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1

Projector Method: theory and examples  

SciTech Connect

The Projector Method technique for numerically analyzing lattice gauge theories was developed to take advantage of certain simplifying features of gauge theory models. Starting from a very general notion of what the Projector Method is, the techniques are applied to several model problems. After these examples have traced the development of the actual algorithm from the general principles of the Projector Method, a direct comparison between the Projector and the Euclidean Monte Carlo is made, followed by a discussion of the application to Periodic Quantum Electrodynamics in two and three spatial dimensions. Some methods for improving the efficiency of the Projector in various circumstances are outlined. 10 refs., 7 figs. (LEW)

Dahl, E.D.

1985-01-01

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

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

4

New mass spectroscopic methods for waste management.  

National Technical Information Service (NTIS)

The Photophysics Group at Oak Ridge National Laboratory has developed two new optical mass spectroscopic methods which can provide important applications to waste management programs. The first method involves the invention of an isotopically selective ra...

C. H. Chen W. R. Garrett S. L. Allman R. C. Phillips

1992-01-01

5

An Introduction To Computer Simulation Methods Examples  

NSDL National Science Digital Library

Ready to run Launcher package containing examples for An Introduction to Computer Simulation Methods by Harvey Gould, Jan Tobochnik, and Wolfgang Christian. Source code for examples in this textbook is distributed in the Open Source Physics Eclipse Workspace.

Christian, Wolfgang; Gould, Harvey; Tobochnik, Jan

2008-05-17

6

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

7

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

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 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

9

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)

2009-01-01

10

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

11

Spectroscopic Chemical Analysis Methods and Apparatus  

NASA Technical Reports Server (NTRS)

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

Hug, William F.; Reid, Ray D.

2012-01-01

12

Event sorting methods of ?-ray spectroscopic data  

NASA Astrophysics Data System (ADS)

The paper presents several sorting methods of ?-ray events which were implemented in the data acquisition, processing and visualization system, developed at the Institute of Physics of the Slovak Academy of Sciences. The sorting methods using various shapes of gates (conditions) are presented, including rectangular windows, polygons, gates defined by arithmetic functions, spherical, ellipsoidal and composed gates. The examples illustrating the use of these methods are presented as well.

Morhá?, Miroslav; Matoušek, Vladislav

2011-03-01

13

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

14

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

1994-01-01

15

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

16

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

17

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.

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

2013-01-01

18

Spectroscopic Methods of Remote Sensing for Vegetation Characterization  

NASA Astrophysics Data System (ADS)

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

Kokaly, R. F.

2013-12-01

19

New background correction method for liquid chromatography with diode array detection, infrared spectroscopic detection and Raman spectroscopic detection  

Microsoft Academic Search

A new method to eliminate the background spectrum (EBS) during analyte elution in column liquid chromatography (LC) coupled to spectroscopic techniques is proposed. This method takes into account the shape and also intensity differences of the background eluent spectrum. This allows the EBS method to make a better estimation of the background eluent spectrum during analyte elution. This is an

Hans F. M. Boelens; Reyer J. Dijkstra; Paul H. C. Eilers; Fiona Fitzpatrick; Johan A. Westerhuis

2004-01-01

20

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

21

Ceramic microstructures and their elucidation by imaging, diffraction and spectroscopic methods  

SciTech Connect

The development and potential utilization of ceramic materials is dependent on a systematic effort involving processing, characterization and appropriate property measurements. The methods of characterization are numerous and it is important to employ the one that is appropriate to the problem both in terms of its information content and the achievable level of resolution. With the incorporation of fine probe forming capabilities in a transmission electron microscope and the development of related diffraction, imaging and spectroscopic methods, it is now possible to obtain structural and chemical information from the same region of the sample at high spatial resolution. In this review, recent advances along with representative examples in the application of high resolution electron microscopy (HREM), convergent beam electron diffraction (CBED), low atomic number element microanalysis by x-ray emission spectroscopy (XES), fine structures in electron energy-loss spectroscopy (EELS) and specific site occupancy determination by channeling experiments are discussed.

Kirshnan, K.M.

1992-02-01

22

Characterization of cell-penetrating lipopeptide micelles by spectroscopic methods.  

PubMed

The transport of bioactive compounds to the site of action is a great challenge. A promising approach to overcome application-related problems is the development of targeting colloidal transport systems, such as micelles which are equipped with uptake mediating moieties. Here, we investigated a set of novel lipopeptides which exhibit a surfactant-like structure due to attachment of two palmitoyl chains to the N-terminus of cationic or anionic amino acid sequences. We analyzed the association behavior of these lipopeptides by using 5(6)-carboxyfluorescein (CF)-labeled derivatives as a fluorescent probe and different spectroscopic methods such as fluorescence anisotropy and fluorescence correlation spectroscopy (FCS). The photophysical properties as well as the diffusion and rotational movements of the CF-labeled lipopeptides were exploited to determine the cmc and the size of the micelles consisting of lipopeptides. We could distinguish cationic and anionic lipopeptides by their association behavior and by studying the interactions with mouse brain capillary endothelial cells (b.end3). The cationic derivatives turned out to be very strong surfactants with a very low cmc in the micromolar range (0.5-14 ?M). The unique combination of micelle-forming property and cell-penetrating ability can pave the road for the development of a novel class of efficient drug carrier systems. PMID:24188016

Gehne, Sören; Sydow, Karl; Dathe, Margitta; Kumke, Michael U

2013-11-21

23

Using Crowdsourcing to Evaluate Published Scientific Literature: Methods and Example  

PubMed Central

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

Brown, Andrew W.; Allison, David B.

2014-01-01

24

Infrared Spectroscopic Methods for the Study of Lubricant Oxidation Products  

Microsoft Academic Search

Data processing techniques have been developed for the manipulation and enhancement of spectroscopic data. They have been applied to the infrared spectra of degraded base oils and lubricants to provide information on oxidation processes and additive depletion. Samples have been acquired from oils that have been subjected to laboratory scale oxidation and from lubricants during standard engine tests. Results are

John P. Coates; Lynn C. Setti

1986-01-01

25

Spectroscopic methods for the photodiagnosis of nonmelanoma skin cancer.  

PubMed

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. PMID:23264965

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

2013-06-01

26

Spectroscopic methods for the photodiagnosis of nonmelanoma skin cancer.  

PubMed

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. PMID:23748702

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

2013-01-01

27

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

28

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

Microsoft Academic Search

Multivariate calibration methods have been applied extensively to the quantitative analysis of Fourier transform infrared (FT-IR) spectral data. Partial least squares (PLS) methods have become the most widely used multivariate method for quantitative spectroscopic analyses. Most often these methods are limited by model error or the accuracy or precision of the reference methods. However, in some cases, the precision of

David M. Haaland; Howland D. T. Jones

1998-01-01

29

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

30

Configuration-constrained Hartree-Fock method -an illustrative example  

Microsoft Academic Search

The structure of solutions of the constrained Hartree-Fock method is studied within the time-dependent Hartree-Fock formalism. A new method for reaching various stationary Hartree-Fock points, not accessible by the usual adiabatic constrained Hartree-Fock method, is proposed.

K. Iwasawa; F. Sakata; W. Nazarewicz; T. Marumori; J. Terasaki

1994-01-01

31

Methods for trend analysis: Examples with problem/failure data  

NASA Technical Reports Server (NTRS)

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

Church, Curtis K.

1989-01-01

32

Configuration-constrained Hartree-Fock method. An illustrative example.  

National Technical Information Service (NTIS)

The structure of solutions of the constrained Hartree-Fock method is studied within the time-dependent Hartree-Fock formalism. A new method for reaching various stationary Hartree-Fock points, not accessible by the usual adiabatic constrained Hartree-Fock...

K. Iwasawa F. Sakata W. Nazarewicz T. Marumori J. Terasaki

1994-01-01

33

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

PubMed

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

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

2013-03-01

34

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

35

Computer Controlled Oral Test Administration: A Method and Example.  

ERIC Educational Resources Information Center

A computer/tape recorder interface was designed, which permits automatic oral adminstration of "true-false" or "multiple-choice" type tests. This paper describes the hardware and control program software, which were developed to implement the method on a DEC PDP 11 computer. (Author/JKS)

Milligan, W. Lloyd

1978-01-01

36

Classification in Multidimensional Parameter Space: Methods and Examples  

NASA Astrophysics Data System (ADS)

We put forward two classification algorithms, support vector machines (SVM) and learning vector quantization (LVQ), to study the distribution of various astronomical sources in the multidimensional parameter space. By positional cross-correlation, the multiwavelength data of 1656 active galactic nuclei (AGNs), 3718 stars, and 173 galaxies are obtained from optical (USNO-A2.0), X-ray (ROSAT), and infrared (Two Micron All-Sky Survey) bands. We have applied principal component analysis (PCA) to the sample, unveiling correlations between parameters and reducing the dimensionality of the input parameter space. Then, taking the preprocessed data of PCA as input, we apply SVM and LVQ to classify stars, AGNs, and normal galaxies and compare their performances. From the classified results, we conclude that PCA+LVQ and PCA+SVM are effective methods to classify sources with multiwavelength data; moreover, the two methods gave comparable results in a number of situations. Generally, PCA+SVM gave better results; however, PCA+LVQ was considerably faster in terms of computation time. What is more, the classifiers derived by these methods can be used to preselect candidates for large surveys, reducing time and energy wasted. Therefore, the efficiency of high-cost telescopes will be improved. In addition, these methods will be useful to develop the toolkits of the International Virtual Observatory.

Zhang, Yanxia; Zhao, Yongheng

2003-08-01

37

Spectroscopically Enhanced Method and System for Multi-Factor Biometric Authentication  

NASA Astrophysics Data System (ADS)

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

Pishva, Davar

38

Review of UV spectroscopic, chromatographic, and electrophoretic methods for the cholinesterase reactivating antidote pralidoxime (2-PAM).  

PubMed

Pralidoxime (2-PAM) belongs to the class of monopyridinium oximes with reactivating potency on cholinesterases inhibited by phosphylating organophosphorus compounds (OPC), for example, pesticides and nerve agents. 2-PAM represents an established antidote for the therapy of anticholinesterase poisoning since the late 1950s. Quite high therapeutic concentrations in human plasma (about 13?µg/ml) lead to concentrations in urine being about 100 times higher allowing the use of less sensitive analytical techniques that were used especially in the early years after 2-PAM was introduced. In this time (mid-1950s until the end of the 1970s) 2-PAM was most often analyzed by either paper chromatography or simple UV spectroscopic techniques omitting any sample separation step. These methods were displaced completely after the establishment of column liquid chromatography in the early 1980s. Since then, diverse techniques including cation exchange, size-exclusion, reversed-phase, and ligand-exchange chromatography have been introduced. Today, the most popular method for 2-PAM quantification is ion pair chromatography often combined with UV detection representing more than 50% of all column chromatographic procedures published. Furthermore, electrophoretic approaches by paper and capillary zone electrophoresis have been successfully used but are seldom applied. This review provides a commentary and exhaustive summary of analytical techniques applied to detect 2-PAM in pharmaceutical formulations and biological samples to characterize stability and pharmacokinetics as well as decomposition and biotransformation products. Separation techniques as well as diverse detectors are discussed in appropriate detail allowing comparison of individual preferences and limitations. In addition, novel data on mass spectrometric fragmentation of 2-PAM are provided. PMID:21953823

John, Harald; Blum, Marc-Michael

2012-01-01

39

Quantifying Prefibrillar Amyloids in vitro by Using a "Thioflavin-Like" Spectroscopic Method  

PubMed Central

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-?(A?). 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 A? 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 A?. 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.

Reinke, Ashley A.; Abulwerdi, Gelareh A.

2011-01-01

40

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

41

Origin of palladium black by an infrared spectroscopic method  

SciTech Connect

Metal blacks are used as catalysts in a number of organic synthesis processes. Using the method of matrix insulation of blacks obtained from organometallic compounds in the inert atmosphere the IR spectra have been recorded for carbon monoxide adsorbed on actual palladium blacks. The controllable mild conditions for reduction of the initial complex by hydrazine hydrate provide a means of separating the intermediate states of this process. By discontinuing at various stages the reduction of the organometallic complex being investigated the authors have obtained IR spectra of carbon monoxide characterizing the stages of forming the metallic palladium black.

Vozdvizhenskii, V.F.; Levintova, T.D.; Sokol'skii, D.V.

1987-03-01

42

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

43

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

44

Application of Spectroscopic Methods for Characterization of the Composition of Piassava  

Microsoft Academic Search

AbstractSpectroscopic methods—infrared absorption, atomic emission spectroscopy, and x-ray diffraction—were used for the characterization of the organic and inorganic composition and structure of piassava. The analysis of the infrared spectra revealed that pias-sava fibers consist mainly of cellulose, lignin, and hemicellulose, and that this chemical composition is similar to that of jute. The infrared spectra together with the x-ray diffraction of

Z. A. El-Sayed

1995-01-01

45

Real data examples in statistical methods papers: Tremendously valuable, and also tremendously misvalued  

PubMed Central

When a statistical methods paper is submitted to a journal for publication, examples in which the method is applied to real data are highly encouraged by many journals and in some cases are explicitly demanded. In this commentary, we argue that real data examples serve several useful purposes. However, we also argue that in many cases, particularly in the fields of genetics and genomics, there is an implicit or explicit expectation for examples to support purposes for which they are ill-suited and furthermore that these inappropriate expectations have negative consequences for the field. We conclude by noting that real data examples can be tremendously valuable and should continue to be used where appropriate, but that the demands for, expectations of, and conclusions drawn from them need to be scaled back.

Williams, K. Y.; Yoo, Yun Joo; Patki, Amit; Allison, David B.

2011-01-01

46

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.

Kumirska, Jolanta; Czerwicka, Malgorzata; Kaczynski, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thoming, Jorg; Stepnowski, Piotr

2010-01-01

47

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.

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

2010-01-01

48

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

NASA Astrophysics Data System (ADS)

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

Masychev, Victor I.

2000-11-01

49

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

50

Worked examples of alternative methods for the synthesis of qualitative and quantitative research in systematic reviews  

Microsoft Academic Search

BACKGROUND: The inclusion of qualitative studies in systematic reviews poses methodological challenges. This paper presents worked examples of two methods of data synthesis (textual narrative and thematic), used in relation to one review, with the aim of enabling researchers to consider the strength of different approaches. METHODS: A systematic review of lay perspectives of infant size and growth was conducted,

Patricia J Lucas; Janis Baird; Lisa Arai; Catherine Law; Helen M Roberts

2007-01-01

51

Multicore computing of the lattice Boltzmann method: A backward-facing step flow example  

Microsoft Academic Search

Recently, several methods were proposed to accelerate lattice Boltzmann computing. In this paper, we present a multicore scheme to accelerate a lattice Boltzmann model and the two-dimensional backward-facing step flow system is taken as an example to show the powerful capability of the multicore computing. The parallel algorithm has been implemented in Visual studio C++ 2005 augmented with calls to

Weibin Guo; Zhaoli Guo; Baochang Shi

2010-01-01

52

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

PubMed

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 241.5nm and 274.9nm for HPSAM and the wavelength was selected in ranges 232.0-254.0nm and 216.0-229.0nm 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 290.0nm, using ??=145.0nm. 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. PMID:24820323

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

2014-10-15

53

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

54

Quantitative infrared spectroscopic method for the study of the hydration of ions in aqueous solutions  

SciTech Connect

An infrared spectroscopic method for the study of the hydration of ions in aqueous solutions has been developed. OD stretching bands of isotopically dilute HDO molecules in the first hydration sphere of ions are obtained when the absorption from H/sub 2/O molecules and HDO molecules in the bulk water are removed by a double difference technique. The method is applied to aqueous solutions of Ni(ClO/sub 4/)/sub 2/, Ni(BF/sub 4/)/sub 2/, and Ni(PF/sub 6/)/sub 2/. Coordination numbers of 4.6 +/- 0.8 for the ClO/sub 4//sup -/ anion and 3.9 +/- 0.8 for the BF/sub 4//sup -/ anion are obtained. A systematic study of the influence of different salt and HDO concentrations has been undertaken. It is found that Lambert-Beer's law is valid in the concentration ranges studied.

Kristiansson, O.; Lindgren, J.; de Villepin, J.

1988-05-05

55

Novel carbazole-pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies  

PubMed Central

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

Irfan, Madiha; Samra, Shahid Ameen

2011-01-01

56

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

NASA Astrophysics Data System (ADS)

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

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

2007-07-01

57

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

DOEpatents

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

Kazmerski, Lawrence L. (Lakewood, CO)

1990-01-01

58

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

DOEpatents

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

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

1997-03-04

59

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

DOEpatents

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

Gourley, Paul L. (12508 Loyola, NE., Albuquerque, NM 87112) [12508 Loyola, NE., Albuquerque, NM 87112; Gourley, Mark F. (7509 Spring Lake Dr., Apt. B1, Bethesda, MD 20817) [7509 Spring Lake Dr., Apt. B1, Bethesda, MD 20817

1997-01-01

60

In vivo evaluation of the penetration of topically applied drugs into human skin by spectroscopic methods.  

PubMed

Spectroscopic techniques are reported on which allow to study in vivo the penetration behaviour of topically applied light-absorbing drugs into human skin. Remittance spectroscopy, a purely optical method, provides a good tool in both, skin adaptation by use of a remote viewing head coupled to the spectrometer via optical fibres, and adequate sensitivity for the detection of small amounts of the applied drugs. The measuring depth in the skin is determined by the wavelength-dependent optical penetration depth, which itself depends on light absorption and light scattering. In the UV-spectral region the optical penetration depth is of the order of the thickness of the stratum corneum (UV-A) or of only a superficial part of it (UV-B, UV-C). Fluorescence spectroscopy, another optical method, offers two kinds of drug detection, a direct one in case of self-fluorescent drugs or an indirect one being based on the light absorption of the drug, which may give rise to a screening of the self-fluorescence of the skin itself or of an applied marker. The measuring depth is comparable to that achieved with remittance spectroscopy. A third method is photothermal spectroscopy which is determined by thermal properties of the skin in addition to optical properties. Photothermal spectroscopy is unique in that it allows depth profiles of drug concentration to be measured non-invasively, as the photothermal measuring depth can be changed by varying the modulation frequency of the intensity-modulated incident light. Results of measurements demonstrating the potentials of these spectroscopic methods are presented. PMID:8352952

Sennhenn, B; Giese, K; Plamann, K; Harendt, N; Kölmel, K

1993-01-01

61

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

62

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

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

63

Growing string method with interpolation and optimization in internal coordinates: Method and examples  

NASA Astrophysics Data System (ADS)

The growing string method (GSM) has proven especially useful for locating chemical reaction paths at low computational cost. While many string methods use Cartesian coordinates, these methods can be substantially improved by changes in the coordinate system used for interpolation and optimization steps. The quality of the interpolation scheme is especially important because it determines how close the initial path is to the optimized reaction path, and this strongly affects the rate of convergence. In this article, a detailed description of the generation of internal coordinates (ICs) suitable for use in GSM as reactive tangents and in string optimization is given. Convergence of reaction paths is smooth because the IC tangent and orthogonal directions are better representations of chemical bonding compared to Cartesian coordinates. This is not only important quantitatively for reducing computational cost but also allows reaction paths to be described with smoothly varying chemically relevant coordinates. Benchmark computations with challenging reactions are compared to previous versions of GSM and show significant speedups. Finally, a climbing image scheme is included to improve the quality of the transition state approximation, ensuring high reliability of the method.

Zimmerman, Paul M.

2013-05-01

64

Growing string method with interpolation and optimization in internal coordinates: method and examples.  

PubMed

The growing string method (GSM) has proven especially useful for locating chemical reaction paths at low computational cost. While many string methods use Cartesian coordinates, these methods can be substantially improved by changes in the coordinate system used for interpolation and optimization steps. The quality of the interpolation scheme is especially important because it determines how close the initial path is to the optimized reaction path, and this strongly affects the rate of convergence. In this article, a detailed description of the generation of internal coordinates (ICs) suitable for use in GSM as reactive tangents and in string optimization is given. Convergence of reaction paths is smooth because the IC tangent and orthogonal directions are better representations of chemical bonding compared to Cartesian coordinates. This is not only important quantitatively for reducing computational cost but also allows reaction paths to be described with smoothly varying chemically relevant coordinates. Benchmark computations with challenging reactions are compared to previous versions of GSM and show significant speedups. Finally, a climbing image scheme is included to improve the quality of the transition state approximation, ensuring high reliability of the method. PMID:23676024

Zimmerman, Paul M

2013-05-14

65

Dual window method for processing spectroscopic optical coherence tomography signals with high spectral and spatial resolution  

NASA Astrophysics Data System (ADS)

The generation of spectroscopic optical coherence tomography (SOCT) signals suffers from an inherent trade off between spatial and spectral resolution. Here, we present a dual window (DW) method that uses two Gaussian windows to simultaneously obtain high spectral and spatial resolution. We show that the DW method probes the Winger time-frequency distribution (TFD) with two orthogonal windows set by the standard deviation of the Gaussian windows used for processing. We also show that in the limit of an infinitesimally narrow window, combined with a large window, this method is equivalent to the Kirkwood & Richaczek TFD and, if the real part is taken, it is equivalent to the Margenau & Hill (MH) TFD. We demonstrate the effectiveness of the method by simulating a signal with four components separated in depth or center frequency. Six TFD are compared: the ideal, the Wigner, the MH, narrow window short time Fourier transform (STFT), wide window STFT, and the DW. The results show that the DW method contains features of the Wigner TFD, and that it contains the highest spatial and spectral resolution that is free of artifacts. This method can enable powerful applications, including accurate acquisition of the spectral information for cancer diagnosis.

Robles, Francisco E.; Graf, Robert N.; Wax, Adam

2009-02-01

66

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

PubMed

An overview is provided of the present population analysis methods and an assessment of which software packages are most appropriate for various PK/PD modeling problems. Four PK/PD example problems were solved using the programs NONMEM VI beta version, PDx-MCPEM, S-ADAPT, MONOLIX, and WinBUGS, informally assessed for reasonable accuracy and stability in analyzing these problems. Also, for each program we describe their general interface, ease of use, and abilities. We conclude with discussing which algorithms and software are most suitable for which types of PK/PD problems. NONMEM FO method is accurate and fast with 2-compartment models, if intra-individual and interindividual variances are small. The NONMEM FOCE method is slower than FO, but gives accurate population values regardless of size of intra- and interindividual errors. However, if data are very sparse, the NONMEM FOCE method can lead to inaccurate values, while the Laplace method can provide more accurate results. The exact EM methods (performed using S-ADAPT, PDx-MCPEM, and MONOLIX) have greater stability in analyzing complex PK/PD models, and can provide accurate results with sparse or rich data. MCPEM methods perform more slowly than NONMEM FOCE for simple models, but perform more quickly and stably than NONMEM FOCE for complex models. WinBUGS provides accurate assessments of the population parameters, standard errors and 95% confidence intervals for all examples. Like the MCPEM methods, WinBUGS's efficiency increases relative to NONMEM when solving the complex PK/PD models. PMID:17408237

Bauer, Robert J; Guzy, Serge; Ng, Chee

2007-01-01

67

Apparatus for and method of performing spectroscopic analysis on an article  

DOEpatents

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

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

1999-04-20

68

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

69

Spectroscopic studies of copper ions doped in tellurate glasses obtained by sol - gel method  

NASA Astrophysics Data System (ADS)

The preparation of copper nitrate doped tellurate glasses by sol- gel method and spectroscopic studies of this tellurate system are reported. FTIR spectroscopy results show that this glass consists of [TeO6], [TeO4] and [TeO3] structural units and indicate that six- coordinated tellurium (VI) in [TeO6] units were partially changed to fourcoordinated tellurium (IV) in [TeO4] units during the doping with Cu(NO3)2. EPR spectra of the studied glasses were obtained due to the presence of Cu2+ paramagnetic ions and reveal the local order in matrix, the distribution and valence state of cooper ions. Thus, the EPR spectra show a partially resolved parallel hyperfine structure and no resolved perpendicular structure. The EPR spectra could be a superposition of two signals, one due to isolated Cu2+ ions in axial neighborhood, and the other due to the presence of magnetically coupled Cu2+ species.

Dehelean, A.; Rada, S.; Danciu, V.; Culea, E.; Stan, M.; Popa, A.; Raita, O.

2012-02-01

70

Magnetic and Mössbauer spectroscopic studies of NiZn ferrite nanoparticles synthesized by a combustion method  

NASA Astrophysics Data System (ADS)

The properties of nanocrystalline Ni0.5Zn0.5Fe2O4 synthesized by an auto-combustion method have been investigated by magnetic measurements and Mössbauer spectroscopy. The as-synthesized single phase nanosized ferrite powder is annealed at different temperatures in the range 673 1,273 K to obtain nanoparticles of different sizes. The powders are characterized by powder X-ray diffraction, vibrating sample magnetometer, transmission electron microscopy and Mössbauer spectroscopy. The as-synthesized powder with average particle size of ~9 nm is superparamagnetic. Magnetic transition temperature increases up to 665 K for the nanosized powder as compared to the transition temperature of 548 K for the bulk ferrite. This has been confirmed as due to the abnormal cation distribution, as evidenced from room temperature Mössbauer spectroscopic studies.

Sreeja, V.; Vijayanand, S.; Deka, S.; Joy, P. A.

2008-04-01

71

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

NASA Astrophysics Data System (ADS)

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

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

1999-04-01

72

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

NASA Astrophysics Data System (ADS)

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

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

1999-05-01

73

Gel electrophoretic methods for the analysis of biosimilar pharmaceuticals using the example of recombinant erythropoietin.  

PubMed

Due to their versatility and cost-effectiveness, gel electrophoretic methods provide an important set of tools for the analysis of therapeutic proteins. As an increasing number of biosimilar pharmaceuticals are entering the market, techniques are required that allow reliable demonstration of comparability of these products with the reference products. Isoelectric focusing, SDS-PAGE, native PAGE and 2D electrophoresis (2D-PAGE) have been frequently applied for this purpose. Supplementary techniques are fluorophore-assisted carbohydrate electrophoresis and sarcosyl-PAGE. Of additional importance is the comparison of recombinant with endogenously synthesized glycoproteins. Reagent array analysis combined with SDS-PAGE and western blotting proved especially useful for this purpose. As an example for the application of these methods, the analysis of recombinant originator erythropoietins and some of their biosimilar counterparts is described. PMID:23425274

Reichel, Christian; Thevis, Mario

2013-03-01

74

Silica gel modified with lumogallion for aluminum determination by spectroscopic methods.  

PubMed

Simple, easy to use and selective method of Al(III) sorption-spectroscopic (SS) determination was proposed. For this purpose, silica modified with tridecyloctadecylammonium chloride(SGII) using adsorption technique and glass slide modified with thin silica-poly(dimethyldiallyl-ammonium chloride) (SGI) composite film obtained by sol-gel technique were worked out. It was shown that lumogallion (LG) easily absorbs on SGI and SGII. Obtained sorbents SGIII and SGIV, respectively, were used for aluminum(III) determination by diffuse reflectance and spectrophotometric methods. The ranges of determination were (mg L(-1)): (0.08-0.54), s(r)< or =0.13, n=4 for SGIII and (0.05-2.0), s(r)< or =0.11, n=4 for SGIV. The detection limits (blank+3sigma) for aluminum were 70 and 30 microg L(-1) using SGIII and SGIV, respectively, where sigma is the standard deviation of blank estimation. The accuracy of the developed spectrophotometric method was examined by the determination of standard addition of aluminum in alcohol-free beverages. The relative error did not exceed 9%. SGIII can be regenerated by 0.05M EDTANa(2)H(2) solution and reused. SGIV was shown to be perspective for determination of aluminum in solution in the range of 0.01-0.13 mg L(-1) by solid phase luminescent technique. PMID:18970238

Nadzhafova, Oksana Yu; Zaporozhets, Olga A; Rachinska, Irina V; Fedorenko, Leonid L; Yusupov, Nikolai

2005-10-15

75

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

NASA Astrophysics Data System (ADS)

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

Cheng, Zhengjun; Liu, Rong; jiang, Xiaohui

2013-11-01

76

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

77

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

PubMed Central

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

Abad-Javier, Mario E.; Romero-Diaz, Alexis J.; Villasenor-Ortega, Francisco; Perez, Nestor O.; Flores-Ortiz, Luis F.

2014-01-01

78

Novel example-based method for super-resolution and denoising of medical images.  

PubMed

In this paper, we propose a novel example-based method for denoising and super-resolution of medical images. The objective is to estimate a high-resolution image from a single noisy low-resolution image, with the help of a given database of high and low-resolution image patch pairs. Denoising and super-resolution in this paper is performed on each image patch. For each given input low-resolution patch, its high-resolution version is estimated based on finding a nonnegative sparse linear representation of the input patch over the low-resolution patches from the database, where the coefficients of the representation strongly depend on the similarity between the input patch and the sample patches in the database. The problem of finding the nonnegative sparse linear representation is modeled as a nonnegative quadratic programming problem. The proposed method is especially useful for the case of noise-corrupted and low-resolution image. Experimental results show that the proposed method outperforms other state-of-the-art super-resolution methods while effectively removing noise. PMID:24808354

Dinh-Hoan Trinh; Luong, Marie; Dibos, Francoise; Rocchisani, Jean-Marie; Canh-Duong Pham; Nguyen, Truong Q

2014-04-01

79

Determination of Cephalexin Monohydrate in Pharmaceutical Dosage Form by Stability-Indicating RP-UFLC and UV Spectroscopic Methods  

PubMed Central

An ultra-fast liquid chromatographic method and two UV spectroscopic methods were developed for the determination of cephalexin monohydrate in pharmaceutical dosage forms. Isocratic separation was performed on an Enable C18G column (250 mm × 4.6 mm i.d., 5 ?m) using methanol:0.01 M TBAHS (50:50, v/v) as the mobile phase at a flow rate of 1.0 ml/min. The PDA detection wavelength was set at 254 nm. The UV spectroscopic method was performed at 261 nm and at 256–266 nm for the AUC method using a phosphate buffer (pH=5.5). The linearity was observed over a concentration range of 1.0–120 ?g/ml for UFLC and both of the UV spectroscopic methods (correlation coefficient=0.999). The developed methods were validated according to ICH guidelines. The relative standard deviation values for the intraday and interday precision studies were < 2%, and the accuracy was > 99% for all of the three methods. The developed methods were used successfully for the determination of cephalexin in dry syrup formulation.

Panda, Sagar Suman; Ravi Kumar, Bera V. V.; Dash, Rabisankar; Mohanta, Ganeswar

2013-01-01

80

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

81

Chromatographic and spectroscopic methods for the determination of solvent properties of room temperature ionic liquids.  

PubMed

Room temperature ionic liquids are novel solvents with favorable environmental and technical features. Synthetic routes to over 200 room temperature ionic liquids are known but for most ionic liquids physicochemical data are generally lacking or incomplete. Chromatographic and spectroscopic methods afford suitable tools for the study of solvation properties under conditions that approximate infinite dilution. Gas-liquid chromatography is suitable for the determination of gas-liquid partition coefficients and activity coefficients as well as thermodynamic constants derived from either of these parameters and their variation with temperature. The solvation parameter model can be used to define the contribution from individual intermolecular interactions to the gas-liquid partition coefficient. Application of chemometric procedures to a large database of system constants for ionic liquids indicates their unique solvent properties: low cohesion for ionic liquids with weakly associated ions compared with non-ionic liquids of similar polarity; greater hydrogen-bond basicity than typical polar non-ionic solvents; and a range of dipolarity/polarizability that encompasses the same range as occupied by the most polar non-ionic liquids. These properties can be crudely related to ion structures but further work is required to develop a comprehensive approach for the design of ionic liquids for specific applications. Data for liquid-liquid partition coefficients is scarce by comparison with gas-liquid partition coefficients. Preliminary studies indicate the possibility of using the solvation parameter model for interpretation of liquid-liquid partition coefficients determined by shake-flask procedures as well as the feasibility of using liquid-liquid chromatography for the convenient and rapid determination of liquid-liquid partition coefficients. Spectroscopic measurements of solvatochromic and fluorescent probe molecules in room temperature ionic liquids provide insights into solvent intermolecular interactions although interpretation of the different and generally uncorrelated "polarity" scales is sometimes ambiguous. All evidence points to the ionic liquids as a unique class of polar solvents suitable for technical development. In terms of designer solvents, however, further work is needed to fill the gaps in our knowledge of the relationship between ion structures and physicochemical properties. PMID:15214660

Poole, Colin F

2004-05-28

82

Mechanism and conformational studies of farrerol binding to bovine serum albumin by spectroscopic methods  

NASA Astrophysics Data System (ADS)

The mechanism and conformational changes of farrerol binding to bovine serum albumin (BSA) were studied by spectroscopic methods including fluorescence quenching technique, UV-vis absorption, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that farrerol could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The thermodynamic parameters enthalpy change and entropy change for the binding were calculated to be -29.92 kJ mol -1 and 5.06 J mol -1 K -1 according to the van't Hoff equation, which suggested that the both hydrophobic interactions and hydrogen bonds play major role in the binding of farrerol to BSA. The binding distance r deduced from the efficiency of energy transfer was 3.11 nm for farrerol-BSA system. The displacement experiments of site markers and the results of fluorescence anisotropy showed that warfarin and farrerol shared a common binding site I corresponding to the subdomain IIA of BSA. Furthermore, the studies of synchronous fluorescence, CD and FT-IR spectroscopy showed that the binding of farrerol to BSA induced conformational changes in BSA.

Zhang, Guowen; Wang, Lin; Fu, Peng; Hu, Mingming

2011-11-01

83

Toxic interaction between acid yellow 23 and trypsin: spectroscopic methods coupled with molecular docking.  

PubMed

Acid yellow 23 (AY23) is a pervasive azo dye used in many fields which is potentially harmful to the environment and human health. This paper studied the toxic effects of AY23 on trypsin by spectroscopic and molecular docking methods. The addition of AY23 effectively quenched the intrinsic fluorescence of trypsin via static quenching with association constants of K(290 K) = 3.67 × 10(5) L mol(-1) and K(310 K) = 1.83 × 10(5) L mol(-1). The calculated thermodynamic parameters conformed that AY23 binds to trypsin predominantly via electrostatic forces with one binding site. Conformational investigations indicated the skeletal structure of trypsin unfolded and the microenvironment of tryptophan changed with the addition of AY23. Molecular docking study showed that AY23 interacted with the His 57 and Lys 224 residue of trypsin and led to the inhibition of enzyme activity. This study offers a more comprehensive picture of AY23-trypsin interaction and indicates their interaction may perform toxic effects within the organism. PMID:22807329

Wang, Jing; Liu, Rutao; Qin, Pengfei

2012-09-01

84

Dual window method for processing spectroscopic optical coherence tomography signals with simultaneously high spectral and temporal resolution  

PubMed Central

Current methods for analysis of spectroscopic optical coherence tomography (SOCT) signals suffer from an inherent tradeoff between time (depth) and frequency (wavelength) resolution. Here, we present a dual window (DW) method for reconstructing time frequency distributions (TFDs) that applies two orthogonal Gaussian windows that independently determine the spectral and temporal resolution. The effectiveness of the method is demonstrated in simulations and in processing of measured OCT signals that contain fields which vary in time and frequency. The DW method yields TFDs that maintain high spectral and temporal resolution and are free from the artifacts and limitations commonly observed with other processing methods.

Robles, Francisco; Graf, Robert N.; Wax, Adam

2010-01-01

85

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

National Technical Information Service (NTIS)

The US Department of Energy's former uranium production facility located at Fernald, OH (18 mi NW of Cincinnati) is the host site for an Integrated Demonstration for remediation of uranium-contaminated soils. A wide variety of source terms for uranium con...

P. G. Allen, J. M. Berg, C. J. Chisholm-Brause, S. D. Conradson, R. J. Donohoe

1994-01-01

86

Spectroscopic bulge-disc decomposition: a new method to study the evolution of lenticular galaxies  

NASA Astrophysics Data System (ADS)

A new method for spectroscopic bulge-disc decomposition is presented, in which the spatial light profile in a two-dimensional spectrum is decomposed wavelength by wavelength into bulge and disc components, allowing separate one-dimensional spectra for each component to be constructed. This method has been applied to observations of a sample of nine lenticular galaxies (S0s) in the Fornax Cluster in order to obtain clean high-quality spectra of their individual bulge and disc components. So far this decomposition has only been fully successful when applied to galaxies with clean light profiles, without contamination from dust lanes, etc. This has consequently limited the number of galaxies that could be separated into bulge and disc components. The Lick index stellar population analysis of the component spectra reveals that in those galaxies where the bulge and disc could be distinguished, the bulges have systematically higher metallicities and younger stellar populations than the discs. This correlation is consistent with a picture in which S0 formation comprises the shutting down of star formation in the disc accompanied by a final burst of star formation in the bulge. Similarly, a trend was found to exist whereby galaxies with younger stellar populations have higher metallicities. The variation in spatial-fit parameters with wavelength also allows us to measure approximate colour gradients in the individual components. Such gradients were detected separately in both bulges and discs, in the sense that redder light is systematically more centrally concentrated in all components. However, a search for radial variations in the absorption line strengths determined for the individual components revealed that, although they can be sensitively detected where present, they are absent from the vast majority of S0 discs and bulges. The absence of gradients in line indices for most galaxies implies that the colour gradient cannot be attributed to age or metallicity variations and is therefore most likely associated with varying degrees of obscuration by dust.

Johnston, E. J.; Aragón-Salamanca, A.; Merrifield, M. R.; Bedregal, A. G.

2012-05-01

87

The Use of Matrix Methods in the Modeling of Spectroscopic Data Sets  

PubMed Central

We describe a general approach to the model-based analysis of sets of spectroscopic data that is built upon the techniques of matrix analysis. A model hypothesis may often be expressed by writing a matrix of measured spectra as the product of a matrix of spectra of individual molecular species and a matrix of corresponding species populations as a function of experimental conditions. The modeling procedure then requires the simultaneous determination of a set of species spectra and a set of model parameters (from which the populations are derived), such that this product yields an optimal description of the measured spectra. This procedure may be implemented as an optimization problem in the space of the (possibly nonlinear) model parameters alone, coupled with the efficient solution of a corollary linear optimization problem using matrix decomposition methods to obtain a set of species spectra corresponding to any set of model parameters. Known species spectra, as well as other information and assumptions about spectral shapes, may be incorporated into this general framework, using parametrized analytical functional forms and basis-set techniques. The method by which assumed relationships between global features (e.g., peak positions) of different species spectra may be enforced in the modeling without otherwise specifying the shapes of the spectra will be shown. We also consider the effect of measurement errors on this approach and suggest extensions of the matrix-based least-squares procedures applicable to situations in which measurement errors may not be assumed to be normally distributed. A generalized analysis procedure is introduced for cases in which the species spectra vary with experimental conditions.

Henry, Eric R.

1997-01-01

88

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

89

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.

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

2003-01-01

90

Characterization of Mannitol Polymorphic Forms in Lyophilized Protein Formulations Using a Multivariate Curve Resolution (MCR)Based Raman Spectroscopic Method  

Microsoft Academic Search

Purpose  To develop a novel multivariate curve resolution (MCR)-based Raman spectroscopic method to characterize and quantify five\\u000a known mannitol solid-state forms in lyophilized protein formulations.\\u000a \\u000a \\u000a \\u000a Materials and Methods  The multivariate quantitation method was developed based on second derivative Raman spectra of three anhydrous crystalline\\u000a forms (?-, ?-, and ?-mannitol), a hemihydrate and an amorphous mannitol form. The method showed a 5% quantitation

Yong Xie; Wenjin Cao; Sampathkumar Krishnan; Hong Lin; Nina Cauchon

2008-01-01

91

Structural studies of oxalohydroxamic acid by single crystal X-ray diffraction and spectroscopic methods  

Microsoft Academic Search

The structure of oxalohydroxamic acid has been investigated by X-ray and spectroscopic analyses. It has been shown that oxalohydroxamic acid exists in the oxamic form in the solid as well as in solution. The variable-temperature nuclear magnetic resonance (NMR) studies reveal an exchange of OH and NH protons, the exchange being faster at higher temperatures. The kinetic and the thermodynamic

A. Sameena Begum; V. K. Jain; C. L. Khetrapal; N. C. Shivaprakash

1987-01-01

92

Gradualism: A Method for Primary Instruction on Spectroscopic Analysis in Introductory Organic Chemistry  

Microsoft Academic Search

The pedagogical style of gradualism is described for the instruction of spectroscopic analysis in the introductory organic chemistry laboratory. Gradualism is defined as a series of steps or lessons that build one upon the other until the student is able to solve complex problems. Each step is briefly described as part of a pre-laboratory study assignment with follow-up application by

Christopher W. Alexander; Gary L. Asleson; Charles F. Beam; Marion T. Doig; Frederick J. Heldrich; Shannon Studer-Martinez

1999-01-01

93

Polychloroprene Structure Study. Ii. A Quantitative Infrared Spectroscopic Method for Polychloroprene Microstructure Investigation.  

National Technical Information Service (NTIS)

A quantitative ir spectroscopic determination was developed using low-mol.-wt. compds. (cis-4-chloro-4-octene, cis-5-chloro-5 decene, trans-4-chloro-4-octene, and 2-chloro-1-hexens) as model polychloroprene (I) units representing various modes of monomer ...

E. O. Azhandzhyan L. G. Melkonyan

1968-01-01

94

Rapid and Inexpensive Method for the Spectroscopic Determination of Innate Immune Activity of Crocodilians  

Microsoft Academic Search

We have employed a spectroscopic assay based on the hemolysis of sheep red blood cells (SRBCs) to assess the immune system of the American alligator (Alligator mississippiensis). The assay is based on the hemolytic disruption of the SRBCs by the immunological proteins in the crocodilian serum. Incubation of 1% SRBCs (vIv) with alligator serum resulted in hemolysis that was measured

Mark Merchant; Tony Hammack; Paige Sanders; Jessica Dronette

2006-01-01

95

An Effective-Substrate Method to Investigate AN Iron Native Oxide Layer on AN Iron Substrate by Spectroscopic Ellipsometry  

NASA Astrophysics Data System (ADS)

An effective-substrate method was presented to obtain the optical constants of an iron native oxide layer with unknown optical constants and film thickness on an iron substrate with unknown optical constants by using spectroscopic ellipsometry (SE). "Thick" iron films were deposited on silicon wafer by magnetron sputtering and were exposed to air at room temperature. They were measured by spectroscopic ellipsometry during this procedure at different time points from ten minutes to seven months. Pseudo optical constants were calculated from the initially measured data and were introduced into the modeling work of subsequent measurements as an effective substrate in order to obtain the optical constants and film thickness of the native oxide layer. After obtaining the optical constants of the subsequent native oxide layer, they were employed in the modeling work of the initially measured data and the optical constants of the iron substrate and the film thickness of the initial native oxide layer was obtained.

Gao, Shang; Lian, Jie; Sun, Zhaozong; Wang, Xiao; Li, Ping; Li, Qinghao

2013-03-01

96

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

NASA Astrophysics Data System (ADS)

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

Masychev, Victor I.

2001-05-01

97

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

98

Electronic structure and molecular spectroscopic constants of ScN and ScP investigated by several quantum chemistry methods  

NASA Astrophysics Data System (ADS)

The electronic structure of the ScN and ScP molecules is a subject of controversy and turns out to be a challenging problem in quantum chemistry. We show that the ground-state electronic structure for both molecules depends critically on the choice of methods used which incorporate different ways of accounting for electron correlation. A parallel ab initio, DFT and TD-DFT study is performed for this purpose and uses sufficiently flexible basis sets able to reproduce accurate electronic structures, as well as correct spectroscopic constants. In the ab initio methodology, results have been obtained with methods such as Hartree-Fock (HF), Møller-Plesset perturbation theory (MPn), direct configuration interaction (CI), quadratic configuration interaction (QC), coupled cluster configuration interaction (CC), complete active space self-consistent field (CASSCF) and multireference configuration interaction (CIPSI) methods. In the DFT methodology, various 'pure' and 'hybrid' density functionals are used and the corresponding results are compared to sophisticated ab initio methods and to available experimental data. All the methods used show that the ground state of both molecules is 1?+, but two electronic structure natures, 1?+ open-shell or 1?+ closed-shell, are competitive and depend on the method employed. All the ab initio methods based on a single determinant wavefunction suffer seriously in predicting clearly the exact nature of the ground state or its correct structural and spectroscopic parameters. However, the ab initio methods based on a multiconfigurational wavefunction appear to be successful in describing correctly, within one shot, the electronic structure and the molecular spectroscopic constants. The ground state, particularly for the ScN molecule, presents an unusual electronic structure: the presence of degenerate determinants, quasidegeneracy with other states and one avoided crossing in the region around the equilibrium distances. The bonding of the ground state is a two open-shell 1?+ state described as a ? double bond and a ? dative bond; the real triple bond 1?+ state, i.e. closed-shell state, is found to lie higher in energy. The potential energy curves of the low-lying electronic states, the derived electronic structures and various molecular spectroscopic constants are presented and discussed for each method employed.

Daoudi, Abdelali; Filali Baba, Mohamed; Elkhattabi, Souad; Rogemond, François; Chermette, Henry

99

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

USGS Publications Warehouse

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

Williams, G. P.

1984-01-01

100

Investigations on the Interaction between Cuprous Oxide Nanocubes and Bovine Serum Albumin with Comprehensive Spectroscopic Methods  

Microsoft Academic Search

The interaction between cuprous oxide (Cu2O) nanocubes and bovine serum albumin (BSA) was investigated from a spectroscopic angle under simulative physiological conditions.\\u000a Under pH 7.4, Cu2O could effectively quench the intrinsic fluorescence of BSA via static quenching. The apparent binding constant (K\\u000a A) was 3.23, 1.91, and 1.20?×?104 M-1 at 298, 304, and 310 K, respectively, and the number of binding sites

Peng Ju; Hai Fan; Tao Liu; Lin Cui; Shiyun Ai; Xiaona Wu

101

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

102

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

103

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

104

Pharmacovigilance methods in public health programmes: the example of miltefosine and visceral leishmaniasis.  

PubMed

Pharmacovigilance is concerned with the assessment of benefit and harm. Disease burden, status of healthcare delivery through government centres and practitioners, existing pharmacovigilance programmes, relevant pre-marketing studies and the likely effectiveness and risks of drugs must be considered for planning pharmacovigilance activity. The risk of a drug may be known, unknown, potential or specific to the context of the programme. The potential benefits of a public health programme aimed at reducing or eliminating a specific condition will depend on the health burden due to that condition, which is a function of the seriousness of the condition and its frequency, as well as the likely efficacy of the programme in reaching its goals. The present article has outlined an approach to pharmacovigilance for such a donor-funded programme, using pharmacovigilance in leishmaniasis as an example. PMID:21185045

Kshirsagar, Nilima; Ferner, Robin; Figueroa, Byron Alfredo Arana; Ghalib, Hashim; Lazdin, Janis

2011-02-01

105

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

106

Method for data analysis in different institutions: example of image guidance of prostate cancer patients.  

PubMed

Multi-institutional collaborations allow for more information to be analyzed but the data from different sources may vary in the subgroup sizes and/or conditions of measuring. Rigorous statistical analysis is required for pooling the data in a larger set. Careful comparison of all the components of the data acquisition is indispensable: identical conditions allow for enlargement of the database with improved statistical analysis, clearly defined differences provide opportunity for establishing a better practice. The optimal sequence of required normality, asymptotic normality, and independence tests is proposed. An example of analysis of six subgroups of position corrections in three directions obtained during image guidance procedures for 216 prostate cancer patients from two institutions is presented. PMID:23721940

Piotrowski, T; Rodrigues, G; Bajon, T; Yartsev, S

2014-03-01

107

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

108

Including mixed methods research in systematic reviews: Examples from qualitative syntheses in TB and malaria control  

PubMed Central

Background Health policy makers now have access to a greater number and variety of systematic reviews to inform different stages in the policy making process, including reviews of qualitative research. The inclusion of mixed methods studies in systematic reviews is increasing, but these studies pose particular challenges to methods of review. This article examines the quality of the reporting of mixed methods and qualitative-only studies. Methods We used two completed systematic reviews to generate a sample of qualitative studies and mixed method studies in order to make an assessment of how the quality of reporting and rigor of qualitative-only studies compares with that of mixed-methods studies. Results Overall, the reporting of qualitative studies in our sample was consistently better when compared with the reporting of mixed methods studies. We found that mixed methods studies are less likely to provide a description of the research conduct or qualitative data analysis procedures and less likely to be judged credible or provide rich data and thick description compared with standalone qualitative studies. Our time-related analysis shows that for both types of study, papers published since 2003 are more likely to report on the study context, describe analysis procedures, and be judged credible and provide rich data. However, the reporting of other aspects of research conduct (i.e. descriptions of the research question, the sampling strategy, and data collection methods) in mixed methods studies does not appear to have improved over time. Conclusions Mixed methods research makes an important contribution to health research in general, and could make a more substantial contribution to systematic reviews. Through our careful analysis of the quality of reporting of mixed methods and qualitative-only research, we have identified areas that deserve more attention in the conduct and reporting of mixed methods research.

2012-01-01

109

Different methods of evaluating sharp-peaked compounds in FTIR spectra using benzene as an example  

NASA Astrophysics Data System (ADS)

The quantification of benzene in FTIR spectra is restricted by the interference of benzene with carbon dioxide. In this paper different methods are presented to overcome these problems with a detector of medium resolution of 0.5 cm-1. The experiments were performed either in a 10 m gas cell or as open path experiments. One method compares the peak at 673.76 cm-1 with the strongest absorption band of benzene in the single beam spectrum to the neighboring peaks, one method analyzes the shape of the peak at 674 cm-1. Another method works with an artificial background and the latest methods analyze the absorbance spectrum and serve as a reference. The results from all these methods agreed very well down to the level of 30 to 50 ppb.

Lechner, Bernhard; Sturm, Peter J.

1998-12-01

110

Raman Spectroscopic Methods for Classification of Normal and Malignant Hypopharyngeal Tissues: An Exploratory Study  

PubMed Central

Laryngeal cancer is more common in males. The present study is aimed at exploration of potential of conventional Raman spectroscopy in classifying normal from a malignant laryngopharyngeal tissue. We have recorded Raman spectra of twenty tissues (aryepiglottic fold) using an in-house built Raman setup. The spectral features of mean malignant spectrum suggests abundance proteins whereas spectral features of mean normal spectrum indicate redundancy of lipids. PCA was employed as discriminating algorithm. Both, unsupervised and supervised modes of analysis as well as match/mismatch “limit test” methodology yielded clear classification among tissue types. The findings of this study demonstrate the efficacy of conventional Raman spectroscopy in classification of normal and malignant laryngopharyngeal tissues. A rigorous evaluation of the models with development of suitable fibreoptic probe may enable real-time Raman spectroscopic diagnosis of laryngopharyngeal cancers in future.

Pujary, Parul; Maheedhar, K.; Krishna, C. Murali; Pujary, Kailesh

2011-01-01

111

A Parallel Spectroscopic Method for Examining Dynamic Phenomena on the Millisecond Time Scale  

PubMed Central

An infrared spectroscopic technique based on planar array infrared (PAIR) spectroscopy has been developed that allows the acquisition of spectra from multiple samples simultaneously. Using this technique, it is possible to acquire spectra over a spectral range of 950–1900cm?1 with a temporal resolution of 2.2ms. The performance of this system was demonstrated by determining the shear-induced orientational response of several low molecular weight liquid crystals. Five different liquid crystals were examined in combination with five different alignment layers, and both primary and secondary screens were demonstrated. Implementation of this high throughput PAIR technique resulted in a reduction in acquisition time as compared to both step-scan and ultra-rapid-scanning FTIR spectroscopy.

Snively, Christopher M.; Chase, D. Bruce; Rabolt, John F.

2009-01-01

112

Integral Field Spectroscopic Data Reduction Method for High Resolution Infrared Observation  

NASA Astrophysics Data System (ADS)

We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ?m H2 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

Lee, Sungho; Pak, Soojong; Choi, Minho

2010-12-01

113

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

114

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.

2013-01-01

115

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

ERIC Educational Resources Information Center

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

Schonfeld, Irvin Sam; Farrell, Edwin

2010-01-01

116

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

PubMed

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. PMID:22086367

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

2012-09-01

117

Spectroscopic Studies of Semiconductor Structures in Magnetic Fields  

NASA Astrophysics Data System (ADS)

The aptitude of magneto-spectroscopic methods for studying the electronic and spin properties of semiconductor structures is demonstrated with a few examples of our recent work on two-dimensional electron gases and semiconductor quantum dots, on bulk GaAs and GaN, as well as on thin graphitic layers.

Potemski, Marek

118

Composite analysis with Monte Carlo methods: an example with cosmic rays and clouds  

NASA Astrophysics Data System (ADS)

The composite (superposed epoch) analysis technique has been frequently employed to examine a hypothesized link between solar activity and the Earth's atmosphere, often through an investigation of Forbush decrease (Fd) events (sudden high-magnitude decreases in the flux cosmic rays impinging on the upper-atmosphere lasting up to several days). This technique is useful for isolating low-amplitude signals within data where background variability would otherwise obscure detection. The application of composite analyses to investigate the possible impacts of Fd events involves a statistical examination of time-dependent atmospheric responses to Fds often from aerosol and/or cloud datasets. Despite the publication of numerous results within this field, clear conclusions have yet to be drawn and much ambiguity and disagreement still remain. In this paper, we argue that the conflicting findings of composite studies within this field relate to methodological differences in the manner in which the composites have been constructed and analyzed. Working from an example, we show how a composite may be objectively constructed to maximize signal detection, robustly identify statistical significance, and quantify the lower-limit uncertainty related to hypothesis testing. Additionally, we also demonstrate how a seemingly significant false positive may be obtained from non-significant data by minor alterations to methodological approaches.

Laken, B. A.; ?alogovi?, J.

2013-09-01

119

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

120

Models of near-field spectroscopic studies: comparison between Finite-Element and Finite-Difference methods  

NASA Astrophysics Data System (ADS)

We compare the numerical results obtained by the Finite Element Method (FEM) and the Finite Difference Time Domain Method (FDTD) for near-field spectroscopic studies and intensity map computations. We evaluate their respective efficiencies and we show that an accurate description of the dispersion and of the geometry of the material must be included for a realistic modeling. In particular for the nano-objects, we show that a grid size around ??a ? 4?a/? (expressed in ? units) as well as a Drude-Lorentz' model of dispersion for FDTD should be used in order to describe more accurately the confinement of the light around the nanostructures (i.e. the high gradients of the electromagnetic field) and to assure the convergence to the physical solution.

Grosges, Thomas; Vial, Alexandre; Barchiesi, Dominique

2005-10-01

121

Substrate influence in Young's modulus determination of thin films by indentation methods: Cubic boron nitride as an example  

Microsoft Academic Search

This paper deals with the determination of Young's modulus of thin films by indentation methods using cubic boron nitride (c-BN) as an example. This is a non-trivial task because the Young's modulus of this material comes close to that of the diamond indenter. An analysis of results from literature revealed that Young's moduli of c-BN thin films are generally distinctly

F. Richter; M. Herrmann; F. Molnar; T. Chudoba; N. Schwarzer; M. Keunecke; K. Bewilogua; X. W. Zhang; H.-G. Boyen; P. Ziemann

2006-01-01

122

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

123

A practical implicit finite-difference method: examples from seismic modelling  

NASA Astrophysics Data System (ADS)

We derive explicit and new implicit finite-difference formulae for derivatives of arbitrary order with any order of accuracy by the plane wave theory where the finite-difference coefficients are obtained from the Taylor series expansion. The implicit finite-difference formulae are derived from fractional expansion of derivatives which form tridiagonal matrix equations. Our results demonstrate that the accuracy of a (2N + 2)th-order implicit formula is nearly equivalent to that of a (6N + 2)th-order explicit formula for the first-order derivative, and (2N + 2)th-order implicit formula is nearly equivalent to (4N + 2)th-order explicit formula for the second-order derivative. In general, an implicit method is computationally more expensive than an explicit method, due to the requirement of solving large matrix equations. However, the new implicit method only involves solving tridiagonal matrix equations, which is fairly inexpensive. Furthermore, taking advantage of the fact that many repeated calculations of derivatives are performed by the same difference formula, several parts can be precomputed resulting in a fast algorithm. We further demonstrate that a (2N + 2)th-order implicit formulation requires nearly the same memory and computation as a (2N + 4)th-order explicit formulation but attains the accuracy achieved by a (6N + 2)th-order explicit formulation for the first-order derivative and that of a (4N + 2)th-order explicit method for the second-order derivative when additional cost of visiting arrays is not considered. This means that a high-order explicit method may be replaced by an implicit method of the same order resulting in a much improved performance. Our analysis of efficiency and numerical modelling results for acoustic and elastic wave propagation validates the effectiveness and practicality of the implicit finite-difference method.

Liu, Yang; Sen, Mrinal K.

2009-09-01

124

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

125

Methods for data assimilation in chaotic systems - examples from simple geophysical models  

NASA Astrophysics Data System (ADS)

Data assimilation has wide ranging applications, including neuroscience, oceanography and climate science. In this dissertation we will examine data assimilation as a tool for systems of partial differential equations on a discretized spacial grid, using simple geophysical models as a twin for our study. We will use the 1 layer shallow water equations (SWE), and describe how to extend the method to a 2 layer SWE. Although we only used the SWE for this dissertation, we examine how we would use the barotropic vorticity equations (BVE) as the twin in the same study. We will examine two different methods for performing data assimilation on chaotic systems. The first method relies on the measurements to smooth the synchronization manifold, allowing a nonlinear optimizer to correctly determine the most likely path, or the path which minimizes the cost function. The second method we call Metropolis-Hastings Monte Carlo (MHMC) integration scheme. MHMC also allows retention of a group of path samples whose statistics reflect the probability of each path, allowing histograms of state vector values for analysis or inputs to particle filter methods for prediction. The study uses MHMC with the SWE as twin. in this chapter we will examine a data set used for the study. We then describe he various numbers of state vectors needed as data, and the increase in the quality of the fit. We determine the number of state vectors needed as measurements to accurately predict the unmeasured ones.

Whartenby, William G.

126

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

PubMed

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

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

2010-02-01

127

Methods for assessing gene content diversity of KIR with examples from a global set of populations  

PubMed Central

A number of statistical methods are widely used to describe allelic variation at specific genetic loci and its implication on the evolutionary history of these loci. Although the methods were developed primarily to study allelic variation at loci that are virtually always present in the genome, they are often applied to data of gene content variation (i.e. presence/absence of multiple homologous genes) at the killer immunoglobulin-like receptor (KIR) gene cluster. In this paper we discuss methodological issues involved in the analysis of gene content variation data in the KIR region, and also its covariation with polymorphism at the HLA class I loci, which encode ligands for KIR. A comparison of several statistical methods and measures (gene frequency, haplotype frequency, and linkage disequilibrium estimation) using CEPH data will be provided using KIR haplotypes that have been determined by segregation analysis, noting the strengths and weaknesses of the methods when only the presence/absence data is considered. Finally, application of these methods to a set of globally distributed populations is described (see Single et al. 2007) in order to illustrate the challenges faced when inferring the joint effects of natural selection and demographic history on these immune related genes.

Single, Richard M.; Martin, Maureen P.; Meyer, Diogo; Gao, Xiaojiang; Carrington, Mary

2009-01-01

128

Methods of Fitting a Straight Line to Data: Examples in Water Resources  

USGS Publications Warehouse

Three methods of fitting straight lines to data are described and their purposes are discussed and contrasted in terms of their applicability in various water resources contexts. The three methods are ordinary least squares (OLS), least normal squares (LNS), and the line of organic correlation (OC). In all three methods the parameters are based on moment statistics of the data. When estimation of an individual value is the objective, OLS is the most appropriate. When estimation of many values is the objective and one wants the set of estimates to have the appropriate variance, then OC is most appropriate. When one wishes to describe the relationship between two variables and measurement error is unimportant, then OC is most appropriate. Where the error is important in descriptive problems or in calibration problems, then structural analysis techniques may be most appropriate. Finally, if the problem is one of describing some geographic trajectory, then LNS is most appropriate.

Hirsch, Robert, M.; Gilroy, Edward, J.

1984-01-01

129

Some illustrative examples of the use of a spectral-element method in ocean acoustics.  

PubMed

Some numerical results in the time domain obtained with the spectral-element method are presented in order to illustrate the high potential of this technique for modeling the propagation of acoustic waves in the ocean in complex configurations. A validation for a simple configuration with a known solution is shown, followed by some simulations of the propagation of acoustic waves over different types of ocean bottoms (fluid, elastic, and porous) to emphasize the wide variety of media that can be considered within the framework of this method. Finally, a movie illustrating upslope propagation over a viscoelastic wedge is presented and discussed. PMID:22423813

Cristini, Paul; Komatitsch, Dimitri

2012-03-01

130

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

Code of Federal Regulations, 2010 CFR

...capitalization method . (i) MicroDent, Inc. (MDI) is a publicly traded company that developed...surgical procedures. On January 1 of Year 1, MDI entered into a CSA with a wholly-owned...associated with ScopeX-1, as well as MDI's research capabilities are...

2009-04-01

131

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

Code of Federal Regulations, 2010 CFR

...capitalization method . (i) MicroDent, Inc. (MDI) is a publicly traded company that developed...surgical procedures. On January 1 of Year 1, MDI entered into a CSA with a wholly-owned...associated with ScopeX-1, as well as MDI's research capabilities are...

2010-04-01

132

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

ERIC Educational Resources Information Center

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

Schulz, E. Matthew

2006-01-01

133

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

134

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

135

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

136

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

137

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

138

High-Quality Cross-Sectioning Method: Examples of Applications in Optimizing Solar Cell Contact Firing  

SciTech Connect

A damage-free polishing method is developed to prepare a high-quality cross-section of a large length of a solar cell. A 1-inch-long sample is diced from the solar cell and embedded in wax using a specially designed chuck. The sample edge is sequentially polished by progressively reducing the grit sizes. The final polishing is done by Chemical Mechanical Polishing (CMP). This polishing procedure produces a highly flat edge, with excellent interfaces between metal contacts and the Si cell. The planarity of the wafer edge makes it possible to perform a variety of analyses of various regions and the interfaces of the cell, using optical microscopy, EDX, scanning electron microscopy (SEM), and conductive AFM (C-AFM). Here, we will discuss some details of the chuck and the polishing procedure, and present some applications for optimizing the contact firing process. This method has an added advantage of delineating the back surface field for optical observation.

Sopori, B.; Sahoo, S.; Mehta, V.; Guhabiswas, D.; Spiller, S.; Moutinho, H.

2011-01-01

139

Hermeneutic interviewing: an example of its development and use as research method.  

PubMed

In a study exploring the practice knowledge of nursing on adolescent mental health units, I chose hermeneutic philosophy to guide the conduct of the research. Immediately, I encountered the problem that hermeneutics is essentially unconcerned with its use as research method. The need for congruence between the study's hermeneutic foundations and the methodological processes of the research, led me to develop a style of hermeneutic interviewing for the purpose of information gathering. I did this using Gadamer's (1979) fundamental principles of: (1) tradition, (2) dialectics of interpretation, and (3) dialectic of question and answer. These principles are examined and discussed. The actualization of hermeneutic interviewing, as a means of information gathering, proved challenging. Using interview excerpts, I demonstrate my use of hermeneutic interviewing as research method, and critique my interviewing skills in relation to the fundamental principles from which this style of interviewing was developed. PMID:11096794

Geanellos, R

1999-06-01

140

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

USGS Publications Warehouse

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

Williams, G. P.

1983-01-01

141

Evaluation of methods for estimating time to steady state with examples from phase 1 studies.  

PubMed

An overview is provided of the methodologies used in determining the time to steady state for Phase 1 multiple dose studies. These methods include NOSTASOT (no-statistical-significance-of-trend), Helmert contrasts, spline (quadratic) regression, effective half life for accumulation, nonlinear mixed effects modeling, and Bayesian approach using Markov Chain Monte Carlo (MCMC) methods. For each methodology we describe its advantages and disadvantages. The first two methods do not require any distributional assumptions for the pharmacokinetic (PK) parameters and are limited to average assessment of steady state. Also spline regression which provides both average and individual assessment of time to steady state does not require any distributional assumptions for the PK parameters. On the other hand, nonlinear mixed effects modeling and Bayesian hierarchical modeling which allow for the estimation of both population and subject-specific estimates of time to steady state do require distributional assumptions on PK parameters. The current investigation presents eight case studies for which the time to steady state was assessed using the above mentioned methodologies. The time to steady state estimates obtained from nonlinear mixed effects modeling, Bayesian hierarchal approach, effective half life, and spline regression were generally similar. PMID:18446514

Maganti, Lata; Panebianco, Deborah L; Maes, Andrea L

2008-01-01

142

A method of assessing the resilience of whole communities of children: An example from rural Australia  

PubMed Central

Background Children living in socioeconomic disadvantage are at risk of poor mental health outcomes. In order to focus and evaluate population health programs to facilitate children’s resilience, it is important to accurately assess baseline levels of functioning. With this end in mind, the aim of this study was to test the utility of 1) a voluntary random sampling method and 2) quantitative measures of adaptation (with national normative data) for assessing the resilience of children in an identified community. Method This cross-sectional study utilized a sample of participants (N?=?309), including parents (n?=?169), teachers (n?=?20) and children (n?=?170; age range?=?5-16 years), recruited from the schools in Tenterfield; a socioeconomically disadvantaged community in New South Wales, Australia. The Strengths and Difficulties Questionnaire (SDQ; including parent, teacher and youth versions) was used to measure psychological well-being and pro-social functioning, and NAPLAN results (individual children’s and whole school’s performance in literacy and numeracy) were used to measure level of academic achievement. Results The community’s disadvantage was evident in the whole school NAPLAN performance but not in the sample’s NAPLAN or SDQ results. The teacher SDQ ratings appeared to be more reliable than parent’s ratings. The voluntary random sampling method (requiring parental consent) led to sampling bias. Conclusions The key indicators of resilience - psychological well-being, pro-social functioning and academic achievement – can be measured in whole communities using the teacher version of the SDQ and whole school results on a national test of literacy and numeracy (e.g., Australia’s NAPLAN). A voluntary random sample (dependent upon parental consent) appears to have limited value due to the likelihood of sampling bias.

2012-01-01

143

The identification of buried volcanic edifices: examples, methods, modelling and significance  

NASA Astrophysics Data System (ADS)

It makes the identification to the ancient volcanic edifices difficult for their deep buried depth, complex diagenesis environment and incomplete preservation due to deuteric weathering and denudation. In this paper, the synthetic information such as rock cores, well loggings and seismic was used to identify the Carboniferous volcanic edifices located in Dixi area of Junggar basin in China, as a case study of complex buried volcanic edifices. A suit of methods for identifying the volcanic rocks base on well logging were presented. The seismic response characteristics of typical combined rocks were summarized. An identification process for buried volcanic edifice was summarized. Finally, the model of the volcanic edifices were made base on the structural rehabilitation. The methods used in this paper are available to the anatomy of volcanic edifices in other areas especially the adjacent areas. They also can be used as some basis for the exploration and development of the oil and gas in this area since the important industrial gas has been developed from these volcanic edifices.

Wang, Luo; Li, Jianghai; Shi, Yongmin

2010-05-01

144

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

145

Toxicological methods for tracing drug abuse: chromatographic, spectroscopic and biological characterisation of ecstasy derivatives.  

PubMed

Analysis often reveals variability in the composition of ecstasy pills from pure 3,4-methylenedioxymethamphetamine (MDMA) to mixtures of MDMA derivatives, amphetamine, and other unidentified substances. For a comprehensive toxicological analysis one needs to know all steps to MDMA synthesis which may originate impurities. The aim of this study was to synthesise and determine the chemical-physical and in vitro biological properties of a series of MDMA derivatives.3,4-methylendioxyphenyl-2-nitropropene (MDNP) was obtained by condensation of piperonal with an excess of nitroethane in the presence of ammonium acetate. MDNP was then reduced to methylenedioxyamphetamine (MDA) by LiAlH3. All compounds were analysed using HPLC and spectroscopic technique [Raman, nuclear magnetic resonance (NMR), or infrared (IR)] at all the steps of synthesis. In addition, we assessed the biological potentials of these compounds by measuring in vitro their (i) blood cell/whole blood partition coefficient, (ii) binding to plasmatic proteins (Fbp), and (iii) membrane adsorption. Chemical structure was determined with antibody fluorescence polarisation immunoassay (FPIA). This study showed the presence of solid impurities, particularly of a neurotoxic compound of Al3+ in the final products. FPIA identified the aminoethane group close to the substituted benzene ring, but did not detect the two major precursors of MDMA: MDNP and piperonal. Raman spectroscopy is an attractive alternative technique to characterise ecstasy pills and it can identify stereoisomeric forms such as cis-MDNP and trans-MDNP, which exhibit signals at 1650 cm-1 and 1300 cm-1, respectively. PMID:20338868

Belhadj-Tahar, Hafid; Payoux, Pierre; Tafani, Mathieu; Coulais, Yvon; Calet, Serge; Bousseksou, Azzedine

2010-03-01

146

Dust formation in winds of long-period variables. I - Equations, method of solution, simple examples  

NASA Astrophysics Data System (ADS)

Time-dependent numerical calculations of the formation and growth of dust particles in stellar winds are presented. The production rate and the properties of the dust are obtained by solving the moment equations derived by Gail & Sedlmayr (1988) and generalized by Gauger et al. (1990). The equations are reformulated to allow arbitrary motions of grid points. The numerical technique used is similar to an implicit formulation of the equations of radiation hydrodynamics in conservative form and will allow an incorporation into the existing radiation hydrodynamics code. A new numerical method is calculated for the formation of carbon dust in stationary stellar winds around cool C-rich stars to compare these results with models available in the literature.

Dorfi, E. A.; Hoefner, S.

1991-08-01

147

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.

2014-01-01

148

Estimation of benefit of prevention of occupational cancer for comparative risk assessment: methods and examples  

PubMed Central

Objectives To quantify the life years gained and financial savings by preventing a case of occupational cancer. Methods The authors retrieved data from the Taiwan Cancer Registry and linked them with the National Mortality Registry to estimate the survival functions for major occupational cancers: lung, pleural mesothelioma, urinary bladder and leukaemia. Assuming a constant excess hazard for each type of cancer, the authors extrapolated lifetime survival functions by the Monte Carlo method. For each patient with cancer, the authors simulated an age- and gender-matched person without cancer based on vital statistics of Taiwan to estimate life expectancy and expected years of life lost (EYLL). By using the reimbursement data from the National Health Insurance Research Database, the authors calculated the average monthly healthcare expenditures, which were summed to estimate the lifetime healthcare expenditures after adjusting for the corresponding monthly survival probability. Results A total of 51?408, 136, 12?891 and 5285 new cases of lung, pleural mesothelioma, bladder and leukaemia cancers, respectively, were identified during 1997–2005 and followed until the end of 2007. The EYLL was predicted to be 13.7±0.1, 18.9±0.7, 4.7±0.3 and 19.4±0.5?years for these cancers, respectively, and the lifetime healthcare expenditures with a 3% annual discount were predicted to be US$22?359, US$14?900, US$51?987 and US$59?741, respectively. Conclusions The burden of these occupational cancers, in terms of EYLL and lifetime healthcare expenditures, was substantial. Such estimates may provide useful empirical evidence for comparative risk assessment that can be applied in health policy-making and clinical decision-making.

Lee, Lukas Jyuhn-Hsiarn; Chang, Yu-Yin; Liou, Saou-Hsing

2012-01-01

149

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

150

General method for calculating polarization electric fields produced by auroral Cowling mechanism and application examples  

NASA Astrophysics Data System (ADS)

The Cowling mechanism is characterized by the generation of polarization space charges in the ionosphere in consequence of a partial or total blockage of FAC flowing between the ionosphere and the magnetosphere. Thus a secondary polarization electric field builds up in the ionosphere, which guarantees that the whole (primary + secondary) ionospheric current system is again in balance with the FAC. In the Earth's ionosphere the Cowling mechanism is long known to operate in the equatorial electrojet, and several studies indicate that it is important also in auroral current systems. We present a general method for calculate the secondary polarization electric field, when the ionospheric conductances, the primary (modeled) or the total (measured) electric field, and the Cowling efficiency are given. Here the Cowling efficiency is defined as the fraction of the divergent Hall current canceled by secondary Pedersen current. In contrast to previous studies, our approach is a general solution which is not limited to specific geometrical setups (like an auroral arc), and all parameters may have any kind of spatial dependence. The solution technique is based on spherical elementary current (vector) systems (SECS). This way, we avoid the need to specify explicit boundary conditions for the searched polarization electric field or its potential, which would be required if the problem was solved in a differential equation approach. Instead, we solve an algebraic matrix equation, for which the implicit boundary condition that the divergence of the polarization electric field vanishes outside our analysis area is sufficient. In order to illustrate the effect of Cowling mechanism on ionospheric current systems, we apply our method to two simple models of auroral electrodynamic situations: 1) a mesoscale strong conductance enhancement in the early morning sector within a relatively weak southward primary electric field, 2) a morning sector auroral arc with only a weak conductance enhancement, but a large southward primary electric field at the poleward flank of the arc. While the significance of the polarization electric field for maximum Cowling efficiency is large for the first case, it is rather minor for the second one. Both models show that the Cowling effect may not only change the magnitude of the current systems, but also their overall geometry. Further, the polarization electric field may extend into regions where the primary electric field is small, thus even dominating the total electric field in these regions. For the first model case, the total Joule heating integrated over the analysis area decreases by a factor of about 4 for maximum Cowling efficiency as compared to the case of vanishing Cowling efficiency. Further, for this case the resulting total electric field structurally shows a strong resemblance to that frequently observed during auroral omega band events.

Vanhamäki, Heikki; Amm, Olaf; Fujii, Ryo; Yoshikawa, Aki; Ieda, Aki

2013-04-01

151

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

152

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

SciTech Connect

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

REYNOLDS JG

2011-07-27

153

Fourier transform infrared spectroscopic method for the quantitative trace analysis of transition-metal carbonyl-labeled bioligands.  

PubMed

A quantitative FT-IR spectroscopic method has been developed for the trace analysis in chlorinated organic solvents of transition-metal carbonyl-labeled bioligands. In order to illustrate the widespread analytical potential of the method, three derivatives of the female hormonal steroid 17 beta-estradiol, containing Cr(CO)3, Cp2Mo2(CO)4 (Cp = eta 5-C5H5), and Co2(CO)6 as labels, and the anticonvulsant drug phenobarbital, labeled with (eta 5-C5H4)Mn(CO)3, were examined. The cobalt carbonyl marker proved to be the best sulted for quantitative analysis purposes, and the minimum tracer quantity detectable for this particular marker (64 scans, 4-cm-1 resolution, 3.5 min) was optimized in CCl4 solution at about 300 fmol (or 0.3 pmol, 180 pg) by using an ultralow volume (23.0 microL), gold light-pipe IR solution cell and a liquid nitrogen cooled, InSb (indium antimonide) IR detector. The repeatability of this radically different analytical procedure over the concentration range 1.0 x 10(-6) to 5.0 x 10(-8) M was good (coefficient of variance less than or equal to 6%) and the method provides the basis for a new immunological test--carbonylmetalloimmunoassay (CMIA). PMID:1759715

Salmain, M; Vessières, A; Jaouen, G; Butler, I S

1991-10-15

154

A spectroscopic method for determining lignin content of softwood and hardwood kraft pulps  

Microsoft Academic Search

A rapid method for determining the kappa number of unbleached and oxygen-delignified kraft pulps in the range 3–35 is presented. This novel method was based on the multivariate analysis of VIS spectral data on pulp samples. The calculated models and the test results indicated that partial least squares (PLS) and principal component regression (PCR) models yielded similar results, PLS being

Petteri Malkavaara; Raimo Alén

1998-01-01

155

Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of some fluoroquinolone antibacterials using ammonium reineckate  

NASA Astrophysics Data System (ADS)

Three accurate, rapid and simple atomic absorption spectrometric (AAS), conductometric and colorimetric methods were developed for the determination of gatifloxacin (GTF), moxifloxacin (MXF) and sparfloxacin (SPF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at ?max 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone. The optimizations of various experimental conditions were described. Optimum concentration ranges for the determination of GTF, MXF and SPF were 5.0-150, 40-440 ?g mL -1 and 0.10-1.5 mg mL -1 using atomic absorption (AAS), conductometric and colorimetric methods, respectively. Detection and quantification limits are ranges from 1.5 to 2.3 ?g mL -1 using AAS method or 30-45 ?g mL -1 using colorimetric method. The proposed procedures have been applied successfully to the analysis of these drugs in pharmaceutical formulations and the results are favourably comparable to the reference methods.

Al-Ghannam, Sheikha M.

2008-04-01

156

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

NASA Astrophysics Data System (ADS)

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

Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

2010-09-01

157

Multi-spectroscopic methods combined with molecular modeling dissect the interaction mechanisms of ractopamine and calf thymus DNA.  

PubMed

The toxic interaction of ractopamine (RAC) with calf thymus DNA (ct DNA) was studied in vitro using multi-spectroscopic methods and molecular modeling methods. The hypochromic effect without a noticeable shift in UV-vis absorption indicated that the minor groove binding mode existed in the interaction between RAC and DNA. The fluorescence quenching of RAC was observed with the increasing addition of DNA and was proved to be the static quenching. The binding constant and the binding site sizes were 4.13 × 10(3) and 0.97, respectively. The thermodynamic calculation demonstrated that the hydrogen bond and van der Waals were main acting forces. This result further confirmed the existence of groove binding mode. Afterwards, we found another interaction mode, electrostatic binding mode through the fluorescence polarization, ionic effects and denatured DNA experiments. Circular dichroism spectroscopy (CD) was then employed to monitor the conformation changes of DNA. Molecular modeling studies illustrated the visual display of the binding mode and the detailed information of the H-bond. PMID:22610465

Chai, Jun; Wang, Juyuan; Xu, Qifei; Hao, Fang; Liu, Rutao

2012-07-01

158

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 ...

159

DNA interaction studies of new nano metal based anticancer agent: validation by spectroscopic methods  

Microsoft Academic Search

A new nano dimensional heterobimetallic Cu-Sn containing complex as a potential drug candidate was designed, synthesized and characterized by analytical and spectral methods. The electronic absorption and electron paramagnetic resonance parameters of the complex revealed that the Cu(II) ion exhibits a square pyramidal geometry with the two pyrazole nitrogen atoms, the amine nitrogen atom and the carboxylate oxygen of the

Sartaj Tabassum; Girish Chandra Sharma; Farukh Arjmand; Ameer Azam

2010-01-01

160

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

PubMed

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

Stambulchik, E; Tsigutkin, K; Maron, Y

2007-06-01

161

[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

162

A quantitative solid-state Raman spectroscopic method for control of fungicides.  

PubMed

A new analytical procedure using solid-state Raman spectroscopy within the THz-region for the quantitative determination of mixtures of different conformations of trifloxystrobin (EE, EZ, ZE and ZZ), tebuconazole (1), and propiconazole (2) as an effective method for the fungicide product quality monitoring programmes and control has been developed and validated. The obtained quantities were controlled independently by the validated hybrid HPLC electrospray ionization (ESI) tandem mass spectrometric (MS) and matrix-assisted laser desorption/ionization (MALDI) MS methods in the condensed phase. The quantitative dependences were obtained on the twenty binary mixtures of the analytes and were further tested on the three trade fungicide products, containing mixtures of trifloxystrobin-tebuconazole and trifloxystrobin-propiconazole, as an emissive concentrate or water soluble granules of the active ingredients. The present methods provided sufficient sensitivity as reflected by the metrologic quantities, evaluating the concentration limit of detection (LOD) and quantification (LOQ), linear limit (LL), measurement accuracy and precision, true quantity value, trueness of measurement and more. PMID:22679621

Ivanova, Bojidarka; Spiteller, Michael

2012-07-21

163

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.

164

Hardware and Methods of the Optical End-to-End Test of the Far Ultraviolet Spectroscopic Explorer (FUSE)  

NASA Technical Reports Server (NTRS)

The Far Ultraviolet Spectroscopic Explorer (FUSE), currently being tested and scheduled for a 1999 launch, is an astrophysics satellite designed to provide high spectral resolving power (Lambda/(Delta)Lambda = 24,000-30,000) over the interval 90.5-118.7 nm. The FUSE optical path consists of four co-aligned, normal incidence, off-axis parabolic, primary 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, 15" Cassegrain telescopes which were 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 closeout 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, Doug B.; Smee, Stephen; Ohl, Raymond G.; Kushner, Gary

1999-01-01

165

Spectroscopic properties of Yb doped YLF grown by a vertical Bridgman method  

Microsoft Academic Search

Laser crystals of LiYF4 (YLF) doped with 5–64at.% of trivalent ytterbium ions (Yb3+) were grown by a vertical Bridgman method. As crystal growth materials of YbF3 and YF3 including YOF impurities caused opaque crystal, the YOF reduction procedure using PbF2 was essential before starting the crystal growth. We derived seven energy levels from the 2F7\\/2 and 2F5\\/2 manifolds of Yb3+:YLF

Akira Sugiyama; Masamichi Katsurayama; Yutaka Anzai; Taiju Tsuboi

2006-01-01

166

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

167

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

NASA Astrophysics Data System (ADS)

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

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

2010-11-01

168

Interactions between CdSe/CdS quantum dots and DNA through spectroscopic and electrochemical methods  

NASA Astrophysics Data System (ADS)

The interaction of CdSe/CdS quantum dots (QDs) with Herring sperm-DNA (hs-DNA) has been studied by UV-vis spectroscopy and electrochemical method. Cu(phen) 22+/1+ (phen = 1, 10-phenanthroline) was used as an indicator for electroactive dsDNA or ssDNA. The apparent association constant has been deduced (4.94 × 10 3 M -1 and 2.39 × 10 2 M -1) from the absorption spectral changes of the dsDNA-QDs and ssDNA-QDs. The results of dissociation method suggest that Cu(phen) 22+/1+ is more easily dissociated from dsDNA or ssDNA modified gold electrode (dsDNA/Au or dsDNA/Au) in presence of QDs. The dissociation rate constant ( k) of Cu(phen) 22+/1+ on dsDNA/Au is 4.48 times higher than that in absence of QDs, while k is 2.34 times higher than that in absence of QDs on ssDNA/Au in Tris buffer with low ionic strength (pH 7.0, 0.5 mM NaCl). The results illuminate that hs-DNA has high affinity for QDs due to electrostatic force, hydrogen bonds, and van der Waals interactions, and the binding force of QDs with dsDNA is stronger than ssDNA.

Wang, Qisui; Yang, Lu; Fang, Tingting; Wu, Shuang; Liu, Peng; Min, Xinmin; Li, Xi

2011-09-01

169

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

170

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

NASA Astrophysics Data System (ADS)

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

Cyra?ski, Micha? K.; Jezierska, Aneta; Klimentowska, Paulina; Panek, Jaros?aw J.; ?ukowska, Gra?yna Z.; Sporzy?ski, Andrzej

2008-03-01

171

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

PubMed Central

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.

Stambuk, Nikola; Manojlovic, Zoran; Turcic, Petra; Martinic, Roko; Konjevoda, Pasko; Weitner, Tin; Wardega, Piotr; Gabricevic, Mario

2014-01-01

172

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

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

2014-01-01

173

Spectroscopic characterization of porous nanohydroxyapatite synthesized by a novel amino acid soft solution freezing method  

NASA Astrophysics Data System (ADS)

In this paper, we have reported a novel method to synthesize nanoporous hydroxyapatite (HAP) powders by freezing organic-inorganic soft solutions. The formation of porous and crystalline HAP nanopowder was achieved via calcining the samples at 600 °C followed by sintering at temperatures ranging from 900 °C to 1100 °C. The samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. The results showed the formation of a carbon free nanoporous hydroxyapatite powders due to the decomposition of organic template enclosing the precipitated HAP. It was also observed that the rapid grain growth with retainment of pores while the crystallinity of the HAP nanopowder increased with the increase in sintering temperature which is substantiated from the XRD and SEM results. Such organized porous materials can act as a better biomaterial for bone tissue engineering.

Gopi, D.; Indira, J.; Prakash, V. Collins Arun; Kavitha, L.

2009-09-01

174

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

PubMed Central

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

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

2013-01-01

175

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

176

DNA interaction studies of new nano metal based anticancer agent: validation by spectroscopic methods.  

PubMed

A new nano dimensional heterobimetallic Cu-Sn containing complex as a potential drug candidate was designed, synthesized and characterized by analytical and spectral methods. The electronic absorption and electron paramagnetic resonance parameters of the complex revealed that the Cu(II) ion exhibits a square pyramidal geometry with the two pyrazole nitrogen atoms, the amine nitrogen atom and the carboxylate oxygen of the phenyl glycine chloride ligand located at the equatorial sites and the coordinated chloride ion occupying an apical position. (119)Sn NMR spectral data showed a hexa-coordinated environment around the Sn(IV) metal ion. TEM, AFM and XRD measurements illustrate that the complex could induce the condensation of CT-DNA to a particulate nanostructure. The interaction of the Cu-Sn complex with CT-DNA was investigated by UV-vis absorption and emission spectroscopy, as well as cyclic voltammetric measurements. The results indicated that the complex interacts with DNA through an electrostatic mode of binding with an intrinsic binding constant K(b) = 8.42 x 10(4) M( - 1). The Cu-Sn complex exhibits effective cleavage of pBR322 plasmid DNA by an oxidative cleavage mechanism, monitored at different concentrations both in the absence and in the presence of reducing agents. PMID:20407140

Tabassum, Sartaj; Chandra Sharma, Girish; Arjmand, Farukh; Azam, Ameer

2010-05-14

177

Intermolecular interaction of prednisolone with bovine serum albumin: Spectroscopic and molecular docking methods  

NASA Astrophysics Data System (ADS)

The intermolecular interaction of prednisolone with bovine serum albumin (BSA) was studied using fluorescence, circular dichroism (CD) and molecular docking methods. The experimental results showed that the fluorescence quenching of the BSA at 338 nm by prednisolone resulted from the formation of prednisolone-BSA complex. The number of binding sites (n) for prednisolone binding on BSA was approximately equal to 1. Base on the sign and magnitude of the enthalpy and entropy changes (?H0 = -149.6 kJ mol-1 and ?S0 = -370.7 J mol-1 K-1) and the results of molecular docking, it could be suggested that the interaction forces were mainly Van der Waals and hydrogen bonding interactions. Moreover, in the binding process of BSA with prednisolone, prednisolone molecule can be inserted into the hydrophobic cavity of subdomain IIIA (site II) of BSA. The distance between prednisolone and Trp residue of BSA was calculated as 2.264 nm according to Forster's non-radiative energy transfer theory.

Shi, Jie-hua; Zhu, Ying-Yao; Wang, Jing; Chen, Jun; Shen, Ya-Jing

2013-02-01

178

Apparatus and methods for compensation of blood volume effects on NIR spectroscopic measurements of blood analytes  

US Patent & Trademark Office Database

The present invention provides a method for measuring a blood analyte concentration of a body part comprising removing a portion or all of the blood from the body part to produce a modified body part, and recording a first absorbance value of the modified body part. This is followed by filling the body part with blood to produce a filled body part, and recording a second absorbance value of the filled body part. A difference spectrum is obtained by subtracting the first absorbance values from the second absorbance values, and a calibration algorithm for the blood analyte is applied to the difference spectrum, thereby measuring the concentration of the blood analyte. Also provided is an apparatus for determining the concentration of a blood analyte of a body part. The apparatus comprising a chamber of a size and shape to receive the body part, where the chamber comprises an element for withdrawing and reintroducing blood from the body part, when the body part is inserted within the chamber. The chamber also comprising one or more than one port for introducing electromagnetic radiation into the chamber and onto that body part, and collecting remaining electromagnetic radiation following interaction with the body part.

2009-11-03

179

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

PubMed

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. PMID:24747330

Muthu, S; Prabhakaran, A

2014-08-14

180

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

181

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

182

Rietveld refinement and spectroscopic studies of sodium lead fluoroapatite lacunaire synthesized by hydrothermal method  

SciTech Connect

The structure of NaPb{sub 9}(PO{sub 4}){sub 6}F(H{sub 2}O){sub 0.33}, isostructural with apatite, was determined by X-ray powder diffraction methods and the result of Rietveld refinement is P6{sub 3}/m, a = 9.76396(8) A and c = 7.27520(9) A. The final refinement led to R{sub F} = 5.4%, R{sub B} = 6.6%. In the tunnel, the water molecule (O{sub w}) and F{sup -} ions appear to be located in 2b and 4e sites, with occupancies of 0.028(6) and 0.075(8), respectively. In the M(1) and M(2) sites the occupancies of Pb and Na are 0.282(3)/0.051(3) and 0.467(5)/0.033(5), respectively. The formula assigned to the compound is [Pb{sub 3.38(4)}Na{sub 0.62(4)}](1)[Pb{sub 5.60(6)}Na{sub 0.40(6)}](2)(PO{sub =} 4){sub 6}F{sub 0.90(10)}(H{sub 2}O){sub 0.33(7)}{open_square}{sub 0.77(17)}, where {open_square} = vacancy. The assignment of the observed frequencies in the Raman and infrared spectra is discussed on the basis of a unit-cell group analysis and by comparison with fluor and chloroapatite analogs. The result of {sup 31}P and {sup 23}Na magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies confirmed the structural results.

Toumi, M. [Laboratoire de L'Etat Solide (LES), Faculte des Sciences de Sfax, Route de Soukra Km 3.5, BP 802, 3018 Sfax (Tunisia)], E-mail: mohamed.toumi@fss.rnu.tn; Mhiri, T. [Laboratoire de L'Etat Solide (LES), Faculte des Sciences de Sfax, Route de Soukra Km 3.5, BP 802, 3018 Sfax (Tunisia)

2008-06-03

183

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

NASA Astrophysics Data System (ADS)

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

Bradley, James Thomson

184

Methods for preparing crystals of reversibly oxidized proteins: crystallization of protein tyrosine phosphatase 1B as an example.  

PubMed

Regulation of protein activity through the oxidation and reduction of cysteines is emerging as an important mechanism in the control of cell-signaling pathways. Protein tyrosine phosphatase 1B (PTP1B), for example, is reversibly inhibited by oxidation at the catalytic cysteine in response to stimulation of cells by insulin or epidermal growth factor. We have conducted structural studies on the redox regulation of PTP1B and have demonstrated that the oxidation of the catalytic cysteine results in the formation of a bond between the sulfur atom of the catalytic cysteine and the amide nitrogen of the neighboring serine. This bond, referred to here as a sulfenamide bond, is reversible upon the addition of glutathione, indicating that this sulfenamide intermediate could function within signaling pathways to protect the cysteine from overoxidation to less readily reducible states. Formation of the sulfenamide bond is accompanied by changes in the tertiary structure at the catalytic site, and these changes may be important for additional regulation of the enzyme. Here, we present methods for preparing crystals ofPTP1B with a sulfenamide bond at the catalytic cysteine. The methods may be adaptable for other proteins that are subject to redox regulation. PMID:19157012

Salmeen, Annette; Barford, David

2008-01-01

185

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

186

Studies of the interaction between demeclocycline and human serum albumin by multi-spectroscopic and molecular docking methods  

NASA Astrophysics Data System (ADS)

This study was designed to examine the interaction of demeclocycline (DMCTC) with human serum albumin (HSA) by multi-spectroscopic and molecular docking methods. The inner filter effect was corrected before we calculated the binding parameters. Fluorescence and UV-vis spectroscopy revealed that DMCTC induced the fluorescence quenching of HSA though a static quenching procedure. Thermodynamic analysis by Van Hoff equation found enthalpy change (?H) and entropy change (?S) were -53.01 kJ mol-1 and -65.13 J mol-1 K-1, respectively, which indicated hydrogen bond and van der Waals force were the predominant force in the binding process. According to fluorescence resonance energy transfer (FRET), the specific binding distances between Trp-214 (donor) and DMCTC (acceptor) were 3.18 nm. Through site marker competitive experiments, subdomain IIA of HSA has been assigned to possess the high-affinity binding site of DMCTC. The three dimensional fluorescence showed that the conformation of HSA was changed after its complexation with DMCTC, and the alternations of protein secondary structure were quantitatively calculated from FT-IR with reduction of ?-helices content about 4.8%, ?-sheet from 30.3% to 21.6% and with increases of ?-turn from 15.6% to 22.2%. Furthermore, the binding details between DMCTC and HSA were further confirmed by molecular docking studies, which revealed that DMCTC was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, polar forces and ?-? interactions. Moreover, the coexist metal ions such as Al3+, Fe3+, Cu2+, Cr3+ and Cd2+ can decrease the binding constants of DMCTC-HSA.

Dong, Chengyu; Ma, Shuying; Liu, Ying

2013-02-01

187

Characterization of novel lithium battery cathode materials by spectroscopic methods: the Li5+xFeO? system.  

PubMed

The novel, lithium-rich oxide-phase Li?FeO? (LFO) could, in theory, deliver a specific capacity >900 mAh/g when deployed as a cathode or cathode precursor in a battery with a lithium-based anode. However, research results to date on LFO indicate that less than one of the five Li? cations can be reversibly de-intercalated/re-intercalated during repetitive charging and discharging cycles. In the present research, the system Li5+xFeO? with x values in the range of 0.0-2.0 was investigated by a combination of Raman and X-ray absorption spectroscopic methods supported by X-ray diffraction (XRD) analysis in order to determine if the Li?FeO? lattice would accommodate additional Li? ions, with concomitant lowering of the valence on the FeIII cations. Both the Raman phonon spectra and the XRD patterns were invariant for all values of x, strongly indicating that additional Li? did not enter the Li?FeO? lattice. Also, Raman spectral results and high-resolution synchrotron XRD data revealed the presence of second-phase Li?O in all samples with x greater than 0.0. Synchrotron X-ray absorption spectroscopy at the Fe k? edge performed on the sample with a Li-Fe ratio of 7.0 (i.e., x = 2.0) showed no evidence for the presence of FeII. This resistance to accepting more lithium into the Li?FeO? structure is attributed to the exceedingly stable nature of high-spin FeIII in tetrahedral "FeIIIO?" structural units of Li?FeO?. Partial substitution of the FeIII with other cations could provide a path toward increasing the reversible Li? content of Li5xFeO?-type phases. PMID:23876729

Maroni, Victor A; Johnson, Christopher S; Rood, Shawn C M; Kropf, A Jeremy; Bass, Dean A

2013-08-01

188

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

189

Infrared spectroscopic characterization of mineralized tissues  

PubMed Central

Vibrational spectroscopy (Infrared and Raman), and in particular micro-spectroscopy and micro-spectroscopic imaging has been used to characterize developmental changes in bone and other mineralized tissues, to monitor these changes in cell cultures, and to detect disease and drug-induced modifications. Examples of the use of infrared micro-spectroscopy and micro-spectroscopic imaging are discussed in this review.

Boskey, Adele L.; Mendelsohn, Richard

2006-01-01

190

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

191

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

NASA Astrophysics Data System (ADS)

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

Smith, Duane H.; Seshadri, Kal S.

1999-04-01

192

Laboratory spectroscopic diagnostics of TLE-like air plasmas: methods to derive the rotational (gas) temperature in TLEs  

NASA Astrophysics Data System (ADS)

Laboratory low pressure (0.1 mbar < p < 2 mbar) glow air discharges have been studies by optical emission spectroscopy to illustrate several spectroscopic techniques that, depending on the available spectral resolution, could be implemented by different field spectrographs to experimentally quantify the gas temperature associated with Transient Luminous Events (TLEs) occurring at different altitudes including blue jets, giant blue jets and sprites. The laboratory air plasmas investigated have been analysed from the near UV (300 nm) to the near IR (1060 nm) with high (up to 0.01 nm) and low (2 nm) spectral resolution commercial grating spectrographs and by an in-house developed intensified CCD grating spectrograph that we have recently developed in our group at IAA - CSIC for TLE spectral diagnostic surveys with 0.45 nm spectral resolution. We discuss the results of laboratory tests and comment on the convenience of using one or another technique for rotational (gas) temperature determination during TLE spectroscopic campaigns. Finally, we will also show a comparison of the vibrational distribution function (VDF) of N2(B) obtained from (a) experiments in low pressure laboratory air plasmas produced in conditions similar to TLEs, (b) spectroscopic emissions from real TLE air plasmas and (c) compute from kinetic modeling.

Gordillo-Vazquez, F.; Parra-Rojas, F.; Passas, M.; Carrasco, E.; Luque, A.; Tanarro, I.; Simek, M.

2013-12-01

193

Raman spectroscopic analysis of human tissue engineered oral mucosa constructs (EVPOME) perturbed by physical and biochemical methods  

NASA Astrophysics Data System (ADS)

We show the application of near-infrared Raman Spectroscopy to in-vitro monitoring of the viability of tissue constructs (EVPOMEs). During their two week production period EVPOME may encounter thermal, chemical or biochemical stresses that could cause development to cease, rendering the affected constructs useless. We discuss the development of a Raman spectroscopic technique to study EVPOMEs noninvasively, with the ultimate goal of applying it in-vivo. We identify Raman spectroscopic failure indicators for EVPOMEs, which are stressed by temperature, and discuss the implications of varying calcium concentration and pre-treatment of the human keratinocytes with Rapamycin. In particular, Raman spectra show correlation of the peak height ratios of CH2 deformation to phenylalanine ring breathing, providing a Raman metric to distinguish between viable and nonviable constructs. We also show the results of singular value decomposition analysis, demonstrating the applicability of Raman spectroscopic technique to both distinguish between stressed and non-stressed EVPOME constructs, as well as between EVPOMEs and bare AlloDerm® substrates, on which the oral keratinocytes have been cultured. We also discuss complications arising from non-uniform thickness of the AlloDerm® substrate and the cultured constructs, as well as sampling protocols used to detect local stress and other problems that may be encountered in the constructs.

Khmaladze, Alexander; Ganguly, Arindam; Raghavan, Mekhala; Kuo, Shiuhyang; Cole, Jacqueline H.; Marcelo, Cynthia L.; Feinberg, Stephen E.; Izumi, Kenji; Morris, Michael D.

2012-02-01

194

Study on the site selection of logistics park based on the AHP method: Take Jiaozuo city for an example  

Microsoft Academic Search

In order to provide the planning basis and explore the best layout program for logistics park layout, this paper takes Jiaozuo city as an example and selects several factors, such as position, facilities, function and development potential to design a comprehensive evaluation indicator system in site selection of logistics park with the GIS platform, and then At last, the paper

Zhongmei Guan; Hongwu Niu

2011-01-01

195

Aspects of Manpower Planning at a Dutch University, an Example of Aggregation and Decomposition Methods in Manpower Planning.  

National Technical Information Service (NTIS)

The choice of the categories for the medium term manpower planning in an organization is considered in a system with a simple personnel structure, consisting of two function groups on different hierarchical levels. An example of such a system is the resea...

N. Aerts J. D. Vanderbij J. Wessels

1983-01-01

196

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

197

Towards a wave-extraction method for numerical relativity. III. Analytical examples for the Beetle-Burko radiation scalar  

SciTech Connect

Beetle and Burko recently introduced a background-independent scalar curvature invariant for general relativity that carries information about the gravitational radiation in generic spacetimes, in cases where such radiation is incontrovertibly defined. In this paper we adopt a formalism that only uses spatial data as they are used in numerical relativity and compute the Beetle-Burko radiation scalar for a number of analytical examples, specifically linearized Einstein-Rosen cylindrical waves, linearized quadrupole waves, the Kerr spacetime, Bowen-York initial data, and the Kasner spacetime. These examples illustrate how the Beetle-Burko radiation scalar can be used to examine the gravitational wave content of numerically generated spacetimes, and how it may provide a useful diagnostic for initial data sets.

Burko, Lior M. [Department of Physics and Astronomy, Bates College, Lewiston, Maine 04240 (United States); Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Baumgarte, Thomas W. [Department of Physics and Astronomy, Bowdoin College, Brunswick, Maine 04011 (United States); Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Beetle, Christopher [Department of Physics, Florida Atlantic University, Boca Raton, Florida 33431 (United States); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada)

2006-01-15

198

Spectroscopic detection  

DOEpatents

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

Woskov, Paul P. (Bedford, MA); Hadidi, Kamal (Cambridge, MA)

2003-01-01

199

Raman spectroscopic method for the determination of medroxyprogesterone acetate in a pharmaceutical suspension: validation of quantifying abilities, uncertainty assessment and comparison with the high performance liquid chromatography reference method  

Microsoft Academic Search

An alternative fast and non-destructive validated Raman spectroscopic analytical procedure, requiring no sample preparation, was compared with the industrially applied HPLC reference method (Pfizer Manufacturing Belgium) for the quantitative determination of medroxyprogesterone acetate (MPA) in DepoProvera® suspensions (150mgmL?1, Pfizer). The Raman calibration model was developed by plotting the peak intensity of the baseline-corrected and normalized spectral band (corrected by external

T. R. M. De Beer; W. R. G. Baeyens; A. Vermeire; D. Broes; J. P. Remon; C. Vervaet

2007-01-01

200

Compressed domain content-based retrieval of MP3 audio example using quantization tree indexing and melody-line tracking method  

Microsoft Academic Search

In this paper, the content-based retrieval of audio example based on MP3 digital music archive is considered. In our proposed method, the sub-band coefficients (SBC) in a MP3 frame is used for feature extraction. Both quantization-tree indexing (QT) approach and the melody-line tracking (MLT) approach are proposed for indexing MP3 objects. Finally, a two-stage comparison method is used to measure

Tsung-han Tsai; Yung-tsung Wang; Jui Hong Hung; Chin-long Wey

2006-01-01

201

Comparative investigation of several sperm analysis methods for evaluation of spermatotoxicity of industrial chemical: 2-bromopropane as an example.  

PubMed

Reproductive toxicity of 2-bromopropane (2BP), a substitute for ozone layer-depleting chloro-fluorocarbon, was found among the workers in an electronics factory in Korea in 1995. Furthermore the importance of testicular toxicity has been realized since the problem of endocrine disruptors arose all over the world, but manual methods must rely on subjective assessment. Recently, computer-assisted sperm analysis (CASA) was proposed but this system requires vast investment. We then investigated the applicability of the MTT method with a microplate and sperm quality analyzer (SQA) as simple, rapid, and economic instrumental methods for the examination of sperm quality in rats, comparing it with the manual microscopic method and CASA. Epididymal fluid derived from male F344/N Slc (Fischer) rats intraperitoneally injected with 2BP in the dose range of 125-1,000 mg/kg/d twice a week (total 8 times) were examined by these methods as a model experiment. Sperm count measured by the manual method and CASA in the epididymal fluid, absorbance by the MTT method and sperm motility index value by the SQA method were significantly lower in the 2BP 1,000 mg/kg administered group than in the control group. This result suggests that the MTT method can detect oligospermia. With the microplate and microplate reader, the efficiency of detection becomes much better. Sperm analyses by the MTT method with the microplate reader and the SQA method are available for reproductive toxicity study in rats. PMID:15128172

Ohtani, Katsumi; Yamazaki, Shigeru; Kubota, Hisayo; Miyagawa, Muneyuki; Saegusa, Junzo

2004-04-01

202

PNS and statistical experiments simulation in subcritical systems using Monte-Carlo method on example of Yalina-Thermal assembly  

NASA Astrophysics Data System (ADS)

In subcritical systems driven by an external neutron source, the experimental methods based on pulsed neutron source and statistical techniques play an important role for reactivity measurement. Simulation of these methods is very time-consumed procedure. For simulations in Monte-Carlo programs several improvements for neutronic calculations have been made. This paper introduces a new method for simulation PNS and statistical measurements. In this method all events occurred in the detector during simulation are stored in a file using PTRAC feature in the MCNP. After that with a special code (or post-processing) PNS and statistical methods can be simulated. Additionally different shapes of neutron pulses and its lengths as well as dead time of detectors can be included into simulation. The methods described above were tested on subcritical assembly Yalina-Thermal, located in Joint Institute for Power and Nuclear Research SOSNY, Minsk, Belarus. A good agreement between experimental and simulated results was shown.

Sadovich, Sergey; Talamo, A.; Burnos, V.; Kiyavitskaya, H.; Fokov, Yu.

2014-06-01

203

Towards automated mapping of depth to magnetic\\/gravity basement — examples using new extensions to an old method  

Microsoft Academic Search

SUMMARY The Euler method of automating depth to source from potential field data has undergone resurgence in popularity, with several new extensions to the method developed. Perhaps the most revolutionary of these provides a solution of the structural index as part of the inversion process. Previously, structural index was a required input parameter. Many solutions are generated with the Euler

Peter R. Milligan; Gary Reed; Tony Meixner; Desmond FitzGerald

204

[Methods of the multivariate statistical analysis of so-called polyetiological diseases using the example of coronary heart disease].  

PubMed

General characteristics of the multivariate statistical analysis (MSA) is given. Methodical premises and criteria for the selection of an adequate MSA method applicable to pathoanatomic investigations of the epidemiology of multicausal diseases are presented. The experience of using MSA with computors and standard computing programs in studies of coronary arteries aterosclerosis on the materials of 2060 autopsies is described. The combined use of 4 MSA methods: sequential, correlational, regressional, and discriminant permitted to quantitate the contribution of each of the 8 examined risk factors in the development of aterosclerosis. The most important factors were found to be the age, arterial hypertension, and heredity. Occupational hypodynamia and increased fatness were more important in men, whereas diabetes melitus--in women. The registration of this combination of risk factors by MSA methods provides for more reliable prognosis of the likelihood of coronary heart disease with a fatal outcome than prognosis of the degree of coronary aterosclerosis. PMID:154880

Lifshits, A M

1979-01-01

205

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

206

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

PubMed

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

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

2013-01-24

207

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

NASA Astrophysics Data System (ADS)

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

Bazuhair, Abdulghaffar S.; Wood, Warren W.

1996-11-01

208

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

USGS Publications Warehouse

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

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

1996-01-01

209

Accuracy of Molecular Properties by Coupled-Cluster Methods for Some Difficult Examples: Oxygen Atom, Iron Atom and Cyano Radical.  

National Technical Information Service (NTIS)

Coupled-cluster (CC) methods at the level of CCSD, CCSD+T(CCSD), CCSD(T), CCSDT-1, and CCSDT-3 are applied to calculations of the dipole moment and polarizability of the CN molecule, ionization potentials and electron affinities of the oxygen and iron ato...

M. Urban J. D. Watts R. J. Bartlett

1994-01-01

210

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

Microsoft Academic Search

The effective elastic thickness, Te, represents the response to long-term loading of the lithosphere; it is thus a useful measure of its strength. However, the use of different methods and assumptions to calculate Te yield different results, leading to controversial interpretations of the relationship of Te to rheology. We investigate the ability of the Bouguer coherence and free air admittance

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

2003-01-01

211

Towards a Comprehensive Method for Evaluating Social Studies Curriculum Materials: With Examples from the Elementary School Curriculum.  

ERIC Educational Resources Information Center

The evaluation methodology delineated in this paper is a work in progress. The purpose is to develop a method for evaluating social studies curriculum materials that encompasses the materials' comprehensibility and the perspective offered. The paper draws from past evaluations that focused on either comprehensibility or perspective but have not…

Bisland, Beverly Milner

212

The energy method for analyzing the piezoelectric electroacoustic transducers. II. (With the examples of the flexural plate transducer)  

Microsoft Academic Search

The energy method for analyzing piezoelectric electro-acoustic transducers, described in the previous paper [B. S. Aronov, J. Acoust. Soc. Am. 117, 210-220 (2005)] is used here in application to transducers operating in the receive mode. Changes to the equivalent circuit of a transducer are introduced, arising from the action of the sound field considered as the external source of energy.

Boris Aronov

2005-01-01

213

Electrical Resistivity Methods to Characterize Sediment Deformation; Examples from Large-scale Glaciotectonic Structures in Michigan, USA  

NASA Astrophysics Data System (ADS)

An outcrop at the western edge of a large NW-SE trending ridge along the eastern shore of Lake Michigan south of Ludington contains Late Wisconsin deformation structures. Differential loading associated with a glacial re-advance caused glaciolacustrine loamy material to deform into several narrow anticlinal structures that rise from below beach level to near the top of the ~50 m high cliff. The anticlines separate ~100 m broad synclines that control local ground water flow and impact cliff stability. The objective of this study was to characterize the orientation and lateral extent of the structures below the ridge using different galvanic electrical resistivity methods. These methods exploit the large electrical contrast between the glaciolacustrine loams and overlying sandy outwash material. Electrical resistivity methods have long been part of the geophysical tool set. Recent advances, including the availability of multi-electrode systems and advanced data processing software, have made electrical resistivity tomography (ERT) a popular tool to obtain 2D models of subsurface resistivity. In this study, vertical electrical soundings (VES) were combined with borehole logs and lab-derived petrophysical relationships to characterize the site stratigraphy. Constant-spread traverses (CST) and ERT data were used to map the spatial extent of deformation structures. Field, lab, and modeling results presented in this work identify various strengths and limitations of electrical resistivity methods for the characterization of deformation structures in general and glaciotectonic structures in particular.

van Dam, R. L.

2010-12-01

214

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

NASA Astrophysics Data System (ADS)

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

Grzyb, Tomasz; W?c?awiak, Mariusz; P?dzi?ski, Tomasz; Lis, Stefan

2013-10-01

215

In vitro studies on the interaction between human serum albumin and fosfomycin disodium salt, an antibiotic drug by multi-spectroscopic and molecular docking methods.  

PubMed

The interaction between the human serum albumin (HSA) and drug, fosfomycin disodium salt (FOS) has been studied by different spectroscopic techniques. The experimental results showed a static quenching mechanism in the interaction of FOS with HSA. The number of binding sites, n and observed binding constant K a were measured by fluorescence quenching method. The thermodynamic parameters ?G°, ?H° and ?S° were calculated according to van't Hoff equation. The calculated distance r between FOS and the protein is evaluated according to the theory of Förster energy transfer. A change in the secondary structure of the protein was evident from the circular dichroism measurements, synchronous fluorescence and three-dimensional fluorescence spectra. PMID:24443227

Meti, Manjunath D; Byadagi, Kirthi S; Nandibewoor, Sharanappa T; Joshi, Shrinivas D; More, Uttam A; Chimatadar, Shivamurti A

2014-04-01

216

Interaction of coomassie brilliant blue G250 with human serum albumin: Probing of the binding mechanism and binding site by spectroscopic and molecular modeling methods  

NASA Astrophysics Data System (ADS)

The interaction between coomassie brilliant blue G250 and human serum albumin was investigated by spectroscopic methods such as fluorescence quenching, synchronous fluorescence , 3D fluorescence spectra, circular dichroism spectra and UV-vis absorption as well as molecular modeling. The fluorescence quenching of human serum albumin by coomassie brilliant blue G250 was attributed to static interaction. The binding reaction was mainly enthalpy-driven. Both van der Waals and hydrogen bonding forces played major roles in stabilizing the coomassie brilliant blue G250-human serum albumin complex. The Stern-Volmer quenching constant ( KSV) and corresponding thermodynamic parameters (? H?, ? G? and ? S?) were determined. Site marker competitive experiments indicated that coomassie brilliant blue G250 bound to site I (subdomain IIA) of human serum albumin. Molecular docking study further confirmed the binding mode obtained by experimental study. The conformational investigation demonstrated very minor micro-environmental and conformational changes in human serum albumin molecules.

Li, Yue-Sheng; Ge, Yu-Shu; Zhang, Yue; Zhang, Ai-Qing; Sun, Shao-Fa; Jiang, Feng-Lei; Liu, Yi

2010-04-01

217

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

218

An objective method for mapping hazardous flow deposits from the stratigraphic record of stratovolcanoes: a case example from Montagne Pelée  

Microsoft Academic Search

A method is described that enables a variety of maps, which indicate the probabilities of deposition, to be constructed in\\u000a a reproducible manner from the stratigraphie information typically available at well-studied stratovoicanoes. These maps can\\u000a then be used as a basis for hazard assessment. The sampling of the deposits of previous eruptions is subject to uncertainties\\u000a due to erosion, sectoral

M. L. Burt; G. Wadge; R. N. Curnow

2001-01-01

219

Method Validation and Quality Management in the Flexible Scope of Accreditation: An Example of Laboratories Testing for Genetically Modified Organisms  

Microsoft Academic Search

Quality assurance is a prerequisite for accurate and reliable results in food and feed testing, ISO\\/IEC 17025 being recognized\\u000a worldwide as the base standard. A flexible scope of accreditation enables testing laboratories to react quickly to customer\\u000a demand and to cope with the large number of new methods, which have to be introduced in the laboratory. Precisely defined\\u000a procedures for

Jana Žel; Marco Mazzara; Cristian Savini; Stephane Cordeil; Marjana Camloh; Dejan Štebih; Katarina Cankar; Kristina Gruden; Dany Morisset; Guy Van den Eede

2008-01-01

220

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

221

A method for multi-hazard mapping in poorly known volcanic areas: an example from Kanlaon (Philippines)  

NASA Astrophysics Data System (ADS)

Hazard mapping in poorly known volcanic areas is complex since much evidence of volcanic and non-volcanic hazards is often hidden by vegetation and alteration. In this paper, we propose a semi-quantitative method based on hazard event tree and multi-hazard map constructions developed in the frame of the FP7 MIAVITA project. We applied this method to the Kanlaon volcano (Philippines), which is characterized by poor geologic and historical records. We combine updated geological (long-term) and historical (short-term) data, building an event tree for the main types of hazardous events at Kanlaon and their potential frequencies. We then propose an updated multi-hazard map for Kanlaon, which may serve as a working base map in the case of future unrest. The obtained results extend the information already contained in previous volcanic hazard maps of Kanlaon, highlighting (i) an extensive, potentially active ~5 km long summit area striking north-south, (ii) new morphological features on the eastern flank of the volcano, prone to receiving volcanic products expanding from the summit, and (iii) important riverbeds that may potentially accumulate devastating mudflows. This preliminary study constitutes a basis that may help local civil defence authorities in making more informed land use planning decisions and in anticipating future risk/hazards at Kanlaon. This multi-hazard mapping method may also be applied to other poorly known active volcanoes.

Neri, M.; Le Cozannet, G.; Thierry, P.; Bignami, C.; Ruch, J.

2013-08-01

222

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.

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

2014-01-01

223

Novel method to identify the optimal antimicrobial peptide in a combination matrix, using anoplin as an example.  

PubMed

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

Munk, J K; Ritz, C; Fliedner, F P; Frimodt-Møller, N; Hansen, P R

2014-02-01

224

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

225

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

PubMed

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

Yang, Feng; Zhu, Ling

2014-03-01

226

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

NASA Astrophysics Data System (ADS)

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

Hoverman, Suzanne; Ayre, Margaret

2012-12-01

227

Comparison of Active and Passive Seismic Methods for Calculating Shear-wave Velocity Profiles: An Example from Hartford County, Connecticut  

NASA Astrophysics Data System (ADS)

Seismic hazard classifications have been developed for Hartford County, Connecticut based primarily on mapping of surficial materials and depositional environment using criteria specified by the National Earthquake Hazard Reduction Program (NEHRP). A study using near-surface seismic techniques to measure shear-wave velocities in Connecticut was initiated in support of broader seismic hazard mapping efforts undertaken by New England State Geologists. Thirty field sites in Hartford County representative of the range of mapped seismic hazard classes were chosen based on the availability of boring logs and adequate open space for the geophysical surveys. Because it can be difficult to acquire multi-channel seismic data in urban areas due to unwanted noise and open space restrictions, we also investigated the use of passive single-station seismometer measurements as a compact supplement and potential alternative to long-offset multi-channel measurements. Here we compare the results of active-source multi-channel analysis of surface waves (MASW) and passive horizontal-to-vertical spectral ratio (HVSR) seismic methods to determine shear-wave velocity profiles and seismic hazard classification based on Vs30 in glacial sediments throughout Hartford County, Connecticut. HVSR-derived seismic resonances were used as a constraint during inversion of the MASW dispersion curve to reduce model misfit and improve model comparison to site lithology.

Morton, S.; Lane, J. W.; Liu, L.; Thomas, M. A.

2013-12-01

228

A general method to measure the Hall effect in nanowires: examples of FeS2 and MnSi.  

PubMed

We present a general methodology for measuring the Hall effect on nanostructures with one-dimensional (1D) nanowire morphology. Relying only on typical e-beam lithography, the methodology developed herein utilizes an angled electrode evaporation technique so that the nanowire itself is a shadow mask and an intimate sidewall contact can be formed for the Hall electrodes. A six-contact electrode scheme with offset transverse contacts is utilized that allows monitoring of both the longitudinal resistivity and the Hall resistivity which is extracted from the raw voltage from the transverse electrodes using an antisymmetrization procedure. Our method does not require the use of a highly engineered lithographic process to produce directly opposing Hall electrodes with a very small gap. Hall effect measurements on semiconducting iron pyrite (FeS2) nanowire devices are validated by comparing to Hall effect measurements in the conventional Hall geometry using FeS2 plate devices. This Hall effect measurement is further extended to MnSi nanowires, and the distinct anomalous Hall effect signature is identified for the first time in chiral magnetic MnSi nanowires, a significant step toward identifying the topological Hall effect due to skyrmions in chiral magnetic nanowires. PMID:23701294

DeGrave, John P; Liang, Dong; Jin, Song

2013-06-12

229

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.

Shestopaloff, Yuri K.

2014-01-01

230

Image Retrieval by Examples  

Microsoft Academic Search

A currently important research field in information sciences is the management of nontraditional distributed multimedia databases. Two related key issues are to achieve an efficient content-based query by example retrieval and a fast response time. This paper presents the architecture of a distributed image retrieval system which provides novel solutions to these key issues. In particular, a method to quantify

Roberto Brunelli; Ornella Mich

2000-01-01

231

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

232

Melt Structure and Properties: a Spectroscopic Perspective  

NASA Astrophysics Data System (ADS)

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

Stebbins, J.

2006-12-01

233

Fouriertransform infrared spectroscopic imaging of prostate histopathology  

Microsoft Academic Search

Vibrational spectroscopic imaging techniques have emerged as powerful methods of obtaining sensitive spatially resolved molecular information from microscopic samples. The data obtained from such techniques reflect the intrinsic molecular chemistry of the sample and in particular yield a wealth of information regarding functional groups which comprise the majority of important molecules found in cells and tissue. These spectroscopic imaging techniques

Daniel Celestino Fernandez

2003-01-01

234

Total organic carbon and gas chromatography: Mass spectroscopic methods to determine total carbon and hydrocarbons in mercuric iodide single crystals  

SciTech Connect

Total organic carbon was by measuring the CO/sub 2/ produced by combustion in a sealed quartz vessel. The CO/sub 2/ was quantified by nondispersive IR and by titration using commercial detectors. The total organic carbon was found to be around 10 to 100 ..mu..g/g in both starting materials and in single crystals. Gas chromatography--mass spectroscopy (GC/MS) measurements were made hexane extracts of mercuric iodide (HgI/sub 2/) dissolved in potassium iodide solution. Hydrocarbons starting with C/sub 10/ (DIENE) and up to C/sub 26/ were found. In addition, phthalates, such as diethyl and dioctyl phthalate were also found. Some of the organic compounds, for example, such hydrocarbons as branched nC/sub 16/, nC/sub 20/, nC/sub 21/, nC/sub 22/, nC/sub 23/, and nC/sub 24/, were present in some HgI/sub 2/ materials in quantities of the order of weight ppM, but were eliminated in the purification process and were not found in the single crystals. Other organic compounds such as the phthalates were not always eliminated and were identified in the single crystals. In general, the GC/MS could identify only hydrocarbons of C/sub 10/ and higher could account for few percentages of the total organic carbon determined by oxidation. 10 refs., 7 figs., 4 tabs.

Steinberg, S.; Kaplan, I.; Schieber, M..; Ortale, C.; Skinner, N.; van den Berg, L.

1987-01-01

235

The evaluation of a new method to extract spectroscopic factors using asymptotic normalization coefficients and the astrophysical ^14C(n,?)^15C reaction rate  

NASA Astrophysics Data System (ADS)

A new method to determine spectroscopic factors (SFs) that utilizes asymptotic normalization coefficients (ANCs) has been tested at Texas A&M, using ^15C as a test case. The method would use the ANC to fix the external contribution to a non-peripheral reaction which would otherwise be free to vary to unphysical values in a traditional approach. The investigation consisted of two parts. First, the ANC for the ^14C+n configuration in ^15C was determined from the heavy ion neutron transfer reaction ^13C(^14C,^15C)^12C and the inverse kinematics reaction d(^14C,p)^15C. Both of these reactions were measured at sufficiently low energy to be peripheral. Next, a non-peripheral reaction ^14C(d,p)^15C was measured with an incident deuteron energy of 60 MeV, and this reaction was used along with the previously determined ANC to attempt to find the SF. The ANC was also used to calculate the astrophysical neutron direct capture rate for ^14C(n,?)^15C, which was compared with recent direct experimental results.

McCleskey, M.; Mukhamedzhanov, A. M.; Trache, L.; Banu, A.; Goldberg, V.; Roeder, B. T.; Simmons, E. N.; Spiridon, A.; Tribble, R. E.

2011-10-01

236

Determination of the weight percentage gain and of the acetyl group content of acetylated wood by means of different infrared spectroscopic methods.  

PubMed

The weight percentage gain (WPG) and the acetyl group content of wood due to acetylation with acetic anhydride have been analyzed by means of Fourier transform infrared spectroscopy (FTIR) and near-infrared spectroscopy (NIR). Band height ratios (BHR) (1240/1030 (1230/1030) and 1745/1030 (1740/1030)) of the bands at 1745 (1740), 1240 (1230), and 1030 cm-1 were calculated from FTIR-KBr and FTIR-ATR (attenuated total reflection) spectra. The good linear correlation with a coefficient of determination of about 0.94 over a range from 0 to 27% WPG existing between BHRs and WPG and acetyl group content, respectively, requires only a few samples to calibrate FTIR. Partial least-squares regression models based on second derivatives of the NIR spectra in the wavenumber range from 6080 to 5760 cm-1 resulted in a R2 value of 0.99, number of PLS components (rank) between 3 and 5, root-mean-square error of cross-validation between 0.6 and 0.79%, and a residual prediction deviation up to 10. Although a wide range of input parameters (i.e., various wood species and different procedures of acetylation) was used, highly satisfactory results were obtained. Both FTIR and NIR spectroscopic means fulfill the need for determining the WPG and the acetyl content of acetylated wood. By reason of its additional potential for on-line process control, the NIR method may even outperform the FTIR method. PMID:18197697

Stefke, Barbara; Windeisen, Elisabeth; Schwanninger, Manfred; Hinterstoisser, Barbara

2008-02-15

237

Spectroscopic Analysis of H? Dots  

NASA Astrophysics Data System (ADS)

We present spectroscopic measurements of ~200 faint point sources of emission - called H? dots - found in narrow-band images taken for the ALFALFA H? project. Our image analysis catalogs emission-line sources that are not optically associated with the target ALFALFA galaxy. Analyzing spectra of these sources, we find isolated extragalactic HII regions, ultra-low luminosity dwarf galaxies, background (higher redshift) galaxies, and QSOs. We give a summary of the photometric and spectroscopic properties of the full sample of H? dots discovered to date. We also illustrate why these objects are of astrophysical interest. For example, using coarse oxygen abundance measurements of the low luminosity dwarf galaxies, we detect signs of a possible flattening in the local Luminosity-Metallicity relation. We also find luminous [O III]-detected star-forming galaxies at z ~ 0.32 with unusually low oxygen abundances.

Feddersen, Jesse; Salzer, J. J.; Gronwall, C.

2013-06-01

238

Correlation mapping: rapid method for identification of histological features and pathological classification in mid infrared spectroscopic images of lymph nodes  

Microsoft Academic Search

In this work, a novel technique for rapid image analysis of Fourier transform infrared (FTIR) data obtained from human lymph nodes is explored. It uses the mathematical principle of orthogonality as a method to quickly and efficiently obtain tissue and pathology information from a spectral image cube. It requires less computational power and time compared to most forms of cluster

Martin Isabelle; Keith Rogers; Nicholas Stone

2010-01-01

239

Aplicacion de metodos espectroscopicos para estudiar efectos de la radiacion en polimeros. (Application of spectroscopic methods to the study of ionizing radiation effects in polymers).  

National Technical Information Service (NTIS)

In general the interaction of ionizing radiation with polymers generates physic-chemical changes. Aiming to quantity these changes, three spectroscopic analytical techniques were used (UV, IR and EPR) and the chemical corrosion technique was used for thre...

G. Jimenez

1995-01-01

240

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

NASA Astrophysics Data System (ADS)

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

Ragab, Gamal H.; Amin, Alaa S.

2004-03-01

241

Development and Validation of a Stability-indicating UV Spectroscopic Method for Candesartan in Bulk and Formulations.  

PubMed

A simple, specific, accurate and stability-indicating UV- Spectrophotometric method was developed for the estimation of candesartan cilexitil, using a Shimadzu, model 1700 spectrophotometer and a mobile phase composed of methanol: water in the ratio of 9:1 at wave length (?(max)) 254 nm. Linearity was established for candesartan in the range of 10-90 ?g/ml. The percentage recovery of was found to be in the range of 99.76-100.79%. The drug was subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, UV light and photolytic degradation. Validation experiments performed to demonstrate system suitability, specificity, precision, linearity, accuracy, interday assay, intraday assay, robustness, ruggedness, LOD, and LOQ. While estimating the commercial formulation there was no interference of excipients and other additives. Hence this method can be used for routine determination of candesartan cilexetil in bulk and their pharmaceutical dosage forms. The proposed method for stability study shows that there was appreciable degradation found in stress condition of candesartan. PMID:23112408

Pradhan, K K; Mishra, U S; Pattnaik, S; Panda, C K; Sahu, K C

2011-11-01

242

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

243

Development and Validation of a Stability-indicating UV Spectroscopic Method for Candesartan in Bulk and Formulations  

PubMed Central

A simple, specific, accurate and stability-indicating UV- Spectrophotometric method was developed for the estimation of candesartan cilexitil, using a Shimadzu, model 1700 spectrophotometer and a mobile phase composed of methanol: water in the ratio of 9:1 at wave length (?max) 254 nm. Linearity was established for candesartan in the range of 10-90 ?g/ml. The percentage recovery of was found to be in the range of 99.76-100.79%. The drug was subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, UV light and photolytic degradation. Validation experiments performed to demonstrate system suitability, specificity, precision, linearity, accuracy, interday assay, intraday assay, robustness, ruggedness, LOD, and LOQ. While estimating the commercial formulation there was no interference of excipients and other additives. Hence this method can be used for routine determination of candesartan cilexetil in bulk and their pharmaceutical dosage forms. The proposed method for stability study shows that there was appreciable degradation found in stress condition of candesartan.

Pradhan, K. K.; Mishra, U. S.; Pattnaik, S.; Panda, C. K.; Sahu, K. C.

2011-01-01

244

Proton nuclear magnetic resonance spectroscopic detection of oligomannosidic n glycans in alpha-mannosidosis: a method of monitoring treatment.  

PubMed

In Alpha-mannosidosis (MIM 248500) the patients accumulate mainly unbranched oligosaccharide chains in the lysosomes in all body tissues, including the brain. With ensuing therapeutic modalities in man (BMT and ERT) non-invasive methods of monitoring the effect of treatment are needed. Paramount is the possible effect of the treatment on the brain, since this organ is regarded as difficult to reach because of the blood-brain barrier. We therefore performed proton nuclear magnetic resonance spectroscopy (MRS) of the brain in two untreated patients, and a 16-year-old patient treated with BMT at the age of 10 to assess whether this non-invasive method could be applied in the monitoring of the accumulation of abnormal chemicals in the brain of patients. We found an abnormal peak that was not present in the treated patient. A similar pattern was also found in MRS of urine from patients, reflecting the concentration of oligosaccharides in serum and tissues. We therefore conclude that MRS can be a useful method to monitor the effect of treatment for Alpha-Mannosidosis. PMID:21541723

Avenarius, Derk Frederik Matthaus; Svendsen, John-Sigurd; Malm, Dag

2011-10-01

245

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

PubMed

A novel water-soluble 1,8-naphthalimide derivative 1, bearing two acetic carboxylic groups, exhibited fluorescent turn-on recognition for casein based on the aggregation induced emission (AIE) character. The photophysical properties of 1 consisting of donor and acceptor units were investigated in different solutions. The fluorescence intensity decreased through taking advantage of twisted intramolecular charge transfer (TICT) and self-association emission with increasing solvent polarity. Moreover, the spectral red-shift and intensity quench in protic solvents were caused by the excited-state hydrogen bond strengthening effect. Density Functional Theory (DFT) calculations revealed that 1 exhibited a strong TICT character. The AIE mechanism of 1 with casein was due to 1 docked in the hydrophobic cavity between sub-micelles and bound with Tyr and Trp residues, resulting in the aggregation of 1 on the casein surface and emission enhancement. Based on this, a novel casein assay method was developed. The proposed exhibited a good linear range from 0.1 to 22 ?g mL(-1), with the detection limit of 2.8 ng mL(-1). Satisfactory reproducibility, reversibility and a short response time were realized. This method was applied to the determination of casein in milk powder samples and the results were in good agreement with the result of Biuret method. PMID:23454708

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

2013-05-01

246

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

PubMed

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

Mol?anov, Krešimir; Stare, Jernej; Vener, Mikhail V; Koji?-Prodi?, Biserka; Mali, Gregor; Grdadolnik, Jože; Moha?ek-Grošev, Vlasta

2014-01-21

247

New spectroscopic method for aqueous solutions: Raman ?-function dispersion for NaClO4 in water  

NASA Astrophysics Data System (ADS)

A new Raman method is exemplified by ??-RT[? ln(I?/IREF)/?X1]T,P,n2,n3 for ternary NaClO4/D2O/H2O, or by ??-RT[? ln(I?/IREF)/?X2]T,P for binary NaClO4/H2O solutions. (Fundamental differences exist between ? and the chemical potential ?.) I? is the Raman intensity at ?, IREF is the reference intensity, e.g., at the isosbestic frequency, X2 is the H2O and X1 the small D2O mol fraction, and n2 and n3 are constant mols of H2O and NaClO4, respectively. Maxima (max) and minima (min) were observed in ? versus ? (cm-1) ?max-?min=??max. ??max=8050+/-100 cal/mol H2O for the coupled, binary solution OH stretch, and ??max=4200+/-200 cal/mol H bond for the decoupled, ternary solution OD stretch. The perchlorate ion breaks the H bonds in water. 8050 cal/mol H2O corresponds to the maximum tetrahedral ??max value for two H bonds, i.e., ??max=4025 cal/mol H bond, in agreement with the HDO ??max=4200+/-200 cal/mol H bond. [??max is not the H bond enthalpy (energy).] Minima occur in ? at the peak ? values corresponding to the HDO/H2O and H2O ices, and maxima in ? at 2637+/-5 cm-1 (OD) and 3575+/-10 cm-1 (OH) correspond to the peak OD and OH stretching ? values from dense supercritical water. Enthalpy dispersion curves were also determined for saturated, binary, and ternary NaClO4 solutions and for D2O in H2O. The ?-function method is shown to be applicable to infrared absorbance spectra.

Walrafen, George E.

2005-03-01

248

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

249

Deciphering P-T paths in metamorphic rocks involving zoned minerals using quantified maps (XMapTools software) and thermodynamics methods: Examples from the Alps and the Himalaya.  

NASA Astrophysics Data System (ADS)

Metamorphic rocks are made by mosaic of local thermodynamic equilibria involving minerals that grew at different temporal, pressure (P) and temperature (T) conditions. These local (in space but also in time) equilibria can be identified using micro-structural and textural criteria, but also tested using multi-equilibrium techniques. However, linking deformation with metamorphic conditions requires spatially continuous estimates of P and T conditions in least two dimensions (P-T maps), which can be superimposed to the observed structures of deformation. To this end, we have developed a new Matlab-based GUI software for microprobe X-ray map processing (XMapTools, http://www.xmaptools.com) based on the quantification method of De Andrade et al. (2006). XMapTools software includes functions for quantification processing, two chemical modules (Chem2D, Triplot3D), the structural formula functions for common minerals, and more than 50 empirical and semi-empirical geothermobarometers obtained from the literature. XMapTools software can be easily coupled with multi-equilibrium thermobarometric calculations. We will present examples of application for two natural cases involving zoned minerals. The first example is a low-grade metapelite from the paleo-subduction wedge in the Western Alps (Schistes Lustrés unit) that contains only both zoned chlorite and phengite, and also quartz. The second sample is a Himalayan eclogite from the high-pressure unit of Stak (Pakistan) with an eclogitic garnet-omphacite assemblage retrogressed into clinopyroxene-plagioclase-amphibole symplectite, and later into amphibole-biotite during the collisional event under crustal conditions. In both samples, P-T paths were recovered using multi-equilibrium, or semi-empirical geothermobarometers included in the XMapTools package. The results will be compared and discussed with pseudosections calculated with the sample bulk composition and with different local bulk rock compositions estimated with XMapTools. De Andrade, V., Vidal, O., Lewin, E., O'Brien, P., Agard, P., 2006. Quantification of electron microprobe compositional maps of rock thin sections: an optimized method and examples. Journal of Metamorphic Geology 24, 655-668.

Lanari, P.; Vidal, O.; Schwartz, S.; Riel, N.; Guillot, S.; Lewin, E.

2012-04-01

250

Characterization of intermolecular interaction between cyanidin-3-glucoside and bovine serum albumin: Spectroscopic and molecular docking methods.  

PubMed

The intermolecular interaction between cyanidin-3-glucoside (Cy-3-G) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism and molecular docking methods. The experimental results revealed that the fluorescence quenching of BSA at 338?nm by Cy-3-G resulted from the formation of Cy-3-G-BSA complex. The number of binding sites (n) for Cy-3-G binding on BSA was approximately equal to 1. The experimental and molecular docking results revealed that after binding Cy-3-G to BSA, Cy-3-G is closer to the Tyr residue than the Trp residue, the secondary structure of BSA almost not change, the binding process of Cy-3-G with BSA is spontaneous, and Cy-3-G can be inserted into the hydrophobic cavity of BSA (site II') in the binding process of Cy-3-G with BSA. Moreover, based on the sign and magnitude of the enthalpy and entropy changes (?H(0) ?=?- 29.64?kcal/mol and ?S(0) ?=?- 69.51?cal/mol?K) and the molecular docking results, it can be suggested that the main interaction forces of Cy-3-G with BSA are Van der Waals and hydrogen bonding interactions. Copyright © 2013 John Wiley & Sons, Ltd. PMID:24123897

Shi, Jie-Hua; Wang, Jing; Zhu, Ying-Yao; Chen, Jun

2014-08-01

251

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

PubMed

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 degrees 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 degrees C. PMID:19836296

Prabakaran, K; Rajeswari, S

2009-12-01

252

Development of a method for nondestructive NIR transmittance spectroscopic analysis of acetaminophen and caffeine anhydrate in intact bilayer tablets.  

PubMed

Calibration models for nondestructive NIR analysis of API (active pharmaceutical ingredient) contents in two separate layers of intact bilayer tablets were established. These models will enable the use of NIR transmittance spectroscopy in bilayer tableting processes for the control of API contents in separate layers. Acetaminophen and caffeine anhydrate were used as APIs, and tablets were made by the direct compression method. Their NIR spectra were measured in the transmittance mode. The reference assay was performed by HPLC. Calibration models were generated by the partial least-squares (PLS) regression. The initial calibration generated models with insufficient linearity and accuracy because the fluctuation range of tablet thickness was excessively large and irrelevant information on the thickness fluctuation was included in the models. By narrowing the fluctuation range to determine the proper range for acceptable prediction accuracy, it was confirmed that calibration models with less irrelevant information can be generated when the range was 4.30+/-0.06 mm or narrower. Furthermore, the fluctuation range of 4.30+/-0.06 mm was considered to be empirically valid in covering the fluctuation actually observed in ordinary tableting processes. Thus, the sample tablets within this range were used to generate the final calibration models, and calibration models sufficient in linearity and accuracy were established. In addition, it was proven that controlling the irradiated side was unnecessary. Namely, it is not necessary to keep the same side of sampled tablets for the online NIR analysis during bilayer tableting. It is useful, in order to obtain adequate calibration models, to evaluate the variable factors that affect the linearity and accuracy of the generated models and restrict the range of models or use a subset of prepared samples. Loading vectors, explained variances, and correlation coefficients between components and scores are important for the evaluation of variable factors. PMID:20547027

Ito, Masatomo; Suzuki, Tatsuya; Yada, Shuichi; Nakagami, Hiroaki; Teramoto, Hiroshi; Yonemochi, Etsuo; Terada, Katsuhide

2010-11-01

253

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).

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

2012-01-01

254

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

PubMed

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

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

2014-04-01

255

Isobaric Analog States for Neutron Spectroscopic Factors.  

National Technical Information Service (NTIS)

A survey of the modified R-matrix method for extraction of neutron spectroscopic factors from isobaric analog resonances in proton elastic scattering polarization and cross section excitation functions is presented for several parent analog states in Zirc...

W. J. Thompson J. L. Ellis

1969-01-01

256

Using data mining techniques to explore physicians' therapeutic decisions when clinical guidelines do not provide recommendations: methods and example for type 2 diabetes  

PubMed Central

Background Clinical guidelines carry medical evidence to the point of practice. As evidence is not always available, many guidelines do not provide recommendations for all clinical situations encountered in practice. We propose an approach for identifying knowledge gaps in guidelines and for exploring physicians' therapeutic decisions with data mining techniques to fill these knowledge gaps. We demonstrate our method by an example in the domain of type 2 diabetes. Methods We analyzed the French national guidelines for the management of type 2 diabetes to identify clinical conditions that are not covered or those for which the guidelines do not provide recommendations. We extracted patient records corresponding to each clinical condition from a database of type 2 diabetic patients treated at Avicenne University Hospital of Bobigny, France. We explored physicians' prescriptions for each of these profiles using C5.0 decision-tree learning algorithm. We developed decision-trees for different levels of detail of the therapeutic decision, namely the type of treatment, the pharmaco-therapeutic class, the international non proprietary name, and the dose of each medication. We compared the rules generated with those added to the guidelines in a newer version, to examine their similarity. Results We extracted 27 rules from the analysis of a database of 463 patient records. Eleven rules were about the choice of the type of treatment and thirteen rules about the choice of the pharmaco-therapeutic class of each drug. For the choice of the international non proprietary name and the dose, we could extract only a few rules because the number of patient records was too low for these factors. The extracted rules showed similarities with those added to the newer version of the guidelines. Conclusion Our method showed its usefulness for completing guidelines recommendations with rules learnt automatically from physicians' prescriptions. It could be used during the development of guidelines as a complementary source from practice-based knowledge. It can also be used as an evaluation tool for comparing a physician's therapeutic decisions with those recommended by a given set of clinical guidelines. The example we described showed that physician practice was in some ways ahead of the guideline.

2009-01-01

257

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

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

258

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

PubMed

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

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

2010-12-28

259

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

260

Approaches to spectroscopic characterization of cations  

NASA Astrophysics Data System (ADS)

Ions, the essence of mass spectrometry, are on the whole spectroscopically rather poorly characterized. This situation has, however, been changing rapidly with the development and application of laser methods. One of the ways to obtain information on the electronic, vibrational and rotational structure of polyatomic catios is via their electronic transitions. This is the subject of this review. In the first part, earlier studies aimed at determining vibrational frequencies, as well as the geometry of such ions, are illustrated by a couple of examples. The bulk of the article outlines our current developments which aim at spectral characterization of mass-selected ions, including fragments. The first success has been the study of C+2. A new method enables mass selected ions, which are co-deposited with neon to form a 5K matrix, to be studied by measurement of their electronic absorption spectra. In a gas phase method, electronic transitions between bound states of an ion can be probed using a two-colour laser photon, absorption-dissociation approach, with fragment ion detection. Recent results illustrate the potential of these techniques.

Maier, John P.

1991-01-01

261

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

262

THE WORKED EXAMPLE  

Microsoft Academic Search

In this essay, we begin with a theoretical articulation the worked example as a form of invitational scholarship that provides new media scholars, in particular, an important outlet for their work. A worked example leverages

263

Frequency domain optical coherence tomography with subsequent depth resolved spectroscopic image analysis  

Microsoft Academic Search

We present a method to obtain additional depth resolved spectroscopic information from standard frequency domain optical coherence tomography (FDOCT) images. This method utilizes Fourier transforms of signal peaks within the complex FDOCT depth profiles to extract depth resolved spectroscopic information. For verification of the depth resolved spectroscopic image analysis method, theoretical simulations as well as experimental studies are demonstrated. Both

Christoph Kasseck; Volker Jaedicke; Nils C. Gerhardt; Hubert Welp; Martin R. Hofmann

2010-01-01

264

Editing by example  

Microsoft Academic Search

An editing by example system is an automatic program synthesis facility embedded in a text editor that can be used to solve repetitive text editing problems. The user provides the editor with a few examples of a text transformation. The system analyzes the examples and generalizes them into a program that can perform the transformation to the rest of the

Robert P. Nix

1984-01-01

265

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.

266

Specular spectroscopic scatterometry  

Microsoft Academic Search

Scatterometry is one of the few metrology candidates that has true in situ\\/in-line potential for deep submicrometer critical dimension (CD) and profile analysis. Most existing scatterometers are designed to measure multiple incident angles at a single wavelength on periodic gratings. We extend this idea by deploying specular spectroscopic scatterometry. Specular spectroscopic scatterometry (SS) is designed to measure the zeroth-order diffraction

Xinhui Niu; Nickhil Jakatdar; Junwei Bao; Costas J. Spanos

2001-01-01

267

Example based lesion segmentation  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

268

Direct electrochemistry and electrocatalysis of anthraquinone-monosulfonate/polyaniline hybrid film synthesized by a novel electrochemical doping-dedoping-redoping method on pre-activated spectroscopically pure graphite surface.  

PubMed

Polyaniline (PANI) film in the form of emeraldine salt (ES) doped with anthraquinone-2-sulfonate (AQS) was synthesized by a novel electrochemical doping-dedoping-redoping method on pre-activated spectroscopically pure graphite electrode surface. SEM showed the highly porous microstructure with sponge-like morphology of the AQS/PANI hybrid film, which has more available active sites for facilitating electron transfer and energy efficiency of redox reactions. FTIR and UV-vis spectra demonstrated the incorporation of AQS into the conductive PANI matrix. Cyclic voltammetric (CV), electrochemical impedance spectroscope (EIS), rotating ring-disk electrode (RRDE) and chronoamperometry (CA) techniques indicated that the AQS/PANI composite has high electrocatalytic activity and remarkable stability for the two-electron reduction of oxygen via an electrochemical-chemical mechanism at the base of the porous PANI film. The acid centers of PANI (protonated imine group) played an important role not only in two internal redox transform processes, but also in an external charge transfer reaction during the electrocatalytic reduction of oxygen. The incorporation of anionic AQS groups into PANI matrix to prepare electroactive PANI using the electrochemical doping-dedoping-redoping method is conceptually new, and may be extended to the development of new functional materials from many other conducting polymers and quinonoid compounds for wide applications in catalysis, sensors, molecular electronics, and so on. PMID:21212886

Zhang, Guoquan; Yang, Fenglin

2011-02-28

269

The Origin, Composition and History of Comets from Spectroscopic Studies  

NASA Technical Reports Server (NTRS)

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

Allamandola, L. J.

1997-01-01

270

Generating Rules and Examples.  

ERIC Educational Resources Information Center

This seventh in a series of articles discussing expert system construction focuses on two ways to create a structure that determines a decision: (1) rule-based, or deductive, implementation; and (2) example-based, or inductive, implementation. Probability factors and confidence levels are discussed, and an example is given for selecting an…

Grabinger, R. Scott; Jonassen, David H.

1989-01-01

271

Rapid Flow Analysis Studies with Spectroscopic Detectors.  

NASA Astrophysics Data System (ADS)

A rapid flow analysis study based on segmented flow and flow injection principles is described in this thesis. The main objective of this study was to establish the response characteristics in continuous flow analysis systems in order to improve sampling rates with several types of spectroscopic detectors. It was found from flame photometric studies that non-segmented flowing streams are applicable to rapid flow analysis with automatic sample aspiration. Calcium was used as a typical example and determined at sampling rates up to 360 h('-1) with a detection limit of 0.05 mg L(' -1). A rapid flow system is reported using direct aspiration for AAS analysis with both manual injection and automatic aspiration techniques, and found to give sampling rates of up to 600-720 samples h('-1). Speed of analysis was reduced by about 50% when using an external peristaltic pump in the flow system design, due to increased sample dispersion. A novel aspect of a rapid flow injection approach reported with ICPAES detection includes the method of injecting samples via a peristaltic pump with simultaneous computer data processing. Determination of serum cations (Na, K, Ca, Mg and Fe) was demonstrated as an example of an application of the technique at sampling rates of 240 h('-1). Precision and detection limits for 13 elements in a single standard solution are reported. The use of automated aspiration sampling is also reported in this method for comparison. Further studies on flow characteristics were carried out by a combination of the rapid flow system with very short sampling times as low as 2 seconds using UV-visible spectrophotometric detection. Analysis of human blood serum samples was used as an example where total protein and inorganic phosphate were determined at sampling rates of 240 h('-1) and 360 h('-1) respectively. The novel aspects of the results from these studies include the very rapid sample throughput developed with simple and inexpensive experimental approaches in comparison to bubble gating and loop injection techniques. Part of this thesis has already been published and the abstracts are presented in the Appendix.

Thalib, Amlius

272

Example-based Volume Illustrations  

Microsoft Academic Search

Scientic illustrations use accepted conventions and methodologies to effectively convey object properties and improve our understand- ing. We present a method to illustrate volume datasets by emulating example illustrations. As with technical illustrations, our volume illustrations more clearly delineate objects, enrich details, and ar- tistically visualize volume datasets. For both color and scalar 3D volumes, we have developed an automatic

Aidong Lu; David S. Ebert

2005-01-01

273

Example-based volume illustrations  

Microsoft Academic Search

Scientific illustrations use accepted conventions and methodologies to effectively convey object properties and improve our understanding. We present a method to illustrate volume datasets by emulating example illustrations. As with technical illustrations, our volume illustrations more clearly delineate objects, enrich details, and artistically visualize volume datasets. For both color and scalar 3D volumes, we have developed an automatic color transfer

Aidong Lu; D. S. Ebert

2005-01-01

274

An effective eigenchannel R-matrix calculation of electron-ion scattering processes with spectroscopic precision  

NASA Astrophysics Data System (ADS)

Using our eigenchannel R-matrix method, the scattering matrices in the whole energy regions can be directly calculated with spectroscopic precision. From the short range scattering matrices, various scattering cross sections, such as total excitation cross sections, differential cross sections and so on, can be obtained. The e+Kr+ system is used as an illustration example, the degree of accuracies of scattering matrices is calculated within about 6%, which should be much more accurate than state-of-the-art scattering experiments.

Gao, Xiang; Li, Jia-Ming

2014-04-01

275

A Spectroscopic-Based Laboratory Experiment for Protein Conformational Studies  

ERIC Educational Resources Information Center

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

Ramos, Carlos Henrique I.

2004-01-01

276

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

SciTech Connect

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

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

2007-07-10

277

LRC Applet: Example 2  

NSDL National Science Digital Library

All circuit components in the LRC Applet are data sources and can pass current and voltage values to a data listener. In this example, the current, voltage, and power delivered by the source are plotted on a data graph.

Christian, Wolfgang; Belloni, Mario

2008-02-09

278

[Meningiomas. Clinical case examples].  

PubMed

Using four case reports as examples the best treatment is discussed by considering the specific history and magnetic resonance imaging (MRI) findings. In many cases different therapeutic alternatives are possible for treatment of meningiomas. PMID:23595649

Wilhelm, H; Batra, M; Honegger, J; Paulsen, F

2013-05-01

279

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.

280

MAMA Spectroscopic Throughputs  

NASA Astrophysics Data System (ADS)

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

Lennon, Daniel

2008-07-01

281

Handmade compact disc spectroscope  

NASA Astrophysics Data System (ADS)

Astronomy data center held some programs for the open house day of 2005, and a program of handmade compact disc spectroscope in craft corner received a favorable review. We report a summary of the program and the product in this article.

Kawanomoto, Satoshi

2006-10-01

282

Algebra I Worked Examples  

NSDL National Science Digital Library

This series of videos contains 180 Worked Algebra I examples (problems written by the Monterey Institute of Technology and Education). You should look at the "Algebra" playlist if you've never seen algebra before or if you want instruction on topics in Algebra II. Use this playlist to see a ton of example problems in every topic in the California Algebra I Standards. If you can do all of these problems on your own, you should probably succeed in Algebra I,

Khan, Salman

2011-01-05

283

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

Microsoft Academic Search

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

Jacques Zlotnicki; Y. Sasai; E. Villacorte; M. Harada; P. Yvetot; F. Fauquet; A. Bernard; T. Nagao

2008-01-01

284

Application of RES methods for computation of hydrodynamic flows by an example of a 2D flow past a circular cylinder for Re = 5–200  

Microsoft Academic Search

An effective method of simulation of multidimensional hydrodynamic problems for small Mach numbers is described. The method is based on utilization of FFT (fast Fourier transform) for solving the Poisson equation on a rectangular grid in domains with complicated geometry (particularly multi-linked). Simulation was performed with zero numerical viscosity. The speed of calculation of the Poisson equation is 1–2 orders

Igor M. Kozlov; Kirill V. Dobrego; Nickolai N. Gnesdilov

2011-01-01

285

Neutron Spectroscopic Factors from Isobaric Analog States.  

National Technical Information Service (NTIS)

The spectroscopic factors S sub n of bound neutron states are usually found from (d,p) stripping reactions. An alternative method of finding S sub n for medium-to-heavy nuclei is to analyze isobaric analog resonances observed in (p,p) scattering from thes...

W. J. Thompson J. L. Adams D. Robson

1968-01-01

286

Application of correlation constrained multivariate curve resolution alternating least-squares methods for determination of compounds of interest in biodiesel blends using NIR and UV-visible spectroscopic data.  

PubMed

This study describes two applications of a variant of the multivariate curve resolution alternating least squares (MCR-ALS) method with a correlation constraint. The first application describes the use of MCR-ALS for the determination of biodiesel concentrations in biodiesel blends using near infrared (NIR) spectroscopic data. In the second application, the proposed method allowed the determination of the synthetic antioxidant N,N'-Di-sec-butyl-p-phenylenediamine (PDA) present in biodiesel mixtures from different vegetable sources using UV-visible spectroscopy. Well established multivariate regression algorithm, partial least squares (PLS), were calculated for comparison of the quantification performance in the models developed in both applications. The correlation constraint has been adapted to handle the presence of batch-to-batch matrix effects due to ageing effects, which might occur when different groups of samples were used to build a calibration model in the first application. Different data set configurations and diverse modes of application of the correlation constraint are explored and guidelines are given to cope with different type of analytical problems, such as the correction of matrix effects among biodiesel samples, where MCR-ALS outperformed PLS reducing the relative error of prediction RE (%) from 9.82% to 4.85% in the first application, or the determination of minor compound with overlapped weak spectroscopic signals, where MCR-ALS gave higher (RE (%)=3.16%) for prediction of PDA compared to PLS (RE (%)=1.99%), but with the advantage of recovering the related pure spectral profile of analytes and interferences. The obtained results show the potential of the MCR-ALS method with correlation constraint to be adapted to diverse data set configurations and analytical problems related to the determination of biodiesel mixtures and added compounds therein. PMID:24840439

de Oliveira, Rodrigo Rocha; de Lima, Kássio Michell Gomes; Tauler, Romà; de Juan, Anna

2014-07-01

287

Construction of reservoir flow models using deterministic and stochastic methods and driven by seismic acoustic impedance--a Gulf of Mexico example  

SciTech Connect

Rapid and accurate subsurface descriptions and flow predictions contribute to profitable field development, particularly for deep water fields of modest size. This paper shows how 3-D seismic acoustic impedance played an essential roll in that process. This Tertiary field example exhibits a classic Gulf of Mexico {open_quotes}bright{close_quotes} seismic response. The slope channel deposits yielded reflections from stacked pay zones that were often interfering vertically and laterally variable. Seismic acoustic impedance inversion for volume estimation, well placement and flow model construction. Flow model construction was facilitated using Stratamodel, where reservoir boundaries, porosity and permeability were estimated from seismic acoustic impedance. This provided a {open_quotes}deterministic{close_quotes} flow model with which well choices and development economics were explored. Alternate flow models were developed in which the effect of fine scale (sub-seismic) heterogeneities were investigated. A 3-D {open_quotes}stochastic{close_quotes} model was developed that honored geostatistical parameters as well as seismic acoustic impedance. This gave insight to permeability distributions and confirmed that connectivity between scattered sand bodies would not significantly degrade the field performance predicted by deterministic models.

Meanley, E.; Guderjahn, C.; Litvak, M. [BP Exploration, Houston, TX (United States)] [and others

1995-08-01

288

[Calculation of disease-related costs in claims data analyses with the example of attention-deficit hyperactivity disorder. Comparison of methods].  

PubMed

Claims data have proven useful for carrying out cost-of-illness studies. To avoid overestimating disease-related costs, only those costs that are related to a specific disease should be considered. The present study demonstrates two basic approaches for identifying disease-related costs. Using the example of attention-deficit hyperactivity disorder (ADHD), the advantages and drawbacks of expert-based approaches and those based on control groups are compared. Anonymized data from the "Techniker Krankenkasse" for 2008 were available for the study. The study population encompassed all ADHD patients and a control group that was five times bigger. Additionally, a systematic literature review was carried out on 65 relevant studies. Compared with the control group, disease-related costs were EUR 2,902 per ADHD patient on average. However, using the expert-based approach, costs were established to be EUR 923 lower. This is mainly because a comparison with an appropriate control group incorporates all costs for possible comorbidities and concomitant diseases. Both approaches have specific advantages and drawbacks, and when planning studies the respective limitations need to be considered. PMID:23455561

Zeidler, J; Lange, A; Braun, S; Linder, R; Engel, S; Verheyen, F; Graf von der Schulenburg, J-M

2013-03-01

289

A comparative study of caffeine and theophylline binding to Mg(II) and Ca(II) ions: studied by FTIR and UV spectroscopic methods  

NASA Astrophysics Data System (ADS)

The interactions of calcium and magnesium ions with caffeine and theophylline have been investigated in aqueous solution at physiological pH. Fourier Transform infrared (FTIR) spectroscopy and absorption spectra were used to determine the cation binding mode and the association constants. Our spectroscopic results showed that calcium and magnesium ions do not complex with caffeine strongly and the weak interactions between caffeine and Mg 2+ and Ca 2+ might be via O6 atom. In Ca 2+-theophylline complex, binding between Ca 2+ with C?O and N7 is observed, however in Mg 2+-theophylline complex, binding between Mg 2+ and N7 is more likely. The k values of these complexes are as follows: k(caffeine-Ca)=29.8 M -1, k(caffeine-Mg)=22.4 M -1, k(theophylline-Ca)=59.8 M -1 and k(theophylline-Mg)=33.8 M -1. These values are evidence for a weak cation interaction in these metal complexes.

Nafisi, Shohreh; Shamloo, Delaram Sadraii; Mohajerani, Nasser; Omidi, Akram

2002-08-01

290

Influence of pattern of missing data on performance of imputation methods: an example using national data on drug injection in prisons.  

PubMed

Background: Policy makers need models to be able to detect groups at high risk of HIV infection. Incomplete records and dirty data are frequently seen in national data sets. Presence of missing data challenges the practice of model development. Several studies suggested that performance of imputation methods is acceptable when missing rate is moderate. One of the issues which was of less concern, to be addressed here, is the role of the pattern of missing data. Methods: We used information of 2720 prisoners. Results derived from fitting regression model to whole data were served as gold standard. Missing data were then generated so that 10%, 20% and 50% of data were lost. In scenario 1, we generated missing values, at above rates, in one variable which was significant in gold model (age). In scenario 2, a small proportion of each of independent variable was dropped out. Four imputation methods, under different Event Per Variable (EPV) values, were compared in terms of selection of important variables and parameter estimation. Results: In scenario 2, bias in estimates was low and performances of all methods for handing missing data were similar. All methods at all missing rates were able to detect significance of age. In scenario 1, biases in estimations were increased, in particular at 50% missing rate. Here at EPVs of 10 and 5, imputation methods failed to capture effect of age. Conclusion: In scenario 2, all imputation methods at all missing rates, were able to detect age as being significant. This was not the case in scenario 1. Our results showed that performance of imputation methods depends on the pattern of missing data. PMID:24596839

Haji-Maghsoudi, Saiedeh; Haghdoost, Ali-Akbar; Rastegari, Azam; Baneshi, Mohammad Reza

2013-06-01

291

Spectroscopic patterns encode unimolecular dynamics  

NASA Astrophysics Data System (ADS)

This thesis investigates the unimolecular vibrational dynamics of acetylene with up to 15,000 cm-1 of internal energy, as encoded by dispersed fluorescence spectra of the acetylene S 1 --> S0 system. Above 10,000 cm -1 of vibrational energy, these spectra are extremely congested and cannot be analyzed using conventional spectroscopic assignment procedures. Instead, a numerical pattern recognition technique entitled Extended Cross Correlation (XCC) is introduced which utilizes methods of robust estimation to identify a priori unknown patterns that are repeated in multiple spectra. In particular, the XCC identifies spectroscopic patterns in the dispersed fluorescence spectra that are associated with approximately conserved polyad quantum numbers. This pattern recognition analysis makes possible detailed modelling, using an effective Hamiltonian, of the acetylene unimolecular vibrational dynamics up to 15,000 cm-1. Of special interest are the large-amplitude bending motions of acetylene at high energy (22 quanta of bend excitation), which are investigated using techniques of quantum, semiclassical, and nonlinear classical mechanics. At 15,000 cm-1, the classical mechanics associated with the bending system is profoundly different from that at low energy, where normal mode motions (trans and cis bend) dominate. Specifically, classical chaos coexists with stable classical motions that are unrelated to the normal mode motions. The most stable large amplitude bending motions include ``local bend'' (one hydrogen bending) and ``counter-rotation'' (the two hydrogens undergoing circular motion at opposite ends of the molecule) motions. The existence of these stable motions at high energy is a manifestation of a normal-to- local transition in the bend degrees of freedom that is analogous to, but substantially more complicated than, the well-known normal-to-local transitions in the stretch degrees of freedom of ABA molecules. In addition to the XCC, two additional numerical tools for spectroscopic analysis are discussed: Hybrid Linear Pattern Analysis (HLPA) and Robust Baseline Estimation (RBE). HLPA is a hybrid of conventional least-squares fitting and XCC which is applicable when certain patterns contained in a spectroscopic data set are known a priori but others are not. HLPA is applied to investigate the kinetics of intermolecular energy transfer in atmospheric simulation experiments involving carbon monoxide. RBE is a technique for baseline removal; that is, it permits the separation of the sharp features in a spectrum from a continuous, slowly varying baseline. (Copies available exclusively from MIT Libraries, Rm. 14- 0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Jacobson, Matthew Paul

1999-12-01

292

Active Learning with Irrelevant Examples  

NASA Technical Reports Server (NTRS)

An improved active learning method has been devised for training data classifiers. One example of a data classifier is the algorithm used by the United States Postal Service since the 1960s to recognize scans of handwritten digits for processing zip codes. Active learning algorithms enable rapid training with minimal investment of time on the part of human experts to provide training examples consisting of correctly classified (labeled) input data. They function by identifying which examples would be most profitable for a human expert to label. The goal is to maximize classifier accuracy while minimizing the number of examples the expert must label. Although there are several well-established methods for active learning, they may not operate well when irrelevant examples are present in the data set. That is, they may select an item for labeling that the expert simply cannot assign to any of the valid classes. In the context of classifying handwritten digits, the irrelevant items may include stray marks, smudges, and mis-scans. Querying the expert about these items results in wasted time or erroneous labels, if the expert is forced to assign the item to one of the valid classes. In contrast, the new algorithm provides a specific mechanism for avoiding querying the irrelevant items. This algorithm has two components: an active learner (which could be a conventional active learning algorithm) and a relevance classifier. The combination of these components yields a method, denoted Relevance Bias, that enables the active learner to avoid querying irrelevant data so as to increase its learning rate and efficiency when irrelevant items are present. The algorithm collects irrelevant data in a set of rejected examples, then trains the relevance classifier to distinguish between labeled (relevant) training examples and the rejected ones. The active learner combines its ranking of the items with the probability that they are relevant to yield a final decision about which item to present to the expert for labeling. Experiments on several data sets have demonstrated that the Relevance Bias approach significantly decreases the number of irrelevant items queried and also accelerates learning speed.

Wagstaff, Kiri; Mazzoni, Dominic

2009-01-01

293

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

294

Solid phase excitation-emission fluorescence method for the classification of complex substances: Cortex Phellodendri and other traditional Chinese medicines as examples.  

PubMed

A novel, simple and direct fluorescence method for analysis of complex substances and their potential substitutes has been researched and developed. Measurements involved excitation and emission (EEM) fluorescence spectra of powdered, complex, medicinal herbs, Cortex Phellodendri Chinensis (CPC) and the similar Cortex Phellodendri Amurensis (CPA); these substances were compared and discriminated from each other and the potentially adulterated samples (Caulis mahoniae (CM) and David poplar bark (DPB)). Different chemometrics methods were applied for resolution of the complex spectra, and the excitation spectra were found to be the most informative; only the rank-ordering PROMETHEE method was able to classify the samples with single ingredients (CPA, CPC, CM) or those with binary mixtures (CPA/CPC, CPA/CM, CPC/CM). Interestingly, it was essential to use the geometrical analysis for interactive aid (GAIA) display for a full understanding of the classification results. However, these two methods, like the other chemometrics models, were unable to classify composite spectral matrices consisting of data from samples of single ingredients and binary mixtures; this suggested that the excitation spectra of the different samples were very similar. However, the method is useful for classification of single-ingredient samples and, separately, their binary mixtures; it may also be applied for similar classification work with other complex substances. PMID:22920634

Gu, Yao; Ni, Yongnian; Kokot, Serge

2012-09-13

295

The article critique as a problem-based teaching method for medical students early in their training: a French example using anatomy.  

PubMed

In France, "article critique" became a particular teaching method in the second part of the medical curriculum. It approaches a reading exercise of scientific medical papers similar to that of journal club. It could be compared to reviewing a paper as performed by reviewers of a scientific journal. We studied the relevancy of that teaching method for the youngest medical students. Our questions were about the understanding and the analyzing ability of a scientific paper while students have just learned basic medical sciences as anatomy. We have included 54 "article critique" written by voluntary students in second and third years of medical cursus. All of the IMRaD structure items (introduction, materials and methods, results and discussion) were analyzed using a qualitative scale for understanding as for analyzing ability. For understanding, 89-96% was good or fair and for the analyzing ability, 93-100% was good or fair. The anatomical papers were better understood than therapeutic or paraclinical studies, but without statistical difference, except for the introduction chapter. Results for analyzing ability were various according to the subject of the papers. This teaching method could be compared to a self-learning method, but also to a problem-based learning method. For the youngest students, the lack of medical knowledge aroused the curiosity. Their enthusiasm to learn new medical subjects remained full. The authors would insist on the requirement of rigorous lessons about evidence-based medicine and IMRaD structure and on a necessary companionship of the students by the teachers. PMID:22130493

Havet, Eric; Duparc, Fabrice; Peltier, Johan; Tobenas-Dujardin, Anne-Claire; Fréger, Pierre

2012-01-01

296

Interactive Methods for Teaching Action Potentials, an Example of Teaching Innovation from Neuroscience Postdoctoral Fellows in the Fellowships in Research and Science Teaching (FIRST) Program.  

PubMed

Acquiring a faculty position in academia is extremely competitive and now typically requires more than just solid research skills and knowledge of one's field. Recruiting institutions currently desire new faculty that can teach effectively, but few postdoctoral positions provide any training in teaching methods. Fellowships in Research and Science Teaching (FIRST) is a successful postdoctoral training program funded by the National Institutes of Health (NIH) providing training in both research and teaching methodology. The FIRST program provides fellows with outstanding interdisciplinary biomedical research training in fields such as neuroscience. The postdoctoral research experience is integrated with a teaching program which includes a How to Teach course, instruction in classroom technology and course development and mentored teaching. During their mentored teaching experiences, fellows are encouraged to explore innovative teaching methodologies and to perform science teaching research to improve classroom learning. FIRST fellows teaching neuroscience to undergraduates have observed that many of these students have difficulty with the topic of neuroscience. Therefore, we investigated the effects of interactive teaching methods for this topic. We tested two interactive teaching methodologies to determine if they would improve learning and retention of this information when compared with standard lectures. The interactive methods for teaching action potentials increased understanding and retention. Therefore, FIRST provides excellent teaching training, partly by enhancing the ability of fellows to integrate innovative teaching methods into their instruction. This training in turn provides fellows that matriculate from this program more of the characteristics that hiring institutions desire in their new faculty. PMID:23493377

Keen-Rhinehart, E; Eisen, A; Eaton, D; McCormack, K

2009-01-01

297

Using data mining techniques to explore physicians' therapeutic decisions when clinical guidelines do not provide recommendations: methods and example for type 2 diabetes  

Microsoft Academic Search

BACKGROUND: Clinical guidelines carry medical evidence to the point of practice. As evidence is not always available, many guidelines do not provide recommendations for all clinical situations encountered in practice. We propose an approach for identifying knowledge gaps in guidelines and for exploring physicians' therapeutic decisions with data mining techniques to fill these knowledge gaps. We demonstrate our method by

Massoud Toussi; Jean-Baptiste Lamy; Philippe Le Toumelin; Alain Venot

2009-01-01

298

Vector image method for the derivation of elastostatic solutions for point sources in a plane layered medium. Part 1: Derivation and simple examples  

NASA Technical Reports Server (NTRS)

An image method algorithm is presented for the derivation of elastostatic solutions for point sources in bonded halfspaces assuming the infinite space point source is known. Specific cases were worked out and shown to coincide with well known solutions in the literature.

Fares, Nabil; Li, Victor C.

1986-01-01

299

A dynamic multiple reaction monitoring method for the multiple components quantification of complex traditional Chinese medicine preparations: Niuhuang Shangqing pill as an example.  

PubMed

It is a challenging task to simultaneously and quantitatively analyze multiple components in DFF [Da-Fu-Fang, namely, complex traditional Chinese medicine (TCM) preparations containing more than ten TCMs] due to their numerous and extreme complex chemical compositions possessing a wide variety of chemical and physical features, and their very low content. Rather than using a conventional mass spectrometry (MS) method with multiple reaction monitoring (MRM), in the current study, this challenge was addressed by using dynamic multiple reaction monitoring (DMRM). Using a DFF, Niuhuang Shangqing pill, which is composed of 19 TCMs, as a model, a rapid (one run in 20min), sensitive [lower limit of detection (LOD) and limit of quantitation (LOQ) were achieved comparable with MRM] and accessible (a standard HPLC/MS/MS instrumentation was employed) MS method was successfully developed for the simultaneous quantification of 41 bioactive components which represented 15 of the 19 medicinal plants. A comparison of LOD and LOQ using MRM and DMRM was made to quantitatively reveal that the latter demonstrated advantages over the former. Meanwhile, a standard operating procedure concerning the development of a new DMRM method was recommended. The MS data were obtained in the positive ion mode with electrospray ionization as the ion source, acetonitrile and water as mobile phase and a Kinetex C18 core-shell column (100mm×2.10mm, 2.6?m, Phenomenex Inc.) as the analytical column. This method was then applied to 32 batches of samples. It transpired, through principal component analysis and orthogonal partial least squares discriminant analysis, that the consistency of the products was relatively good within one company, but poor among different companies among the 32 samples; one failed to qualify in terms of the Chinese Pharmacopeia. This work illustrated that the proposed DMRM method was particularly suitable for quantifying the trace components in DFF and capable of ensuring the quality of DFF. PMID:23647610

Liang, Jian; Wu, Wan-ying; Sun, Guo-xiang; Wang, Dan-dan; Hou, Jin-jun; Yang, Wen-zhi; Jiang, Bao-hong; Liu, Xuan; Guo, De-an

2013-06-14

300

Spectroscopic Binary Stars  

NASA Astrophysics Data System (ADS)

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

Batten, A.; Murdin, P.

2000-11-01

301

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

302

IZ Applet: Example 2  

NSDL National Science Digital Library

The unknown component in the IZApplet is a data source object. It can, therefore, pass its current and voltage values to any 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

303

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

304

Interaction: Examples and Possibilities.  

ERIC Educational Resources Information Center

Explores examples of software that employs interactivity to engage students in a dialogue with the past: (1) "Reverse America"; (2) "Pilgrims and Indians"; (3) "Keys to Victory in the War for Independence"; (4) "Monmouth"; (5) "Critical Period"; (6) "Translating"; (7) "Founders"; and (8) "Convention". (CMK)

Schick, James B. M.

2000-01-01

305

EXAMPLE OF GROSS DICTATION  

Cancer.gov

EXAMPLE OF GROSS DICTATION EXTERNAL DESCRIPTION: The body is that of a well-developed, well-nourished white man appearing about the stated age of 65 years, measuring 170 cm long and weighing approximately 77 kg. Abundant grey-brown hair covers the head

306

An efficient and rapid method for gene cloning from eukaryotic genomic DNA using overlap-PCR: With an example of cattle Ghrelin gene.  

PubMed

In this study, overlap-PCR, an efficient and rapid method, was used to clone cattle Ghrelin gene CDS (coding sequence) from genomic DNA. The procedure included seven primers and three-step PCRs. Cattle Ghrelin gene consists of four exons and the CDS contains 351 bps. In the first step three PCRs were performed to generate extended exon1, exon2, and exon3 that contained overlapped nucleotides and were used as the templates for second ligation PCR. Secondly, exon1 and exon2 were spliced together. And it was same with exon3 and exon4. Lastly, the four exons were linked together with outermost primers and the templates from the second step. Comparison analysis on the obtained CDS of Ghrelin gene and cDNA by RT-PCR showed that the two sequences were same. As an efficient and rapid method, overlap-PCR is feasible and acceptable for gene cloning from genomic DNA. PMID:20034467

Zhang, Ai-Ling; Zhang, Li; Zhang, Liang-Zhi; Chen, Hong; Lan, Xian-Yong; Zhang, Chun-Lei; Zhang, Cun-Fang

2010-01-15

307

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

308

Effects of Worked Examples, Example-Problem, and Problem-Example Pairs on Novices' Learning  

ERIC Educational Resources Information Center

Research has demonstrated that instruction that relies more heavily on example study is more effective for novices' learning than instruction consisting of problem solving. However, "a heavier reliance on example study" has been implemented in different ways. For example, worked examples only (WE), example-problem pairs (WE-PS), or problem-example

van Gog, Tamara; Kester, Liesbeth; Paas, Fred

2011-01-01

309

An Improved Method for TIMS High Precision Nd Isotopic Analysis of Very Small Aliquots (1- 10ng) With Example Application in Garnet Sm/Nd Geochronology  

NASA Astrophysics Data System (ADS)

Technological and scientific developments have demonstrated both the attainability and the utility of very high precision (i.e. 5-20ppm 2 ?) Nd isotopic measurements with TIMS. However such high precision has been limited to relatively large aliquots of Nd, on the order of several hundred nanograms. Several potential applications of precise Nd isotopic measurements, including garnet Sm/Nd geochronology, do not always permit such large samples, instead yielding only a few nanograms of Nd. We have explored and tested an improved method for Nd isotopic analysis of such small (1-10ng) aliquots of Nd using the NdO+ method with a Triton TIMS at Boston University. Analyzing Nd isotopes as the oxide is a well known technique, frequently involving an oxygen bleed valve. Instead, we forego the bleed valve and load samples with a TaO slurry which provides the oxygen source. Using an in-house Nd isotopic standard solution, 4ng loads easily yield stable 2.0-2.5 volt beams resulting in internal precisions of 10ppm 2 ? RSE. Within barrel external precision of 4ng loads of the Nd standard is 13ppm 2 ? RSD (n=20). Long term (6 months, six analysts) external precision of 4ng loads of the standard is currently 23ppm 2 ? RSD (n=55) suggesting that further improvements are possible. As a further test of this method, we dissolved a natural rock sample (a metapelite), separated the Nd using TRU- spec and MLA column chemistry, and loaded nineteen 4ng loads in one barrel. Within barrel external precision was 21ppm 2 ? RSD (n=18). This precision represents a significant advance over previous NdO+ analyses of small samples using an oxygen bleed valve. The TaO loading method for small Nd aliquots is useful in Sm/Nd garnet geochronology as exemplified by two case studies. Garnets from eclogite facies gneisses from Norway ran very well with 2.4-18ng loads and yielded age precision as good as 0.8 million years 2 ?. Conversely, garnets from blueschist facies rocks from Sifnos, Greece, ran poorly with similarly sized 1-17ng loads and consequently yielded generally poorer age precision. Differences between the two garnet sample suites must relate to the garnets themselves (notably including much lower Nd concentration in Sifnos garnets), not the identical column chemistry nor the TaO loading method. Additional procedures may be required to cleanly separate Nd from samples where Nd concentrations are very low (?1ppm). As always, clean separation and column chemistry represents an unavoidable limiting factor in achieving precise isotopic measurements.

Baxter, E. F.; Harvey, J.; Mehl, L. Y.; Peterman, E. M.

2007-12-01

310

An alternative NMR method to determine nuclear shielding anisotropies for molecules in liquid-crystalline solutions with (13)C shielding anisotropy of methyl iodide as an example.  

PubMed

An alternative NMR method for determining nuclear shielding anisotropies in molecules is proposed. The method is quite simple, linear and particularly applicable for heteronuclear spin systems. In the technique, molecules of interest are dissolved in a thermotropic liquid crystal (LC) which is confined in a mesoporous material, such as controlled pore glass (CPG) used in this study. CPG materials consist of roughly spherical particles with a randomly oriented and connected pore network inside. LC Merck Phase 4 was confined in the pores of average diameter from 81 to 375 A and LC Merck ZLI 1115 in the pores of average diameter 81 A. In order to demonstrate the functionality of the method, the (13)C shielding anisotropy of (13)C-enriched methyl iodide, (13)CH(3)I, was determined as a function of temperature using one dimensional (13)C NMR spectroscopy. Methane gas, (13)CH(4), was used as an internal chemical shift reference. It appeared that methyl iodide molecules experience on average an isotropic environment in LCs inside the smallest pores within the whole temperature range studied, ranging from bulk solid to isotropic phase. In contrast, in the spaces in between the particles, whose diameter is approximately 150 microm, LCs behave as in the bulk. Consequently, isotropic values of the shielding tensor can be determined from spectra arising from molecules inside the pores at exactly the same temperature as the anisotropic ones from molecules outside the pores. Thus, for the first time in the solution state, shielding anisotropies can easily be determined as a function of temperature. The effects of pore size as well as of different LC media on the shielding anisotropy are examined and discussed. PMID:18338070

Tallavaara, Pekka; Jokisaari, Jukka

2008-03-28

311

The transcorrelated method for accurate correlation energies using gaussian-type functions: examples on He, H 2 , LiH and H 2 O  

NASA Astrophysics Data System (ADS)

The first transcorrelated calculations for correlated wavefuPinctions C ?which use purely analytical integration methods are presented. If we write C = ?i>j where G T is a linear combination of functions like exp (-ari 2 j) and exp (-br 2 B), and ?is a Slater determinant whose orbital basis set is the usual gaussians, then Boys showed that all the integrals of the transcorrelated method could be evaluated. These are the bases used here. However, the use of a limited gaussian orbital basis set makes ?a bad approximation to the best determinant. The results in atomic units are (giving the S.C.F. energy W SCF = < ?|H| ?>/< ?| ?> and the correlation energy W c , with their exact values in parenthesis): He: W SCF =-2.710 (-2.862), W c =-0.0399 (-0.0420), H 2 : W SCF =-0.976 (-1.133), W c =-0.0419 (-0.0405), LiH: W SCF =-7.589 (-7.987), W c =-0.0759 (-0.082), H 2 O: W SCF =-64.23 (-76.07), W c =-0.254 (-0.364). Calculations were performed at the experimental geometry. A few three-electron integrals used in the determination of parameters, but not in the determination of energies, were ignored in LiH and H 2 O, but this is not thought to affect the nature of the results. The reason why the convergence of the energy in these calculations is much closer to variational-type convergence than in previous transcorrelated calculations is explained. These results give great potentiality for the method when bigger orbital basis sets are used, which is already possible with the faster computers now available.

Handy, N. C.

2002-01-01

312

Is the amphibian X. laevis WEC a good alternative method to rodent WEC teratogenicity assay? The example of the three triazole derivative fungicides Triadimefon, Tebuconazole, Cyproconazole.  

PubMed

The aim of the present work is the assessment of teratogenic effects of three triazole-derived fungicides (Triadimefon, FON, Tebuconazole, TEBU, Cyproconazole, CYPRO) on rat and Xenopus laevis embryos cultured in vitro. Rat embryos, exposed to FON 31.25-250?M, CYPRO 31.25-62.5?M and to TEBU 62.5-250?M, showed specific malformations (fusions) at the level of the first and second branchial arches, with a concentration-dependent increase of severity of malformative pictures. After immunostaining, the ectomesenchyme has been identified as the target tissue. X. laevis larvae showed, at the same concentrations, specific malformations at the level of cartilaginous element derived from the first and second branchial arch ectomesenchyme. This work indicates the three tested triazoles as teratogenic both in rodents and in amphibian, inducing ectomesenchymal abnormalities, and suggests, at least for this class of molecules, the X. laevis method as adequate alternative model for teratogenic screening. PMID:21601633

Di Renzo, Francesca; Bacchetta, Renato; Bizzo, Andrea; Giavini, Erminio; Menegola, Elena

2011-09-01

313

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

314

RC Applet: Example 2  

NSDL National Science Digital Library

All circuit components in the RC Applet are data sources and can pass current and voltage values to a data listener. In this example, the current, voltage, and power delivered by the source are plotted on a data graph. Notice the the power, i.e., the blue graph, is negative for some portion of each cycle but that it is positive when averaged over a whole cycle.

Christian, Wolfgang; Belloni, Mario

2008-02-09

315

[A method of suture-free anastomosis of nerve transplantation is being reported, using facial nerve as the example (author's transl)].  

PubMed

After microsurgery preparation, the endings of the nerve trunk, which have been freed from epineurium, are approxiamated on top of a gelatin platelet (gel foam) which has been soaked in a nutrient solution. The gelatin platet is then formed like a tube and wrapped around the ends of the anastomosis. Using this procedure, suture-induced reactions in the vicinity of the anastomosis are prevented. The connection is sufficiently firm so as to withstand tension incurred in chewing and in movement of the head. Additionally, the gelatin coating prevents early onset of fibrosis, which as a process is normally induced by the surrounding tissues onto transplants. Simultaneously, nutrition of the transplant is guaranteed during the first post-operative days. In all cases operated hitherto, good to satisfactory return of function has been observed. The earliest onset of function-return was observed at four (4) months after the operation and the latest completion occurred at eighteen (18) months. Thus far, no negative results have been observed using this method. PMID:431234

Fischer, H

1979-02-01

316

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

Abstract 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, Jw; Smirnova, Iv; McIff, Te

2014-07-01

317

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

318

Evaluation of endogenous allergens for the safety evaluation of genetically engineered food crops: review of potential risks, test methods, examples and relevance.  

PubMed

The safety of food produced from genetically engineered (GE) crops is assessed for potential risks of food allergy on the basis of an international consensus guideline outlined by the Codex Alimentarius Commission (2003). The assessment focuses on evaluation of the potential allergenicity of the newly expressed protein(s) as the primary potential risk using a process that markedly limits risks to allergic consumers. However, Codex also recommended evaluating a second concern, potential increases in endogenous allergens of commonly allergenic food crops that might occur due to insertion of the gene. Unfortunately, potential risks and natural variation of endogenous allergens in non-GE varieties are not understood, and risks from increases have not been demonstrated. Because regulatory approvals in some countries are delayed due to increasing demands for measuring endogenous allergens, we present a review of the potential risks of food allergy, risk management for food allergy, and test methods that may be used in these evaluations. We also present new data from our laboratory studies on the variation of the allergenic lipid transfer protein in non-GE maize hybrids as well as data from two studies of endogenous allergen comparisons for three GE soybean lines, their nearest genetic soy lines, and other commercial lines. We conclude that scientifically based limits of acceptable variation cannot been established without an understanding of natural variation in non-GE crops. Furthermore, the risks from increased allergen expression are minimal as the risk management strategy for food allergy is for allergic individuals to avoid consuming any food containing their allergenic source, regardless of the crop variety. PMID:23848840

Goodman, Richard E; Panda, Rakhi; Ariyarathna, Harsha

2013-09-01

319

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.

2014-01-01

320

Spectroscopic topological Stokes polarimeter  

NASA Astrophysics Data System (ADS)

In this paper, we have developed a spectroscopic topological Stokes polarimeter using an axisymmetrical quarter wave plate (AQWP). The AQWP is fabricated by the alignment of segments of quarter wave films. The azimuthal angles of the polarization element are changed in according with its own segment. This element works as same the technique as the rotating quarter wave plate. In the experiment, we evaluated birefringence distribution of the AQWP. By changing a position of polarized singularity point in the beam spot, we can measure states of polarization. We demonstrate that the change of polarization states is corresponded with the change of the polarized singularity points.

Wakayama, Toshitaka; Otani, Yukitoshi; Yoshizawa, Toru

2010-11-01

321

Examples of Interactive Lecture Techniques  

NSDL National Science Digital Library

This page currently houses examples from the geosciences. Examples specific to economics may be found at the economic examples page. In addition to this collection there is a large collection of ConcepTest ...

322

Validated spectrophotometric method for the determination, spectroscopic characterization and thermal structural analysis of duloxetine with 1,2-naphthoquinone-4-sulphonate  

NASA Astrophysics Data System (ADS)

A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation of this complex was also confirmed by UV-visible, FTIR, 1H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines. Beer's law is obeyed in a range of 5.0-60 ?g/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99 ?g/mL and the recovery rate is in a range of 98.10-99.57%. The proposed methods was validated and applied to the determination of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of a reference UV spectrophotometric method.

Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

2012-03-01

323

Procedure and Program Examples  

NASA Astrophysics Data System (ADS)

Here some modules, procedures and whole programs are described, that may be useful to the reader, as they have been, to the author. They are all in Fortran 90/95 and start with a generally useful module, that will be used in most procedures and programs in the examples, and another module useful for programs using a Rosenbrock variant. The source texts (except for the two modules) are not reproduced here, but can be downloaded from the web site www.springerlink.com/openurl.asp?genre=issue &issn=1616-6361&volume=666 (the two lines form one contiguous URL!).

Britz, Dieter

324

Spectroscopically Accurate Line Lists for Application in Sulphur Chemistry  

NASA Astrophysics Data System (ADS)

Monitoring sulphur chemistry is thought to be of great importance for exoplanets. Doing this requires detailed knowledge of the spectroscopic properties of sulphur containing molecules such as hydrogen sulphide (H2S) [1], sulphur dioxide (SO2), and sulphur trioxide (SO3). Each of these molecules can be found in terrestrial environments, produced in volcano emissions on Earth, and analysis of their spectroscopic data can prove useful to the characterisation of exoplanets, as well as the study of planets in our own solar system, with both having a possible presence on Venus. A complete, high temperature list of line positions and intensities for H32 2 S is presented. The DVR3D program suite is used to calculate the bound ro-vibration energy levels, wavefunctions, and dipole transition intensities using Radau coordinates. The calculations are based on a newly determined, spectroscopically refined potential energy surface (PES) and a new, high accuracy, ab initio dipole moment surface (DMS). Tests show that the PES enables us to calculate the line positions accurately and the DMS gives satisfactory results for line intensities. Comparisons with experiment as well as with previous theoretical spectra will be presented. The results of this study will form an important addition to the databases which are considered as sources of information for space applications; especially, in analysing the spectra of extrasolar planets, and remote sensing studies for Venus and Earth, as well as laboratory investigations and pollution studies. An ab initio line list for SO3 was previously computed using the variational nuclear motion program TROVE [2], and was suitable for modelling room temperature SO3 spectra. The calculations considered transitions in the region of 0-4000 cm-1 with rotational states up to J = 85, and includes 174,674,257 transitions. A list of 10,878 experimental transitions had relative intensities placed on an absolute scale, and were provided in a form suitable for inclusion in standard atmospheric and planetary spectroscopic databases. The methods involved in computing the ab initio potential energy and dipole moment surfaces involved minor corrections to the equilibrium S-O distance, which produced a good agreement with experimentally determined rotational energies. However the purely ab initio method was not been able to reproduce an equally spectroscopically accurate representation of vibrational motion. We therefore present an empirical refinement to this original, ab initio potential surface, based on the experimental data available. This will not only be used to reproduce the room-temperature spectrum to a greater degree of accuracy, but is essential in the production of a larger, accurate line list necessary for the simulation of higher temperature spectra: we aim for coverage suitable for T ? 800 K. Our preliminary studies on SO3 have also shown it to exhibit an interesting "forbidden" rotational spectrum and "clustering" of rotational states; to our knowledge this phenomenon has not been observed in other examples of trigonal planar molecules and is also an investigative avenue we wish to pursue. Finally, the IR absorption bands for SO2 and SO3 exhibit a strong overlap, and the inclusion of SO2 as a complement to our studies is something that we will be interested in doing in the near future.

Underwood, D. S.; Azzam, A. A. A.; Yurchenko, S. N.; Tennyson, J.

2013-09-01

325

The limit of detection for explosives in spectroscopic differential reflectometry  

NASA Astrophysics Data System (ADS)

In the wake of recent terrorist attacks, such as the 2008 Mumbai hotel explosion or the December 25th 2009 "underwear bomber", our group has developed a technique (US patent #7368292) to apply differential reflection spectroscopy to detect traces of explosives. Briefly, light (200-500 nm) is shone on a surface such as a piece of luggage at an airport. Upon reflection, the light is collected with a spectrometer combined with a CCD camera. A computer processes the data and produces in turn a differential reflection spectrum involving two adjacent areas of the surface. This differential technique is highly sensitive and provides spectroscopic data of explosives. As an example, 2,4,6, trinitrotoluene (TNT) displays strong and distinct features in differential reflectograms near 420 nm. Similar, but distinctly different features are observed for other explosives. One of the most important criteria for explosive detection techniques is the limit of detection. This limit is defined as the amount of explosive material necessary to produce a signal to noise ratio of three. We present here, a method to evaluate the limit of detection of our technique. Finally, we present our sample preparation method and experimental set-up specifically developed to measure the limit of detection for our technology. This results in a limit ranging from 100 nano-grams to 50 micro-grams depending on the method and the set-up parameters used, such as the detector-sample distance.

Dubroca, Thierry; Vishwanathan, Karthik; Hummel, Rolf E.

2011-05-01

326

Determination of the asymptotic normalization coefficients for C14 + n ?C15, the C14(n,?)C15 reaction rate, and evaluation of a new method to determine spectroscopic factors  

NASA Astrophysics Data System (ADS)

The C14 + n ?C15 system has been used as a test case in the evaluation of a new method to determine spectroscopic factors that uses the asymptotic normalization coefficient (ANC). The method proved to be unsuccessful for this case. As part of this experimental program, the ANCs for the 15C ground state and first excited state were determined using a heavy-ion neutron transfer reaction as well as the inverse kinematics (d,p) reaction, measured at the Texas A&M Cyclotron Institute. The values C2s1/22=1.88±0.18 fm-1 for the ground state and C1d5/22=4.25±0.38×10-3 fm-1 for the first excited state (Eexc=740 keV) were obtained. The ANCs were used to evaluate the astrophysical direct neutron capture rate on C14, which was then compared with the most recent direct measurement and found to be in good agreement. A study of the C15 SF via its mirror nucleus F15 and a new insight into deuteron stripping theory are also presented.

McCleskey, M.; Mukhamedzhanov, A. M.; Trache, L.; Tribble, R. E.; Banu, A.; Eremenko, V.; Goldberg, V. Z.; Lui, Y.-W.; McCleskey, E.; Roeder, B. T.; Spiridon, A.; Carstoiu, F.; Burjan, V.; Hons, Z.; Thompson, I. J.

2014-04-01

327

Spectroscopic Imaging with Prospective Motion Correction and Retrospective Phase Correction  

PubMed Central

Motion-induced artefacts in magnetic resonance spectroscopic imaging are much harder to recognize than in imaging experiments and can therefore lead to erroneous interpretation. A method for prospective motion correction based on an optical tracking system has recently been proposed and has already been successfully applied to single voxel spectroscopy. In this work, the utility of prospective motion correction in combination with retrospective phase correction is evaluated for spectroscopic imaging in the human brain. Retrospective phase correction, based on the interleaved reference scan method, is used to correct for motion-induced frequency shifts and ensure correct phasing of the spectra across the whole spectroscopic imaging slice. It is demonstrated that the presented correction methodology can reduce motion-induced degradation of spectroscopic imaging data.

Lange, Thomas; Maclaren, Julian; Buechert, Martin; Zaitsev, Maxim

2011-01-01

328

A comparison of spectroscopic methods for detecting the starlight scattered by transiting hot Jupiters, with an application to Subaru data for HD 209458b and HD 189733b  

NASA Astrophysics Data System (ADS)

The measurement of the light scattered from extrasolar planets informs atmospheric and formation models. With the discovery of many hot Jupiter planets orbiting nearby stars, this motivates the development of robust methods of characterization from follow-up observations. In this paper, we discuss two methods for determining the planetary albedo in transiting systems. First, the most widely used method for measuring the light scattered by hot Jupiters is investigated for application for typical echelle spectra of a transiting planet system, showing that a detection requires high-signal-to-noise-ratio data of bright planets. Secondly, a new Fourier analysis method is also presented, which is model-independent and utilizes the benefits of the reduced number of unknown parameters in transiting systems. This approach involves solving for the planet and stellar spectra in Fourier space by least squares. The sensitivities of the methods are determined via Monte Carlo simulations for a range of planet-to-star flux ratios. We find the Fourier analysis method to be better suited to the ideal case of typical observations of a well-constrained transiting system than the Collier Cameron et al. method. To guide future observations of transiting planets with ground-based capabilities, the expected sensitivity to the planet-to-star flux ratio is quantified as a function of the signal-to-noise ratio and wavelength range. We apply the Fourier analysis method for extracting the light scattered by transiting hot Jupiters from high-resolution spectra to echelle spectra of HD 209458 and HD 189733. Unfortunately, we are unable to improve on the previous upper limit of the planet-to-star flux ratio for HD 209458b set by space-based observations. A 1? upper limit on the planet-to-star flux ratio of HD 189733b is measured in the wavelength range of 558.83-599.56 nm yielding ? < 4.5 × 10-4. This limit is not sufficiently strong to constrain models. Improvement in the measurement of the upper limit of the planet-to-star flux ratio of this system, with ground-based capabilities, requires data with a higher signal-to-noise ratio and increased stability of the telescope.

Langford, Sally V.; Wyithe, J. Stuart B.; Turner, Edwin L.; Jenkins, Edward B.; Narita, Norio; Liu, Xin; Suto, Yasushi; Yamada, Toru

2011-07-01

329

Trends in Fourier transform infrared spectroscopic imaging  

Microsoft Academic Search

Fourier transform infrared (FTIR) spectroscopic imaging is a relatively new method that has received great attention as a\\u000a new field of analytical chemistry. The greatest benefit of this technique lies in the high molecular sensitivity combined\\u000a with a spatial resolution down to a few micrometers. Another advantage is the ability to probe samples under native conditions,\\u000a which allows new insights

Gerald Steiner; Edmund Koch

2009-01-01

330

An example reduction of WFC3/IR slitless data  

NASA Astrophysics Data System (ADS)

The G102 and G141 grisms in the WFC3 IR channel together cover the wavelength range 0.8-1.6?m with resolutions of R 210 and R 130, respectively. In this contribution we present an example reduction of G102 and G141 slitless data taken during theWFC3 Early Release Science programme. All core tasks are done by the spectroscopic extraction software aXe, which was specifically designed to handle data from the HST slitless modes. The reduction scheme includes a sky background subtraction with a master sky image to achieve a homogeneous, flat background for the spectral extraction and the most recent on-orbit calibrations. Moreover we present a new method for co-adding data from individual slitless images that, similar to MultiDrizzle in direct imaging, allows the rejection of deviating pixels from e.g. cosmic ray hits. As a result of applying this processing we show the spectra of some emission line galaxies down to magAB(F140W) = 24.5, demonstrating the remarkable efficiency and capability of the WFC3 NIR grisms.

Kummel, M.; Kuntschner, H.; Walsh, J. R.; Bushouse, H.; Straughn, A.

2010-07-01

331

Simulated Radiative Transfer DOAS - A new method for improving volcanic SO2 emissions retrievals from ground-based UV-spectroscopic measurements of scattered solar radiation  

NASA Astrophysics Data System (ADS)

Passive Differential Optical Absorption Spectroscopy (DOAS) has become a standard tool for measuring SO2 at volcanoes. More recently, ultra-violet (UV) cameras have also been applied to obtain 2D images of SO2-bearing plumes. Both techniques can be used to derive SO2 emission rates by measuring SO2 column densities, integrating these along the plume cross-section, and multiplying by the wind speed. Recent measurements and model studies have revealed that the dominating source of uncertainty in these techniques often originates from an inaccurate assessment of radiative transfer through the volcanic plume. The typical assumption that all detected radiation is scattered behind the volcanic plume and takes a straight path from there to the instrument is often incorrect. We recently showed that the straight path assumption can lead to column density errors of 50% or more in cases where plumes with high SO2 and aerosol concentrations are measured from several kilometers distance, or where the background atmosphere contains a large amount of scattering aerosols. Both under- and overestimation are possible depending on the atmospheric conditions and geometry during spectral acquisition. Simulated Radiative Transfer (SRT) DOAS is a new evaluation scheme that combines radiative transfer modeling with spectral analysis of passive DOAS measurements in the UV region to derive more accurate SO2 column densities than conventional DOAS retrievals, which in turn leads to considerably more accurate emission rates. A three-dimensional backward Monte Carlo radiative transfer model is used to simulate realistic light paths in and around the volcanic plume containing variable amounts of SO2 and aerosols. An inversion algorithm is then applied to derive the true SO2 column density. For fast processing of large datasets, a linearized algorithm based on lookup tables was developed and tested on a number of example datasets. In some cases, the information content of the spectral data is sufficient to allow the retrieval of additional atmospheric parameters such as the aerosol optical thickness of the volcanic plume. Thus, the SRT-DOAS approach provides a great advancement in the ability to assess and improve the accuracy of SO2 emission rates determined from UV remote sensing instruments. The impact of the new methodology is far-reaching, as other volcanic volatile emissions are often calculated by scaling remotely determined SO2 emission rates by the respective X/SO2 concentration ratios; therefore emission rates of such constituents would be equally affected.

Kern, C.; Deutschmann, T.; Vogel, L.; Bobrowski, N.; Hoermann, C.; Werner, C. A.; Sutton, A. J.; Elias, T.

2011-12-01

332

X-ray absorption spectroscopic and magnetic characterization of cobalt-doped zinc oxide nanocrystals prepared by the molten-salt method  

Microsoft Academic Search

The local atomic arrangement and electronic structure of the Co-doped Zn1?xCoxO nanocrystal have been quantitatively examined along with its magnetic properties. According to our analysis using powder X-ray diffraction, electron microscopy, and Zn K-edge X-ray absorption spectroscopy (XAS), phase-pure wurzite-structured Zn1?xCoxO nanocrystals have been successfully synthesized via the molten-salt method. The Co K-edge XAS analysis clearly demonstrates that all the

Ah Reum Han; Seong-Ju Hwang; Yongnan Zhao; Young-Uk Kwon

2008-01-01

333

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

334

Growth by the induced nucleated floating crystal (INFC) method and spectroscopic properties of KY 1- xNd x(WO 4) 2 laser materials  

NASA Astrophysics Data System (ADS)

Double molybdates and tungstates of alkaline yttrium or gadolinium element beloning to the monoclinic structure are beginning to appear like very promising laser materials. They can be easily doped by IR laser rare-earth ions such as neodymium, ytterbium or erbium and, in addition, it is also possible to take benefit of the nonlinear properties of the host in so-called Raman shifter solid-state laser crystals. Unfortunately, it is difficult to grow high quality single crystals by using the usual pulling methods. The INFC method, previously used for the growth of KNbO 3 crystals, is also suitable for pure or doped tungstates/molybdates. We report in this work the first experiments on pure or Nd 3+-doped KY(WO 4) 2. Contrary to classical growth methods (Kyropoulos, Czochralski, floating zone), no crystal seed supply is used: by continuous growth from a nucleus, created by controlled local transient supersaturation on the melt surface, large enough (13 x 13 x 5 mm), high optical quality crystals are made in one day (growth rate: 0.5 mm/h). During the early stage of growth, the crystals float freely. When they become too heavy, they must be kept up by a pumping device to avoid sinking. Floating crystal are unstrained because mechanical stresses and internal thermal gradients are lowered in the growing solid. No inclusions and striations are observed owing to solvent rejection and dope feeding promoted by the thermal convection on the liquid. Melt composition was 63 mol% of K 2WO 4 and 37 mol% of KY 1- xNd x(Wo 4) 2, x varying from 0-5 at%. The growth temperature, measured by a pyrometer, controlled by a PID 818P Eurotherm controller, was 925°C during the growth time. The optical properties have been studied. The first data obtained on the infrared emission from 4F{3}/{2} to 4I{9}/{2}, {11}/{2}, {13}/{2} under ˜ 800 nm excitation, that is to say a laser-diode pump one, will be given. Life-time and branching ratio measurements at room-temperature will be also added. Site-selection laser spectroscopy at low temperature has been performed in order to probe the multicenter existence of Nd 3+ ions.

Métrat, G.; Muhlstein, N.; Brenier, A.; Boulon, G.

1997-07-01

335

Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire  

NASA Astrophysics Data System (ADS)

A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ˜0.9 nms-1. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

Banerjee, Amit; Banerjee, S. S.

2014-05-01

336

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.

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

2012-01-01

337

Infrared spectroscopic imaging of kidney tumor tissue  

NASA Astrophysics Data System (ADS)

Infrared spectroscopic imaging of cancerous kidney tissue was performed by means of FTIR microscopy. The spectra of thin tissue cryosections were collected with 64x64 MCT FPA detector and imaging area was increased up to 5.4×5.4 mm by mapping by means of PC controlled x,y stage. Chemical images of the samples were constructed using statistical treatment of the raw spectra. Several unsupervised and supervised statistical methods were used. The imaging results are compared with results of the standard histopathological analysis. It was concluded that application of method of cluster analysis ensures the best contrast of the images. It was found that border between cancerous and normal tissues visible in the infrared spectroscopic image corresponds with the border visible in histopathological image. Closer examination of the infrared spectroscopic image reveals that small domains of cancerous cells are found beyond the border in areas distant from the border up to 3 mm. Such domains are not visible in the histopathological images. The smallest domains found in the infrared images are approx. 60 ?m.

Sablinskas, V.; Steiner, G.; Koch, E.; Ceponkus, J.; Pucetaite, M.; Strazdaite, S.; Urboniene, V.; Jankevicius, F.

2011-02-01

338

ATR-FTIR spectroscopic imaging: recent advances and applications to biological systems.  

PubMed

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging is a highly versatile, label free and non-destructive chemical imaging method which can be applied to study a wide range of samples and systems. This review summarises some of the recent advances and applications of this imaging method in the area of biomedical studies, including examples of section of aorta, skin tissue and live cells. Two of the major advantages of measuring in ATR mode are the opportunity to measure samples that absorb strongly in the IR spectrum, such as aqueous systems, without significant sample preparation and the ability to increase the spatial resolution of the measured image. The implications of these advantages as well as some limitations of this imaging approach are discussed and a brief outlook at some of the possible future developments in this area is provided. PMID:23400222

Kazarian, Sergei G; Chan, K L Andrew

2013-04-01

339

Polymorphism of 2-nitroaniline studied by calorimetric (DSC), structural (X-ray diffraction) and spectroscopic (FT-IR, Raman, UV Vis) methods  

NASA Astrophysics Data System (ADS)

The separation and growth methods of three ortho-nitroaniline ( o-NA) polymorphs were found. The irreversible character of the ? ? ? and ? ? ? phase transitions was revealed by differential scanning calorimetry (DSC) measurements and microscopic hot stage observations. The X-ray structure of the ?-form was determined and compared with the ? phase structure solved by Daneshwar et al. [N.N. Daneshwar et al. Acta Crystallogr., Sect. B 34 (1978) 2507]. Intramolecular hydrogen bonding (intra H-bond) interactions are dominant in both structures. The IR and Raman spectral features of the solutions and of three polycrystalline o-NA polymorphs are specific for intramolecular resonance assisted H-bonds (RAHB's). The DFT calculations facilitated the almost complete assignments of bands to normal vibrations and the analysis of the measured spectra. The manifestations of weak inter H-bonds in the ? and ? crystals and in the vibrational spectra of all polymorphs are observed as well; the strongest inter H-bonds occur in the ? polymorph. The differences in lowest electronic transition energies of three ?, ? and ? layers explain their different colours: the yellowish-green of the ? form and the orange ones of the ?- and ?- phases. The least stable ? form is probably an amorphous one with the weakest inter H-bonds. The differences in relative orientations of the -NH 2, -NO 2 groups and phenyl rings in the ?- and ?-phases indicate that the o-NA polymorphism has conformational character.

Zych, Tomasz; Misiaszek, Tomasz; Szostak, M. Magdalena

2007-11-01

340

Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV and NBO analysis of 2-chlorobenzonitrile by density functional method.  

PubMed

In this work, we will report a combined experimental and theoretical study on molecular structure, vibrational spectra, NBO and UV spectral analysis of 2-chlorobenzonitrile (2-ClBN). The FT-IR solid phase (4000-400 cm(-1)), and FT-Raman spectra (3500-50 cm(-1)) of 2-ClBN was recorded. The molecular geometry, harmonic vibrational frequencies and bonding features of 2-ClBN in the ground state have been calculated by using the density functional methods (BLYP, B3LYP) with 6-31G(d,p) as basis set. 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 Field Methodology (SQMFF). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the ?* and ?* anti bonding orbitals and E2 energies confirms the occurrence of ICT (Intra molecular Charge Transfer) within the molecule. The UV spectrum was measured in ethanol solution. 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 also confirm that charge transfer occurs within the molecule. Finally calculated results were applied to simulated Infrared and Raman spectra of the title compound which show good agreement with observed spectra. PMID:21190895

Krishnan, Akhil R; Saleem, H; Subashchandrabose, S; Sundaraganesan, N; Sebastain, S

2011-02-01

341

Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV and NBO analysis of 2-chlorobenzonitrile by density functional method  

NASA Astrophysics Data System (ADS)

In this work, we will report a combined experimental and theoretical study on molecular structure, vibrational spectra, NBO and UV spectral analysis of 2-chlorobenzonitrile (2-ClBN). The FT-IR solid phase (4000-400 cm -1), and FT-Raman spectra (3500-50 cm -1) of 2-ClBN was recorded. The molecular geometry, harmonic vibrational frequencies and bonding features of 2-ClBN in the ground state have been calculated by using the density functional methods (BLYP, B3LYP) with 6-31G(d,p) as basis set. 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 Field Methodology (SQMFF). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the ?* and ?* anti bonding orbitals and E2 energies confirms the occurrence of ICT (Intra molecular Charge Transfer) within the molecule. The UV spectrum was measured in ethanol solution. 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 also confirm that charge transfer occurs within the molecule. Finally calculated results were applied to simulated Infrared and Raman spectra of the title compound which show good agreement with observed spectra.

Krishnan, Akhil R.; Saleem, H.; Subashchandrabose, S.; Sundaraganesan, N.; Sebastain, S.

2011-02-01

342

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

343

Comprehensive study of the interaction between a potential antiprion cationic porphyrin and human prion protein at different pH by using multiple spectroscopic methods.  

PubMed

Cationic porphyrins are potential antiprion drugs; however, the action mechanisms remain poorly understood. Herein, the interaction between a cationic porphyrin and recombinant human prion protein (rPrP(C)) was comprehensively studied by using surface plasmon resonance (SPR), fluorescence, resonance light scattering (RLS), and circular dichroism (CD) spectroscopy. The experimental results showed that the interaction between the cationic porphyrin and rPrP(C) was pH dependent. The equilibrium association constants obtained from SPR spectroscopy were 4.12 × 10(3) M(-1) at pH 4.0, 1.74 × 10(5) M(-1) at pH 6.0, and 5.98 × 10(5) M(-1) at pH 7.0. The binding constants at 298?K obtained from the fluorescence quenching method were 7.286 × 10(4) M(-1) at pH 4.0 and 1.457 × 10(5) M(-1) at pH 6.0. The thermodynamic parameters such as enthalpy change, entropy change, and free energy change were calculated, and the results indicated hydrogen bonds and van der Waals interactions played a major role in the binding reaction. The RLS experiment was performed to study the influence of porphyrin on the rPrP(C) aggregation at different pH values. The CD experiments were conducted to investigate the effects of porphyrin on the secondary structure and thermal stability of rPrP(C). Finally, the comparison of SPR measurement and fluorescence quenching measurement was discussed. PMID:23280556

Xiao, Chang-Qing; Feng, Bo-Ya; Ge, Yu-Su; Fan, Xiao-Yang; Jiang, Feng-Lei; Xiao, Gengfu; Liu, Yi

2013-03-01

344

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

345

Real time spectroscopic ellipsometry for characterization of thin film optical properties and microstructural evolution  

Microsoft Academic Search

A rotating polarizer multichannel ellipsometer was applied in spectroscopic (1.3 - 4.2 eV) investigations of thin films during deposition. In this review, two examples are selected which demonstrate real time spectroscopic ellipsometry. In the first, we compare results for amorphous silicon and germanium sputtered to approximately 50 A on native oxide-covered c-Si. For these films, the evolution of the effective

R. W. Collins; Ilsin An; H. V. Nguyen; T. Gu

1991-01-01

346

Validation of an in-line Raman spectroscopic method for continuous active pharmaceutical ingredient quantification during pharmaceutical hot-melt extrusion.  

PubMed

A calibration model for in-line API determination was developed based on Raman spectra collected during hot-melt extrusion. This predictive model was validated by calculating the accuracy profile based on the analysis results of validation experiments. Furthermore, based on the data of the accuracy profile, the measurement uncertainty was determined. Finally, the robustness of the model was evaluated. A Raman probe was implemented in the die of a twin-screw extruder, to monitor the drug concentration during extrusion of physical mixtures containing 15, 20, 25, 30 and 35% (w/w) metoprolol tartrate (MPT) in Eudragit(®) RS PO, an amorphous copolymer of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups, which are present as salts. Several different calibration models for the prediction of the MPT content were developed, based on the use of single spectra or averaged spectra, and using partial least squares (PLS) regression or multivariate curve resolution (MCR). These predictive models were validated by extruding and monitoring mixtures containing 17.5, 22.5, 25.0, 27.5 and 32.5% (w/w) MPT. Each validated concentration was monitored on three different days, by two different operators. The ?-expectation tolerance intervals were calculated for each model and for each of the validated MPT concentration levels (? was set at 95%), and acceptance limits were set at 10% (relative bias), indicating that at least 95% of future measurements should not deviate more than 10% from the true value. The only model where these acceptance limits were not exceeded was the MCR model based on averaged Raman spectra. The uncertainty measurements for this model showed that the unknown true value can be found at a maximum of ±7.00% around the measured result, with a confidence level of 95%. The robustness of this model was evaluated via an experimental design varying throughput, screw speed and barrel temperature. The robustness designs showed no significant influence of any of the process settings on the predicted concentration values. Raman spectroscopy proved to be a fast, non-destructive and reliable method for the quantification of MPT during hot-melt extrusion. From the accuracy profile of the MCR model based on averaged spectra, it was concluded that for each MPT concentration in the validated concentration range, 95 out 100 future routine measurements will be included within the acceptance limits (10%). PMID:24331054

Saerens, L; Segher, N; Vervaet, C; Remon, J P; De Beer, T

2014-01-01

347

SDSS Spectroscopic Survey of Stars.  

National Technical Information Service (NTIS)

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 fr...

A. Uomoto C. A. Prieto D. Schlegel N. Bond T. Beers Z. Ivezic

2007-01-01

348

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

349

Learning by Example.  

ERIC Educational Resources Information Center

A dialog shows how student-teacher interaction on problems can help students learn. Fifty sample problems are provided as starting points for class discussions from grade three through college. Six purposes such problems can serve are identified. A method of classroom presentation, the mathematical scavenger hunt, is discussed. (MP)

Butts, Thomas

1982-01-01

350

Spectroscopic planetary detection  

NASA Technical Reports Server (NTRS)

The Sun-as-a-star was monitored using the McMath Fourier transform spectometer (FTS) on Kitt Peak in 1983. In 1985 the first measurement was made using the laser heterodyne technique. The FTS measurements now extend for three years, with errors of order 3 meters/sec at a given epoch. Over this 3 year period, a 33 meter/sec change was measured in the apparent velocity of integrated sunlight. The sense of the effect is that a greater blueshift is seen near solar minimum, which is consistent with expectations based on considering the changing morphology of solar granular convection. Presuming this effect is solar-cycle-related, it will mimic the Doppler reflex produced by a planetary companion of approximately two Jupiter masses, with an 11 year orbital period. Thus, Jupiter itself is below the threshold for detection by spectroscopic means, without an additional technique for discrimination. However, for planetary companions in shorter period orbits (P approx. 3 years) the threshold for unambiguous detection is well below one Jupiter mass.

Deming, D.; Espenak, F.; Hillman, J. J.; Kostiuk, T.; Mumma, M. J.; Jennings, D. E.

1986-01-01

351

Raman spectroscopic sensing using whispering gallery microresonators  

NASA Astrophysics Data System (ADS)

We investigate Raman spectroscopic sensing using whispering gallery microresonators as a label-free method toward single particle detection. Whispering gallery mode microresonators are used as platforms to perform sensitive particle detection by exploiting the strong, evanescent field of a resonant mode exposed on the surface of the microresonator. Particles adhered to the microresonator surface interact with the field and scatter photons circulating within the resonator. In particular, Raman scattered photons are detected, providing molecular-specific "fingerprint" information regarding the adhered particles. The exploitation of a resonant mode allows for enhancement of generated Raman signal over traditional methods of spontaneous Raman scattering. Preliminary proof-of-concept experimental results are shown.

Edwards, Perry; Janisch, Corey; Peng, Bo; Ozdemir, Sahin K.; Yang, Lan; Liu, Zhiwen

2013-09-01

352

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

2006-03-01

353

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

354

An investigation using Spectroscopic Ellipsometery in Bio-Physical  

NASA Astrophysics Data System (ADS)

The present work is an investigation of bio-physical systems using spectroscopic ellipsometry (SE), with wavelengths ranging from deep-ultraviolet to the far infrared. Recent advances in SE hardware, software and data analysis permit rapid, non-contact investigation of physical properties of nano-dimensional soft-material films and interfaces such as bio-films under liquids. The kinetics of attachment, layer thickness, density of coverage, and identification of interfacial chemistry of proteins, for example, on surfaces is of practical and fundamental importance in biology and medicine, and are potentially measurable by SE. Our initial findings determine adsorption rates of Bovine Serum Albumin (BSA) and other bio-films on gold and polystyrene substrates, as well as their spatial distributions. We were also able to identify attachment of a 2.5 nm layer of the diarrhea causing E. coli enterotoxin (LT) to ganglioside (GM1) receptor, potentially simplifying and providing more information to standard enzyme linked immuno sorbent assay (ELISA) methods. Results of studies of several different bio-physical systems using SE will be discussed.

Pfeiffer, Galen; Thompson, Daniel; Berberov, Emil; Woollam, John; Bleiweiss, Michael; Datta, Timir

2001-03-01

355

Halo Nucleus Be11: A Spectroscopic Study via Neutron Transfer  

NASA Astrophysics Data System (ADS)

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightly bound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct-reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus Be11, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the Be10(d,?p) reaction has been used in inverse kinematics at four beam energies to study the structure of Be11. The spectroscopic factors extracted using the adiabatic model were found to be consistent across the four measurements and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in an n?j=2s1/2 state coupled to the ground state of Be10 is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p1/2 state.

Schmitt, K. T.; Jones, K. L.; Bey, A.; Ahn, S. H.; Bardayan, D. W.; Blackmon, J. C.; Brown, S. M.; Chae, K. Y.; Chipps, K. A.; Cizewski, J. A.; Hahn, K. I.; Kolata, J. J.; Kozub, R. L.; Liang, J. F.; Matei, C.; Matoš, M.; Matyas, D.; Moazen, B.; Nesaraja, C.; Nunes, F. M.; O'Malley, P. D.; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Roberts, A.; Shapira, D.; Shriner, J. F., Jr.; Smith, M. S.; Spassova, I.; Stracener, D. W.; Villano, A. N.; Wilson, G. L.

2012-05-01

356

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

357

Spectroscopic analysis of insulating crystal fibers  

NASA Technical Reports Server (NTRS)

A new technique is described for investigating the optical properties of solid-state laser materials using single-crystal fibers grown by a laser-heated pedestal-growth technique. Single-crystal fiber samples can be prepared more rapidly and less expensively than crystals grown by more conventional methods; however, they are smaller and less uniform, making spectroscopic measurements difficult. A simple procedure for extracting the optical absorption and emission spectra of insulating crystal fibers is demonstrated with a titanium-doped sapphire fiber sample; results are comparable to those from Czochralski-grown material.

Buoncristiani, A. M.; Byvik, C. E.; Albin, S.

1988-01-01

358

An overview of methods for monitoring social disparities in cancer with an example using trends in lung cancer incidence by area-socioeconomic position and race-ethnicity, 1992-2004.  

PubMed

The authors provide an overview of methods for summarizing social disparities in health using the example of lung cancer. They apply four measures of relative disparity and three measures of absolute disparity to trends in US lung cancer incidence by area-socioeconomic position and race-ethnicity from 1992 to 2004. Among females, measures of absolute and relative disparity suggested that area-socioeconomic and race-ethnic disparities increased over these 12 years but differed widely with respect to the magnitude of the change. Among males, the authors found substantial disagreement among summary measures of relative disparity with respect to the magnitude and the direction of change in disparities. Among area-socioeconomic groups, the index of disparity increased by 47% and the relative concentration index decreased by 116%, while for race-ethnicity the index of disparity increased by 36% and the Theil index increased by 13%. The choice of a summary measure of disparity may affect the interpretation of changes in health disparities. Important issues to consider are the reference point from which differences are measured, whether to measure disparity on the absolute or relative scale, and whether to weight disparity measures by population size. A suite of indicators is needed to provide a clear picture of health disparity change. PMID:18344513

Harper, Sam; Lynch, John; Meersman, Stephen C; Breen, Nancy; Davis, William W; Reichman, Marsha E

2008-04-15

359

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

360

Rent Seeking: A Textbook Example  

ERIC Educational Resources Information Center

The author argues that the college textbook market provides a clear example of monopoly seeking as described by Tullock (1967, 1980). This behavior is also known as rent seeking. Because this market is important to students, this example of rent seeking will be of particular interest to them. (Contains 24 notes.)

Pecorino, Paul

2007-01-01

361

Uncertainty modeling: Examples and issues  

Microsoft Academic Search

New techniques in uncertainty analysis are illustrated with simplified examples from recent applications of interest for safety science. The applications are: BLEVE (boiling liquid expanding vapor explosions) models, satellite life distributions, dispersion coefficients and modeling contamination in food chains. The examples illustrate the importance of carefully modeling dependence in uncertainties. They also illustrate new uses of conditional Monte Carlo sampling.

Roger M. Cooke

1997-01-01

362

Learning Automata from Ordered Examples  

Microsoft Academic Search

Connectionist learning models have had considerable empirical success, but it is hard to characterize exactly what they learn. The learning of finite-state languages (FSL) from example strings is a domain which has been extensively studied and might provide an opportunity to help understand connectionist learning. A majot problem is that traditional FSL learning assumes the storage of all examples and

Sara Porat; JEROME A. FELDMANt

1991-01-01

363

Spectroscopic assessment of Australian cotton waxes.  

PubMed

An investigation into the spectroscopic analysis of cotton waxes on Australian cottons was undertaken. The chemical composition of cotton wax is complex and contains a number of lipid classes. Infrared transmission spectroscopy coupled with principal component analysis was found to be capable of discriminating between solvent-extracted cotton waxes with differences in their alkyl functionality. Based on high-performance thin-layer chromatography (HPTLC) results, these differences were associated with an increase in levels of the alkane wax component. On the basis of these results, a photo-acoustic spectroscopic method was developed that could be used to distinguish raw cottons on the basis of these differences. This method was utilized to screen cottons from the Cotton Seed Distributors 2001 seed trial. A preliminary assessment of the scouring and dyeing properties of the various cottons, identified using the photo-acoustic method, was carried out. The results tended to confirm that cottons with increased alkyl functionality, most likely associated with alkane wax, were more difficult to remove and residual wax on the fiber acted as a barrier to dyestuff penetration, thus lowering color yield. PMID:17132453

Church, Jeffrey S; Woodhead, Andrea L

2006-11-01

364

Examples  

NSDL National Science Digital Library

There are lots of ways to use cooperative learning in your classroom. These links will take you to other areas of the Starting Point site with resources that can be adapted using the techniques of cooperative ...

365

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

366

Spectroscopic imaging of serum proteins using quantum cascade lasers  

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

367

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.

368

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

369

Spectroscopic ellipsometry: a historical overview  

Microsoft Academic Search

The historical development of spectroscopic ellipsometry (SE) from the very early stages to the present will be briefly reviewed. It is shown that SE is a truly powerful technique of great interest and use to physicists, chemists, electrochemists, electrical and chemical engineers, etc., as will be evident from the following few of the many reasons. (a) Firstly, the full spectra

K. Vedam

1998-01-01

370

Synthesizing a color algorithm from examples.  

PubMed

A lightness algorithm that separates surface reflectance from illumination in a Mondrian world is synthesized automatically from a set of examples, which consist of pairs of input (intensity signal) and desired output (surface reflectance) images. The algorithm, which resembles a new lightness algorithm recently proposed by Land, is approximately equivalent to filtering the image through a center-surround receptive field in individual chromatic channels. The synthesizing technique, optimal linear estimation, requires only one assumption, that the operator that transforms input into output is linear. This assumption is true for a certain class of early vision algorithms that may therefore be synthesized in a similar way from examples. Other methods of synthesizing algorithms from examples, or "learning," such as back-propagation, do not yield a significantly better lightness algorithm. PMID:3340834

Hurlbert, A C; Poggio, T A

1988-01-29

371

Comprehensive processing, display and analysis forin vivo MR spectroscopic imaging  

Microsoft Academic Search

Image reconstruction for magnetic resonance spectroscopic imaging (MRSI) requires specialized spatial and spectral data processing methods and benefits from the use of several sources of prior information that are not commonly available, including MRI-derived tissue segmentation, morphological analysis and spectral characteristics of the observed metabolites. In addition, incorporating information obtained from MRI data can enhance the display of low-resolution metabolite

A. A. Maudsley; A. Darkazanli; J. R. Alger; L. O. Hall; N. Schuff; C. Studholme; Y. Yu; A. Ebel; A. Frew; D. Goldgof; Y. Gu; R. Pagare; F. Rousseau; K. Sivasankaran; B. J. Soher; P. Weber; K. Young; X. Zhu

2006-01-01

372

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

373

Spectroscopic and theoretical constraints on the differentiation of planetesimals  

Microsoft Academic Search

The differentiation of small proto-planetary bodies into metallic cores, silicate mantles and basaltic crusts was a common occurrence in the first few million years of Solar System history. In this thesis, observational and theoretical methods are employed to investigate this process. Particular focus is given to the basaltic, crustal remnants of those differentiated parent bodies. A visible-wavelength spectroscopic survey was

Nicholas A. Moskovitz

2009-01-01

374

Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation  

EPA Science Inventory

Arsenate adsorption on amorphous (RuO2?1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

375

Spectroscopic studies of cathode materials for lithium-ion batteries  

Microsoft Academic Search

Structural changes that occur during electrochemical cycling of lithium-ion battery cathode materials have been investigated using in situ spectroscopic techniques. A new method was developed for the preparation of carbon and binder free cathodes utilizing powder materials of interest for commercial batteries. The extraordinary quality of the cyclic voltammetric curves recorded for this type of electrodes during the in situ

Dana Alexa Totir

2000-01-01

376

Optical Spectroscopic Diagnostics Of Dusty Plasma In RF Discharge  

SciTech Connect

The parameters of the buffer plasma containing dust particles were measured by means of spectroscopic methods. The change in the emission spectrum of the buffer plasma with addition of dust was observed. It seems to relate to changing in temperature and number density of electrons due to the influence of dusts.

Orazbayev, S. A.; Jumagulov, M. N.; Dosbolayev, M. K.; Silamiya, M.; Ramazanov, T. S. [IETP, Al Farabi Kazakh National University, 96a, Tole bi, Almaty, 050012 (Kazakhstan); Boufendi, L. [Universite d'Orleans, 14 Rue d'Issoudun, B.P. 6744-45067 Orleans Cedex 2 (France)

2011-11-29

377

MR Spectroscopic Changes in the Rat Hippocampus following Proton Radiosurgery  

Microsoft Academic Search

Purpose: To identify MR spectroscopic changes in the rat hippocampus following proton radiosurgery. Methods and Materials: A group of 12 rats were treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 30 CGE, 50 CGE, 70 CGE, 90 CGE were delivered to groups of 3 animals using single fraction technique. Animals were imaged using a

J. D. Rabinov; L. L. Cheng; P. L. Lee; J. L. Brisman; J. S. Loeffler; A. J. Cole; G. R. Cosgrove; M. R. Bussiere; T. Chaves; R. G. Gonzalez

2006-01-01

378

Numerical Improvement of Terahertz Time-Domain Spectroscopic Measurements  

NASA Astrophysics Data System (ADS)

We have developed an algorithm to efficiently eliminate unwanted reflections typically observed in the data obtained by Terahertz time-domain spectroscopic (THz-TDS) methods. The algorithm works by eliminating the reflections from the boundaries. The numerical improvement of the data allows better analysis of the critical parameters obtained by THz-TDS systems.

Koseoglu, D.; Berberoglu, H.; Altan, H.

379

Military Examples of Coastal Engineering.  

National Technical Information Service (NTIS)

Coastal engineering is required for military ports and harbors and across-the-beach amphibious operations. Examples are given for operations during World War II, the Korean War, and the Vietnam Conflict, one very large (Normandy, France), and some small. ...

R. L. Wiegel

1999-01-01

380

Traversable wormholes: Some simple examples  

SciTech Connect

Building on the work of Morris, Thorne, and Yurtsever, some particularlysimple examples of traversable wormholes are exhibited. These examples arenotable both because the analysis is not limited to spherically symmetric casesand because it is possible to in some sense minimize the use of exotic matter.In particular, it is possible for a traveler to traverse such a wormholewithout passing through a region of exotic matter. As in previous analyses, theweak-energy condition is violated in these traversable wormholes.

Visser, M.

1989-05-15

381

A Universal Fiber-Optic Spectroscope for Studying the Modulated Reflection of Semiconductor Structures  

Microsoft Academic Search

A universal fiber-optic spectroscope has been developed that allows one to study state-of-the-art semiconductor structures by various methods employing the modulated reflection of light. Among these are both the well-known traditional methods of photoreflection and electroreflection and the new methods of longitudinal current modulated reflection and below-bandgap photoreflection. The possibilities of the spectroscope are demonstrated by studies of the semiconductor

A. E. Sotnikov; M. A. Chernikov; O. A. Ryabushkin

2004-01-01

382

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

383

Spectroscopic detection of nitrogen concentrations in sagebrush  

SciTech Connect

The ability to estimate foliar nitrogen (N) in semi-arid landscapes can yield information on nutritional status and improve our limited understanding of controls on canopy photosynthesis. We examined two spectroscopic methods for estimating sagebrush dried leaf and live shrub N content: first derivative reflectance (FDR) and continuum removal. Both methods used partial least squares (PLS) regression to select wavebands most significantly correlated with N concentrations in the samples. Sagebrush dried leaf spectra produced PLS models (R2 = 0.76–0.86) that could predict N concentrations within the dataset more accurately than PLS models generated from live shrub spectra (R2 = 0.41–0.63). Inclusion of wavelengths associated with leaf water in the FDR transformations appeared to improve regression results. Findings are encouraging and warrant further exploration into sagebrush reflectance spectra to characterize N concentrations.

J. J. MITCHELL; N. F. GLENN; T.T. SANKEY; D. R. DERRYBERRY; R. C. HRUSKA; M. O. Anderson

2012-07-01

384

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

385

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

386

Spectroscopic Studies of Zinc Benzenethiolate Complexes: Electron Transfer to Methyl Viologen. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Mononuclear and tetranuclear zinc benzenethiolate complexes are studied by both spectroscopic and electrochemical methods. Zn(SPh)4 2- and Zn4(SPh)102- represent tetrahedral fragments of the cubic zinc sulfide lattice. The structured absorption spectra of...

T. Turk U. Resch M. A. Fox A. Vogler

1992-01-01

387

Characterization of ion-implanted aluminum and iron by spectroscopic ellipsometry.  

National Technical Information Service (NTIS)

The change in the optical constants of aluminum alloy and iron samples caused by implantation with nitrogen and chromium ions has been investigated by spectroscopic ellipsometry. The objective is to develop a method for simple, non-destructive characteriz...

J. S. Brodkin W. Franzen R. J. Culbertson J. M. Williams

1990-01-01

388

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

389

New Insight into the Observation of Spectroscopic Strength Reduction in Atomic Nuclei: Implication for the Physical Meaning of Spectroscopic Factors  

SciTech Connect

Experimental studies of one-nucleon knockout from magic nuclei suggest that their nucleon orbits are not fully occupied. This conflicts a commonly accepted view of the shell closure associated with such nuclei. The conflict can be reconciled if the overlap between initial and final nuclear states in a knockout reaction are calculated by a nonstandard method. The method employs an inhomogeneous equation based on correlation-dependent effective nucleon-nucleon interactions and allows the simplest wave functions, in which all nucleons occupy only the lowest nuclear orbits, to be used. The method also reproduces the recently established relation between reduction of spectroscopic strength, observed in knockout reactions on other nuclei, and nucleon binding energies. The implication of the inhomogeneous equation method for the physical meaning of spectroscopic factors is discussed.

Timofeyuk, N. K. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2009-12-11

390

Vibrational spectroscopic and DFT study of trimethoprim  

NASA Astrophysics Data System (ADS)

Structural investigations by different vibrational spectroscopic methods: FTIR, FT-Raman and surface-enhanced Raman scattering (SERS) spectroscopy, as well as density functional theory (DFT) calculations were performed on trimethoprim (5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine). A reliable assignment of vibrational IR, Raman and SERS bands was possible by a proper choice of model used in quantum chemical calculations. Based on SERS spectrum analysis it is shown that the molecule is adsorbed on the silver surface through the pyrimidine ring, in a perpendicular orientation. Two theoretical models were used in order to simulate the silver surface and the interaction with trimethoprim molecule, the accuracy of the models being evaluated by comparing the predicted bands position of the two complexes with the SERS result.

Ungurean, Alia; Leopold, Nicolae; David, Leontin; Chi?, Vasile

2013-02-01

391

Compact fluorescence spectroscopic tool for cancer detection  

NASA Astrophysics Data System (ADS)

We describe a compact fluorescence spectroscopic tool for in vivo point monitoring of aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence and autofluorescence, as a non-invasive method of differentiating normal and cancerous tissue. This instrument incorporates a 405nm diode laser with a shutter to prevent exposure of tissue to harmful light doses and reduce photobleaching, a bifurcated optical fibre to allow illumination of tissue and collection of fluorescence with a single fibre, a compact grating spectrometer for collection of spectra and a PC for system control. We present spectra obtained using this system both during routine gastro-intestinal (GI) endoscopy for cancer detection and during photodynamic therapy (PDT) of anal intraepithelial neoplasia (AIN) for monitoring of treatment progress. These results illustrate the potential of the system to be used for fluorescence monitoring in a variety of clinical applications.

Nadeau, Valerie; Hamdan, Khaled; Hewett, Jacqueline; Makaryceva, Juljia; Tait, Iain; Cuschieri, Alfred; Padgett, Miles J.

2002-05-01

392

Laser and Spectroscopic Properties of Chromium - Forsterite  

Microsoft Academic Search

This thesis describes the discovery of a new tunable solid state laser, chromium-doped forsterite (Cr:Mg _2SiO_4), its spectroscopic, quantum electronic and laser characteristics. The main goal of spectroscopic investigations was to identify optically active ions in chromium-doped forsterite. The spectroscopic studies performed on Cr:Mg _2SiO_4 crystals grown under different conditions include: measurements of the polarized absorption and fluorescence spectra, polarized

Vladimir Petricevic

1990-01-01

393

Re-construction of detached divertor plasma conditions in DIII-D using spectroscopic and probe data  

NASA Astrophysics Data System (ADS)

For some divertor aspects, such as detached plasmas or the private flux zone, it is not clear that the controlling physics has been fully identified. This is a particular concern when the details of the plasma are likely to be important in modeling the problem - for example, modeling co-deposition in detached inner divertors. An empirical method of 'reconstructing' the plasma based on direct experimental measurements may be useful in such situations. It is shown that a detached plasma in the outer divertor leg of DIII-D can be reconstructed reasonably well using spectroscopic and probe data as input to a simple onion-skin model and the Monte Carlo hydrogenic code, EIRENE. The calculated 2D distributions of ne and Te in the detached divertor were compared with direct measurements from the divertor Thomson scattering system, a diagnostic capability unique to DIII-D.

Lisgo, S.; Stangeby, P. C.; Elder, J. D.; Boedo, J. A.; Bray, B. D.; Brooks, N. H.; Fenstermacher, M. E.; Groth, M.; Reiter, D.; Rudakov, D. L.; Watkins, J. G.; West, W. P.; Whyte, D. G.

2005-03-01

394

Some examples of Internet planetology  

NASA Astrophysics Data System (ADS)

When thinking about planetology, one usually invokes robotic or humanm space missions and other forms of state of the art technology. This line of reasoning may lead to the conclusion that planetology is a "reserved domain" for a restricted number of scientists. The aim of this lecture is to show on several realistic examples what can be done in planetology using the Internet, publicly available data banks and shareware software packages.

Celebonovic, Vladan

395

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

396

[The spectroscopic study of topaz].  

PubMed

In this paper, the natural gem material--Topaz (colorless transparent samples and reactor irradiation induced blue color samples) was studied on the spectroscopic analysis of Fourier transformation infrared spectrum (FTIR) and FT-Raman spectrum. The structure of topaz consists of OH groups and SiO4 groups. Si-O vibration spectrum was characterized with the group theoretical analysis. OH stretching modes of vibration showed many changes among the different color samples, the reason of the changes was explained. The color origin was preliminary investigated by ultra-violet and visible absorption spectrum. PMID:12953446

Wang, B; Tu, J

2000-02-01

397

A Spectroscopic Orbit for Regulus  

NASA Astrophysics Data System (ADS)

We present a radial velocity study of the rapidly rotating B star Regulus that indicates the star is a single-lined spectroscopic binary. The orbital period (40.11 days) and probable semimajor axis (0.35 AU) are large enough that the system is not interacting at present. However, the mass function suggests that the secondary has a low mass (M2>0.30 Msolar), and we argue that the companion may be a white dwarf. Such a star would be the remnant of a former mass donor that was the source of the large spin angular momentum of Regulus itself.

Gies, D. R.; Dieterich, S.; Richardson, N. D.; Riedel, A. R.; Team, B. L.; McAlister, H. A.; Bagnuolo, W. G., Jr.; Grundstrom, E. D.; Štefl, S.; Rivinius, Th.; Baade, D.

2008-08-01

398

NASTRAN: User experience with four example problems  

NASA Technical Reports Server (NTRS)

Four different structural problems are solved to gain familiarity with the NASTRAN computer program. The problems are: (1) a simply-supported beam subjected to lateral loads, (2) a rotating filamentary composite bar under the action of centrifugal forces, (3) a missile body with aerodynamic, gravitational, and inertial forces, and (4) a square simply-supported plate with in-plane temperature changes capable of buckling the plate. Input and output data are given for each problem. The results are compared with those obtained by other methods. However, except for the examples employing beam elements in which the agreement is excellent, the element breakup chosen for convenience in obtaining program familiarity is too coarse to draw conclusions regarding the program accuracy. The example problems disclosed errors in the plotting and thermal-buckling routines of the program.

Rivello, R. M.

1972-01-01

399

Longitudinal Data Analysis Examples with Random Coefficient Models.  

ERIC Educational Resources Information Center

Longitudinal panel data examples are used to illustrate estimation methods for individual growth curve models. These examples demonstrate issues and concerns in the application of hierarchical modeling estimation, specifically the hierarchical linear models of A. S. Bryk and S. W. Raudenbush. (SLD)

Rogosa, David; Saner, Hilary

1995-01-01

400

CTM: An Example-Based Translation Aid System  

Microsoft Academic Search

This paper describes a Japanese-English translation aid system, CTM, which has a useful capability for flexible retrieval of texts from bilingual corpora or translation databases. Translation examples (pairs of a text and its translation equivalent) are very helpful for us to translate the similar text. Our character-based best match retrieval method can retrieve translation examples similar to the given input.

Satoshi Sato

1992-01-01

401

Semi-Supervised Learning with Very Few Labeled Training Examples  

Microsoft Academic Search

In semi-supervised learning, a number of labeled exam- ples are usually required for training an initial weakly useful predictor which is in turn used for exploiting the unlabeled examples. However, in many real-world applications there may exist very few labeled train- ing examples, which makes the weakly useful pre- dictor difficult to generate, and therefore these semi- supervised learning methods

Zhi-hua Zhou; De-chuan Zhan; Qiang Yang

2007-01-01

402

Toward an Instructionally Oriented Theory of Example-Based Learning  

ERIC Educational Resources Information Center

Learning from examples is a very effective means of initial cognitive skill acquisition. There is an enormous body of research on the specifics of this learning method. This article presents an instructionally oriented theory of example-based learning that integrates theoretical assumptions and findings from three research areas: learning from…

Renkl, Alexander

2014-01-01

403

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

404

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

405

Spectroscopic imaging in electron microscopy  

SciTech Connect

In the scanning transmission electron microscope, multiple signals can be simultaneously collected, including the transmitted and scattered electron signals (bright field and annular dark field or Z-contrast images), along with spectroscopic signals such as inelastically scattered electrons and emitted photons. In the last few years, the successful development of aberration correctors for the electron microscope has transformed the field of electron microscopy, opening up new possibilities for correlating structure to functionality. Aberration correction not only allows for enhanced structural resolution with incident probes into the sub-angstrom range, but can also provide greater probe currents to facilitate mapping of intrinsically weak spectroscopic signals at the nanoscale or even the atomic level. In this issue of MRS Bulletin, we illustrate the power of the new generation of electron microscopes with a combination of imaging and spectroscopy. We show the mapping of elemental distributions at atomic resolution and also the mapping of electronic and optical properties at unprecedented spatial resolution, with applications ranging from graphene to plasmonic nanostructures, and oxide interfaces to biology.

Pennycook, Stephen J [ORNL; Colliex, C. [Universite Paris Sud, Orsay, France

2012-01-01

406