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Sample records for micro-raman analysis application

  1. Micro-Raman analysis of titanium oxide/carbon nanotubes-based nanocomposites for hydrogen sensing applications

    SciTech Connect

    Santangelo, S.; Messina, G.; Faggio, G.; Donato, A.; De Luca, L.; Donato, N.; Bonavita, A.; Neri, G.

    2010-10-15

    Titanium oxide/carbon nanotubes-based nanocomposites (TiO{sub 2}/CNTs, prepared by sol-gel method, and 2%Pt/TiO{sub 2}/CNTs, obtained by wetness impregnation of the TiO{sub 2}/CNTs base material with a solution of platinum acetylacetonate) have been recently used as active layer in hydrogen sensing devices at near room temperature, obtaining quite different responsiveness. The microstructure of these hybrid materials is here systematically investigated by micro-Raman spectroscopy at 2.41 eV. The results show that regardless of the nominal C/Ti molar ratio (3.6 or 17.0) only the anatase phase of titania is formed. Theoretical calculations demonstrate that phonon confinement is fully responsible for the large blue-shift ({approx}10 cm{sup -1}) and broadening ({approx}20 cm{sup -1}) of the lowest-frequency Raman mode with respect to bulk anatase. The average size (4.3-5.0 nm) of TiO{sub 2} crystallites, resulting from Raman spectra fitting, is in excellent agreement with those inferred from transmission electron microscopy and X-ray diffraction measurements. - Graphical Abstract: Micro-Raman analysis of TiO{sub 2}/CNTs and Pt/TiO{sub 2}/CNTs hybrids for H{sub 2} sensing applications evidences that regardless of C/Ti molar ratio titania crystallizes in the anatase phase. The very small size of TiO{sub 2} crystallites (4.3-5.0 nm) is responsible for the observed phonon confinement effects.

  2. Calibration of carbonate composition using micro-Raman analysis: application to planetary surface exploration.

    PubMed

    Rividi, Nicolas; van Zuilen, Mark; Philippot, Pascal; Ménez, Bénédicte; Godard, Gaston; Poidatz, Emmanuel

    2010-04-01

    Stromatolite structures in Early Archean carbonate deposits form an important clue for the existence of life in the earliest part of Earth's history. Since Mars is thought to have had similar environmental conditions early in its history, the question arises as to whether such stromatolite structures also evolved there. Here, we explore the capability of Raman spectroscopy to make semiquantitative estimates of solid solutions in the Ca-Mg-Fe(+Mn) carbonate system, and we assess its use as a rover-based technique for stromatolite characterization during future Mars missions. Raman microspectroscopy analysis was performed on a set of carbonate standards (calcite, ankerite, dolomite, siderite, and magnesite) of known composition. We show that Raman band shifts of siderite-magnesite and ankerite-dolomite solid solutions display a well-defined positive correlation (r(2) > 0.9) with the Mg# = 100 x Mg/(Mg + Fe + Mn + Ca) of the carbonate analyzed. Raman shifts calibrated as a function of Mg# were used in turn to evaluate the chemical composition of carbonates. Raman analysis of a suite of carbonates (siderite, sidero-magnesite, ankerite, and dolomite) of hydrothermal and sedimentary origin from the ca. 3.2 Ga old Barite Syncline, Barberton greenstone belt, South Africa, and from the ca. 3.5 Ga old Dresser Formation, Pilbara Craton, Western Australia, show good compositional agreement with electron microprobe analyses. These results indicate that Raman spectroscopy can provide direct information on the composition and structure of carbonates on planetary surfaces.

  3. Micro-Raman Analysis of Irradiated Diamond Films

    NASA Technical Reports Server (NTRS)

    Newton, R. L.; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    Owing to its unique and robust physical properties, diamond is a much sought after material for use in advanced technologies such as Microelectromechanical Systems (MEMS). The volume and weight savings promised by MEMS-based devices are of particular interest to spaceflight applications. However, much basic materials science research remains to be completed in this field. Results of micro-Raman analysis of proton (1015 - 1017 H+/cm2 doses) irradiated chemical vapor deposited (CVD) diamond reveals that the microstructure is retained even after high radiation exposure.

  4. Micro-Raman Analysis of Irradiated Diamond Films

    NASA Technical Reports Server (NTRS)

    Newton, Robert L.

    2003-01-01

    Owing to its unique and robust physical properties, diamond is a much sought after material for use in advanced technologies, even in Microelectromechanical Systems (MEMS). The volume and weight savings promised by MEMS-based devices are of particular interest to spaceflight applications. However, much basic materials science research remains to be completed in this field. Results of micro-Raman analysis of proton (10(exp 15) - 10(exp 17) H(+)/sq cm doses) irradiated chemical vapor deposited (CVD) films are presented and indicate that their microstructure is retained even after high radiation exposure.

  5. Drug analysis by Raman and micro-Raman spectroscopy.

    PubMed

    Huong, P V

    1986-01-01

    The technique of Raman spectroscopy, resonance Raman spectroscopy and micro-Raman spectroscopy is described for application to drug analysis and investigation. Possibilities and limits are mentioned for qualitative and quantitative analyses as well as for studies of structure and interactions. Some principal interaction modes, such as hydrogen bonding, proton transfer, charge transfer and ion-molecule attraction, are shown to explain drug reactivity. Illustrations are given based on several drug families, in particular vitamins, anti-depressants, cardio-active and anticancer drugs.

  6. MicroRaman measurements for nuclear fuel reprocessing applications

    DOE PAGES

    Casella, Amanda; Lines, Amanda; Nelson, Gilbert; ...

    2016-12-01

    Treatment and reuse of used nuclear fuel is a key component in closing the nuclear fuel cycle. Solvent extraction reprocessing methods that have been developed contain various steps tailored to the separation of specific radionuclides, which are highly dependent upon solution properties. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices. Our group has been investigating the use of optical spectroscopy for the on-line monitoring of actinides, lanthanides, and acid strength within fuel reprocessing streams. This paper willmore » focus on the development and application of a new MicroRaman probe for on-line real-time monitoring of the U(VI)/nitrate ion/nitric acid in solutions relevant to used nuclear fuel reprocessing. Previous research has successfully demonstrated the applicability on the macroscopic scale, using sample probes requiring larger solution volumes. In an effort to minimize waste and reduce dose to personnel, we have modified this technique to allow measurement at the microfluidic scale using a Raman microprobe. Under the current sampling environment, Raman samples typically require upwards of 10 mL and larger. Using the new sampling system, we can sample volumes at 10 μL or less, which is a scale reduction of over 1,000 fold in sample size. Finally, this paper will summarize our current work in this area including: comparisons between the macroscopic and microscopic probes for detection limits, optimized channel focusing, and application in a flow cell with varying levels of HNO3, and UO2(NO3)2.« less

  7. MicroRaman measurements for nuclear fuel reprocessing applications

    SciTech Connect

    Casella, Amanda; Lines, Amanda; Nelson, Gilbert; Bello, Job; Bryan, Samuel

    2016-12-01

    Treatment and reuse of used nuclear fuel is a key component in closing the nuclear fuel cycle. Solvent extraction reprocessing methods that have been developed contain various steps tailored to the separation of specific radionuclides, which are highly dependent upon solution properties. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices. Our group has been investigating the use of optical spectroscopy for the on-line monitoring of actinides, lanthanides, and acid strength within fuel reprocessing streams. This paper will focus on the development and application of a new MicroRaman probe for on-line real-time monitoring of the U(VI)/nitrate ion/nitric acid in solutions relevant to used nuclear fuel reprocessing. Previous research has successfully demonstrated the applicability on the macroscopic scale, using sample probes requiring larger solution volumes. In an effort to minimize waste and reduce dose to personnel, we have modified this technique to allow measurement at the microfluidic scale using a Raman microprobe. Under the current sampling environment, Raman samples typically require upwards of 10 mL and larger. Using the new sampling system, we can sample volumes at 10 μL or less, which is a scale reduction of over 1,000 fold in sample size. Finally, this paper will summarize our current work in this area including: comparisons between the macroscopic and microscopic probes for detection limits, optimized channel focusing, and application in a flow cell with varying levels of HNO3, and UO2(NO3)2.

  8. MicroRaman Measurements for Nuclear Fuel Reprocessing Applications

    SciTech Connect

    Casella, Amanda; Lines, Amanda; Nelson, Gilbert; Bello, Job; Bryan, Samuel

    2016-01-01

    Treatment and reuse of used nuclear fuel is a key component in closing the nuclear fuel cycle. Solvent extraction reprocessing methods that have been developed contain various steps tailored to the separation of specific radionuclides, which are highly dependent upon solution properties. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices. Our group has been investigating the use of optical spectroscopy for the on-line monitoring of actinides, lanthanides, and acid strength within fuel reprocessing streams. This paper will focus on the development and application of a new MicroRaman probe for on-line real-time monitoring of the U(VI)/nitrate ion/nitric acid in solutions relevant to used nuclear fuel reprocessing. Previous research has successfully demonstrated the applicability on the macroscopic scale, using sample probes requiring larger solution volumes. In an effort to minimize waste and reduce dose to personnel, we have modified this technique to allow measurement at the microfluidic scale using a Raman microprobe. Under the current sampling environment, Raman samples typically require upwards of 10 mL and larger. Using the new sampling system, we can sample volumes at 10 μL or less, which is a scale reduction of over 1,000 fold in sample size. This paper will summarize our current work in this area including: comparisons between the macroscopic and microscopic probes for detection limits, optimized channel focusing, and application in a flow cell with varying levels of HNO3, and UO2(NO3)2.

  9. Oral pathology follow-up by means of micro-Raman spectroscopy on tissue and blood serum samples: an application of wavelet and multivariate data analysis

    NASA Astrophysics Data System (ADS)

    Delfino, I.; Camerlingo, C.; Zenone, F.; Perna, G.; Capozzi, V.; Cirillo, N.; Gaeta, G. M.; De Mol, E.; Lepore, M.

    2009-02-01

    Pemphigus vulgaris (PV) is a potentially fatal autoimmune disease that cause blistering of the skin and oral cavity. It is characterized by disruption of cell-cell adhesion within the suprabasal layers of epithelium, a phenomenon termed acantholysis Patients with PV develop IgG autoantibodies against normal constituents of the intercellular substance of keratinocytes. The mechanisms by which such autoantibodies induce blisters are not clearly understood. The qualitative analysis of such effects provides important clues in the search for a specific diagnosis, and the quantitative analysis of biochemical abnormalities is important in measuring the extent of the disease process, designing therapy and evaluating the efficacy of treatment. Improved diagnostic techniques could permit the recognition of more subtle forms of disease and reveal incipient lesions clinically unapparent, so that progression of potentially severe forms could be reversed with appropriate treatment. In this paper, we report the results of our micro-Raman spectroscopy study on tissue and blood serum samples from ill, recovered and under therapy PV patients. The complexity of the differences among their characteristic Raman spectra has required a specific strategy to obtain reliable information on the illness stage of the patients For this purpose, wavelet techniques and advanced multivariate analysis methods have been developed and applied to the experimental Raman spectra. Promising results have been obtained.

  10. Wavelet data analysis of micro-Raman spectra for follow-up monitoring in oral pathologies

    NASA Astrophysics Data System (ADS)

    Camerlingo, C.; Zenone, F.; Perna, G.; Capozzi, V.; Cirillo, N.; Gaeta, G. M.; Lepore, M.

    2008-02-01

    A wavelet multi-component decomposition algorithm has been used for data analysis of micro-Raman spectra from human biological samples. In particular, measurements have been performed on some samples of oral tissue and blood serum from patients affected by pemphigus vulgaris at different stages. Pemphigus is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. The disease is characterized histologically by intradermal blisters and immunopathologically by the finding of tissue bound and circulating immunoglobulin G (IgG) antibody directed against the cell surface of keratinocytes. More than 150 spectra were measured by means of a Raman confocal microspectrometer apparatus using the 632.8 nm line of a He-Ne laser source. A discrete wavelet transform decomposition method has been applied to the recorded Raman spectra in order to overcome related to low-level signals and the presence of noise and background components due to light scattering and fluorescence. The results indicate that appropriate data processing can contribute to enlarge the medical applications of micro-Raman spectroscopy.

  11. Study on the strain in a silicon microchannel plate by micro-Raman analysis

    NASA Astrophysics Data System (ADS)

    Xu, Shaohui; Fang, Jiabing; Wu, Dajun; Zhang, Chi; Zhu, Yiping; Xiong, Dayuan; Wang, Lianwei; Yang, Pingxiong; Chu, Paul K.

    2016-05-01

    Micro-Raman analysis was used to identify the oxidation of a silicon microchannel plate (SiMCP) and it indicated that the bend phenomenon of the SiMCP was related to the release of stress and the volume expending of the silicon wall during the oxidation process.

  12. Quantitative micro-Raman analysis of volcanic glasses: influence and correction of matrix effects

    NASA Astrophysics Data System (ADS)

    Di Muro, Andrea

    2014-05-01

    . Geochimica et Cosmochimica Acta, 74, 5641-5656. Mercier, M., Di Muro, A., Giordano, D., Métrich, N.,Pichavant, M., Clocchiatti, R., Montagnac, G. (2009) The influence of glass polymerization and oxidation on micro-Raman water analysis in alumino-silicate glasses. Geochimica et Cosmochimica Acta, 73, 197-217 Di Muro, A., Métrich, N., Mercier, M., Giordano, D., Massare, D., Montagnac, G. (2009) Micro-Raman determination of iron redox state in dry natural glasses : application to peralkaline rhyolites and basalts. Chemical Geology (Special volume on experimental techniques for the study of hydrothermal fluids and silicate melts) 259:78-88. Di Muro A, Villemant B, Montagnac G, Scaillet B, Reynard B (2006) The influence of glass composition on the determination of water content and speciation by Raman spectrometry. Geochimica and Cosmochimica Acta, 70, 2868-2884 Di Muro A, Giordano D., Villemant B, Montagnac G, Romano C. (2006) Influence of composition and thermal history of volcanic glasses on water content determination by microRaman spectrometry. Applied Geochemistry (Special volume on developments in analytical geochemistry). 21, 802-812. Application Di Muro, A., Staudacher, T., Ferrazzini, V., Villemant, B., Besson, P., Garofalo, C. (2014) Tracking magma injection in the Piton de la Fournaise volcanic edifice after the 2007 Summit Caldera Collapse by Pele's Hair Composition. Chapman Special Volume on Hawaiian volcanoes, AGU Books. Ardia, P., Di Muro, A., Giordano, D., Massare, D., Sanchez-Valle, C., Schmidt, M.W. (2014) Densification mechanisms of haplogranite glasses as a function of water content and pressure based on density and Raman data. Under review, submitted to Geochimica et Cosmochimica Acta. Métrich, N, Allard, P., Aiuppa, A., Bani, P., Bertagnini, A., Belhadj, O., Di Muro, A., Garaebiti, E., Massare, D., Parello, F., Shinohara, H. (2011) Magma and volatile feeding of post-caldera Yasur volcanism and block resurgence in Tanna island (Vanuatu arc). Journal of

  13. Combined micro-Raman/UV-visible/fluorescence spectrometer for high-throughput analysis of microsamples.

    PubMed

    Noh, Jermim; Suh, Yung Doug; Park, Yong Ki; Jin, Seung Min; Kim, Soo Ho; Woo, Seong Ihl

    2007-07-01

    Combined micro-Raman/UV-visible (vis)/fluorescence spectroscopy system, which can evaluate an integrated array of more than 10,000 microsamples with a minimuma size of 5 microm within a few hours, has been developed for the first time. The array of microsamples is positioned on a computer-controlled XY translation microstage with a spatial resolution of 1 mum so that the spectra can be mapped with micron precision. Micro-Raman spectrometers have a high spectral resolution of about 2 cm(-1) over the wave number range of 150-3900 cm(-1), while UV-vis and fluorescence spectrometers have high spectral resolutions of 0.4 and 0.1 nm over the wavelength range of 190-900 nm, respectively. In particular, the signal-to-noise ratio of the micro-Raman spectroscopy has been improved by using a holographic Raman grating and a liquid-nitrogen-cooled charge-coupled device detector. The performance of the combined spectroscopy system has been demonstrated by the high-throughput screening of a combinatorial ferroelectric (i.e., BaTi(x)Zr(1-x)O(3)) library. This system makes possible the structure analysis of various materials including ferroelectrics, catalysts, phosphors, polymers, alloys, and so on for the development of novel materials and the ultrasensitive detection of trace amounts of pharmaceuticals and diagnostic agents.

  14. Micro-Raman spectroscopy: The analysis of micrometer and submicrometer atmospheric aerosols

    NASA Technical Reports Server (NTRS)

    Klainer, S. M.; Milanovich, F. P.

    1985-01-01

    A nondestructive method of molecular analysis which is required to fully utilize the information contained within a collected particle is discussed. Upper atmosphere reaction mechanisms are assessed when the chemical compounds, the use of micro-Raman spectrometric techniques to perform micron and submicron particle analysis was evaluated. The results are favorable and it is concluded that micron and submicron particles can be analyzed by the micron-Raman approach. Completely automatic analysis should be possible to 0.3 micro m. No problems are anticipated with photo or thermal decomposition. Sample and impurity fluorescence are the key source of background as they cannot be completely eliminated.

  15. Micro-Raman Spectroscopy and Univariate Analysis for Monitoring Disease Follow-Up

    PubMed Central

    Camerlingo, Carlo; Delfino, Ines; Perna, Giuseppe; Capozzi, Vito; Lepore, Maria

    2011-01-01

    Micro-Raman spectroscopy is a very promising tool for medical applications, thanks to its sensitivity to subtle changes in the chemical and structural characteristics of biological specimens. To fully exploit these promises, building a method of data analysis properly suited for the case under study is crucial. Here, a linear or univariate approach using a R2 determination coefficient is proposed for discriminating Raman spectra even with small differences. The validity of the proposed approach has been tested using Raman spectra of high purity glucose solutions collected in the 600 to 1,600 cm−1 region and also from solutions with two known solutes at different concentrations. After this validation step, the proposed analysis has been applied to Raman spectra from oral human tissues affected by Pemphigus Vulgaris (PV), a rare life-threatening autoimmune disease, for monitoring disease follow-up. Raman spectra have been obtained in the wavenumber regions from 1,050 to 1,700 cm−1 and 2,700 to 3,200 cm−1 from tissues of patients at different stages of pathology (active PV, under therapy and PV in remission stage) as confirmed by histopathological and immunofluorescence analysis. Differences in the spectra depending on tissue illness stage have been detected at 1,150–1,250 cm−1 (amide III) and 1,420–1,450 cm−1 (CH3 deformation) regions and around 1,650 cm−1 (amide I) and 2,930 cm−1 (CH3 symmetric stretch). The analysis of tissue Raman spectra by the proposed univariate method has allowed us to effectively differentiate tissues at different stages of pathology. PMID:22164077

  16. Micro-Raman spectroscopy and univariate analysis for monitoring disease follow-up.

    PubMed

    Camerlingo, Carlo; Delfino, Ines; Perna, Giuseppe; Capozzi, Vito; Lepore, Maria

    2011-01-01

    Micro-Raman spectroscopy is a very promising tool for medical applications, thanks to its sensitivity to subtle changes in the chemical and structural characteristics of biological specimens. To fully exploit these promises, building a method of data analysis properly suited for the case under study is crucial. Here, a linear or univariate approach using a R2 determination coefficient is proposed for discriminating Raman spectra even with small differences. The validity of the proposed approach has been tested using Raman spectra of high purity glucose solutions collected in the 600 to 1,600 cm(-1) region and also from solutions with two known solutes at different concentrations. After this validation step, the proposed analysis has been applied to Raman spectra from oral human tissues affected by Pemphigus Vulgaris (PV), a rare life-threatening autoimmune disease, for monitoring disease follow-up. Raman spectra have been obtained in the wavenumber regions from 1,050 to 1,700 cm(-1) and 2,700 to 3,200 cm(-1) from tissues of patients at different stages of pathology (active PV, under therapy and PV in remission stage) as confirmed by histopathological and immunofluorescence analysis. Differences in the spectra depending on tissue illness stage have been detected at 1,150-1,250 cm(-1) (amide III) and 1,420-1,450 cm(-1) (CH3 deformation) regions and around 1,650 cm(-1) (amide I) and 2,930 cm(-1) (CH3 symmetric stretch). The analysis of tissue Raman spectra by the proposed univariate method has allowed us to effectively differentiate tissues at different stages of pathology.

  17. Near-infrared confocal micro-Raman spectroscopy combined with PCA-LDA multivariate analysis for detection of esophageal cancer

    NASA Astrophysics Data System (ADS)

    Chen, Long; Wang, Yue; Liu, Nenrong; Lin, Duo; Weng, Cuncheng; Zhang, Jixue; Zhu, Lihuan; Chen, Weisheng; Chen, Rong; Feng, Shangyuan

    2013-06-01

    The diagnostic capability of using tissue intrinsic micro-Raman signals to obtain biochemical information from human esophageal tissue is presented in this paper. Near-infrared micro-Raman spectroscopy combined with multivariate analysis was applied for discrimination of esophageal cancer tissue from normal tissue samples. Micro-Raman spectroscopy measurements were performed on 54 esophageal cancer tissues and 55 normal tissues in the 400-1750 cm-1 range. The mean Raman spectra showed significant differences between the two groups. Tentative assignments of the Raman bands in the measured tissue spectra suggested some changes in protein structure, a decrease in the relative amount of lactose, and increases in the percentages of tryptophan, collagen and phenylalanine content in esophageal cancer tissue as compared to those of a normal subject. The diagnostic algorithms based on principal component analysis (PCA) and linear discriminate analysis (LDA) achieved a diagnostic sensitivity of 87.0% and specificity of 70.9% for separating cancer from normal esophageal tissue samples. The result demonstrated that near-infrared micro-Raman spectroscopy combined with PCA-LDA analysis could be an effective and sensitive tool for identification of esophageal cancer.

  18. Rapid detection of Listeria monocytogenes in milk using confocal micro-Raman spectroscopy and chemometric analysis.

    PubMed

    Wang, Junping; Xie, Xinfang; Feng, Jinsong; Chen, Jessica C; Du, Xin-jun; Luo, Jiangzhao; Lu, Xiaonan; Wang, Shuo

    2015-07-02

    Listeria monocytogenes is a facultatively anaerobic, Gram-positive, rod-shape foodborne bacterium causing invasive infection, listeriosis, in susceptible populations. Rapid and high-throughput detection of this pathogen in dairy products is critical as milk and other dairy products have been implicated as food vehicles in several outbreaks. Here we evaluated confocal micro-Raman spectroscopy (785 nm laser) coupled with chemometric analysis to distinguish six closely related Listeria species, including L. monocytogenes, in both liquid media and milk. Raman spectra of different Listeria species and other bacteria (i.e., Staphylococcus aureus, Salmonella enterica and Escherichia coli) were collected to create two independent databases for detection in media and milk, respectively. Unsupervised chemometric models including principal component analysis and hierarchical cluster analysis were applied to differentiate L. monocytogenes from Listeria and other bacteria. To further evaluate the performance and reliability of unsupervised chemometric analyses, supervised chemometrics were performed, including two discriminant analyses (DA) and soft independent modeling of class analogies (SIMCA). By analyzing Raman spectra via two DA-based chemometric models, average identification accuracies of 97.78% and 98.33% for L. monocytogenes in media, and 95.28% and 96.11% in milk were obtained, respectively. SIMCA analysis also resulted in satisfied average classification accuracies (over 93% in both media and milk). This Raman spectroscopic-based detection of L. monocytogenes in media and milk can be finished within a few hours and requires no extensive sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine.

    PubMed

    Stefaniak, Elzbieta A; Alsecz, Anita; Frost, Ray; Máthé, Zoltán; Sajó, István E; Török, Szabina; Worobiec, Anna; Van Grieken, René

    2009-08-30

    Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm(-1) which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles.

  20. Quantitative analysis of urinary stone composition with micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Yu; Chiu, Yi-Chun; Chiang, Huihua Kenny; Chou, Y. H. Jet; Lu, Shing-Hwa; Chiu, Allen W.

    2010-02-01

    Urolithiasis is a common, disturbing disease with high recurrent rate (60% in five years). Accurate identification of urinary stone composition is important for treatment and prevention purpose. Our previous studies have demonstrated that micro-Raman spectroscopy (MRS)-based approach successfully detects the composition of tiny stone powders after minimal invasive urological surgery. But quantitative analysis of urinary stones was not established yet. In this study, human urinary stone mixed with two compositions of COM, HAP, COD, and uric acid, were analyzed quantitatively by using a 632.98 nm Raman spectrometric system. This quantitative analysis was based on the construction of calibration curves of known mixtures of synthetically prepared pure COM, HAP, COD and uric acid. First, the various concentration (mole fraction) ratio of binary mixtures including COM and HAP, COM and COD, or COM and uric acid, were produced. Second, the intensities of the characteristic bands at 1462cm -1(IRCOM), 1477cm-1(IRCOD), 961cm-1(IRHAP) and 1402cm-1(IRuric acid), for COD, COM, HAP and uric acid were used respectively for intensity calculation. Various binary mixtures of known concentration ratio were recorded as the basis for the quantitative analysis. The ratios of the relative intensities of the Raman bands corresponding to binary mixtures of known composition on the inverse of the COM concentration yielded a linear dependence. Third, urinary stone fragments collected from patients after management were analyzed with the use of the calibration curve and the quantitative analysis of unknown samples was made by the interpolation analysis. We successfully developed a MRS-based quantitative analytical method for measuring two composition.

  1. An Investigation on Micro-Raman Spectra and Wavelet Data Analysis for Pemphigus Vulgaris Follow-up Monitoring.

    PubMed

    Camerlingo, Carlo; Zenone, Flora; Perna, Giuseppe; Capozzi, Vito; Cirillo, Nicola; Gaeta, Giovanni Maria; Lepore, Maria

    2008-06-01

    A wavelet multi-component decomposition algorithm has been used for data analysis of micro-Raman spectra of blood serum samples from patients affected by pemphigus vulgaris at different stages. Pemphigus is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. Spectra were measured by means of a Raman confocal microspectrometer apparatus using the 632.8 nm line of a He-Ne laser source. A discrete wavelet transform decomposition method has been applied to the recorded Raman spectra in order to overcome problems related to low-level signals and the presence of noise and background components due to light scattering and fluorescence. This numerical data treatment can automatically extract quantitative information from the Raman spectra and makes more reliable the data comparison. Even if an exhaustive investigation has not been done in this work, the feasibility of the follow-up monitoring of pemphigus vulgaris pathology has been clearly proved with useful implications for the clinical applications.

  2. An Investigation on Micro-Raman Spectra and Wavelet Data Analysis for Pemphigus Vulgaris Follow-up Monitoring

    PubMed Central

    Camerlingo, Carlo; Zenone, Flora; Perna, Giuseppe; Capozzi, Vito; Cirillo, Nicola; Gaeta, Giovanni Maria; Lepore, Maria

    2008-01-01

    A wavelet multi-component decomposition algorithm has been used for data analysis of micro-Raman spectra of blood serum samples from patients affected by pemphigus vulgaris at different stages. Pemphigus is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. Spectra were measured by means of a Raman confocal microspectrometer apparatus using the 632.8 nm line of a He-Ne laser source. A discrete wavelet transform decomposition method has been applied to the recorded Raman spectra in order to overcome problems related to low-level signals and the presence of noise and background components due to light scattering and fluorescence. This numerical data treatment can automatically extract quantitative information from the Raman spectra and makes more reliable the data comparison. Even if an exhaustive investigation has not been done in this work, the feasibility of the follow-up monitoring of pemphigus vulgaris pathology has been clearly proved with useful implications for the clinical applications. PMID:27879899

  3. Analysis of the molecular structure of human enamel with fluorosis using micro-Raman spectroscopy.

    PubMed

    Zavala-Alonso, Verónica; Loyola-Rodríguez, Juan P; Terrones, Humberto; Patiño-Marín, Nuria; Martínez-Castañón, Gabriel A; Anusavice, Kenneth

    2012-03-01

    The aim of this study was to analyze the molecular structure of enamel with fluorosis using micro-Raman spectroscopy and compare it with that of healthy enamel. Eighty extracted human molars were classified into four fluorosis groups according to the Thylstrup-Fejerskov Index (TFI) [TFI: 0, Healthy enamel; 1-3, mild; 4-5, moderate; 6-9, severe fluorosis]. All samples were analyzed by micro-Raman spectroscopy. The integral areas of ν(1) (960 cm(-1)) phosphate peak as well as B-type carbonate peak (1070 cm(-1)) were obtained to analyze structural differences among the specimens. Although the differences were not statistically significant (P > 0.05), the mean of integral areas of ν(1) phosphate peak among groups indicated greater mineralization in the severe fluorosis group. However, there were statistically significant differences in the intensities, and the integral areas of B-type carbonate peak among groups (P < 0.05). Therefore, mineralization of the carbonate peak at 1070 cm(-1) decreased significantly in fluorotic groups, suggesting that carbonate ions are easily dissolved in the presence of fluoride. Although structurally fluorotic teeth are not more susceptible to dental caries, serious alteration in its surface topography may cause retention of bacterial plaque and formation of enamel caries. Micro-Raman spectroscopy is a useful tool for analyzing the molecular structure of healthy and fluorotic human enamel.

  4. Non-destructive micro-Raman analysis of Si near Cu through silicon via

    NASA Astrophysics Data System (ADS)

    Kim, Jae Hyun; Yoo, Woo Sik; Han, Seung Min

    2017-03-01

    Silicon near Cu through-silicon vias (TSVs) develops stresses during processing steps, and the local stress of Si around Cu TSVs of sizes ranging from 4 to 8 μm was characterized using micro-Raman spectroscopy as a function of processing steps. Micro-Raman measurements showed that the max stress sum, σ r + σ θ, is size dependent, where the stress sum of 88.7 MPa in the compressive direction was measured in Si for 8 μm sized Cu via, and this max stress sum, σ r + σ θ, decreased to 21 MPa in compression for 4 μm sized Cu via. With the deposition of oxide/nitride overlayers, the stress sum was found to switch sign to 138.9 MPa in the tensile direction for 8 μm sized Cu via after deposition of the SiN overlayers with residual compressive stress caused by ion bombardment. The measured stresses by micro-Raman was used to determine the keep-off-zone that can be used in device design to ensure reliability, and compared against the TCAD simulations results.

  5. Rapid and label-free identification of normal spermatozoa based on image analysis and micro-Raman spectroscopy.

    PubMed

    Huang, Zufang; Chen, Guannan; Chen, Xiwen; Wang, Jing; Chen, Jinhua; Lu, Peng; Chen, Rong

    2014-09-01

    Semen analysis is performed for evaluation of fertility disorders, however it is susceptible to subjectivity of investigators, and lacking of objective criterion for sperm cell quality remains a problem. There is an ongoing debate on which criteria should be employed to define normal spermatozoa. Here, the aim of our study is to evaluate the possibility of label-free and rapid identification of normal sperm cell through the use of image analysis combined with micro-Raman spectroscopy. By using a smooth-surfaced and hydrophobic substrate, spermatozoa smear was rapidly prepared for microscopic imaging and acrosome area can be clearly visualized without any extra stains; then a self-written image analysis program was utilized to segment sperm head and acrosome area and automatically calculates morphological indices. Most important, intensity ratio of 1055 cm(-1) to 1095 cm(-1) from the obtained Raman spectra is found to indicate a potential biomarker for assessing the sperm DNA integrity. Our preliminary study demonstrates that micro-Raman spectroscopy combined with image analysis can be a potentially useful tool for rapid and label-free identification of normal sperm cell by providing both morphological and biochemical information. Copyright © 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Application of slope-polishing technique for depth profile of selenized CIGS by micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Kwon, Min-Su; Kang, Jeong-yoon; Kim, SeongYeon; Kim, JunHo; Jeon, Chan-Wook

    2016-08-01

    Micro-Raman analysis was carried out on two Cu(In,Ga)Se2 films to determine the location of the secondary phases, which were suspected of being formed during the selenization process of Cu-In-Ga metallic precursor films. A slope polishing technique using a dimple grinder was applied to physically expand the film thickness by several hundred fold, which allowed high resolution Raman analysis. Various secondary phases including CuxSe, InSe, Se, and MoySe at different depths were identified without need for time-consuming sputter etching, which may adversely affect the film chemistry. With the help of the new sample preparation method for depth analysis of thin film, a precise decision on the location of those secondary phases along the film thickness and better understanding of the reaction mechanism was enabled.

  7. Micro-Raman, FTIR, SEM-EDX and structural analysis of the Çanakkale meteorite.

    PubMed

    Unsalan, O; Yilmaz, A; Bolukbasi, O; Ozturk, B; Esenoglu, H H; Ildiz, G O; Ornek, C Y

    2012-06-15

    This study demonstrates for the first time, the spectroscopic characterization of Çanakkale Meteorite that fell at Çanakkale, Republic of Turkey (40°8'44″N; 26°24'23″E). The olivine group [(Mg, Fe)(2)SiO(4)], enstatite [Mg(2)Si(2)O(6)] (one of the orthopyroxene minerals) and plagioclase were identified by the micro-Raman and FTIR spectroscopies and EDX-SEM analyses. This meteorite has not yet been classified in the World's Database of Meteorites. The aim of this study is to investigate this meteorite by vibrational spectroscopic techniques and open the possibility to classify it and list in the World's Database of Meteorites.

  8. Analysis of green copper pigments in illuminated manuscripts by micro-Raman spectroscopy.

    PubMed

    Gilbert, B; Denoël, S; Weber, G; Allart, D

    2003-10-01

    In the majority of the literature describing green coloured materials used on ancient painting layers (15th or 16th century), two copper greens are mainly cited: malachite [CuCOr3 x Cu(OH)2] and verdigris [Cu(CH3COO)2 x [Cu(OH)2]3 x 2H2O]. It is shown, by micro-Raman spectroscopy, that the artists were actually employing more than these two copper greens, in particular various copper sulfates, among which the most common pigment found is posnjakite [CuSO4 x 3Cu(OH)2 x H2O]. In contrast to the PIXE (particle induced X-ray emission) technique, Raman spectroscopy is a technique of choice, able to distinguish not only a copper sulfate from a carbonate or acetate but also the different sulfates themselves; in this respect, we found that the high wavenumber region (2800-4000 cm(-1)), characteristic of H2O vibrations, is of particular interest. It is also shown that numerous green areas were created with mixtures of a copper sulfate mixed with other pigments, for instance to enhance the colour depth. Finally, in some cases, no green pigment is actually employed but the colour is obtained by intimately mixing yellow and blue pigments. All these results led to a new look at the pigments which were in use on the palettes of the ancient artists.

  9. Combined use of direct analysis in real-time/Orbitrap mass spectrometry and micro-Raman spectroscopy for the comprehensive characterization of real explosive samples.

    PubMed

    Bridoux, Maxime C; Schwarzenberg, Adrián; Schramm, Sébastien; Cole, Richard B

    2016-08-01

    Direct Analysis in Real Time (DART™) high-resolution Orbitrap™ mass spectrometry (HRMS) in combination with Raman microscopy was used for the detailed molecular level characterization of explosives including not only the charge but also the complex matrix of binders, plasticizers, polymers, and other possible organic additives. A total of 15 defused military weapons including grenades, mines, rockets, submunitions, and mortars were examined. Swabs and wipes were used to collect trace (residual) amounts of explosives and their organic constituents from the defused military weapons and micrometer-size explosive particles were transferred using a vacuum suction-impact collection device (vacuum impactor) from wipe and swap samples to an impaction plate made of carbon. The particles deposited on the carbon plate were then characterized using micro-Raman spectroscopy followed by DART-HRMS providing fingerprint signatures of orthogonal nature. The optical microscope of the micro-Raman spectrometer was first used to localize and characterize the explosive charge on the impaction plate which was then targeted for identification by DART-HRMS analysis in both the negative and positive modes. Raman spectra of the explosives TNT, RDX and PETN were acquired from micrometer size particles and characterized by the presence of their characteristic Raman bands obtained directly at the surface of the impaction plate nondestructively without further sample preparation. Negative mode DART-HRMS confirmed the types of charges contained in the weapons (mainly TNT, RDX, HMX, and PETN; either as individual components or as mixtures). These energetic compounds were mainly detected as deprotonated species [M-H](-), or as adduct [M + (35)Cl](-), [M + (37)Cl](-), or [M + NO3](-) anions. Chloride adducts were promoted in the heated DART reagent gas by adding chloroform vapors to the helium stream using an "in-house" delivery method. When the polarity was switched to positive mode

  10. Micro-Raman Spectroscopy to Complement Proton-Induced X-Ray Emission in the Analysis of Atmospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Safiq, Alexandrea; Ali, Salina; Nadarski, Benjamin; Smith, Jeremy; Yoskowitz, Josh; Labrake, Scott; Vineyard, Michael; Union College Team

    2013-10-01

    There is an active research program in the Union College Ion-Beam Analysis Laboratory on proton-induced X-ray emission (PIXE) analysis of atmospheric aerosols. PIXE is a powerful tool for the study of airborne pollution because it provides information on a broad range of elements simultaneously, has low detection limits, is nondestructive, does not require large samples, and the analysis can be performed in a short amount of time. However, PIXE provides only elemental information. We are investigating the use of Micro-Raman spectroscopy (MRS) to complement PIXE analysis of aerosol samples by providing chemical information. In MRS, laser light is inelastically scattered from a sample and the vibrational spectrum of the scattered light is used to identify molecules and their functional groups. We are focusing on aerosol samples collected in the Adirondack Mountains that have considerable concentrations of sulfur that may contribute to acid rain. The MRS spectra collected on aerosol samples are being compared with a library of standards to try to determine the molecular structures in which the sulfur is bound. We will describe the analysis and present preliminary results. Union College Undergraduate Research Program.

  11. Application of micro-Raman spectroscopy for fight against terrorism and smuggling

    NASA Astrophysics Data System (ADS)

    Almaviva, Salvatore; Botti, Sabina; Palucci, Antonio; Puiu, Adriana; Schnürer, Frank; Schweikert, Wenka; Romolo, Francesco Saverio

    2014-04-01

    We report the results of Raman measurements on some common military explosives and explosives precursors deposited on clothing fabrics, both synthetic and natural, in concentration comparable to those obtained from a single fingerprint or mixed with similar harmless substances to detect illegal compounds for smuggling activities. Raman spectra were obtained using an integrated portable Raman system equipped with an optical microscope and a 785-nm laser in an analysis of <1 min. The spectral features of each illicit substance have been identified and distinguished from those belonging to the substrate fabric or from the interfering compound. Our results show that the application of Raman spectroscopy (RS) with a microscope-based portable apparatus can provide interpretable Raman spectra for a fast, in-situ analysis, directly from explosive particles of some μ, despite the contribution of the substrate, leaving the sample completely unaltered for further, more specific, and propedeutic laboratory analysis. We also show how the RS is suitable for detecting illegal compounds mixed with harmless substances for smuggling purposes or for counterfeiting activities.

  12. Process induced transformations during tablet manufacturing: phase transition analysis of caffeine using DSC and low frequency micro-Raman spectroscopy.

    PubMed

    Hubert, Sébastien; Briancon, Stéphanie; Hedoux, Alain; Guinet, Yannick; Paccou, Laurent; Fessi, Hatem; Puel, François

    2011-11-25

    The phase transition of a model API, caffeine Form I, was studied during tableting process monitored with an instrumented press. The formulation used had a plastic flow behavior according to the Heckel model in the compression pressure range of 70-170 MPa. The quantitative methods of analysis used were Differential Scanning Calorimetry (DSC) and low frequency Micro Raman Spectroscopy (MRS) which was used for the first time for the mapping of polymorphs in tablets. They brought complementary contributions since MRS is a microscopic spectral analysis with a spatial resolution of 5 μm(3) and DSC takes into account a macroscopic fraction (10mg) of the tablet. Phase transitions were present at the surfaces, borders and center of the tablets. Whatever the pressure applied during the compression process, the transition degree of caffeine Form I toward Form II was almost constant. MRS provided higher transition degrees (50-60%) than DSC (20-35%). MRS revealed that caffeine Form I particles were partially transformed in all parts of the tablets at a microscopic scale. Moreover, tablet surfaces showed local higher transition degree compared to the other parts.

  13. In situ micro-Raman analysis and X-ray diffraction of nickel silicide thin films on silicon.

    PubMed

    Bhaskaran, M; Sriram, S; Perova, T S; Ermakov, V; Thorogood, G J; Short, K T; Holland, A S

    2009-01-01

    This article reports on the in situ analysis of nickel silicide (NiSi) thin films formed by thermal processing of nickel thin films deposited on silicon substrates. The in situ techniques employed for this study include micro-Raman spectroscopy (microRS) and X-ray diffraction (XRD); in both cases the variations for temperatures up to 350 degrees C has been studied. Nickel silicide thin films formed by vacuum annealing of nickel on silicon were used as a reference for these measurements. In situ analysis was carried out on nickel thin films on silicon, while the samples were heated from room temperature to 350 degrees C. Data was gathered at regular temperature intervals and other specific points of interest (such as 250 degrees C, where the reaction between nickel and silicon to form Ni(2)Si is expected). The transformations from the metallic state, through the intermediate reaction states, until the desired metal-silicon reaction product is attained, are discussed. The evolution of nickel silicide from the nickel film can be observed from both the microRS and XRD in situ studies. Variations in the evolution of silicide from metal for different silicon substrates are discussed, and these include (100) n-type, (100) p-type, and (110) p-type silicon substrates.

  14. Degree of conversion of luting resins around ceramic inlays in natural deep cavities: a micro-Raman spectroscopy analysis.

    PubMed

    Lohbauer, Ulrich; Pelka, Matthias; Belli, Renan; Schmitt, Johannes; Mocker, Eike; Jandt, Klaus D; Müller, Frank A

    2010-01-01

    This study evaluated the degree of conversion (%DC) of luting agents around ceramic inlays placed in deep natural cavities. Thirty-six cylindrical Class I cavities (diameter = 4 mm, depth = 4 mm) were prepared in freshly extracted human teeth and randomly divided according to the luting materials used for luting CAD/CAM fabricated inlays (Empress CAD). The dual-cure resin cements Clearfil Esthetic Cement and Variolink II Low and the light-cure composites Grandio Flow and Grandio were luted using the total-etch technique. The self-adhesive dual-cure cements RelyX Unicem and Maxcem Elite were used as recommended by the manufacturer. All of the restorations were photo-activated using a quartz halogen unit (Elipar TriLight; 750 mW/cm2) for 40 seconds. After 24 hour dry-storage in the dark, all the teeth were vertically sectioned into two halves (n = 12 per group) using a slow-speed diamond-saw in the bucco-vestibular direction under constant water lubrication to avoid specimen heating. The DC of the luting materials was measured by vibrational spectroscopy using a micro-Raman spectrometer at depths of 1, 3 and 4 mm on each side of the tooth halves (n = 24). Disc-shaped samples were produced for measurement of the maximum %DC of each material. Two-way ANOVA and the Student-Newman-Keuls post-hoc test were used in the statistical analysis (alpha = 0.05). All the materials showed no statistical differences in degree of conversion at all tested depths, except for Grandio Flow and Maxcem Elite. Dual-cure and light-cure luting materials showed polymerization homogeneity around ceramic inlays, although dual-cure conventional resin cements tended to show an overall higher conversion.

  15. Biochemical and molecular characterization of thyroid tissue by micro-Raman spectroscopy and gene expression analysis

    NASA Astrophysics Data System (ADS)

    Neto, Lázaro P. M.; Martin, Aírton A.; Soto, Claudio A. T.; Santos, André B. O.; Mello, Evandro S.; Pereira, Marina A.; Cernea, Cláudio R.; Brandão, Lenine G.; Canevari, Renata A.

    2016-02-01

    Thyroid carcinomas represent the main endocrine malignancy and their diagnosis may produce inconclusive results. Raman spectroscopy and gene expression analysis have shown excellent results on the differentiation of carcinomas. This study aimed to improve the discrimination between different thyroid pathologies combining of both analyses. A total of 35 thyroid tissues samples including normal tissue (n=10), goiter (n=10), papillary (n=10) and follicular carcinomas (n=5) were analyzed. Confocal Raman spectra was obtain by using a Rivers Diagnostic System, 785 nm laser excitation and CCD detector. The data was processed by the software Labspec5 and Origin 8.5 and analyzed by Minitab® program. The gene expression analysis was performed by qRT-PCR technique for TG, TPO, PDGFB, SERPINA1, LGALS3 and TFF3 genes and statistically analyzed by Mann-Whitney test. The confocal Raman spectroscopy allowed a maximum discrimination of 91.1% between normal and tumor tissues, 84.8% between benign and malignant pathologies and 84.6% among carcinomas analyzed. Significant differences was observed for TG, LGALS3, SERPINA1 and TFF3 genes between benign lesions and carcinomas, and SERPINA1 and TFF3 genes between papillary and follicular carcinomas. Principal component analysis was performed using PC1 and PC2 in the papillary carcinoma samples that showed over gene expression when compared with normal sample, where 90% of discrimination was observed at the Amide 1 (1655 cm-1), and at the tyrosine spectra region (856 cm-1). The discrimination of tissues thyroid carried out by confocal Raman spectroscopy and gene expression analysis indicate that these techniques are promising tools to be used in the diagnosis of thyroid lesions.

  16. Micro-Raman spectroscopy of algae: composition analysis and fluorescence background behavior.

    PubMed

    Huang, Y Y; Beal, C M; Cai, W W; Ruoff, R S; Terentjev, E M

    2010-04-01

    Preliminary feasibility studies were performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella sorokiniana (UTEX #1230) and Neochloris oleoabundans (UTEX #1185), were chosen for this study. Both species were considered to be candidates for biofuel production. Raman signals due to storage lipids (specifically triglycerides) were clearly identified in the nitrogen-starved C. sorokiniana and N. oleoabundans, but not in their healthy counterparts. On the other hand, signals resulting from the carotenoids were found to be present in all of the samples. Composition mapping was conducted in which Raman spectra were acquired from a dense sequence of locations over a small region of interest. The spectra obtained for the mapping images were filtered for the wavelengths of characteristic peaks that correspond to components of interest (i.e., triglyceride or carotenoid). The locations of the components of interest could be identified by the high intensity areas in the composition maps. Finally, the time evolution of fluorescence background was observed while acquiring Raman signals from the algae. The time dependence of fluorescence background is characterized by a general power law decay interrupted by sudden high intensity fluorescence events. The decreasing trend is likely a result of photo-bleaching of cell pigments due to prolonged intense laser exposure, while the sudden high intensity fluorescence events are not understood.

  17. NanoSIMS and Micro-Raman Spectroscopy applied to the Analysis of Uranium Oxyfluoride Particles for Nuclear Safeguards

    NASA Astrophysics Data System (ADS)

    Kips, R.; Kristo, M.; Crowhurst, J.; Stefaniak, E.; Hutcheon, I. D.

    2010-12-01

    Environmental swipe sampling is used by safeguards organizations to verify the absence of undeclared nuclear activities. Particulate material collected in environmental swipe samples is typically analyzed for its uranium isotopic composition. At enrichment facilities, these swipe samples often contain UO2F2 particles formed from the hydrolysis of uranium hexafluoride gas. Since UO2F2 particulate material has been found to be unstable with respect to the loss of fluorine (J.A. Carter et al. Task A.200.3 K/NSP-777, 1998) the measurement of the residual amount of fluorine has the potential of placing boundaries on the particle’s age and exposure history. To investigate the decomposition of UO2F2 and its potential applications in nuclear safeguards and nuclear forensics, a suite of micro-analytical tools was applied to a set of lab-synthesized UO2F2 particles. Samples were either stored in an inert atmosphere or exposed to different levels of humidity, temperature and light to identify those environmental conditions that accelerate the decomposition of UO2F2. Given the small size of the particles, secondary ion mass spectrometry with nanometer-scale spatial resolution (NanoSIMS) was used to measure the relative amount of fluorine. The elemental data from the NanoSIMS was complemented with micro-Raman spectroscopy for molecular fingerprinting. These measurements showed that even though the decomposition of UO2F2 generally happens very slowly, subtle differences can be distinguished depending on the environmental conditions to which they were exposed. The exposure to humidity was identified as the main factor accelerating the loss of fluorine in UO2F2 particles. Particles exposed to 30 % relative humidity and higher showed a decrease in the relative amount of fluorine and a shift of the UO22+ symmetric stretching frequency towards lower frequencies. These changes were attributed to an increase in hydration of the UO2F2 particles. This work was performed under the

  18. Study of the reaction products of SF6 and C in the laser heated diamond anvil cell by pair distribution function analysis and micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Rademacher, N.; Bayarjargal, L.; Morgenroth, W.; Bauer, J. D.; Milman, V.; Winkler, B.

    2015-05-01

    The decomposition of SF6 in the presence of glassy carbon was induced in laser heated diamond anvil cells at 10-11 GPa and 2000-2500 K. The reaction products were characterised by synchrotron X-ray diffraction, including high pressure pair distribution function analysis, and micro-Raman spectroscopy combined with atomistic model calculations. The decomposition leads to elemental amorphous helical sulfur and crystalline CF4-III. Two different sulfur phases, namely helical Sμ and crystalline α-S8, were observed after recovering the laser heated samples of different experiments at ambient conditions.

  19. Ochre-differentiation through micro-Raman and micro-FTIR spectroscopies: application on wall paintings at Meteora and Mount Athos, Greece.

    PubMed

    Bikiaris, D; Daniilia Sister; Sotiropoulou, S; Katsimbiri, O; Pavlidou, E; Moutsatsou, A P; Chryssoulakis, Y

    2000-01-01

    The most widely-used inorganic pigments of Byzantine and post-Byzantine hagiography are earth pigments called ochres such as, red and yellow ochres, limonite, goethite, raw and burnt sienna, caput mortuum and hematite. The present experimental work proposes a technique of differentiation that allows one to distinguish among all the different kinds of iron oxides, thereby providing a better understanding of the painting technique used on portable icons and wall paintings. The ratios between the main spectroscopic peaks, attributable to the major components usually present in ochres, were calculated and compared, one against the another, from the spectra obtained through micro-Raman spectroscopy. Elementary composition is also revealed through a scanning electron microscopy (SEM) analysis. The possibility for detailed study on a particular Byzantine ochre palette can thus be performed based on the small differences in its nature and composition. These differences can first be observed and then measured among all of the natural earth pigments, through microRaman and microFTIR spectroscopies.

  20. The efficiency of micro-Raman spectroscopy in the analysis of complicated mixtures in modern paints: Munch's and Kupka's paintings under study

    NASA Astrophysics Data System (ADS)

    Košařová, Veronika; Hradil, David; Hradilová, Janka; Čermáková, Zdeňka; Němec, Ivan; Schreiner, Manfred

    2016-03-01

    Twenty one mock-up samples containing inorganic pigments primarily used at the turn of the 19th and 20th century were selected for comparative study and measured by micro-Raman and portable Raman spectrometers. They included pure grounds (chalk-based, earth-based and lithopone-based), grounds covered by resin-based varnish, and different paint layers containing mixtures of white, yellow, orange, red, green, blue and black pigments, usually in combination with white pigments (titanium, zinc and barium whites or chalk). In addition, ten micro-samples obtained from seven paintings of two world-famous modern painters Edvard Munch and František Kupka have been investigated. Infrared reflection spectroscopy (FTIR), portable X-ray fluorescence (XRF) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) were used as supplementary methods. The measurements showed that blue pigments (ultramarine, Prussian blue and azurite), vermilion and ivory black in mixture with whites provided characteristic Raman spectra, while Co-, Cd- and Cr- pigments' bands were suppressed by fluorescence. The best success rate of micro-Raman spectroscopy has been achieved using the 780 nm excitation, however, the sensitivity of this excitation laser in a portable Raman instrument significantly decreased. The analyses of micro-samples of paintings by E. Munch and F. Kupka showed that micro-Raman spectroscopy identified pigments which would remain unidentified if analyzed only by SEM-EDS (zinc yellow, Prussian blue). On the other hand, chromium oxide green and ultramarine were not detected together in a sample due to overlap of their main bands. In those cases, it is always necessary to complement Raman analysis with other analytical methods.

  1. The efficiency of micro-Raman spectroscopy in the analysis of complicated mixtures in modern paints: Munch's and Kupka's paintings under study.

    PubMed

    Košařová, Veronika; Hradil, David; Hradilová, Janka; Čermáková, Zdeňka; Němec, Ivan; Schreiner, Manfred

    2016-03-05

    Twenty one mock-up samples containing inorganic pigments primarily used at the turn of the 19th and 20th century were selected for comparative study and measured by micro-Raman and portable Raman spectrometers. They included pure grounds (chalk-based, earth-based and lithopone-based), grounds covered by resin-based varnish, and different paint layers containing mixtures of white, yellow, orange, red, green, blue and black pigments, usually in combination with white pigments (titanium, zinc and barium whites or chalk). In addition, ten micro-samples obtained from seven paintings of two world-famous modern painters Edvard Munch and František Kupka have been investigated. Infrared reflection spectroscopy (FTIR), portable X-ray fluorescence (XRF) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) were used as supplementary methods. The measurements showed that blue pigments (ultramarine, Prussian blue and azurite), vermilion and ivory black in mixture with whites provided characteristic Raman spectra, while Co-, Cd- and Cr- pigments' bands were suppressed by fluorescence. The best success rate of micro-Raman spectroscopy has been achieved using the 780 nm excitation, however, the sensitivity of this excitation laser in a portable Raman instrument significantly decreased. The analyses of micro-samples of paintings by E. Munch and F. Kupka showed that micro-Raman spectroscopy identified pigments which would remain unidentified if analyzed only by SEM-EDS (zinc yellow, Prussian blue). On the other hand, chromium oxide green and ultramarine were not detected together in a sample due to overlap of their main bands. In those cases, it is always necessary to complement Raman analysis with other analytical methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Micro-Raman spectroscopy and E-SEM analysis of hybrid layer at the dentine/resin interface of three different composite restorative resins

    NASA Astrophysics Data System (ADS)

    Camerlingo, C.; Gaeta, G. M.; Riccio, R.; Rosso, F.; Muscariello, L.; Lepore, M.

    2006-02-01

    The formation of a hybrid layer at the dentin/resin interface is a critical point in the curative processes. New restorative materials are currently under investigation in order to improve the characteristics of this interface layer. In this paper micro-Raman spectroscopy and Environmental Scanning Electron Microscope (E-SEM) analysis have been performed to investigate the interface properties of three different restorative materials. The experimental investigation has been performed on tooth cavities prepared both by Er:YAG laser ablation and by conventional diamond bur. Laser prepared cavities were realized using 100 ms pulsed light beam with energy of 350 mJ, at a frequency of 20 Hz. The cavities were filled with three different composites: True-Vitality (Den-Mat), Enamel Plus (Micerium), Supreme (3M). The treated samples were sectioned perpendicularly to the exposed dentin surface and the morphological characterization of the samples was performed by means of E-SEM operating in wet mode. This equipment permits to obtain a high-resolution image of surface without conductive coating process. The same samples were then examined by micro-Raman spectroscopy that has already shown its validity in the study of dentin/resin interfaces.

  3. An investigation into the use of micro-Raman spectroscopy for the analysis of car paints and single textile fibres

    NASA Astrophysics Data System (ADS)

    Zięba-Palus, Janina; Wąs-Gubała, Jolanta

    2011-05-01

    Micro-Raman spectroscopy was applied to identification and differentiation between criminalistic traces such as micropaint chips and single fibres. The aim was to determine the degree of discrimination between fibres coloured by defined chemical dye classes and to differentiate between paint samples on the basis of pigment/dye content. Samples of coloured cotton fibres and samples of green car paints were examined. It was found that the majority of the obtained Raman spectra provided information about the main dyes present in the sample. However, in some cases fluorescence of the samples made dye identification impossible. Spectral libraries for examined paint samples and single fibres were created in order to facilitate quick recognition of similar forensic traces using this analytical method.

  4. Improvements in the wallpaper industry during the second half of the 19th century: micro-Raman spectroscopy analysis of pigmented wallpapers.

    PubMed

    Castro, K; Vandenabeele, P; Rodríguez-Laso, M D; Moens, L; Madariaga, J M

    2005-08-01

    Scientific studies of the pigments used in the manufacturing process of some pigmented wallpapers are presented in this work. Non-destructive micro-Raman spectroscopy was selected for this purpose, and provides important information about how the 19th century wallpaper industry incorporated new materials in their works and designs. At the same time, analysis can help to date the samples of uncatalogued wallpapers. Chrome yellow, burnt Sienna, Prussian blue, ultramarine blue, red lead, carbon black, calcium carbonate, red iron oxide and a red organic pigment were identified. According to the palette used, as well as to the manufacturing process, the wallpapers in this study can be dated to the second half of the 19th century.

  5. Improvements in the wallpaper industry during the second half of the 19th century: Micro-Raman spectroscopy analysis of pigmented wallpapers

    NASA Astrophysics Data System (ADS)

    Castro, K.; Vandenabeele, P.; Rodríguez-Laso, M. D.; Moens, L.; Madariaga, J. M.

    2005-08-01

    Scientific studies of the pigments used in the manufacturing process of some pigmented wallpapers are presented in this work. Non-destructive micro-Raman spectroscopy was selected for this purpose, and provides important information about how the 19th century wallpaper industry incorporated new materials in their works and designs. At the same time, analysis can help to date the samples of uncatalogued wallpapers. Chrome yellow, burnt Sienna, Prussian blue, ultramarine blue, red lead, carbon black, calcium carbonate, red iron oxide and a red organic pigment were identified. According to the palette used, as well as to the manufacturing process, the wallpapers in this study can be dated to the second half of the 19th century.

  6. A Novel Technique for Raman Analysis of Highly Radioactive Samples Using Any Standard Micro-Raman Spectrometer

    PubMed Central

    Colle, Jean-Yves; Naji, Mohamed; Sierig, Mark; Manara, Dario

    2017-01-01

    A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a tight capsule that isolates the material from the atmosphere. The capsule can optionally be filled with a chosen gas pressurized up to 20 bars. The micro-Raman measurement is performed through an optical-grade quartz window. This technique permits accurate Raman measurements with no need for the spectrometer to be enclosed in an alpha-tight containment. It therefore allows the use of all options of the Raman spectrometer, like multi-wavelength laser excitation, different polarizations, and single or triple spectrometer modes. Some examples of measurements are shown and discussed. First, some spectral features of a highly radioactive americium oxide sample (AmO2) are presented. Then, we report the Raman spectra of neptunium oxide (NpO2) samples, the interpretation of which is greatly improved by employing three different excitation wavelengths, 17O doping, and a triple mode configuration to measure the anti-stokes Raman lines. This last feature also allows the estimation of the sample surface temperature. Finally, data that were measured on a sample from Chernobyl lava, where phases are identified by Raman mapping, are shown. PMID:28448046

  7. A Novel Technique for Raman Analysis of Highly Radioactive Samples Using Any Standard Micro-Raman Spectrometer.

    PubMed

    Colle, Jean-Yves; Naji, Mohamed; Sierig, Mark; Manara, Dario

    2017-04-12

    A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a tight capsule that isolates the material from the atmosphere. The capsule can optionally be filled with a chosen gas pressurized up to 20 bars. The micro-Raman measurement is performed through an optical-grade quartz window. This technique permits accurate Raman measurements with no need for the spectrometer to be enclosed in an alpha-tight containment. It therefore allows the use of all options of the Raman spectrometer, like multi-wavelength laser excitation, different polarizations, and single or triple spectrometer modes. Some examples of measurements are shown and discussed. First, some spectral features of a highly radioactive americium oxide sample (AmO2) are presented. Then, we report the Raman spectra of neptunium oxide (NpO2) samples, the interpretation of which is greatly improved by employing three different excitation wavelengths, (17)O doping, and a triple mode configuration to measure the anti-stokes Raman lines. This last feature also allows the estimation of the sample surface temperature. Finally, data that were measured on a sample from Chernobyl lava, where phases are identified by Raman mapping, are shown.

  8. Bone quality around bioactive silica-based coated stainless steel implants: analysis by micro-Raman, XRF and XAS techniques.

    PubMed

    Ballarre, Josefina; Desimone, Paula M; Chorro, Matthieu; Baca, Matías; Orellano, Juan Carlos; Ceré, Silvia M

    2013-11-01

    Surface modification of surgical stainless steel implants by sol gel coatings has been proposed as a tool to generate a surface that besides being protective could also create a "bioactive" interface to generate a natural bonding between the metal surface and the existing bone. The aim of this work is to analyze the quality and bone formation around hybrid bioactive coatings containing glass-ceramic particles, made by sol-gel process on 316L stainless steel used as permanent implant in terms of mineralization, calcium content and bone maturity with micro Raman, X-ray microfluorescence and X-ray absorption techniques. Uncoated implants seem to generate a thin bone layer at the beginning of osseointegration process and then this layer being separated from the surface with time. The hybrid coatings without glass-ceramic particles generate new bone around implants, with high concentration of Ca and P at the implant/tissue interface. This fact seems to be related with the presence of silica nanoparticles in the layer. The addition of bioactive particles promotes and enhances the bone quality with a homogeneous Ca and P content and a low rate of beta carbonate substitution and crystallinity, similar to young and mechanical resistant bone.

  9. Degree of conversion of two-step etch-and-rinse adhesives: In situ micro-Raman analysis.

    PubMed

    Navarra, Chiara Ottavia; Breschi, Lorenzo; Turco, Gianluca; Diolosà, Marina; Fontanive, Luca; Manzoli, Lucia; Di Lenarda, Roberto; Cadenaro, Milena

    2012-09-01

    DC of three commercial two-step etch-and-rinse adhesives across the dentine-adhesive interface was investigated using micro-Raman spectroscopy. The hypothesis tested was that no difference in DC would exist among the adhesives tested. Adper Scotchbond 1XT (3M ESPE), Prime&Bond NT (Dentsply DeTrey), and Ambar (FGM) were applied on human dentine disks (n=9). Composite increments of 2mm were then applied on the adhesive surface. Raman spectra were collected along the dentine-adhesive interface. The relative intensities of the peaks associated with the mineral (PO(4)(3-) at 960cm(-1)) and the adhesive (CC at 1640cm(-1); phenyl CC at 1610cm(-1)) were used to identify the adhesive within the hybrid layer and calculate its DC. Adper Scotchbond 1XT and Ambar showed similar DC (79±7% and 77±7%, respectively), while a lower DC was found for Prime&Bond NT (70±7%; p<0.05). The hypothesis tested was rejected because differences were found among the adhesives tested. The difference in DC among the three adhesive systems can be attributed to different monomer compositions and solvents. Further studies are needed to correlate DC with other mechanical properties of these adhesives. Insufficient polymerization of an adhesive can result in a weak hybrid layer, and the presence of unreacted monomers may result in degradation of the polymeric network, decreasing the strength and longevity of the bond. In the present study, Adper Scotchbond 1XT and Ambar performed significantly better than Prime&Bond NT. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Micro-Raman spectroscopy on oral tissues

    NASA Astrophysics Data System (ADS)

    Zenone, F.; Lepore, M.; Perna, G.; Carmone, P.; Riccio, R.; Gaeta, G. M.; Capozzi, V.

    2006-02-01

    Micro-Raman Spectroscopy (μ-RS) provides a unique tool in medicine for a not invasive and real time analysis of biological tissue for biopsy and "in vivo" investigation. Based on the evaluation of molecular vibration frequencies, the μ-RS is able to detect the main molecular bonds of protein constituents, as the C-H and C-C ones. Changes in frequency or in the relative intensity of the vibration modes revealed by μ-RS can be related to changes of chemical bond and of protein structure induced by pathology. The μ-RS has been performed on samples of oral tissue from informed patients, affected by pemphigus vulgaris (an oral pathology) in an advanced regression state. The biopsies were thin slices (about 1mm thick) with 6mm diameter. The sample was measured through a 170 μm thick cover-glass. The experimental set-up was mainly composed by a He-Ne laser and a monochromator equipped with a Peltier cell and with a grating of 1800 grooves/mm. The laser light was focused on the sample surface by means of a long focal length 50X optical objective. The main protein bonds are clearly detectable in the considered samples and this give important information on the integrity and on the state of tissue components (lipids and proteins), and consequently on the occurrence of pathology. The potential application of this method for in vivo analysis is an invaluable alternative to biopsy and pathological examinations for many medical application as screening diagnostic, therapy progress examination, and surgical support.

  11. Ochre-differentiation through micro-Raman and micro-FTIR spectroscopies: application on wall paintings at Meteora and Mount Athos, Greece

    NASA Astrophysics Data System (ADS)

    Bikiaris, D.; Daniilia, Sister; Sotiropoulou, S.; Katsimbiri, O.; Pavlidou, E.; Moutsatsou, A. P.; Chryssoulakis, Y.

    2000-01-01

    The most widely-used inorganic pigments of Byzantine and post-Byzantine hagiography are earth pigments called ochres such as, red and yellow ochres, limonite, goethite, raw and burnt sienna, caput mortuum and hematite. The present experimental work proposes a technique of differentiation that allows one to distinguish among all the different kinds of iron oxides, thereby providing a better understanding of the painting technique used on portable icons and wall paintings. The ratios between the main spectroscopic peaks, attributable to the major components usually present in ochres, were calculated and compared, one against the another, from the spectra obtained through micro-Raman spectroscopy. Elementary composition is also revealed through a scanning electron microscopy (SEM) analysis. The possibility for detailed study on a particular Byzantine ochre palette can thus be performed based on the small differences in its nature and composition. These differences can first be observed and then measured among all of the natural earth pigments, through μRaman and μFTIR spectroscopies.

  12. Non-invasive and non-destructive micro-XRF and micro-Raman analysis of a decorative wallpaper from the beginning of the 19th century.

    PubMed

    Castro, Kepa; Pérez-Alonso, Maite; Rodríguez-Laso, María Dolores; Etxebarria, Nestor; Madariaga, Juan Manuel

    2007-02-01

    Non-destructive and non-invasive micro-Raman fibre optic and micro-XRF analyses were performed to study a wallpaper from the beginning of the 19th century. The complementarity of these two non-destructive techniques is shown in this work. The analysed artwork is considered one of the most beautiful wallpapers ever manufactured according to the catalogues and books; it is known as Chasse de Compiègne, manufactured by Jacquemart, Paris, in 1812. During the analysis, an unexpected pigment was detected by both analytical techniques: lead-tin yellow type II. This pigment was used until ca. 1750, when other yellow pigments replaced it, thus it is very difficult to find it in paintings afterwards. Together with this pigment, red lead, Prussian blue, brochantite, yellow iron oxide, calcium carbonate, vermilion, carbon black of animal origin (bone black), lead white, and raw and burnt sienna were also determined by combining the analytical information provided by both techniques. A possible degradation of brochantite to antlerite is also discussed.

  13. Identifying a common origin of toner printed counterfeit banknotes by micro-Raman spectroscopy.

    PubMed

    Skenderović Božičević, Martina; Gajović, Andreja; Zjakić, Igor

    2012-11-30

    This study explores the applicability of micro-Raman spectroscopy as a non-destructive technique for the analysis of color toner printed counterfeits. The main aim of the research paper was to find out whether Raman spectroscopy is a suitable method for establishing the connection between different specimens of counterfeits suspected to be printed with the same toner on the same machine. Specimens of different types of toners printed on different types of paper are analyzed by means of the micro-Raman spectroscopy system with the excitation line at 514.5 nm. For each specimen cyan, magenta and yellow toners are analyzed separately. The yellow toners displayed the most distinctive Raman spectra. The results show that micro-Raman spectroscopy can be successfully applied as a method for the analysis of color toner printed counterfeits, such as banknotes and documents, in order to establish links between more or less different specimens of counterfeits by measuring the properties of a color toner.

  14. In vitro analysis of riboflavin-modified, experimental, two-step etch-and-rinse dentin adhesive: Fourier transform infrared spectroscopy and micro-Raman studies.

    PubMed

    Daood, Umer; Swee Heng, Chan; Neo Chiew Lian, Jennifer; Fawzy, Amr S

    2015-06-26

    To modify two-step experimental etch-and-rinse dentin adhesive with different concentrations of riboflavin and to study its effect on the bond strength, degree of conversion, along with resin infiltration within the demineralized dentin substrate, an experimental adhesive-system was modified with different concentrations of riboflavin (m/m, 0, 1%, 3%, 5% and 10%). Dentin surfaces were etched with 37% phosphoric acid, bonded with respective adhesives, restored with restorative composite-resin, and sectioned into resin-dentin slabs and beams to be stored for 24 h or 9 months in artificial saliva. Micro-tensile bond testing was performed with scanning electron microscopy to analyse the failure of debonded beams. The degree of conversion was evaluated with Fourier transform infrared spectroscopy (FTIR) at different time points along with micro-Raman spectroscopy analysis. Data was analyzed with one-way and two-way analysis of variance followed by Tukey's for pair-wise comparison. Modification with 1% and 3% riboflavin increased the micro-tensile bond strength compared to the control at 24 h and 9-month storage with no significant differences in degree of conversion (P<0.05). The most predominant failure mode was the mixed fracture among all specimens except 10% riboflavin-modified adhesive specimens where cohesive failure was predominant. Raman analysis revealed that 1% and 3% riboflavin adhesives specimens showed relatively higher resin infiltration. The incorporation of riboflavin in the experimental two-step etch-and-rinse adhesive at 3% (m/m) improved the immediate bond strengths and bond durability after 9-month storage in artificial saliva without adversely affecting the degree of conversion of the adhesive monomers and resin infiltration.

  15. In vitro analysis of riboflavin-modified, experimental, two-step etch-and-rinse dentin adhesive: Fourier transform infrared spectroscopy and micro-Raman studies

    PubMed Central

    Daood, Umer; Swee Heng, Chan; Neo Chiew Lian, Jennifer; Fawzy, Amr S

    2015-01-01

    To modify two-step experimental etch-and-rinse dentin adhesive with different concentrations of riboflavin and to study its effect on the bond strength, degree of conversion, along with resin infiltration within the demineralized dentin substrate, an experimental adhesive-system was modified with different concentrations of riboflavin (m/m, 0, 1%, 3%, 5% and 10%). Dentin surfaces were etched with 37% phosphoric acid, bonded with respective adhesives, restored with restorative composite–resin, and sectioned into resin–dentin slabs and beams to be stored for 24 h or 9 months in artificial saliva. Micro-tensile bond testing was performed with scanning electron microscopy to analyse the failure of debonded beams. The degree of conversion was evaluated with Fourier transform infrared spectroscopy (FTIR) at different time points along with micro-Raman spectroscopy analysis. Data was analyzed with one-way and two-way analysis of variance followed by Tukey's for pair-wise comparison. Modification with 1% and 3% riboflavin increased the micro-tensile bond strength compared to the control at 24 h and 9-month storage with no significant differences in degree of conversion (P<0.05). The most predominant failure mode was the mixed fracture among all specimens except 10% riboflavin-modified adhesive specimens where cohesive failure was predominant. Raman analysis revealed that 1% and 3% riboflavin adhesives specimens showed relatively higher resin infiltration. The incorporation of riboflavin in the experimental two-step etch-and-rinse adhesive at 3% (m/m) improved the immediate bond strengths and bond durability after 9-month storage in artificial saliva without adversely affecting the degree of conversion of the adhesive monomers and resin infiltration. PMID:25257880

  16. X-ray diffraction analysis and scanning micro-Raman spectroscopy of structural irregularities and strains deep inside the multilayered InGaN/GaN heterostructure

    SciTech Connect

    Strelchuk, V. V. Kladko, V. P.; Avramenko, E. A.; Kolomys, O. F.; Safryuk, N. V.; Konakova, R. V.; Yavich, B. S.; Valakh, M. Ya.; Machulin, V. F.; Belyaev, A. E.

    2010-09-15

    High-resolution X-ray diffraction analysis and scanning confocal Raman spectroscopy are used to study the spatial distribution of strains in the In{sub x}Ga{sub 1-x}N/GaN layers and structural quality of these layers in a multilayered light-emitting diode structure produced by metal-organic chemical vapor deposition onto (0001)-oriented sapphire substrates. It is shown that elastic strains almost completely relax at the heterointerface between the thick GaN buffer layer and In{sub x}Ga{sub 1-x}N/GaN buffer superlattice. It is established that the GaN layers in the superlattice are in a stretched state, whereas the alloy layers are in a compressed state. In magnitude, the stretching strains in the GaN layers are lower than the compressive strains in the InGaN layers. It is shown that, as compared to the buffer layers, the layers of the superlattice contain a smaller number of dislocations and the distribution of dislocations is more randomly disordered. In micro-Raman studies on scanning through the thickness of the multilayered structure, direct evidence is obtained for the asymmetric gradient distributions of strains and crystal imperfections of the epitaxial nitride layers along the direction of growth. It is shown that the emission intensity of the In{sub x}Ga{sub 1-x}N quantum well is considerably (more than 30 times) higher than the emission intensity of the GaN barrier layers, suggesting the high efficiency of trapping of charge carriers by the quantum well.

  17. Micro-Raman spectroscopy and chemometrical analysis for the distinction of copper phthalocyanine polymorphs in paint layers.

    PubMed

    Defeyt, C; Van Pevenage, J; Moens, L; Strivay, D; Vandenabeele, P

    2013-11-01

    In art analysis, copper phthalocyanine (CuPc) is often identified as an important pigment (PB15) in 20th century artworks. Raman spectroscopy is a very valuable technique for the detection of this pigment in paint systems. However, PB15 is used in different polymorphic forms and identification of the polymorph could retrieve information on the production process of the pigment at the moment. Raman spectroscopy, being a molecular spectroscopic method of analysis, is able to discriminate between polymorphs of crystals. However, in the case of PB15, spectral interpretation is not straightforward, and Raman data treatment requires some improvements concerning the PB15 polymorphic discrimination in paints. Here, Raman spectroscopy is combined with chemometrical analysis in order to develop a procedure allowing us to identify the PB15 crystalline structure in painted layers and in artworks. The results obtained by Linear Discriminant Analysis (LDA), using intensity ratios as variables, demonstrate the ability of this procedure to predict the crystalline structure of a PB15 pigment in unknown paint samples.

  18. Characterization and differentiation of normal and abnormal semen samples using micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Zufang; Chen, Xiwen; Chen, Jinhua; Li, Yongzeng; Lei, Jinping; Chen, Rong

    2012-12-01

    Growth in the percentage of male infertility has caused extensive concerns. The fast and reliable method is urgently required for diagnosis of semen samples. In our study, micro-Raman spectroscopy was employed to characterize and differentiate the normal and abnormal semen samples based on the differences of their specific Raman spectra which originated from biochemical components. Our preliminary results demonstrate that micro-Raman spectroscopy combined with multivariate analysis methods has the potential of being used to detect and differentiate semen samples.

  19. Modifying single-crystalline silicon by femtosecond laser pulses: an analysis by micro Raman spectroscopy, scanning laser microscopy and atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Bonse, J.; Brzezinka, K.-W.; Meixner, A. J.

    2004-01-01

    The surface modification of single-crystalline silicon induced by single 130 femtosecond (fs) Ti:sapphire laser pulses (wavelength 800 nm) in air is investigated by means of micro Raman spectroscopy (μ-RS), atomic force microscopy and scanning laser microscopy. Depending on the laser fluence, in some regions the studies indicate a thin amorphous top-layer as well as ablated and recrystallized zones. The single-pulse threshold fluences for melting, ablation and polycrystalline recrystallization are determined quantitatively. Several different topographical surface structures (rims and protrusions) are found. Their formation is discussed in the context of recent studies of the laser irradiation of silicon. In combination with a thin-film optical model, the thickness of the amorphous layer is determined by two independent and nondestructive optical methods to be in the order of several 10 nm.

  20. The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy/energy dispersive X-ray analysis

    NASA Astrophysics Data System (ADS)

    Jin, Pu-jun; Huang, Wei; Jianhua-Wang; Zhao, Gang; Wang, Xiao-ling

    2010-11-01

    The application of micro-Raman spectroscopy (μ-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum + quartz), blue (lapis lazuli) and green (Paris green + Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad.

  1. Analysis of molecular structure, spectroscopic properties (FT-IR, micro-Raman and UV-vis) and quantum chemical calculations of free and ligand 2-thiopheneglyoxylic acid in metal halides (Cd, Co, Cu, Ni and Zn).

    PubMed

    Gökce, Halil; Bahçeli, Semiha

    2013-12-01

    In this study, molecular geometries, experimental vibrational wavenumbers, electronic properties and quantum chemical calculations of 2-thiopheneglyoxylic acid molecule, (C6H4O3S), and its metal halides (Cd, Co, Cu, Ni and Zn) which are used as pharmacologic agents have been investigated experimentally by FT-IR, micro-Raman and UV-visible spectroscopies and elemental analysis. Meanwhile the vibrational calculations were verified by DFT/B3LYP method with 6-311++G(d,p) and LANL2DZ basis sets in the ground state, for free TPGA molecule and its metal halide complexes, respectively, for the first time. The calculated fundamental vibrational frequencies for the title compounds are in a good agreement with the experimental data.

  2. Diamond micro-Raman thermometers for accurate gate temperature measurements

    SciTech Connect

    Simon, Roland B.; Pomeroy, James W.; Kuball, Martin

    2014-05-26

    Determining the peak channel temperature in AlGaN/GaN high electron mobility transistors and other devices with high accuracy is an important and challenging issue. A surface-sensitive thermometric technique is demonstrated, utilizing Raman thermography and diamond microparticles to measure the gate temperature. This technique enhances peak channel temperature estimation, especially when it is applied in combination with standard micro-Raman thermography. Its application to other metal-covered areas of devices, such as field plates is demonstrated. Furthermore, this technique can be readily applied to other material/device systems.

  3. Micro-Raman spectroscopy Detects Individual Neoplastic and Normal Hematopoietic Cells

    SciTech Connect

    Chan, J W; Taylor, D; Zwerdling, T; Lane, S M; Ihara, K; Huser, T

    2005-01-18

    Current methods for identifying neoplastic cells and discerning them from their normal counterparts are often non-specific, slow, biologically perturbing, or a combination, thereof. Here, we show that single-cell micro-Raman spectroscopy averts these shortcomings and can be used to discriminate between unfixed normal human lymphocytes and transformed Jurkat and Raji lymphocyte cell lines based on their biomolecular Raman signatures. We demonstrate that single-cell Raman spectra provide a highly reproducible biomolecular fingerprint of each cell type. Characteristic peaks, mostly due to different DNA and protein concentrations, allow for discerning normal lymphocytes from transformed lymphocytes with high confidence (p << 0.05). Spectra are also compared and analyzed by principal component analysis (PCA) to demonstrate that normal and transformed cells form distinct clusters that can be defined using just two principal components. The method is shown to have a sensitivity of 98.3% for cancer detection, with 97.2% of the cells being correctly classified as belonging to the normal or transformed type. These results demonstrate the potential application of confocal micro-Raman spectroscopy as a clinical tool for single cell cancer detection based on intrinsic biomolecular signatures, therefore eliminating the need for exogenous fluorescent labeling.

  4. Micro-Raman analysis of the pigments on painted pottery figurines from two tombs of the Northern Wei Dynasty in Luoyang.

    PubMed

    Liu, Zhaojun; Han, Yunxia; Han, Ligang; Cheng, Yongjian; Ma, Yiqiang; Fang, Li

    2013-05-15

    The pigments on the painted pottery figurines from two tombs of Northern Wei Dynasty (AD 386-534) in Luoyang were analyzed by Raman microscopy. All the pigments were identified compared with the Raman spectra of standard pigments. The red pigments were identified as haematite, the blue pigment as lapis lazuli, the green pigment as malachite, the black pigment as carbon black and the white pigment as calcite. Similar pigments were used in the two tombs despite the pottery figurines were very different in artistic style. The use of lapis lazuli as blue pigment on Chinese painted pottery figurines was found for the first time. This pigment and the painted pottery figurine of Sogdians are of great archaeological significance because it demonstrated that the trade and cultural exchanges via the Silk Road had extended to Luoyang city in the Northern Wei Dynasty. The result also confirms that micro-Raman spectroscopy is a powerful analytical method for the identification of pigments on ancient artworks. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Micro-Raman analysis of the pigments on painted pottery figurines from two tombs of the Northern Wei Dynasty in Luoyang

    NASA Astrophysics Data System (ADS)

    Liu, Zhaojun; Han, Yunxia; Han, Ligang; Cheng, Yongjian; Ma, Yiqiang; Fang, Li

    2013-05-01

    The pigments on the painted pottery figurines from two tombs of Northern Wei Dynasty (AD 386-534) in Luoyang were analyzed by Raman microscopy. All the pigments were identified compared with the Raman spectra of standard pigments. The red pigments were identified as haematite, the blue pigment as lapis lazuli, the green pigment as malachite, the black pigment as carbon black and the white pigment as calcite. Similar pigments were used in the two tombs despite the pottery figurines were very different in artistic style. The use of lapis lazuli as blue pigment on Chinese painted pottery figurines was found for the first time. This pigment and the painted pottery figurine of Sogdians are of great archaeological significance because it demonstrated that the trade and cultural exchanges via the Silk Road had extended to Luoyang city in the Northern Wei Dynasty. The result also confirms that micro-Raman spectroscopy is a powerful analytical method for the identification of pigments on ancient artworks.

  6. Micro-Raman spectroscopy for monitoring changes in periodontal ligaments and gingival crevicular fluid.

    PubMed

    Camerlingo, Carlo; d'Apuzzo, Fabrizia; Grassia, Vincenzo; Perillo, Letizia; Lepore, Maria

    2014-11-27

    Micro-Raman Spectroscopy is an efficient method for analyzing biological specimens due to its sensitivity to subtle chemical and structural changes. The aim of this study was to use micro-Raman spectroscopy to analyze chemical and structural changes in periodontal ligament after orthodontic force application and in gingival crevicular fluid in presence of periodontal disease. The biopsy of periodontal ligament samples of premolars extracted for orthodontic reasons and the gingival crevicular fluid samples collected by using absorbent paper cones; were analyzed by micro-Raman spectroscopy. Changes of the secondary protein structure related to different times of orthodontic force application were reported; whereas an increase of carotene was revealed in patients affected by periodontal inflammation.

  7. Micro-Raman Spectroscopy for Monitoring Changes in Periodontal Ligaments and Gingival Crevicular Fluid

    PubMed Central

    Camerlingo, Carlo; d'Apuzzo, Fabrizia; Grassia, Vincenzo; Perillo, Letizia; Lepore, Maria

    2014-01-01

    Micro-Raman Spectroscopy is an efficient method for analyzing biological specimens due to its sensitivity to subtle chemical and structural changes. The aim of this study was to use micro-Raman spectroscopy to analyze chemical and structural changes in periodontal ligament after orthodontic force application and in gingival crevicular fluid in presence of periodontal disease. The biopsy of periodontal ligament samples of premolars extracted for orthodontic reasons and the gingival crevicular fluid samples collected by using absorbent paper cones; were analyzed by micro-Raman spectroscopy. Changes of the secondary protein structure related to different times of orthodontic force application were reported; whereas an increase of carotene was revealed in patients affected by periodontal inflammation. PMID:25436655

  8. Note: Mobile micro-Raman analyzer integrated with a lab-on-a-chip

    NASA Astrophysics Data System (ADS)

    Li, Haibo; Chen, Gang; Zhang, Yuxin; Geng, Yijia; Gu, Yuejiao; Wang, Hailong; Xu, Shuping; Xu, Weiqing

    2013-05-01

    A mobile micro-Raman microfluidic analyzer was designed and built for label-free, nondestructive, fingerprint detection of samples on microfluidic chip systems. It mainly includes an optical module (including the Raman detection system and the microscopic imaging system), 3-axis stages with step motors and other auxiliary circuits. The setup of the analyzer was designed with fully considering the characters of the microfluidics system. The experimental results prove that this microfluidics analyzer is practical and very convenient to use. This micro-Raman microfluidics analyzer with high performance to cost ratio has wide application potential in lab-on-a-chip fields as a powerful analytical tool.

  9. Micro-Raman spectra of ugrandite garnet.

    PubMed

    Moroz, T; Ragozin, A; Salikhov, D; Belikova, G; Puchkov, V; Kagi, H

    2009-08-01

    The natural garnets from chromite ores associated with pegmatoid pyroxenites of Sangalyk area (Uchaly ore district, southern Urals, Russia) were studied by means of micro-Raman spectroscopy. The compositions of these garnets were close to ugrandite, an isomorphous intermediate group of uvarovite-grossularite-andradite, X(3)Y(2)(SiO(4))(3), X = Ca(2+), Y = Al(3+), Fe(3+), Cr(3+), according to Raman spectra and X-ray microprobe analyses. An assignment of most of the observed bands in visible and near infrared Raman spectra is reported.

  10. Micro-Raman spectra of ugrandite garnet

    NASA Astrophysics Data System (ADS)

    Moroz, T.; Ragozin, A.; Salikhov, D.; Belikova, G.; Puchkov, V.; Kagi, H.

    2009-08-01

    The natural garnets from chromite ores associated with pegmatoid pyroxenites of Sangalyk area (Uchaly ore district, southern Urals, Russia) were studied by means of micro-Raman spectroscopy. The compositions of these garnets were close to ugrandite, an isomorphous intermediate group of uvarovite-grossularite-andradite, X 3Y 2(SiO 4) 3, X = Ca 2+, Y = Al 3+, Fe 3+, Cr 3+, according to Raman spectra and X-ray microprobe analyses. An assignment of most of the observed bands in visible and near infrared Raman spectra is reported.

  11. New insight into UO2F2 particulate structure by micro-Raman spectroscopy

    DOE PAGES

    Stefaniak, Elzbieta A.; Darchuk, Larysa; Sapundjiev, Danislav; ...

    2013-02-19

    Uranyl fluoride particles produced via hydrolysis of uranium hexafluoride have been deposited on different substrates: polished graphite disks, silver foil, stainless steel and gold-coated silicon wafer, and measured with micro-Raman spectroscopy (MRS). All three metallic substrates enhanced the Raman signal delivered by UO2F2 in comparison to graphite. The fundamental stretching of the U–O band appeared at 867 cm–1 in case of the graphite substrate, while in case of the others it was shifted to lower frequencies (down to 839 cm–1). All applied metallic substrates showed the expected effect of Raman signal enhancement; however the gold layer appeared to be mostmore » effective. Lastly, application of new substrates provides more information on the molecular structure of uranyl fluoride precipitation, which is interesting for nuclear safeguards and nuclear environmental analysis.« less

  12. New insight into UO2F2 particulate structure by micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Stefaniak, Elżbieta A.; Darchuk, Larysa; Sapundjiev, Danislav; Kips, Ruth; Aregbe, Yetunde; Van Grieken, René

    2013-05-01

    Uranyl fluoride particles produced via hydrolysis of uranium hexafluoride have been deposited on different substrates: polished graphite disks, silver foil, stainless steel and gold-coated silicon wafer, and measured with micro-Raman spectroscopy (MRS). All three metallic substrates enhanced the Raman signal delivered by UO2F2 in comparison to graphite. The fundamental stretching of the U-O band appeared at 867 cm-1 in case of the graphite substrate, while in case of the others it was shifted to lower frequencies (down to 839 cm-1). All applied metallic substrates showed the expected effect of Raman signal enhancement; however the gold layer appeared to be most effective. Application of new substrates provides more information on the molecular structure of uranyl fluoride precipitation, which is interesting for nuclear safeguards and nuclear environmental analysis.

  13. Study of molecule variations in renal tumor based on confocal micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhuang, Zhengfei; Li, Ning; Guo, Zhouyi; Zhu, Meifang; Xiong, Ke; Chen, Sijin

    2013-03-01

    Confocal micro-Raman spectroscopy-a valuable analytical tool in biological and medical field of research-allows probing molecular vibrations of samples without external labels or extensive preparation. We employ confocal micro-Raman spectroscopy to characterize renal tumors and normal tissue. Results show that Raman peaks of the renal tumor at 788 and 1087 cm-1, which belong to νs and νas stretching, respectively, have an obvious increase. At the same time, the ratio of I855/I831 in renal tumor tissue is 1.39±0.08, while that in normal renal tissue is 2.44±0.05 (p<0.01). This means that more tyrosine conformation transform from "buried" to "exposed" in the presence of cancer. Principal component analysis is used to classify the Raman spectra of renal tumor tissue and normal tissue.

  14. Micro-Raman spectroscopy for meat type detection

    NASA Astrophysics Data System (ADS)

    De Biasio, M.; Stampfer, P.; Leitner, R.; Huck, C. W.; Wiedemair, V.; Balthasar, D.

    2015-06-01

    The recent horse meat scandal in Europe increased the demand for optical sensors that can identify meat type. Micro-Raman spectroscopy is a promising technique for the discrimination of meat types. Here, we present micro-Raman measurements of chicken, pork, turkey, mutton, beef and horse meat test samples. The data was analyzed with different combinations of data normalization and classification approaches. Our results show that Raman spectroscopy can discriminate between different meat types. Red and white meat are easily discriminated, however a sophisticated chemometric model is required to discriminate species within these groups.

  15. New insight into UO2F2 particulate structure by micro-Raman spectroscopy

    SciTech Connect

    Stefaniak, Elzbieta A.; Darchuk, Larysa; Sapundjiev, Danislav; Kips, Ruth E.; Aregbe, Yetunde; Grieken, Rene Van

    2013-02-19

    Uranyl fluoride particles produced via hydrolysis of uranium hexafluoride have been deposited on different substrates: polished graphite disks, silver foil, stainless steel and gold-coated silicon wafer, and measured with micro-Raman spectroscopy (MRS). All three metallic substrates enhanced the Raman signal delivered by UO2F2 in comparison to graphite. The fundamental stretching of the U–O band appeared at 867 cm–1 in case of the graphite substrate, while in case of the others it was shifted to lower frequencies (down to 839 cm–1). All applied metallic substrates showed the expected effect of Raman signal enhancement; however the gold layer appeared to be most effective. Lastly, application of new substrates provides more information on the molecular structure of uranyl fluoride precipitation, which is interesting for nuclear safeguards and nuclear environmental analysis.

  16. Micro-Raman Measurements and Depth Profiling of SiC

    NASA Astrophysics Data System (ADS)

    Roughani, Bahram; Ramabadran, Uma

    2003-03-01

    Recent progress in growth of high quality 4H- SiC and 6H-SiC polytypes materials may lead to new applications for SiC as high power, high temperature, and high frequency devices that can tolerate harsh environments. Nondestructive techniques that could be used in analyzing various layers of such materials after growth or after exposure to harsh environment could be used in investigation of induced defects or structural damages. We have utilized micro-Raman scattering to investigate the depth profiling of Nitrogen doped 4H-SiC samples. Heavily N-doped 4H-SiC epilayers grown on low doped 4H-SiC substrates were examined. Each SiC sample was placed on micro-positioning translational stage in order to accurately control the focal plane of the laser beam within the sample by adjusting normal distance of the microscope objective with respect to the SiC wafer. We were able to clearly distinguish the epilayer from the SiC substrate. Strong phonon peaks and distinct coupled plasmon-LO phonon modes from the N-doped epilayer were used in this depth profiling analysis. A scattering efficiency model describing the optimal focusing condition for backscattering from a translucent sample was developed. The experimental results of depth profiling and our model for optimal backscattering condition will be presented and discussed.

  17. Influence of the coordination number Z on the micro-Raman spectra of ternary chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Iovu, M. S.; Iaseniuc, O. V.; Dinescu, D.; Enachescu, M.

    2016-12-01

    Chalcogenide glasses are attractive materials due to its application in photonics and optoelectronics. Chalcogenide glasses GexAsxSe1-2x (average coordination number Z=2.15÷2.90) and (As4S3Se3)1-xSnx (average coordination number Z=2.4÷2.56), which contain elements of IV group of the Periodic Table, such as Ge and Sn are important for a wide range of technical applications, such as infrared optical elements, acousto-optic and alloptical switching devices, holographic recording media, diffractive optics, photonic crystals, etc. [1, 2]. Raman spectroscopy is an efficient method for obtaining information on the local structure of the disordered material, especially when the composition is varied. In this paper are reported the Micro-Raman spectra of GexAsxSe1-2x and (As4S3Se3)1-xSnx bulk glasses and amorphous thin films. The Micro-Raman spectra of bulk glasses and thermally deposited amorphous (As4S3Se3)1-xSnx thin films consist of two broad bands located at around ν=236 cm-1 and ν=345 cm-1, which corresponds to the symmetric stretching vibration modes of AsSe3/2 and AsS3/2 pyramids, respectively. Tin impurities didn't change the shape of Micro-Raman spectra, but shift the both bands to low frequency region. The Micro-Raman spectra of bulk glasses and thermally deposited amorphous (GexAsxSe1-2x thin films consist of one main vibration band located at around ν=246 cm-1 for lower concentration of Ge and As, and is attributed to (AsSe1/2)3 pyramidal units. With increasing of Ge and As concentrations this band shifts to lower frequency region up to ν=236 cm-1 for x=0.30. The vibration band situated around ν=205 cm-1 is attributed to Ge(Se1/2)4 tetrahedral units and increase in the intensity with increasing of Ge and As concentrations. Some shoulders in high frequency regions at ν=365-390 cm-1 and ν=500-530 cm-1, caused by the presence of As-Se bands and Se-Se chains also was observed.

  18. Micro-Raman Spectroscopy of Silver Nanoparticle Induced Stress on Optically-Trapped Stem Cells

    PubMed Central

    Bankapur, Aseefhali; Krishnamurthy, R. Sagar; Zachariah, Elsa; Santhosh, Chidangil; Chougule, Basavaraj; Praveen, Bhavishna; Valiathan, Manna; Mathur, Deepak

    2012-01-01

    We report here results of a single-cell Raman spectroscopy study of stress effects induced by silver nanoparticles in human mesenchymal stem cells (hMSCs). A high-sensitivity, high-resolution Raman Tweezers set-up has been used to monitor nanoparticle-induced biochemical changes in optically-trapped single cells. Our micro-Raman spectroscopic study reveals that hMSCs treated with silver nanoparticles undergo oxidative stress at doping levels in excess of 2 µg/ml, with results of a statistical analysis of Raman spectra suggesting that the induced stress becomes more dominant at nanoparticle concentration levels above 3 µg/ml. PMID:22514708

  19. Micro Raman spectroscopy of carbonaceous material in microfossils and meteorites: improving a method for life detection.

    PubMed

    Bower, D M; Steele, A; Fries, M D; Kater, L

    2013-01-01

    The identification of biosignatures in Earth's ancient rock record and detection of extraplanetary life is one of the primary goals in astrobiology. Intrinsic to this goal is the improvement of analytical techniques and protocols used to identify an unambiguous signal of life. Micro Raman spectroscopy is a nondestructive method that allows for in situ identification of a wide range of minerals and compounds. The use of D (∼1350 cm(-1)) and G (∼1580 cm(-1)) band parameters to infer the biogenicity of carbonaceous materials in fossils has become a commonly used analytical tool, but carbonaceous compounds from different sources often share the same spectroscopic characteristics. Microfossil studies do not always take into consideration a nonbiological source for the carbon in their samples and therefore still rely on morphology as the primary mode of identification. Comprehensive studies that consider all carbon sources are typically done on metasediments, coals, or meteorites, and the results are not clearly applicable to microfossil identification. In this study, microfossils from a suite of sedimentary rock samples of various ages were analyzed with micro Raman spectroscopy to investigate the nature and provenance of carbonaceous material. To further constrain D- and G-band carbon characteristics, micro Raman analyses were also performed on well-characterized meteorite samples as abiological controls. The results appear to show a correlation of precursor carbonaceous material with D-band parameters and thermal history with G-band parameters. This systematic study lays the groundwork for improving the use of the G- and D-band trends as useful indicators of the origin of carbon in microfossils. Before unambiguous biosignatures can be established, further work characterizing the carbonaceous material in microfossils of different ages, thermal histories, and host rock compositions is needed.

  20. Characterizing and identifying incipient carious lesions in dental enamel using micro-Raman spectroscopy.

    PubMed

    Mohanty, B; Dadlani, D; Mahoney, D; Mann, A B

    2013-01-01

    Early detection of dental caries is vital if improved patient outcomes are to be achieved by reversal of the demineralization process. Current techniques used by dentists for identifying carious lesions are effective in identifying more advanced lesions, but do not have sufficient sensitivity and specificity to detect them at the earliest stages. This study focused on characterizing the growth of incipient carious lesions in vitro using micro-Raman spectroscopy. The incipient carious lesions were grown on the buccal faces of human molars by controlled exposure to lactic acid. Lesions were cross-sectioned to expose the subsurface body of the lesion and then examined using micro-Raman spectroscopy. The intensity of the phosphate peaks in the Raman spectra was found to differ significantly between healthy enamel and the demineralized region of the lesions. The sensitivity of the phosphate peaks to the degree of demineralization was observed by taking a series of spectra over the cross section of the lesions. This revealed that the body of the lesion is highly demineralized, but in a narrow surface region (up to 10 µm) there is little demineralization. All the phosphate peaks were found to be sensitive to the degree of demineralization; however, changes in the intensity of the pronounced phosphate peak at 961 cm(-1) offer the most promise for identifying lesions. The results indicate that micro-Raman spectroscopy has both the sensitivity and selectivity to identify incipient carious lesions, but the presence of a surface layer with a relatively high mineral content could complicate the analysis.

  1. Micro Raman, Mossbauer and magnetic studies of manganese substituted zinc ferrite nanoparticles: Role of Mn

    NASA Astrophysics Data System (ADS)

    Thota, Suneetha; Kashyap, Subhash C.; Sharma, Shiv K.; Reddy, V. R.

    2016-04-01

    A series of Mn-Zn Ferrite nanoparticles (<15 nm) with formula MnxZn1-xFe2O4 (where x=0.00, 0.35, 0.50, 0.65) were successfully prepared by citrate-gel method at low temperature (400 °C). X-ray diffraction analysis confirmed the formation of single cubic spinel phase in these nanoparticles. The FESEM and TEM micrographs revealed the nanoparticles to be nearly spherical in shape and of fairly uniform size. The fractions of Mn2+, Zn2+ and Fe3+ cations occupying tetrahedral sites along with Fe occupying octahedral sites within the unit cell of different ferrite samples are estimated by room temperature micro-Raman spectroscopy. Low temperature Mossbauer measurement on Mn0.5Zn0.5Fe2O4 has reconfirmed the mixed spinel phase of these nanoparticles. Room temperature magnetization studies (PPMS) of Mn substituted samples showed superparamagnetic behavior. Manganese substitution for Zn in the ferrite caused the magnetization to increase from 04 to18 emu/g and Lande's g factor (estimated from ferromagnetic resonance measurement) from 2.02 to 2.12 when x was increased up to 0.50. The FMR has shown that higher Mn cationic substitution leads to increase in dipolar interaction and decrease in super exchange interaction. Thermomagnetic (M-T) and magnetization (M-H) measurements have shown that the increase in Mn concentration (up to x=0.50) enhances the spin ordering temperature up to 150 K (blocking temperature). Magnetocrystalline anisotropy in the nanoparticles was established by Mossbauer, ferromagnetic resonance and thermomagnetic measurements. The optimized substitution of manganese for zinc improves the magnetic properties and makes these nanoparticles a potential candidate for their applications in microwave region and biomedical field.

  2. Multi-fiber strains measured by micro-Raman spectroscopy: Principles and experiments

    NASA Astrophysics Data System (ADS)

    Lei, Zhenkun; Wang, Yunfeng; Qin, Fuyong; Qiu, Wei; Bai, Ruixiang; Chen, Xiaogang

    2016-02-01

    Based on widely used axial strain measurement method of Kevlar single fiber, an original theoretical model and measurement principle of application of micro-Raman spectroscopy to multi-fiber strains in a fiber bundle were established. The relationship between the nominal Raman shift of fiber bundle and the multi-fiber strains was deduced. The proposed principle for multi-fiber strains measurement is consistent with two special cases: single fiber deformation and multi-fiber deformation under equal strain. It is found experimentally that the distribution of Raman scattering intensity of a Kevlar 49 fiber as a function of distance between a fiber and the laser spot center follows a Gaussian function. Combining the Raman-shift/strain relationship of the Kevlar 49 single fiber and the uniaxial tension measured by micro-Raman spectroscopy, the Raman shift as a function of strain was obtained. Then the Raman peak at 1610 cm-1 for the Kevlar 49 fiber was fitted to a Lorentzian function and the FWHM showed a quadratic increase with the fiber strain. Finally, a dual-fiber tensile experiment was performed to verify the adequacy of the Raman technique for the measurement of multi-fiber strains.

  3. Design and simulation of arrayed waveguide grating (AWG) for micro-Raman spectrometer

    NASA Astrophysics Data System (ADS)

    Cheng, Yaqin; Deng, Shengfeng; Xu, Yingchao; Lu, Miao

    2012-10-01

    Micro Raman spectrometer has broad applications for monitoring harmful chemicals in food, water and environment. Arrayed waveguide grating (AWG) is a promising device to build a dispersive micro Raman spectrometer. Comparing with the widely used demultiplexer in optical communication, AWG in spectrometer is unique due to its broad spectral range and low insert loss. In this paper, a computer algorithm routine was explored to accomplish the design of a broadband, arbitrary AWG structure. First, the focal length, length increment of adjacent waveguide and diffraction order of an AWG were figured out by a MATLAB program, the coordinates was then input into a VBScript program to generate the layout, and the layout was analyzed in OptiwaveBPM software for optical characterization. The proposed MATLAB and VBScript program was verified by the design and simulation of a 800-1000 nm range, 40 channels asymmetric AWG, a spectral resolution of 5 nm was demonstrated with insert loss of 5.03-7.16 dB. In addition, an approach to realize multimode input was introduced to reduce the optical coupling loss. Multimode light beam was firstly converted to a series of single mode beams by the methods proposed by S. G. Leon-Saval et al. in 2005. Next, these single mode beams were coupled into the input star coupler of an AWG. As a proof of this concept, a three inputs, 20 channel, 850-950 nm spectral range AWG was simulated, and merits and drawbacks of this approach were discussed.

  4. Micro-Raman spectroscopy of meteorite Košice

    NASA Astrophysics Data System (ADS)

    Kaňuchová, Z.; Baratta, G. A.

    2014-07-01

    The Raman microscope technique was used to characterize 3-5 μm structures in the matrix of the Košice meteorite, an H5 ordinary chondrite. Its fall is associated with a bright fireball that appeared over central-eastern Slovakia on February 28, 2010. Several micro-Raman spectra of the interior part of meteorite KoŠice sample were collected. On the basis of characteristic frequencies of Raman modes the main types of minerals (olivines, pyroxenes) as well as carbon material were identified. The Raman signature of the carbon material is consistent with the second stage of the amorphization trajectory between amorphous carbon and nanocrystalline graphite.

  5. Evaluation of thermal residual stresses in laser drilled alumina ceramics using Micro-Raman spectroscopy and COMSOL Multiphysics

    NASA Astrophysics Data System (ADS)

    Bharatish, A.; Narasimha Murthy, H. N.; Aditya, G.; Anand, B.; Satyanarayana, B. S.; Krishna, M.

    2015-07-01

    This paper presents evaluation of thermal residual stresses in the heat affected zone of laser drilled alumina ceramic by using Micro-Raman spectroscopy. The residual stresses were evaluated for the holes corresponding to the optimal parameters of laser power, scanning speed, frequency and hole diameter. Three such cases were considered for the study. Residual stresses were obtained as a function of the Raman shifts. The nature and magnitude of the residual stresses were indicative of the extent of damage caused in the heat affected zone. In cases where the initial tensile residual stresses exceeded the tensile strength of alumina, cracks were initiated. Laser drilling with higher laser power and lower scanning speed induced initially high compressive and cyclic thermal stresses, causing greater damage to the hole. Transient thermal analysis was performed using COMSOL Multiphysics to predict residual thermal stresses and to validate the micro-Raman results. Scanning Electron Microscopy was used to confirm the damage caused in the heat affected zone.

  6. Micro-Raman studies of hydrous ferrous sulfates and jarosites.

    PubMed

    Chio, Chi Hong; Sharma, Shiv K; Muenow, David W

    2005-08-01

    Ferrous sulfates of various hydration states (FeSO(4) X xH(2)O; x=7, 4, 1) and jarosites (MFe(3)(SO(4))(2)(OH)(6); M=Na or K) were synthesized and studied by micro-Raman spectroscopy between 295 and 8K. Spectral analyses of the sulfate and water/hydroxyl vibrational modes are presented. Fingerprint regions attributed to the symmetric (nu(1)) and antisymmetric (nu(3)) stretching vibrations of the sulfate group are found to vary with the degree of hydration in hydrous ferrous sulfate. In jarosites, the Raman shift of the OH stretching mode is related to the type of alkali metal present between the tetrahedral and octahedral layers. The Raman technique can thus unambiguously identify ferrous sulfate of various hydration states and jarosites bearing different alkali metal ions.

  7. Confocal micro-Raman spectroscopy of black soap films

    NASA Astrophysics Data System (ADS)

    Lecourt, B.; Capelle, F.; Adamietz, F.; Malaplate, A.; Blaudez, D.; Kellay, H.; Turlet, J. M.

    1998-01-01

    Black soap films from aqueous solutions of sodium dodecyl sulphate are studied by micro-Raman confocal spectroscopy. At the end of the draining process films of different thicknesses are obtained depending on the experimental conditions: Working in a closed humidified chamber leads to common black films while, under evaporation or in the presence of electrolyte, Newton black films are observed. From the Raman spectra of these films, quantitative information is deduced about the conformational and lateral order of the aliphatic surfactant chains, as well as the thickness of the residual water layer. More accurate measurements of the thickness of these ultimate films have been carried out by transmission ellipsometry and their effective refractive index measured by Brewster angle reflectivity. The thinner films present higher molecular organization and their aqueous core exhibits unusual spectral features.

  8. Micro-Raman spectroscopy a powerful technique to identify crocidolite and erionite fibers in tissue sections

    NASA Astrophysics Data System (ADS)

    Rinaudo, C.; Croce, A.; Allegrina, M.; Baris, I. Y.; Dogan, A.; Powers, A.; Rivera, Z.; Bertino, P.; Yang, H.; Gaudino, G.; Carbone, M.

    2013-05-01

    Exposure to mineral fibers such asbestos and erionite is widely associated with the development of lung cancer and pleural malignant mesothelioma (MM). Pedigree and mineralogical studies indicated that genetics may influence mineral fiber carcinogenesis. Although dimensions strongly impact on the fiber carcinogenic potential, also the chemical composition and the fiber is relevant. By using micro-Raman spectroscopy we show here persistence and identification of different mineral phases, directly on histopathological specimens of mice and humans. Fibers of crocidolite asbestos and erionite of different geographic areas (Oregon, US and Cappadocia, Turkey) were injected in mice intra peritoneum. MM developed in 10/15 asbestos-treated mice after 5 months, and in 8-10/15 erionite-treated mice after 14 months. The persistence of the injected fibers was investigated in pancreas, liver, spleen and in the peritoneal tissue. The chemical identification of the different phases occurred in the peritoneal cavity or at the organ borders, while only rarely fibers were localized in the parenchyma. Raman patterns allow easily to recognize crocidolite and erionite fibers. Microscopic analysis revealed that crocidolite fibers were frequently coated by ferruginous material ("asbestos bodies"), whereas erionite fibers were always free from coatings. We also analyzed by micro-Raman spectroscopy lung tissues, both from MM patients of the Cappadocia, where a MM epidemic developed because of environmental exposure to erionite, and from Italian MM patients with occupational exposure to asbestos. Our findings demonstrate that micro-Raman spectroscopy is technique able to identify mineral phases directly on histopathology specimens, as routine tissue sections prepared for diagnostic purpose. REFERENCES A.U. Dogan, M. Dogan. Environ. Geochem. Health 2008, 30(4), 355. M. Carbone, S. Emri, A.U. Dogan, I. Steele, M. Tuncer, HI. Pass, et al. Nat. Rev. Cancer. 2007, 7 (2),147. M. Carbone, Y

  9. Micro-Raman Properties of Quartz in Suevite Breccia from Ries Impact Crater, Germany

    NASA Astrophysics Data System (ADS)

    Varga, T. N.; Gucsik, A.; Bérczi, Sz.; Nagy, Sz.; Veres, M.; Varga, T. P.

    2011-03-01

    The purpose of this study is to determine the possible shock pressures observable in the suevite found in the Ries Crater by micro-Raman spectroscopy, and by comparison with previous studies, thus utilizing the method of shock barometry.

  10. Evaluation of the effectiveness of micro-Raman spectroscopy in monitoring the mineral contents change of human enamel in vitro.

    PubMed

    Sa, Yue; Feng, Xiaowei; Lei, Chang; Yu, Yan; Jiang, Tao; Wang, Yining

    2017-07-01

    The purpose of this in vitro study was to investigate the efficacy of micro-Raman spectroscopy on detecting mineral content change during the demineralization and de/remineralization cycling process. The enamel samples (n = 55) were randomly divided into three groups and separately treated with demineralization solution (n = 20), de/remineralization cycling solution (n = 30), and distilled water (n = 5). Micro-Raman spectroscopy, microhardness (MHS), and the released calcium ions concentration were performed before and after treatment, respectively. A one-way analysis of variance (ANOVA) with a post hoc Tukey test was used to analyze the results. The Spearman correlation coefficients among the parameters of Raman relative intensity decrease (RRID%), the percentage of MHS loss (PML), and the released calcium ions concentration were also analyzed. In demineralization group, RRID%, PML, and released calcium ions concentration were highly correlated with each other (r = 0.979, p < 0.001; r = 0.984, p < 0.001; and r = 0.983, p < 0.001, respectively). While for the de/remineralization cycling group, there also existed a high correlation between RRID% and PML (r = 0.987, p < 0.001). In conclusion, micro-Raman spectroscopy could effectively monitor the mineral content change, and its efficacy was validated by the measurement of released calcium ions concentration and MHS.

  11. Visible micro-Raman spectroscopy of single human mammary epithelial cells exposed to x-ray radiation

    NASA Astrophysics Data System (ADS)

    Delfino, Ines; Perna, Giuseppe; Lasalvia, Maria; Capozzi, Vito; Manti, Lorenzo; Camerlingo, Carlo; Lepore, Maria

    2015-03-01

    A micro-Raman spectroscopy investigation has been performed in vitro on single human mammary epithelial cells after irradiation by graded x-ray doses. The analysis by principal component analysis (PCA) and interval-PCA (i-PCA) methods has allowed us to point out the small differences in the Raman spectra induced by irradiation. This experimental approach has enabled us to delineate radiation-induced changes in protein, nucleic acid, lipid, and carbohydrate content. In particular, the dose dependence of PCA and i-PCA components has been analyzed. Our results have confirmed that micro-Raman spectroscopy coupled to properly chosen data analysis methods is a very sensitive technique to detect early molecular changes at the single-cell level following exposure to ionizing radiation. This would help in developing innovative approaches to monitor radiation cancer radiotherapy outcome so as to reduce the overall radiation dose and minimize damage to the surrounding healthy cells, both aspects being of great importance in the field of radiation therapy.

  12. A micro-Raman spectroscopic investigation of leukemic U-937 cells in aged cultures

    NASA Astrophysics Data System (ADS)

    Fazio, Enza; Trusso, Sebastiano; Franco, Domenico; Nicolò, Marco Sebastiano; Allegra, Alessandro; Neri, Fortunato; Musolino, Caterina; Guglielmino, Salvatore P. P.

    2016-04-01

    Recently it has been shown that micro-Raman spectroscopy combined with multivariate analysis is able to discriminate among different types of tissues and tumoral cells by the detection of significant alterations and/or reorganizations of complex biological molecules, such as nucleic acids, lipids and proteins. Moreover, its use, being in principle a non-invasive technique, appears an interesting clinical tool for the evaluation of the therapeutical effects and of the disease progression. In this work we analyzed molecular changes in aged cultures of leukemia model U937 cells with respect to fresh cultures of the same cell line. In fact, structural variations of individual neoplastic cells on aging may lead to a heterogeneous data set, therefore falsifying confidence intervals, increasing error levels of analysis and consequently limiting the use of Raman spectroscopy analysis. We found that the observed morphological changes of U937 cells corresponded to well defined modifications of the Raman contributions in selected spectral regions, where markers of specific functional groups, useful to characterize the cell state, are present. A detailed subcellular analysis showed a change in cellular organization as a function of time, and correlated to a significant increase of apoptosis levels. Besides the aforementioned study, Raman spectra were used as input for principal component analysis (PCA) in order to detect and classify spectral changes among U937 cells.

  13. Electrochemical anodic oxidation of nitrogen doped carbon nanowall films: X-ray photoelectron and Micro-Raman spectroscopy study

    NASA Astrophysics Data System (ADS)

    Achour, A.; Vizireanu, S.; Dinescu, G.; Le Brizoual, L.; Djouadi, M.-A.; Boujtita, M.

    2013-05-01

    Unintentional nitrogen doped carbon nanowall (CNW) films were oxidized through anodic polarization in different applied potential windows, in a mild neutral K2SO4 electrolyte solution. Applied potentials in the range of [0-1], [0-1.5] and [0-2] V vs. SCE were explored. The films were characterized with X-ray photoelectron (XPS) and Micro-Raman spectroscopy, in order to investigate the surface chemistry and structural changes after treatment, respectively. The XPS analysis revealed that this electrochemical treatment leads to an increase of oxygen functional groups, and influences the nitrogen proportion and bonding configuration (such as pyridinic/pyridonic nitrogen) on the film surface at room temperature. In particular, an obvious enhancement of pyrrolic/pyridonic nitrogen doping of CNWs via electrochemical cycling in the range of [0-1.5] and [0-2] V vs. SCE was achieved. Such enhancement happened, because of the oxidation of nitrogen atoms in pyridine as a result of OH ions injection upon electrochemical cycling. Micro-Raman analysis indicates structural quality degradation with increasing the applied potential window. Moreover, the electrochemical capacitance of CNW films was increased after treatment in the range of [0-1] and [0-1.5] and decreased in the range of [0-2] V vs. SCE. The results show that harsh oxidation happened in the range [0-2] V.

  14. Highly p-doped regions in silicon solar cells quantitatively analyzed by small angle beveling and micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Becker, M.; Gösele, U.; Hofmann, A.; Christiansen, S.

    2009-10-01

    Highly p-doped regions in multicrystalline silicon solar cells, such as the back surface field region, are analyzed by means of small angle beveling and micro-Raman spectroscopy. Small angle beveling and subsequent Secco etching are used to enhance the lateral resolution of the micro-Raman spectroscopic measurements and to investigate the microstructure of the back surface field region in detail. The position-dependent analysis of the free carrier concentrations within the back surface field region is based on the Raman specific Fano resonances. The Raman spectroscopic measurement results are compared to results obtained from electrochemical capacitance-voltage measurements, which allows a subsequent calibration of the Raman data for the quantitative analysis of the free carrier concentrations within the highly p-doped regions of silicon solar cells and other devices. Our investigations show that the free carrier as well as the dopant concentration profiles within the back surface field region exhibit a nearly step-functional shape instead of the extended gradient shape which the electrochemical capacitance-voltage measurements suggest. Moreover, we show that the shape of the back surface field is often influenced by grain boundaries and other defects that occur in multicrystalline silicon wafers.

  15. Development of an optimal filter substrate for the identification of small microplastic particles in food by micro-Raman spectroscopy.

    PubMed

    Oßmann, Barbara E; Sarau, George; Schmitt, Sebastian W; Holtmannspötter, Heinrich; Christiansen, Silke H; Dicke, Wilhelm

    2017-06-01

    When analysing microplastics in food, due to toxicological reasons it is important to achieve clear identification of particles down to a size of at least 1 μm. One reliable, optical analytical technique allowing this is micro-Raman spectroscopy. After isolation of particles via filtration, analysis is typically performed directly on the filter surface. In order to obtain high qualitative Raman spectra, the material of the membrane filters should not show any interference in terms of background and Raman signals during spectrum acquisition. To facilitate the usage of automatic particle detection, membrane filters should also show specific optical properties. In this work, beside eight different, commercially available membrane filters, three newly designed metal-coated polycarbonate membrane filters were tested to fulfil these requirements. We found that aluminium-coated polycarbonate membrane filters had ideal characteristics as a substrate for micro-Raman spectroscopy. Its spectrum shows no or minimal interference with particle spectra, depending on the laser wavelength. Furthermore, automatic particle detection can be applied when analysing the filter surface under dark-field illumination. With this new membrane filter, analytics free of interference of microplastics down to a size of 1 μm becomes possible. Thus, an important size class of these contaminants can now be visualized and spectrally identified. Graphical abstract A newly developed aluminium coated polycarbonate membrane filter enables automatic particle detection and generation of high qualitative Raman spectra allowing identification of small microplastics.

  16. Oral pathology diagnosis by means of micro-Raman spectroscopy on biopsies and blood serum

    NASA Astrophysics Data System (ADS)

    Zenone, F.; Lepore, M.; Perna, G.; Carmone, P.; Delfino, I.; Gaeta, G. M.; Capozzi, V.

    2007-02-01

    Pemphigus vulgaris is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. In this case micro-Raman spectroscopy (μ-RS) can provide a powerful tool for a not invasive analysis of biological tissue for biopsy and in vivo investigation. Based on the evaluation of molecular vibration frequencies, the μ-RS is able to detect the main molecular bonds of protein constituents, as the C-H and C-C ones. Changes in frequency or in the relative intensity of the vibration modes revealed by μ-RS can be related to changes of chemical bond and of protein structure induced by pathology. Quantitative information on the intensity variation of specific Raman lines can be extracted by Partial Least Square (PLS) analysis. μ-RS was performed on some samples of oral tissue and blood serum from informed patients affected by pemphigus vulgaris (an oral pathology) at different pathology stages. The spectra were measured by means of a Raman confocal microspectrometer apparatus using the 633 nm line of a He- Ne laser source. The main protein bonds are clearly detectable in the considered samples giving important information on the integrity and on the state of tissue and blood serum components (lipids and proteins), and consequently on the occurrence of pathology.

  17. Study of molecule variations in human xanthelasma skin based on confocal micro-raman spectroscopy.

    PubMed

    Qiu, Xuejun; Xiong, Ke; Ye, Xiangping; Huang, Zhitong; Chen, Ying; Su, Chengkang; Zhuang, Zhengfei; Guo, Zhouyi; Liu, Songhao

    2015-01-01

    Confocal micro-Raman spectroscopy was used to distinguish human xanthelasma skin (HXS) from the human normal skin (HNS). Results showed that intensive Raman peaks at 1,269, 1,336, 1,448, and 1,656 cm(-1) increased obviously. Both 1,269 and 1,656 cm(-1) peaks showed that the proteins in HXS were mostly in the anti-parallel ß sheet conformation. While the intensities of bands at 1,032, 1,087, 1,300, and 1,448 cm(-1) belonged to lipids were enhanced in HXS spectrum compared to those in HNS spectrum. There were main intercellular lipids alkyl chains with minor proteins contribution at 1,087 cm(-1) and phenylalanine at 1,032 cm(-1) . To quantitative analysis of the difference, the ratio of I852/I829 was calculated, which was 1:1.04 ± 0.04 and 1:1.11 ± 0.02 for HNS and HXS (p < 0.01), respectively. The data indicated that some tyrosine residues, which form a hydrogen bond with H2 O prior to aggregation, were captured by strong hydrogen-bond acceptors in the aggregate. The decreased ratio of I852/I829 indicated more hydrophobic in HXS than HNS. Principal component analysis showed a one-to-one relationship between human xanthelasma skin and the corresponding Raman spectra. It could be given useful help for the diagnostication of xanthelasma.

  18. Accelerated Detection of Viral Particles by Combining AC Electric Field Effects and Micro-Raman Spectroscopy

    PubMed Central

    Tomkins, Matthew Robert; Liao, David Shiqi; Docoslis, Aristides

    2015-01-01

    A detection method that combines electric field-assisted virus capture on antibody-decorated surfaces with the “fingerprinting” capabilities of micro-Raman spectroscopy is demonstrated for the case of M13 virus in water. The proof-of-principle surface mapping of model bioparticles (protein coated polystyrene spheres) captured by an AC electric field between planar microelectrodes is presented with a methodology for analyzing the resulting spectra by comparing relative peak intensities. The same principle is applied to dielectrophoretically captured M13 phage particles whose presence is indirectly confirmed with micro-Raman spectroscopy using NeutrAvidin-Cy3 as a labeling molecule. It is concluded that the combination of electrokinetically driven virus sampling and micro-Raman based signal transduction provides a promising approach for time-efficient and in situ detection of viruses. PMID:25580902

  19. Wavelet data processing of micro-Raman spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Camerlingo, C.; Zenone, F.; Gaeta, G. M.; Riccio, R.; Lepore, M.

    2006-02-01

    A wavelet multi-component decomposition algorithm is proposed for processing data from micro-Raman spectroscopy (μ-RS) of biological tissue. The μ-RS has been recently recognized as a promising tool for the biopsy test and in vivo diagnosis of degenerative human tissue pathologies, due to the high chemical and structural information contents of this spectroscopic technique. However, measurements of biological tissues are usually hampered by typically low-level signals and by the presence of noise and background components caused by light diffusion or fluorescence processes. In order to overcome these problems, a numerical method based on discrete wavelet transform is used for the analysis of data from μ-RS measurements performed in vitro on animal (pig and chicken) tissue samples and, in a preliminary form, on human skin and oral tissue biopsy from normal subjects. Visible light μ-RS was performed using a He-Ne laser and a monochromator with a liquid nitrogen cooled charge coupled device equipped with a grating of 1800 grooves mm-1. The validity of the proposed data procedure has been tested on the well-characterized Raman spectra of reference acetylsalicylic acid samples.

  20. Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection

    NASA Astrophysics Data System (ADS)

    Lawton, Penelope F.; Saunter, Christopher D.; Girkin, John M.

    2014-03-01

    Since their invention by Ashkin optical tweezers have demonstrated their ability and versatility as a non-invasive tool for micromanipulation. One of the most useful additions to the basic optical tweezers system is micro-Raman spectroscopy, which permits highly sensitive analysis of single cells or particles. We report on the development of a dual laser system combining two spatial light modulators to holographically manipulate multiple traps (at 1064nm) whilst undertaking Raman spectroscopy using a 532nm laser. We can thus simultaneously trap multiple particles and record their Raman spectra, without perturbing the trapping system. The dual beam system is built around micro-fluidic channels where crystallisation of calcium carbonate occurs on polymethylmethacrylate (PMMA) beads. The setup is designed to simulate at a microscopic level the reactions that occur on items in a dishwasher, where permanent filming of calcium carbonate on drinking glasses is a problem. Our system allows us to monitor crystal growth on trapped particles in which the Raman spectrum and changes in movement of the bead are recorded. Due to the expected low level of crystallisation on the bead surfaces this allows us to obtain results quickly and with high sensitivity. The long term goal is to study the development of filming on samples in-situ with the microfl.uidic system acting as a model dishwasher.

  1. Investigation on Clarified Fruit Juice Composition by Using Visible Light Micro-Raman Spectroscopy

    PubMed Central

    Camerlingo, Carlo; Zenone, Flora; Delfino, Ines; Diano, Nadia; Mita, Damiano Gustavo; Lepore, Maria

    2007-01-01

    Liquid samples of clarified apple and apricot juices at different production stages were investigated using visible light micro-Raman spectroscopy in order to assess its potential in monitoring fruit juice production. As is well-known, pectin plays a strategic role in the production of clarified juice and the possibility of using Raman for its detection during production was therefore evaluated. The data analysis has enabled the clear identification of pectin. In particular, Raman spectra of apple juice samples from washed and crushed fruits revealed a peak at 845 cm-1 (typical of pectin) which disappears in the Raman spectra of depectinised samples. The fructose content was also revealed by the presence of four peaks at 823 cm-1, 872 cm-1, 918 cm-1 and 975 cm-1. In the case of apricot juice, several Raman fingerprints of β-carotene at 1008, 1159 and 1520 cm-1 were also highlighted. Present results resulted interesting for the exclusive use of optical methods for the quantitative determination of the above-mentioned substances in place of the biochemical assays generally used for this purpose, which are time consuming and require different chemical reagents for each of them.

  2. Vibrational and structural investigation of SOUL protein single crystals by using micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Rossi, Barbara; Giarola, Marco; Mariotto, Gino; Ambrosi, Emmanuele; Monaco, Hugo L.

    2010-05-01

    Protein SOUL is a new member of the recently discovered putative heme-binding protein family called SOUL/HEBP and, to date, no structural information exists for this protein. Here, micro-Raman spectroscopy is used to study the vibrational properties of single crystals obtained from recombinant protein SOUL by means of two different optimization routes. This spectroscopic approach offers the valuable advantage of the in-situ collection of experimental data from protein crystals, placed onto a hanging-drop plate, under the same conditions used to grow the crystals. By focusing on the regions of amides I and III bands, some secondary structure characteristic features have been recognized. Moreover, some side-chain marker bands were observed in the Raman spectra of SOUL crystals and the unambiguous assignment of these peaks inferred by comparing the experimental Raman spectra of pure amino acids and their Raman intensities computed using quantum chemical calculations. Our comparative analysis allows to get a deeper understanding of the side-chain environments and of the interactions involving these specific amino acids in the two different SOUL crystals.

  3. Micro-Raman spectroscopy study of the effect of Mid-Ultraviolet radiation on erythrocyte membrane.

    PubMed

    Li, N; Li, S X; Guo, Z Y; Zhuang, Z F; Li, R; Xiong, K; Chen, S J; Liu, S H

    2012-07-02

    Mid-Ultraviolet (UVB) has a significant influence on human health. In this study, human erythrocytes were exposed to UVB to investigate the effects of UVB radiation on erythrocytes membrane. And Micro-Raman spectroscopy was employed to detect the damage. Principal component analysis (PCA) was used to classify the control erythrocytes and the irradiated erythrocytes. Results showed that the erythrocytes membrane was damaged by Mid-Ultraviolet (UVB) radiation. The intensity of the Raman peaks at 1126 cm(-1) and 1082 cm(-1) were used to calculate the Longitudinal Order-Parameters in Chains (S(trans)) which can present the liquidity and ionic permeability of erythrocyte membrane. After UVB radiation for 30 min, both the liquidity and ionic permeability decreased. At the same time, the intensity of the peaks at 1302 cm(-1) (α-helix), 1254 cm(-1) (random coil), 1452 cm(-1) and 1430 cm(-1) (CH(2)/CH(3) stretch) have also changed which indicated the membrane protein also been damaged by UVB. In the whole process of radiation, the more UVB radiation dose the more damage on the erythrocyte membrane.

  4. Micro-Raman spectroscopy for optical pathology of oral squamous cell carcinoma.

    PubMed

    Krishna, C Murali; Sockalingum, G D; Kurien, Jacob; Rao, Lakshmi; Venteo, L; Pluot, M; Manfait, M; Kartha, V B

    2004-09-01

    Micro-Raman spectra of formalin-fixed oral squamous normal and carcinoma tissues, stored at room temperature for 2 months, have been recorded. Spectra were recorded both in the epithelial and subepithelial regions of the tissues. No noticeable spectral contamination due to formalin was observed. Very significant differences between spectra of normal epithelial and malignant epithelial samples were found. No such differences in spectra of subepithelial malignant and subepithelial normal samples could be observed. This study shows that spectra from the epithelial region changes drastically because of malignancy-induced biochemical changes in this region. Major differences between normal and malignant spectra seem to arise from the protein composition, conformational/structural changes, and possible increase in protein content in malignant epithelia. The differences between normal epithelial and subepithelial spectra, as expected, arise mainly from the collagen in subepithelial tissue. Principal component analysis of the combined sets of spectra-epithelial and subepithelial, normal and malignant- showed that very good discrimination can be achieved by Raman microspectroscopy. This study thus validates the suitability of formalin-fixed tissues for optical pathology in oral malignancy.

  5. Characterization and differentiation of normal and abnormal spermatozoa via micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Z. F.; Chen, X. W.; Chen, G. N.; Chen, J. H.; Wang, J.; Lin, J. Q.; Zeng, H. S.; Chen, R.

    2013-03-01

    Growth in the percentage of spermatozoa with aberrant sperm head morphologies has been correlated with a rise in male infertility. In our study, micro-Raman spectroscopy using a new substrate was utilized to characterize and differentiate the morphologically normal and abnormal human sperm cells based on their different biochemical components by showing their different specific Raman spectra. A detailed classification based on the PCA-LDA method was performed showing a diagnostic sensitivity of 76% and specificity of 91%, with 80% classification accuracy. Our results suggest that micro-Raman spectroscopy can serve as a reliable and non-invasive tool for detection and differentiation of human spermatozoa.

  6. Micro-Raman spectroscopy and X-ray fluorescence spectrometry on the characterization of the Persian pigments used in the pre-seventeenth century wall paintings of Masjid-i Jāme of Abarqū, central Iran.

    PubMed

    Holakooei, Parviz; Karimy, Amir-Hossein

    2015-01-05

    The pigments used in the wall paintings of the Masjid-i Jāme of Abarqū, central Iran, as less-known pigments used in the history of Persian painting, were investigated with micro-Raman spectroscopy, micro X-ray fluorescence (micro-XRF), scanning electron microscopy (SEM), and polarised light microscopy (PLM). The results showed that the green, red, and blue pigments were atacamite, red lead, and smalt mixed with natural ultramarine blue respectively applied on a white substrate composed of white huntite. Moreover, the blue smalt was identified to be used on the white huntite and under the paint layer in order to delineate the design of the wall paintings and to act as a rough sketch for the subsequent use of the other pigments. Glushinskite, as a less-reported mineral in historical wall paintings, was identified by micro-Raman spectroscopy and hypothesised to be associated with the degradation of the white huntite binder. Furthermore, micro-Raman spectroscopy studies surprisingly revealed the mineral woodhouseite sparely mixed with the green pigment. This paper strongly suggests micro-Raman spectroscopy for identifying archaeological pigments and for diagnosing their deterioration products. Conducting scientific methods of analysis, the pigments identified in this study are reported for the first time to be used in Persian wall paintings.

  7. Micro-Raman spectroscopy and X-ray fluorescence spectrometry on the characterization of the Persian pigments used in the pre-seventeenth century wall paintings of Masjid-i Jāme of Abarqū, central Iran

    NASA Astrophysics Data System (ADS)

    Holakooei, Parviz; Karimy, Amir-Hossein

    2015-01-01

    The pigments used in the wall paintings of the Masjid-i Jāme of Abarqū, central Iran, as less-known pigments used in the history of Persian painting, were investigated with micro-Raman spectroscopy, micro X-ray fluorescence (micro-XRF), scanning electron microscopy (SEM), and polarised light microscopy (PLM). The results showed that the green, red, and blue pigments were atacamite, red lead, and smalt mixed with natural ultramarine blue respectively applied on a white substrate composed of white huntite. Moreover, the blue smalt was identified to be used on the white huntite and under the paint layer in order to delineate the design of the wall paintings and to act as a rough sketch for the subsequent use of the other pigments. Glushinskite, as a less-reported mineral in historical wall paintings, was identified by micro-Raman spectroscopy and hypothesised to be associated with the degradation of the white huntite binder. Furthermore, micro-Raman spectroscopy studies surprisingly revealed the mineral woodhouseite sparely mixed with the green pigment. This paper strongly suggests micro-Raman spectroscopy for identifying archaeological pigments and for diagnosing their deterioration products. Conducting scientific methods of analysis, the pigments identified in this study are reported for the first time to be used in Persian wall paintings.

  8. A novel micro-Raman technique to detect and characterize 4H-SiC stacking faults

    NASA Astrophysics Data System (ADS)

    Piluso, N.; Camarda, M.; La Via, F.

    2014-10-01

    A novel Micro-Raman technique was designed and used to detect extended defects in 4H-SiC homoepitaxy. The technique uses above band-gap high-power laser densities to induce a local increase of free carriers in undoped epitaxies (n < 1016 at/cm-3), creating an electronic plasma that couples with the longitudinal optical (LO) Raman mode. The Raman shift of the LO phonon-plasmon-coupled mode (LOPC) increases as the free carrier density increases. Crystallographic defects lead to scattering or recombination of the free carriers which results in a loss of coupling with the LOPC, and in a reduction of the Raman shift. Given that the LO phonon-plasmon coupling is obtained thanks to the free carriers generated by the high injection level induced by the laser, we named this technique induced-LOPC (i-LOPC). This technique allows the simultaneous determination of both the carrier lifetime and carrier mobility. Taking advantage of the modifications on the carrier lifetime induced by extended defects, we were able to determine the spatial morphology of stacking faults; the obtained morphologies were found to be in excellent agreement with those provided by standard photoluminescence techniques. The results show that the detection of defects via i-LOPC spectroscopy is totally independent from the stacking fault photoluminescence signals that cover a large energy range up to 0.7 eV, thus allowing for a single-scan simultaneous determination of any kind of stacking fault. Combining the i-LOPC method with the analysis of the transverse optical mode, the micro-Raman characterization can determine the most important properties of unintentionally doped film, including the stress status of the wafer, lattice impurities (point defects, polytype inclusions) and a detailed analysis of crystallographic defects, with a high spectral and spatial resolution.

  9. Detection of Receptor-Induced Glycoprotein Conformational Changes on Enveloped Virions by Using Confocal Micro-Raman Spectroscopy

    PubMed Central

    Lu, Xiaonan; Liu, Qian; Benavides-Montano, Javier A.; Nicola, Anthony V.; Aston, D. Eric; Rasco, Barbara A.

    2013-01-01

    Conformational changes in the glycoproteins of enveloped viruses are critical for membrane fusion, which enables viral entry into cells and the pathological cell-cell fusion (syncytia) associated with some viral infections. However, technological capabilities for identifying viral glycoproteins and their conformational changes on actual enveloped virus surfaces are generally scarce, challenging, and time-consuming. Our model, Nipah virus (NiV), is a syncytium-forming biosafety level 4 pathogen with a high mortality rate (40 to 75%) in humans. Once the NiV attachment glycoprotein (G) (NiV-G) binds the cell receptor ephrinB2 or -B3, G triggers conformational changes in the fusion glycoprotein (F) that result in membrane fusion and viral entry. We demonstrate that confocal micro-Raman spectroscopy can, within minutes, simultaneously identify specific G and F glycoprotein signals and receptor-induced conformational changes in NiV-F on NiV virus-like particles (VLPs). First, we identified reproducible G- and F-specific Raman spectral features on NiV VLPs containing M (assembly matrix protein), G, and/or F or on NiV/vesicular stomatitis virus (VSV) pseudotyped virions via second-derivative transformations and principal component analysis (PCA). Statistical analyses validated our PCA models. Dynamic temperature-induced conformational changes in F and G or receptor-induced target membrane-dependent conformational changes in F were monitored in NiV pseudovirions in situ in real time by confocal micro-Raman spectroscopy. Advantageously, Raman spectroscopy can identify specific protein signals in relatively impure samples. Thus, this proof-of-principle technological development has implications for the rapid identification and biostability characterization of viruses in medical, veterinary, and food samples and for the analysis of virion glycoprotein conformational changes in situ during viral entry. PMID:23283947

  10. A novel micro-Raman technique to detect and characterize 4H-SiC stacking faults

    SciTech Connect

    Piluso, N. Camarda, M.; La Via, F.

    2014-10-28

    A novel Micro-Raman technique was designed and used to detect extended defects in 4H-SiC homoepitaxy. The technique uses above band-gap high-power laser densities to induce a local increase of free carriers in undoped epitaxies (n < 10{sup 16} at/cm{sup −3}), creating an electronic plasma that couples with the longitudinal optical (LO) Raman mode. The Raman shift of the LO phonon-plasmon-coupled mode (LOPC) increases as the free carrier density increases. Crystallographic defects lead to scattering or recombination of the free carriers which results in a loss of coupling with the LOPC, and in a reduction of the Raman shift. Given that the LO phonon-plasmon coupling is obtained thanks to the free carriers generated by the high injection level induced by the laser, we named this technique induced-LOPC (i-LOPC). This technique allows the simultaneous determination of both the carrier lifetime and carrier mobility. Taking advantage of the modifications on the carrier lifetime induced by extended defects, we were able to determine the spatial morphology of stacking faults; the obtained morphologies were found to be in excellent agreement with those provided by standard photoluminescence techniques. The results show that the detection of defects via i-LOPC spectroscopy is totally independent from the stacking fault photoluminescence signals that cover a large energy range up to 0.7 eV, thus allowing for a single-scan simultaneous determination of any kind of stacking fault. Combining the i-LOPC method with the analysis of the transverse optical mode, the micro-Raman characterization can determine the most important properties of unintentionally doped film, including the stress status of the wafer, lattice impurities (point defects, polytype inclusions) and a detailed analysis of crystallographic defects, with a high spectral and spatial resolution.

  11. Micro-Raman spectroscopic study of fine-grained, shock-metamorphosed rock fragments from the Australasian microtektite layer

    NASA Astrophysics Data System (ADS)

    Glass, B. P.; Fries, M.

    2008-11-01

    Shock-metamorphosed rock fragments have been found in the Australasian microtektite layer from the South China Sea. Previous X-ray diffraction (XRD) studies indicate that the most abundant crystalline phases in the rock fragments are coesite, quartz, and a 10 Å phase (mica/clay?). In addition, the presence of numerous other phases was suggested by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. In the present research, ten of the rock fragments, which had previously been studied using SEM/EDX, were studied by micro-Raman spectroscopy. The presence of K-feldspar, plagioclase, rutile, ilmenite, titanite, magnetite, calcite, and dolomite were confirmed. In addition, the high-pressure TiO2 polymorph with an α-PbO2 structure (i.e., TiO2II) was found in several rock fragments. Two grains previously thought to have been zircon, based on their compositions, were found to have Raman spectra that do not match the Raman spectra of zircon, reidite, or any of the possible decomposition products of zircon or their high-pressure polymorphs. We speculate that the ZrSiO4 phase might be a previously unknown high-pressure polymorph of zircon or one of its decomposition products (i.e., ZrO2 or SiO2). The presence of coesite and TiO2 II, and partial melting and vesiculation suggest that the rock fragments containing the unknown ZrSiO4 phase must have experienced shock pressures between 45 and 60 GPa. We conclude that micro-Raman spectroscopy, in combination with XRD and SEM/EDX, is a powerful tool for the study of small, fine-grained impact ejecta.

  12. Thermal conductivity measurements of suspended graphene with and without wrinkles by micro-Raman mapping.

    PubMed

    Chen, Shanshan; Li, Qiongyu; Zhang, Qimin; Qu, Yan; Ji, Hengxing; Ruoff, Rodney S; Cai, Weiwei

    2012-09-14

    The thermal conductivity (κ) of suspended graphene membranes made by chemical vapor deposition (CVD) was measured by micro-Raman mapping. Cracks and wrinkles present in these suspended graphene membranes were identified by micro-Raman mapping, and κ values and their statistics were obtained on membranes free of such imperfections in a single mapping. Based on this new technique, an average κ value of 1875 ± 220 W m(-1) K(-1) at 420 K was measured on 26 suspended graphene membranes that were free of wrinkles, ~27% higher than the average value measured from 12 graphene membranes with wrinkles. These results suggest that the variation in published thermal conductivity values for suspended graphene samples could, at least in part, be due to the presence or absence of wrinkles.

  13. Combined Micro-Infrared (IR) and Micro-Raman Measurements on Stratospheric Interplanetery Dust Particles

    NASA Astrophysics Data System (ADS)

    Rotundi, A.; Ferrini, G.; Baratta, G. A.; Palumbo, M. E.; Palomba, E.; Colangeli, L.

    2007-01-01

    In preparation for the Stardust sample analyses, we performed combined micro-IR/micro-Raman measurements on five Interplanetary Dust Particles (IDPs) that were characterized by Field Emission Scanning Electron Microscope analyses. We demonstrate the synergy between these techniques to detect Fe-oxides and the degree of ordering in amorphous carbons, and IR-based classification of these IDPs collected in the lower stratosphere. We present IR spectra and micro-Raman data that offer new insight in the evolution of the amorphous carbon component in (1) three chondritic aggregate IDPs, (2) a sulfide IDP and (3) a Fe-rich IDP sphere with a vestige of sulfur remnant after ablation and melting of a sulfide IDP.

  14. Near-ultraviolet micro-Raman study of diamond grown on GaN

    SciTech Connect

    Nazari, M. Hancock, B. L.; Anderson, J.; Savage, A.; Piner, E. L.; Holtz, M.; Graham, S.; Faili, F.; Oh, S.; Francis, D.; Twitchen, D.

    2016-01-18

    Ultraviolet (UV) micro-Raman measurements are reported of diamond grown on GaN using chemical vapor deposition. UV excitation permits simultaneous investigation of the diamond (D) and disordered carbon (DC) comprising the polycrystalline layer. From line scans of a cross-section along the diamond growth direction, the DC component of the diamond layer is found to be highest near the GaN-on-diamond interface and diminish with characteristic length scale of ∼3.5 μm. Transmission electron microscopy (TEM) of the diamond near the interface confirms the presence of DC. Combined micro-Raman and TEM are used to develop an optical method for estimating the DC volume fraction.

  15. Micro-Raman spectroscopy study of ALVAC virus infected chicken embryo cells

    NASA Astrophysics Data System (ADS)

    Misra, Anupam K.; Kamemoto, Lori E.; Hu, Ningjie; Dykes, Ava C.; Yu, Qigui; Zinin, Pavel V.; Sharma, Shiv K.

    2011-05-01

    Micro- Raman spectroscopic investigation of ALVAC virus and of normal chicken embryo fibroblast cells and the cells infected with ALVAC virus labeled with green fluorescence protein (GFP) were performed with a 785 nm laser. Good quality Micro-Raman spectra of the Alvac II virus were obtained. These spectra show that the ALVAC II virus contains buried tyrosine residues and the coat protein of the virus has α-helical structure. A comparison of Raman spectra of normal and virus infected chicken embryo fibroblast cells revealed that the virus infected cells show additional bands at 535, 928, and 1091 cm-1, respectively, corresponding to δ(C-O-C) glycosidic ring, protein α-helix, and DNA (O-P-O) modes. In addition, the tyrosine resonance double (833 and 855 cm-1) shows reversal in the intensity of the higher-frequency band as compared to the normal cells that can be used to identify the infected cells. In the C-H stretching region, the infected cells show bands with higher intensity as compared to that of the corresponding bands in the normal cells. We also found that the presence of GFP does not affect the Raman spectra of samples when using a 785 nm micro-Raman system because the green fluorescence wavelength of GFP is well below the Stokes-Raman shifted spectral region.

  16. Micro-Raman spectroscopic study of thyroid tissues.

    PubMed

    Medeiros Neto, Lázaro Pinto; das Chagas E Silva de Carvalho, Luis Felipe; Santos, Laurita Dos; Tellez Soto, Cláudio Alberto; de Azevedo Canevari, Renata; de Oliveira Santos, André Bandiera; Mello, Evandro Sobroza; Pereira, Marina Aparecida; Cernea, Cláudio Roberto; Brandão, Lenine Garcia; Martin, Aírton Abrahão

    2017-03-01

    Thyroid carcinomas are the most common endocrine malignancy. Inconclusive results for the analysis of malignancies are an issue in the diagnosis of thyroid carcinomas; 20% of thyroid cancer diagnoses are indeterminate or suspicious, resulting in a surgical procedure without immediate need. The use of Raman spectroscopy may help improve the diagnosis of thyroid carcinoma. In this study, 30 thyroid samples, including normal thyroid, goiter and thyroid cancer, were analyzed by confocal Raman spectroscopy. Principal component analysis (PCA), linear discriminant analysis (LDA) with cross validation and binary logistic regression (BLR) analysis were applied to discriminate among tissues. Significant discrimination was observed, with a consistent rate of concordant pairs of 89.2% for normal thyroid versus cancer, 85.7% for goiter versus cancer and 80.6% for normal thyroid versus goiter using just the amide III region. Raman spectroscopy was thus proven to be an important and fast tool for the diagnosis of thyroid tissues. The spectral region of 1200-1400cm(-1) discriminated normal versus goiter tissues despite the great similarity of these tissues.

  17. Polarized micro Raman spectroscopy of multiferroic BiFeO3 single crystals

    NASA Astrophysics Data System (ADS)

    Beekman, C.; Cheong, Sang-Wook; Burch, Kenneth

    2011-03-01

    In Bismuth ferrite (BiFe O3) antiferromagnetic and ferroelectric order parameters coexist at room temperature, making this material an excellent candidate for new functionalities, such as electrical control of ferromagnetism. Despite extensive reports on Raman scattering experiments on single crystals and thin films, controversy still remains in the observation and assignment of the phonon modes. However, proper Raman mode assignment to describe the phonons critical for the multiferroic behavior is necessary. We present polarized micro Raman spectroscopy of single crystals with uniform ferroelectric polarization. Careful examination of the Raman spectra upon crystal rotation enables us to unambiguously assign several (A1 , Ex and Ey) modes.

  18. The superelastic mechanism of Si3N4 microsprings using micro-Raman spectroscopy.

    PubMed

    Fu, Yan; Li, Jili; Cao, Chuanbao

    2014-07-28

    Silicon nitride microsprings with superelasticity are characterized using SEM, XRD, TEM and micro-Raman methods. The internal structure and the superelastic mechanism of silicon nitride microsprings are proposed through analyzing the variation of Raman peaks upon stretching gradually. During the stretching process, since all the vibrations are internal vibrations within the primitive unit cell, the basic structure has no changes and the residual stress never concentrates. The special structure of the fine grains and no sharp grain boundaries make the silicon nitride microsprings possess such good superelastic properties.

  19. Extended x-ray absorption fine structure and micro-Raman spectra of Bridgman grown Cd1-xZnxTe ternary alloys

    NASA Astrophysics Data System (ADS)

    Talwar, Devki N.; Feng, Zhe Chuan; Lee, Jyh-Fu; Becla, P.

    2014-03-01

    We have performed low-temperature micro-Raman scattering and extended x-ray absorption fine-structure (EXAFS) measurements on the Bridgman-grown bulk zinc-blende Cd1-x Zn x Te (1.0 ≧̸ x ≧̸ 0.03) ternary alloys to comprehend their structural and lattice dynamical properties. The micro-Raman results are carefully appraised to authenticate the classical two-phonon mode behavior insinuated by far-infrared (FIR) reflectivity study. The composition-dependent EXAFS experiments have revealed a bimodal distribution of the nearest-neighbor bond lengths—its analysis by first-principles bond-orbital model enabled us to estimate the lattice relaxations around Zn/Cd atoms in CdTe/ZnTe to help evaluate the necessary force constant variations for constructing the impurity-perturbation matrices. The simulated results of impurity vibrational modes by average-t-matrix Green’s function (ATM-GF) theory has put our experimental findings of the gap mode ˜153 cm-1 near x ≈ 1 on a much firmer ground.

  20. Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

    PubMed Central

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-01-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems. PMID:27877486

  1. Rheological and micro-Raman time-series characterization of enzyme sol-gel solution toward morphological control of electrospun fibers

    NASA Astrophysics Data System (ADS)

    Oriero, Dennis A.; Weakley, Andrew T.; Aston, D. Eric

    2012-04-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol-gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol-gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200-300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol-gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol-gel systems.

  2. Rheological and micro-Raman time-series characterization of enzyme sol-gel solution toward morphological control of electrospun fibers.

    PubMed

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-04-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol-gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol-gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200-300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol-gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol-gel systems.

  3. Rapid and direct screening of H:C ratio in Archean kerogen via microRaman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ferralis, N.; Matys, E. D.; Allwood, A.; Knoll, A. H.; Summons, R. E.

    2015-12-01

    Rapid evaluation of the preservation of biosignatures in ancient kerogens is essential for the evaluation of the usability of Earth analogues as proxies of Martian geological materials. No single, non-destructive and non-invasive technique currently exists to rapidly determine such state of preservation of the organic matter in relation to its geological and mineral environment. Due to its non-invasive nature, microRaman spectroscopy is emerging as a candidate technique for the qualitative determination maturity of organic matter, by correlating Raman spectral features and aromatic carbon cluster size. Here we will present a novel quantitative method in which before-neglected Raman spectral features are correlated directly and with excellent accuracy with the H:C ratio. In addition to providing a chemical justification of the found direct correlation, we will show its applicability and predictive capabilities in evaluating H:C in Archean kerogens. This novel method opens new opportunities for the use of Raman spectroscopy and mapping. This includes the non-invasively determination of kerogen preservation and microscale chemical diversity within a particular Earth analogue, to be potentially extended to evaluate Raman spectra acquired directly on Mars.

  4. The effects of machine parameters on residual stress determined using micro-Raman spectroscopy

    SciTech Connect

    Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

    1988-12-01

    The effects of machine parameters on residual stresses in single point diamond turned silicon and germanium have been investigated using micro-Raman spectroscopy. Residual stresses were sampled across ductile feed cuts in < 100 > silicon and germanium which were single point diamond turned using a variety of feed rates, rake angles and clearance angles. High spatial resolution micro-Raman spectra (1{mu}m spot) were obtained in regions of ductile cutting where no visible surface damage was present. The use of both 514-5nm and 488.0nm excitation wavelengths, by virtue of their differing characteristic penetration depths in the materials, allowed determinations of stress profiles as a function of depth into the sample. Previous discussions have demonstrated that such Raman spectra will exhibit asymmetrically broadened peaks which are characteristic of the superposition of a continuum of Raman scatterers from the various depths probed. Depth profiles of residual stress were obtained using computer deconvolution of the resulting asymmetrically broadened raman spectra.

  5. Inhomogeneous laser heating and phonon confinement in silicon nanowires: A micro-Raman scattering study

    NASA Astrophysics Data System (ADS)

    Adu, K. W.; Gutiérrez, H. R.; Kim, U. J.; Eklund, P. C.

    2006-04-01

    Results of a systematic set of micro-Raman experiments on the changes in the line shape of the ˜520cm-1 one-phonon band in Si nanowires with laser flux Φ are presented. A complicated dependence of the 520cm-1 Raman band asymmetry (A) with Φ is observed that depends both on the nanowire diameter and on the thermal anchoring of the wires to an indium foil substrate. With increasing power density in a ˜1μ focal spot common to micro-Raman spectroscopy, we see a clear growth in A that has nothing to do with phonon confinement. In fact, we can explain the complex changes in A(Φ) by extending the model [H. Richter, Z. P. Wang, and Y. Ley, Solid State Commun. 39, 625 (1981)] to include an inhomogeneous heating in the Raman volume. The effects we observe in Si nanowires should be common to all semiconducting nanostructures and underscores the importance of demonstrating a flux-independent line shape when studying pure phonon confinement effects by Raman scattering.

  6. Micro-Raman of mineral phases in the strongly shocked Taiban ordinary chondrite: ringwoodite coloration

    NASA Astrophysics Data System (ADS)

    Acosta, T. E.; Scott, E. R. D.; Sharma, S. K. S.; Misra, A. K.

    2012-09-01

    High pressure polymorphs of major minerals are commonly found in shocked meteorites. During the formation evolution of the Solar System asteroids have collided with each other and with larger bodies triggering shock waves. The produced Meteorites show different shock effects depending on the peak pressures and temperatures, and duration of the collision events [5]. Taiban is a very strongly shocked, shock stage S6 ordinary L6 chondrite. It shows multiple veins of opaque shock melt forming a network of complex branches surrounding pockets of highly shock altered, mosaicized, relict or recrystalized silicates, and their high pressure polymorphs [4,5]. Micro-Raman spectroscopy has been used to provide univocal identification of minerals and glassy phases in meteorites as well as a tool to obtain additional information on structural and compositional variations inside mineral grains [7]. We studied the polished thin section UNM297 of Taiban meteorite with micro-Raman spectroscopy and Raman mapping to identify and characterize major and minor phases. Ringwoodite g-(Fe,Mg)2Si04 is the high-pressure polymorph of olivine with the spinel structure.

  7. Micro-Raman and Micro-FTIR Spectroscopy of Experimentally Shocked Bytownite

    NASA Astrophysics Data System (ADS)

    Jaret, S.; Sims, M.; Johnson, J. R.; Glotch, T. D.

    2016-12-01

    During impact events, feldspars undergo progressive shock metamorphic transformations that change their internal structure. These changes are detectable optically in thin section and with X-ray analyses and vibrational spectroscopy. As part of an ongoing study of the compositional effects on these shock transformations in plagioclase, we report new micro-Raman and micro-FTIR results on experimentally shocked bytownite and compare these to similar studies of andesine and albite. With increasing shock pressure, micro-Raman patterns show a decrease in overall intensity of peaks. At shock pressures below 29 GPa, this manifests as an increase in the 486:507 Dcm-1 peak ratio. Above 29 GPa, bytownite shows micro-Raman patterns indicative of an amorphous material: two broad peaks centered near 500 Dcm-1 and 950 Dcm-1. For comparison, andesine and albite exhibit a broad peak at 490 Dcm-1 and a weak peak (if present) at 950 Dcm-1. Micro-FTIR results also show a pattern of decreasing crystallinity with increased pressure, indicated by loss of the peak at 1050 cm-1 above 29 GPa. Above 38.2 GPa, only one peak near 960 cm-1 is present. In some high pressure samples the peak position varies slightly, which could be due to a crystal orientation effect or minor compositional variations across a given sample. This may suggest that the highly shocked bytownite has retained some small scale remnant feldspar topology despite being amorphous at large scales. Bytownite shares similar patterns to other plagioclases in spectroscopic response to shock. Raman spectra show loss of cation modes first, and an overall decrease in Raman intensity. IR spectra of highly shocked samples show an overall amorphous spectral shape with possible remnant crystal orientation effects. Amorphization pressures for bytownite are slightly lower than andesine and significantly lower than albite. This is consistent with a Ca dependency on shock transformations, as suggested previously. Future work will include

  8. Stress transfer of a Kevlar 49 fiber pullout test studied by micro-Raman spectroscopy.

    PubMed

    Lei, Zhenkun; Wang, Quan; Qiu, Wei

    2013-06-01

    The interfacial stress transfer behavior of a Kevlar 49 aramid fiber-epoxy matrix was studied with fiber pullout tests, the fibers of which were stretched by a homemade microloading device. Raman spectra on the embedded fiber were recorded by micro-Raman spectroscopy, under different strain levels. Then, the fiber axial stress was obtained by the relationship between the stress and Raman shift of the aramid fiber. Experimental results revealed that the fiber axial stress increased significantly with the load. The shear stress concentration occurred at the fiber entry to the epoxy resin. Thus, interfacial friction stages exist in the debonded fiber segment, and the interfacial friction shear stress is constant within one stage. The experimental results are consistent with the theoretical model predictions.

  9. Local residual stress monitoring of aluminum nitride MEMS using UV micro-Raman spectroscopy

    SciTech Connect

    Choi, Sukwon; Griffin, Benjamin A.

    2016-01-06

    Localized stress variation in aluminum nitride (AlN) sputtered on patterned metallization has been monitored through the use of UV micro-Raman spectroscopy. This technique utilizing 325 nm laser excitation allows detection of the AlN E2(high) phonon mode in the presence of metal electrodes beneath the AlN layer with a high spatial resolution of less than 400 nm. The AlN film stress shifted 400 MPa from regions where AlN was deposited over a bottom metal electrode versus silicon dioxide. Thus, across wafer stress variations were also investigated showing that wafer level stress metrology, for example using wafer curvature measurements, introduces large uncertainties for predicting the impact of AlN residual stress on the device performance.

  10. Local residual stress monitoring of aluminum nitride MEMS using UV micro-Raman spectroscopy

    DOE PAGES

    Choi, Sukwon; Griffin, Benjamin A.

    2016-01-06

    Localized stress variation in aluminum nitride (AlN) sputtered on patterned metallization has been monitored through the use of UV micro-Raman spectroscopy. This technique utilizing 325 nm laser excitation allows detection of the AlN E2(high) phonon mode in the presence of metal electrodes beneath the AlN layer with a high spatial resolution of less than 400 nm. The AlN film stress shifted 400 MPa from regions where AlN was deposited over a bottom metal electrode versus silicon dioxide. Thus, across wafer stress variations were also investigated showing that wafer level stress metrology, for example using wafer curvature measurements, introduces large uncertaintiesmore » for predicting the impact of AlN residual stress on the device performance.« less

  11. Comparative study of carbonaceous meteoritic fragments by micro-Raman spectroscopy and SEM/EDS.

    NASA Astrophysics Data System (ADS)

    Dall'Asén, AnalíA.; Mittelstaedt, Jacob; Kim, Jin-Sun; Baer, Brandon; Paul, Raka; Gerton, Jordan; Bromley, Benjamin; Kenyon, Scott

    2017-01-01

    Meteorites provide precious clues about the formation of planets in the solar system. In particular, carbonaceous chondritic meteorites, considered the most primitive surviving materials from the early Solar System, can contribute to understand how planetisimals (the precursors to planets, of 1-100 km in radius) formed from dust (micron-size grains). These relics are mainly composed of chondrules (micro/millimeter-sized inclusions) surrounded by a matrix of microparticles. Here we present a comparative study of the structure and composition of the chondrules and surrounding matrix of different carbonaceous chondritic meteorites using low- and high-resolution micro-Raman spectroscopy and SEM/EDS (Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy). We examine how these properties vary in different regions of the chondrules and matrix, capturing details from micrometer to millimeter scales. We compare the structure and composition between different samples, looking for signatures of the physical processes that drove their formation.

  12. MicroRaman Spectroscopy and Raman Imaging of Basal Cell Carcinoma

    NASA Astrophysics Data System (ADS)

    Short, M. A.; Zeng, H.; Lui, H.

    2005-03-01

    We have measured the Raman spectra of normal and cancerous skin tissues using a confocal microRaman spectrograph with a sub-micron spatial resolution. We found that the Raman spectrum of a cell nucleolus is different from the spectra measured outside the nucleolus and considerably different from those measured outside the nucleus. In addition, we found significant spectroscopic differences between normal and cancer-bearing sites in the dermis region. In order to utilize these differences for non-invasive skin cancer diagnosis, we have developed a Raman imaging system that clearly demonstrates the structure, location and distribution of cells in unstained skin biopsy samples. Our method is expected to be useful for the detection and characterization of skin cancer based on the known distinct cellular differences between normal and malignant skin.

  13. Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers

    NASA Astrophysics Data System (ADS)

    Wang, R. X.; Xu, S. J.; Fung, S.; Beling, C. D.; Wang, K.; Li, S.; Wei, Z. F.; Zhou, T. J.; Zhang, J. D.; Huang, Ying; Gong, M.

    2005-07-01

    GaN epilayers grown on sapphire substrate were irradiated with various dosages of neutrons and were characterized using Micro-Raman and photoluminescence. It was found that the A1(LO) peak in the Raman spectra clearly shifted with neutron irradiation dosage. Careful curve fitting of the Raman data was carried out to obtain the carrier concentration which was found to vary with the neutron irradiation dosage. The variation of the full width at half maximum height of the photoluminescence was consistent with the Raman results. The neutron irradiation-induced structural defects (likely to be GeGa) give rise to carrier trap centers which are responsible for the observed reduction in carrier concentration of the irradiated GaN.

  14. Quantitative Micro-Raman Spectroscopy for Partial Pressure Measurement in Small Volumes.

    PubMed

    Karlen, Sylvain; Gobet, Jean; Overstolz, Thomas; Haesler, Jacques; Lecomte, Steve

    2017-01-01

    We demonstrate the quantitative capabilities of Raman confocal microscopy as a nondestructive method to measure the partial pressure of molecular gases in mm(3) range sealed volume having an optical access. Thanks to a calibration procedure, we apply this technique for the characterization of the absolute nitrogen partial pressure inside buffered micro electromechanical system (MEMS) atomic vapor cells developed for atomic clocks. Our results are compared with measurements obtained by rubidium hyperfine frequency spectroscopy and a good agreement is demonstrated between the two methods, with a three-sigma detection limit below 10 mbar for a 1 h integration time, using a 33 mW 532 nm excitation laser. These results prove the potential of confocal micro-Raman spectroscopy as a simple and nondestructive method for small-scale pressure measurements.

  15. Micro-Raman spectroscopic study of extremely large atmospheric ice conglomerations (megacryometeors).

    PubMed

    Rull, F; Delgado, A; Martínez-Frías, J

    2010-07-13

    For the first time, micro-Raman spectroscopy has been applied to the structural study of four megacryometeors (extremely large atmospheric ice conglomerations that fall in general under blue-sky atmospheric conditions) that fell in Spain. The Raman spectra taken on the megacryometeor cores have been compared with those obtained from an in situ and online study performed on the crystallization process of water in the laboratory. A detailed comparison of the band profiles obtained made it possible to place the formation of the megacryometeors within a particular range of temperatures (-10 to -20 degrees C), which in turn can be related with the altitude of formation in the atmosphere. These results have also been compared with isotope concentrations (delta(18)O and deltaD) previously obtained in these cores. The two sets of results show a close correlation.

  16. Characterization of biofumigated Ralstonia solanacearum cells using micro-Raman spectroscopy and electron microscopy.

    PubMed

    Paret, Mathews L; Sharma, Shiv K; Alvarez, Anne M

    2012-01-01

    Essential oils of palmarosa, lemongrass, and eucalyptus have shown promise as biofumigants for control of the bacterial wilt disease of edible ginger (Zingiber officinale) caused by Ralstonia solanacearum race 4 in previous potting medium studies. Biochemical changes in R. solanacearum cells were evaluated with micro-Raman spectroscopy following treatment with essential oils at different concentrations (0.04, 0.07, and 0.14% [vol/vol] of culture medium) and changes in cell structure were observed using electron microscopy. All treatments except palmarosa oil at 0.04% caused significant reductions in levels of amino acids, purine and pyrimidine bases of nucleic acids, carbohydrates, and lipids, as indicated by significant reduction in Raman peak heights at 621, 1,003, and 1,031 inverse centimeters (cm(-1)) (phenylalanine); 643, 827, 852, 1,158, and 1,172 cm(-1) (tyrosine); 758 cm(-1) (tryptophan); 725, 782, 1,337, and 1,578 cm(-1) (adenine, cytosine plus uracil, adenine, and adenine plus guanine, respectively); 1,097 cm(-1) (carbohydrates); and 1,127, 1,450, and 2,932 cm(-1) (lipids) compared with untreated controls. Lemongrass oil treatments were the most effective in degrading cellular components. Scanning electron microscopy of palmarosa and lemongrass-oil-treated cells showed rupture of cell walls and cell debris but no degradation was noted for eucalyptus-oil-treated cells. Palmarosa- and lemongrass-oil-treated cells were positively stained with uranyl acetate when viewed by transmission electron microscopy whereas controls and eucalyptus-oil-treated cells were negatively stained, indicating that the cell membranes were intact. The viability of eucalyptus-oil-treated cells was confirmed by cell culture following treatment. Micro-Raman spectroscopy is a powerful tool which can be further employed to better understand effects of fumigants and other bactericides on bacterial cells.

  17. Three-dimensional mapping of stresses in plastically deformed diamond using micro-Raman and photoluminescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Erasmus, R. M.; Daniel, R. D.; Comins, J. D.

    2011-01-01

    The extreme mechanical properties of diamond have made it the material of choice for many industrial applications, ranging from cutting and grinding to wire-drawing dies. A detailed knowledge of its mechanical properties, also at high temperature, is thus of importance. Micro-Raman and photoluminescence (PL) spectroscopy were used to map the three-dimensional (3D) stress distribution surrounding a plastic impression made in a synthetic, type Ib single crystal diamond. The impression was created on a (100) face of the crystal with an Si3N4 impressor at 1400 °C using the so-called soft impressor technique. The diamond Raman peak was mapped at room temperature at the surface and at fixed intervals of 10 μm below the surface using a motorised X-Y stage. The depth (Z)-resolution was limited to 10 μm by means of a confocal pinhole. Using data from the Raman peak position, a 3D map of the stress contours surrounding the impression was generated, while the Raman width data yielded a map of the plastic deformation volume. The surface stress map shows a cross-shaped rosette pattern that corresponds very closely with micrographs imaging the pile-up on the surface due to dislocation movement. The "arms" of the pattern are in compression (˜1.5 GPa), while the center of the impression is in tension (˜1 GPa). The deformation map shows a radially symmetric area of deformation centered on the impression, with the maximum degree of deformation at the center. The stress contours compare favorably with the resolved shear stress contours calculated for diamond. PL intensity maps of the zero phonon line (ZPL) associated with the [N-V]- defect center at 1.945 eV provide images of the extent of vacancy formation and movement during the impression process. Data concerning the position and width of the ZPL correspond well with the Raman results.

  18. Characterization of Organic Materials in the Xenolithic Clasts in Sharps (H3.4) Meteorite Using Micro-Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Kebukawa, Y.

    2015-01-01

    Graphitization of carbon is an irreversible process which alters the structure of graphitic materials in response to the increase in metamorphic grade (temperature and/or pressure). Carbonaceous materials offer a reliable geothermometer as their Raman spectra change systematically with increasing metamorphic grade. In this study, we identified carbonaceous materials in the xenolithic clasts in Sharps and interpreted their metamorphic history by revealing the structural organization (order) of the polyaromatic organic phases using micro-Raman spectroscopy.

  19. Structural and vibrational characterization of sugar arabinitol structures employing micro-Raman spectra and DFT calculations

    NASA Astrophysics Data System (ADS)

    Hédoux, Alain; Guinet, Yannick; Carpentier, Laurent; Paccou, Laurent; Derollez, Patrick; Brandán, Silvia Antonia

    2017-06-01

    In this work, three monomeric forms of arabinitol, usually named arabitol, and their dimeric species have been structural and vibrationally studied by using the micro-Raman spectra in the solid phase accomplished with theoretical calculations based on the theory of the functional of the density (DFT). The hybrid B3LYP method was used for all the calculations together with the 6-31G* and 6-311++g** basis sets. Two different L structures with minima energies were predicted in accordance to the two polymorphic structures revealed by recent X-ray diffraction experiments. The studies by natural bond orbital (NBO) calculations reveals high stabilities of the L form as compared with the D one but the topological properties by using the atoms in molecules (AIM) suggest a higher stability of the D form due to a strong H bond interactions. The scaled mechanical force fields (SQMFF) procedure was used to perform the complete vibrational assignments for the monomeric forms and their dimer. On the other hand, the similarity in the gap values computed for the three forms of arabitol with those observed for sucrose, trehalose, maltose and lactose in gas phase at the same level of theory could partially explain the sweetening property of this alcohol. In addition, the influences of the size of the basis set on some properties were evidenced.

  20. Microstructure and micro-Raman studies of nitridation and structure transition of gallium oxide nanowires

    SciTech Connect

    Ning, J.Q.; Xu, S.J.; Wang, P.W.; Song, Y.P.; Yu, D.P.; Shan, Y.Y.; Lee, S.T.; Yang, H.

    2012-11-15

    Here we present a detailed study on nitridation and structure transition in monoclinic gallium oxide ({beta}-Ga{sub 2}O{sub 3}) nanowires grown on Si substrates with chemical vapor phase epitaxy. The nanowires were systematically nitridated at different temperatures. Their morphologies and microstructures were precisely characterized using field-emission scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and confocal micro-Raman spectroscopy. It is found that heat treatment of Ga{sub 2}O{sub 3} nanowires in the gas of ammonia results in rich substructures including the Ga{sub 2}O{sub 3} phase, the crystalline GaN phase, and other meta structures. The identification of these structures helps to understand some interesting phenomena observed in nanostructures, such as the microstructural origin of the unknown Raman lines in GaN nanowires. - Highlights: Black-Right-Pointing-Pointer Nitridation and structure transition of Ga{sub 2}O{sub 3} significantly depend on temperature. Black-Right-Pointing-Pointer G-N bonds form at lower temperatures but the Ga{sub 2}O{sub 3} lattice is still dominant. Black-Right-Pointing-Pointer Amorphous GaN coexists with crystalline Ga{sub 2}O{sub 3} at higher temperatures. Black-Right-Pointing-Pointer Crystalline GaN with distinct morphology is obtained at much higher temperatures.

  1. Study of hemoglobin response to mid-ultraviolet (UVB) radiation using micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Y. Y.; Li, N.; Zhou, S. N.; Huang, Z. T.; Zhuang, Z. F.

    2017-09-01

    Confocal micro-Raman spectroscopy is employed to monitor the damage to haemoglobin from mid-ultraviolet (UVB) radiation. We obtained the Raman spectra of an erythrocyte, which indicated that a peroxidation reaction occurs after UVB radiation. Further, the surface enhanced Raman scattering (SERS) spectra of isolated haemoglobin show that the intensities of the 1375 and 1399 cm-1 bands, which are markers of haem aggregation, obviously increase with prolonged UVB irradiation. This increase reveals that haem aggregation occurs in the peroxidation of erythrocytes. The UV-Vis spectra of isolated haemoglobin indicate that the Soret band, which is indicative of excitonic interactions in the aggregated haems, has a redshift ( 12 nm) after 30 min of UVB irradiation of erythrocytes. It can be deduced that an excitonic interaction occurs in the aggregated haems, which is caused by haemoglobin denaturation following UVB irradiation. In addition, the changes of the Raman marker bands during aggregation primarily originate from excitonic interactions. Throughout the process, a higher UVB radiation dose causes greater damage to haemoglobin.

  2. Structural Modification of Single-Layer Graphene Under Laser Irradiation Featured by Micro-Raman Spectroscopy.

    PubMed

    Stubrov, Yurii; Nikolenko, Andrii; Strelchuk, Viktor; Nedilko, Sergii; Chornii, Vitalii

    2017-12-01

    Confocal micro-Raman spectroscopy is used as a sensitive tool to study the nature of laser-induced defects in single-layer graphene. Appearance and drastic intensity increase of D- and D' modes in the Raman spectra at high power of laser irradiation is related to generation of structural defects. Time- and power-dependent evolution of Raman spectra is studied. The dependence of relative intensity of defective D- and D' bands is analyzed to relate the certain types of structural defects. The surface density of structural defects is estimated from the intensity ratio of D- and G bands using the D-band activation model. Unusual broadening of the D band and splitting of the G band into G(-) and G(+) components with redistribution of their intensities is observed at high laser power and exposition. Position of the G(+) band is discussed in relation with nonuniform doping of graphene with charge impurities. Simultaneous presence in the Raman spectra of heavily irradiated graphene of rather narrow G band and broaden D band is explained by coexistence within the Raman probe of more and less damaged graphene areas. This assumption is additionally confirmed by confocal Raman mapping of the heavily irradiated area.

  3. Preliminary micro-Raman images of normal and malignant human skin cells

    NASA Astrophysics Data System (ADS)

    Short, Michael A.; Lui, Harvey; McLean, David I.; Zeng, Haishan; Chen, Michael X.

    2006-02-01

    Micro-Raman spectroscopy covering a frequency range from 200 to 4000 cm -1 was used to image human skin melanocytes and keratinocytes with a spatial resolution of 0.5 μm. The cells were either cultivated on glass microscope slides or were located within thin sections of skin biopsies mounted on low fluorescence BaF II. A commercially available system was used to obtain the spectra utilizing a x100 long working distance objective with a numerical aperture of 0.8, and a cooled CCD. Both 633 and 515 nm excitations were tried, although the latter proved to be more effcient at producing Raman emission mostly due to the 1/λ 4 dependence in light scattering. Fluorescence emission from the cells was surprisingly low. The excitation power at the sample was kept below about 2 mW to avoid damaging the cells; this was the limiting factor on how quickly a Raman image could be obtained. Despite this diffculty we were able to obtain Raman images with rich information about the spectroscopic and structural features within the cytoplasm and cell nuclei. Differences were observed between the Raman images of normal and malignant cells. Spectra from purified DNA, RNA, lipids, proteins and melanin were obtained and these spectra were compared with the skin cell spectra with the aim of understanding how they are distributed over a cell and how the distribution changes between different cells.

  4. Bacterial identification in real samples by means of micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Rösch, Petra; Stöckel, Stephan; Meisel, Susann; Bossecker, Anja; Münchberg, Ute; Kloss, Sandra; Schumacher, Wilm; Popp, Jürgen

    2011-07-01

    Pathogen detection is essential without time delay especially for severe diseases like sepsis. Here, the survival rate is dependent on a prompt antibiosis. For sepsis three hours after the onset of shock the survival rate of the patient drops below 60 %. Unfortunately, the results from standard diagnosis methods like PCR or microbiology can normally be received after 12 or 36 h, respectively. Therefore diagnosis methods which require less cultivation or even no cultivation at all have to be established for medical diagnosis. Here, Raman spectroscopy, as a vibrational spectroscopic method, is a very sensitive and selective approach and monitors the biochemical composition of the investigated sample. Applying micro-Raman spectroscopy allows for a spatial resolution below 1 μm and is therefore in the size range of bacteria. Raman spectra of bacteria depend on the physiological status. Therefore, the databases require the inclusion of the necessary environmental parameters such as temperature, pH, nutrition, etc. Such large databases therefore require a specialized chemometric approach, since the variation between different strains is small. In this contribution we will demonstrate the capability of Raman spectroscopy to identify pathogens without cultivation even from real environmental or medical samples.

  5. High-pressure Fourier transform micro-Raman spectroscopic investigation of diiodine-heterocyclic thioamide adducts.

    PubMed

    dos Santos, João Henrique Z; Butler, Ian S; Daga, Vasiliki; Hadjikakou, Sotiris; Hadjiliadis, Nick

    2002-10-01

    The pressure dependences of the Fourier transform micro-Raman spectra of four heterocyclic thioamides [[(bztzdtH)I2] x I2] (1) (bztzdtH = benzothiazole-2-thione), [(bztzdtH)I2] (2), [[(tzdtH)2I+] x I3- x 2I2] (3) (tzdtH = thiazoline-2-thione), and [[(bzimtH)I2]2 x I2 x 2H2O] (4) (bzimtH = benzimidazole-2-thione) have been studied between ambient pressure and 50 kbar. For 1, generation of I3- ions through disproportionation reactions is evident as the pressure is increased. There are empirical linear correlations between the frequency and (I-I) bond length and the applied pressure. The iodine adduct of thioamide 2 is more sensitive to pressure when compared to the 1 or 4 iodine adducts. This difference in behavior may be attributed to differences in crystal structures or to a lower I-I bond order. Monitoring of other vibrational transitions of the thiomide structure reveals several less important pressure dependences.

  6. Study of Thermal Conductivity of Si Nanowires with micro-Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Bingqing; Murphy, Kathryn F.; Gianola, Daniel S.; Cheng, X. M.

    2013-03-01

    Nanowires have played an increasingly important role in thermoelectric technology due to their high figure of merit ZT resulting from the reduced thermal conductivity, K, and good electrical conductivity. In this work, we report the measurement of K of individual silicon nanowires (SiNWs) by mapping Raman temperature profiles along the testing nanowires using a microelectromechanical system (MEMS) device and a micro-Raman system with a 530 nm laser beam. Thermal conductivity was measured as a function of uniaxial tensile stress applied to the SiNWs, which was varied from 0 to 1.2 GPa. The measured K results for the unstrained nanowires agree well with the predictions based on diffuse phonon boundary scattering. The dependence of SiNWs' thermal conductivity on engineering stress can provide significant information for nanowires fabrication. The work at University of Pennsylvania is supported by the Department of Energy, Basic Energy Sciences, through an Early Career Award (DE-SC0008135). The work at Bryn Mawr College is supported by NSF Career Award (DMR- 1053854).

  7. An induction heating diamond anvil cell for high pressure and temperature micro-Raman spectroscopic measurements.

    PubMed

    Shinoda, Keiji; Noguchi, Naoki

    2008-01-01

    A new external heating configuration is presented for high-temperature diamond anvil cell instruments. The supporting rockers are thermally excited by induction from an externally mounted copper coil passing a 30 kHz alternating current. The inductive heating configuration therefore avoids the use of breakable wires, yet is capable of cell temperatures of 1100 K or higher. The diamond anvil cell has no resistive heaters, but uses a single-turn induction coil for elevating the temperature. The induction coil is placed near the diamonds and directly heats the tungsten carbide rockers that support the diamond. The temperature in the cell is determined from a temperature-power curve calibrated by the ratio between the intensities of the Stokes and anti-Stokes Raman lines of silicon. The high-pressure transformation of quartz to coesite is successfully observed by micro-Raman spectroscopy using this apparatus. The induction heating diamond anvil cell is thus a useful alternative to resistively heated diamond anvil cells.

  8. Micro-Raman and FTIR studies of synthetic and natural apatites.

    PubMed

    Antonakos, Anastasios; Liarokapis, Efthymios; Leventouri, Theodora

    2007-07-01

    B-type synthetic carbonate hydroxyapatite (CHAp), natural carbonate fluorapatite (CFAp) and silicon-substituted hydroxyapatite (SiHAp) have been studied by using micro-Raman and infrared (IR) spectroscopy. It was found that while B-type carbonate substitution predominates in carbonate apatites (CAps), A-type is also detected. B-type carbonate substitution causes a broadening of the v(1) P-O stretching mode that is associated with the atomic disorder and lowering of the local symmetry in CAps from C(6h)(2) to C(3h). An approximately 15 cm(-1) shift of the v(3c) PO(4) stretching IR mode was observed upon decarbonation of the CFAp. Such shift which was confirmed by lattice dynamics calculations points out that the P-O bond lengths on the mirror plane increase when carbonate leaves the apatite structure. The present results support the substitution mechanism proposed on the basis of neutron powder diffraction studies of the same samples whereby carbonate substitutes on the mirror plane of the phosphate tetrahedron. The intensity ratios of the v(2) IR CO(3) and v(1) PO(4) bands in samples of various carbonate contents provide a measure of the degree of carbonation for CAps.

  9. Ultraviolet micro-Raman spectrograph for the detection of small numbers of bacterial cells

    NASA Astrophysics Data System (ADS)

    Chadha, S.; Nelson, W. H.; Sperry, J. F.

    1993-11-01

    The construction of a practical UV micro-Raman spectrograph capable of selective excitation of bacterial cells and other microscopic samples has been described. A reflective objective is used to focus cw laser light on a sample and at the same time collect the scattered light at 180°. With the aid of a quartz lens the image produced is focused on the slits of a spectrograph equipped with a single 2400 grooves/mm grating optimized for 250 nm. Spectra were detected by means of a blue-intensified diode array detector. Resonance Raman spectra of Bacillus subtilis and Flavobacterium capsulatum excited by the 257.2 nm output of a cw laser were recorded in the 900-1800 cm-1 region. Bacterial cells were immobilized on a quartz plate by means of polylysine and were counted visually. Cooling was required to retard sample degradation. Sample sizes ranged from 1 to 50 cells with excitation times varying from 15 to 180 s. Excellent spectra have been obtained from 20 cells in 15 s using a spectrograph having only 3% throughput.

  10. Micro-Raman spectroscopy as a tool for the characterization of silicon carbide in power semiconductor material processing

    NASA Astrophysics Data System (ADS)

    De Biasio, M.; Kraft, M.; Schultz, M.; Goller, B.; Sternig, D.; Esteve, R.; Roesner, M.

    2017-05-01

    Silicon carbide (SiC) is a wide band-gap semi-conductor material that is used increasingly for high voltage power devices, since it has a higher breakdown field strength and better thermal conductivity than silicon. However, in particular its hardness makes wafer processing difficult and many standard semi-conductor processes have to be specially adapted. We measure the effects of (i) mechanical processing (i.e. grinding of the backside) and (ii) chemical and thermal processing (i.e. doping and annealing), using confocal microscopy to measure the surface roughness of ground wafers and micro-Raman spectroscopy to measure the stresses induced in the wafers by grinding. 4H-SiC wafers with different dopings were studied before and after annealing, using depth-resolved micro-Raman spectroscopy to observe how doping and annealing affect: i.) the damage and stresses induced on the crystalline structure of the samples and ii.) the concentration of free electrical carriers. Our results show that mechanical, chemical and thermal processing techniques have effects on this semiconductor material that can be observed and characterized using confocal microscopy and high resolution micro Raman spectroscopy.

  11. Observation on the ion association equilibria in NaNO3 droplets using micro-Raman spectroscopy.

    PubMed

    Yu, Jun-Ying; Zhang, Yun; Tan, See-Hua; Liu, Yong; Zhang, Yun-Hong

    2012-10-18

    Ion association ratios as a function of concentration were estimated in single NaNO(3) droplets (5-60 μm) on a polytetrafluoroethylene (PTFE) substrate with molar water-to-solute ratios (WSRs) of 0.8-28 and bulk NaNO(3) solutions with WSRs of 35-200 by combining micro-Raman spectroscopy and component band analysis. Concentrations of the NaNO(3) droplets were accurately controlled by adjusting relative humidity (RH) in a sample chamber. As the WSRs decreased from 200 to 0.8, symmetric stretching band (ν(1)-NO(3)(-)) was observed to shift from 1047 to 1058 cm(-1) along with a change in full width at half-maximum (fwhm) from ∼10 to ∼16 cm(-1), indicative of formation of ion pairs with different structures. Through the component band analysis of the ν(1)-NO(3)(-) band, five bands centered at 1040.0, 1042.9, 1048.5, 1053.5, and 1057.0 cm(-1) were identified and assigned to coupled wagging modes of water molecules hydrated with nitrate ions, free hydrated nitrate anions, solvent-shared ion pairs (SIPs), contact ion pairs (CIPs), and the complex ion aggregates (CIAs), respectively. There were large amounts of SIPs and CIPs in dilute NaNO(3) solution even at an extremely low concentration (WSR ∼ 200), and each accounted for 50% and 20% of total nitrate species, respectively. This finding is in good agreement with earlier reported observations. In the dilute solutions (45 < WSR < 200), there is the same amount of free hydrated ions transformed into SIPs as that of SIPs transformed into CIPs. As a result, the overall amount of SIPs remained unchanged over the concentration range. With a decrease in WSR from 45 to 0.8, the amounts of SIPs and free solvated NO(3)(-) ions kept decreasing, whereas the amount of CIPs rose to a maximum at WSR = 7 and then fell with a further decreasing WSR. Formation of CIAs started at WSR ∼ 45, and its amount continuously increased as the WSR is further reduced to 0.8. The effect of temperature on ion association structure in the Na

  12. Residual stress measurement in a metal microdevice by micro Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Song, Chang; Du, Liqun; Qi, Leijie; Li, Yu; Li, Xiaojun; Li, Yuanqi

    2017-10-01

    Large residual stress induced during the electroforming process cannot be ignored to fabricate reliable metal microdevices. Accurate measurement is the basis for studying the residual stress. Influenced by the topological feature size of micron scale in the metal microdevice, residual stress in it can hardly be measured by common methods. In this manuscript, a methodology is proposed to measure the residual stress in the metal microdevice using micro Raman spectroscopy (MRS). To estimate the residual stress in metal materials, micron sized β-SiC particles were mixed in the electroforming solution for codeposition. First, the calculated expression relating the Raman shifts to the induced biaxial stress for β-SiC was derived based on the theory of phonon deformation potentials and Hooke’s law. Corresponding micro electroforming experiments were performed and the residual stress in Ni–SiC composite layer was both measured by x-ray diffraction (XRD) and MRS methods. Then, the validity of the MRS measurements was verified by comparing with the residual stress measured by XRD method. The reliability of the MRS method was further validated by the statistical student’s t-test. The MRS measurements were found to have no systematic error in comparison with the XRD measurements, which confirm that the residual stresses measured by the MRS method are reliable. Besides that, the MRS method, by which the residual stress in a micro inertial switch was measured, has been confirmed to be a convincing experiment tool for estimating the residual stress in metal microdevice with micron order topological feature size.

  13. A micro-Raman and infrared study of several Hayabusa category 3 (organic) particles

    NASA Astrophysics Data System (ADS)

    Kitajima, Fumio; Uesugi, Masayuki; Karouji, Yuzuru; Ishibashi, Yukihiro; Yada, Toru; Naraoka, Hiroshi; Abe, Masanao; Fujimura, Akio; Ito, Motoo; Yabuta, Hikaru; Mita, Hajime; Takano, Yoshinori; Okada, Tatsuaki

    2015-02-01

    Three category 3 (organic) particles (RB-QD04-0001, RB-QD04-0047-02, and RA-QD02-0120) and so-called `white object' found in the sample container have been examined by micro-Raman and infrared (IR) spectroscopy. In addition, several artificial substances that could occur as possible contaminants and chondritic insoluble organic matter (IOM) prepared from the Murchison CM2 chondrite were analyzed. The Raman spectra of the particles show broad G-band and weak D-band. The G-band parameters plot in the disordered region and close to the artifact produced from a Viton glove after laser exposure rather than chondritic IOM. The particles were therefore originally at low maturity level, suggesting that they have not experienced strong heating and are therefore not related to the LL4-6 parent body. The IR spectra are not similar to that of chondritic IOM. Furthermore, the particles cannot be identified as some artificial carbonaceous substances, including the white object, which are the possible contaminants, examined in this investigation. Although it cannot be determined exactly whether the three category 3 particles are extraterrestrial, the limited IR and Raman results in this investigation strongly suggest their terrestrial origin. Although they could not be directly related to the artificial contaminants examined in this investigation, they may yet be reaction products from similar substances that flew on the mission. In particular, RB-QD04-0047-02 shows several infrared spectral absorption bands in common with the `white object.' This may relate to the degradation of a polyimide/polyamide resin.

  14. Investigation of stratigraphic mapping in paintings using micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Karagiannis, Georgios Th.; Apostolidis, Georgios K.

    2016-04-01

    In this work, microRaman spectroscopy is used to investigate the stratigraphic mapping in paintings. The objective of mapping imaging is to segment the dataset, here spectra, into clusters each of which consisting spectra that have similar characteristics; hence, similar chemical composition. The spatial distribution of such clusters can be illustrated in pseudocolor images, in which each pixel of image is colored according to its cluster membership. Such mapping images convey information about the spatial distribution of the chemical substances in an object. Moreover, the laser light source that is used has excitation in 1064 nm, i.e., near infrared (NIR), allowing the penetration of the radiation in deeper layers. Thus, the mapping images that are produced by clustering the acquired spectra (specifying specific bands of Raman shifts) can provide stratigraphic information in the mapping images, i.e., images that convey information of the distribution of substances from deeper, as well. To cluster the spectra, unsupervised machine learning algorithms are applied, e.g., hierarchical clustering. Furthermore, the optical microscopy camera (×50), where the Raman probe (B and WTek iRaman EX) is plugged in, is attached to a computerized numerical control (CNC) system which is driven by a software that is specially developed for Raman mapping. This software except for the conventional CNC operation allows the user to parameterize the spectrometer and check each and every measurement to ensure proper acquisition. This facility is important in painting investigation because some materials are vulnerable to such specific parameterization that other materials demand. The technique is tested on a portable experimental overpainted icon of a known stratigraphy. Specifically, the under icon, i.e., the wavy hair of "Saint James", can be separated from upper icon, i.e., the halo of Mother of God in the "Descent of the Cross".

  15. Biochemical characterization of Gram-positive and Gram-negative plant-associated bacteria with micro-Raman spectroscopy.

    PubMed

    Paret, Mathews L; Sharma, Shiv K; Green, Lisa M; Alvarez, Anne M

    2010-04-01

    Raman spectra of Gram-positive and Gram-negative plant bacteria have been measured with micro-Raman spectrometers equipped with 785 and 514.5 nm lasers. The Gram-positive bacteria Microbacterium testaceum, Paenibacillus validus, and Clavibacter michiganensis subsp. michiganensis have strong carotenoid bands in the regions 1155-1157 cm(-1) and 1516-1522 cm(-1) that differentiate them from other tested Gram-negative bacteria. In the Raman spectrum of Gram-positive bacteria Bacillus megaterium excited with 785 nm laser, the Raman bands at 1157 and 1521 cm(-1) are weak in intensity compared to other Gram-positive bacteria, and these bands did not show significant resonance Raman enhancement in the spectrum recorded with 514.5 nm laser excitation. The Gram-positive bacteria could be separated from each other based on the bands associated with the in-phase C=C (v(1)) vibrations of the polyene chain of carotenoids. None of the Gram-negative bacteria tested had carotenoid bands. The bacteria in the genus Xanthomonas have a carotenoid-like pigment, xanthomonadin, identified in Xanthomonas axonopodis pv. dieffenbachiae, and it is a unique Raman marker for the bacteria. The representative bands for xanthomonadin were the C-C stretching (v(2)) vibrations of the polyene chain at 1135-1136 cm(-1) and the in-phase C=C (v(1)) vibrations of the polyene chain at 1529-1531 cm(-1), which were distinct from the carotenoid bands of other tested bacteria. The tyrosine peak in the region 1170-1175 cm(-1) was the only other marker present in Gram-negative bacteria that was absent in all tested Gram-positives. A strong-intensity exopolysaccharide-associated marker at 1551 cm(-1) is a distinguishable feature of Enterobacter cloacae. The Gram-negative Agrobacterium rhizogenes and Ralstonia solanacearum were differentiated from each other and other tested bacteria on the basis of presence or absence and relative intensities of peaks. The principal components analysis (PCA) of the spectra

  16. Microstructure imaging of C54-TiSi2 polycrystalline thin films by micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Meinardi, F.; Quilici, S.; Borghesi, A.; Artioli, G.

    1999-11-01

    The morphology of C54-TiSi2 polycrystalline films has been revealed by the micro-Raman imaging technique. This was based on the calculation of the symmetries of the Raman active vibrations of the C54-TiSi2 single crystal and subsequent polarized Raman measurements to detect and unambiguously label all the expected peaks. The relative intensity of two suitable peaks was monitored and mapped on C54-TiSi2 blanket films. Grains with different orientation are clearly detectable, and the microstructure properties of the film can be analyzed.

  17. Pressure-tuning micro-Raman spectra of artists' pigments: α- and β-copper phthalocyanine polymorphs.

    PubMed

    Beaulieu-Houle, Guillaume; Gilson, Denis F R; Butler, Ian S

    2014-01-03

    The two polymorphs of copper phthalocyanine, α- and β-CuPc, have been examined by micro-Raman spectroscopy at pressures approaching 5.0 GPa. The metastable α-polymorph does not exhibit any structural changes, while the more thermodynamically stable β-polymorph does exhibit a reversible phase transition at 2.0 GPa. The pressure dependences (dν/dP) for a selected number of vibrational modes are reported. Two regions of the Raman spectra, 800-900 cm(-1) and 1100-1200 cm(-1), are sensitive to pressure such that they can be used as indicators of the polymorphic form.

  18. Micro-FTIR and micro-raman studies of a carbon film prepared from furfuryl alcohol polymerization.

    PubMed

    Bertarione, S; Bonino, F; Cesano, F; Jain, S; Zanetti, M; Scarano, D; Zecchina, A

    2009-08-06

    The synthesis of a carbon film by the acid-catalyzed polymerization and resinification of furfuryl alcohol with a diluted solution of HCl is studied by combining micro-FTIR and micro-Raman spectroscopies. The detailed study of the evolution of spectra as a function of dosage of furfuryl alcohol and temperature shows that neutral and protonated species are formed at 80 degrees C, while upon gradually increasing the temperature up to 600 degrees C, the viscous polyfurfuryl alcohol resin is transformed into a carbon phase, containing a heterogeneous distribution of pores, with a size in the 100-2000 nm range, as shown by SEM and AFM analyses.

  19. Characterization of atmospheric aerosols in the Adirondack Mountains using PIXE, SEM/EDX, and Micro-Raman spectroscopies

    NASA Astrophysics Data System (ADS)

    Vineyard, M. F.; LaBrake, S. M.; Ali, S. F.; Nadareski, B. J.; Safiq, A. D.; Smith, J. W.; Yoskowitz, J. T.

    2015-05-01

    We are making detailed measurements of the composition of atmospheric aerosols collected in the Adirondack Mountains as a function of particle size using proton-induced X-ray emission, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and Micro-Raman spectroscopy. These measurements provide valuable data to help identify the sources and understand the transport, transformation, and effects of airborne pollutants in upstate New York. Preliminary results indicate significant concentrations of sulfur in small particles that can travel great distances, and that this sulfur may be in the form of oxides that can contribute to acid rain.

  20. Cu-Ag core-shell nanoparticles: A direct correlation between micro-Raman and electron microscopy

    NASA Astrophysics Data System (ADS)

    Cazayous, M.; Langlois, C.; Oikawa, T.; Ricolleau, C.; Sacuto, A.

    2006-03-01

    Vibration modes of metal core-shell nanoparticles have been measured by confocal micro-Raman spectroscopy. Compared to a standard macroscopic scale, the number of analyzed nanoparticles is reduced to 103 104 . We observed two distinct contributions in the same Raman spectrum originating from Cu-Ag core-shell and pure Ag nanoparticles. The nanoparticle sizes are calculated and successfully compared to the ones obtained by electron microscopy on the same micron-scale area. The bond matching between Cu core and Ag shell is pointed out from a conjugated Raman and transmission electron microscopy study.

  1. Study of the decomposition pathway of 12-molybdophosphoric acid in aqueous solutions by micro Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Bajuk-Bogdanović, D.; Uskoković-Marković, S.; Hercigonja, R.; Popa, A.; Holclajtner-Antunović, I.

    2016-01-01

    Micro Raman spectroscopy was applied to investigate the speciation of heteropoly and isopoly molybdates in 0.05 and 0.005 M aqueous solutions of 12-molybdophosphoric acid at pH values between 1 and 6. For comparative purposes, 31P NMR spectroscopy was applied too. It is shown that stability of Keggin anion is influenced both by pH and concentration of solution. The Keggin structure is stable in acidic solutions (pH < 1.6) while defective Keggin structures are formed with further alkalization (up to pH 5.6). Monolacunary anion PMo11O397 - is the main component in the pH region from 1.6 to 3.4. Further removal of molybdenyl species causes the appearance of other vacant Keggin structures such as PMo9O31(OH)36 - and PMo6O259 - at about pH 4. At pH 5.0, anion PMo6O259 - is the main species. In solutions with pH greater than 5.0, heteropolymolybdates disappear completely and isopolymolybdates Mo7O246 - and MoO42 - are formed in higher amounts. In more diluted solution of 0.005 M, the decomposition scheme of 12-molybdophosphoric acid solution with increasing of pH takes place without observation of significant amounts of Mo7O246 - species. If alkalinization is performed with 0.5 M instead of 5 M NaOH, there are no significant changes in the Raman spectra of solutions. It is shown that the spectra of evaporated samples may be used for the identification of molecular species in corresponding concentrated solutions. However, Raman spectra of dry residues of more diluted solutions differ from spectra of corresponding solutions due to the reactions performed during the process of drying and cannot be used for unambiguous identification of species in solution. Acidification of 0.05 M solution of Na2MoO4 shows that at pH > 5.6, molybdate anion MoO42 - dominates, while in the pH range between 5.6 and 1, heptamolybdate anion Mo7O246 - is preferentially formed.

  2. Study of Hygroscopic Properties of Aminium Sulfate Particles Using Micro-Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Chu, Y.; Sauerwein, M.; Chan, C. K.

    2014-12-01

    As one of the organic nitrogen species, amines are alkaline compounds ubiquitously detected in the atmosphere. Amines have been found to have the potential to enhance atmospheric new particle formation via forming aminium sulfate salts as much as 1000-fold when compared with ammonia, albeit at relatively low atmospheric contents (Almeida et al., 2013). Hygroscopicity of aminium sulfate particles can affect their cloud condensation nuclei (CCN) activity, light scattering or absorption and reactivity in the atmosphere. However, aerosol thermodynamic models such as Extended Aerosol Thermodynamics Model (E-AIM) assume that aminium ions behave similarly to ammonium ions, thus resulting in inaccuracy in predictinghygroscopicity of such compounds. In this study, Micro-Raman spectroscopy was applied to investigate the hygroscopicity of mono-methylaminium sulfate (MMAS), di-methylaminium sulfate (DMAS), tri-methylaminium sulfate (TMAS) and mono-ethylaminium sulfate (MEAS) particles. Since amine can evaporate from stock solutions, Ion Chromatography was used to determine aminium-to-sulfate ion molar ratio (A/S) of studied particles. Results were compared with literature data (Clegg et al., 2013). Due to amine evaporation upon mixing, A/S of stock solutions for particle generation can be below 2.0. In fact, initial A/S were 1.59, 1.91, 1.33 and 2.00 of MMAS, DMAS, TMAS and MEAS particles respectively. Ultimately A/S decreased to 1.5 and 1.0 for DMAS and TMAS, suggesting di-methylamine (DMA) and tri-methylamine (TMA) evaporated from corresponding particles. A/S of MMAS and MEAS kept relatively constant during the relative humidity (RH) cycle in hygroscopic measurements. Unlike (NH4)2SO4, all studied aminium sulfate particles can take up water at low RH. MMAS and MEAS particles underwent phase transition at around 45% and 20% RH respectively, while particles of other aminium sulfates showed continuous hygroscopic trends. References: Almeida, J. et al., 2013. Nature 502, 359

  3. FT-IR, micro-Raman and UV-vis spectroscopic and quantum chemical calculation studies on the 6-chloro-4-hydroxy-3-phenyl pyridazine compound

    NASA Astrophysics Data System (ADS)

    Sarıkaya, Ebru Karakaş; Bahçeli, Semiha; Varkal, Döndü; Dereli, Ömer

    2017-08-01

    In this work, the study of the6-chloro-4-hydroxy-3-phenyl pyridazine compound, (C10 H7 N2 O Cl with synonym 4-pyridazinol, 6-chloro-3-phenyl-), was verified experimentally by using the Fourier Transformed Infrared (FT-IR), micro-Raman and UV/vis (in N,N-dimethylformamide solvent) spectroscopies. Furthermore, the optimized molecular geometry, conformatinal analysis, vibrational frequencies, the simulated UV/vis spectra (in gas and in N,N-dimethylformamide solvent), 1H and 13C NMR chemical shift (in gas, in chloroform and N,N-dimethylformamide in solvents) values, HOMO-LUMO analysis, the molecular electrostatic potential (MEP) surface and thermodynamic parameters ofthe6-chloro-4-hydroxy-3-phenyl pyridazine compound were calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set in ground state. The comparison of the calculated and vibrational frequencies with the experimental values provides important information about the title compound.

  4. Micro-photoluminescence and micro-Raman studies near the amorphous-to-microcrystalline transition in Si:H

    NASA Astrophysics Data System (ADS)

    Das, Debajyoti

    2003-08-01

    Micro-photoluminescence and micro-Raman studies have been performed in the silicon-hydrogen system, near the onset of microcrystallinity, during the transition from amorphous-like to microcrystalline-like phase. Amorphous-like Si:H films before the onset of microcrystallization, as determined by a micro-Raman probe, exhibit a microcrystalline-like photoluminescence (PL) band, which is a doublet within the 1.0-1.2 eV energy band. These two satellite components exhibit two different natures of energy shifts with variation of either excitation intensity or temperature; however, both attribute to the germinate recombination of carriers. The ultimate line shape is determined by the low-energy component, because of its faster quenching with temperature. Two different characteristic temperatures of exponential band-tail states are obtained, contributing tail widths of 22 and 17 meV at lower and higher temperature regimes, respectively, across 200 K, as calculated in terms of the carrier thermalization model. PL-spectroscopy may offer a new means of diagnostics for Si:H network before the onset of microcrystallinity.

  5. FTIR, Micro-Raman and Ellipsometry Studies on Silicon Oxynitride Layers Synthesized by Low Energy Ion Implantation

    SciTech Connect

    Chauhan, Alka R.; Yadav, A. D.; Dubey, S. K.

    2008-04-23

    Single crystal silicon were implanted at room temperature with {sup 16}O{sub 2}{sup +} and {sup 14}N{sub 2}{sup +} 30 keV ions in 1:1 ratio with fluences of 2.5x10{sup 17}, 5x10{sup 17}, 7.5x10{sup 17} and 1x10{sup 18} ions-cm{sup -2} to form silicon oxynitride layers. Rapid thermal annealing (RTA) of these samples was carried out at temperature of 623, 873 and 1173 K in nitrogen ambient for 5 min. Fourier transform infrared (FTIR), Micro-Raman and ellipsometry measurements were performed on RTA samples to investigate the structure and phase. The FTIR studies show that the structures of ion-beam synthesized oxynitride layers are strongly dependent on total ion-fluence and annealing temperature. The Micro-Raman studies on annealing revealed formation of partially amorphous oxygen and nitrogen rich silicon oxynitride structures for lower and higher ion fluences respectively with crystalline silicon beneath it. From the ellipsometry studies, the refractive index of the ion beam synthesized layers were found to be in 1.54-1.96 range.

  6. FT-IR and Micro-Raman spectroscopic studies of archaeological potteries recently excavated in Poompuhar, Tamilnadu, India

    NASA Astrophysics Data System (ADS)

    Kiruba, S.; Ganesan, S.

    2015-06-01

    Ancient ceramics are the abundant artifacts that give the knowledge of the past societies. Therefore it is of great importance to acquire knowledge about the chemical composition of the clay in archaeological artifacts. The spectroscopic techniques represent one of the most powerful tools to investigate the structure of all the materials and chemical composition of the cultural object like potteries. An attempt has been made in the present work to estimate the firing temperature of the archaeological pottery shreds excavated from the archaeological site Poompuhar in the state of Tamilnadu in India. The firing temperature of the archaeological pottery shreds were estimated by recording the corresponding FT-IR spectra in the range 4000-450 cm-1 and Micro Raman spectra in the range 1800-400 cm-1. The clay mineral present in the pottery samples are identified through FT-IR method and was confirmed with Micro Raman spectroscopy as both are complement to each other. The major primary mineral present in the samples is Kaolinite and the secondary mineral present is quartz and the accessory minerals present in the samples are hematite, magnetite and feldspar. The results of Raman spectra showed that the potters of this site used a mixture of clays as raw materials. The firing temperature for some of the samples did not exceed 800 °C which suggests the use of open fire.

  7. FT-IR and micro-Raman spectroscopic studies of archaeological potteries recently excavated in Poompuhar, Tamilnadu, India.

    PubMed

    Kiruba, S; Ganesan, S

    2015-06-15

    Ancient ceramics are the abundant artifacts that give the knowledge of the past societies. Therefore it is of great importance to acquire knowledge about the chemical composition of the clay in archaeological artifacts. The spectroscopic techniques represent one of the most powerful tools to investigate the structure of all the materials and chemical composition of the cultural object like potteries. An attempt has been made in the present work to estimate the firing temperature of the archaeological pottery shreds excavated from the archaeological site Poompuhar in the state of Tamilnadu in India. The firing temperature of the archaeological pottery shreds were estimated by recording the corresponding FT-IR spectra in the range 4000-450 cm(-1) and Micro Raman spectra in the range 1800-400 cm(-1). The clay mineral present in the pottery samples are identified through FT-IR method and was confirmed with Micro Raman spectroscopy as both are complement to each other. The major primary mineral present in the samples is Kaolinite and the secondary mineral present is quartz and the accessory minerals present in the samples are hematite, magnetite and feldspar. The results of Raman spectra showed that the potters of this site used a mixture of clays as raw materials. The firing temperature for some of the samples did not exceed 800°C which suggests the use of open fire.

  8. Polymerization behavior within adhesive layer of one- and two-step self-etch adhesives: a micro-Raman spectroscopic study.

    PubMed

    Sakano, Wakae; Nakajima, Masatoshi; Prasansuttiporn, Taweesak; Foxton, Richard M; Tagami, Junji

    2013-01-01

    This study investigated the polymerization behavior within the adhesive layer of one- and two-step self-etch adhesives at the dentincomposite interface. Dentin surfaces were applied with Clearfil S(3) Bond (TS), Clearfil S(3) Bond Plus (TSP) and Clearfil SE Bond (SE), and then placed with a light-curing resin composite. After water storage for 24 h, the bonded teeth were sectioned and polished perpendicular to the adhesive interface, and the degree of conversion (DC) of the adhesive layer between the dentin and composite were determined using micro-Raman analysis. For all the adhesives, the DCs of the adhesive layers significantly decreased near the adhesive-composite join (p<0.05). For the maximum DC value (Pmax) and the DC value at the adhesive-composite join (Pitf), TS was significantly lower than TSP and SE (p<0.05). The polymerization of oxygen-inhibited layer at the top of the adhesive could not reach maximum DC even after polymerization of the overlying resin composite.

  9. A micro-Raman spectroscopic investigation of leukemic U-937 cells treated with Crotalaria agatiflora Schweinf and the isolated compound madurensine

    NASA Astrophysics Data System (ADS)

    le Roux, Karlien; Prinsloo, Linda C.; Hussein, Ahmed A.; Lall, Namrita

    In South Africa traditional medicine plays an important role in primary health care and therefore it is very important that the medicinal use of plants is scientifically tested for toxicity and effectiveness. It was established that the ethanolic extract of the leaves of Crotalaria agatiflora, as well as the isolated compound madurensine, is moderately toxic against leukemic U-937 cells. Light microscopic investigations indicated that symptoms of cell death are induced during treatments, but flow cytometry analysis of treated cells, using annexin-V and propidium iodide, showed that apoptosis and necrosis are insignificantly induced. The Raman results suggested that protein extraction and DNA melting occur in the cells during treatment with the ethanolic extracts (IC50 value 73.9 μg/mL), drastically changing the molecular content of the cells. In contrast, treatment with madurensine (IC50 value 136.5 μg/mL), an isolated pyrrolizidine alkaloid from the ethanolic extract of the leaves, did not have the same effect. The results are also compared to that of cells treated with actinomycin D, a compound known to induce apoptosis. The investigation showed that micro-Raman spectroscopy has great promise to be used for initial screening of samples to determine the effects of different treatments on cancerous cell lines together with conventional methods. The results highlight the fact that for many natural products used for medicinal purposes, the therapeutic effect of the crude plant extract tends to be significantly more effective than the particular action of its individual constituents.

  10. Micro-Raman Study of Orientation Effects of CuxSe-Crystallites on Cu-rich CuGaSe2 Thin Films

    NASA Astrophysics Data System (ADS)

    Xue, C.; Papadimitriou, D.; Raptis, Y. S.; Richter, W.; Esser, N.; Siebentritt, S.; Lux-Steiner, M. Ch.

    2004-08-01

    The structural properties of copper selenide (CuxSe), formed as a secondary phase on the surface of CuGaSe2 films grown under Cu-rich conditions on GaAs (100) substrates, were studied by micro-Raman spectroscopy. Raman bands at 45 and 263cm-1, observed on crystallites dispersed on the CuGaSe2 film, are in agreement with the Raman modes of CuSe and Cu2Se. Polarization- and angular-dependent micro-Raman measurements reveal that the CuxSe-crystallites are grown with a preferential orientation on the CuGaSe2 surface.

  11. Biomedical Applications of Micro-Raman and Surface-Enhanced Raman Scattering (SERS) Technology

    DTIC Science & Technology

    2012-10-01

    the solution was filtered and then rotoevaporated to remove the solvent. The product was then recrystallized as a yellow powder with acetone/hexane...stretch of protein, =C-C= carotenoid 1175 43 1177 35 1176 34 Cytosine, guanine 1181 62 1182 23 1183 35 Cytosine, guanine, adenine 30 Table 4...breathing mode in DNA bases) 1515 19 1515 81 Amide II 1521 76 1521 68 Amide II, Carotenoid -C=C- 1525 77 1529 2 1524 68 Amide II

  12. Observation on the Ion Association Equilibria in NaNO3 Droplets Using Micro-Raman Spectroscopy

    SciTech Connect

    Yu, Jun-Ying; Zhang, Yun; Tan, See-Hua; Liu, Yong; Zhang, Yun-Hong

    2012-10-18

    Ion association ratios as a function of concentration were estimated in single NaNO3 droplets (5–60 μm) on a polytetrafluoroethylene (PTFE) substrate with molar water-to-solute ratios (WSRs) of 0.8–28 and bulk NaNO3 solutions with WSRs of 35–200 by combining micro-Raman spectroscopy and component band analysis. Concentrations of the NaNO3 droplets were accurately controlled by adjusting relative humidity (RH) in a sample chamber. As the WSRs decreased from 200 to 0.8, symmetric stretching band (ν1-NO3–) was observed to shift from 1047 to 1058 cm–1 along with a change in full width at half-maximum (fwhm) from ~10 to ~16 cm–1, indicative of formation of ion pairs with different structures. Through the component band analysis of the ν1-NO3– band, five bands centered at 1040.0, 1042.9, 1048.5, 1053.5, and 1057.0 cm–1 were identified and assigned to coupled wagging modes of water molecules hydrated with nitrate ions, free hydrated nitrate anions, solvent-shared ion pairs (SIPs), contact ion pairs (CIPs), and the complex ion aggregates (CIAs), respectively. There were large amounts of SIPs and CIPs in dilute NaNO3 solution even at an extremely low concentration (WSR ~ 200), and each accounted for 50% and 20% of total nitrate species, respectively. This finding is in good agreement with earlier reported observations. In the dilute solutions (45 < WSR < 200), there is the same amount of free hydrated ions transformed into SIPs as that of SIPs transformed into CIPs. As a result, the overall amount of SIPs remained unchanged over the concentration range. With a decrease in WSR from 45 to 0.8, the amounts of SIPs and free solvated NO3– ions kept decreasing, whereas the amount of CIPs rose to a maximum at WSR = 7 and then fell with a further decreasing WSR. Formation of CIAs started at WSR ~ 45, and its amount continuously

  13. In-vitro micro-Raman study of tissue samples for detecting cervical and ovarian cancer with 785-nm laser excitation

    NASA Astrophysics Data System (ADS)

    Sharma, S. K.; Kamemoto, L. E.; Misra, A. K.; Goodman, M. T.; Luk, H. W.; Killeen, J. L.

    2010-04-01

    We present results of in vitro micro-Raman spectroscopy of normal and cancerous cervical and ovarian tissues excited with 785 nm near-infrared (NIR) laser. Micro- Raman spectra of squamous cervical cells of both cervix and ovarian tissues show significant differences in the spectra of normal and cancerous cells. In particular, several well-defined Raman peaks in the 775-975 cm-1 region are observed in the spectra of normal cervix squamous cells but are completely missing in the spectra of invasive cervical cancer cells. In the high-frequency 2800-3100 cm-1 region it is shown that the peak area under CH stretching band is much lower than the corresponding area in the spectra of normal cells. In the case of ovarian tissues, the micro-Raman spectra show noticeable spectral differences between normal cells and ovarian serous cancer cells. In particular, we observed the accumulation of β-carotene in ovarian serous cancer cells compared to normal ovarian cells from women with no ovarian cancer. The NIR micro-Raman spectroscopy offers a potential molecular technique for detecting cervical and ovarian cancer from the respective tissues.

  14. FT-IR and micro-Raman spectroscopic study of decorated potteries from VI and VII century BC, excavated in ancient Ainos Turkey

    NASA Astrophysics Data System (ADS)

    Akyuz, S.; Akyuz, T.; Basaran, S.; Bolcal, C.; Gulec, A.

    2007-05-01

    Ancient decorated pottery fragments belong to sixth and seventh century BC, excavated in the archaeological district of Enez - Turkey (Ancient Ainos) were analysed using micro-Raman and FT-IR spectroscopy. The experimental results allowed us to identify the peculiar components of the ceramic body and the main pigments of the decoration. The presence of albite and anatase suggests low firing temperatures.

  15. Kinetics of the drying process of an anti-adherent coating using Photothermal Radiometry and Micro-Raman

    NASA Astrophysics Data System (ADS)

    Hurtado-Castañeda, D. M.; Fernández, J.; Velázquez, R.; Estévez, M.; Vargas, S.; Rodríguez, R.; Rodríguez, M. E.

    2005-06-01

    The kinetics of the drying process of a new anti-adherent (anti-graffiti) polymeric coating containing organic solvent was determined using Photothermal Radiometry (PTR) and Micro-Raman (μ-R) Spectroscopy. PTR Spectroscopy was used to study, in real time, the kinetics of the drying process in samples protected with coatings with and without anti-adherent molecules. These were applied on a metal and silicon substrates. The PTR spectrum for coating without anti-adherent, shows a single relaxation time, while for coating containing anti-adherent shows two relaxation times corresponding to two different mechanisms: the solvent evaporation and the molecular re-arrangements of the two different molecular species present in the coating; the kinetic of the solvent evaporation is strongly dependent, as expected, on the solvent concentration.

  16. Characterization of azurite and lazurite based pigments by laser induced breakdown spectroscopy and micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Bicchieri, M.; Nardone, M.; Russo, P. A.; Sodo, A.; Corsi, M.; Cristoforetti, G.; Palleschi, V.; Salvetti, A.; Tognoni, E.

    2001-06-01

    The most commonly used blue pigments in medieval manuscripts are azurite and lapis-lazuli. The first one is a copper-based pigment; the coloring compound of the latter is lazurite, a sodium silicoaluminate in a sulfur matrix. Knowledge of the chemical composition of the materials is essential for the study of illuminated manuscripts. In this paper, micro-Raman and LIBS have been used for the study of azurite and lapis-lazuli, as well as different mixtures of these pigments applied to parchment to simulate an illuminated manuscript. The results of our work show the importance of using more than one technique for a good comprehension of a manuscript. In particular, the opportunity of combining elemental information (obtained from laser induced breakdown spectroscopy) and vibrational spectroscopy information (obtained from Raman) will be fully exploited.

  17. MicroRaman, PXRD, EDS and microscopic investigation of magnesium calcite biomineral phases. The case of sea urchin biominerals

    NASA Astrophysics Data System (ADS)

    Borzęcka-Prokop, B.; Wesełucha-Birczyńska, A.; Koszowska, E.

    2007-02-01

    This study concerns Mg-calcite characterization (and in particular molecular structure and microstructural studies of mineral phases) of a sea urchin mineralised test and spines. Sea urchins are spiny sea animals (kingdom Animalia, phylum Echinodermata, class Echinoidea). Microscopic observations, SEM, EDS, PXRD and spectroscopic microRaman methods have been applied to characterize the biomineral parts of the sea urchin. The latter technique is very useful in research of biological systems and especially suitable for monitoring differences within biomineral phases exhibiting varieties of morphological forms. Crystalline magnesium calcium carbonate, Mg xCa 1- xCO 3 (magnesian calcite; space group R-3 cH; a = 4.9594(8) Å, c = 16.886(6) Å), has been identified as the predominant biomineral component.

  18. Micro-Raman spectroscopic study of nanolaminated Ti{sub 5}Al{sub 2}C{sub 3}

    SciTech Connect

    Zhang, H.; Li, Z. J.; Wang, X. H.; Xiang, H. M.; Zhou, Y. C

    2014-03-31

    Micro-Raman spectroscopic study and lattice dynamics calculations were conducted to study a recently identified layered ternary carbide, Ti{sub 5}Al{sub 2}C{sub 3}. The experimental Raman shifts were remarkably consistent with the calculated values. Polarized Raman spectrum was collected in the polycrystalline sample, which confirmed the theoretical symmetry assignment of the Raman modes. In addition, the atomic vibrations of the peaks at 192 cm{sup −1}, 311 cm{sup −1}, and 660 cm{sup −1} were identified to be the combination of the counterparts in Ti{sub 2}AlC and Ti{sub 3}AlC{sub 2}.

  19. Micro-Raman study of copper hydroxychlorides and other corrosion products of bronze samples mimicking archaeological coins.

    PubMed

    Bertolotti, Giulia; Bersani, Danilo; Lottici, Pier Paolo; Alesiani, Marcella; Malcherek, Thomas; Schlüter, Jochen

    2012-02-01

    Three bronze samples created by CNR-ISMN (National Research Council-Institute of Nanostructured Materials) to be similar to Punic and Roman coins found in Tharros (OR, Sardinia, Italy) were studied to identify the corrosion products on their surfaces and to evaluate the reliability of the reproduction process. Micro-Raman spectroscopy was chosen to investigate the corroded surfaces because it is a non-destructive technique, it has high spatial resolution, and it gives the opportunity to discriminate between polymorphs and to correlate colour and chemical composition. A significant amount of green copper hydroxychlorides (Cu(2)(OH)(3)Cl) was detected on all the coins. Their discrimination by Raman spectroscopy was challenging because the literature on the topic is currently confusing. Thus, it was necessary to determine the characteristic peaks of atacamite, clinoatacamite, and the recently discovered anatacamite by acquiring Raman spectra of comparable natural mineral samples. Clinoatacamite, with different degrees of order in its structure, was the major component identified on the three coins. The most widespread corrosion product, besides hydroxychlorides, was the red copper oxide cuprite (Cu(2)O). Other corrosion products of the elements of the alloy (laurionite, plumbonacrite, zinc carbonate) and those resulting from burial in the soil (anatase, calcite, hematite) were also found. This study shows that identification of corrosion products, including discrimination of copper hydroxychlorides, could be accomplished by micro-Raman on valuable objects, for example archaeological findings or works of art, avoiding any damage because of extraction of samples or the use of a destructive analytical technique.

  20. Correlating low-energy electron microscopy and micro-Raman imaging of epitaxial graphene on SiC

    NASA Astrophysics Data System (ADS)

    Cheng, Guangjun; Calizo, Irene; Meade, Patrick; He, Guowei; Real, M. A.; Elmquist, R. E.; Feenstra, R. M.; Hight Walker, A. R.

    2013-03-01

    Several techniques exist for determining the number of graphene layers grown on SiC such as low-energy electron microscopy (LEEM) and Raman spectroscopy. The method which is arguably the most definitive for SiC-grown graphene isLEEM. Low-energy (0 - 10 eV) electrons interfere with the graphene layers, yielding minima in the electron reflectivity vs. energy curve that can be used to determine the layer number.1 LEEM also provides the means of collecting selected-area diffraction on ?m-size surface regions (micro-LEED), giving access to further useful structural information. While Raman spectroscopy is also commonly used to determine graphene layer number on SiC substrates; such measurements have no definitive calibration for large-area graphene on SiC, unlike the case of exfoliated graphene on SiO2. In this talk, results of correlated LEEM/micro-Raman imaging of large-area, mono and multilayer graphene samples are presented. These initial findings show that LEEM can show the contrast between terrace regions and step edges at particular areas of monolayer-graphene surfaces. Micro-Raman imaging of these same locations show Raman shifts in the G' (2D) band. The influence of heterogeneities on electrical behavior of graphene will be discussed. Comparative studies of multilayer graphene are in progress, and will also be reported. 1. H. Hibino, et al., Phys. Rev. B 77, 075413 (2008). 2. L. I. Johansson, et al., Phys. Rev. B 84, 125405 (2011).

  1. Investigating the Responses of Cronobacter sakazakii to Garlic-Drived Organosulfur Compounds: a Systematic Study of Pathogenic-Bacterium Injury by Use of High-Throughput Whole-Transcriptome Sequencing and Confocal Micro-Raman Spectroscopy

    PubMed Central

    Feng, Shaolong; Eucker, Tyson P.; Holly, Mayumi K.; Konkel, Michael E.

    2014-01-01

    We present the results of a study using high-throughput whole-transcriptome sequencing (RNA-seq) and vibrational spectroscopy to characterize and fingerprint pathogenic-bacterium injury under conditions of unfavorable stress. Two garlic-derived organosulfur compounds were found to be highly effective antimicrobial compounds against Cronobacter sakazakii, a leading pathogen associated with invasive infection of infants and causing meningitis, necrotizing entercolitis, and bacteremia. RNA-seq shows changes in gene expression patterns and transcriptomic response, while confocal micro-Raman spectroscopy characterizes macromolecular changes in the bacterial cell resulting from this chemical stress. RNA-seq analyses showed that the bacterial response to ajoene differed from the response to diallyl sulfide. Specifically, ajoene caused downregulation of motility-related genes, while diallyl sulfide treatment caused an increased expression of cell wall synthesis genes. Confocal micro-Raman spectroscopy revealed that the two compounds appear to have the same phase I antimicrobial mechanism of binding to thiol-containing proteins/enzymes in bacterial cells generating a disulfide stretching band but different phase II antimicrobial mechanisms, showing alterations in the secondary structures of proteins in two different ways. Diallyl sulfide primarily altered the α-helix and β-sheet, as reflected in changes in amide I, while ajoene altered the structures containing phenylalanine and tyrosine. Bayesian probability analysis validated the ability of principal component analysis to differentiate treated and control C. sakazakii cells. Scanning electron microscopy confirmed cell injury, showing significant morphological variations in cells following treatments by these two compounds. Findings from this study aid in the development of effective intervention strategies to reduce the risk of C. sakazakii contamination in the food production environment and on food contact surfaces

  2. Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886-1970): The EDXRF, FT-IR and micro Raman spectroscopic studies

    NASA Astrophysics Data System (ADS)

    Akyuz, Sevim; Akyuz, Tanil; Emre, Gulder; Gulec, Ahmet; Basaran, Sait

    2012-04-01

    The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm × 136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artist's paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C + Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones.

  3. Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886-1970): the EDXRF, FT-IR and micro Raman spectroscopic studies.

    PubMed

    Akyuz, Sevim; Akyuz, Tanil; Emre, Gulder; Gulec, Ahmet; Basaran, Sait

    2012-04-01

    The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm×136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artist's paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C+Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones.

  4. Micro-Raman spectroscopy of gem-quality chrysoprase from the Biga-Çanakkale region of Turkey

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Ören, Ufuk; Kibici, Yaşar

    2011-11-01

    The commercial quantities of gem-quality dark green chrysoprase are found as the fracture fillings covered with a weathering crust in the silicified serpentinites throughout the border of a metamorphic zone in the Biga-Çanakkale region of Turkey. However, the green-stained opaque quartz materials are also present in the same deposit, but these materials are common and in low-demand according to chrysoprase in terms of gemmological importance. Thus, it is necessary to distinguish these two similar materials from each other non-destructively. In addition, all chrysoprase roughs in this deposit also have alpha-quartz and moganite inclusions. Accordingly, dispersive (visible) confocal micro-Raman spectroscopy (DCμRS) allows us to distinguish clearly the chalcedonic-quartz silica phase (fibrous quartz (chalcedony)) from the crystalline-quartz silica phase (fine-grained alpha-quartz) in the case of both quartz inclusions in the chrysoprase material and itself of the green-stained quartz material in the same deposit. This study characterizes the Biga chrysoprase (Turkey) in terms of silica building phases, chemical content, and individual Raman bands, using several destructive and non-destructive analytical techniques. The Raman spectra show that the most characteristic intensive and the widest Raman bands peaked at about 498 and 460 cm -1 can be inferred to ν2 doubly symmetric bending mode of [SiO 4/M] centers. The "M" includes the some cationic substitutions of Si by Fe, Cr, Mn, As, Ni, Pb, Sb, and Zn, and K and Na as well. The second characteristic Raman band peaked at about 206 cm -1 can be inferred to single translational libration mode. The last readable Raman bands peaked at about 139 and 126 cm -1 can be inferred to doubly translational libration modes as well. In addition, the weaker Raman bands peaked at about 1577, 1430, 1303, 1160, 1082, 549, 394, 352, and 259 cm -1 are also present. As a result, the dispersive confocal micro-Raman spectrum of chrysoprase

  5. Contributed Review: Experimental characterization of inverse piezoelectric strain in GaN HEMTs via micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Bagnall, Kevin R.; Wang, Evelyn N.

    2016-06-01

    Micro-Raman thermography is one of the most popular techniques for measuring local temperature rise in gallium nitride (GaN) high electron mobility transistors with high spatial and temporal resolution. However, accurate temperature measurements based on changes in the Stokes peak positions of the GaN epitaxial layers require properly accounting for the stress and/or strain induced by the inverse piezoelectric effect. It is common practice to use the pinched OFF state as the unpowered reference for temperature measurements because the vertical electric field in the GaN buffer that induces inverse piezoelectric stress/strain is relatively independent of the gate bias. Although this approach has yielded temperature measurements that agree with those derived from the Stokes/anti-Stokes ratio and thermal models, there has been significant difficulty in quantifying the mechanical state of the GaN buffer in the pinched OFF state from changes in the Raman spectra. In this paper, we review the experimental technique of micro-Raman thermography and derive expressions for the detailed dependence of the Raman peak positions on strain, stress, and electric field components in wurtzite GaN. We also use a combination of semiconductor device modeling and electro-mechanical modeling to predict the stress and strain induced by the inverse piezoelectric effect. Based on the insights gained from our electro-mechanical model and the best values of material properties in the literature, we analyze changes in the E2 high and A1 (LO) Raman peaks and demonstrate that there are major quantitative discrepancies between measured and modeled values of inverse piezoelectric stress and strain. We examine many of the hypotheses offered in the literature for these discrepancies but conclude that none of them satisfactorily resolves these discrepancies. Further research is needed to determine whether the electric field components could be affecting the phonon frequencies apart from the inverse

  6. Contributed Review: Experimental characterization of inverse piezoelectric strain in GaN HEMTs via micro-Raman spectroscopy

    SciTech Connect

    Bagnall, Kevin R.; Wang, Evelyn N.

    2016-06-15

    Micro-Raman thermography is one of the most popular techniques for measuring local temperature rise in gallium nitride (GaN) high electron mobility transistors with high spatial and temporal resolution. However, accurate temperature measurements based on changes in the Stokes peak positions of the GaN epitaxial layers require properly accounting for the stress and/or strain induced by the inverse piezoelectric effect. It is common practice to use the pinched OFF state as the unpowered reference for temperature measurements because the vertical electric field in the GaN buffer that induces inverse piezoelectric stress/strain is relatively independent of the gate bias. Although this approach has yielded temperature measurements that agree with those derived from the Stokes/anti-Stokes ratio and thermal models, there has been significant difficulty in quantifying the mechanical state of the GaN buffer in the pinched OFF state from changes in the Raman spectra. In this paper, we review the experimental technique of micro-Raman thermography and derive expressions for the detailed dependence of the Raman peak positions on strain, stress, and electric field components in wurtzite GaN. We also use a combination of semiconductor device modeling and electro-mechanical modeling to predict the stress and strain induced by the inverse piezoelectric effect. Based on the insights gained from our electro-mechanical model and the best values of material properties in the literature, we analyze changes in the E{sub 2} high and A{sub 1} (LO) Raman peaks and demonstrate that there are major quantitative discrepancies between measured and modeled values of inverse piezoelectric stress and strain. We examine many of the hypotheses offered in the literature for these discrepancies but conclude that none of them satisfactorily resolves these discrepancies. Further research is needed to determine whether the electric field components could be affecting the phonon frequencies apart from the

  7. Contributed Review: Experimental characterization of inverse piezoelectric strain in GaN HEMTs via micro-Raman spectroscopy.

    PubMed

    Bagnall, Kevin R; Wang, Evelyn N

    2016-06-01

    Micro-Raman thermography is one of the most popular techniques for measuring local temperature rise in gallium nitride (GaN) high electron mobility transistors with high spatial and temporal resolution. However, accurate temperature measurements based on changes in the Stokes peak positions of the GaN epitaxial layers require properly accounting for the stress and/or strain induced by the inverse piezoelectric effect. It is common practice to use the pinched OFF state as the unpowered reference for temperature measurements because the vertical electric field in the GaN buffer that induces inverse piezoelectric stress/strain is relatively independent of the gate bias. Although this approach has yielded temperature measurements that agree with those derived from the Stokes/anti-Stokes ratio and thermal models, there has been significant difficulty in quantifying the mechanical state of the GaN buffer in the pinched OFF state from changes in the Raman spectra. In this paper, we review the experimental technique of micro-Raman thermography and derive expressions for the detailed dependence of the Raman peak positions on strain, stress, and electric field components in wurtzite GaN. We also use a combination of semiconductor device modeling and electro-mechanical modeling to predict the stress and strain induced by the inverse piezoelectric effect. Based on the insights gained from our electro-mechanical model and the best values of material properties in the literature, we analyze changes in the E2 high and A1 (LO) Raman peaks and demonstrate that there are major quantitative discrepancies between measured and modeled values of inverse piezoelectric stress and strain. We examine many of the hypotheses offered in the literature for these discrepancies but conclude that none of them satisfactorily resolves these discrepancies. Further research is needed to determine whether the electric field components could be affecting the phonon frequencies apart from the inverse

  8. Characterization of ceramic ware fragments from Aizanoi-Turkey by micro Raman, XRPD and SEM-EDX spectrometry

    NASA Astrophysics Data System (ADS)

    Caner, Evin; Güney, Bilge Alp

    2017-04-01

    Ceramic fragments from the antique city of Aizanoi, Turkey were investigated by micro Raman spectrometry in conjunction with XRPD and SEM-EDX analyses. Some basic physical characteristics of the ceramic samples were also investigated. Illite and muscovite were determined as the main clay types in the ceramic fragments. Clay used in the production of ceramic wares was found to be calcareous in most of the samples. No high temperature clay minerals were detected in the ceramics. All ceramic fragments were found to be rich in iron content. Hematite and magnetite were identified to be the principle coloring agents in the investigated samples. The ceramics with hematite content were assessed to be fired in an oxygen rich atmosphere whereas the samples having magnetite were proposed to be fired in an inadequately ventilated kiln. Based on the presence of calcite, dolomite and TiO2 in the crystal form of anatase in the samples, firing temperature during production was estimated to be below 750 °C.

  9. Micro-structural characterization of black crust and laser cleaning of building stones by micro-Raman and SEM techniques.

    PubMed

    Potgieter-Vermaak, S S; Godoi, R H M; Grieken, R Van; Potgieter, J H; Oujja, M; Castillejo, M

    2005-09-01

    Research concerning the formation and removal of black crusts on various historical objects is approached from many different angles. The so-called "yellowing effect", observed after laser treatment for cleaning purposes, has also received a lot of attention. Evidence regarding this phenomenon differs considerably and the actual mechanisms are still speculated on by researchers. In an attempt to elucidate the processes involved in the yellowing effect associated with laser cleaning, a new analytical technique has been used to investigate the black crust, a region of the sample cleaned by laser irradiation at 1064 nm and another region of the same sample subjected to further laser irradiation at 355 nm, on a limestone sample from the cathedral of Seville in Spain. Micro-Raman spectrometry offers the advantage of spatial chemical characterization of the stone, based upon its molecular makeup and was performed on the bulk body of the stone. Raman and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDXS) results indicate that the surfaces cleaned by irradiation at 1064 nm and by double irradiation at 1064 and 355 nm differed in terms of their calcium sulphate, calcium oxalate and iron oxide content, and that this could contribute to the difference in colour observed.

  10. Micro-structural characterization of black crust and laser cleaning of building stones by micro-Raman and SEM techniques

    NASA Astrophysics Data System (ADS)

    Potgieter-Vermaak, S. S.; Godoi, R. H. M.; Grieken, R. Van; Potgieter, J. H.; Oujja, M.; Castillejo, M.

    2005-09-01

    Research concerning the formation and removal of black crusts on various historical objects is approached from many different angles. The so-called "yellowing effect", observed after laser treatment for cleaning purposes, has also received a lot of attention. Evidence regarding this phenomenon differs considerably and the actual mechanisms are still speculated on by researchers. In an attempt to elucidate the processes involved in the yellowing effect associated with laser cleaning, a new analytical technique has been used to investigate the black crust, a region of the sample cleaned by laser irradiation at 1064 nm and another region of the same sample subjected to further laser irradiation at 355 nm, on a limestone sample from the cathedral of Seville in Spain. Micro-Raman spectrometry offers the advantage of spatial chemical characterization of the stone, based upon its molecular makeup and was performed on the bulk body of the stone. Raman and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDXS) results indicate that the surfaces cleaned by irradiation at 1064 nm and by double irradiation at 1064 and 355 nm differed in terms of their calcium sulphate, calcium oxalate and iron oxide content, and that this could contribute to the difference in colour observed.

  11. Characterization of ceramic ware fragments from Aizanoi-Turkey by micro Raman, XRPD and SEM-EDX spectrometry.

    PubMed

    Caner, Evin; Güney, Bilge Alp

    2017-04-15

    Ceramic fragments from the antique city of Aizanoi, Turkey were investigated by micro Raman spectrometry in conjunction with XRPD and SEM-EDX analyses. Some basic physical characteristics of the ceramic samples were also investigated. Illite and muscovite were determined as the main clay types in the ceramic fragments. Clay used in the production of ceramic wares was found to be calcareous in most of the samples. No high temperature clay minerals were detected in the ceramics. All ceramic fragments were found to be rich in iron content. Hematite and magnetite were identified to be the principle coloring agents in the investigated samples. The ceramics with hematite content were assessed to be fired in an oxygen rich atmosphere whereas the samples having magnetite were proposed to be fired in an inadequately ventilated kiln. Based on the presence of calcite, dolomite and TiO2 in the crystal form of anatase in the samples, firing temperature during production was estimated to be below 750°C.

  12. Remote-Raman and Micro-Raman Studies of Solid CO2, CH4, Gas Hydrates and Ice

    NASA Technical Reports Server (NTRS)

    Sharma, S. K.; Misra, A. K.; Lucey, P. G.; Exarhos, G. J.; Windisch, C. F., Jr.

    2004-01-01

    It is well known that on Mars CO2 is the principal constituent of the thin atmosphere and on a seasonal basis CO2 snow and frost coats the polar caps. Also over 25% of the Martian atmosphere freezes out and sublimes again each year. The Mars Odyssey Emission Imaging system (THEMIS) has discovered water ice exposed near the edge of Mars southern perennials cap. In recent years, it has been suggested that in Martian subsurface CO2 may exist as gas hydrate (8CO2 + 44 H2O) with melting temperature of 10C. Since the crust of Mars has been stable for enough time there is also a possibility that methane formed by magmatic processes and/or as a byproduct of anaerobic deep biosphere activity to have raised toward the planet s surface. This methane would have been captured and stored as methane hydrate, which concentrates methane and water. Determination of abundance and distribution of these ices on the surface and in the near surface are of fundamental importance for understanding Martian atmosphere, and for future exploration of Mars. In this work, we have evaluated feasibility of using remote Raman and micro-Raman spectroscopy as potential nondestructive and non-contact techniques for detecting solid CO2, CH4 gas, and gas hydrates as well as water-ice on planetary surfaces.

  13. Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures

    SciTech Connect

    Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming; Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang

    2013-11-15

    In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 μm thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

  14. Remote-Raman and Micro-Raman Studies of Solid CO2, CH4, Gas Hydrates and Ice

    NASA Technical Reports Server (NTRS)

    Sharma, S. K.; Misra, A. K.; Lucey, P. G.; Exarhos, G. J.; Windisch, C. F., Jr.

    2004-01-01

    It is well known that on Mars CO2 is the principal constituent of the thin atmosphere and on a seasonal basis CO2 snow and frost coats the polar caps. Also over 25% of the Martian atmosphere freezes out and sublimes again each year. The Mars Odyssey Emission Imaging system (THEMIS) has discovered water ice exposed near the edge of Mars southern perennials cap. In recent years, it has been suggested that in Martian subsurface CO2 may exist as gas hydrate (8CO2 + 44 H2O) with melting temperature of 10C. Since the crust of Mars has been stable for enough time there is also a possibility that methane formed by magmatic processes and/or as a byproduct of anaerobic deep biosphere activity to have raised toward the planet s surface. This methane would have been captured and stored as methane hydrate, which concentrates methane and water. Determination of abundance and distribution of these ices on the surface and in the near surface are of fundamental importance for understanding Martian atmosphere, and for future exploration of Mars. In this work, we have evaluated feasibility of using remote Raman and micro-Raman spectroscopy as potential nondestructive and non-contact techniques for detecting solid CO2, CH4 gas, and gas hydrates as well as water-ice on planetary surfaces.

  15. Strain determination in silicon microstructures by combined convergent beam electron diffraction, process simulation, and micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Senez, Vincent; Armigliato, Aldo; De Wolf, Ingrid; Carnevale, Gianpietro; Balboni, Roberto; Frabboni, Stefano; Benedetti, Alessandro

    2003-11-01

    Test structures consisting of shallow trench isolation (STI) structures are fabricated using advanced silicon (Si) technology. Different process parameters and geometrical features are implemented to investigate the residual mechanical stress in the structures. A technology computer aided design homemade tool, IMPACT, is upgraded and optimized to yield strain fields in deep submicron complementary metal-oxide-semiconductor devices. Residual strain in the silicon substrate is measured with micro-Raman spectroscopy (μ-RS) and/or convergent beam electron diffraction (CBED) for large (25 μm) and medium size (2 μm), while only CBED is used for deep submicron STI (0.22 μm). We propose a methodology combining CBED and technology computer aided design (TCAD) with μ-RS to assess the accuracy of the CBED measurements and TCAD calculations on the widest structures. The method is extended to measure (by CBED) and calculate (by TCAD) the strain tensor in the smallest structures, out of the reach of the μ-RS technique. The capability of determining, by both measurement and calculation, the strain field distribution in the active regions of deep submicron devices is demonstrated. In particular, it is found that for these structures an elastoplastic model for Si relaxation must be assumed.

  16. Micro-Raman spectroscopy of Si nanowires: Influence of diameter and temperature

    NASA Astrophysics Data System (ADS)

    Torres, A.; Martín-Martín, A.; Martínez, O.; Prieto, A. C.; Hortelano, V.; Jiménez, J.; Rodríguez, A.; Sangrador, J.; Rodríguez, T.

    2010-01-01

    Raman spectroscopy provides nondestructive information about nanoscaled semiconductors by modeling the phonon confinement effect. However, the Raman spectrum is also sensitive to the temperature, which can mix with the size effects borrowing the interpretation of the Raman spectrum. We present an analysis of the Raman spectra of Si nanowires (NWs). The influence of the excitation conditions and the temperature increase in the NWs are discussed. The interpretation of the data is supported by the calculation of the temperature inside the NWs with different diameters.

  17. Polarized micro Raman scattering spectroscopy for curved edges of epitaxial graphene

    SciTech Connect

    Islam, Md. Sherajul Makino, T.; Hashimoto, A.; Bhuiyan, A. G.; Tanaka, S.

    2014-12-15

    This letter performed polarized microscopic laser Raman scattering spectroscopy on the curved edges of transferred epitaxial graphene on SiO{sub 2}/Si. The intensity ratio between the parallel and perpendicular polarized D band is evolved, providing a spectroscopy-based technique to probe the atomic-scale edge structures in graphene. A detailed analysis procedure for non-ideal disordered curved edges of graphene is developed combining the atomic-scale zigzag and armchair edge structures along with some point defects. These results could provide valuable information of the realistic edges of graphene at the atomic-scale that can strongly influence the performance of graphene-based nanodevices.

  18. Micro-Raman spectroscopy of tissue samples for oral pathology follow-up monitoring

    NASA Astrophysics Data System (ADS)

    Delfino, I.; Camerlingo, C.; Zenone, F.; Perna, G.; Capozzi, V.; Cirillo, N.; Gaeta, G. M.; Lepore, M.

    2010-04-01

    An "in vitro" study of Raman spectra from oral human tissues is reported in order to the develop a diagnostic method suitable for "in vivo" oral pathology follow-up. The investigated pathology is Pemphigus Vulgaris (PV) for which new techniques for guiding and monitoring therapy would be particularly useful. Raman spectra were obtained in the wavenumber regions from 1000 to 1800 cm-1 and 2700 to 3200 cm-1 from tissues from patients at different stages of pathology (active PV, under therapy and in PV remission stage) as confirmed by histopathological and immunofluorescence analysis. Differences in the spectra depending on tissue illness stage arise in 1150-1250 cm-1 (amide III) and 1420-1450 cm-1 (CH3 deformation) regions and around 1650 cm-1 (amide I) and 2930 cm-1 (CH3 symmetric stretch). A wavelet deconvolution procedure was applied to the spectra for better discriminating among the three different stages of illness and a linear regression analysis was used to fully exploit the content of information of Raman spectra.

  19. Micro-Raman spectroscopy characterization of silicon with different structures irradiated with energetic Bi-ions

    NASA Astrophysics Data System (ADS)

    Zhu, Yabin; Yao, Cunfeng; Wang, Ji; Zhu, Huiping; Shen, Tielong; Gao, Xing; Sun, Jianrong; Wei, Kongfang; Wang, Dong; Sheng, Yanbin; Wang, Zhiguang

    2015-12-01

    Researches of irradiation effects on silicon possess not only fundamental interests but also potential application prospects. Comparison studies about structural modification of silicon materials with different structures under identical irradiation conditions can reveal the irradiation mechanisms for amorphous and crystalline phases of silicon. For this purpose, amorphous silicon (a-Si) and nano-crystalline silicon (nc-Si) films as well as mono-crystalline silicon (c-Si) samples were irradiated with 6.0 MeV Bi-ions at room temperature. The ion fluences are 1.0 × 1013, 5.0 × 1013 and 1.0 × 1014 ions/cm2. All samples were analyzed by using a Raman spectrometer. The obtained results show that the crystalline fraction of c-Si and nc-Si decrease with increasing fluence, which indicates that the irradiation induces the amorphization of nc-Si and c-Si samples. In addition, the variation in Raman frequency of crystalline peak after irradiation reveals that the irradiation also results in the increased stress in crystalline phase of c-Si and nc-Si samples. As the fluence increases, the bond angle deviation and the ratio of TA to TO mode of amorphous network of a-Si and nc-Si films initially increase and then decrease by a diminishing degree, while the bond angle deviation and the ratio of TA to TO mode of amorphous network of c-Si samples increase continuously. This gives the dependence of short-range structural order of amorphous network of a-Si, nc-Si and c-Si samples on the ion fluence, which is related with the irradiation induced variation of local free energy. It is considered that the irradiation induced structural modification of silicon samples is mainly attributed to the nuclear energy loss. The irradiation effects of energetic heavy-ions on crystalline and amorphous phases of silicon have been discussed, respectively.

  20. Micro-Raman spectroscopy in the identification of wulfenite and vanadinite in a Sasanian painted stucco fragment of the Ghaleh Guri in Ramavand, western Iran

    NASA Astrophysics Data System (ADS)

    Holakooei, Parviz; Karimy, Amir-Hossein; Hasanpour, Ata; Oudbashi, Omid

    2016-12-01

    This paper reports the results of studies performed on a painted stucco fragment excavated at the Ghaleh Guri in Ramavand, western Iran, and dated back to the late Sasanian period (224-651 AD). Analytical studies including micro-Raman spectroscopy (μ-Raman), micro-X-ray spectrometry (μ-XRF) and optical microscopy showed that red lead and vermilion were used as main pigments on this fragment. Moreover, carbon black was diagnosed to thinly cover some parts of the red lead. Peculiarly, wulfenite (PbMoO4) associated with vanadinite (Pb5(VO4)3Cl) was identified to compose a yellow stain sporadically dispersed on the other pigments.

  1. Phonons and crystal structures of the β -pyrochlore superconductors KOs2O6 and RbOs2O6 from micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Schoenes, J.; Racu, A.-M.; Doll, K.; Bukowski, Z.; Karpinski, J.

    2008-04-01

    The phonons and the crystal structures of the β -pyrochlore superconductors KOs2O6 and RbOs2O6 are studied on single crystals by using micro-Raman spectroscopy. The symmetry of the modes is determined by polarization dependent measurements for various scattering geometries. It is concluded that the crystal structures are centrosymmetric (Fd3¯m) . The vibrational frequencies have been computed from first principles and are in good agreement with the experimental data. The Raman-active rattling mode of the alkali ion is identified at 75 and 60cm-1 for the K and Rb compounds, respectively.

  2. Combined micro-Raman, micro-infrared, and field emission scanning electron microscope analyses of comet 81P/Wild 2 particles collected by Stardust

    NASA Astrophysics Data System (ADS)

    Rotundi, A.; Baratta, G. A.; Borg, J.; Brucato, J. R.; Busemann, H.; Colangeli, L.; D'Hendecourt, L.; Djouadi, Z.; Ferrini, G.; Franchi, I. A.; Fries, M.; Grossemy, F.; Keller, L. P.; Mennella, V.; Nakamura, K.; Nittler, L. R.; Palumbo, M. E.; Sandford, S. A.; Steele, A.; Wopenka, B.

    2008-02-01

    We report combined micro-infrared, micro-Raman, and field emission scanning electron microscope (FESEM) analyses of particles collected by the Stardust spacecraft during its flyby of comet 81P/Wild 2 on 2 January 2004 and successfully returned back to Earth on 15 January 2006. We present mid-infrared (IR) spectra of six of these particles. The CH2/CH3 ratios inferred from the infrared data are greater than those seen in organics in the diffuse interstellar medium, possibly indicating the presence of longer or less branched aliphatic chains. The micro-Raman data offer insights into the state of the order of the carbonaceous component present in the particles. Raman parameters for most of the particles span a similar range to that observed in interplanetary dust particles (IDPs) and the most primitive meteorites. Both the IR and Raman data imply the presence of a very labile carbonaceous component. Hydrated silicates may be present in two particles of Track 35, one of which may also contain carbonates, but further investigations with other techniques need to be performed to confirm these findings. In some cases, the analyses are difficult to interpret because of the presence of compressed aerogel mixed with the grains.

  3. Micro-Raman and micro-transmission imaging of epitaxial graphene grown on the Si and C faces of 6H-SiC

    PubMed Central

    2011-01-01

    Micro-Raman and micro-transmission imaging experiments have been done on epitaxial graphene grown on the C- and Si-faces of on-axis 6H-SiC substrates. On the C-face it is shown that the SiC sublimation process results in the growth of long and isolated graphene ribbons (up to 600 μm) that are strain-relaxed and lightly p-type doped. In this case, combining the results of micro-Raman spectroscopy with micro-transmission measurements, we were able to ascertain that uniform monolayer ribbons were grown and found also Bernal stacked and misoriented bilayer ribbons. On the Si-face, the situation is completely different. A full graphene coverage of the SiC surface is achieved but anisotropic growth still occurs, because of the step-bunched SiC surface reconstruction. While in the middle of reconstructed terraces thin graphene stacks (up to 5 layers) are grown, thicker graphene stripes appear at step edges. In both the cases, the strong interaction between the graphene layers and the underlying SiC substrate induces a high compressive thermal strain and n-type doping. PMID:21801347

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

    PubMed

    Akyuz, Tanil; Akyuz, Sevim; Gulec, Ahmet

    2015-10-05

    The characterization of the plasters and coloring agents of the wall paintings of Fatih Mosque have been performed using combined micro-Raman, FTIR and EDXRF techniques. The investigations show that the plaster used on the walls has mixed gypsum-lime binders. Cinnabar {HgS}, lead red {Pb3O4} and hematite {α-Fe2O3} were identified in the red surfaces. Blue color is attributed to ultramarine blue {Na8-10Al6Si6O24S2-4}. Green color is assigned to mixtures of green earth, copper phthalocyanine {Cu(C32Cl16N8)} and brochantite {CuSO4·3Cu(OH)2}. Strontium yellow {SrCrO4} and zinc white {ZnO} were also used to ensure the color tone. The results provide a basis for future restoration of wall paints. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. XANES and micro-Raman spectroscopy study of the barium titanosilicates BaTiSi2O7 and BaTiSi4O11

    NASA Astrophysics Data System (ADS)

    Viani, A.; Pollastri, S.; Macova, P.; Palermo, A.; Peréz-Estébanez, M.; Gualtieri, A. F.

    2016-04-01

    The coordination environment around Ti4+ in the photoluminescent compound BaTiSi2O7 and in BaTiSi4O11 was investigated with X-ray absorption near-edge structure spectroscopy and micro-Raman spectroscopy. The presence of VTi in TiO5 pyramidal units with one short Ti-O bond involving the apical oxygen was detected in both compounds. Interpretation of the vibrational signal from the silicate framework suggested that BaTiSi4O11 is a metasilicate containing building units of SiO4 tetrahedra, which are larger than in other barium titanosilicates. These results confirmed the same structural environment of Ti4+ as recently disclosed by structure refinement of BaTiSi2O7 and provided new insights into the unknown structure of BaTiSi4O11 in the light of the study of its physical properties as potential functional material.

  6. The characterization of canvas painting by the Serbian artist Milo Milunović using X-ray fluorescence, micro-Raman and FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Damjanović, Lj.; Gajić-Kvaščev, M.; Đurđević, J.; Andrić, V.; Marić-Stojanović, M.; Lazić, T.; Nikolić, S.

    2015-10-01

    A canvas painting by Milo Milunović "The Inspiration of the poet" was studied by energy dispersive X-Ray fluorescence (EDXRF), micro-Raman and Fourier transform infrared (FTIR) spectroscopy in order to identify materials used by the artist and his painting technique. Study is perfomed combining in situ non-destructive method with the preparation and study of cross-section samples and raw fragments of the samples. Milo Milunović, an eminent painter from Balkan region, made a copy of the Nicolas Poussin's original painting in Louvre in 1926/27. Obtained results revealed following pigments on the investigated canvas painting: vermilion, minium, cobalt blue, ultramarine, lead white, zinc white, cadmium yellow, chrome-based green pigment and several earth pigments - red and yellow ocher, green earth and umber. Ground layer was made of lead white mixed with calcium carbonate.

  7. Length-Scale-Dependent Phase Transformation of LiFePO4 : An In situ and Operando Study Using Micro-Raman Spectroscopy and XRD.

    PubMed

    Siddique, N A; Salehi, Amir; Wei, Zi; Liu, Dong; Sajjad, Syed D; Liu, Fuqiang

    2015-08-03

    The charge and discharge of lithium ion batteries are often accompanied by electrochemically driven phase-transformation processes. In this work, two in situ and operando methods, that is, micro-Raman spectroscopy and X-ray diffraction (XRD), have been combined to study the phase-transformation process in LiFePO4 at two distinct length scales, namely, particle-level scale (∼1 μm) and macroscopic scale (∼several cm). In situ Raman studies revealed a discrete mode of phase transformation at the particle level. Besides, the preferred electrochemical transport network, particularly the carbon content, was found to govern the sequence of phase transformation among particles. In contrast, at the macroscopic level, studies conducted at four different discharge rates showed a continuous but delayed phase transformation. These findings uncovered the intricate phase transformation in LiFePO4 and potentially offer valuable insights into optimizing the length-scale-dependent properties of battery materials.

  8. Influence of curvature strain and Van der Waals force on the inter-layer vibration mode of WS2 nanotubes: A confocal micro-Raman spectroscopic study

    NASA Astrophysics Data System (ADS)

    Wang, Xiao Hu; Zheng, Chang Cheng; Ning, Ji Qiang

    2016-09-01

    Transition-metal dichalcogenides (TMDs) nanostructures including nanotubes and monolayers have attracted great interests in materials science, chemistry to condensed matter physics. We present an interesting study of the vibration modes in multi-walled tungsten sulfide (WS2) nanotubes prepared via sulfurizing tungsten oxide (WO3) nanowires which are investigated by confocal micro-Raman spectroscopy. The inter-layer vibration mode of WS2 nanotubes, A1g, is found to be sensitive to the diameter and curvature strain, while the in-plane vibration mode, E12g, is not. A1g mode frequency shows a redshift by 2.5 cm‑1 for the multi-layered nanotubes with small outer-diameters, which is an outcome of the competition between the Van der Waals force stiffening and the curvature strain softening. We also show that the Raman peak intensity ratio is significantly different between the 1–2 wall layered nanotubes and monolayer flat sheets.

  9. Micro-Raman and FT-IR spectroscopic studies of ceramic shards excavated from ancient Stratonikeia city at Eskihisar village in West-South Turkey

    NASA Astrophysics Data System (ADS)

    Bahçeli, Semiha; Güleç, Gamze; Erdoğan, Hasan; Söğüt, Bilal

    2016-02-01

    In this study, micro-Raman and Fourier transformed infrared (FT-IR) spectroscopies, X-ray diffraction (XRD) and scanning electron microscope with energy dispersive X-ray (SEM-EDX) were used to characterize the mineralogical structures of pigments of four ceramic fragments in which one of them belongs to Hellenistic period (1st - IVth century BC) and other three ceramic shards belong to Early Rome (IVth century BC- 1st century AD) excavated from Stratonikeia ancient city. In the results of investigations on these four ceramic fragments, the various phases were identified: quartz, kaolinite, albit (or Na-feldspar), calcite, anastase, hematite and magnetite. Furthermore, the obtained findings indicate that firing temperature is about 800-850 °C for all the shards.

  10. Micro-Raman study on the softening and stiffening of phonons in rutile titanium dioxide film: Competing effects of structural defects, crystallite size, and lattice strain

    SciTech Connect

    Gautam, Subodh K.; Singh, Fouran Sulania, I.; Kulriya, P. K.; Singh, R. G.; Pippel, E.

    2014-04-14

    Softening and stiffening of phonons in rutile titanium dioxide films are investigated by in situ micro-Raman studies during energetic ion irradiation. The in situ study minimized other possible mechanisms of phonon dynamics. Initial softening and broadening of Raman shift are attributed to the phonon confinement by structural defects and loss of stoichiometry. The stiffening of A{sub 1g} mode is ascribed to large distortion of TiO{sub 6} octahedra under the influence of lattice strain in the (110) plane, which gives rise to lengthening of equatorial Ti-O bond and shortening of apical Ti-O bond. The shortening of apical Ti-O bond induces stiffening of A{sub 1g} mode in the framework of the bond-order-length-strength correlation mechanism.

  11. Evaluation of local free carrier concentrations in individual heavily-doped GaN:Si micro-rods by micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Mohajerani, M. S.; Khachadorian, S.; Schimpke, T.; Nenstiel, C.; Hartmann, J.; Ledig, J.; Avramescu, A.; Strassburg, M.; Hoffmann, A.; Waag, A.

    2016-02-01

    Three-dimensional III-nitride micro-structures are being developed as a promising candidate for the future opto-electrical devices. In this study, we demonstrate a quick and straight-forward method to locally evaluate free-carrier concentrations and a crystalline quality in individual GaN:Si micro-rods. By employing micro-Raman mapping and analyzing lower frequency branch of A1(LO)- and E1(LO)-phonon-plasmon-coupled modes (LPP-), the free carrier concentrations are determined in axial and planar configurations, respectively. Due to a gradual doping profile along the micro-rods, a highly spatially resolved mapping on the sidewall is exploited to reconstruct free carrier concentration profile along the GaN:Si micro-rods. Despite remarkably high free carrier concentrations above 1 × 1020 cm-3, the micro-rods reveal an excellent crystalline quality, without a doping-induced stress.

  12. Micro-raman assessment of the ratio of carbon-carbon double bonds of two adhesive systems cured with LED or halogen light-curing units.

    PubMed

    Miletic, Vesna; Santini, Ario

    2010-12-01

    the purpose of the study was to compare the ratio of carbon-carbon double bonds (RDB) of two adhesive systems cured by five different light-curing units (LCUs) using micro-Raman spectroscopy. materials and methods: ten samples of an etch-and-rinse (Excite), a two-step self-etching adhesive system (AdheSE) - ie, primer and bond mixed - and AdheSE Bond only were prepared and cured with one of the following LEDs: Elipar Freelight2; Bluephase; SmartLite; Coltolux, each for 10 s; or a conventional halogen Prismetics Lite for 10 s or 20 s. Micro-Raman spectra were obtained from uncured and cured samples of all three groups to calculate the RDB. Data were statistically analyzed using ANOVA. the mean RDB values were 62% to 76% (Excite), 36% to 50% (AdheSE Primer+Bond) and 58% to 63% (AdheSE Bond). At 20 s, Prismetics Lite produced significantly higher RDB in Excite than the other LCUs and Prismetics Lite at 10 s (p < 0.05). Prismetics Lite at 20 s and Elipar produced comparable RDB values of AdheSE Bond and AdheSE Primer+Bond (p > 0.05). Excite showed significantly higher RDB values than AdheSE (p < 0.05) whilst AdheSE Bond showed significantly higher RDB than AdheSE Primer+Bond (p < 0.05). the etch-and-rinse adhesive cured with the halogen LCU for 20 s gave higher conversion than LED LCUs or halogen for 10 s curing time. The highest intensity LED [Elipar] produced higher or comparable conversion compared to the lower intensity LED LCUs for the same curing time. The etch-and-rinse adhesive showed higher RDB than the self-etching adhesive system. The presence of the primer in the self-etching adhesive compromised polymerisation.

  13. Understanding the Organo-Carbonate Associations in Carbonaceous Chondrites with the Use of Micro-Raman Analysis

    NASA Technical Reports Server (NTRS)

    Chan, Q. H. S.; Zolensky, M. E.

    2015-01-01

    Carbonates can potentially provide sites for organic materials to accrue and develop into complex macromolecules. This study examines the organics associated with carbonates in carbonaceous chondrites using µ-Raman imaging.

  14. Understanding the Organo-Carbonate Associations in Carbonaceous Chondrites with the Use of Micro-Raman Analysis

    NASA Technical Reports Server (NTRS)

    Chan, Q. H. S.; Zolensky, M. E.

    2015-01-01

    Carbonates can potentially provide sites for organic materials to accrue and develop into complex macromolecules. This study examines the organics associated with carbonates in carbonaceous chondrites using micron-Raman imaging.

  15. Integrated archeomagnetic and micro-Raman spectroscopy study of pre-Columbian ceramics from the Mesoamerican formative village of Cuanalan, Teotihuacan Valley, Mexico

    NASA Astrophysics Data System (ADS)

    Rodriguez Ceja, Maria; Goguitchaichvili, Avto; Morales, Juan; Ostrooumov, Mikhail; Manzanilla, Linda R.; Aguilar Reyes, Bertha; Urrutia-Fucugauchi, Jaime

    2009-04-01

    We report a detailed archeomagnetic and micro-Raman spectroscopy investigation on pre-Columbian pottery fragments from Cuanalan (a formative village in the valley of Teotihuacan, central Mexico). Available radiocarbon ages range from 2320 ± 80 to 2060 ± 90 B.P. Continuous low-field susceptibility versus temperature curves performed in air indicate Ti-poor titanomagnetites as magnetization carriers. Few samples, however, show two ferrimagnetic phases with Curie temperatures compatible with both Ti-poor and Ti-rich titanomagnetites. Hysteresis parameter ratios fall essentially in the pseudosingle-domain region, which may indicate a mixture of multidomain and a significant amount of single-domain grains. Mineralogical composition of the Teotihuacan ceramics has been investigated using micro-Raman spectroscopy. Samples are characterized by highly heterogeneous body matrix mineralogy due to the presence of a large variety of minerals with several mineralogical phases. Observed titanomagnetite and magnetite bands shift toward higher wave numbers, confirming a reducing atmosphere and a relatively high temperature (about 800-900°C) during the ceramic production. This definitively indicates the thermoremanent origin of magnetic magnetization. Archeointensity values have been determined from 7 pottery fragments (47 samples) out of 10 (70 samples) analyzed. Anisotropy of thermoremanent magnetization and the cooling rate effect upon thermoremanent magnetization intensity acquisition have been investigated in all the samples. The mean archeointensity values obtained in this study range from 24.2 ± 3.2 to 40.0 ± 1.7 μT, and corresponding virtual axial dipole moments range from 4.8 ± 0.6 to 8.0 ± 0.4 (1022 A m2). This corresponds to a mean virtual dipole moment value of 5.9 ± 1.1 × 1022 A m2, which is lower than the present-day field strength and the predicted values by global models and the latest data compilation. However, our data agree well with currently available

  16. Low laser power micro-Raman study of Co{sub (1−x)}Mn{sub (x)}Fe{sub 2}O{sub 4} prepared by flash combustion method

    SciTech Connect

    Baraliya, J. D.

    2016-05-23

    Manganese substituted Cobalt ferrites of composition with nominal formula Co{sub (1−x)}Mn{sub (x)}Fe{sub 2}O{sub 4} (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) prepared by the Flash Combustion Method(FCM). The single phase spinel formation of nano ferrites was confirmed by X-ray diffraction techniques and micro - Raman spectroscopy. The particle size calculated from the Scherrer formula varied within 13 to 17 nm. Lattice parameter, nano particle size, and cation distribution were quantified as a function of the Mn-content in the range x = 0.0 to 1.0. Micro-Raman spectroscopic studies yielded convincing evidence for a transformation of the structure.

  17. Near infrared excited micro-Raman spectra of 4:1 methanol-ethanol mixture and ruby fluorescence at high pressure

    NASA Astrophysics Data System (ADS)

    Wang, X. B.; Shen, Z. X.; Tang, S. H.; Kuok, M. H.

    1999-06-01

    Near infrared (NIR) lasers, as a new excitation source for Raman spectroscopy, has shown its unique advantages and is being increasingly used for some special samples, such as those emitting strong fluorescence in the visible region. This article focuses on some issues related to high-pressure micro-Raman spectroscopy using NIR excitation source. The Raman spectra of 4:1 methanol-ethanol mixture (4:1 M-E) show a linear variation in both Raman shifts and linewidths under pressure up to 18 GPa. This result is useful in distinguishing Raman scattering of samples from that of the alcohol mixture, an extensively used pressure-transmitting medium. The R1 fluorescence in the red region induced by two-photon absorption of the NIR laser is strong enough to be used as pressure scale. The frequency and line width of the R1 lines are very sensitive to pressure change and the glass transition of the pressure medium. Our results manifest that it is reliable and convenient to use NIR induced two-photon excited fluorescence of ruby for both pressure calibration and distribution of pressure in the 4:1 M-E pressure transmitting medium.

  18. Influence of curvature strain and Van der Waals force on the inter-layer vibration mode of WS2 nanotubes: A confocal micro-Raman spectroscopic study

    PubMed Central

    Wang, Xiao Hu; Zheng, Chang Cheng; Ning, Ji Qiang

    2016-01-01

    Transition-metal dichalcogenides (TMDs) nanostructures including nanotubes and monolayers have attracted great interests in materials science, chemistry to condensed matter physics. We present an interesting study of the vibration modes in multi-walled tungsten sulfide (WS2) nanotubes prepared via sulfurizing tungsten oxide (WO3) nanowires which are investigated by confocal micro-Raman spectroscopy. The inter-layer vibration mode of WS2 nanotubes, A1g, is found to be sensitive to the diameter and curvature strain, while the in-plane vibration mode, E12g, is not. A1g mode frequency shows a redshift by 2.5 cm−1 for the multi-layered nanotubes with small outer-diameters, which is an outcome of the competition between the Van der Waals force stiffening and the curvature strain softening. We also show that the Raman peak intensity ratio is significantly different between the 1–2 wall layered nanotubes and monolayer flat sheets. PMID:27620879

  19. SU-E-T-44: A Micro-Raman Spectroscopy Study of the Dose-Dependence of EBT3 GafChromicTM Films for Quantifying the Degree of Molecular Polymerization

    SciTech Connect

    Callens, M; Van Den Abeele, K; Crijns, W; Depuydt, T; Maes, F; Haustermans, K; Simons, V; De Wolf, I; D’hooge, J; D’Agostino, E; Pfeiffer, H

    2015-06-15

    Purpose: Radiochromic films, such as the poly-diacetylene-based EBT3 GafChromic{sup TM} films (Ashland Specialty Ingredients, Wayne, NY, USA), are widely used for dosimetry applications because of their clear energy independence, high spatial resolution, near tissue equivalence and easy handling. The films undergo a slight color change by radiation-induced polymerization of diacetylene monomers. But more importantly, the film becomes optically less transparent with increasing radiation dose, with a saturation starting between 10 and 20 Gy, i.e. a common SBRT dose level. In contrast to the chromatic properties, less attention has been given to the underlying molecular mechanism that induces this partial color change and strongly reduces the transparency. Therefore, the current work investigates the variation of the molecular composition of the active layer of EBT3 films for an SBRT dose range. Method: Uncoated EBT3 films were irradiated with a 6 MV photon beam using dose levels between 0 and 20 Gy. The relative variation of the polymer content as a function of the applied radiation dose was studied using micro-Raman spectroscopy. Raman spectroscopy with a 633 nm probe laser incident on the active layer allowed to identify the film constituents and to estimate the amount of poly-diacetylenes from the intensities of the unique molecular vibrations of the molecule. Results: The normalized intensity of all polymeric vibrations, and most notably the polymeric triple and double carbon-carbon bonds at 2058 cm{sup −1} and 1446 cm{sup −1} respectively, increase with increasing dose up to a saturation level starting at about 10 Gy, indicating a corresponding increase and saturation of the amount of polymers. This molecular saturation process is the main cause of the non-linear dose response (i.e. a transparency reduction) and of the limited dose range of the studied films. Conclusion: Raman spectroscopy provides new and more fundamental insights in the mechanism of the

  20. Geochemistry of the Medieval Climate Anomaly varve sequence in Deep Inlet, Alaska, using core-scanning XRF, synchrotron micro-XRF and XANES spectroscopy, and micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Addison, J. A.; Hayes, S. M.; Sliwinski, M. G.; Routson, C.; Foster, A. L.

    2013-12-01

    The seasonal time resolution preserved in varved sediments make them critical archives of paleoclimate records. Our research group presents new geochemical data from a late Holocene varve sequence recovered from EW0408-44JC in Deep Inlet, an anoxic fjord in Southeast Alaska, with a particular focus on those varves deposited during the Medieval Climate Anomaly (~AD 1000) which is considered to be drier than at present in the Gulf of Alaska region. We utilize a combination of techniques: [1] scanning X-ray fluorescence (XRF) analysis of an 18-m-long split sediment core surface measured at 200-micron sampling resolution; [2] synchrotron-radiation micro-XRF (SR-μ-XRF) mapping of epoxy-impregnated thin sections at 6-to-50 micron spatial scales; [3] X-ray absorption near-edge spectroscopy (XANES) for Fe speciation; and [4] micro-Raman spectroscopy to determine varve mineralogy. Using these complementary techniques, we seek to determine if total iron concentration in Deep Inlet sediments can be used as a robust proxy for terrestrial erosion, and by inference, local precipitation and fluvial discharge. Our scanning XRF results show that total Fe concentration maxima tend to be co-located with dark-colored detrital mineral-rich sublaminae and turbidites, but there are several instances where this relationship is inconsistent. Thin-section SR-μ-XRF analysis of the same intervals reveal that high Fe concentrations are associated with detrital sublaminae, but Fe XANES reveal complex speciation in these fjord sediments, including sulfides (FeII), oxides and oxyhydroxides (FeIII), and mixed FeII/FeIII mineral phases. These diverse data imply a complex Fe cycle in Deep Inlet, comprising sources of Fe that likely include both detrital oxides and authigenic sulfides. Taken together, these data indicate caution is necessary in using total Fe concentrations as a proxy for paleoprecipitation reconstructions at this site. Studies of other redox-sensitive elements are underway (e

  1. Micro-Raman spectroscopy and μ-XRF in the investigation of ancient glass beads from the archaeological sites, eastern Taiwan

    NASA Astrophysics Data System (ADS)

    San Liou, Ying; Liu, Yi Chang

    2017-04-01

    Ancient glass beads with different colors, shapes, and stylistics unearthed from the archaeological sites of eastern Taiwan, dating back to approximately 1850-310 BP, have been investigated. It is generally known that glass bead is alien to invade into Taiwan along with metal ware, glass, agate, etc. since the Metal Age of Taiwan. Nevertheless, souring provenance and trade routes still remain controversial. Micro-Raman spectroscopy and μ-XRF have been applied on fifty-six ancient glass beads to reveal the mineralogical and chemical compositions and to help decipher the raw materials used and souring provenance. Micro-Raman measurements indicate the presence of hematite, zincite, siderite, sphalerite, lead tin yellow type II, quartz, feldspar, anatase, rutite, ankerite, graphite, calcite, etc. Among them, hematite, zincite, siderite, sphalerite, lead tin yellow type II, and rutile were found to be colorants/opacifiers. Moreover, crystalline phases such as lead tin yellow type II (PbSn1-xSixO3), zincite (ZnO), tricalcium diphosphate (Ca2(PO4)2), sphalerite ((Zn, Fe)S) and ankerite (Ca(Fe, Mg, Mn)(CO3)2) were detected in ancient glass beads unearthed from Taiwan for the first time. The chemical results obtained by μXRF show SiO2, Al2O3, Na2O, K2O, MgO, CaO, and PbO as the most abundant oxides. Na2O, K2O, Al2O3, MgO, and PbO could be the main/minor fluxes and colorants. In general, results of mineralogical and chemical analyses are compatible. According to chemical results, ancient glass beads can be classified as mineral soda alumina glass (m-Na-Al glass), soda plant ash glass (v-Na-Ca glass), lead silicate glass, and some less well known types. Mineral soda alumina and soda plant ash glass beads, as well as lead silicate glass beads are generally believed to be the distinct phases of production and exchange in Southeast Asia and China, respectively. In terms of chronology of glass bead, beads excavated from sites of 1850-930 BP are mineral soda alumina glass (m

  2. Micro-Raman and micro-infrared spectroscopic studies of Pb- and Au-irradiated ZrSiO4: Optical properties, structural damage, and amorphization

    SciTech Connect

    Zhang, Ming; Boatner, Lynn A; Salje, Ekhard K.H.; Ewing, Rodney C.; Daniel, Philippe; Weber, William J.; Zhang, Yanwen; Farnan, Ian

    2008-01-01

    The optical properties of damaged periodic and aperiodic domains created by Pb+ 280 keV and Au4+ 10 MeV implantation of zircon were studied using micro-infrared IR and micro-Raman spectroscopy. The Pb+ and Au4+ irradiations caused a dramatic decrease in the IR reflectivity similar to that observed for metamict natural zircon. The irradiation with 10 MeV Au4+ ions to fluences of 11015 Au4+ ions/cm2 also results in the formation of an amorphized phase similar to that observed in metamict zircon. These results show that high-energy, heavy-ion irradiations provide a good simulation of the ballistic effects of the recoil nucleus of an alpha-decay event and, in both cases, the result is the creation of aperiodic domains. Additional IR and Raman features were recorded in samples irradiated with 280 keV Pb+ ions to fluences of 11014 and 1 1015 Pb+ ions/cm2, indicating the formation of an irradiation-induced additional phases. The frequencies of the features are consistent with lead silicates, ZrO2, and SiO2. The results show that spectral features of the Au4+- and Pb+-irradiated zircon are different from those of quenched ZrSiO4 melts, and the finding further confirms that the amorphous state produced by high-energy ion irradiations is structurally different from the glassy state that results from quenching a high temperature melt. In contrast to significant changes in the frequency and width of the Raman 3 band observed in metamict zircon, the Pb+ and Au4+ irradiations do not cause similar variations, indicating that the remaining zircon crystalline domains in irradiated samples have a crystalline structure with fewer defects than those of metamict zircon.

  3. Low temperature micro-Raman measurements under magnetic field of Pr1-xCaxMnO3 thin films

    NASA Astrophysics Data System (ADS)

    Antonakos, A.; Lampakis, D.; Palles, D.; Liarokapis, E.; Prellier, W.; Mercey, B.

    2007-03-01

    We have investigated the temperature (78-295 K) and the magnetic field dependence of the Raman active phonons of Pr1-xCaxMnO3 thin films deposited on LaAlO3 substrates for two different Ca concentrations ( x=0.5 and 0.6) and for SrTiO3 substrates with x=0.6 at room temperature. The comparison between the two substrates did not show any effect from the strains. At low temperatures close to the phase transitions certain modes are affected by the application of the field (˜1 T) produced by permanent magnets, indicating possible spin coupling with the lattice.

  4. A Method for accurate in vivo micro-Raman spectroscopic measurements under guidance of advanced microscopy imaging

    PubMed Central

    Wang, Hequn; Lee, Anthony M. D.; Lui, Harvey; McLean, David I.; Zeng, Haishan

    2013-01-01

    The movement from the subjects during in vivo confocal Raman spectral measurements could change the measurement volume, leading to non-specific signals and inaccurate interpretation of the acquired spectrum. Here we introduce a generally applicable method that includes (1) developing a multimodal system to achieve real-time monitoring of every spectral measurement with reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) imaging; (2) performing region-of-interest measurement by scanning an area of the tissue during spectral acquisition. The developed method has been validated by measuring different micro-structures of in vivo human skin. Our results demonstrated great consistency between RCM images and confocal Raman spectra. The superior quality of the images and spectra allows us to derive blood flow velocity and blood glucose level. We believe this method is valuable for realizing accurate microscopic spectral measurement and have great potential to be adapted into clinic to achieve non-invasive measurement of important biological parameters. PMID:23712517

  5. Vibrational Properties of Zr(Hf)B2-SiC UHTC Composites by Micro-Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Donohue, M.; Carpenter, C.; Orlovskaya, N.

    Development and characterization of novel materials that are lightweight, possess high mechanical properties, can withstand high temperatures, and provide superior thermal properties are crucial to meet the future demands of Air Force, Army, Navy, Missile Defense Agency (MDA), and other military and space agencies. Materials for such applications (hypersonic air-breathing vehicles, including Single-To-Orbit vehicles and Two-Stage-To-Orbit aerospace planes, fully reusable space transport vehicles, hypersonic cruise missiles) experience severe aero-thermal loads with nose-cone and nozzle temperatures in excess of 2,000°F and 4,000°F, respectively. High G acceleration is also a problem. Even the most advanced materials, such as Ti, Inconel X, carbon-carbon, and silicon carbide based composites cannot withstand the excessive heat generated, especially during re-entry, and they cannot meet the guidelines for future high performance aircrafts, kinetic energy interceptors and reusable space planes. Thus, the demand for low-cost, light weight high temperature materials for thermal protection systems (TPS) is expected to be on the significant rise in the near future.

  6. Identification of antibody isotypes in biological fluids by means of micro-Raman spectroscopy and chemometric methods

    NASA Astrophysics Data System (ADS)

    Araujo-Andrade, C.; Pichardo-Molina, J. L.; Barbosa-Sabanero, G.; Frausto-Reyes, C.

    2008-02-01

    Clinical diagnosis of infections, generally are realized by serological methods, which identifies the antibodies presents in serum or tissue fluids of the patient. Antibodies are proteins present in our bodies that aid in the elimination of pathogens or antigens. Identification of antibodies isotypes is important because can help to predict when and whether patients will recover from infections and are commonly diagnosed by means of indirect methods such as serological test. In the other hand, the majority of these methods requires specific kits for the analysis, special sample preparation, chemical reagents, expensive equipment and require long time for getting results. In this work we show the feasibility to discriminate antibody isotypes in biological fluids like human colostrum by means of Raman spectroscopy and chemometrics. Spectra were obtained using an excitation wavelength of 514 nm over dried samples of human colostrum labeled previously as positives to specific IgG and IgM antibodies against Toxoplasma Gondii by means of ELISA test. Partial least square-discriminant analysis (PLS-DA) was used to discriminate among antibody isotypes by use second derivative of Raman spectra of colostrum samples.

  7. Rapid in situ detection of street samples of drugs of abuse on textile substrates using microRaman spectroscopy

    NASA Astrophysics Data System (ADS)

    Ali, Esam M. A.; Edwards, Howell G. M.; Scowen, Ian J.

    2011-10-01

    Trace amounts of street samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine (MDMA) on natural and synthetic textiles were successfully detected in situ using confocal Raman microscopy. The presence of some excipient bands in the spectra of the drugs did not prevent the unambiguous identification of the drugs. Raman spectra of the drugs were readily obtained without significant interference from the fibre substrates. Interfering bands arising from the fibre natural or synthetic polymer structure and/or dye molecules did not overlap with the characteristic Raman bands of the drugs. If needed, interfering bands could be successfully removed by spectral subtraction. Also, Raman spectra could be acquired from drug particles trapped between the fibres of highly fluorescent textile specimens. The total acquisition time of the spectra of the drug particles was 90 s accomplished non-destructively and without detachment from their substrates. Sample preparation was not required and spectra of the drugs could be obtained non-invasively preserving the integrity of the evidential material for further analysis.

  8. Occurrence and distribution of ``moganite'' in agate/chalcedony: a combined micro-Raman, Rietveld, and cathodoluminescence study

    NASA Astrophysics Data System (ADS)

    Götze, Jens; Nasdala, Lutz; Kleeberg, Reinhard; Wenzel, Marita

    Agate/chalcedony samples of different origin were investigated by performing Raman, X-ray diffraction (using Rietveld refinement), and cathodoluminescence measurements. These analyses were performed to measure the content and spatial distribution of the silica polymorph moganite, which is considered to represent periodic Brazil-law twinning of α-quartz at the unit-cell scale in agate/chalcedonies. Homogeneous standard samples including the nearly α-quartz free moganite type material from Gran Canaria were analysed in order to compare results of the X-ray diffractometry and Raman spectroscopy techniques and to provide a calibration curve for the Raman results. However, due to the different length scales analysed by the two techniques, the ``moganite content'' in microcrystalline SiO2 samples measured by Raman spectroscopy (short-range order) was found to be considerably higher than the ``moganite content'' measured by X-ray diffractometry (long-range order). The difference is explained by the presence of moganite nanocrystals, nano-range moganite lamellae, and single Brazil-law twin-planes that are detected by vibrational spectroscopy but that are not large enough (in the sense of coherently scattering lattice domains) to be detected by X-ray diffractometry. High resolution Raman analysis provides a measure of the moganite content and its spatial variation in microcrystalline silica samples with a lateral resolution in the μm-range. Variations in the moganite-to-quartz ratio are revealed by varying intensity ratios of the main symmetric stretching-bending vibrations (A1 modes) of α-quartz (465cm-1) and moganite (502cm-1), respectively. Traces of Raman microprobe analyses perpendicular to the rhythmic zoning of agates revealed that the moganite-to-quartz ratio is often not uniform but shows a cyclic pattern that correlates with the observed cathodoluminescence pattern (colour and intensity). Data obtained from an agate sample from a fluorite deposit near Okorusu

  9. Raman-spectroscopy-based biosensing for applications in ophthalmology

    NASA Astrophysics Data System (ADS)

    Rusciano, Giulia; Capriglione, Paola; Pesce, Giuseppe; Zito, Gianluigi; Del Prete, Antonio; Cennamo, Giovanni; Sasso, Antonio

    2013-05-01

    Cell-based biosensors rely on the detection and identification of single cells as well as monitoring of changes induced by interaction with drugs and/or toxic agents. Raman spectroscopy is a powerful tool to reach this goal, being non-destructive analytical technique, allowing also measurements of samples in aqueous environment. In addition, micro-Raman measurements do not require preliminary sample preparation (as in fluorescence spectroscopy), show a finger-print spectral response, allow a spatial resolution below typical cell sizes, and are relatively fast (few s or even less). All these properties make micro-Raman technique particularly promising for high-throughput on-line analysis integrated in lab-on-a-chip devices. Herein, we demonstrate some applications of Raman analysis in ophthalmology. In particular, we demonstrate that Raman analysis can provide useful information for the therapeutic treatment of keratitis caused by Acanthamoeba Castellanii (A.), an opportunistic protozoan that is widely distributed in the environment and is known to produce blinding keratitis and fatal encephalitis. In particular, by combining Raman analysis with Principal Component Analysis (PCA), we have demonstrated that is possible to distinguish between live and dead cells, enabling, therefore to establish the effectiveness of therapeutic strategies to vanquish the protozoa. As final step, we have analyzed the presence of biochemical differences in the conjunctival epithelial tissues of patients affected by keratitis with respect to healthy people. As a matter of facts, it is possible to speculate some biochemical alterations of the epithelial tissues, rendering more favorable the binding of the protozoan. The epithelial cells were obtained by impression cytology from eyes of both healthy and keratitis-affected individuals. All the samples were analyzed by Raman spectroscopy within a few hours from cells removal from eyes. The results of this analysis are discussed.

  10. Study by micro-Raman spectroscopy of wall paints (external parts and cross-sections) from reales alcazares of Seville (Spain)

    NASA Astrophysics Data System (ADS)

    Perez-Rodriguez, José Luis; Centeno, Miguel Angel; Robador, María Dolores; Siguenza, Belinda; Durán, Adrián

    2013-04-01

    the other one by iron oxides. The green and white colours were constituted by atacamite and calcite, respectively. In addition lead white was detected in green colour. The white layers (plaster) located under the colour layers were constituted by calcite, quartz and feldspars. These data confirm the use of fresco technique. The study of the surface (external part) by micro-Raman spectroscopy limited the characterization of the pigments present in these wall pains, due to the presence of a layer of gypsum deposited on the surface. By other hand, the study by Raman spectroscopy of the cross-sections allowed the characterization of different pigments and support used in the manufacture of these wall paints.

  11. Micro-Raman observation on the H2PO4(-) association structures in a supersaturated droplet of potassium dihydrogen phosphate (KH2PO4).

    PubMed

    Syed, Kamran Ajmal; Pang, Shu-Feng; Zhang, Yun; Zhang, Yun-Hong

    2013-01-14

    The efflorescence of an individual KH(2)PO(4) droplet on Teflon substrate was investigated by micro-Raman spectroscopy. With the decrease of relative humidity (RH) from 98.0% to 73.0%, the KH(2)PO(4) droplet lost water gradually and entered into supersaturated state, which was reflected by the area ratio between the water stretching band to the sum of ν(s)-PO(2) and ν(s)-P(OH)(2) bands of the H(2)PO(4)(-) (A(H(2)O)/(A((ν(s)-PO(2))+A(ν(s)-P(OH)(2))))). In 1.0 mol l(-1) KH(2)PO(4) solution, the ν(s)-P(OH)(2) and ν(s)-PO(2) bands appeared at 877 and 1077 cm(-1). In the KH(2)PO(4) droplet, the two bands shifted to 894 and 1039 cm(-1) at 98.0% RH, to 899 and 1031 cm(-1) at 89.6% RH, and then to 904 and 997 cm(-1) at 73.0% RH. Moreover, the aggregation process between the H(2)PO(4)(-) ions was observed from the spectral characteristic of the ν(s)-P(OH)(2) band in the concentration process, including the transitions of the H(2)PO(4)(-) ions from monomer in bulk solutions (0.5-1.0 mol l(-1)) to possible dimers at 98.0% RH and then further to oligomers in the droplet with the RH decrease, which were indicated by the blueshift of the ν(s)-P(OH)(2) band and its full width at half-height as a function of the RH. When the RH reached at 72.0%, the anhydrous crystal was obtained. A strong peak appeared at 928 cm(-1), implying that the four oxygen atoms of the H(2)PO(4 (-) were all hydrogen bonding through the bridge hydrogen atoms to get the extensive hydrogen-bonded network structure of the H(2)PO(4)(-) association, leading to the symmetric increase of the H(2)PO(4)(-) ion from C(2v) in dilute solution to quasi-T(d) in the anhydrous crystal.

  12. Micro-Raman and Micro-Infrared Spectroscopic Studies of Pb- and Au-Irradiated ZrSiO4. Optical Properties, Structural Damage and Amorphization

    SciTech Connect

    Zhang, Ming; Boatner, Lynn A.; Salje, Ekhard; Ewing, Rodney C.; Daniel, Philippe; Weber, William J; Zhang, Yanwen; Farnan, Ian E.

    2008-04-22

    The optical properties of damaged, periodic and aperiodic domains created by Pb+ (280 keV) and Au4+ (10 MeV) implantation of zircon were studied using micro-infrared (IR) and micro-Raman spectroscopy. The Pb+ and Au4+ irradiations caused a dramatic decrease in the IR reflectivity similar to that observed for metamict natural zircon. The irradiation with 10 MeV Au4+ ions (to fluences of 1x1015 Au4+ ions/cm2) also results in the formation of an amorphized phase similar to that observed in metamict zircon. These results show that high-energy, heavy-ion irradiations provide a good simulation of the ballistic effects of the recoil nucleus of an alpha-decay event, and in both cases, the result is the creation of aperiodic domains. Additional IR and Raman features were recorded in samples irradiated with 280 keV Pb+ ions (to fluences of 1x1014 and 1x1015 Pb+ ions/cm2), indicating the formation of an irradiation-induced new phase(s). The frequencies of the features are consistent with lead silicates, ZrO2 and SiO2. The results show that spectral features of the Au4+ and Pb+ irradiated zircon are different from those of quenched ZrSiO4 melts, and the finding further confirms that the amorphous state produced by high-energy ion irradiations is structurally different from the glassy state that results from quenching a high temperature melt. In contrast to significant changes in the frequency and width of the Raman v3 band observed in metamict zircon, the Pb+ and Au4+ irradiations do not cause similar variations, indicating that the remaining zircon crystalline domains in irradiated samples have a crystalline structure with fewer defects than those of metamict zircon.

  13. Micro-Raman and micro-infrared spectroscopic studies of Pb- and Au-irradiated ZrSiO{sub 4}: Optical properties, structural damage, and amorphization

    SciTech Connect

    Zhang Ming; Salje, Ekhard K. H.; Farnan, Ian; Boatner, Lynn A.; Ewing, Rodney C.; Daniel, Philippe; Weber, William J.; Zhang Yanwen

    2008-04-01

    The optical properties of damaged periodic and aperiodic domains created by Pb{sup +} (280 keV) and Au{sup 4+} (10 MeV) implantation of zircon were studied using micro-infrared (IR) and micro-Raman spectroscopy. The Pb{sup +} and Au{sup 4+} irradiations caused a dramatic decrease in the IR reflectivity similar to that observed for metamict natural zircon. The irradiation with 10 MeV Au{sup 4+} ions (to fluences of 1x10{sup 15} Au{sup 4+} ions/cm{sup 2}) also results in the formation of an amorphized phase similar to that observed in metamict zircon. These results show that high-energy, heavy-ion irradiations provide a good simulation of the ballistic effects of the recoil nucleus of an alpha-decay event and, in both cases, the result is the creation of aperiodic domains. Additional IR and Raman features were recorded in samples irradiated with 280 keV Pb{sup +} ions (to fluences of 1x10{sup 14} and 1x10{sup 15} Pb{sup +} ions/cm{sup 2}), indicating the formation of an irradiation-induced additional phase(s). The frequencies of the features are consistent with lead silicates, ZrO{sub 2}, and SiO{sub 2}. The results show that spectral features of the Au{sup 4+}- and Pb{sup +}-irradiated zircon are different from those of quenched ZrSiO{sub 4} melts, and the finding further confirms that the amorphous state produced by high-energy ion irradiations is structurally different from the glassy state that results from quenching a high temperature melt. In contrast to significant changes in the frequency and width of the Raman {nu}{sub 3} band observed in metamict zircon, the Pb{sup +} and Au{sup 4+} irradiations do not cause similar variations, indicating that the remaining zircon crystalline domains in irradiated samples have a crystalline structure with fewer defects than those of metamict zircon.

  14. Micro-Raman observation on the H2PO4- association structures in a supersaturated droplet of potassium dihydrogen phosphate (KH2PO4)

    NASA Astrophysics Data System (ADS)

    Syed, Kamran Ajmal; Pang, Shu-Feng; Zhang, Yun; Zhang, Yun-Hong

    2013-01-01

    The efflorescence of an individual KH2PO4 droplet on Teflon substrate was investigated by micro-Raman spectroscopy. With the decrease of relative humidity (RH) from 98.0% to 73.0%, the KH2PO4 droplet lost water gradually and entered into supersaturated state, which was reflected by the area ratio between the water stretching band to the sum of νs-PO2 and νs-P(OH)2 bands of the H2PO4- (A_{H_2 O} /(A_{(ν _s -PO_2 } {+ A}_{ν _s -P(OH)_2 {)}} {)}). In 1.0 mol l-1 KH2PO4 solution, the νs-P(OH)2 and νs-PO2 bands appeared at 877 and 1077 cm-1. In the KH2PO4 droplet, the two bands shifted to 894 and 1039 cm-1 at 98.0% RH, to 899 and 1031 cm-1 at 89.6% RH, and then to 904 and 997 cm-1 at 73.0% RH. Moreover, the aggregation process between the H2PO4- ions was observed from the spectral characteristic of the νs-P(OH)2 band in the concentration process, including the transitions of the H2PO4- ions from monomer in bulk solutions (0.5-1.0 mol l-1) to possible dimers at 98.0% RH and then further to oligomers in the droplet with the RH decrease, which were indicated by the blueshift of the νs-P(OH)2 band and its full width at half-height as a function of the RH. When the RH reached at 72.0%, the anhydrous crystal was obtained. A strong peak appeared at 928 cm-1, implying that the four oxygen atoms of the H2PO4- were all hydrogen bonding through the bridge hydrogen atoms to get the extensive hydrogen-bonded network structure of the H2PO4- association, leading to the symmetric increase of the H2PO4- ion from C2v in dilute solution to quasi-Td in the anhydrous crystal.

  15. Sight Application Analysis Tool

    SciTech Connect

    Bronevetsky, G.

    2014-09-17

    The scale and complexity of scientific applications makes it very difficult to optimize, debug and extend them to support new capabilities. We have developed a tool that supports developers’ efforts to understand the logical flow of their applications and interactions between application components and hardware in a way that scales with application complexity and parallelism.

  16. Applicant Analysis: 2001 Entering Class.

    ERIC Educational Resources Information Center

    Weaver, Richard G.; Haden, N. Karl; Ramanna, Satyan; Valachovic, Richard W.

    2003-01-01

    Presents findings of the annual analysis of dental school applicant numbers and characteristics conducted by the American Dental Education Association. There were 7,412 applicants to dental schools in 2001, and 57.6% were enrolled in 2001. Provides other data about applicants and admissions. (SLD)

  17. Application Power Signature Analysis

    SciTech Connect

    Hsu, Chung-Hsing; Combs, Jacob; Nazor, Jolie; Santiago, Fabian; Thysell, Rachelle; Rivoire, Suzanne; Poole, Stephen W

    2014-01-01

    The high-performance computing (HPC) community has been greatly concerned about energy efficiency. To address this concern, it is essential to understand and characterize the electrical loads of HPC applications. In this work, we study whether HPC applications can be distinguished by their power-consumption patterns using quantitative measures in an automatic manner. Using a collection of 88 power traces from 4 different systems, we find that basic statistical measures do a surprisingly good job of summarizing applications' distinctive power behavior. Moreover, this study opens up a new area of research in power-aware HPC that has a multitude of potential applications.

  18. Sol-gel synthesis and characterization of undoped and Al-doped ZnO thin films for memristive application

    NASA Astrophysics Data System (ADS)

    Ayana, Dawit G.; Prusakova, Valentina; Collini, Cristian; Nardi, Marco V.; Tatti, Roberta; Bortolotti, Mauro; Lorenzelli, Leandro; Chiappini, Andrea; Chiasera, Alessandro; Ferrari, Maurizio; Lunelli, Lorenzo; Dirè, Sandra

    2016-11-01

    The Sol-gel route is a versatile method to fabricate multi-layer, dense and homogeneous ZnO thin films with a controlled thickness and defects for a memristive application. In this work, sol-gel derived multi-layer undoped and Al-doped ZnO thin films were prepared by a spin-coating technique on SiO2/Ti/Pt and silica glass substrates. The effect of both Al doping and curing conditions on the structural and morphological features of ZnO films was investigated by complementary techniques, including electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction analysis. Electrical measurements were performed on SiO2/Ti/Pt/ZnO/Pt(dishes) and SiO2/Ti/Pt/ZnO(Al)/Pt(dishes) fabricated memristive cells and preliminary current-voltage curves were acquired.

  19. IMS applications analysis

    SciTech Connect

    RODACY,PHILIP J.; REBER,STEPHEN D.; SIMONSON,ROBERT J.; HANCE,BRADLEY G.

    2000-03-01

    This report examines the market potential of a miniature, hand-held Ion Mobility Spectrometer. Military and civilian markets are discussed, as well as applications in a variety of diverse fields. The strengths and weaknesses of competing technologies are discussed. An extensive Ion Mobility Spectrometry (IMS) bibliography is included. The conclusions drawn from this study are: (1) There are a number of competing technologies that are capable of detecting explosives, drugs, biological, or chemical agents. The IMS system currently represents the best available compromise regarding sensitivity, specificity, and portability. (2) The military market is not as large as the commercial market, but the military services are more likely to invest R and D funds in the system. (3) Military applications should be addressed before commercial applications are addressed. (4) There is potentially a large commercial market for rugged, hand-held Ion Mobility Spectrometer systems. Commercial users typically do not invest R and D funds in this type of equipment rather, they wait for off-the-shelf availability.

  20. Sneak Analysis Application Guidelines

    DTIC Science & Technology

    1982-06-01

    hardware and software systems. P SU IPORIQTS HARDWARE 1. o SOMMAE "" , SNEAK SNEAK ANALYSIS ANALYSIS REPORT REPORT AVERAGES AVIRACE1S- S. 11- 141. 3l4- 11...COMMUNICATION 0 1 5 21 I SUMrrTAL.X 0 3 4, 34 Z0 - 9 a:1H• 04 I 1 :3 1. 9. OOUIAIN 0 SUNOTALS 1 0J 1 *oi4 9 3 26 L OTALS Ia 13 52 FZ Il A ¶9_W1 35 .. . 4 dI ...equipment beyond the system bounds will have to be postulated which would dis - guise the real system configuration. c. Limited clues would be applied

  1. Applications Of Modern Systems Analysis

    NASA Technical Reports Server (NTRS)

    Wagner, Robert C.; Biernacki, John V.; Bodi, Robert F.; Juhasz, John E.

    1994-01-01

    cour papers discuss applications of interdisciplinary methodologies incorporating elaborate mathematical models and computer programs as paradigms of modern systems analysis. Unifying concept underlying presentations is need for more sophisticated methods of systems analysis to manage increasingly complex engineering and socioeconomic systems.

  2. Applications of Raman spectroscopy in life science

    NASA Astrophysics Data System (ADS)

    Martin, Airton A.; T. Soto, Cláudio A.; Ali, Syed M.; Neto, Lázaro P. M.; Canevari, Renata A.; Pereira, Liliane; Fávero, Priscila P.

    2015-06-01

    Raman spectroscopy has been applied to the analysis of biological samples for the last 12 years providing detection of changes occurring at the molecular level during the pathological transformation of the tissue. The potential use of this technology in cancer diagnosis has shown encouraging results for the in vivo, real-time and minimally invasive diagnosis. Confocal Raman technics has also been successfully applied in the analysis of skin aging process providing new insights in this field. In this paper it is presented the latest biomedical applications of Raman spectroscopy in our laboratory. It is shown that Raman spectroscopy (RS) has been used for biochemical and molecular characterization of thyroid tissue by micro-Raman spectroscopy and gene expression analysis. This study aimed to improve the discrimination between different thyroid pathologies by Raman analysis. A total of 35 thyroid tissues samples including normal tissue (n=10), goiter (n=10), papillary (n=10) and follicular carcinomas (n=5) were analyzed. The confocal Raman spectroscopy allowed a maximum discrimination of 91.1% between normal and tumor tissues, 84.8% between benign and malignant pathologies and 84.6% among carcinomas analyzed. It will be also report the application of in vivo confocal Raman spectroscopy as an important sensor for detecting advanced glycation products (AGEs) on human skin.

  3. An Analysis of Application Generators.

    DTIC Science & Technology

    1983-03-01

    include software modules for very specialized applications, such as financial modelling or statistical analysis packages. In summary application...retrieving and processing data records. The Report Preparation System of RAMIS is designed in the form of an English-like language and lets the user retrieve...sort, calculate, and format data into tabular or graphic reports . In RAMIS the report generator and the graphics language were designed to have a

  4. Application Analysis and Decision with Dynamic Analysis

    DTIC Science & Technology

    2014-12-01

    debugging tool, “ adb ”. The tool, adb , is used several times to interact with the mobile VM, by capturing the screenshot, sending SMS messages, executing...and logcat to watch log files. Analysis is ready to begin in earnest. The application is installed on the phone and then launched, all via adb

  5. Orientation of thin YBa2Cu3O7-delta/YSZ films characterization by micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, M. S.; Shen, Z. X.; Zhou, W. Z.; Xu, S. Y.; Ong, C. K.

    1999-05-01

    Micro-Raman scattering of thin YBa2Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> films of various thicknesses, deposited by pulsed laser deposition on the yttrium-stabilized zirconia (001) substrates, was carried out at different scattering geometries. The fraction of c-axis orientation of the films was calculated from the intensity ratio of the O(2,3)-B1g and O(4)-Ag modes. It is shown that it is strongly dependent on the film thickness and the highest fraction of c-axis orientation occurs for film thickness around 80 nm. The lower c-axis fraction for thinner films was explained by the simultaneous growth of a- and c-axis-oriented grains at the interface region, while the lower c-axis fraction for thicker films was due to the faults and voids in the films. Several a- and b-axis in-plane orientations have been identified using polarized Raman spectra.

  6. Clinical applications of phenotypic analysis.

    PubMed

    Pálóczi, K

    1992-08-01

    The ability to track lymphocyte differentiation and activation via the expression of cell surface marker molecules has had an enormous impact on diagnosis, monitoring and therapy of a wide range of diseases. Here, Katalin Pálóczi highlights studies from Hungary on the clinical applications of such analysis.

  7. Tribological applications of surface analysis

    NASA Technical Reports Server (NTRS)

    Wheeler, D. R.

    1984-01-01

    For some years, surface analysis was used in fundamental studies of solid-solid contacts existing in tribological systems. Analysis was used to detect material transfer in sliding contacts. The effects of surface films on the adhesion of contacts was monitored. Finally electron spectroscopic analysis of interfaces has shed some light on the fundamental electronic nature of the interfacial bond. More recently, surface analysis was applied to many tribological engineering problems. In particular, identification of chemical films formed during the sliding contact of lubricated systems and study of the surface chemistry of lubricant additives were active areas of research. One or more of four properties of the analytical technique will be important in determining its utility. The four are: lateral resolution, specimen damage, depth resolution and the availability of chemical information. In each of the applications discussed here, the important factors are brought out.

  8. Planning applications in image analysis

    NASA Technical Reports Server (NTRS)

    Boddy, Mark; White, Jim; Goldman, Robert; Short, Nick, Jr.

    1994-01-01

    We describe two interim results from an ongoing effort to automate the acquisition, analysis, archiving, and distribution of satellite earth science data. Both results are applications of Artificial Intelligence planning research to the automatic generation of processing steps for image analysis tasks. First, we have constructed a linear conditional planner (CPed), used to generate conditional processing plans. Second, we have extended an existing hierarchical planning system to make use of durations, resources, and deadlines, thus supporting the automatic generation of processing steps in time and resource-constrained environments.

  9. Information Requirements Analysis: An Application.

    DTIC Science & Technology

    1984-03-01

    Requirements Analysis: An Application by Richard Bray Renner Commander, Supply Corps, United States Navy B.S., United States Naval Academy, 1957 M.S., Naval...Stanford Research Institute study reported that during the 1960’s, industrial productivity in the United States increased by 83%, while "knowl -e workers...flow emanating from various sources within the department . Usually the request will be from faculty and can be handled with departmental funds (0 MN

  10. Micro-Raman spectroscopy studies of changes in lipid composition in breast and prostate cancer cells treated with MPA and R1881 hormones

    NASA Astrophysics Data System (ADS)

    Potcoava, Mariana C.; Futia, Gregory L.; Aughenbaugh, Jessica; Schlaepfer, Isabel; Gibson, Emily A.

    2014-03-01

    Increasing interest in the role of lipids in cancer cell proliferation or resistance to drug therapies has motivated the need to develop better tools for cellular lipid analysis. Quantification of lipids in cells is typically done by destructive chromatography protocols that do not provide spatial information on lipid distribution and prevent dynamic live cell studies. Methods that allow the analysis of lipid content in live cells is therefore of great importance for research. Using Raman micro-spectroscopy we investigated whether the female hormone medroxyprogesterone acetate (MPA) and the synthetic androgen R1881 affect the lipid expression in breast (T47D) and prostate (LNCaP) cancer cells. Differences were noted in the spectral regions at 830-1800 cm-1 and 2800-3000 cm-1 when comparing different drug treatments. Significant changes were noticed for saturated (1063 - 1125 cm-1, 1295 cm-1 and 1439 cm-1), unsaturated (1262 cm-1 and 1656 cm-1, and 1720 - 1748 cm-1) chemical bonds, suggesting that the composition of the lipid droplets was changed by the hormone treatments. Also, significant differences were observed in the high frequency regions of lipids and proteins at 2851 cm-1 and around 2890 cm-1. Principal component analysis with Linear Discriminant Analysis (PCA-LDA) of the Raman spectra was able to differentiate between cancer cells that were treated with MPA, R1881 or vehicle (P < 0.05). Future work includes analysis to determine exact lipid composition and concentrations as well as development of clinical techniques to characterize differences in patient tumor lipid profiles to determine response to drug treatment and prognosis.

  11. Power-dependent Raman analysis of highly strained Si nanobridges.

    PubMed

    Süess, M J; Minamisawa, R A; Geiger, R; Bourdelle, K K; Sigg, H; Spolenak, R

    2014-03-12

    Strain analysis of complex three-dimensional nanobridges conducted via Raman spectroscopy requires careful experimentation and data analysis supported by simulations. A method combining micro-Raman spectroscopy with finite element analysis is presented, enabling a detailed understanding of strain-sensitive Raman data measured on Si nanobridges. Power-dependent measurements are required to account for the a priori unknown scattering efficiency related to size and geometry. The experimental data is used to assess the validity of previously published phonon deformation potentials.

  12. Network analysis applications in hydrology

    NASA Astrophysics Data System (ADS)

    Price, Katie

    2017-04-01

    Applied network theory has seen pronounced expansion in recent years, in fields such as epidemiology, computer science, and sociology. Concurrent development of analytical methods and frameworks has increased possibilities and tools available to researchers seeking to apply network theory to a variety of problems. While water and nutrient fluxes through stream systems clearly demonstrate a directional network structure, the hydrological applications of network theory remain under­explored. This presentation covers a review of network applications in hydrology, followed by an overview of promising network analytical tools that potentially offer new insights into conceptual modeling of hydrologic systems, identifying behavioral transition zones in stream networks and thresholds of dynamical system response. Network applications were tested along an urbanization gradient in Atlanta, Georgia, USA. Peachtree Creek and Proctor Creek. Peachtree Creek contains a nest of five long­term USGS streamflow and water quality gages, allowing network application of long­term flow statistics. The watershed spans a range of suburban and heavily urbanized conditions. Summary flow statistics and water quality metrics were analyzed using a suite of network analysis techniques, to test the conceptual modeling and predictive potential of the methodologies. Storm events and low flow dynamics during Summer 2016 were analyzed using multiple network approaches, with an emphasis on tomogravity methods. Results indicate that network theory approaches offer novel perspectives for understanding long­ term and event­based hydrological data. Key future directions for network applications include 1) optimizing data collection, 2) identifying "hotspots" of contaminant and overland flow influx to stream systems, 3) defining process domains, and 4) analyzing dynamic connectivity of various system components, including groundwater­surface water interactions.

  13. Investigation of Rhombohedral-to-Tetragonal Phase Transition in 0.5Ba(Ti0.8Zr0.2)-0.5(Ba0.7Ca0.3)TiO3 Lead-Free Ferroelectric Using Micro-Raman Scattering

    NASA Astrophysics Data System (ADS)

    Singh, Gurvinderjit; Sathe, Vasant; Tiwari, V. S.

    2017-08-01

    Phase transition in a 0.5Ba(Ti0.8Zr0.2)-0.5(Ba0.7Ca0.3)TiO3 ferroelectric ceramic was investigated by temperature-dependent micro-Raman scattering. Presence of rhombohedral-to-tetragonal cross-over was indicated by softening of the A(TO3) mode and disappearance of the A(LO1) mode. The hysteresis in the heating-cooling measurement shows a coexistence of rhombohedral and tetragonal phases in the temperature range of 310-320 K.

  14. Film analysis systems and applications

    SciTech Connect

    Yonekura, Y.; Brill, A.B.

    1981-01-01

    The different components that can be used in modern film analysis systems are reviewed. TV camera and charge-coupled device sensors coupled to computers provide low cost systems for applications such as those described. The autoradiography (ARG) method provides an important tool for medical research and is especially useful for the development of new radiopharmaceutical compounds. Biodistribution information is needed for estimation of radiation dose, and for interpretation of the significance of observed patterns. The need for such precise information is heightened when one seeks to elucidate physiological principles/factors in normal and experimental models of disease. The poor spatial resolution achieved with current PET-imaging systems limits the information on radioreceptor mapping, neutrotransmitter, and neuroleptic drug distribution that can be achieved from patient studies. The artful use of ARG in carefully-controlled animal studies will be required to provide the additional information needed to fully understand results obtained with this new important research tool. (ERB)

  15. The Supernovae Analysis Application (SNAP)

    NASA Astrophysics Data System (ADS)

    Bayless, Amanda J.; Fryer, Chris L.; Wollaeger, Ryan; Wiggins, Brandon; Even, Wesley; de la Rosa, Janie; Roming, Peter W. A.; Frey, Lucy; Young, Patrick A.; Thorpe, Rob; Powell, Luke; Landers, Rachel; Persson, Heather D.; Hay, Rebecca

    2017-09-01

    The SuperNovae Analysis aPplication (SNAP) is a new tool for the analysis of SN observations and validation of SN models. SNAP consists of a publicly available relational database with observational light curve, theoretical light curve, and correlation table sets with statistical comparison software, and a web interface available to the community. The theoretical models are intended to span a gridded range of parameter space. The goal is to have users upload new SN models or new SN observations and run the comparison software to determine correlations via the website. There are problems looming on the horizon that SNAP is beginning to solve. For example, large surveys will discover thousands of SNe annually. Frequently, the parameter space of a new SN event is unbounded. SNAP will be a resource to constrain parameters and determine if an event needs follow-up without spending resources to create new light curve models from scratch. Second, there is no rapidly available, systematic way to determine degeneracies between parameters, or even what physics is needed to model a realistic SN. The correlations made within the SNAP system are beginning to solve these problems.

  16. Filtering Applications on Seismogram Analysis

    NASA Astrophysics Data System (ADS)

    Djordjevic, M.

    2004-12-01

    Useful data extraction from registered signals is an everyday problem. Seismogram filtering can be used to enhance the earthquake signal, especially, knowing that period range is strongly amplified by the seismograph itself. The goal of this project was to estimate tradeoffs between noise reduction and the sharpness of the filtered earthquake signal. The different filter bands were applied on the seismograms from different epicentral distances, including both local and regional earthquakes, in order to see the quality of the data. During the seismogram analysis we had two approaches: reading the wave phase (arrival time, amplitude, period) and spectral analysis, since frequency filtering is essential. The well-known set of Fourier orthogonal basis functions was used for spectral analysis. The main purpose of filtering was to remove the noise from the seismograms and to get as much possible information from the record. Practical application was obtained using custom made "Analysis" software. We processed 5 earthquake signals; four local and one distant earthquake. The data came from Djerdap Seismological Station, Serbia. Filtering was based on a band-pass filter with frequency cut-offs from 0.2Hz to 10Hz. Every record was filtered with five filters (10-1Hz,10-2.5Hz, 2.5-1Hz, 1-0.2Hz). The manipulation with different filter bands allowed us to define precisely the beginning of the earthquakes and first arrivals of different wave phases. The best result for the 45km epicentral distance earthquake was obtained using window 0.1-0.5sec, where very clear Pg and Sg arrivals could be distinguished. The distant earthquake showed the advantages of filtering seismograms to enhance the long period energy. The lowest frequency band-pass filter (1-0.2Hz) was the most successful. The results of the experiment were with very clear Pg and Sg arrivals when the right bands were used for filtering. This improved the quality of the original signals by emphasizing the temporal and

  17. Effects of sonic application of adhesive systems on bonding fiber posts to root canals.

    PubMed

    Cuadros-Sanchez, Johanna; Szesz, Anna; Hass, Viviane; Patzlaff, Rafael Tiago; Reis, Alessandra; Loguercio, Alessandro D

    2014-08-01

    Luting posts inside the root canal is still a challenge because of the difficulty of bonding adhesive materials in the apical third of roots. This study evaluated the effect of the application mode of 3 simplified etch-and-rinse adhesives on the push-out bond strength (PBS), nanoleakage (NL), and in situ degree of conversion (DC) of fiber posts in the root canal. The roots of human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar, FGM, Joinville, SC, Brazil; Adper Single Bond 2, 3MESPE, St Paul, MN; and XP Bond+self-cure activator, DeTrey Dentsply, Konstanz, Germany) and application mode (manual or sonic). The posts were cemented and the PBS tested at 0.5 mm/min. The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate. Micro-Raman spectroscopy was used to measure the in situ DC. Root third was also considered in the statistical evaluation. Data were analyzed by 3-way repeated measures analysis of variance and Tukey tests (5%). Under sonic application, the PBS and the in situ DC increased, whereas NL decreased significantly for all groups in the middle and apical thirds (P < .05). The application of simplified adhesives by sonic mode in the root canal is a feasible tool to increase the fiber post bond to root canals. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Applications analysis of high energy lasers

    NASA Technical Reports Server (NTRS)

    Arno, R. D.; Mackay, J. S.; Nishioka, K.

    1972-01-01

    An analysis and comparison of laser technology with competing technologies were made to determine possible laser applications. The analysis was undertaken as follows: (1) possible applications were listed and categorized; (2) required components were enumerated and the characteristics of these components were extrapolated; (3) complete system characteristics were calculated parametrically for selected applications using the postulated component characteristics; and (4) where possible and appropriate, comparisons were made with competing systems. It was found that any large scale replacement of existing systems and methods by lasers requires many technological advances in laser and associated systems. However, several applications appear feasible, such as low orbit drag make-up, orbit changing, communications, and illumination applications.

  19. Application of laser tweezers Raman spectroscopy techniques to the monitoring of single cell response to stimuli

    NASA Astrophysics Data System (ADS)

    Chan, James W.; Liu, Rui; Matthews, Dennis L.

    2012-06-01

    Laser tweezers Raman spectroscopy (LTRS) combines optical trapping with micro-Raman spectroscopy to enable label-free biochemical analysis of individual cells and small biological particles in suspension. The integration of the two technologies greatly simplifies the sample preparation and handling of suspension cells for spectroscopic analysis in physiologically meaningful conditions. In our group, LTRS has been used to study the effects of external perturbations, both chemical and mechanical, on the biochemistry of the cell. Single cell dynamics can be studied by performing longitudinal studies to continuously monitor the response of the cell as it interacts with its environment. The ability to carry out these measurements in-vitro makes LTRS an attractive tool for many biomedical applications. Here, we discuss the use of LTRS to study the response of cancer cells to chemotherapeutics and bacteria cells to antibiotics and show that the life cycle and apoptosis of the cells can be detected. These results show the promise of LTRS for drug discovery/screening, antibiotic susceptibility testing, and chemotherapy response monitoring applications. In separate experiments, we study the response of red blood cells to the mechanical forces imposed on the cell by the optical tweezers. A laser power dependent deoxygenation of the red blood cell in the single beam trap is reported. Normal, sickle cell, and fetal red blood cells have a different behavior that enables the discrimination of the cell types based on this mechanochemical response. These results show the potential utility of LTRS for diagnosing and studying red blood cell diseases.

  20. Multifarious applications of atomic force microscopy in forensic science investigations.

    PubMed

    Pandey, Gaurav; Tharmavaram, Maithri; Rawtani, Deepak; Kumar, Sumit; Agrawal, Y

    2017-04-01

    Forensic science is a wide field comprising of several subspecialties and uses methods derived from natural sciences for finding criminals and other evidence valid in a legal court. A relatively new area; Nano-forensics brings a new era of investigation in forensic science in which instantaneous results can be produced that determine various agents such as explosive gasses, biological agents and residues in different crime scenes and terrorist activity investigations. This can be achieved by applying Nanotechnology and its associated characterization techniques in forensic sciences. Several characterization techniques exist in Nanotechnology and nano-analysis is one such technique that is used in forensic science which includes Electron microscopes (EM) like Transmission (TEM) and Scanning (SEM), Raman microscopy (Micro -Raman) and Scanning Probe Microscopes (SPMs) like Atomic Force Microscope (AFM). Atomic force microscopy enables surface characterization of different materials by examining their morphology and mechanical properties. Materials that are immeasurable such as hair, body fluids, textile fibers, documents, polymers, pressure sensitive adhesives (PSAs), etc. are often encountered during forensic investigations. This review article will mainly focus on the use of AFM in the examination of different evidence such as blood stains, forged documents, human hair samples, ammunitions, explosives, and other such applications in the field of Forensic Science. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Ion beam analysis techniques in interdisciplinary applications

    SciTech Connect

    Respaldiza, Miguel A.; Ager, Francisco J.

    1999-11-16

    The ion beam analysis techniques emerge in the last years as one of the main applications of electrostatic accelerators. A short summary of the most used IBA techniques will be given as well as some examples of applications in interdisciplinary sciences.

  2. Ion Beam Analysis Techniques in Interdisciplinary Applications

    SciTech Connect

    Respaldiza, Miguel A.; Ager, Francisco J.

    1999-12-31

    The ion beam analysis techniques emerge in the last years as one of the main applications of electrostatic accelerators. A short summary of the most used IBA techniques will be given as well as some examples of applications in interdisciplinary sciences.

  3. Synthesis of carbon nanofibres from waste chicken fat for field electron emission applications

    SciTech Connect

    Suriani, A.B.; Dalila, A.R.; Mohamed, A.; Isa, I.M.; Kamari, A.; Hashim, N.; Soga, T.; Tanemura, M.

    2015-10-15

    Highlights: • Waste chicken fat is used as a starting material to produce CNFs via TCVD method. • High heating rate applied resulted in aggregation of catalyst particles. • Aggregated catalyst produced sea urchin-like CNFs with amorphous nature. • The as-grown CNFs presented a potential for field electron emission applications. - Abstract: Carbon nanofibres (CNFs) with sea urchin-like morphology were synthesised from waste chicken fat precursor via catalytic thermal chemical vapour deposition method at 750 °C. The CNFs showed amorphous structures under high-resolution transmission electron microscopy, micro-Raman spectroscopy and X-ray diffraction examination. X-ray photoelectron spectroscopy analysis confirmed that the core of the sea urchin-like CNFs was composed of Fe{sub 3}C formed within the first 20 min of synthesis time. The growth of amorphous CNFs from agglomerated Fe{sub 3}C particles was favourable due to the high heating rate applied during the synthesis. Field electron emission examination of the CNFs indicated turn-on and threshold field values of 5.4 and 6.6 V μm{sup −1} at current density of 1 and 10 μA cm{sup −2}, respectively. This study demonstrates that waste chicken fat, a low-cost and readily available resource, can be used as an inexpensive carbon source for the production of CNFs with a potential application in field electron emitters.

  4. Small wind systems application analysis. Executive summary

    NASA Astrophysics Data System (ADS)

    1981-06-01

    The potential market for SWECS, or wind machines smaller than 100 kW for five selected applications was estimated. The goals of the study were to aid manufacturers in attaining financing by convincing venture capital investors of the potential of SWECS and to aid government planners in allocating R and D expenditures that will effectively advance SWECS commercialization. The five applications were selected through an initial screening and priority-ranking analysis. The year of analysis was 1985, but all dollar amounts, such as fuel costs, are expressed in 1980 dollars. The five SWECS applications investigated were farm residences, non-farm residences rural electric cooperatives, feed grinders, and remote communities.

  5. Microcomputer Applications in Interaction Analysis.

    ERIC Educational Resources Information Center

    Wadham, Rex A.

    The Timed Interval Categorical Observation Recorder (TICOR), a portable, battery powered microcomputer designed to automate the collection of sequential and simultaneous behavioral observations and their associated durations, was developed to overcome problems in gathering subtle interaction analysis data characterized by sequential flow of…

  6. Failure environment analysis tool applications

    NASA Technical Reports Server (NTRS)

    Pack, Ginger L.; Wadsworth, David B.

    1994-01-01

    Understanding risks and avoiding failure are daily concerns for the women and men of NASA. Although NASA's mission propels us to push the limits of technology, and though the risks are considerable, the NASA community has instilled within it, the determination to preserve the integrity of the systems upon which our mission and, our employees lives and well-being depend. One of the ways this is being done is by expanding and improving the tools used to perform risk assessment. The Failure Environment Analysis Tool (FEAT) was developed to help engineers and analysts more thoroughly and reliably conduct risk assessment and failure analysis. FEAT accomplishes this by providing answers to questions regarding what might have caused a particular failure; or, conversely, what effect the occurrence of a failure might have on an entire system. Additionally, FEAT can determine what common causes could have resulted in other combinations of failures. FEAT will even help determine the vulnerability of a system to failures, in light of reduced capability. FEAT also is useful in training personnel who must develop an understanding of particular systems. FEAT facilitates training on system behavior, by providing an automated environment in which to conduct 'what-if' evaluation. These types of analyses make FEAT a valuable tool for engineers and operations personnel in the design, analysis, and operation of NASA space systems.

  7. Failure environment analysis tool applications

    NASA Technical Reports Server (NTRS)

    Pack, Ginger L.; Wadsworth, David B.

    1993-01-01

    Understanding risks and avoiding failure are daily concerns for the women and men of NASA. Although NASA's mission propels us to push the limits of technology, and though the risks are considerable, the NASA community has instilled within, the determination to preserve the integrity of the systems upon which our mission and, our employees lives and well-being depend. One of the ways this is being done is by expanding and improving the tools used to perform risk assessment. The Failure Environment Analysis Tool (FEAT) was developed to help engineers and analysts more thoroughly and reliably conduct risk assessment and failure analysis. FEAT accomplishes this by providing answers to questions regarding what might have caused a particular failure; or, conversely, what effect the occurrence of a failure might have on an entire system. Additionally, FEAT can determine what common causes could have resulted in other combinations of failures. FEAT will even help determine the vulnerability of a system to failures, in light of reduced capability. FEAT also is useful in training personnel who must develop an understanding of particular systems. FEAT facilitates training on system behavior, by providing an automated environment in which to conduct 'what-if' evaluation. These types of analyses make FEAT a valuable tool for engineers and operations personnel in the design, analysis, and operation of NASA space systems.

  8. Machine learning applications in cell image analysis.

    PubMed

    Kan, Andrey

    2017-04-04

    Machine learning (ML) refers to a set of automatic pattern recognition methods that have been successfully applied across various problem domains, including biomedical image analysis. This review focuses on ML applications for image analysis in light microscopy experiments with typical tasks of segmenting and tracking individual cells, and modelling of reconstructed lineage trees. After describing a typical image analysis pipeline and highlighting challenges of automatic analysis (for example, variability in cell morphology, tracking in presence of clutters) this review gives a brief historical outlook of ML, followed by basic concepts and definitions required for understanding examples. This article then presents several example applications at various image processing stages, including the use of supervised learning methods for improving cell segmentation, and the application of active learning for tracking. The review concludes with remarks on parameter setting and future directions.Immunology and Cell Biology advance online publication, 4 April 2017; doi:10.1038/icb.2017.16.

  9. Structural sensitivity analysis: Methods, applications and needs

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Camarda, C. J.; Walsh, J. L.

    1984-01-01

    Innovative techniques applicable to sensitivity analysis of discretized structural systems are reviewed. The techniques include a finite difference step size selection algorithm, a method for derivatives of iterative solutions, a Green's function technique for derivatives of transient response, simultaneous calculation of temperatures and their derivatives, derivatives with respect to shape, and derivatives of optimum designs with respect to problem parameters. Computerized implementations of sensitivity analysis and applications of sensitivity derivatives are also discussed. Some of the critical needs in the structural sensitivity area are indicated along with plans for dealing with some of those needs.

  10. Structural sensitivity analysis: Methods, applications, and needs

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Camarda, C. J.; Walsh, J. L.

    1984-01-01

    Some innovative techniques applicable to sensitivity analysis of discretized structural systems are reviewed. These techniques include a finite-difference step-size selection algorithm, a method for derivatives of iterative solutions, a Green's function technique for derivatives of transient response, a simultaneous calculation of temperatures and their derivatives, derivatives with respect to shape, and derivatives of optimum designs with respect to problem parameters. Computerized implementations of sensitivity analysis and applications of sensitivity derivatives are also discussed. Finally, some of the critical needs in the structural sensitivity area are indicated along with Langley plans for dealing with some of these needs.

  11. Application of capillary isotachophoresis in peptide analysis.

    PubMed

    Kasicka, V; Prusík, Z

    1991-09-13

    This paper gives a broad and detailed review of the applications of one of the modern high-performance electromigration separation techniques--capillary isotachophoresis (ITP)--in peptide analysis. Examples are presented of the utilization of capillary ITP for peptide analysis in the fields of chemistry, general and clinical biochemistry, biology, biotechnology, pharmacy and the food industry. The complete composition of all the electrolyte systems used for peptide ITP analyses in both cationic and anionic techniques is given in tabular form. According to the purpose of analysis the applications are divided into several sections: model studies, determination of physico-chemical characteristics, purity control of both intermediate and final peptide preparations, including the determination of low-molecular-mass ionogenic admixtures, and the analysis of peptides in biological fluids and tissue extracts. In addition to the main applications the theoretical and methodological aspects of peptide ITP analysis are discussed. The basic electromigration properties of peptides (their polyampholyte character, effective and absolute mobilities, acid-base equilibria) are explained and the selection of parameters for peptide ITP analysis is described in detail. The advantages and disadvantages of ITP compared with other electrophoretic and chromatographic methods used for peptide analysis are discussed.

  12. Synthesis and Characterization of Potentiostatically Electrodeposited Tungsten Oxide Thin Films for Smart Window Application

    NASA Astrophysics Data System (ADS)

    More, A. J.; Patil, R. S.; Dalavi, D. S.; Suryawanshi, M. P.; Burungale, V. V.; Kim, J. H.; Patil, P. S.

    2017-02-01

    Tungsten oxide (WO3) thin films have been synthesized using electrodeposition in potentiostatic mode and the effect of different deposition potentials on their structural, morphological, optical, and electrochromic (EC) properties investigated. The deposition potential versus saturated calomel electrode (SCE) was varied from -0.35 V to -0.50 V in steps of -0.05 V for 20 min each. The electrodeposited WO3 thin films were characterized using x-ray diffraction analysis, micro-Raman spectroscopy, field-emission scanning electron microscopy, and ultraviolet-visible (UV-Vis) spectrophotometry, revealing amorphous nature with nanograins having average size from 40 nm to 60 nm. The EC performance of the WO3 thin films exhibited response times of 1.35 s for bleaching ( t b) and 3.1 s for coloration ( t c) with excellent reversibility of 64.36%. The highest coloration efficiency of the electrodeposited WO3 thin films was found to be 87.95 cm2/C. The electrochemical reversibility and stability of the WO3 thin films obtained in this study make them promising for use in smart window applications.

  13. Principles and clinical applications of image analysis.

    PubMed

    Kisner, H J

    1988-12-01

    Image processing has traveled to the lunar surface and back, finding its way into the clinical laboratory. Advances in digital computers have improved the technology of image analysis, resulting in a wide variety of medical applications. Offering improvements in turnaround time, standardized systems, increased precision, and walkaway automation, digital image analysis has likely found a permanent home as a diagnostic aid in the interpretation of microscopic as well as macroscopic laboratory images.

  14. Nuclear data for ion beam analysis applications

    NASA Astrophysics Data System (ADS)

    Dimitriou, Paraskevi; Semkova, Valentina; Zerkin, Viktor

    2017-09-01

    Nuclear data for Ion Beam Analysis have been compiled and disseminated by the Nuclear Data Section through the Ion Beam Analysis Nuclear Data Library (IBANDL) for over a decade. Recent efforts to enrich IBANDL with gamma-ray producing nuclear reaction cross sections, and to improve search and retrieval features are presented. The coordinated effort to produce reliable evaluated cross-section data for charged-particle reactions for a wider range of applications is also discussed.

  15. Pharmaceutical applications of dynamic mechanical thermal analysis.

    PubMed

    Jones, David S; Tian, Yiwei; Abu-Diak, Osama; Andrews, Gavin P

    2012-04-01

    The successful development of polymeric drug delivery and biomedical devices requires a comprehensive understanding of the viscoleastic properties of polymers as these have been shown to directly affect clinical efficacy. Dynamic mechanical thermal analysis (DMTA) is an accessible and versatile analytical technique in which an oscillating stress or strain is applied to a sample as a function of oscillatory frequency and temperature. Through cyclic application of a non-destructive stress or strain, a comprehensive understanding of the viscoelastic properties of polymers may be obtained. In this review, we provide a concise overview of the theory of DMTA and the basic instrumental/operating principles. Moreover, the application of DMTA for the characterization of solid pharmaceutical and biomedical systems has been discussed in detail. In particular we have described the potential of DMTA to measure and understand relaxation transitions and miscibility in binary and higher-order systems and describe the more recent applications of the technique for this purpose.

  16. Software applications for flux balance analysis.

    PubMed

    Lakshmanan, Meiyappan; Koh, Geoffrey; Chung, Bevan K S; Lee, Dong-Yup

    2014-01-01

    Flux balance analysis (FBA) is a widely used computational method for characterizing and engineering intrinsic cellular metabolism. The increasing number of its successful applications and growing popularity are possibly attributable to the availability of specific software tools for FBA. Each tool has its unique features and limitations with respect to operational environment, user-interface and supported analysis algorithms. Presented herein is an in-depth evaluation of currently available FBA applications, focusing mainly on usability, functionality, graphical representation and inter-operability. Overall, most of the applications are able to perform basic features of model creation and FBA simulation. COBRA toolbox, OptFlux and FASIMU are versatile to support advanced in silico algorithms to identify environmental and genetic targets for strain design. SurreyFBA, WEbcoli, Acorn, FAME, GEMSiRV and MetaFluxNet are the distinct tools which provide the user friendly interfaces in model handling. In terms of software architecture, FBA-SimVis and OptFlux have the flexible environments as they enable the plug-in/add-on feature to aid prospective functional extensions. Notably, an increasing trend towards the implementation of more tailored e-services such as central model repository and assistance to collaborative efforts was observed among the web-based applications with the help of advanced web-technologies. Furthermore, most recent applications such as the Model SEED, FAME, MetaFlux and MicrobesFlux have even included several routines to facilitate the reconstruction of genome-scale metabolic models. Finally, a brief discussion on the future directions of FBA applications was made for the benefit of potential tool developers.

  17. Liquid phase microextraction applications in food analysis.

    PubMed

    Asensio-Ramos, María; Ravelo-Pérez, Lidia M; González-Curbelo, Miguel Ángel; Hernández-Borges, Javier

    2011-10-21

    Over the last years, liquid-phase microextraction (LPME) in its different application modes (single drop microextraction, dispersive liquid-liquid microextraction and hollow fiber-LPME) has been increasingly applied for the extraction of both inorganic and organic analytes from different matrices. Its advantages over conventional extraction procedures (simplicity, effectiveness, rapidity and low consumption of organic solvents) has also attracted its application in the complex food analysis field, in which it has clearly provided good and challenging results. A comprehensive review dealing with those articles published since its introduction till the end of March 2011 is presented, offering also a critical vision of the analytical potential of LPME for the analysis of foods. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Military housing foam application and analysis

    SciTech Connect

    Torres, J. J.

    2012-03-01

    Sandia and Forest City have established a Cooperative Research and Development Agreement (CRADA), the partnership provides a unique opportunity to take technology research and development from demonstration to application in sustainable communities. This project consists of two activities conducted in Hawaii that focus on performance, integration and application of energy saving technologies. Hawaii has many energy challenges, making this location an excellent testbed for these activities. Under this project, spray foam technology was applied at military housing on Oahu and the consumption data collected. A cost benefit and operational analysis of the foam was completed. The second phase of this project included design, integration, and analysis of photovoltaic systems at a military community on Oahu. This phase of the project was conducted as part of Forest City's second Solar America Showcase Award.

  19. Application of MCBEND to PBMR shielding analysis.

    PubMed

    Wright, G A; Wall, S J

    2005-01-01

    Shielding analysis of an early design of Pebble Bed Modular Reactor (PBMR) has been carried out by using the Monte Carlo code MCBEND. The issues of concern were damage to the core barrel and the reactor pressure vessel (RPV), activation of the core barrel, RPV, top plate and bottom plate, and also burn-up of boron in the control layer underneath the core. The analysis below the core was complicated due to the presence of the de-fuelling chute, which meant that multiplication had to be taken into account. The analysis of boron burn-up was particularly challenging and was tackled using a combination of MCBEND and the criticality code MONK in the depletion mode. The application of MCBEND to the shielding analysis of the PBMR is described, with particular attention being paid to the regions below the core.

  20. Error analysis of quartz crystal resonator applications

    SciTech Connect

    Lucklum, R.; Behling, C.; Hauptmann, P.; Cernosek, R.W.; Martin, S.J.

    1996-12-31

    Quartz crystal resonators in chemical sensing applications are usually configured as the frequency determining element of an electrical oscillator. By contrast, the shear modulus determination of a polymer coating needs a complete impedance analysis. The first part of this contribution reports the error made if common approximations are used to relate the frequency shift to the sorbed mass. In the second part the authors discuss different error sources in the procedure to determine shear parameters.

  1. Probabilistic structural analysis methods and applications

    NASA Technical Reports Server (NTRS)

    Cruse, T. A.; Wu, Y.-T.; Dias, B.; Rajagopal, K. R.

    1988-01-01

    An advanced algorithm for simulating the probabilistic distribution of structural responses due to statistical uncertainties in loads, geometry, material properties, and boundary conditions is reported. The method effectively combines an advanced algorithm for calculating probability levels for multivariate problems (fast probability integration) together with a general-purpose finite-element code for stress, vibration, and buckling analysis. Application is made to a space propulsion system turbine blade for which the geometry and material properties are treated as random variables.

  2. Analysis of pigments and coverings by X-ray diffraction (XRD) and micro Raman spectroscopy (MRS) in the cemetery of Tutugi (Galera, Granada, Spain) and the settlement convento 2 (Montemayor, Córdoba, Spain)

    NASA Astrophysics Data System (ADS)

    Parras-Guijarro, D.; Montejo-Gámez, M.; Ramos-Martos, N.; Sánchez, Alberto

    2006-08-01

    This paper focuses on the identification of the composition of the coverings and pigments of two archaeological sites. The sites researched here lie in Andalusia and show two contexts, which have a highly symbolic and ritual meaning. The first, Convento 2 (Montemayor, Córdoba), dates back to the period of formation of the Iberian Culture (VIIth century B.C.). The second is the cemetery of Tutugi (Galera, Granada), of the mid-Iberian period (IVth century B.C.). The analytical procedure consisted in combined and complementary use of XRD and MRS. This allowed to identify the materials used, namely hematite, goethite, coal, gypsum and calcite. Identification of these materials proves essential for the restoration and musealization of both archaeological sites.

  3. Analysis of pigments and coverings by X-ray diffraction (XRD) and micro Raman spectroscopy (MRS) in the cemetery of Tutugi (Galera, Granada, Spain) and the settlement convento 2 (Montemayor, Córdoba, Spain).

    PubMed

    Parras-Guijarro, D; Montejo-Gámez, M; Ramos-Martos, N; Sánchez, Alberto

    2006-08-01

    This paper focuses on the identification of the composition of the coverings and pigments of two archaeological sites. The sites researched here lie in Andalusia and show two contexts, which have a highly symbolic and ritual meaning. The first, Convento 2 (Montemayor, Córdoba), dates back to the period of formation of the Iberian Culture (VIIth century b.c.). The second is the cemetery of Tutugi (Galera, Granada), of the mid-Iberian period (IVth century b.c.). The analytical procedure consisted in combined and complementary use of XRD and MRS. This allowed to identify the materials used, namely hematite, goethite, coal, gypsum and calcite. Identification of these materials proves essential for the restoration and musealization of both archaeological sites.

  4. Effect of application mode on interfacial morphology and chemistry between dentine and self-etch adhesives.

    PubMed

    Zhang, Ying; Wang, Yong

    2013-03-01

    To investigate the influence of application mode on the interfacial morphology and chemistry between dentine and self-etch adhesives with different aggressiveness. The occlusal one-third of the crown was removed from un-erupted human third molars, followed by abrading with 600 grit SiC under water. Rectangular dentine slabs were prepared by sectioning the tooth specimens perpendicular to the abraded surfaces. The obtained dentine slabs were treated with one of the two one-step self-etch adhesives: Adper Easy Bond (AEB, pH∼2.5) and Adper Prompt L-Pop (APLP, pH∼0.8) with (15s, active application) or without (15s, inactive application) agitation. The dentine slabs were fractured and the exposed adhesive/dentine (A/D) interfaces were examined with micro-Raman spectroscopy and scanning electron microscopy (SEM). The interfacial morphology, degree of dentine demineralization (DD) and degree of conversion (DC) of the strong self-etch adhesive APLP showed more significant dependence on the application mode than the mild AEB. APLP exhibited inferior bonding at the A/D interface if applied without agitation, evidenced by debonding from the dentine substrate. The DDs and DCs of the APLP with agitation were higher than those of without agitation in the interface, in contrast to the comparable DD and DC values of two AEB specimen groups with different application modes. Raman spectral analysis revealed the important role of chemical interaction between acid monomers of self-etch adhesives and dentine in the above observations. The chemical interaction with dentine is especially important for improving the DC of the strong self-etching adhesive at the A/D interface. Agitation could benefit polymerization efficacy of the strong self-etch adhesive through enhancing the chemical interaction with tooth substrate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. INTERNAL HAZARDS ANALYSIS FOR LICENSE APPLICATION

    SciTech Connect

    R.J. Garrett

    2005-02-17

    The purpose of this internal hazards analysis is to identify and document the internal hazards and potential initiating events associated with preclosure operations of the repository at Yucca Mountain. Internal hazards are those hazards presented by the operation of the facility and by its associated processes that can potentially lead to a radioactive release or cause a radiological hazard. In contrast to external hazards, internal hazards do not involve natural phenomena and external man-made hazards. This internal hazards analysis was performed in support of the preclosure safety analysis and the License Application for the Yucca Mountain Project. The methodology for this analysis provides a systematic means to identify internal hazards and potential initiating events that may result in a radiological hazard or radiological release during the repository preclosure period. These hazards are documented in tables of potential internal hazards and potential initiating events (Section 6.6) for input to the repository event sequence categorization process. The results of this analysis will undergo further screening and analysis based on the criteria that apply to the performance of event sequence analyses for the repository preclosure period. The evolving design of the repository will be re-evaluated periodically to ensure that internal hazards that have not been previously evaluated are identified.

  6. Information theory applications for biological sequence analysis.

    PubMed

    Vinga, Susana

    2014-05-01

    Information theory (IT) addresses the analysis of communication systems and has been widely applied in molecular biology. In particular, alignment-free sequence analysis and comparison greatly benefited from concepts derived from IT, such as entropy and mutual information. This review covers several aspects of IT applications, ranging from genome global analysis and comparison, including block-entropy estimation and resolution-free metrics based on iterative maps, to local analysis, comprising the classification of motifs, prediction of transcription factor binding sites and sequence characterization based on linguistic complexity and entropic profiles. IT has also been applied to high-level correlations that combine DNA, RNA or protein features with sequence-independent properties, such as gene mapping and phenotype analysis, and has also provided models based on communication systems theory to describe information transmission channels at the cell level and also during evolutionary processes. While not exhaustive, this review attempts to categorize existing methods and to indicate their relation with broader transversal topics such as genomic signatures, data compression and complexity, time series analysis and phylogenetic classification, providing a resource for future developments in this promising area.

  7. Dynamic Analysis of Mobile Device Applications

    SciTech Connect

    Corey Thuen

    2013-01-01

    The On-Device Dynamic Analysis of Mobile Applications (ODAMA) project was started in an effort to protect mobile devices used in Industrial Control Systems (ICS) from cyber attack. Because mobile devices hide as much of the “computer” as possible, the user’s ability to assess the software running on their system is limited. The research team chose Google’s Android platform for this initial research because it is open source and it would give us freedom in our approach, including the ability to modify the mobile device’s operating system itself. The research team concluded that a Privileged Application was the right approach, and the result was ODAMA. This project is an important piece of the work to secure the expanding use of mobile devices with our nation’s critical infrastructure.

  8. Environmental applications of the Particle Analysis System

    SciTech Connect

    Moritz, E.J.; Hoffman, C.R.

    1994-12-31

    This study demonstrates the applicability of particle counting technology for analysis of various water treatment systems at the Rocky Flats Plant. The Particle Analysis System determined the water quality of samples from environmental remediation, storm water treatment, and drinking water treatment operations. samples were measured in either discrete or on-line mode. This data showed filtration efficiencies, particle counts, particle size distributions, and real-time treatment system performance. Sample dilution, handling, and background techniques were also evaluated and utilized in this study. Particle counting indicated water quality changes after the range of 0.0 nephelometric turbidity units (NTU) was achieved. In the environmental remediation treatment process on-line monitoring, less than 1,000 total particle count resulted in turbidity of 0.0 NTU, but filter efficiency improved to approximately 500 total particle count with no change in turbidity. Filter removal efficiency improved with time because previously retained particles serve as additional collectors for other suspended particles. This was shown by comparing filtration before and after backflushing. Particle counting can be used to evaluate the filter cleaning process (backflushing) capability by measuring immediate post-filter performance. The Particle Analysis System proved to be an efficient and reliable water quality measurement tool, and it is applicable to a variety of water treatment systems at the Rocky Flats Plant.

  9. Guidebook for analysis of tether applications

    NASA Technical Reports Server (NTRS)

    Carroll, J. A.

    1985-01-01

    This guidebook is intended as a tool to facilitate initial analyses of proposed tether applications in space. The guiding philosophy is that a brief analysis of all the common problem areas is far more useful than a detailed study in any one area. Such analyses can minimize the waste of resources on elegant but fatally flawed concepts, and can identify the areas where more effort is needed on concepts which do survive the initial analyses. The simplified formulas, approximations, and analytical tools included should be used only for preliminary analyses. For detailed analyses, the references with each topic and in the bibliography may be useful.

  10. Constructivism theory analysis and application to curricula.

    PubMed

    Brandon, Amy F; All, Anita C

    2010-01-01

    Today's nursing programs are struggling to accommodate the changing needs of the health care environment and need to make changes in how students are taught. Using constructivism theory, whereby learning is an active process in which learners construct new ideas or concepts based upon their current or past knowledge, leaders in nursing education can make a paradigm shift toward concept-based curricula. This article presents a summary and analysis of constructivism and an innovative application of its active-learning principles to curriculum development, specifically for the education of nursing students.

  11. Application of shape analysis to mammographic calcifications

    SciTech Connect

    Shen, L.; Rangayyan, R.M. . Dept. of Electrical and Computer Engineering); Desautels, J.E.L. . Dept. of Radiology)

    1994-06-01

    The authors have developed a set of shape factors to measure the roughness of contours of calcifications in mammograms and for use in their classification as malignant or benign. The analysis of mammograms is performed in three stages. First, a region growing technique is used to obtain the contours of calcifications. Then, three measures of shape features, including compactness, moments, and Fourier descriptors are computed for each region. Finally, their applicability for classification is studied by using the three shape measures to form feature vectors. Classification of 143 calcifications from 18 biopsy-proven cases as benign or malignant using the three measures with the nearest-neighbor method was 100% accurate.

  12. Application of discourse analysis to nursing inquiry.

    PubMed

    Campbell, Jim; Arnold, Sheila

    2004-01-01

    Discourse analysis (DA) has frequently been misapplied within nursing research, demonstrating a lack of understanding among some nurse researchers of theoretical/ methodological approaches within DA. To date, there are few specific nursing examples illustrating the application of DA, which presents a further obstacle for the new researcher In this paper, Jim Campbell and Sheila Arnold outline a specific nursing example of DA research and describe the process of applying DA to nursing research via the personal experiences of the authors. Two different ways of 'coming to' a DA approach, will be described, one using a structured framework and the other a personal narrative.

  13. [Application of wavelet transform to infrared analysis].

    PubMed

    Li, Dan-ting; Zhang, Chang-jiang; Wang, Jin; Cheng, Cun-gui

    2006-11-01

    In the present article the FTIR spectra of the xylems of Smilax glabra Roxb. and its three kinds of counterfeits were obtained by Fourier transform infrared spectroscopy (FTIR) with OMNI-sampler directly, fast and accurately. By adopting wavelet transform analytical method the samples were studied in detail. The results showed that wavelet transform could remove the noises and condense variable, and have the advantages of fast operating speed, high degree of accuracy, and no noise disposal. It will have a good application prospect in infrared spectroscopic analysis.

  14. Femtosecond-laser direct writing in polymers and potential applications in microfluidics and memory devices

    NASA Astrophysics Data System (ADS)

    Kallepalli, Lakshmi Narayana Deepak; Soma, Venugopal Rao; Desai, Narayana Rao

    2012-07-01

    We have investigated femtosecond-laser-induced microstructures (on the surface and within the bulk), gratings, and craters in four different polymers: polymethyl methacrylate, polydimethylsiloxane, polystyrene, and polyvinyl alcohol. The structures were achieved using a Ti:sapphire laser delivering 100-fs pulses at 800 nm with a repetition rate of 1 kHz and a maximum pulse energy of 1 mJ. Local chemical modifications leading to the formation of optical centers and peroxide radicals were studied using ultraviolet-visible absorption and emission, confocal micro-Raman and electron spin resonance spectroscopic techniques. Potential applications of these structures in microfluidics, waveguides, and memory-based devices are demonstrated.

  15. Application of Electromigration Techniques in Environmental Analysis

    NASA Astrophysics Data System (ADS)

    Bald, Edward; Kubalczyk, Paweł; Studzińska, Sylwia; Dziubakiewicz, Ewelina; Buszewski, Bogusław

    Inherently trace-level concentration of pollutants in the environment, together with the complexity of sample matrices, place a strong demand on the detection capabilities of electromigration methods. Significant progress is continually being made, widening the applicability of these techniques, mostly capillary zone electrophoresis, micellar electrokinetic chromatography, and capillary electrochromatography, to the analysis of real-world environmental samples, including the concentration sensitivity and robustness of the developed analytical procedures. This chapter covers the recent major developments in the domain of capillary electrophoresis analysis of environmental samples for pesticides, polycyclic aromatic hydrocarbons, phenols, amines, carboxylic acids, explosives, pharmaceuticals, and ionic liquids. Emphasis is made on pre-capillary and on-capillary chromatography and electrophoresis-based concentration of analytes and detection improvement.

  16. Autoregressive and bispectral analysis techniques: EEG applications.

    PubMed

    Ning, T; Bronzino, J D

    1990-01-01

    Some basic properties of autoregressive (AR) modeling and bispectral analysis are reviewed, and examples of their application in electroencephalography (EEG) research are provided. A second-order AR model was used to score cortical EEGs in order. In tests performed on five adult rats to distinguish between different vigilance states such a quiet-waking (QW), rapid-eye-movement (REM), and slow-wave sleep (SWS), SWS activity was correctly identified over 96% of the time, and a 95% agreement rate was achieved in recognizing the REM sleep stage. In a bispectral analysis of the rat EEG, third-order cumulant (TOC) sequences of 32 epochs belonging to the same vigilance state were estimated and then averaged. Preliminary results have shown that bispectra of hippocampal EEGs during REM Sleep exhibit significant quadratic phase couplings between frequencies in the 6-8-Hz range, associated with the theta rhythm.

  17. Hierarchical task analysis: developments, applications, and extensions.

    PubMed

    Stanton, Neville A

    2006-01-01

    Hierarchical task analysis (HTA) is a core ergonomics approach with a pedigree of over 30 years continuous use. At its heart, HTA is based upon a theory of performance and has only three governing principles. Originally developed as a means of determining training requirements, there was no way the initial pioneers of HTA could have foreseen the extent of its success. HTA has endured as a way of representing a system sub-goal hierarchy for extended analysis. It has been used for a range of applications, including interface design and evaluation, allocation of function, job aid design, error prediction, and workload assessment. Ergonomists are still developing new ways of using HTA which has assured the continued use of the approach for the foreseeable future.

  18. Applications of cellular fatty acid analysis.

    PubMed Central

    Welch, D F

    1991-01-01

    More than ever, new technology is having an impact on the tools of clinical microbiologists. The analysis of cellular fatty acids by gas-liquid chromatography (GLC) has become markedly more practical with the advent of the fused-silica capillary column, computer-controlled chromatography and data analysis, simplified sample preparation, and a commercially available GLC system dedicated to microbiological applications. Experience with applications in diagnostic microbiology ranges from substantial success in work with mycobacteria, legionellae, and nonfermentative gram-negative bacilli to minimal involvement with fungi and other nonbacterial agents. GLC is a good alternative to other means for the identification of mycobacteria or legionellae because it is rapid, specific, and independent of other specialized testing, e.g., DNA hybridization. Nonfermenters show features in their cellular fatty acid content that are useful in identifying species and, in some cases, subspecies. Less frequently encountered nonfermenters, including those belonging to unclassified groups, can ideally be characterized by GLC. Information is just beginning to materialize on the usefulness of cellular fatty acids for the identification of gram-positive bacteria and anaerobes, despite the traditional role of GLC in detecting metabolic products as an aid to identification of anaerobes. When species identification of coagulase-negative staphylococci is called for, GLC may offer an alternative to biochemical testing. Methods for direct analysis of clinical material have been developed, but in practical and economic terms they are not yet ready for use in the clinical laboratory. Direct analysis holds promise for detecting markers of infection due to an uncultivable agent or in clinical specimens that presently require cultures and prolonged incubation to yield an etiologic agent. PMID:1747860

  19. Creep analysis of silicone for podiatry applications.

    PubMed

    Janeiro-Arocas, Julia; Tarrío-Saavedra, Javier; López-Beceiro, Jorge; Naya, Salvador; López-Canosa, Adrián; Heredia-García, Nicolás; Artiaga, Ramón

    2016-10-01

    This work shows an effective methodology to characterize the creep-recovery behavior of silicones before their application in podiatry. The aim is to characterize, model and compare the creep-recovery properties of different types of silicone used in podiatry orthotics. Creep-recovery phenomena of silicones used in podiatry orthotics is characterized by dynamic mechanical analysis (DMA). Silicones provided by Herbitas are compared by observing their viscoelastic properties by Functional Data Analysis (FDA) and nonlinear regression. The relationship between strain and time is modeled by fixed and mixed effects nonlinear regression to compare easily and intuitively podiatry silicones. Functional ANOVA and Kohlrausch-Willians-Watts (KWW) model with fixed and mixed effects allows us to compare different silicones observing the values of fitting parameters and their physical meaning. The differences between silicones are related to the variations of breadth of creep-recovery time distribution and instantaneous deformation-permanent strain. Nevertheless, the mean creep-relaxation time is the same for all the studied silicones. Silicones used in palliative orthoses have higher instantaneous deformation-permanent strain and narrower creep-recovery distribution. The proposed methodology based on DMA, FDA and nonlinear regression is an useful tool to characterize and choose the proper silicone for each podiatry application according to their viscoelastic properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Electron Spectroscopy: Applications for Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Hercules, David M.

    2004-12-01

    The development of X-ray photoelectron spectroscopy (ESCA, XPS) is reviewed from an historical perspective that is relevant to its use for analytical chemistry. The emphasis is on early development of the technique, primarily during the period, 1964 1977. During these years there were significant developments in instrumentation, accompanied by significant advances in understanding the fundamentals of the technique. First, a historical perspective is presented to establish the backdrop against which XPS was developed. The early work in the field dealt mainly with measuring and understanding chemical shifts for elements and particularly for organic compounds. This was an exciting time because XPS appeared to provide chemical information unavailable otherwise. A detailed summary of some of the early work on chemical shifts is presented. It was also established that XPS could be used for quantitative analysis of elements, compounds, and different oxidation states of the same element. As the development of XPS occurred, emphasis changed from measuring chemical shifts to developing XPS as a surface analytical tool, a role that it fills today. Early applications to the analysis of catalysts and polymers, use to study adsorption and surface reactions, application of XPS to electrochemistry and corrosion, and studies of atmospheric particulates are all reviewed.

  1. Ion beam analysis in cultural heritage studies: Milestones and perspectives

    SciTech Connect

    Dran, Jean-Claude; Calligaro, Thomas

    2013-07-18

    For three decades, ion beam analysis (IBA) in external mode was considered as the best choice for the characterisation of cultural heritage materials, as it combines excellent analytical performance and non-invasive character. However, in recent years, other analytical techniques arose as serious competitors, such as those based on synchrotron radiation (X-ray absorption, fluorescence or diffraction) or those using portable instruments (XRF, micro-Raman). It is shown that nevertheless IBA remains unmatched thanks to two unique features, namely the analysis of light elements and the high-resolution 3D chemical imaging.

  2. Identification of the man-made barium copper silicate pigments among some ancient Chinese artifacts through spectroscopic analysis.

    PubMed

    Li, Q H; Yang, J C; Li, L; Dong, J Q; Zhao, H X; Liu, S

    2015-03-05

    This article describes the complementary application of non-invasive micro-Raman spectroscopy and energy dispersive X-ray fluorescence spectrometry to the characterization of some ancient Chinese silicate artifacts. A total of 28 samples dated from fourth century BC to third century AD were analyzed. The results of chemical analysis showed that the vitreous PbO-BaO-SiO2 material was used to sinter these silicate artifacts. The barium copper silicate pigments including BaCuSi4O10, BaCuSi2O6 and BaCu2Si2O7 were widely identified from colorful areas of the samples by Raman spectroscopy. In addition, other crystalline phases such as Fe2O3, BaSi2O5, BaSO4, PbCO3 and quartz were also identified. The present study provides very valuable information to trace the technical evolution of man-made barium copper silicate pigments and their close relationship with the making of ancient PbO-BaO-SiO2 glaze and glass.

  3. Acceleration of Data Analysis Applications using GPUs

    NASA Astrophysics Data System (ADS)

    Fillmore, D.; Messmer, P.; Mullowney, P.; Amyx, K.

    2008-12-01

    The vast amount of data collected by present and future scientific instruments, sensors and numerical models requires a significant increase in computing power for analysis. In many cases, processing time on a single workstation becomes impractical. While clusters of commodity processors can be utilized to accelerate some of these tasks, the relatively high software development cost, as well as acquisition and operational costs, make them less attractive for broad use. Over the past few years, another class of architectures has gained some popularity, namely heterogeneous architectures, which consist of general purpose processors connected to specialized processors. One of the most prominent examples are Graphics Processing Units (GPUs), which offer a tremendous amount of floating-point processing power due to demand for high-quality graphics in the computer game market. However, in order to harness this processing power, software developers have to develop with a detailed understanding of the underlying hardware. This burden on the developer is often hardly justifiable considering the rapid evolution of the hardware. In this talk, we will introduce GPULib, an open source library that enables scientists to accelerate their data analysis tasks using the GPUs already installed in their system from within high-level languages like IDL or MATLAB, and present examples and possible speedup from real-world data analysis applications. This work is funded through NASA Phase II SBIR Grant NNG06CA13C.

  4. Application of PRA to HEMP vulnerability analysis

    SciTech Connect

    Mensing, R.W.

    1985-09-01

    Vulnerability analyses of large systems, e.g., control and communication centers, aircraft, ships, are subject to many uncertainties. A basic source of uncertainty is the random variation inherent in the physical world. Thus, vulnerability is appropriately described by an estimate of the probability of survival (or failure). A second source of uncertainty that also needs to be recognized is the uncertainty associated with the analysis or estimation process itself. This uncertainty, often called modeling uncertainty, has many contributors. There are the approximations introduced by using mathematical models to describe reality. Also, the appropriate values of the model parameters are derived from several sources, e.g., based on experimental or test data, based on expert judgment and opinion. In any case, these values are subject to uncertainty. This uncertainty must be considered in the description of vulnerability. Thus, the estimate of the probability of survival is not a single value but a range of values. Probabilistic risk analysis (PRA) is a methodology which deals with these uncertainty issues. This report discusses the application of PRA to HEMP vulnerability analyses. Vulnerability analysis and PRA are briefly outlined and the need to distinguish between random variation and modeling uncertainty is discussed. Then a sequence of steps appropriate for applying PRA to vulnerability problems is outlined. Finally, methods for handling modeling uncertainty are identified and discussed.

  5. Residual energy applications program systems analysis report

    SciTech Connect

    Yngve, P.W.

    1980-10-01

    Current DOE plans call for building an Energy Applied Systems Test (EAST) Facility at the Savannah River Plant in close proximity to the 140 to 150/sup 0/F waste heat from one of several operating nuclear reactors. The waste water flow from each reactor, approximately 165,000 gpm, provides a unique opportunity to test the performance and operating characteristics of large-scale waste heat power generation and heat pump system concepts. This report provides a preliminary description of the potential end-use market, parametric data on heat pump and the power generation system technology, a preliminary listing of EAST Facility requirements, and an example of an integrated industrial park utilizing the technology to maximize economic pay back. The parametric heat pump analysis concluded that dual-fluid Rankine cycle heat pumps with capacities as high as 400 x 10/sup 6/ Btu/h, can utilize large sources of low temperature residual heat to provide 300/sup 0/F saturatd steam for an industrial park. The before tax return on investment for this concept is 36.2%. The analysis also concluded that smaller modular heat pumps could fulfill the same objective while sacrificing only a moderate rate of return. The parametric power generation analysis concluded that multi-pressure Rankine cycle systems not only are superior to single pressure systems, but can also be developed for large systems (approx. = 17 MW/sub e/). This same technology is applicable to smaller systems at the sacrifice of higher investment per unit output.

  6. Application Experiences of NASTRAN Thermal Analysis in Engineering

    NASA Technical Reports Server (NTRS)

    Go, J. C. D.

    1975-01-01

    The application of the thermal analysis phase of NASTRAN in engineering is described. Some illustrative samples are presented to demonstrate the applicability and limitation of NASTRAN thermal analysis capability. The results of the evaluation of the relative efficiency, applicability and accuracy among NASTRAN, other finite element programs, and finite difference programs are also presented.

  7. The applicability and effectiveness of cluster analysis

    NASA Technical Reports Server (NTRS)

    Ingram, D. S.; Actkinson, A. L.

    1973-01-01

    An insight into the characteristics which determine the performance of a clustering algorithm is presented. In order for the techniques which are examined to accurately cluster data, two conditions must be simultaneously satisfied. First the data must have a particular structure, and second the parameters chosen for the clustering algorithm must be correct. By examining the structure of the data from the Cl flight line, it is clear that no single set of parameters can be used to accurately cluster all the different crops. The effectiveness of either a noniterative or iterative clustering algorithm to accurately cluster data representative of the Cl flight line is questionable. Thus extensive a prior knowledge is required in order to use cluster analysis in its present form for applications like assisting in the definition of field boundaries and evaluating the homogeneity of a field. New or modified techniques are necessary for clustering to be a reliable tool.

  8. Tongue Color Analysis for Medical Application

    PubMed Central

    Wang, Xingzheng; You, Jane

    2013-01-01

    An in-depth systematic tongue color analysis system for medical applications is proposed. Using the tongue color gamut, tongue foreground pixels are first extracted and assigned to one of 12 colors representing this gamut. The ratio of each color for the entire image is calculated and forms a tongue color feature vector. Experimenting on a large dataset consisting of 143 Healthy and 902 Disease (13 groups of more than 10 samples and one miscellaneous group), a given tongue sample can be classified into one of these two classes with an average accuracy of 91.99%. Further testing showed that Disease samples can be split into three clusters, and within each cluster most if not all the illnesses are distinguished from one another. In total 11 illnesses have a classification rate greater than 70%. This demonstrates a relationship between the state of the human body and its tongue color. PMID:23737824

  9. Fabrication of highly transparent diamond-like carbon anti-reflecting coating for Si solar cell application

    SciTech Connect

    Banerjee, Amit Das, Debajyoti

    2014-04-24

    ARC grade highly transparent unhydrogenated diamond-like carbon (DLC) films were produced, directly from a-C target, using RF magnetron sputtering deposition technique, for optoelectronic applications. Optical band gap, transmittance, reflectance, sp{sup 3} fraction, I{sub D}/I{sub G}, density, and refractive index of the films have been estimated with the help of optical tools like Uv-vis spectrophotometer, ellipsometer and micro-Raman. Optimum ARC-qualities have been identified in low-temperature grown DLC films at an Ar pressure of 4 mTorr in the reactor, accomplishing its key requirements for use in silicon solar cells.

  10. Generic element processor (application to nonlinear analysis)

    NASA Technical Reports Server (NTRS)

    Stanley, Gary

    1989-01-01

    The focus here is on one aspect of the Computational Structural Mechanics (CSM) Testbed: finite element technology. The approach involves a Generic Element Processor: a command-driven, database-oriented software shell that facilitates introduction of new elements into the testbed. This shell features an element-independent corotational capability that upgrades linear elements to geometrically nonlinear analysis, and corrects the rigid-body errors that plague many contemporary plate and shell elements. Specific elements that have been implemented in the Testbed via this mechanism include the Assumed Natural-Coordinate Strain (ANS) shell elements, developed with Professor K. C. Park (University of Colorado, Boulder), a new class of curved hybrid shell elements, developed by Dr. David Kang of LPARL (formerly a student of Professor T. Pian), other shell and solid hybrid elements developed by NASA personnel, and recently a repackaged version of the workhorse shell element used in the traditional STAGS nonlinear shell analysis code. The presentation covers: (1) user and developer interfaces to the generic element processor, (2) an explanation of the built-in corotational option, (3) a description of some of the shell-elements currently implemented, and (4) application to sample nonlinear shell postbuckling problems.

  11. Application of factor analysis to FTIR microscopy

    NASA Astrophysics Data System (ADS)

    Donahue, Steven M.; Reffner, John A.; Wihlborg, William T.; Strawn, A. W.

    1992-03-01

    Applying chemometrics methods to the analysis of FT-IR microscopy data extends and improves compositional mapping. With an FT-IR microscope, it is possible to record mid-IR spectra from areas as small as 5 X 5 micrometers 2 and to step-scan over large areas in a regular sequence, thereby recording an array of spectra for compositional mapping. Initially, compositional maps were produced by inspecting individual spectra to identify an absorption that changed intensity with its coordinates in the data array. This band intensity would then be plotted against its spatial coordinates to produce a three-dimensional composition map. This form of mapping was generally called 'functional group mapping.' However, these data sets can be analyzed more effectively by using chemometrics principals to derive detailed quantitative maps and 'pure' principal-component spectra. The factor analysis also reduces the data set and improves the signal-to-noise ratio of compositional maps. Factor mapping has been applied to identify and plot the distribution of polymer film contaminates, foreign bodies in tissues, and adhesive bonding layers in polymer laminates. In addition, this combination of FT-IR microscopy and chemometrics has been used to test the uniformity of polymer blends and alloys. These examples are presented to illustrate the general applicability of these technologies and the strength of their union.

  12. Computer Applications in Behavior Analysis: A Review of the Literature.

    ERIC Educational Resources Information Center

    Williams, Betty Fry

    1990-01-01

    Reviews research studies that involved computer applications in behavior analysis. Highlights include interactive videodisc; teacher benefits of computer applications; studies involving retarded students; behavioral treatment for obesity; multimedia; adaptations of computer hardware and software; automated data collection; reinforcement of…

  13. Application of Risk Analysis: Response from a Systems Division,

    DTIC Science & Technology

    A review of theoretical literature reveals that most technical aspects of risk analysis have become a reasonably well-defined process with many... risk analysis in order to enhance its application. Also needed are better tools to enhance use of both subjective judgment and group decision processes...hope that it would lead to increased application of risk analysis in the acquisition process.

  14. Performance, Applications, and Analysis of Rotating Detonation Engine Technologies (Preprint)

    DTIC Science & Technology

    2015-12-01

    AFRL-RQ-WP-TP-2015-0171 PERFORMANCE, APPLICATION , AND ANALYSIS OF ROTATING DETONATION ENGINE TECHNOLOGIES (PREPRINT) Brent A. Rankin...SUBTITLE PERFORMANCE, APPLICATION , AND ANALYSIS OF ROTATING DETONATION ENGINE TECHNOLOGIES (PREPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER...compact engine designs for a broad range of power and propulsion applications . Recent accomplishments related to the performance, application , and

  15. Voxel-Based LIDAR Analysis and Applications

    NASA Astrophysics Data System (ADS)

    Hagstrom, Shea T.

    One of the greatest recent changes in the field of remote sensing is the addition of high-quality Light Detection and Ranging (LIDAR) instruments. In particular, the past few decades have been greatly beneficial to these systems because of increases in data collection speed and accuracy, as well as a reduction in the costs of components. These improvements allow modern airborne instruments to resolve sub-meter details, making them ideal for a wide variety of applications. Because LIDAR uses active illumination to capture 3D information, its output is fundamentally different from other modalities. Despite this difference, LIDAR datasets are often processed using methods appropriate for 2D images and that do not take advantage of its primary virtue of 3-dimensional data. It is this problem we explore by using volumetric voxel modeling. Voxel-based analysis has been used in many applications, especially medical imaging, but rarely in traditional remote sensing. In part this is because the memory requirements are substantial when handling large areas, but with modern computing and storage this is no longer a significant impediment. Our reason for using voxels to model scenes from LIDAR data is that there are several advantages over standard triangle-based models, including better handling of overlapping surfaces and complex shapes. We show how incorporating system position information from early in the LIDAR point cloud generation process allows radiometrically-correct transmission and other novel voxel properties to be recovered. This voxelization technique is validated on simulated data using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) software, a first-principles based ray-tracer developed at the Rochester Institute of Technology. Voxel-based modeling of LIDAR can be useful on its own, but we believe its primary advantage is when applied to problems where simpler surface-based 3D models conflict with the requirement of realistic geometry. To

  16. Uncertainty Analysis of Instrument Calibration and Application

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Tcheng, Ping

    1999-01-01

    Experimental aerodynamic researchers require estimated precision and bias uncertainties of measured physical quantities, typically at 95 percent confidence levels. Uncertainties of final computed aerodynamic parameters are obtained by propagation of individual measurement uncertainties through the defining functional expressions. In this paper, rigorous mathematical techniques are extended to determine precision and bias uncertainties of any instrument-sensor system. Through this analysis, instrument uncertainties determined through calibration are now expressed as functions of the corresponding measurement for linear and nonlinear univariate and multivariate processes. Treatment of correlated measurement precision error is developed. During laboratory calibration, calibration standard uncertainties are assumed to be an order of magnitude less than those of the instrument being calibrated. Often calibration standards do not satisfy this assumption. This paper applies rigorous statistical methods for inclusion of calibration standard uncertainty and covariance due to the order of their application. The effects of mathematical modeling error on calibration bias uncertainty are quantified. The effects of experimental design on uncertainty are analyzed. The importance of replication is emphasized, techniques for estimation of both bias and precision uncertainties using replication are developed. Statistical tests for stationarity of calibration parameters over time are obtained.

  17. Digraph matrix analysis applications to systems interactions

    SciTech Connect

    Alesso, H.P.; Altenbach, T.; Lappa, D.; Kimura, C.; Sacks, I.J.; Ashmore, B.C.; Fromme, D.; Smith, C.F.; Williams, W.

    1984-01-01

    Complex events such as Three Mile Island-2, Brown's Ferry-3 and Crystal River-3 have demonstrated that previously unidentified system interdependencies can be important to safety. A major aspect of these events was dependent faults (common cause/mode failures). The term systems interactions has been introduced by the Nuclear Regulatory Commission (NRC) to identify the concepts of spatial and functional coupling of systems which can lead to system interdependencies. Spatial coupling refers to dependencies resulting from a shared environmental condition; functional coupling refers to both dependencies resulting from components shared between safety and/or support systems, and to dependencies involving human actions. The NRC is currently developing guidelines to search for and evaluate adverse systems interactions at light water reactors. One approach utilizes graph theoretical methods and is called digraph matrix analysis (DMA). This methodology has been specifically tuned to the systems interaction problem. The objective of this paper is to present results from two DMA applications and to contrast them with the results from more traditional fault tree approaches.

  18. Terahertz Josephson spectral analysis and its applications

    NASA Astrophysics Data System (ADS)

    Snezhko, A. V.; Gundareva, I. I.; Lyatti, M. V.; Volkov, O. Y.; Pavlovskiy, V. V.; Poppe, U.; Divin, Y. Y.

    2017-04-01

    Principles of Hilbert-transform spectral analysis (HTSA) are presented and advantages of the technique in the terahertz (THz) frequency range are discussed. THz HTSA requires Josephson junctions with high values of characteristic voltages I c R n and dynamics described by a simple resistively shunted junction (RSJ) model. To meet these requirements, [001]- and [100]-tilt YBa2Cu3O7‑x bicrystal junctions with deviations from the RSJ model less than 1% have been developed. Demonstrators of Hilbert-transform spectrum analyzers with various cryogenic environments, including integration into Stirling coolers, are described. Spectrum analyzers have been characterized in the spectral range from 50 GHz to 3 THz. Inside a power dynamic range of five orders, an instrumental function of the analyzers has been found to have a Lorentz form around a single frequency of 1.48 THz with a spectral resolution as low as 0.9 GHz. Spectra of THz radiation from optically pumped gas lasers and semiconductor frequency multipliers have been studied with these spectrum analyzers and the regimes of these radiation sources were optimized for a single-frequency operation. Future applications of HTSA will be related with quick and precise spectral characterization of new radiation sources and identification of substances in the THz frequency range.

  19. PATHA: Performance Analysis Tool for HPC Applications

    SciTech Connect

    Yoo, Wucherl; Koo, Michelle; Cao, Yi; Sim, Alex; Nugent, Peter; Wu, Kesheng

    2016-02-18

    Large science projects rely on complex workflows to analyze terabytes or petabytes of data. These jobs are often running over thousands of CPU cores and simultaneously performing data accesses, data movements, and computation. It is difficult to identify bottlenecks or to debug the performance issues in these large workflows. In order to address these challenges, we have developed Performance Analysis Tool for HPC Applications (PATHA) using the state-of-art open source big data processing tools. Our framework can ingest system logs to extract key performance measures, and apply the most sophisticated statistical tools and data mining methods on the performance data. Furthermore, it utilizes an efficient data processing engine to allow users to interactively analyze a large amount of different types of logs and measurements. To illustrate the functionality of PATHA, we conduct a case study on the workflows from an astronomy project known as the Palomar Transient Factory (PTF). This study processed 1.6 TB of system logs collected on the NERSC supercomputer Edison. Using PATHA, we were able to identify performance bottlenecks, which reside in three tasks of PTF workflow with the dependency on the density of celestial objects.

  20. PATHA: Performance Analysis Tool for HPC Applications

    DOE PAGES

    Yoo, Wucherl; Koo, Michelle; Cao, Yi; ...

    2016-02-18

    Large science projects rely on complex workflows to analyze terabytes or petabytes of data. These jobs are often running over thousands of CPU cores and simultaneously performing data accesses, data movements, and computation. It is difficult to identify bottlenecks or to debug the performance issues in these large workflows. In order to address these challenges, we have developed Performance Analysis Tool for HPC Applications (PATHA) using the state-of-art open source big data processing tools. Our framework can ingest system logs to extract key performance measures, and apply the most sophisticated statistical tools and data mining methods on the performance data.more » Furthermore, it utilizes an efficient data processing engine to allow users to interactively analyze a large amount of different types of logs and measurements. To illustrate the functionality of PATHA, we conduct a case study on the workflows from an astronomy project known as the Palomar Transient Factory (PTF). This study processed 1.6 TB of system logs collected on the NERSC supercomputer Edison. Using PATHA, we were able to identify performance bottlenecks, which reside in three tasks of PTF workflow with the dependency on the density of celestial objects.« less

  1. Decision analysis applications and the CERCLA process

    SciTech Connect

    Purucker, S.T.; Lyon, B.F. |

    1994-06-01

    Quantitative decision methods can be developed during environmental restoration projects that incorporate stakeholder input and can complement current efforts that are undertaken for data collection and alternatives evaluation during the CERCLA process. These decision-making tools can supplement current EPA guidance as well as focus on problems that arise as attempts are made to make informed decisions regarding remedial alternative selection. In examining the use of such applications, the authors discuss the use of decision analysis tools and their impact on collecting data and making environmental decisions from a risk-based perspective. They will look at the construction of objective functions for quantifying different risk-based perspective. They will look at the construction of objective functions for quantifying different risk-based decision rules that incorporate stakeholder concerns. This represents a quantitative method for implementing the Data Quality Objective (DQO) process. These objective functions can be expressed using a variety of indices to analyze problems that currently arise in the environmental field. Examples include cost, magnitude of risk, efficiency, and probability of success or failure. Based on such defined objective functions, a project can evaluate the impact of different risk and decision selection strategies on data worth and alternative selection.

  2. System Safety Analysis Application Guide. Safety Analysis Report Update Program

    SciTech Connect

    Not Available

    1993-05-01

    Martin Marietta Energy Systems, Inc., (Energy Systems) is committed to performing and documenting safety analyses for facilities it manages for the Department of Energy (DOE). Safety analyses are performed to identify hazards and potential accidents; to analyze the adequacy of measures taken to eliminate, control, or mitigate hazards; and to evaluate potential accidents and determine associated risks. Safety Analysis Reports (SARs) are prepared to document the safety analysis to ensure facilities can be operated safely and in accordance with regulations. SARs include Technical Safety Requirements (TSRs), which are specific technical and administrative requirements that prescribe limits and controls to ensure safe operation of DOE facilities. These documented descriptions and analyses contribute to the authorization basis for facility operation. Energy Systems has established a process to perform Unreviewed Safety Question Determinations (USQDs) for planned changes and as-found conditions that are not described and analyzed in existing safety analyses. The process evaluates changes and as-found conditions to determine whether revisions to the authorization basis must be reviewed and approved by DOE. There is an Unreviewed Safety Question (USQ) if a change introduces conditions not bounded by the facility authorization basis. When it is necessary to request DOE approval to revise the authorization basis, preparation of a System Safety Analysis (SSA) is recommended. This application guide describes the process of preparing an SSA and the desired contents of an SSA. Guidance is provided on how to identify items and practices which are important to safety; how to determine the credibility and significance of consequences of proposed accident scenarios; how to evaluate accident prevention and mitigation features of the planned change; and how to establish special requirements to ensure that a change can be implemented with adequate safety.

  3. FT-IR, micro-Raman and UV-vis spectroscopic and quantum chemical investigations of free 2,2'-dithiodipyridine and its metal (Co, Cu and Zn) halide complexes.

    PubMed

    Gökce, Halil; Bahçeli, Semiha

    2013-10-01

    In this study the elemental analysis results, molecular geometries, vibrational and electronic absorption spectra of free 2,2'-dithiodipyridine(C10H8N2S2), (or DTDP) (with synonym, 2,2'-dipyridyl disulfide) and M(C10H8N2S2)Cl2 (M=Co, Cu and Zn) complexes have been reported. Vibrational wavenumbers of free DTDP and its metal halide complexes have been calculated by using DFT/B3LYP calculation method with 6-31++G(d,p) and Lanl2DZ basis sets, respectively, in the ground state, for the first time. The calculated fundamental vibrational frequencies are in a good agreement with experimental data. The HOMO, LUMO and MEP analyses of all compounds are performed by DFT method.

  4. Texture analysis: a review of neurologic MR imaging applications.

    PubMed

    Kassner, A; Thornhill, R E

    2010-05-01

    Texture analysis describes a variety of image-analysis techniques that quantify the variation in surface intensity or patterns, including some that are imperceptible to the human visual system. Texture analysis may be particularly well-suited for lesion segmentation and characterization and for the longitudinal monitoring of disease or recovery. We begin this review by outlining the general procedure for performing texture analysis, identifying some potential pitfalls and strategies for avoiding them. We then provide an overview of some intriguing neuro-MR imaging applications of texture analysis, particularly in the characterization of brain tumors, prediction of seizures in epilepsy, and a host of applications to MS.

  5. Space Telecommunications Radio System (STRS) Application Repository Design and Analysis

    NASA Technical Reports Server (NTRS)

    Handler, Louis M.

    2013-01-01

    The Space Telecommunications Radio System (STRS) Application Repository Design and Analysis document describes the STRS application repository for software-defined radio (SDR) applications intended to be compliant to the STRS Architecture Standard. The document provides information about the submission of artifacts to the STRS application repository, to provide information to the potential users of that information, and for the systems engineer to understand the requirements, concepts, and approach to the STRS application repository. The STRS application repository is intended to capture knowledge, documents, and other artifacts for each waveform application or other application outside of its project so that when the project ends, the knowledge is retained. The document describes the transmission of technology from mission to mission capturing lessons learned that are used for continuous improvement across projects and supporting NASA Procedural Requirements (NPRs) for performing software engineering projects and NASAs release process.

  6. Applicability analysis of wavelet-transform profilometry.

    PubMed

    Zhang, Zibang; Zhong, Jingang

    2013-08-12

    The applicability of the wavelet-transform profilometry is examined in detail. The wavelet-ridge-based phase demodulation is an integral operation of the fringe signal in the spatial domain. The accuracy of the phase demodulation is related to the local linearity of the phase modulated by the object surface. We present a more robust applicability condition which is based on the evaluation of the local linearity. Since high carrier frequency leads to the phase demodulation integral in a narrow interval and the narrow interval results in the high local linearity of modulated phase, we propose to increase the carrier fringe frequency to improve the applicability of the wavelet-transform profilometry and the measurement accuracy. The numerical simulations and the experiment are presented.

  7. Image analysis applications for grain science

    NASA Astrophysics Data System (ADS)

    Zayas, Inna Y.; Steele, James L.

    1991-02-01

    Morphometrical features of single grain kernels or particles were used to discriminate two visibly similar wheat varieties foreign material in wheat hardsoft and spring-winter wheat classes and whole from broken corn kernels. Milled fractions of hard and soft wheat were evaluated using textural image analysis. Color image analysis of sound and mold damaged corn kernels yielded high recognition rates. The studies collectively demonstrate the potential for automated classification and assessment of grain quality using image analysis.

  8. Application of Microchip for Biomarker Analysis

    NASA Astrophysics Data System (ADS)

    Kataoka, Masatoshi; Yatsushiro, Shouki; Yamamura, Shouhei; Abe, Hiroko

    Microchip technologies have received considerable attention, due to their competitive advantages, especially in regards to reduced sample and reagent consumption, analysis time, and easy operation. This approach has been successfully used to analyze DNA, amino acids, proteins, and carbohydrates. In the present study, we showed the potential of microchip technologies for the biomarker analysis, blood carbohydrate analysis on microchip electrophoresis, quantitative analysis of protein with antigen-antibody reaction on microchip, and the detection of malaria-infected erythrocyte with a cell microarray chip.

  9. Silicon Substrate Strained and Structured via Cavitation Effect for Photovoltaic and Biomedical Application

    NASA Astrophysics Data System (ADS)

    Savkina, Rada K.; Gudymenko, Aleksandr I.; Kladko, Vasyl P.; Korchovyi, Andrii A.; Nikolenko, Andrii S.; Smirnov, Aleksey B.; Stara, Tatyana R.; Strelchuk, Viktor V.

    2016-04-01

    A hybrid structure, which integrates the nanostructured silicon with a bio-active silicate, is fabricated using the method of MHz sonication in the cryogenic environment. Optical, atomic force, and scanning electron microscopy techniques as well as energy dispersive X-ray spectroscopy were used for the investigation of the morphology and chemical compound of the structured surface. Micro-Raman as well as X-ray diffraction, ellipsometry, and photovoltage spectroscopy was used for the obtained structures characterization. Ellipsometer measurements demonstrated the formation of the layer with the thicknesses ~700 nm and optical parameters closed to SiO2 compound with an additional top layer of the thicknesses ~15 nm and the refractive index ~1. Micro-Raman investigation detects an appearance of Ca-O local vibrational mode, and the stretching vibration of SiO4 chains characterized the wollastonite form of CaSiO3. A significant rise in the value and an expansion of the spectral range of the surface photovoltage for silicon structured via the megasonic processing was found. The concept of biocompatible photovoltaic cell on the base of Si/CaSiO3 structure for the application in bioelectronics was proposed.

  10. Silicon Substrate Strained and Structured via Cavitation Effect for Photovoltaic and Biomedical Application.

    PubMed

    Savkina, Rada K; Gudymenko, Aleksandr I; Kladko, Vasyl P; Korchovyi, Andrii A; Nikolenko, Andrii S; Smirnov, Aleksey B; Stara, Tatyana R; Strelchuk, Viktor V

    2016-12-01

    A hybrid structure, which integrates the nanostructured silicon with a bio-active silicate, is fabricated using the method of MHz sonication in the cryogenic environment. Optical, atomic force, and scanning electron microscopy techniques as well as energy dispersive X-ray spectroscopy were used for the investigation of the morphology and chemical compound of the structured surface. Micro-Raman as well as X-ray diffraction, ellipsometry, and photovoltage spectroscopy was used for the obtained structures characterization. Ellipsometer measurements demonstrated the formation of the layer with the thicknesses ~700 nm and optical parameters closed to SiO2 compound with an additional top layer of the thicknesses ~15 nm and the refractive index ~1. Micro-Raman investigation detects an appearance of Ca-O local vibrational mode, and the stretching vibration of SiO4 chains characterized the wollastonite form of CaSiO3. A significant rise in the value and an expansion of the spectral range of the surface photovoltage for silicon structured via the megasonic processing was found. The concept of biocompatible photovoltaic cell on the base of Si\\CaSiO3 structure for the application in bioelectronics was proposed.

  11. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    EPA Science Inventory

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  12. BOREHOLE FLOWMETERS: FIELD APPLICATION AND DATA ANALYSIS

    EPA Science Inventory

    This paper reviews application of borehole flowmeters in granular and fractured rocks. Basic data obtained in the field are the ambient flow log and the pumping-induced flow log. These basic logs may then be used to calculate other quantities of interest. The paper describes the ...

  13. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    EPA Science Inventory

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  14. BOREHOLE FLOWMETERS: FIELD APPLICATION AND DATA ANALYSIS

    EPA Science Inventory

    This paper reviews application of borehole flowmeters in granular and fractured rocks. Basic data obtained in the field are the ambient flow log and the pumping-induced flow log. These basic logs may then be used to calculate other quantities of interest. The paper describes the ...

  15. Guidebook for analysis of tether applications

    NASA Technical Reports Server (NTRS)

    Carroll, J. A.

    1985-01-01

    This guidebook is intended as a tool to facilitate initial analyses of proposed tether applications in space. Topics disscussed include: orbit and orbit transfer equations; orbital perturbations; aerodynamic drag; thermal balance; micrometeoroids; gravity gradient effects; tether control strategies; momentum transfer; orbit transfer by tethered release/rendezvous; impact hazards for tethers; electrodynamic tether principles; and electrodynamic libration control issues.

  16. THE NATURE AND APPLICATIONS OF PROCESS ANALYSIS,

    DTIC Science & Technology

    The ultimate goal of the process analysis project is to produce a model of the technological capabilities of the economy as a whole. The purpose of...Characteristic of the process analysis approach is the use of detailed engineering data, modern computing techniques and high speed computing machines.

  17. Miscue Analysis: Applications to Reading Instruction.

    ERIC Educational Resources Information Center

    Goodman, Kenneth S., Ed.

    This book is a series of essays on the subject of miscue analysis, a diagnostic procedure rooted in the psycholinguistic view of reading. The focus of miscue analysis is on the broad field of reading comprehension rather than the isolated decoding of individual words and letters. The contents of this book include: "Introduction" by Sister Rosemary…

  18. Regression Analysis: Legal Applications in Institutional Research

    ERIC Educational Resources Information Center

    Frizell, Julie A.; Shippen, Benjamin S., Jr.; Luna, Andrew L.

    2008-01-01

    This article reviews multiple regression analysis, describes how its results should be interpreted, and instructs institutional researchers on how to conduct such analyses using an example focused on faculty pay equity between men and women. The use of multiple regression analysis will be presented as a method with which to compare salaries of…

  19. Regression Analysis: Legal Applications in Institutional Research

    ERIC Educational Resources Information Center

    Frizell, Julie A.; Shippen, Benjamin S., Jr.; Luna, Andrew L.

    2008-01-01

    This article reviews multiple regression analysis, describes how its results should be interpreted, and instructs institutional researchers on how to conduct such analyses using an example focused on faculty pay equity between men and women. The use of multiple regression analysis will be presented as a method with which to compare salaries of…

  20. Computer applications for engineering/structural analysis

    SciTech Connect

    Zaslawsky, M.; Samaddar, S.K.

    1991-01-01

    Analysts and organizations have a tendency to lock themselves into specific codes with the obvious consequences of not addressing the real problem and thus reaching the wrong conclusion. This paper discusses the role of the analyst in selecting computer codes. The participation and support of a computation division in modifying the source program, configuration management, and pre- and post-processing of codes are among the subjects discussed. Specific examples illustrating the computer code selection process are described in the following problem areas: soil structure interaction, structural analysis of nuclear reactors, analysis of waste tanks where fluid structure interaction is important, analysis of equipment, structure-structure interaction, analysis of the operation of the superconductor supercollider which includes friction and transient temperature, and 3D analysis of the 10-meter telescope being built in Hawaii. Validation and verification of computer codes and their impact on the selection process are also discussed.

  1. Dance Dynamics. Laban Movement Analysis: Theory and Application.

    ERIC Educational Resources Information Center

    Schwartz, Peggy; And Others

    1995-01-01

    Several articles provide a theoretical overview of the Laban Movement Analysis (LMA) and describe its application. Rudolf Laban's work has many applications relevant to dance, physical education, recreation, and movement education. LMA involves training and refining how one perceives movement. It can help educators better understand students from…

  2. Potential applications of computational fluid dynamics to biofluid analysis

    NASA Technical Reports Server (NTRS)

    Kwak, D.; Chang, J. L. C.; Rogers, S. E.; Rosenfeld, M.; Kwak, D.

    1988-01-01

    Computational fluid dynamics was developed to the stage where it has become an indispensable part of aerospace research and design. In view of advances made in aerospace applications, the computational approach can be used for biofluid mechanics research. Several flow simulation methods developed for aerospace problems are briefly discussed for potential applications to biofluids, especially to blood flow analysis.

  3. [X-ray fluorescence analysis in archaeometry: application and expectation].

    PubMed

    Zhu, Jian; Mao, Zhen-wei; Zhang, Shi-ding

    2006-12-01

    This article describes the applications of X-ray fluorescence in archaeology research, including the appraisal, dating, provenance and mine material origin analysis of cultural relic, the study of manufacturing technics and production of cultural relic, etc. It also suggests some expectation and problems, in order to draw attention of X-ray fluorescence analysts and archaeologists, promote the in-depth development of X-ray fluorescence analysis application in archaeology research, and further make more contributions to Chinese archaeology research.

  4. Cost analysis of energy storage systems for electric utility applications

    SciTech Connect

    Akhil, A.; Swaminathan, S.; Sen, R.K.

    1997-02-01

    Under the sponsorship of the Department of Energy, Office of Utility Technologies, the Energy Storage System Analysis and Development Department at Sandia National Laboratories (SNL) conducted a cost analysis of energy storage systems for electric utility applications. The scope of the study included the analysis of costs for existing and planned battery, SMES, and flywheel energy storage systems. The analysis also identified the potential for cost reduction of key components.

  5. Applications of Parallelism to Current Algorithms for Intelligence Analysis

    DTIC Science & Technology

    1987-07-10

    ALGORITHMS FOR INTELLIGENCE ANALYSIS Martha Ann Griesel * J. Steven Hughes Beth R. Moore 10 July 1987 National Aeronautics and Space Administration...INTELLIGENCE CENTER AND SCHOOL Software Analysis and Management System Applications of Parallelism to Current Algorithms for Intelligence Analysis 10 July 1987...rates and a growing diversity of IEW information sources create a void in current intelligence analysis methods. New ways are needed to quickly

  6. Transient loads analysis for space flight applications

    NASA Technical Reports Server (NTRS)

    Thampi, S. K.; Vidyasagar, N. S.; Ganesan, N.

    1992-01-01

    A significant part of the flight readiness verification process involves transient analysis of the coupled Shuttle-payload system to determine the low frequency transient loads. This paper describes a methodology for transient loads analysis and its implementation for the Spacelab Life Sciences Mission. The analysis is carried out using two major software tools - NASTRAN and an external FORTRAN code called EZTRAN. This approach is adopted to overcome some of the limitations of NASTRAN's standard transient analysis capabilities. The method uses Data Recovery Matrices (DRM) to improve computational efficiency. The mode acceleration method is fully implemented in the DRM formulation to recover accurate displacements, stresses, and forces. The advantages of the method are demonstrated through a numerical example.

  7. Thermal Creep Force: Analysis And Application

    DTIC Science & Technology

    2016-06-01

    AND APPLICATION 5. FUNDING NUMBERS 6. AUTHOR(S) David M. Wolfe 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School...Monterey, CA 93943-5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS(ES) N/A 10. SPONSORING...MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and do not reflect the official

  8. [Preliminarily application of content analysis to qualitative nursing data].

    PubMed

    Liang, Shu-Yuan; Chuang, Yeu-Hui; Wu, Shu-Fang

    2012-10-01

    Content analysis is a methodology for objectively and systematically studying the content of communication in various formats. Content analysis in nursing research and nursing education is called qualitative content analysis. Qualitative content analysis is frequently applied to nursing research, as it allows researchers to determine categories inductively and deductively. This article examines qualitative content analysis in nursing research from theoretical and practical perspectives. We first describe how content analysis concepts such as unit of analysis, meaning unit, code, category, and theme are used. Next, we describe the basic steps involved in using content analysis, including data preparation, data familiarization, analysis unit identification, creating tentative coding categories, category refinement, and establishing category integrity. Finally, this paper introduces the concept of content analysis rigor, including dependability, confirmability, credibility, and transferability. This article elucidates the content analysis method in order to help professionals conduct systematic research that generates data that are informative and useful in practical application.

  9. Cross-impacts analysis development and energy policy analysis applications

    SciTech Connect

    Roop, J.M.; Scheer, R.M.; Stacey, G.S.

    1986-12-01

    Purpose of this report is to describe the cross-impact analysis process and microcomputer software developed for the Office of Policy, Planning, and Analysis (PPA) of DOE. First introduced in 1968, cross-impact analysis is a technique that produces scenarios of future conditions and possibilities. Cross-impact analysis has several unique attributes that make it a tool worth examining, especially in the current climate when the outlook for the economy and several of the key energy markets is uncertain. Cross-impact analysis complements the econometric, engineering, systems dynamics, or trend approaches already in use at DOE. Cross-impact analysis produces self-consistent scenarios in the broadest sense and can include interaction between the economy, technology, society and the environment. Energy policy analyses that couple broad scenarios of the future with detailed forecasting can produce more powerful results than scenario analysis or forecasts can produce alone.

  10. Retinal image analysis: concepts, applications and potential.

    PubMed

    Patton, Niall; Aslam, Tariq M; MacGillivray, Thomas; Deary, Ian J; Dhillon, Baljean; Eikelboom, Robert H; Yogesan, Kanagasingam; Constable, Ian J

    2006-01-01

    As digital imaging and computing power increasingly develop, so too does the potential to use these technologies in ophthalmology. Image processing, analysis and computer vision techniques are increasing in prominence in all fields of medical science, and are especially pertinent to modern ophthalmology, as it is heavily dependent on visually oriented signs. The retinal microvasculature is unique in that it is the only part of the human circulation that can be directly visualised non-invasively in vivo, readily photographed and subject to digital image analysis. Exciting developments in image processing relevant to ophthalmology over the past 15 years includes the progress being made towards developing automated diagnostic systems for conditions, such as diabetic retinopathy, age-related macular degeneration and retinopathy of prematurity. These diagnostic systems offer the potential to be used in large-scale screening programs, with the potential for significant resource savings, as well as being free from observer bias and fatigue. In addition, quantitative measurements of retinal vascular topography using digital image analysis from retinal photography have been used as research tools to better understand the relationship between the retinal microvasculature and cardiovascular disease. Furthermore, advances in electronic media transmission increase the relevance of using image processing in 'teleophthalmology' as an aid in clinical decision-making, with particular relevance to large rural-based communities. In this review, we outline the principles upon which retinal digital image analysis is based. We discuss current techniques used to automatically detect landmark features of the fundus, such as the optic disc, fovea and blood vessels. We review the use of image analysis in the automated diagnosis of pathology (with particular reference to diabetic retinopathy). We also review its role in defining and performing quantitative measurements of vascular topography

  11. Application of synchrotron radiation to elemental analysis

    SciTech Connect

    Jones, K.W.; Gordon, B.M.; Hanson, A.L.; Hastings, J.B.; Howells, M.R.; Kraner, H.W.; Chen, J.R.

    1983-01-01

    The use of a synchrotron storage ring as a high brightness source for production of monoergic, variable energy, and highly polarized x-ray beams promises to revolutionize the field of elemental analysis. The results of exploratory work using the Cornell synchrotron facility, CHESS, will be described. Design considerations and features of the new X-Ray Microprobe Facility now under construction at the Brookhaven National Synchrotron Light Source will be presented. This facility will be used for bulk analysis and for microanalysis with an initial spatial resolution of the order of 30 ..mu..m.

  12. Applications of breath gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Poupart, Guy; Telser, Stefan; Ledochowski, Maximilian; Schmid, Alex; Mechtcheriakov, Sergei

    2004-12-01

    Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

  13. PREFACE: Dielectrics 2009: Measurement Analysis and Applications

    NASA Astrophysics Data System (ADS)

    Vaughan, Alun; Williams, Graham

    2009-07-01

    The conference Dielectrics 2009: Measurements, Analysis and Applications represents a significant milestone in the evolution of dielectrics research in the UK. It is reasonable to state that the academic study of dielectrics has led to many fundamental advances and that dielectric materials underpin the modern world in devices ranging from field effect transistors, which operate at extremely high fields, albeit low voltages, to the high voltage plants that provide the energy that powers our economy. The origins of the Dielectrics Group of the Institute of Physics (IOP), which organized this conference, can be traced directly back to the early 1960s, when Professor Mansel Davies was conducting research into the dielectric relaxation behaviour of polar liquids and solids at The Edward Davies Chemical Laboratories of the University College of Wales, Aberystwyth. He was already well-known internationally for his studies of molecular structure and bonding of small molecules, using infra-red-spectroscopy, and of the physical properties of hydrogen-bonded liquids and solids, using thermodynamic methods. Dielectric spectroscopy was a fairly new area for him and he realized that opportunities for scientists in the UK to gather together and discuss their research in this developing area of physical chemistry/chemical physics were very limited. He conceived the idea of forming a Dielectrics Discussion Group (DDG), which would act as a meeting point and provide a platform for dielectrics research in the UK and beyond and, as a result, a two-day Meeting was convened in the spring of 1968 at Gregynog Hall of the University of Wales, near Newtown, Montgomeryshire. It was organized by Mansel Davies, Alun Price and Graham Williams, all physical chemists from the UCW, Aberystwyth. Fifty scientists attended, being a mix of physical chemists, theoretical chemists, physicists, electrical engineers, polymer and materials scientists, all from the UK, except Dr Brendan Scaife of Trinity

  14. Immunobiosensors: Applications in environmental, clinical, and food analysis. Volume 148

    SciTech Connect

    Ramsay, G.

    1998-12-31

    Combining design aspects of biotechnology and analytical instrumentation, immunobiosensors are a method of rapid, in-field detection of toxins such as pesticides and hazardous wastes. Easy-to-use and manufacture, inexpensive, reusable, and accurate, immunobiosensors are attracting a great deal of attention from analytical chemists involved with environmental, clinical and food analysis. This book provides the reader with a thorough understanding of immunobiosensors, with an emphasis on their sensitivity, application, accuracy, and analytical protocols. The contents include: Applications to clinical samples; Applications to bioprocess samples; and Applications to environmental samples.

  15. Uncooled LWIR imaging: applications and market analysis

    NASA Astrophysics Data System (ADS)

    Takasawa, Satomi

    2015-05-01

    The evolution of infrared (IR) imaging sensor technology for defense market has played an important role in developing commercial market, as dual use of the technology has expanded. In particular, technologies of both reduction in pixel pitch and vacuum package have drastically evolved in the area of uncooled Long-Wave IR (LWIR; 8-14 μm wavelength region) imaging sensor, increasing opportunity to create new applications. From the macroscopic point of view, the uncooled LWIR imaging market is divided into two areas. One is a high-end market where uncooled LWIR imaging sensor with sensitivity as close to that of cooled one as possible is required, while the other is a low-end market which is promoted by miniaturization and reduction in price. Especially, in the latter case, approaches towards consumer market have recently appeared, such as applications of uncooled LWIR imaging sensors to night visions for automobiles and smart phones. The appearance of such a kind of commodity surely changes existing business models. Further technological innovation is necessary for creating consumer market, and there will be a room for other companies treating components and materials such as lens materials and getter materials and so on to enter into the consumer market.

  16. Biomass compositional analysis for energy applications.

    PubMed

    Hames, Bonnie R

    2009-01-01

    In its broadest definition, biomass can be described as all material that was or is a part of a living organism. For renewable energy applications, however, the definition of biomass is usually limited to include only materials that are plant-derived such as agricultural residues (e.g., wheat straw, corn stover) by-products of industrial processes (e.g., sawdust, sugar cane bagasse, pulp residues, distillers grains), or dedicated energy crops (e.g., switchgrass, sorghum, Miscanthus, short-rotation woody crops). This chapter describes analytical methods developed to measure plant components with an emphasis on the measurement of components that are important for biomass conversion. The methods described here can be viewed as a portfolio of analytical methods, with consistent assumptions and compatible sample preparation steps, selected for simplicity, robust application, and the ability to obtain a summative mass closure on most samples that accurately identifies greater than 95% of the mass of a plant biomass sample. The portfolio of methods has been successfully applied to a wide variety of biomass feedstock as well as liquid and solid fractions of both thermochemical pretreatment and enzymatic saccharification (1).

  17. Nonlinear Principal Components Analysis: Introduction and Application

    ERIC Educational Resources Information Center

    Linting, Marielle; Meulman, Jacqueline J.; Groenen, Patrick J. F.; van der Koojj, Anita J.

    2007-01-01

    The authors provide a didactic treatment of nonlinear (categorical) principal components analysis (PCA). This method is the nonlinear equivalent of standard PCA and reduces the observed variables to a number of uncorrelated principal components. The most important advantages of nonlinear over linear PCA are that it incorporates nominal and ordinal…

  18. Systems Analysis Applications in Educational Research.

    ERIC Educational Resources Information Center

    Alkin, Marvin C.; Skager, Rodney W.

    There are basically four dimensions to a systems analysis that we find in current educational research: (1) Collecting information, (2) analyzing input-output relationships, (3) deriving models built upon these relationships to evaluate alternatives and to derive feasible solutions, and (4) attempting to derive the best solution consistent with…

  19. Electron Spectroscopy: Applications for Chemical Analysis

    ERIC Educational Resources Information Center

    Heercules, David M.

    2004-01-01

    The development of XPS as an effective method for surface analysis during the period 1964-1977 is presented. The study shows that unlike other surface methods, XPS data can be obtained for both conductors and insulators and a variety of samples can be handled effectively, which is one of the major reasons for the popularity of the technique.

  20. Introduction to Latent Class Analysis with Applications

    ERIC Educational Resources Information Center

    Porcu, Mariano; Giambona, Francesca

    2017-01-01

    Latent class analysis (LCA) is a statistical method used to group individuals (cases, units) into classes (categories) of an unobserved (latent) variable on the basis of the responses made on a set of nominal, ordinal, or continuous observed variables. In this article, we introduce LCA in order to demonstrate its usefulness to early adolescence…

  1. Introduction to Latent Class Analysis with Applications

    ERIC Educational Resources Information Center

    Porcu, Mariano; Giambona, Francesca

    2017-01-01

    Latent class analysis (LCA) is a statistical method used to group individuals (cases, units) into classes (categories) of an unobserved (latent) variable on the basis of the responses made on a set of nominal, ordinal, or continuous observed variables. In this article, we introduce LCA in order to demonstrate its usefulness to early adolescence…

  2. Nonlinear Principal Components Analysis: Introduction and Application

    ERIC Educational Resources Information Center

    Linting, Marielle; Meulman, Jacqueline J.; Groenen, Patrick J. F.; van der Koojj, Anita J.

    2007-01-01

    The authors provide a didactic treatment of nonlinear (categorical) principal components analysis (PCA). This method is the nonlinear equivalent of standard PCA and reduces the observed variables to a number of uncorrelated principal components. The most important advantages of nonlinear over linear PCA are that it incorporates nominal and ordinal…

  3. Theory and Application of DNA Histogram Analysis.

    ERIC Educational Resources Information Center

    Bagwell, Charles Bruce

    The underlying principles and assumptions associated with DNA histograms are discussed along with the characteristics of fluorescent probes. Information theory was described and used to calculate the information content of a DNA histogram. Two major types of DNA histogram analyses are proposed: parametric and nonparametric analysis. Three levels…

  4. Ordinal symbolic analysis and its application to biomedical recordings

    PubMed Central

    Amigó, José M.; Keller, Karsten; Unakafova, Valentina A.

    2015-01-01

    Ordinal symbolic analysis opens an interesting and powerful perspective on time-series analysis. Here, we review this relatively new approach and highlight its relation to symbolic dynamics and representations. Our exposition reaches from the general ideas up to recent developments, with special emphasis on its applications to biomedical recordings. The latter will be illustrated with epilepsy data. PMID:25548264

  5. Application of automatic image analysis in wood science

    Treesearch

    Charles W. McMillin

    1982-01-01

    In this paper I describe an image analysis system and illustrate with examples the application of automatic quantitative measurement to wood science. Automatic image analysis, a powerful and relatively new technology, uses optical, video, electronic, and computer components to rapidly derive information from images with minimal operator interaction. Such instruments...

  6. Fabrication, structural characterization, and applications of langmuir and langmuir-blodgett films of a poly(azo)urethane.

    PubMed

    Alessio, Priscila; Ferreira, Daniele M; Job, Aldo E; Aroca, Ricardo F; Riul, Antonio; Constantino, Carlos J L; Gonzalez, Eduardo R Pérez

    2008-05-06

    The synthesis of a poly(azo)urethane by fixing CO(2) in bis-epoxide followed by a polymerization reaction with an azodiamine is presented. Since isocyanate is not used in the process, it is termed "clean method" and the polymers obtained are named "NIPUs" (non-isocyanate polyurethanes). Langmuir films were formed at the air-water interface and were characterized by surface pressure vs mean molecular area per mer unit (Pi-A) isotherms. The Langmuir monolayers were further studied by running stability tests and cycles of compression/expansion (possible hysteresis) and by varying the compression speed of the monolayer formation, the subphase temperature, and the solvents used to prepare the spreading polymer solutions. The Langmuir-Blodgett (LB) technique was used to fabricate ultrathin films of a particular polymer (PAzoU). It is possible to grow homogeneous LB films of up to 15 layers as monitored using UV-vis absorption spectroscopy. Higher number of layers can be deposited when PAzoU is mixed with stearic acid, producing mixed LB films. Fourier transform infrared (FTIR) absorption spectroscopy and Raman scattering showed that the materials do not interact chemically in the mixed LB films. The atomic force microscopy (AFM) and micro-Raman technique (optical microscopy coupled to Raman spectrograph) revealed that mixed LB films present a phase separation distinguishable at micrometer or nanometer scale. Finally, mixed and neat LB films were successfully characterized using impedance spectroscopy at different temperatures, a property that may lead to future application as temperature sensors. Principal component analysis (PCA) was used to correlate the data.

  7. Applications of cluster analysis to satellite soundings

    NASA Technical Reports Server (NTRS)

    Munteanu, M. J.; Jakubowicz, O.; Kalnay, E.; Piraino, P.

    1984-01-01

    The advantages of the use of cluster analysis in the improvement of satellite temperature retrievals were evaluated since the use of natural clusters, which are associated with atmospheric temperature soundings characteristic of different types of air masses, has the potential for improving stratified regression schemes in comparison with currently used methods which stratify soundings based on latitude, season, and land/ocean. The method of discriminatory analysis was used. The correct cluster of temperature profiles from satellite measurements was located in 85% of the cases. Considerable improvement was observed at all mandatory levels using regression retrievals derived in the clusters of temperature (weighted and nonweighted) in comparison with the control experiment and with the regression retrievals derived in the clusters of brightness temperatures of 3 MSU and 5 IR channels.

  8. Application and Development of Wavelet Analysis

    DTIC Science & Technology

    1992-08-15

    found that optics is quite suitable to generate and display both the direct and the inverse wavelet transforms in parallel. Unlike the digital...toward identifying the suitability of using optics for the multichannel signal analysis. Both the Gabor and the wavelet transforms were studied in terms...inverse wavelet transforms . This is the case for processing both the one and two dimensional signals. A detail comparison of the space-bandwidth

  9. Towards sentiment analysis application in housing projects

    NASA Astrophysics Data System (ADS)

    Mahadzir, Nurul Husna; Omar, Mohd Faizal; Nawi, Mohd Nasrun Mohd

    2016-08-01

    In becoming a develop nation by 2020, Malaysia Government realized the need in providing affordable house to the public. Since Second Malaysia Plan, government has implemented various affordable housing projects and it continues until recent Malaysia Plan. To measure the effectiveness of the initiatives taken, public opinion is necessary. A social media platform has been seen as the most effective mechanism to get information on people's thought and feeling towards certain issues. One of the best ways to extract emotions and thoughts from what people post in social media is through Sentiment Analysis (SA). There are three different levels of analysis: document level, sentence level and feature level. Most of previous research focused on the classification of sentiment at document or sentence level. Unfortunately, both document and sentence level does not discover what exactly people like or not. While the analysis based on feature, there exist accuracy problem when classifying the sentiment scores. This paper will propose a new framework that focuses on sentiment classification scores at feature level to overcome the uncertainty and accuracy issues on the result.

  10. Integrated fire analysis: Application to offshore cases

    SciTech Connect

    Saubestre, V.; Khalfi, J.P.; Paygnard, J.C.

    1995-12-31

    Evaluating thermal loads from different fire scenarios and then response of the structure to these loads covers several fields. It is also difficult and time consuming to implement. Interfaces are necessary between the heat calculation, transient propagation and structural analysis software packages. Nevertheless, it is necessary to design structures to accommodate heat loads in order to meet safety requirements or functional specification. Elf, along with several operators and organizations, have sponsored a research project on this topic. The project, managed by SINTEF NBL (Norwegian Fire Research Laboratory), has delivered an integrated fire analysis software package which can be used to address design-to-fire-related issues in various contexts. The core modules of the integrated package are robust, well validated analysis tools. This paper describes some benefits (technical or cost related) of using an integrated approach to assess the response of a structure to thermal loads. Three examples are described: consequence of an accidental scenario on the living quarters in an offshore complex, necessity for the reinforcement of a flareboom following a change in process, evaluation of the amount of insulation needed for a topside process primary structure. The paper focuses on the importance for the operator to have a practical tool which can lead to substantial cost saving while reducing the uncertainty linked to safety issues.

  11. Strategic marketing applications of conjoint analysis: an HMO perspective.

    PubMed

    Rosko, M D; DeVita, M; McKenna, W F; Walker, L R

    1985-01-01

    The purpose of this article is to demonstrate how data from a conjoint analysis study can be used to help determine the most appropriate marketing mix for an operational HMO which is entering a new market--the geriatric population. Included are two features which are absent in previous articles on health care applications of conjoint analysis: external validation of results, and a demonstration of how conjoint analysis can be used to simulate market responses to changes in the provider's marketing mix.

  12. Applications of stable isotope analysis in mammalian ecology.

    PubMed

    Walter, W David; Kurle, Carolyn M; Hopkins, John B

    2014-01-01

    In this editorial, we provide a brief introduction and summarize the 10 research articles included in this Special Issue on Applications of stable isotope analysis in mammalian ecology. The first three articles report correction and discrimination factors that can be used to more accurately estimate the diets of extinct and extant mammals using stable isotope analysis. The remaining seven applied research articles use stable isotope analysis to address a variety of wildlife conservation and management questions from the oceans to the mountains.

  13. Application Of Moire Analysis Of Strain Using Fourier Transform

    NASA Astrophysics Data System (ADS)

    Morimoto, Yoshiharu; Seguchi, Yasuyuki; Higashi, Toshihiko

    1988-08-01

    By shifting the discrete Fourier spectrum of the image of a deformed grating, we obtain the "complex moire pattern," from which strain distribution is given as the derivatives of the phases of the complex moire fringes. The analysis is completely automated by digital image processing. All of the laborious and subjective procedures required in the conventional analysis such as fringe sign determination, fringe ordering, and fringe interpolation are thus eliminated, permitting objective, fast, and accurate analysis. Some applications for rubber plates are shown.

  14. Applications of ripple analysis in hydro-acoustics

    NASA Astrophysics Data System (ADS)

    Leducq, D.; Schlegel, R.

    Software developed for ripple analysis in hydro-acoustic applications is described. Noise and vibration analysis using this software is shown to be particularly effective. The importance of post treatment of the data in order to obtain dependable results is stressed. Examples are presented of the use of the ripple analysis software in measuring the noise and vibration produced by a pump. The software is used in the analysis of cavitation noise. Cavitation noise frequency graphs are presented to illustrate the experimented results. The advantages of the ripple analysis techniques in obtaining a better understanding of the underlying physics of the processes studied are stressed.

  15. Application of multidisciplinary analysis to gene expression.

    SciTech Connect

    Wang, Xuefel; Kang, Huining; Fields, Chris; Cowie, Jim R.; Davidson, George S.; Haaland, David Michael; Sibirtsev, Valeriy; Mosquera-Caro, Monica P.; Xu, Yuexian; Martin, Shawn Bryan; Helman, Paul; Andries, Erik; Ar, Kerem; Potter, Jeffrey; Willman, Cheryl L.; Murphy, Maurice H.

    2004-01-01

    Molecular analysis of cancer, at the genomic level, could lead to individualized patient diagnostics and treatments. The developments to follow will signal a significant paradigm shift in the clinical management of human cancer. Despite our initial hopes, however, it seems that simple analysis of microarray data cannot elucidate clinically significant gene functions and mechanisms. Extracting biological information from microarray data requires a complicated path involving multidisciplinary teams of biomedical researchers, computer scientists, mathematicians, statisticians, and computational linguists. The integration of the diverse outputs of each team is the limiting factor in the progress to discover candidate genes and pathways associated with the molecular biology of cancer. Specifically, one must deal with sets of significant genes identified by each method and extract whatever useful information may be found by comparing these different gene lists. Here we present our experience with such comparisons, and share methods developed in the analysis of an infant leukemia cohort studied on Affymetrix HG-U95A arrays. In particular, spatial gene clustering, hyper-dimensional projections, and computational linguistics were used to compare different gene lists. In spatial gene clustering, different gene lists are grouped together and visualized on a three-dimensional expression map, where genes with similar expressions are co-located. In another approach, projections from gene expression space onto a sphere clarify how groups of genes can jointly have more predictive power than groups of individually selected genes. Finally, online literature is automatically rearranged to present information about genes common to multiple groups, or to contrast the differences between the lists. The combination of these methods has improved our understanding of infant leukemia. While the complicated reality of the biology dashed our initial, optimistic hopes for simple answers from

  16. Analysis of wavelet technology for NASA applications

    NASA Technical Reports Server (NTRS)

    Wells, R. O., Jr.

    1994-01-01

    The purpose of this grant was to introduce a broad group of NASA researchers and administrators to wavelet technology and to determine its future role in research and development at NASA JSC. The activities of several briefings held between NASA JSC scientists and Rice University researchers are discussed. An attached paper, 'Recent Advances in Wavelet Technology', summarizes some aspects of these briefings. Two proposals submitted to NASA reflect the primary areas of common interest. They are image analysis and numerical solutions of partial differential equations arising in computational fluid dynamics and structural mechanics.

  17. Application of Enzymes in Food Analysis

    NASA Astrophysics Data System (ADS)

    Powers, Joseph R.

    Enzymes are protein catalysts that are capable of very great specificity and reactivity under physiological conditions. Enzymatic analysis is the measurement of compoundswith the aid of added enzymes or themeasurement of endogenous enzyme activity to give an indication of the state of a biological system including foods. The fact that enzyme catalysis can take place under relatively mild conditions allows for measurement of relatively unstable compounds not amenable to some other techniques. In addition, the specificity of enzyme reactions can allow for measurement of components of complex mixtures without the time and expense of complicated chromatographic separation techniques.

  18. Application of TIMS data in stratigraphic analysis

    NASA Technical Reports Server (NTRS)

    Lang, H. R.

    1986-01-01

    An in-progress study demonstrates the utility of Thermal Infrared Multispectral Scanner (TIMS) data for unraveling the stratigraphic sequence of a western interior, North American foreland basin. The TIMS data can be used to determine the stratigraphic distribution of minerals that are diagnostic of specific depositional distribution. The thematic mapper (TM) and TIMS data were acquired in the Wind River/Bighorn area of central Wyoming in November 1982, and July 1983, respectively. Combined image processing, photogeologic, and spectral analysis methods were used to: map strata; construct stratigraphic columns; correlate data; and identify mineralogical facies.

  19. Hand geometry field application data analysis

    SciTech Connect

    Ruehle, M.; Ahrens, J.

    1997-03-01

    Over the last fifteen years, Sandia National Laboratories Security Systems and Technology Center, Department 5800, has been involved in several laboratory tests of various biometric identification devices. These laboratory tests were conducted to verify the manufacturer`s performance claims, to determine strengths and weaknesses of particular devices, and to evaluate which devices meet the US Department of Energy`s unique needs for high-security devices. However, during a recent field installation of one of these devices, significantly different performance was observed than had been predicted by these laboratory tests. This report documents the data analysis performed in the search for an explanation of these differences.

  20. Applications of chemiluminescence to bacterial analysis

    NASA Technical Reports Server (NTRS)

    Searle, N. D.

    1975-01-01

    Luminol chemiluminescence method for detecting bacteria was based on microbial activation of the oxidation of the luminol monoanion by hydrogen peroxide. Elimination of the prior lysing step, previously used in the chemiluminescence technique, was shown to improve considerably the reproducibility and accuracy of the method in addition to simplifying it. An inexpensive, portable photomultiplier detector was used to measure the maximum light intensity produced when the sample is added to the reagent. Studies of cooling tower water show that the luminol chemiluminescence technique can be used to monitor changes in viable cell population both under normal conditions and during chlorine treatment. Good correlation between chemiluminescence and plate counts was also obtained in the analysis of process water used in paper mills. This method showed good potential for monitoring the viable bacteria populations in activated sludge used in waste treatment plants to digest organic matter.

  1. Flammability Configuration Analysis for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Pedley, Michael D.

    2014-01-01

    Fire is one of the many potentially catastrophic hazards associated with the operation of crewed spacecraft. A major lesson learned by NASA from the Apollo 204 fire in 1966 was that ignition sources in an electrically powered vehicle should and can be minimized, but can never be eliminated completely. For this reason, spacecraft fire control is based on minimizing potential ignition sources and eliminating materials that can propagate fire. Fire extinguishers are always provided on crewed spacecraft, but are not considered as part of the fire control process. "Eliminating materials that can propagate fire" does not mean eliminating all flammable materials - the cost of designing and building spacecraft using only nonflammable materials is extraordinary and unnecessary. It means controlling the quantity and configuration of such materials to eliminate potential fire propagation paths and thus ensure that any fire would be small, localized, and isolated, and would self-extinguish without harm to the crew. Over the years, NASA has developed many solutions for controlling the configuration of flammable materials (and potentially flammable materials in commercial "off-the-shelf" hardware) so that they can be used safely in air and oxygen-enriched environments in crewed spacecraft. This document describes and explains these design solutions so payload customers and other organizations can use them in designing safe and cost-effective flight hardware. Proper application of these guidelines will produce acceptable flammability configurations for hardware located in any compartment of the International Space Station or other program crewed vehicles and habitats. However, use of these guidelines does not exempt hardware organizations of the responsibility for safety of the hardware under their control.

  2. Camera systems in human motion analysis for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chin, Lim Chee; Basah, Shafriza Nisha; Yaacob, Sazali; Juan, Yeap Ewe; Kadir, Aida Khairunnisaa Ab.

    2015-05-01

    Human Motion Analysis (HMA) system has been one of the major interests among researchers in the field of computer vision, artificial intelligence and biomedical engineering and sciences. This is due to its wide and promising biomedical applications, namely, bio-instrumentation for human computer interfacing and surveillance system for monitoring human behaviour as well as analysis of biomedical signal and image processing for diagnosis and rehabilitation applications. This paper provides an extensive review of the camera system of HMA, its taxonomy, including camera types, camera calibration and camera configuration. The review focused on evaluating the camera system consideration of the HMA system specifically for biomedical applications. This review is important as it provides guidelines and recommendation for researchers and practitioners in selecting a camera system of the HMA system for biomedical applications.

  3. Application of flow analysis in determination of selected radionuclides.

    PubMed

    Kołacińska, Kamila; Trojanowicz, Marek

    2014-07-01

    The subject of this article is the review of developed applications of flow analysis methods for determination of radionuclides hard-to-detect in reactor cooling waters ((90)Sr, (239,240)Pu, and (241)Am), and also (99)Tc, which are released to the environment primarily through nuclear fuel processing. Flow analysis, which developed for decades parallel to flow methods of chemical synthesis, is widely employed in modern chemical analysis, mainly for environmental, food analysis and pharmaceutical applications. It allows the simplification of design of analytical instruments and procedures, the shortening of analysis time, improvement of precision, and often the automation of whole analytical procedure. All those factors can be also advantageous for determination of critical radionuclides for process needs and protection of environment. The review is based on 84 references, published mainly in leading analytical journals. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. [Infrared absorption spectrum analysis and its application to blood].

    PubMed

    Wang, Le-xin; Zhao, Zhi-min; Yao, Hong-bing; Chen, Yu-ming; Shi, Lei; Gao, Yong

    2002-12-01

    The technology of infrared absorption spectrum is a branch of optical ment measurement technology, and the research on the application of infrared spectrum plays an important role in the development of technology of optical measurement. In this paper, the analysis technology of blood infrared absorption spectrum is presented. By comparison, the difference of the spectra between normal and abnormal blood samples was obtained. The infrared absorption spectra of normal blood sample and abnormal blood sample were detected, and the differences between the spectra are presented. And the analysis results of the infrared absorption spectra of normal whole blood, serum and hyperglycemia are presented also. All of these provide an experimental basis for the diagnosis of diseases, which is valuable for application. This technology features easy operation, convenient analysis and suitability for advanced experiment. The work offers a new way in the research on the application of infrared absorption spectrum.

  5. Techniques of EMG signal analysis: detection, processing, classification and applications

    PubMed Central

    Hussain, M.S.; Mohd-Yasin, F.

    2006-01-01

    Electromyography (EMG) signals can be used for clinical/biomedical applications, Evolvable Hardware Chip (EHW) development, and modern human computer interaction. EMG signals acquired from muscles require advanced methods for detection, decomposition, processing, and classification. The purpose of this paper is to illustrate the various methodologies and algorithms for EMG signal analysis to provide efficient and effective ways of understanding the signal and its nature. We further point up some of the hardware implementations using EMG focusing on applications related to prosthetic hand control, grasp recognition, and human computer interaction. A comparison study is also given to show performance of various EMG signal analysis methods. This paper provides researchers a good understanding of EMG signal and its analysis procedures. This knowledge will help them develop more powerful, flexible, and efficient applications. PMID:16799694

  6. Fabrication of monolithic diamond probes for scanning probe microscopy applications

    NASA Astrophysics Data System (ADS)

    Scholz, Wenzel; Albert, D.; Malave, A.; Werner, Stephfan; Mihalcea, Christopher; Kulisch, Wilhelm; Oesterschulze, Egbert

    1997-04-01

    A process relying on the molding technique for the fabrication of diamond cantilevers with diamond tips integrated on silicon wafers for scanning probe microscopy applications is described. Either hot filament or microwave CVD diamond deposition and standard techniques of silicon micro-machining are employed. The deposition of well- developed tips depends critically on the pretreatment applied to enhance nucleation density; abrasive treatment with diamond powder as well as the bias-enhanced nucleation turned out to be successful. With optimized processes, well- shaped tips with a radius of curvature in the order of 30 nm can be obtained. They consist of high quality diamond according to micro-Raman spectroscopy. The definition of the cantilever area is another critical step which can be solved by proper process design. The fabrication of conductive tips/cantilevers is possible by boron doping. Finally, first performance tests of the diamond tips and cantilevers are presented.

  7. EO-1 analysis applicable to coastal characterization

    NASA Astrophysics Data System (ADS)

    Burke, Hsiao-hua K.; Misra, Bijoy; Hsu, Su May; Griffin, Michael K.; Upham, Carolyn; Farrar, Kris

    2003-09-01

    The EO-1 satellite is part of NASA's New Millennium Program (NMP). It consists of three imaging sensors: the multi-spectral Advanced Land Imager (ALI), Hyperion and Atmospheric Corrector. Hyperion provides a high-resolution hyperspectral imager capable of resolving 220 spectral bands (from 0.4 to 2.5 micron) with a 30 m resolution. The instrument images a 7.5 km by 100 km land area per image. Hyperion is currently the only space-borne HSI data source since the launch of EO-1 in late 2000. The discussion begins with the unique capability of hyperspectral sensing to coastal characterization: (1) most ocean feature algorithms are semi-empirical retrievals and HSI has all spectral bands to provide legacy with previous sensors and to explore new information, (2) coastal features are more complex than those of deep ocean that coupled effects are best resolved with HSI, and (3) with contiguous spectral coverage, atmospheric compensation can be done with more accuracy and confidence, especially since atmospheric aerosol effects are the most pronounced in the visible region where coastal feature lie. EO-1 data from Chesapeake Bay from 19 February 2002 are analyzed. In this presentation, it is first illustrated that hyperspectral data inherently provide more information for feature extraction than multispectral data despite Hyperion has lower SNR than ALI. Chlorophyll retrievals are also shown. The results compare favorably with data from other sources. The analysis illustrates the potential value of Hyperion (and HSI in general) data to coastal characterization. Future measurement requirements (air borne and space borne) are also discussed.

  8. An Expert Image Analysis System For Chromosome Analysis Application

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Suetens, P.; Oosterlinck, A.; Van den Berghe, H.

    1987-01-01

    This paper reports a recent study on applying a knowledge-based system approach as a new attempt to solve the problem of chromosome classification. A theoretical framework of an expert image analysis system is proposed, based on such a study. In this scheme, chromosome classification can be carried out under a hypothesize-and-verify paradigm, by integrating a rule-based component, in which the expertise of chromosome karyotyping is formulated with an existing image analysis system which uses conventional pattern recognition techniques. Results from the existing system can be used to bring in hypotheses, and with the rule-based verification and modification procedures, improvement of the classification performance can be excepted.

  9. Performance Analysis of Multilevel Parallel Applications on Shared Memory Architectures

    NASA Technical Reports Server (NTRS)

    Jost, Gabriele; Jin, Haoqiang; Labarta, Jesus; Gimenez, Judit; Caubet, Jordi; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    In this paper we describe how to apply powerful performance analysis techniques to understand the behavior of multilevel parallel applications. We use the Paraver/OMPItrace performance analysis system for our study. This system consists of two major components: The OMPItrace dynamic instrumentation mechanism, which allows the tracing of processes and threads and the Paraver graphical user interface for inspection and analyses of the generated traces. We describe how to use the system to conduct a detailed comparative study of a benchmark code implemented in five different programming paradigms applicable for shared memory

  10. Time domain finite element analysis of multimode microwave applicators

    SciTech Connect

    Dibben, D.C.; Metaxas, R.

    1996-05-01

    Analysis of multimode applicators in the frequency domain via the finite element technique produces a set of very ill-conditioned equations. This paper outlines a time domain finite element method (TDFE) for analyzing three dimensional microwave applicators where this ill-conditioning is avoided. Edge elements are used in order to handle sharp metal edges and to avoid spurious solutions. Analysis in the time domain allows field distributions at a range of different frequencies to be obtained with a single calculation. Lumping is investigated as a means of reducing the time taken for the calculation. The reflection coefficient is also obtained.

  11. Dynamic mechanical analysis: A practical introduction to techniques and applications

    SciTech Connect

    Menard, K.

    1999-03-01

    This introduction provides the chemist, chemical engineer, or materials scientists with a starting point to understand the applications of dynamic mechanical analysis, its workings, and its advantages and limitations. This book serves as a systematic study of manufacturing polymeric materials and components as well as for developing new materials. Contents include: introduction to dynamic mechanical analysis; basic rheological concepts: stress, strain, and flow; rheology basic: creep-recovery and stress relaxation; dynamic testing; time-temperature scans part 1: transitions in polymers; time and temperature studies part 2: thermosets; frequency scans; DMA applications to real problems: guidelines; and appendix: sample experiments for the DMA.

  12. Multispectroscopic and Isotopic Ratio Analysis To Characterize the Inorganic Binder Used on Pompeian Pink and Purple Lake Pigments.

    PubMed

    Marcaida, Iker; Maguregui, Maite; Morillas, Héctor; García-Florentino, Cristina; Knuutinen, Ulla; Carrero, Jose Antonio; Fdez-Ortiz de Vallejuelo, Silvia; Pitarch Martı́, Africa; Castro, Kepa; Madariaga, Juan Manuel

    2016-06-21

    Because of the fact that pigments are not ubiquitous in the archeological record, the application of noninvasive analytical methods is a necessity. In this work, pink and purple lake pigments recovered from the excavations of the ancient city of Pompeii (Campania, Italy) and preserved in their original bowls at the Naples National Archaeological Museum (Italy) were analyzed to characterize the composition of their inorganic binders (mordants). In situ preliminary analyses using a hand-held energy dispersive X-ray fluorescence spectrometer (HH-ED-XRF) allowed us to determine the use of an aluminosilicate enriched in Cu and Pb. Scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM-EDS) and benchtop ED-XRF analyses confirmed these results, while inductively coupled plasma mass spectrometry (ICPMS) allowed one to determine the concentration of major, minor, and trace elements. The use of other techniques such as X-ray diffraction (XRD), and micro-Raman and infrared spectroscopies allowed one to characterize the pigments at the molecular level. The high concentration of Cu detected in the pigments (1228-12937 μg g(-1)) could be related to the addition of Cu salts to obtain the desired final hue. The concentrations of Pb (987-2083 μg g(-1)) was also remarkable. Lead isotopic ratio analysis ((206)Pb/(207)Pb) suggested a possible origin related to the leaching of the ancient lead pipes from Pompeii and the subsequent transfer to the buried pigments or to the inorganic binder. Molecular analysis also showed that the binder is composed of an allophane-like clay. Moreover, it was possible to determine that to obtain the final purple hue of a specific pigment, Pompeian blue pigment was also mixed into the dyed clay.

  13. Surface chemical-bonds analysis of silicon particles from diamond-wire cutting of crystalline silicon

    NASA Astrophysics Data System (ADS)

    Benayad, Anass; Hajjaji, Hamza; Coustier, Fabrice; Benmansour, Malek; Chabli, Amal

    2016-12-01

    The recycling of the Si powder resulting from the kerf loss during silicon ingot cutting into wafers for photovoltaic application shows both significant and achievable economic and environmental benefits. A combined x-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR)-Fourier transform infrared (FTIR) and micro-Raman spectral analyses were applied to kerf-loss Si powders reclaimed from the diamond wire cutting using different cutting fluids. These spectroscopies performed in suitable configurations for the analysis of particles, yield detailed insights on the surface chemical properties of the powders demonstrating the key role of the cutting fluid nature. A combined XPS core peak, plasmon loss, and valence band study allow assessing a qualitative and quantitative chemical, structural change of the kerf-loss Si powders. The relative contribution of the LO and TO stretching modes to the Si-O-Si absorption band in the ATR-FTIR spectra provide a consistent estimation of the effective oxidation level of the Si powders. The change in the cutting media from deionized water to city water, induces a different silicon oxide layer thickness at the surface of the final kerf-loss Si, depending on the powder reactivity to the media. The surfactant addition induces an enhanced carbon contamination in the form of grafted carbonated species on the surface of the particles. The thickness of the modified surface, depending on the cutting media, was estimated based on a simple model derived from the combined XPS core level and plasmon peak intensities. The effective nature of these carbonated species, sensitive to the water quality, was evidenced based on coupled XPS core peak and valence band study. The present work paves the way to a controlled process to reclaim the kerf-loss Si powder without heavy chemical etching steps.

  14. High-resolution particle analysis--its application to platelet counting and suggestions for further application in blood cell analysis.

    PubMed

    Haynes, J L

    1980-01-01

    The characteristics of an instrument for high-resolution particle analysis in flow are discussed. It employs a combination of hydrodynamic focusing, fluid resistors, and electronic techniques to achieve precision and ease of use heretofore unobtainable in a moderate-cost clinical instrument. Its application to whole blood platelet counting is discussed, and suggestions are made for its possible application to a wide variety of blood cell measurements.

  15. Applications of Mass Spectrometry to Structural Analysis of Marine Oligosaccharides

    PubMed Central

    Lang, Yinzhi; Zhao, Xia; Liu, Lili; Yu, Guangli

    2014-01-01

    Marine oligosaccharides have attracted increasing attention recently in developing potential drugs and biomaterials for their particular physical and chemical properties. However, the composition and sequence analysis of marine oligosaccharides are very challenging for their structural complexity and heterogeneity. Mass spectrometry (MS) has become an important technique for carbohydrate analysis by providing more detailed structural information, including molecular mass, sugar constituent, sequence, inter-residue linkage position and substitution pattern. This paper provides an overview of the structural analysis based on MS approaches in marine oligosaccharides, which are derived from some biologically important marine polysaccharides, including agaran, carrageenan, alginate, sulfated fucan, chitosan, glycosaminoglycan (GAG) and GAG-like polysaccharides. Applications of electrospray ionization mass spectrometry (ESI-MS) are mainly presented and the general applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) are also outlined. Some technical challenges in the structural analysis of marine oligosaccharides by MS have also been pointed out. PMID:24983643

  16. Applications of mass spectrometry to structural analysis of marine oligosaccharides.

    PubMed

    Lang, Yinzhi; Zhao, Xia; Liu, Lili; Yu, Guangli

    2014-06-30

    Marine oligosaccharides have attracted increasing attention recently in developing potential drugs and biomaterials for their particular physical and chemical properties. However, the composition and sequence analysis of marine oligosaccharides are very challenging for their structural complexity and heterogeneity. Mass spectrometry (MS) has become an important technique for carbohydrate analysis by providing more detailed structural information, including molecular mass, sugar constituent, sequence, inter-residue linkage position and substitution pattern. This paper provides an overview of the structural analysis based on MS approaches in marine oligosaccharides, which are derived from some biologically important marine polysaccharides, including agaran, carrageenan, alginate, sulfated fucan, chitosan, glycosaminoglycan (GAG) and GAG-like polysaccharides. Applications of electrospray ionization mass spectrometry (ESI-MS) are mainly presented and the general applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) are also outlined. Some technical challenges in the structural analysis of marine oligosaccharides by MS have also been pointed out.

  17. Universal calibration of Raman spectroscopy for the analysis of volatiles in glasses of variable composition

    NASA Astrophysics Data System (ADS)

    Schiavi, Federica; Bolfan-Casanova, Nathalie

    2017-04-01

    The amount and distribution of volatiles (water, carbon dioxide …) in magmas represent key parameters for the understanding of magma processes and dynamics within volcanic plumbing systems. Micro-Raman spectroscopy is an excellent technique for accurate determination of volatile contents in magmas, as it combines several advantages. The technique is non-destructive and requires minimal sample preparation before the analysis. Its high lateral and in-depth spatial resolution is crucial for the study of small objects and samples that are chemically and texturally heterogeneous at the small scale (microns). Moreover, the high confocality allows analysis of sample regions not exposed to the surface and 3D mapping. We present a universal calibration of Raman spectroscopy for quantification of volatiles in silicate glasses. The proposed method is based on internal calibration, i.e., on the correlation between the glass water content and the ratio between the areas of the water and silicate Raman bands. Synthetic glasses with variable major element compositions (basaltic, andesitic, rhyolitic, dacitic ..) bearing different H2O (up to 7 wt%) and CO2 contents are used as standard glasses. Natural silicate glasses, mainly in the form of melt inclusions, are used to test the goodness of the proposed method. In addition to quantification of volatiles in glass, in bubble-bearing melt inclusions we perform micro-Raman spectroscopy investigation of gas-bearing bubbles for accurate determination of total volatile contents in melt inclusions.

  18. Applications of Mass Spectrometry for Cellular Lipid Analysis

    PubMed Central

    Wang, Chunyan; Wang, Miao; Han, Xianlin

    2015-01-01

    Mass spectrometric analysis of cellular lipids is an enabling technology for lipidomics, which is a rapidly-developing research field. In this review, we briefly discuss the principles, advantages, and possible limitations of electrospray ionization (ESI) and matrix assisted laser desorption/ionization (MALDI) mass spectrometry-based methodologies for the analysis of lipid species. The applications of these methodologies to lipidomic research are also summarized. PMID:25598407

  19. Application of carbohydrate analysis to verify honey authenticity.

    PubMed

    Cotte, J F; Casabianca, H; Chardon, S; Lheritier, J; Grenier-Loustalot, M F

    2003-12-22

    Gas chromatography and liquid chromatography have been used simultaneously to analyze sugars in honey. After statistical processing by principal components analysis, additions of exogenous sugars could be detected by the appropriate fingerprints of adulteration. Application to acacia, chestnut and lavender honeys enabled the detection of fraud resulting from 5 to 10% addition of sugar syrups. This method may be considered as a replacement of isotopic analysis, that has some limitations.

  20. Practical Application of Finite Element Analysis to Aircraft Structural Design

    DTIC Science & Technology

    1986-08-01

    t] Cook, Robert D., "Concepts and Applications of Finite element Analysis," John Wiley & Sons, Inc., New York, 1981. [5] Rao, S. S., "The Finite...generation large-scale computer programs is discussed. V.P. Analysis of aircraft structure using applied fracture mechanics (AA) WILHEM , D. P. Northrop...Analytical, finite element for surface flaws, holes (AA) WILHEM , D. P. Northrop Corp., Hawthorne, Calif. (N5631231) Aircraft Group. In AGARD Fracture

  1. Advanced stress analysis methods applicable to turbine engine structures

    NASA Technical Reports Server (NTRS)

    Pian, T. H. H.

    1985-01-01

    Advanced stress analysis methods applicable to turbine engine structures are investigated. Constructions of special elements which containing traction-free circular boundaries are investigated. New versions of mixed variational principle and version of hybrid stress elements are formulated. A method is established for suppression of kinematic deformation modes. semiLoof plate and shell elements are constructed by assumed stress hybrid method. An elastic-plastic analysis is conducted by viscoplasticity theory using the mechanical subelement model.

  2. Elementary Applications of a Rotorcraft Dynamic Stability Analysis

    NASA Technical Reports Server (NTRS)

    Johnson, W.

    1976-01-01

    A number of applications of a rotorcraft aeroelastic analysis are presented to verify that the analysis encompasses the classical solutions of rotor dynamics, and to examine the influence of certain features of the model. Results are given for the following topics: flapping frequency response to pitch control; forward flight flapping stability; pitch/flap flutter and divergence; ground resonance instability; and the flight dynamics of several representative helicopters.

  3. Ordinal symbolic analysis and its application to biomedical recordings.

    PubMed

    Amigó, José M; Keller, Karsten; Unakafova, Valentina A

    2015-02-13

    Ordinal symbolic analysis opens an interesting and powerful perspective on time-series analysis. Here, we review this relatively new approach and highlight its relation to symbolic dynamics and representations. Our exposition reaches from the general ideas up to recent developments, with special emphasis on its applications to biomedical recordings. The latter will be illustrated with epilepsy data. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  4. Use of application containers and workflows for genomic data analysis

    PubMed Central

    Schulz, Wade L.; Durant, Thomas J. S.; Siddon, Alexa J.; Torres, Richard

    2016-01-01

    Background: The rapid acquisition of biological data and development of computationally intensive analyses has led to a need for novel approaches to software deployment. In particular, the complexity of common analytic tools for genomics makes them difficult to deploy and decreases the reproducibility of computational experiments. Methods: Recent technologies that allow for application virtualization, such as Docker, allow developers and bioinformaticians to isolate these applications and deploy secure, scalable platforms that have the potential to dramatically increase the efficiency of big data processing. Results: While limitations exist, this study demonstrates a successful implementation of a pipeline with several discrete software applications for the analysis of next-generation sequencing (NGS) data. Conclusions: With this approach, we significantly reduced the amount of time needed to perform clonal analysis from NGS data in acute myeloid leukemia. PMID:28163975

  5. Application of independent component analysis in face images: a survey

    NASA Astrophysics Data System (ADS)

    Huang, Yuchi; Lu, Hanqing

    2003-09-01

    Face technologies which can be applied to access control and surveillance, are essential to intelligent vision-based human computer interaction. The research efforts in this field include face detecting, face recognition, face retrieval, etc. However, these tasks are challenging because of variability in view point, lighting, pose and expression of human faces. The ideal face representation should consider the variability so as to we can develop robust algorithms for our applications. Independent Component Analysis (ICA) as an unsupervised learning technique has been used to find such a representation and obtained good performances in some applications. In the first part of this paper, we depict the models of ICA and its extensions: Independent Subspace Analysis (ISA) and Topographic ICA (TICA).Then we summaraize the process in the applications of ICA and its extension in Face images. At last we propose a promising direction for future research.

  6. Dynamic mechanical analysis: A practical introduction to techniques and applications

    SciTech Connect

    Menard, K.

    1999-01-01

    This book introduces DMA, its history, and its current position as part of thermal analysis on polymers. It discusses major types of instrumentation, including oscillatory rotational, oscillatory axial, and torsional pendulum. It also describes analytical techniques in terms of utility, quality of data, methods of calibration, and suitability for different types of materials and assesses applications for thermoplastics, thermosetting systems, and thermosets.

  7. Household Refuse Analysis: Theory, Method, and Applications in Social Science.

    ERIC Educational Resources Information Center

    Rathje, William L., Ed.; Ritenbaugh, Cheryl K., Ed.

    1984-01-01

    The articles in this issue explore the current parameters of household refuse analysis. An overview of garbage research studies is presented; research methodology, theories, and applications are examined. U.S. household refuse is compared to the discards of households in Mexico City. (RM)

  8. Review and classification of variability analysis techniques with clinical applications

    PubMed Central

    2011-01-01

    Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis. PMID:21985357

  9. Application of Intermittent Microwave Irradiation to Western Blot Analysis.

    PubMed

    Liu, Yu-Ting; Toyokuni, Shinya

    2015-01-01

    We established a shortened protocol for Western blot analysis using intermittent microwave irradiation. With this method, the procedure is completed within 1 h after applying the primary antibody, and thus greatly saves time. This procedure appears to be applicable to any antibody based on our experience of several years.

  10. Application of software technology to automatic test data analysis

    NASA Technical Reports Server (NTRS)

    Stagner, J. R.

    1991-01-01

    The verification process for a major software subsystem was partially automated as part of a feasibility demonstration. The methods employed are generally useful and applicable to other types of subsystems. The effort resulted in substantial savings in test engineer analysis time and offers a method for inclusion of automatic verification as a part of regression testing.

  11. Review and classification of variability analysis techniques with clinical applications.

    PubMed

    Bravi, Andrea; Longtin, André; Seely, Andrew J E

    2011-10-10

    Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis.

  12. Applications of computer-aided text analysis in natural resources.

    Treesearch

    David N. Bengston

    2000-01-01

    Ten contributed papers describe the use of a variety of approaches to computer-aided text analysis and their application to a wide range of research questions related to natural resources and the environment. Taken together, these papers paint a picture of a growing and vital area of research on the human dimensions of natural resource management.

  13. Application of Sediment Backstripping Corrections for Basin Analysis Using Microcomputers.

    ERIC Educational Resources Information Center

    Wilkerson, Marlon Scott; Hsui, Albert Tong-Kwan

    1989-01-01

    Discussed is a program created to serve as an instructional tool for teaching basin analysis. Described is the use of the program for interpreting plots resulting from backstripping methods. Included in the discussion are implementation, applications and availability of the "Subside!" program. (CW)

  14. Household Refuse Analysis: Theory, Method, and Applications in Social Science.

    ERIC Educational Resources Information Center

    Rathje, William L., Ed.; Ritenbaugh, Cheryl K., Ed.

    1984-01-01

    The articles in this issue explore the current parameters of household refuse analysis. An overview of garbage research studies is presented; research methodology, theories, and applications are examined. U.S. household refuse is compared to the discards of households in Mexico City. (RM)

  15. The Adversarial Route Analysis Tool: A Web Application

    SciTech Connect

    Casson, William H. Jr.

    2012-08-02

    The Adversarial Route Analysis Tool is a type of Google maps for adversaries. It's a web-based Geospatial application similar to Google Maps. It helps the U.S. government plan operations that predict where an adversary might be. It's easily accessible and maintainble and it's simple to use without much training.

  16. Application of Sediment Backstripping Corrections for Basin Analysis Using Microcomputers.

    ERIC Educational Resources Information Center

    Wilkerson, Marlon Scott; Hsui, Albert Tong-Kwan

    1989-01-01

    Discussed is a program created to serve as an instructional tool for teaching basin analysis. Described is the use of the program for interpreting plots resulting from backstripping methods. Included in the discussion are implementation, applications and availability of the "Subside!" program. (CW)

  17. Fluorimetric analysis of pesticides: Methods, recent developments and applications.

    PubMed

    Coly, A; Aaron, J J

    1998-08-01

    The fluorimetric analysis of pesticides is reviewed with emphasis on the description of direct and indirect fluorimetric methods, including chemical derivatization, fluorogenic labelling, and photochemically-induced fluorescence. The use of fluorescence detection in TLC, HPLC and FIA as well as applications to environmental samples are discussed in detail.

  18. Game-theoretic equilibrium analysis applications to deregulated electricity markets

    NASA Astrophysics Data System (ADS)

    Joung, Manho

    This dissertation examines game-theoretic equilibrium analysis applications to deregulated electricity markets. In particular, three specific applications are discussed: analyzing the competitive effects of ownership of financial transmission rights, developing a dynamic game model considering the ramp rate constraints of generators, and analyzing strategic behavior in electricity capacity markets. In the financial transmission right application, an investigation is made of how generators' ownership of financial transmission rights may influence the effects of the transmission lines on competition. In the second application, the ramp rate constraints of generators are explicitly modeled using a dynamic game framework, and the equilibrium is characterized as the Markov perfect equilibrium. Finally, the strategic behavior of market participants in electricity capacity markets is analyzed and it is shown that the market participants may exaggerate their available capacity in a Nash equilibrium. It is also shown that the more conservative the independent system operator's capacity procurement, the higher the risk of exaggerated capacity offers.

  19. Analysis of estimation algorithms for CDTI and CAS applications

    NASA Technical Reports Server (NTRS)

    Goka, T.

    1985-01-01

    Estimation algorithms for Cockpit Display of Traffic Information (CDTI) and Collision Avoidance System (CAS) applications were analyzed and/or developed. The algorithms are based on actual or projected operational and performance characteristics of an Enhanced TCAS II traffic sensor developed by Bendix and the Federal Aviation Administration. Three algorithm areas are examined and discussed. These are horizontal x and y, range and altitude estimation algorithms. Raw estimation errors are quantified using Monte Carlo simulations developed for each application; the raw errors are then used to infer impacts on the CDTI and CAS applications. Applications of smoothing algorithms to CDTI problems are also discussed briefly. Technical conclusions are summarized based on the analysis of simulation results.

  20. The application of risk analysis in aquatic animal health management.

    PubMed

    Peeler, E J; Murray, A G; Thebault, A; Brun, E; Giovaninni, A; Thrush, M A

    2007-09-14

    Risk analysis has only been regularly used in the management of aquatic animal health in recent years. The Agreement on the Application of Sanitary and Phytosanitary measures (SPS) stimulated the application of risk analysis to investigate disease risks associated with international trade (import risk analysis-IRA). A majority (9 of 17) of the risk analyses reviewed were IRA. The other major focus has been the parasite of Atlantic salmon--Gyrodactylus salaris. Six studies investigated the spread of this parasite, between countries, rivers and from farmed to wild stocks, and clearly demonstrated that risk analysis can support aquatic animal health policy development, from international trade and biosecurity to disease interaction between wild and farmed stocks. Other applications of risk analysis included the spread of vertically transmitted pathogens and disease emergence in aquaculture. The Covello-Merkhofer, risk analysis model was most commonly used and appears to be a flexible tool not only for IRA but also the investigation of disease spread in other contexts. The limitations of the identified risk assessments were discussed. A majority were qualitative, partly due to the lack of data for quantitative analysis, and this, it can be argued, constrained their usefulness for trade purposes (i.e. setting appropriate sanitary measures); in other instances, a qualitative result was found to be adequate for decision making. A lack of information about the disease hazards of the large number of fish species traded is likely to constrain quantitative analysis for a number of years. The consequence assessment element of a risk analysis was most likely to be omitted, or limited in scope and depth, rarely extending beyond examining the evidence of susceptibility of farmed and wild species to the identified hazard. The reasons for this are discussed and recommendations made to develop guidelines for a consistent, systematic and multi-disciplinary approach to consequence

  1. Modern Era Retrospective-Analysis for Research and Applications

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Robertson, Franklin R.; Chen, Junye

    2009-01-01

    The Modern Era Retrospective-analysis for Research and Applications (MERRA) reanalyses has produced several years of data, on the way to a. completing the 1979-present modern satellite era. Here, we present a preliminary evaluation of those years currently available, including comparisons with the existing long reanalyses (ERA40, JPA25 and NCEP I and II) as well as with global data sets for the water and energy cycle. Time series shows that the MERRA budgets can change with some of the variations in observing systems. We will present all terms of the budgets in MERRA including the time rates of change and analysis increments (tendency due to the analysis of observations).

  2. Application Of Moire Analysis Of Strain Using Fourier Transform

    NASA Astrophysics Data System (ADS)

    Morimoto, Yoshiharu; Seguchi, Yasuyuki; Higashi, Toshihiko

    1987-02-01

    By shifting the discrete Fourier spectrum of the image of a deformed grating, we can obtain "the complex moire pattern", from which strain distribution is given as the derivatives of the phases of the complex moire fringes. The analysis is completely automatized by introducing the digital image processing. All of the laborious and subjective procedures required in the conventional analysis such as fringe sign determination, fringe ordering, fringe interpolation are so eliminated that objective, fast and accurate analysis can be made. Some applications for rubber plates are shown.

  3. Genre Analysis of Personal Statements: Analysis of Moves in Application Essays to Medical and Dental Schools

    ERIC Educational Resources Information Center

    Ding, Huiling

    2007-01-01

    Despite the important role the personal statement plays in the graduate school application processes, little research has been done on its functional features and little instruction has been given about it in academic writing courses. The author conducted a multi-level discourse analysis on a corpus of 30 medical/dental school application letters,…

  4. Genre Analysis of Personal Statements: Analysis of Moves in Application Essays to Medical and Dental Schools

    ERIC Educational Resources Information Center

    Ding, Huiling

    2007-01-01

    Despite the important role the personal statement plays in the graduate school application processes, little research has been done on its functional features and little instruction has been given about it in academic writing courses. The author conducted a multi-level discourse analysis on a corpus of 30 medical/dental school application letters,…

  5. Study of Discussion Record Analysis Using Temporal Data Crystallization and Its Application to TV Scene Analysis

    DTIC Science & Technology

    2015-03-31

    Crystallization and Its Application to TV Scene Analysis 5a. CONTRACT NUMBER FA2386-13-1-4044 5b. GRANT NUMBER Grant AOARD-134044 5c...methods – Scene analysis and Logical analysis. Scene analysis focuses on topic change in the record and divides a record into several scenes using...Temporal Data Crystallization (TDC). Then, by measuring the polarity of words and the volume of utterance, the atmosphere and emotion in the scene were

  6. Capillary electrophoresis in pharmaceutical analysis: a survey on recent applications.

    PubMed

    Suntornsuk, Leena

    2007-10-01

    Capillary electrophoresis (CE) has a significant role in drug discovery and manufacturing processes and has a potential to grow further, due to new developments that can provide highly sensitive and high throughput analysis. This review illustrates recent applications of CE in pharmaceutical analysis (2005-present). The history, principles, instruments, and conventional modes of CE are briefly described. Applications for drug analysis by various techniques of CE are presented in six tables: capillary zone electrophoresis (CZE) (Table I), micellar electrokinetic chromatography (MEKC) and microemulsion electrokinetic chromatography (MEEKC) (Table II), non-aqueous CE (NACE) (Table III), chiral CE (Table IV), CE-mass spectrometry (MS) microchip CE (Table V), and multiplexed CE (MCE) (Table VI).

  7. Raman Imaging in Semiconductor Physics: Applications to Microelectronic Materials and Devices

    NASA Astrophysics Data System (ADS)

    Tiberj, Antoine; Camassel, Jean

    The unique versatility of micro-Raman spectroscopy (\\upmu RS) in semiconductor physics remains in Raman imaging. Numerous applications cover the whole development of modern electronic and optoelectronic devices: from semiconductor growth to advanced device inspection tools. In this chapter, a wide variety of semiconductors (SiC, graphene, GaN, GaAs, SiGe, strained Si, sSOI, SGOI) and devices (FETs, lasers, MEMS) are addressed. First, it will be shown how Raman mapping enables to check the crystalline quality, the composition, the doping, and the uniformity of as-grown semiconductors. Then, we will focus on the most popular application in microelectronics: strain measurements either at the device or at the full wafer scale. Finally, we will show how \\upmu RS imaging can be used for final device inspection through the temperature mapping of operating devices (FETs, lasers, actuators).

  8. p{sup +}-doping analysis of laser fired contacts for silicon solar cells by Kelvin probe force microscopy

    SciTech Connect

    Ebser, J. Sommer, D.; Fritz, S.; Schiele, Y.; Hahn, G.; Terheiden, B.

    2016-03-14

    Local rear contacts for silicon passivated emitter and rear contact solar cells can be established by point-wise treating an Al layer with laser radiation and thereby establishing an electrical contact between Al and Si bulk through the dielectric passivation layer. In this laser fired contacts (LFC) process, Al can establish a few μm thick p{sup +}-doped Si region below the metal/Si interface and forms in this way a local back surface field which reduces carrier recombination at the contacts. In this work, the applicability of Kelvin probe force microscopy (KPFM) to the investigation of LFCs considering the p{sup +}-doping distribution is demonstrated. The method is based on atomic force microscopy and enables the evaluation of the lateral 2D Fermi-level characteristics at sub-micrometer resolution. The distribution of the electrical potential and therefore the local hole concentration in and around the laser fired region can be measured. KPFM is performed on mechanically polished cross-sections of p{sup +}-doped Si regions formed by the LFC process. The sample preparation is of great importance because the KPFM signal is very surface sensitive. Furthermore, the measurement is responsive to sample illumination and the height of the applied voltage between tip and sample. With other measurement techniques like micro-Raman spectroscopy, electrochemical capacitance-voltage, and energy dispersive X-ray analysis, a high local hole concentration in the range of 10{sup 19 }cm{sup −3} is demonstrated in the laser fired region. This provides, in combination with the high spatial resolution of the doping distribution measured by KPFM, a promising approach for microscopic understanding and further optimization of the LFC process.

  9. p+-doping analysis of laser fired contacts for silicon solar cells by Kelvin probe force microscopy

    NASA Astrophysics Data System (ADS)

    Ebser, J.; Sommer, D.; Fritz, S.; Schiele, Y.; Hahn, G.; Terheiden, B.

    2016-03-01

    Local rear contacts for silicon passivated emitter and rear contact solar cells can be established by point-wise treating an Al layer with laser radiation and thereby establishing an electrical contact between Al and Si bulk through the dielectric passivation layer. In this laser fired contacts (LFC) process, Al can establish a few μm thick p+-doped Si region below the metal/Si interface and forms in this way a local back surface field which reduces carrier recombination at the contacts. In this work, the applicability of Kelvin probe force microscopy (KPFM) to the investigation of LFCs considering the p+-doping distribution is demonstrated. The method is based on atomic force microscopy and enables the evaluation of the lateral 2D Fermi-level characteristics at sub-micrometer resolution. The distribution of the electrical potential and therefore the local hole concentration in and around the laser fired region can be measured. KPFM is performed on mechanically polished cross-sections of p+-doped Si regions formed by the LFC process. The sample preparation is of great importance because the KPFM signal is very surface sensitive. Furthermore, the measurement is responsive to sample illumination and the height of the applied voltage between tip and sample. With other measurement techniques like micro-Raman spectroscopy, electrochemical capacitance-voltage, and energy dispersive X-ray analysis, a high local hole concentration in the range of 1019 cm-3 is demonstrated in the laser fired region. This provides, in combination with the high spatial resolution of the doping distribution measured by KPFM, a promising approach for microscopic understanding and further optimization of the LFC process.

  10. Raman spectroscopy and capillary electrophoresis applied to forensic colour inkjet printer inks analysis.

    PubMed

    Król, Małgorzata; Karoly, Agnes; Kościelniak, Paweł

    2014-09-01

    Forensic laboratories are increasingly engaged in the examination of fraudulent documents, and what is important, in many cases these are inkjet-printed documents. That is why systematic approaches to inkjet printer inks comparison and identification have been carried out by both non-destructive and destructive methods. In this study, micro-Raman spectroscopy and capillary electrophoresis (CE) were applied to the analysis of colour inkjet printer inks. Micro-Raman spectroscopy was used to study the chemical composition of colour inks in situ on a paper surface. It helps to characterize and differentiate inkjet inks, and can be used to create a spectra database of inks taken from different cartridge brands and cartridge numbers. Capillary electrophoresis in micellar electrophoretic capillary chromatography mode was applied to separate colour and colourless components of inks, enabling group identification of those components which occur in a sufficient concentration (giving intensive peaks). Finally, on the basis of the obtained results, differentiation of the analysed inks was performed. Twenty-three samples of inkjet printer inks were examined and the discriminating power (DP) values for both presented methods were established in the routine work of experts during the result interpretation step. DP was found to be 94.0% (Raman) and 95.6% (CE) when all the analysed ink samples were taken into account, and it was 96.7% (Raman) and 98.4% (CE), when only cartridges with different index numbers were considered. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Polyglot programming in applications used for genetic data analysis.

    PubMed

    Nowak, Robert M

    2014-01-01

    Applications used for the analysis of genetic data process large volumes of data with complex algorithms. High performance, flexibility, and a user interface with a web browser are required by these solutions, which can be achieved by using multiple programming languages. In this study, I developed a freely available framework for building software to analyze genetic data, which uses C++, Python, JavaScript, and several libraries. This system was used to build a number of genetic data processing applications and it reduced the time and costs of development.

  12. Polyglot Programming in Applications Used for Genetic Data Analysis

    PubMed Central

    Nowak, Robert M.

    2014-01-01

    Applications used for the analysis of genetic data process large volumes of data with complex algorithms. High performance, flexibility, and a user interface with a web browser are required by these solutions, which can be achieved by using multiple programming languages. In this study, I developed a freely available framework for building software to analyze genetic data, which uses C++, Python, JavaScript, and several libraries. This system was used to build a number of genetic data processing applications and it reduced the time and costs of development. PMID:25197633

  13. Programmable multi-timer for TRU waste analysis applications

    SciTech Connect

    Lawrence, R.S.; Nieschmidt, E.B.; Tsang, F.Y.

    1981-01-01

    A programmable, multiple-function timing module has been developed for use in transuranic (TRU) waste analysis applications at the Idaho National Engineering Laboratory. The Programmable Multi-Timer (PRMT) is an expanded version of a module originally built for accelerator-based active photon interrogation experiments. During the course of the experiments, it became obvious that a more versatile timer was needed to meet several unforeseen requirements. The PRMT was designed to meet the new requirements and to serve as a general-purpose timing module for other applications.

  14. Market penetration analysis for direct heat geothermal energy applications

    SciTech Connect

    Thomas, R.J.; Nelson, R.A.

    1981-06-01

    This study is concerned with the estimation of the National geothermal market potential and penetration in direct heat applications for residences and certain industry segments. An important aspect of this study is that the analysis considers both known and anticipated goethermal resources. This allows for an estimation of the longer-range potential for geothermal applications. Thus the approach and results of this study provide new insights and valuable information not obtained from more limited, site-specific types of analyses. Estimates made in this study track geothermal market potential and projected penetration from the present to the year 2020. Private sector commercialization of geothermal energy over this period requires assistance in the identification of markets and market sizes, potential users, and appropriate technical applications.

  15. Differential analysis of Social Security disability and vocational rehabilitation applicants.

    PubMed

    McClure, Robert F

    2002-06-01

    An effort was made to differentiate the characteristics of clients who applied for Social Security Disability from those who applied for Vocational Rehabilitation. Psychological, diagnostic, intellectual, academic ability differences, and demographic factors of sex, age, and race between social security disability applicants and vocational rehabilitation applicants were examined. The latter were more intelligent and had higher academic functioning. Applicants for social security disability were less intelligent and tended to be functionally illiterate. Multiple discriminant analysis indicated that mathematics scores and differences in intelligence were the primary discriminants. Another difference appeared to be that rehabilitation clients tended to be diagnosed as substance abusers or learning disabled, while disability clients were more likely to be diagnosed as mentally retarded or having dementia.

  16. Applications of functional data analysis: A systematic review

    PubMed Central

    2013-01-01

    Background Functional data analysis (FDA) is increasingly being used to better analyze, model and predict time series data. Key aspects of FDA include the choice of smoothing technique, data reduction, adjustment for clustering, functional linear modeling and forecasting methods. Methods A systematic review using 11 electronic databases was conducted to identify FDA application studies published in the peer-review literature during 1995–2010. Papers reporting methodological considerations only were excluded, as were non-English articles. Results In total, 84 FDA application articles were identified; 75.0% of the reviewed articles have been published since 2005. Application of FDA has appeared in a large number of publications across various fields of sciences; the majority is related to biomedicine applications (21.4%). Overall, 72 studies (85.7%) provided information about the type of smoothing techniques used, with B-spline smoothing (29.8%) being the most popular. Functional principal component analysis (FPCA) for extracting information from functional data was reported in 51 (60.7%) studies. One-quarter (25.0%) of the published studies used functional linear models to describe relationships between explanatory and outcome variables and only 8.3% used FDA for forecasting time series data. Conclusions Despite its clear benefits for analyzing time series data, full appreciation of the key features and value of FDA have been limited to date, though the applications show its relevance to many public health and biomedical problems. Wider application of FDA to all studies involving correlated measurements should allow better modeling of, and predictions from, such data in the future especially as FDA makes no a priori age and time effects assumptions. PMID:23510439

  17. A hyperspectral image analysis workbench for environmental science applications

    SciTech Connect

    Christiansen, J.H.; Zawada, D.G.; Simunich, K.L.; Slater, J.C.

    1992-10-01

    A significant challenge to the information sciences is to provide more powerful and accessible means to exploit the enormous wealth of data available from high-resolution imaging spectrometry, or ``hyperspectral`` imagery, for analysis, for mapping purposes, and for input to environmental modeling applications. As an initial response to this challenge, Argonne`s Advanced Computer Applications Center has developed a workstation-based prototype software workbench which employs Al techniques and other advanced approaches to deduce surface characteristics and extract features from the hyperspectral images. Among its current capabilities, the prototype system can classify pixels by abstract surface type. The classification process employs neural network analysis of inputs which include pixel spectra and a variety of processed image metrics, including image ``texture spectra`` derived from fractal signatures computed for subimage tiles at each wavelength.

  18. A hyperspectral image analysis workbench for environmental science applications

    SciTech Connect

    Christiansen, J.H.; Zawada, D.G.; Simunich, K.L.; Slater, J.C.

    1992-01-01

    A significant challenge to the information sciences is to provide more powerful and accessible means to exploit the enormous wealth of data available from high-resolution imaging spectrometry, or hyperspectral'' imagery, for analysis, for mapping purposes, and for input to environmental modeling applications. As an initial response to this challenge, Argonne's Advanced Computer Applications Center has developed a workstation-based prototype software workbench which employs Al techniques and other advanced approaches to deduce surface characteristics and extract features from the hyperspectral images. Among its current capabilities, the prototype system can classify pixels by abstract surface type. The classification process employs neural network analysis of inputs which include pixel spectra and a variety of processed image metrics, including image texture spectra'' derived from fractal signatures computed for subimage tiles at each wavelength.

  19. Random vectors and spatial analysis by geostatistics for geotechnical applications

    SciTech Connect

    Young, D.S.

    1987-08-01

    Geostatistics is extended to the spatial analysis of vector variables by defining the estimation variance and vector variogram in terms of the magnitude of difference vectors. Many random variables in geotechnology are in vectorial terms rather than scalars, and its structural analysis requires those sample variable interpolations to construct and characterize structural models. A better local estimator will result in greater quality of input models; geostatistics can provide such estimators; kriging estimators. The efficiency of geostatistics for vector variables is demonstrated in a case study of rock joint orientations in geological formations. The positive cross-validation encourages application of geostatistics to spatial analysis of random vectors in geoscience as well as various geotechnical fields including optimum site characterization, rock mechanics for mining and civil structures, cavability analysis of block cavings, petroleum engineering, and hydrologic and hydraulic modelings.

  20. ACTION: application and extension of the GENESIS community analysis model.

    PubMed

    Russell, C K; Gregory, D M; Wotton, D; Mordoch, E; Counts, M M

    1996-06-01

    GENESIS (General Ethnographic and Nursing Evaluation Studies In the State) is a tested and proven community analysis strategy that integrates ethnographic and epidemiologic data to arrive at a comprehensive, holistic description of the health of a community and its residents. Communities analyzed in most project GENESIS studies have been rural or semirural. ACTION (Assessing Communities Together in the Identification Of Needs) is an extension of the GENESIS community analysis model that was developed to meet the unique needs of community-level research and analysis in an urban, multicultural setting. Significant differences in the context in which the ACTION projects took place necessitated extensions in specific components of the GENESIS model. Application of the GENESIS model by the ACTION team is described. Based on the experiences with ACTION, recommendations are offered for future urban, multicultural community analysis projects.

  1. Application Of Shakedown Analysis To Cyclic Creep Damage Limits

    SciTech Connect

    Carter, Peter; Jetter, Robert I; Sham, Sam

    2012-01-01

    Shakedown analysis may be used to provide a conservative estimate of local rupture and hence cyclic creep damage for use in a creep-fatigue assessment. The shakedown analysis is based on an elastic-perfectly plastic material with a temperature-dependent pseudo yield stress defined to guarantee that a shakedown solution exists which does not exceed rupture stress and temperature for a defined life. The ratio of design life to the estimated maximum cyclic life is the shakedown creep damage. The methodology does not require stress classification and is also applicable to cycles over the full range of temperature above and below the creep regime. Full cyclic creep and damage analysis is the alternative when shakedown analysis appears to be excessively conservative.

  2. Why social network analysis is important to Air Force applications

    NASA Astrophysics Data System (ADS)

    Havig, Paul R.; McIntire, John P.; Geiselman, Eric; Mohd-Zaid, Fairul

    2012-06-01

    Social network analysis is a powerful tool used to help analysts discover relationships amongst groups of people as well as individuals. It is the mathematics behind such social networks as Facebook and MySpace. These networks alone cause a huge amount of data to be generated and the issue is only compounded once one adds in other electronic media such as e-mails and twitter. In this paper we outline the basics of social network analysis and how it may be used in current and future Air Force applications.

  3. Advances in urinary proteome analysis and applications in systems biology.

    PubMed

    Filip, Szymon; Zoidakis, Jerome; Vlahou, Antonia; Mischak, Harald

    2014-01-01

    The urinary proteome is the focus of many studies due to the ease of urine collection and the relative proteome stability. Systems biology allows the combination of multiple omics studies, forming a link between proteomics, metabolomics, genomics and transcriptomics. In-depth data interpretation is achieved by bioinformatics analysis of -omics data sets. It is expected that the contribution of systems biology to the study of the urinary proteome will offer novel insights. The main focus of this review is on technical aspects of proteomics studies, available tools for systems biology analysis and the application of urinary proteomics in clinical studies and systems biology.

  4. Advanced stress analysis methods applicable to turbine engine structures

    NASA Technical Reports Server (NTRS)

    Pian, Theodore H. H.

    1991-01-01

    The following tasks on the study of advanced stress analysis methods applicable to turbine engine structures are described: (1) constructions of special elements which contain traction-free circular boundaries; (2) formulation of new version of mixed variational principles and new version of hybrid stress elements; (3) establishment of methods for suppression of kinematic deformation modes; (4) construction of semiLoof plate and shell elements by assumed stress hybrid method; and (5) elastic-plastic analysis by viscoplasticity theory using the mechanical subelement model.

  5. Application of integrated fluid-thermal-structural analysis methods

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken

    1988-01-01

    Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods is not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.

  6. Application of integrated fluid-thermal structural analysis methods

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken

    1988-01-01

    Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods are not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.

  7. Single-molecule detection: applications to ultrasensitive biochemical analysis

    NASA Astrophysics Data System (ADS)

    Castro, Alonso; Shera, E. Brooks

    1995-06-01

    Recent developments in laser-based detection of fluorescent molecules have made possible the implementation of very sensitive techniques for biochemical analysis. We present and discuss our experiments on the applications of our recently developed technique of single-molecule detection to the analysis of molecules of biological interest. These newly developed methods are capable of detecting and identifying biomolecules at the single-molecule level of sensitivity. In one case, identification is based on measuring fluorescence brightness from single molecules. In another, molecules are classified by determining their electrophoretic velocities.

  8. Analysis of small crack behavior for airframe applications

    NASA Technical Reports Server (NTRS)

    Mcclung, R. C.; Chan, K. S.; Hudak, S. J., Jr.; Davidson, D. L.

    1994-01-01

    The small fatigue crack problem is critically reviewed from the perspective of airframe applications. Different types of small cracks-microstructural, mechanical, and chemical-are carefully defined and relevant mechanisms identified. Appropriate analysis techniques, including both rigorous scientific and practical engineering treatments, are briefly described. Important materials data issues are addressed, including increased scatter in small crack data and recommended small crack test methods. Key problems requiring further study are highlighted.

  9. On One Application of Fourier Analysis in Plastic Surgery

    NASA Astrophysics Data System (ADS)

    Rakhimov, Abdumalik; Zainuddin, Hishamuddin

    In present paper, we discuss the spectral methods of measurement of the degree of speech and/or quality of sound by comparing the coefficient of performance indicators depending on energy distributions, ratio of energy of the fundamental tone and energy of overtones. Such a method is very efficient for string oscillation with different initial conditions and it is useful for justification of applications of Fourier analysis in plastic surgery in treatment of some medical diseases.

  10. Application of Cortical Processing Theory to Acoustical Analysis

    DTIC Science & Technology

    2007-07-27

    intelligibility (albeit with a noticeable degradation in quality ) while the acoustic signature of the phonemic features in the simulated AN representations is... Experiments I and II Application of Cortical Processing Theory to Acoustical Analysis Ghitza (PI) there were four listeners (L1, L2, L4 were female ...among 6 acoustic -phonetic distinctive features and among 8 vowels (hence 2 word-pairs per [quadrantxfeature] cell). The feature classification (outlined

  11. Application of activation techniques to biological analysis. [813 references

    SciTech Connect

    Bowen, H.J.M.

    1981-12-01

    Applications of activation analysis in the biological sciences are reviewed for the period of 1970 to 1979. The stages and characteristics of activation analysis are described, and its advantages and disadvantages enumerated. Most applications involve activation by thermal neutrons followed by either radiochemical or instrumental determination. Relatively little use has been made of activation by fast neutrons, photons, or charged particles. In vivo analyses are included, but those based on prompt gamma or x-ray emission are not. Major applications include studies of reference materials, and the elemental analysis of plants, marine biota, animal and human tissues, diets, and excreta. Relatively little use of it has been made in biochemistry, microbiology, and entomology, but it has become important in toxicology and environmental science. The elements most often determined are Ag, As, Au, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, Hg, I, K, Mn, Mo, Na, Rb, Sb, Sc, Se, and Zn, while few or no determinations of B, Be, Bi, Ga, Gd, Ge, H, In, Ir, Li, Nd, Os, Pd, Pr, Pt, Re, Rh, Ru, Te, Tl, or Y have been made in biological materials.

  12. Seismic Analysis Issues in Design Certification Applications for New Reactors

    SciTech Connect

    Miranda, M.; Morante, R.; Xu, J.

    2011-07-17

    The licensing framework established by the U.S. Nuclear Regulatory Commission under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” provides requirements for standard design certifications (DCs) and combined license (COL) applications. The intent of this process is the early reso- lution of safety issues at the DC application stage. Subsequent COL applications may incorporate a DC by reference. Thus, the COL review will not reconsider safety issues resolved during the DC process. However, a COL application that incorporates a DC by reference must demonstrate that relevant site-specific de- sign parameters are within the bounds postulated by the DC, and any departures from the DC need to be justified. This paper provides an overview of several seismic analysis issues encountered during a review of recent DC applications under the 10 CFR Part 52 process, in which the authors have participated as part of the safety review effort.

  13. Statistical Scalability Analysis of Communication Operations in Distributed Applications

    SciTech Connect

    Vetter, J S; McCracken, M O

    2001-02-27

    Current trends in high performance computing suggest that users will soon have widespread access to clusters of multiprocessors with hundreds, if not thousands, of processors. This unprecedented degree of parallelism will undoubtedly expose scalability limitations in existing applications, where scalability is the ability of a parallel algorithm on a parallel architecture to effectively utilize an increasing number of processors. Users will need precise and automated techniques for detecting the cause of limited scalability. This paper addresses this dilemma. First, we argue that users face numerous challenges in understanding application scalability: managing substantial amounts of experiment data, extracting useful trends from this data, and reconciling performance information with their application's design. Second, we propose a solution to automate this data analysis problem by applying fundamental statistical techniques to scalability experiment data. Finally, we evaluate our operational prototype on several applications, and show that statistical techniques offer an effective strategy for assessing application scalability. In particular, we find that non-parametric correlation of the number of tasks to the ratio of the time for individual communication operations to overall communication time provides a reliable measure for identifying communication operations that scale poorly.

  14. Steps towards choosing Martian samples for fossil biosignature analysis of kerogen: fluorescence microscopy and Raman spectroscopy applications to various analog samples

    NASA Astrophysics Data System (ADS)

    Shkolyar, S.; Farmer, J.

    2012-12-01

    Answering whether life existed on Mars is likely to come via searching for fossil biosignatures.1 Although definitive identification of Martian life may not be possible remotely, Mars Sample Return (MSR) is a logical next step in this endeavor, if the returned samples have been selected by precursor in situ missions.1 Fluorescence and Raman spectroscopy are useful tools for in situ identification of kerogen (insoluble carbonaceous matter of biological origin) within mineral matrices without altering samples, making them appealing tools for selecting samples to return. Still, a successful surface analysis system has yet to be flown to Mars. Examples of the challenges involved with these techniques are drawn from the development of the Mars Microbeam Raman Spectrometer (MMRS), which is a prototype instrument for a landed Mars mission, designed to provide on-surface determination of mineralogy and to assist in sample selection.2 While Raman spectroscopy alone cannot prove a sample's biogenicity,3 more development of this technique as well as coupling with other techniques could make it a promising tool for not only in-situ analysis but also for sample selection for MSR. The goal of this work is to identify the challenges of laser Raman by analysing a suite of natural materials containing kerogen, and to offer recommendations for further steps and development. This work analyzed 7 thin sections from samples representing diverse Mars analog environments and ages. Samples included an Archean chert, a Proterozoic chert, two Permian sulfates, an Eocene oil shale, a Holocene stromatolitic limestone, and a Holocene sulfate. This was done coupling three techniques: (1) mapping and imaging the suspected kerogen regions using UV fluorescence (330-380 nm, 540 nm, and 450-490 nm excitation ranges) and petrographic analyses to understand microtextural context, (2) using a commercial micro-Raman system (523 nm laser, point analysis configuration, 90-2000 cm-1 range) to perform

  15. Introduction and application of the multiscale coefficient of variation analysis.

    PubMed

    Abney, Drew H; Kello, Christopher T; Balasubramaniam, Ramesh

    2016-09-20

    Quantifying how patterns of behavior relate across multiple levels of measurement typically requires long time series for reliable parameter estimation. We describe a novel analysis that estimates patterns of variability across multiple scales of analysis suitable for time series of short duration. The multiscale coefficient of variation (MSCV) measures the distance between local coefficient of variation estimates within particular time windows and the overall coefficient of variation across all time samples. We first describe the MSCV analysis and provide an example analytical protocol with corresponding MATLAB implementation and code. Next, we present a simulation study testing the new analysis using time series generated by ARFIMA models that span white noise, short-term and long-term correlations. The MSCV analysis was observed to be sensitive to specific parameters of ARFIMA models varying in the type of temporal structure and time series length. We then apply the MSCV analysis to short time series of speech phrases and musical themes to show commonalities in multiscale structure. The simulation and application studies provide evidence that the MSCV analysis can discriminate between time series varying in multiscale structure and length.

  16. Characterization of population exposure to organochlorines: a cluster analysis application.

    PubMed

    Guimarães, Raphael Mendonça; Asmus, Carmen Ildes Rodrigues Fróes; Burdorf, Alex

    2013-06-01

    This study aimed to show the results from a cluster analysis application in the characterization of population exposure to organochlorines through variables related to time and exposure dose. Characteristics of 354 subjects in a population exposed to organochlorine pesticides residues related to time and exposure dose were subjected to cluster analysis to separate them into subgroups. We performed hierarchical cluster analysis. To evaluate the classification accuracy, compared to intra-group and inter-group variability by ANOVA for each dimension. The aggregation strategy was accomplished by the method of Ward. It was, for the creation of clusters, variables associated with exposure and routes of contamination. The information on the estimated intake doses of compound were used to weight the values of exposure time at each of the routes, so as to obtain values proxy exposure intensity. The results showed three clusters: cluster 1 (n = 45), characteristics of greatest exposure, the cluster 2 (n = 103), intermediate exposure, and cluster 3 (n = 206), less exposure. The bivariate analyzes performed with groups that are groups showed a statistically significant difference. This study demonstrated the applicability of cluster analysis to categorize populations exposed to organochlorines and also points to the relevance of typological studies that may contribute to a better classification of subjects exposed to chemical agents, which is typical of environmental epidemiology studies to a wider understanding of etiological, preventive and therapeutic contamination.

  17. 3D Network Analysis for Indoor Space Applications

    NASA Astrophysics Data System (ADS)

    Tsiliakou, E.; Dimopoulou, E.

    2016-10-01

    Indoor space differs from outdoor environments, since it is characterized by a higher level of structural complexity, geometry, as well as topological relations. Indoor space can be considered as the most important component in a building's conceptual modelling, on which applications such as indoor navigation, routing or analysis are performed. Therefore, the conceptual meaning of sub spaces or the activities taking place in physical building boundaries (e.g. walls), require the comprehension of the building's indoor hierarchical structure. The scope of this paper is to perform 3D network analysis in a building's interior and is structured as follows: In Section 1 the definition of indoor space is provided and indoor navigation requirements are analysed. Section 2 describes the processes of indoor space modeling, as well as routing applications. In Section 3, a case study is examined involving a 3D building model generated in CityEngine (exterior shell) and ArcScene (interior parts), in which the use of commercially available software tools (ArcGIS, ESRI), in terms of indoor routing and 3D network analysis, are explored. The fundamentals of performing 3D analysis with the ArcGIS Network Analyst extension were tested. Finally a geoprocessing model was presented, which was specifically designed to be used to interactively find the best route in ArcScene. The paper ends with discussion and concluding remarks on Section 4.

  18. Applicability of DNA analysis on adhesive tape in forensic casework.

    PubMed

    Zech, Wolf-Dieter; Malik, Naseem; Thali, Michael

    2012-07-01

    Adhesive tape is commonly used in crimes and is often the subject of forensic evaluation. DNA analysis of adhesive tape can provide DNA profiles of suspects. The object of this study was to evaluate the applicability of DNA analysis on adhesive tape samples in forensic casework. We retrospectively reviewed all cases involving adhesive tape or similar items received by our institute for DNA analysis during the past 11 years. From 100 forensic cases reviewed, 150 adhesive tape samples were examined. A total of 98 DNA profiles were obtained from these samples. Sixty-two of the profiles provided feasible case-relevant information. In conclusion, DNA profiling of adhesive tape samples can be useful in a variety of forensic cases.

  19. Larch: X-ray Analysis for Synchrotron Applications using Python

    NASA Astrophysics Data System (ADS)

    Newville, Matthew

    2017-03-01

    Larch is an open-source library and toolkit written in Python for processing and analyzing X-ray spectroscopic data. The primary emphasis is on X-ray spectroscopic and scattering data collected at modern synchrotron sources. Larch provides a wide selection of general-purpose processing, analysis, and visualization tools for processing X-ray data; its related target application areas include X-ray absorption fine structure (XAFS), micro-X-ray fluorescence (XRF) maps, quantitative X-ray fluorescence, X-ray absorption near edge spectroscopy (XANES), and X-ray standing waves and surface scattering. Larch provides a complete set of XAFS Analysis tools and has support for visualizing and analyzing XRF maps and spectra, and additional tools for X-ray spectral analysis, data handling, and general-purpose data modeling.

  20. Neutron resonance analysis for nuclear safeguards and security applications

    NASA Astrophysics Data System (ADS)

    Paradela, Carlos; Heyse, Jan; Kopecky, Stefan; Schillebeeckx, Peter; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi

    2017-09-01

    Neutron-induced reactions can be used to study the properties of nuclear materials of interest in the fields of nuclear safeguards and security. The elemental and isotopic composition of these materials can be determined by using the presence of resonance structures. This idea is the basis of two non-destructive analysis techniques which have been developed at the GELINA neutron time-of-flight facility at JRC-Geel: Neutron Resonance Capture Analysis (NRCA) and Neutron Resonance Transmission Analysis (NRTA). A combination of NRTA and NRCA has been proposed for the characterisation of particle-like debris of melted fuel formed in severe nuclear accidents. In this work, we present a quantitative validation of the NRTA technique which was used to determine the areal densities of Pu enriched reference samples used for safeguards applications. Less than 2% bias has been obtained for the fissile isotopes, with well-known total cross sections.

  1. 75 FR 38800 - Jordan Hydroelectric Limited Partnership; Notice of Application Ready for Environmental Analysis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-06

    ...] Jordan Hydroelectric Limited Partnership; Notice of Application Ready for Environmental Analysis and... the following hydroelectric application has been filed with the Commission and is available for public... 13, 2009. d. Applicant: Jordan Hydroelectric Limited Partnership. e. Name of Project: Flannagan...

  2. Application of total organic carbon analysis to cleaning validation.

    PubMed

    Jenkins, K M; Vanderwielen, A J; Armstrong, J A; Leonard, L M; Murphy, G P; Piros, N A

    1996-01-01

    Cleaning validation is the process of assuring that cleaning procedures effectively remove residue from manufacturing equipment/facilities below a predetermined level. This is necessary to assure the quality of future products using the equipment, to prevent cross-contamination and as a GMP requirement. Currently, cleaning validation samples are measured using HPLC or spectrophotometric methods of analysis which are often time consuming and subject to a number of interferences. Total Organic Carbon (TOC) analysis is a new method which has previously only been applied to measurement of carbon residues on production surfaces for biopharmaceuticals. We have applied the TOC analysis method to a number of traditional pharmaceutical products including antibiotics, steroids, and antinauseants in addition to biopharmaceuticals. The method offers extremely low detection capability (ppm and ppb), rapid sample analysis time and therefore quick turn-around of production equipment and facilities. TOC analysis is also applicable to on-line analysis. The method allows the measurement of extraneous materials such as process intermediates, cleaning agents, and protein materials not possible by other methods.

  3. Breath Analysis in Disease Diagnosis: Methodological Considerations and Applications

    PubMed Central

    Lourenço, Célia; Turner, Claire

    2014-01-01

    Breath analysis is a promising field with great potential for non-invasive diagnosis of a number of disease states. Analysis of the concentrations of volatile organic compounds (VOCs) in breath with an acceptable accuracy are assessed by means of using analytical techniques with high sensitivity, accuracy, precision, low response time, and low detection limit, which are desirable characteristics for the detection of VOCs in human breath. “Breath fingerprinting”, indicative of a specific clinical status, relies on the use of multivariate statistics methods with powerful in-built algorithms. The need for standardisation of sample collection and analysis is the main issue concerning breath analysis, blocking the introduction of breath tests into clinical practice. This review describes recent scientific developments in basic research and clinical applications, namely issues concerning sampling and biochemistry, highlighting the diagnostic potential of breath analysis for disease diagnosis. Several considerations that need to be taken into account in breath analysis are documented here, including the growing need for metabolomics to deal with breath profiles. PMID:24957037

  4. [Failure mode and effect analysis: application in chemotherapy].

    PubMed

    Chuang, Ching-Hui; Chuang, Sheu-Wen

    2009-08-01

    Medical institutions are increasingly concerned about ensuring the safety of patients under their care. Failure mode and effect analysis (FMEA) is a qualitative approach based on a proactive process. Strongly promoted by the Joint Commission Accredited of Health Organization (JCAHO) since 2002, FMEA has since been adopted and widely practiced in healthcare organizations to assess and analyze clinical error events. FMEA has proven to be an effective method of minimizing errors in both manufacturing and healthcare industries. It predicts failure points in systems and allows an organization to address proactively the causes of problems and prioritize improvement strategies. The application of FMEA in chemotherapy at our department identified three main failure points: (1) inappropriate chemotherapy standard operating procedures (SOPs), (2) communication barriers, and (3) insufficient training of nurses. The application of FMEA in chemotherapy is expected to enhance the sensitivity and proactive abilities of healthcare practitioners during potentially risky situations as well as to improve levels of patient care safety.

  5. Application of thermal analysis techniques in activated carbon production

    USGS Publications Warehouse

    Donnals, G.L.; DeBarr, J.A.; Rostam-Abadi, M.; Lizzio, A.A.; Brady, T.A.

    1996-01-01

    Thermal analysis techniques have been used at the ISGS as an aid in the development and characterization of carbon adsorbents. Promising adsorbents from fly ash, tires, and Illinois coals have been produced for various applications. Process conditions determined in the preparation of gram quantities of carbons were used as guides in the preparation of larger samples. TG techniques developed to characterize the carbon adsorbents included the measurement of the kinetics of SO2 adsorption, the performance of rapid proximate analyses, and the determination of equilibrium methane adsorption capacities. Thermal regeneration of carbons was assessed by TG to predict the life cycle of carbon adsorbents in different applications. TPD was used to determine the nature of surface functional groups and their effect on a carbon's adsorption properties.

  6. Applications of Raman Spectroscopy to Virology and Microbial Analysis

    NASA Astrophysics Data System (ADS)

    Harz, Michaela; Stöckel, Stephan; Ciobotă, Valerian; Cialla, Dana; Rösch, Petra; Popp, Jürgen

    This chapter reports from the utilization of Raman spectroscopic techniques like Raman microscopy, Raman optical activity (ROA), UV-resonance Raman (UVRR)-spectroscopy, surface enhanced Raman spectroscopy (SERS), and tip-enhanced Raman spectroscopy (TERS) for the investigation of viruses and microorganisms, especially bacteria and yeasts for medical and pharmaceutical applications. The application of these Raman techniques allows for the analysis of chemical components of cells and subcellular regions, as well as the monitoring of chemical differences occurring as a result of the growth of microorganisms. In addition, the interaction of microorganisms with active pharmaceutical agents can be investigated. In combination with chemometric methods Raman spectroscopy can also be applied to identify microorganisms both in micro colonies and even on single cells.

  7. Recent applications of the transonic wing analysis computer code, TWING

    NASA Technical Reports Server (NTRS)

    Subramanian, N. R.; Holst, T. L.; Thomas, S. D.

    1982-01-01

    An evaluation of the transonic-wing-analysis computer code TWING is given. TWING utilizes a fully implicit approximate factorization iteration scheme to solve the full potential equation in conservative form. A numerical elliptic-solver grid-generation scheme is used to generate the required finite-difference mesh. Several wing configurations were analyzed, and the limits of applicability of this code was evaluated. Comparisons of computed results were made with available experimental data. Results indicate that the code is robust, accurate (when significant viscous effects are not present), and efficient. TWING generally produces solutions an order of magnitude faster than other conservative full potential codes using successive-line overrelaxation. The present method is applicable to a wide range of isolated wing configurations including high-aspect-ratio transport wings and low-aspect-ratio, high-sweep, fighter configurations.

  8. Hypermedia support for engineering design systems: Application to fatigue analysis

    NASA Astrophysics Data System (ADS)

    Saeaeski, Juha; Sipilae, Sisko; Marquis, Gary

    1992-12-01

    The possibilities of using hypermedia for supporting engineering design systems are discussed. The application selected to test the hypermedia ideas was fatigue analysis. In addition, the possibility of combining hypermedia and expert system ideas into a fatigue expert system is reported. Hypermedia's underlying notion of linking nodes of information and its capability to handle these information entities stored appear to be well suited for engineering system support systems, especially in those engineering design systems where there exists a great demand for representing graphical information in a convenient way. This can be realized using hypermedia tools that are based on hypermedia techniques. The resulting fatigue handbook covers only part of the hypermedia's possibilities. The development of a prototype application indicates the efficiency of a hypermedia tool to create an electronic manual.

  9. Correlation analysis of waves above a capacitive plasma applicator.

    PubMed

    Gekelman, W; Barnes, M; Vincena, S; Pribyl, P

    2009-07-24

    Capacitively coupled plasma glow discharges have been extensively used for materials processing in numerous industrial applications. Considerable research has been performed on plasma sheaths and standing waves over a capacitive applicator, which typically holds the processed substrate (e.g., a semiconductor wafer). In this work, we demonstrate for the first time the existence of normal modes in electric potential analogous to the vibrational modes in circular membranes and plates. These modes are exhibited through cross spectral analysis of the plasma potential measured with an emissive probe at 208 spatial positions and sampled at 1 GHz. These modes exist at several frequencies and are described by a series of Bessel functions. The data further suggests a nonlinear interaction between modes of different frequencies.

  10. Correlation Analysis of Waves above a Capacitive Plasma Applicator

    SciTech Connect

    Gekelman, W.; Vincena, S.; Pribyl, P.; Barnes, M.

    2009-07-24

    Capacitively coupled plasma glow discharges have been extensively used for materials processing in numerous industrial applications. Considerable research has been performed on plasma sheaths and standing waves over a capacitive applicator, which typically holds the processed substrate (e.g., a semiconductor wafer). In this work, we demonstrate for the first time the existence of normal modes in electric potential analogous to the vibrational modes in circular membranes and plates. These modes are exhibited through cross spectral analysis of the plasma potential measured with an emissive probe at 208 spatial positions and sampled at 1 GHz. These modes exist at several frequencies and are described by a series of Bessel functions. The data further suggests a nonlinear interaction between modes of different frequencies.

  11. Application of Autoregressive processing to the analysis of seismograms

    NASA Astrophysics Data System (ADS)

    Leonard, Mark

    The application of Autoregressive processing to the analysis of seismograms has been of value to seismologists for several decades. Work in the 1960s and 1970s focused primarily on using Autoregressive (AR) filtering and other error predictive filters for improving the signal to noise ratio of small seismic signals. In the eighties and nineties most interest has been in the application of AR filtering to onset time estimation. Onset time pickers which utilise AR filtering have proved to be very effective for a wide range of seismic signals including, local and teleseismic events. A key advantage of them over other methods is that they are robust even for phases with a small signal to noise ratio. The accuracy of automatic AR picks compare well with those of experienced seismic analysts. *** DIRECT SUPPORT *** A04BD016 00003

  12. Recent applications of microchip electrophoresis to biomedical analysis.

    PubMed

    Nuchtavorn, Nantana; Suntornsuk, Worapot; Lunte, Susan M; Suntornsuk, Leena

    2015-09-10

    Many separation methods have been developed for biomedical analysis, including chromatographic (e.g. high performance liquid chromatography (HPLC) and gas chromatography (GC)) and electrophoretic methods (e.g. gel electrophoresis and capillary electrophoresis (CE)). Among these techniques, CE provides advantages in terms of high separation efficiency, simplicity, low sample and solvent volume consumption, short analysis time and applicability to a wide range of biomedically important substances. Microchip electrophoresis (ME) is a miniaturized platform of CE and is now considered as a simpler and more convenient alternative, which has demonstrated potential in analytical chemistry. High-throughput, cost-effective and portable analysis systems can be developed using ME. The current review describes different separation modes and detectors that have been employed in ME to analyze various classes of biomedical analytes (e.g. pharmaceuticals and related substances, nucleic acids, amino acids, peptides, proteins, antibodies and antigens, carbohydrates, cells, cell components and lysates). Recent applications (during 2010-2014) in these areas are presented in tables and some significant findings are highlighted. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Application of risk analysis in water resourses management

    NASA Astrophysics Data System (ADS)

    Varouchakis, Emmanouil; Palogos, Ioannis

    2017-04-01

    A common cost-benefit analysis approach, which is novel in the risk analysis of hydrologic/hydraulic applications, and a Bayesian decision analysis are applied to aid the decision making on whether or not to construct a water reservoir for irrigation purposes. The alternative option examined is a scaled parabolic fine variation in terms of over-pumping violations in contrast to common practices that usually consider short-term fines. Such an application, and in such detail, represents new feedback. The results indicate that the probability uncertainty is the driving issue that determines the optimal decision with each methodology, and depending on the unknown probability handling, each methodology may lead to a different optimal decision. Thus, the proposed tool can help decision makers (stakeholders) to examine and compare different scenarios using two different approaches before making a decision considering the cost of a hydrologic/hydraulic project and the varied economic charges that water table limit violations can cause inside an audit interval. In contrast to practices that assess the effect of each proposed action separately considering only current knowledge of the examined issue, this tool aids decision making by considering prior information and the sampling distribution of future successful audits. This tool is developed in a web service for the easier stakeholders' access.

  14. Application of capillary nongel sieving electrophoresis for gene analysis.

    PubMed

    Shen, Y; Xu, Q; Han, F; Ding, K; Song, F; Fan, Y; Zhu, N; Wu, G; Lin, B

    1999-07-01

    Capillary electrophoresis (CE) has proved to be a strong tool for DNA analysis and has found abundant applications in the fields of restriction fragment sizing, mutation screening, polymerase chain reaction (PCR) product characterizing and forensic identifying. CE may be the main alternative to slab gel electrophoresis. Capillary nongel electrophoresis is the most favorable mode when aiming for this purpose because of its advantages of long lifetime, easy operation, good reproducibility, and low expense. In this paper, a new kind of sieving matrix, with mannitol as the additive for capillary electrophoresis, as well as related methods and their application for gene analysis were reported. Nine DNA fragments amplified by multiplex PCR from a normal dystrophin gene were well separated by this system. Three different deletions were found in Duchenne muscular dystrophy (DMD) patients. Three to four copies of the sex-determination region of the Y chromosome (SRY) gene, as well as the phenylalanine hydroxylase (PAH) gene, could be detected in mixed samples. The frequencies of short tandem repeats (STR) in PAH genes was analyzed in 61 normal Chinese individuals and 6 phenylketonuria families. One case of prenatal gene diagnosis was performed. By using this matrix, CE coupled with reverse transcription PCR (RT-PCR), the analysis of the alternative splicing expression pattern of the fragile X mental retardation 1 (FMR1) gene in adult lung tissue was achieved.

  15. Discriminant analysis in wildlife research: Theory and applications

    USGS Publications Warehouse

    Williams, B.K.; Capen, D.E.

    1981-01-01

    Discriminant analysis, a method of analyzing grouped multivariate data, is often used in ecological investigations. It has both a predictive and an explanatory function, the former aiming at classification of individuals of unknown group membership. The goal of the latter function is to exhibit group separation by means of linear transforms, and the corresponding method is called canonical analysis. This discussion focuses on the application of canonical analysis in ecology. In order to clarify its meaning, a parametric approach is taken instead of the usual data-based formulation. For certain assumptions the data-based canonical variates are shown to result from maximum likelihood estimation, thus insuring consistency and asymptotic efficiency. The distorting effects of covariance heterogeneity are examined, as are certain difficulties which arise in interpreting the canonical functions. A 'distortion metric' is defined, by means of which distortions resulting from the canonical transformation can be assessed. Several sampling problems which arise in ecological applications are considered. It is concluded that the method may prove valuable for data exploration, but is of limited value as an inferential procedure.

  16. A Global Sensitivity Analysis Methodology for Multi-physics Applications

    SciTech Connect

    Tong, C H; Graziani, F R

    2007-02-02

    Experiments are conducted to draw inferences about an entire ensemble based on a selected number of observations. This applies to both physical experiments as well as computer experiments, the latter of which are performed by running the simulation models at different input configurations and analyzing the output responses. Computer experiments are instrumental in enabling model analyses such as uncertainty quantification and sensitivity analysis. This report focuses on a global sensitivity analysis methodology that relies on a divide-and-conquer strategy and uses intelligent computer experiments. The objective is to assess qualitatively and/or quantitatively how the variabilities of simulation output responses can be accounted for by input variabilities. We address global sensitivity analysis in three aspects: methodology, sampling/analysis strategies, and an implementation framework. The methodology consists of three major steps: (1) construct credible input ranges; (2) perform a parameter screening study; and (3) perform a quantitative sensitivity analysis on a reduced set of parameters. Once identified, research effort should be directed to the most sensitive parameters to reduce their uncertainty bounds. This process is repeated with tightened uncertainty bounds for the sensitive parameters until the output uncertainties become acceptable. To accommodate the needs of multi-physics application, this methodology should be recursively applied to individual physics modules. The methodology is also distinguished by an efficient technique for computing parameter interactions. Details for each step will be given using simple examples. Numerical results on large scale multi-physics applications will be available in another report. Computational techniques targeted for this methodology have been implemented in a software package called PSUADE.

  17. Application of human error analysis to aviation and space operations

    SciTech Connect

    Nelson, W.R.

    1998-03-01

    For the past several years at the Idaho National Engineering and Environmental Laboratory (INEEL) the authors have been working to apply methods of human error analysis to the design of complex systems. They have focused on adapting human reliability analysis (HRA) methods that were developed for Probabilistic Safety Assessment (PSA) for application to system design. They are developing methods so that human errors can be systematically identified during system design, the potential consequences of each error can be assessed, and potential corrective actions (e.g. changes to system design or procedures) can be identified. The primary vehicle the authors have used to develop and apply these methods has been a series of projects sponsored by the National Aeronautics and Space Administration (NASA) to apply human error analysis to aviation operations. They are currently adapting their methods and tools of human error analysis to the domain of air traffic management (ATM) systems. Under the NASA-sponsored Advanced Air Traffic Technologies (AATT) program they are working to address issues of human reliability in the design of ATM systems to support the development of a free flight environment for commercial air traffic in the US. They are also currently testing the application of their human error analysis approach for space flight operations. They have developed a simplified model of the critical habitability functions for the space station Mir, and have used this model to assess the affects of system failures and human errors that have occurred in the wake of the collision incident last year. They are developing an approach so that lessons learned from Mir operations can be systematically applied to design and operation of long-term space missions such as the International Space Station (ISS) and the manned Mars mission.

  18. Application of forensic image analysis in accident investigations.

    PubMed

    Verolme, Ellen; Mieremet, Arjan

    2017-09-01

    Forensic investigations are primarily meant to obtain objective answers that can be used for criminal prosecution. Accident analyses are usually performed to learn from incidents and to prevent similar events from occurring in the future. Although the primary goal may be different, the steps in which information is gathered, interpreted and weighed are similar in both types of investigations, implying that forensic techniques can be of use in accident investigations as well. The use in accident investigations usually means that more information can be obtained from the available information than when used in criminal investigations, since the latter require a higher evidence level. In this paper, we demonstrate the applicability of forensic techniques for accident investigations by presenting a number of cases from one specific field of expertise: image analysis. With the rapid spread of digital devices and new media, a wealth of image material and other digital information has become available for accident investigators. We show that much information can be distilled from footage by using forensic image analysis techniques. These applications show that image analysis provides information that is crucial for obtaining the sequence of events and the two- and three-dimensional geometry of an accident. Since accident investigation focuses primarily on learning from accidents and prevention of future accidents, and less on the blame that is crucial for criminal investigations, the field of application of these forensic tools may be broader than would be the case in purely legal sense. This is an important notion for future accident investigations. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. On the Application of Hilbert Spectral Analysis for Climate Studies

    NASA Technical Reports Server (NTRS)

    Huang, Norden E.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    The Hilbert spectral analysis (Huang et al, 1998, Proceedings of the Royal Society of London, A 454, pp 903-995) consisted of two steps: First, the data has to be reduced into a finite number of Intrinsic Mode Function by the Empirical Mode Decomposition method, then the resulting Intrinsic Mode Functions are converted to time-frequency-energy distribution through Hilbert transform. In this approach, the Empirical Mode Functions served as the basis functions with which the data is expanded. This basis function is adaptive, and the decomposition is nonlinear. Furthermore, as the Hilbert transform is a singular transform, it retains a high degree of local information. The instantaneous frequency is determined by differentiation of the phase function; therefore, there is no restriction of the 'uncertainty principle' for all the time-frequency analysis resulting from a priori basis approach. With the adaptive basis and the instantaneous frequency, the Hilbert Spectral analysis can represent data from nonlinear and nonstationary processes without resorting to the harmonics. Another advantage of using instantaneous frequency is the ability to find out frequency from limited length of data, which is a critical problem in climate studies. As the processes driving the climate changes could be both nonlinear and nonstationary, the Hilbert Spectral Analysis could be of great use in examining the underlying mechanisms. A preliminary study based on the length of day data will be presented as example for the application of the Hilbert Spectral Analysis for climate study.

  20. Extreme learning machine for ranking: generalization analysis and applications.

    PubMed

    Chen, Hong; Peng, Jiangtao; Zhou, Yicong; Li, Luoqing; Pan, Zhibin

    2014-05-01

    The extreme learning machine (ELM) has attracted increasing attention recently with its successful applications in classification and regression. In this paper, we investigate the generalization performance of ELM-based ranking. A new regularized ranking algorithm is proposed based on the combinations of activation functions in ELM. The generalization analysis is established for the ELM-based ranking (ELMRank) in terms of the covering numbers of hypothesis space. Empirical results on the benchmark datasets show the competitive performance of the ELMRank over the state-of-the-art ranking methods.

  1. APPLICATION OF SPATIAL INFORMATION TECHNOLOGY TO PETROLEUM RESOURCE ASSESSMENT ANALYSIS.

    USGS Publications Warehouse

    Miller, Betty M.; Domaratz, Michael A.

    1984-01-01

    Petroleum resource assessment procedures require the analysis of a large volume of spatial data. The US Geological Survey (USGS) has developed and applied spatial information handling procedures and digital cartographic techniques to a recent study involving the assessment of oil and gas resource potential for 74 million acres of designated and proposed wilderness lands in the western United States. The part of the study which dealt with the application of spatial information technology to petroleum resource assessment procedures is reviewed. A method was designed to expedite the gathering, integrating, managing, manipulating and plotting of spatial data from multiple data sources that are essential in modern resource assessment procedures.

  2. Cell cycle analysis by flow cytometry: principles and applications.

    PubMed

    Jayat, C; Ratinaud, M H

    1993-01-01

    Numerous flow cytometric analyses are based on DNA content studies. We have considered firstly monoparametric cell cycle analyses, which only take DNA content into account, but are sometimes of limited interest. Then, we have presented multiparametric analyses, which can be used to improve cycle phase identification by taking simultaneously into account DNA and other cellular components, or by considering some events occurring during cell cycle. Finally, we have discussed monoparametric and multiparametric cell cycle analysis interest in various application fields, particularly in pharmacology, toxicology, tumoral pathology and higher plant system studies.

  3. Remotely piloted vehicle: Application of the GRASP analysis method

    NASA Technical Reports Server (NTRS)

    Andre, W. L.; Morris, J. B.

    1981-01-01

    The application of General Reliability Analysis Simulation Program (GRASP) to the remotely piloted vehicle (RPV) system is discussed. The model simulates the field operation of the RPV system. By using individual component reliabilities, the overall reliability of the RPV system is determined. The results of the simulations are given in operational days. The model represented is only a basis from which more detailed work could progress. The RPV system in this model is based on preliminary specifications and estimated values. The use of GRASP from basic system definition, to model input, and to model verification is demonstrated.

  4. Applications of digital image analysis capability in Idaho

    NASA Technical Reports Server (NTRS)

    Johnson, K. A.

    1981-01-01

    The use of digital image analysis of LANDSAT imagery in water resource assessment is discussed. The data processing systems employed are described. The determination of urban land use conversion of agricultural land in two southwestern Idaho counties involving estimation and mapping of crop types and of irrigated land is described. The system was also applied to an inventory of irrigated cropland in the Snake River basin and establishment of a digital irrigation water source/service area data base for the basin. Application of the system to a determination of irrigation development in the Big Lost River basin as part of a hydrologic survey of the basin is also described.

  5. Applications of surface analysis and surface theory in tribology

    NASA Technical Reports Server (NTRS)

    Ferrante, John

    1989-01-01

    Tribology, the study of adhesion, friction and wear of materials, is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science, and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid-state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture, and friction are discussed.

  6. Application of portfolio theory in decision tree analysis.

    PubMed

    Galligan, D T; Ramberg, C; Curtis, C; Ferguson, J; Fetrow, J

    1991-07-01

    A general application of portfolio analysis for herd decision tree analysis is described. In the herd environment, this methodology offers a means of employing population-based decision strategies that can help the producer control economic variation in expected return from a given set of decision options. An economic decision tree model regarding the use of prostaglandin in dairy cows with undetected estrus was used to determine the expected return of the decisions to use prostaglandin and breed on a timed basis, use prostaglandin and then breed on sign of estrus, or breed on signs of estrus. The risk attributes of these decision alternatives were calculated from the decision tree, and portfolio theory was used to find the efficient decision combinations (portfolios with the highest return for a given variance). The resulting combinations of decisions could be used to control return variation.

  7. Applications of surface analysis and surface theory in tribology

    NASA Technical Reports Server (NTRS)

    Ferrante, John

    1988-01-01

    Tribology, the study of adhesion, friction and wear of materials is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture and friction are discussed.

  8. Applications of surface analysis and surface theory in tribology

    NASA Technical Reports Server (NTRS)

    Ferrante, John

    1989-01-01

    Tribology, the study of adhesion, friction and wear of materials, is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science, and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid-state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture, and friction are discussed.

  9. Wireless Technology Use Case Requirement Analysis for Future Space Applications

    NASA Technical Reports Server (NTRS)

    Abedi, Ali; Wilkerson, DeLisa

    2016-01-01

    This report presents various use case scenarios for wireless technology -including radio frequency (RF), optical, and acoustic- and studies requirements and boundary conditions in each scenario. The results of this study can be used to prioritize technology evaluation and development and in the long run help in development of a roadmap for future use of wireless technology. The presented scenarios cover the following application areas: (i) Space Vehicles (manned/unmanned), (ii) Satellites and Payloads, (iii) Surface Explorations, (iv) Ground Systems, and (v) Habitats. The requirement analysis covers two parallel set of conditions. The first set includes the environmental conditions such as temperature, radiation, noise/interference, wireless channel characteristics and accessibility. The second set of requirements are dictated by the application and may include parameters such as latency, throughput (effective data rate), error tolerance, and reliability. This report provides a comprehensive overview of all requirements from both perspectives and details their effects on wireless system reliability and network design. Application area examples are based on 2015 NASA Technology roadmap with specific focus on technology areas: TA 2.4, 3.3, 5.2, 5.5, 6.4, 7.4, and 10.4 sections that might benefit from wireless technology.

  10. Orthogonal analysis of functional gold nanoparticles for biomedical applications.

    PubMed

    Tsai, De-Hao; Lu, Yi-Fu; DelRio, Frank W; Cho, Tae Joon; Guha, Suvajyoti; Zachariah, Michael R; Zhang, Fan; Allen, Andrew; Hackley, Vincent A

    2015-11-01

    We report a comprehensive strategy based on implementation of orthogonal measurement techniques to provide critical and verifiable material characteristics for functionalized gold nanoparticles (AuNPs) used in biomedical applications. Samples were analyzed before and after ≈50 months of cold storage (≈4 °C). Biomedical applications require long-term storage at cold temperatures, which could have an impact on AuNP therapeutics. Thiolated polyethylene glycol (SH-PEG)-conjugated AuNPs with different terminal groups (methyl-, carboxylic-, and amine-) were chosen as a model system due to their high relevancy in biomedical applications. Electrospray-differential mobility analysis, asymmetric-flow field flow fractionation, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, inductively coupled plasma mass spectrometry, and small-angle X-ray scattering were employed to provide both complementary and orthogonal information on (1) particle size and size distribution, (2) particle concentrations, (3) molecular conjugation properties (i.e., conformation and surface packing density), and (4) colloidal stability. Results show that SH-PEGs were conjugated on the surface of AuNPs to form a brush-like polymer corona. The surface packing density of SH-PEG was ≈0.42 nm(-2) for the methyl-PEG-SH AuNPs, ≈0.26 nm(-2) for the amine-SH-PEG AuNPs, and ≈0.18 nm(-2) for the carboxylic-PEG-SH AuNPs before cold storage, approximately 10 % of its theoretical maximum value. The conformation of surface-bound SH-PEGs was then estimated to be in an intermediate state between brush-like and random-coiled, based on the measured thicknesses in liquid and in dry states. By analyzing the change in particle size distribution and number concentration in suspension following cold storage, the long term colloidal stability of AuNPs was shown to be significantly improved via functionalization with SH-PEG, especially in the case of methyl-PEG-SH and carboxylic

  11. Application of spectroscopic techniques for the analysis of kidney stones: a pilot study

    NASA Astrophysics Data System (ADS)

    Shameem, K. M., Muhammed; Chawla, Arun; Bankapur, Aseefhali; Unnikrishnan, V. K.; Santhosh, C.

    2016-03-01

    Identification and characterization of kidney stone remains one of the important analytical tasks in the medical field. Kidney stone is a common health complication throughout the world, which may cause severe pain, obstruction and infection of urinary tract, and can lead to complete renal damage. It commonly occurs in both sexes regardless of age. Kidney stones have different composition, although each stones have a major single characteristic component. A complete understanding of a sample properties and their function can only be feasible by utilizing elemental and molecular information simultaneously. Two laser based analytical techniques; Laser Induced Breakdown spectroscopy (LIBS) and Raman spectroscopy have been used to study different types of kidney stones from different patients. LIBS and Raman spectroscopy are highly complementary spectroscopic techniques, which provide elemental and molecular information of a sample. Q-switched Nd:YAG laser at 355 nm laser having energy 17mJ per pulse at 10 Hz repetition rate was used for getting LIBS spectra. Raman measurements were carried out using a home assembled micro-Raman spectrometer. Using the recorded Raman spectra of kidney stones, we were able to differentiate different kinds of kidney stones. LIBS spectra of the same stones are showing the evidence of C, Ca, H, and O and also suggest the presence of certain pigments.

  12. Application of multivariate statistical analysis to STEM X-ray spectral images: interfacial analysis in microelectronics.

    PubMed

    Kotula, Paul G; Keenan, Michael R

    2006-12-01

    Multivariate statistical analysis methods have been applied to scanning transmission electron microscopy (STEM) energy-dispersive X-ray spectral images. The particular application of the multivariate curve resolution (MCR) technique provides a high spectral contrast view of the raw spectral image. The power of this approach is demonstrated with a microelectronics failure analysis. Specifically, an unexpected component describing a chemical contaminant was found, as well as a component consistent with a foil thickness change associated with the focused ion beam specimen preparation process. The MCR solution is compared with a conventional analysis of the same spectral image data set.

  13. The Nonverbal Accommodation Analysis System (NAAS): Initial application and evaluation

    PubMed Central

    D'Agostino, Thomas A.; Bylund, Carma L.

    2016-01-01

    Objective To describe the development, initial application, and evaluation of the Nonverbal Accommodation Analysis System (NAAS). Grounded in Communication Accommodation Theory, this coding system provides a method for analyzing physician and patient nonverbal accommodation behaviors within medical consultations. Methods Video recordings of 45 new visit consultations at a comprehensive cancer center were coded using the NAAS. Inter-rater and intra-rater reliability were assessed. For validation purposes, two independent coders rated all consultations for theoretically-related constructs. Results The NAAS demonstrated high levels of reliability. Statistically significant correlations were observed across all 10 behavior categories for both inter-rater and intra-rater reliability. Evidence of content and construct validity was also observed. Conclusion The current study presents the initial application and evaluation of a coding system meant for analysis of the nonverbal behavior of physicians and patients within medical consultations. The results of this initial trial and psychometric evaluation provide evidence of the NAAS as a valid and reliable nonverbal accommodation coding system. PMID:20851559

  14. The Nonverbal Accommodation Analysis System (NAAS): initial application and evaluation.

    PubMed

    D'Agostino, Thomas A; Bylund, Carma L

    2011-10-01

    To describe the development, initial application, and evaluation of the Nonverbal Accommodation Analysis System (NAAS). Grounded in Communication Accommodation Theory, this coding system provides a method for analyzing physician and patient nonverbal accommodation behaviors within medical consultations. Video recordings of 45 new visit consultations at a comprehensive cancer center were coded using the NAAS. Inter-rater and intra-rater reliability were assessed. For validation purposes, two independent coders rated all consultations for theoretically related constructs. The NAAS demonstrated high levels of reliability. Statistically significant correlations were observed across all 10 behavior categories for both inter-rater and intra-rater reliability. Evidence of content and construct validity was also observed. The current study presents the initial application and evaluation of a coding system meant for analysis of the nonverbal behavior of physicians and patients within medical consultations. The results of this initial trial and psychometric evaluation provide evidence of the NAAS as a valid and reliable nonverbal accommodation coding system. The NAAS enables researchers to investigate the way in which physicians and patients manage social distance through nonverbal behavior within medical interactions from a theoretically-informed perspective. Such efforts can aid in the development of communication skill interventions. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. IFDOTMETER: A New Software Application for Automated Immunofluorescence Analysis.

    PubMed

    Rodríguez-Arribas, Mario; Pizarro-Estrella, Elisa; Gómez-Sánchez, Rubén; Yakhine-Diop, S M S; Gragera-Hidalgo, Antonio; Cristo, Alejandro; Bravo-San Pedro, Jose M; González-Polo, Rosa A; Fuentes, José M

    2016-04-01

    Most laboratories interested in autophagy use different imaging software for managing and analyzing heterogeneous parameters in immunofluorescence experiments (e.g., LC3-puncta quantification and determination of the number and size of lysosomes). One solution would be software that works on a user's laptop or workstation that can access all image settings and provide quick and easy-to-use analysis of data. Thus, we have designed and implemented an application called IFDOTMETER, which can run on all major operating systems because it has been programmed using JAVA (Sun Microsystems). Briefly, IFDOTMETER software has been created to quantify a variety of biological hallmarks, including mitochondrial morphology and nuclear condensation. The program interface is intuitive and user-friendly, making it useful for users not familiar with computer handling. By setting previously defined parameters, the software can automatically analyze a large number of images without the supervision of the researcher. Once analysis is complete, the results are stored in a spreadsheet. Using software for high-throughput cell image analysis offers researchers the possibility of performing comprehensive and precise analysis of a high number of images in an automated manner, making this routine task easier.

  16. Application of fuzzy expert systems for EOR project risk analysis

    SciTech Connect

    Ting-Horng, Chung; Carroll, H.B.; Lindsey, R.

    1995-12-31

    This work describes a new method for enhanced oil recovery (EOR) project preassessment. Instead of using the conventional costly simulation approach, a fuzzy expert system was developed. A database of EOR project costs and oil prices of the past decades was incorporated into the expert system. The EOR project risk-analysis includes three stages: (1) preliminary screening of EOR methods, (2) field performance estimation, and (3) economic analysis. Since this fuzzy expert system has incorporated both implemented EOR technology and experts` experience, it thus reduces the requirements of massive laboratory and field data for input. Estimates of displacement efficiency (E{sub d}) and sweep efficiency (E{sub v}) were formulated for each EOR process. E{sub d} and E{sub v} were treated as fuzzy variables. The overall recovery efficiency is evaluated from the product of Ed and Ev using fuzzy set arithmetic. Economic analysis is based on the estimated recovery efficiency, residual oil inplace, oil price, and operating costs. Examples of the application of the developed method for a CO{sub 2}-flooding project analysis is presented.

  17. Supporting secure programming in web applications through interactive static analysis.

    PubMed

    Zhu, Jun; Xie, Jing; Lipford, Heather Richter; Chu, Bill

    2014-07-01

    Many security incidents are caused by software developers' failure to adhere to secure programming practices. Static analysis tools have been used to detect software vulnerabilities. However, their wide usage by developers is limited by the special training required to write rules customized to application-specific logic. Our approach is interactive static analysis, to integrate static analysis into Integrated Development Environment (IDE) and provide in-situ secure programming support to help developers prevent vulnerabilities during code construction. No additional training is required nor are there any assumptions on ways programs are built. Our work is motivated in part by the observation that many vulnerabilities are introduced due to failure to practice secure programming by knowledgeable developers. We implemented a prototype interactive static analysis tool as a plug-in for Java in Eclipse. Our technical evaluation of our prototype detected multiple zero-day vulnerabilities in a large open source project. Our evaluations also suggest that false positives may be limited to a very small class of use cases.

  18. Supporting secure programming in web applications through interactive static analysis

    PubMed Central

    Zhu, Jun; Xie, Jing; Lipford, Heather Richter; Chu, Bill

    2013-01-01

    Many security incidents are caused by software developers’ failure to adhere to secure programming practices. Static analysis tools have been used to detect software vulnerabilities. However, their wide usage by developers is limited by the special training required to write rules customized to application-specific logic. Our approach is interactive static analysis, to integrate static analysis into Integrated Development Environment (IDE) and provide in-situ secure programming support to help developers prevent vulnerabilities during code construction. No additional training is required nor are there any assumptions on ways programs are built. Our work is motivated in part by the observation that many vulnerabilities are introduced due to failure to practice secure programming by knowledgeable developers. We implemented a prototype interactive static analysis tool as a plug-in for Java in Eclipse. Our technical evaluation of our prototype detected multiple zero-day vulnerabilities in a large open source project. Our evaluations also suggest that false positives may be limited to a very small class of use cases. PMID:25685513

  19. Analysis of Low Temperature Organic Rankine Cycles for Solar Applications

    NASA Astrophysics Data System (ADS)

    Li, Yunfei

    The present work focuses on Organic Rankine Cycle (ORC) systems and their application to low temperature waste heat recovery, combined heat and power as well as off-grid solar power generation applications. As CO_2 issues come to the fore front and fossil fuels become more expensive, interest in low grade heat recovery has grown dramatically in the past few years. Solar energy, as a clean, renewable, pollution-free and sustainable energy has great potential for the use of ORC systems. Several ORC solutions have been proposed to generate electricity from low temperature sources. The ORC systems discussed here can be applied to fields such as solar thermal, biological waste heat, engine exhaust gases, small-scale cogeneration, domestic boilers, etc. The current work presents a thermodynamic and economic analysis for the use of ORC systems to convert solar energy or low exergy energy to generate electrical power. The organic working fluids investigated here were selected to investigate the effect of the fluid saturation temperature on the performance of ORCs. The working fluids under investigation are R113, R245fa, R123, with boiling points between 40°C and 200°C at pressures from 10 kPa to 10 MPa. Ambient temperature air at 20oC to 30oC is utilized as cooling resource, and allowing for a temperature difference 10°C for effective heat transfer. Consequently, the working fluids are condensed at 40°C. A combined first- and second-law analysis is performed by varying some system independent parameters at various reference temperatures. The present work shows that ORC systems can be viable and economical for the applications such as waste heat use and off-grid power generation even though they are likely to be more expensive than grid power.

  20. Integrated Modeling Tools for Thermal Analysis and Applications

    NASA Technical Reports Server (NTRS)

    Milman, Mark H.; Needels, Laura; Papalexandris, Miltiadis

    1999-01-01

    model. Conductances for temperature varying materials are accommodated. This capability both streamlines the process of developing the thermal model from the finite element model, and also makes the structural and thermal models compatible in the sense that each structural node is associated with a thermal node. This is particularly useful when the purpose of the analysis is to predict structural deformations due to thermal loads. The steady state solver uses a restricted step size Newton method, and the transient solver is an adaptive step size implicit method applicable to general differential algebraic systems. Temperature dependent conductances and capacitances are accommodated by the solvers. In addition to discussing the modeling and solution methods. applications where the thermal modeling is "in the loop" with sensitivity analysis, optimization and optical performance drawn from our experiences with the Space Interferometry Mission (SIM), and the Next Generation Space Telescope (NGST) are presented.