, electronic, vibrational, optical, and magnetic properties of dipicolinic acid (DPA) and its dianion DPA -2. Our full geometrical optimization and Mulliken charge analysis show that DFT does not lead to the significant discrepancies between charges on symmetric carbon, hydrogen, and oxygen atoms that are found in less accurate calculations based on the complete active space MCSCF method. Our calculated vibrational frequencies, Raman spectra, and infrared spectra for ground-state DPA and DPA -2 are in good agreement with experiment, and this is also true of the four calculated 13C NMR spectral lines (for ?, ?, ?, and carboxyl sites). Our time-dependent DFT study of the optical excitation and absorption of both DPA and DPA -2 provides the first interpretation of the observed near ultraviolet absorption and fluorescence spectra. Finally, we discuss for the first time the effect of a solvent on the spectral properties of DPA.

Xie, John Rui-Hua; Smith, Vedene H.; Allen, Roland E.

2006-03-01

390

Contrast agents and spectroscopic probes in NMR  

SciTech Connect

The demand for higher diagnostic specificity has led to the increased use of ''foreign'' agents to increase tissue contrast and/or spectroscopic sensitivity in NMR studies. The primary agents used to enhance tissue contrast in NMR imaging are paramagnetic. They cause a decrease in the proton T/sub 1/ of H/sub 2/O, leading to enhanced signal intensity. This effect depends on the large gyromagnetic ratio of the electron, the number of unpaired electrons, the concentration of paramagnetic ions, the number of coordinated water molecules, and the rate of exchange of water. Spectroscopic enhancement has relied primarily on attempts as isotopic enrichment (usually C-13), which causes a direct increase in signal.

Koutcher, J.A.; Burt, C.T.; Lauffer, R.B.; Brady, T.J.

1984-04-01

391

The HITRAN 2008 Molecular Spectroscopic Database  

NASA Technical Reports Server (NTRS)

This paper describes the status of the 2008 edition of the HITRAN molecular spectroscopic database. The new edition is the first official public release since the 2004 edition, although a number of crucial updates had been made available online since 2004. The HITRAN compilation consists of several components that serve as input for radiative-transfer calculation codes: individual line parameters for the microwave through visible spectra of molecules in the gas phase; absorption cross-sections for molecules having dense spectral features, i.e., spectra in which the individual lines are not resolved; individual line parameters and absorption cross sections for bands in the ultra-violet; refractive indices of aerosols, tables and files of general properties associated with the database; and database management software. The line-by-line portion of the database contains spectroscopic parameters for forty-two molecules including many of their isotopologues.

Rothman, Laurence S.; Gordon, Iouli E.; Barbe, Alain; Benner, D. Chris; Bernath, Peter F.; Birk, Manfred; Boudon, V.; Brown, Linda R.; Campargue, Alain; Champion, J.-P.; Chance, Kelly V.; Coudert, L. H.; Sung, K.; Toth, R. A.

2009-01-01

392

The Lyman far ultraviolet spectroscopic explorer mission  

NASA Technical Reports Server (NTRS)

The Lyman-FUSE (Far Ultraviolet Spectroscopic Explorer) mission selected in 1989 for definition and development for flight is described. FUSE will obtain spectra in the 912 to 1250 angstrom region with unprecedented sensitivity. This spectral interval is extraordinarily rich in strong atomic and molecular transitions, including the Lyman series of hydrogen and deuterium, molecular hydrogen (H2 and HD) and the strong transitions of important ions such as N I to III, C I to IV, P II to V, O VI and S III to VI. FUSE will bridge the spectral gap between Hubble Space Telescope and the x ray regime with an additional moderate resolution spectroscopic capability covering 100 to 912 angstroms.

Sonneborn, George

1990-01-01

393

Soil Organic Phosphorus Speciation Using Spectroscopic Techniques  

Microsoft Academic Search

\\u000a The most commonly used differentiation of soil phosphorus (P) is between inorganic and organic forms, despite the fact that\\u000a this is only the beginning of soil P speciation. Forms of inorganic and organic soil P include a large range of specific P\\u000a compounds, and spectroscopic techniques can offer the best potential for determining the speciation of soil organic P. The

Ashlea L. Doolette; Ronald J. Smernik

394

Spectroscopic investigation of unstudied southern PNe  

E-print Network

We present a spectroscopic investigation of two hitherto unstudied galactic planetary nebulae (MeWe 1-10 and MeWe 1-11) and one candidate object (MeWe 2-5). The candidate object clearly has been identified as a bipolar hourglass shaped PN. The galactic foreground extinction was derived and using photoionization models with CLOUDY the two round objects were classified as highly evolved nebulae.

Emprechtinger, M

2004-01-01

395

Spectroscopic investigation of unstudied southern PNe  

E-print Network

We present a spectroscopic investigation of two hitherto unstudied galactic planetary nebulae (MeWe 1-10 and MeWe 1-11) and one candidate object (MeWe 2-5). The candidate object clearly has been identified as a bipolar hourglass shaped PN. The galactic foreground extinction was derived and using photoionization models with CLOUDY the two round objects were classified as highly evolved nebulae.

M. Emprechtinger; T. Forveille; S. Kimeswenger

2004-05-28

396

Spectroscopic investigation of unstudied southern PNe  

NASA Astrophysics Data System (ADS)

We present a spectroscopic investigation of two hitherto unstudied galactic planetary nebulae (MeWe 1-10 and MeWe 1-11) and one candidate object (MeWe 2-5). The candidate object clearly has been identified as a bipolar hourglass-shaped PN. The galactic foreground extinction was derived and using photoionization models with CLOUDY the two round objects were classified as highly evolved nebulae. Based on observations collected at the European Southern Observatory, La Silla.

Emprechtinger, M.; Forveille, T.; Kimeswenger, S.

2004-09-01

397

Integrated Spectroscopic Studies of MIL03346  

NASA Technical Reports Server (NTRS)

Spectroscopic studies of the SNC meteorites continue to be of great interest because they provide the only "ground truth" available for ongoing Mossbauer, thermal emittance, MidIR, nearIR, and visible spectral analysis of the martian surface. We present here results of an integrated series of measurements made on the same split of MIL03346, in order to expand our understanding of the properties of these materials and to relate them to other SNCs.

Dyar, M. D.; Pieters, C. M.; Hiroi, T.; Lane, M. D.; Marchand, G. J.

2005-01-01

398

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812), the OGLE-IV Transient Search (see Wyrzykowski et al., ATEL #4495), and the CATA Supernova Search (which is part of the Center of Astrophysics and Associated Technologies, CATA) with the 0.50-m CATA500 telescope located at Cerro Tololo.

Lyman, J.; Bersier, D.; Dennefeld, M.; Fraser, M.; Taubenberger, S.; Anderson, Joe; Benetti, S.; Pastorello, A.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Valenti, S.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, L.; Maza, J.; Gonzalez-Gaitan, S.; Maureira, E.; Forster, F.; Cosgrove, E.; Gonzalez, L. E.; Antezana, R.; Pignata, G.

2013-12-01

399

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the Catalina Real-time Transient Survey (http://crts.caltech.edu/) and OGLE-IV (ATel #4495; Wyrzykowski et al. 2012). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 Dec 26, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Baumont, S.; Balland, C.; Leget, P.-F.; Fleury, M.; Guillou, L. Le; Pastorello, A.; Benetti, S.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Taubenberger, S.; Valenti, S.; Fraser, M.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Wyrzykowski, L.

2013-12-01

400

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812) and OGLE-IV (ATel #4495; Wyrzykowski et al. 2012). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 Nov 30, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Dennefeld, M.; Bersier, D.; Lyman, J.; Maund, J. R.; Pastorello, A.; De Cia, A.; Benetti, S.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Taubenberger, S.; Valenti, S.; Fraser, M.; Yaron, O.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, L.

2013-12-01

401

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812). All observations were performed on the ESO New Technology Telescope at La Silla in the night starting on 2013 December 8 UT, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Dennefeld, M.; Bersier, D.; Lyman, J.; Taubenberger, S.; Fraser, M.; Anderson, Joe; Benetti, S.; Pastorello, A.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Valenti, S.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.

2013-12-01

402

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812), the Catalina Real-time Transient Survey (http://crts.caltech.edu/), and the OGLE-IV Transient Search (see Wyrzykowski et al., ATEL #4495).

Bersier, D.; Lyman, J.; Dennefeld, M.; Taubenberger, S.; Fraser, M.; Anderson, Joe; Benetti, S.; Pastorello, A.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Valenti, S.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, L.

2013-12-01

403

Pessto spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the Catalina Real-time Transient Survey (http://crts.caltech.edu/) and OGLE-IV (ATel #4495; Wyrzykowski et al. 2012). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 Dec 23, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Le Guillou, L.; Fleury, M.; Leget, P.-F.; Balland, C.; Baumont, S.; Pastorello, A.; Benetti, S.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Taubenberger, S.; Valenti, S.; Fraser, M.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Wyrzykowski, L.

2013-12-01

404

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812), the SkyMapper Transient (SMT) and Supernova Survey (see Scalzo et al., ATel #5480) and OGLE-IV (ATel #4495; Wyrzykowski et al. 2012).

Dennefeld, M.; Bersier, D.; Lyman, J.; Maund, J. R.; Smartt, S. J.; Smith, K.; Benetti, S.; Pastorello, A.; Valenti, S.; Taubenberger, S.; Young, D.; Inserra, C.; Sullivan, M.; Fraser, M.; Gal-Yam, A.; Yaron, O.; Manulis, I.; Scalzo, R.; Yuan, F.; Childress, M.; Tucker, B.; Schmidt, B.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, L.

2013-12-01

405

Pessto spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 Dec 20, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Le Guillou, L.; Fleury, M.; Leget, P.-F.; Baumont, S.; Balland, C.; Pastorello, A.; Benetti, S.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Taubenberger, S.; Valenti, S.; Fraser, M.; Yaron, O.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.

2013-12-01

406

Pessto spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812) and OGLE-IV (ATel #4495; Wyrzykowski et al. 2012). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 Dec 21, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Leget, P.-F.; Guillou, L. Le; Fleury, M.; Baumont, S.; Balland, C.; Pastorello, A.; Benetti, S.; Inserra, C.; Smartt, S.; Smith, K.; Young, D.; Sullivan, M.; Taubenberger, S.; Valenti, S.; Fraser, M.; Yaron, O.; Manulis, I.; Gal-Yam, A.; Knapic, C.; Smareglia, R.; Molinaro, M.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, L.

2013-12-01

407

Spectroscopic temperature measurements in oxygen discharges  

Microsoft Academic Search

The rotational temperature values for the excited state O2 (b1Sigma(+) sub g, v = 0) were deduced from spectroscopic measurements made of the excited state of O2 in the positive column of an oxygen glow discharge at pressures between 0.5 and 5 torr and discharge current up to 100 mA. The rotational temperature of the excited state O2 was deduced

M. Touzeau; M. Vialle; A. Zellagui; G. Gousset; M. Lefebvre; M. Pealat

1992-01-01

408

Spectroscopic classification of two optical transients  

NASA Astrophysics Data System (ADS)

Further to S. Shurpakov et al. (ATel #4805) we report the spectroscopic classification of the transient MASTER OT J133253.32+355733.3. A spectrum obtained at the 4.2m William Herschel Telescope (+ISIS) (range 350-950nm) on 2013 Feb. 13.26 UT and fitted using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) shows reasonable matches to Type-Ia supernovae between -5 days and peak magnitude at z=0.06.

Gall, E.; Inserra, C.; Wright, D.; Fraser, M.; Smartt, S. J.; Lawrence, A.

2013-02-01

409

Quantitative spectroscopic studies of a pulsed plasma microthruster  

NASA Astrophysics Data System (ADS)

The absolute intensity of the emission spectra emitted from a PPT plume was studied from both experimental measurements and theoretical analysis to investigate its interference with an optical sensor/signal. The results were also used to estimate the absolute radiant-energy emitted from the PPT plume to compare with the input energy for the energy-budget analysis. Initially the radiating species in the PPT plume were identified by the spectroscopic measurements. For the identified species, the absolute intensity was obtained in three methods. In the first method, the intensity was experimentally measured with the quantitative spectroscopic apparatus to provide the experimental intensity. In the second method, the intensity was theoretically calculated with the experimental results assuming the observed plasma to be spatially uniform and temporally constant for simplification to provide the spatially and temporally uniform (STU) semi-empirical theoretical intensity. In the third method, the intensity was theoretically calculated independently from the experimental results using the MACH2 magnetohydrodynamic code to provide the spatially and temporally nonuniform (STN) fully theoretical intensity. The STU theoretical intensity has reasonable agreement with the experimental intensity to capture the trend although the STU values are larger by up to four times. This discrepancy was reduced by STN theoretical intensity which predicted well the experimental value. Using the result of the experimental intensity and the STN theoretical intensity, the radiant energy was estimated. The experimental and the theoretical radiant energies increase with the input energy in an approximately linear fashion. The result indicates that the radiative loss due to the spontaneous line emission in the range of 400 to 700 nm is at most 0.02% of the input energy. The comparisons of absolute intensity measurements and calculations of radiant energy based on MACH2 MHD simulations indicate that such simulations can provide adequate guides for estimating the amount of radiation from PPTs.

Umeki, Tomokazu

2001-06-01

410

The Dark Energy Spectroscopic Instrument (DESI)  

NASA Astrophysics Data System (ADS)

The Dark Energy Spectroscopic Instrument (DESI) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar spectroscopic redshift survey. The DESI instrument consists of a new wide-field (3.2 deg. linear field of view) corrector plus a multi-object spectrometer with up to 5000 robotically positioned optical fibers and will be installed at prime focus on the Mayall 4m telescope at Kitt Peak, Arizona. The fibers feed 10 three-arm spectrographs producing spectra that cover a wavelength range from 360-980 nm and have resolution of 2000-5500 depending on the wavelength. The DESI instrument is designed for a 14,000 sq. deg. multi-year survey of targets that trace the evolution of dark energy out to redshift 3.5 using the redshifts of luminous red galaxies (LRGs), emission line galaxies (ELGs) and quasars. DESI is the successor to the successful Stage-III BOSS spectroscopic redshift survey and complements imaging surveys such as the Stage-III Dark Energy Survey (DES, currently operating) and the Stage-IV Large Synoptic Survey Telescope (LSST, planned start early in the next decade).

Flaugher, Brenna; Bebek, Chris

2014-07-01

411

The Dark Energy Spectroscopic Instrument (DESI)  

SciTech Connect

The Dark Energy Spectroscopic Instrument (DESI) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar spectroscopic redshift survey. The DESI instrument consists of a new wide-#12;eld (3.2 deg. linear #12;eld of view) corrector plus a multi-object spectrometer with up to 5000 robotically positioned optical #12;bers and will be installed at prime focus on the Mayall 4m telescope at Kitt Peak, Arizona. The #12;bers feed 10 three-arm spectrographs producing spectra that cover a wavelength range from 360-980 nm and have resolution of 2000-5500 depending on the wavelength. The DESI instrument is designed for a 14,000 sq. deg. multi-year survey of targets that trace the evolution of dark energy out to redshift 3.5 using the redshifts of luminous red galaxies (LRGs), emission line galaxies (ELGs) and quasars. DESI is the successor to the successful Stage-III BOSS spectroscopic redshift survey and complements imaging surveys such as the Stage-III Dark Energy Survey (DES, currently operating) and the Stage-IV Large Synoptic Survey Telescope (LSST, planned start early in the next decade.

Flaugher, Brenna [Fermilab

1998-03-01

412

The HITRAN2012 molecular spectroscopic database  

NASA Astrophysics Data System (ADS)

This paper describes the status of the 2012 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2008 and its updates during the intervening years. The HITRAN molecular absorption compilation is comprised of six major components structured into folders that are freely accessible on the internet. These folders consist of the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, ultraviolet spectroscopic parameters, aerosol indices of refraction, collision-induced absorption data, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, and validity. Molecules and isotopologues have been added that address the issues of atmospheres beyond the Earth. Also discussed is a new initiative that casts HITRAN into a relational database format that offers many advantages over the long-standing sequential text-based structure that has existed since the initial release of HITRAN in the early 1970s.

Rothman, L. S.; Gordon, I. E.; Babikov, Y.; Barbe, A.; Chris Benner, D.; Bernath, P. F.; Birk, M.; Bizzocchi, L.; Boudon, V.; Brown, L. R.; Campargue, A.; Chance, K.; Cohen, E. A.; Coudert, L. H.; Devi, V. M.; Drouin, B. J.; Fayt, A.; Flaud, J.-M.; Gamache, R. R.; Harrison, J. J.; Hartmann, J.-M.; Hill, C.; Hodges, J. T.; Jacquemart, D.; Jolly, A.; Lamouroux, J.; Le Roy, R. J.; Li, G.; Long, D. A.; Lyulin, O. M.; Mackie, C. J.; Massie, S. T.; Mikhailenko, S.; Müller, H. S. P.; Naumenko, O. V.; Nikitin, A. V.; Orphal, J.; Perevalov, V.; Perrin, A.; Polovtseva, E. R.; Richard, C.; Smith, M. A. H.; Starikova, E.; Sung, K.; Tashkun, S.; Tennyson, J.; Toon, G. C.; Tyuterev, Vl. G.; Wagner, G.

2013-11-01

413

Spectroscopic studies of the transplutonium elements  

SciTech Connect

The challenging opportunity to develop insights into both atomic structure and the effects of bonding in compounds makes the study of actinide spectroscopy a particularly fruitful and exciting area of scientific endeavor. It is also the interpretation of f-element spectra that has stimulated the development of the most sophisticated theoretical modeling attempted for any elements in the periodic table. The unique nature of the spectra and the wealth of fine detail revealed make possible sensitive tests of both physical models and the results of Hartree-Fock type ab initio calculations. This paper focuses on the unique character of heavy actinide spectroscopy. It discusses how it differs from that of the lighter member of the series and what are the special properties that are manifested. Following the introduction, the paper covers the following: (1) the role of systematic studies and the relationships of heavy-actinide spectroscopy to ongoing spectroscopic investigations of the lighter members of the series; (2) atomic (free-ion) spectra which covers the present status of spectroscopic studies with transplutonium elements, and future needs and directions in atomic spectroscopy; (3) the spectra of actinide compounds which covers the present status and future directions of spectroscopic studies with compounds of the transplutonium elements; and other spectroscopies. 1 figure, 2 tables.

Carnall, W.T.; Conway, J.G.

1983-01-01

414

Spectroscopic Methods in Photosynthesis: Photosystem Stoichiometry and Chlorophyll Antenna Size  

Microsoft Academic Search

Light-induced absorbance change and fluorescence measurements were employed in the quantitation of photosystem stoichiometry and in the measurement of the chlorophyll (Chl) antenna size in thylakoid membranes. Results with thylakoid membranes from diverse photosynthetic tissues indicated a PSII\\/PSI reaction-centre stoichiometry that deviates from unity. Cyanobacteria and red algae have a PSII\\/PSI ratio in the range of 0.3 to 0.7. Chloroplasts

A. Melis

1989-01-01

415

Effects of Identical Example-Problem and Problem-Example Pairs on Learning  

ERIC Educational Resources Information Center

Examples are often an integral part of online learning environments directed at the acquisition of problem-solving skills. An unresolved issue, however, is when examples should be provided to learners. Prior research has suggested that example-problem pairs are more effective than problem-example pairs for novice learners. However, in those…

van Gog, Tamara

2011-01-01

416

Synthesis, structural and spectroscopic investigations of nanostructured samarium oxalate crystals.  

PubMed

Nanostructured samarium oxalate crystals were prepared via microwave assisted co-precipitation method. The crystal structure and morphology of the sample were analyzed using X-ray powder diffraction, Scanning electron microscopy and Transmission electron microscopy. The presence of functional groups is ascertained by Fourier transform infrared spectroscopy. Samarium oxalate nanocrystals of average size 20 nm were aggregated together to form nano-plate structure in sub-microrange. Detailed spectroscopic investigation of the prepared phosphor material was carried out by Judd-Ofelt analysis based on the UV-Visible-NIR absorption spectra and photoluminescence emission spectra. The analysis reveals that the transition from energy level (4)G5/2 to (6)H7/2 of Sm(3+) ion has maximum branching ratio and the corresponding orange emission can be used for display applications. PMID:24334063

Vimal, G; Mani, Kamal P; Biju, P R; Joseph, Cyriac; Unnikrishnan, N V; Ittyachen, M A

2014-03-25

417

Synthesis, structural and spectroscopic investigations of nanostructured samarium oxalate crystals  

NASA Astrophysics Data System (ADS)

Nanostructured samarium oxalate crystals were prepared via microwave assisted co-precipitation method. The crystal structure and morphology of the sample were analyzed using X-ray powder diffraction, Scanning electron microscopy and Transmission electron microscopy. The presence of functional groups is ascertained by Fourier transform infrared spectroscopy. Samarium oxalate nanocrystals of average size 20 nm were aggregated together to form nano-plate structure in sub-microrange. Detailed spectroscopic investigation of the prepared phosphor material was carried out by Judd-Ofelt analysis based on the UV-Visible-NIR absorption spectra and photoluminescence emission spectra. The analysis reveals that the transition from energy level 4G5/2 to 6H7/2 of Sm3+ ion has maximum branching ratio and the corresponding orange emission can be used for display applications.

Vimal, G.; Mani, Kamal P.; Biju, P. R.; Joseph, Cyriac; Unnikrishnan, N. V.; Ittyachen, M. A.

2014-03-01

418

Irradiation effects on canvas oil painting: Spectroscopic observations  

NASA Astrophysics Data System (ADS)

"Winter" oil painting, by Romanian contemporary artist George Alexandrescu was used as experimental model for the substantiation of gamma radiation treatment, as the best choice to stop the biological attack of paintings. In this purpose, spectroscopic and colorimetric methods were used to analyse in situ, non-destructively and non-contact, the experimental model before and after 60Co gamma irradiation. Chemical structure and colour changes were monitored by FTIR, FT-Raman and Vis reflectance spectroscopy. Negligible Infrared spectral transformations have been observed after irradiation. Furthermore, it was found that gamma irradiation did not induce any significant colour alterations. Insignificant structural and colour changes observed, recommend the use of gamma irradiation in the disinfection of oil paintings.

Manea, Mihaela Maria; Negut, C. D.; Stanculescu, Ioana Rodica; Ponta, C. C.

2012-10-01

419

On spectroscopic factors of magic and semimagic nuclei  

NASA Astrophysics Data System (ADS)

Single-particle spectroscopic factors (SF) of magic and semimagic nuclei are analyzed within the self-consistent theory of finite Fermi systems. The the in-volume energy dependence of the mass operator ? is taken into account in addition to the energy dependence induced by the surface-phonon coupling effects which is commonly considered. It appears due to the effect of high-lying collective and non-collective particle-hole excitations and persists in nuclear matter. The self-consistent basis of the energy density functional method by Fayans et al. is used. Both the surface and in-volume contributions to the SFs turned out to be of comparable magnitude. Results for magic 208Pb nucleus and semimagic lead isotopes are presented.

Saperstein, E. E.; Gnezdilov, N. V.; Tolokonnikov, S. V.

2014-10-01

420

Raman spectroscopic study of a genetically altered kidney cell  

NASA Astrophysics Data System (ADS)

A Raman spectroscopic investigation of a genetically altered Human Embryonic Kidney Cell (HEK293) along with a pathologically normal cell has been carried out by a conventional method. The genetic alteration was carried out with a standard protocol by using a Green Fluorescence Protein (GFP). Raman spectra show that there are dramatic differences between the spectrum obtained from a genetically altered cell and that obtained from a pathologically normal cell. The former shows three broad bands; meanwhile the latter shows several sharp peaks corresponding to the ring vibrational modes of Phen, GFP and DNA. The present analysis provides an indication that the force field near Phen located at 64, 65 and 66 was altered during the genetic transformation. The Raman spectrum could be a direct experimental evidence for substantial modifications triggered due to the expression of specific genes.

Joshi, Joel; Garcia, Francisco; Centeno, Silvia P.; Joshi, N. V.

2008-02-01

421

Fabrication and spectroscopic investigation of branched silver nanowires and nanomeshworks.  

PubMed

Wide wavelength ranges of light localization and scattering characteristics can be attributed to shape-dependent longitude surface plasmon resonance in complicated nanostructures. We have studied this phenomenon by spectroscopic measurement and a three-dimensional numerical simulation, for the first time, on the high-density branched silver nanowires and nanomeshworks at room temperature. These nanostructures were fabricated with simple light-induced colloidal method. In the range from the visible to the near-infrared wavelengths, light has been found effectively trapped in those trapping sites which were randomly distributed at the corners, the branches, and the junctions of the nanostructures in those nanostructures in three dimensions. The broadened bandwidth electromagnetic field enhancement property makes these branched nanostructures useful in optical processing and photovoltaic applications. PMID:23101991

Zhang, Xiao-Yang; Zhang, Tong; Zhu, Sheng-Qing; Wang, Long-De; Liu, Xuefeng; Wang, Qi-Long; Song, Yuan-Jun

2012-01-01

422

Spectroscopic investigation of a low-power arcjet plume  

NASA Technical Reports Server (NTRS)

We report the results of spectroscopic measurements on the exhaust plume from a 1 kW NASA Lewis arcjet operated on simulated ammonia. In particular, we analyze emissions from the Balmer lines of atomic hydrogen and from one of the rotational bands of the NH radical. We find that exit plane temperatures are in the range 2000 to 3500 K, depending on the measurement method, and that the electron density upstream of the exit plane is on the order of 1.5 x 10 exp 14/cu cm as determined by the Stark width of the Balmer-alpha line. Also, we have determined that the average velocity of atomic hydrogen at the exit plane is about 4 km/sec, and that strong acceleration (to 5.5 km/sec) of the flow occurs just beyond the exit plane.

Ruyten, W. M.; Burtner, D.; Keefer, D.

1993-01-01

423

Tutorial Counting and Tracking -Useful Examples from Digital Image Processing  

E-print Network

Tutorial Counting and Tracking - Useful Examples from Digital Image Processing Jonathan Kollmer, A3 Tutorial Surface Characterization Methods Christian Papp, Physical Chemistry II Tutorial t.b.a. t.b.a. THURSDAY, JUNE 28 FRIDAY, JUNE 29 SATURDAY, JUNE 30 30 00 12 -14 Lunch Tutorials for EAM Researchers 00 45

Sanderson, Yasmine

424

Searching for Complex Human Activities with No Visual Examples  

Microsoft Academic Search

We describe a method of representing human ac- tivities that allows a collection of motions to be queried without examples, using a simple and effective query lan- guage. Our approach is based on units of activity at seg- ments of the body, that can be composed across space and across the body to produce complex queries. The presence of search

David A. Forsyth

2008-01-01

425

Avoiding infinite estimates in logistic regression { theory, solutions, examples  

Microsoft Academic Search

In logistic regression analyses of small or sparse data sets, results obtained by maximum likelihood methods cannot be generally trusted. In such analyses, although the likelihood meets the convergence criterion, at least one parameter may diverge to plus or minus inflnity. This situation has been termed 'separation'. Examples of two studies are given, where the phe- nomenon of separation occurred:

Georg Heinze

2009-01-01

426

Conic Optimization Models for Robust Truss Topology Design with Examples  

E-print Network

Conic Optimization Models for Robust Truss Topology Design with Examples C. Roos #3; Y. Bai #3;y D a set of given loads. Several methods for solving the robust TTD problem are presented using Conic Optimization models. We include a brief introduction to the recent #12;eld of Conic Optimization. We present

Roos, Kees

427

Accessing remote sensing technology The microBRIAN example  

Microsoft Academic Search

Image processing technology for remote sensing has benefited substantially by the increase in the power of microcomputers over the past five years. This paper uses the development of the CSIRO (Commonwealth Scientific and Industrial Research Organization, Australia) microBRIAN system as an example of how access to image processing methods can contribute to greater acceptance of remote sensing technology for resource

B. A. HARRISON; D. L. B. JUPP; P. G. HUTTON; K. K. MAYO

1989-01-01

428

Training Models of Shape from Sets of Examples  

Microsoft Academic Search

A method for building flexible shape models is presented in which a shape is represented by a set of labelled points. The technique determines the statistics of the points over a collection of example shapes. The mean positions of the points give an average shape and a number of modes of variation are deter- mined describing the main ways in

D. H. Cooper; J. Graham

1992-01-01

429

Selection of Relevant Features and Examples in Machine Learning  

Microsoft Academic Search

In this survey, we review work in machine learning on methods for handling data sets containinglarge amounts of irrelevant information. We focus on two key issues: the problem of selectingrelevant features, and the problem of selecting relevant examples. We describe the advances thathave been made on these topics in both empirical and theoretical work in machine learning, andwe present a

Avrim L. Blum; Pat Langley

1997-01-01

430

1 Introduction 1 2 A Motivating Example 5  

E-print Network

17 30 1 #12; Contents 1 Introduction 1 2 A Motivating Example 5 3 Formal Definitions: Prioritized Research, Moffett