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1

Calibration method for spectroscopic systems  

DOEpatents

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

Sandison, David R. (Edgewood, NM)

1998-01-01

2

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

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

2011-11-18

4

Plasma diagnostics by spectroscopic methods.  

PubMed

Spectroscopic techniques for the measurement of plasma parameters are reviewed for a range of temperatures up to 10(6) degrees K. Tables and figures of useful data have been prepared or have been collected from the literature for ready application to experimental measurements. The problem of making spatially resolved intensity measurements in an optically thin axisymmetric plasma column is discussed. PMID:20062112

Robinson, D; Lenn, P D

1967-06-01

5

Selective spectroscopic methods for water analysis  

SciTech Connect

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

Vaidya, B.

1997-06-24

6

Multivariate analysis methods for spectroscopic blood analysis  

NASA Astrophysics Data System (ADS)

Blood tests are an essential tool in clinical medicine with the ability diagnosis or monitor various diseases and conditions; however, the complexities of these measurements currently restrict them to a laboratory setting. P&P Optica has developed and currently produces patented high performance spectrometers and is developing a spectrometer-based system for rapid reagent-free blood analysis. An important aspect of this analysis is the need to extract the analyte specific information from the measured signal such that the analyte concentrations can be determined. To this end, advanced chemometric methods are currently being investigated and have been tested using simulated spectra. A blood plasma model was used to generate Raman, near infrared, and optical rotatory dispersion spectra with glucose as the target analyte. The potential of combined chemometric techniques, where multiple spectroscopy modalities are used in a single regression model to improve the prediction ability was investigated using unfold partial least squares and multiblock partial least squares. Results show improvement in the predictions of glucose levels using the combined methods and demonstrate potential for multiblock chemometrics in spectroscopic blood analysis.

Wood, Michael F. G.; Rohani, Arash; Ghazalah, Rashid; Vitkin, I. Alex; Pawluczyk, Romuald

2012-02-01

7

Apparatus and method for spectroscopic analysis of scattering media  

DOEpatents

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

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

1994-01-01

8

Spectroscopic methods for detection of impurities in water  

Microsoft Academic Search

Optical photoluminescence spectroscopic method for detection of impurities, hazardous materials, pesticides, and pollutants in water resources, both qualitatively and quantitatively, is presented. The method is based on synchronous fluorescence spectroscopy (SFS) of organic aromatic compounds, or poly-aromatic hydrocarbons (PAH), and is carried out by following simultaneously their excitation and emission spectra. The full excitation emission matrix (EEM) generated in this

Natalia V. Strashnikova; Nona Papiashvili; Rivka Cohen-Luria; Shlomo Mark; Guy Shilon; Daniel Khankin; Yehoshua Kalisky; Ofra Kalisky; Abraham H. Parola

2011-01-01

9

A spectroscopic method for determining thickness of quartz wave plate  

Microsoft Academic Search

A spectroscopic method to determine thickness of quartz wave plate is presented. The method is based on chromatic polarization interferometry. With the polarization-resolved transmission spectrum (PRTS) curve, the phase retardation of quartz wave plate can be determined at a wide spectral range from 200 to 2000 nm obviously. Through accurate judgment of extreme points of PRTS curve at long-wave band,

Weiwei Feng; Lihuang Lin; Ligang Chen; Huafeng Zhu; Ruxin Li; Zhizhan Xu

2006-01-01

10

A computer method for the automatic reduction of spectroscopic data.  

PubMed

A computer program, written in Fortran IV and for use with an associated spectral comparator, has been developed at The Naval Research Laboratory for the purpose of automatically reducing spectroscopic data. A Datex digitalizing magnetic tape recorder in conjunction with a modified Jarrell-Ash microphotometer allows the reading of spectral information from a photographic plate at the rate of twentyfive data pairs per second. Spectra of local interest analyzed by this method are (1) absorption, (2) emission, (3) plasma type, obtained from time-resolved spectroscopic techniques, and (4) solar echellegrams obtained from rocket probings of the upper atmosphere. Markedly useful features of the program are its capabilities of (a) recognizing spectral peaks from a background of variable density, (b) obtaining absolute values for the radiance or irradiance. An essential characteristic of the method is the saving of significant amounts of time in the reduction of photographic spectroscopic data. PMID:20062364

Ditzel, E F; Giddings, L E

1967-12-01

11

Mixed Methods Sampling: A Typology with Examples  

ERIC Educational Resources Information Center

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

Teddlie, Charles; Yu, Fen

2007-01-01

12

Mixed Methods Sampling: A Typology with Examples  

ERIC Educational Resources Information Center

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

Teddlie, Charles; Yu, Fen

2007-01-01

13

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

PubMed Central

In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species’ identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted.

Rewald, Boris; Meinen, Catharina

2013-01-01

14

Spectroscopic studies of protein folding: Linear and nonlinear methods  

PubMed Central

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

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

2012-01-01

15

Spectroscopic methods for detection of impurities in water  

NASA Astrophysics Data System (ADS)

Optical photoluminescence spectroscopic method for detection of impurities, hazardous materials, pesticides, and pollutants in water resources, both qualitatively and quantitatively, is presented. The method is based on synchronous fluorescence spectroscopy (SFS) of organic aromatic compounds, or poly-aromatic hydrocarbons (PAH), and is carried out by following simultaneously their excitation and emission spectra. The full excitation emission matrix (EEM) generated in this way provides a 2-D and 3-D fluorescence map of the tested sample and the diagonals through the axes origin provide the synchronous fluorescence spectra at a constant wavelengths differences between the emission and excitation wavelengths, thus enabling multitude components identification. This map contains all the relevant spectroscopic information of the tested sample, and serves as a unique "fingerprint" with a very specific and accurate identification. When compared with pre-determined spectra and calibration curves from a "databank", there is a one-toone correspondence between the image and the specific compound, and it can be identified accurately both qualitatively and quantitatively. This method offers several significant advantages, and it provides a sensitive (ppm detection level), accurate and simple spectroscopic tool to monitor impurities and pollutants in water. The design and performance of the spectrofluorimeter prototype, as well as the software development and analysis of chemical organic compounds and mixtures in water will be discussed in this paper.

Strashnikova, Natalia V.; Papiashvili, Nona; Cohen-Luria, Rivka; Mark, Shlomo; Shilon, Guy; Khankin, Daniel; Kalisky, Yehoshua; Kalisky, Ofra; Parola, Abraham H.

2011-10-01

16

Method of absorbance correction in a spectroscopic heating value sensor  

DOEpatents

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

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

2013-09-17

17

Analysis of cancer tissues by means of spectroscopic methods  

PubMed Central

The personalized approach in cancer treatment stimulates the search for new analytical techniques, including spectroscopic methods such as Raman spectroscopy, mass spectrometry MALDI (matrix-assisted laser desorption/ionization) imaging and high-resolution magic angle spinning nuclear magnetic resonance (HR MAS NMR). The purpose of these studies is determination of metabolic profiles of cancer tissues, and their application in diagnostics and therapy of cancers. The review is mainly focused on application of HR MAS NMR technique. Qualitative and quantitative analysis of metabolites by means of this method is described for breast cancer tissues. In the near future HR MAS NMR in vitro studies of metabolic profiles combined with in vivo studies using MRI scanners may be applied as a new diagnostic tool.

Pacholczyk, Barbara; Fabianska, Anna; Kusinska, Renata; Potemski, Piotr; Kordek, Radzislaw

2012-01-01

18

New Spectroscopic Methods in Gas-Phase Chemical Kinetics  

Microsoft Academic Search

The possibilities provided by the application of advances in laser technology to the solution of problems in gas-phase chemical kinetics have been analysed. The basic principles of various laser methods for producing and recording active chemical species have been described. Examples of the use of lasers to study the reactions of radicals and excited species, in the diagnostics of complex

Oleg M. Sarkisov; S. G. Cheskis

1985-01-01

19

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

NASA Astrophysics Data System (ADS)

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.PRLTAO0031-900710.1103/PhysRevLett.104.030401 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.

2011-02-01

20

Nonyrast states of 108Cd: Investigation with complementary ??-spectroscopic methods  

NASA Astrophysics Data System (ADS)

We investigated 108Cd using a powerful combination of complementary ?? spectroscopic methods. Excited states were populated in the ? decay of 108In and with the 105Pd(?,n) fusion-evaporation reaction near the Coulomb barrier. From ?? angular correlation analyses we found dominant M1 character for decays of three 2+ states between 2.1 and 2.65 MeV, indicating that the fundamental isovector quadrupole excitation in the valence shell, the so-called 2+ms state, is fragmented in 108Cd. Effective lifetimes from the Doppler-shift attenuation method (DSAM) provided lower limits for the absolute transition strengths of the interesting decays. Our findings on mixed-symmetry 2+ states were compared to the neighboring nucleus 112Cd and IBM-2 predictions in the vicinity of the pure U(5) and O(6) dynamical symmetry limits. Furthermore, indications for the 1+ms excitation of 108Cd were found. In total we established more than 120 new states and more than 580 new transitions, 30 spins and 80 multipole mixing ratios were determined and eight effective lifetimes stem from DSAM. This huge amount of new data enabled an investigation of the excitation spectrum even under statistical aspects. We discuss the frequency of spin values below 3.13 MeV in the framework of the constant temperature model.

Gade, A.; Fitzler, A.; Fransen, C.; Jolie, J.; Kasemann, S.; Klein, H.; Linnemann, A.; Werner, V.; von Brentano, P.

2002-09-01

21

A spectroscopic method of determining the isotopic composition of magnesium  

Microsoft Academic Search

The composition is determined from the isotopic shift of the Mgl 880.68 nm line. The coefficient of variation for magnesium metal is 1.8%, but 4% for magnesium oxide. Several spectroscopic analyses can be performed in the time needed for one mass-spectrometer analysis, which reduces the error of analysis by a factor two or three.

A. G. Zhiglinskii; E. N. Fafurina

1966-01-01

22

Landscape planning: A method applied to a growth management example  

NASA Astrophysics Data System (ADS)

This article is the first in a series of three. These articles were prepared to document the growth management process undertaken in Teller County, Colorado, USA. In this article, an 11-step method for landscape planning is proposed. In step 1, an issue, or set of related issues, is identified as posing a problem and/or opportunity to people and/or the environment. In step 2, a goal, or several goals, is established to address the problem or opportunity. In steps 3 and 4, inventories and analyses of biophysical and sociocultural processes are conducted, first at the regional level and then at the local level. Step 5 involves detailed studies (such as suitability analyses) that link the inventory and analysis information to the problems or opportunities and goals. Detailed studies link regional and local information to specific sites. Thus, this method involves a regional-local-specific site hierarchy. In step 6, concepts are developed that lead to a landscape plan in step 7. During step 8, the plan is explained through a systematic educational and citizen involvement effort to the affected public. In step 9, detailed designs are developed that again are explained to the specific individuals who will be impacted by the designs. It is in step 10 when the plan and designs are implemented. Step 11 involves the administration of the plan. The method is illustrated through an example of growth management planning for Teller County and the city of Woodland Park, Colorado.

Steiner, Frederick

1991-07-01

23

Method and complexity in bioethics: the example of community genetics.  

PubMed

This article describes the need to develop a new methodology in bioethics that can consider multiple interactions, creativity and the organisation specific to complex systems. Community genetics is taken as an example of complexity in bioethics. Community genetics involves large populations and illustrates certain characteristics of complex adaptive systems which are discussed in the article. PMID:11831265

de Langavant, G C

2000-01-01

24

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

2011-09-27

25

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

Microsoft Academic Search

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

Colin F. Poole

2004-01-01

26

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

2012-11-20

27

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

28

Using Dreams in Cognitive Behavioral Psychotherapy: Theory, Method, and Examples  

Microsoft Academic Search

Dream analysis can be a fruitful complementary technique in cognitive–behavioral therapy, providing it is based on a theoretical conception of dreaming and an interpretation method that are both compatible with the principles and methodology of CBT. The present paper first presents some aspects of a cognitive conception of dreaming explaining the occurrence and specificities of dream representations by their production

Jacques Montangero

2009-01-01

29

Characterization of mesoporous materials via flourescent spectroscopic methods  

NASA Astrophysics Data System (ADS)

There are three components that need to be understood to create new porous membranes for industrial applications. 1) To understand appropriate synthesis conditions to create a successful membrane system. 2) To understand how the microstructures generated in synthesis affect the transport properties of that system. 3) To be able to characterize the heterogeneity of the fabricated membrane's transport and physical structure. Presented within this manuscript are new characterization methods to increase the understanding in membrane technology. It will be demonstrated that the novel application of standard fluorescent methods and the development of new fluorescent methods techniques allows for the measurement of molecular interactions and transport properties on length scales capable of providing valuable information in the field of membrane science, as well as expanding new applications in fluorescent techniques.

Kennard, Raymond Russell

30

Estimating duration in partnership studies: issues, methods and examples  

PubMed Central

Background and objectives Understanding the time course of sexual partnerships is important for understanding sexual behaviour, transmission risks for sexually transmitted infections (STI) and development of mathematical models of disease transmission. Study design The authors describe issues and biases relating to censoring, truncation and sampling that arise when estimating partnership duration. Recommendations for study design and analysis methods are presented and illustrated using data from a sexual-behaviour survey that enrolled individuals from an adolescent-health clinic and two STD clinics. Survey participants were queried, for each of (up to) four partnerships in the last 3 months, about the month and year of first sex, the number of days since last sex and whether partnerships were limited to single encounters. Participants were followed every 4 months for up to 1 year. Results After adjustment for censoring and truncation, the estimated median duration of sexual partnerships declined from 9 months (unadjusted) to 1.6 months (adjusted). Similarly, adjustment for censoring and truncation reduced the bias in relative risks for the effect of age in a Cox model. Other approaches, such as weighted estimation, also reduced bias in the estimated duration distribution. Conclusion Methods are available for estimating partnership duration from censored and truncated samples. Ignoring censoring, truncation and other sampling issues results in biased estimates.

Burington, Bart; Hughes, James P; Whittington, William L H; Stoner, Brad; Garnett, Geoff; Aral, Sevgi O; Holmes, King K

2011-01-01

31

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

NASA Astrophysics Data System (ADS)

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

Savageau, Michael A.

2001-03-01

32

A fourier transform infrared spectroscopic method for determining butylated hydroxytoluene in palm olein and palm oil  

Microsoft Academic Search

A simple, rapid, and direct FTIR spectroscopic method was developed for the determination of BHT content in refined, bleached,\\u000a and deodorized (RBD) palm olein and RBD palm oil. The method used sodium chloride windows with a 50-mm transmission path.\\u000a Fifty stripped oil samples of both RBD palm olein and RBD palm oil were spiked with known amounts of BHT concentrations

W. Ammawath; Y. B. Che Man; R. B. Abdul Rahman; B. S. Baharin

2006-01-01

33

Using Example-Based Machine Translation Method For Automatic Image Annotation  

Microsoft Academic Search

The paper proposes that the image annotation task can be thought of as similar to the machine translation problem and apply the example-based machine translation method to this problem. The method is based on the idea of performing automatic annotation by imitating annotation examples of images with similar visual scene. It can make full use of both correlation of annotation

Linsen Yu; Yongmei Liu; Tianwen Zhang

2006-01-01

34

A complementary technique to PIXE: The nuclear interaction analysis method - advantages, possibilities and typical application examples  

Microsoft Academic Search

The various possibilities of the nuclear interaction methods are discussed. The advantages of their utilization in conjunction with PIXE is emphasized. Typical application examples are briefly described. A comparative table of the main instrumental microanalysis techniques is given.

Ch. Engelmann

1990-01-01

35

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

SciTech Connect

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

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

1997-09-01

36

Spectroscopic method of diagnostics of the bone marrow and peripheral blood  

NASA Astrophysics Data System (ADS)

The first results of comparative spectral analysis of the bone marrow and blood taken from one and the same donor are presented and the new potentialities of the spectroscopic method for hematologic diseases diagnostics and for testing the pathologic process together with the morphologic investigations of bone marrow punctates are considered. We present here the results of comparative spectral analysis of the bone marrow and blood taken from one and the same donor. We found out what differences in spectra are for normal and pathology bone marrow composition and what causes this difference.

Kochubey, Vyacheslav I.; Medvedev, Boris A.; Sedova, Yuliya G.; Brill, Grigory E.; Stepanova, Valentina Y.

1994-02-01

37

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

38

A new method for the spectroscopic identification of stellar non-radial pulsation modes. I. The method and numerical tests  

NASA Astrophysics Data System (ADS)

Aims.We present the Fourier parameter fit method, a new method for spectroscopically identifying stellar radial and non-radial pulsation modes based on the high-resolution time-series spectroscopy of absorption-line profiles. In contrast to previous methods this one permits a quantification of the statistical significance of the computed solutions. The application of genetic algorithms in seeking solutions makes it possible to search through a large parameter space. Methods: .The mode identification is carried out by minimizing ?^2, using the observed amplitude and phase across the line profile and their modeled counterparts. Computations of the theoretical line profiles are based on a stellar displacement field, which is described as superposition of spherical harmonics and that includes the first order effects of the Coriolis force. Results: .We made numerical tests of the method on a grid of different mono- and multi-mode models for 0 ? ? ? 4 in order to explore its capabilities and limitations. Our results show that whereas the azimuthal order m can be unambiguously identified for low-order modes, the error of ? is in the range of ± 1. The value of m can be determined with higher precision than with other spectroscopic mode identification methods. Improved values for the inclination can be obtained from the analysis of non-axisymmetric pulsation modes. The new method is ideally suited to intermediatley rotating ? Scuti and ? Cephei stars.

Zima, W.

2006-08-01

39

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…

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

2012-01-01

40

The accuracy of numerical conformal mapping methods: A survey of examples and results  

Microsoft Academic Search

This paper shows how the geometry of the region affects the conditioning and the accuracy of numerical conformal mapping methods for simply connected regions, especially Fourier series methods. Both explicit examples of popular test cases and more general estimates are discussed. The severe ill conditioning that is known as the crowding phenomenon is discussed and its effect on a conformally

Thomas K. DeLillo

1994-01-01

41

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

SciTech Connect

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

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

2002-05-21

42

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

NASA Astrophysics Data System (ADS)

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

Gupta, Lokesh Kumar

2012-11-01

43

Application of method of OTE staining of ultrathin sections based on example of microsporidia (Protozoa: Microsporidia)  

Microsoft Academic Search

A comparative analysis of ultrastructure of some organelles stained by different methods of staining of ultrathin sections\\u000a has been performed using the example of intracellular parasites, i.e., microsporidia. The distinctive peculiarities are revealed\\u000a and the advantages and disadvantages are substantiated of the traditional method of contrasting with uranyl acetate and the\\u000a nontraditional method of contrasting using black Chinese tea extract,

A. A. Miller; A. V. Simakova

2010-01-01

44

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

45

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

46

Statistical methods for comparing mortality among ESRD patients: Examples of regional\\/international variations  

Microsoft Academic Search

Statistical methods for comparing mortality among ESRD patients: Examples of regional\\/international variations. There have been a number of recent large-scale registry studies comparing mortality between patients receiving hemodialysis (HD) and peritoneal dialysis (PD). Results from these studies are mixed with some indicating a difference in mortality in favor of hemodialysis, others finding no difference in mortality and still others observing

Edward F. Vonesh; Douglas E. Schaubel; Wenli Hao; Allan J. Collins

2000-01-01

47

Methods to Study Everyday Use of Products in Households: The Wageningen Mouthing Study as an Example  

Microsoft Academic Search

Several methods exist to study human behaviour in everyday life: e.g. an oral or written interview, measurement of physical variables and observation. All of them have their advantages and disadvantages, which are described in this paper. When a clear picture of actual human behaviour and information about an entire activity are required, for example to assess risks of exposure to

L. P. A. Steenbekkers

2001-01-01

48

Development of new marker methods?an example from oil palm  

Microsoft Academic Search

This paper reviews marker methods based on retrotransposons and illustrates examples from oil palm. Prior to this study, very little had been known about the repetitive DNA present in oil palm and no marker systems based on retrotransposons had been developed. Firstly, copia- like retrotransposons of Elaeis oleifera, Elaeis guineensis and Cocos nucifera were character- ized by performing phylogenetic analyses

Zuzana Price; Alan H. Schulman; Sean Mayes

2003-01-01

49

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

50

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

51

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

52

Semiempirical method for extracting electron molecule cross sections from experimental data: CF 4 as an example  

Microsoft Academic Search

A semiempirical method is described for calculating electron-molecule interaction potential, electron density, and elastic and vibrational inelastic cross sections using experimental data.CF4 was considered as un example. Experimental data from IR and Raman spectra, molecular property calculations (dipole matrix elements, polarizability, distance between atoms in molecule), beam measurements of total, momentum transfer, and differential cross sections, and swarm data (diffusion

B. Stefanov; P. Pirgov

1993-01-01

53

Elemental and spectroscopic methods with chemometric analysis for characterizing composition and transformation of dissolved organic matter during chicken manure composting.  

PubMed

Dissolved organic matter was extracted from chicken manure after 1, 8, 16, 28 and 40 days of composting and characterized by combining elemental and spectroscopic methods with chemometric analysis to investigate the evolution of composting materials. The elemental and spectroscopic analysis results showed that the composting process was characterized by the biodegradation of aliphatics, polysaccharide and proteins, as well as by the synthesis of aromatic structures, humic-like substances and macromolecules. Principal component analysis and correlation analysis indicated that the data from elemental and spectroscopic analysis fell into three main groups, and corresponded to the biodegradation, aromatization, and humification and polymerization state of the composting materials. Hierarchical cluster analysis indicated rapid biodegradation of organic matter during the first eight days, and the formation of aromatic structures, humic-like materials and macromolecules in dissolved organic matter after eight days. PMID:23240197

He, Xiao-Song; Xi, Bei-Dou; Jiang, Yong-Hai; Li, Ming-Xiao; Yu, Hui-Bin; An, Da; Yang, Yu; Liu, Hong-Liang

2012-09-01

54

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

55

Investigation of the PSF-choice method for reduced lipid contamination in prostate MR spectroscopic imaging.  

PubMed

The purpose of this work was to evaluate a previously proposed approach that aims to improve the point spread function (PSF) of MR spectroscopic imaging (MRSI) to avoid corruption by lipid signal arising from neighboring voxels. Retrospective spatial filtering can be used to alter the PSF; however, this either reduces spatial resolution or requires extending the acquisition in k-space at the cost of increased imaging time. Alternatively, the method evaluated here, PSF-choice, can modify the PSF localization to reduce the contamination from adjacent lipids by conforming the signal response more closely to the desired MRSI voxel grid. This is done without increasing scan time or degrading SNR of important metabolites. PSF-choice achieves improvements in spatial localization through modifications to the radiofrequency excitation pulses. An implementation of this method is reported for MRSI of the prostate, where it is demonstrated that, in 13 of 16 pilot prostate MRSI scans, intravoxel spectral contamination from lipid was significantly reduced when using PSF-choice. Phantom studies were also performed that demonstrate, compared with MRSI with standard Fourier phase encoding, out-of-voxel signal contamination of spectra was significantly reduced in MRSI with PSF-choice. PMID:22648701

Panych, Lawrence P; Roebuck, Joseph R; Chen, Nan-kuei; Tang, Yi; Madore, Bruno; Tempany, Clare M; Mulkern, Robert V

2012-11-01

56

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

57

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

Code of Federal Regulations, 2010 CFR

...more reliable than any other available measure of the arm's length result. The following examples illustrate the comparative analysis required to apply this rule. As with all of the examples in these regulations, these examples are based on...

2009-04-01

58

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

59

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

NASA Astrophysics Data System (ADS)

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

Cai, Changqun; Chen, Xiaoming; Ge, Fei

2010-07-01

60

Estimation of ?- and ?-donor properties of heterocyclic thioamides by spectroscopic and magnetic resonance methods  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

61

Comparison of correction methods for inhomogeneities in daily time series on example of Central European datasets  

NASA Astrophysics Data System (ADS)

Prior any data analysis, data quality control and homogenization have to be undertaken to get rid of erroneous values in time series. In this work we focused especially on comparison of methods for daily data inhomogeneities correction. Two basic approaches for inhomogeneity adjustments were adopted and compared: (i) "delta" method - adjustment of monthly series and projection of estimated smoothed monthly adjustments into annual variation of daily adjustments and (ii) "variable" correction of daily values according to the corresponding percentiles. "Variable" correction methods emerged only in recent years. Their results were investigated in this work more deeply and they were mutually compared. Among the analyzed methods belong HOM of Paul Della-Marta, SPLIDHOM method of Olivier Mestre and own methods (DAP). We applied multi-element approach (using e.g. weather types) as well and investigated if it can improve the models. Comparison of the available correction methods is also current task of the ongoing COST action ESO601 (www. homogenisation.org). Performance of the available correction methods (on daily scale) is shown on example of Central European series of various meteorological elements (air temperature, precipitation, relative humidity, sunshine duration). Comparisons among the methods as well as its various modifications (parameters settings) were investigated. For the task, ProClimDB software has been used (read more at www.climahom.eu).

Stepanek, P.; Zahradnicek, P.,

2010-09-01

62

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

SciTech Connect

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

G. Michael Shook

2005-01-01

63

The benefit of atmospheric science methods for cryospheric research: Two examples  

NASA Astrophysics Data System (ADS)

Glacier-climate studies in the cryospheric sciences are still focusing strongly on the local scale in the case of mountain glaciers. However, individual mountain glaciers do show the potential to reveal climate change details beyond the local scale, as we have found from intensive studies of Kilimanjaro (East Africa). Exploitation of this potential requires, in our opinion, a look beyond the border of traditional glaciological methods as well. Here we present two such examples. The first refers to statistical downscaling of reanalysis data to daily precipitation on a glacier (which is an important quantity for mass balance studies), by using statistical weather forecasting methods and idealized numerical atmospheric modelling; Second, quantifying the local effect of vegetation changes on glacier mass balance (which is important to assess the role of local vs. large-scale drivers), by employing a numerical atmospheric model along with a physically-based glacier mass balance model; On-site measurements have been conducted on Kilimanjaro since 2000 (four automated weather stations in the meantime) and are available for validation of models used in the two examples. Preliminary results demonstrate that the inclusion of these techniques is capable of revealing more information about the climatic controls of glacier recession than traditional glaciological methods alone.

Mölg, Thomas; Cullen, Nicolas J.; Hardy, Douglas R.; Hofer, Marlis; Kaser, Georg; Marzeion, Ben

2010-05-01

64

A correlation of spectroscopic parameters from different magnetic resonance spectroscopies for thiazides: a study by NQR, NMR, EPR and DFT methods  

Microsoft Academic Search

A Letter is devoted to a detailed parallel analysis of the spectroscopic parameters such as quadrupole coupling constant (NQR), chemical shift, chemical shift anisotropy, asymmetry parameter (NMR) and hyperfine coupling constant (EPR) for thiazides. The compounds were studied in solid state by the resonance (NQR, NMR and EPR) and density functional theory (DFT) methods. The spectroscopic parameters determined at room

J. N. Latosi?ska

2004-01-01

65

Combination of simple chemical and spectroscopic methods for the identification of Thai Hom Mali rice  

NASA Astrophysics Data System (ADS)

As the Thai Dawk Mali (KDML105) rice variety is popular due to its high sensory after cook, there is an increase in mixing the KDML105 rice with other rice varieties that leads to unqualified KDML105 milled rice products for export and unqualified unmilled rice seeds for next plants. Instead of using traditional time consuming methods based on the disintegration of the rice kernel in an alkali solution and the inspection of rice cooked in boiling water, this paper proposes to analyze the milled rice powder dissolved in our alkali solution via a spectroscopic method. In our study, 0.1 g, 0.2 g, and 0.3 of milled rice powder from four Thai rice varieties, i.e., KDML105, Pathumthani1, Chainat1, and RD6, are selected. Then each milled rice sample is ground and then dissolved in a 10% potassium hydroxide (KOH) solution. At the specified minutes of dissolution, the relative optical transmission spectrum of the milled rice solution in a 500-800 nm wavelength is measured and only its first derivative is used for the identification of the KDML105 milled rice. We find that the use of 0.10 g of the milled rice powder dissolved in our KOH solution for 10 minutes provides the lowest false rejection rate of 15%, indicating that we have a faster approach with less amount of waste produced. With the 0.2-g milled rice powder, 5 minutes of dissolution is needed but with a slightly higher false rejection rate of 18.3%.

Suwansukho, Kajpanya; Sumriddetchkajorn, Sarun; Buranasiri, Prathan

2009-05-01

66

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

67

Infrared study of aging of edible oils by oxidative spectroscopic index and MCR-ALS chemometric method.  

PubMed

One of the most suitable analytical techniques used for edible oil quality control is Fourier transform mid infrared spectroscopy (FT-MIR). FT-MIR spectroscopy was used to continuously characterize the aging of various edible oils thanks to a specific aging cell. There were differences in the spectra of fresh and aged oils from different vegetable sources, which provide the basis of a method to classify them according to the oxidative spectroscopic index value. The use of chemometric treatment such as multivariate curve resolution-alternative least square (MCR-ALS) made it possible to extract the spectra of main formed and degraded species. The concentration profiles gave interesting information about the ability of the various oils to support the oxidative treatment and showed that all oils present the same aging process. Both methods led to concordant results in terms of induction times determined by the oxidative spectroscopic index and the appearance of oxidation products revealed by MCR-ALS. PMID:19159793

Le Dréau, Y; Dupuy, N; Artaud, J; Ollivier, D; Kister, J

2008-10-17

68

Cellulose crystallinity and ordering of hemicelluloses in pine and birch pulps as revealed by solid-state NMR spectroscopic methods  

Microsoft Academic Search

Solid-state 13C NMR spectroscopy was used to determine the degree of cellulose crystallinity (CrI) in kraft, flow-through kraft and polysulphide–anthraquinone (PS–AQ) pulps of pine and birch containing various amounts of hemicelluloses. The applicability of acid hydrolysis and the purely spectroscopic proton spin-relaxation based spectral edition (PSRE) method to remove the interfering hemicellulose signals prior to the determination of CrI were

Tiina Liitiä; Sirkka Liisa Maunu; Bo Hortling; Tarja Tamminen; Osmo Pekkala; Antero Varhimo

2003-01-01

69

Molecular structures of gas-phase polyatomic molecules determined by spectroscopic methods  

Microsoft Academic Search

Spectroscopic data related to the structures of polyatomic molecules in the gas phase have been reviewed, critically evaluated, and compiled. All reported bond distances and angles have been classified as equilibrium (re), average (rz), substitution (rs), or effective (ro) parameters, and have been given a quality rating which is a measure of the parameter uncertainty. The surveyed literature includes work

Marlin D. Harmony; Victor W. Laurie; Robert L. Kuczkowski; R. H. Schwendeman; D. A. Ramsay; Frank J. Lovas; Walter J. Lafferty; Arthur G. Maki

1979-01-01

70

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

71

High-energy spectroscopic astrophysics  

NASA Astrophysics Data System (ADS)

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

Güdel, Manuel; Walter, Roland

72

An example of record linkage methods to monitor mortality and cancer incidence  

PubMed Central

Linkage of New York State record systems was the key strategy in a restrospective cohort study with a 24–34 year followup interval. Parents of children with anencephaly or spina bifida and matched control parents were traced to determine the parents' cancer and death experience. Birth certificates for Upstate New York for 1945–55 were the source of the study groups. This report describes the methodology employed. The New York State Health Department's Cancer Registry and vital records, the State motor vehicle license files, and city and phone directories were searched for the most recent record indicating residence in Upstate New York, cancer incidence, or death. Among the parents of the 1,152 index children were 18,571 person-years of followup for mothers and 21,675 person-years for fathers. Among the 1,152 controls, there were 19,682 person-years of followup for mothers and 22,596 person-years for fathers. Although losses were larger than the optimal, a large proportion of the maximum possible person-years were obtained, regardless of the birth year of the index child. Patterns of loss to followup were similar for cases and controls. Record linkage techniques are especially applicable in followup studies if the risk factor is identifiiable from routinely collected information (for example, congenital neural tube defects listed on birth certificates) and the outcome is also identifiable from such records (for example, cancer registry certificate or death certificate). If the outcome is definitive, reported routinely and comprehensively, and stored on a machine-readable medium, use of a computerized record linkage design is very efficient. A major advantage of the design is that cases and controls are treated equally with respect to outcome ascertainment and followup, so that some potential biases are eliminated. Finally, the method is non-intrusive; the subjects are never contacted or interviewed. Strictly maintained confidentiality is, of course, required.

Stark, Alice D.; Janerich, Dwight T.; Jereb, Susan K.; Hoff, Margaret

1983-01-01

73

Methods and Effects of Introduction of Failure Examples on Machine Design Education  

NASA Astrophysics Data System (ADS)

Examples of failure in engineering fields are introduced as educational tools, as students show interest in failure in general. After being presented with examples of failure, students were surveyed on their interest and understanding of failure by questionnaire. In some cases, students given examples of failure are more interested in effects, whereas teachers are often more interested in process, and vice versa. This resulted in a mismatch of comprehension between the teacher and students. Case studies in failure can be approached from many points of view including causes, processes, effects and measures for safety. On one hand teachers should emphasize the notable point from multiple aspects in the failure example, in introducing examples of specific topics in machine design. On the other hand teachers should explain multiple aspects in the failure example, to educate students about the complexity of actual accidents.

Arimitsu, Yutaka; Yagi, Hidetsugu

74

Solid dispersion in pharmaceutical technology. Part II. The methods of analysis of solid dispersions and examples of their application.  

PubMed

In the first part of the article solid dispersions were classified the properties and methods of their preparation were described. This section presents methods of analysis of solid dispersions i.e.: thermoanalytical methods, XRPD, FTIR, microscopic methods, dissolution studies and examples of drug forms where solid dispersions were used. PMID:23016440

Karolewicz, Bozena; Górniak, Agata; Owczarek, Artur; Nartowski, Karol; Zurawska-P?aksej, Ewa; Pluta, Janusz

2012-01-01

75

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

76

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

DOEpatents

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

Zelepouga, Serguei A. (Hoffman Estates, IL); Rue, David M. (Chicago, IL); Saveliev, Alexei V. (Chicago, IL)

2011-03-15

77

Using spectroscopic and microscopic methods to probe the structural stability of human adenovirus type 4.  

PubMed

Adenovirus serotype 4 (Ad4) is a major cause of Ad-associated human diseases. Ad4 is also considered to be a potential delivery vector for gene therapy. In this study, multiple spectroscopic techniques together with transmission electron microscopy (TEM) were employed to probe viral stability and to improve pharmaceutical formulations of Ad4-based vaccines and DNA carriers. Perturbations of secondary, tertiary and quaternary structure of Ad4 proteins induced by elevated temperatures over a wide pH range (3-8) were analyzed using circular dichroism, UV absorption and intrinsic and extrinsic fluorescence spectroscopy as well as static and dynamic light scattering. The spectroscopic results obtained indicate a decrease in Ad4 stability as pH increases from 4 to 8, similar to the behavior reported previously for Ad2 and Ad5, although the Ad4 virion appears to possess slightly more tolerance to thermal stress. An empirical phase diagram (EPD) approach was used to summarize the data in the form of a colored map. In addition, the different physical states of Ad4 identified by the EPD were confirmed by TEM images. The results obtained in this study reveal both structural similarities among three commonly employed Ad subtypes (2, 4 and 5) as well as unique properties of Ad4. PMID:19946219

He, Feng; Joshi, Sangeeta B; Moore, David S; Shinogle, Heather E; Ohtake, Satoshi; Lechuga-Ballesteros, David; Martin, Russell A; Truong-Le, Vu L; Middaugh, C Russell

2010-02-06

78

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

SciTech Connect

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

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

1994-07-01

79

Macromolecular competition titration method accessing thermodynamics of the unmodified macromolecule-ligand interactions through spectroscopic titrations of fluorescent analogs.  

PubMed

Analysis of thermodynamically rigorous binding isotherms provides fundamental information about the energetics of the ligand-macromolecule interactions and often an invaluable insight about the structure of the formed complexes. The Macromolecular Competition Titration (MCT) method enables one to quantitatively obtain interaction parameters of protein-nucleic acid interactions, which may not be available by other methods, particularly for the unmodified long polymer lattices and specific nucleic acid substrates, if the binding is not accompanied by adequate spectroscopic signal changes. The method can be applied using different fluorescent nucleic acids or fluorophores, although the etheno-derivatives of nucleic acid are especially suitable as they are relatively easy to prepare, have significant blue fluorescence, their excitation band lies far from the protein absorption spectrum, and the modification eliminates the possibility of base pairing with other nucleic acids. The MCT method is not limited to the specific size of the reference nucleic acid. Particularly, a simple analysis of the competition titration experiments is described in which the fluorescent, short fragment of nucleic acid, spanning the exact site-size of the protein-nucleic acid complex, and binding with only a 1:1 stoichiometry to the protein, is used as a reference macromolecule. Although the MCT method is predominantly discussed as applied to studying protein-nucleic acid interactions, it can generally be applied to any ligand-macromolecule system by monitoring the association reaction using the spectroscopic signal originating from the reference macromolecule in the presence of the competing macromolecule, whose interaction parameters with the ligand are to be determined. PMID:21195223

Bujalowski, Wlodzimierz; Jezewska, Maria J

2011-01-01

80

Study of the complexation of different methacrylates with cyclodextrins employing a combination of electrophoretic, chromatographic, and NMR-spectroscopic methods.  

PubMed

The present study describes the application of capillary electromigration techniques; CEC and micellar EKC (MEKC), and the application of spectroscopic methods; 1H NMR and 1H NOESY spectroscopy to investigate interactions between CDs (alpha-CD, statistically methylated beta-CD, hydroxypropyl-beta-CD, and 2-hydroxypropyl-gamma-CD) and different methacrylates (adamantyl, isobornyl, cyclohexyl, and phenyl methacrylate). It is shown that these methods complement each other. While CD-mediated MEKC is a rapid screening technique for comparing complex stabilities in aqueous media, 1H NMR chemical shift analysis provides quantitative data for very strong methacrylate-CD complexes and CD-mediated CEC provides quantitative data for complexes with lower complex forming constants. CD-mediated MEKC did not prove to be suitable for the calculation of complex forming constants. Reasons are discussed. 1H NOESY spectra were used to study spatial relationships between host and guest atoms. PMID:17461118

Al-Rimawi, Fuad; Pyell, Ute

2007-03-01

81

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

82

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

PubMed

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 × 10(4) and 3.302 × 10(4)M(-1) at 298K, 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). PMID:22484270

Cheng, Zhengjun

2012-03-17

83

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

84

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

85

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

86

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

2013-05-28

87

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

Microsoft Academic Search

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. The three-step method is based off of the theory

David Miller

2010-01-01

88

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

89

Examples for Modelling, Simulation and Visualization with the Discrete Element Method in Mechanical Engineering  

Microsoft Academic Search

In geo-physics, mining, civil and chemical engineering the Discrete Element Method (DEM) is a well established tool for physicists\\u000a and engineers. It is used to simulate particle flows of granules and powders and to investigate shear effects and the nature\\u000a of granular packings. In contrast to most other methods from the growing group of meshless methods, which are mainly designed

Florian Fleissner; Peter Eberhard

90

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

91

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

92

Appearance of anomalies in the Takatsuka-McKoy variational method: An illustrative example  

SciTech Connect

It is demonstrated that the method of fractional functional proposed by Takatsuka and McKoy and the variational method of Moe and Saxon and of Kolsrud are identical. In particular, we show that the method is, contrary to Takatsuka and McKoy's claim, not free of anomalies, it implies the incorporation of the boundary conditions, it does not satisfy a minimum principle, and suffers from inconsistency. In order to illustrate the validity of our arguments, we investigate the s wave scattering of electrons by Yukawa potentials.

Abdel-Raouf, M.A.

1984-11-01

93

Photothermal Spectroscopic Measurements by Dual Sampling Method in Intermittent-Contact-Mode Atomic Force Microscopy  

NASA Astrophysics Data System (ADS)

We have proposed a dual sampling method in intermittent-contact-mode atomic force microscopy with a piezoresistive cantilever for photothermal (PT) measurements. This method realizes a sensitive detection of thermal expansion in a sample by excluding crosstalk from photoabsorption signals generated at the piezoresistive sensor on the cantilever. We have confirmed the feasibility of this method through the excitation photon energy dependence of the PT signal measured on Si and GaAs.

Hara, Kenji; Takahashi, Takuji

2009-08-01

94

Variational iteration method – a kind of non-linear analytical technique: some examples  

Microsoft Academic Search

In this paper, a new kind of analytical technique for a non-linear problem called the variational iteration method is described and used to give approximate solutions for some well-known non-linear problems. In this method, the problems are initially approximated with possible unknowns. Then a correction functional is constructed by a general Lagrange multiplier, which can be identified optimally via the

Ji-Huan He

1999-01-01

95

A Method for Designing Ant Colony Models and Two Examples of Its Application  

Microsoft Academic Search

\\u000a An ant colony shows collective behavior through signal patterns formed by individual ants communicating among themselves.\\u000a In this paper I devise a method for designing ant colony model and apply the method to design two types of ant colonies, focusing\\u000a on ant sensitivity to signals. In the first type, I design three foraging models (trail, attraction and desensitization),\\u000a by modifying

Mari Nakamura; Koichi Kurumatani

2005-01-01

96

Alternative solution methods for crack problems in plane anisotropic elasticity, with examples  

Microsoft Academic Search

Two-dimensional crack problems of homogeneous, anisotropic, linear elasticity are solved using the Riemann–Hilbert method. To this end, the Riemann–Hilbert problem of line-discontinuity is formulated for anisotropic plane problems and the necessary parameters and functions are identified. For illustration, the method is applied to obtain the complete stress field and the stress intensity factors for a crack in an infinite anisotropic

Abbas Azhdari; Makoto Obata; Sia Nemat-Nasser

2000-01-01

97

[Use of molecular methods in food microbiology with the example of probiotic use of lactobacilli].  

PubMed

The aim of molecular methods in food microbiology is the identification or strain specific differentiation of microorganisms. Identification methods include besides taxonomic purposes also the detection of virulence genes or resistance markers. Strain specific differentiation is used for epidemiological investigations or the quality control of technologically used bacteria. Probiotic strains of the Lactobacillus acidophilus-group were investigated with different molecular methods: for identification proteinfingerprinting and RAPD-PCR (Random Amplified Polymorphic DNA-PCR) were applied, for strain specific differentiation pulsed field gel electrophoresis (PFGE) and again RAPD-PCR were used. The molecular methods applied should be chosen depending on the objective (identification, differentiation) and with respect to the organism to be tested. In case of probiotic lactic acid bacteria like the L. acidophilus-group proteinfingerprinting has proved to be successful for identification and with some limitation also RAPD-PCR. For differentiation PFGE is suitable as well as RAPD-PCR. Those methods differ substantially in their work load and in personal requirements, and show different power of discrimination and reproducibility within and between laboratories. This should be considered while choosing the appropriate method. PMID:14655631

Klein, Günter

98

Comprehensive Chromatographic and Spectroscopic Methods for the Separation and Identification of Intact Glucosinolates  

Microsoft Academic Search

Much effort has been devoted to developing methods for the efficient isolation and identification of glucosinolates. Existing methods for separation involve ion exchange, GLC, and HPLC (mostly after chemical modification by enzymatic sulfate removal and\\/or silylation). We demonstrate a simple and direct strategy for analyzing the glucosinolate content of plant extracts, made possible by a new combination of widely available

Tory Prestera; Jed W. Fahey; W. David Holtzclaw; Chitrananda Abeygunawardana; Joseph L. Kachinski; Paul Talalay

1996-01-01

99

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

Microsoft Academic Search

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

Sheikha M. Al-Ghannam

2008-01-01

100

Active sites of two orthologous cytochromes P450 2E1: Differences revealed by spectroscopic methods  

SciTech Connect

Cytochromes P450 2E1 of human and minipig origin were examined by absorption spectroscopy under high hydrostatic pressure and by resonance Raman spectroscopy. Human enzyme tends to denature to the P420 form more easily than the minipig form; moreover, the apparent compressibility of the heme active site (as judged from a redshift of the absorption maximum with pressure) is greater than that of the minipig counterpart. Relative compactness of the minipig enzyme is also seen in the Raman spectra, where the presence of planar heme conformation was inferred from band positions characteristic of the low-spin heme with high degree of symmetry. In this respect, the CYP2E1 seems to be another example of P450 conformational heterogeneity as shown, e.g., by Davydov et al. for CYP3A4 [Biochem. Biophys. Res. Commun. 312 (2003) 121-130]. The results indicate that the flexibility of the CYP active site is likely one of its basic structural characteristics.

Anzenbacherova, Eva [Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacky University, CZ-775 15 Olomouc (Czech Republic); Hudecek, Jiri [Department of Biochemistry, Faculty of Sciences, Charles University, CZ-128 40, Prague 2 (Czech Republic); Murgida, Daniel [Max-Volmer-Laboratory for Biophysical Chemistry, Technical University Berlin, 10623 Berlin (Germany); Hildebrandt, Peter [Max-Volmer-Laboratory for Biophysical Chemistry, Technical University Berlin, 10623 Berlin (Germany); Marchal, Stephane [INSERM U710, University of Montpellier 2, 34095 Montpellier Cedex 5 (France); Lange, Reinhard [INSERM U710, University of Montpellier 2, 34095 Montpellier Cedex 5 (France); Anzenbacher, Pavel [Institute of Pharmacology, Faculty of Medicine, Palacky University, CZ-775 15 Olomouc (Czech Republic)]. E-mail: anzen@tunw.upol.cz

2005-12-09

101

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

SciTech Connect

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

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

2011-01-20

102

Analytical methods for the detection of viruses in food by example of CCL-3 bioagents.  

PubMed

This critical review presents challenges and strategies in the detection of viral contaminants in food products. Adenovirus, caliciviruses, enteroviruses, and hepatitis A are emerging contaminant viruses. These viruses contaminate a variety of food products, including fruits, vegetables, shellfish, and ready-to-eat processed foods. The diversity of targets and sample matrices presents unique challenges to virus monitoring that have been addressed by a wide array of processing and detection methods. This review covers sample acquisition and handling, virus recovery/concentration, and the determination of targets using molecular biology and mass-spectrometric approaches. The concentration methods discussed include precipitation, antibody-based concentration, and filtration; the detection methods discussed include microscopy, polymerase chain reaction, nucleic acid sequence-based amplification, and mass spectrometry. PMID:22526652

Hartmann, E M; Halden, R U

2012-04-24

103

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

104

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

105

[Statistical methods for analysis of communities' species structure (with riverine macrozoobenthos as an example)].  

PubMed

Species turnover or coherence in species co-occurrence as well as boundary clumping and nestedness in structural composition of ecological communities reflect the extent of determinancy in their organization (Leibold, Mikkelson, 2002). These phenomena may be a consequence of either interactions between species or heterogeneity in spatial distribution of populations density. We have examined statistical patterns of species structure variability using benthic communities of riverine ecosystems as an example. The ecosystems studied are characterized by strongly pronounced linear gradient of landscape features and environmental factors. The results of a long-term hydrobiological survey being conducted at 22 observational stations on the Sok River along with its tributary, the Baytugan River (Lower Volga basin, total watercourse length is 375 km) are involved into the analysis. A spreadsheet for statistical processing of the data included 375 macrozoobenthic taxa contained in 147 samples. An assessment of species structure nestedness in benthic communities at separate sites and along the watercourse as a whole has been carried out using various metrics such as nestedness "temperature" (Patterson, Atmar, 2000), discrepancy measure (Brualdi, Sanderson, 1999), nestedness based on overlap and decreasing fill (NODE--Almeida-Neto et al., 2008) and others. Statistical significance of ecosystems structural determinancy has been tested by means of randomization procedures and standard null models (Gotelli, 2000). The conclusions seem to be ambiguous and dependent on a level and scale of an ecosystem resolution into separate blocks, also on configuration and completion of initial bio-geographical tables. A searching for reliable and representative criteria of nestedness, invariant to various non-ecological modifications of the matrices but sensitive to estimation of analyzed ecological processes and suitable for comparisons of communities, is clearly needed. A quantitative estimation of species turnover and coherence in species cooccurrence has been performed using different indices of unique combinations and checkerboard score (Stone, Roberts, 1992) as well as Schluter's variance test. By means of empirical Bayesian approach (Gotelli, Ulrich, 2010) records of species pairwise combinations are formed where the frequency of species co-occurrence cannot be interpreted as a random value. Positive and negative relationships between taxa in macrozoobenthic communities, which are found out to be statistically significant, in most cases can be explained as being not the consequence of competition for resources but of spatial heterogeneity of biotopical conditions along the whole length of the watercourse. PMID:22121574

Shitikov, V K; Zinchenko, T D

106

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

107

Methods to Create ArcMap (Trade Name) Styles with Examples for Lithology and Time.  

National Technical Information Service (NTIS)

ArcMap style files (.style extension) can be used to standardize map symbolization. This report describes the methods used to create several styles for lithology or geologic time. The styles are color fills which were created by assigning RGB color values...

L. A. Moyer J. T. Hastings G. L. Raines

2005-01-01

108

An extremal optimization search method for the protein folding problem: the go-model example  

Microsoft Academic Search

The protein folding problem consists of predicting the functional (native)structure of the protein given its linear sequence of amino acids. Despite extensive progress made in understanding the process of protein folding, this problem still remains extremely challenging. In this paper we introduce, implement and evaluate the Extremal Optimization method - a biologically inspired approach which has been applied very successfully

Alena Shmygelska

2007-01-01

109

Applying usability methods to identify health literacy issues: an example using a Personal Health Record.  

PubMed

The prevalence of consumer health information systems is increasing. However, usability and health literacy impact both the value and adoption of these systems. Health literacy and usability are closely related in that systems may not be used accurately if users cannot understand the information therein. Thus, it is imperative to focus on mitigating the demands on health literacy in consumer health information systems. This study modified two usability evaluation methods (heuristic evaluation and usability testing) to incorporate the identification of potential health literacy issues in a Personal Health Record (PHR). Heuristic evaluation is an analysis of a system performed by a usability specialist who evaluates how well the system abides by usability principles. In contrast, a usability test involves a post hoc analysis of a representative user interacting with the system. These two methods revealed several health literacy issues and suggestions to ameliorate them were made. Thus, it was demonstrated that usability methods could be successfully augmented for the purpose of investigating health literacy issues. To improve users' health knowledge, the adoption of consumer health information systems, and the accuracy of the information contained therein, it is encouraged that usability methods be applied with an added focus on health literacy. PMID:23388278

Monkman, Helen; Kushniruk, Andre

2013-01-01

110

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

NASA Astrophysics Data System (ADS)

Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques (e.g., Ellsworth et al., 1999). In this paper I present a method that attempts to fit wide ranges of distribution parameters to short paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most likely recurrence PDF parameters, and a ranked distribution of parameters is returned that can be used to assess uncertainties in hazard calculations. In tests on short synthetic earthquake series, the method gives results that cluster around the mean of the input distribution, whereas maximum likelihood methods return the sample means (e.g., NIST/SEMATECH, 2006). For short series (fewer than 10 intervals), sample means tend to reflect the median of an asymmetric recurrence distribution, possibly leading to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach may be useful for assessing recurrence from limited paleoearthquake records. Further, the degree of functional dependence among parameters like mean recurrence interval and coefficient of variation can be established. The method is described for use with time-independent and time-dependent PDFs, and results from 19 paleoseismic sequences on strike-slip faults throughout the state of California are given.

Parsons, Tom

2008-03-01

111

Development of NMR spectroscopic methods for dynamic detection of acetylcholine synthesis by choline acetyltransferase in hippocampal tissue.  

PubMed

Choline acetyltransferase (ChAT) is the key enzyme for acetylcholine (ACh) synthesis and constitutes a reliable marker for the integrity of cholinergic neurons. Cortical ChAT activity is decreased in the brain of patients suffering from Alzheimer's and Parkinson's diseases. The standard method used to measure the activity of ChAT enzyme relies on a very sensitive radiometric assay, but can only be performed on post-mortem tissue samples. Here, we demonstrate the possibility to monitor ACh synthesis in rat brain homogenates in real time using NMR spectroscopy. First, the experimental conditions of the radiometric assay were carefully adjusted to produce maximum ACh levels. This was important for translating the assay to NMR, which has a low intrinsic sensitivity. We then used (15) N-choline and a pulse sequence designed to filter proton polarization by nitrogen coupling before (1) H-NMR detection. ACh signal was resolved from choline signal and therefore it was possible to monitor ChAT-mediated ACh synthesis selectively over time. We propose that the present approach using a labeled precursor to monitor the enzymatic synthesis of ACh in rat brain homogenates through real-time NMR represents a useful tool to detect neurotransmitter synthesis. This method may be adapted to assess the state of the cholinergic system in the brain in vivo in a non-invasive manner using NMR spectroscopic techniques. PMID:23004566

Hall, Hélène; Cuellar-Baena, Sandra; Denisov, Vladimir; Kirik, Deniz

2012-10-10

112

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

USGS Publications Warehouse

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

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

1996-01-01

113

Applying systematic review methods to studies of people's views: an example from public health research  

PubMed Central

Methods for systematic reviews are well developed for trials, but not for non-experimental or qualitative research. This paper describes the methods developed for reviewing research on people's perspectives and experiences ("views" studies) alongside trials within a series of reviews on young people's mental health, physical activity, and healthy eating. Reports of views studies were difficult to locate; could not easily be classified as "qualitative" or "quantitative"; and often failed to meet seven basic methodological reporting standards used in a newly developed quality assessment tool. Synthesising views studies required the adaptation of qualitative analysis techniques. The benefits of bringing together views studies in a systematic way included gaining a greater breadth of perspectives and a deeper understanding of public health issues from the point of view of those targeted by interventions. A systematic approach also aided reflection on study methods that may distort, misrepresent, or fail to pick up people's views. This methodology is likely to create greater opportunities for people's own perspectives and experiences to inform policies to promote their health.

Harden, A.; Garcia, J.; Oliver, S.; Rees, R.; Shepherd, J.; Brunton, G.; Oakley, A.

2004-01-01

114

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

Microsoft Academic Search

In this thesis, advanced spectroscopy methods are discussed and applied to gain understanding of the physical properties of organic conjugated molecules, II-VI thin film semiconductors, and vertical cavity surface emitting lasers (VCSEL). Experiments include single photon and two-photon excitation with lasers, with subsequent measurements of the absorption and photoluminescence, as well as photocurrent measurements using tungsten and xenon lamps, measuring

Raoul Schroeder

2001-01-01

115

Spectroscopic studies on distorted structure molecules by using U(2) Lie algebraic method  

NASA Astrophysics Data System (ADS)

Resonance Raman spectra of oxygenated and deoxygenated functional erythrocytes are calculated by using Lie algebraic technique at 785 nm. The results are obtained by this method is accuracy with the experimental data. So, the algebraic techniques are appropriate to the Raman spectra of red blood cells.

Karumuri, Srinivasa Rao; Sekhar, J. Vijaya; Sreeram, V.; Uma Maheswara Rao, V.; Basaveswara Rao, M. V.

2011-09-01

116

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

117

The compositional characterisation of Romanian grape seed oils using spectroscopic methods.  

PubMed

In the present study, we developed a method for the grape seed oil compositional characterisation using (1)H NMR spectroscopy directly applied on oils without sample derivatisation (as triglycerides). Using (1)H NMR spectroscopy data and systems of chemometric equations, we established the composition of grape seed oils on four classes of fatty acids. Spectral information from (1)H NMR and FT-IR spectroscopy was used to make the differences between grape seed oils and genuine common oils. Applying the PCA (Principal Component Analysis) method to the spectral information, it was evaluated the application potential in authenticity control of grape seed oils from common genuine oils (sunflower, soybean, linseed and rapeseed). PMID:23442710

Hanganu, Anamaria; Toda?c?, Maria-Cristina; Chira, Nicoleta-Aurelia; Maganu, Maria; Ro?ca, Sorin

2012-04-17

118

Physical Methods in Studying Polyoxometalates: Extended HÜCkel Molecular Orbital Calculations and Spectroscopic Properties  

Microsoft Academic Search

\\u000a Polyoxometalates (POMs) of vanadium, molybdenum and tungsten and to some extent, niobium and tantalum are very important and\\u000a interesting classes of complexes with great potential in many applications [1–4]. Since in many cases their structures prove to be unchanged in solution, many methods are applicable for studying their\\u000a molecular and electronic structures. These studies are expected to be useful for

L. P. KAZANSKY

119

Spectroscopic Properties of Porphyrin-doped Silica Films by the Liquid Phase Deposition Method  

Microsoft Academic Search

Silica films doped with water soluble porphyrin, 5,10,15,20-tetrakis[4-(N-trimethyl)ammonio]phenylporphyrin (TTMAPP), were deposited on the surface of a glass slide at 25–35°C by the liquid phase deposition (LPD) method from saturated hydrofluorosilicic acid or fluorosilicate solutions containing TTMAPP. It was doped as protonated (cationic) or neutral forms depending on the deposition condition. Two forms are reversibly converted by heat treatment or environments.

Toshihiko Nagamura; Hirohisa Smmizu; Hiroyasu Ohkoso

1998-01-01

120

Production of ultracold potassium molecules and development of high sensitivity spectroscopic methods  

NASA Astrophysics Data System (ADS)

In the first part of this dissertation we develop and successfully demonstrate two methods, based on photoassociation of ultracold potassium atoms, for producing ultracold K2 molecules, with sub mK temperatures, in deeply bound vibrational levels of the ground XS+g 1 state. The principal objective has been to develop an ``ultracold molecule factory'' that can be used to support experiments on spectroscopy, collisions, and chemistry of ultracold molecules. In the first experiment the ground-state molecules are produced by the radiative decay of excited, n?191 AS+u 1 state molecules, photoassociated from ultracold potassium atoms in a vapor-cell MOT. The decay is primarily into the vibrational continuum, but a small fraction decays into bound levels of the X state near n = 36. The experimentally observed molecule production rate is about 103 per second. In our second experiment, we use two-step laser excitation to effect an ``R-transfer'' from long-range to intermediate internuclear separations, greatly increasing the efficiency for radiative production of low- n molecules in the X state. Molecules are formed in the Pg1 state by photoassociation, then excited by a second laser to the 51Pu or 61Pu Rydberg states, in selected vibrational levels from n = 13-18. Finally, radiative decay produces very large numbers of X state molecules with n?25 and significant numbers of molecules in very low vibrational levels, including n = 0. We have observed production rates up to about 105 molecules/second per vibrational level. In both experiments the ground-state molecules are detected with a sensitive and selective resonant two- color photoionization with nanosecond pulses. In the second part of this dissertation we demonstrate a novel method for high sensitivity absorption measurements, that combines a phase modulated, high- resolution pulsed laser with an actively stabilized optical cavity to achieve a sensitivity of ~10-9 per cm. This is comparable to the best existing methods for pulsed absorption measurements, but unlike most other methods, it can also be readily extended to the UV region and to Doppler-free spectroscopy.

Nikolov, Anguel Nikolov

2000-10-01

121

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

122

A spectroscopic method for identifying terrestrial biocarbonates and application to Mars  

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

123

Cell-metal interaction studied by cytotoxic and FT-IR spectroscopic methods.  

PubMed

The main purpose of this work is to investigate the possibility of utilizing both a classical biological method to test cytotoxicity and a physical measurement procedure as the FT-IR spectroscopy to study the interaction between cells lines and heavy metals. Jurkart, a lymphocyte cell line, was treated with cadmium chloride, cadmium oxide and the organic germanium compound named Ge-oxy-132. The utilized value of heavy metal concentration allows us to obtain significant results with both methods and with all metals. In fact by using lower values of concentration any effect is revealed after treatment with germanium. The results of the simultaneous measurements by both experimental procedures are here reported for the first time and show that, while the cytotoxic effects of the two cadmium compounds are confirmed, the organic germanium compound reveals a very different and interesting interaction with Jurkart cells. The behaviour of the Jurkart cells upon the uptake of cadmium or organic germanium is very different: while treatment with CdO and CdCl(2) determines proteins denaturation and lipids oxidation in cells until the death, these processes are not revealed after Ge-oxy-132 treatment. PMID:21782662

Gaudenzi, Silvia; Furfaro, Maria Grazia; Pozzi, Deleana; Silvestri, Ida; Congiu Castellano, Agostina

2003-06-01

124

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

125

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

NASA Astrophysics Data System (ADS)

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

Duller, Geoff; Tooth, Stephen; Barham, Larry

2013-04-01

126

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

127

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

NASA Astrophysics Data System (ADS)

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. 119Sn 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 Kb = 8.42 × 104 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.

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

2010-05-01

128

Example bearing guide to the use of a set of products and method of using the same  

US Patent & Trademark Office Database

A method of creating a guide to the use of a set of products, which includes an example set of the products. This method includes providing at least one product guide apparatus that includes transparent, flexible material formed into a set of pockets of sufficient size to receive and retain any one of the set of products. The guide also includes material that can be written upon and an associative assembly, adapted to physically associate the material that can be written upon to the transparent flexible material formed into a set of pockets. A first one of the products is placed in a first one of the set of pockets and a second one of the products is placed in a second one of the set of pockets. Next, descriptions of the first and second products are written on the material that can be written upon.

2003-06-10

129

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

NASA Astrophysics Data System (ADS)

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. The application of the energy method is demonstrated by an example of the circular flexural plate transducer. The validity of the single degree of freedom approximation for calculating the transducer parameters is considered, and estimation is made of inaccuracies arising from the simplifying assumptions regarding the mode of transducer vibration. The acceptable tolerance levels for accuracy in the calculation of the transducer parameters are also discussed.

Aronov, Boris

2005-08-01

130

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

131

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

132

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

133

Isolation and characterization of two new alkaloids, norpandamarilactonine-A and -B, from Pandanus amaryllifolius by spectroscopic and synthetic methods.  

PubMed

Two new alkaloids, norpandamarilactonine-A (1) and -B (2), which have a pyrrolidinyl-alpha,beta-unsaturated gamma-lactone moiety as in the known pandamarilactonine alkaloids, were isolated from the leaves of Pandanus amaryllifolius. Their structures were determined by spectroscopic analysis and total synthesis. PMID:11575961

Takayama, H; Ichikawa, T; Kitajima, M; Nonato, M G; Aimi, N

2001-09-01

134

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

135

Method to estimate the electron temperature and neutral density in a plasma from spectroscopic measurements using argon atom and ion collisional-radiative models  

SciTech Connect

We present a method to infer the electron temperature in argon plasmas using a collisional-radiative model for argon ions and measurements of electron density to interpret absolutely calibrated spectroscopic measurements of argon ion (Ar II) line intensities. The neutral density, and hence the degree of ionization of this plasma, can then be estimated using argon atom (Ar I) line intensities and a collisional-radiative model for argon atoms. This method has been tested for plasmas generated on two different devices at the University of Texas at Austin: the helicon experiment and the helimak experiment. We present results that show good correlation with other measurements in the plasma.

Sciamma, Ella M.; Bengtson, Roger D.; Rowan, W. L.; Lee, Charles A.; Berisford, Dan; Lee, Kevin; Gentle, K. W. [University of Texas at Austin, 1 University Station Austin, Texas 78712 (United States); Keesee, Amy [West Virginia University, P.O. Box 6315, Morgantown, West Virginia 26506 (United States)

2008-10-15

136

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

137

Comparative study of an argon plasma and an argon copper plasma produced by an ICP torch at atmospheric pressure based on spectroscopic methods  

NASA Astrophysics Data System (ADS)

The aim of the paper is to test the accuracy of classical spectroscopic methods in the visible domain dedicated to measurements of temperature and electron density in order to conclude about the validity of thermal disequilibrium. The influence of various factors is studied: accuracy of the intensity calibration, Abel inversion of the experimental spectra, excitation temperature deduced from the relative method, absolute excitation temperature, influence of the transition probability accuracy, influence of the Biberman factor value, electron temperature from the line-to-continuum intensity ratio, electron density deduced from Stark broadening, and electron density deduced from the continuum intensity. This spectroscopic investigation is carried out for argon plasma and argon copper plasma both produced by means of an ICP torch operating at atmospheric pressure. Results are given with uncertainties for each evaluated parameter. We show that, first, the electron temperature deduced from the line-to-continuum intensity ratio has to be considered with great care; second, for argon plasma no evidence of thermal disequilibrium can be discerned, whereas for argon copper plasma a small disequilibrium of 1.2 to 1.4 at most is experimentally observed.

Bussière, W.; Vacher, D.; Menecier, S.; André, P.

2011-08-01

138

Shining examples  

SciTech Connect

Creative financing for setting up individual solar power systems and energy efficient appliances is beginning to come of age in developing countries. This article describes the practical implementation of such solar energy financing as well as the broader implications, using India, Indonesia and the Dominican Republic as examples. Also included is a discussion of the government and publically supported organizations which are encouraging solar energy use and realistic financing.

Flavin, C.; O`Meara, M.

1997-05-01

139

Spectroscopic analysis of immobilised redox enzymes under direct electrochemical control.  

PubMed

This article reviews recent developments in spectroscopic analysis of electrode-immobilised enzymes under direct, unmediated electrochemical control. These methods unite the suite of spectroscopic methods available for characterisation of structural, electronic and coordination changes in proteins with the exquisite control over complex redox enzymes that can be achieved in protein film electrochemistry in which immobilised protein molecules exchange electrons directly with an electrode. This combination is particularly powerful in studies of highly active enzymes where redox states can be controlled even under fast electrocatalytic turnover. We examine examples in which UV-visible, IR, Raman and MCD spectroscopy have been combined with direct electrochemistry to probe redox-dependent chemistry, and consider future opportunities for 'direct' spectroelectrochemistry of immobilised enzymes. PMID:22057715

Ash, Philip A; Vincent, Kylie A

2011-11-07

140

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

PubMed Central

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

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

2013-01-01

141

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

142

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

143

Quercetin immobilized on silica gel as a solid phase reagent for tin(IV) determination by using the sorption-spectroscopic method.  

PubMed

New chelating sorbents are prepared by 3,3',4',5,7-pentahydroxyflavone adsorption from butanol and acetone-hexane (1:4) solutions, characterized by isotherm of sorption, IR-spectroscopy and studied for pre-concentrating and sorption-spectroscopic determination of Sn(IV). The solid-phase Quercetin with satisfactory analytical characteristics was formed by adsorption from acetone-hexane (1:4) mixture. The quantitative recovery of Sn(IV) from aqueous solution with modified sorbent was observed at pH 1.8-2.2. The tolerance limits of heavy metal ions in the sorption of Sn(IV) are reported. The limit of Sn detection is 0.06 mg l(-1). The linearity of calibration graph has been observed up to 1.2 mg l(-1). The method has been applied to determine Sn in high purity zinc materials. PMID:18968375

Zaporozhets, O A; Ivanko, L S; Marchenko, I V; Orlichenko, E V; Sukhan, V V

2001-08-30

144

The use and value of multiple methods to capture the diversity of endogenous agroforestry knowledge: an example from Rwanda  

Microsoft Academic Search

To understand endogenous agroforestry knowledge and the processes behind the generation of such knowledge, multiple methods are needed. In this paper, the identification and characterization of farmer agroforestry experts will illustrate the necessity of multiple methods. Nonformal, participatory methods were employed to identify the research subjects (farmer agroforestry experts) and to gain insights into the emic conception and understanding of

C. Den Biggelaar; M. A. Gold

1995-01-01

145

A new, non-destructive method for analysis of clinical samples with FT-IR microspectroscopy. Breast cancer tissue as an example.  

PubMed

A new method for infrared analysis of tissues and cells is presented. The method is based on Fourier transform infrared microspectroscopy coupled with attenuated total reflectance. The technique allows spectroscopic measurements on the same samples used by pathologists for histopathological evaluation, e.g. stained samples on plain glass slides. Since the same specimen can be used as for histopathology, the method does not require sample preparation or modification. Significantly, the sample is not damaged. Glass absorbs in the infrared and thus has not been used previously in infrared analysis of tissues and cells. Conventional infrared techniques utilize expensive substrates, such as BaF2 windows and gold coated slides which do not absorb infrared radiation. However, these measurements require special preparation and result in the destruction of the sample. Breast cancer tissues were examined to demonstrate the feasibility and reproducibility of the new method. Linear discriminant analysis was used to discriminate and classify three types of cells: benign, atypical hyperplasia and malignant. It was demonstrated that benign vs. malignant cells were discriminated with 100% accuracy, benign vs. atypical hyperplasia were discriminated with 100% accuracy and malignant vs. atypical hyperplasia were discriminated with an accuracy of 90% and higher. PMID:9551652

Dukor, R K; Liebman, M N; Johnson, B L

1998-02-01

146

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.  

PubMed

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 (150 mg mL(-1), Pfizer). The Raman calibration model was developed by plotting the peak intensity of the baseline-corrected and normalized spectral band (corrected by external standard measurements) between 1595 and 1620 cm(-1) against known MPA concentrations in standards. At this band, no spectral interferences from the suspension medium are observed. The most suitable model for the calibration data (straight line or higher order polynomial) was determined by evaluating the fit and predictive properties of the models. In a second step, the developed Raman spectroscopic analytical method was validated by calculating the accuracy profile on the basis of the analysis results of validation samples. Furthermore, based on the data of the accuracy profile, the measurement uncertainty was determined. Finally, as the aim of the alternative method is to replace the destructive, time-consuming HPLC method, requiring sample preparation, it needs to be demonstrated that the new Raman method performs at least as good as the HPLC method. Therefore, the performance (precision and bias) of both methods was compared. A second order polynomial calibration curve through the calibration data supplies the best predictive properties and gives an acceptable fit. From the accuracy profile, it was concluded that at the target concentration (150 mg mL(-1)), 95 out 100 future routine measurements will be included within the acceptance limits (5%). Comparison of the alternative method with the reference method at the target concentration indicates that the Raman method performs at least as good as the HPLC method for precision (repeatability and intermediate precision) and bias. The fast and non-destructive Raman method hence provides an alternative for the destructive and time-consuming HPLC procedure. PMID:17418181

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

2007-03-12

147

[Quantitative analysis of protein concentration by absorption peak integration method of UV spectroscopy--taking alkaline phosphatase as an example].  

PubMed

Adsorption of alkaline phosphatase (APase) on minerals (goethite, montmorillonite) and sediments from Taihu Lake was studied. However, the concentration of alkaline phosphatase in the supernatant cannot be analyzed by the adsorption at 280 nm due to that the UV spectroscopy was changed. Quantitative analysis of alkaline phosphatase in the supernatant by the absorption peak (252-305 nm) integration method of UV spectroscopy was developed. This method determined the concentrations of alkaline phosphatase well. Compared to the results of Bradford, the absorption peak integration method can determine the concentrations of supernatant fast, conveniently, and accurately. This method can also be applied to other protein solution analysis and similar experiments. The drawbacks of traditional single wavelength method (280nm) were overcome to some extent based on the method of absorption peak integration. PMID:24059187

Zhu, Yuan-Rong; Wu, Feng-Chang; Lin, Ying

2013-07-01

148

Assessment of the variations in fat content in normal liver using a fast MR imaging method in comparison with results obtained by spectroscopic imaging.  

PubMed

A recently published Dixon-based MRI method for quantifying liver fat content using dual-echo breath-hold gradient echo imaging was validated by phantom experiments and compared with results of biopsy in two patients (Radiology 2005;237:1048-1055). We applied this method in ten healthy volunteers and compared the outcomes with the results of MR spectroscopy (MRS), the gold standard in quantifying liver fat content. Novel was the use of spectroscopic imaging yielding the variations in fat content across the liver rather than a single value obtained by single voxel MRS. Compared with the results of MRS, liver fat content according to MRI was too high in nine subjects (range 3.3-10.7% vs. 0.9-7.7%) and correct in one (21.1 vs. 21.3%). Furthermore, in one of the ten subjects the MRI fat content according to the Dixon-based MRI method was incorrect due to a (100-x) versus x percent lipid content mix-up. The second problem was fixed by a minor adjustment of the MRI algorithm. Despite systematic overestimation of liver fat contents by MRI, Spearman's correlation between the adjusted MRI liver fat contents with MRS was high (r = 0.927, P < 0.001). Even after correction of the algorithm, the problem remaining with the Dixon-based MRI method for the assessment of liver fat content,is that, at the lower end range, liver fat content is systematically overestimated by 4%. PMID:17999066

Irwan, Roy; Edens, Mireille A; Sijens, Paul E

2007-11-13

149

An Updated Method for the Measurement of Silicon Isotopes From Opal, Examples From Cariaco Basin Sediment Traps  

NASA Astrophysics Data System (ADS)

We modified a new method for the complete digestion of silicate minerals (van den Boorn et al., 2006, JAAS, 21, 734-742), replacing a Parr bomb NaOH digestion with a hot plate digestion using Teflon beakers. The method is ideal for amorphous silicate minerals such as opal, and has been tested using diatoms recovered from the >125 ?m fraction of sediment trap samples from the Cariaco Basin. A complete digestion of these samples was achieved using this revised method. The method has been used to prepare samples for silicon (Si) isotope analyses on a Neptune MC-ICPMS. The MC-ICPMS method was tested using the Si isotope reference material 'big batch', correcting for mass bias by standard-sample bracketing. The ?29Si and ?30Si values of big batch, normalized to NIST RM-8546 (formerly NBS-28), are in agreement with published values (van den Boorn et al., 2006). This method will be evaluated with other Si reference materials (e.g., diatomite). Ultimately the new digestion method and MC-ICPMS method will be used to measure Si isotope variability in diatoms from the Cariaco Basin sediment trap samples. Furthermore, replicates will be used in an interlaboratory calibration to test the reproducibility between different techniques (e.g., MC-ICPMS vs. gas source).

Scher, H. D.; Thunell, R. C.; Delaney, M. L.

2007-12-01

150

Method for estimating materials fluxes from coastal wetlands into the Great Lakes, with an example from lake Erie. Technical bulletin  

SciTech Connect

A method is presented in detail for the quantitative estimation of the flux of water and dissolved or suspended materials through coastal wetlands of the Great Lakes where the juncture of the wetland and lake is constricted by a narrow opening. Application of the method requires frequent (e.g., hourly or daily) data on atmospheric deposition, precipitation, evaporation, upstream discharges from tributaries, wetland water level changes, and water chemistry data at upstream and downstream locations, as well as a detailed knowledge of wetland depth-area and depth-volume relationships. Data collected during October 1989 are used to demonstrate the method.

Krieger, K.A.

1993-01-01

151

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

Microsoft Academic Search

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

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

2009-01-01

152

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

153

Evaluation of psychotherapeutic interpretations : an example of the application of the phenomenological method to discovery-based psychotherapy research.  

PubMed

If much psychotherapy literature goes unread and unused by therapists, one reason may be the apparent irrelevance of theory-derived hypotheses to actual practice. Methods that uncover tacit knowledge that practicing therapists already possess can provide the empirical basis for more relevant theories and the testing of more meaningful hypotheses. This study demonstrates application of the phenomenological method to the question of evaluating psychotherapy. To discover how experienced psychotherapists evaluate interpretations made in actual psychotherapy sessions, therapists were asked to evaluate such interpretations from videotapes; analysis of responses yielded a set of 10 dimensions of evaluation. Such methods offer both practical utility and a source of theoretical growth anchored in the real world of the practicing therapist. PMID:22700101

Pogge, D L; Dougher, M J

1992-01-01

154

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

155

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

156

FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): The Self-Heating Effect of Quantum Cascade Lasers Based on a Spectroscopic Method  

NASA Astrophysics Data System (ADS)

We investigate the self-heating effect of mid-infrared quantum cascade lasers by using a direct-based pulse injecting current and spectroscopy method. Based on the characterization system, the thermal characteristics of gas source MBE grown 8.4 ?m InP-based GaInAs/AlInAs DFB-QCLs are evaluated. The method and characterization system are also useful in evaluating the thermal characteristics of other types of mid-infrared diode lasers.

Wei, Lin; Li, Ai-Zhen; Zhang, Yong-Gang; Li, Yao-Yao

2009-08-01

157

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

158

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

159

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

160

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

PubMed

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

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

2011-12-22

161

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

NASA Astrophysics Data System (ADS)

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

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

2008-06-01

162

Reflectance near-infrared spectroscopic method with Chemometric techniques for simultaneous determination of Chondroitin, glucosamine, and methyl sulfonyl methane.  

PubMed

Reflectance near-IR (RNIR) spectroscopy was used for the simultaneous determination of chondroitin (CH), glucosamine (GO), and methyl sulfonyl methane (MSM) in tablets. Simple sample preparation was done by grinding, sieving, and compression of the tablets for improving RNIR spectra. Principal component regression and partial least squares (PLS-1 and PLS-2) were successfully applied to quantify the three components in the studied mixture using information included in RNIR spectra in the range of 4350-9100 cm(-1). The calibration model was developed with drug concentration ranges of 14.5-44.2% (w/w) for CH, 18.4-55.3% (w/w) for GO, and 6-18.6% (w/w) for MSM with addition of tablet excipients to the calibration set in the same ratio as in the tested tablets. The calibration models were evaluated by internal validation, cross-validation, and external validation using synthetic and pharmaceutical preparations. The proposed method was applied for analysis of six batches of the pharmaceutical product. The results of the proposed method were compared with the results of the pharmacopoeial method for the same batch of the pharmaceutical product. No significant differences between the results were found. The RNIR method is accurate and precise, and can be used for QC of pharmaceutical products. PMID:22970568

El-Gindy, Alaa; Attia, Khalid Abdel-Salam; Nassar, Mohammad Wafaa; Seda, Hamed Hamed Abu; Shoeib, Maisra Al-Shabrawi

163

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

PubMed

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

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

2013-07-27

164

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

PubMed Central

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

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

2013-01-01

165

Comparison of Fluorescence, 31P NMR, and 7Li NMR Spectroscopic Methods for Investigating Li +\\/Mg 2+ Competition for Biomolecules  

Microsoft Academic Search

The biochemical action of lithium in the treatment of manic-depressive illness is still unknown. One hypothesis is that Li+ competes for Mg2+-binding sites in biomolecules. We report here our studies on metal ion competition by three distinct methods: fluorescence, 31P NMR, and 7Li NMR spectroscopy, using ATP as a model ligand. By fluorescence spectroscopy, we used the dye, furaptra, by

Louis Amari; Brian Layden; Qinfen Rong; Carlos F. G. C. Geraldes; Duarte Mota de Freitas

1999-01-01

166

A method for the separation of beryllium from spectral interfering elements in inductively coupled plasma-atomic emission spectroscopic analysis  

Microsoft Academic Search

A quick, simple and effective chromatographic method for the separation of beryllium from a wide range of elements is described. The elements selected comprise elements which can interfere with the determination of beryllium by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and elements which commonly occur in environmental and industrial sample matrices. Beryllium is separated from all possible ICP-AES spectral interfering

Daniel R. McAlister; E. Philip Horwitz

2005-01-01

167

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

168

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

USGS Publications Warehouse

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

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

2006-01-01

169

Biophysical studies on the interactions of jatrorrhizine with bovine serum albumin by spectroscopic and molecular modeling methods.  

PubMed

The interaction between jatrorrhizine (JAT) and bovine serum albumin (BSA) has been studied. The studies were carried out in a buffer medium at pH 7.4 using fluorescence spectroscopy, UV-vis spectroscopy, and molecular modeling methods. The results of fluorescence quenching and UV-vis absorption spectra experiments indicated the formation of the complex of BSA-JAT. Binding parameters were determined using the Stern-Volmer equation and Scatchard equation. The results of thermodynamic parameters ?G, ?H and ?S at different temperatures indicate that the electrostatic interactions and hydrogen bonds play a major role for JAT-BSA association. Site marker competitive displacement experiments and molecular modeling calculation demonstrating that JAT is mainly located within the hydrophobic pocket of the subdomain IIIA of BSA. Furthermore, The distance between donor (BSA) and acceptor (JAT) was estimated according to fluorescence resonance energy transfer. PMID:23645029

Mi, Ran; Li, Pei-Qi; Hu, Yan-Jun; Fan, Xiao-Yang; Li, Hai-Ying; Yu, Xue-Cheng; Ouyang, Yu

2013-05-05

170

A new spectroscopic method for resolving the electronic symmetry properties of the highly excited molecules produced in photoexcitation.  

PubMed

A novel method of spectroscopy for highly excited states of molecules in the valence excitation range has been established through the detection of metastable hydrogen atoms in the 2s state formed by photoexcitation. The detector for the metastable hydrogen atom is composed of a stack of parallel plate electrodes that creates a localized electric field and triggers the emission of the Lyman-alpha photon from the atom and a chevron pair of microchannel plates that detects the photon. For linear molecules, the angle-resolved detection of the metastable hydrogen atom enables us to measure cross sections in which electronic symmetries of highly excited molecular states are resolved. Such symmetry-resolved cross section measurements were carried out for doubly excited states of H(2). PMID:20590226

Odagiri, Takeshi; Kumagai, Yoshiaki; Tanabe, Takehiko; Nakano, Motoyoshi; Suzuki, Isao H; Kitajima, Masashi; Kouchi, Noriyuki

2010-06-01

171

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

NASA Astrophysics Data System (ADS)

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

Prabakaran, K.; Rajeswari, S.

2009-12-01

172

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

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

173

Spectroscopic Methods of Steroid Analysis  

NASA Astrophysics Data System (ADS)

Modern chemical laboratories contain equipment capable of measuring many of the physical properties of single chemical compounds and mixtures of compounds, particularly their spectral properties, which can, if interpreted correctly, provide valuable information about both structure (of single compounds) and composition (of mixtures). Over the past 50 years, the author have witnessed enormous progress in the technical capabilities of this equipment. Automation and speed of analysis have greatly improved the ease of use and the versatility of the technology.

Kasal, Alexander; Budesinsky, Milos; Griffiths, William J.

174

Electron Spectroscopic Methods in Teaching.  

ERIC Educational Resources Information Center

|Discusses electron-loss spectroscopy and the experimentally observed excitation energies in terms of qualitative MO theory. Reviews information on photoelectron spectroscopy and electron transmission spectroscopy and their relation to the occupied and unoccupied orbital levels. Focuses on teaching applications. (ML)|

Allan, Michael

1987-01-01

175

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

176

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

177

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

PubMed

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

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

2010-12-13

178

A generalized series approach to MR spectroscopic imaging  

Microsoft Academic Search

The problem of precise spatial localization of spectral information in magnetic resonance (MR) spectroscopic imaging is addressed. A novel method, called GSLIM (generalized spectral location by imaging), is proposed to make possible the marriage of high-resolution proton imaging with spectroscopic imaging and localization. This method improves on the conventional Fourier series inversion method used in chemical shift imaging (CSI) and

Zhi-Pei Liang; Paul C. Lauterbur

1991-01-01

179

Learning from Ambiguously Labeled Examples  

Microsoft Academic Search

Inducing a classification function from a set of examples in the form of labeled instances is a standard problem in supervised machine learning. In this paper, we are concerned with ambiguous label classifica- tion (ALC), an extension of this setting in which several candidate labels may be assigned to a single example. By extending three concrete clas- sification methods to

Eyke Hüllermeier; Jürgen Beringer

2005-01-01

180

Learning from ambiguously labeled examples  

Microsoft Academic Search

Abstract. Inducing a classification function from a set of examples in the form of labeled instances is a standard problem in supervised machine learning. In this paper, we are concerned with ambiguous label classification (ALC), an extension of this setting in which several candidate labels may,be assigned to a single example. By extending three concrete classification methods to the ALC

Eyke Hüllermeier; Jürgen Beringer

2006-01-01

181

NMR-spectroscopic analysis of mixtures: from structure to function  

PubMed Central

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

Forseth, Ry R.; Schroeder, Frank C.

2010-01-01

182

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.

183

Examples of basis pursuit  

NASA Astrophysics Data System (ADS)

The Time-Frequency and Time-Scale communities have recently developed a large number of overcomplete waveform dictionaries. Decomposition into overcomplete systems is not unique, and several methods for decomposition have been proposed--including the Method of Frames, Matching Pursuit, and, for special dictionaries, the Best Orthogonal Basis. Basis Pursuit is a principle for decomposing a signal into an `optimal' superposition of dictionary elements-- where optimal means having the smallest l1 norm of coefficients among all such decompositions. We give examples exhibiting several advantages over the Method of Frames, Matching Pursuit and Best Ortho Basis, including better sparsity, and super-resolution. Basis Pursuit in highly overcomplete dictionaries leads to large-scale optimization problems. We obtain reasonable success with a primal-dual logarithmic barrier method and conjugate gradient solver.

Chen, Shaobing; Donoho, David L.

1995-09-01

184

Action Recognition from One Example  

Microsoft Academic Search

We present a novel action recognition method based on space-time locally adaptive regression kernels and the matrix cosine similarity measure. The proposed method uses a single example of an action as a query to find similar matches. It does not require prior knowledge about actions, foreground\\/background segmentation, or any motion estimation or tracking. Our method is based on the computation

Hae Jong Seo; Peyman Milanfar

2011-01-01

185

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

2011-01-07

186

Survey Design in Marine Environment: Three Examples.  

National Technical Information Service (NTIS)

Three examples are used to illustrate the range of statistical design problems encountered in marine research. The first example uses nonlinear design methods to find the optimum survey pattern for accurately locating the positions of acoustic beacons use...

W. Smith

1978-01-01

187

Prototype Portable Ultrasonic Spectroscope.  

National Technical Information Service (NTIS)

A portable ultrasonic system designated as the Model 5030 Ultrasonic Spectroscope, has been completed. This system displays both the time-domain rf signal and the spectral content of selected portions of the signal on a single CRT. This advancement signif...

B. J. Spencer G. M. Elfbaum J. L. Hunerwadel K. A. Fowler

1973-01-01

188

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

189

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

190

Spectroscopic measurements of solar wind generation  

NASA Astrophysics Data System (ADS)

Spectroscopically observable quantities are described which are sensitive to the primary plasma parameters of the solar wind's source region. The method is discussed in which those observable quantities are used as constraints in the construction of empirical models of various coronal structures. Simulated observations are used to examine the fractional contributions to observed spectral intensities from coronal structures of interest which co-exist with other coronal structures along simulated lines-of-sight. The sensitivity of spectroscopic observables to the physical parameters within each of those structures is discussed.

Kohl, J. L.; Withbroe, G. L.; Zapata, C. A.; Noci, G.

1983-11-01

191

Quantitative analysis of electron spectroscopic imaging series  

Microsoft Academic Search

We have developed new methods to quantify the data acquired by electron spectroscopic imaging (ESI) which are based on recording series of energy filtered images across inner shell loss edges or in the low loss region. From the series of ESI images, electron energy loss (EEL) spectra can be extracted for any given image area, i.e. each individual pixel or

J Mayer; U Eigenthaler; J. M Plitzko; F Dettenwanger

1997-01-01

192

A database of examples  

Microsoft Academic Search

This report describes the construction of a database of examples of consumer involvement in research. It summarises the material on the accompanying database and discusses some of the problems of finding and classifying suitable examples. The database was commissioned to: map the field of consumer involvement in research, by recording both current and recent initiatives, and the individuals and groups

Paul Dixon; Edwina Peart; Roy Carr-Hill

1999-01-01

193

Understanding Why Worked Examples Work  

Microsoft Academic Search

Worked examples are among the most tested and most successful methods for teaching science. Why? This chapter is a description of the mechanisms underlying the learning process with an appeal for applying this knowledge to the teaching of chemistry. Our intent is to provide background material and mostly make use of summary references rather than the references underpinning those summaries.

David W. Brooks; Kent J. Crippen

194

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

195

An accurate spectroscopic calibration for non-invasive glucose monitoring by modeling the physiological glucose dynamics  

PubMed Central

The physiological lag between blood and interstitial fluid (ISF) glucose is a major challenge for non-invasive glucose concentration measurements. This is a particular problem for spectroscopic techniques, which predominantly probe ISF glucose, creating inconsistencies in calibration, where blood glucose measurements are used as reference. To overcome this problem, we present a dynamic concentration correction (DCC) scheme, based on the mass transfer of glucose between blood and ISF, to ensure consistency with the spectral measurements. The proposed formalism allows the transformation of glucose in the concentration domain, ensuring consistency with the acquired spectra in the calibration model. Taking Raman spectroscopy as a specific example, we demonstrate that the predicted glucose concentrations using DCC-based calibration model closely match the measured glucose concentrations, while those generated with the conventional calibration methods show significantly larger deviations from the measured values. In addition, we provide an analytical formula for a previously unidentified source of limiting uncertainty arising in spectroscopic glucose monitoring from a lack of knowledge of glucose kinetics in prediction samples. A study with human volunteers undergoing glucose tolerance tests indicate that this lag uncertainty, which is comparable in magnitude to the uncertainty arising from noise and nonorthogonality in the spectral dataset, can be reduced substantially by employing the DCC in spectroscopic calibration.

Barman, Ishan; Kong, Chae-Ryon; Singh, Gajendra P.; Dasari, Ramachandra R.; Feld, Michael S.

2010-01-01

196

Simple Harmonic Motion - Example  

NSDL National Science Digital Library

This website contains a detailed development and comparison of a classical and a quantum mechanical description of motion in a simple harmonic potential "spring force", complete with figures. This example is a part of a larger collection of examples in which the classical and quantum mechanical descriptions are compared. (Note that there are thirteen pages, and that the user must use the navigation buttons at the bottom of the page)

Kirkman, Tom

2005-07-26

197

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

198

Spectroscopic observations of the 2011 Draconids meteor shower  

NASA Astrophysics Data System (ADS)

Spectroscopic observations of meteors reveals the chemical composition of parent bodies and interplanetary dust. Draconids are an example of most fragile meteoroids, bringing us information about physical properties of the comet 21P/Giacobini-Zinner. During the 2011 Draconids meteor shower, airborne and ground-based meteor spectroscopic observations carried out. Here, we report on the results for spectra captured by cameras provided by the IMCCE, ESA, SETI Institute, and Ondrejov Observatory. Collected by us spectra show two dominant emissions of sodium line at 5890 Å and the magnesium line at 5180 Å. Moreover, other emision lines belong to iron and the N2 molecule. 3

Rudawska, R.; Zender, J.; Jenniskens, P.; Borovicka, J.

2012-09-01

199

Optimization of a simple field method to determine mercury volatilization from soils—Examples of 13 sites in floodplain ecosystems at the Elbe River (Germany)  

Microsoft Academic Search

Mercury fluxes between soil and atmosphere have often been determined by using dynamic flux chambers and micrometeorological methods to assess ecological risks. However, both systems are complex, stationary, and expensive impeding measurements of Hg emissions at various field sites.The mobile, easy to handle, and cost-effective field method to determine total gaseous mercury (TGM), according to [Böhme, F., Rinklebe, J., Stärk,

Jörg Rinklebe; Mark Overesch; Rainer Wennrich; Hans-Joachim Stärk; Sibylle Mothes; Heinz-Ulrich Neue

2009-01-01

200

A statistics-based method for the short-wave infrared spectral analysis of altered rocks: An example from the Acoculco Caldera, Eastern Trans-Mexican Volcanic Belt  

Microsoft Academic Search

We propose a simple graphic and statistical method for processing short-wave infrared (SWIR) reflectivity spectra of alteration minerals, which classifies spectra according to their shape and absorption features, thus obtaining groups of spectra equivalent to mineral assemblages. It also permits selection of fewer samples for further mineralogical verification. This method uses the SWIR spectra without hull subtraction. The first step

Carles Canet; Lilia Arana; Eduardo González-Partida; Teresa Pi; Rosa María Prol-Ledesma; Sara I. Franco; Ruth Esther Villanueva-Estrada; Antoni Camprubí; Germán Ramírez-Silva; Aída López-Hernández

2010-01-01

201

A simple method for estimating recombination percentages and linkage intensities from F 2 data: examples from Triticum monococcum and other self-fertilizing diploid plant species  

Microsoft Academic Search

We offer an alternative approach to the extensively used maximum likelihood and product methods for calculating recombination values and linkage intensities from F2 data. This new method which we designate as the square root approach is simpler than the ones in current use in that it obviates the need for formulae and tables. It can be applied to autosomal F2

J. Kuspira; R. N. Bhambhani

1984-01-01

202

Focused library design in GPCR projects on the example of 5-HT(2c) agonists: comparison of structure-based virtual screening with ligand-based search methods.  

PubMed

The aim of this study was to investigate the usefulness of structure-based virtual screening (VS) for focused library design in G protein-coupled receptors (GPCR) projects on the example of 5-HT(2c) agonists. We compared the performance of structure-based VS against two different homology models using FRED for docking and ScreenScore, FlexX, and PMF for rescoring with the results of 12 ligand-based similarity searches using four different query compounds and three different similarity metrics (Daylight, FTree, Phacir). The result of the similarity search showed much variation, from an enrichment factor up to 3.2 to worse than random, whereas the structure-based VS gave a more stable result with a constant enrichment factor around 2. Additionally, actives retrieved by the structure-based approach were more diverse than the actives among the top scorers of the similarity searches. Based on these results, we suggest basing a focused library design for a GPCR project on a combination of a ligand-based similarity search and structure-based docking. PMID:16224780

Bissantz, Caterina; Schalon, Claire; Guba, Wolfgang; Stahl, Martin

2005-12-01

203

A Systems Engineering Evaluation Method for Piloted Aircraft and Other Man-Operated Vehicles and Machines, with Hypothetical Example of a Systems Evaluation.  

National Technical Information Service (NTIS)

A system evaluation method is presented which systematizes and quantifies both PRP pilot rating procedures and ECP engineering calculation procedure measures of system performance on a logarithmic ratio basis of test aircraft configurations compared to a ...

T. H. Higgins

1978-01-01

204

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

205

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas  

SciTech Connect

Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

B.C. Stratton, M. Bitter, K.W. Hill, D.L. Hillis, and J.T. Hogan

2007-07-18

206

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

207

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

208

Confocal light absorption and scattering spectroscopic microscopy  

NASA Astrophysics Data System (ADS)

We have developed a novel optical method for observing submicrometer intracellular structures in living cells, which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light-scattering spectroscopy. CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales of the order of 100 nm.

Fang, Hui; Qiu, Le; Vitkin, Edward; Zaman, Munir M.; Andersson, Charlotte; Salahuddin, Saira; Kimerer, Lauren M.; Cipolloni, Patsy B.; Modell, Mark D.; Turner, Bradley S.; Keates, Sarah E.; Bigio, Irving; Itzkan, Irving; Freedman, Steven D.; Bansil, Rama; Hanlon, Eugene B.; Perelman, Lev T.

2007-04-01

209

A Unifying Probability Example.  

ERIC Educational Resources Information Center

Presents an example from probability and statistics that ties together several topics including the mean and variance of a discrete random variable, the binomial distribution and its particular mean and variance, the sum of independent random variables, the mean and variance of the sum, and the central limit theorem. Uses Excel to illustrate these…

Maruszewski, Richard F., Jr.

2002-01-01

210

The spectral element method applied to the study of dynamic soil-structure interaction problems, an applicative example: the Acquasanta railway viaduct  

Microsoft Academic Search

The spectral element method (SEM) is a powerful numerical technique naturally suited for wave propagation and dynamic soil-structure interaction (DSSI) analyses. A class of SEM has been widely used in the seismological field (local or global seismology) thanks to its capability of providing high accuracy and allowing the implementation of optimized parallel algorithms. We illustrate in this contribution a typical

M. Stupazzini; K. Demartinos; R. Paolucci; C. Smerzini

211

Gender Differences in Prediction of Graduate Course Performance from Admissions Test Scores: An Empirical Example of Statistical Methods for Investigating Prediction Bias. AIR 1998 Annual Forum Paper.  

ERIC Educational Resources Information Center

|This study focused on gender differences in examining the extent to which Graduate Record Examination (GRE) scores predicted subsequent achievement. Data on 275 graduate students in professional psychology programs at a large midwestern university were collected and analyzed. Two methods for the identification of prediction bias were used and…

House, J. Daniel

212

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

2009-06-15

213

A comparison of three methods for estimating pro-glacial suspended sediment loads: an example from Castle Creek, Cariboo Mountains, British Columbia  

NASA Astrophysics Data System (ADS)

In terms of landscape dynamics, the widespread retreat of mountain glaciers is revealing new expanses of fresh glacial debris, the stability, dynamics and potential fluvial transport of which is little understood. Robust estimates of suspended sediment loads (SSL) are therefore essential in order to assess changes in sediment flux across pro-glacial zones and to assess changes over time. This study, based in the pro-glacial zone of the Castle Creek glacier in the Cariboo Mountains of northern British Columbia, estimated suspended sediment flux at three stations, 0, 0.5 and 1.0 km from the glacier snout, over 34-days in July-August 2008. ISCO automatic pumping samplers, a pressure transducer and turbidity sensors were deployed and 459 water samples were retrieved from the three stations and analysed gravimetrically for their suspended sediment concentration (SSC). A stage-discharge (Q) rating relationship was established at the distal end of the pro-glacial zone and an hourly Q record was maintained from 9 July - 12 August 2008. Three methods of calculating SSLs were compared for 214 hours for the 9-18 July phase of the study: (1) SSC v Q rating relationships were developed using 116 synchronous samples collected at each of the three stations and these were applied to the 1-h Q record to estimate SSL, (2) SSC v Q rating relationships were developed using all samples collected at each of the stations: n = 160, 151 and 148 at the proximal, middle and distal stations respectively, and these rating curves were applied to the 1-h Q record to estimate SSL, (3) an unbroken record of 3-hr samples at each of the three locations was obtained from 9-18 July and the product of each 3-hr SSC and Q value was used to represent each 3-hr time period and these were summed. Method 1 (n = 214) estimated SSLs of 213.969 ± 0.019 t, 272.284 ± 0.026 t and 411.605 ± 0.033 t respectively at the proximal, middle and distal stations. Method 2 (n = 214) estimated SSLs of 221.110 ± 0.020 t, 279.020 ± 0.031 t and 377.579±0.028 t respectively at the proximal, middle and distal stations while method 3, using the 3-hr samples, estimated SSLs of 218.694 ± 0.111 t, 322.361 ± 0.400 t and 468.392 ± 0.033 t respectively at the proximal, middle and distal stations. Comparing the SSL estimates with the mean of the three methods, method 1 was 98, 93 and 98% of the mean at the three stations, method 2 was 101, 96 and 90% and method 3 was 100, 111 and 112% of the mean estimates. The degree of scatter in the SSC v Q rating relationships increases across the pro-glacial zone from proximal to distal station. These results raise interesting questions as to which is the best method to choose. Also in this study, two Partech infrared (IR15C) 0-10 000 mg/L range turbidity (Tu) sensors were later deployed at the middle and distal stations. The SSC v Tu rating relationships are slightly stronger than those between SSC and Q which is promising for the future use of Tu sensors as a surrogate for SSC in this environment. Synchronous SSC traces for the Middle and Distal stations reveal some interesting observations which suggest that the system here is transport limited for the duration of the study and that there is no evidence to suggest a sediment supply limitation. KEYWORDS: estimation of suspended sediment loads; pro-glacial; British Columbia; turbidity

Forrester, B. F.; Stott, T. A.; Owens, P. N.; Lee, J.

2009-04-01

214

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

NASA Astrophysics Data System (ADS)

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

Miyatake, Takahiro; Pezzotti, Giuseppe

2011-11-01

215

A new heart rate variability-based method for the estimation of oxygen consumption without individual laboratory calibration: Application example on postal workers  

Microsoft Academic Search

Traditionally, the estimation of oxygen consumption (VO2) at work using heart rate (HR) has required the determination of individual HR\\/VO2 calibration curves in a separate exercise test in a laboratory (VO2-TRAD). Recently, a new neural network-, and heart rate variability-based method has been developed (Firstbeat PRO heartbeat analysis software) for the estimation of VO2 without individual calibration (VO2-HRV). In the

Juhani Smolander; Tanja Juuti; Marja-Liisa Kinnunen; Kari Laine; Veikko Louhevaara; Kaisa Männikkö; Heikki Rusko

2008-01-01

216

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

217

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

218

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

219

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

220

Comparison of fluorescence, (31)P NMR, and (7)Li NMR spectroscopic methods for investigating Li(+)/Mg(2+) competition for biomolecules.  

PubMed

The biochemical action of lithium in the treatment of manic-depressive illness is still unknown. One hypothesis is that Li(+) competes for Mg(2+)-binding sites in biomolecules. We report here our studies on metal ion competition by three distinct methods: fluorescence, (31)P NMR, and (7)Li NMR spectroscopy, using ATP as a model ligand. By fluorescence spectroscopy, we used the dye, furaptra, by measuring the increases in Mg(2+) levels in an ATP solution as Li(+) levels were increased in the solution. This increase in Mg(2+) levels was indicated by increases in the fluorescence intensity ratio (335/370) of furaptra. By (31)P NMR spectroscopy, this competition was demonstrated by changes in the (31)P NMR spectrum of ATP. The Li(+)/Mg(2+) competition was indicated by predictable changes in the separation between the alpha and beta resonances of the phosphates of ATP. For (7)Li NMR spectroscopy, spin-lattice relaxation measurements were used, which provided free Li(+) concentrations that could be used for determining the free Mg(2+) values in ATP solutions. The values of the free Mg(2+) concentrations obtained by all three methods were in good agreement. The fluorescence and (7)Li NMR methods, however, proved to be more sensitive to low concentrations of Li(+) than the (31)P NMR method. PMID:10405286

Amari, L; Layden, B; Rong, Q; Geraldes, C F; Mota de Freitas, D

1999-07-15

221

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

PubMed Central

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 and audio-computer assisted survey interviewing (ACASI) methods were employed. Dried blood spots were collected for unlinked anonymous antibody testing. Belgrade IDUs were offered voluntary confidential rapid HIV testing using a parallel testing algorithm, the performance of which was compared with standard laboratory tests. Predictors of anti-HCV positivity and the diagnostic accuracy of the rapid HIV test algorithm were calculated. Results Overall population prevalence of anti-HIV and anti-HCV in IDUs were 3% and 63% respectively in Belgrade (n = 433) and 0% and 22% in Podgorica (n = 328). Around a quarter of IDUs in each city had injected with used needles and syringes in the last four weeks. In both cities anti-HCV positivity was associated with increasing number of years injecting (eg Belgrade adjusted odds ratio (AOR) 5.6 (95% CI 3.2–9.7) and Podgorica AOR 2.5 (1.3–5.1) for ? 10 years v 0–4 years), daily injecting (Belgrade AOR 1.6 (1.0–2.7), Podgorica AOR 2.1 (1.3–5.1)), and having ever shared used needles/syringes (Belgrade AOR 2.3 (1.0–5.4), Podgorica AOR 1.9 (1.4–2.6)). Half (47%) of Belgrade participants accepted rapid HIV testing, and there was complete concordance between rapid test results and subsequent confirmatory laboratory tests (sensitivity 100% (95%CI 59%–100%), specificity 100% (95%CI 98%–100%)). Conclusion The combination of community recruitment, ACASI, rapid testing and a linked diagnostic accuracy study provide enhanced methods for conducting blood borne virus sero-prevalence studies in IDUs. The relatively high uptake of rapid testing suggests that introducing this method in community settings could increase the number of people tested in high risk populations. The high prevalence of HCV and relatively high prevalence of injecting risk behaviour indicate that further HIV transmission is likely in IDUs in both cities. Urgent scale up of HIV prevention interventions is needed.

2009-01-01

222

Complex-scaled equation-of-motion coupled-cluster method with single and double substitutions for autoionizing excited states: theory, implementation, and examples.  

PubMed

Theory and implementation of complex-scaled variant of equation-of-motion coupled-cluster method for excitation energies with single and double substitutions (EOM-EE-CCSD) is presented. The complex-scaling formalism extends the EOM-EE-CCSD model to resonance states, i.e., excited states that are metastable with respect to electron ejection. The method is applied to Feshbach resonances in atomic systems (He, H(-), and Be). The dependence of the results on one-electron basis set is quantified and analyzed. Energy decomposition and wave function analysis reveal that the origin of the dependence is in electron correlation, which is essential for the lifetime of Feshbach resonances. It is found that one-electron basis should be sufficiently flexible to describe radial and angular electron correlation in a balanced fashion and at different values of the scaling parameter, ?. Standard basis sets that are optimized for not-complex-scaled calculations (? = 0) are not sufficiently flexible to describe the ?-dependence of the wave functions even when heavily augmented by additional sets. PMID:23556708

Bravaya, Ksenia B; Zuev, Dmitry; Epifanovsky, Evgeny; Krylov, Anna I

2013-03-28

223

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

Microsoft Academic Search

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

Tomasz Zych; Tomasz Misiaszek; M. Magdalena Szostak

2007-01-01

224

Electron spectroscopic tomography of specific chromatin domains.  

PubMed

The eukaryotic genome is packaged within the nucleus as poly-nucleosome 10 nm chromatin fibres. The nucleosome core particle, the fundamental chromatin subunit, consists of a DNA molecule wrapped around a histone octamer. Biochemical modifications of both the DNA and histone proteins have been characterized that influence chromatin structure and function. These modifications include DNA methylation, histone variants and posttranslational modifications of the core histone protein tails. An outstanding area for investigation in the field of nuclear cell biology is the characterization of the functional relation between these biochemical modifications and the underlying chromatin structure and nuclear sub-compartmentalization. Electron spectroscopic tomography is a high-resolution microscopy technique that facilitates visualization of individual 10 nm chromatin fibres in three dimensions. The method, therefore, has a role to play in exploring the relationships of the epigenome and nuclear organization. Correlating immunofluorescence microscopy with electron spectroscopic tomography provides a powerful approach to relate epigenetic marks with high resolution chromatin organization. PMID:23980008

Even-Faitelson, Liron; Fussner, Eden; Li, Ren; Strauss, Mike; Bazett-Jones, David P

2013-01-01

225

A near-infrared reflectance spectroscopy method for direct analysis of several chemical components and properties of fruit, for example, Chinese hawthorn.  

PubMed

Near-infrared spectroscopy (NIRS) calibrations were developed for the discrimination of Chinese hawthorn (Crataegus pinnatifida Bge. var. major) fruit from three geographical regions as well as for the estimation of the total sugar, total acid, total phenolic content, and total antioxidant activity. Principal component analysis (PCA) was used for the discrimination of the fruit on the basis of their geographical origin. Three pattern recognition methods, linear discriminant analysis, partial least-squares-discriminant analysis, and back-propagation artificial neural networks, were applied to classify and compare these samples. Furthermore, three multivariate calibration models based on the first derivative NIR spectroscopy, partial least-squares regression, back-propagation artificial neural networks, and least-squares-support vector machines, were constructed for quantitative analysis of the four analytes, total sugar, total acid, total phenolic content, and total antioxidant activity, and validated by prediction data sets. PMID:23265446

Dong, Wenjiang; Ni, Yongnian; Kokot, Serge

2013-01-11

226

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

2011-05-13

227

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

228

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

NASA Astrophysics Data System (ADS)

The aim of this paper is to compare the results of two statistical methods for landslide susceptibility analysis: 1) univariate probabilistic method based on landslide susceptibility index, 2) multivariate method (logistic regression). The study area is the Febbraro valley, located in the central Italian Alps, where different types of metamorphic rocks croup out. On the eastern part of the studied basin a quaternary cover represented by colluvial and secondarily, by glacial deposits, is dominant. In this study 110 earth flows, mainly located toward NE portion of the catchment, were analyzed. They involve only the colluvial deposits and their extension mainly ranges from 36 to 3173 m2. Both statistical methods require to establish a spatial database, in which each landslide is described by several parameters that can be assigned using a main scarp central point of landslide. The spatial database is constructed using a Geographical Information System (GIS). Each landslide is described by several parameters corresponding to the value of main scarp central point of the landslide. Based on bibliographic review a total of 15 predisposing factors were utilized. The width of the intervals, in which the maps of the predisposing factors have to be reclassified, has been defined assuming constant intervals to: elevation (100 m), slope (5 °), solar radiation (0.1 MJ/cm2/year), profile curvature (1.2 1/m), tangential curvature (2.2 1/m), drainage density (0.5), lineament density (0.00126). For the other parameters have been used the results of the probability-probability plots analysis and the statistical indexes of landslides site. In particular slope length (0 ÷ 2, 2 ÷ 5, 5 ÷ 10, 10 ÷ 20, 20 ÷ 35, 35 ÷ 260), accumulation flow (0 ÷ 1, 1 ÷ 2, 2 ÷ 5, 5 ÷ 12, 12 ÷ 60, 60 ÷27265), Topographic Wetness Index 0 ÷ 0.74, 0.74 ÷ 1.94, 1.94 ÷ 2.62, 2.62 ÷ 3.48, 3.48 ÷ 6,00, 6.00 ÷ 9.44), Stream Power Index (0 ÷ 0.64, 0.64 ÷ 1.28, 1.28 ÷ 1.81, 1.81 ÷ 4.20, 4.20 ÷ 9.40). Geological map and land use map were also used, considering geological and land use properties as categorical variables. Appling the univariate probabilistic method the Landslide Susceptibility Index (LSI) is defined as the sum of the ratio Ra/Rb calculated for each predisposing factor, where Ra is the ratio between number of pixel of class and the total number of pixel of the study area, and Rb is the ratio between number of landslides respect to the pixel number of the interval area. From the analysis of the Ra/Rb ratio the relationship between landslide occurrence and predisposing factors were defined. Then the equation of LSI was used in GIS to trace the landslide susceptibility maps. The multivariate method for landslide susceptibility analysis, based on logistic regression, was performed starting from the density maps of the predisposing factors, calculated with the intervals defined above using the equation Rb/Rbtot, where Rbtot is a sum of all Rb values. Using stepwise forward algorithms the logistic regression was performed in two successive steps: first a univariate logistic regression is used to choose the most significant predisposing factors, then the multivariate logistic regression can be performed. The univariate regression highlighted the importance of the following factors: elevation, accumulation flow, drainage density, lineament density, geology and land use. When the multivariate regression was applied the number of controlling factors was reduced neglecting the geological properties. The resulting final susceptibility equation is: P = 1 / (1 + exp-(6.46-22.34*elevation-5.33*accumulation flow-7.99* drainage density-4.47*lineament density-17.31*land use)) and using this equation the susceptibility maps were obtained. To easy compare the results of the two methodologies, the susceptibility maps were reclassified in five susceptibility intervals (very high, high, moderate, low and very low) using natural breaks. Then the maps were validated using two cumulative distribution curves, one related to the landslides (number of landslides in e

Rossi, M.; Apuani, T.; Felletti, F.

2009-04-01

229

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.  

PubMed

In this study; the experimental (NMR, infrared and Raman) and theoretical (HF and DFT) analysis of dinicotinic acid were presented. (1)H and (13)C 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. PMID:23747433

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

2013-05-23

230

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

231

Information for decision makers at hospital laboratory level: an example of a graphical method of representing costs and effects for a replacement automated technology in a haematology laboratory.  

PubMed

The costs and effects on patient management following the introduction of a fully automated blood count analyser have been evaluated for a hospital haematology laboratory in England, during 1985. In the case of the relatively high throughput observed in the laboratory studied, the automated technology was judged to be cheaper if considering laboratory-centred costs alone. But this was no longer necessarily the case once wider costs, including extra medical workload generated for hospital and community physicians, were included. Effects on patient management were measured for all types of patient, including hospital in-patients, out-patients and general practice patients. A graphical method allowing comparison of the costs and effects of the replacement automated system, termed a Technology MAP (Management Awareness Profile) is presented in the paper. MAPs provide a flexible information display which can be tailored to an individual laboratory's situation producing an overall picture of expected costs and effects on patient management following the introduction of a new technology--a full value-in-use assessment. The authors argue that there is a need for a central source of such value-in-use assessments, especially for new medium-priced diagnostic technologies which are likely to become widely spread in Britain. PMID:3128877

Szczepura, A K; Stilwell, J A

1988-01-01

232

Spectroscopic optical coherence elastography  

PubMed Central

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

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

2010-01-01

233

Spectroscopic studies of glass structure  

SciTech Connect

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

Brow, R.K.

1994-08-01

234

Reconstructing seawater ? 18O from paired coral ? 18O and Sr/Ca ratios: Methods, error analysis and problems, with examples from Tahiti (French Polynesia) and Timor (Indonesia)  

NASA Astrophysics Data System (ADS)

We compare several statistical routines that may be used to calculate ? 18O sw and SSS from paired coral Sr/Ca and ? 18O measurements. Typically, the ? 18O coral-SST relationship is estimated by linear regression of coral ? 18O vs. SST. If this method is applied, evidence should be given that at a particular site SST and SSS do not co-vary. In the tropical oceans, SST and ? 18O sw (SSS) often co-vary, and this will bias the estimate of the regression slope of ? 18O coral-SST. Using a stochastic model, we show that covariance leads to a bias in the coefficients of the univariate regression equations. As the slope of the ? 18O coral-SST relationship has known, we propose to insert this value for ?1 in the regression models. This requires that the constants of the regression equations are removed. To omit the constants, we propose to center the regression equations (i.e., to remove the mean values from the variables). The statistical error propagation is calculated to assess our ability to resolve past variations in ? 18O sw (SSS). At Tahiti, we find that the combined analytical uncertainties of coral ? 18O and Sr/Ca equal the amplitude of the seasonal cycle of ? 18O sw (SSS). Therefore, we cannot resolve the seasonal cycle of SSS at Tahiti. At Timor, the error of reconstructed ? 18O sw (SSS) is lower than the magnitude of seasonal variations of ? 18O sw (SSS), and the seasonal cycle of ? 18O sw (SSS) can be resolved.

Yudawati Cahyarini, Sri; Pfeiffer, Miriam; Timm, Oliver; Dullo, Wolf-Christian; Schönberg, Dieter Garbe

235

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…

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

2011-01-01

236

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

237

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

PubMed

Coffee is the most heavily consumed beverage in the world after water, for which quality is a key consideration in commercial trade. Therefore, caffeine content which has a significant effect on the final quality of the coffee products requires to be determined fast and reliably by new analytical techniques. The main purpose of this work was to establish a powerful and practical analytical method based on near infrared spectroscopy (NIRS) and chemometrics for quantitative determination of caffeine content in roasted Arabica coffees. Ground coffee samples within a wide range of roasted levels were analyzed by NIR, meanwhile, in which the caffeine contents were quantitative determined by the most commonly used HPLC-UV method as the reference values. Then calibration models based on chemometric analyses of the NIR spectral data and reference concentrations of coffee samples were developed. Partial least squares (PLS) regression was used to construct the models. Furthermore, diverse spectra pretreatment and variable selection techniques were applied in order to obtain robust and reliable reduced-spectrum regression models. Comparing the respective quality of the different models constructed, the application of second derivative pretreatment and stability competitive adaptive reweighted sampling (SCARS) variable selection provided a notably improved regression model, with root mean square error of cross validation (RMSECV) of 0.375 mg/g and correlation coefficient (R) of 0.918 at PLS factor of 7. An independent test set was used to assess the model, with the root mean square error of prediction (RMSEP) of 0.378 mg/g, mean relative error of 1.976% and mean relative standard deviation (RSD) of 1.707%. Thus, the results provided by the high-quality calibration model revealed the feasibility of NIR spectroscopy for at-line application to predict the caffeine content of unknown roasted coffee samples, thanks to the short analysis time of a few seconds and non-destructive advantages of NIRS. PMID:23786975

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

2013-05-29

238

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

2013-02-12

239

Improving the classification accuracy for IR spectroscopic diagnosis of stomach and colon malignancy using non-linear spectral feature extraction methods.  

PubMed

Non-linear feature extraction methods, neighborhood preserving embedding (NPE) and supervised NPE (SNPE), were employed to effectively represent the IR spectral features of stomach and colon biopsy tissues for classification, and improve the classification accuracy for diagnosis of malignancy. The motivation was to utilize the NPE and SNPE's capability of capturing non-linear spectral behaviors by simultaneously preserving local relationships in order that minute spectral differences among classes would be effectively recognized. NPE and SNPE derive an optimal embedding feature such that the local neighborhood structure can be preserved in reduced spaces (variables). The IR spectra collected from stomach and colon tissues were represented by several new variables through NPE and SNPE, and also by using the principal component analysis (PCA). Then, the feature-extracted variables were subsequently classified into normal, adenoma and cancer tissues by using both k-nearest neighbor (k-NN) and support vector machine (SVM), and the resulting accuracies were compared with each other. In both cases, the combination of SNPE-SVM provided the best classification performance, and the accuracy was substantially improved compared to when PCA-SVM was used. Overall results demonstrate that NPE and SNPE could be potential feature-representation strategies useful in biomedical diagnosis based on vibrational spectroscopy where effective recognition of minute spectral differences is critical. PMID:23687649

Lee, Sanguk; Kim, Kyoungok; Lee, Hyeseon; Jun, Chi-Hyuck; Chung, Hoeil; Park, Jong-Jae

2013-07-21

240

Combination of chiroptical, absorption and fluorescence spectroscopic methods reveals multiple, hydrophobicity-driven human serum albumin binding of the antimalarial atovaquone and related hydroxynaphthoquinone compounds.  

PubMed

High-affinity human serum albumin (HSA) binding of the C3-substituted antimalarial 2-hydroxy-1,4-naphthoquinone derivative atovaquone (ATQ) has been demonstrated and studied by circular dichroism (CD), UV/VIS absorption, fluorescence spectroscopy and affinity chromatography methods. The analysis of induced CD data generated upon HSA binding of ATQ revealed two high-affinity binding sites (K(a) ? 2 × 10(6) M(-1)). CD interaction studies and displacement of specific fluorescent and radioactive marker ligands indicated the contribution of both principal drug binding sites of HSA to complexation of ATQ, and also suggested the possibility of simultaneous binding of ATQ and some other drugs (e.g. warfarin, phenylbutazone, diazepam). Comparison of UV/VIS spectra of ATQ measured in aqueous solutions indicated the prevalence of the anionic species formed by dissociation of the 2-hydroxyl group. HSA binding of related natural hydroxynaphthoquinones, lapachol and lawsone also induces similar CD spectra. The much weaker binding affinity of lawsone (K(a) ? 10(4) M(-1)) bearing no C3 substituent highlights the importance of hydrophobic interactions in the strong HSA binding of ATQ and lapachol. Since neither drug exhibited significant binding to serum ?(1)-acid glycoprotein, HSA must be the principal plasma protein for the binding and transportation of 2-hydroxy-1,4-naphthoquinone-type compounds which are ionized at physiological pH values. PMID:20737064

Zsila, Ferenc; Fitos, Ilona

2010-08-24

241

Raman spectroscopic study of the electrical properties of 6H-SiC crystals grown by hydrogen-assisted physical vapor transport method  

NASA Astrophysics Data System (ADS)

Raman spectroscopy has been used to determine the carrier concentration of 6H-SiC crystal so as to understand the effects of hydrogen on the electrical property of 6H-SiC crystal grown by hydrogen-assisted physical vapor transport method. The spatial distribution of the carrier concentration is determined in a longitudinally-cut sample grown by an on-off hydrogen supply based on the empirical relationship between the frequency of the LO-phonon-plasmon-coupled modes (LOPC modes) and carrier concentration. It is found that the carrier concentration dramatically drops when the supply of hydrogen turns on and decreases more quickly in the hydrogen-assisted region than that in the undoped region. It is proposed that the vapor phase shifts toward more C-rich condition in case of hydrogen-assisted growth. As a consequence, the N incorporation in 6H-SiC crystal is depressed and the inactive electrically center Vc+H complexes are formed during hydrogen-assisted physical vapor transport SiC crystal growth.

Peng, Yan; Xu, Xiangang; Hu, Xiaobo; Jiang, Kai; Song, Sheng; Gao, Yuqiang; Xu, Huayong

2010-05-01

242

The mass ratio in spectroscopic binaries  

NASA Astrophysics Data System (ADS)

The process of formation of binary and multiple stars is not yet fully understood. Possibilities range from simultaneous processes of condensation from the primeval nebula, to isolated star formation and eventual capture to form a double system. Models exist that predict success probabilities for each theoretical process, and comparison with observational data is crucial. Spectroscopic binaries are specially suited to be used as observational data, since several biases that can arise from general catalogues of binary stars can be avoided, including dominance of systems with large separations between components. A very important parameter in these studies is the mass ratio, the quocient of the masses of primary and secundary members. The histogram of mass ratios provides crucial information to models of binary formation, linked to condensation processes and evolutionaty rates.In this case, spectroscopic binaries can be chosen as the observational sample, provided that the spectrum of the primary is from a non-evolved, main-sequence star,whose mass can be derived reliably from its spectral type. Defining an adequate limiting magnitude (6.5), one avoids bias from eclipsing systems with high inclinations, since nearly all systems up to 6.5 mag were detected. In this paper, a critical review is presented of the existing methods for deriving the distribution of the mass ratios from spectroscopic binary orbital data. After showing the incorrectness of some results published in the litterature, the available data (Batten's 8th Catalogue, 1989) is discussed. Simulations for several distributions of mass ratios (constant, quadratic, etc) are performed. It is shown that the existing data permits only to assert that the spectroscopic binaries with small mass ratios (q < 0.4) are more frequent that those with large mass ratios (q = 0.9 to 1.0).

Ducati, J. R.; Penteado, E. M.; Turcati, R.

2003-08-01

243

New Orbital Parameters and Radial Velocity Curve Analysis of Spectroscopic Binary Stars  

NASA Astrophysics Data System (ADS)

We use a Probabilistic Neural Network (PNN) technique to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of five double-lined spectroscopic binary systems (i.e., EQ Tau, V376 And, V776 Cas, V2377 Oph and EE Cet), we find the corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by other groups via more traditional methods.

Ghaderi, Kamal; Pirkhedri, Ali; Rostami, Touba; Khodamoradi, Salem; Fatahi, Hedayat

2012-02-01

244

Halo Nucleus 11Be: A Spectroscopic Study via Neutron Transfer  

SciTech Connect

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 11Be, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the 10Be d;p reaction has been used in inverse kinematics at four beam energies to study the structure of 11Be. 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 10Be 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, Kyle [University of Tennessee, Knoxville (UTK); Jones, K. L. [University of Tennessee, Knoxville (UTK); Bey, A. [University of Tennessee, Knoxville (UTK); Ahn, S.H. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Blackmon, Jeffery C [Louisiana State University; Brown, S. [University of Surrey, UK; Chae, Kyung Yuk [ORNL; Chipps, K. [Colorado School of Mines, Golden; Cizewski, J. A. [Rutgers University; Kozub, R. L. [Tennessee Technological University; Liang, J Felix [ORNL; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Matos, M. [Louisiana State University; Moazen, Brian H [ORNL; Nesaraja, Caroline D [ORNL; Nunes, F. M. [Michigan State University, East Lansing; O'Malley, Patrick [Rutgers University; Pain, Steven D [ORNL; Peters, W. A. [Rutgers University; Pittman, S. T. [University of Tennessee, Knoxville (UTK); Wilson, G. [University of Surrey, UK

2012-01-01

245

Halo nucleus 11Be: a spectroscopic study via neutron transfer.  

PubMed

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 11Be, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the 10Be(d,?p) reaction has been used in inverse kinematics at four beam energies to study the structure of 11Be. 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=2s(1/2) state coupled to the ground state of 10Be 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 1p(1/2) state. PMID:23003029

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; Smith, M S; Spassova, I; Stracener, D W; Villano, A N; Wilson, G L

2012-05-08

246

Examples of Mathematical Modeling  

PubMed Central

Mathematical modeling is being increasingly recognized within the biomedical sciences as an important tool that can aid the understanding of biological systems. The heavily regulated cell renewal cycle in the colonic crypt provides a good example of how modeling can be used to find out key features of the system kinetics, and help to explain both the breakdown of homeostasis and the initiation of tumorigenesis. We use the cell population model by Johnston et al.5 to illustrate the power of mathematical modeling by considering two key questions about the cell population dynamics in the colonic crypt. We ask: how can a model describe both homeostasis and unregulated growth in tumorigenesis; and to which parameters in the system is the model most sensitive? In order to address these questions, we discuss what type of modeling approach is most appropriate in the crypt. We use the model to argue why tumorigenesis is observed to occur in stages with long lag phases between periods of rapid growth, and we identify the key parameters.

Johnston, Matthew D.; Edwards, Carina M.; Bodmer, Walter F.; Maini, Philip K.; Chapman, S. Jonathan

2008-01-01

247

Reconstruction of Detached Divertor Plasma Conditions in DIII-D Using Spectroscopic and Probe Data  

SciTech Connect

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

Stangeby, P; Fenstermacher, M

2004-12-03

248

Confocal light scattering and absorption spectroscopic microscopy  

NASA Astrophysics Data System (ADS)

We have developed a novel optical method for observing submicron intracellular structures in living cells which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light scattering spectroscopy (LSS). CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales on the order of 100 nm. In addition, it provides not only size information but also information about the biochemical and physical properties of the cell.

Qiu, Le; Vitkin, Edward; Salahuddin, Saira; Zaman, Munir M.; Andersson, Charlotte; Freedman, Steven D.; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.

2008-05-01

249

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

ERIC Educational Resources Information Center

Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

Wakabayashi, Fumitaka; Hamada, Kiyohito

2006-01-01

250

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

NASA Astrophysics Data System (ADS)

Conventional FTIR spectroscopy and microscopy has been widely used in forensic science. New opportunities exist to obtain rapid chemical images and to enhance the sensitivity of detection of trace materials using attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy coupled with a focal-plane array (FPA) detector. In this work, the sensitivity of ATR-FTIR spectroscopic imaging using three different kinds of ATR crystals (Ge coupled with an infrared microscope, ZnSe and diamond) and resulting in three different optical arrangements for the detection of model drug particles is discussed. Model systems of ibuprofen and paracetamol particles having a size below 32 micrometers have been prepared by sieving. The sensitivity level in the three different approaches has been compared and it has been found that both micro and macro-ATR imaging methods have proven to be a promising techniques for the identification of concealed drug particles. To demonstrate the power and applicability of FTIR chemical imaging to forensic research, various examples are discussed. This includes investigation of the changes of chemical nature of latent fingerprint residue under controlled conditions of humidity and temperature studied by ATR-FTIR imaging. This study demonstrates the potential of spectroscopic imaging for visualizing the chemical changes of fingerprints.

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

2006-10-01

251

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

252

Spectroscopic Properties of Asteroid Families  

Microsoft Academic Search

Asteroid families have been the target of several dedicated campaigns of spectroscopic observations during the last 10 years. Preliminary studies were mainly devoted to obtain a confirmation of the cosmochemical reliability of groupings identified by purely statistical analyses of the distributions of objects in the space of the orbital proper elements. These early attempts led to some spectacular confirmations of

A. Cellino; S. J. Bus; A. Doressoundiram; D. Lazzaro

2002-01-01

253

Spectroscopic and Laser Characterization Emerald.  

National Technical Information Service (NTIS)

The spectroscopic characteristics and laser properties of emerald were investigated. The laser measurements showed that the emerald laser tuning range was 720-842 nm and exhibited a high gain and high efficiency in the 760-790 nm range. Under a crystal gr...

S. T. Lai B. H. Chai

1986-01-01

254

Spectroscopic Properties of Alexandrite Crystals.  

National Technical Information Service (NTIS)

Details of the optical-spectroscopic properties of alexandrite (BeAl sub 2 0 sub 4: Cr 3+ crystals were studied by different laser-spectroscopy techniques. The temperature dependences of the fluorescence lifetimes and widths of the zero-phonon lines were ...

R. C. Powell L. Xi X. Gang G. J. Quarles

1985-01-01

255

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

256

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

257

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

258

Multidimensional Design by Examples  

Microsoft Academic Search

In this paper we present a method to validate user multidi- mensional requirements expressed in terms of SQL queries. Furthermore, our approach automatically generates and proposes the set of multidi- mensional schemas satisfying the user requirements, from the organiza- tional operational schemas. If no multidimensional schema is generated for a query, we can state that requirement is not multidimensional.

Oscar Romero; Alberto Abelló

2006-01-01

259

WAAS MOPS: Practical Examples  

Microsoft Academic Search

The WAAS MOPS describes the method by which a Wide Area Augmentation System (WAAS) transmits its differential GPS corrections and integrity information to users in 250 bit messages. These messages must be decoded and interpreted every second. The corrections even for a single satellite are distributed across several individual messages. The corrections for individual satellites must be combined with receiver

Todd Walter

1999-01-01

260

Spectroscopic studies of cold, gas-phase biomolecular ions  

NASA Astrophysics Data System (ADS)

While the marriage of mass spectrometry and laser spectroscopy is not new, developments over the last few years in this relationship have opened up new horizons for the spectroscopic study of biological molecules. The combination of electrospray ionisation for producing large biological molecules in the gas phase together with cooled ion traps and multiple-resonance laser schemes are allowing spectroscopic investigation of individual conformations of peptides with more than a dozen amino acids. Highly resolved infrared spectra of single conformations of such species provide important benchmarks for testing the accuracy of theoretical calculations. This review presents a number of techniques employed in our laboratory and in others for measuring the spectroscopy of cold, gas-phase protonated peptides. We show examples that demonstrate the power of these techniques and evaluate their extension to still larger biological molecules.

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

261

Learning dependency transduction models from unannotated examples  

Microsoft Academic Search

We present a method for constructing a statistical machine translation system automatically from unannotated examples in a manner consistent with the principles of dependency grammar. The method involves learning a generative statistical model of paired dependency derivations of source and target sentences. Such a dependency transduction model consists of collections of weighted head transducers. Head transducers are finite-state machines with

Hiyan Alshawi; Shona Douglas

2000-01-01

262

A rapid method for the differentiation of yeast cells grown under carbon and nitrogen-limited conditions by means of partial least squares discriminant analysis employing infrared micro-spectroscopic data of entire yeast cells  

PubMed Central

This paper shows the ease of application and usefulness of mid-IR measurements for the investigation of orthogonal cell states on the example of the analysis of Pichia pastoris cells. A rapid method for the discrimination of entire yeast cells grown under carbon and nitrogen-limited conditions based on the direct acquisition of mid-IR spectra and partial least squares discriminant analysis (PLS-DA) is described. The obtained PLS-DA model was extensively validated employing two different validation strategies: (i) statistical validation employing a method based on permutation testing and (ii) external validation splitting the available data into two independent sub-sets. The Variable Importance in Projection scores of the PLS-DA model provided deeper insight into the differences between the two investigated states. Hence, we demonstrate the feasibility of a method which uses IR spectra from intact cells that may be employed in a second step as an in-line tool in process development and process control along Quality by Design principles.

Kuligowski, Julia; Quintas, Guillermo; Herwig, Christoph; Lendl, Bernhard

2012-01-01

263

Action recognition from one example.  

PubMed

We present a novel action recognition method based on space-time locally adaptive regression kernels and the matrix cosine similarity measure. The proposed method uses a single example of an action as a query to find similar matches. It does not require prior knowledge about actions, foreground/background segmentation, or any motion estimation or tracking. Our method is based on the computation of novel space-time descriptors from the query video which measure the likeness of a voxel to its surroundings. Salient features are extracted from said descriptors and compared against analogous features from the target video. This comparison is done using a matrix generalization of the cosine similarity measure. The algorithm yields a scalar resemblance volume, with each voxel indicating the likelihood of similarity between the query video and all cubes in the target video. Using nonparametric significance tests by controlling the false discovery rate, we detect the presence and location of actions similar to the query video. High performance is demonstrated on challenging sets of action data containing fast motions, varied contexts, and complicated background. Further experiments on the Weizmann and KTH data sets demonstrate state-of-the-art performance in action categorization. PMID:20733220

Seo, Hae Jong; Milanfar, Peyman

2011-05-01

264

Infrared spectroscopic imaging for noninvasive detection of latent fingerprints.  

PubMed

The capability of Fourier transform infrared (FTIR) spectroscopic imaging to provide detailed images of unprocessed latent fingerprints while also preserving important trace evidence is demonstrated. Unprocessed fingerprints were developed on various porous and nonporous substrates. Data-processing methods used to extract the latent fingerprint ridge pattern from the background material included basic infrared spectroscopic band intensities, addition and subtraction of band intensity measurements, principal components analysis (PCA) and calculation of second derivative band intensities, as well as combinations of these various techniques. Additionally, trace evidence within the fingerprints was recovered and identified. PMID:17209909

Crane, Nicole J; Bartick, Edward G; Perlman, Rebecca Schwartz; Huffman, Scott

2007-01-01

265

About the problems to interpret spectroscopic data from plasmas  

SciTech Connect

Continued developments of quantitative spectroscopy and related atomic physics are originating from inertial and magnetic fusion research. In almost all experimental facilities, non-equilibrium phenomena are now a central issue and the interpretation of related spectroscopic data is a great challenge. We discuss new general diagnostic/spectroscopic approaches and usual point of views: high density methods and high density atomic physics for magnetic fusion research like ITER and the Virtual Contour Shape Kinetic Theory VCSKT which unifies low and high density plasma regimes and therefore allows to employ complex satellite transitions in non-equilibrium, non-LTE and non-Coronal plasmas.

Rosmej, F. B.; Guedda, E. H.; Stamm, R. [Universite de Provence et CNRS, UMR 6633, Centre St. Jerome, PIIM-DGP, case 232, Av. Escadrille Niemen, 13397 Marseille Cedex 20 (France); Lisitsa, V. S. [Russian Research Center ' Kurchatov Institute', 123182 Moscow (Russian Federation); Capes, H. [DRFC, Association Euratom-CEA, 13108 Saint Paul lez Durance Cedex (France)

2006-01-15

266

Velocity Curve Analysis of Spectroscopic Binary Stars AI Phe, GM Dra, HD 93917 and V502 Oph by Nonlinear Regression  

NASA Astrophysics Data System (ADS)

We introduce a new method to derive the orbital parameters of spectroscopic binary stars by nonlinear least squares of (o-c). Using the measured radial velocity data of the four double lined spectroscopic binary systems, AI Phe, GM Dra, HD 93917 and V502 Oph, we derived both the orbital and combined spectroscopic elements of these systems. Our numerical results are in good agreement with the those obtained using the method of Lehmann-Filhé.

Karami, K.; Mohebi, R.

2007-08-01

267

Compact Disk Spectroscopes Revisited!  

NASA Astrophysics Data System (ADS)

The recent article by Tim Knauer1 indicates again that the CD provides a wonderful learning resource for physics teachers and students. There is much to be learned by examining the nature of the way information is stored and retrieved on the disk as well as the physical medium itself. Books such as Muller's Upgrading and Repairing PC's2 provide a useful compendium of the properties of the medium as well as the methods of encoding.

Byrne, Aidan

2003-03-01

268

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

269

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

270

Application of a probabilistic neural network in radial-velocity curve analysis of the spectroscopic binary stars HD 152218, HD 143511, HD 27149, and ER Vul  

NASA Astrophysics Data System (ADS)

We use an Artificial Neural Network (ANN) to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of four double-lined spectroscopic binary systems HD 152218, HD 143511, HD 27149, and ER Vul, we find corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by others using more traditional methods.

Pirkhedri, A.; Ghaderi, K.; Javadi, H. H. S.; Karimizadeh, K.

2012-04-01

271

Knockout, Transfer and Spectroscopic Factors  

NASA Astrophysics Data System (ADS)

As derived quantities rather than observables, spectroscopic factors extracted from fits to data are model dependent. The main source of uncertainty is the choice of binding potential, but other factors such as adequate modeling of the reaction mechanism, the Perey effect, choice of distorting nuclear potentials etc. can also play a significant role. Recently, there has been some discussion of apparent discrepancies in spectroscopic factors derived from knockout reactions compared to those obtained from low-energy direct reactions. It should be possible to reconcile these discrepancies and we explore this prospect by attempting to describe the ^10Be(d,t)^9Be data of Nucl. Phys. A157, 305 (1970) using the ^10Be/^9Be form factors from a recent knockout study, Phys. Rev. Lett. 106, 162502 (2011). The influence of such factors as choice of distorting potentials and multi-step reactions paths will be explored.

Kemper, Kirby; Keeley, Nicholas; Rusek, Krzysztof

2011-10-01

272

NIRSPEC brown dwarf spectroscopic survey  

Microsoft Academic Search

The NIRSPEC Brown Dwarf Spectroscopic Survey is a project to obtain a consistent set of high-quality near-IR spectra for each spectral class and sub-class of low-mass and\\/or sub- stellar objects to provide a new data base for models of the atmosphere of brown dwarfs and extra-solar giant planets. Most of the current targets are L-dwarfs and T-dwarfs discovered by the

Mavourneen K. Wilcox; Ian S. McLean; Eric E. Becklin; Donald F. Figer; Andrea M. Gilbert; James R. Graham; James E. Larkin; N. A. Levenson; Harry I. Teplitz; J. D. Kirkpatrick; Adam J. Burgasser

2000-01-01

273

Spectroscopic radiation portal monitor prototype  

Microsoft Academic Search

A spectroscopic radiation portal monitor (SPM) prototype consisting of four 10.16-cmtimes10.16-cmtimes40.64-cm sodium iodide (NaI) crystals has been constructed at Pacific Northwest National Laboratory (PNNL). The prototype was put through a variety of tests, including measurements of the absolute detection efficiency of unshielded sources and the detection efficiency and isotopic identification capability of the detector for shielded isotopic sources. The monitor's

Kathleen R. McCormick; David C. Stromswold; James H. Ely; John E. Schweppe; Richard T. Kouzes

2005-01-01

274

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

275

New spectroscopic components in multiple systems. V.  

NASA Astrophysics Data System (ADS)

Aims: This paper aims to improve the knowledge of orbits, physical parameters, and statistics of nearby multiple systems. Methods: Radial velocities were measured with a correlation spectrometer during 2001-2006 to determine or improve the spectroscopic orbits of the components of some visual multiple systems. We compiled all available observational data and estimated masses and orbital periods in these hierarchical multiple systems. The masses and ages of evolved components are derived by fitting isochrones. Results: We determined three new spectroscopic orbits of close sub-systems (HD 52452B, 157358Aab, 219877B) and improved one more orbit (HD 139461). The composite-spectrum system HD 157358Aab was resolved by speckle-interferometry, and its preliminary combined orbit was computed to guide future interferometric observations. A tentative 21-day orbit for HD 219877A based on published velocities is computed. Table 4 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/465/257

Tokovinin, A. A.; Gorynya, N. A.

2007-04-01

276

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

277

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

2008-03-15

278

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 Central

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.

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

2008-01-01

279

Learning Translation Templates from Examples  

Microsoft Academic Search

This paper proposes a mechanism for learning lexical level correspondences between two languages from a set of translated sentence pairs. The proposed mechanism is based on an analogical reasoning between two translation examples. Given two translation examples, the similar parts of the sentences in the source language must correspond the similar parts of the sentences in the target language. Similarly,

Halil Altay Güvenir; Ilyas Cicekli

1998-01-01

280

Specifying Generation of Referring Expressions by Example  

Microsoft Academic Search

A module for generation of referring expressions (GRE) de- rives descriptions that identify specified entities in context. In the implemented system I describe here for specifying simple cases of GRE by example, system-builders pair entities with descriptions of them that would be satisfactory for a system to use in context. Automatic methods then construct a suit- able knowledge base and

Matthew Stone

2003-01-01

281

Visualizing the zero order basis of the spectroscopic Hamiltonian  

NASA Astrophysics Data System (ADS)

Recent works have shown that a generalization of the spectroscopic effective Hamiltonian can describe spectra in surprising regions, such as isomerization barriers. In this work, we seek to explain why the effective Hamiltonian is successful where there was reason to doubt that it would work at all. All spectroscopic Hamiltonians have an underlying abstract zero-order basis (ZOB) which is the ``ideal'' basis for a given form and parameterization of the Hamiltonian. Without a physical model there is no way to transform this abstract basis into a coordinate representation. To this end, we present a method of obtaining the coordinate space representation of the abstract ZOB of a spectroscopic effective Hamiltonian. This method works equally well for generalized effective Hamiltonians that encompass above-barrier multiwell behavior, and standard effective Hamiltonians for the vicinity of a single potential minimum. Our approach relies on a set of converged eigenfunctions obtained from a variational calculation on a potential surface. By making a one-to-one correspondence between the energy eigenstates of the effective Hamiltonian and those of the coordinate space Hamiltonian, a physical representation of the abstract ZOB is calculated. We find that the ZOB basis naturally adjusts its complexity depending on the underlying nature of phase space, which allows spectroscopic Hamiltonians to succeed for systems sampling multiple stationary points.

Barnes, George L.; Kellman, Michael E.

2012-01-01

282

Visualizing the zero order basis of the spectroscopic Hamiltonian.  

PubMed

Recent works have shown that a generalization of the spectroscopic effective Hamiltonian can describe spectra in surprising regions, such as isomerization barriers. In this work, we seek to explain why the effective Hamiltonian is successful where there was reason to doubt that it would work at all. All spectroscopic Hamiltonians have an underlying abstract zero-order basis (ZOB) which is the "ideal" basis for a given form and parameterization of the Hamiltonian. Without a physical model there is no way to transform this abstract basis into a coordinate representation. To this end, we present a method of obtaining the coordinate space representation of the abstract ZOB of a spectroscopic effective Hamiltonian. This method works equally well for generalized effective Hamiltonians that encompass above-barrier multiwell behavior, and standard effective Hamiltonians for the vicinity of a single potential minimum. Our approach relies on a set of converged eigenfunctions obtained from a variational calculation on a potential surface. By making a one-to-one correspondence between the energy eigenstates of the effective Hamiltonian and those of the coordinate space Hamiltonian, a physical representation of the abstract ZOB is calculated. We find that the ZOB basis naturally adjusts its complexity depending on the underlying nature of phase space, which allows spectroscopic Hamiltonians to succeed for systems sampling multiple stationary points. PMID:22260571

Barnes, George L; Kellman, Michael E

2012-01-14

283

Supplementary information on the near-infrared spectroscopic data of the infrared camera (IRC) onboard AKARI  

NASA Astrophysics Data System (ADS)

We have investigated the on-orbit properties of the spectroscopic data taken with NIR channel of the Infrared Camera (IRC) onboard AKARI during the phases 1, 2 and 3. We have determined the boundary shape of the aperture mask of NIR channel by using the spectroscopic data of uniform zodiacal background emission. The information on the aperture mask shape is indispensable in modeling and subtracting the spectroscopic background patterns made by the diffuse background emission such as zodiacal emission and the Galactic cirrus emission. We also have examined the wavelength dependency on the profile of the point spread function and its effect on the spectroscopic data. The obtained information is useful, for example, in reducing the spectroscopic data of a point source badly affected by bad pixels and in decomposing the overlapping spectra of sources that are aligned in the dispersion direction with a small offset the cross dispersion direction. In this paper, we summarize the supplementary knowledge that will be useful for the advanced data reduction procedures of NIR spectroscopic datasets.

Sakon, Itsuki; Onaka, Takashi; Ootsubo, Takafumi; Matsuhara, Hideo; Noble, Jennifer

2012-09-01

284

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

NASA Astrophysics Data System (ADS)

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

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

1991-06-01

285

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

286

Chiral ALGEBRAS—TWO Examples  

NASA Astrophysics Data System (ADS)

We examine the chiral algebras of quotient superconformal theories by studying two examples: the SO(n) HSS models and the models based on the SU(n) group. We study the automorphism group which identifies fields in each model, and its fixed-point fields. We calculate the Poincare polynomial for the SU(n) example, see whether there are duality relations and find new Landau-Ginzburg scalar theories. For the second example we explain how to calculate the number of fields in the algebra and show a duality relation by giving the duality map explicitly.

Cohen, Ron

287

CSP spectroscopic classifications of optical transients  

NASA Astrophysics Data System (ADS)

Carnegie Supernova Project reports four spectroscopic classifications using optical spectra obtained with the Nordic Optical Telescope (+Alfosc) and the Las Campanas Observatory du Pont Telescope (+WFCCD).

Morrell, N.; Hsiao, E. Y.; Stritzinger, M.; Taddia, F.; Hadjiyska, E.; Walker, E. S.; Rabinowitz, D.; Baltay, C.; Ellman, N.; McKinnon, R.; Feindt, U.; Nugent, P.

2013-04-01

288

Laser spectroscopic measurement of helium isotope ratios.  

SciTech Connect

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

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

2003-06-13

289

Spectroscopic evaluation of time-resolved fluoroimmunoassay  

NASA Astrophysics Data System (ADS)

The lanthanide trivalence ion and its chelates are used for marking substance in time-resolved fluorescence immunoassay(TRFIA), marking the protein, hormone, antibody, nucleic acid probe or biologic alive cell, to measure the concentration of the analysis substance inside the reaction system with time-resolved fluorometry after the reaction system occurred, and attain the quantitative analysis's purpose. TRFIA has been therefore become a kind of new and more sensitive measure method after radioisotope marking, enzymatic marking, chemiluminescence, electrochemiluminescence, it primarily is decided by the special physics and chemistry characteristic of lanthanide trivalence ion and its chelates. In this paper, the result of spectroscopic evaluation of europium trivalence ion and its chelate, and the principle of time-resolved technology and fluorescence-enhanced technology is reported. At the same time, the experiment shows that excitation wavelength chosen between 336 and 337nm benefits the excitation and the energy transfer of chelate diketone of europium trivalence ion.

Guo, Zhouyi; Tian, Zhen; Jia, Yali

2003-12-01

290

Spectroscopic Properties of Chlorophyll f.  

PubMed

The absorption and fluorescence spectra of chlorophyll f (newly discovered in 2010) have been measured in acetone and methanol at different temperatures. The spectral analysis and assignment are compared with the spectra of chlorophyll a and d under the same experimental conditions. The spectroscopic properties of these chlorophylls have further been studied by the aid of density functional CAM-B3LYP and high-level symmetric adapted coupled-cluster configuration interaction calculations. The main Q and Soret bands and possible sidebands of chlorophylls have been determined. The photophysical properties of chlorophyll f are discussed. PMID:23614570

Li, Yaqiong; Cai, Zheng-Li; Chen, Min

2013-05-06

291

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

292

A Drug Supply Chain Example  

Center for Drug Evaluation (CDER)

Text Version... Pharmacy or Hospital Patient (Primary) Wholesaler Distributor Repackager (Secondary) A Drug Supply Chain Example From Supplier to Patient More results from www.fda.gov/downloads/drugs/drugsafety

293

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

294

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

295

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

296

Spectroscopic evidence for helicity in explosive events  

NASA Astrophysics Data System (ADS)

Aims: We report spectroscopic observations in support of a novel view of transition region explosive events, observations that lend empirical evidence that at least in some cases explosive events may be nothing else but spinning narrow spicule-like structures. Methods: Our spectra of textbook explosive events with simultaneous Doppler flow of a red and a blue component are extreme cases of high spectroscopic velocities that lack apparent motion, to be expected if interpreted as a pair of collimated, linearly moving jets. The awareness of this conflict led us to the alternative interpretation of redshift and blueshift as a spinning motion of a small plasma volume. In contrast to the bidirectional jet scenario, a small volume of spinning plasma would be fully compatible with the observation of flows without detectable apparent motion. We suspect that these small volumes could be spicule-like structures and try to find evidence for this. We show observations of helical motion in macrospicules and argue that these features - if scaled down to a radius comparable to the slit size of a spectrometer - should have a spectroscopic signature similar to that observed in explosive events, which is admittedly not easily detectable by imagers. Despite of this difficulty, evidence of helicity in spicules has been reported in the literature. This led us to the new insight that the same narrow spinning structures may be the drivers in both cases, structures that imagers observe as spicules and that in spectrometers cross the slit and are seen as explosive events. Results: We arrive at a concept that supports the idea that explosive events and spicules are different manifestations of the same helicity-driven scenario. In contrast to the conventional view of explosive events as linear bidirectional jets that are triggered by a reconnection event in the transition region, this new interpretation is compatible with the observational results. Consequently, in this case a photospheric or subphotospheric trigger has to be assumed. Conclusions: We suggest that explosive events/spicules are to be compared to the unwinding of a loaded torsional spring.

Curdt, W.; Tian, H.

2011-08-01

297

The Spectroscopic Diversity of Type Ia Supernovae  

NASA Astrophysics Data System (ADS)

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 ?6355 line, we propose improved methods for measuring velocity gradients, revealing a larger range than previously suspected, from ~0 to ~400 km s-1 day-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 ?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 ~4700 Å and ?m 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. Based in part on observations obtained at the F. L. Whipple Observatory, which is operated by the Smithsonian Astrophysical Observatory, the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona, and with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Blondin, S.; Matheson, T.; Kirshner, R. P.; Mandel, K. S.; Berlind, P.; Calkins, M.; Challis, P.; Garnavich, P. M.; Jha, S. W.; Modjaz, M.; Riess, A. G.; Schmidt, B. P.

2012-05-01

298

New Electrocatalysts by Combinatorial Methods  

NASA Astrophysics Data System (ADS)

Combinatorial methods provide a means for accelerating the discovery of fuel cell catalysts. The first example of parallel fuel cell catalysts screening was an indirect method that used fluorescent chemosensors to detect changes in pH in proximity to electrocatalyst spots. Serial direct electrochemical methods have been developed that use voltammetry, chronoamperometry, and scanning electrochemical microscopy. An array fuel cell screens catalysts simultaneously, using high-performance fuel cell components. Heuristic models based on mechanistic and spectroscopic studies provide guidance for library development, and detailed studies of discovered catalysts can help to refine these models. The remaining challenges are the development of high throughput synthetic methods that can enable the use of discovery level and focus level screening. Until these synthetic methods are developed, a greater emphasis should be placed on smaller libraries with design of experiment strategies leveraged with informatics and data mining.

Smotkin, Eugene S.; Diaz-Morales, Robert R.

2003-08-01

299

Some properties of spectroscopic binary stars  

SciTech Connect

The masses of the components, the mass ratio, the semiaxis of the orbit, and the orbit angular momentum have been calculated for 826 spectroscopic binary stars. The distributions of the stars with respect to these parameters and their correlations are analyzed. The dependence of the statistical properties of spectroscopic binaries on their origin and evolution is discussed.

Kraicheva, Z.T.; Popova, E.I.; Tutukov, A.V.; Yungel'son, L.R.

1978-11-01

300

Automated heuristic analysis of spectroscopic data  

Microsoft Academic Search

Spectroscopic data consists of a set of numbers which may be plotted on a graph. These numbers indicate a range of values rather than a single discrete value. It is straightforward to assign a meaning to a single value, but interpreting the meaning of a range of values requires more judgment. In nuclear physics, spectroscopic data is related to the

Hank Simon

1988-01-01

301

Spectroscopic Optical Coherence Tomography and Microscopy  

Microsoft Academic Search

Imaging biological tissues using optical coherence tomography is enhanced with spectroscopic analysis, providing new metrics for functional imaging. Recent advances in spectroscopic optical coherence tomography (SOCT) include techniques for the discrimination of endogenous tissue types and for the detection of exogenous contrast agents. In this paper, we review these techniques and their associated signal processing algorithms, while highlighting their potential

Amy L. Oldenburg; Chenyang Xu; Stephen A. Boppart

2007-01-01

302

Gradient Moment Compensated Magnetic Resonance Spectroscopic Imaging  

PubMed Central

Spectroscopic imaging applications outside of the brain can suffer from artifacts due to inherent long scan times and susceptibility to motion. A fast spectroscopic imaging sequence has been devised with reduced sensitivity to motion. The sequence uses oscillating readout gradients and acquires k-space data in a spiral out–in fashion, which allows fast k-space coverage. We show that a spiral out–in readout acquisition is characterized by small gradient moments, reducing sensitivity to motion-induced artifacts. Data are acquired comparing the sequence to normal phase encoded spectroscopic imaging and conventional spiral spectroscopic imaging protocols. In addition, in vivo data are acquired from the liver, demonstrating potential usage as a multivoxel fat/water spectroscopic imaging tool. Results indicate that in the presence of motion, ghosting effects are reduced while metabolite signal increases of approximately 10% can be achieved.

Kim, Dong-Hyun; Gu, Meng; Spielman, Daniel M.

2010-01-01

303

Spectroscopic Measurement of Air Temperature  

NASA Astrophysics Data System (ADS)

Optical dimensional measurements have to be corrected for the refractive index of air. The refractive index is conventionally calculated from parameters of ambient air using either Edlén or Ciddor equations or their modified versions. However, these equations require an accurate knowledge of ambient conditions and especially the temperature of air. For example, to reach an uncertainty of 10-7 in dimensions, the air temperature has to be known at ~100 mK level. This does not necessarily cause problems in a stable laboratory environment. However, if measurements are done outdoors or in an industrial environment, variations in temperature can be very rapid and local temperature gradients can cause significant error if not taken into account. Moreover, if the required distance is long, the temperature over the whole measurement path can be impractical or impossible to determine at sufficient temporal or spatial resolution by conventional temperature measurement techniques. The developed method based on molecular spectroscopy of oxygen allows both lateral spatial and temporal overlap of the temperature measurement with the actual distance measurement. Temperature measurement using spectroscopy is based on a line intensity ratio measurement of two oxygen absorption lines, previously applied for measurements of high temperatures in flames. The oxygen absorption band at 762 nm is a convenient choice for two-line thermometry since the line strengths are practical for short- and long-distance measurements and suitable distributed feedback lasers are commercially available. Measurements done on a 67 m path at ambient conditions demonstrate that the RMS noise of 22mK, or 7.5 × 10-5, near 293 K using 60 s measurement time can be achieved, which is to our knowledge the best reported resolution.

Hieta, T.; Merimaa, M.

2010-09-01

304

Application of a probabilistic neural network in analysis of the radial velocity curve of spectroscopic binary stars  

NASA Astrophysics Data System (ADS)

Using measured radial velocity data of five double-lined spectroscopic binary systems, HD 89959, HD 143705, HD 146361, HD 165052 and HD 152248, we find corresponding orbital and spectroscopic elements via a Probabilistic Neural Network. Our numerical results are in good agreement with those obtained by others using more traditional methods.

Ghaderi, Kamal; Karami, Kayoomars; Pirkhedri, Ali; Haj Seyyed Javadi, Hamid; Rostami, Touba

2012-12-01

305

The Nuclear Spectroscopic Telescope Array  

NASA Astrophysics Data System (ADS)

The Nuclear Spectroscopic Telescope Array is a Small Explorer (SMEX) mission scheduled for launch in August 2011. NuSTAR will be the first focusing high energy satellite sensitive in the hard X-ray band, and will probe the X-ray sky approximately two orders of magnitude more sensitively than currently achievable. NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos, and what is their contribution to the Cosmic X-ray Background? How were the heavy elements forged in the explosions of massive stars? What powers the relativistic jets in the most extreme active galaxies? This presentation will discuss the current status of NuSTAR and the baseline, 2-year science program.

Harrison, Fiona; NuSTAR Team

2010-01-01

306

Remote spectroscopic identification of bloodstains.  

PubMed

Blood detection and identification at crime scenes are crucial for harvesting forensic evidence. Unfortunately, most tests for the identification of blood are destructive and time consuming. We present a fast and nondestructive identification test for blood, using noncontact reflectance spectroscopy. We fitted reflectance spectra of 40 bloodstains and 35 nonbloodstains deposited on white cotton with spectroscopic features of the main compounds of blood. Each bloodstain was measured 30 times to account for aging effects. The outcome of the blood measurements was compared with the reflectance of blood-mimicking stains and various body fluids. We found that discrimination between blood and nonblood deposited on white cotton is possible with a specificity of 100% and a sensitivity of 98%. In conclusion, a goodness of fit between the sample's reflectance and the blood component fit may allow identification of blood at crime scenes by remote spectroscopy. PMID:21827464

Bremmer, Rolf H; Edelman, Gerda; Vegter, Tessa Dijn; Bijvoets, Ted; Aalders, Maurice C G

2011-08-09

307

Transition moment directions and selected spectroscopic properties of Ivabradine  

NASA Astrophysics Data System (ADS)

Based on the Kawski-Gryczynski method the value of angle ? = 38° between absorption and fluorescence transition moments of Ivabradine was determined. Such a high value of ? is responsible for low emission anisotropy of Ivabradine in a rigid polyvinyl alcohol matrix and in anhydrous glycerol despite the elongated shape of the fluorophore. Selected steady-state and time-resolved spectroscopic results support the analysis.

Synak, A.; Pikul, P.; Bojarski, P.; Nowakowska, J.; Wiczk, W.; ?ukaszewicz, A.; Kubicki, A. A.

2013-01-01

308

Transition moment directions and selected spectroscopic properties of Ivabradine.  

PubMed

Based on the Kawski-Gryczynski method the value of angle ?=38° between absorption and fluorescence transition moments of Ivabradine was determined. Such a high value of ? is responsible for low emission anisotropy of Ivabradine in a rigid polyvinyl alcohol matrix and in anhydrous glycerol despite the elongated shape of the fluorophore. Selected steady-state and time-resolved spectroscopic results support the analysis. PMID:23103456

Synak, A; Pikul, P; Bojarski, P; Nowakowska, J; Wiczk, W; ?ukaszewicz, A; Kubicki, A A

2012-09-28

309

Learning Word Meanings From Examples  

Microsoft Academic Search

This paper describes work in progress on a computer program that uses syntactic constraints to derive the meanings of verbs from an analysis of simple English example stories. The central idea is an extension of Winston's (Winston 1975) program that learned the structural descriptions of blocks world scenes. In the new research, English verbs take the place of blocks world

Robert C. Berwick

1983-01-01

310

Ideals into Reality: Some Examples.  

ERIC Educational Resources Information Center

|Examples of innovations in college and adult reading reading programs in five states are described. At Maricopa Technical College (Arizona) adult students have access to a special reading program emphasizing the language experience approach, capitalizing on students' life experiences and oral language facility. Otero Junior College (Colorado)…

Capuzzi, Dave; And Others

311

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

312

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

313

David Maloney's Physics Examples: Kinematics Example 12-Working Backwards  

NSDL National Science Digital Library

This item is an annotated homework problem relating to position, velocity and acceleration for introductory physics students. This item is an example of "Working Backwards", in which equations are presented, with students required to visualize and construct physical situations that could have produced the equations. This resource is intended to supplement classroom instruction and traditional text materials. It is part of a larger collection of similar physics homework problems.

Maloney, David

2009-12-04

314

Detecting dark matter substructure spectroscopically in strong gravitational lenses  

NASA Astrophysics Data System (ADS)

The cold dark matter (CDM) model for galaxy formation predicts that a significant fraction of mass in the dark matter haloes that surround L~L* galaxies is bound in substructures of mass 104-107 Msolar. The number of observable baryonic substructures (such as dwarf galaxies and globular clusters) falls short of these predictions by at least an order of magnitude. We present a method for searching for substructure in the haloes of gravitational lenses that produce multiple images of quasi-stellar objects (QSOs), such as four-image Einstein Cross lenses. Current methods based on broad-band flux ratios cannot cleanly distinguish between substructure, differential extinction, scattering in the radio by ionized regions in the lens galaxy, microlensing by stars and, most importantly, ambiguities in the host lens model. These difficulties may be overcome by utilizing the prediction that, when substructure is present, the magnification will be a function of source size. QSO broad-line and narrow-line emission regions are ~1 pc and >100 pc in size, respectively. The radio emission region is typically intermediate to these and the continuum emission region is much smaller. When narrow-line region (NLR) features are used as a normalization, the relative intensity and equivalent width of broad-line region (BLR) features will respectively reflect substructure-lensing and microlensing effects. Spectroscopic observations of just a few image pairs would probably be able to extract the desired substructure signature cleanly and distinguish it from microlensing - depending on the actual level of projected mass in substructure. In the rest-optical, the H?/[OIII] region is ideal, since the narrow wavelength range also largely eliminates differential reddening problems. In the rest-ultraviolet, the region longward of and including Ly? may also work. Simulations of Q2237+0305 are done as an example, to determine the level of substructure that is detectable in this way. Possible systematic difficulties are also discussed. This is an ideal experiment to be carried out with near-infrared integral field unit spectrographs on 8-m class telescopes, and will provide a fundamentally new probe of the internal structure of dark matter haloes.

Moustakas, Leonidas A.; Metcalf, R. Benton

2003-03-01

315

Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection  

SciTech Connect

The ability to monitor the integrity of gas volumes is of interest to the stockpile surveillance community. Specifically, the leak detection of noble gases, at relevant concentration ranges and distinguished from other chemical species that may be simultaneously present, is particularly challenging. Aside from the laboratory-based method of gas chromatography-mass spectrometry (GC-MS), where samples may be collected by solid-phase microextraction (SPME) or cryofocusing, the other major approaches for gas-phase detection employ lasers typically operating in the mid-infrared wavelength region. While mass spectrometry can readily detect noble gases - the helium leak detector is an obvious example - laser-based methods such as infrared (IR) or Raman spectroscopy are completely insensitive to them as their monatomic nature precludes a non-zero dipole moment or changes in polarizability upon excitation. Therefore, noble gases can only be detected by one of two methods: (1) atomic emission spectroscopies which require the generation of plasmas through laser-induced breakdown, electrical arcing, or similar means; (2) non-spectroscopic methods which measure one or more physical properties (e.g., mass, thermal conductivity, density). In this report, we present our progress during Fiscal Year 2011 (FY11) in the research and development of a non-spectroscopic method for noble gas detection. During Fiscal Year 2010 (FY10), we demonstrated via proof-of-concept experiments that the combination of thermal conductivity detection (TCD) and coating-free damped resonance detection (CFDRD) using micro-electromechanical systems (MEMS) could provide selective sensing of these inert species. Since the MEMS-based TCD technology was directly adapted from a brassboard prototype commissioned by a previous chemical sensing project, FY11 efforts focused on advancing the state of the newer CFDRD method. This work, guided by observations previously reported in the open literature, has not only resulted in a substantially measureable increase in selectivity but has also revealed a potential method for mitigating or eliminating thermal drift that does not require a secondary reference sensor. The design of an apparatus to test this drift compensation scheme will be described. We will conclude this report with a discussion of planned efforts in Fiscal Year 2012 (FY12).

Loui, A; McCall, S K

2011-10-24

316

Spectroscopic characterization of III-V semiconductor nanomaterials  

NASA Astrophysics Data System (ADS)

III-V semiconductor materials form a broad basis for optoelectronic applications, including the broad basis of the telecom industry as well as smaller markets for high-mobility transistors. In a somewhat analogous manner as the traditional silicon logic industry has so heavily depended upon process manufacturing development, optoelectronics often relies instead on materials innovations. This thesis focuses particularly on III-V semiconductor nanomaterials, detailed characterization of which is invaluable for translating the exhibited behavior into useful applications. Specifically, the original research described in these thesis chapters is an investigation of semiconductors at a fundamental materials level, because the nanostructures in which they appear crystallize in quite atypical forms for the given semiconductors. Rather than restricting the experimental approaches to any one particular technique, many different types of optical spectroscopies are developed and applied where relevant to elucidate the connection between the crystalline structure and exhibited properties. In the first chapters, for example, a wurtzite crystalline form of the prototypical zincblende III-V binary semiconductor, GaAs, is explored through polarization-dependent Raman spectroscopy and temperature-dependent photoluminescence, as well as second-harmonic generation (SHG). The altered symmetry properties of the wurtzite crystalline structure are particularly evident in the Raman and SHG polarization dependences, all within a bulk material realm. A rather different but deeply elegant aspect of crystalline symmetry in GaAs is explored in a separate study on zincblende GaAs samples quantum-confined in one direction, i.e. quantum well structures, whose quantization direction corresponds to the (110) direction. The (110) orientation modifies the low-temperature electron spin relaxation mechanisms available compared to the usual (001) samples, leading to altered spin coherence times explored through a novel spectroscopic technique first formulated for the rather different purpose of dispersion engineering for slow-light schemes. The frequency-resolved technique combined with the unusual (110) quantum wells in a furthermore atypical waveguide experimental geometry has revealed fascinating behavior of electron spin splitting which points to the possibility of optically orienting electron spins with linearly polarized light---an experimental result supporting a theoretical description of the phenomenon itself only a few years old. Lastly, to explore a space of further-restricted dimensionality, the final chapters describe InP semiconductor nanowires with dimensions small enough to be considered truly one-dimensional. Like the bulk GaAs of the first few chapters, the InP nanowires here crystallize in a wurtzite structure. In the InP nanowire case, though, the experimental techniques explored for characterization are temperature-dependent time-integrated photoluminescence at the single-wire level (including samples with InAsP insertions) and time-resolved photoluminescence at the ensemble level. The carrier dynamics revealed through these time-resolved studies are the first of their kind for wurtzite InP nanowires. The chapters are thus ordered as a progression from three (bulk), to two (quantum well), to one (nanowire), to zero dimensions (axially-structured nanowire), with the uniting theme the emphasis on connecting the semiconductor nanomaterials' crystallinity to its exhibited properties by relevant experimental spectroscopic techniques, whether these are standard methods or effectively invented for the case at hand.

Crankshaw, Shanna Marie

317

Spectroscopic characteristics of polar plumes  

NASA Astrophysics Data System (ADS)

Extreme ultraviolet observations of plumes in polar coronal holes are presented and their spectroscopic signatures discussed. The study focuses on the base of plumes seen on the disk of the Sun with the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) satellite. Spectroscopic diagnostic techniques are applied to characterise the plumes in terms of density, temperature, emission measure and element abundance. Attention is drawn to the particular limitations of some of the techniques when applied to plume structures. In particular, we revisit the Widing & Feldman (1992) findings of a plume having a large first ionization potential (FIP) effect of 10, showing that instead the Skylab data are consistent with no FIP effect. We present for the first time CDS-GIS (grazing incidence spectrometer) observations of a plume. These observations have been used to confirm the results obtained from normal incidence (NIS) observations. We find that polar plumes exhibit the same characteristics as the Elephant's Trunk equatorial plume. The most striking characteristic of the plume bases is that they are near-isothermal with a peak emission measure at transition region temperatures =~ 8 x 105 K. At these temperatures, plumes have averaged densities Nlo {e} =~ 1.2 x 109 cm-3, about twice the value of the surrounding coronal hole region. Element abundances in the plumes are found to be close to photospheric, with the exception of neon which appears to be depleted by 0.2 dex relative to oxygen. The absence of a significant FIP effect in plumes is consistent with fast solar wind plasma, although it is not sufficient to prove a link between the two. Finally, we present a comparison between GIS spectra and the SOHO EIT (EUV Imaging Telescope) broad-band images, showing that temperatures derived from the EIT ratio technique are largely overestimated, for plumes and coronal holes. This is partly due to the fact that the so called ``Fe XII 195 Å'' and ``Fe XV 284 Å'' filters are not isothermal, and in coronal holes and plumes lower-temperature lines dominate the EIT signal.

Del Zanna, G.; Bromage, B. J. I.; Mason, H. E.

2003-02-01

318

Identification and differentiation of single cells from peripheral blood by Raman spectroscopic imaging.  

PubMed

Medical diagnosis can be improved significantly by fast, highly sensitive and quantitative cell identification from easily accessible body fluids. Prominent examples are disseminated tumor cells circulating in the peripheral blood of cancer patients. These cells are extremely rare and therefore difficult to detect. In this contribution we present the Raman spectroscopic characterization of different cells that can be found in peripheral blood such as leukocytes, leukemic cells and solid tumor cells. Leukocytes were isolated from the peripheral blood from healthy donors. Breast carcinoma derived tumor cells (MCF-7, BT-20) and myeloid leukaemia cells (OCI-AML3) were prepared from cell cultures. Raman images were collected from dried cells on calcium fluoride slides using 785 nm laser excitation. Unsupervised statistical methods (hierarchical cluster analysis and principal component analysis) were used to visualize spectral differences and cluster formation according to the cell type. With the help of supervised statistical methods (support vector machines) a classification model with 99.7% accuracy rates for the differentiation of the cells was built. The model was successfully applied to identify single cells from an independent mixture of cells based on their vibrational spectra. The classification was confirmed by fluorescence staining of the cells after the Raman measurement. PMID:20449831

Neugebauer, Ute; Clement, Joachim H; Bocklitz, Thomas; Krafft, Christoph; Popp, Jürgen

2010-08-01

319

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

SciTech Connect

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

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

2010-09-15

320

Origin of evolutionary novelty: examples from limbs.  

PubMed

Classic hypotheses of vertebrate morphology are being informed by new data and new methods. Long nascent issues, such as the origin of tetrapod limbs, are being explored by paleontologists, molecular biologists, and functional anatomists. Progress in this arena will ultimately come down to knowing how macroevolutionary differences between taxa emerge from the genetic and phenotypic variation that arises within populations. The assembly of limbs over developmental and evolutionary time offers examples of the major processes at work in the origin of novelties. Recent comparative developmental analyses demonstrate that many of the mechanisms used to pattern limbs are ancient. One of the major consequences of this phenomenon is parallelism in the evolution of anatomical structures. Studies of both the fossil record and intrapopulational variation of extant populations reveal regularities in the origin of variation. These examples reveal processes acting at the level of populations that directly affect the patterns of diversity observed at higher taxonomic levels. PMID:11921033

Shubin, Neil H

2002-04-01

321

Advanced APD-Based Spectroscopic Radiation Monitor.  

National Technical Information Service (NTIS)

In response to DOE needs, RMD, Inc. proposed to develop an advanced, spectroscopic, radiation-imaging instrument based upon recent advancements in detector technology. This research was to provide an effective solution to critical DOE remediation problems...

J. F. Christian M. Woodring

2004-01-01

322

The Role Of Negative Examples in Protein Remote Homology Detection  

Microsoft Academic Search

3 Conclusion We show that discriminative methods for remote homology detection can be applied even when no particular negative examples are given. Our results indicate that carefully selected negative examples in combination with discriminative learning techniques still provide the best performance. However, we demonstrate that large and heterogeneous negative training data can be used to build discriminative profiles with state-of-the-

Thomas Lingner; Peter Meinicke

2006-01-01

323

EOS Family: A Spectroscopic Study  

NASA Astrophysics Data System (ADS)

The Eos family detected by Hirayama in 1918 has been always considered to be compositionally homogeneous. To investigate the composition and the homogeneity of the members of this family, we started a spectroscopic survey at the European Southern Observatory (ESO) with wavelength coverage ranging from 4800 to 9200 Å. We observed 45 Eos asteroid members, which constitutes the first large survey of this family. Our results reveal the Eos objects have spectral signature characterizing the whole family: a maximum at ? ˜ 8000-8500 Å and a reflectivity gradient spanning a continuous range. Only two of the 45 investigated objects seem to be interlopers. While the lower range of this spectral distribution has been easily connected with CO-CV chondrites, we have found no satisfactory meteorite counterpart to the upper range. We have interpreted the spread out of Eos spectra to be the results of compositional variation among the Eos members, implying that the Eos parent body was partially differentiated. Moreover, a space weathering effect has been proven to be present, but with a minor role played in the diversity of Eos family, the major role being the compositional variation.

Doressoundiram, A.; Barucci, M. A.; Fulchignoni, M.; Florczak, M.

1998-01-01

324

Adaptive optics photoacoustic spectroscopic imaging  

NASA Astrophysics Data System (ADS)

For decreasing wavefront error and obtaining higher resolution image of biological tissues, an adaptive optics photoacoustic spectroscopic imaging (AOPSI) system is proposed in this paper. In this system, an adaptive optics (AO) sub-system consisting of a Shack-Hartmann wavefront sensor (SHWS) and a liquid crystal on silicon (LCOS) is designed to correct the wavefront aberration of the illuminating light for getting high resolution image. The photoacoustic (PA) signals of AOPSI generated by irradiating the sample with a tunable optical parametric oscillator (OPO) lasers emitting light at 680-950 nm are received by a broadband ultrasound transducer. The received data are rearranged according to the wavelength sequences and decoded for image reconstruction. Moreover, the PA spectroscopy is used to obtain different wavelength PA images, with which one can accurately distinguish organization structures and identify organizational components, etc. The final simulation results demonstrated that when the wavefront errors were corrected by the AO system, the AOPSI images showed significant quality improvement which will be helpful to enhance the ability and application of PA imaging.

Jian, Xiaohua; Cui, Yaoyao; Xiang, Yongjia; Han, Zhile; Gu, Tianming; Lv, Tiejun

2013-01-01

325

NIRSPEC brown dwarf spectroscopic survey  

NASA Astrophysics Data System (ADS)

The NIRSPEC Brown Dwarf Spectroscopic Survey is a project to obtain a consistent set of high-quality near-IR spectra for each spectral class and sub-class of low-mass and/or sub- stellar objects to provide a new data base for models of the atmosphere of brown dwarfs and extra-solar giant planets. Most of the current targets are L-dwarfs and T-dwarfs discovered by the 2MASS. The survey is begin performed with the recently-commissioned near-IR spectrometer, NIRSPEC, a 1-5 micrometers cryogenic spectrograph at the WM Keck Observatory on Mauna Kea, using resolving powers of R equals 2,500-25,000. Preliminary results for four sources, three L-dwarfs and one T-dwarf, are presented here. Spectra from 1.13-2.33 micrometers at an average resolution of R equals 2,500 illustrate the development of deep steam bands and the weakening of FeH through the L-sequence, and the emergence of methane bands in the T-dwarfs. Complex detail in the spectra are the result of blending of numerous unresolved molecular transitions.

Wilcox, Mavourneen K.; McLean, Ian S.; Becklin, Eric E.; Figer, Donald F.; Gilbert, Andrea M.; Graham, James R.; Larkin, James E.; Levenson, N. A.; Teplitz, Harry I.; Kirkpatrick, J. D.; Burgasser, Adam J.

2000-06-01

326

Spectroscopic study of carbaryl sorption on smectite from aqueous suspension.  

PubMed

Sorption of carbaryl (1-naphthyl-N-methyl-carbamate) from aqueous suspension to smectite was studied using Fourier transform infrared (FTIR), high-performance liquid chromatography (HPLC) (for batch sorption), and quantum chemical methods. The amount of carbaryl sorbed was strongly dependent on the surface-charge density of the smectite with more sorption occurring on the two "low" surface-charge density smectites (SHCa-1 and SWy-2) compared to that of the high surface-charge SAz-1 smectite. In addition, the amount of carbaryl sorbed was strongly dependent on the nature of the exchangeable cation and followed the order of Ba approximately Cs approximately Ca > Mg approximately K > Na approximately Li for SWy-2. A similartrend was found for hectorite (SHCa-1) of Cs > Ba > Ca > K approximately Mg > Na approximately Li. Using the shift of the carbonyl stretching band as an indicator of the strength of interaction between carbaryl and the exchangeable cation, the observed order was Mg > Ca > Ba approximately K > Na > Cs. The position of the carbonyl stretching band shifted to lower wavenumbers with increasing ionic potential of the exchangeable cation. Density functional theory predicted a cation-induced lengthening of the C=O bond, resulting from the carbonyl group interacting directly with the exchangeable cation in support of the spectroscopic observations. Further evidence was provided by a concomitant shift in the opposite direction by several vibrational bands in the 1355-1375 cm(-1) region assigned to stretching bands of the carbamate N-Ccarbonyl and Oether-Ccarbonyl bonds. These data indicate that carbaryl sorption is due, in part, to site-specific interactions between the carbamate functional group and exchangeable cations, as evidenced by the FTIR data. However, these data suggest that hydrophobic interactions also contribute to the overall amount of carbaryl sorbed. For example, the FTIR data indicated thatthe weakest interaction occurred when Cs+ was the exchangeable cation. In contrast, the highest amount of carbaryl sorption was observed on Cs-exchanged smectite. Of all the cations studied, Cs has the lowest enthalpy of hydration. It is suggested that this low hydration energy provides the carbaryl with greater access to the hydrophobic regions of the siloxane surface. PMID:16382933

de Oliveira, Maurilio Fernandes; Johnston, Cliff T; Premachandra, G S; Teppen, Brian J; Li, Hui; Laird, David A; Zhu, Dongqiang; Boyd, Stephen A

2005-12-01

327

EXAMPLES OF RADIATION SHIELDING MODELS  

SciTech Connect

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

Willison, J

2006-07-27

328

Infrared spectroscopic ellipsometry in semiconductor manufacturing  

NASA Astrophysics Data System (ADS)

Infrared spectroscopic ellipsometry (IRSE) metrology is an emerging technology in semiconductor production environment. Infineon Technologies SC300 implemented the first worldwide automated IRSE in a class 1 clean room in 2002. Combining properties of IR light -- large wavelength, low absorption in silicon -- with a short focus optics -- no backside reflection -- which allow model-based analysis, a large number of production applications were developed. Part of Infineon IRSE development roadmap is now focused on depth monitoring for arrays of 3D dry-etched structures. In trench DRAM manufacturing, the areal density is high, and critical dimensions are much lower than mid-IR wavelength. Therefore, extensive use of effective medium theory is made to model 3D structures. IR-SE metrology is not limited by shrinking critical dimensions, as long as the areal density is above a specific cut-off value determined by trenches dimensions, trench-filling and surrounding materials. Two applications for depth monitoring are presented. 1D models were developed and successfully applied to the DRAM trench capacitor structures. Modeling and correlation to reference methods are shown as well as dynamic repeatability and gauge capability results. Limitations of the current tool configuration are reviewed for shallow structures.

Guittet, Pierre-Yves; Mantz, Ulrich; Weidner, Peter; Stehle, Jean-Louis; Bucchia, Marc; Bourtault, Sophie; Zahorski, Dorian

2004-05-01

329

Spectroscopic generalized ellipsometry based on fourier analysis.  

PubMed

The extension of a spectroscopic ellipsometer that consists of a fixed polarizer, a rotating polarizer, a sample, and a fixed analyzer (PRPSE) to generalized ellipsometry to determining the generalized ellipsometric angles and the optical functions of an anisotropic medium is reported. The PRPSE configuration eliminates the polarization sensitivity of the light source. A general numerical technique has been derived to characterize the optical properties of the anisotropic material without intermediate generalized ellipsometric angles. The proposed method is experimentally verified for uniaxial mercuric iodide. The ordinary and the extraordinary refractive and absorption indices, respectively, N(o) = n(o)--ik(o) and N(e) = n(e)--ik(e), can be extracted directly from the Fourier coefficients measured by the PRPSE on a HgI(2) crystal face that contains the optical axis. The orientations of the optical axis with respect to the plane of incidence were also determined by direct analysis of the measured Fourier coefficients. Measurements were made of reflection across a spectral range of 1.5-4.13 eV at one angle of incidence (Phi = 70 degrees ) for several azimuths phi of the optical axis with respect to the plane of incidence. The generalized ellipsometric angles were obtained from numerical inversion by changes of both polarizer and analyzer azimuth angles P and A. PMID:18323969

En Naciri, A; Johann, L; Kleim, R

1999-08-01

330

Example Procedures for Developing Acceptance-Range Criteria for BESTEST-EX  

Microsoft Academic Search

This document provides an example procedure for establishing acceptance-range criteria to assess results from software undergoing BESTEST-EX. This example method for BESTEST-EX is a modified version of the method described in HERS BESTEST.

R. Judkoff; B. Polly; M. Bianchi; J. Neymark

2010-01-01

331

Face detection by learning from positive examples  

NASA Astrophysics Data System (ADS)

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

Li, Shijin; Lu, Jianfeng; Yang, Jingyu

2000-10-01

332

EEL spectroscopic tomography: towards a new dimension in nanomaterials analysis.  

PubMed

Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe(x)Co((3-x))O(4)@Co(3)O(4) mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. PMID:22974761

Yedra, Lluís; Eljarrat, Alberto; Arenal, Raúl; Pellicer, Eva; Cabo, Moisés; López-Ortega, Alberto; Estrader, Marta; Sort, Jordi; Baró, Maria Dolors; Estradé, Sònia; Peiró, Francesca

2012-07-24

333

Semiclassical mean-trajectory approximation for nonlinear spectroscopic response functions.  

PubMed

Observables in nonlinear and multidimensional infrared spectroscopy may be calculated from nonlinear response functions. Numerical challenges associated with the fully quantum-mechanical calculation of these dynamical response functions motivate the development of semiclassical methods based on the numerical propagation of classical trajectories. The Herman-Kluk frozen Gaussian approximation to the quantum propagator has been demonstrated to produce accurate linear and third-order spectroscopic response functions for thermal ensembles of anharmonic oscillators. However, the direct application of this propagator to spectroscopic response functions is numerically impractical. We analyze here the third-order response function with Herman-Kluk dynamics with the two related goals of understanding the origins of the success of the approximation and developing a simplified representation that is more readily implemented numerically. The result is a semiclassical approximation to the nth-order spectroscopic response function in which an integration over n pairs of classical trajectories connected by distributions of discontinuous transitions is collapsed to a single phase-space integration, in which n continuous trajectories are linked by deterministic transitions. This significant simplification is shown to retain a full description of quantum effects. PMID:19045039

Gruenbaum, Scott M; Loring, Roger F

2008-09-28

334

Spectroscopic features of cytochrome P450 reaction intermediates  

PubMed Central

Preface Cytochromes P450 constitute a broad class of heme monooxygenase enzymes with more than 11,500 isozymes which have been identified in organisms from all biological kingdoms [1]. These enzymes are responsible for catalyzing dozens chemical oxidative transformations such as hydroxylation, epoxidation, N-demethylation, etc., with very broad range of substrates [2-3]. Historically these enzymes received their name from ‘pigment 450’ due to the unusual position of the Soret band in UV-Vis absorption spectra of the reduced CO-saturated state [4-5]. Despite detailed biochemical characterization of many isozymes, as well as later discoveries of other ‘P450-like heme enzymes’ such as nitric oxide synthase and chloroperoxidase, the phenomenological term ‘cytochrome P450’ is still commonly used as indicating an essential spectroscopic feature of the functionally active protein which is now known to be due to the presence of a thiolate ligand to the heme iron [6]. Heme proteins with an imidazole ligand such as myoglobin and hemoglobin as well as an inactive form of P450 are characterized by Soret maxima at 420 nm [7]. This historical perspective highlights the importance of spectroscopic methods for biochemical studies in general, and especially for heme enzymes, where the presence of the heme iron and porphyrin macrocycle provides rich variety of specific spectroscopic markers available for monitoring chemical transformations and transitions between active intermediates of catalytic cycle.

Luthra, Abhinav; Denisov, Ilia G.; Sligar, Stephen G.

2010-01-01

335

QUANTIFYING PHOTOMETRIC REDSHIFT ERRORS IN THE ABSENCE OF SPECTROSCOPIC REDSHIFTS  

SciTech Connect

Much of the science that is made possible by multiwavelength redshift surveys requires the use of photometric redshifts. But as these surveys become more ambitious, and as we seek to perform increasingly accurate measurements, it becomes crucial to take proper account of the photometric redshift uncertainties. Ideally the uncertainties can be directly measured using a comparison with spectroscopic redshifts, but this may yield misleading results since spectroscopic samples are frequently small and not representative of the parent photometric samples. We present a simple and powerful empirical method to constrain photometric redshift uncertainties in the absence of spectroscopic redshifts. Close pairs of galaxies on the sky have a significant probability of being physically associated and therefore of lying at nearly the same redshift. The difference in photometric redshifts in close pairs is therefore a measure of the redshift uncertainty. Some observed close pairs will arise from chance projections along the line of sight, but it is straightforward to perform a statistical correction for this effect. We demonstrate the technique using both simulated data and actual observations, and discuss how its usefulness can be limited by the presence of systematic photometric redshift errors. Finally, we use this technique to show how photometric redshift accuracy can depend on galaxy type.

Quadri, Ryan F.; Williams, Rik J., E-mail: quadri@strw.leidenuniv.n [Leiden Observatory, Leiden University, NL-2300 RA, Leiden (Netherlands)

2010-12-10

336

QUANTIFYING THE BIASES OF SPECTROSCOPICALLY SELECTED GRAVITATIONAL LENSES  

SciTech Connect

Spectroscopic selection has been the most productive technique for the selection of galaxy-scale strong gravitational lens systems with known redshifts. Statistically significant samples of strong lenses provide a powerful method for measuring the mass-density parameters of the lensing population, but results can only be generalized to the parent population if the lensing selection biases are sufficiently understood. We perform controlled Monte Carlo simulations of spectroscopic lens surveys in order to quantify the bias of lenses relative to parent galaxies in velocity dispersion, mass axis ratio, and mass-density profile. For parameters typical of the SLACS and BELLS surveys, we find (1) no significant mass axis ratio detection bias of lenses relative to parent galaxies; (2) a very small detection bias toward shallow mass-density profiles, which is likely negligible compared to other sources of uncertainty in this parameter; (3) a detection bias toward smaller Einstein radius for systems drawn from parent populations with group- and cluster-scale lensing masses; and (4) a lens-modeling bias toward larger velocity dispersions for systems drawn from parent samples with sub-arcsecond mean Einstein radii. This last finding indicates that the incorporation of velocity-dispersion upper limits of non-lenses is an important ingredient for unbiased analyses of spectroscopically selected lens samples. In general, we find that the completeness of spectroscopic lens surveys in the plane of Einstein radius and mass-density profile power-law index is quite uniform, up to a sharp drop in the region of large Einstein radius and steep mass-density profile, and hence that such surveys are ideally suited to the study of massive field galaxies.

Arneson, Ryan A.; Brownstein, Joel R.; Bolton, Adam S., E-mail: arnesonr@uci.edu, E-mail: joelbrownstein@astro.utah.edu, E-mail: bolton@astro.utah.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)

2012-07-01

337

Asymptotic safety: A simple example  

NASA Astrophysics Data System (ADS)

We use the Gross-Neveu model in 2example for Weinberg’s asymptotic safety scenario: despite being perturbatively nonrenormalizable, the model defines an interacting quantum field theory being valid to arbitrarily high momentum scales owing to the existence of a non-Gaussian fixed point. Using the functional renormalization group, we study the uv behavior of the model in both the purely fermionic as well as a partially bosonized language. We show that asymptotic safety is realized at non-Gaussian fixed points in both formulations, the universal critical exponents of which we determine quantitatively. The partially bosonized formulation allows to make contact to the large-Nf expansion where the model is known to be renormalizable to all orders. In this limit, the fixed-point action as well as all universal critical exponents can be computed analytically. As asymptotic safety has become an important scenario for quantizing gravity, our description of a well-understood model is meant to provide for an easily accessible and controllable example of modern nonperturbative quantum field theory.

Braun, Jens; Gies, Holger; Scherer, Daniel D.

2011-04-01

338

MR Spectroscopy and Spectroscopic Imaging of the Brain  

PubMed Central

Magnetic resonance spectroscopy (MRS) and the related technique of magnetic resonance spectroscopic imaging (MRSI) are widely used in both clinical and preclinical research for the non-invasive evaluation of brain metabolism. They are also used in medical practice, although their ultimate clinical value continues to be a source of discussion. This chapter reviews the general information content of brain spectra and commonly used protocols for both MRS and MRSI and also touches on data analysis methods and quantitation. The main focus is on proton MRS for application in humans, but many of the methods are also applicable to other nuclei and studies of animal models as well.

Zhu, He; Barker, Peter B.

2012-01-01

339

Assessing tree and stand biomass: a review with examples and ...  

Treesearch

Source: Forest Science. ... Subsampling methods on trees to derive unbiased weight estimates are examined, and ratio and difference ... This paper reviews quantitative principles and gives specific examples for prediction of tree biomass.

340

Spectroscopic studies (FTIR, FT-Raman and UV), potential energy surface scan, normal coordinate analysis and NBO analysis of (2R,3R,4R,5S)-1-(2-hydroxyethyl)-2-(hydroxymethyl) piperidine-3,4,5-triol by DFT methods.  

PubMed

This work presents the characterization of (2R,3R,4R,5S)-1-(2-hydroxyethyl)-2-(hydroxymethyl)piperidine-3,4,5-triol (abbreviated as HEHMPT) by quantum chemical calculations and spectral techniques. The spectroscopic properties were investigated by FT-IR, FT-Raman and UV-Vis techniques. The FT-IR spectrum (4000-400 cm(-1)) and FT-Raman spectrum (4000-100 cm(-1)) in solid phase was recorded for HEHMPT. The UV-Vis absorption spectrum of the HEHMPT that dissolved in water was recorded in the range of 100-400 nm. The structural and spectroscopic data of the molecule were obtained from B3LYP and M06-2X with 6-31G(d,p) basis set calculations. The theoretical wavenumbers were scaled and compared with experimental FT-IR and FT-Raman spectra. The complete assignments were performed on the basis of the normal co-ordinate analysis (NCA), experimental results and potential energy distribution (PED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method, interpreted in terms of fundamental modes. The stable geometry of the compound has been determined from the potential energy surface scan. The stability of molecule has been analyzed by NBO analysis. The molecule orbital contributions were studied by using the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. The electronic properties like UV spectral analysis and HOMO-LUMO energies were reported. The calculated HOMO and LUMO energies shows that charge transfer interactions taking place within the molecule. Mulliken population analysis on atomic charges is also calculated. PMID:23454843

Isac Paulraj, E; Muthu, S

2013-02-06

341

The Structuring of Personal Example Spaces  

ERIC Educational Resources Information Center

|This paper elaborates the notion of a personal example space as the set of mathematical objects and construction techniques that a learner has access to as examples of a concept while working on a given task. This is different from the conventional space of examples that is represented by the worked examples and exercises in textbooks. We refer…

Sinclair, Nathalie; Watson, Anne; Zazkis, Rina; Mason, John

2011-01-01

342

Examples in Legal Reasoning: Legal Hypotheticals  

Microsoft Academic Search

This paper discusses examples, particularly hypotheticals, their use and generation, in legal reasoning. It examines the use of sequences of hypotheticals. I INTRODUCTION In the legal domain, as in many others like mathematics, linguistics and computer science, examples are crucial to reasoning. In the law, cases play the role of examples; many of the examples considered are \\

Edwina L. Rissland

1983-01-01

343

On the DMSO-dissolved state of insulin: a vibrational spectroscopic study of structural disorder.  

PubMed

Upon dissolving in dimethyl sulfoxide (DMSO), native insulin and insulin amyloid fibrils convert into an identical disordered structural state based on IR spectral characteristics. Here, we investigate the DMSO-denatured state of insulin using a number of spectroscopic methods: near-UV circular dichroism, infrared absorption spectroscopy, vibrational circular dichroism (VCD), Raman scattering, and Raman optical activity (ROA), as well as by carrying out 140-ns-long molecular dynamics (MD) simulations of DMSO-dissolved native insulin monomers. According to this work, the DMSO-solvated state of insulin is an ensemble of conformations including polyproline II-type helix and possibly a residual ?-helical structure. Effects of DMSO-specific solvation and conformation-restricting covalent structure of insulin (including the three intact disulfide bridges) are argued to play important roles in stabilizing the disordered state of the protein. A comparison of ROA spectra of insulin dissolved in fully deuterated and nondeuterated DMSO suggested transfer of chirality from the protein to the otherwise ROA-silent solvent. Our study provides an example of a biological protein that acquires a substantial population of PP II conformation in an entirely nonaqueous environment. The DMSO-unfolded state of insulin and its dynamics are also discussed in the context of the established link between PP II conformation and protein misfolding. PMID:22963549

Dzwolak, Wojciech; Kalinowski, Jaros?aw; Johannessen, Christian; Babenko, Viktoria; Zhang, Ge; Keiderling, Timothy A

2012-09-19

344

Complex computer based system example problem: an advanced ship combat system  

Microsoft Academic Search

A key element of research addressing development of advanced system engineering methods and tools is the demonstration and testing of evolving methods and tools using example problems. Typically these example problems are small well known systems such as the automobile cruise control. These small example problems do not provide the complexity or scope necessary to evaluate emerging methods and tools,

Nicholas E. Karangelen; NgocDung T. Hoang

1995-01-01

345

Two examples from chemical physics  

SciTech Connect

Now that parallel vector processors are replacing scalar processors as a computational tool, scientists must reexamine the efficiency of existing code. The algorithms used and the code developed on scalar machines should be replaced by codes optimized for vector and parallel machines. New codes adapted to parallel computing should be written for a whole range of problems in chemistry and physics. Because most scientific application programs are - and will probably continue to be - written in Fortran, we will have to rely on Fortran as a programming language for supercomputers. Extensions of Fortran 77, usually referred to as Fortran 8X, are being discussed. These changes - for example, operations on whole vectors expressed in one statement - would incorporate instructions tailored to machines with parallel architectures. However, we are still a long way from setting and implementing a standard for general use. In fact, the proliferation of different vector processors and architectures could create a jungle of new Fortran hybrids, a highly unsatisfactory situation.

Wallqvist, A.; Berne, B.J.; Pangali, C.

1987-05-01

346

Radiative transfer corrections for accurate spectroscopic measurements of volcanic gas emissions  

NASA Astrophysics Data System (ADS)

There is widespread use of passive remote sensing techniques to quantify trace gas column densities in volcanic plumes utilizing scattered sunlight as a light source. Examples include passive DOAS, COSPEC, and the SO2 camera. In order to calculate trace gas concentrations or volcanic emission fluxes, knowledge about the optical path through the plume is necessary. In the past, a straight photon path through the plume has always been assumed although it was known that this is not always true. Here we present the results of model studies conducted specifically to quantify the effects of realistic radiative transfer in and around volcanic plumes on ground-based remote sensing measurements of SO2. The results show that measurements conducted without additional information on average photon paths can be inaccurate under certain conditions, with possible errors spanning more than an order of magnitude. Both over and underestimation of the true column density can occur. Actual errors depend on parameters such as distance between instrument and plume, plume SO2 concentration, plume aerosol load, as well as aerosol conditions in the ambient atmosphere. As an example, a measurement conducted with an SO2 camera is discussed, the results of which can only be correctly interpreted if realistic radiative transfer is considered. Finally, a method is presented which for the first time allows the retrieval of actual average photon paths in spectroscopic (i.e. DOAS) measurements of adequate resolution. By allowing for a wavelength dependent column density during the evaluation of DOAS measurements, we show how radiative transfer effects can be corrected using information inherently available in the measured spectra, thus greatly enhancing the accuracy of DOAS measurements of volcanic emissions.

Kern, Christoph; Deutschmann, Tim; Vogel, Leif; Wöhrbach, Markus; Wagner, Thomas; Platt, Ulrich

2010-03-01

347

A Raman spectroscopic approach for the cultivation-free identification of microbes  

NASA Astrophysics Data System (ADS)

In the last years the identification of microorganisms by means of different IR and Raman spectroscopic techniques has become quite popular. Most of the studies however apply the various vibrational spectroscopic methods to bulk samples which require at least a short cultivation time of several hours. Nevertheless, bulk identification methods achieve high classification rates which enable even the discrimination between closely related strains or the distinction between resistance capabilities. However, applying micro-Raman spectroscopy with visible excitation wavelengths enables for the detection of single microorganisms. Especially for time critical process like the fast diagnosis of severe diseases or the identification of bacterial contamination on food samples or pharmaceuticals, a cultivation-free identification of bacteria is required. In doing so, we established different isolation techniques in combination with Raman spectroscopic identification. Isolating bacteria from different matrixes always has an impact on the Raman spectroscopic identification capability. Therefore, these isolation techniques have to be specially designed to fulfill the spectroscopic requirements. In total the method should enable the identification of pathogens within the first 3 hours.

Rösch, Petra; Stöckel, Stephan; Meisel, Susann; Münchberg, Ute; Kloß, Sandra; Kusic, Dragana; Schumacher, Wilm; Popp, Jürgen

2011-11-01

348

False-positive selection identified by ML-based methods: examples from the Sig1 gene of the diatom Thalassiosira weissflogii and the tax gene of a human T-cell lymphotropic virus.  

PubMed

Sexually induced gene 1 (Sig1) in the centric diatom Thalassiosira weissflogii is considered to encode a gamete recognition protein. Sorhannus (2003) analyzed nucleotide sequences of Sig1 using parsimony analysis and the maximum-likelihood (ML)-based Bayesian method for inferring positive selection at single amino acid sites and reported that positively selected sites were detected by the latter method but not by the former. He then concluded that for this type of study, the ML-based method is more reliable than parsimony analysis. Here we show that his results apparently represent false-positive cases of the ML-based method and that there is no solid evidence that this gene contains positively selected sites. We further demonstrate that in the tax gene of human T-cell lymphotropic virus type I (HTLV-I), all codon sites, including invariable sites, can be inferred as positively selected sites by the ML-based method. These observations indicate that the ML-based method may produce many false-positive sites. One of the main reasons for the occurrence of false positives is that in the ML-based method, codon sites are grouped into several categories, with different nonsynonymous/synonymous rate ratios (omegas), on a purely statistical basis, and positive selection is inferred indirectly by examining whether the average omega for each category is greater than 1. In parsimony analysis, however, the evolutionary change of nucleotides at each codon site is examined. For this reason, parsimony-based methods rarely produce false positives and are safer than ML-based methods for detecting positive selection at individual codon sites, although a large number of sequences are necessary. PMID:15014169

Suzuki, Yoshiyuki; Nei, Masatoshi

2004-03-10

349

Spectroscopic Study of Sulfates Applied to Mars  

NASA Astrophysics Data System (ADS)

Definitive evidence for sulfates on Mars has been presented in 2004, including the Mars Exploration Rover Moessbauer spectroscopic identification of jarosite in Meridiani Planum and the Mars Express OMEGA visible/near infrared spectroscopic identification of kieserite in Valles Marineris and elsewhere. In addition to Moessbauer and VIS/NIR, other spectroscopic techniques can be employed for determining which sulfate minerals are present on Mars. This study focuses on the use of the thermal infrared range of the electromagnetic spectrum and the study of sulfates using emission spectroscopy to uniquely identify sulfate minerals. The fundamental molecular vibrational modes of sulfates are present in thermal infrared spectra. These modes influence the overtones and combination bands seen in VIS/NIR data. Clearly sulfate minerals are important Martian geologic materials and, because sulfates form under diverse environmental conditions, can help understand the specific formational and chemical settings that once existed on Mars.

Lane, M. D.

2004-12-01

350

Infrared spectroscopic imaging of renal tumor tissue  

NASA Astrophysics Data System (ADS)

Fourier transform infrared (FTIR) spectroscopic imaging has been used to probe the biochemical composition of human renal tumor tissue and adjacent normal tissue. Freshly resected renal tumor tissue from surgery was prepared as a thin cryosection and examined by FTIR spectroscopic imaging. Tissue types could be discriminated by utilizing a combination of fuzzy k-means cluster analysis and a supervised classification algorithm based on a linear discriminant analysis. The spectral classification is compared and contrasted with the histological stained image. It is further shown that renal tumor cells have spread in adjacent normal tissue. This study demonstrates that FTIR spectroscopic imaging can potentially serve as a fast and objective approach for discrimination of renal tumor tissue from normal tissue and even in the detection of tumor infiltration in adjacent tissue.

Šablinskas, Valdas; Urbonien?, Vidita; Ceponkus, Justinas; Laurinavicius, Arvydas; Dasevicius, Darius; Jankevi?ius, Feliksas; Hendrixson, Vaiva; Koch, Edmund; Steiner, Gerald

2011-09-01

351

A Systems Engineering Evaluation Method for Piloted Aircraft and Other Man-Operated Vehicles and Mahcines with Hypothetical Example of a Systems Evaluation and Quantified System Performance-Workload Rating Scales.  

National Technical Information Service (NTIS)

A system evaluation method is presented which systematizes and quantifies both PRP pilot rating procedures and ECP engineering calculation procedure measures of system performance on a logarithmic ratio basis of test aircraft configurations compared to a ...

T. H. Higgins

1981-01-01

352

High resolution spectroscopic diagnostic techniques for investigation of plasmas in electrical discharges  

Microsoft Academic Search

The authors describe the investigation of pulsed power systems using recently developed spectroscopic techniques. These methods allow for nonperturbing measurements with relatively high spectral, temporal and spatial resolutions. Spatial resolution along the line of sight is obtained by locally doping the plasma with various species whose emission is then utilized. A few methods developed for doping solid and gaseous materials

R. Arad; Y. Maron

1998-01-01

353

Chapter 15 Isolation of Saccharomyces Cerevisiae Mitochondria for Mössbauer, Epr, and Electronic Absorption Spectroscopic Analyses  

Microsoft Academic Search

Methods are presented to aid in the study of iron metabolism in isolated mitochondria. The “iron?ome” of mitochondria, including the type and concentration of all Fe?containing species in the organelle, is evaluated by integrating the results of four spectroscopic methods, including Mössbauer spectroscopy, electron paramagnetic resonance, electronic absorption spectroscopy, and inductively coupled plasma mass spectrometry. Although this systems biology approach

Paul A. Lindahl; Jessica Garber Morales; Ren Miao

2009-01-01

354

False-Positive Selection Identified by ML-Based Methods: Examples from the Sig1 Gene of the Diatom Thalassiosira weissflogii and the tax Gene of a Human T-cell Lymphotropic Virus  

Microsoft Academic Search

Sexually induced gene 1 (Sig1) in the centric diatom Thalassiosira weissflogii is considered to encode a gamete recognition protein. Sorhannus (2003) analyzed nucleotide sequences of Sig1 using parsimony analysis and the maximum-likelihood (ML)-based Bayesian method for inferring positive selection at single amino acid sites and reported that positively selected sites were detected by the latter method but not by the

Yoshiyuki Suzuki; Masatoshi Nei

2004-01-01

355

Discrete quantum gravity: cosmological examples  

NASA Astrophysics Data System (ADS)

We consider the application of the 'consistent lattice quantum gravity' approach we introduced recently to the situation of a Friedmann cosmology and also to Bianchi cosmological models. This allows us to work out in detail the computations involved in the determination of the Lagrange multipliers that impose consistency of the discretized equations, and the implications of this determination. It also allows us to study the removal of the Big Bang singularity. Different discretizations can be achieved depending on the version of the classical theory chosen as a starting point and their relationships studied. We analyse in some detail how the continuum limit arises in various models. In particular, we note how remnants of the symmetries of the continuum theory are embodied in constants of the motion of the consistent discrete theory. The unconstrained nature of the discrete theory allows the consistent introduction of a relational time in quantum cosmology, free from the usual conceptual problems. The examples show that in simple settings the proposal works satisfactorily.

Gambini, Rodolfo; Pullin, Jorge

2003-08-01

356

Crystal growth, structural and spectroscopic analysis of hypoxanthinium chloride monohydrate  

NASA Astrophysics Data System (ADS)

Protonated form of hypoxanthinium chloride monohydrate single crystal has been grown from dilute hydrochloric acid. Single crystal X-ray analysis was carried out and the titled crystal belong to the monoclinic P2 1/ c space group. Hypoxanthine is protonated at N(1) with the hypoxanthine cations, linked to chlorine anion via weak bifurcated N-H⋯Cl hydrogen bonds and interconnected by hydrogen bonding contacts of the type N-H⋯O. Infrared, Raman and UV spectroscopic tools were applied to characterize hypoxanthinium chloride monohydrate. By applying group theoretical methods the internal and external modes of vibrations of the title crystal have been identified and discussed.

Kalyanaraman, S.; Krishnakumar, V.; Ganesan, K.

2007-07-01

357

Raman Spectroscopic Investigation of Dyes in Spices  

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

358

Example Elaboration as a Neglected Instructional Strategy  

SciTech Connect

Over the last decade an unfolding cognitive-psychology research program on how learners use examples to develop effective problem solving expertise has yielded well-established empirical findings. Chi et al., Renkl, Reimann, and Neubert (in various papers) have confirmed statistically significant differences in how good and poor learners inferentially elaborate (self explain) example steps as they study. Such example elaboration is highly relevant to software documentation and training, yet largely neglected in the current literature. This paper summarizes the neglected research on example use and puts its neglect in a disciplinary perspective. The author then shows that differences in support for example elaboration in commercial software documentation reveal previously over looked usability issues. These issues involve example summaries, using goals and goal structures to reinforce example elaborations, and prompting readers to recognize the role of example parts. Secondly, I show how these same example elaboration techniques can build cognitive maturity among underperforming high school students who study technical writing. Principle based elaborations, condition elaborations, and role recognition of example steps all have their place in innovative, high school level, technical writing exercises, and all promote far transfer problem solving. Finally, I use these studies to clarify the constructivist debate over what writers and readers contribute to text meaning. I argue that writers can influence how readers elaborate on examples, and that because of the great empirical differences in example study effectiveness (and reader choices) writers should do what they can (through within text design features) to encourage readers to elaborate examples in the most successful ways. Example elaboration is a uniquely effective way to learn from worked technical examples. This paper summarizes years of research that clarifies example elaboration. I then show how example elaboration can make complex software documentation more useful, improve the benefits of technical writing exercises for underperforming students, and enlighten the general discussion of how writers can and should help their readers.

Girill, T R

2001-07-18

359

Terahertz pulsed imaging in vivo: measurements and processing methods  

NASA Astrophysics Data System (ADS)

This paper presents a number of data processing algorithms developed to improve the accuracy of results derived from datasets acquired by a recently designed terahertz handheld probe. These techniques include a baseline subtraction algorithm and a number of algorithms to extract the sample impulse response: double Gaussian inverse filtering, frequency-wavelet domain deconvolution, and sparse deconvolution. In vivo measurements of human skin are used as examples, and a comparison is made of the terahertz impulse response from a number of different skin positions. The algorithms presented enables both the spectroscopic and time domain properties of samples measured in reflection geometry to be better determined compared to previous calculation methods.

Parrott, Edward P. J.; Sy, Stanley M. Y.; Blu, Thierry; Wallace, Vincent P.; Pickwell-MacPherson, Emma

2011-10-01

360

Research Methods and Methodologies for Multicultural and Cross-Cultural Issues in Art Education. Crossing Cultural, Artistic, and Cyber Borders: Issues and Examples in Art Education Conference (Tempe, Arizona, January 7-8, 2000).  

ERIC Educational Resources Information Center

|This monograph is the outgrowth of a conference that explored research concerns related to multi-cultural and cross-cultural contexts in art education. In the monograph, presentations are organized into three sections. Section 1 deals with basic research methods and methodologies, and introduces new methodological perspectives for consideration.…

La Pierre, Sharon D., Ed; Stokrocki, Mary, Ed.; Zimmerman, Enid, Ed.

361

Analog Computer Laboratory with Biological Examples.  

ERIC Educational Resources Information Center

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

Strebel, Donald E.

1979-01-01

362

Simple Perturbation Example for Quantum Chemistry.  

ERIC Educational Resources Information Center

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

Goodfriend, P. L.

1985-01-01

363

Precise radial velocities of giant stars. III. Spectroscopic stellar parameters  

NASA Astrophysics Data System (ADS)

Context: A radial velocity survey of about 380 G and K giant stars is ongoing at Lick observatory. For each star we have a high signal to noise ratio template spectrum, which we use to determine spectroscopic stellar parameters. Aims: The aim of this paper is to present spectroscopic stellar parameters, i.e. effective temperature, surface gravity, metallicity and rotational velocity for our sample of G and K giant stars. Methods: Effective temperatures, surface gravities and metallicities are determined from the equivalent width of iron lines, by imposing excitation and ionisation equilibrium through stellar atmosphere models. Rotational velocities are determined from the full width at half maximum (FWHM) of moderate spectral lines. A calibration between the FWHM and total broadening (rotational velocity and macro turbulence) is obtained from stars in common between our sample and the sample from Gray (1989, ApJ, 347, 1021). Macro turbulence is determined from the macro turbulence vs. spectral type relations from Gray (2005, The Observation and Analysis of Stellar Photospheres). Results: The metallicity we derive is essentially equal to the literature values, while the effective temperature and surface gravity are slightly higher by 56 K and 0.15 dex, respectively. A method comparison is performed with 72 giants in common with Luck & Heiter (2007, AJ, 133, 2464), which shows that both methods give similar results. Our rotational velocities are comparable with those obtained by Gray (1989, ApJ, 347, 1021), but somewhat higher than those of de Medeiros & Mayor (1999, A&AS, 139, 433), which is consistent with the different diagnostics used to determine them. Conclusions: We are able to determine spectroscopic stellar parameters for about 380 G and K giant stars uniformly (112 stars are being analysed spectroscopically for the first time). For stars available in the literature, we find reasonable agreement between literature values and values determined in the present work. In addition, we show that the metallicity enhancement of companion hosting stars might also be valid for giant stars, with the planet hosting giants being 0.13 ± 0.03 dex (i.e. 35 ± 10%) more metal rich than our total sample of stars. Based on data obtained at UCO/Lick Observatory, USA. Table 4 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/475/1003

Hekker, S.; Meléndez, J.

2007-12-01

364

Spectroscopic carbon dioxide sensor for automotive applications  

Microsoft Academic Search

In this paper, we present the first spectroscopic carbon dioxide sensor designed for automotive applications. The sensor is based on the well known infrared measurement principle. It includes a new robust infrared gas-detector and a corresponding, newly developed, ASIC. First application studies show its suitability for automatic vehicle ventilation systems and for leak detection in R744 air conditioning systems.

Michael Arndt; Maximilian Sauer

2004-01-01

365

Spectroscopic Applications of Laser-Induced Plasmas  

Microsoft Academic Search

Recent spectroscopic applications of laser-induced plasmas are reviewed. Virtually all substances are susceptible to breakdown when illuminated by a sufficiently intense laser beam. In a plasma, matter breaks apart into atoms, ions, and electrons, producing a visible flash and an audible popping sound due to the acoustical shock wave generated by the sudden, high-velocity expansion of matter outward from the

Vahid Majidi; Martha R. Joseph

1992-01-01

366

Spectroscopic ellipsometry applications in photomask technology  

Microsoft Academic Search

Development and manufacture of advanced photomasks requires understanding the optical properties of mask materials and the ability to carefully monitor and control the film thickness, refractive index, and absorption of each film layer. Spectroscopic Ellipsometry (SE), a nondestructive optical analysis technique for determination of film thickness, refractive index, absorption, and film microstructure has been applied to many applications in current

Ron A. Synowicki; James N. Hilfiker

2008-01-01

367

Spectroscopic madness - A golden age for amateurs  

Microsoft Academic Search

Today, professional instrumentation is dominated by heavily oversubscribed telescopes which focus mainly on a limited number of ``fashionable'' research topics. As a result, time acquisition for massive star research including extended observation campaigns, becomes more difficult. On the other hand, massive star investigations by amateur astronomers performing spectroscopic measurements are on a level which can fulfil professional needs. I describe

Thomas Eversberg

2011-01-01

368

Nuclear Spectroscopic Telescope Array (NuSTAR).  

National Technical Information Service (NTIS)

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing hard X-ray (5 - 80 keV) telescope to orbit. NuSTAR will offer a factor 50 - 100 sensitivity improvement compared to previous collimated ...

A. Hornstrup B. Grefenstette C. Hailey C. C. Liebe D. Stern F. Christensen F. A. Harrison G. Madejski H. J. An J. Koglin K. K. Madsen L. Angelini L. Cominsky M. Doll N. Brejnholt P. Giommi P. Mao R. Cook S. Boggs T. Kitaguchi V. Bhalereo V. M. Kaspi W. Craig W. Zhang Y. Kim

2010-01-01

369

Spectroscopic applications of the plasma dispersion function  

Microsoft Academic Search

Using as a starting point a previously published approximate expression for the spectroscopic absorption Voigt profile, an absorption-dispersion pair for mildly Gaussian lines is constructed. With this information, the full asymptotic expansion of the plasma dispersion function (PDF) is obtained for the case of Im z > 0. As shapes and widths of spectral lines contain much information about the

H. Jimenezdominguez; S. Cruz-Jiménez; A. Cabral-Prieto

1996-01-01

370

The HITRAN 2008 molecular spectroscopic database  

Microsoft Academic Search

This paper describes the status of the 2008 edition of the HITRAN molecular spectroscopic database. The new edition is the first official public release since the 2004 edition, although a number of crucial updates had been made available online since 2004. The HITRAN compilation consists of several components that serve as input for radiative-transfer calculation codes: individual line parameters for

L. S. Rothman; I. E. Gordon; A. Barbe; D. Chris Benner; P. F. Bernath; M. Birk; V. Boudon; L. R. Brown; A. Campargue; J.-P. Champion; K. Chance; L. H. Coudert; V. Dana; V. M. Devi; S. Fally; J.-M. Flaud; R. R. Gamache; A. Goldman; D. Jacquemart; I. Kleiner; N. Lacome; W. J. Lafferty; J.-Y. Mandin; S. T. Massie; S. N. Mikhailenko; C. E. Miller; N. Moazzen-Ahmadi; O. V. Naumenko; A. V. Nikitin; J. Orphal; V. I. Perevalov; A. Perrin; A. Predoi-Cross; C. P. Rinsland; M. Rotger; M. Šime?ková; M. A. H. Smith; K. Sung; S. A. Tashkun; J. Tennyson; R. A. Toth; A. C. Vandaele; J. Vander Auwera

2009-01-01

371

An Improved Diffraction Grating Spectroscope Experiment.  

ERIC Educational Resources Information Center

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

Scherzer, Robert

1995-01-01

372

Spectroscopic Properties of Alexandrite Crystals 2,  

National Technical Information Service (NTIS)

Several aspects of the optical spectroscopic properties of alexandrite crystals not previously investigated are reported. For cr (3+) ions occupying the Al (3+) lattice sites with mirror symmetry in Be-Al2O4, the positions of the zero-phonon lines for abs...

A. B. Suchocki G. D. Gilliland R. C. Powell J. M. Bowen J. C. Walling

1987-01-01

373

Rapid Flow Analysis Studies with Spectroscopic Detectors  

Microsoft Academic Search

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

Amlius Thalib

1984-01-01

374

Leading by Example and International Collective Action  

Microsoft Academic Search

This paper investigates leading by example as a policy prescription for international collective action to provide summation public goods. A country leads by example by committing to a minimal level of provision, and by matching higher contributions there beyond. In an evolutionary game-theoretic setting, we establish conditions for leading by example to be a neutrally stable strategy; i.e., to noncooperatively

ANDRÉ ROSSI DE OLIVEIRA; JOAO RICARDO FARIA

2005-01-01

375

Interactively Defining Examples to be Generalized  

Microsoft Academic Search

In a programming by demonstration system, examples pro- vided by the user are generalized to form abstractions that are used by the system. There are several reasons why the system and the user should collaborate to annotate examples with knowledge that guides generalization. These include deal- ing with inconsistencies among examples or the underlying domain theory, making queries in order

Andrew Garland

2001-01-01

376

Algebraic methods in vibrational spectroscopy  

SciTech Connect

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

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

2011-03-21

377

Spectroscopic Techniques for Atmospheric Analysis  

SciTech Connect

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

Bililign, Solomon [Department of Physics, North Carolina Agricultural and technical state University Greensboro, NC 27411 (United States)

2009-07-06

378

Earthquake data analysis: An example from Sweden  

NASA Astrophysics Data System (ADS)

Methods and results of earthquake data analysis are illustrated by the seismicity of Sweden in the period 1951-1976, summarizing a comprehensive research project for the past five years. Starting from the regional structural properties, methods are given for the evaluation of instrumental and macroseismic observations, including error analysis and source identification. The resulting earthquake distribution is investigated in relation to space (various types of seismicity mapping), time (periodicities) and magnitude (frequency-magnitude and energy-magnitude relations). The tectonophysical explanations of the earthquake origin are still subject to considerable uncertainty and can be treated only by way of discussions. The engineering applications, stimulated recently by the nuclear power industry, can be placed on much more reliable ground. They include calculations of seismic risk and fracture risk as well as investigations of certain phenomena of practical consequences, especially rockbursts. This review is primarily addressed to those who have use for seismological data in their work, especially geologists, tectonophysicists and engineers. It is important for them to realize how the seismological data are obtained, their reliability and their range of application. Sweden is here mainly used as an example, but the developed methods have a general applicability to any earthquake region, with proper modifications. In short, our purpose is two-fold: (1) to summarize recent research on the seismicity of Sweden: (2) to introduce all users of seismological data into methods and results.

Båth, Markus

1983-06-01

379

Dine on Rich Functional Examples  

ERIC Educational Resources Information Center

|Given the importance of algebra, middle school mathematics teachers have a responsibility to help students transition from understanding arithmetic to understanding the algebra that will be necessary for success in high school. One method of transition involves introducing algebraic concepts in concrete ways using meaningful contexts. The series…

Robichaux, Rebecca R.; Rodrigue, Paulette R.

2011-01-01

380

Bidelman-Parsons Spectroscopic/Bibliographic Cat (Parsons+ 1980)  

NASA Astrophysics Data System (ADS)

The Bidelman-Parsons Spectroscopic and Bibliographical Catalog (BPSB; Parsons, Buta, and Bidelman 1980a, b) contains data compiled from the astronomical literature by W. P. Bidelman. These data include diverse catalogs and lists, especially from pre-1950 journals (minor as well as major), and from pre-1962 observatory publications. From more recent years, the data on any object frequently are limited to one item with a reference; for example, a spectral type. No data published after 1973 are included. Over 200 publications are represented. The BPSB has information on 40,312 objects. The catalog contains most of the same information on MK spectral types as the Catalogue of Stellar Spectra Classified in the Morgan-Keenan System (Jaschek, Conde, and de Sierra 1964) and its updates, but it also includes such items as spectral types without a luminosity class (certainly better than nothing); spectroscopic absolute magnitudes; notes on multiplicity; notes on high proper motion or radial velocity (with the values, if probably variable, or if greater than 60 km/s); unpublished remarks and spectral types from several sources, including Bidelman and Henize; and Bidelman's preliminary identifications of many sources in the Two-Micron Sky Survey (Neugebauer and Leighton 1969). Some of the longer lists included in the catalog are those of OB stars from the Tonantzintla-Tacubaya and Heidelberg-Koenigstuhl surveys (Iriarte and Chavira 1957; Chavira 1958; Klare and Szeidl 1966); that of OB stars with emission from the Case-Hamburg surveys (Hardorp et al. 1959; Stock, Nassau, and Stephenson 1960; Hardorp, Theile, and Voigt 1964; Nassau and Stephenson 1963; Hardorp, Theile, and Voigt 1965; Nassau, Stephenson, and MacConnell 1965; Stephenson and Sanduleak 1971); and stars from the General Catalogue of Variable Stars (Kukarkin et al. 1969); and the Catalogue of Suspected Variable Stars (Kukarkin et al. 1951, 1965). Although the catalog is mainly of stellar data, it includes many galactic nebulae of various kinds. (3 data files).

Parsons, S. B.; Buta, N. S.; Bidelman, W. P.

1996-11-01

381

Conformational stability, the spectroscopic (FT-IR and UV), first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 6,8-diphenylimidazo[1,2-?]pyrazine molecule by ab initio HF and density functional methods  

NASA Astrophysics Data System (ADS)

The conformational analysis of 6,8-diphenylimidazo[1,2-?]pyrazine molecule (abbreviated as 68DIP) was performed by using B3LYP/6-31G(d) level of theory to find the most stable form. Two staggered stable conformers were observed on the torsional potential energy surface. The equilibrium geometry, bonding features and vibrational frequencies of 68DIP have been investigated by using the DFT (B3LYP) and HF methods for the lowest energy conformer. The first order hyperpolarizability ( ?total) of this molecular system and related properties ( ?, ?, < ?> and ? ?) are calculated using HF/6-311++G(d,p) and B3LYP/6-311++G(d,p) methods based on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions, charge delocalization and C-H⋯N intramolecular hydrogen-bond-like weak interaction has been analyzed using natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the ?* and ?* antibonding orbitals and second order delocalization energies E(2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. UV-vis spectrum of the compound was recorded and electronic properties, such as HOMO, LUMO energies, excitation energies and wavelength were performed by TD-DFT/B3LYP, CIS and TD-HF methods by using 6-311++G(d,p) basis set. Finally, the calculation results were applied to simulated infrared spectra of the title compound which show good agreement with observed spectra.

S?d?r, ?sa; S?d?r, Yadigar Gülseven; Kayagil, ?smail

2011-10-01

382

Spectroscopic properties of Y3TaO7 powders activated with Eu, Er and co-activated with Yb  

Microsoft Academic Search

A new synthesis method of Y3TaO7 is reported. Pure phase powders were prepared by modified Pechini technique. Precursors obtained through that route were heated at the temperature about 1000°C with or without use of Li2SO4 flux. That implicates in different morphology of specimens and also their spectroscopic properties. Eu ions were used as a spectroscopic probe to prove inhomogeneous broadening

Adam Walasek; Eugeniusz Zych; An Liqiong; Jian Zhang; Shiwei Wang

2007-01-01

383

Estimation of return periods for extreme sea levels: a simplified empirical correction of the joint probabilities method with examples from the French Atlantic coast and three ports in the southwest of the UK  

NASA Astrophysics Data System (ADS)

The joint probability method (JPM) to estimate the probability of extreme sea levels (Pugh and Vassie, Extreme sea-levels from tide and surge probability. Proc. 16th Coastal Engineering Conference, 1978, Hamburg, American Society of Civil Engineers, New York, pp 911 930, 1979) has been applied to the hourly records of 13 tide-gauge stations of the tidally dominated Atlantic coast of France (including Brest, since 1860) and to three stations in the southwest of the UK (including Newlyn, since 1916). The cumulative total length of the available records (more than 426 years) is variable from 1 to 130 years when individual stations are considered. It appears that heights estimated with the JPM are almost systematically greater than the extreme heights recorded. Statistical analysis shows that this could be due: (1) to surge tide interaction (that may tend to damp surge values that occur at the time of the highest tide levels), and (2) to the fact that major surges often occur in seasonal periods that may not correspond to those of extreme astronomical tides. We have determined at each station empirical ad hoc correction coefficients that take into account the above two factors separately, or together, and estimated return periods for extreme water levels also at stations where only short records are available. For seven long records, for which estimations with other computing methods (e.g. generalized extreme value [GEV] distribution and Gumbel) can be attempted, average estimations of extreme values appear slightly overestimated in relation to the actual maximum records by the uncorrected JPM (+16.7 ± 7.2 cm), and by the Gumbel method alone (+10.3 ± 6.3 cm), but appear closer to the reality with the GEV distribution (-2.0 ± 5.3 cm) and with the best-fitting correction to the JPM (+2.9 ± 4.4 cm). Because the GEV analysis can hardly be extended to short records, it is proposed to apply at each station, especially for short records, the JPM and the site-dependent ad hoc technique of correction that is able to give the closest estimation to the maximum height actually recorded. Extreme levels with estimated return times of 10, 50 and 100 years, respectively, are finally proposed at all stations. Because astronomical tide and surges have been computed (or corrected) in relation to the yearly mean sea level, possible changes in the relative sea level of the past, or foreseeable in the future, can be considered separately and easily added to (or deduced from) the extremes obtained. Changes in climate, on the other hand, may modify surge and tide distribution and hence return times of extreme sea levels, and should be considered separately.

Pirazzoli, Paolo Antonio; Tomasin, Alberto

2007-04-01

384

Some examples of nondestructive flaw detection by shearography  

Microsoft Academic Search

This paper presents some examples of nondestructive flaw detection using an optical method based on speckle shearing interferometry called shearography. In the method, a structure under study is illuminated by laser and imaged by a special image-shearing camera. After suitable processing, a fringe pattern which represents loci of surface displacement derivatives, i.e., strains, is observed in the image. Since defects

F. S. Chau; S. L. Toh; C. J. Tay; H. M. Shang

1989-01-01

385

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

NASA Astrophysics Data System (ADS)

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

Coanga, Jean-Maurice

2013-04-01

386

New Developments of Broadband Cavity Enhanced Spectroscopic Techniques  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

387

Denoising MR Spectroscopic Imaging Data With Low-Rank Approximations  

PubMed Central

This paper addresses the denoising problem associated with magnetic resonance spectroscopic imaging (MRSI), where signal-to-noise ratio (SNR) has been a critical problem. A new scheme is proposed, which exploits two low-rank structures that exist in MRSI data, one due to partial separability and the other due to linear predictability. Denoising is performed by arranging the measured data in in appropriate matrix forms (i.e., Casorati and Hankel) and applying low-rank approximations by singular value decomposition (SVD). The proposed method has been validated using simulated and experimental data, producing encouraging results. Specifically, the method can effectively denoise MRSI data in a wide range of SNR values while preserving spatial-spectral features. The method could prove useful for denoising MRSI data and other spatial-spectral and spatial-temporal imaging data as well.

Peng, Xi; Do, Minh N.; Liang, Zhi-Pei

2013-01-01

388

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

NASA Astrophysics Data System (ADS)

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

Flöer, L.; Winkel, B.

2012-01-01

389

Design and realization of the IP control core in field controllers for LAMOST spectroscopes  

NASA Astrophysics Data System (ADS)

The China-made telescope, LAMOST, consists of 16 spectroscopes to detect stellar spectra via 4000 optical fibers. In each spectroscope, many movable parts work in phase. Those parts are real-time controlled and managed by field controllers based on FPGA. This paper mainly introduces how to use DSP Builder module library in MATLAB / Simulink to construct the IP control core on FPGA chip. This method can also be used to design the control core of PID arithmetic, to carry out arithmetic simulation and generate VHDL language file, as well as to integrate it into SOPC developing environment so as to repeatedly use. In this way, the design period of the control system may be shortened and design process simplified. Finally due to the reversibility and programmability of the IP control core ,a system on a chip for field controllers of spectroscope is realized, which meets astronomical control requirements, providing an effective scheme for embedded system in astronomical instrument applications.

Wang, Jianing; Han, Zhongyi; Zeng, Yizhong; Dai, Songxin; Hu, Zhongwen; Zhu, Yongtian; Wang, Lei; Hou, Yonghui

2010-07-01

390

Spectroscopic determinations of solar rotation  

Microsoft Academic Search

Spectral line shift data obtained from full-disk magnetograms recorded at Mt. Wilson are analyzed for differential rotation. The method of analysis is discussed and the results from the data for 1966 through 1968 are presented. The average equatorial velocity over this period is found to be 1.93 km\\/sec or 13.76 deg\\/day (sidereal). This corresponds to a sidereal period of 26.16

Robert Howard; J. Harvey

1970-01-01

391

Combined magnetic resonance imaging and spectroscopic imaging approach to molecular imaging of prostate cancer  

Microsoft Academic Search

Magnetic resonance spectroscopic imaging (MRSI) provides a noninvasive method of detecting small molecular mark- ers (historically the metabolites choline and citrate) within the cytosol and extracellular spaces of the prostate, and is performed in conjunction with high-resolution anatomic imaging. Recent studies in pre-prostatectomy patients have indicated that the metabolic information provided by MRSI combined with the anatomical information provided by

John Kurhanewicz; Mark G. Swanson; Sarah J. Nelson; Daniel B. Vigneron

2002-01-01

392

Chemical and spectroscopic analysis of organic matter transformations during composting of pig manure  

Microsoft Academic Search

Composting of separated pig manure (SPM) was studied in an attempt to elaborate upon organic matter (OM) transformation during the process and define parameters for product maturity using both chemical and spectroscopical methods. Composting was performed in two piles and the following parameters were measured in 10 samples during 122 days of composting: temperature, ash content, C\\/N ratio, water-soluble organic

Jenn-Hung Hsu; Shang-Lien Lo

1999-01-01

393

Variability in the determination of total atmospheric ozone using remote sensing spectroscopic techniques  

Microsoft Academic Search

A spectroscopic method for optical remote sensing of total ozone (O3) is described. It involves detailed spectral matching of near ultraviolet solar observations with synthetic profiles containing various amounts of ozone absorption. Application of this technique is made to airborne solar measurements in the 3100 to 3600 Å wavelength region. In the 3100 to 3200 Å region, measurements made above

G. G. Sivjee; G. J. Romick; W. B. Murcray

1978-01-01

394

On the Mass Ratio Distribution of Single-Lined Spectroscopic Binaries  

Microsoft Academic Search

A mathematically rigorous, nonparametric statistical model is derived for the inference of mass ratio distributions from observed mass function distributions of single-lined spectroscopic binaries. The mathematical relation between these distributions is that of a deterministic integral equation, which is shown to be ill-posed and very poorly conditioned. Three nearly equivalent methods of solution of this relation are developed and demonstrated

William D. Heacox

1995-01-01

395

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

PubMed

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

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

2007-08-11

396

STM system for spectroscopic and topographic studies at liquid--helium temperatures  

SciTech Connect

A cryogenic STM system for high-sensitivity topographic and spectroscopic measurements is presented. The methods of noise suppression are discussed. The efficiency of the system is demonstrated via the imaging of gold surfaces and measurements of {ital I}--{ital V} characteristics showing Coulomb effects. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Weinstein, V.; Arenshtam, A.; Slutzky, M.; Ben-Jacob, E. [School of Physics and Astronomy, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978 (Israel)

1995-06-01

397

Proton MR Spectroscopic Findings Correspond to Neuropsychological Function in Traumatic Brain Injury  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Traumatic brain injury (TBI) causes substantial irrevers- ible damage to neurons. Our aim was to investigate whether proton MR spectroscopic measures of diffuse cellular integrity were related to neuropsychological dysfunction after TBI. METHODS: Twelve patients with TBI (mean, 53 6 23 days postinjury) and 14 control subjects were included in the study using paired MR spectroscopy and

Seth D. Friedman; William M. Brooks; Rex E. Jung; Blaine L. Hart; Ronald A. Yeo

1998-01-01

398

Spectroscopic studies on the interaction of cinnamic acid and its hydroxyl derivatives with human serum albumin  

Microsoft Academic Search

Cinnamic acid and its derivatives possess various biological effects in remedy of many diseases. Interaction of cinnamic acid and its hydroxyl derivatives, p-coumaric acid and caffeic acid, with human serum albumin (HSA), and concomitant changes in its conformation were studied using fluorescence and Fourier transform infrared spectroscopic methods. Fluorescence data revealed the presence of one binding site on HSA for

Jiang Min; Xie Meng-Xia; Zheng Dong; Liu Yuan; Li Xiao-Yu; Chen Xing

2004-01-01

399

Structural and spectroscopic characteristics of two lignans from Taxus baccata L  

Microsoft Academic Search

As a part of our ongoing investigations on Taxus baccata L. (Taxaceae), we have isolated two lignans, lariciresinol (1) and taxiresinol (2), from chloroform extract of the heartwood of this plant. This is the first report for the isolation of lariciresinol from T. baccata. Their structures were elucidated on the basis of spectroscopic methods (IR, EIMS, DCI, 1D and 2D

N. Erdemoglu; E Sahin; B Sener; S Ide

2004-01-01

400

Spectroscopic Characterization of Bendazac and Benzydamine: Possible Photochemical Modes of Action  

Microsoft Academic Search

The involvement of near-UV light in cataract development suggests that potential anti-cataract drugs may display unusual spectroscopic properties. As bendazac impedes certain effects associated with lens opacification, we have characterized the singlet and triplet states of bendazac and its analog, benzydamine, by fluorescence and phosphorescence methods. These compounds have much shorter triplet state lifetimes compared to the triplet state lifetimes

Joseph M. Jez; Jane M. Vanderkooi; Alan M. Laties

1996-01-01

401

Extension of Finite-support Extrapolation using the Generalized Series Model for MR Spectroscopic Imaging  

Microsoft Academic Search

In magnetic resonance (MR) imaging, limited data sampling in -space leads to the well-known Fourier truncation artifact, which includes ringing and blurring. This problem is particularly severe for MR spectroscopic imaging, where only 16-24 points are typically acquired along each spatial dimension. Several methods have been proposed to overcome this problem by incorporating prior information in the image reconstruction. These

Jeffrey Tsao

2001-01-01

402

Spectroscopic distances of 28 nearby star candidates  

NASA Astrophysics Data System (ADS)

Aims: Twenty eight hitherto neglected candidates for the Catalogue of Nearby Stars (CNS) were investigated to verify their classification and to improve their distance estimates. All targets had at least a preliminary status of being nearby dwarf stars based on their large proper motions and relatively faint magnitudes. Better photometric and/or spectroscopic distances were required for selecting stars for further trigonometric parallax measurements. Methods: Low-resolution spectra were obtained with NASPEC at the Tautenburg 2 m telescope and with CAFOS at the Calar Alto 2.2 m telescope. The spectral types of M-type stars were determined by direct comparison of the target's spectra with those of comparison stars of known spectral types observed with the same instrument. The classification of earlier types was performed based on comparison with published spectral libraries. Results: For most of the target stars reliable spectral types could be determined and in combination with 2MASS photometry new improved distance estimates became available. The majority were classified as M dwarfs including 11 stars within 25 pc. The fainter component of LDS 1365, previously thought to form a nearby common proper motion pair, is according to our results an unrelated high-velocity background star. For several other nearby common proper motion pairs our distance estimates of the fainter components are in good agreement with Hipparcos distances of the brighter components. The three stars in our sample that were previously thought to be white dwarfs (GJ 2091, GJ 2094, GJ 2098) turned out to be more distant high-velocity F- to K-type (sub)dwarfs. For the star with the largest tangential velocity (GJ 2091; v_ tan>500 km s-1) we have additional evidence for its probable Galactic halo membership from a measured large radial velocity of 266 ± 25 km s-1 and from its UBV photometry indicating a low metallicity. Based on observations with the 2 m telescope of the Thüringer Landessternwarte Tautenburg and with the 2.2 m telescope of the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC).

Jahreiß, H.; Meusinger, H.; Scholz, R.-D.; Stecklum, B.

2008-06-01

403

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

NASA Astrophysics Data System (ADS)

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

Subramanian, N.; Sundaraganesan, N.; Jayabharathi, J.

2010-07-01

404

Crystal structure characterization as well as theoretical study of spectroscopic properties of novel Schiff bases containing pyrazole group  

NASA Astrophysics Data System (ADS)

A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. All as-synthesized Schiff bases were characterized by means of NMR, FT-IR, and MS; and the molecular geometries of two Schiff bases as typical examples were determined by means of single crystal X-ray diffraction. In the meantime, the ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were also measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method. It has been found that all as-synthesized Schiff bases show a remarkable absorption peak in a wavelength range of 270-370 nm; and their maximum emission peaks are around 344 nm and 332 nm, respectively.

Guo, Jia; Ren, Tiegang; Zhang, Jinglai; Li, Guihui; Li, Weijie; Yang, Lirong

2012-09-01

405

A Spectroscopic Determination of em  

Microsoft Academic Search

Rydberg constants for hydrogen and helium.-By an interferometer method the wave-lengths of the hydrogen lines at 6563A and 4861A were measured with reference to lambda5015.6750 of He as standard. The values so obtained were, for the doublet at 6563A, 6562.7110+\\/-.0018 and 6562.8473+\\/-.0009 and for the doublet at 4861, 4861.2800+\\/-.0013 and 4861.3578+\\/-0022. Similarly the wave-lengths of the 4686 lines of ionized

William V. Houston

1927-01-01

406

A Spectroscopic Survey of AGN in COSMOS  

NASA Astrophysics Data System (ADS)

We describe a spectroscopic survey of AGN in the 2 deg2 COSMOS field. The size, depth, and extensive multi-wavelength observations of the survey allow for bolometric studies of AGN in a wide variety of environments. Here we present the spectroscopic redshifts for the first ˜500 X-ray and radio-selected AGN targets. Spectra were obtained with the Magellan (Baade) IMACS instrument, using the nod-and-shuffle technique. We identify a variety of Type 1 and Type 2 AGN, as well as red galaxies with no emission lines. Our redshift yield is 72% down to i AB=24, but we expect the yield to increase as the survey continues. When our survey is complete and additional redshifts from the ESO VLT are included, we expect ˜ 1100 AGN with redshifts over the entire COSMOS field.

Trump, J. R.; Impey, C. D.; McCarthy, P. J.; Elvis, M.; Huchra, J. P.; Brusa, M.; Hasinger, G.; Schinnerer, E.; Lilly, S. J.; Scoville, N. Z.

2005-12-01

407

Stellar Distance Determination From Rave Spectroscopic Data  

NASA Astrophysics Data System (ADS)

RAVE is expected to be the largest spectroscopic survey of the Solar neighbourhood in the coming decade, but with a significant fraction of giant stars reaching out to 10 kpc from the Sun. The survey measures values of stellar parameters (radial velocity, temperature, gravity, metallicity) for a vast number of general field stars from a randomly selected magnitude limited sample spanning all components of the Galaxy. The most probable absolute magnitude can be derived using a set of stellar isochrone solutions, thus yielding spectroscopic distance. Some of the recent approaches and innovative ideas to this well known problem will be reviewed. Distances derived for 300.000 RAVE spectra will be presented. Results will be checked against astrometric distances for Hipparcos stars and against distances of stellar clusters.

Zwitter, Tomaz; Matijevic, G.; RAVE Collaboration

2010-01-01

408

Raman spectroscopic studies on bacteria  

NASA Astrophysics Data System (ADS)

Routine clinical microbiological identification of pathogenic micro-organisms is largely based on nutritional and biochemical tests. Laboratory results can be presented to a clinician after 2 - 3 days for most clinically relevant micro- organisms. Most of this time is required to obtain pure cultures and enough biomass for the tests to be performed. In the case of severely ill patients, this unavoidable time delay associated with such identification procedures can be fatal. A novel identification method based on confocal Raman microspectroscopy will be presented. With this method it is possible to obtain Raman spectra directly from microbial microcolonies on the solid culture medium, which have developed after only 6 hours of culturing for most commonly encountered organisms. Not only does this technique enable rapid (same day) identifications, but also preserves the sample allowing it to be double-checked with traditional tests. This, combined with the speed and minimal sample handling indicate that confocal Raman microspectroscopy has much potential as a powerful new tool in clinical diagnostic microbiology.

Maquelin, K.; Choo-Smith, Lin-P'ing; Endtz, H. P.; Bruining, Hajo A.; Puppels, Gerwin J.

2000-11-01

409

Query by image example: The CANDID approach  

Microsoft Academic Search

CANDID (Comparison Algorithm for Navigating Digital Image Databases) was developed to enable content-based retrieval of digital imagery from large databases using a query-by-example methodology. A user provides an example image to the system, and images in the database that are similar to that example are retrieved. The development of CANDID was inspired by the N-gram approach to document fingerprinting, where

P. M. Kelly; M. Cannon; D. R. Hush

1995-01-01

410

Pegylated Phthalocyanines: Synthesis and Spectroscopic Properties  

PubMed Central

The syntheses and spectroscopic properties of a series of pegylated zinc(II)-phthalocyanines (Zn-Pcs) containing one, two or eight tri(ethylene glycol) chains are described. The single molecular structure of a phthalonitrile precursor containing one hydroxyl and one PEG group, and its unique intermolecular hydrogen bonding are presented. The pegylated Pcs are highly soluble in polar organic solvents and have fluorescence quantum yields in the range 0.08–0.28.

Li, Hairong; Fronczek, Frank R.; Vicente, M. Graca H.

2011-01-01

411

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the Catalina Real-time Transient Survey (http://crts.caltech.edu/). All observations were performed on the ESO New Technology Telescope at La Silla on 2012 October 09, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

El-Hage, Patrick; Fraser, M.; Sternberg, A.; Inserra, C.; Taubenberger, S.; Pastorello, A.; Valenti, S.; Benetti, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Gal-Yam, A.; Yaron, O.; Dimai, A.; Howerton, S.; Parker, S.

2012-10-01

412

HR3626 - Double-Line Spectroscopic Binary  

NASA Astrophysics Data System (ADS)

Orbital elements are determined for the double-lined spectroscopic binary HR 3626, which had previously been recognized as being only a single-lined system. A mass ratio of 1.26 + 0.02 is determined, and a magnitude difference ?mB = 1.0 ± 0.2 is inferred from the photoelectric radial velocity dips. This leads to the conclusion that the system consists of a pair of G dwarf or subgiant stars.

Beavers, W. I.; Salzer, J. J.

1982-04-01

413

Spectroscopic and Solubility Characteristics of Oxidized Soots  

Microsoft Academic Search

Spectroscopic and solubility studies of reaction products of soot (black carbon) with O3, NO2\\/N2O4, and SO2 have revealed a relationship between reactivity and product solubility and structure. A remarkably high solubility of ozonated n-hexane soot has its origin in the formation of anhydride and lactone surface structures and their subsequent hydrolysis to carboxylic acid species. Calculations indicate that the rate

A. R. Chughtai; J. A. Jassim; J. H. Peterson; D. H. Stedman; D. M. Smith

1991-01-01

414

Spectroscopic-guided brain tumor resection  

NASA Astrophysics Data System (ADS)

A pilot in vivo study was conducted to investigate the feasibility of using optical spectroscopy for brain tumor margin detection. Fluorescence and diffuse reflectance spectra were acquired using a portable clinical spectroscopic system from normal brain tissues, tumors, and tumor margins in 21 brain tumor patients undergoing craniotomy. Results form this study show the potential of optical spectroscopy in detecting infiltrating tumor margins of primary brain tumors.

Lin, Wei-Chiang; Toms, Steven A.; Jansen, E. Duco; Mahadevan-Jansen, Anita

2000-05-01

415

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org), reports the following supernova classifications. The targets were supplied by amateur astronomers (http://www.cbat.eps.harvard.edu/unconf/tocp.html). All observations were performed on the ESO New Technology Telescope at La Silla on 2013 January 27, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Garoffolo, A. Morales; Elias-Rosa, N.; Benitez-Herrera, S.; Taubenberger, S.; Walker, E. S.; Benetti, S.; Pastorello, A.; Valenti, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Gal-Yam, A.; Yaron, O.

2013-01-01

416

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org), reports the following supernova classifications. Targets were supplied by amateur astronomers (http://www.cbat.eps.harvard.edu/unconf/tocp.html). All observations were performed on the ESO New Technology Telescope at La Silla in the night starting on 2013 February 6 UT, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Garoffolo, A. Morales; Elias-Rosa, N.; Benitez-Herrera, S.; Taubenberger, S.; Botticella, M. T.; Benetti, S.; Pastorello, A.; Valenti, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Gal-Yam, A.; Yaron, O.

2013-02-01

417

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

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

Kankare, E.; Kangas, T.; Inserra, C.; Mattila, S.; Fraser, M.; Scalzo, R.; Nicholl, M.; Gal-Yam, A.; Yaron, O.; Benetti, S.; Pastorello, A.; Valenti, S.; Taubenberger, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Knapic, C.; Molinaro, M.; Smareglia, R.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.; Wyrzykowski, Lukasz

2013-08-01

418

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the La Silla-Quest survey (see Hadjiyska et al., ATel #3812) and TOCP webpages. All observations were performed on the ESO New Technology Telescope at La Silla on 2013 August 26 (UT), using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Kankare, E.; Kangas, T.; Inserra, C.; Mattila, S.; Fraser, M.; Scalzo, R.; Nicholl, M.; Gal-Yam, A.; Yaron, O.; Benetti, S.; Pastorello, A.; Valenti, S.; Taubenberger, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Knapic, C.; Molinaro, M.; Smareglia, R.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Walker, E. S.; Feindt, U.; Kowalski, M.; Nugent, P.

2013-08-01

419

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets was supplied by the Catalina Real-time Transient Survey (http://crts.caltech.edu/). The observation was performed on the ESO New Technology Telescope at La Silla on 2013 September 07 (UT), using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Kankare, E.; Kangas, T.; Inserra, C.; Mattila, S.; Maguire, K.; Gal-Yam, A. Pastorello A.; Yaron, O.; Manulis, I.; Benetti, S.; Valenti, S.; Taubenberger, S.; Smartt, S. J.; Smith, K.; Young, D.; Fraser, M.; Sullivan, M.; Knapic, C.; Molinaro, M.; Smareglia, R.

2013-09-01

420

PESSTO spectroscopic classification of optical transients  

NASA Astrophysics Data System (ADS)

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Valenti et al., ATel #4037; http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by the Catalina Real-time Transient Survey (http://crts.caltech.edu/), the CHASE project and the TOCP page. All observations were performed on the ESO New Technology Telescope at La Silla on 2013 March 16, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution).

Wyrzykowski, Lukasz; Blagorodnova, Nadia; Nicholl, Matt; Inserra, Cosimo; Polshaw, Joe; Fraser, Morgan; Benetti, S.; Pastorello, A.; Valenti, S.; Taubenberger, S.; Smartt, S. J.; Smith, K.; Young, D.; Sullivan, M.; Gal-Yam, A.; Yaron, O.

2013-03-01

421

Detection of glutamate and glutamine (Glx) by turbo spectroscopic imaging.  

PubMed

Turbo spectroscopic imaging (TSI) is a spin echo spectroscopic imaging technique in which two or more echoes are acquired per excitation to reduce the acquisition time. The application of TSI has primarily been limited to the detection of uncoupled spins because the signal from coupled spins is modulated as a function of echo time. In this work we demonstrate how the TSI sequence can be modified to observe spins like the C(2) protons of Glx (approximately 3.75 ppm) which are involved solely in weak-coupling interactions. The technique exploits the chemical shift displacement effect by employing TSI refocusing pulses that have bandwidths which are less than the chemical shift difference between the target spins and the spins to which they are weakly coupled. The modified TSI sequence rewinds the J-evolution of the target protons in the slice of interest independently of the echo time or echo spacing, thereby removing any signal variation between successive echoes (apart from T(2) relaxation effects). In this study we tailored the narrow-bandwidth TSI sequence for observation of the C(2) Glx protons. The echo time was experimentally optimized to minimize signal contamination from myo-inositol, and the efficacy of the method was verified on phantom solutions of Glx and on brain in vivo. PMID:19071046

Yahya, Atiyah; Fallone, B Gino

2008-11-24

422

Structure, spectroscopic properties, and photochemistry of the hydroxymethoxy radical  

SciTech Connect

The hydroxymethoxy (HMO) radical is proposed to be the primary product of photodissociation of the atmospherically important hydroxymethyl hydroperoxide (HMHP). This transient species is still unknown and the present study provides theoretical predictions of properties, spectroscopy, and photochemistry of this radical for the first time. Structures, harmonic frequencies, vertical and vibrationally resolved absorption spectra are computed for several electronic states, using state-of-the-art ab initio electronic structure methods. The lowest excited state, absorbing in the mid to near infrared, seems to be the most promising candidate for spectroscopic identification of HMO. The electron affinity of 2.232 eV and the characteristic photodetachment spectrum is also predicted to be suitable for experimental investigations. By contrast, the B-tilde state absorbing around 3.5 eV is proposed to undergo fast photodissociation, forming CH{sub 2}O and OH, and thus appears less useful for spectroscopic detection of HMO. However, the photodissociation may be important for the atmospheric chemistry of HMHP. Ionization of HMO will also lead to dissociation or rearrangement of the cation and will yield only unspecific spectra.

Eisfeld, Wolfgang [Theoretische Chemie, Fakultaet fuer Chemie, Universitaet Bielefeld, Postfach 100131, D-33501 Bielefeld (Germany); Francisco, Joseph S. [Department of Chemistry and Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47907-2084 (United States)

2009-10-07

423

Spectroscopic ellipsometry data analysis: Measured vs. calculated quantities  

SciTech Connect

Spectroscopic ellipsometry is a very powerful technique for optical characterization of thin-film and bulk materials, but the technique measures functions of complex reflection coefficients, which are usually not of interest per se. The interesting characteristics such as film thickness, surface roughness thickness, and optical functions can be determined only by modeling the near-surface region of the sample. However, the measured quantities are not equivalent to those determined from the modeling. Ellipsometry measurements determine elements of the sample Mueller matrix, but the usual result of modeling calculations are elements of the sample. Often this difference is academic, but if the sample depolarizes the light, it is not. Ellipsometry calculations also include methods for determining the optical functions of materials. Data for bulk materials are usually accurate for substrates, but are not appropriate for most thin films. Therefore, reasonable parameterizations are quite useful in performing spectroscopic ellipsometry data analysis. Recently, there has been an increased interest in anisotropic materials, both in thin-film and bulk form. A generalized procedure will be presented for calculating the elements of the Jones matrix for any number of layers, any one of which may or may not be uniaxial.

Jellison, G.E. Jr.

1997-05-01

424

Time resolved spectroscopic NMR imaging using hyperpolarized 129Xe  

NASA Astrophysics Data System (ADS)

We have visualized the melting and dissolution processes of xenon (Xe) ice into different solvents using the methods of nuclear magnetic resonance (NMR) spectroscopy, imaging, and time resolved spectroscopic imaging by means of hyperpolarized 129Xe. Starting from the initial condition of a hyperpolarized solid Xe layer frozen on top of an ethanol (ethanol/water) ice block we measured the Xe phase transitions as a function of time and temperature. In the pure ethanol sample, pieces of Xe ice first fall through the viscous ethanol to the bottom of the sample tube and then form a thin layer of liquid Xe/ethanol. The xenon atoms are trapped in this liquid layer up to room temperature and keep their magnetization over a time period of 11min. In the ethanol/water mixture (80 vol%/20%), most of the polarized Xe liquid first stays on top of the ethanol/water ice block and then starts to penetrate into the pores and cracks of the ethanol/water ice block. In the final stage, nearly all the Xe polarization is in the gas phase above the liquid and trapped inside the pores. NMR spectra of homogeneous samples of pure ethanol containing thermally polarized Xe and the spectroscopic images of the melting process show that very high concentrations of hyperpolarized Xe (about half of the density of liquid Xe) can be stored or delivered in pure ethanol.

Han, S.; Kühn, H.; Häsing, F. W.; Münnemann, K.; Blümich, B.; Appelt, S.

2004-04-01

425

The HITRAN2012 molecular spectroscopic database  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

426

Spectroscopic studies of the transplutonium elements  

SciTech Connect

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

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

1983-01-01

427

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

PubMed Central

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

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

2013-01-01

428

Investigation on interaction of prulifloxacin with pepsin: A spectroscopic analysis  

NASA Astrophysics Data System (ADS)

The interaction between prulifloxacin, a kind of new oral taking antibiotic and pepsin, a kind of enzyme in the stomach has been investigated in vitro under a simulated physiological condition by different spectroscopic methods. The intrinsic fluorescence of pepsin was strongly quenched by prulifloxacin. This effect was rationalized in terms of a static quenching procedure. The binding parameters have been evaluated by fluorescence quenching methods. The negative value of ? G0 reveals that the binding process is a spontaneous process. The binding distance R between donor (pepsin) and acceptor (prulifloxacin) was obtained according to the Förster's resonance energy transfer theory and found to be 0.95 nm. The results obtained herein will be of biological significance in pharmacology and clinical medicine.

Huang, Yabei; Yan, Jie; Liu, Benzhi; Yu, Zhang; Gao, Xiaoyan; Tang, Yingcai; Zi, Yanqin

2010-03-01

429

A SIMILARITY MEASURE FOR AUDIO QUERY BY EXAMPLE BASED ON PERCEPTUAL CODING AND COMPRESSION  

Microsoft Academic Search

Query by example for multimedia signals aims at automatic re- trieval of samples from the media database similar to a user- provided example. This paper proposes a similarity measure for query by example of audio signals. The method first represents audio signals using perceptual audio coding and second estimates the similarity of two signals from the advantage gained by com-

Marko Helén; Tuomas Virtanen

2007-01-01

430

Evaluating Educational Performance: A Sourcebook of Methods, Instruments, and Examples.  

ERIC Educational Resources Information Center

This book is a collection of 20 articles and research reports that deal with practical, technical issues of research methodology applicable to the